mb/up/squared: Enable Vtd

[coreboot.git] / util / romcc / romcc.c

#undef VERSION_MAJOR
#undef VERSION_MINOR
#undef RELEASE_DATE
#undef VERSION
#define VERSION_MAJOR "0"
#define VERSION_MINOR "80"
#define RELEASE_DATE "18 November 2015"
#define VERSION VERSION_MAJOR "." VERSION_MINOR

#include <stdarg.h>
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <limits.h>
#include <locale.h>
#include <time.h>

#define MAX_CWD_SIZE 4096
#define MAX_ALLOCATION_PASSES 100

/* NOTE: Before you even start thinking to touch anything
 * in this code, set DEBUG_ROMCC_WARNINGS to 1 to get an
 * insight on the original author's thoughts. We introduced
 * this switch as romcc was about the only thing producing
 * massive warnings in our code..
 */
#define DEBUG_ROMCC_WARNINGS 0

#define DEBUG_CONSISTENCY 1
#define DEBUG_SDP_BLOCKS 0
#define DEBUG_TRIPLE_COLOR 0

#define DEBUG_DISPLAY_USES 1
#define DEBUG_DISPLAY_TYPES 1
#define DEBUG_REPLACE_CLOSURE_TYPE_HIRES 0
#define DEBUG_DECOMPOSE_PRINT_TUPLES 0
#define DEBUG_DECOMPOSE_HIRES  0
#define DEBUG_INITIALIZER 0
#define DEBUG_UPDATE_CLOSURE_TYPE 0
#define DEBUG_LOCAL_TRIPLE 0
#define DEBUG_BASIC_BLOCKS_VERBOSE 0
#define DEBUG_CPS_RENAME_VARIABLES_HIRES 0
#define DEBUG_SIMPLIFY_HIRES 0
#define DEBUG_SHRINKING 0
#define DEBUG_COALESCE_HITCHES 0
#define DEBUG_CODE_ELIMINATION 0

#define DEBUG_EXPLICIT_CLOSURES 0

#if DEBUG_ROMCC_WARNINGS
#warning "FIXME give clear error messages about unused variables"
#warning "FIXME properly handle multi dimensional arrays"
#warning "FIXME handle multiple register sizes"
#endif

/*  Control flow graph of a loop without goto.
 *
 *        AAA
 *   +---/
 *  /
 * / +--->CCC
 * | |    / \
 * | |  DDD EEE    break;
 * | |    \    \
 * | |    FFF   \
 *  \|    / \    \
 *   |\ GGG HHH   |   continue;
 *   | \  \   |   |
 *   |  \ III |  /
 *   |   \ | /  /
 *   |    vvv  /
 *   +----BBB /
 *         | /
 *         vv
 *        JJJ
 *
 *
 *             AAA
 *     +-----+  |  +----+
 *     |      \ | /     |
 *     |       BBB  +-+ |
 *     |       / \ /  | |
 *     |     CCC JJJ / /
 *     |     / \    / /
 *     |   DDD EEE / /
 *     |    |   +-/ /
 *     |   FFF     /
 *     |   / \    /
 *     | GGG HHH /
 *     |  |   +-/
 *     | III
 *     +--+
 *
 *
 * DFlocal(X) = { Y <- Succ(X) | idom(Y) != X }
 * DFup(Z)    = { Y <- DF(Z) | idom(Y) != X }
 *
 *
 * [] == DFlocal(X) U DF(X)
 * () == DFup(X)
 *
 * Dominator graph of the same nodes.
 *
 *           AAA     AAA: [ ] ()
 *          /   \
 *        BBB    JJJ BBB: [ JJJ ] ( JJJ )  JJJ: [ ] ()
 *         |
 *        CCC        CCC: [ ] ( BBB, JJJ )
 *        / \
 *     DDD   EEE     DDD: [ ] ( BBB ) EEE: [ JJJ ] ()
 *      |
 *     FFF           FFF: [ ] ( BBB )
 *     / \
 *  GGG   HHH        GGG: [ ] ( BBB ) HHH: [ BBB ] ()
 *   |
 *  III              III: [ BBB ] ()
 *
 *
 * BBB and JJJ are definitely the dominance frontier.
 * Where do I place phi functions and how do I make that decision.
 *
 */

struct filelist {
        const char *filename;
        struct filelist *next;
};

struct filelist *include_filelist = NULL;

static void __attribute__((noreturn)) die(char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        vfprintf(stderr, fmt, args);
        va_end(args);
        fflush(stdout);
        fflush(stderr);
        exit(1);
}

static void *xmalloc(size_t size, const char *name)
{
        void *buf;
        buf = malloc(size);
        if (!buf) {
                die("Cannot malloc %ld bytes to hold %s: %s\n",
                        size + 0UL, name, strerror(errno));
        }
        return buf;
}

static void *xcmalloc(size_t size, const char *name)
{
        void *buf;
        buf = xmalloc(size, name);
        memset(buf, 0, size);
        return buf;
}

static void *xrealloc(void *ptr, size_t size, const char *name)
{
        void *buf;
        buf = realloc(ptr, size);
        if (!buf) {
                die("Cannot realloc %ld bytes to hold %s: %s\n",
                        size + 0UL, name, strerror(errno));
        }
        return buf;
}

static void xfree(const void *ptr)
{
        free((void *)ptr);
}

static char *xstrdup(const char *str)
{
        char *new;
        int len;
        len = strlen(str);
        new = xmalloc(len + 1, "xstrdup string");
        memcpy(new, str, len);
        new[len] = '\0';
        return new;
}

static void xchdir(const char *path)
{
        if (chdir(path) != 0) {
                die("chdir to `%s' failed: %s\n",
                        path, strerror(errno));
        }
}

static int exists(const char *dirname, const char *filename)
{
        char cwd[MAX_CWD_SIZE];
        int does_exist;

        if (getcwd(cwd, sizeof(cwd)) == 0) {
                die("cwd buffer to small");
        }

        does_exist = 1;
        if (chdir(dirname) != 0) {
                does_exist = 0;
        }
        if (does_exist && (access(filename, O_RDONLY) < 0)) {
                if ((errno != EACCES) && (errno != EROFS)) {
                        does_exist = 0;
                }
        }
        xchdir(cwd);
        return does_exist;
}

static off_t get_file_size(FILE *f)
{
        struct stat s;
        int fd = fileno(f);
        if (fd == -1) return -1;
        if (fstat(fd, &s) == -1) return -1;
        return s.st_size;
}

static char *slurp_file(const char *dirname, const char *filename, off_t *r_size)
{
        char cwd[MAX_CWD_SIZE];
        char *buf;
        off_t size, progress;
        ssize_t result;
        FILE* file;

        if (!filename) {
                *r_size = 0;
                return 0;
        }
        if (getcwd(cwd, sizeof(cwd)) == 0) {
                die("cwd buffer to small");
        }
        xchdir(dirname);
        file = fopen(filename, "rb");
        xchdir(cwd);
        if (file == NULL) {
                die("Cannot open '%s' : %s\n",
                        filename, strerror(errno));
        }
        size = get_file_size(file);
        if (size == -1) {
                die("Could not fetch size of '%s': %s\n", filename, strerror(errno));
        }
        *r_size = size +1;
        buf = xmalloc(size +2, filename);
        buf[size] = '\n'; /* Make certain the file is newline terminated */
        buf[size+1] = '\0'; /* Null terminate the file for good measure */
        progress = 0;
        while(progress < size) {
                result = fread(buf + progress, 1, size - progress, file);
                if (result < 0) {
                        if ((errno == EINTR) || (errno == EAGAIN))
                                continue;
                        die("read on %s of %ld bytes failed: %s\n",
                                filename, (size - progress)+ 0UL, strerror(errno));
                }
                progress += result;
        }
        fclose(file);
        return buf;
}

/* Types on the destination platform */
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME this assumes 32bit x86 is the destination"
#endif
typedef int8_t   schar_t;
typedef uint8_t  uchar_t;
typedef int8_t   char_t;
typedef int16_t  short_t;
typedef uint16_t ushort_t;
typedef int32_t  int_t;
typedef uint32_t uint_t;
typedef int32_t  long_t;
#define ulong_t uint32_t

#define SCHAR_T_MIN (-128)
#define SCHAR_T_MAX 127
#define UCHAR_T_MAX 255
#define CHAR_T_MIN  SCHAR_T_MIN
#define CHAR_T_MAX  SCHAR_T_MAX
#define SHRT_T_MIN  (-32768)
#define SHRT_T_MAX  32767
#define USHRT_T_MAX 65535
#define INT_T_MIN   (-LONG_T_MAX - 1)
#define INT_T_MAX   2147483647
#define UINT_T_MAX  4294967295U
#define LONG_T_MIN  (-LONG_T_MAX - 1)
#define LONG_T_MAX  2147483647
#define ULONG_T_MAX 4294967295U

#define SIZEOF_I8    8
#define SIZEOF_I16   16
#define SIZEOF_I32   32
#define SIZEOF_I64   64

#define SIZEOF_CHAR    8
#define SIZEOF_SHORT   16
#define SIZEOF_INT     32
#define SIZEOF_LONG    (sizeof(long_t)*SIZEOF_CHAR)


#define ALIGNOF_CHAR    8
#define ALIGNOF_SHORT   16
#define ALIGNOF_INT     32
#define ALIGNOF_LONG    (sizeof(long_t)*SIZEOF_CHAR)

#define REG_SIZEOF_REG     32
#define REG_SIZEOF_CHAR    REG_SIZEOF_REG
#define REG_SIZEOF_SHORT   REG_SIZEOF_REG
#define REG_SIZEOF_INT     REG_SIZEOF_REG
#define REG_SIZEOF_LONG    REG_SIZEOF_REG

#define REG_ALIGNOF_REG     REG_SIZEOF_REG
#define REG_ALIGNOF_CHAR    REG_SIZEOF_REG
#define REG_ALIGNOF_SHORT   REG_SIZEOF_REG
#define REG_ALIGNOF_INT     REG_SIZEOF_REG
#define REG_ALIGNOF_LONG    REG_SIZEOF_REG

/* Additional definitions for clarity.
 * I currently assume a long is the largest native
 * machine word and that a pointer fits into it.
 */
#define SIZEOF_WORD     SIZEOF_LONG
#define SIZEOF_POINTER  SIZEOF_LONG
#define ALIGNOF_WORD    ALIGNOF_LONG
#define ALIGNOF_POINTER ALIGNOF_LONG
#define REG_SIZEOF_POINTER  REG_SIZEOF_LONG
#define REG_ALIGNOF_POINTER REG_ALIGNOF_LONG

struct file_state {
        struct file_state *prev;
        const char *basename;
        char *dirname;
        const char *buf;
        off_t size;
        const char *pos;
        int line;
        const char *line_start;
        int report_line;
        const char *report_name;
        const char *report_dir;
        int macro      : 1;
        int trigraphs  : 1;
        int join_lines : 1;
};
struct hash_entry;
struct token {
        int tok;
        struct hash_entry *ident;
        const char *pos;
        int str_len;
        union {
                ulong_t integer;
                const char *str;
                int notmacro;
        } val;
};

/* I have two classes of types:
 * Operational types.
 * Logical types.  (The type the C standard says the operation is of)
 *
 * The operational types are:
 * chars
 * shorts
 * ints
 * longs
 *
 * floats
 * doubles
 * long doubles
 *
 * pointer
 */


/* Machine model.
 * No memory is useable by the compiler.
 * There is no floating point support.
 * All operations take place in general purpose registers.
 * There is one type of general purpose register.
 * Unsigned longs are stored in that general purpose register.
 */

/* Operations on general purpose registers.
 */

#define OP_SDIVT      0
#define OP_UDIVT      1
#define OP_SMUL       2
#define OP_UMUL       3
#define OP_SDIV       4
#define OP_UDIV       5
#define OP_SMOD       6
#define OP_UMOD       7
#define OP_ADD        8
#define OP_SUB        9
#define OP_SL        10
#define OP_USR       11
#define OP_SSR       12
#define OP_AND       13
#define OP_XOR       14
#define OP_OR        15
#define OP_POS       16 /* Dummy positive operator don't use it */
#define OP_NEG       17
#define OP_INVERT    18

#define OP_EQ        20
#define OP_NOTEQ     21
#define OP_SLESS     22
#define OP_ULESS     23
#define OP_SMORE     24
#define OP_UMORE     25
#define OP_SLESSEQ   26
#define OP_ULESSEQ   27
#define OP_SMOREEQ   28
#define OP_UMOREEQ   29

#define OP_LFALSE    30  /* Test if the expression is logically false */
#define OP_LTRUE     31  /* Test if the expression is logcially true */

#define OP_LOAD      32
#define OP_STORE     33
/* For OP_STORE ->type holds the type
 * RHS(0) holds the destination address
 * RHS(1) holds the value to store.
 */

#define OP_UEXTRACT  34
/* OP_UEXTRACT extracts an unsigned bitfield from a pseudo register
 * RHS(0) holds the pseudo register to extract from
 * ->type holds the size of the bitfield.
 * ->u.bitfield.size holds the size of the bitfield.
 * ->u.bitfield.offset holds the offset to extract from
 */
#define OP_SEXTRACT  35
/* OP_SEXTRACT extracts a signed bitfield from a pseudo register
 * RHS(0) holds the pseudo register to extract from
 * ->type holds the size of the bitfield.
 * ->u.bitfield.size holds the size of the bitfield.
 * ->u.bitfield.offset holds the offset to extract from
 */
#define OP_DEPOSIT   36
/* OP_DEPOSIT replaces a bitfield with a new value.
 * RHS(0) holds the value to replace a bitifield in.
 * RHS(1) holds the replacement value
 * ->u.bitfield.size holds the size of the bitfield.
 * ->u.bitfield.offset holds the deposit into
 */

#define OP_NOOP      37

#define OP_MIN_CONST 50
#define OP_MAX_CONST 58
#define IS_CONST_OP(X) (((X) >= OP_MIN_CONST) && ((X) <= OP_MAX_CONST))
#define OP_INTCONST  50
/* For OP_INTCONST ->type holds the type.
 * ->u.cval holds the constant value.
 */
#define OP_BLOBCONST 51
/* For OP_BLOBCONST ->type holds the layout and size
 * information.  u.blob holds a pointer to the raw binary
 * data for the constant initializer.
 */
#define OP_ADDRCONST 52
/* For OP_ADDRCONST ->type holds the type.
 * MISC(0) holds the reference to the static variable.
 * ->u.cval holds an offset from that value.
 */
#define OP_UNKNOWNVAL 59
/* For OP_UNKNOWNAL ->type holds the type.
 * For some reason we don't know what value this type has.
 * This allows for variables that have don't have values
 * assigned yet, or variables whose value we simply do not know.
 */

#define OP_WRITE     60
/* OP_WRITE moves one pseudo register to another.
 * MISC(0) holds the destination pseudo register, which must be an OP_DECL.
 * RHS(0) holds the pseudo to move.
 */

#define OP_READ      61
/* OP_READ reads the value of a variable and makes
 * it available for the pseudo operation.
 * Useful for things like def-use chains.
 * RHS(0) holds points to the triple to read from.
 */
#define OP_COPY      62
/* OP_COPY makes a copy of the pseudo register or constant in RHS(0).
 */
#define OP_CONVERT   63
/* OP_CONVERT makes a copy of the pseudo register or constant in RHS(0).
 * And then the type is converted appropriately.
 */
#define OP_PIECE     64
/* OP_PIECE returns one piece of a instruction that returns a structure.
 * MISC(0) is the instruction
 * u.cval is the LHS piece of the instruction to return.
 */
#define OP_ASM       65
/* OP_ASM holds a sequence of assembly instructions, the result
 * of a C asm directive.
 * RHS(x) holds input value x to the assembly sequence.
 * LHS(x) holds the output value x from the assembly sequence.
 * u.blob holds the string of assembly instructions.
 */

#define OP_DEREF     66
/* OP_DEREF generates an lvalue from a pointer.
 * RHS(0) holds the pointer value.
 * OP_DEREF serves as a place holder to indicate all necessary
 * checks have been done to indicate a value is an lvalue.
 */
#define OP_DOT       67
/* OP_DOT references a submember of a structure lvalue.
 * MISC(0) holds the lvalue.
 * ->u.field holds the name of the field we want.
 *
 * Not seen after structures are flattened.
 */
#define OP_INDEX     68
/* OP_INDEX references a submember of a tuple or array lvalue.
 * MISC(0) holds the lvalue.
 * ->u.cval holds the index into the lvalue.
 *
 * Not seen after structures are flattened.
 */
#define OP_VAL       69
/* OP_VAL returns the value of a subexpression of the current expression.
 * Useful for operators that have side effects.
 * RHS(0) holds the expression.
 * MISC(0) holds the subexpression of RHS(0) that is the
 * value of the expression.
 *
 * Not seen outside of expressions.
 */

#define OP_TUPLE     70
/* OP_TUPLE is an array of triples that are either variable
 * or values for a structure or an array.  It is used as
 * a place holder when flattening compound types.
 * The value represented by an OP_TUPLE is held in N registers.
 * LHS(0..N-1) refer to those registers.
 * ->use is a list of statements that use the value.
 *
 * Although OP_TUPLE always has register sized pieces they are not
 * used until structures are flattened/decomposed into their register
 * components.
 * ???? registers ????
 */

#define OP_BITREF    71
/* OP_BITREF describes a bitfield as an lvalue.
 * RHS(0) holds the register value.
 * ->type holds the type of the bitfield.
 * ->u.bitfield.size holds the size of the bitfield.
 * ->u.bitfield.offset holds the offset of the bitfield in the register
 */


#define OP_FCALL     72
/* OP_FCALL performs a procedure call.
 * MISC(0) holds a pointer to the OP_LIST of a function
 * RHS(x) holds argument x of a function
 *
 * Currently not seen outside of expressions.
 */
#define OP_PROG      73
/* OP_PROG is an expression that holds a list of statements, or
 * expressions.  The final expression is the value of the expression.
 * RHS(0) holds the start of the list.
 */

/* statements */
#define OP_LIST      80
/* OP_LIST Holds a list of statements that compose a function, and a result value.
 * RHS(0) holds the list of statements.
 * A list of all functions is maintained.
 */

#define OP_BRANCH    81 /* an unconditional branch */
/* For branch instructions
 * TARG(0) holds the branch target.
 * ->next holds where to branch to if the branch is not taken.
 * The branch target can only be a label
 */

#define OP_CBRANCH   82 /* a conditional branch */
/* For conditional branch instructions
 * RHS(0) holds the branch condition.
 * TARG(0) holds the branch target.
 * ->next holds where to branch to if the branch is not taken.
 * The branch target can only be a label
 */

#define OP_CALL      83 /* an uncontional branch that will return */
/* For call instructions
 * MISC(0) holds the OP_RET that returns from the branch
 * TARG(0) holds the branch target.
 * ->next holds where to branch to if the branch is not taken.
 * The branch target can only be a label
 */

#define OP_RET       84 /* an uncontinonal branch through a variable back to an OP_CALL */
/* For call instructions
 * RHS(0) holds the variable with the return address
 * The branch target can only be a label
 */

#define OP_LABEL     86
/* OP_LABEL is a triple that establishes an target for branches.
 * ->use is the list of all branches that use this label.
 */

#define OP_ADECL     87
/* OP_ADECL is a triple that establishes an lvalue for assignments.
 * A variable takes N registers to contain.
 * LHS(0..N-1) refer to an OP_PIECE triple that represents
 * the Xth register that the variable is stored in.
 * ->use is a list of statements that use the variable.
 *
 * Although OP_ADECL always has register sized pieces they are not
 * used until structures are flattened/decomposed into their register
 * components.
 */

#define OP_SDECL     88
/* OP_SDECL is a triple that establishes a variable of static
 * storage duration.
 * ->use is a list of statements that use the variable.
 * MISC(0) holds the initializer expression.
 */


#define OP_PHI       89
/* OP_PHI is a triple used in SSA form code.
 * It is used when multiple code paths merge and a variable needs
 * a single assignment from any of those code paths.
 * The operation is a cross between OP_DECL and OP_WRITE, which
 * is what OP_PHI is generated from.
 *
 * RHS(x) points to the value from code path x
 * The number of RHS entries is the number of control paths into the block
 * in which OP_PHI resides.  The elements of the array point to point
 * to the variables OP_PHI is derived from.
 *
 * MISC(0) holds a pointer to the orginal OP_DECL node.
 */

#if 0
/* continuation helpers
 */
#define OP_CPS_BRANCH    90 /* an unconditional branch */
/* OP_CPS_BRANCH calls a continuation
 * RHS(x) holds argument x of the function
 * TARG(0) holds OP_CPS_START target
 */
#define OP_CPS_CBRANCH   91  /* a conditional branch */
/* OP_CPS_CBRANCH conditionally calls one of two continuations
 * RHS(0) holds the branch condition
 * RHS(x + 1) holds argument x of the function
 * TARG(0) holds the OP_CPS_START to jump to when true
 * ->next holds the OP_CPS_START to jump to when false
 */
#define OP_CPS_CALL      92  /* an uncontional branch that will return */
/* For OP_CPS_CALL instructions
 * RHS(x) holds argument x of the function
 * MISC(0) holds the OP_CPS_RET that returns from the branch
 * TARG(0) holds the branch target.
 * ->next holds where the OP_CPS_RET will return to.
 */
#define OP_CPS_RET       93
/* OP_CPS_RET conditionally calls one of two continuations
 * RHS(0) holds the variable with the return function address
 * RHS(x + 1) holds argument x of the function
 * The branch target may be any OP_CPS_START
 */
#define OP_CPS_END       94
/* OP_CPS_END is the triple at the end of the program.
 * For most practical purposes it is a branch.
 */
#define OP_CPS_START     95
/* OP_CPS_START is a triple at the start of a continuation
 * The arguments variables takes N registers to contain.
 * LHS(0..N-1) refer to an OP_PIECE triple that represents
 * the Xth register that the arguments are stored in.
 */
#endif

/* Architecture specific instructions */
#define OP_CMP         100
#define OP_TEST        101
#define OP_SET_EQ      102
#define OP_SET_NOTEQ   103
#define OP_SET_SLESS   104
#define OP_SET_ULESS   105
#define OP_SET_SMORE   106
#define OP_SET_UMORE   107
#define OP_SET_SLESSEQ 108
#define OP_SET_ULESSEQ 109
#define OP_SET_SMOREEQ 110
#define OP_SET_UMOREEQ 111

#define OP_JMP         112
#define OP_JMP_EQ      113
#define OP_JMP_NOTEQ   114
#define OP_JMP_SLESS   115
#define OP_JMP_ULESS   116
#define OP_JMP_SMORE   117
#define OP_JMP_UMORE   118
#define OP_JMP_SLESSEQ 119
#define OP_JMP_ULESSEQ 120
#define OP_JMP_SMOREEQ 121
#define OP_JMP_UMOREEQ 122

/* Builtin operators that it is just simpler to use the compiler for */
#define OP_INB         130
#define OP_INW         131
#define OP_INL         132
#define OP_OUTB        133
#define OP_OUTW        134
#define OP_OUTL        135
#define OP_BSF         136
#define OP_BSR         137
#define OP_RDMSR       138
#define OP_WRMSR       139
#define OP_HLT         140

struct op_info {
        const char *name;
        unsigned flags;
#define PURE       0x001 /* Triple has no side effects */
#define IMPURE     0x002 /* Triple has side effects */
#define PURE_BITS(FLAGS) ((FLAGS) & 0x3)
#define DEF        0x004 /* Triple is a variable definition */
#define BLOCK      0x008 /* Triple stores the current block */
#define STRUCTURAL 0x010 /* Triple does not generate a machine instruction */
#define BRANCH_BITS(FLAGS) ((FLAGS) & 0xe0 )
#define UBRANCH    0x020 /* Triple is an unconditional branch instruction */
#define CBRANCH    0x040 /* Triple is a conditional branch instruction */
#define RETBRANCH  0x060 /* Triple is a return instruction */
#define CALLBRANCH 0x080 /* Triple is a call instruction */
#define ENDBRANCH  0x0a0 /* Triple is an end instruction */
#define PART       0x100 /* Triple is really part of another triple */
#define BITFIELD   0x200 /* Triple manipulates a bitfield */
        signed char lhs, rhs, misc, targ;
};

#define OP(LHS, RHS, MISC, TARG, FLAGS, NAME) { \
        .name = (NAME), \
        .flags = (FLAGS), \
        .lhs = (LHS), \
        .rhs = (RHS), \
        .misc = (MISC), \
        .targ = (TARG), \
         }
static const struct op_info table_ops[] = {
[OP_SDIVT      ] = OP( 2,  2, 0, 0, PURE | BLOCK , "sdivt"),
[OP_UDIVT      ] = OP( 2,  2, 0, 0, PURE | BLOCK , "udivt"),
[OP_SMUL       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "smul"),
[OP_UMUL       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "umul"),
[OP_SDIV       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "sdiv"),
[OP_UDIV       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "udiv"),
[OP_SMOD       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "smod"),
[OP_UMOD       ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "umod"),
[OP_ADD        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "add"),
[OP_SUB        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "sub"),
[OP_SL         ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "sl"),
[OP_USR        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "usr"),
[OP_SSR        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "ssr"),
[OP_AND        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "and"),
[OP_XOR        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "xor"),
[OP_OR         ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "or"),
[OP_POS        ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK , "pos"),
[OP_NEG        ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK , "neg"),
[OP_INVERT     ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK , "invert"),

[OP_EQ         ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "eq"),
[OP_NOTEQ      ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "noteq"),
[OP_SLESS      ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "sless"),
[OP_ULESS      ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "uless"),
[OP_SMORE      ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "smore"),
[OP_UMORE      ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "umore"),
[OP_SLESSEQ    ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "slesseq"),
[OP_ULESSEQ    ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "ulesseq"),
[OP_SMOREEQ    ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "smoreeq"),
[OP_UMOREEQ    ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK , "umoreeq"),
[OP_LFALSE     ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK , "lfalse"),
[OP_LTRUE      ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK , "ltrue"),

[OP_LOAD       ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "load"),
[OP_STORE      ] = OP( 0,  2, 0, 0, PURE | BLOCK , "store"),

[OP_UEXTRACT   ] = OP( 0,  1, 0, 0, PURE | DEF | BITFIELD, "uextract"),
[OP_SEXTRACT   ] = OP( 0,  1, 0, 0, PURE | DEF | BITFIELD, "sextract"),
[OP_DEPOSIT    ] = OP( 0,  2, 0, 0, PURE | DEF | BITFIELD, "deposit"),

[OP_NOOP       ] = OP( 0,  0, 0, 0, PURE | BLOCK | STRUCTURAL, "noop"),

[OP_INTCONST   ] = OP( 0,  0, 0, 0, PURE | DEF, "intconst"),
[OP_BLOBCONST  ] = OP( 0,  0, 0, 0, PURE , "blobconst"),
[OP_ADDRCONST  ] = OP( 0,  0, 1, 0, PURE | DEF, "addrconst"),
[OP_UNKNOWNVAL ] = OP( 0,  0, 0, 0, PURE | DEF, "unknown"),

#if DEBUG_ROMCC_WARNINGS
#warning "FIXME is it correct for OP_WRITE to be a def?  I currently use it as one..."
#endif
[OP_WRITE      ] = OP( 0,  1, 1, 0, PURE | DEF | BLOCK, "write"),
[OP_READ       ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "read"),
[OP_COPY       ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "copy"),
[OP_CONVERT    ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "convert"),
[OP_PIECE      ] = OP( 0,  0, 1, 0, PURE | DEF | STRUCTURAL | PART, "piece"),
[OP_ASM        ] = OP(-1, -1, 0, 0, PURE, "asm"),
[OP_DEREF      ] = OP( 0,  1, 0, 0, 0 | DEF | BLOCK, "deref"),
[OP_DOT        ] = OP( 0,  0, 1, 0, PURE | DEF | PART, "dot"),
[OP_INDEX      ] = OP( 0,  0, 1, 0, PURE | DEF | PART, "index"),

[OP_VAL        ] = OP( 0,  1, 1, 0, 0 | DEF | BLOCK, "val"),
[OP_TUPLE      ] = OP(-1,  0, 0, 0, 0 | PURE | BLOCK | STRUCTURAL, "tuple"),
[OP_BITREF     ] = OP( 0,  1, 0, 0, 0 | DEF | PURE | STRUCTURAL | BITFIELD, "bitref"),
/* Call is special most it can stand in for anything so it depends on context */
[OP_FCALL      ] = OP( 0, -1, 1, 0, 0 | BLOCK | CALLBRANCH, "fcall"),
[OP_PROG       ] = OP( 0,  1, 0, 0, 0 | IMPURE | BLOCK | STRUCTURAL, "prog"),
/* The sizes of OP_FCALL depends upon context */

[OP_LIST       ] = OP( 0,  1, 1, 0, 0 | DEF | STRUCTURAL, "list"),
[OP_BRANCH     ] = OP( 0,  0, 0, 1, PURE | BLOCK | UBRANCH, "branch"),
[OP_CBRANCH    ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "cbranch"),
[OP_CALL       ] = OP( 0,  0, 1, 1, PURE | BLOCK | CALLBRANCH, "call"),
[OP_RET        ] = OP( 0,  1, 0, 0, PURE | BLOCK | RETBRANCH, "ret"),
[OP_LABEL      ] = OP( 0,  0, 0, 0, PURE | BLOCK | STRUCTURAL, "label"),
[OP_ADECL      ] = OP( 0,  0, 0, 0, PURE | BLOCK | STRUCTURAL, "adecl"),
[OP_SDECL      ] = OP( 0,  0, 1, 0, PURE | BLOCK | STRUCTURAL, "sdecl"),
/* The number of RHS elements of OP_PHI depend upon context */
[OP_PHI        ] = OP( 0, -1, 1, 0, PURE | DEF | BLOCK, "phi"),

#if 0
[OP_CPS_BRANCH ] = OP( 0, -1, 0, 1, PURE | BLOCK | UBRANCH,     "cps_branch"),
[OP_CPS_CBRANCH] = OP( 0, -1, 0, 1, PURE | BLOCK | CBRANCH,     "cps_cbranch"),
[OP_CPS_CALL   ] = OP( 0, -1, 1, 1, PURE | BLOCK | CALLBRANCH,  "cps_call"),
[OP_CPS_RET    ] = OP( 0, -1, 0, 0, PURE | BLOCK | RETBRANCH,   "cps_ret"),
[OP_CPS_END    ] = OP( 0, -1, 0, 0, IMPURE | BLOCK | ENDBRANCH, "cps_end"),
[OP_CPS_START  ] = OP( -1, 0, 0, 0, PURE | BLOCK | STRUCTURAL,  "cps_start"),
#endif

[OP_CMP        ] = OP( 0,  2, 0, 0, PURE | DEF | BLOCK, "cmp"),
[OP_TEST       ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "test"),
[OP_SET_EQ     ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_eq"),
[OP_SET_NOTEQ  ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_noteq"),
[OP_SET_SLESS  ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_sless"),
[OP_SET_ULESS  ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_uless"),
[OP_SET_SMORE  ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_smore"),
[OP_SET_UMORE  ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_umore"),
[OP_SET_SLESSEQ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_slesseq"),
[OP_SET_ULESSEQ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_ulesseq"),
[OP_SET_SMOREEQ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_smoreq"),
[OP_SET_UMOREEQ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "set_umoreq"),
[OP_JMP        ] = OP( 0,  0, 0, 1, PURE | BLOCK | UBRANCH, "jmp"),
[OP_JMP_EQ     ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_eq"),
[OP_JMP_NOTEQ  ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_noteq"),
[OP_JMP_SLESS  ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_sless"),
[OP_JMP_ULESS  ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_uless"),
[OP_JMP_SMORE  ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_smore"),
[OP_JMP_UMORE  ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_umore"),
[OP_JMP_SLESSEQ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_slesseq"),
[OP_JMP_ULESSEQ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_ulesseq"),
[OP_JMP_SMOREEQ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_smoreq"),
[OP_JMP_UMOREEQ] = OP( 0,  1, 0, 1, PURE | BLOCK | CBRANCH, "jmp_umoreq"),

[OP_INB        ] = OP( 0,  1, 0, 0, IMPURE | DEF | BLOCK, "__inb"),
[OP_INW        ] = OP( 0,  1, 0, 0, IMPURE | DEF | BLOCK, "__inw"),
[OP_INL        ] = OP( 0,  1, 0, 0, IMPURE | DEF | BLOCK, "__inl"),
[OP_OUTB       ] = OP( 0,  2, 0, 0, IMPURE| BLOCK, "__outb"),
[OP_OUTW       ] = OP( 0,  2, 0, 0, IMPURE| BLOCK, "__outw"),
[OP_OUTL       ] = OP( 0,  2, 0, 0, IMPURE| BLOCK, "__outl"),
[OP_BSF        ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "__bsf"),
[OP_BSR        ] = OP( 0,  1, 0, 0, PURE | DEF | BLOCK, "__bsr"),
[OP_RDMSR      ] = OP( 2,  1, 0, 0, IMPURE | BLOCK, "__rdmsr"),
[OP_WRMSR      ] = OP( 0,  3, 0, 0, IMPURE | BLOCK, "__wrmsr"),
[OP_HLT        ] = OP( 0,  0, 0, 0, IMPURE | BLOCK, "__hlt"),
};
#undef OP
#define OP_MAX      (sizeof(table_ops)/sizeof(table_ops[0]))

static const char *tops(int index)
{
        static const char unknown[] = "unknown op";
        if (index < 0) {
                return unknown;
        }
        if (index >= OP_MAX) {
                return unknown;
        }
        return table_ops[index].name;
}

struct asm_info;
struct triple;
struct block;
struct triple_set {
        struct triple_set *next;
        struct triple *member;
};

#define MAX_LHS  63
#define MAX_RHS  127
#define MAX_MISC 3
#define MAX_TARG 1

struct occurrence {
        int count;
        const char *filename;
        const char *function;
        int line;
        int col;
        struct occurrence *parent;
};
struct bitfield {
        ulong_t size : 8;
        ulong_t offset : 24;
};
struct triple {
        struct triple *next, *prev;
        struct triple_set *use;
        struct type *type;
        unsigned int op : 8;
        unsigned int template_id : 7;
        unsigned int lhs  : 6;
        unsigned int rhs  : 7;
        unsigned int misc : 2;
        unsigned int targ : 1;
#define TRIPLE_SIZE(TRIPLE) \
        ((TRIPLE)->lhs + (TRIPLE)->rhs + (TRIPLE)->misc + (TRIPLE)->targ)
#define TRIPLE_LHS_OFF(PTR)  (0)
#define TRIPLE_RHS_OFF(PTR)  (TRIPLE_LHS_OFF(PTR) + (PTR)->lhs)
#define TRIPLE_MISC_OFF(PTR) (TRIPLE_RHS_OFF(PTR) + (PTR)->rhs)
#define TRIPLE_TARG_OFF(PTR) (TRIPLE_MISC_OFF(PTR) + (PTR)->misc)
#define LHS(PTR,INDEX) ((PTR)->param[TRIPLE_LHS_OFF(PTR) + (INDEX)])
#define RHS(PTR,INDEX) ((PTR)->param[TRIPLE_RHS_OFF(PTR) + (INDEX)])
#define TARG(PTR,INDEX) ((PTR)->param[TRIPLE_TARG_OFF(PTR) + (INDEX)])
#define MISC(PTR,INDEX) ((PTR)->param[TRIPLE_MISC_OFF(PTR) + (INDEX)])
        unsigned id; /* A scratch value and finally the register */
#define TRIPLE_FLAG_FLATTENED   (1 << 31)
#define TRIPLE_FLAG_PRE_SPLIT   (1 << 30)
#define TRIPLE_FLAG_POST_SPLIT  (1 << 29)
#define TRIPLE_FLAG_VOLATILE    (1 << 28)
#define TRIPLE_FLAG_INLINE      (1 << 27) /* ???? */
#define TRIPLE_FLAG_LOCAL       (1 << 26)

#define TRIPLE_FLAG_COPY TRIPLE_FLAG_VOLATILE
        struct occurrence *occurrence;
        union {
                ulong_t cval;
                struct bitfield bitfield;
                struct block  *block;
                void *blob;
                struct hash_entry *field;
                struct asm_info *ainfo;
                struct triple *func;
                struct symbol *symbol;
        } u;
        struct triple *param[2];
};

struct reg_info {
        unsigned reg;
        unsigned regcm;
};
struct ins_template {
        struct reg_info lhs[MAX_LHS + 1], rhs[MAX_RHS + 1];
};

struct asm_info {
        struct ins_template tmpl;
        char *str;
};

struct block_set {
        struct block_set *next;
        struct block *member;
};
struct block {
        struct block *work_next;
        struct triple *first, *last;
        int edge_count;
        struct block_set *edges;
        int users;
        struct block_set *use;
        struct block_set *idominates;
        struct block_set *domfrontier;
        struct block *idom;
        struct block_set *ipdominates;
        struct block_set *ipdomfrontier;
        struct block *ipdom;
        int vertex;

};

struct symbol {
        struct symbol *next;
        struct hash_entry *ident;
        struct triple *def;
        struct type *type;
        int scope_depth;
};

struct macro_arg {
        struct macro_arg *next;
        struct hash_entry *ident;
};
struct macro {
        struct hash_entry *ident;
        const char *buf;
        int buf_len;
        struct macro_arg *args;
        int argc;
};

struct hash_entry {
        struct hash_entry *next;
        const char *name;
        int name_len;
        int tok;
        struct macro *sym_define;
        struct symbol *sym_label;
        struct symbol *sym_tag;
        struct symbol *sym_ident;
};

#define HASH_TABLE_SIZE 2048

struct compiler_state {
        const char *label_prefix;
        const char *ofilename;
        unsigned long flags;
        unsigned long debug;
        unsigned long max_allocation_passes;

        size_t include_path_count;
        const char **include_paths;

        size_t define_count;
        const char **defines;

        size_t undef_count;
        const char **undefs;
};
struct arch_state {
        unsigned long features;
};
struct basic_blocks {
        struct triple *func;
        struct triple *first;
        struct block *first_block, *last_block;
        int last_vertex;
};
#define MAX_PP_IF_DEPTH 63
struct compile_state {
        struct compiler_state *compiler;
        struct arch_state *arch;
        FILE *output;
        FILE *errout;
        FILE *dbgout;
        struct file_state *file;
        struct occurrence *last_occurrence;
        const char *function;
        int    token_base;
        struct token token[6];
        struct hash_entry *hash_table[HASH_TABLE_SIZE];
        struct hash_entry *i_switch;
        struct hash_entry *i_case;
        struct hash_entry *i_continue;
        struct hash_entry *i_break;
        struct hash_entry *i_default;
        struct hash_entry *i_return;
        struct hash_entry *i_noreturn;
        struct hash_entry *i_unused;
        struct hash_entry *i_packed;
        /* Additional hash entries for predefined macros */
        struct hash_entry *i_defined;
        struct hash_entry *i___VA_ARGS__;
        struct hash_entry *i___FILE__;
        struct hash_entry *i___LINE__;
        /* Additional hash entries for predefined identifiers */
        struct hash_entry *i___func__;
        /* Additional hash entries for attributes */
        struct hash_entry *i_noinline;
        struct hash_entry *i_always_inline;
        int scope_depth;
        unsigned char if_bytes[(MAX_PP_IF_DEPTH + CHAR_BIT -1)/CHAR_BIT];
        int if_depth;
        int eat_depth, eat_targ;
        struct file_state *macro_file;
        struct triple *functions;
        struct triple *main_function;
        struct triple *first;
        struct triple *global_pool;
        struct basic_blocks bb;
        int functions_joined;
};

/* visibility global/local */
/* static/auto duration */
/* typedef, register, inline */
#define STOR_SHIFT         0
#define STOR_MASK     0x001f
/* Visibility */
#define STOR_GLOBAL   0x0001
/* Duration */
#define STOR_PERM     0x0002
/* Definition locality */
#define STOR_NONLOCAL 0x0004  /* The definition is not in this translation unit */
/* Storage specifiers */
#define STOR_AUTO     0x0000
#define STOR_STATIC   0x0002
#define STOR_LOCAL    0x0003
#define STOR_EXTERN   0x0007
#define STOR_INLINE   0x0008
#define STOR_REGISTER 0x0010
#define STOR_TYPEDEF  0x0018

#define QUAL_SHIFT         5
#define QUAL_MASK     0x00e0
#define QUAL_NONE     0x0000
#define QUAL_CONST    0x0020
#define QUAL_VOLATILE 0x0040
#define QUAL_RESTRICT 0x0080

#define TYPE_SHIFT         8
#define TYPE_MASK     0x1f00
#define TYPE_INTEGER(TYPE)    ((((TYPE) >= TYPE_CHAR) && ((TYPE) <= TYPE_ULLONG)) || ((TYPE) == TYPE_ENUM) || ((TYPE) == TYPE_BITFIELD))
#define TYPE_ARITHMETIC(TYPE) ((((TYPE) >= TYPE_CHAR) && ((TYPE) <= TYPE_LDOUBLE)) || ((TYPE) == TYPE_ENUM) || ((TYPE) == TYPE_BITFIELD))
#define TYPE_UNSIGNED(TYPE)   ((TYPE) & 0x0100)
#define TYPE_SIGNED(TYPE)     (!TYPE_UNSIGNED(TYPE))
#define TYPE_MKUNSIGNED(TYPE) (((TYPE) & ~0xF000) | 0x0100)
#define TYPE_RANK(TYPE)       ((TYPE) & ~0xF1FF)
#define TYPE_PTR(TYPE)        (((TYPE) & TYPE_MASK) == TYPE_POINTER)
#define TYPE_DEFAULT  0x0000
#define TYPE_VOID     0x0100
#define TYPE_CHAR     0x0200
#define TYPE_UCHAR    0x0300
#define TYPE_SHORT    0x0400
#define TYPE_USHORT   0x0500
#define TYPE_INT      0x0600
#define TYPE_UINT     0x0700
#define TYPE_LONG     0x0800
#define TYPE_ULONG    0x0900
#define TYPE_LLONG    0x0a00 /* long long */
#define TYPE_ULLONG   0x0b00
#define TYPE_FLOAT    0x0c00
#define TYPE_DOUBLE   0x0d00
#define TYPE_LDOUBLE  0x0e00 /* long double */

/* Note: TYPE_ENUM is chosen very carefully so TYPE_RANK works */
#define TYPE_ENUM     0x1600
#define TYPE_LIST     0x1700
/* TYPE_LIST is a basic building block when defining enumerations
 * type->field_ident holds the name of this enumeration entry.
 * type->right holds the entry in the list.
 */

#define TYPE_STRUCT   0x1000
/* For TYPE_STRUCT
 * type->left holds the link list of TYPE_PRODUCT entries that
 * make up the structure.
 * type->elements hold the length of the linked list
 */
#define TYPE_UNION    0x1100
/* For TYPE_UNION
 * type->left holds the link list of TYPE_OVERLAP entries that
 * make up the union.
 * type->elements hold the length of the linked list
 */
#define TYPE_POINTER  0x1200
/* For TYPE_POINTER:
 * type->left holds the type pointed to.
 */
#define TYPE_FUNCTION 0x1300
/* For TYPE_FUNCTION:
 * type->left holds the return type.
 * type->right holds the type of the arguments
 * type->elements holds the count of the arguments
 */
#define TYPE_PRODUCT  0x1400
/* TYPE_PRODUCT is a basic building block when defining structures
 * type->left holds the type that appears first in memory.
 * type->right holds the type that appears next in memory.
 */
#define TYPE_OVERLAP  0x1500
/* TYPE_OVERLAP is a basic building block when defining unions
 * type->left and type->right holds to types that overlap
 * each other in memory.
 */
#define TYPE_ARRAY    0x1800
/* TYPE_ARRAY is a basic building block when definitng arrays.
 * type->left holds the type we are an array of.
 * type->elements holds the number of elements.
 */
#define TYPE_TUPLE    0x1900
/* TYPE_TUPLE is a basic building block when defining
 * positionally reference type conglomerations. (i.e. closures)
 * In essence it is a wrapper for TYPE_PRODUCT, like TYPE_STRUCT
 * except it has no field names.
 * type->left holds the liked list of TYPE_PRODUCT entries that
 * make up the closure type.
 * type->elements hold the number of elements in the closure.
 */
#define TYPE_JOIN     0x1a00
/* TYPE_JOIN is a basic building block when defining
 * positionally reference type conglomerations. (i.e. closures)
 * In essence it is a wrapper for TYPE_OVERLAP, like TYPE_UNION
 * except it has no field names.
 * type->left holds the liked list of TYPE_OVERLAP entries that
 * make up the closure type.
 * type->elements hold the number of elements in the closure.
 */
#define TYPE_BITFIELD 0x1b00
/* TYPE_BITFIED is the type of a bitfield.
 * type->left holds the type basic type TYPE_BITFIELD is derived from.
 * type->elements holds the number of bits in the bitfield.
 */
#define TYPE_UNKNOWN  0x1c00
/* TYPE_UNKNOWN is the type of an unknown value.
 * Used on unknown consts and other places where I don't know the type.
 */

#define ATTRIB_SHIFT                 16
#define ATTRIB_MASK          0xffff0000
#define ATTRIB_NOINLINE      0x00010000
#define ATTRIB_ALWAYS_INLINE 0x00020000

#define ELEMENT_COUNT_UNSPECIFIED ULONG_T_MAX

struct type {
        unsigned int type;
        struct type *left, *right;
        ulong_t elements;
        struct hash_entry *field_ident;
        struct hash_entry *type_ident;
};

#define TEMPLATE_BITS      7
#define MAX_TEMPLATES      (1<<TEMPLATE_BITS)
#define MAX_REG_EQUIVS     16
#define MAX_REGC           14
#define MAX_REGISTERS      75
#define REGISTER_BITS      7
#define MAX_VIRT_REGISTERS (1<<REGISTER_BITS)
#define REG_ERROR          0
#define REG_UNSET          1
#define REG_UNNEEDED       2
#define REG_VIRT0          (MAX_REGISTERS + 0)
#define REG_VIRT1          (MAX_REGISTERS + 1)
#define REG_VIRT2          (MAX_REGISTERS + 2)
#define REG_VIRT3          (MAX_REGISTERS + 3)
#define REG_VIRT4          (MAX_REGISTERS + 4)
#define REG_VIRT5          (MAX_REGISTERS + 5)
#define REG_VIRT6          (MAX_REGISTERS + 6)
#define REG_VIRT7          (MAX_REGISTERS + 7)
#define REG_VIRT8          (MAX_REGISTERS + 8)
#define REG_VIRT9          (MAX_REGISTERS + 9)

#if (MAX_REGISTERS + 9) > MAX_VIRT_REGISTERS
#error "MAX_VIRT_REGISTERS to small"
#endif
#if (MAX_REGC + REGISTER_BITS) >= 26
#error "Too many id bits used"
#endif

/* Provision for 8 register classes */
#define REG_SHIFT  0
#define REGC_SHIFT REGISTER_BITS
#define REGC_MASK (((1 << MAX_REGC) - 1) << REGISTER_BITS)
#define REG_MASK (MAX_VIRT_REGISTERS -1)
#define ID_REG(ID)              ((ID) & REG_MASK)
#define SET_REG(ID, REG)        ((ID) = (((ID) & ~REG_MASK) | ((REG) & REG_MASK)))
#define ID_REGCM(ID)            (((ID) & REGC_MASK) >> REGC_SHIFT)
#define SET_REGCM(ID, REGCM)    ((ID) = (((ID) & ~REGC_MASK) | (((REGCM) << REGC_SHIFT) & REGC_MASK)))
#define SET_INFO(ID, INFO)      ((ID) = (((ID) & ~(REG_MASK | REGC_MASK)) | \
                (((INFO).reg) & REG_MASK) | ((((INFO).regcm) << REGC_SHIFT) & REGC_MASK)))

#define ARCH_INPUT_REGS 4
#define ARCH_OUTPUT_REGS 4

static const struct reg_info arch_input_regs[ARCH_INPUT_REGS];
static const struct reg_info arch_output_regs[ARCH_OUTPUT_REGS];
static unsigned arch_reg_regcm(struct compile_state *state, int reg);
static unsigned arch_regcm_normalize(struct compile_state *state, unsigned regcm);
static unsigned arch_regcm_reg_normalize(struct compile_state *state, unsigned regcm);
static void arch_reg_equivs(
        struct compile_state *state, unsigned *equiv, int reg);
static int arch_select_free_register(
        struct compile_state *state, char *used, int classes);
static unsigned arch_regc_size(struct compile_state *state, int class);
static int arch_regcm_intersect(unsigned regcm1, unsigned regcm2);
static unsigned arch_type_to_regcm(struct compile_state *state, struct type *type);
static const char *arch_reg_str(int reg);
static struct reg_info arch_reg_constraint(
        struct compile_state *state, struct type *type, const char *constraint);
static struct reg_info arch_reg_clobber(
        struct compile_state *state, const char *clobber);
static struct reg_info arch_reg_lhs(struct compile_state *state,
        struct triple *ins, int index);
static struct reg_info arch_reg_rhs(struct compile_state *state,
        struct triple *ins, int index);
static int arch_reg_size(int reg);
static struct triple *transform_to_arch_instruction(
        struct compile_state *state, struct triple *ins);
static struct triple *flatten(
        struct compile_state *state, struct triple *first, struct triple *ptr);
static void print_dominators(struct compile_state *state,
        FILE *fp, struct basic_blocks *bb);
static void print_dominance_frontiers(struct compile_state *state,
        FILE *fp, struct basic_blocks *bb);



#define DEBUG_ABORT_ON_ERROR    0x00000001
#define DEBUG_BASIC_BLOCKS      0x00000002
#define DEBUG_FDOMINATORS       0x00000004
#define DEBUG_RDOMINATORS       0x00000008
#define DEBUG_TRIPLES           0x00000010
#define DEBUG_INTERFERENCE      0x00000020
#define DEBUG_SCC_TRANSFORM     0x00000040
#define DEBUG_SCC_TRANSFORM2    0x00000080
#define DEBUG_REBUILD_SSA_FORM  0x00000100
#define DEBUG_INLINE            0x00000200
#define DEBUG_RANGE_CONFLICTS   0x00000400
#define DEBUG_RANGE_CONFLICTS2  0x00000800
#define DEBUG_COLOR_GRAPH       0x00001000
#define DEBUG_COLOR_GRAPH2      0x00002000
#define DEBUG_COALESCING        0x00004000
#define DEBUG_COALESCING2       0x00008000
#define DEBUG_VERIFICATION      0x00010000
#define DEBUG_CALLS             0x00020000
#define DEBUG_CALLS2            0x00040000
#define DEBUG_TOKENS            0x80000000

#define DEBUG_DEFAULT ( \
        DEBUG_ABORT_ON_ERROR | \
        DEBUG_BASIC_BLOCKS | \
        DEBUG_FDOMINATORS | \
        DEBUG_RDOMINATORS | \
        DEBUG_TRIPLES | \
        0 )

#define DEBUG_ALL ( \
        DEBUG_ABORT_ON_ERROR   | \
        DEBUG_BASIC_BLOCKS     | \
        DEBUG_FDOMINATORS      | \
        DEBUG_RDOMINATORS      | \
        DEBUG_TRIPLES          | \
        DEBUG_INTERFERENCE     | \
        DEBUG_SCC_TRANSFORM    | \
        DEBUG_SCC_TRANSFORM2   | \
        DEBUG_REBUILD_SSA_FORM | \
        DEBUG_INLINE           | \
        DEBUG_RANGE_CONFLICTS  | \
        DEBUG_RANGE_CONFLICTS2 | \
        DEBUG_COLOR_GRAPH      | \
        DEBUG_COLOR_GRAPH2     | \
        DEBUG_COALESCING       | \
        DEBUG_COALESCING2      | \
        DEBUG_VERIFICATION     | \
        DEBUG_CALLS            | \
        DEBUG_CALLS2           | \
        DEBUG_TOKENS           | \
        0 )

#define COMPILER_INLINE_MASK               0x00000007
#define COMPILER_INLINE_ALWAYS             0x00000000
#define COMPILER_INLINE_NEVER              0x00000001
#define COMPILER_INLINE_DEFAULTON          0x00000002
#define COMPILER_INLINE_DEFAULTOFF         0x00000003
#define COMPILER_INLINE_NOPENALTY          0x00000004
#define COMPILER_ELIMINATE_INEFECTUAL_CODE 0x00000008
#define COMPILER_SIMPLIFY                  0x00000010
#define COMPILER_SCC_TRANSFORM             0x00000020
#define COMPILER_SIMPLIFY_OP               0x00000040
#define COMPILER_SIMPLIFY_PHI              0x00000080
#define COMPILER_SIMPLIFY_LABEL            0x00000100
#define COMPILER_SIMPLIFY_BRANCH           0x00000200
#define COMPILER_SIMPLIFY_COPY             0x00000400
#define COMPILER_SIMPLIFY_ARITH            0x00000800
#define COMPILER_SIMPLIFY_SHIFT            0x00001000
#define COMPILER_SIMPLIFY_BITWISE          0x00002000
#define COMPILER_SIMPLIFY_LOGICAL          0x00004000
#define COMPILER_SIMPLIFY_BITFIELD         0x00008000

#define COMPILER_TRIGRAPHS                 0x40000000
#define COMPILER_PP_ONLY                   0x80000000

#define COMPILER_DEFAULT_FLAGS ( \
        COMPILER_TRIGRAPHS | \
        COMPILER_ELIMINATE_INEFECTUAL_CODE | \
        COMPILER_INLINE_DEFAULTON | \
        COMPILER_SIMPLIFY_OP | \
        COMPILER_SIMPLIFY_PHI | \
        COMPILER_SIMPLIFY_LABEL | \
        COMPILER_SIMPLIFY_BRANCH | \
        COMPILER_SIMPLIFY_COPY | \
        COMPILER_SIMPLIFY_ARITH | \
        COMPILER_SIMPLIFY_SHIFT | \
        COMPILER_SIMPLIFY_BITWISE | \
        COMPILER_SIMPLIFY_LOGICAL | \
        COMPILER_SIMPLIFY_BITFIELD | \
        0 )

#define GLOBAL_SCOPE_DEPTH   1
#define FUNCTION_SCOPE_DEPTH (GLOBAL_SCOPE_DEPTH + 1)

static void compile_file(struct compile_state *old_state, const char *filename, int local);



static void init_compiler_state(struct compiler_state *compiler)
{
        memset(compiler, 0, sizeof(*compiler));
        compiler->label_prefix = "";
        compiler->ofilename = "auto.inc";
        compiler->flags = COMPILER_DEFAULT_FLAGS;
        compiler->debug = 0;
        compiler->max_allocation_passes = MAX_ALLOCATION_PASSES;
        compiler->include_path_count = 1;
        compiler->include_paths      = xcmalloc(sizeof(char *), "include_paths");
        compiler->define_count       = 1;
        compiler->defines            = xcmalloc(sizeof(char *), "defines");
        compiler->undef_count        = 1;
        compiler->undefs             = xcmalloc(sizeof(char *), "undefs");
}

struct compiler_flag {
        const char *name;
        unsigned long flag;
};

struct compiler_arg {
        const char *name;
        unsigned long mask;
        struct compiler_flag flags[16];
};

static int set_flag(
        const struct compiler_flag *ptr, unsigned long *flags,
        int act, const char *flag)
{
        int result = -1;
        for(; ptr->name; ptr++) {
                if (strcmp(ptr->name, flag) == 0) {
                        break;
                }
        }
        if (ptr->name) {
                result = 0;
                *flags &= ~(ptr->flag);
                if (act) {
                        *flags |= ptr->flag;
                }
        }
        return result;
}

static int set_arg(
        const struct compiler_arg *ptr, unsigned long *flags, const char *arg)
{
        const char *val;
        int result = -1;
        int len;
        val = strchr(arg, '=');
        if (val) {
                len = val - arg;
                val++;
                for(; ptr->name; ptr++) {
                        if (strncmp(ptr->name, arg, len) == 0) {
                                break;
                        }
                }
                if (ptr->name) {
                        *flags &= ~ptr->mask;
                        result = set_flag(&ptr->flags[0], flags, 1, val);
                }
        }
        return result;
}


static void flag_usage(FILE *fp, const struct compiler_flag *ptr,
        const char *prefix, const char *invert_prefix)
{
        for(;ptr->name; ptr++) {
                fprintf(fp, "%s%s\n", prefix, ptr->name);
                if (invert_prefix) {
                        fprintf(fp, "%s%s\n", invert_prefix, ptr->name);
                }
        }
}

static void arg_usage(FILE *fp, const struct compiler_arg *ptr,
        const char *prefix)
{
        for(;ptr->name; ptr++) {
                const struct compiler_flag *flag;
                for(flag = &ptr->flags[0]; flag->name; flag++) {
                        fprintf(fp, "%s%s=%s\n",
                                prefix, ptr->name, flag->name);
                }
        }
}

static int append_string(size_t *max, const char ***vec, const char *str,
        const char *name)
{
        size_t count;
        count = ++(*max);
        *vec = xrealloc(*vec, sizeof(char *)*count, "name");
        (*vec)[count -1] = 0;
        (*vec)[count -2] = str;
        return 0;
}

static void arg_error(char *fmt, ...);
static void arg_warning(char *fmt, ...);
static const char *identifier(const char *str, const char *end);

static int append_include_path(struct compiler_state *compiler, const char *str)
{
        int result;
        if (!exists(str, ".")) {
                arg_warning("Warning: Nonexistent include path: `%s'\n",
                        str);
        }
        result = append_string(&compiler->include_path_count,
                &compiler->include_paths, str, "include_paths");
        return result;
}

static int append_define(struct compiler_state *compiler, const char *str)
{
        const char *end, *rest;
        int result;

        end = strchr(str, '=');
        if (!end) {
                end = str + strlen(str);
        }
        rest = identifier(str, end);
        if (rest != end) {
                int len = end - str - 1;
                arg_error("Invalid name cannot define macro: `%*.*s'\n",
                        len, len, str);
        }
        result = append_string(&compiler->define_count,
                &compiler->defines, str, "defines");
        return result;
}

static int append_undef(struct compiler_state *compiler, const char *str)
{
        const char *end, *rest;
        int result;

        end = str + strlen(str);
        rest = identifier(str, end);
        if (rest != end) {
                int len = end - str - 1;
                arg_error("Invalid name cannot undefine macro: `%*.*s'\n",
                        len, len, str);
        }
        result = append_string(&compiler->undef_count,
                &compiler->undefs, str, "undefs");
        return result;
}

static const struct compiler_flag romcc_flags[] = {
        { "trigraphs",                 COMPILER_TRIGRAPHS },
        { "pp-only",                   COMPILER_PP_ONLY },
        { "eliminate-inefectual-code", COMPILER_ELIMINATE_INEFECTUAL_CODE },
        { "simplify",                  COMPILER_SIMPLIFY },
        { "scc-transform",             COMPILER_SCC_TRANSFORM },
        { "simplify-op",               COMPILER_SIMPLIFY_OP },
        { "simplify-phi",              COMPILER_SIMPLIFY_PHI },
        { "simplify-label",            COMPILER_SIMPLIFY_LABEL },
        { "simplify-branch",           COMPILER_SIMPLIFY_BRANCH },
        { "simplify-copy",             COMPILER_SIMPLIFY_COPY },
        { "simplify-arith",            COMPILER_SIMPLIFY_ARITH },
        { "simplify-shift",            COMPILER_SIMPLIFY_SHIFT },
        { "simplify-bitwise",          COMPILER_SIMPLIFY_BITWISE },
        { "simplify-logical",          COMPILER_SIMPLIFY_LOGICAL },
        { "simplify-bitfield",         COMPILER_SIMPLIFY_BITFIELD },
        { 0, 0 },
};
static const struct compiler_arg romcc_args[] = {
        { "inline-policy",             COMPILER_INLINE_MASK,
                {
                        { "always",      COMPILER_INLINE_ALWAYS, },
                        { "never",       COMPILER_INLINE_NEVER, },
                        { "defaulton",   COMPILER_INLINE_DEFAULTON, },
                        { "defaultoff",  COMPILER_INLINE_DEFAULTOFF, },
                        { "nopenalty",   COMPILER_INLINE_NOPENALTY, },
                        { 0, 0 },
                },
        },
        { 0, 0 },
};
static const struct compiler_flag romcc_opt_flags[] = {
        { "-O",  COMPILER_SIMPLIFY },
        { "-O2", COMPILER_SIMPLIFY | COMPILER_SCC_TRANSFORM },
        { "-E",  COMPILER_PP_ONLY },
        { 0, 0, },
};
static const struct compiler_flag romcc_debug_flags[] = {
        { "all",                   DEBUG_ALL },
        { "abort-on-error",        DEBUG_ABORT_ON_ERROR },
        { "basic-blocks",          DEBUG_BASIC_BLOCKS },
        { "fdominators",           DEBUG_FDOMINATORS },
        { "rdominators",           DEBUG_RDOMINATORS },
        { "triples",               DEBUG_TRIPLES },
        { "interference",          DEBUG_INTERFERENCE },
        { "scc-transform",         DEBUG_SCC_TRANSFORM },
        { "scc-transform2",        DEBUG_SCC_TRANSFORM2 },
        { "rebuild-ssa-form",      DEBUG_REBUILD_SSA_FORM },
        { "inline",                DEBUG_INLINE },
        { "live-range-conflicts",  DEBUG_RANGE_CONFLICTS },
        { "live-range-conflicts2", DEBUG_RANGE_CONFLICTS2 },
        { "color-graph",           DEBUG_COLOR_GRAPH },
        { "color-graph2",          DEBUG_COLOR_GRAPH2 },
        { "coalescing",            DEBUG_COALESCING },
        { "coalescing2",           DEBUG_COALESCING2 },
        { "verification",          DEBUG_VERIFICATION },
        { "calls",                 DEBUG_CALLS },
        { "calls2",                DEBUG_CALLS2 },
        { "tokens",                DEBUG_TOKENS },
        { 0, 0 },
};

static int compiler_encode_flag(
        struct compiler_state *compiler, const char *flag)
{
        int act;
        int result;

        act = 1;
        result = -1;
        if (strncmp(flag, "no-", 3) == 0) {
                flag += 3;
                act = 0;
        }
        if (strncmp(flag, "-O", 2) == 0) {
                result = set_flag(romcc_opt_flags, &compiler->flags, act, flag);
        }
        else if (strncmp(flag, "-E", 2) == 0) {
                result = set_flag(romcc_opt_flags, &compiler->flags, act, flag);
        }
        else if (strncmp(flag, "-I", 2) == 0) {
                result = append_include_path(compiler, flag + 2);
        }
        else if (strncmp(flag, "-D", 2) == 0) {
                result = append_define(compiler, flag + 2);
        }
        else if (strncmp(flag, "-U", 2) == 0) {
                result = append_undef(compiler, flag + 2);
        }
        else if (act && strncmp(flag, "label-prefix=", 13) == 0) {
                result = 0;
                compiler->label_prefix = flag + 13;
        }
        else if (act && strncmp(flag, "max-allocation-passes=", 22) == 0) {
                unsigned long max_passes;
                char *end;
                max_passes = strtoul(flag + 22, &end, 10);
                if (end[0] == '\0') {
                        result = 0;
                        compiler->max_allocation_passes = max_passes;
                }
        }
        else if (act && strcmp(flag, "debug") == 0) {
                result = 0;
                compiler->debug |= DEBUG_DEFAULT;
        }
        else if (strncmp(flag, "debug-", 6) == 0) {
                flag += 6;
                result = set_flag(romcc_debug_flags, &compiler->debug, act, flag);
        }
        else {
                result = set_flag(romcc_flags, &compiler->flags, act, flag);
                if (result < 0) {
                        result = set_arg(romcc_args, &compiler->flags, flag);
                }
        }
        return result;
}

static void compiler_usage(FILE *fp)
{
        flag_usage(fp, romcc_opt_flags, "", 0);
        flag_usage(fp, romcc_flags, "-f", "-fno-");
        arg_usage(fp,  romcc_args, "-f");
        flag_usage(fp, romcc_debug_flags, "-fdebug-", "-fno-debug-");
        fprintf(fp, "-flabel-prefix=<prefix for assembly language labels>\n");
        fprintf(fp, "--label-prefix=<prefix for assembly language labels>\n");
        fprintf(fp, "-I<include path>\n");
        fprintf(fp, "-D<macro>[=defn]\n");
        fprintf(fp, "-U<macro>\n");
}

static void do_cleanup(struct compile_state *state)
{
        if (state->output) {
                fclose(state->output);
                unlink(state->compiler->ofilename);
                state->output = 0;
        }
        if (state->dbgout) {
                fflush(state->dbgout);
        }
        if (state->errout) {
                fflush(state->errout);
        }
}

static struct compile_state *exit_state;
static void exit_cleanup(void)
{
        if (exit_state) {
                do_cleanup(exit_state);
        }
}

static int get_col(struct file_state *file)
{
        int col;
        const char *ptr, *end;
        ptr = file->line_start;
        end = file->pos;
        for(col = 0; ptr < end; ptr++) {
                if (*ptr != '\t') {
                        col++;
                }
                else {
                        col = (col & ~7) + 8;
                }
        }
        return col;
}

static void loc(FILE *fp, struct compile_state *state, struct triple *triple)
{
        int col;
        if (triple && triple->occurrence) {
                struct occurrence *spot;
                for(spot = triple->occurrence; spot; spot = spot->parent) {
                        fprintf(fp, "%s:%d.%d: ",
                                spot->filename, spot->line, spot->col);
                }
                return;
        }
        if (!state->file) {
                return;
        }
        col = get_col(state->file);
        fprintf(fp, "%s:%d.%d: ",
                state->file->report_name, state->file->report_line, col);
}

static void __attribute__ ((noreturn)) internal_error(struct compile_state *state, struct triple *ptr,
        const char *fmt, ...)
{
        FILE *fp = state->errout;
        va_list args;
        va_start(args, fmt);
        loc(fp, state, ptr);
        fputc('\n', fp);
        if (ptr) {
                fprintf(fp, "%p %-10s ", ptr, tops(ptr->op));
        }
        fprintf(fp, "Internal compiler error: ");
        vfprintf(fp, fmt, args);
        fprintf(fp, "\n");
        va_end(args);
        do_cleanup(state);
        abort();
}


static void internal_warning(struct compile_state *state, struct triple *ptr,
        const char *fmt, ...)
{
        FILE *fp = state->errout;
        va_list args;
        va_start(args, fmt);
        loc(fp, state, ptr);
        if (ptr) {
                fprintf(fp, "%p %-10s ", ptr, tops(ptr->op));
        }
        fprintf(fp, "Internal compiler warning: ");
        vfprintf(fp, fmt, args);
        fprintf(fp, "\n");
        va_end(args);
}



static void __attribute__ ((noreturn)) error(struct compile_state *state, struct triple *ptr,
        const char *fmt, ...)
{
        FILE *fp = state->errout;
        va_list args;
        va_start(args, fmt);
        loc(fp, state, ptr);
        fputc('\n', fp);
        if (ptr && (state->compiler->debug & DEBUG_ABORT_ON_ERROR)) {
                fprintf(fp, "%p %-10s ", ptr, tops(ptr->op));
        }
        vfprintf(fp, fmt, args);
        va_end(args);
        fprintf(fp, "\n");
        do_cleanup(state);
        if (state->compiler->debug & DEBUG_ABORT_ON_ERROR) {
                abort();
        }
        exit(1);
}

static void warning(struct compile_state *state, struct triple *ptr,
        const char *fmt, ...)
{
        FILE *fp = state->errout;
        va_list args;
        va_start(args, fmt);
        loc(fp, state, ptr);
        fprintf(fp, "warning: ");
        if (ptr && (state->compiler->debug & DEBUG_ABORT_ON_ERROR)) {
                fprintf(fp, "%p %-10s ", ptr, tops(ptr->op));
        }
        vfprintf(fp, fmt, args);
        fprintf(fp, "\n");
        va_end(args);
}

#define FINISHME() warning(state, 0, "FINISHME @ %s.%s:%d", __FILE__, __func__, __LINE__)

static void valid_op(struct compile_state *state, int op)
{
        char *fmt = "invalid op: %d";
        if (op >= OP_MAX) {
                internal_error(state, 0, fmt, op);
        }
        if (op < 0) {
                internal_error(state, 0, fmt, op);
        }
}

static void valid_ins(struct compile_state *state, struct triple *ptr)
{
        valid_op(state, ptr->op);
}

#if DEBUG_ROMCC_WARNING
static void valid_param_count(struct compile_state *state, struct triple *ins)
{
        int lhs, rhs, misc, targ;
        valid_ins(state, ins);
        lhs  = table_ops[ins->op].lhs;
        rhs  = table_ops[ins->op].rhs;
        misc = table_ops[ins->op].misc;
        targ = table_ops[ins->op].targ;

        if ((lhs >= 0) && (ins->lhs != lhs)) {
                internal_error(state, ins, "Bad lhs count");
        }
        if ((rhs >= 0) && (ins->rhs != rhs)) {
                internal_error(state, ins, "Bad rhs count");
        }
        if ((misc >= 0) && (ins->misc != misc)) {
                internal_error(state, ins, "Bad misc count");
        }
        if ((targ >= 0) && (ins->targ != targ)) {
                internal_error(state, ins, "Bad targ count");
        }
}
#endif

static struct type void_type;
static struct type unknown_type;
static void use_triple(struct triple *used, struct triple *user)
{
        struct triple_set **ptr, *new;
        if (!used)
                return;
        if (!user)
                return;
        ptr = &used->use;
        while(*ptr) {
                if ((*ptr)->member == user) {
                        return;
                }
                ptr = &(*ptr)->next;
        }
        /* Append new to the head of the list,
         * copy_func and rename_block_variables
         * depends on this.
         */
        new = xcmalloc(sizeof(*new), "triple_set");
        new->member = user;
        new->next   = used->use;
        used->use   = new;
}

static void unuse_triple(struct triple *used, struct triple *unuser)
{
        struct triple_set *use, **ptr;
        if (!used) {
                return;
        }
        ptr = &used->use;
        while(*ptr) {
                use = *ptr;
                if (use->member == unuser) {
                        *ptr = use->next;
                        xfree(use);
                }
                else {
                        ptr = &use->next;
                }
        }
}

static void put_occurrence(struct occurrence *occurrence)
{
        if (occurrence) {
                occurrence->count -= 1;
                if (occurrence->count <= 0) {
                        if (occurrence->parent) {
                                put_occurrence(occurrence->parent);
                        }
                        xfree(occurrence);
                }
        }
}

static void get_occurrence(struct occurrence *occurrence)
{
        if (occurrence) {
                occurrence->count += 1;
        }
}


static struct occurrence *new_occurrence(struct compile_state *state)
{
        struct occurrence *result, *last;
        const char *filename;
        const char *function;
        int line, col;

        function = "";
        filename = 0;
        line = 0;
        col  = 0;
        if (state->file) {
                filename = state->file->report_name;
                line     = state->file->report_line;
                col      = get_col(state->file);
        }
        if (state->function) {
                function = state->function;
        }
        last = state->last_occurrence;
        if (last &&
                (last->col == col) &&
                (last->line == line) &&
                (last->function == function) &&
                ((last->filename == filename) ||
                (filename != NULL && strcmp(last->filename, filename) == 0)))
        {
                get_occurrence(last);
                return last;
        }
        if (last) {
                state->last_occurrence = 0;
                put_occurrence(last);
        }
        result = xmalloc(sizeof(*result), "occurrence");
        result->count    = 2;
        result->filename = filename;
        result->function = function;
        result->line     = line;
        result->col      = col;
        result->parent   = 0;
        state->last_occurrence = result;
        return result;
}

static struct occurrence *inline_occurrence(struct compile_state *state,
        struct occurrence *base, struct occurrence *top)
{
        struct occurrence *result, *last;
        if (top->parent) {
                internal_error(state, 0, "inlining an already inlined function?");
        }
        /* If I have a null base treat it that way */
        if ((base->parent == 0) &&
                (base->col == 0) &&
                (base->line == 0) &&
                (base->function[0] == '\0') &&
                (base->filename[0] == '\0')) {
                base = 0;
        }
        /* See if I can reuse the last occurrence I had */
        last = state->last_occurrence;
        if (last &&
                (last->parent   == base) &&
                (last->col      == top->col) &&
                (last->line     == top->line) &&
                (last->function == top->function) &&
                (last->filename == top->filename)) {
                get_occurrence(last);
                return last;
        }
        /* I can't reuse the last occurrence so free it */
        if (last) {
                state->last_occurrence = 0;
                put_occurrence(last);
        }
        /* Generate a new occurrence structure */
        get_occurrence(base);
        result = xmalloc(sizeof(*result), "occurrence");
        result->count    = 2;
        result->filename = top->filename;
        result->function = top->function;
        result->line     = top->line;
        result->col      = top->col;
        result->parent   = base;
        state->last_occurrence = result;
        return result;
}

static struct occurrence dummy_occurrence = {
        .count    = 2,
        .filename = __FILE__,
        .function = "",
        .line     = __LINE__,
        .col      = 0,
        .parent   = 0,
};

/* The undef triple is used as a place holder when we are removing pointers
 * from a triple.  Having allows certain sanity checks to pass even
 * when the original triple that was pointed to is gone.
 */
static struct triple unknown_triple = {
        .next      = &unknown_triple,
        .prev      = &unknown_triple,
        .use       = 0,
        .op        = OP_UNKNOWNVAL,
        .lhs       = 0,
        .rhs       = 0,
        .misc      = 0,
        .targ      = 0,
        .type      = &unknown_type,
        .id        = -1, /* An invalid id */
        .u = { .cval = 0, },
        .occurrence = &dummy_occurrence,
        .param = { [0] = 0, [1] = 0, },
};


static size_t registers_of(struct compile_state *state, struct type *type);

static struct triple *alloc_triple(struct compile_state *state,
        int op, struct type *type, int lhs_wanted, int rhs_wanted,
        struct occurrence *occurrence)
{
        size_t size, extra_count, min_count;
        int lhs, rhs, misc, targ;
        struct triple *ret, dummy;
        dummy.op = op;
        dummy.occurrence = occurrence;
        valid_op(state, op);
        lhs = table_ops[op].lhs;
        rhs = table_ops[op].rhs;
        misc = table_ops[op].misc;
        targ = table_ops[op].targ;

        switch(op) {
        case OP_FCALL:
                rhs = rhs_wanted;
                break;
        case OP_PHI:
                rhs = rhs_wanted;
                break;
        case OP_ADECL:
                lhs = registers_of(state, type);
                break;
        case OP_TUPLE:
                lhs = registers_of(state, type);
                break;
        case OP_ASM:
                rhs = rhs_wanted;
                lhs = lhs_wanted;
                break;
        }
        if ((rhs < 0) || (rhs > MAX_RHS)) {
                internal_error(state, &dummy, "bad rhs count %d", rhs);
        }
        if ((lhs < 0) || (lhs > MAX_LHS)) {
                internal_error(state, &dummy, "bad lhs count %d", lhs);
        }
        if ((misc < 0) || (misc > MAX_MISC)) {
                internal_error(state, &dummy, "bad misc count %d", misc);
        }
        if ((targ < 0) || (targ > MAX_TARG)) {
                internal_error(state, &dummy, "bad targs count %d", targ);
        }

        min_count = sizeof(ret->param)/sizeof(ret->param[0]);
        extra_count = lhs + rhs + misc + targ;
        extra_count = (extra_count < min_count)? 0 : extra_count - min_count;

        size = sizeof(*ret) + sizeof(ret->param[0]) * extra_count;
        ret = xcmalloc(size, "tripple");
        ret->op        = op;
        ret->lhs       = lhs;
        ret->rhs       = rhs;
        ret->misc      = misc;
        ret->targ      = targ;
        ret->type      = type;
        ret->next      = ret;
        ret->prev      = ret;
        ret->occurrence = occurrence;
        /* A simple sanity check */
        if ((ret->op != op) ||
                (ret->lhs != lhs) ||
                (ret->rhs != rhs) ||
                (ret->misc != misc) ||
                (ret->targ != targ) ||
                (ret->type != type) ||
                (ret->next != ret) ||
                (ret->prev != ret) ||
                (ret->occurrence != occurrence)) {
                internal_error(state, ret, "huh?");
        }
        return ret;
}

struct triple *dup_triple(struct compile_state *state, struct triple *src)
{
        struct triple *dup;
        int src_lhs, src_rhs, src_size;
        src_lhs = src->lhs;
        src_rhs = src->rhs;
        src_size = TRIPLE_SIZE(src);
        get_occurrence(src->occurrence);
        dup = alloc_triple(state, src->op, src->type, src_lhs, src_rhs,
                src->occurrence);
        memcpy(dup, src, sizeof(*src));
        memcpy(dup->param, src->param, src_size * sizeof(src->param[0]));
        return dup;
}

static struct triple *copy_triple(struct compile_state *state, struct triple *src)
{
        struct triple *copy;
        copy = dup_triple(state, src);
        copy->use = 0;
        copy->next = copy->prev = copy;
        return copy;
}

static struct triple *new_triple(struct compile_state *state,
        int op, struct type *type, int lhs, int rhs)
{
        struct triple *ret;
        struct occurrence *occurrence;
        occurrence = new_occurrence(state);
        ret = alloc_triple(state, op, type, lhs, rhs, occurrence);
        return ret;
}

static struct triple *build_triple(struct compile_state *state,
        int op, struct type *type, struct triple *left, struct triple *right,
        struct occurrence *occurrence)
{
        struct triple *ret;
        size_t count;
        ret = alloc_triple(state, op, type, -1, -1, occurrence);
        count = TRIPLE_SIZE(ret);
        if (count > 0) {
                ret->param[0] = left;
        }
        if (count > 1) {
                ret->param[1] = right;
        }
        return ret;
}

static struct triple *triple(struct compile_state *state,
        int op, struct type *type, struct triple *left, struct triple *right)
{
        struct triple *ret;
        size_t count;
        ret = new_triple(state, op, type, -1, -1);
        count = TRIPLE_SIZE(ret);
        if (count >= 1) {
                ret->param[0] = left;
        }
        if (count >= 2) {
                ret->param[1] = right;
        }
        return ret;
}

static struct triple *branch(struct compile_state *state,
        struct triple *targ, struct triple *test)
{
        struct triple *ret;
        if (test) {
                ret = new_triple(state, OP_CBRANCH, &void_type, -1, 1);
                RHS(ret, 0) = test;
        } else {
                ret = new_triple(state, OP_BRANCH, &void_type, -1, 0);
        }
        TARG(ret, 0) = targ;
        /* record the branch target was used */
        if (!targ || (targ->op != OP_LABEL)) {
                internal_error(state, 0, "branch not to label");
        }
        return ret;
}

static int triple_is_label(struct compile_state *state, struct triple *ins);
static int triple_is_call(struct compile_state *state, struct triple *ins);
static int triple_is_cbranch(struct compile_state *state, struct triple *ins);
static void insert_triple(struct compile_state *state,
        struct triple *first, struct triple *ptr)
{
        if (ptr) {
                if ((ptr->id & TRIPLE_FLAG_FLATTENED) || (ptr->next != ptr)) {
                        internal_error(state, ptr, "expression already used");
                }
                ptr->next       = first;
                ptr->prev       = first->prev;
                ptr->prev->next = ptr;
                ptr->next->prev = ptr;

                if (triple_is_cbranch(state, ptr->prev) ||
                        triple_is_call(state, ptr->prev)) {
                        unuse_triple(first, ptr->prev);
                        use_triple(ptr, ptr->prev);
                }
        }
}

static int triple_stores_block(struct compile_state *state, struct triple *ins)
{
        /* This function is used to determine if u.block
         * is utilized to store the current block number.
         */
        int stores_block;
        valid_ins(state, ins);
        stores_block = (table_ops[ins->op].flags & BLOCK) == BLOCK;
        return stores_block;
}

static int triple_is_branch(struct compile_state *state, struct triple *ins);
static struct block *block_of_triple(struct compile_state *state,
        struct triple *ins)
{
        struct triple *first;
        if (!ins || ins == &unknown_triple) {
                return 0;
        }
        first = state->first;
        while(ins != first && !triple_is_branch(state, ins->prev) &&
                !triple_stores_block(state, ins))
        {
                if (ins == ins->prev) {
                        internal_error(state, ins, "ins == ins->prev?");
                }
                ins = ins->prev;
        }
        return triple_stores_block(state, ins)? ins->u.block: 0;
}

static void generate_lhs_pieces(struct compile_state *state, struct triple *ins);
static struct triple *pre_triple(struct compile_state *state,
        struct triple *base,
        int op, struct type *type, struct triple *left, struct triple *right)
{
        struct block *block;
        struct triple *ret;
        int i;
        /* If I am an OP_PIECE jump to the real instruction */
        if (base->op == OP_PIECE) {
                base = MISC(base, 0);
        }
        block = block_of_triple(state, base);
        get_occurrence(base->occurrence);
        ret = build_triple(state, op, type, left, right, base->occurrence);
        generate_lhs_pieces(state, ret);
        if (triple_stores_block(state, ret)) {
                ret->u.block = block;
        }
        insert_triple(state, base, ret);
        for(i = 0; i < ret->lhs; i++) {
                struct triple *piece;
                piece = LHS(ret, i);
                insert_triple(state, base, piece);
                use_triple(ret, piece);
                use_triple(piece, ret);
        }
        if (block && (block->first == base)) {
                block->first = ret;
        }
        return ret;
}

static struct triple *post_triple(struct compile_state *state,
        struct triple *base,
        int op, struct type *type, struct triple *left, struct triple *right)
{
        struct block *block;
        struct triple *ret, *next;
        int zlhs, i;
        /* If I am an OP_PIECE jump to the real instruction */
        if (base->op == OP_PIECE) {
                base = MISC(base, 0);
        }
        /* If I have a left hand side skip over it */
        zlhs = base->lhs;
        if (zlhs) {
                base = LHS(base, zlhs - 1);
        }

        block = block_of_triple(state, base);
        get_occurrence(base->occurrence);
        ret = build_triple(state, op, type, left, right, base->occurrence);
        generate_lhs_pieces(state, ret);
        if (triple_stores_block(state, ret)) {
                ret->u.block = block;
        }
        next = base->next;
        insert_triple(state, next, ret);
        zlhs = ret->lhs;
        for(i = 0; i < zlhs; i++) {
                struct triple *piece;
                piece = LHS(ret, i);
                insert_triple(state, next, piece);
                use_triple(ret, piece);
                use_triple(piece, ret);
        }
        if (block && (block->last == base)) {
                block->last = ret;
                if (zlhs) {
                        block->last = LHS(ret, zlhs - 1);
                }
        }
        return ret;
}

static struct type *reg_type(
        struct compile_state *state, struct type *type, int reg);

static void generate_lhs_piece(
        struct compile_state *state, struct triple *ins, int index)
{
        struct type *piece_type;
        struct triple *piece;
        get_occurrence(ins->occurrence);
        piece_type = reg_type(state, ins->type, index * REG_SIZEOF_REG);

        if ((piece_type->type & TYPE_MASK) == TYPE_BITFIELD) {
                piece_type = piece_type->left;
        }
#if 0
{
        static void name_of(FILE *fp, struct type *type);
        FILE * fp = state->errout;
        fprintf(fp, "piece_type(%d): ", index);
        name_of(fp, piece_type);
        fprintf(fp, "\n");
}
#endif
        piece = alloc_triple(state, OP_PIECE, piece_type, -1, -1, ins->occurrence);
        piece->u.cval  = index;
        LHS(ins, piece->u.cval) = piece;
        MISC(piece, 0) = ins;
}

static void generate_lhs_pieces(struct compile_state *state, struct triple *ins)
{
        int i, zlhs;
        zlhs = ins->lhs;
        for(i = 0; i < zlhs; i++) {
                generate_lhs_piece(state, ins, i);
        }
}

static struct triple *label(struct compile_state *state)
{
        /* Labels don't get a type */
        struct triple *result;
        result = triple(state, OP_LABEL, &void_type, 0, 0);
        return result;
}

static struct triple *mkprog(struct compile_state *state, ...)
{
        struct triple *prog, *head, *arg;
        va_list args;
        int i;

        head = label(state);
        prog = new_triple(state, OP_PROG, &void_type, -1, -1);
        RHS(prog, 0) = head;
        va_start(args, state);
        i = 0;
        while((arg = va_arg(args, struct triple *)) != 0) {
                if (++i >= 100) {
                        internal_error(state, 0, "too many arguments to mkprog");
                }
                flatten(state, head, arg);
        }
        va_end(args);
        prog->type = head->prev->type;
        return prog;
}
static void name_of(FILE *fp, struct type *type);
static void display_triple(FILE *fp, struct triple *ins)
{
        struct occurrence *ptr;
        const char *reg;
        char pre, post, vol;
        pre = post = vol = ' ';
        if (ins) {
                if (ins->id & TRIPLE_FLAG_PRE_SPLIT) {
                        pre = '^';
                }
                if (ins->id & TRIPLE_FLAG_POST_SPLIT) {
                        post = ',';
                }
                if (ins->id & TRIPLE_FLAG_VOLATILE) {
                        vol = 'v';
                }
                reg = arch_reg_str(ID_REG(ins->id));
        }
        if (ins == 0) {
                fprintf(fp, "(%p) <nothing> ", ins);
        }
        else if (ins->op == OP_INTCONST) {
                fprintf(fp, "(%p) %c%c%c %-7s %-2d %-10s <0x%08lx>         ",
                        ins, pre, post, vol, reg, ins->template_id, tops(ins->op),
                        (unsigned long)(ins->u.cval));
        }
        else if (ins->op == OP_ADDRCONST) {
                fprintf(fp, "(%p) %c%c%c %-7s %-2d %-10s %-10p <0x%08lx>",
                        ins, pre, post, vol, reg, ins->template_id, tops(ins->op),
                        MISC(ins, 0), (unsigned long)(ins->u.cval));
        }
        else if (ins->op == OP_INDEX) {
                fprintf(fp, "(%p) %c%c%c %-7s %-2d %-10s %-10p <0x%08lx>",
                        ins, pre, post, vol, reg, ins->template_id, tops(ins->op),
                        RHS(ins, 0), (unsigned long)(ins->u.cval));
        }
        else if (ins->op == OP_PIECE) {
                fprintf(fp, "(%p) %c%c%c %-7s %-2d %-10s %-10p <0x%08lx>",
                        ins, pre, post, vol, reg, ins->template_id, tops(ins->op),
                        MISC(ins, 0), (unsigned long)(ins->u.cval));
        }
        else {
                int i, count;
                fprintf(fp, "(%p) %c%c%c %-7s %-2d %-10s",
                        ins, pre, post, vol, reg, ins->template_id, tops(ins->op));
                if (table_ops[ins->op].flags & BITFIELD) {
                        fprintf(fp, " <%2d-%2d:%2d>",
                                ins->u.bitfield.offset,
                                ins->u.bitfield.offset + ins->u.bitfield.size,
                                ins->u.bitfield.size);
                }
                count = TRIPLE_SIZE(ins);
                for(i = 0; i < count; i++) {
                        fprintf(fp, " %-10p", ins->param[i]);
                }
                for(; i < 2; i++) {
                        fprintf(fp, "           ");
                }
        }
        if (ins) {
                struct triple_set *user;
#if DEBUG_DISPLAY_TYPES
                fprintf(fp, " <");
                name_of(fp, ins->type);
                fprintf(fp, "> ");
#endif
#if DEBUG_DISPLAY_USES
                fprintf(fp, " [");
                for(user = ins->use; user; user = user->next) {
                        fprintf(fp, " %-10p", user->member);
                }
                fprintf(fp, " ]");
#endif
                fprintf(fp, " @");
                for(ptr = ins->occurrence; ptr; ptr = ptr->parent) {
                        fprintf(fp, " %s,%s:%d.%d",
                                ptr->function,
                                ptr->filename,
                                ptr->line,
                                ptr->col);
                }
                if (ins->op == OP_ASM) {
                        fprintf(fp, "\n\t%s", ins->u.ainfo->str);
                }
        }
        fprintf(fp, "\n");
        fflush(fp);
}

static int equiv_types(struct type *left, struct type *right);
static void display_triple_changes(
        FILE *fp, const struct triple *new, const struct triple *orig)
{

        int new_count, orig_count;
        new_count = TRIPLE_SIZE(new);
        orig_count = TRIPLE_SIZE(orig);
        if ((new->op != orig->op) ||
                (new_count != orig_count) ||
                (memcmp(orig->param, new->param,
                        orig_count * sizeof(orig->param[0])) != 0) ||
                (memcmp(&orig->u, &new->u, sizeof(orig->u)) != 0))
        {
                struct occurrence *ptr;
                int i, min_count, indent;
                fprintf(fp, "(%p %p)", new, orig);
                if (orig->op == new->op) {
                        fprintf(fp, " %-11s", tops(orig->op));
                } else {
                        fprintf(fp, " [%-10s %-10s]",
                                tops(new->op), tops(orig->op));
                }
                min_count = new_count;
                if (min_count > orig_count) {
                        min_count = orig_count;
                }
                for(indent = i = 0; i < min_count; i++) {
                        if (orig->param[i] == new->param[i]) {
                                fprintf(fp, " %-11p",
                                        orig->param[i]);
                                indent += 12;
                        } else {
                                fprintf(fp, " [%-10p %-10p]",
                                        new->param[i],
                                        orig->param[i]);
                                indent += 24;
                        }
                }
                for(; i < orig_count; i++) {
                        fprintf(fp, " [%-9p]", orig->param[i]);
                        indent += 12;
                }
                for(; i < new_count; i++) {
                        fprintf(fp, " [%-9p]", new->param[i]);
                        indent += 12;
                }
                if ((new->op == OP_INTCONST)||
                        (new->op == OP_ADDRCONST)) {
                        fprintf(fp, " <0x%08lx>",
                                (unsigned long)(new->u.cval));
                        indent += 13;
                }
                for(;indent < 36; indent++) {
                        putc(' ', fp);
                }

#if DEBUG_DISPLAY_TYPES
                fprintf(fp, " <");
                name_of(fp, new->type);
                if (!equiv_types(new->type, orig->type)) {
                        fprintf(fp, " -- ");
                        name_of(fp, orig->type);
                }
                fprintf(fp, "> ");
#endif

                fprintf(fp, " @");
                for(ptr = orig->occurrence; ptr; ptr = ptr->parent) {
                        fprintf(fp, " %s,%s:%d.%d",
                                ptr->function,
                                ptr->filename,
                                ptr->line,
                                ptr->col);

                }
                fprintf(fp, "\n");
                fflush(fp);
        }
}

static int triple_is_pure(struct compile_state *state, struct triple *ins, unsigned id)
{
        /* Does the triple have no side effects.
         * I.e. Rexecuting the triple with the same arguments
         * gives the same value.
         */
        unsigned pure;
        valid_ins(state, ins);
        pure = PURE_BITS(table_ops[ins->op].flags);
        if ((pure != PURE) && (pure != IMPURE)) {
                internal_error(state, 0, "Purity of %s not known",
                        tops(ins->op));
        }
        return (pure == PURE) && !(id & TRIPLE_FLAG_VOLATILE);
}

static int triple_is_branch_type(struct compile_state *state,
        struct triple *ins, unsigned type)
{
        /* Is this one of the passed branch types? */
        valid_ins(state, ins);
        return (BRANCH_BITS(table_ops[ins->op].flags) == type);
}

static int triple_is_branch(struct compile_state *state, struct triple *ins)
{
        /* Is this triple a branch instruction? */
        valid_ins(state, ins);
        return (BRANCH_BITS(table_ops[ins->op].flags) != 0);
}

static int triple_is_cbranch(struct compile_state *state, struct triple *ins)
{
        /* Is this triple a conditional branch instruction? */
        return triple_is_branch_type(state, ins, CBRANCH);
}

static int triple_is_ubranch(struct compile_state *state, struct triple *ins)
{
        /* Is this triple a unconditional branch instruction? */
        unsigned type;
        valid_ins(state, ins);
        type = BRANCH_BITS(table_ops[ins->op].flags);
        return (type != 0) && (type != CBRANCH);
}

static int triple_is_call(struct compile_state *state, struct triple *ins)
{
        /* Is this triple a call instruction? */
        return triple_is_branch_type(state, ins, CALLBRANCH);
}

static int triple_is_ret(struct compile_state *state, struct triple *ins)
{
        /* Is this triple a return instruction? */
        return triple_is_branch_type(state, ins, RETBRANCH);
}

#if DEBUG_ROMCC_WARNING
static int triple_is_simple_ubranch(struct compile_state *state, struct triple *ins)
{
        /* Is this triple an unconditional branch and not a call or a
         * return? */
        return triple_is_branch_type(state, ins, UBRANCH);
}
#endif

static int triple_is_end(struct compile_state *state, struct triple *ins)
{
        return triple_is_branch_type(state, ins, ENDBRANCH);
}

static int triple_is_label(struct compile_state *state, struct triple *ins)
{
        valid_ins(state, ins);
        return (ins->op == OP_LABEL);
}

static struct triple *triple_to_block_start(
        struct compile_state *state, struct triple *start)
{
        while(!triple_is_branch(state, start->prev) &&
                (!triple_is_label(state, start) || !start->use)) {
                start = start->prev;
        }
        return start;
}

static int triple_is_def(struct compile_state *state, struct triple *ins)
{
        /* This function is used to determine which triples need
         * a register.
         */
        int is_def;
        valid_ins(state, ins);
        is_def = (table_ops[ins->op].flags & DEF) == DEF;
        if (ins->lhs >= 1) {
                is_def = 0;
        }
        return is_def;
}

static int triple_is_structural(struct compile_state *state, struct triple *ins)
{
        int is_structural;
        valid_ins(state, ins);
        is_structural = (table_ops[ins->op].flags & STRUCTURAL) == STRUCTURAL;
        return is_structural;
}

static int triple_is_part(struct compile_state *state, struct triple *ins)
{
        int is_part;
        valid_ins(state, ins);
        is_part = (table_ops[ins->op].flags & PART) == PART;
        return is_part;
}

static int triple_is_auto_var(struct compile_state *state, struct triple *ins)
{
        return (ins->op == OP_PIECE) && (MISC(ins, 0)->op == OP_ADECL);
}

static struct triple **triple_iter(struct compile_state *state,
        size_t count, struct triple **vector,
        struct triple *ins, struct triple **last)
{
        struct triple **ret;
        ret = 0;
        if (count) {
                if (!last) {
                        ret = vector;
                }
                else if ((last >= vector) && (last < (vector + count - 1))) {
                        ret = last + 1;
                }
        }
        return ret;

}

static struct triple **triple_lhs(struct compile_state *state,
        struct triple *ins, struct triple **last)
{
        return triple_iter(state, ins->lhs, &LHS(ins,0),
                ins, last);
}

static struct triple **triple_rhs(struct compile_state *state,
        struct triple *ins, struct triple **last)
{
        return triple_iter(state, ins->rhs, &RHS(ins,0),
                ins, last);
}

static struct triple **triple_misc(struct compile_state *state,
        struct triple *ins, struct triple **last)
{
        return triple_iter(state, ins->misc, &MISC(ins,0),
                ins, last);
}

static struct triple **do_triple_targ(struct compile_state *state,
        struct triple *ins, struct triple **last, int call_edges, int next_edges)
{
        size_t count;
        struct triple **ret, **vector;
        int next_is_targ;
        ret = 0;
        count = ins->targ;
        next_is_targ = 0;
        if (triple_is_cbranch(state, ins)) {
                next_is_targ = 1;
        }
        if (!call_edges && triple_is_call(state, ins)) {
                count = 0;
        }
        if (next_edges && triple_is_call(state, ins)) {
                next_is_targ = 1;
        }
        vector = &TARG(ins, 0);
        if (!ret && next_is_targ) {
                if (!last) {
                        ret = &ins->next;
                } else if (last == &ins->next) {
                        last = 0;
                }
        }
        if (!ret && count) {
                if (!last) {
                        ret = vector;
                }
                else if ((last >= vector) && (last < (vector + count - 1))) {
                        ret = last + 1;
                }
                else if (last == vector + count - 1) {
                        last = 0;
                }
        }
        if (!ret && triple_is_ret(state, ins) && call_edges) {
                struct triple_set *use;
                for(use = ins->use; use; use = use->next) {
                        if (!triple_is_call(state, use->member)) {
                                continue;
                        }
                        if (!last) {
                                ret = &use->member->next;
                                break;
                        }
                        else if (last == &use->member->next) {
                                last = 0;
                        }
                }
        }
        return ret;
}

static struct triple **triple_targ(struct compile_state *state,
        struct triple *ins, struct triple **last)
{
        return do_triple_targ(state, ins, last, 1, 1);
}

static struct triple **triple_edge_targ(struct compile_state *state,
        struct triple *ins, struct triple **last)
{
        return do_triple_targ(state, ins, last,
                state->functions_joined, !state->functions_joined);
}

static struct triple *after_lhs(struct compile_state *state, struct triple *ins)
{
        struct triple *next;
        int lhs, i;
        lhs = ins->lhs;
        next = ins->next;
        for(i = 0; i < lhs; i++) {
                struct triple *piece;
                piece = LHS(ins, i);
                if (next != piece) {
                        internal_error(state, ins, "malformed lhs on %s",
                                tops(ins->op));
                }
                if (next->op != OP_PIECE) {
                        internal_error(state, ins, "bad lhs op %s at %d on %s",
                                tops(next->op), i, tops(ins->op));
                }
                if (next->u.cval != i) {
                        internal_error(state, ins, "bad u.cval of %d %d expected",
                                next->u.cval, i);
                }
                next = next->next;
        }
        return next;
}

/* Function piece accessor functions */
static struct triple *do_farg(struct compile_state *state,
        struct triple *func, unsigned index)
{
        struct type *ftype;
        struct triple *first, *arg;
        unsigned i;

        ftype = func->type;
        if(index >= (ftype->elements + 2)) {
                internal_error(state, func, "bad argument index: %d", index);
        }
        first = RHS(func, 0);
        arg = first->next;
        for(i = 0; i < index; i++, arg = after_lhs(state, arg)) {
                /* do nothing */
        }
        if (arg->op != OP_ADECL) {
                internal_error(state, 0, "arg not adecl?");
        }
        return arg;
}
static struct triple *fresult(struct compile_state *state, struct triple *func)
{
        return do_farg(state, func, 0);
}
static struct triple *fretaddr(struct compile_state *state, struct triple *func)
{
        return do_farg(state, func, 1);
}
static struct triple *farg(struct compile_state *state,
        struct triple *func, unsigned index)
{
        return do_farg(state, func, index + 2);
}


static void display_func(struct compile_state *state, FILE *fp, struct triple *func)
{
        struct triple *first, *ins;
        fprintf(fp, "display_func %s\n", func->type->type_ident->name);
        first = ins = RHS(func, 0);
        do {
                if (triple_is_label(state, ins) && ins->use) {
                        fprintf(fp, "%p:\n", ins);
                }
                display_triple(fp, ins);

                if (triple_is_branch(state, ins)) {
                        fprintf(fp, "\n");
                }
                if (ins->next->prev != ins) {
                        internal_error(state, ins->next, "bad prev");
                }
                ins = ins->next;
        } while(ins != first);
}

static void verify_use(struct compile_state *state,
        struct triple *user, struct triple *used)
{
        int size, i;
        size = TRIPLE_SIZE(user);
        for(i = 0; i < size; i++) {
                if (user->param[i] == used) {
                        break;
                }
        }
        if (triple_is_branch(state, user)) {
                if (user->next == used) {
                        i = -1;
                }
        }
        if (i == size) {
                internal_error(state, user, "%s(%p) does not use %s(%p)",
                        tops(user->op), user, tops(used->op), used);
        }
}

static int find_rhs_use(struct compile_state *state,
        struct triple *user, struct triple *used)
{
        struct triple **param;
        int size, i;
        verify_use(state, user, used);

#if DEBUG_ROMCC_WARNINGS
#warning "AUDIT ME ->rhs"
#endif
        size = user->rhs;
        param = &RHS(user, 0);
        for(i = 0; i < size; i++) {
                if (param[i] == used) {
                        return i;
                }
        }
        return -1;
}

static void free_triple(struct compile_state *state, struct triple *ptr)
{
        size_t size;
        size = sizeof(*ptr) - sizeof(ptr->param) +
                (sizeof(ptr->param[0])*TRIPLE_SIZE(ptr));
        ptr->prev->next = ptr->next;
        ptr->next->prev = ptr->prev;
        if (ptr->use) {
                internal_error(state, ptr, "ptr->use != 0");
        }
        put_occurrence(ptr->occurrence);
        memset(ptr, -1, size);
        xfree(ptr);
}

static void release_triple(struct compile_state *state, struct triple *ptr)
{
        struct triple_set *set, *next;
        struct triple **expr;
        struct block *block;
        if (ptr == &unknown_triple) {
                return;
        }
        valid_ins(state, ptr);
        /* Make certain the we are not the first or last element of a block */
        block = block_of_triple(state, ptr);
        if (block) {
                if ((block->last == ptr) && (block->first == ptr)) {
                        block->last = block->first = 0;
                }
                else if (block->last == ptr) {
                        block->last = ptr->prev;
                }
                else if (block->first == ptr) {
                        block->first = ptr->next;
                }
        }
        /* Remove ptr from use chains where it is the user */
        expr = triple_rhs(state, ptr, 0);
        for(; expr; expr = triple_rhs(state, ptr, expr)) {
                if (*expr) {
                        unuse_triple(*expr, ptr);
                }
        }
        expr = triple_lhs(state, ptr, 0);
        for(; expr; expr = triple_lhs(state, ptr, expr)) {
                if (*expr) {
                        unuse_triple(*expr, ptr);
                }
        }
        expr = triple_misc(state, ptr, 0);
        for(; expr; expr = triple_misc(state, ptr, expr)) {
                if (*expr) {
                        unuse_triple(*expr, ptr);
                }
        }
        expr = triple_targ(state, ptr, 0);
        for(; expr; expr = triple_targ(state, ptr, expr)) {
                if (*expr){
                        unuse_triple(*expr, ptr);
                }
        }
        /* Reomve ptr from use chains where it is used */
        for(set = ptr->use; set; set = next) {
                next = set->next;
                valid_ins(state, set->member);
                expr = triple_rhs(state, set->member, 0);
                for(; expr; expr = triple_rhs(state, set->member, expr)) {
                        if (*expr == ptr) {
                                *expr = &unknown_triple;
                        }
                }
                expr = triple_lhs(state, set->member, 0);
                for(; expr; expr = triple_lhs(state, set->member, expr)) {
                        if (*expr == ptr) {
                                *expr = &unknown_triple;
                        }
                }
                expr = triple_misc(state, set->member, 0);
                for(; expr; expr = triple_misc(state, set->member, expr)) {
                        if (*expr == ptr) {
                                *expr = &unknown_triple;
                        }
                }
                expr = triple_targ(state, set->member, 0);
                for(; expr; expr = triple_targ(state, set->member, expr)) {
                        if (*expr == ptr) {
                                *expr = &unknown_triple;
                        }
                }
                unuse_triple(ptr, set->member);
        }
        free_triple(state, ptr);
}

static void print_triples(struct compile_state *state);
static void print_blocks(struct compile_state *state, const char *func, FILE *fp);

#define TOK_UNKNOWN       0
#define TOK_SPACE         1
#define TOK_SEMI          2
#define TOK_LBRACE        3
#define TOK_RBRACE        4
#define TOK_COMMA         5
#define TOK_EQ            6
#define TOK_COLON         7
#define TOK_LBRACKET      8
#define TOK_RBRACKET      9
#define TOK_LPAREN        10
#define TOK_RPAREN        11
#define TOK_STAR          12
#define TOK_DOTS          13
#define TOK_MORE          14
#define TOK_LESS          15
#define TOK_TIMESEQ       16
#define TOK_DIVEQ         17
#define TOK_MODEQ         18
#define TOK_PLUSEQ        19
#define TOK_MINUSEQ       20
#define TOK_SLEQ          21
#define TOK_SREQ          22
#define TOK_ANDEQ         23
#define TOK_XOREQ         24
#define TOK_OREQ          25
#define TOK_EQEQ          26
#define TOK_NOTEQ         27
#define TOK_QUEST         28
#define TOK_LOGOR         29
#define TOK_LOGAND        30
#define TOK_OR            31
#define TOK_AND           32
#define TOK_XOR           33
#define TOK_LESSEQ        34
#define TOK_MOREEQ        35
#define TOK_SL            36
#define TOK_SR            37
#define TOK_PLUS          38
#define TOK_MINUS         39
#define TOK_DIV           40
#define TOK_MOD           41
#define TOK_PLUSPLUS      42
#define TOK_MINUSMINUS    43
#define TOK_BANG          44
#define TOK_ARROW         45
#define TOK_DOT           46
#define TOK_TILDE         47
#define TOK_LIT_STRING    48
#define TOK_LIT_CHAR      49
#define TOK_LIT_INT       50
#define TOK_LIT_FLOAT     51
#define TOK_MACRO         52
#define TOK_CONCATENATE   53

#define TOK_IDENT         54
#define TOK_STRUCT_NAME   55
#define TOK_ENUM_CONST    56
#define TOK_TYPE_NAME     57

#define TOK_AUTO          58
#define TOK_BREAK         59
#define TOK_CASE          60
#define TOK_CHAR          61
#define TOK_CONST         62
#define TOK_CONTINUE      63
#define TOK_DEFAULT       64
#define TOK_DO            65
#define TOK_DOUBLE        66
#define TOK_ELSE          67
#define TOK_ENUM          68
#define TOK_EXTERN        69
#define TOK_FLOAT         70
#define TOK_FOR           71
#define TOK_GOTO          72
#define TOK_IF            73
#define TOK_INLINE        74
#define TOK_INT           75
#define TOK_LONG          76
#define TOK_REGISTER      77
#define TOK_RESTRICT      78
#define TOK_RETURN        79
#define TOK_SHORT         80
#define TOK_SIGNED        81
#define TOK_SIZEOF        82
#define TOK_STATIC        83
#define TOK_STRUCT        84
#define TOK_SWITCH        85
#define TOK_TYPEDEF       86
#define TOK_UNION         87
#define TOK_UNSIGNED      88
#define TOK_VOID          89
#define TOK_VOLATILE      90
#define TOK_WHILE         91
#define TOK_ASM           92
#define TOK_ATTRIBUTE     93
#define TOK_ALIGNOF       94
#define TOK_FIRST_KEYWORD TOK_AUTO
#define TOK_LAST_KEYWORD  TOK_ALIGNOF

#define TOK_MDEFINE       100
#define TOK_MDEFINED      101
#define TOK_MUNDEF        102
#define TOK_MINCLUDE      103
#define TOK_MLINE         104
#define TOK_MERROR        105
#define TOK_MWARNING      106
#define TOK_MPRAGMA       107
#define TOK_MIFDEF        108
#define TOK_MIFNDEF       109
#define TOK_MELIF         110
#define TOK_MENDIF        111

#define TOK_FIRST_MACRO   TOK_MDEFINE
#define TOK_LAST_MACRO    TOK_MENDIF

#define TOK_MIF           112
#define TOK_MELSE         113
#define TOK_MIDENT        114

#define TOK_EOL           115
#define TOK_EOF           116

static const char *tokens[] = {
[TOK_UNKNOWN     ] = ":unknown:",
[TOK_SPACE       ] = ":space:",
[TOK_SEMI        ] = ";",
[TOK_LBRACE      ] = "{",
[TOK_RBRACE      ] = "}",
[TOK_COMMA       ] = ",",
[TOK_EQ          ] = "=",
[TOK_COLON       ] = ":",
[TOK_LBRACKET    ] = "[",
[TOK_RBRACKET    ] = "]",
[TOK_LPAREN      ] = "(",
[TOK_RPAREN      ] = ")",
[TOK_STAR        ] = "*",
[TOK_DOTS        ] = "...",
[TOK_MORE        ] = ">",
[TOK_LESS        ] = "<",
[TOK_TIMESEQ     ] = "*=",
[TOK_DIVEQ       ] = "/=",
[TOK_MODEQ       ] = "%=",
[TOK_PLUSEQ      ] = "+=",
[TOK_MINUSEQ     ] = "-=",
[TOK_SLEQ        ] = "<<=",
[TOK_SREQ        ] = ">>=",
[TOK_ANDEQ       ] = "&=",
[TOK_XOREQ       ] = "^=",
[TOK_OREQ        ] = "|=",
[TOK_EQEQ        ] = "==",
[TOK_NOTEQ       ] = "!=",
[TOK_QUEST       ] = "?",
[TOK_LOGOR       ] = "||",
[TOK_LOGAND      ] = "&&",
[TOK_OR          ] = "|",
[TOK_AND         ] = "&",
[TOK_XOR         ] = "^",
[TOK_LESSEQ      ] = "<=",
[TOK_MOREEQ      ] = ">=",
[TOK_SL          ] = "<<",
[TOK_SR          ] = ">>",
[TOK_PLUS        ] = "+",
[TOK_MINUS       ] = "-",
[TOK_DIV         ] = "/",
[TOK_MOD         ] = "%",
[TOK_PLUSPLUS    ] = "++",
[TOK_MINUSMINUS  ] = "--",
[TOK_BANG        ] = "!",
[TOK_ARROW       ] = "->",
[TOK_DOT         ] = ".",
[TOK_TILDE       ] = "~",
[TOK_LIT_STRING  ] = ":string:",
[TOK_IDENT       ] = ":ident:",
[TOK_TYPE_NAME   ] = ":typename:",
[TOK_LIT_CHAR    ] = ":char:",
[TOK_LIT_INT     ] = ":integer:",
[TOK_LIT_FLOAT   ] = ":float:",
[TOK_MACRO       ] = "#",
[TOK_CONCATENATE ] = "##",

[TOK_AUTO        ] = "auto",
[TOK_BREAK       ] = "break",
[TOK_CASE        ] = "case",
[TOK_CHAR        ] = "char",
[TOK_CONST       ] = "const",
[TOK_CONTINUE    ] = "continue",
[TOK_DEFAULT     ] = "default",
[TOK_DO          ] = "do",
[TOK_DOUBLE      ] = "double",
[TOK_ELSE        ] = "else",
[TOK_ENUM        ] = "enum",
[TOK_EXTERN      ] = "extern",
[TOK_FLOAT       ] = "float",
[TOK_FOR         ] = "for",
[TOK_GOTO        ] = "goto",
[TOK_IF          ] = "if",
[TOK_INLINE      ] = "inline",
[TOK_INT         ] = "int",
[TOK_LONG        ] = "long",
[TOK_REGISTER    ] = "register",
[TOK_RESTRICT    ] = "restrict",
[TOK_RETURN      ] = "return",
[TOK_SHORT       ] = "short",
[TOK_SIGNED      ] = "signed",
[TOK_SIZEOF      ] = "sizeof",
[TOK_STATIC      ] = "static",
[TOK_STRUCT      ] = "struct",
[TOK_SWITCH      ] = "switch",
[TOK_TYPEDEF     ] = "typedef",
[TOK_UNION       ] = "union",
[TOK_UNSIGNED    ] = "unsigned",
[TOK_VOID        ] = "void",
[TOK_VOLATILE    ] = "volatile",
[TOK_WHILE       ] = "while",
[TOK_ASM         ] = "asm",
[TOK_ATTRIBUTE   ] = "__attribute__",
[TOK_ALIGNOF     ] = "__alignof__",

[TOK_MDEFINE     ] = "#define",
[TOK_MDEFINED    ] = "#defined",
[TOK_MUNDEF      ] = "#undef",
[TOK_MINCLUDE    ] = "#include",
[TOK_MLINE       ] = "#line",
[TOK_MERROR      ] = "#error",
[TOK_MWARNING    ] = "#warning",
[TOK_MPRAGMA     ] = "#pragma",
[TOK_MIFDEF      ] = "#ifdef",
[TOK_MIFNDEF     ] = "#ifndef",
[TOK_MELIF       ] = "#elif",
[TOK_MENDIF      ] = "#endif",

[TOK_MIF         ] = "#if",
[TOK_MELSE       ] = "#else",
[TOK_MIDENT      ] = "#:ident:",
[TOK_EOL         ] = "EOL",
[TOK_EOF         ] = "EOF",
};

static unsigned int hash(const char *str, int str_len)
{
        unsigned int hash;
        const char *end;
        end = str + str_len;
        hash = 0;
        for(; str < end; str++) {
                hash = (hash *263) + *str;
        }
        hash = hash & (HASH_TABLE_SIZE -1);
        return hash;
}

static struct hash_entry *lookup(
        struct compile_state *state, const char *name, int name_len)
{
        struct hash_entry *entry;
        unsigned int index;
        index = hash(name, name_len);
        entry = state->hash_table[index];
        while(entry &&
                ((entry->name_len != name_len) ||
                        (memcmp(entry->name, name, name_len) != 0))) {
                entry = entry->next;
        }
        if (!entry) {
                char *new_name;
                /* Get a private copy of the name */
                new_name = xmalloc(name_len + 1, "hash_name");
                memcpy(new_name, name, name_len);
                new_name[name_len] = '\0';

                /* Create a new hash entry */
                entry = xcmalloc(sizeof(*entry), "hash_entry");
                entry->next = state->hash_table[index];
                entry->name = new_name;
                entry->name_len = name_len;

                /* Place the new entry in the hash table */
                state->hash_table[index] = entry;
        }
        return entry;
}

static void ident_to_keyword(struct compile_state *state, struct token *tk)
{
        struct hash_entry *entry;
        entry = tk->ident;
        if (entry && ((entry->tok == TOK_TYPE_NAME) ||
                (entry->tok == TOK_ENUM_CONST) ||
                ((entry->tok >= TOK_FIRST_KEYWORD) &&
                        (entry->tok <= TOK_LAST_KEYWORD)))) {
                tk->tok = entry->tok;
        }
}

static void ident_to_macro(struct compile_state *state, struct token *tk)
{
        struct hash_entry *entry;
        entry = tk->ident;
        if (!entry)
                return;
        if ((entry->tok >= TOK_FIRST_MACRO) && (entry->tok <= TOK_LAST_MACRO)) {
                tk->tok = entry->tok;
        }
        else if (entry->tok == TOK_IF) {
                tk->tok = TOK_MIF;
        }
        else if (entry->tok == TOK_ELSE) {
                tk->tok = TOK_MELSE;
        }
        else {
                tk->tok = TOK_MIDENT;
        }
}

static void hash_keyword(
        struct compile_state *state, const char *keyword, int tok)
{
        struct hash_entry *entry;
        entry = lookup(state, keyword, strlen(keyword));
        if (entry && entry->tok != TOK_UNKNOWN) {
                die("keyword %s already hashed", keyword);
        }
        entry->tok  = tok;
}

static void romcc_symbol(
        struct compile_state *state, struct hash_entry *ident,
        struct symbol **chain, struct triple *def, struct type *type, int depth)
{
        struct symbol *sym;
        if (*chain && ((*chain)->scope_depth >= depth)) {
                error(state, 0, "%s already defined", ident->name);
        }
        sym = xcmalloc(sizeof(*sym), "symbol");
        sym->ident = ident;
        sym->def   = def;
        sym->type  = type;
        sym->scope_depth = depth;
        sym->next = *chain;
        *chain    = sym;
}

static void symbol(
        struct compile_state *state, struct hash_entry *ident,
        struct symbol **chain, struct triple *def, struct type *type)
{
        romcc_symbol(state, ident, chain, def, type, state->scope_depth);
}

static void var_symbol(struct compile_state *state,
        struct hash_entry *ident, struct triple *def)
{
        if ((def->type->type & TYPE_MASK) == TYPE_PRODUCT) {
                internal_error(state, 0, "bad var type");
        }
        symbol(state, ident, &ident->sym_ident, def, def->type);
}

static void label_symbol(struct compile_state *state,
        struct hash_entry *ident, struct triple *label, int depth)
{
        romcc_symbol(state, ident, &ident->sym_label, label, &void_type, depth);
}

static void start_scope(struct compile_state *state)
{
        state->scope_depth++;
}

static void end_scope_syms(struct compile_state *state,
        struct symbol **chain, int depth)
{
        struct symbol *sym, *next;
        sym = *chain;
        while(sym && (sym->scope_depth == depth)) {
                next = sym->next;
                xfree(sym);
                sym = next;
        }
        *chain = sym;
}

static void end_scope(struct compile_state *state)
{
        int i;
        int depth;
        /* Walk through the hash table and remove all symbols
         * in the current scope.
         */
        depth = state->scope_depth;
        for(i = 0; i < HASH_TABLE_SIZE; i++) {
                struct hash_entry *entry;
                entry = state->hash_table[i];
                while(entry) {
                        end_scope_syms(state, &entry->sym_label, depth);
                        end_scope_syms(state, &entry->sym_tag,   depth);
                        end_scope_syms(state, &entry->sym_ident, depth);
                        entry = entry->next;
                }
        }
        state->scope_depth = depth - 1;
}

static void register_keywords(struct compile_state *state)
{
        hash_keyword(state, "auto",          TOK_AUTO);
        hash_keyword(state, "break",         TOK_BREAK);
        hash_keyword(state, "case",          TOK_CASE);
        hash_keyword(state, "char",          TOK_CHAR);
        hash_keyword(state, "const",         TOK_CONST);
        hash_keyword(state, "continue",      TOK_CONTINUE);
        hash_keyword(state, "default",       TOK_DEFAULT);
        hash_keyword(state, "do",            TOK_DO);
        hash_keyword(state, "double",        TOK_DOUBLE);
        hash_keyword(state, "else",          TOK_ELSE);
        hash_keyword(state, "enum",          TOK_ENUM);
        hash_keyword(state, "extern",        TOK_EXTERN);
        hash_keyword(state, "float",         TOK_FLOAT);
        hash_keyword(state, "for",           TOK_FOR);
        hash_keyword(state, "goto",          TOK_GOTO);
        hash_keyword(state, "if",            TOK_IF);
        hash_keyword(state, "inline",        TOK_INLINE);
        hash_keyword(state, "int",           TOK_INT);
        hash_keyword(state, "long",          TOK_LONG);
        hash_keyword(state, "register",      TOK_REGISTER);
        hash_keyword(state, "restrict",      TOK_RESTRICT);
        hash_keyword(state, "return",        TOK_RETURN);
        hash_keyword(state, "short",         TOK_SHORT);
        hash_keyword(state, "signed",        TOK_SIGNED);
        hash_keyword(state, "sizeof",        TOK_SIZEOF);
        hash_keyword(state, "static",        TOK_STATIC);
        hash_keyword(state, "struct",        TOK_STRUCT);
        hash_keyword(state, "switch",        TOK_SWITCH);
        hash_keyword(state, "typedef",       TOK_TYPEDEF);
        hash_keyword(state, "union",         TOK_UNION);
        hash_keyword(state, "unsigned",      TOK_UNSIGNED);
        hash_keyword(state, "void",          TOK_VOID);
        hash_keyword(state, "volatile",      TOK_VOLATILE);
        hash_keyword(state, "__volatile__",  TOK_VOLATILE);
        hash_keyword(state, "while",         TOK_WHILE);
        hash_keyword(state, "asm",           TOK_ASM);
        hash_keyword(state, "__asm__",       TOK_ASM);
        hash_keyword(state, "__attribute__", TOK_ATTRIBUTE);
        hash_keyword(state, "__alignof__",   TOK_ALIGNOF);
}

static void register_macro_keywords(struct compile_state *state)
{
        hash_keyword(state, "define",        TOK_MDEFINE);
        hash_keyword(state, "defined",       TOK_MDEFINED);
        hash_keyword(state, "undef",         TOK_MUNDEF);
        hash_keyword(state, "include",       TOK_MINCLUDE);
        hash_keyword(state, "line",          TOK_MLINE);
        hash_keyword(state, "error",         TOK_MERROR);
        hash_keyword(state, "warning",       TOK_MWARNING);
        hash_keyword(state, "pragma",        TOK_MPRAGMA);
        hash_keyword(state, "ifdef",         TOK_MIFDEF);
        hash_keyword(state, "ifndef",        TOK_MIFNDEF);
        hash_keyword(state, "elif",          TOK_MELIF);
        hash_keyword(state, "endif",         TOK_MENDIF);
}


static void undef_macro(struct compile_state *state, struct hash_entry *ident)
{
        if (ident->sym_define != 0) {
                struct macro *macro;
                struct macro_arg *arg, *anext;
                macro = ident->sym_define;
                ident->sym_define = 0;

                /* Free the macro arguments... */
                anext = macro->args;
                while(anext) {
                        arg = anext;
                        anext = arg->next;
                        xfree(arg);
                }

                /* Free the macro buffer */
                xfree(macro->buf);

                /* Now free the macro itself */
                xfree(macro);
        }
}

static void do_define_macro(struct compile_state *state,
        struct hash_entry *ident, const char *body,
        int argc, struct macro_arg *args)
{
        struct macro *macro;
        struct macro_arg *arg;
        size_t body_len;

        /* Find the length of the body */
        body_len = strlen(body);
        macro = ident->sym_define;
        if (macro != 0) {
                int identical_bodies, identical_args;
                struct macro_arg *oarg;
                /* Explicitly allow identical redfinitions of the same macro */
                identical_bodies =
                        (macro->buf_len == body_len) &&
                        (memcmp(macro->buf, body, body_len) == 0);
                identical_args = macro->argc == argc;
                oarg = macro->args;
                arg = args;
                while(identical_args && arg) {
                        identical_args = oarg->ident == arg->ident;
                        arg = arg->next;
                        oarg = oarg->next;
                }
                if (identical_bodies && identical_args) {
                        xfree(body);
                        return;
                }
                error(state, 0, "macro %s already defined\n", ident->name);
        }
#if 0
        fprintf(state->errout, "#define %s: `%*.*s'\n",
                ident->name, body_len, body_len, body);
#endif
        macro = xmalloc(sizeof(*macro), "macro");
        macro->ident   = ident;
        macro->buf     = body;
        macro->buf_len = body_len;
        macro->args    = args;
        macro->argc    = argc;

        ident->sym_define = macro;
}

static void define_macro(
        struct compile_state *state,
        struct hash_entry *ident,
        const char *body, int body_len,
        int argc, struct macro_arg *args)
{
        char *buf;
        buf = xmalloc(body_len + 1, "macro buf");
        memcpy(buf, body, body_len);
        buf[body_len] = '\0';
        do_define_macro(state, ident, buf, argc, args);
}

static void register_builtin_macro(struct compile_state *state,
        const char *name, const char *value)
{
        struct hash_entry *ident;

        if (value[0] == '(') {
                internal_error(state, 0, "Builtin macros with arguments not supported");
        }
        ident = lookup(state, name, strlen(name));
        define_macro(state, ident, value, strlen(value), -1, 0);
}

static void register_builtin_macros(struct compile_state *state)
{
        char buf[32];
        char scratch[30];
        time_t now;
        struct tm *tm;
        now = time(NULL);
        tm = localtime(&now);

        register_builtin_macro(state, "__ROMCC__", VERSION_MAJOR);
        register_builtin_macro(state, "__ROMCC_MINOR__", VERSION_MINOR);
        register_builtin_macro(state, "__FILE__", "\"This should be the filename\"");
        register_builtin_macro(state, "__LINE__", "54321");

        strftime(scratch, sizeof(scratch), "%b %e %Y", tm);
        sprintf(buf, "\"%s\"", scratch);
        register_builtin_macro(state, "__DATE__", buf);

        strftime(scratch, sizeof(scratch), "%H:%M:%S", tm);
        sprintf(buf, "\"%s\"", scratch);
        register_builtin_macro(state, "__TIME__", buf);

        /* I can't be a conforming implementation of C :( */
        register_builtin_macro(state, "__STDC__", "0");
        /* In particular I don't conform to C99 */
        register_builtin_macro(state, "__STDC_VERSION__", "199901L");

}

static void process_cmdline_macros(struct compile_state *state)
{
        const char **macro, *name;
        struct hash_entry *ident;
        for(macro = state->compiler->defines; (name = *macro); macro++) {
                const char *body;
                size_t name_len;

                name_len = strlen(name);
                body = strchr(name, '=');
                if (!body) {
                        body = "\0";
                } else {
                        name_len = body - name;
                        body++;
                }
                ident = lookup(state, name, name_len);
                define_macro(state, ident, body, strlen(body), -1, 0);
        }
        for(macro = state->compiler->undefs; (name = *macro); macro++) {
                ident = lookup(state, name, strlen(name));
                undef_macro(state, ident);
        }
}

static int spacep(int c)
{
        int ret = 0;
        switch(c) {
        case ' ':
        case '\t':
        case '\f':
        case '\v':
        case '\r':
                ret = 1;
                break;
        }
        return ret;
}

static int digitp(int c)
{
        int ret = 0;
        switch(c) {
        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
                ret = 1;
                break;
        }
        return ret;
}
static int digval(int c)
{
        int val = -1;
        if ((c >= '0') && (c <= '9')) {
                val = c - '0';
        }
        return val;
}

static int hexdigitp(int c)
{
        int ret = 0;
        switch(c) {
        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
        case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
        case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
                ret = 1;
                break;
        }
        return ret;
}
static int hexdigval(int c)
{
        int val = -1;
        if ((c >= '0') && (c <= '9')) {
                val = c - '0';
        }
        else if ((c >= 'A') && (c <= 'F')) {
                val = 10 + (c - 'A');
        }
        else if ((c >= 'a') && (c <= 'f')) {
                val = 10 + (c - 'a');
        }
        return val;
}

static int octdigitp(int c)
{
        int ret = 0;
        switch(c) {
        case '0': case '1': case '2': case '3':
        case '4': case '5': case '6': case '7':
                ret = 1;
                break;
        }
        return ret;
}
static int octdigval(int c)
{
        int val = -1;
        if ((c >= '0') && (c <= '7')) {
                val = c - '0';
        }
        return val;
}

static int letterp(int c)
{
        int ret = 0;
        switch(c) {
        case 'a': case 'b': case 'c': case 'd': case 'e':
        case 'f': case 'g': case 'h': case 'i': case 'j':
        case 'k': case 'l': case 'm': case 'n': case 'o':
        case 'p': case 'q': case 'r': case 's': case 't':
        case 'u': case 'v': case 'w': case 'x': case 'y':
        case 'z':
        case 'A': case 'B': case 'C': case 'D': case 'E':
        case 'F': case 'G': case 'H': case 'I': case 'J':
        case 'K': case 'L': case 'M': case 'N': case 'O':
        case 'P': case 'Q': case 'R': case 'S': case 'T':
        case 'U': case 'V': case 'W': case 'X': case 'Y':
        case 'Z':
        case '_':
                ret = 1;
                break;
        }
        return ret;
}

static const char *identifier(const char *str, const char *end)
{
        if (letterp(*str)) {
                for(; str < end; str++) {
                        int c;
                        c = *str;
                        if (!letterp(c) && !digitp(c)) {
                                break;
                        }
                }
        }
        return str;
}

static int char_value(struct compile_state *state,
        const signed char **strp, const signed char *end)
{
        const signed char *str;
        int c;
        str = *strp;
        c = *str++;
        if ((c == '\\') && (str < end)) {
                switch(*str) {
                case 'n':  c = '\n'; str++; break;
                case 't':  c = '\t'; str++; break;
                case 'v':  c = '\v'; str++; break;
                case 'b':  c = '\b'; str++; break;
                case 'r':  c = '\r'; str++; break;
                case 'f':  c = '\f'; str++; break;
                case 'a':  c = '\a'; str++; break;
                case '\\': c = '\\'; str++; break;
                case '?':  c = '?';  str++; break;
                case '\'': c = '\''; str++; break;
                case '"':  c = '"';  str++; break;
                case 'x':
                        c = 0;
                        str++;
                        while((str < end) && hexdigitp(*str)) {
                                c <<= 4;
                                c += hexdigval(*str);
                                str++;
                        }
                        break;
                case '0': case '1': case '2': case '3':
                case '4': case '5': case '6': case '7':
                        c = 0;
                        while((str < end) && octdigitp(*str)) {
                                c <<= 3;
                                c += octdigval(*str);
                                str++;
                        }
                        break;
                default:
                        error(state, 0, "Invalid character constant");
                        break;
                }
        }
        *strp = str;
        return c;
}

static const char *next_char(struct file_state *file, const char *pos, int index)
{
        const char *end = file->buf + file->size;
        while(pos < end) {
                /* Lookup the character */
                int size = 1;
                int c = *pos;
                /* Is this a trigraph? */
                if (file->trigraphs &&
                        (c == '?') && ((end - pos) >= 3) && (pos[1] == '?'))
                {
                        switch(pos[2]) {
                        case '=': c = '#'; break;
                        case '/': c = '\\'; break;
                        case '\'': c = '^'; break;
                        case '(': c = '['; break;
                        case ')': c = ']'; break;
                        case '!': c = '!'; break;
                        case '<': c = '{'; break;
                        case '>': c = '}'; break;
                        case '-': c = '~'; break;
                        }
                        if (c != '?') {
                                size = 3;
                        }
                }
                /* Is this an escaped newline? */
                if (file->join_lines &&
                        (c == '\\') && (pos + size < end) && ((pos[1] == '\n') || ((pos[1] == '\r') && (pos[2] == '\n'))))
                {
                        int cr_offset = ((pos[1] == '\r') && (pos[2] == '\n'))?1:0;
                        /* At the start of a line just eat it */
                        if (pos == file->pos) {
                                file->line++;
                                file->report_line++;
                                file->line_start = pos + size + 1 + cr_offset;
                        }
                        pos += size + 1 + cr_offset;
                }
                /* Do I need to ga any farther? */
                else if (index == 0) {
                        break;
                }
                /* Process a normal character */
                else {
                        pos += size;
                        index -= 1;
                }
        }
        return pos;
}

static int get_char(struct file_state *file, const char *pos)
{
        const char *end = file->buf + file->size;
        int c;
        c = -1;
        pos = next_char(file, pos, 0);
        if (pos < end) {
                /* Lookup the character */
                c = *pos;
                /* If it is a trigraph get the trigraph value */
                if (file->trigraphs &&
                        (c == '?') && ((end - pos) >= 3) && (pos[1] == '?'))
                {
                        switch(pos[2]) {
                        case '=': c = '#'; break;
                        case '/': c = '\\'; break;
                        case '\'': c = '^'; break;
                        case '(': c = '['; break;
                        case ')': c = ']'; break;
                        case '!': c = '!'; break;
                        case '<': c = '{'; break;
                        case '>': c = '}'; break;
                        case '-': c = '~'; break;
                        }
                }
        }
        return c;
}

static void eat_chars(struct file_state *file, const char *targ)
{
        const char *pos = file->pos;
        while(pos < targ) {
                /* Do we have a newline? */
                if (pos[0] == '\n') {
                        file->line++;
                        file->report_line++;
                        file->line_start = pos + 1;
                }
                pos++;
        }
        file->pos = pos;
}


static size_t char_strlen(struct file_state *file, const char *src, const char *end)
{
        size_t len;
        len = 0;
        while(src < end) {
                src = next_char(file, src, 1);
                len++;
        }
        return len;
}

static void char_strcpy(char *dest,
        struct file_state *file, const char *src, const char *end)
{
        while(src < end) {
                int c;
                c = get_char(file, src);
                src = next_char(file, src, 1);
                *dest++ = c;
        }
}

static char *char_strdup(struct file_state *file,
        const char *start, const char *end, const char *id)
{
        char *str;
        size_t str_len;
        str_len = char_strlen(file, start, end);
        str = xcmalloc(str_len + 1, id);
        char_strcpy(str, file, start, end);
        str[str_len] = '\0';
        return str;
}

static const char *after_digits(struct file_state *file, const char *ptr)
{
        while(digitp(get_char(file, ptr))) {
                ptr = next_char(file, ptr, 1);
        }
        return ptr;
}

static const char *after_octdigits(struct file_state *file, const char *ptr)
{
        while(octdigitp(get_char(file, ptr))) {
                ptr = next_char(file, ptr, 1);
        }
        return ptr;
}

static const char *after_hexdigits(struct file_state *file, const char *ptr)
{
        while(hexdigitp(get_char(file, ptr))) {
                ptr = next_char(file, ptr, 1);
        }
        return ptr;
}

static const char *after_alnums(struct file_state *file, const char *ptr)
{
        int c;
        c = get_char(file, ptr);
        while(letterp(c) || digitp(c)) {
                ptr = next_char(file, ptr, 1);
                c = get_char(file, ptr);
        }
        return ptr;
}

static void save_string(struct file_state *file,
        struct token *tk, const char *start, const char *end, const char *id)
{
        char *str;

        /* Create a private copy of the string */
        str = char_strdup(file, start, end, id);

        /* Store the copy in the token */
        tk->val.str = str;
        tk->str_len = strlen(str);
}

static void raw_next_token(struct compile_state *state,
        struct file_state *file, struct token *tk)
{
        const char *token;
        int c, c1, c2, c3;
        const char *tokp;
        int eat;
        int tok;

        tk->str_len = 0;
        tk->ident = 0;
        token = tokp = next_char(file, file->pos, 0);
        tok = TOK_UNKNOWN;
        c  = get_char(file, tokp);
        tokp = next_char(file, tokp, 1);
        eat = 0;
        c1 = get_char(file, tokp);
        c2 = get_char(file, next_char(file, tokp, 1));
        c3 = get_char(file, next_char(file, tokp, 2));

        /* The end of the file */
        if (c == -1) {
                tok = TOK_EOF;
        }
        /* Whitespace */
        else if (spacep(c)) {
                tok = TOK_SPACE;
                while (spacep(get_char(file, tokp))) {
                        tokp = next_char(file, tokp, 1);
                }
        }
        /* EOL Comments */
        else if ((c == '/') && (c1 == '/')) {
                tok = TOK_SPACE;
                tokp = next_char(file, tokp, 1);
                while((c = get_char(file, tokp)) != -1) {
                        /* Advance to the next character only after we verify
                         * the current character is not a newline.
                         * EOL is special to the preprocessor so we don't
                         * want to loose any.
                         */
                        if (c == '\n') {
                                break;
                        }
                        tokp = next_char(file, tokp, 1);
                }
        }
        /* Comments */
        else if ((c == '/') && (c1 == '*')) {
                tokp = next_char(file, tokp, 2);
                c = c2;
                while((c1 = get_char(file, tokp)) != -1) {
                        tokp = next_char(file, tokp, 1);
                        if ((c == '*') && (c1 == '/')) {
                                tok = TOK_SPACE;
                                break;
                        }
                        c = c1;
                }
                if (tok == TOK_UNKNOWN) {
                        error(state, 0, "unterminated comment");
                }
        }
        /* string constants */
        else if ((c == '"') || ((c == 'L') && (c1 == '"'))) {
                int multiline;

                multiline = 0;
                if (c == 'L') {
                        tokp = next_char(file, tokp, 1);
                }
                while((c = get_char(file, tokp)) != -1) {
                        tokp = next_char(file, tokp, 1);
                        if (c == '\n') {
                                multiline = 1;
                        }
                        else if (c == '\\') {
                                tokp = next_char(file, tokp, 1);
                        }
                        else if (c == '"') {
                                tok = TOK_LIT_STRING;
                                break;
                        }
                }
                if (tok == TOK_UNKNOWN) {
                        error(state, 0, "unterminated string constant");
                }
                if (multiline) {
                        warning(state, 0, "multiline string constant");
                }

                /* Save the string value */
                save_string(file, tk, token, tokp, "literal string");
        }
        /* character constants */
        else if ((c == '\'') || ((c == 'L') && (c1 == '\''))) {
                int multiline;

                multiline = 0;
                if (c == 'L') {
                        tokp = next_char(file, tokp, 1);
                }
                while((c = get_char(file, tokp)) != -1) {
                        tokp = next_char(file, tokp, 1);
                        if (c == '\n') {
                                multiline = 1;
                        }
                        else if (c == '\\') {
                                tokp = next_char(file, tokp, 1);
                        }
                        else if (c == '\'') {
                                tok = TOK_LIT_CHAR;
                                break;
                        }
                }
                if (tok == TOK_UNKNOWN) {
                        error(state, 0, "unterminated character constant");
                }
                if (multiline) {
                        warning(state, 0, "multiline character constant");
                }

                /* Save the character value */
                save_string(file, tk, token, tokp, "literal character");
        }
        /* integer and floating constants
         * Integer Constants
         * {digits}
         * 0[Xx]{hexdigits}
         * 0{octdigit}+
         *
         * Floating constants
         * {digits}.{digits}[Ee][+-]?{digits}
         * {digits}.{digits}
         * {digits}[Ee][+-]?{digits}
         * .{digits}[Ee][+-]?{digits}
         * .{digits}
         */
        else if (digitp(c) || ((c == '.') && (digitp(c1)))) {
                const char *next;
                int is_float;
                int cn;
                is_float = 0;
                if (c != '.') {
                        next = after_digits(file, tokp);
                }
                else {
                        next = token;
                }
                cn = get_char(file, next);
                if (cn == '.') {
                        next = next_char(file, next, 1);
                        next = after_digits(file, next);
                        is_float = 1;
                }
                cn = get_char(file, next);
                if ((cn == 'e') || (cn == 'E')) {
                        const char *new;
                        next = next_char(file, next, 1);
                        cn = get_char(file, next);
                        if ((cn == '+') || (cn == '-')) {
                                next = next_char(file, next, 1);
                        }
                        new = after_digits(file, next);
                        is_float |= (new != next);
                        next = new;
                }
                if (is_float) {
                        tok = TOK_LIT_FLOAT;
                        cn = get_char(file, next);
                        if ((cn  == 'f') || (cn == 'F') || (cn == 'l') || (cn == 'L')) {
                                next = next_char(file, next, 1);
                        }
                }
                if (!is_float && digitp(c)) {
                        tok = TOK_LIT_INT;
                        if ((c == '0') && ((c1 == 'x') || (c1 == 'X'))) {
                                next = next_char(file, tokp, 1);
                                next = after_hexdigits(file, next);
                        }
                        else if (c == '0') {
                                next = after_octdigits(file, tokp);
                        }
                        else {
                                next = after_digits(file, tokp);
                        }
                        /* crazy integer suffixes */
                        cn = get_char(file, next);
                        if ((cn == 'u') || (cn == 'U')) {
                                next = next_char(file, next, 1);
                                cn = get_char(file, next);
                                if ((cn == 'l') || (cn == 'L')) {
                                        next = next_char(file, next, 1);
                                        cn = get_char(file, next);
                                }
                                if ((cn == 'l') || (cn == 'L')) {
                                        next = next_char(file, next, 1);
                                }
                        }
                        else if ((cn == 'l') || (cn == 'L')) {
                                next = next_char(file, next, 1);
                                cn = get_char(file, next);
                                if ((cn == 'l') || (cn == 'L')) {
                                        next = next_char(file, next, 1);
                                        cn = get_char(file, next);
                                }
                                if ((cn == 'u') || (cn == 'U')) {
                                        next = next_char(file, next, 1);
                                }
                        }
                }
                tokp = next;

                /* Save the integer/floating point value */
                save_string(file, tk, token, tokp, "literal number");
        }
        /* identifiers */
        else if (letterp(c)) {
                tok = TOK_IDENT;

                /* Find and save the identifier string */
                tokp = after_alnums(file, tokp);
                save_string(file, tk, token, tokp, "identifier");

                /* Look up to see which identifier it is */
                tk->ident = lookup(state, tk->val.str, tk->str_len);

                /* Free the identifier string */
                tk->str_len = 0;
                xfree(tk->val.str);

                /* See if this identifier can be macro expanded */
                tk->val.notmacro = 0;
                c = get_char(file, tokp);
                if (c == '$') {
                        tokp = next_char(file, tokp, 1);
                        tk->val.notmacro = 1;
                }
        }
        /* C99 alternate macro characters */
        else if ((c == '%') && (c1 == ':') && (c2 == '%') && (c3 == ':')) {
                eat += 3;
                tok = TOK_CONCATENATE;
        }
        else if ((c == '.') && (c1 == '.') && (c2 == '.')) { eat += 2; tok = TOK_DOTS; }
        else if ((c == '<') && (c1 == '<') && (c2 == '=')) { eat += 2; tok = TOK_SLEQ; }
        else if ((c == '>') && (c1 == '>') && (c2 == '=')) { eat += 2; tok = TOK_SREQ; }
        else if ((c == '*') && (c1 == '=')) { eat += 1; tok = TOK_TIMESEQ; }
        else if ((c == '/') && (c1 == '=')) { eat += 1; tok = TOK_DIVEQ; }
        else if ((c == '%') && (c1 == '=')) { eat += 1; tok = TOK_MODEQ; }
        else if ((c == '+') && (c1 == '=')) { eat += 1; tok = TOK_PLUSEQ; }
        else if ((c == '-') && (c1 == '=')) { eat += 1; tok = TOK_MINUSEQ; }
        else if ((c == '&') && (c1 == '=')) { eat += 1; tok = TOK_ANDEQ; }
        else if ((c == '^') && (c1 == '=')) { eat += 1; tok = TOK_XOREQ; }
        else if ((c == '|') && (c1 == '=')) { eat += 1; tok = TOK_OREQ; }
        else if ((c == '=') && (c1 == '=')) { eat += 1; tok = TOK_EQEQ; }
        else if ((c == '!') && (c1 == '=')) { eat += 1; tok = TOK_NOTEQ; }
        else if ((c == '|') && (c1 == '|')) { eat += 1; tok = TOK_LOGOR; }
        else if ((c == '&') && (c1 == '&')) { eat += 1; tok = TOK_LOGAND; }
        else if ((c == '<') && (c1 == '=')) { eat += 1; tok = TOK_LESSEQ; }
        else if ((c == '>') && (c1 == '=')) { eat += 1; tok = TOK_MOREEQ; }
        else if ((c == '<') && (c1 == '<')) { eat += 1; tok = TOK_SL; }
        else if ((c == '>') && (c1 == '>')) { eat += 1; tok = TOK_SR; }
        else if ((c == '+') && (c1 == '+')) { eat += 1; tok = TOK_PLUSPLUS; }
        else if ((c == '-') && (c1 == '-')) { eat += 1; tok = TOK_MINUSMINUS; }
        else if ((c == '-') && (c1 == '>')) { eat += 1; tok = TOK_ARROW; }
        else if ((c == '<') && (c1 == ':')) { eat += 1; tok = TOK_LBRACKET; }
        else if ((c == ':') && (c1 == '>')) { eat += 1; tok = TOK_RBRACKET; }
        else if ((c == '<') && (c1 == '%')) { eat += 1; tok = TOK_LBRACE; }
        else if ((c == '%') && (c1 == '>')) { eat += 1; tok = TOK_RBRACE; }
        else if ((c == '%') && (c1 == ':')) { eat += 1; tok = TOK_MACRO; }
        else if ((c == '#') && (c1 == '#')) { eat += 1; tok = TOK_CONCATENATE; }
        else if (c == ';') { tok = TOK_SEMI; }
        else if (c == '{') { tok = TOK_LBRACE; }
        else if (c == '}') { tok = TOK_RBRACE; }
        else if (c == ',') { tok = TOK_COMMA; }
        else if (c == '=') { tok = TOK_EQ; }
        else if (c == ':') { tok = TOK_COLON; }
        else if (c == '[') { tok = TOK_LBRACKET; }
        else if (c == ']') { tok = TOK_RBRACKET; }
        else if (c == '(') { tok = TOK_LPAREN; }
        else if (c == ')') { tok = TOK_RPAREN; }
        else if (c == '*') { tok = TOK_STAR; }
        else if (c == '>') { tok = TOK_MORE; }
        else if (c == '<') { tok = TOK_LESS; }
        else if (c == '?') { tok = TOK_QUEST; }
        else if (c == '|') { tok = TOK_OR; }
        else if (c == '&') { tok = TOK_AND; }
        else if (c == '^') { tok = TOK_XOR; }
        else if (c == '+') { tok = TOK_PLUS; }
        else if (c == '-') { tok = TOK_MINUS; }
        else if (c == '/') { tok = TOK_DIV; }
        else if (c == '%') { tok = TOK_MOD; }
        else if (c == '!') { tok = TOK_BANG; }
        else if (c == '.') { tok = TOK_DOT; }
        else if (c == '~') { tok = TOK_TILDE; }
        else if (c == '#') { tok = TOK_MACRO; }
        else if (c == '\n') { tok = TOK_EOL; }

        tokp = next_char(file, tokp, eat);
        eat_chars(file, tokp);
        tk->tok = tok;
        tk->pos = token;
}

static void check_tok(struct compile_state *state, struct token *tk, int tok)
{
        if (tk->tok != tok) {
                const char *name1, *name2;
                name1 = tokens[tk->tok];
                name2 = "";
                if ((tk->tok == TOK_IDENT) || (tk->tok == TOK_MIDENT)) {
                        name2 = tk->ident->name;
                }
                error(state, 0, "\tfound %s %s expected %s",
                        name1, name2, tokens[tok]);
        }
}

struct macro_arg_value {
        struct hash_entry *ident;
        char *value;
        size_t len;
};
static struct macro_arg_value *read_macro_args(
        struct compile_state *state, struct macro *macro,
        struct file_state *file, struct token *tk)
{
        struct macro_arg_value *argv;
        struct macro_arg *arg;
        int paren_depth;
        int i;

        if (macro->argc == 0) {
                do {
                        raw_next_token(state, file, tk);
                } while(tk->tok == TOK_SPACE);
                return NULL;
        }
        argv = xcmalloc(sizeof(*argv) * macro->argc, "macro args");
        for(i = 0, arg = macro->args; arg; arg = arg->next, i++) {
                argv[i].value = 0;
                argv[i].len   = 0;
                argv[i].ident = arg->ident;
        }
        paren_depth = 0;
        i = 0;

        for(;;) {
                const char *start;
                size_t len;
                start = file->pos;
                raw_next_token(state, file, tk);

                if (!paren_depth && (tk->tok == TOK_COMMA) &&
                        (argv[i].ident != state->i___VA_ARGS__))
                {
                        i++;
                        if (i >= macro->argc) {
                                error(state, 0, "too many args to %s\n",
                                        macro->ident->name);
                        }
                        continue;
                }

                if (tk->tok == TOK_LPAREN) {
                        paren_depth++;
                }

                if (tk->tok == TOK_RPAREN) {
                        if (paren_depth == 0) {
                                break;
                        }
                        paren_depth--;
                }
                if (tk->tok == TOK_EOF) {
                        error(state, 0, "End of file encountered while parsing macro arguments");
                }

                len = char_strlen(file, start, file->pos);
                argv[i].value = xrealloc(
                        argv[i].value, argv[i].len + len, "macro args");
                char_strcpy((char *)argv[i].value + argv[i].len, file, start, file->pos);
                argv[i].len += len;
        }
        if (i != macro->argc -1) {
                error(state, 0, "missing %s arg %d\n",
                        macro->ident->name, i +2);
        }
        return argv;
}


static void free_macro_args(struct macro *macro, struct macro_arg_value *argv)
{
        int i;
        for(i = 0; i < macro->argc; i++) {
                xfree(argv[i].value);
        }
        xfree(argv);
}

struct macro_buf {
        char *str;
        size_t len, pos;
};

static void grow_macro_buf(struct compile_state *state,
        const char *id, struct macro_buf *buf,
        size_t grow)
{
        if ((buf->pos + grow) >= buf->len) {
                buf->str = xrealloc(buf->str, buf->len + grow, id);
                buf->len += grow;
        }
}

static void append_macro_text(struct compile_state *state,
        const char *id, struct macro_buf *buf,
        const char *fstart, size_t flen)
{
        grow_macro_buf(state, id, buf, flen);
        memcpy(buf->str + buf->pos, fstart, flen);
#if 0
        fprintf(state->errout, "append: `%*.*s' `%*.*s'\n",
                buf->pos, buf->pos, buf->str,
                flen, flen, buf->str + buf->pos);
#endif
        buf->pos += flen;
}


static void append_macro_chars(struct compile_state *state,
        const char *id, struct macro_buf *buf,
        struct file_state *file, const char *start, const char *end)
{
        size_t flen;
        flen = char_strlen(file, start, end);
        grow_macro_buf(state, id, buf, flen);
        char_strcpy(buf->str + buf->pos, file, start, end);
#if 0
        fprintf(state->errout, "append: `%*.*s' `%*.*s'\n",
                buf->pos, buf->pos, buf->str,
                flen, flen, buf->str + buf->pos);
#endif
        buf->pos += flen;
}

static int compile_macro(struct compile_state *state,
        struct file_state **filep, struct token *tk);

static void macro_expand_args(struct compile_state *state,
        struct macro *macro, struct macro_arg_value *argv, struct token *tk)
{
        int i;

        for(i = 0; i < macro->argc; i++) {
                struct file_state fmacro, *file;
                struct macro_buf buf;

                fmacro.prev        = 0;
                fmacro.basename    = argv[i].ident->name;
                fmacro.dirname     = "";
                fmacro.buf         = (char *)argv[i].value;
                fmacro.size        = argv[i].len;
                fmacro.pos         = fmacro.buf;
                fmacro.line        = 1;
                fmacro.line_start  = fmacro.buf;
                fmacro.report_line = 1;
                fmacro.report_name = fmacro.basename;
                fmacro.report_dir  = fmacro.dirname;
                fmacro.macro       = 1;
                fmacro.trigraphs   = 0;
                fmacro.join_lines  = 0;

                buf.len = argv[i].len;
                buf.str = xmalloc(buf.len, argv[i].ident->name);
                buf.pos = 0;

                file = &fmacro;
                for(;;) {
                        raw_next_token(state, file, tk);

                        /* If we have recursed into another macro body
                         * get out of it.
                         */
                        if (tk->tok == TOK_EOF) {
                                struct file_state *old;
                                old = file;
                                file = file->prev;
                                if (!file) {
                                        break;
                                }
                                /* old->basename is used keep it */
                                xfree(old->dirname);
                                xfree(old->buf);
                                xfree(old);
                                continue;
                        }
                        else if (tk->ident && tk->ident->sym_define) {
                                if (compile_macro(state, &file, tk)) {
                                        continue;
                                }
                        }

                        append_macro_chars(state, macro->ident->name, &buf,
                                file, tk->pos, file->pos);
                }

                xfree(argv[i].value);
                argv[i].value = buf.str;
                argv[i].len   = buf.pos;
        }
        return;
}

static void expand_macro(struct compile_state *state,
        struct macro *macro, struct macro_buf *buf,
        struct macro_arg_value *argv, struct token *tk)
{
        struct file_state fmacro;
        const char space[] = " ";
        const char *fstart;
        size_t flen;
        int i, j;

        /* Place the macro body in a dummy file */
        fmacro.prev        = 0;
        fmacro.basename    = macro->ident->name;
        fmacro.dirname     = "";
        fmacro.buf         = macro->buf;
        fmacro.size        = macro->buf_len;
        fmacro.pos         = fmacro.buf;
        fmacro.line        = 1;
        fmacro.line_start  = fmacro.buf;
        fmacro.report_line = 1;
        fmacro.report_name = fmacro.basename;
        fmacro.report_dir  = fmacro.dirname;
        fmacro.macro       = 1;
        fmacro.trigraphs   = 0;
        fmacro.join_lines  = 0;

        /* Allocate a buffer to hold the macro expansion */
        buf->len = macro->buf_len + 3;
        buf->str = xmalloc(buf->len, macro->ident->name);
        buf->pos = 0;

        fstart = fmacro.pos;
        raw_next_token(state, &fmacro, tk);
        while(tk->tok != TOK_EOF) {
                flen = fmacro.pos - fstart;
                switch(tk->tok) {
                case TOK_IDENT:
                        if (macro->argc < 0) {
                                break;
                        }
                        for(i = 0; i < macro->argc; i++) {
                                if (argv[i].ident == tk->ident) {
                                        break;
                                }
                        }
                        if (i >= macro->argc) {
                                break;
                        }
                        /* Substitute macro parameter */
                        fstart = argv[i].value;
                        flen   = argv[i].len;
                        break;
                case TOK_MACRO:
                        if (macro->argc < 0) {
                                break;
                        }
                        do {
                                raw_next_token(state, &fmacro, tk);
                        } while(tk->tok == TOK_SPACE);
                        check_tok(state, tk, TOK_IDENT);
                        for(i = 0; i < macro->argc; i++) {
                                if (argv[i].ident == tk->ident) {
                                        break;
                                }
                        }
                        if (i >= macro->argc) {
                                error(state, 0, "parameter `%s' not found",
                                        tk->ident->name);
                        }
                        /* Stringize token */
                        append_macro_text(state, macro->ident->name, buf, "\"", 1);
                        for(j = 0; j < argv[i].len; j++) {
                                char *str = argv[i].value + j;
                                size_t len = 1;
                                if (*str == '\\') {
                                        str = "\\";
                                        len = 2;
                                }
                                else if (*str == '"') {
                                        str = "\\\"";
                                        len = 2;
                                }
                                append_macro_text(state, macro->ident->name, buf, str, len);
                        }
                        append_macro_text(state, macro->ident->name, buf, "\"", 1);
                        fstart = 0;
                        flen   = 0;
                        break;
                case TOK_CONCATENATE:
                        /* Concatenate tokens */
                        /* Delete the previous whitespace token */
                        if (buf->str[buf->pos - 1] == ' ') {
                                buf->pos -= 1;
                        }
                        /* Skip the next sequence of whitspace tokens */
                        do {
                                fstart = fmacro.pos;
                                raw_next_token(state, &fmacro, tk);
                        } while(tk->tok == TOK_SPACE);
                        /* Restart at the top of the loop.
                         * I need to process the non white space token.
                         */
                        continue;
                        break;
                case TOK_SPACE:
                        /* Collapse multiple spaces into one */
                        if (buf->str[buf->pos - 1] != ' ') {
                                fstart = space;
                                flen   = 1;
                        } else {
                                fstart = 0;
                                flen   = 0;
                        }
                        break;
                default:
                        break;
                }

                append_macro_text(state, macro->ident->name, buf, fstart, flen);

                fstart = fmacro.pos;
                raw_next_token(state, &fmacro, tk);
        }
}

static void tag_macro_name(struct compile_state *state,
        struct macro *macro, struct macro_buf *buf,
        struct token *tk)
{
        /* Guard all instances of the macro name in the replacement
         * text from further macro expansion.
         */
        struct file_state fmacro;
        const char *fstart;
        size_t flen;

        /* Put the old macro expansion buffer in a file */
        fmacro.prev        = 0;
        fmacro.basename    = macro->ident->name;
        fmacro.dirname     = "";
        fmacro.buf         = buf->str;
        fmacro.size        = buf->pos;
        fmacro.pos         = fmacro.buf;
        fmacro.line        = 1;
        fmacro.line_start  = fmacro.buf;
        fmacro.report_line = 1;
        fmacro.report_name = fmacro.basename;
        fmacro.report_dir  = fmacro.dirname;
        fmacro.macro       = 1;
        fmacro.trigraphs   = 0;
        fmacro.join_lines  = 0;

        /* Allocate a new macro expansion buffer */
        buf->len = macro->buf_len + 3;
        buf->str = xmalloc(buf->len, macro->ident->name);
        buf->pos = 0;

        fstart = fmacro.pos;
        raw_next_token(state, &fmacro, tk);
        while(tk->tok != TOK_EOF) {
                flen = fmacro.pos - fstart;
                if ((tk->tok == TOK_IDENT) &&
                        (tk->ident == macro->ident) &&
                        (tk->val.notmacro == 0))
                {
                        append_macro_text(state, macro->ident->name, buf, fstart, flen);
                        fstart = "$";
                        flen   = 1;
                }

                append_macro_text(state, macro->ident->name, buf, fstart, flen);

                fstart = fmacro.pos;
                raw_next_token(state, &fmacro, tk);
        }
        xfree(fmacro.buf);
}

static int compile_macro(struct compile_state *state,
        struct file_state **filep, struct token *tk)
{
        struct file_state *file;
        struct hash_entry *ident;
        struct macro *macro;
        struct macro_arg_value *argv;
        struct macro_buf buf;

#if 0
        fprintf(state->errout, "macro: %s\n", tk->ident->name);
#endif
        ident = tk->ident;
        macro = ident->sym_define;

        /* If this token comes from a macro expansion ignore it */
        if (tk->val.notmacro) {
                return 0;
        }
        /* If I am a function like macro and the identifier is not followed
         * by a left parenthesis, do nothing.
         */
        if ((macro->argc >= 0) && (get_char(*filep, (*filep)->pos) != '(')) {
                return 0;
        }

        /* Read in the macro arguments */
        argv = 0;
        if (macro->argc >= 0) {
                raw_next_token(state, *filep, tk);
                check_tok(state, tk, TOK_LPAREN);

                argv = read_macro_args(state, macro, *filep, tk);

                check_tok(state, tk, TOK_RPAREN);
        }
        /* Macro expand the macro arguments */
        macro_expand_args(state, macro, argv, tk);

        buf.str = 0;
        buf.len = 0;
        buf.pos = 0;
        if (ident == state->i___FILE__) {
                buf.len = strlen(state->file->basename) + 1 + 2 + 3;
                buf.str = xmalloc(buf.len, ident->name);
                sprintf(buf.str, "\"%s\"", state->file->basename);
                buf.pos = strlen(buf.str);
        }
        else if (ident == state->i___LINE__) {
                buf.len = 30;
                buf.str = xmalloc(buf.len, ident->name);
                sprintf(buf.str, "%d", state->file->line);
                buf.pos = strlen(buf.str);
        }
        else {
                expand_macro(state, macro, &buf, argv, tk);
        }
        /* Tag the macro name with a $ so it will no longer
         * be regonized as a canidate for macro expansion.
         */
        tag_macro_name(state, macro, &buf, tk);

#if 0
        fprintf(state->errout, "%s: %d -> `%*.*s'\n",
                ident->name, buf.pos, buf.pos, (int)(buf.pos), buf.str);
#endif

        free_macro_args(macro, argv);

        file = xmalloc(sizeof(*file), "file_state");
        file->prev        = *filep;
        file->basename    = xstrdup(ident->name);
        file->dirname     = xstrdup("");
        file->buf         = buf.str;
        file->size        = buf.pos;
        file->pos         = file->buf;
        file->line        = 1;
        file->line_start  = file->pos;
        file->report_line = 1;
        file->report_name = file->basename;
        file->report_dir  = file->dirname;
        file->macro       = 1;
        file->trigraphs   = 0;
        file->join_lines  = 0;
        *filep = file;
        return 1;
}

static void eat_tokens(struct compile_state *state, int targ_tok)
{
        if (state->eat_depth > 0) {
                internal_error(state, 0, "Already eating...");
        }
        state->eat_depth = state->if_depth;
        state->eat_targ = targ_tok;
}
static int if_eat(struct compile_state *state)
{
        return state->eat_depth > 0;
}
static int if_value(struct compile_state *state)
{
        int index, offset;
        index = state->if_depth / CHAR_BIT;
        offset = state->if_depth % CHAR_BIT;
        return !!(state->if_bytes[index] & (1 << (offset)));
}
static void set_if_value(struct compile_state *state, int value)
{
        int index, offset;
        index = state->if_depth / CHAR_BIT;
        offset = state->if_depth % CHAR_BIT;

        state->if_bytes[index] &= ~(1 << offset);
        if (value) {
                state->if_bytes[index] |= (1 << offset);
        }
}
static void in_if(struct compile_state *state, const char *name)
{
        if (state->if_depth <= 0) {
                error(state, 0, "%s without #if", name);
        }
}
static void enter_if(struct compile_state *state)
{
        state->if_depth += 1;
        if (state->if_depth > MAX_PP_IF_DEPTH) {
                error(state, 0, "#if depth too great");
        }
}
static void reenter_if(struct compile_state *state, const char *name)
{
        in_if(state, name);
        if ((state->eat_depth == state->if_depth) &&
                (state->eat_targ == TOK_MELSE)) {
                state->eat_depth = 0;
                state->eat_targ = 0;
        }
}
static void enter_else(struct compile_state *state, const char *name)
{
        in_if(state, name);
        if ((state->eat_depth == state->if_depth) &&
                (state->eat_targ == TOK_MELSE)) {
                state->eat_depth = 0;
                state->eat_targ = 0;
        }
}
static void exit_if(struct compile_state *state, const char *name)
{
        in_if(state, name);
        if (state->eat_depth == state->if_depth) {
                state->eat_depth = 0;
                state->eat_targ = 0;
        }
        state->if_depth -= 1;
}

static void raw_token(struct compile_state *state, struct token *tk)
{
        struct file_state *file;
        int rescan;

        file = state->file;
        raw_next_token(state, file, tk);
        do {
                rescan = 0;
                file = state->file;
                /* Exit out of an include directive or macro call */
                if ((tk->tok == TOK_EOF) &&
                        (file != state->macro_file) && file->prev)
                {
                        state->file = file->prev;
                        /* file->basename is used keep it */
                        xfree(file->dirname);
                        xfree(file->buf);
                        xfree(file);
                        file = 0;
                        raw_next_token(state, state->file, tk);
                        rescan = 1;
                }
        } while(rescan);
}

static void pp_token(struct compile_state *state, struct token *tk)
{
        int rescan;

        raw_token(state, tk);
        do {
                rescan = 0;
                if (tk->tok == TOK_SPACE) {
                        raw_token(state, tk);
                        rescan = 1;
                }
                else if (tk->tok == TOK_IDENT) {
                        if (state->token_base == 0) {
                                ident_to_keyword(state, tk);
                        } else {
                                ident_to_macro(state, tk);
                        }
                }
        } while(rescan);
}

static void preprocess(struct compile_state *state, struct token *tk);

static void token(struct compile_state *state, struct token *tk)
{
        int rescan;
        pp_token(state, tk);
        do {
                rescan = 0;
                /* Process a macro directive */
                if (tk->tok == TOK_MACRO) {
                        /* Only match preprocessor directives at the start of a line */
                        const char *ptr;
                        ptr = state->file->line_start;
                        while((ptr < tk->pos)
                                && spacep(get_char(state->file, ptr)))
                        {
                                ptr = next_char(state->file, ptr, 1);
                        }
                        if (ptr == tk->pos) {
                                preprocess(state, tk);
                                rescan = 1;
                        }
                }
                /* Expand a macro call */
                else if (tk->ident && tk->ident->sym_define) {
                        rescan = compile_macro(state, &state->file, tk);
                        if (rescan) {
                                pp_token(state, tk);
                        }
                }
                /* Eat tokens disabled by the preprocessor
                 * (Unless we are parsing a preprocessor directive
                 */
                else if (if_eat(state) && (state->token_base == 0)) {
                        pp_token(state, tk);
                        rescan = 1;
                }
                /* Make certain EOL only shows up in preprocessor directives */
                else if ((tk->tok == TOK_EOL) && (state->token_base == 0)) {
                        pp_token(state, tk);
                        rescan = 1;
                }
                /* Error on unknown tokens */
                else if (tk->tok == TOK_UNKNOWN) {
                        error(state, 0, "unknown token");
                }
        } while(rescan);
}


static inline struct token *get_token(struct compile_state *state, int offset)
{
        int index;
        index = state->token_base + offset;
        if (index >= sizeof(state->token)/sizeof(state->token[0])) {
                internal_error(state, 0, "token array to small");
        }
        return &state->token[index];
}

static struct token *do_eat_token(struct compile_state *state, int tok)
{
        struct token *tk;
        int i;
        check_tok(state, get_token(state, 1), tok);

        /* Free the old token value */
        tk = get_token(state, 0);
        if (tk->str_len) {
                memset((void *)tk->val.str, -1, tk->str_len);
                xfree(tk->val.str);
        }
        /* Overwrite the old token with newer tokens */
        for(i = state->token_base; i < sizeof(state->token)/sizeof(state->token[0]) - 1; i++) {
                state->token[i] = state->token[i + 1];
        }
        /* Clear the last token */
        memset(&state->token[i], 0, sizeof(state->token[i]));
        state->token[i].tok = -1;

        /* Return the token */
        return tk;
}

static int raw_peek(struct compile_state *state)
{
        struct token *tk1;
        tk1 = get_token(state, 1);
        if (tk1->tok == -1) {
                raw_token(state, tk1);
        }
        return tk1->tok;
}

static struct token *raw_eat(struct compile_state *state, int tok)
{
        raw_peek(state);
        return do_eat_token(state, tok);
}

static int pp_peek(struct compile_state *state)
{
        struct token *tk1;
        tk1 = get_token(state, 1);
        if (tk1->tok == -1) {
                pp_token(state, tk1);
        }
        return tk1->tok;
}

static struct token *pp_eat(struct compile_state *state, int tok)
{
        pp_peek(state);
        return do_eat_token(state, tok);
}

static int peek(struct compile_state *state)
{
        struct token *tk1;
        tk1 = get_token(state, 1);
        if (tk1->tok == -1) {
                token(state, tk1);
        }
        return tk1->tok;
}

static int peek2(struct compile_state *state)
{
        struct token *tk1, *tk2;
        tk1 = get_token(state, 1);
        tk2 = get_token(state, 2);
        if (tk1->tok == -1) {
                token(state, tk1);
        }
        if (tk2->tok == -1) {
                token(state, tk2);
        }
        return tk2->tok;
}

static struct token *eat(struct compile_state *state, int tok)
{
        peek(state);
        return do_eat_token(state, tok);
}

static void compile_file(struct compile_state *state, const char *filename, int local)
{
        char cwd[MAX_CWD_SIZE];
        const char *subdir, *base;
        int subdir_len;
        struct file_state *file;
        char *basename;
        file = xmalloc(sizeof(*file), "file_state");

        base = strrchr(filename, '/');
        subdir = filename;
        if (base != 0) {
                subdir_len = base - filename;
                base++;
        }
        else {
                base = filename;
                subdir_len = 0;
        }
        basename = xmalloc(strlen(base) +1, "basename");
        strcpy(basename, base);
        file->basename = basename;

        if (getcwd(cwd, sizeof(cwd)) == 0) {
                die("cwd buffer to small");
        }
        if ((subdir[0] == '/') || ((subdir[1] == ':') && ((subdir[2] == '/') || (subdir[2] == '\\')))) {
                file->dirname = xmalloc(subdir_len + 1, "dirname");
                memcpy(file->dirname, subdir, subdir_len);
                file->dirname[subdir_len] = '\0';
        }
        else {
                const char *dir;
                int dirlen;
                const char **path;
                /* Find the appropriate directory... */
                dir = 0;
                if (!state->file && exists(cwd, filename)) {
                        dir = cwd;
                }
                if (local && state->file && exists(state->file->dirname, filename)) {
                        dir = state->file->dirname;
                }
                for(path = state->compiler->include_paths; !dir && *path; path++) {
                        if (exists(*path, filename)) {
                                dir = *path;
                        }
                }
                if (!dir) {
                        error(state, 0, "Cannot open `%s'\n", filename);
                }
                dirlen = strlen(dir);
                file->dirname = xmalloc(dirlen + 1 + subdir_len + 1, "dirname");
                memcpy(file->dirname, dir, dirlen);
                file->dirname[dirlen] = '/';
                memcpy(file->dirname + dirlen + 1, subdir, subdir_len);
                file->dirname[dirlen + 1 + subdir_len] = '\0';
        }
        file->buf = slurp_file(file->dirname, file->basename, &file->size);

        file->pos = file->buf;
        file->line_start = file->pos;
        file->line = 1;

        file->report_line = 1;
        file->report_name = file->basename;
        file->report_dir  = file->dirname;
        file->macro       = 0;
        file->trigraphs   = (state->compiler->flags & COMPILER_TRIGRAPHS)? 1: 0;
        file->join_lines  = 1;

        file->prev = state->file;
        state->file = file;
}

static struct triple *constant_expr(struct compile_state *state);
static void integral(struct compile_state *state, struct triple *def);

static int mcexpr(struct compile_state *state)
{
        struct triple *cvalue;
        cvalue = constant_expr(state);
        integral(state, cvalue);
        if (cvalue->op != OP_INTCONST) {
                error(state, 0, "integer constant expected");
        }
        return cvalue->u.cval != 0;
}

static void preprocess(struct compile_state *state, struct token *current_token)
{
        /* Doing much more with the preprocessor would require
         * a parser and a major restructuring.
         * Postpone that for later.
         */
        int old_token_base;
        int tok;

        state->macro_file = state->file;

        old_token_base = state->token_base;
        state->token_base = current_token - state->token;

        tok = pp_peek(state);
        switch(tok) {
        case TOK_LIT_INT:
        {
                struct token *tk;
                int override_line;
                tk = pp_eat(state, TOK_LIT_INT);
                override_line = strtoul(tk->val.str, 0, 10);
                /* I have a preprocessor  line marker parse it */
                if (pp_peek(state) == TOK_LIT_STRING) {
                        const char *token, *base;
                        char *name, *dir;
                        int name_len, dir_len;
                        tk = pp_eat(state, TOK_LIT_STRING);
                        name = xmalloc(tk->str_len, "report_name");
                        token = tk->val.str + 1;
                        base = strrchr(token, '/');
                        name_len = tk->str_len -2;
                        if (base != 0) {
                                dir_len = base - token;
                                base++;
                                name_len -= base - token;
                        } else {
                                dir_len = 0;
                                base = token;
                        }
                        memcpy(name, base, name_len);
                        name[name_len] = '\0';
                        dir = xmalloc(dir_len + 1, "report_dir");
                        memcpy(dir, token, dir_len);
                        dir[dir_len] = '\0';
                        state->file->report_line = override_line - 1;
                        state->file->report_name = name;
                        state->file->report_dir = dir;
                        state->file->macro      = 0;
                }
                break;
        }
        case TOK_MLINE:
        {
                struct token *tk;
                pp_eat(state, TOK_MLINE);
                tk = eat(state, TOK_LIT_INT);
                state->file->report_line = strtoul(tk->val.str, 0, 10) -1;
                if (pp_peek(state) == TOK_LIT_STRING) {
                        const char *token, *base;
                        char *name, *dir;
                        int name_len, dir_len;
                        tk = pp_eat(state, TOK_LIT_STRING);
                        name = xmalloc(tk->str_len, "report_name");
                        token = tk->val.str + 1;
                        base = strrchr(token, '/');
                        name_len = tk->str_len - 2;
                        if (base != 0) {
                                dir_len = base - token;
                                base++;
                                name_len -= base - token;
                        } else {
                                dir_len = 0;
                                base = token;
                        }
                        memcpy(name, base, name_len);
                        name[name_len] = '\0';
                        dir = xmalloc(dir_len + 1, "report_dir");
                        memcpy(dir, token, dir_len);
                        dir[dir_len] = '\0';
                        state->file->report_name = name;
                        state->file->report_dir = dir;
                        state->file->macro      = 0;
                }
                break;
        }
        case TOK_MUNDEF:
        {
                struct hash_entry *ident;
                pp_eat(state, TOK_MUNDEF);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;

                ident = pp_eat(state, TOK_MIDENT)->ident;

                undef_macro(state, ident);
                break;
        }
        case TOK_MPRAGMA:
                pp_eat(state, TOK_MPRAGMA);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;
                warning(state, 0, "Ignoring pragma");
                break;
        case TOK_MELIF:
                pp_eat(state, TOK_MELIF);
                reenter_if(state, "#elif");
                if (if_eat(state))   /* quit early when #if'd out */
                        break;
                /* If the #if was taken the #elif just disables the following code */
                if (if_value(state)) {
                        eat_tokens(state, TOK_MENDIF);
                }
                /* If the previous #if was not taken see if the #elif enables the
                 * trailing code.
                 */
                else {
                        set_if_value(state, mcexpr(state));
                        if (!if_value(state)) {
                                eat_tokens(state, TOK_MELSE);
                        }
                }
                break;
        case TOK_MIF:
                pp_eat(state, TOK_MIF);
                enter_if(state);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;
                set_if_value(state, mcexpr(state));
                if (!if_value(state)) {
                        eat_tokens(state, TOK_MELSE);
                }
                break;
        case TOK_MIFNDEF:
        {
                struct hash_entry *ident;

                pp_eat(state, TOK_MIFNDEF);
                enter_if(state);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;
                ident = pp_eat(state, TOK_MIDENT)->ident;
                set_if_value(state, ident->sym_define == 0);
                if (!if_value(state)) {
                        eat_tokens(state, TOK_MELSE);
                }
                break;
        }
        case TOK_MIFDEF:
        {
                struct hash_entry *ident;
                pp_eat(state, TOK_MIFDEF);
                enter_if(state);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;
                ident = pp_eat(state, TOK_MIDENT)->ident;
                set_if_value(state, ident->sym_define != 0);
                if (!if_value(state)) {
                        eat_tokens(state, TOK_MELSE);
                }
                break;
        }
        case TOK_MELSE:
                pp_eat(state, TOK_MELSE);
                enter_else(state, "#else");
                if (!if_eat(state) && if_value(state)) {
                        eat_tokens(state, TOK_MENDIF);
                }
                break;
        case TOK_MENDIF:
                pp_eat(state, TOK_MENDIF);
                exit_if(state, "#endif");
                break;
        case TOK_MDEFINE:
        {
                struct hash_entry *ident;
                struct macro_arg *args, **larg;
                const char *mstart, *mend;
                int argc;

                pp_eat(state, TOK_MDEFINE);
                if (if_eat(state))  /* quit early when #if'd out */
                        break;
                ident = pp_eat(state, TOK_MIDENT)->ident;
                argc = -1;
                args = 0;
                larg = &args;

                /* Parse macro parameters */
                if (raw_peek(state) == TOK_LPAREN) {
                        raw_eat(state, TOK_LPAREN);
                        argc += 1;

                        for(;;) {
                                struct macro_arg *narg, *arg;
                                struct hash_entry *aident;
                                int tok;

                                tok = pp_peek(state);
                                if (!args && (tok == TOK_RPAREN)) {
                                        break;
                                }
                                else if (tok == TOK_DOTS) {
                                        pp_eat(state, TOK_DOTS);
                                        aident = state->i___VA_ARGS__;
                                }
                                else {
                                        aident = pp_eat(state, TOK_MIDENT)->ident;
                                }

                                narg = xcmalloc(sizeof(*arg), "macro arg");
                                narg->ident = aident;

                                /* Verify I don't have a duplicate identifier */
                                for(arg = args; arg; arg = arg->next) {
                                        if (arg->ident == narg->ident) {
                                                error(state, 0, "Duplicate macro arg `%s'",
                                                        narg->ident->name);
                                        }
                                }
                                /* Add the new argument to the end of the list */
                                *larg = narg;
                                larg = &narg->next;
                                argc += 1;

                                if ((aident == state->i___VA_ARGS__) ||
                                        (pp_peek(state) != TOK_COMMA)) {
                                        break;
                                }
                                pp_eat(state, TOK_COMMA);
                        }
                        pp_eat(state, TOK_RPAREN);
                }
                /* Remove leading whitespace */
                while(raw_peek(state) == TOK_SPACE) {
                        raw_eat(state, TOK_SPACE);
                }

                /* Remember the start of the macro body */
                raw_peek(state);
                mend = mstart = get_token(state, 1)->pos;

                /* Find the end of the macro */
                for(tok = raw_peek(state); tok != TOK_EOL; tok = raw_peek(state)) {
                        raw_eat(state, tok);
                        /* Remember the end of the last non space token */
                        raw_peek(state);
                        if (tok != TOK_SPACE) {
                                mend = get_token(state, 1)->pos;
                        }
                }

                /* Now that I have found the body defined the token */
                do_define_macro(state, ident,
                        char_strdup(state->file, mstart, mend, "macro buf"),
                        argc, args);
                break;
        }
        case TOK_MERROR:
        {
                const char *start, *end;
                int len;

                pp_eat(state, TOK_MERROR);
                /* Find the start of the line */
                raw_peek(state);
                start = get_token(state, 1)->pos;

                /* Find the end of the line */
                while((tok = raw_peek(state)) != TOK_EOL) {
                        raw_eat(state, tok);
                }
                end = get_token(state, 1)->pos;
                len = end - start;
                if (!if_eat(state)) {
                        error(state, 0, "%*.*s", len, len, start);
                }
                break;
        }
        case TOK_MWARNING:
        {
                const char *start, *end;
                int len;

                pp_eat(state, TOK_MWARNING);

                /* Find the start of the line */
                raw_peek(state);
                start = get_token(state, 1)->pos;

                /* Find the end of the line */
                while((tok = raw_peek(state)) != TOK_EOL) {
                        raw_eat(state, tok);
                }
                end = get_token(state, 1)->pos;
                len = end - start;
                if (!if_eat(state)) {
                        warning(state, 0, "%*.*s", len, len, start);
                }
                break;
        }
        case TOK_MINCLUDE:
        {
                char *name;
                int local;
                name = 0;

                pp_eat(state, TOK_MINCLUDE);
                if (if_eat(state)) {
                        /* Find the end of the line */
                        while((tok = raw_peek(state)) != TOK_EOL) {
                                raw_eat(state, tok);
                        }
                        break;
                }
                tok = peek(state);
                if (tok == TOK_LIT_STRING) {
                        struct token *tk;
                        const char *token;
                        int name_len;
                        tk = eat(state, TOK_LIT_STRING);
                        name = xmalloc(tk->str_len, "include");
                        token = tk->val.str +1;
                        name_len = tk->str_len -2;
                        if (*token == '"') {
                                token++;
                                name_len--;
                        }
                        memcpy(name, token, name_len);
                        name[name_len] = '\0';
                        local = 1;
                }
                else if (tok == TOK_LESS) {
                        struct macro_buf buf;
                        eat(state, TOK_LESS);

                        buf.len = 40;
                        buf.str = xmalloc(buf.len, "include");
                        buf.pos = 0;

                        tok = peek(state);
                        while((tok != TOK_MORE) &&
                                (tok != TOK_EOL) && (tok != TOK_EOF))
                        {
                                struct token *tk;
                                tk = eat(state, tok);
                                append_macro_chars(state, "include", &buf,
                                        state->file, tk->pos, state->file->pos);
                                tok = peek(state);
                        }
                        append_macro_text(state, "include", &buf, "\0", 1);
                        if (peek(state) != TOK_MORE) {
                                error(state, 0, "Unterminated include directive");
                        }
                        eat(state, TOK_MORE);
                        local = 0;
                        name = buf.str;
                }
                else {
                        error(state, 0, "Invalid include directive");
                }
                /* Error if there are any tokens after the include */
                if (pp_peek(state) != TOK_EOL) {
                        error(state, 0, "garbage after include directive");
                }
                if (!if_eat(state)) {
                        compile_file(state, name, local);
                }
                xfree(name);
                break;
        }
        case TOK_EOL:
                /* Ignore # without a following ident */
                break;
        default:
        {
                const char *name1, *name2;
                name1 = tokens[tok];
                name2 = "";
                if (tok == TOK_MIDENT) {
                        name2 = get_token(state, 1)->ident->name;
                }
                error(state, 0, "Invalid preprocessor directive: %s %s",
                        name1, name2);
                break;
        }
        }
        /* Consume the rest of the macro line */
        do {
                tok = pp_peek(state);
                pp_eat(state, tok);
        } while((tok != TOK_EOF) && (tok != TOK_EOL));
        state->token_base = old_token_base;
        state->macro_file = NULL;
        return;
}

/* Type helper functions */

static struct type *new_type(
        unsigned int type, struct type *left, struct type *right)
{
        struct type *result;
        result = xmalloc(sizeof(*result), "type");
        result->type = type;
        result->left = left;
        result->right = right;
        result->field_ident = 0;
        result->type_ident = 0;
        result->elements = 0;
        return result;
}

static struct type *clone_type(unsigned int specifiers, struct type *old)
{
        struct type *result;
        result = xmalloc(sizeof(*result), "type");
        memcpy(result, old, sizeof(*result));
        result->type &= TYPE_MASK;
        result->type |= specifiers;
        return result;
}

static struct type *dup_type(struct compile_state *state, struct type *orig)
{
        struct type *new;
        new = xcmalloc(sizeof(*new), "type");
        new->type = orig->type;
        new->field_ident = orig->field_ident;
        new->type_ident  = orig->type_ident;
        new->elements    = orig->elements;
        if (orig->left) {
                new->left = dup_type(state, orig->left);
        }
        if (orig->right) {
                new->right = dup_type(state, orig->right);
        }
        return new;
}


static struct type *invalid_type(struct compile_state *state, struct type *type)
{
        struct type *invalid, *member;
        invalid = 0;
        if (!type) {
                internal_error(state, 0, "type missing?");
        }
        switch(type->type & TYPE_MASK) {
        case TYPE_VOID:
        case TYPE_CHAR:         case TYPE_UCHAR:
        case TYPE_SHORT:        case TYPE_USHORT:
        case TYPE_INT:          case TYPE_UINT:
        case TYPE_LONG:         case TYPE_ULONG:
        case TYPE_LLONG:        case TYPE_ULLONG:
        case TYPE_POINTER:
        case TYPE_ENUM:
                break;
        case TYPE_BITFIELD:
                invalid = invalid_type(state, type->left);
                break;
        case TYPE_ARRAY:
                invalid = invalid_type(state, type->left);
                break;
        case TYPE_STRUCT:
        case TYPE_TUPLE:
                member = type->left;
                while(member && (invalid == 0) &&
                        ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        invalid = invalid_type(state, member->left);
                        member = member->right;
                }
                if (!invalid) {
                        invalid = invalid_type(state, member);
                }
                break;
        case TYPE_UNION:
        case TYPE_JOIN:
                member = type->left;
                while(member && (invalid == 0) &&
                        ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        invalid = invalid_type(state, member->left);
                        member = member->right;
                }
                if (!invalid) {
                        invalid = invalid_type(state, member);
                }
                break;
        default:
                invalid = type;
                break;
        }
        return invalid;

}

static struct type void_type    = { .type  = TYPE_VOID };
static struct type char_type    = { .type  = TYPE_CHAR };
static struct type uchar_type   = { .type  = TYPE_UCHAR };
#if DEBUG_ROMCC_WARNING
static struct type short_type   = { .type  = TYPE_SHORT };
#endif
static struct type ushort_type  = { .type  = TYPE_USHORT };
static struct type int_type     = { .type  = TYPE_INT };
static struct type uint_type    = { .type  = TYPE_UINT };
static struct type long_type    = { .type  = TYPE_LONG };
static struct type ulong_type   = { .type  = TYPE_ULONG };
static struct type unknown_type = { .type  = TYPE_UNKNOWN };

static struct type void_ptr_type  = {
        .type = TYPE_POINTER,
        .left = &void_type,
};

#if DEBUG_ROMCC_WARNING
static struct type void_func_type = {
        .type  = TYPE_FUNCTION,
        .left  = &void_type,
        .right = &void_type,
};
#endif

static size_t bits_to_bytes(size_t size)
{
        return (size + SIZEOF_CHAR - 1)/SIZEOF_CHAR;
}

static struct triple *variable(struct compile_state *state, struct type *type)
{
        struct triple *result;
        if ((type->type & STOR_MASK) != STOR_PERM) {
                result = triple(state, OP_ADECL, type, 0, 0);
                generate_lhs_pieces(state, result);
        }
        else {
                result = triple(state, OP_SDECL, type, 0, 0);
        }
        return result;
}

static void stor_of(FILE *fp, struct type *type)
{
        switch(type->type & STOR_MASK) {
        case STOR_AUTO:
                fprintf(fp, "auto ");
                break;
        case STOR_STATIC:
                fprintf(fp, "static ");
                break;
        case STOR_LOCAL:
                fprintf(fp, "local ");
                break;
        case STOR_EXTERN:
                fprintf(fp, "extern ");
                break;
        case STOR_REGISTER:
                fprintf(fp, "register ");
                break;
        case STOR_TYPEDEF:
                fprintf(fp, "typedef ");
                break;
        case STOR_INLINE | STOR_LOCAL:
                fprintf(fp, "inline ");
                break;
        case STOR_INLINE | STOR_STATIC:
                fprintf(fp, "static inline");
                break;
        case STOR_INLINE | STOR_EXTERN:
                fprintf(fp, "extern inline");
                break;
        default:
                fprintf(fp, "stor:%x", type->type & STOR_MASK);
                break;
        }
}
static void qual_of(FILE *fp, struct type *type)
{
        if (type->type & QUAL_CONST) {
                fprintf(fp, " const");
        }
        if (type->type & QUAL_VOLATILE) {
                fprintf(fp, " volatile");
        }
        if (type->type & QUAL_RESTRICT) {
                fprintf(fp, " restrict");
        }
}

static void name_of(FILE *fp, struct type *type)
{
        unsigned int base_type;
        base_type = type->type & TYPE_MASK;
        if ((base_type != TYPE_PRODUCT) && (base_type != TYPE_OVERLAP)) {
                stor_of(fp, type);
        }
        switch(base_type) {
        case TYPE_VOID:
                fprintf(fp, "void");
                qual_of(fp, type);
                break;
        case TYPE_CHAR:
                fprintf(fp, "signed char");
                qual_of(fp, type);
                break;
        case TYPE_UCHAR:
                fprintf(fp, "unsigned char");
                qual_of(fp, type);
                break;
        case TYPE_SHORT:
                fprintf(fp, "signed short");
                qual_of(fp, type);
                break;
        case TYPE_USHORT:
                fprintf(fp, "unsigned short");
                qual_of(fp, type);
                break;
        case TYPE_INT:
                fprintf(fp, "signed int");
                qual_of(fp, type);
                break;
        case TYPE_UINT:
                fprintf(fp, "unsigned int");
                qual_of(fp, type);
                break;
        case TYPE_LONG:
                fprintf(fp, "signed long");
                qual_of(fp, type);
                break;
        case TYPE_ULONG:
                fprintf(fp, "unsigned long");
                qual_of(fp, type);
                break;
        case TYPE_POINTER:
                name_of(fp, type->left);
                fprintf(fp, " * ");
                qual_of(fp, type);
                break;
        case TYPE_PRODUCT:
                name_of(fp, type->left);
                fprintf(fp, ", ");
                name_of(fp, type->right);
                break;
        case TYPE_OVERLAP:
                name_of(fp, type->left);
                fprintf(fp, ",| ");
                name_of(fp, type->right);
                break;
        case TYPE_ENUM:
                fprintf(fp, "enum %s",
                        (type->type_ident)? type->type_ident->name : "");
                qual_of(fp, type);
                break;
        case TYPE_STRUCT:
                fprintf(fp, "struct %s { ",
                        (type->type_ident)? type->type_ident->name : "");
                name_of(fp, type->left);
                fprintf(fp, " } ");
                qual_of(fp, type);
                break;
        case TYPE_UNION:
                fprintf(fp, "union %s { ",
                        (type->type_ident)? type->type_ident->name : "");
                name_of(fp, type->left);
                fprintf(fp, " } ");
                qual_of(fp, type);
                break;
        case TYPE_FUNCTION:
                name_of(fp, type->left);
                fprintf(fp, " (*)(");
                name_of(fp, type->right);
                fprintf(fp, ")");
                break;
        case TYPE_ARRAY:
                name_of(fp, type->left);
                fprintf(fp, " [%ld]", (long)(type->elements));
                break;
        case TYPE_TUPLE:
                fprintf(fp, "tuple { ");
                name_of(fp, type->left);
                fprintf(fp, " } ");
                qual_of(fp, type);
                break;
        case TYPE_JOIN:
                fprintf(fp, "join { ");
                name_of(fp, type->left);
                fprintf(fp, " } ");
                qual_of(fp, type);
                break;
        case TYPE_BITFIELD:
                name_of(fp, type->left);
                fprintf(fp, " : %d ", type->elements);
                qual_of(fp, type);
                break;
        case TYPE_UNKNOWN:
                fprintf(fp, "unknown_t");
                break;
        default:
                fprintf(fp, "????: %x", base_type);
                break;
        }
        if (type->field_ident && type->field_ident->name) {
                fprintf(fp, " .%s", type->field_ident->name);
        }
}

static size_t align_of(struct compile_state *state, struct type *type)
{
        size_t align;
        switch(type->type & TYPE_MASK) {
        case TYPE_VOID:
                align = 1;
                break;
        case TYPE_BITFIELD:
                align = 1;
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
                align = ALIGNOF_CHAR;
                break;
        case TYPE_SHORT:
        case TYPE_USHORT:
                align = ALIGNOF_SHORT;
                break;
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_ENUM:
                align = ALIGNOF_INT;
                break;
        case TYPE_LONG:
        case TYPE_ULONG:
                align = ALIGNOF_LONG;
                break;
        case TYPE_POINTER:
                align = ALIGNOF_POINTER;
                break;
        case TYPE_PRODUCT:
        case TYPE_OVERLAP:
        {
                size_t left_align, right_align;
                left_align  = align_of(state, type->left);
                right_align = align_of(state, type->right);
                align = (left_align >= right_align) ? left_align : right_align;
                break;
        }
        case TYPE_ARRAY:
                align = align_of(state, type->left);
                break;
        case TYPE_STRUCT:
        case TYPE_TUPLE:
        case TYPE_UNION:
        case TYPE_JOIN:
                align = align_of(state, type->left);
                break;
        default:
                error(state, 0, "alignof not yet defined for type\n");
                break;
        }
        return align;
}

static size_t reg_align_of(struct compile_state *state, struct type *type)
{
        size_t align;
        switch(type->type & TYPE_MASK) {
        case TYPE_VOID:
                align = 1;
                break;
        case TYPE_BITFIELD:
                align = 1;
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
                align = REG_ALIGNOF_CHAR;
                break;
        case TYPE_SHORT:
        case TYPE_USHORT:
                align = REG_ALIGNOF_SHORT;
                break;
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_ENUM:
                align = REG_ALIGNOF_INT;
                break;
        case TYPE_LONG:
        case TYPE_ULONG:
                align = REG_ALIGNOF_LONG;
                break;
        case TYPE_POINTER:
                align = REG_ALIGNOF_POINTER;
                break;
        case TYPE_PRODUCT:
        case TYPE_OVERLAP:
        {
                size_t left_align, right_align;
                left_align  = reg_align_of(state, type->left);
                right_align = reg_align_of(state, type->right);
                align = (left_align >= right_align) ? left_align : right_align;
                break;
        }
        case TYPE_ARRAY:
                align = reg_align_of(state, type->left);
                break;
        case TYPE_STRUCT:
        case TYPE_UNION:
        case TYPE_TUPLE:
        case TYPE_JOIN:
                align = reg_align_of(state, type->left);
                break;
        default:
                error(state, 0, "alignof not yet defined for type\n");
                break;
        }
        return align;
}

static size_t align_of_in_bytes(struct compile_state *state, struct type *type)
{
        return bits_to_bytes(align_of(state, type));
}
static size_t size_of(struct compile_state *state, struct type *type);
static size_t reg_size_of(struct compile_state *state, struct type *type);

static size_t needed_padding(struct compile_state *state,
        struct type *type, size_t offset)
{
        size_t padding, align;
        align = align_of(state, type);
        /* Align to the next machine word if the bitfield does completely
         * fit into the current word.
         */
        if ((type->type & TYPE_MASK) == TYPE_BITFIELD) {
                size_t size;
                size = size_of(state, type);
                if ((offset + type->elements)/size != offset/size) {
                        align = size;
                }
        }
        padding = 0;
        if (offset % align) {
                padding = align - (offset % align);
        }
        return padding;
}

static size_t reg_needed_padding(struct compile_state *state,
        struct type *type, size_t offset)
{
        size_t padding, align;
        align = reg_align_of(state, type);
        /* Align to the next register word if the bitfield does completely
         * fit into the current register.
         */
        if (((type->type & TYPE_MASK) == TYPE_BITFIELD) &&
                (((offset + type->elements)/REG_SIZEOF_REG) != (offset/REG_SIZEOF_REG)))
        {
                align = REG_SIZEOF_REG;
        }
        padding = 0;
        if (offset % align) {
                padding = align - (offset % align);
        }
        return padding;
}

static size_t size_of(struct compile_state *state, struct type *type)
{
        size_t size;
        switch(type->type & TYPE_MASK) {
        case TYPE_VOID:
                size = 0;
                break;
        case TYPE_BITFIELD:
                size = type->elements;
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
                size = SIZEOF_CHAR;
                break;
        case TYPE_SHORT:
        case TYPE_USHORT:
                size = SIZEOF_SHORT;
                break;
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_ENUM:
                size = SIZEOF_INT;
                break;
        case TYPE_LONG:
        case TYPE_ULONG:
                size = SIZEOF_LONG;
                break;
        case TYPE_POINTER:
                size = SIZEOF_POINTER;
                break;
        case TYPE_PRODUCT:
        {
                size_t pad;
                size = 0;
                while((type->type & TYPE_MASK) == TYPE_PRODUCT) {
                        pad = needed_padding(state, type->left, size);
                        size = size + pad + size_of(state, type->left);
                        type = type->right;
                }
                pad = needed_padding(state, type, size);
                size = size + pad + size_of(state, type);
                break;
        }
        case TYPE_OVERLAP:
        {
                size_t size_left, size_right;
                size_left = size_of(state, type->left);
                size_right = size_of(state, type->right);
                size = (size_left >= size_right)? size_left : size_right;
                break;
        }
        case TYPE_ARRAY:
                if (type->elements == ELEMENT_COUNT_UNSPECIFIED) {
                        internal_error(state, 0, "Invalid array type");
                } else {
                        size = size_of(state, type->left) * type->elements;
                }
                break;
        case TYPE_STRUCT:
        case TYPE_TUPLE:
        {
                size_t pad;
                size = size_of(state, type->left);
                /* Pad structures so their size is a multiples of their alignment */
                pad = needed_padding(state, type, size);
                size = size + pad;
                break;
        }
        case TYPE_UNION:
        case TYPE_JOIN:
        {
                size_t pad;
                size = size_of(state, type->left);
                /* Pad unions so their size is a multiple of their alignment */
                pad = needed_padding(state, type, size);
                size = size + pad;
                break;
        }
        default:
                internal_error(state, 0, "sizeof not yet defined for type");
                break;
        }
        return size;
}

static size_t reg_size_of(struct compile_state *state, struct type *type)
{
        size_t size;
        switch(type->type & TYPE_MASK) {
        case TYPE_VOID:
                size = 0;
                break;
        case TYPE_BITFIELD:
                size = type->elements;
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
                size = REG_SIZEOF_CHAR;
                break;
        case TYPE_SHORT:
        case TYPE_USHORT:
                size = REG_SIZEOF_SHORT;
                break;
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_ENUM:
                size = REG_SIZEOF_INT;
                break;
        case TYPE_LONG:
        case TYPE_ULONG:
                size = REG_SIZEOF_LONG;
                break;
        case TYPE_POINTER:
                size = REG_SIZEOF_POINTER;
                break;
        case TYPE_PRODUCT:
        {
                size_t pad;
                size = 0;
                while((type->type & TYPE_MASK) == TYPE_PRODUCT) {
                        pad = reg_needed_padding(state, type->left, size);
                        size = size + pad + reg_size_of(state, type->left);
                        type = type->right;
                }
                pad = reg_needed_padding(state, type, size);
                size = size + pad + reg_size_of(state, type);
                break;
        }
        case TYPE_OVERLAP:
        {
                size_t size_left, size_right;
                size_left  = reg_size_of(state, type->left);
                size_right = reg_size_of(state, type->right);
                size = (size_left >= size_right)? size_left : size_right;
                break;
        }
        case TYPE_ARRAY:
                if (type->elements == ELEMENT_COUNT_UNSPECIFIED) {
                        internal_error(state, 0, "Invalid array type");
                } else {
                        size = reg_size_of(state, type->left) * type->elements;
                }
                break;
        case TYPE_STRUCT:
        case TYPE_TUPLE:
        {
                size_t pad;
                size = reg_size_of(state, type->left);
                /* Pad structures so their size is a multiples of their alignment */
                pad = reg_needed_padding(state, type, size);
                size = size + pad;
                break;
        }
        case TYPE_UNION:
        case TYPE_JOIN:
        {
                size_t pad;
                size = reg_size_of(state, type->left);
                /* Pad unions so their size is a multiple of their alignment */
                pad = reg_needed_padding(state, type, size);
                size = size + pad;
                break;
        }
        default:
                internal_error(state, 0, "sizeof not yet defined for type");
                break;
        }
        return size;
}

static size_t registers_of(struct compile_state *state, struct type *type)
{
        size_t registers;
        registers = reg_size_of(state, type);
        registers += REG_SIZEOF_REG - 1;
        registers /= REG_SIZEOF_REG;
        return registers;
}

static size_t size_of_in_bytes(struct compile_state *state, struct type *type)
{
        return bits_to_bytes(size_of(state, type));
}

static size_t field_offset(struct compile_state *state,
        struct type *type, struct hash_entry *field)
{
        struct type *member;
        size_t size;

        size = 0;
        member = 0;
        if ((type->type & TYPE_MASK) == TYPE_STRUCT) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        size += needed_padding(state, member->left, size);
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        size += size_of(state, member->left);
                        member = member->right;
                }
                if (member == NULL)
                        internal_error(state, 0, "Member is NULL");
                size += needed_padding(state, member, size);
        }
        else if ((type->type & TYPE_MASK) == TYPE_UNION) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        member = member->right;
                }
        }
        else {
                internal_error(state, 0, "field_offset only works on structures and unions");
        }

        if (!member || (member->field_ident != field)) {
                error(state, 0, "member %s not present", field->name);
        }
        return size;
}

static size_t field_reg_offset(struct compile_state *state,
        struct type *type, struct hash_entry *field)
{
        struct type *member;
        size_t size;

        size = 0;
        member = 0;
        if ((type->type & TYPE_MASK) == TYPE_STRUCT) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        size += reg_needed_padding(state, member->left, size);
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        size += reg_size_of(state, member->left);
                        member = member->right;
                }
        }
        else if ((type->type & TYPE_MASK) == TYPE_UNION) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        member = member->right;
                }
        }
        else {
                internal_error(state, 0, "field_reg_offset only works on structures and unions");
        }

        if (!member || (member->field_ident != field)) {
                error(state, 0, "member %s not present", field->name);
        }
        size += reg_needed_padding(state, member, size);
        return size;
}

static struct type *field_type(struct compile_state *state,
        struct type *type, struct hash_entry *field)
{
        struct type *member;

        member = 0;
        if ((type->type & TYPE_MASK) == TYPE_STRUCT) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        member = member->right;
                }
        }
        else if ((type->type & TYPE_MASK) == TYPE_UNION) {
                member = type->left;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (member->left->field_ident == field) {
                                member = member->left;
                                break;
                        }
                        member = member->right;
                }
        }
        else {
                internal_error(state, 0, "field_type only works on structures and unions");
        }

        if (!member || (member->field_ident != field)) {
                error(state, 0, "member %s not present", field->name);
        }
        return member;
}

static size_t index_offset(struct compile_state *state,
        struct type *type, ulong_t index)
{
        struct type *member;
        size_t size;
        size = 0;
        if ((type->type & TYPE_MASK) == TYPE_ARRAY) {
                size = size_of(state, type->left) * index;
        }
        else if ((type->type & TYPE_MASK) == TYPE_TUPLE) {
                ulong_t i;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        size += needed_padding(state, member->left, size);
                        if (i == index) {
                                member = member->left;
                                break;
                        }
                        size += size_of(state, member->left);
                        i++;
                        member = member->right;
                }
                if (member == NULL)
                        internal_error(state, 0, "Member is NULL");
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
                size += needed_padding(state, member, size);
        }
        else if ((type->type & TYPE_MASK) == TYPE_JOIN) {
                ulong_t i;
                size = 0;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (i == index) {
                                break;
                        }
                        i++;
                        member = member->right;
                }
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
        }
        else {
                internal_error(state, 0,
                        "request for index %u in something not an array, tuple or join",
                        index);
        }
        return size;
}

static size_t index_reg_offset(struct compile_state *state,
        struct type *type, ulong_t index)
{
        struct type *member;
        size_t size;
        size = 0;
        if ((type->type & TYPE_MASK) == TYPE_ARRAY) {
                size = reg_size_of(state, type->left) * index;
        }
        else if ((type->type & TYPE_MASK) == TYPE_TUPLE) {
                ulong_t i;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        size += reg_needed_padding(state, member->left, size);
                        if (i == index) {
                                member = member->left;
                                break;
                        }
                        size += reg_size_of(state, member->left);
                        i++;
                        member = member->right;
                }
                if (member == NULL)
                        internal_error(state, 0, "Member is NULL");
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
                size += reg_needed_padding(state, member, size);
        }
        else if ((type->type & TYPE_MASK) == TYPE_JOIN) {
                ulong_t i;
                size = 0;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (i == index) {
                                break;
                        }
                        i++;
                        member = member->right;
                }
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
        }
        else {
                internal_error(state, 0,
                        "request for index %u in something not an array, tuple or join",
                        index);
        }
        return size;
}

static struct type *index_type(struct compile_state *state,
        struct type *type, ulong_t index)
{
        struct type *member;
        if (index >= type->elements) {
                internal_error(state, 0, "Invalid element %u requested", index);
        }
        if ((type->type & TYPE_MASK) == TYPE_ARRAY) {
                member = type->left;
        }
        else if ((type->type & TYPE_MASK) == TYPE_TUPLE) {
                ulong_t i;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        if (i == index) {
                                member = member->left;
                                break;
                        }
                        i++;
                        member = member->right;
                }
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
        }
        else if ((type->type & TYPE_MASK) == TYPE_JOIN) {
                ulong_t i;
                member = type->left;
                i = 0;
                while(member && ((member->type & TYPE_MASK) == TYPE_OVERLAP)) {
                        if (i == index) {
                                member = member->left;
                                break;
                        }
                        i++;
                        member = member->right;
                }
                if (i != index) {
                        internal_error(state, 0, "Missing member index: %u", index);
                }
        }
        else {
                member = 0;
                internal_error(state, 0,
                        "request for index %u in something not an array, tuple or join",
                        index);
        }
        return member;
}

static struct type *unpack_type(struct compile_state *state, struct type *type)
{
        /* If I have a single register compound type not a bit-field
         * find the real type.
         */
        struct type *start_type;
        size_t size;
        /* Get out early if I need multiple registers for this type */
        size = reg_size_of(state, type);
        if (size > REG_SIZEOF_REG) {
                return type;
        }
        /* Get out early if I don't need any registers for this type */
        if (size == 0) {
                return &void_type;
        }
        /* Loop until I have no more layers I can remove */
        do {
                start_type = type;
                switch(type->type & TYPE_MASK) {
                case TYPE_ARRAY:
                        /* If I have a single element the unpacked type
                         * is that element.
                         */
                        if (type->elements == 1) {
                                type = type->left;
                        }
                        break;
                case TYPE_STRUCT:
                case TYPE_TUPLE:
                        /* If I have a single element the unpacked type
                         * is that element.
                         */
                        if (type->elements == 1) {
                                type = type->left;
                        }
                        /* If I have multiple elements the unpacked
                         * type is the non-void element.
                         */
                        else {
                                struct type *next, *member;
                                struct type *sub_type;
                                sub_type = 0;
                                next = type->left;
                                while(next) {
                                        member = next;
                                        next = 0;
                                        if ((member->type & TYPE_MASK) == TYPE_PRODUCT) {
                                                next = member->right;
                                                member = member->left;
                                        }
                                        if (reg_size_of(state, member) > 0) {
                                                if (sub_type) {
                                                        internal_error(state, 0, "true compound type in a register");
                                                }
                                                sub_type = member;
                                        }
                                }
                                if (sub_type) {
                                        type = sub_type;
                                }
                        }
                        break;

                case TYPE_UNION:
                case TYPE_JOIN:
                        /* If I have a single element the unpacked type
                         * is that element.
                         */
                        if (type->elements == 1) {
                                type = type->left;
                        }
                        /* I can't in general unpack union types */
                        break;
                default:
                        /* If I'm not a compound type I can't unpack it */
                        break;
                }
        } while(start_type != type);
        switch(type->type & TYPE_MASK) {
        case TYPE_STRUCT:
        case TYPE_ARRAY:
        case TYPE_TUPLE:
                internal_error(state, 0, "irredicible type?");
                break;
        }
        return type;
}

static int equiv_types(struct type *left, struct type *right);
static int is_compound_type(struct type *type);

static struct type *reg_type(
        struct compile_state *state, struct type *type, int reg_offset)
{
        struct type *member;
        size_t size;
#if 1
        struct type *invalid;
        invalid = invalid_type(state, type);
        if (invalid) {
                fprintf(state->errout, "type: ");
                name_of(state->errout, type);
                fprintf(state->errout, "\n");
                fprintf(state->errout, "invalid: ");
                name_of(state->errout, invalid);
                fprintf(state->errout, "\n");
                internal_error(state, 0, "bad input type?");
        }
#endif

        size = reg_size_of(state, type);
        if (reg_offset > size) {
                member = 0;
                fprintf(state->errout, "type: ");
                name_of(state->errout, type);
                fprintf(state->errout, "\n");
                internal_error(state, 0, "offset outside of type");
        }
        else {
                switch(type->type & TYPE_MASK) {
                        /* Don't do anything with the basic types */
                case TYPE_VOID:
                case TYPE_CHAR:         case TYPE_UCHAR:
                case TYPE_SHORT:        case TYPE_USHORT:
                case TYPE_INT:          case TYPE_UINT:
                case TYPE_LONG:         case TYPE_ULONG:
                case TYPE_LLONG:        case TYPE_ULLONG:
                case TYPE_FLOAT:        case TYPE_DOUBLE:
                case TYPE_LDOUBLE:
                case TYPE_POINTER:
                case TYPE_ENUM:
                case TYPE_BITFIELD:
                        member = type;
                        break;
                case TYPE_ARRAY:
                        member = type->left;
                        size = reg_size_of(state, member);
                        if (size > REG_SIZEOF_REG) {
                                member = reg_type(state, member, reg_offset % size);
                        }
                        break;
                case TYPE_STRUCT:
                case TYPE_TUPLE:
                {
                        size_t offset;
                        offset = 0;
                        member = type->left;
                        while(member && ((member->type & TYPE_MASK) == TYPE_PRODUCT)) {
                                size = reg_size_of(state, member->left);
                                offset += reg_needed_padding(state, member->left, offset);
                                if ((offset + size) > reg_offset) {
                                        member = member->left;
                                        break;
                                }
                                offset += size;
                                member = member->right;
                        }
                        if (member == NULL)
                                internal_error(state, 0, "Member is NULL");
                        offset += reg_needed_padding(state, member, offset);
                        member = reg_type(state, member, reg_offset - offset);
                        break;
                }
                case TYPE_UNION:
                case TYPE_JOIN:
                {
                        struct type *join, **jnext, *mnext;
                        join = new_type(TYPE_JOIN, 0, 0);
                        jnext = &join->left;
                        mnext = type->left;
                        while(mnext) {
                                size_t size;
                                member = mnext;
                                mnext = 0;
                                if ((member->type & TYPE_MASK) == TYPE_OVERLAP) {
                                        mnext = member->right;
                                        member = member->left;
                                }
                                size = reg_size_of(state, member);
                                if (size > reg_offset) {
                                        struct type *part, *hunt;
                                        part = reg_type(state, member, reg_offset);
                                        /* See if this type is already in the union */
                                        hunt = join->left;
                                        while(hunt) {
                                                struct type *test = hunt;
                                                hunt = 0;
                                                if ((test->type & TYPE_MASK) == TYPE_OVERLAP) {
                                                        hunt = test->right;
                                                        test = test->left;
                                                }
                                                if (equiv_types(part, test)) {
                                                        goto next;
                                                }
                                        }
                                        /* Nope add it */
                                        if (!*jnext) {
                                                *jnext = part;
                                        } else {
                                                *jnext = new_type(TYPE_OVERLAP, *jnext, part);
                                                jnext = &(*jnext)->right;
                                        }
                                        join->elements++;
                                }
                        next:
                                ;
                        }
                        if (join->elements == 0) {
                                internal_error(state, 0, "No elements?");
                        }
                        member = join;
                        break;
                }
                default:
                        member = 0;
                        fprintf(state->errout, "type: ");
                        name_of(state->errout, type);
                        fprintf(state->errout, "\n");
                        internal_error(state, 0, "reg_type not yet defined for type");

                }
        }
        /* If I have a single register compound type not a bit-field
         * find the real type.
         */
        member = unpack_type(state, member);
                ;
        size  = reg_size_of(state, member);
        if (size > REG_SIZEOF_REG) {
                internal_error(state, 0, "Cannot find type of single register");
        }
#if 1
        invalid = invalid_type(state, member);
        if (invalid) {
                fprintf(state->errout, "type: ");
                name_of(state->errout, member);
                fprintf(state->errout, "\n");
                fprintf(state->errout, "invalid: ");
                name_of(state->errout, invalid);
                fprintf(state->errout, "\n");
                internal_error(state, 0, "returning bad type?");
        }
#endif
        return member;
}

static struct type *next_field(struct compile_state *state,
        struct type *type, struct type *prev_member)
{
        struct type *member;
        if ((type->type & TYPE_MASK) != TYPE_STRUCT) {
                internal_error(state, 0, "next_field only works on structures");
        }
        member = type->left;
        while((member->type & TYPE_MASK) == TYPE_PRODUCT) {
                if (!prev_member) {
                        member = member->left;
                        break;
                }
                if (member->left == prev_member) {
                        prev_member = 0;
                }
                member = member->right;
        }
        if (member == prev_member) {
                prev_member = 0;
        }
        if (prev_member) {
                internal_error(state, 0, "prev_member %s not present",
                        prev_member->field_ident->name);
        }
        return member;
}

typedef void (*walk_type_fields_cb_t)(struct compile_state *state, struct type *type,
        size_t ret_offset, size_t mem_offset, void *arg);

static void walk_type_fields(struct compile_state *state,
        struct type *type, size_t reg_offset, size_t mem_offset,
        walk_type_fields_cb_t cb, void *arg);

static void walk_struct_fields(struct compile_state *state,
        struct type *type, size_t reg_offset, size_t mem_offset,
        walk_type_fields_cb_t cb, void *arg)
{
        struct type *tptr;
        ulong_t i;
        if ((type->type & TYPE_MASK) != TYPE_STRUCT) {
                internal_error(state, 0, "walk_struct_fields only works on structures");
        }
        tptr = type->left;
        for(i = 0; i < type->elements; i++) {
                struct type *mtype;
                mtype = tptr;
                if ((mtype->type & TYPE_MASK) == TYPE_PRODUCT) {
                        mtype = mtype->left;
                }
                walk_type_fields(state, mtype,
                        reg_offset +
                        field_reg_offset(state, type, mtype->field_ident),
                        mem_offset +
                        field_offset(state, type, mtype->field_ident),
                        cb, arg);
                tptr = tptr->right;
        }

}

static void walk_type_fields(struct compile_state *state,
        struct type *type, size_t reg_offset, size_t mem_offset,
        walk_type_fields_cb_t cb, void *arg)
{
        switch(type->type & TYPE_MASK) {
        case TYPE_STRUCT:
                walk_struct_fields(state, type, reg_offset, mem_offset, cb, arg);
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
        case TYPE_SHORT:
        case TYPE_USHORT:
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_LONG:
        case TYPE_ULONG:
                cb(state, type, reg_offset, mem_offset, arg);
                break;
        case TYPE_VOID:
                break;
        default:
                internal_error(state, 0, "walk_type_fields not yet implemented for type");
        }
}

static void arrays_complete(struct compile_state *state, struct type *type)
{
        if ((type->type & TYPE_MASK) == TYPE_ARRAY) {
                if (type->elements == ELEMENT_COUNT_UNSPECIFIED) {
                        error(state, 0, "array size not specified");
                }
                arrays_complete(state, type->left);
        }
}

static unsigned int get_basic_type(struct type *type)
{
        unsigned int basic;
        basic = type->type & TYPE_MASK;
        /* Convert enums to ints */
        if (basic == TYPE_ENUM) {
                basic = TYPE_INT;
        }
        /* Convert bitfields to standard types */
        else if (basic == TYPE_BITFIELD) {
                if (type->elements <= SIZEOF_CHAR) {
                        basic = TYPE_CHAR;
                }
                else if (type->elements <= SIZEOF_SHORT) {
                        basic = TYPE_SHORT;
                }
                else if (type->elements <= SIZEOF_INT) {
                        basic = TYPE_INT;
                }
                else if (type->elements <= SIZEOF_LONG) {
                        basic = TYPE_LONG;
                }
                if (!TYPE_SIGNED(type->left->type)) {
                        basic += 1;
                }
        }
        return basic;
}

static unsigned int do_integral_promotion(unsigned int type)
{
        if (TYPE_INTEGER(type) && (TYPE_RANK(type) < TYPE_RANK(TYPE_INT))) {
                type = TYPE_INT;
        }
        return type;
}

static unsigned int do_arithmetic_conversion(
        unsigned int left, unsigned int right)
{
        if ((left == TYPE_LDOUBLE) || (right == TYPE_LDOUBLE)) {
                return TYPE_LDOUBLE;
        }
        else if ((left == TYPE_DOUBLE) || (right == TYPE_DOUBLE)) {
                return TYPE_DOUBLE;
        }
        else if ((left == TYPE_FLOAT) || (right == TYPE_FLOAT)) {
                return TYPE_FLOAT;
        }
        left = do_integral_promotion(left);
        right = do_integral_promotion(right);
        /* If both operands have the same size done */
        if (left == right) {
                return left;
        }
        /* If both operands have the same signedness pick the larger */
        else if (!!TYPE_UNSIGNED(left) == !!TYPE_UNSIGNED(right)) {
                return (TYPE_RANK(left) >= TYPE_RANK(right)) ? left : right;
        }
        /* If the signed type can hold everything use it */
        else if (TYPE_SIGNED(left) && (TYPE_RANK(left) > TYPE_RANK(right))) {
                return left;
        }
        else if (TYPE_SIGNED(right) && (TYPE_RANK(right) > TYPE_RANK(left))) {
                return right;
        }
        /* Convert to the unsigned type with the same rank as the signed type */
        else if (TYPE_SIGNED(left)) {
                return TYPE_MKUNSIGNED(left);
        }
        else {
                return TYPE_MKUNSIGNED(right);
        }
}

/* see if two types are the same except for qualifiers */
static int equiv_types(struct type *left, struct type *right)
{
        unsigned int type;
        /* Error if the basic types do not match */
        if ((left->type & TYPE_MASK) != (right->type & TYPE_MASK)) {
                return 0;
        }
        type = left->type & TYPE_MASK;
        /* If the basic types match and it is a void type we are done */
        if (type == TYPE_VOID) {
                return 1;
        }
        /* For bitfields we need to compare the sizes */
        else if (type == TYPE_BITFIELD) {
                return (left->elements == right->elements) &&
                        (TYPE_SIGNED(left->left->type) == TYPE_SIGNED(right->left->type));
        }
        /* if the basic types match and it is an arithmetic type we are done */
        else if (TYPE_ARITHMETIC(type)) {
                return 1;
        }
        /* If it is a pointer type recurse and keep testing */
        else if (type == TYPE_POINTER) {
                return equiv_types(left->left, right->left);
        }
        else if (type == TYPE_ARRAY) {
                return (left->elements == right->elements) &&
                        equiv_types(left->left, right->left);
        }
        /* test for struct equality */
        else if (type == TYPE_STRUCT) {
                return left->type_ident == right->type_ident;
        }
        /* test for union equality */
        else if (type == TYPE_UNION) {
                return left->type_ident == right->type_ident;
        }
        /* Test for equivalent functions */
        else if (type == TYPE_FUNCTION) {
                return equiv_types(left->left, right->left) &&
                        equiv_types(left->right, right->right);
        }
        /* We only see TYPE_PRODUCT as part of function equivalence matching */
        /* We also see TYPE_PRODUCT as part of of tuple equivalence matchin */
        else if (type == TYPE_PRODUCT) {
                return equiv_types(left->left, right->left) &&
                        equiv_types(left->right, right->right);
        }
        /* We should see TYPE_OVERLAP when comparing joins */
        else if (type == TYPE_OVERLAP) {
                return equiv_types(left->left, right->left) &&
                        equiv_types(left->right, right->right);
        }
        /* Test for equivalence of tuples */
        else if (type == TYPE_TUPLE) {
                return (left->elements == right->elements) &&
                        equiv_types(left->left, right->left);
        }
        /* Test for equivalence of joins */
        else if (type == TYPE_JOIN) {
                return (left->elements == right->elements) &&
                        equiv_types(left->left, right->left);
        }
        else {
                return 0;
        }
}

static int equiv_ptrs(struct type *left, struct type *right)
{
        if (((left->type & TYPE_MASK) != TYPE_POINTER) ||
                ((right->type & TYPE_MASK) != TYPE_POINTER)) {
                return 0;
        }
        return equiv_types(left->left, right->left);
}

static struct type *compatible_types(struct type *left, struct type *right)
{
        struct type *result;
        unsigned int type, qual_type;
        /* Error if the basic types do not match */
        if ((left->type & TYPE_MASK) != (right->type & TYPE_MASK)) {
                return 0;
        }
        type = left->type & TYPE_MASK;
        qual_type = (left->type & ~STOR_MASK) | (right->type & ~STOR_MASK);
        result = 0;
        /* if the basic types match and it is an arithmetic type we are done */
        if (TYPE_ARITHMETIC(type)) {
                result = new_type(qual_type, 0, 0);
        }
        /* If it is a pointer type recurse and keep testing */
        else if (type == TYPE_POINTER) {
                result = compatible_types(left->left, right->left);
                if (result) {
                        result = new_type(qual_type, result, 0);
                }
        }
        /* test for struct equality */
        else if (type == TYPE_STRUCT) {
                if (left->type_ident == right->type_ident) {
                        result = left;
                }
        }
        /* test for union equality */
        else if (type == TYPE_UNION) {
                if (left->type_ident == right->type_ident) {
                        result = left;
                }
        }
        /* Test for equivalent functions */
        else if (type == TYPE_FUNCTION) {
                struct type *lf, *rf;
                lf = compatible_types(left->left, right->left);
                rf = compatible_types(left->right, right->right);
                if (lf && rf) {
                        result = new_type(qual_type, lf, rf);
                }
        }
        /* We only see TYPE_PRODUCT as part of function equivalence matching */
        else if (type == TYPE_PRODUCT) {
                struct type *lf, *rf;
                lf = compatible_types(left->left, right->left);
                rf = compatible_types(left->right, right->right);
                if (lf && rf) {
                        result = new_type(qual_type, lf, rf);
                }
        }
        else {
                /* Nothing else is compatible */
        }
        return result;
}

/* See if left is a equivalent to right or right is a union member of left */
static int is_subset_type(struct type *left, struct type *right)
{
        if (equiv_types(left, right)) {
                return 1;
        }
        if ((left->type & TYPE_MASK) == TYPE_JOIN) {
                struct type *member, *mnext;
                mnext = left->left;
                while(mnext) {
                        member = mnext;
                        mnext = 0;
                        if ((member->type & TYPE_MASK) == TYPE_OVERLAP) {
                                mnext = member->right;
                                member = member->left;
                        }
                        if (is_subset_type( member, right)) {
                                return 1;
                        }
                }
        }
        return 0;
}

static struct type *compatible_ptrs(struct type *left, struct type *right)
{
        struct type *result;
        if (((left->type & TYPE_MASK) != TYPE_POINTER) ||
                ((right->type & TYPE_MASK) != TYPE_POINTER)) {
                return 0;
        }
        result = compatible_types(left->left, right->left);
        if (result) {
                unsigned int qual_type;
                qual_type = (left->type & ~STOR_MASK) | (right->type & ~STOR_MASK);
                result = new_type(qual_type, result, 0);
        }
        return result;

}
static struct triple *integral_promotion(
        struct compile_state *state, struct triple *def)
{
        struct type *type;
        type = def->type;
        /* As all operations are carried out in registers
         * the values are converted on load I just convert
         * logical type of the operand.
         */
        if (TYPE_INTEGER(type->type)) {
                unsigned int int_type;
                int_type = type->type & ~TYPE_MASK;
                int_type |= do_integral_promotion(get_basic_type(type));
                if (int_type != type->type) {
                        if (def->op != OP_LOAD) {
                                def->type = new_type(int_type, 0, 0);
                        }
                        else {
                                def = triple(state, OP_CONVERT,
                                        new_type(int_type, 0, 0), def, 0);
                        }
                }
        }
        return def;
}


static void arithmetic(struct compile_state *state, struct triple *def)
{
        if (!TYPE_ARITHMETIC(def->type->type)) {
                error(state, 0, "arithmetic type expexted");
        }
}

static void ptr_arithmetic(struct compile_state *state, struct triple *def)
{
        if (!TYPE_PTR(def->type->type) && !TYPE_ARITHMETIC(def->type->type)) {
                error(state, def, "pointer or arithmetic type expected");
        }
}

static int is_integral(struct triple *ins)
{
        return TYPE_INTEGER(ins->type->type);
}

static void integral(struct compile_state *state, struct triple *def)
{
        if (!is_integral(def)) {
                error(state, 0, "integral type expected");
        }
}


static void bool(struct compile_state *state, struct triple *def)
{
        if (!TYPE_ARITHMETIC(def->type->type) &&
                ((def->type->type & TYPE_MASK) != TYPE_POINTER)) {
                error(state, 0, "arithmetic or pointer type expected");
        }
}

static int is_signed(struct type *type)
{
        if ((type->type & TYPE_MASK) == TYPE_BITFIELD) {
                type = type->left;
        }
        return !!TYPE_SIGNED(type->type);
}
static int is_compound_type(struct type *type)
{
        int is_compound;
        switch((type->type & TYPE_MASK)) {
        case TYPE_ARRAY:
        case TYPE_STRUCT:
        case TYPE_TUPLE:
        case TYPE_UNION:
        case TYPE_JOIN:
                is_compound = 1;
                break;
        default:
                is_compound = 0;
                break;
        }
        return is_compound;
}

/* Is this value located in a register otherwise it must be in memory */
static int is_in_reg(struct compile_state *state, struct triple *def)
{
        int in_reg;
        if (def->op == OP_ADECL) {
                in_reg = 1;
        }
        else if ((def->op == OP_SDECL) || (def->op == OP_DEREF)) {
                in_reg = 0;
        }
        else if (triple_is_part(state, def)) {
                in_reg = is_in_reg(state, MISC(def, 0));
        }
        else {
                internal_error(state, def, "unknown expr storage location");
                in_reg = -1;
        }
        return in_reg;
}

/* Is this an auto or static variable location? Something that can
 * be assigned to.  Otherwise it must must be a pure value, a temporary.
 */
static int is_lvalue(struct compile_state *state, struct triple *def)
{
        int ret;
        ret = 0;
        if (!def) {
                return 0;
        }
        if ((def->op == OP_ADECL) ||
                (def->op == OP_SDECL) ||
                (def->op == OP_DEREF) ||
                (def->op == OP_BLOBCONST) ||
                (def->op == OP_LIST)) {
                ret = 1;
        }
        else if (triple_is_part(state, def)) {
                ret = is_lvalue(state, MISC(def, 0));
        }
        return ret;
}

static void clvalue(struct compile_state *state, struct triple *def)
{
        if (!def) {
                internal_error(state, def, "nothing where lvalue expected?");
        }
        if (!is_lvalue(state, def)) {
                error(state, def, "lvalue expected");
        }
}
static void lvalue(struct compile_state *state, struct triple *def)
{
        clvalue(state, def);
        if (def->type->type & QUAL_CONST) {
                error(state, def, "modifable lvalue expected");
        }
}

static int is_pointer(struct triple *def)
{
        return (def->type->type & TYPE_MASK) == TYPE_POINTER;
}

static void pointer(struct compile_state *state, struct triple *def)
{
        if (!is_pointer(def)) {
                error(state, def, "pointer expected");
        }
}

static struct triple *int_const(
        struct compile_state *state, struct type *type, ulong_t value)
{
        struct triple *result;
        switch(type->type & TYPE_MASK) {
        case TYPE_CHAR:
        case TYPE_INT:   case TYPE_UINT:
        case TYPE_LONG:  case TYPE_ULONG:
                break;
        default:
                internal_error(state, 0, "constant for unknown type");
        }
        result = triple(state, OP_INTCONST, type, 0, 0);
        result->u.cval = value;
        return result;
}


static struct triple *read_expr(struct compile_state *state, struct triple *def);

static struct triple *do_mk_addr_expr(struct compile_state *state,
        struct triple *expr, struct type *type, ulong_t offset)
{
        struct triple *result;
        clvalue(state, expr);


        result = 0;
        if (expr->op == OP_ADECL) {
                error(state, expr, "address of auto variables not supported");
        }
        else if (expr->op == OP_SDECL) {
                struct type *ptr_type;
                ptr_type = new_type(TYPE_POINTER | (type->type & QUAL_MASK), type, 0);

                result = triple(state, OP_ADDRCONST, ptr_type, 0, 0);
                MISC(result, 0) = expr;
                result->u.cval = offset;
        }
        else if (expr->op == OP_DEREF) {
                struct type *ptr_type;
                ptr_type = new_type(TYPE_POINTER | (type->type & QUAL_MASK), type, 0);

                result = triple(state, OP_ADD, ptr_type,
                        RHS(expr, 0),
                        int_const(state, &ulong_type, offset));
        }
        else if (expr->op == OP_BLOBCONST) {
                FINISHME();
                internal_error(state, expr, "not yet implemented");
        }
        else if (expr->op == OP_LIST) {
                error(state, 0, "Function addresses not supported");
        }
        else if (triple_is_part(state, expr)) {
                struct triple *part;
                part = expr;
                expr = MISC(expr, 0);
                if (part->op == OP_DOT) {
                        offset += bits_to_bytes(
                                field_offset(state, expr->type, part->u.field));
                }
                else if (part->op == OP_INDEX) {
                        offset += bits_to_bytes(
                                index_offset(state, expr->type, part->u.cval));
                }
                else {
                        internal_error(state, part, "unhandled part type");
                }
                result = do_mk_addr_expr(state, expr, type, offset);
        }
        if (!result) {
                internal_error(state, expr, "cannot take address of expression");
        }
        return result;
}

static struct triple *mk_addr_expr(
        struct compile_state *state, struct triple *expr, ulong_t offset)
{
        return do_mk_addr_expr(state, expr, expr->type, offset);
}

static struct triple *mk_deref_expr(
        struct compile_state *state, struct triple *expr)
{
        struct type *base_type;
        pointer(state, expr);
        base_type = expr->type->left;
        return triple(state, OP_DEREF, base_type, expr, 0);
}

/* lvalue conversions always apply except when certain operators
 * are applied.  So I apply apply it when I know no more
 * operators will be applied.
 */
static struct triple *lvalue_conversion(struct compile_state *state, struct triple *def)
{
        /* Tranform an array to a pointer to the first element */
        if ((def->type->type & TYPE_MASK) == TYPE_ARRAY) {
                struct type *type;
                type = new_type(
                        TYPE_POINTER | (def->type->type & QUAL_MASK),
                        def->type->left, 0);
                if ((def->op == OP_SDECL) || IS_CONST_OP(def->op)) {
                        struct triple *addrconst;
                        if ((def->op != OP_SDECL) && (def->op != OP_BLOBCONST)) {
                                internal_error(state, def, "bad array constant");
                        }
                        addrconst = triple(state, OP_ADDRCONST, type, 0, 0);
                        MISC(addrconst, 0) = def;
                        def = addrconst;
                }
                else {
                        def = triple(state, OP_CONVERT, type, def, 0);
                }
        }
        /* Transform a function to a pointer to it */
        else if ((def->type->type & TYPE_MASK) == TYPE_FUNCTION) {
                def = mk_addr_expr(state, def, 0);
        }
        return def;
}

static struct triple *deref_field(
        struct compile_state *state, struct triple *expr, struct hash_entry *field)
{
        struct triple *result;
        struct type *type, *member;
        ulong_t offset;
        if (!field) {
                internal_error(state, 0, "No field passed to deref_field");
        }
        result = 0;
        type = expr->type;
        if (((type->type & TYPE_MASK) != TYPE_STRUCT) &&
                ((type->type & TYPE_MASK) != TYPE_UNION)) {
                error(state, 0, "request for member %s in something not a struct or union",
                        field->name);
        }
        member = field_type(state, type, field);
        if ((type->type & STOR_MASK) == STOR_PERM) {
                /* Do the pointer arithmetic to get a deref the field */
                offset = bits_to_bytes(field_offset(state, type, field));
                result = do_mk_addr_expr(state, expr, member, offset);
                result = mk_deref_expr(state, result);
        }
        else {
                /* Find the variable for the field I want. */
                result = triple(state, OP_DOT, member, expr, 0);
                result->u.field = field;
        }
        return result;
}

static struct triple *deref_index(
        struct compile_state *state, struct triple *expr, size_t index)
{
        struct triple *result;
        struct type *type, *member;
        ulong_t offset;

        result = 0;
        type = expr->type;
        member = index_type(state, type, index);

        if ((type->type & STOR_MASK) == STOR_PERM) {
                offset = bits_to_bytes(index_offset(state, type, index));
                result = do_mk_addr_expr(state, expr, member, offset);
                result = mk_deref_expr(state, result);
        }
        else {
                result = triple(state, OP_INDEX, member, expr, 0);
                result->u.cval = index;
        }
        return result;
}

static struct triple *read_expr(struct compile_state *state, struct triple *def)
{
        int op;
        if  (!def) {
                return 0;
        }
#if DEBUG_ROMCC_WARNINGS
#warning "CHECK_ME is this the only place I need to do lvalue conversions?"
#endif
        /* Transform lvalues into something we can read */
        def = lvalue_conversion(state, def);
        if (!is_lvalue(state, def)) {
                return def;
        }
        if (is_in_reg(state, def)) {
                op = OP_READ;
        } else {
                if (def->op == OP_SDECL) {
                        def = mk_addr_expr(state, def, 0);
                        def = mk_deref_expr(state, def);
                }
                op = OP_LOAD;
        }
        def = triple(state, op, def->type, def, 0);
        if (def->type->type & QUAL_VOLATILE) {
                def->id |= TRIPLE_FLAG_VOLATILE;
        }
        return def;
}

int is_write_compatible(struct compile_state *state,
        struct type *dest, struct type *rval)
{
        int compatible = 0;
        /* Both operands have arithmetic type */
        if (TYPE_ARITHMETIC(dest->type) && TYPE_ARITHMETIC(rval->type)) {
                compatible = 1;
        }
        /* One operand is a pointer and the other is a pointer to void */
        else if (((dest->type & TYPE_MASK) == TYPE_POINTER) &&
                ((rval->type & TYPE_MASK) == TYPE_POINTER) &&
                (((dest->left->type & TYPE_MASK) == TYPE_VOID) ||
                        ((rval->left->type & TYPE_MASK) == TYPE_VOID))) {
                compatible = 1;
        }
        /* If both types are the same without qualifiers we are good */
        else if (equiv_ptrs(dest, rval)) {
                compatible = 1;
        }
        /* test for struct/union equality  */
        else if (equiv_types(dest, rval)) {
                compatible = 1;
        }
        return compatible;
}

static void write_compatible(struct compile_state *state,
        struct type *dest, struct type *rval)
{
        if (!is_write_compatible(state, dest, rval)) {
                FILE *fp = state->errout;
                fprintf(fp, "dest: ");
                name_of(fp, dest);
                fprintf(fp,"\nrval: ");
                name_of(fp, rval);
                fprintf(fp, "\n");
                error(state, 0, "Incompatible types in assignment");
        }
}

static int is_init_compatible(struct compile_state *state,
        struct type *dest, struct type *rval)
{
        int compatible = 0;
        if (is_write_compatible(state, dest, rval)) {
                compatible = 1;
        }
        else if (equiv_types(dest, rval)) {
                compatible = 1;
        }
        return compatible;
}

static struct triple *write_expr(
        struct compile_state *state, struct triple *dest, struct triple *rval)
{
        struct triple *def;

        def = 0;
        if (!rval) {
                internal_error(state, 0, "missing rval");
        }

        if (rval->op == OP_LIST) {
                internal_error(state, 0, "expression of type OP_LIST?");
        }
        if (!is_lvalue(state, dest)) {
                internal_error(state, 0, "writing to a non lvalue?");
        }
        if (dest->type->type & QUAL_CONST) {
                internal_error(state, 0, "modifable lvalue expexted");
        }

        write_compatible(state, dest->type, rval->type);
        if (!equiv_types(dest->type, rval->type)) {
                rval = triple(state, OP_CONVERT, dest->type, rval, 0);
        }

        /* Now figure out which assignment operator to use */
        if (is_in_reg(state, dest)) {
                def = triple(state, OP_WRITE, dest->type, rval, dest);
                if (MISC(def, 0) != dest) {
                        internal_error(state, def, "huh?");
                }
                if (RHS(def, 0) != rval) {
                        internal_error(state, def, "huh?");
                }
        } else {
                def = triple(state, OP_STORE, dest->type, dest, rval);
        }
        if (def->type->type & QUAL_VOLATILE) {
                def->id |= TRIPLE_FLAG_VOLATILE;
        }
        return def;
}

static struct triple *init_expr(
        struct compile_state *state, struct triple *dest, struct triple *rval)
{
        struct triple *def;

        def = 0;
        if (!rval) {
                internal_error(state, 0, "missing rval");
        }
        if ((dest->type->type & STOR_MASK) != STOR_PERM) {
                rval = read_expr(state, rval);
                def = write_expr(state, dest, rval);
        }
        else {
                /* Fill in the array size if necessary */
                if (((dest->type->type & TYPE_MASK) == TYPE_ARRAY) &&
                        ((rval->type->type & TYPE_MASK) == TYPE_ARRAY)) {
                        if (dest->type->elements == ELEMENT_COUNT_UNSPECIFIED) {
                                dest->type->elements = rval->type->elements;
                        }
                }
                if (!equiv_types(dest->type, rval->type)) {
                        error(state, 0, "Incompatible types in inializer");
                }
                MISC(dest, 0) = rval;
                insert_triple(state, dest, rval);
                rval->id |= TRIPLE_FLAG_FLATTENED;
                use_triple(MISC(dest, 0), dest);
        }
        return def;
}

struct type *arithmetic_result(
        struct compile_state *state, struct triple *left, struct triple *right)
{
        struct type *type;
        /* Sanity checks to ensure I am working with arithmetic types */
        arithmetic(state, left);
        arithmetic(state, right);
        type = new_type(
                do_arithmetic_conversion(
                        get_basic_type(left->type),
                        get_basic_type(right->type)),
                0, 0);
        return type;
}

struct type *ptr_arithmetic_result(
        struct compile_state *state, struct triple *left, struct triple *right)
{
        struct type *type;
        /* Sanity checks to ensure I am working with the proper types */
        ptr_arithmetic(state, left);
        arithmetic(state, right);
        if (TYPE_ARITHMETIC(left->type->type) &&
                TYPE_ARITHMETIC(right->type->type)) {
                type = arithmetic_result(state, left, right);
        }
        else if (TYPE_PTR(left->type->type)) {
                type = left->type;
        }
        else {
                internal_error(state, 0, "huh?");
                type = 0;
        }
        return type;
}

/* boolean helper function */

static struct triple *ltrue_expr(struct compile_state *state,
        struct triple *expr)
{
        switch(expr->op) {
        case OP_LTRUE:   case OP_LFALSE:  case OP_EQ:      case OP_NOTEQ:
        case OP_SLESS:   case OP_ULESS:   case OP_SMORE:   case OP_UMORE:
        case OP_SLESSEQ: case OP_ULESSEQ: case OP_SMOREEQ: case OP_UMOREEQ:
                /* If the expression is already boolean do nothing */
                break;
        default:
                expr = triple(state, OP_LTRUE, &int_type, expr, 0);
                break;
        }
        return expr;
}

static struct triple *lfalse_expr(struct compile_state *state,
        struct triple *expr)
{
        return triple(state, OP_LFALSE, &int_type, expr, 0);
}

static struct triple *mkland_expr(
        struct compile_state *state,
        struct triple *left, struct triple *right)
{
        struct triple *def, *val, *var, *jmp, *mid, *end;
        struct triple *lstore, *rstore;

        /* Generate some intermediate triples */
        end = label(state);
        var = variable(state, &int_type);

        /* Store the left hand side value */
        lstore = write_expr(state, var, left);

        /* Jump if the value is false */
        jmp =  branch(state, end,
                lfalse_expr(state, read_expr(state, var)));
        mid = label(state);

        /* Store the right hand side value */
        rstore = write_expr(state, var, right);

        /* An expression for the computed value */
        val = read_expr(state, var);

        /* Generate the prog for a logical and */
        def = mkprog(state, var, lstore, jmp, mid, rstore, end, val, 0UL);

        return def;
}

static struct triple *mklor_expr(
        struct compile_state *state,
        struct triple *left, struct triple *right)
{
        struct triple *def, *val, *var, *jmp, *mid, *end;

        /* Generate some intermediate triples */
        end = label(state);
        var = variable(state, &int_type);

        /* Store the left hand side value */
        left = write_expr(state, var, left);

        /* Jump if the value is true */
        jmp = branch(state, end, read_expr(state, var));
        mid = label(state);

        /* Store the right hand side value */
        right = write_expr(state, var, right);

        /* An expression for the computed value*/
        val = read_expr(state, var);

        /* Generate the prog for a logical or */
        def = mkprog(state, var, left, jmp, mid, right, end, val, 0UL);

        return def;
}

static struct triple *mkcond_expr(
        struct compile_state *state,
        struct triple *test, struct triple *left, struct triple *right)
{
        struct triple *def, *val, *var, *jmp1, *jmp2, *top, *mid, *end;
        struct type *result_type;
        unsigned int left_type, right_type;
        bool(state, test);
        left_type = left->type->type;
        right_type = right->type->type;
        result_type = 0;
        /* Both operands have arithmetic type */
        if (TYPE_ARITHMETIC(left_type) && TYPE_ARITHMETIC(right_type)) {
                result_type = arithmetic_result(state, left, right);
        }
        /* Both operands have void type */
        else if (((left_type & TYPE_MASK) == TYPE_VOID) &&
                ((right_type & TYPE_MASK) == TYPE_VOID)) {
                result_type = &void_type;
        }
        /* pointers to the same type... */
        else if ((result_type = compatible_ptrs(left->type, right->type))) {
                ;
        }
        /* Both operands are pointers and left is a pointer to void */
        else if (((left_type & TYPE_MASK) == TYPE_POINTER) &&
                ((right_type & TYPE_MASK) == TYPE_POINTER) &&
                ((left->type->left->type & TYPE_MASK) == TYPE_VOID)) {
                result_type = right->type;
        }
        /* Both operands are pointers and right is a pointer to void */
        else if (((left_type & TYPE_MASK) == TYPE_POINTER) &&
                ((right_type & TYPE_MASK) == TYPE_POINTER) &&
                ((right->type->left->type & TYPE_MASK) == TYPE_VOID)) {
                result_type = left->type;
        }
        if (!result_type) {
                error(state, 0, "Incompatible types in conditional expression");
        }
        /* Generate some intermediate triples */
        mid = label(state);
        end = label(state);
        var = variable(state, result_type);

        /* Branch if the test is false */
        jmp1 = branch(state, mid, lfalse_expr(state, read_expr(state, test)));
        top = label(state);

        /* Store the left hand side value */
        left = write_expr(state, var, left);

        /* Branch to the end */
        jmp2 = branch(state, end, 0);

        /* Store the right hand side value */
        right = write_expr(state, var, right);

        /* An expression for the computed value */
        val = read_expr(state, var);

        /* Generate the prog for a conditional expression */
        def = mkprog(state, var, jmp1, top, left, jmp2, mid, right, end, val, 0UL);

        return def;
}


static int expr_depth(struct compile_state *state, struct triple *ins)
{
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME move optimal ordering of subexpressions into the optimizer"
#endif
        int count;
        count = 0;
        if (!ins || (ins->id & TRIPLE_FLAG_FLATTENED)) {
                count = 0;
        }
        else if (ins->op == OP_DEREF) {
                count = expr_depth(state, RHS(ins, 0)) - 1;
        }
        else if (ins->op == OP_VAL) {
                count = expr_depth(state, RHS(ins, 0)) - 1;
        }
        else if (ins->op == OP_FCALL) {
                /* Don't figure the depth of a call just guess it is huge */
                count = 1000;
        }
        else {
                struct triple **expr;
                expr = triple_rhs(state, ins, 0);
                for(;expr; expr = triple_rhs(state, ins, expr)) {
                        if (*expr) {
                                int depth;
                                depth = expr_depth(state, *expr);
                                if (depth > count) {
                                        count = depth;
                                }
                        }
                }
        }
        return count + 1;
}

static struct triple *flatten_generic(
        struct compile_state *state, struct triple *first, struct triple *ptr,
        int ignored)
{
        struct rhs_vector {
                int depth;
                struct triple **ins;
        } vector[MAX_RHS];
        int i, rhs, lhs;
        /* Only operations with just a rhs and a lhs should come here */
        rhs = ptr->rhs;
        lhs = ptr->lhs;
        if (TRIPLE_SIZE(ptr) != lhs + rhs + ignored) {
                internal_error(state, ptr, "unexpected args for: %d %s",
                        ptr->op, tops(ptr->op));
        }
        /* Find the depth of the rhs elements */
        for(i = 0; i < rhs; i++) {
                vector[i].ins = &RHS(ptr, i);
                vector[i].depth = expr_depth(state, *vector[i].ins);
        }
        /* Selection sort the rhs */
        for(i = 0; i < rhs; i++) {
                int j, max = i;
                for(j = i + 1; j < rhs; j++ ) {
                        if (vector[j].depth > vector[max].depth) {
                                max = j;
                        }
                }
                if (max != i) {
                        struct rhs_vector tmp;
                        tmp = vector[i];
                        vector[i] = vector[max];
                        vector[max] = tmp;
                }
        }
        /* Now flatten the rhs elements */
        for(i = 0; i < rhs; i++) {
                *vector[i].ins = flatten(state, first, *vector[i].ins);
                use_triple(*vector[i].ins, ptr);
        }
        if (lhs) {
                insert_triple(state, first, ptr);
                ptr->id |= TRIPLE_FLAG_FLATTENED;
                ptr->id &= ~TRIPLE_FLAG_LOCAL;

                /* Now flatten the lhs elements */
                for(i = 0; i < lhs; i++) {
                        struct triple **ins = &LHS(ptr, i);
                        *ins = flatten(state, first, *ins);
                        use_triple(*ins, ptr);
                }
        }
        return ptr;
}

static struct triple *flatten_prog(
        struct compile_state *state, struct triple *first, struct triple *ptr)
{
        struct triple *head, *body, *val;
        head = RHS(ptr, 0);
        RHS(ptr, 0) = 0;
        val  = head->prev;
        body = head->next;
        release_triple(state, head);
        release_triple(state, ptr);
        val->next        = first;
        body->prev       = first->prev;
        body->prev->next = body;
        val->next->prev  = val;

        if (triple_is_cbranch(state, body->prev) ||
                triple_is_call(state, body->prev)) {
                unuse_triple(first, body->prev);
                use_triple(body, body->prev);
        }

        if (!(val->id & TRIPLE_FLAG_FLATTENED)) {
                internal_error(state, val, "val not flattened?");
        }

        return val;
}


static struct triple *flatten_part(
        struct compile_state *state, struct triple *first, struct triple *ptr)
{
        if (!triple_is_part(state, ptr)) {
                internal_error(state, ptr,  "not a part");
        }
        if (ptr->rhs || ptr->lhs || ptr->targ || (ptr->misc != 1)) {
                internal_error(state, ptr, "unexpected args for: %d %s",
                        ptr->op, tops(ptr->op));
        }
        MISC(ptr, 0) = flatten(state, first, MISC(ptr, 0));
        use_triple(MISC(ptr, 0), ptr);
        return flatten_generic(state, first, ptr, 1);
}

static struct triple *flatten(
        struct compile_state *state, struct triple *first, struct triple *ptr)
{
        struct triple *orig_ptr;
        if (!ptr)
                return 0;
        do {
                orig_ptr = ptr;
                /* Only flatten triples once */
                if (ptr->id & TRIPLE_FLAG_FLATTENED) {
                        return ptr;
                }
                switch(ptr->op) {
                case OP_VAL:
                        RHS(ptr, 0) = flatten(state, first, RHS(ptr, 0));
                        return MISC(ptr, 0);
                        break;
                case OP_PROG:
                        ptr = flatten_prog(state, first, ptr);
                        break;
                case OP_FCALL:
                        ptr = flatten_generic(state, first, ptr, 1);
                        insert_triple(state, first, ptr);
                        ptr->id |= TRIPLE_FLAG_FLATTENED;
                        ptr->id &= ~TRIPLE_FLAG_LOCAL;
                        if (ptr->next != ptr) {
                                use_triple(ptr->next, ptr);
                        }
                        break;
                case OP_READ:
                case OP_LOAD:
                        RHS(ptr, 0) = flatten(state, first, RHS(ptr, 0));
                        use_triple(RHS(ptr, 0), ptr);
                        break;
                case OP_WRITE:
                        ptr = flatten_generic(state, first, ptr, 1);
                        MISC(ptr, 0) = flatten(state, first, MISC(ptr, 0));
                        use_triple(MISC(ptr, 0), ptr);
                        break;
                case OP_BRANCH:
                        use_triple(TARG(ptr, 0), ptr);
                        break;
                case OP_CBRANCH:
                        RHS(ptr, 0) = flatten(state, first, RHS(ptr, 0));
                        use_triple(RHS(ptr, 0), ptr);
                        use_triple(TARG(ptr, 0), ptr);
                        insert_triple(state, first, ptr);
                        ptr->id |= TRIPLE_FLAG_FLATTENED;
                        ptr->id &= ~TRIPLE_FLAG_LOCAL;
                        if (ptr->next != ptr) {
                                use_triple(ptr->next, ptr);
                        }
                        break;
                case OP_CALL:
                        MISC(ptr, 0) = flatten(state, first, MISC(ptr, 0));
                        use_triple(MISC(ptr, 0), ptr);
                        use_triple(TARG(ptr, 0), ptr);
                        insert_triple(state, first, ptr);
                        ptr->id |= TRIPLE_FLAG_FLATTENED;
                        ptr->id &= ~TRIPLE_FLAG_LOCAL;
                        if (ptr->next != ptr) {
                                use_triple(ptr->next, ptr);
                        }
                        break;
                case OP_RET:
                        RHS(ptr, 0) = flatten(state, first, RHS(ptr, 0));
                        use_triple(RHS(ptr, 0), ptr);
                        break;
                case OP_BLOBCONST:
                        insert_triple(state, state->global_pool, ptr);
                        ptr->id |= TRIPLE_FLAG_FLATTENED;
                        ptr->id &= ~TRIPLE_FLAG_LOCAL;
                        ptr = triple(state, OP_SDECL, ptr->type, ptr, 0);
                        use_triple(MISC(ptr, 0), ptr);
                        break;
                case OP_DEREF:
                        /* Since OP_DEREF is just a marker delete it when I flatten it */
                        ptr = RHS(ptr, 0);
                        RHS(orig_ptr, 0) = 0;
                        free_triple(state, orig_ptr);
                        break;
                case OP_DOT:
                        if (RHS(ptr, 0)->op == OP_DEREF) {
                                struct triple *base, *left;
                                ulong_t offset;
                                base = MISC(ptr, 0);
                                offset = bits_to_bytes(field_offset(state, base->type, ptr->u.field));
                                left = RHS(base, 0);
                                ptr = triple(state, OP_ADD, left->type,
                                        read_expr(state, left),
                                        int_const(state, &ulong_type, offset));
                                free_triple(state, base);
                        }
                        else {
                                ptr = flatten_part(state, first, ptr);
                        }
                        break;
                case OP_INDEX:
                        if (RHS(ptr, 0)->op == OP_DEREF) {
                                struct triple *base, *left;
                                ulong_t offset;
                                base = MISC(ptr, 0);
                                offset = bits_to_bytes(index_offset(state, base->type, ptr->u.cval));
                                left = RHS(base, 0);
                                ptr = triple(state, OP_ADD, left->type,
                                        read_expr(state, left),
                                        int_const(state, &long_type, offset));
                                free_triple(state, base);
                        }
                        else {
                                ptr = flatten_part(state, first, ptr);
                        }
                        break;
                case OP_PIECE:
                        ptr = flatten_part(state, first, ptr);
                        use_triple(ptr, MISC(ptr, 0));
                        break;
                case OP_ADDRCONST:
                        MISC(ptr, 0) = flatten(state, first, MISC(ptr, 0));
                        use_triple(MISC(ptr, 0), ptr);
                        break;
                case OP_SDECL:
                        first = state->global_pool;
                        MISC(ptr, 0) = flatten(state, first, MISC(ptr, 0));
                        use_triple(MISC(ptr, 0), ptr);
                        insert_triple(state, first, ptr);
                        ptr->id |= TRIPLE_FLAG_FLATTENED;
                        ptr->id &= ~TRIPLE_FLAG_LOCAL;
                        return ptr;
                case OP_ADECL:
                        ptr = flatten_generic(state, first, ptr, 0);
                        break;
                default:
                        /* Flatten the easy cases we don't override */
                        ptr = flatten_generic(state, first, ptr, 0);
                        break;
                }
        } while(ptr && (ptr != orig_ptr));
        if (ptr && !(ptr->id & TRIPLE_FLAG_FLATTENED)) {
                insert_triple(state, first, ptr);
                ptr->id |= TRIPLE_FLAG_FLATTENED;
                ptr->id &= ~TRIPLE_FLAG_LOCAL;
        }
        return ptr;
}

static void release_expr(struct compile_state *state, struct triple *expr)
{
        struct triple *head;
        head = label(state);
        flatten(state, head, expr);
        while(head->next != head) {
                release_triple(state, head->next);
        }
        free_triple(state, head);
}

static int replace_rhs_use(struct compile_state *state,
        struct triple *orig, struct triple *new, struct triple *use)
{
        struct triple **expr;
        int found;
        found = 0;
        expr = triple_rhs(state, use, 0);
        for(;expr; expr = triple_rhs(state, use, expr)) {
                if (*expr == orig) {
                        *expr = new;
                        found = 1;
                }
        }
        if (found) {
                unuse_triple(orig, use);
                use_triple(new, use);
        }
        return found;
}

static int replace_lhs_use(struct compile_state *state,
        struct triple *orig, struct triple *new, struct triple *use)
{
        struct triple **expr;
        int found;
        found = 0;
        expr = triple_lhs(state, use, 0);
        for(;expr; expr = triple_lhs(state, use, expr)) {
                if (*expr == orig) {
                        *expr = new;
                        found = 1;
                }
        }
        if (found) {
                unuse_triple(orig, use);
                use_triple(new, use);
        }
        return found;
}

static int replace_misc_use(struct compile_state *state,
        struct triple *orig, struct triple *new, struct triple *use)
{
        struct triple **expr;
        int found;
        found = 0;
        expr = triple_misc(state, use, 0);
        for(;expr; expr = triple_misc(state, use, expr)) {
                if (*expr == orig) {
                        *expr = new;
                        found = 1;
                }
        }
        if (found) {
                unuse_triple(orig, use);
                use_triple(new, use);
        }
        return found;
}

static int replace_targ_use(struct compile_state *state,
        struct triple *orig, struct triple *new, struct triple *use)
{
        struct triple **expr;
        int found;
        found = 0;
        expr = triple_targ(state, use, 0);
        for(;expr; expr = triple_targ(state, use, expr)) {
                if (*expr == orig) {
                        *expr = new;
                        found = 1;
                }
        }
        if (found) {
                unuse_triple(orig, use);
                use_triple(new, use);
        }
        return found;
}

static void replace_use(struct compile_state *state,
        struct triple *orig, struct triple *new, struct triple *use)
{
        int found;
        found = 0;
        found |= replace_rhs_use(state, orig, new, use);
        found |= replace_lhs_use(state, orig, new, use);
        found |= replace_misc_use(state, orig, new, use);
        found |= replace_targ_use(state, orig, new, use);
        if (!found) {
                internal_error(state, use, "use without use");
        }
}

static void propagate_use(struct compile_state *state,
        struct triple *orig, struct triple *new)
{
        struct triple_set *user, *next;
        for(user = orig->use; user; user = next) {
                /* Careful replace_use modifies the use chain and
                 * removes use.  So we must get a copy of the next
                 * entry early.
                 */
                next = user->next;
                replace_use(state, orig, new, user->member);
        }
        if (orig->use) {
                internal_error(state, orig, "used after propagate_use");
        }
}

/*
 * Code generators
 * ===========================
 */

static struct triple *mk_cast_expr(
        struct compile_state *state, struct type *type, struct triple *expr)
{
        struct triple *def;
        def = read_expr(state, expr);
        def = triple(state, OP_CONVERT, type, def, 0);
        return def;
}

static struct triple *mk_add_expr(
        struct compile_state *state, struct triple *left, struct triple *right)
{
        struct type *result_type;
        /* Put pointer operands on the left */
        if (is_pointer(right)) {
                struct triple *tmp;
                tmp = left;
                left = right;
                right = tmp;
        }
        left  = read_expr(state, left);
        right = read_expr(state, right);
        result_type = ptr_arithmetic_result(state, left, right);
        if (is_pointer(left)) {
                struct type *ptr_math;
                int op;
                if (is_signed(right->type)) {
                        ptr_math = &long_type;
                        op = OP_SMUL;
                } else {
                        ptr_math = &ulong_type;
                        op = OP_UMUL;
                }
                if (!equiv_types(right->type, ptr_math)) {
                        right = mk_cast_expr(state, ptr_math, right);
                }
                right = triple(state, op, ptr_math, right,
                        int_const(state, ptr_math,
                                size_of_in_bytes(state, left->type->left)));
        }
        return triple(state, OP_ADD, result_type, left, right);
}

static struct triple *mk_sub_expr(
        struct compile_state *state, struct triple *left, struct triple *right)
{
        struct type *result_type;
        result_type = ptr_arithmetic_result(state, left, right);
        left  = read_expr(state, left);
        right = read_expr(state, right);
        if (is_pointer(left)) {
                struct type *ptr_math;
                int op;
                if (is_signed(right->type)) {
                        ptr_math = &long_type;
                        op = OP_SMUL;
                } else {
                        ptr_math = &ulong_type;
                        op = OP_UMUL;
                }
                if (!equiv_types(right->type, ptr_math)) {
                        right = mk_cast_expr(state, ptr_math, right);
                }
                right = triple(state, op, ptr_math, right,
                        int_const(state, ptr_math,
                                size_of_in_bytes(state, left->type->left)));
        }
        return triple(state, OP_SUB, result_type, left, right);
}

static struct triple *mk_pre_inc_expr(
        struct compile_state *state, struct triple *def)
{
        struct triple *val;
        lvalue(state, def);
        val = mk_add_expr(state, def, int_const(state, &int_type, 1));
        return triple(state, OP_VAL, def->type,
                write_expr(state, def, val),
                val);
}

static struct triple *mk_pre_dec_expr(
        struct compile_state *state, struct triple *def)
{
        struct triple *val;
        lvalue(state, def);
        val = mk_sub_expr(state, def, int_const(state, &int_type, 1));
        return triple(state, OP_VAL, def->type,
                write_expr(state, def, val),
                val);
}

static struct triple *mk_post_inc_expr(
        struct compile_state *state, struct triple *def)
{
        struct triple *val;
        lvalue(state, def);
        val = read_expr(state, def);
        return triple(state, OP_VAL, def->type,
                write_expr(state, def,
                        mk_add_expr(state, val, int_const(state, &int_type, 1)))
                , val);
}

static struct triple *mk_post_dec_expr(
        struct compile_state *state, struct triple *def)
{
        struct triple *val;
        lvalue(state, def);
        val = read_expr(state, def);
        return triple(state, OP_VAL, def->type,
                write_expr(state, def,
                        mk_sub_expr(state, val, int_const(state, &int_type, 1)))
                , val);
}

static struct triple *mk_subscript_expr(
        struct compile_state *state, struct triple *left, struct triple *right)
{
        left  = read_expr(state, left);
        right = read_expr(state, right);
        if (!is_pointer(left) && !is_pointer(right)) {
                error(state, left, "subscripted value is not a pointer");
        }
        return mk_deref_expr(state, mk_add_expr(state, left, right));
}


/*
 * Compile time evaluation
 * ===========================
 */
static int is_const(struct triple *ins)
{
        return IS_CONST_OP(ins->op);
}

static int is_simple_const(struct triple *ins)
{
        /* Is this a constant that u.cval has the value.
         * Or equivalently is this a constant that read_const
         * works on.
         * So far only OP_INTCONST qualifies.
         */
        return (ins->op == OP_INTCONST);
}

static int constants_equal(struct compile_state *state,
        struct triple *left, struct triple *right)
{
        int equal;
        if ((left->op == OP_UNKNOWNVAL) || (right->op == OP_UNKNOWNVAL)) {
                equal = 0;
        }
        else if (!is_const(left) || !is_const(right)) {
                equal = 0;
        }
        else if (left->op != right->op) {
                equal = 0;
        }
        else if (!equiv_types(left->type, right->type)) {
                equal = 0;
        }
        else {
                equal = 0;
                switch(left->op) {
                case OP_INTCONST:
                        if (left->u.cval == right->u.cval) {
                                equal = 1;
                        }
                        break;
                case OP_BLOBCONST:
                {
                        size_t lsize, rsize, bytes;
                        lsize = size_of(state, left->type);
                        rsize = size_of(state, right->type);
                        if (lsize != rsize) {
                                break;
                        }
                        bytes = bits_to_bytes(lsize);
                        if (memcmp(left->u.blob, right->u.blob, bytes) == 0) {
                                equal = 1;
                        }
                        break;
                }
                case OP_ADDRCONST:
                        if ((MISC(left, 0) == MISC(right, 0)) &&
                                (left->u.cval == right->u.cval)) {
                                equal = 1;
                        }
                        break;
                default:
                        internal_error(state, left, "uknown constant type");
                        break;
                }
        }
        return equal;
}

static int is_zero(struct triple *ins)
{
        return is_simple_const(ins) && (ins->u.cval == 0);
}

static int is_one(struct triple *ins)
{
        return is_simple_const(ins) && (ins->u.cval == 1);
}

#if DEBUG_ROMCC_WARNING
static long_t bit_count(ulong_t value)
{
        int count;
        int i;
        count = 0;
        for(i = (sizeof(ulong_t)*8) -1; i >= 0; i--) {
                ulong_t mask;
                mask = 1;
                mask <<= i;
                if (value & mask) {
                        count++;
                }
        }
        return count;

}
#endif

static long_t bsr(ulong_t value)
{
        int i;
        for(i = (sizeof(ulong_t)*8) -1; i >= 0; i--) {
                ulong_t mask;
                mask = 1;
                mask <<= i;
                if (value & mask) {
                        return i;
                }
        }
        return -1;
}

static long_t bsf(ulong_t value)
{
        int i;
        for(i = 0; i < (sizeof(ulong_t)*8); i++) {
                ulong_t mask;
                mask = 1;
                mask <<= 1;
                if (value & mask) {
                        return i;
                }
        }
        return -1;
}

static long_t ilog2(ulong_t value)
{
        return bsr(value);
}

static long_t tlog2(struct triple *ins)
{
        return ilog2(ins->u.cval);
}

static int is_pow2(struct triple *ins)
{
        ulong_t value, mask;
        long_t log;
        if (!is_const(ins)) {
                return 0;
        }
        value = ins->u.cval;
        log = ilog2(value);
        if (log == -1) {
                return 0;
        }
        mask = 1;
        mask <<= log;
        return  ((value & mask) == value);
}

static ulong_t read_const(struct compile_state *state,
        struct triple *ins, struct triple *rhs)
{
        switch(rhs->type->type &TYPE_MASK) {
        case TYPE_CHAR:
        case TYPE_SHORT:
        case TYPE_INT:
        case TYPE_LONG:
        case TYPE_UCHAR:
        case TYPE_USHORT:
        case TYPE_UINT:
        case TYPE_ULONG:
        case TYPE_POINTER:
        case TYPE_BITFIELD:
                break;
        default:
                fprintf(state->errout, "type: ");
                name_of(state->errout, rhs->type);
                fprintf(state->errout, "\n");
                internal_warning(state, rhs, "bad type to read_const");
                break;
        }
        if (!is_simple_const(rhs)) {
                internal_error(state, rhs, "bad op to read_const");
        }
        return rhs->u.cval;
}

static long_t read_sconst(struct compile_state *state,
        struct triple *ins, struct triple *rhs)
{
        return (long_t)(rhs->u.cval);
}

int const_ltrue(struct compile_state *state, struct triple *ins, struct triple *rhs)
{
        if (!is_const(rhs)) {
                internal_error(state, 0, "non const passed to const_true");
        }
        return !is_zero(rhs);
}

int const_eq(struct compile_state *state, struct triple *ins,
        struct triple *left, struct triple *right)
{
        int result;
        if (!is_const(left) || !is_const(right)) {
                internal_warning(state, ins, "non const passed to const_eq");
                result = -1;
        }
        else if (left == right) {
                result = 1;
        }
        else if (is_simple_const(left) && is_simple_const(right)) {
                ulong_t lval, rval;
                lval = read_const(state, ins, left);
                rval = read_const(state, ins, right);
                result = (lval == rval);
        }
        else if ((left->op == OP_ADDRCONST) &&
                (right->op == OP_ADDRCONST)) {
                result = (MISC(left, 0) == MISC(right, 0)) &&
                        (left->u.cval == right->u.cval);
        }
        else {
                internal_warning(state, ins, "incomparable constants passed to const_eq");
                result = -1;
        }
        return result;

}

int const_ucmp(struct compile_state *state, struct triple *ins,
        struct triple *left, struct triple *right)
{
        int result;
        if (!is_const(left) || !is_const(right)) {
                internal_warning(state, ins, "non const past to const_ucmp");
                result = -2;
        }
        else if (left == right) {
                result = 0;
        }
        else if (is_simple_const(left) && is_simple_const(right)) {
                ulong_t lval, rval;
                lval = read_const(state, ins, left);
                rval = read_const(state, ins, right);
                result = 0;
                if (lval > rval) {
                        result = 1;
                } else if (rval > lval) {
                        result = -1;
                }
        }
        else if ((left->op == OP_ADDRCONST) &&
                (right->op == OP_ADDRCONST) &&
                (MISC(left, 0) == MISC(right, 0))) {
                result = 0;
                if (left->u.cval > right->u.cval) {
                        result = 1;
                } else if (left->u.cval < right->u.cval) {
                        result = -1;
                }
        }
        else {
                internal_warning(state, ins, "incomparable constants passed to const_ucmp");
                result = -2;
        }
        return result;
}

int const_scmp(struct compile_state *state, struct triple *ins,
        struct triple *left, struct triple *right)
{
        int result;
        if (!is_const(left) || !is_const(right)) {
                internal_warning(state, ins, "non const past to ucmp_const");
                result = -2;
        }
        else if (left == right) {
                result = 0;
        }
        else if (is_simple_const(left) && is_simple_const(right)) {
                long_t lval, rval;
                lval = read_sconst(state, ins, left);
                rval = read_sconst(state, ins, right);
                result = 0;
                if (lval > rval) {
                        result = 1;
                } else if (rval > lval) {
                        result = -1;
                }
        }
        else {
                internal_warning(state, ins, "incomparable constants passed to const_scmp");
                result = -2;
        }
        return result;
}

static void unuse_rhs(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_rhs(state, ins, 0);
        for(;expr;expr = triple_rhs(state, ins, expr)) {
                if (*expr) {
                        unuse_triple(*expr, ins);
                        *expr = 0;
                }
        }
}

static void unuse_lhs(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_lhs(state, ins, 0);
        for(;expr;expr = triple_lhs(state, ins, expr)) {
                unuse_triple(*expr, ins);
                *expr = 0;
        }
}

#if DEBUG_ROMCC_WARNING
static void unuse_misc(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_misc(state, ins, 0);
        for(;expr;expr = triple_misc(state, ins, expr)) {
                unuse_triple(*expr, ins);
                *expr = 0;
        }
}

static void unuse_targ(struct compile_state *state, struct triple *ins)
{
        int i;
        struct triple **slot;
        slot = &TARG(ins, 0);
        for(i = 0; i < ins->targ; i++) {
                unuse_triple(slot[i], ins);
                slot[i] = 0;
        }
}

static void check_lhs(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_lhs(state, ins, 0);
        for(;expr;expr = triple_lhs(state, ins, expr)) {
                internal_error(state, ins, "unexpected lhs");
        }

}
#endif

static void check_misc(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_misc(state, ins, 0);
        for(;expr;expr = triple_misc(state, ins, expr)) {
                if (*expr) {
                        internal_error(state, ins, "unexpected misc");
                }
        }
}

static void check_targ(struct compile_state *state, struct triple *ins)
{
        struct triple **expr;
        expr = triple_targ(state, ins, 0);
        for(;expr;expr = triple_targ(state, ins, expr)) {
                internal_error(state, ins, "unexpected targ");
        }
}

static void wipe_ins(struct compile_state *state, struct triple *ins)
{
        /* Becareful which instructions you replace the wiped
         * instruction with, as there are not enough slots
         * in all instructions to hold all others.
         */
        check_targ(state, ins);
        check_misc(state, ins);
        unuse_rhs(state, ins);
        unuse_lhs(state, ins);
        ins->lhs  = 0;
        ins->rhs  = 0;
        ins->misc = 0;
        ins->targ = 0;
}

#if DEBUG_ROMCC_WARNING
static void wipe_branch(struct compile_state *state, struct triple *ins)
{
        /* Becareful which instructions you replace the wiped
         * instruction with, as there are not enough slots
         * in all instructions to hold all others.
         */
        unuse_rhs(state, ins);
        unuse_lhs(state, ins);
        unuse_misc(state, ins);
        unuse_targ(state, ins);
        ins->lhs  = 0;
        ins->rhs  = 0;
        ins->misc = 0;
        ins->targ = 0;
}
#endif

static void mkcopy(struct compile_state *state,
        struct triple *ins, struct triple *rhs)
{
        struct block *block;
        if (!equiv_types(ins->type, rhs->type)) {
                FILE *fp = state->errout;
                fprintf(fp, "src type: ");
                name_of(fp, rhs->type);
                fprintf(fp, "\ndst type: ");
                name_of(fp, ins->type);
                fprintf(fp, "\n");
                internal_error(state, ins, "mkcopy type mismatch");
        }
        block = block_of_triple(state, ins);
        wipe_ins(state, ins);
        ins->op = OP_COPY;
        ins->rhs  = 1;
        ins->u.block = block;
        RHS(ins, 0) = rhs;
        use_triple(RHS(ins, 0), ins);
}

static void mkconst(struct compile_state *state,
        struct triple *ins, ulong_t value)
{
        if (!is_integral(ins) && !is_pointer(ins)) {
                fprintf(state->errout, "type: ");
                name_of(state->errout, ins->type);
                fprintf(state->errout, "\n");
                internal_error(state, ins, "unknown type to make constant value: %ld",
                        value);
        }
        wipe_ins(state, ins);
        ins->op = OP_INTCONST;
        ins->u.cval = value;
}

static void mkaddr_const(struct compile_state *state,
        struct triple *ins, struct triple *sdecl, ulong_t value)
{
        if ((sdecl->op != OP_SDECL) && (sdecl->op != OP_LABEL)) {
                internal_error(state, ins, "bad base for addrconst");
        }
        wipe_ins(state, ins);
        ins->op = OP_ADDRCONST;
        ins->misc = 1;
        MISC(ins, 0) = sdecl;
        ins->u.cval = value;
        use_triple(sdecl, ins);
}

#if DEBUG_DECOMPOSE_PRINT_TUPLES
static void print_tuple(struct compile_state *state,
        struct triple *ins, struct triple *tuple)
{
        FILE *fp = state->dbgout;
        fprintf(fp, "%5s %p tuple: %p ", tops(ins->op), ins, tuple);
        name_of(fp, tuple->type);
        if (tuple->lhs > 0) {
                fprintf(fp, " lhs: ");
                name_of(fp, LHS(tuple, 0)->type);
        }
        fprintf(fp, "\n");

}
#endif

static struct triple *decompose_with_tuple(struct compile_state *state,
        struct triple *ins, struct triple *tuple)
{
        struct triple *next;
        next = ins->next;
        flatten(state, next, tuple);
#if DEBUG_DECOMPOSE_PRINT_TUPLES
        print_tuple(state, ins, tuple);
#endif

        if (!is_compound_type(tuple->type) && (tuple->lhs > 0)) {
                struct triple *tmp;
                if (tuple->lhs != 1) {
                        internal_error(state, tuple, "plain type in multiple registers?");
                }
                tmp = LHS(tuple, 0);
                release_triple(state, tuple);
                tuple = tmp;
        }

        propagate_use(state, ins, tuple);
        release_triple(state, ins);

        return next;
}

static struct triple *decompose_unknownval(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple;
        ulong_t i;

#if DEBUG_DECOMPOSE_HIRES
        FILE *fp = state->dbgout;
        fprintf(fp, "unknown type: ");
        name_of(fp, ins->type);
        fprintf(fp, "\n");
#endif

        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, ins->type, -1, -1,
                ins->occurrence);

        for(i = 0; i < tuple->lhs; i++) {
                struct type *piece_type;
                struct triple *unknown;

                piece_type = reg_type(state, ins->type, i * REG_SIZEOF_REG);
                get_occurrence(tuple->occurrence);
                unknown = alloc_triple(state, OP_UNKNOWNVAL, piece_type, 0, 0,
                        tuple->occurrence);
                LHS(tuple, i) = unknown;
        }
        return decompose_with_tuple(state, ins, tuple);
}


static struct triple *decompose_read(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple, *lval;
        ulong_t i;

        lval = RHS(ins, 0);

        if (lval->op == OP_PIECE) {
                return ins->next;
        }
        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, lval->type, -1, -1,
                ins->occurrence);

        if ((tuple->lhs != lval->lhs) &&
                (!triple_is_def(state, lval) || (tuple->lhs != 1)))
        {
                internal_error(state, ins, "lhs size inconsistency?");
        }
        for(i = 0; i < tuple->lhs; i++) {
                struct triple *piece, *read, *bitref;
                if ((i != 0) || !triple_is_def(state, lval)) {
                        piece = LHS(lval, i);
                } else {
                        piece = lval;
                }

                /* See if the piece is really a bitref */
                bitref = 0;
                if (piece->op == OP_BITREF) {
                        bitref = piece;
                        piece = RHS(bitref, 0);
                }

                get_occurrence(tuple->occurrence);
                read = alloc_triple(state, OP_READ, piece->type, -1, -1,
                        tuple->occurrence);
                RHS(read, 0) = piece;

                if (bitref) {
                        struct triple *extract;
                        int op;
                        if (is_signed(bitref->type->left)) {
                                op = OP_SEXTRACT;
                        } else {
                                op = OP_UEXTRACT;
                        }
                        get_occurrence(tuple->occurrence);
                        extract = alloc_triple(state, op, bitref->type, -1, -1,
                                tuple->occurrence);
                        RHS(extract, 0) = read;
                        extract->u.bitfield.size   = bitref->u.bitfield.size;
                        extract->u.bitfield.offset = bitref->u.bitfield.offset;

                        read = extract;
                }

                LHS(tuple, i) = read;
        }
        return decompose_with_tuple(state, ins, tuple);
}

static struct triple *decompose_write(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple, *lval, *val;
        ulong_t i;

        lval = MISC(ins, 0);
        val = RHS(ins, 0);
        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, ins->type, -1, -1,
                ins->occurrence);

        if ((tuple->lhs != lval->lhs) &&
                (!triple_is_def(state, lval) || tuple->lhs != 1))
        {
                internal_error(state, ins, "lhs size inconsistency?");
        }
        for(i = 0; i < tuple->lhs; i++) {
                struct triple *piece, *write, *pval, *bitref;
                if ((i != 0) || !triple_is_def(state, lval)) {
                        piece = LHS(lval, i);
                } else {
                        piece = lval;
                }
                if ((i == 0) && (tuple->lhs == 1) && (val->lhs == 0)) {
                        pval = val;
                }
                else {
                        if (i > val->lhs) {
                                internal_error(state, ins, "lhs size inconsistency?");
                        }
                        pval = LHS(val, i);
                }

                /* See if the piece is really a bitref */
                bitref = 0;
                if (piece->op == OP_BITREF) {
                        struct triple *read, *deposit;
                        bitref = piece;
                        piece = RHS(bitref, 0);

                        /* Read the destination register */
                        get_occurrence(tuple->occurrence);
                        read = alloc_triple(state, OP_READ, piece->type, -1, -1,
                                tuple->occurrence);
                        RHS(read, 0) = piece;

                        /* Deposit the new bitfield value */
                        get_occurrence(tuple->occurrence);
                        deposit = alloc_triple(state, OP_DEPOSIT, piece->type, -1, -1,
                                tuple->occurrence);
                        RHS(deposit, 0) = read;
                        RHS(deposit, 1) = pval;
                        deposit->u.bitfield.size   = bitref->u.bitfield.size;
                        deposit->u.bitfield.offset = bitref->u.bitfield.offset;

                        /* Now write the newly generated value */
                        pval = deposit;
                }

                get_occurrence(tuple->occurrence);
                write = alloc_triple(state, OP_WRITE, piece->type, -1, -1,
                        tuple->occurrence);
                MISC(write, 0) = piece;
                RHS(write, 0) = pval;
                LHS(tuple, i) = write;
        }
        return decompose_with_tuple(state, ins, tuple);
}

struct decompose_load_info {
        struct occurrence *occurrence;
        struct triple *lval;
        struct triple *tuple;
};
static void decompose_load_cb(struct compile_state *state,
        struct type *type, size_t reg_offset, size_t mem_offset, void *arg)
{
        struct decompose_load_info *info = arg;
        struct triple *load;

        if (reg_offset > info->tuple->lhs) {
                internal_error(state, info->tuple, "lhs to small?");
        }
        get_occurrence(info->occurrence);
        load = alloc_triple(state, OP_LOAD, type, -1, -1, info->occurrence);
        RHS(load, 0) = mk_addr_expr(state, info->lval, mem_offset);
        LHS(info->tuple, reg_offset/REG_SIZEOF_REG) = load;
}

static struct triple *decompose_load(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple;
        struct decompose_load_info info;

        if (!is_compound_type(ins->type)) {
                return ins->next;
        }
        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, ins->type, -1, -1,
                ins->occurrence);

        info.occurrence = ins->occurrence;
        info.lval      = RHS(ins, 0);
        info.tuple     = tuple;
        walk_type_fields(state, ins->type, 0, 0, decompose_load_cb, &info);

        return decompose_with_tuple(state, ins, tuple);
}


struct decompose_store_info {
        struct occurrence *occurrence;
        struct triple *lval;
        struct triple *val;
        struct triple *tuple;
};
static void decompose_store_cb(struct compile_state *state,
        struct type *type, size_t reg_offset, size_t mem_offset, void *arg)
{
        struct decompose_store_info *info = arg;
        struct triple *store;

        if (reg_offset > info->tuple->lhs) {
                internal_error(state, info->tuple, "lhs to small?");
        }
        get_occurrence(info->occurrence);
        store = alloc_triple(state, OP_STORE, type, -1, -1, info->occurrence);
        RHS(store, 0) = mk_addr_expr(state, info->lval, mem_offset);
        RHS(store, 1) = LHS(info->val, reg_offset);
        LHS(info->tuple, reg_offset/REG_SIZEOF_REG) = store;
}

static struct triple *decompose_store(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple;
        struct decompose_store_info info;

        if (!is_compound_type(ins->type)) {
                return ins->next;
        }
        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, ins->type, -1, -1,
                ins->occurrence);

        info.occurrence = ins->occurrence;
        info.lval      = RHS(ins, 0);
        info.val       = RHS(ins, 1);
        info.tuple     = tuple;
        walk_type_fields(state, ins->type, 0, 0, decompose_store_cb, &info);

        return decompose_with_tuple(state, ins, tuple);
}

static struct triple *decompose_dot(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple, *lval;
        struct type *type;
        size_t reg_offset;
        int i, idx;

        lval = MISC(ins, 0);
        reg_offset = field_reg_offset(state, lval->type, ins->u.field);
        idx  = reg_offset/REG_SIZEOF_REG;
        type = field_type(state, lval->type, ins->u.field);
#if DEBUG_DECOMPOSE_HIRES
        {
                FILE *fp = state->dbgout;
                fprintf(fp, "field type: ");
                name_of(fp, type);
                fprintf(fp, "\n");
        }
#endif

        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, type, -1, -1,
                ins->occurrence);

        if (((ins->type->type & TYPE_MASK) == TYPE_BITFIELD) &&
                (tuple->lhs != 1))
        {
                internal_error(state, ins, "multi register bitfield?");
        }

        for(i = 0; i < tuple->lhs; i++, idx++) {
                struct triple *piece;
                if (!triple_is_def(state, lval)) {
                        if (idx > lval->lhs) {
                                internal_error(state, ins, "inconsistent lhs count");
                        }
                        piece = LHS(lval, idx);
                } else {
                        if (idx != 0) {
                                internal_error(state, ins, "bad reg_offset into def");
                        }
                        if (i != 0) {
                                internal_error(state, ins, "bad reg count from def");
                        }
                        piece = lval;
                }

                /* Remember the offset of the bitfield */
                if ((type->type & TYPE_MASK) == TYPE_BITFIELD) {
                        get_occurrence(ins->occurrence);
                        piece = build_triple(state, OP_BITREF, type, piece, 0,
                                ins->occurrence);
                        piece->u.bitfield.size   = size_of(state, type);
                        piece->u.bitfield.offset = reg_offset % REG_SIZEOF_REG;
                }
                else if ((reg_offset % REG_SIZEOF_REG) != 0) {
                        internal_error(state, ins,
                                "request for a nonbitfield sub register?");
                }

                LHS(tuple, i) = piece;
        }

        return decompose_with_tuple(state, ins, tuple);
}

static struct triple *decompose_index(struct compile_state *state,
        struct triple *ins)
{
        struct triple *tuple, *lval;
        struct type *type;
        int i, idx;

        lval = MISC(ins, 0);
        idx = index_reg_offset(state, lval->type, ins->u.cval)/REG_SIZEOF_REG;
        type = index_type(state, lval->type, ins->u.cval);
#if DEBUG_DECOMPOSE_HIRES
{
        FILE *fp = state->dbgout;
        fprintf(fp, "index type: ");
        name_of(fp, type);
        fprintf(fp, "\n");
}
#endif

        get_occurrence(ins->occurrence);
        tuple = alloc_triple(state, OP_TUPLE, type, -1, -1,
                ins->occurrence);

        for(i = 0; i < tuple->lhs; i++, idx++) {
                struct triple *piece;
                if (!triple_is_def(state, lval)) {
                        if (idx > lval->lhs) {
                                internal_error(state, ins, "inconsistent lhs count");
                        }
                        piece = LHS(lval, idx);
                } else {
                        if (idx != 0) {
                                internal_error(state, ins, "bad reg_offset into def");
                        }
                        if (i != 0) {
                                internal_error(state, ins, "bad reg count from def");
                        }
                        piece = lval;
                }
                LHS(tuple, i) = piece;
        }

        return decompose_with_tuple(state, ins, tuple);
}

static void decompose_compound_types(struct compile_state *state)
{
        struct triple *ins, *next, *first;
        first = state->first;

        /* Pass one expand compound values into pseudo registers.
         */
        next = first;
        do {
                ins = next;
                next = ins->next;
                switch(ins->op) {
                case OP_UNKNOWNVAL:
                        next = decompose_unknownval(state, ins);
                        break;

                case OP_READ:
                        next = decompose_read(state, ins);
                        break;

                case OP_WRITE:
                        next = decompose_write(state, ins);
                        break;


                /* Be very careful with the load/store logic. These
                 * operations must convert from the in register layout
                 * to the in memory layout, which is nontrivial.
                 */
                case OP_LOAD:
                        next = decompose_load(state, ins);
                        break;
                case OP_STORE:
                        next = decompose_store(state, ins);
                        break;

                case OP_DOT:
                        next = decompose_dot(state, ins);
                        break;
                case OP_INDEX:
                        next = decompose_index(state, ins);
                        break;

                }
#if DEBUG_DECOMPOSE_HIRES
                fprintf(fp, "decompose next: %p\n", next);
                fflush(fp);
                fprintf(fp, "next->op: %d %s\n",
                        next->op, tops(next->op));
                /* High resolution debugging mode */
                print_triples(state);
#endif
        } while (next != first);

        /* Pass two remove the tuples.
         */
        ins = first;
        do {
                next = ins->next;
                if (ins->op == OP_TUPLE) {
                        if (ins->use) {
                                internal_error(state, ins, "tuple used");
                        }
                        else {
                                release_triple(state, ins);
                        }
                }
                ins = next;
        } while(ins != first);
        ins = first;
        do {
                next = ins->next;
                if (ins->op == OP_BITREF) {
                        if (ins->use) {
                                internal_error(state, ins, "bitref used");
                        }
                        else {
                                release_triple(state, ins);
                        }
                }
                ins = next;
        } while(ins != first);

        /* Pass three verify the state and set ->id to 0.
         */
        next = first;
        do {
                ins = next;
                next = ins->next;
                ins->id &= ~TRIPLE_FLAG_FLATTENED;
                if (triple_stores_block(state, ins)) {
                        ins->u.block = 0;
                }
                if (triple_is_def(state, ins)) {
                        if (reg_size_of(state, ins->type) > REG_SIZEOF_REG) {
                                internal_error(state, ins, "multi register value remains?");
                        }
                }
                if (ins->op == OP_DOT) {
                        internal_error(state, ins, "OP_DOT remains?");
                }
                if (ins->op == OP_INDEX) {
                        internal_error(state, ins, "OP_INDEX remains?");
                }
                if (ins->op == OP_BITREF) {
                        internal_error(state, ins, "OP_BITREF remains?");
                }
                if (ins->op == OP_TUPLE) {
                        internal_error(state, ins, "OP_TUPLE remains?");
                }
        } while(next != first);
}

/* For those operations that cannot be simplified */
static void simplify_noop(struct compile_state *state, struct triple *ins)
{
        return;
}

static void simplify_smul(struct compile_state *state, struct triple *ins)
{
        if (is_const(RHS(ins, 0)) && !is_const(RHS(ins, 1))) {
                struct triple *tmp;
                tmp = RHS(ins, 0);
                RHS(ins, 0) = RHS(ins, 1);
                RHS(ins, 1) = tmp;
        }
        if (is_const(RHS(ins, 0)) && is_const(RHS(ins, 1))) {
                long_t left, right;
                left  = read_sconst(state, ins, RHS(ins, 0));
                right = read_sconst(state, ins, RHS(ins, 1));
                mkconst(state, ins, left * right);
        }
        else if (is_zero(RHS(ins, 1))) {
                mkconst(state, ins, 0);
        }
        else if (is_one(RHS(ins, 1))) {
                mkcopy(state, ins, RHS(ins, 0));
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, tlog2(RHS(ins, 1)));
                ins->op = OP_SL;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_umul(struct compile_state *state, struct triple *ins)
{
        if (is_const(RHS(ins, 0)) && !is_const(RHS(ins, 1))) {
                struct triple *tmp;
                tmp = RHS(ins, 0);
                RHS(ins, 0) = RHS(ins, 1);
                RHS(ins, 1) = tmp;
        }
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left * right);
        }
        else if (is_zero(RHS(ins, 1))) {
                mkconst(state, ins, 0);
        }
        else if (is_one(RHS(ins, 1))) {
                mkcopy(state, ins, RHS(ins, 0));
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, tlog2(RHS(ins, 1)));
                ins->op = OP_SL;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_sdiv(struct compile_state *state, struct triple *ins)
{
        if (is_const(RHS(ins, 0)) && is_const(RHS(ins, 1))) {
                long_t left, right;
                left  = read_sconst(state, ins, RHS(ins, 0));
                right = read_sconst(state, ins, RHS(ins, 1));
                mkconst(state, ins, left / right);
        }
        else if (is_zero(RHS(ins, 0))) {
                mkconst(state, ins, 0);
        }
        else if (is_zero(RHS(ins, 1))) {
                error(state, ins, "division by zero");
        }
        else if (is_one(RHS(ins, 1))) {
                mkcopy(state, ins, RHS(ins, 0));
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, tlog2(RHS(ins, 1)));
                ins->op = OP_SSR;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_udiv(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left / right);
        }
        else if (is_zero(RHS(ins, 0))) {
                mkconst(state, ins, 0);
        }
        else if (is_zero(RHS(ins, 1))) {
                error(state, ins, "division by zero");
        }
        else if (is_one(RHS(ins, 1))) {
                mkcopy(state, ins, RHS(ins, 0));
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, tlog2(RHS(ins, 1)));
                ins->op = OP_USR;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_smod(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                long_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left % right);
        }
        else if (is_zero(RHS(ins, 0))) {
                mkconst(state, ins, 0);
        }
        else if (is_zero(RHS(ins, 1))) {
                error(state, ins, "division by zero");
        }
        else if (is_one(RHS(ins, 1))) {
                mkconst(state, ins, 0);
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, RHS(ins, 1)->u.cval - 1);
                ins->op = OP_AND;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_umod(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left % right);
        }
        else if (is_zero(RHS(ins, 0))) {
                mkconst(state, ins, 0);
        }
        else if (is_zero(RHS(ins, 1))) {
                error(state, ins, "division by zero");
        }
        else if (is_one(RHS(ins, 1))) {
                mkconst(state, ins, 0);
        }
        else if (is_pow2(RHS(ins, 1))) {
                struct triple *val;
                val = int_const(state, ins->type, RHS(ins, 1)->u.cval - 1);
                ins->op = OP_AND;
                insert_triple(state, state->global_pool, val);
                unuse_triple(RHS(ins, 1), ins);
                use_triple(val, ins);
                RHS(ins, 1) = val;
        }
}

static void simplify_add(struct compile_state *state, struct triple *ins)
{
        /* start with the pointer on the left */
        if (is_pointer(RHS(ins, 1))) {
                struct triple *tmp;
                tmp = RHS(ins, 0);
                RHS(ins, 0) = RHS(ins, 1);
                RHS(ins, 1) = tmp;
        }
        if (is_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                if (RHS(ins, 0)->op == OP_INTCONST) {
                        ulong_t left, right;
                        left  = read_const(state, ins, RHS(ins, 0));
                        right = read_const(state, ins, RHS(ins, 1));
                        mkconst(state, ins, left + right);
                }
                else if (RHS(ins, 0)->op == OP_ADDRCONST) {
                        struct triple *sdecl;
                        ulong_t left, right;
                        sdecl = MISC(RHS(ins, 0), 0);
                        left  = RHS(ins, 0)->u.cval;
                        right = RHS(ins, 1)->u.cval;
                        mkaddr_const(state, ins, sdecl, left + right);
                }
                else {
                        internal_warning(state, ins, "Optimize me!");
                }
        }
        else if (is_const(RHS(ins, 0)) && !is_const(RHS(ins, 1))) {
                struct triple *tmp;
                tmp = RHS(ins, 1);
                RHS(ins, 1) = RHS(ins, 0);
                RHS(ins, 0) = tmp;
        }
}

static void simplify_sub(struct compile_state *state, struct triple *ins)
{
        if (is_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                if (RHS(ins, 0)->op == OP_INTCONST) {
                        ulong_t left, right;
                        left  = read_const(state, ins, RHS(ins, 0));
                        right = read_const(state, ins, RHS(ins, 1));
                        mkconst(state, ins, left - right);
                }
                else if (RHS(ins, 0)->op == OP_ADDRCONST) {
                        struct triple *sdecl;
                        ulong_t left, right;
                        sdecl = MISC(RHS(ins, 0), 0);
                        left  = RHS(ins, 0)->u.cval;
                        right = RHS(ins, 1)->u.cval;
                        mkaddr_const(state, ins, sdecl, left - right);
                }
                else {
                        internal_warning(state, ins, "Optimize me!");
                }
        }
}

static void simplify_sl(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 1))) {
                ulong_t right;
                right = read_const(state, ins, RHS(ins, 1));
                if (right >= (size_of(state, ins->type))) {
                        warning(state, ins, "left shift count >= width of type");
                }
        }
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins,  left << right);
        }
}

static void simplify_usr(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 1))) {
                ulong_t right;
                right = read_const(state, ins, RHS(ins, 1));
                if (right >= (size_of(state, ins->type))) {
                        warning(state, ins, "right shift count >= width of type");
                }
        }
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left >> right);
        }
}

static void simplify_ssr(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 1))) {
                ulong_t right;
                right = read_const(state, ins, RHS(ins, 1));
                if (right >= (size_of(state, ins->type))) {
                        warning(state, ins, "right shift count >= width of type");
                }
        }
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                long_t left, right;
                left  = read_sconst(state, ins, RHS(ins, 0));
                right = read_sconst(state, ins, RHS(ins, 1));
                mkconst(state, ins, left >> right);
        }
}

static void simplify_and(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_simple_const(left) && is_simple_const(right)) {
                ulong_t lval, rval;
                lval = read_const(state, ins, left);
                rval = read_const(state, ins, right);
                mkconst(state, ins, lval & rval);
        }
        else if (is_zero(right) || is_zero(left)) {
                mkconst(state, ins, 0);
        }
}

static void simplify_or(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_simple_const(left) && is_simple_const(right)) {
                ulong_t lval, rval;
                lval = read_const(state, ins, left);
                rval = read_const(state, ins, right);
                mkconst(state, ins, lval | rval);
        }
#if 0 /* I need to handle type mismatches here... */
        else if (is_zero(right)) {
                mkcopy(state, ins, left);
        }
        else if (is_zero(left)) {
                mkcopy(state, ins, right);
        }
#endif
}

static void simplify_xor(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t left, right;
                left  = read_const(state, ins, RHS(ins, 0));
                right = read_const(state, ins, RHS(ins, 1));
                mkconst(state, ins, left ^ right);
        }
}

static void simplify_pos(struct compile_state *state, struct triple *ins)
{
        if (is_const(RHS(ins, 0))) {
                mkconst(state, ins, RHS(ins, 0)->u.cval);
        }
        else {
                mkcopy(state, ins, RHS(ins, 0));
        }
}

static void simplify_neg(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t left;
                left = read_const(state, ins, RHS(ins, 0));
                mkconst(state, ins, -left);
        }
        else if (RHS(ins, 0)->op == OP_NEG) {
                mkcopy(state, ins, RHS(RHS(ins, 0), 0));
        }
}

static void simplify_invert(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t left;
                left = read_const(state, ins, RHS(ins, 0));
                mkconst(state, ins, ~left);
        }
}

static void simplify_eq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_eq(state, ins, left, right);
                if (val >= 0) {
                        mkconst(state, ins, val == 1);
                }
        }
        else if (left == right) {
                mkconst(state, ins, 1);
        }
}

static void simplify_noteq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_eq(state, ins, left, right);
                if (val >= 0) {
                        mkconst(state, ins, val != 1);
                }
        }
        if (left == right) {
                mkconst(state, ins, 0);
        }
}

static void simplify_sless(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_scmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val < 0);
                }
        }
        else if (left == right) {
                mkconst(state, ins, 0);
        }
}

static void simplify_uless(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_ucmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val < 0);
                }
        }
        else if (is_zero(right)) {
                mkconst(state, ins, 0);
        }
        else if (left == right) {
                mkconst(state, ins, 0);
        }
}

static void simplify_smore(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_scmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val > 0);
                }
        }
        else if (left == right) {
                mkconst(state, ins, 0);
        }
}

static void simplify_umore(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_ucmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val > 0);
                }
        }
        else if (is_zero(left)) {
                mkconst(state, ins, 0);
        }
        else if (left == right) {
                mkconst(state, ins, 0);
        }
}


static void simplify_slesseq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_scmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val <= 0);
                }
        }
        else if (left == right) {
                mkconst(state, ins, 1);
        }
}

static void simplify_ulesseq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_ucmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val <= 0);
                }
        }
        else if (is_zero(left)) {
                mkconst(state, ins, 1);
        }
        else if (left == right) {
                mkconst(state, ins, 1);
        }
}

static void simplify_smoreeq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_scmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val >= 0);
                }
        }
        else if (left == right) {
                mkconst(state, ins, 1);
        }
}

static void simplify_umoreeq(struct compile_state *state, struct triple *ins)
{
        struct triple *left, *right;
        left = RHS(ins, 0);
        right = RHS(ins, 1);

        if (is_const(left) && is_const(right)) {
                int val;
                val = const_ucmp(state, ins, left, right);
                if ((val >= -1) && (val <= 1)) {
                        mkconst(state, ins, val >= 0);
                }
        }
        else if (is_zero(right)) {
                mkconst(state, ins, 1);
        }
        else if (left == right) {
                mkconst(state, ins, 1);
        }
}

static void simplify_lfalse(struct compile_state *state, struct triple *ins)
{
        struct triple *rhs;
        rhs = RHS(ins, 0);

        if (is_const(rhs)) {
                mkconst(state, ins, !const_ltrue(state, ins, rhs));
        }
        /* Otherwise if I am the only user... */
        else if ((rhs->use) &&
                (rhs->use->member == ins) && (rhs->use->next == 0)) {
                int need_copy = 1;
                /* Invert a boolean operation */
                switch(rhs->op) {
                case OP_LTRUE:   rhs->op = OP_LFALSE;  break;
                case OP_LFALSE:  rhs->op = OP_LTRUE;   break;
                case OP_EQ:      rhs->op = OP_NOTEQ;   break;
                case OP_NOTEQ:   rhs->op = OP_EQ;      break;
                case OP_SLESS:   rhs->op = OP_SMOREEQ; break;
                case OP_ULESS:   rhs->op = OP_UMOREEQ; break;
                case OP_SMORE:   rhs->op = OP_SLESSEQ; break;
                case OP_UMORE:   rhs->op = OP_ULESSEQ; break;
                case OP_SLESSEQ: rhs->op = OP_SMORE;   break;
                case OP_ULESSEQ: rhs->op = OP_UMORE;   break;
                case OP_SMOREEQ: rhs->op = OP_SLESS;   break;
                case OP_UMOREEQ: rhs->op = OP_ULESS;   break;
                default:
                        need_copy = 0;
                        break;
                }
                if (need_copy) {
                        mkcopy(state, ins, rhs);
                }
        }
}

static void simplify_ltrue (struct compile_state *state, struct triple *ins)
{
        struct triple *rhs;
        rhs = RHS(ins, 0);

        if (is_const(rhs)) {
                mkconst(state, ins, const_ltrue(state, ins, rhs));
        }
        else switch(rhs->op) {
        case OP_LTRUE:   case OP_LFALSE:  case OP_EQ:      case OP_NOTEQ:
        case OP_SLESS:   case OP_ULESS:   case OP_SMORE:   case OP_UMORE:
        case OP_SLESSEQ: case OP_ULESSEQ: case OP_SMOREEQ: case OP_UMOREEQ:
                mkcopy(state, ins, rhs);
        }

}

static void simplify_load(struct compile_state *state, struct triple *ins)
{
        struct triple *addr, *sdecl, *blob;

        /* If I am doing a load with a constant pointer from a constant
         * table get the value.
         */
        addr = RHS(ins, 0);
        if ((addr->op == OP_ADDRCONST) && (sdecl = MISC(addr, 0)) &&
                (sdecl->op == OP_SDECL) && (blob = MISC(sdecl, 0)) &&
                (blob->op == OP_BLOBCONST)) {
                unsigned char buffer[SIZEOF_WORD];
                size_t reg_size, mem_size;
                const char *src, *end;
                ulong_t val;
                reg_size = reg_size_of(state, ins->type);
                if (reg_size > REG_SIZEOF_REG) {
                        internal_error(state, ins, "load size greater than register");
                }
                mem_size = size_of(state, ins->type);
                end = blob->u.blob;
                end += bits_to_bytes(size_of(state, sdecl->type));
                src = blob->u.blob;
                src += addr->u.cval;

                if (src > end) {
                        error(state, ins, "Load address out of bounds");
                }

                memset(buffer, 0, sizeof(buffer));
                memcpy(buffer, src, bits_to_bytes(mem_size));

                switch(mem_size) {
                case SIZEOF_I8:  val = *((uint8_t *) buffer); break;
                case SIZEOF_I16: val = *((uint16_t *)buffer); break;
                case SIZEOF_I32: val = *((uint32_t *)buffer); break;
                case SIZEOF_I64: val = *((uint64_t *)buffer); break;
                default:
                        internal_error(state, ins, "mem_size: %d not handled",
                                mem_size);
                        val = 0;
                        break;
                }
                mkconst(state, ins, val);
        }
}

static void simplify_uextract(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t val;
                ulong_t mask;
                val = read_const(state, ins, RHS(ins, 0));
                mask = 1;
                mask <<= ins->u.bitfield.size;
                mask -= 1;
                val >>= ins->u.bitfield.offset;
                val &= mask;
                mkconst(state, ins, val);
        }
}

static void simplify_sextract(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t val;
                ulong_t mask;
                long_t sval;
                val = read_const(state, ins, RHS(ins, 0));
                mask = 1;
                mask <<= ins->u.bitfield.size;
                mask -= 1;
                val >>= ins->u.bitfield.offset;
                val &= mask;
                val <<= (SIZEOF_LONG - ins->u.bitfield.size);
                sval = val;
                sval >>= (SIZEOF_LONG - ins->u.bitfield.size);
                mkconst(state, ins, sval);
        }
}

static void simplify_deposit(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0)) && is_simple_const(RHS(ins, 1))) {
                ulong_t targ, val;
                ulong_t mask;
                targ = read_const(state, ins, RHS(ins, 0));
                val  = read_const(state, ins, RHS(ins, 1));
                mask = 1;
                mask <<= ins->u.bitfield.size;
                mask -= 1;
                mask <<= ins->u.bitfield.offset;
                targ &= ~mask;
                val <<= ins->u.bitfield.offset;
                val &= mask;
                targ |= val;
                mkconst(state, ins, targ);
        }
}

static void simplify_copy(struct compile_state *state, struct triple *ins)
{
        struct triple *right;
        right = RHS(ins, 0);
        if (is_subset_type(ins->type, right->type)) {
                ins->type = right->type;
        }
        if (equiv_types(ins->type, right->type)) {
                ins->op = OP_COPY;/* I don't need to convert if the types match */
        } else {
                if (ins->op == OP_COPY) {
                        internal_error(state, ins, "type mismatch on copy");
                }
        }
        if (is_const(right) && (right->op == OP_ADDRCONST) && is_pointer(ins)) {
                struct triple *sdecl;
                ulong_t offset;
                sdecl  = MISC(right, 0);
                offset = right->u.cval;
                mkaddr_const(state, ins, sdecl, offset);
        }
        else if (is_const(right) && is_write_compatible(state, ins->type, right->type)) {
                switch(right->op) {
                case OP_INTCONST:
                {
                        ulong_t left;
                        left = read_const(state, ins, right);
                        /* Ensure I have not overflowed the destination. */
                        if (size_of(state, right->type) > size_of(state, ins->type)) {
                                ulong_t mask;
                                mask = 1;
                                mask <<= size_of(state, ins->type);
                                mask -= 1;
                                left &= mask;
                        }
                        /* Ensure I am properly sign extended */
                        if (size_of(state, right->type) < size_of(state, ins->type) &&
                                is_signed(right->type)) {
                                uint64_t val;
                                int shift;
                                shift = SIZEOF_LONG - size_of(state, right->type);
                                val = left;
                                val <<= shift;
                                val >>= shift;
                                left = (ulong_t)val;
                        }
                        mkconst(state, ins, left);
                        break;
                }
                default:
                        internal_error(state, ins, "uknown constant");
                        break;
                }
        }
}

static int phi_present(struct block *block)
{
        struct triple *ptr;
        if (!block) {
                return 0;
        }
        ptr = block->first;
        do {
                if (ptr->op == OP_PHI) {
                        return 1;
                }
                ptr = ptr->next;
        } while(ptr != block->last);
        return 0;
}

static int phi_dependency(struct block *block)
{
        /* A block has a phi dependency if a phi function
         * depends on that block to exist, and makes a block
         * that is otherwise useless unsafe to remove.
         */
        if (block) {
                struct block_set *edge;
                for(edge = block->edges; edge; edge = edge->next) {
                        if (phi_present(edge->member)) {
                                return 1;
                        }
                }
        }
        return 0;
}

static struct triple *branch_target(struct compile_state *state, struct triple *ins)
{
        struct triple *targ;
        targ = TARG(ins, 0);
        /* During scc_transform temporary triples are allocated that
         * loop back onto themselves. If I see one don't advance the
         * target.
         */
        while(triple_is_structural(state, targ) &&
                (targ->next != targ) && (targ->next != state->first)) {
                targ = targ->next;
        }
        return targ;
}


static void simplify_branch(struct compile_state *state, struct triple *ins)
{
        int simplified, loops;
        if ((ins->op != OP_BRANCH) && (ins->op != OP_CBRANCH)) {
                internal_error(state, ins, "not branch");
        }
        if (ins->use != 0) {
                internal_error(state, ins, "branch use");
        }
        /* The challenge here with simplify branch is that I need to
         * make modifications to the control flow graph as well
         * as to the branch instruction itself.  That is handled
         * by rebuilding the basic blocks after simplify all is called.
         */

        /* If we have a branch to an unconditional branch update
         * our target.  But watch out for dependencies from phi
         * functions.
         * Also only do this a limited number of times so
         * we don't get into an infinite loop.
         */
        loops = 0;
        do {
                struct triple *targ;
                simplified = 0;
                targ = branch_target(state, ins);
                if ((targ != ins) && (targ->op == OP_BRANCH) &&
                        !phi_dependency(targ->u.block))
                {
                        unuse_triple(TARG(ins, 0), ins);
                        TARG(ins, 0) = TARG(targ, 0);
                        use_triple(TARG(ins, 0), ins);
                        simplified = 1;
                }
        } while(simplified && (++loops < 20));

        /* If we have a conditional branch with a constant condition
         * make it an unconditional branch.
         */
        if ((ins->op == OP_CBRANCH) && is_simple_const(RHS(ins, 0))) {
                struct triple *targ;
                ulong_t value;
                value = read_const(state, ins, RHS(ins, 0));
                unuse_triple(RHS(ins, 0), ins);
                targ = TARG(ins, 0);
                ins->rhs  = 0;
                ins->targ = 1;
                ins->op = OP_BRANCH;
                if (value) {
                        unuse_triple(ins->next, ins);
                        TARG(ins, 0) = targ;
                }
                else {
                        unuse_triple(targ, ins);
                        TARG(ins, 0) = ins->next;
                }
        }

        /* If we have a branch to the next instruction,
         * make it a noop.
         */
        if (TARG(ins, 0) == ins->next) {
                unuse_triple(TARG(ins, 0), ins);
                if (ins->op == OP_CBRANCH) {
                        unuse_triple(RHS(ins, 0), ins);
                        unuse_triple(ins->next, ins);
                }
                ins->lhs = 0;
                ins->rhs = 0;
                ins->misc = 0;
                ins->targ = 0;
                ins->op = OP_NOOP;
                if (ins->use) {
                        internal_error(state, ins, "noop use != 0");
                }
        }
}

static void simplify_label(struct compile_state *state, struct triple *ins)
{
        /* Ignore volatile labels */
        if (!triple_is_pure(state, ins, ins->id)) {
                return;
        }
        if (ins->use == 0) {
                ins->op = OP_NOOP;
        }
        else if (ins->prev->op == OP_LABEL) {
                /* In general it is not safe to merge one label that
                 * imediately follows another.  The problem is that the empty
                 * looking block may have phi functions that depend on it.
                 */
                if (!phi_dependency(ins->prev->u.block)) {
                        struct triple_set *user, *next;
                        ins->op = OP_NOOP;
                        for(user = ins->use; user; user = next) {
                                struct triple *use, **expr;
                                next = user->next;
                                use = user->member;
                                expr = triple_targ(state, use, 0);
                                for(;expr; expr = triple_targ(state, use, expr)) {
                                        if (*expr == ins) {
                                                *expr = ins->prev;
                                                unuse_triple(ins, use);
                                                use_triple(ins->prev, use);
                                        }

                                }
                        }
                        if (ins->use) {
                                internal_error(state, ins, "noop use != 0");
                        }
                }
        }
}

static void simplify_phi(struct compile_state *state, struct triple *ins)
{
        struct triple **slot;
        struct triple *value;
        int zrhs, i;
        ulong_t cvalue;
        slot = &RHS(ins, 0);
        zrhs = ins->rhs;
        if (zrhs == 0) {
                return;
        }
        /* See if all of the rhs members of a phi have the same value */
        if (slot[0] && is_simple_const(slot[0])) {
                cvalue = read_const(state, ins, slot[0]);
                for(i = 1; i < zrhs; i++) {
                        if (    !slot[i] ||
                                !is_simple_const(slot[i]) ||
                                !equiv_types(slot[0]->type, slot[i]->type) ||
                                (cvalue != read_const(state, ins, slot[i]))) {
                                break;
                        }
                }
                if (i == zrhs) {
                        mkconst(state, ins, cvalue);
                        return;
                }
        }

        /* See if all of rhs members of a phi are the same */
        value = slot[0];
        for(i = 1; i < zrhs; i++) {
                if (slot[i] != value) {
                        break;
                }
        }
        if (i == zrhs) {
                /* If the phi has a single value just copy it */
                if (!is_subset_type(ins->type, value->type)) {
                        internal_error(state, ins, "bad input type to phi");
                }
                /* Make the types match */
                if (!equiv_types(ins->type, value->type)) {
                        ins->type = value->type;
                }
                /* Now make the actual copy */
                mkcopy(state, ins, value);
                return;
        }
}


static void simplify_bsf(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t left;
                left = read_const(state, ins, RHS(ins, 0));
                mkconst(state, ins, bsf(left));
        }
}

static void simplify_bsr(struct compile_state *state, struct triple *ins)
{
        if (is_simple_const(RHS(ins, 0))) {
                ulong_t left;
                left = read_const(state, ins, RHS(ins, 0));
                mkconst(state, ins, bsr(left));
        }
}


typedef void (*simplify_t)(struct compile_state *state, struct triple *ins);
static const struct simplify_table {
        simplify_t func;
        unsigned long flag;
} table_simplify[] = {
#define simplify_sdivt    simplify_noop
#define simplify_udivt    simplify_noop
#define simplify_piece    simplify_noop

[OP_SDIVT      ] = { simplify_sdivt,    COMPILER_SIMPLIFY_ARITH },
[OP_UDIVT      ] = { simplify_udivt,    COMPILER_SIMPLIFY_ARITH },
[OP_SMUL       ] = { simplify_smul,     COMPILER_SIMPLIFY_ARITH },
[OP_UMUL       ] = { simplify_umul,     COMPILER_SIMPLIFY_ARITH },
[OP_SDIV       ] = { simplify_sdiv,     COMPILER_SIMPLIFY_ARITH },
[OP_UDIV       ] = { simplify_udiv,     COMPILER_SIMPLIFY_ARITH },
[OP_SMOD       ] = { simplify_smod,     COMPILER_SIMPLIFY_ARITH },
[OP_UMOD       ] = { simplify_umod,     COMPILER_SIMPLIFY_ARITH },
[OP_ADD        ] = { simplify_add,      COMPILER_SIMPLIFY_ARITH },
[OP_SUB        ] = { simplify_sub,      COMPILER_SIMPLIFY_ARITH },
[OP_SL         ] = { simplify_sl,       COMPILER_SIMPLIFY_SHIFT },
[OP_USR        ] = { simplify_usr,      COMPILER_SIMPLIFY_SHIFT },
[OP_SSR        ] = { simplify_ssr,      COMPILER_SIMPLIFY_SHIFT },
[OP_AND        ] = { simplify_and,      COMPILER_SIMPLIFY_BITWISE },
[OP_XOR        ] = { simplify_xor,      COMPILER_SIMPLIFY_BITWISE },
[OP_OR         ] = { simplify_or,       COMPILER_SIMPLIFY_BITWISE },
[OP_POS        ] = { simplify_pos,      COMPILER_SIMPLIFY_ARITH },
[OP_NEG        ] = { simplify_neg,      COMPILER_SIMPLIFY_ARITH },
[OP_INVERT     ] = { simplify_invert,   COMPILER_SIMPLIFY_BITWISE },

[OP_EQ         ] = { simplify_eq,       COMPILER_SIMPLIFY_LOGICAL },
[OP_NOTEQ      ] = { simplify_noteq,    COMPILER_SIMPLIFY_LOGICAL },
[OP_SLESS      ] = { simplify_sless,    COMPILER_SIMPLIFY_LOGICAL },
[OP_ULESS      ] = { simplify_uless,    COMPILER_SIMPLIFY_LOGICAL },
[OP_SMORE      ] = { simplify_smore,    COMPILER_SIMPLIFY_LOGICAL },
[OP_UMORE      ] = { simplify_umore,    COMPILER_SIMPLIFY_LOGICAL },
[OP_SLESSEQ    ] = { simplify_slesseq,  COMPILER_SIMPLIFY_LOGICAL },
[OP_ULESSEQ    ] = { simplify_ulesseq,  COMPILER_SIMPLIFY_LOGICAL },
[OP_SMOREEQ    ] = { simplify_smoreeq,  COMPILER_SIMPLIFY_LOGICAL },
[OP_UMOREEQ    ] = { simplify_umoreeq,  COMPILER_SIMPLIFY_LOGICAL },
[OP_LFALSE     ] = { simplify_lfalse,   COMPILER_SIMPLIFY_LOGICAL },
[OP_LTRUE      ] = { simplify_ltrue,    COMPILER_SIMPLIFY_LOGICAL },

[OP_LOAD       ] = { simplify_load,     COMPILER_SIMPLIFY_OP },
[OP_STORE      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },

[OP_UEXTRACT   ] = { simplify_uextract, COMPILER_SIMPLIFY_BITFIELD },
[OP_SEXTRACT   ] = { simplify_sextract, COMPILER_SIMPLIFY_BITFIELD },
[OP_DEPOSIT    ] = { simplify_deposit,  COMPILER_SIMPLIFY_BITFIELD },

[OP_NOOP       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },

[OP_INTCONST   ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_BLOBCONST  ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_ADDRCONST  ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_UNKNOWNVAL ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },

[OP_WRITE      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_READ       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_COPY       ] = { simplify_copy,     COMPILER_SIMPLIFY_COPY },
[OP_CONVERT    ] = { simplify_copy,     COMPILER_SIMPLIFY_COPY },
[OP_PIECE      ] = { simplify_piece,    COMPILER_SIMPLIFY_OP },
[OP_ASM        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },

[OP_DOT        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_INDEX      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },

[OP_LIST       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_BRANCH     ] = { simplify_branch,   COMPILER_SIMPLIFY_BRANCH },
[OP_CBRANCH    ] = { simplify_branch,   COMPILER_SIMPLIFY_BRANCH },
[OP_CALL       ] = { simplify_noop,     COMPILER_SIMPLIFY_BRANCH },
[OP_RET        ] = { simplify_noop,     COMPILER_SIMPLIFY_BRANCH },
[OP_LABEL      ] = { simplify_label,    COMPILER_SIMPLIFY_LABEL },
[OP_ADECL      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_SDECL      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_PHI        ] = { simplify_phi,      COMPILER_SIMPLIFY_PHI },

[OP_INB        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_INW        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_INL        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_OUTB       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_OUTW       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_OUTL       ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_BSF        ] = { simplify_bsf,      COMPILER_SIMPLIFY_OP },
[OP_BSR        ] = { simplify_bsr,      COMPILER_SIMPLIFY_OP },
[OP_RDMSR      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_WRMSR      ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
[OP_HLT        ] = { simplify_noop,     COMPILER_SIMPLIFY_OP },
};

static inline void debug_simplify(struct compile_state *state,
        simplify_t do_simplify, struct triple *ins)
{
#if DEBUG_SIMPLIFY_HIRES
                if (state->functions_joined && (do_simplify != simplify_noop)) {
                        /* High resolution debugging mode */
                        fprintf(state->dbgout, "simplifing: ");
                        display_triple(state->dbgout, ins);
                }
#endif
                do_simplify(state, ins);
#if DEBUG_SIMPLIFY_HIRES
                if (state->functions_joined && (do_simplify != simplify_noop)) {
                        /* High resolution debugging mode */
                        fprintf(state->dbgout, "simplified: ");
                        display_triple(state->dbgout, ins);
                }
#endif
}
static void simplify(struct compile_state *state, struct triple *ins)
{
        int op;
        simplify_t do_simplify;
        if (ins == &unknown_triple) {
                internal_error(state, ins, "simplifying the unknown triple?");
        }
        do {
                op = ins->op;
                do_simplify = 0;
                if ((op < 0) || (op >= sizeof(table_simplify)/sizeof(table_simplify[0]))) {
                        do_simplify = 0;
                }
                else {
                        do_simplify = table_simplify[op].func;
                }
                if (do_simplify &&
                        !(state->compiler->flags & table_simplify[op].flag)) {
                        do_simplify = simplify_noop;
                }
                if (do_simplify && (ins->id & TRIPLE_FLAG_VOLATILE)) {
                        do_simplify = simplify_noop;
                }

                if (!do_simplify) {
                        internal_error(state, ins, "cannot simplify op: %d %s",
                                op, tops(op));
                        return;
                }
                debug_simplify(state, do_simplify, ins);
        } while(ins->op != op);
}

static void rebuild_ssa_form(struct compile_state *state);

static void simplify_all(struct compile_state *state)
{
        struct triple *ins, *first;
        if (!(state->compiler->flags & COMPILER_SIMPLIFY)) {
                return;
        }
        first = state->first;
        ins = first->prev;
        do {
                simplify(state, ins);
                ins = ins->prev;
        } while(ins != first->prev);
        ins = first;
        do {
                simplify(state, ins);
                ins = ins->next;
        }while(ins != first);
        rebuild_ssa_form(state);

        print_blocks(state, __func__, state->dbgout);
}

/*
 * Builtins....
 * ============================
 */

static void register_builtin_function(struct compile_state *state,
        const char *name, int op, struct type *rtype, ...)
{
        struct type *ftype, *atype, *ctype, *crtype, *param, **next;
        struct triple *def, *result, *work, *first, *retvar, *ret;
        struct hash_entry *ident;
        struct file_state file;
        int parameters;
        int name_len;
        va_list args;
        int i;

        /* Dummy file state to get debug handling right */
        memset(&file, 0, sizeof(file));
        file.basename = "<built-in>";
        file.line = 1;
        file.report_line = 1;
        file.report_name = file.basename;
        file.prev = state->file;
        state->file = &file;
        state->function = name;

        /* Find the Parameter count */
        valid_op(state, op);
        parameters = table_ops[op].rhs;
        if (parameters < 0 ) {
                internal_error(state, 0, "Invalid builtin parameter count");
        }

        /* Find the function type */
        ftype = new_type(TYPE_FUNCTION | STOR_INLINE | STOR_STATIC, rtype, 0);
        ftype->elements = parameters;
        next = &ftype->right;
        va_start(args, rtype);
        for(i = 0; i < parameters; i++) {
                atype = va_arg(args, struct type *);
                if (!*next) {
                        *next = atype;
                } else {
                        *next = new_type(TYPE_PRODUCT, *next, atype);
                        next = &((*next)->right);
                }
        }
        if (!*next) {
                *next = &void_type;
        }
        va_end(args);

        /* Get the initial closure type */
        ctype = new_type(TYPE_JOIN, &void_type, 0);
        ctype->elements = 1;

        /* Get the return type */
        crtype = new_type(TYPE_TUPLE, new_type(TYPE_PRODUCT, ctype, rtype), 0);
        crtype->elements = 2;

        /* Generate the needed triples */
        def = triple(state, OP_LIST, ftype, 0, 0);
        first = label(state);
        RHS(def, 0) = first;
        result = flatten(state, first, variable(state, crtype));
        retvar = flatten(state, first, variable(state, &void_ptr_type));
        ret = triple(state, OP_RET, &void_type, read_expr(state, retvar), 0);

        /* Now string them together */
        param = ftype->right;
        for(i = 0; i < parameters; i++) {
                if ((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                        atype = param->left;
                } else {
                        atype = param;
                }
                flatten(state, first, variable(state, atype));
                param = param->right;
        }
        work = new_triple(state, op, rtype, -1, parameters);
        generate_lhs_pieces(state, work);
        for(i = 0; i < parameters; i++) {
                RHS(work, i) = read_expr(state, farg(state, def, i));
        }
        if ((rtype->type & TYPE_MASK) != TYPE_VOID) {
                work = write_expr(state, deref_index(state, result, 1), work);
        }
        flatten(state, first, work);
        flatten(state, first, label(state));
        flatten(state, first, ret);
        name_len = strlen(name);
        ident = lookup(state, name, name_len);
        ftype->type_ident = ident;
        symbol(state, ident, &ident->sym_ident, def, ftype);

        state->file = file.prev;
        state->function = 0;
        state->main_function = 0;

        if (!state->functions) {
                state->functions = def;
        } else {
                insert_triple(state, state->functions, def);
        }
        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->dbgout;
                fprintf(fp, "\n");
                loc(fp, state, 0);
                fprintf(fp, "\n__________ %s _________\n", __FUNCTION__);
                display_func(state, fp, def);
                fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
        }
}

static struct type *partial_struct(struct compile_state *state,
        const char *field_name, struct type *type, struct type *rest)
{
        struct hash_entry *field_ident;
        struct type *result;
        int field_name_len;

        field_name_len = strlen(field_name);
        field_ident = lookup(state, field_name, field_name_len);

        result = clone_type(0, type);
        result->field_ident = field_ident;

        if (rest) {
                result = new_type(TYPE_PRODUCT, result, rest);
        }
        return result;
}

static struct type *register_builtin_type(struct compile_state *state,
        const char *name, struct type *type)
{
        struct hash_entry *ident;
        int name_len;

        name_len = strlen(name);
        ident = lookup(state, name, name_len);

        if ((type->type & TYPE_MASK) == TYPE_PRODUCT) {
                ulong_t elements = 0;
                struct type *field;
                type = new_type(TYPE_STRUCT, type, 0);
                field = type->left;
                while((field->type & TYPE_MASK) == TYPE_PRODUCT) {
                        elements++;
                        field = field->right;
                }
                elements++;
                symbol(state, ident, &ident->sym_tag, 0, type);
                type->type_ident = ident;
                type->elements = elements;
        }
        symbol(state, ident, &ident->sym_ident, 0, type);
        ident->tok = TOK_TYPE_NAME;
        return type;
}


static void register_builtins(struct compile_state *state)
{
        struct type *div_type, *ldiv_type;
        struct type *udiv_type, *uldiv_type;
        struct type *msr_type;

        div_type = register_builtin_type(state, "__builtin_div_t",
                partial_struct(state, "quot", &int_type,
                partial_struct(state, "rem",  &int_type, 0)));
        ldiv_type = register_builtin_type(state, "__builtin_ldiv_t",
                partial_struct(state, "quot", &long_type,
                partial_struct(state, "rem",  &long_type, 0)));
        udiv_type = register_builtin_type(state, "__builtin_udiv_t",
                partial_struct(state, "quot", &uint_type,
                partial_struct(state, "rem",  &uint_type, 0)));
        uldiv_type = register_builtin_type(state, "__builtin_uldiv_t",
                partial_struct(state, "quot", &ulong_type,
                partial_struct(state, "rem",  &ulong_type, 0)));

        register_builtin_function(state, "__builtin_div",   OP_SDIVT, div_type,
                &int_type, &int_type);
        register_builtin_function(state, "__builtin_ldiv",  OP_SDIVT, ldiv_type,
                &long_type, &long_type);
        register_builtin_function(state, "__builtin_udiv",  OP_UDIVT, udiv_type,
                &uint_type, &uint_type);
        register_builtin_function(state, "__builtin_uldiv", OP_UDIVT, uldiv_type,
                &ulong_type, &ulong_type);

        register_builtin_function(state, "__builtin_inb", OP_INB, &uchar_type,
                &ushort_type);
        register_builtin_function(state, "__builtin_inw", OP_INW, &ushort_type,
                &ushort_type);
        register_builtin_function(state, "__builtin_inl", OP_INL, &uint_type,
                &ushort_type);

        register_builtin_function(state, "__builtin_outb", OP_OUTB, &void_type,
                &uchar_type, &ushort_type);
        register_builtin_function(state, "__builtin_outw", OP_OUTW, &void_type,
                &ushort_type, &ushort_type);
        register_builtin_function(state, "__builtin_outl", OP_OUTL, &void_type,
                &uint_type, &ushort_type);

        register_builtin_function(state, "__builtin_bsf", OP_BSF, &int_type,
                &int_type);
        register_builtin_function(state, "__builtin_bsr", OP_BSR, &int_type,
                &int_type);

        msr_type = register_builtin_type(state, "__builtin_msr_t",
                partial_struct(state, "lo", &ulong_type,
                partial_struct(state, "hi", &ulong_type, 0)));

        register_builtin_function(state, "__builtin_rdmsr", OP_RDMSR, msr_type,
                &ulong_type);
        register_builtin_function(state, "__builtin_wrmsr", OP_WRMSR, &void_type,
                &ulong_type, &ulong_type, &ulong_type);

        register_builtin_function(state, "__builtin_hlt", OP_HLT, &void_type,
                &void_type);
}

static struct type *declarator(
        struct compile_state *state, struct type *type,
        struct hash_entry **ident, int need_ident);
static void decl(struct compile_state *state, struct triple *first);
static struct type *specifier_qualifier_list(struct compile_state *state);
#if DEBUG_ROMCC_WARNING
static int isdecl_specifier(int tok);
#endif
static struct type *decl_specifiers(struct compile_state *state);
static int istype(int tok);
static struct triple *expr(struct compile_state *state);
static struct triple *assignment_expr(struct compile_state *state);
static struct type *type_name(struct compile_state *state);
static void statement(struct compile_state *state, struct triple *first);

static struct triple *call_expr(
        struct compile_state *state, struct triple *func)
{
        struct triple *def;
        struct type *param, *type;
        ulong_t pvals, index;

        if ((func->type->type & TYPE_MASK) != TYPE_FUNCTION) {
                error(state, 0, "Called object is not a function");
        }
        if (func->op != OP_LIST) {
                internal_error(state, 0, "improper function");
        }
        eat(state, TOK_LPAREN);
        /* Find the return type without any specifiers */
        type = clone_type(0, func->type->left);
        /* Count the number of rhs entries for OP_FCALL */
        param = func->type->right;
        pvals = 0;
        while((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                pvals++;
                param = param->right;
        }
        if ((param->type & TYPE_MASK) != TYPE_VOID) {
                pvals++;
        }
        def = new_triple(state, OP_FCALL, type, -1, pvals);
        MISC(def, 0) = func;

        param = func->type->right;
        for(index = 0; index < pvals; index++) {
                struct triple *val;
                struct type *arg_type;
                val = read_expr(state, assignment_expr(state));
                arg_type = param;
                if ((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                        arg_type = param->left;
                }
                write_compatible(state, arg_type, val->type);
                RHS(def, index) = val;
                if (index != (pvals - 1)) {
                        eat(state, TOK_COMMA);
                        param = param->right;
                }
        }
        eat(state, TOK_RPAREN);
        return def;
}


static struct triple *character_constant(struct compile_state *state)
{
        struct triple *def;
        struct token *tk;
        const signed char *str, *end;
        int c;
        int str_len;
        tk = eat(state, TOK_LIT_CHAR);
        str = (signed char *)tk->val.str + 1;
        str_len = tk->str_len - 2;
        if (str_len <= 0) {
                error(state, 0, "empty character constant");
        }
        end = str + str_len;
        c = char_value(state, &str, end);
        if (str != end) {
                error(state, 0, "multibyte character constant not supported");
        }
        def = int_const(state, &char_type, (ulong_t)((long_t)c));
        return def;
}

static struct triple *string_constant(struct compile_state *state)
{
        struct triple *def;
        struct token *tk;
        struct type *type;
        const signed char *str, *end;
        signed char *buf, *ptr;
        int str_len;

        buf = 0;
        type = new_type(TYPE_ARRAY, &char_type, 0);
        type->elements = 0;
        /* The while loop handles string concatenation */
        do {
                tk = eat(state, TOK_LIT_STRING);
                str = (signed char *)tk->val.str + 1;
                str_len = tk->str_len - 2;
                if (str_len < 0) {
                        error(state, 0, "negative string constant length");
                }
                /* ignore empty string tokens */
                if ('"' == *str && 0 == str[1])
                        continue;
                end = str + str_len;
                ptr = buf;
                buf = xmalloc(type->elements + str_len + 1, "string_constant");
                memcpy(buf, ptr, type->elements);
                free(ptr);
                ptr = buf + type->elements;
                do {
                        *ptr++ = char_value(state, &str, end);
                } while(str < end);
                type->elements = ptr - buf;
        } while(peek(state) == TOK_LIT_STRING);

        /* buf contains the allocated buffer for the string constant. However,
           if buf is NULL, then the string constant is empty, but we still
           need to allocate one byte for the null character. */
        if (buf == NULL) {
                buf = xmalloc(1, "string_constant");
                ptr = buf;
        }

        *ptr = '\0';
        type->elements += 1;
        def = triple(state, OP_BLOBCONST, type, 0, 0);
        def->u.blob = buf;

        return def;
}


static struct triple *integer_constant(struct compile_state *state)
{
        struct triple *def;
        unsigned long val;
        struct token *tk;
        char *end;
        int u, l, decimal;
        struct type *type;

        tk = eat(state, TOK_LIT_INT);
        errno = 0;
        decimal = (tk->val.str[0] != '0');
        val = strtoul(tk->val.str, &end, 0);
        if (errno == ERANGE) {
                error(state, 0, "Integer constant out of range");
        }
        u = l = 0;
        if ((*end == 'u') || (*end == 'U')) {
                u = 1;
                        end++;
        }
        if ((*end == 'l') || (*end == 'L')) {
                l = 1;
                end++;
        }
        if ((*end == 'u') || (*end == 'U')) {
                u = 1;
                end++;
        }
        if (*end) {
                error(state, 0, "Junk at end of integer constant");
        }
        if (u && l)  {
                type = &ulong_type;
        }
        else if (l) {
                type = &long_type;
                if (!decimal && (val > LONG_T_MAX)) {
                        type = &ulong_type;
                }
        }
        else if (u) {
                type = &uint_type;
                if (val > UINT_T_MAX) {
                        type = &ulong_type;
                }
        }
        else {
                type = &int_type;
                if (!decimal && (val > INT_T_MAX) && (val <= UINT_T_MAX)) {
                        type = &uint_type;
                }
                else if (!decimal && (val > LONG_T_MAX)) {
                        type = &ulong_type;
                }
                else if (val > INT_T_MAX) {
                        type = &long_type;
                }
        }
        def = int_const(state, type, val);
        return def;
}

static struct triple *primary_expr(struct compile_state *state)
{
        struct triple *def;
        int tok;
        tok = peek(state);
        switch(tok) {
        case TOK_IDENT:
        {
                struct hash_entry *ident;
                /* Here ident is either:
                 * a varable name
                 * a function name
                 */
                ident = eat(state, TOK_IDENT)->ident;
                if (!ident->sym_ident) {
                        error(state, 0, "%s undeclared", ident->name);
                }
                def = ident->sym_ident->def;
                break;
        }
        case TOK_ENUM_CONST:
        {
                struct hash_entry *ident;
                /* Here ident is an enumeration constant */
                ident = eat(state, TOK_ENUM_CONST)->ident;
                if (!ident->sym_ident) {
                        error(state, 0, "%s undeclared", ident->name);
                }
                def = ident->sym_ident->def;
                break;
        }
        case TOK_MIDENT:
        {
                struct hash_entry *ident;
                ident = eat(state, TOK_MIDENT)->ident;
                warning(state, 0, "Replacing undefined macro: %s with 0",
                        ident->name);
                def = int_const(state, &int_type, 0);
                break;
        }
        case TOK_LPAREN:
                eat(state, TOK_LPAREN);
                def = expr(state);
                eat(state, TOK_RPAREN);
                break;
        case TOK_LIT_INT:
                def = integer_constant(state);
                break;
        case TOK_LIT_FLOAT:
                eat(state, TOK_LIT_FLOAT);
                error(state, 0, "Floating point constants not supported");
                def = 0;
                FINISHME();
                break;
        case TOK_LIT_CHAR:
                def = character_constant(state);
                break;
        case TOK_LIT_STRING:
                def = string_constant(state);
                break;
        default:
                def = 0;
                error(state, 0, "Unexpected token: %s\n", tokens[tok]);
        }
        return def;
}

static struct triple *postfix_expr(struct compile_state *state)
{
        struct triple *def;
        int postfix;
        def = primary_expr(state);
        do {
                struct triple *left;
                int tok;
                postfix = 1;
                left = def;
                switch((tok = peek(state))) {
                case TOK_LBRACKET:
                        eat(state, TOK_LBRACKET);
                        def = mk_subscript_expr(state, left, expr(state));
                        eat(state, TOK_RBRACKET);
                        break;
                case TOK_LPAREN:
                        def = call_expr(state, def);
                        break;
                case TOK_DOT:
                {
                        struct hash_entry *field;
                        eat(state, TOK_DOT);
                        field = eat(state, TOK_IDENT)->ident;
                        def = deref_field(state, def, field);
                        break;
                }
                case TOK_ARROW:
                {
                        struct hash_entry *field;
                        eat(state, TOK_ARROW);
                        field = eat(state, TOK_IDENT)->ident;
                        def = mk_deref_expr(state, read_expr(state, def));
                        def = deref_field(state, def, field);
                        break;
                }
                case TOK_PLUSPLUS:
                        eat(state, TOK_PLUSPLUS);
                        def = mk_post_inc_expr(state, left);
                        break;
                case TOK_MINUSMINUS:
                        eat(state, TOK_MINUSMINUS);
                        def = mk_post_dec_expr(state, left);
                        break;
                default:
                        postfix = 0;
                        break;
                }
        } while(postfix);
        return def;
}

static struct triple *cast_expr(struct compile_state *state);

static struct triple *unary_expr(struct compile_state *state)
{
        struct triple *def, *right;
        int tok;
        switch((tok = peek(state))) {
        case TOK_PLUSPLUS:
                eat(state, TOK_PLUSPLUS);
                def = mk_pre_inc_expr(state, unary_expr(state));
                break;
        case TOK_MINUSMINUS:
                eat(state, TOK_MINUSMINUS);
                def = mk_pre_dec_expr(state, unary_expr(state));
                break;
        case TOK_AND:
                eat(state, TOK_AND);
                def = mk_addr_expr(state, cast_expr(state), 0);
                break;
        case TOK_STAR:
                eat(state, TOK_STAR);
                def = mk_deref_expr(state, read_expr(state, cast_expr(state)));
                break;
        case TOK_PLUS:
                eat(state, TOK_PLUS);
                right = read_expr(state, cast_expr(state));
                arithmetic(state, right);
                def = integral_promotion(state, right);
                break;
        case TOK_MINUS:
                eat(state, TOK_MINUS);
                right = read_expr(state, cast_expr(state));
                arithmetic(state, right);
                def = integral_promotion(state, right);
                def = triple(state, OP_NEG, def->type, def, 0);
                break;
        case TOK_TILDE:
                eat(state, TOK_TILDE);
                right = read_expr(state, cast_expr(state));
                integral(state, right);
                def = integral_promotion(state, right);
                def = triple(state, OP_INVERT, def->type, def, 0);
                break;
        case TOK_BANG:
                eat(state, TOK_BANG);
                right = read_expr(state, cast_expr(state));
                bool(state, right);
                def = lfalse_expr(state, right);
                break;
        case TOK_SIZEOF:
        {
                struct type *type;
                int tok1, tok2;
                eat(state, TOK_SIZEOF);
                tok1 = peek(state);
                tok2 = peek2(state);
                if ((tok1 == TOK_LPAREN) && istype(tok2)) {
                        eat(state, TOK_LPAREN);
                        type = type_name(state);
                        eat(state, TOK_RPAREN);
                }
                else {
                        struct triple *expr;
                        expr = unary_expr(state);
                        type = expr->type;
                        release_expr(state, expr);
                }
                def = int_const(state, &ulong_type, size_of_in_bytes(state, type));
                break;
        }
        case TOK_ALIGNOF:
        {
                struct type *type;
                int tok1, tok2;
                eat(state, TOK_ALIGNOF);
                tok1 = peek(state);
                tok2 = peek2(state);
                if ((tok1 == TOK_LPAREN) && istype(tok2)) {
                        eat(state, TOK_LPAREN);
                        type = type_name(state);
                        eat(state, TOK_RPAREN);
                }
                else {
                        struct triple *expr;
                        expr = unary_expr(state);
                        type = expr->type;
                        release_expr(state, expr);
                }
                def = int_const(state, &ulong_type, align_of_in_bytes(state, type));
                break;
        }
        case TOK_MDEFINED:
        {
                /* We only come here if we are called from the preprocessor */
                struct hash_entry *ident;
                int parens;
                eat(state, TOK_MDEFINED);
                parens = 0;
                if (pp_peek(state) == TOK_LPAREN) {
                        pp_eat(state, TOK_LPAREN);
                        parens = 1;
                }
                ident = pp_eat(state, TOK_MIDENT)->ident;
                if (parens) {
                        eat(state, TOK_RPAREN);
                }
                def = int_const(state, &int_type, ident->sym_define != 0);
                break;
        }
        default:
                def = postfix_expr(state);
                break;
        }
        return def;
}

static struct triple *cast_expr(struct compile_state *state)
{
        struct triple *def;
        int tok1, tok2;
        tok1 = peek(state);
        tok2 = peek2(state);
        if ((tok1 == TOK_LPAREN) && istype(tok2)) {
                struct type *type;
                eat(state, TOK_LPAREN);
                type = type_name(state);
                eat(state, TOK_RPAREN);
                def = mk_cast_expr(state, type, cast_expr(state));
        }
        else {
                def = unary_expr(state);
        }
        return def;
}

static struct triple *mult_expr(struct compile_state *state)
{
        struct triple *def;
        int done;
        def = cast_expr(state);
        do {
                struct triple *left, *right;
                struct type *result_type;
                int tok, op, sign;
                done = 0;
                tok = peek(state);
                switch(tok) {
                case TOK_STAR:
                case TOK_DIV:
                case TOK_MOD:
                        left = read_expr(state, def);
                        arithmetic(state, left);

                        eat(state, tok);

                        right = read_expr(state, cast_expr(state));
                        arithmetic(state, right);

                        result_type = arithmetic_result(state, left, right);
                        sign = is_signed(result_type);
                        op = -1;
                        switch(tok) {
                        case TOK_STAR: op = sign? OP_SMUL : OP_UMUL; break;
                        case TOK_DIV:  op = sign? OP_SDIV : OP_UDIV; break;
                        case TOK_MOD:  op = sign? OP_SMOD : OP_UMOD; break;
                        }
                        def = triple(state, op, result_type, left, right);
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return def;
}

static struct triple *add_expr(struct compile_state *state)
{
        struct triple *def;
        int done;
        def = mult_expr(state);
        do {
                done = 0;
                switch( peek(state)) {
                case TOK_PLUS:
                        eat(state, TOK_PLUS);
                        def = mk_add_expr(state, def, mult_expr(state));
                        break;
                case TOK_MINUS:
                        eat(state, TOK_MINUS);
                        def = mk_sub_expr(state, def, mult_expr(state));
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return def;
}

static struct triple *shift_expr(struct compile_state *state)
{
        struct triple *def;
        int done;
        def = add_expr(state);
        do {
                struct triple *left, *right;
                int tok, op;
                done = 0;
                switch((tok = peek(state))) {
                case TOK_SL:
                case TOK_SR:
                        left = read_expr(state, def);
                        integral(state, left);
                        left = integral_promotion(state, left);

                        eat(state, tok);

                        right = read_expr(state, add_expr(state));
                        integral(state, right);
                        right = integral_promotion(state, right);

                        op = (tok == TOK_SL)? OP_SL :
                                is_signed(left->type)? OP_SSR: OP_USR;

                        def = triple(state, op, left->type, left, right);
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return def;
}

static struct triple *relational_expr(struct compile_state *state)
{
#if DEBUG_ROMCC_WARNINGS
#warning "Extend relational exprs to work on more than arithmetic types"
#endif
        struct triple *def;
        int done;
        def = shift_expr(state);
        do {
                struct triple *left, *right;
                struct type *arg_type;
                int tok, op, sign;
                done = 0;
                switch((tok = peek(state))) {
                case TOK_LESS:
                case TOK_MORE:
                case TOK_LESSEQ:
                case TOK_MOREEQ:
                        left = read_expr(state, def);
                        arithmetic(state, left);

                        eat(state, tok);

                        right = read_expr(state, shift_expr(state));
                        arithmetic(state, right);

                        arg_type = arithmetic_result(state, left, right);
                        sign = is_signed(arg_type);
                        xfree(arg_type);
                        op = -1;
                        switch(tok) {
                        case TOK_LESS:   op = sign? OP_SLESS : OP_ULESS; break;
                        case TOK_MORE:   op = sign? OP_SMORE : OP_UMORE; break;
                        case TOK_LESSEQ: op = sign? OP_SLESSEQ : OP_ULESSEQ; break;
                        case TOK_MOREEQ: op = sign? OP_SMOREEQ : OP_UMOREEQ; break;
                        }
                        def = triple(state, op, &int_type, left, right);
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return def;
}

static struct triple *equality_expr(struct compile_state *state)
{
#if DEBUG_ROMCC_WARNINGS
#warning "Extend equality exprs to work on more than arithmetic types"
#endif
        struct triple *def;
        int done;
        def = relational_expr(state);
        do {
                struct triple *left, *right;
                int tok, op;
                done = 0;
                switch((tok = peek(state))) {
                case TOK_EQEQ:
                case TOK_NOTEQ:
                        left = read_expr(state, def);
                        arithmetic(state, left);
                        eat(state, tok);
                        right = read_expr(state, relational_expr(state));
                        arithmetic(state, right);
                        op = (tok == TOK_EQEQ) ? OP_EQ: OP_NOTEQ;
                        def = triple(state, op, &int_type, left, right);
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return def;
}

static struct triple *and_expr(struct compile_state *state)
{
        struct triple *def;
        def = equality_expr(state);
        while(peek(state) == TOK_AND) {
                struct triple *left, *right;
                struct type *result_type;
                left = read_expr(state, def);
                integral(state, left);
                eat(state, TOK_AND);
                right = read_expr(state, equality_expr(state));
                integral(state, right);
                result_type = arithmetic_result(state, left, right);
                def = triple(state, OP_AND, result_type, left, right);
        }
        return def;
}

static struct triple *xor_expr(struct compile_state *state)
{
        struct triple *def;
        def = and_expr(state);
        while(peek(state) == TOK_XOR) {
                struct triple *left, *right;
                struct type *result_type;
                left = read_expr(state, def);
                integral(state, left);
                eat(state, TOK_XOR);
                right = read_expr(state, and_expr(state));
                integral(state, right);
                result_type = arithmetic_result(state, left, right);
                def = triple(state, OP_XOR, result_type, left, right);
        }
        return def;
}

static struct triple *or_expr(struct compile_state *state)
{
        struct triple *def;
        def = xor_expr(state);
        while(peek(state) == TOK_OR) {
                struct triple *left, *right;
                struct type *result_type;
                left = read_expr(state, def);
                integral(state, left);
                eat(state, TOK_OR);
                right = read_expr(state, xor_expr(state));
                integral(state, right);
                result_type = arithmetic_result(state, left, right);
                def = triple(state, OP_OR, result_type, left, right);
        }
        return def;
}

static struct triple *land_expr(struct compile_state *state)
{
        struct triple *def;
        def = or_expr(state);
        while(peek(state) == TOK_LOGAND) {
                struct triple *left, *right;
                left = read_expr(state, def);
                bool(state, left);
                eat(state, TOK_LOGAND);
                right = read_expr(state, or_expr(state));
                bool(state, right);

                def = mkland_expr(state,
                        ltrue_expr(state, left),
                        ltrue_expr(state, right));
        }
        return def;
}

static struct triple *lor_expr(struct compile_state *state)
{
        struct triple *def;
        def = land_expr(state);
        while(peek(state) == TOK_LOGOR) {
                struct triple *left, *right;
                left = read_expr(state, def);
                bool(state, left);
                eat(state, TOK_LOGOR);
                right = read_expr(state, land_expr(state));
                bool(state, right);

                def = mklor_expr(state,
                        ltrue_expr(state, left),
                        ltrue_expr(state, right));
        }
        return def;
}

static struct triple *conditional_expr(struct compile_state *state)
{
        struct triple *def;
        def = lor_expr(state);
        if (peek(state) == TOK_QUEST) {
                struct triple *test, *left, *right;
                bool(state, def);
                test = ltrue_expr(state, read_expr(state, def));
                eat(state, TOK_QUEST);
                left = read_expr(state, expr(state));
                eat(state, TOK_COLON);
                right = read_expr(state, conditional_expr(state));

                def = mkcond_expr(state, test, left, right);
        }
        return def;
}

struct cv_triple {
        struct triple *val;
        int id;
};

static void set_cv(struct compile_state *state, struct cv_triple *cv,
        struct triple *dest, struct triple *val)
{
        if (cv[dest->id].val) {
                free_triple(state, cv[dest->id].val);
        }
        cv[dest->id].val = val;
}
static struct triple *get_cv(struct compile_state *state, struct cv_triple *cv,
        struct triple *src)
{
        return cv[src->id].val;
}

static struct triple *eval_const_expr(
        struct compile_state *state, struct triple *expr)
{
        struct triple *def;
        if (is_const(expr)) {
                def = expr;
        }
        else {
                /* If we don't start out as a constant simplify into one */
                struct triple *head, *ptr;
                struct cv_triple *cv;
                int i, count;
                head = label(state); /* dummy initial triple */
                flatten(state, head, expr);
                count = 1;
                for(ptr = head->next; ptr != head; ptr = ptr->next) {
                        count++;
                }
                cv = xcmalloc(sizeof(struct cv_triple)*count, "const value vector");
                i = 1;
                for(ptr = head->next; ptr != head; ptr = ptr->next) {
                        cv[i].val = 0;
                        cv[i].id  = ptr->id;
                        ptr->id   = i;
                        i++;
                }
                ptr = head->next;
                do {
                        valid_ins(state, ptr);
                        if ((ptr->op == OP_PHI) || (ptr->op == OP_LIST)) {
                                internal_error(state, ptr,
                                        "unexpected %s in constant expression",
                                        tops(ptr->op));
                        }
                        else if (ptr->op == OP_LIST) {
                        }
                        else if (triple_is_structural(state, ptr)) {
                                ptr = ptr->next;
                        }
                        else if (triple_is_ubranch(state, ptr)) {
                                ptr = TARG(ptr, 0);
                        }
                        else if (triple_is_cbranch(state, ptr)) {
                                struct triple *cond_val;
                                cond_val = get_cv(state, cv, RHS(ptr, 0));
                                if (!cond_val || !is_const(cond_val) ||
                                        (cond_val->op != OP_INTCONST))
                                {
                                        internal_error(state, ptr, "bad branch condition");
                                }
                                if (cond_val->u.cval == 0) {
                                        ptr = ptr->next;
                                } else {
                                        ptr = TARG(ptr, 0);
                                }
                        }
                        else if (triple_is_branch(state, ptr)) {
                                error(state, ptr, "bad branch type in constant expression");
                        }
                        else if (ptr->op == OP_WRITE) {
                                struct triple *val;
                                val = get_cv(state, cv, RHS(ptr, 0));

                                set_cv(state, cv, MISC(ptr, 0),
                                        copy_triple(state, val));
                                set_cv(state, cv, ptr,
                                        copy_triple(state, val));
                                ptr = ptr->next;
                        }
                        else if (ptr->op == OP_READ) {
                                set_cv(state, cv, ptr,
                                        copy_triple(state,
                                                get_cv(state, cv, RHS(ptr, 0))));
                                ptr = ptr->next;
                        }
                        else if (triple_is_pure(state, ptr, cv[ptr->id].id)) {
                                struct triple *val, **rhs;
                                val = copy_triple(state, ptr);
                                rhs = triple_rhs(state, val, 0);
                                for(; rhs; rhs = triple_rhs(state, val, rhs)) {
                                        if (!*rhs) {
                                                internal_error(state, ptr, "Missing rhs");
                                        }
                                        *rhs = get_cv(state, cv, *rhs);
                                }
                                simplify(state, val);
                                set_cv(state, cv, ptr, val);
                                ptr = ptr->next;
                        }
                        else {
                                error(state, ptr, "impure operation in constant expression");
                        }

                } while(ptr != head);

                /* Get the result value */
                def = get_cv(state, cv, head->prev);
                cv[head->prev->id].val = 0;

                /* Free the temporary values */
                for(i = 0; i < count; i++) {
                        if (cv[i].val) {
                                free_triple(state, cv[i].val);
                                cv[i].val = 0;
                        }
                }
                xfree(cv);
                /* Free the intermediate expressions */
                while(head->next != head) {
                        release_triple(state, head->next);
                }
                free_triple(state, head);
        }
        if (!is_const(def)) {
                error(state, expr, "Not a constant expression");
        }
        return def;
}

static struct triple *constant_expr(struct compile_state *state)
{
        return eval_const_expr(state, conditional_expr(state));
}

static struct triple *assignment_expr(struct compile_state *state)
{
        struct triple *def, *left, *right;
        int tok, op, sign;
        /* The C grammer in K&R shows assignment expressions
         * only taking unary expressions as input on their
         * left hand side.  But specifies the precedence of
         * assignemnt as the lowest operator except for comma.
         *
         * Allowing conditional expressions on the left hand side
         * of an assignement results in a grammar that accepts
         * a larger set of statements than standard C.   As long
         * as the subset of the grammar that is standard C behaves
         * correctly this should cause no problems.
         *
         * For the extra token strings accepted by the grammar
         * none of them should produce a valid lvalue, so they
         * should not produce functioning programs.
         *
         * GCC has this bug as well, so surprises should be minimal.
         */
        def = conditional_expr(state);
        left = def;
        switch((tok = peek(state))) {
        case TOK_EQ:
                lvalue(state, left);
                eat(state, TOK_EQ);
                def = write_expr(state, left,
                        read_expr(state, assignment_expr(state)));
                break;
        case TOK_TIMESEQ:
        case TOK_DIVEQ:
        case TOK_MODEQ:
                lvalue(state, left);
                arithmetic(state, left);
                eat(state, tok);
                right = read_expr(state, assignment_expr(state));
                arithmetic(state, right);

                sign = is_signed(left->type);
                op = -1;
                switch(tok) {
                case TOK_TIMESEQ: op = sign? OP_SMUL : OP_UMUL; break;
                case TOK_DIVEQ:   op = sign? OP_SDIV : OP_UDIV; break;
                case TOK_MODEQ:   op = sign? OP_SMOD : OP_UMOD; break;
                }
                def = write_expr(state, left,
                        triple(state, op, left->type,
                                read_expr(state, left), right));
                break;
        case TOK_PLUSEQ:
                lvalue(state, left);
                eat(state, TOK_PLUSEQ);
                def = write_expr(state, left,
                        mk_add_expr(state, left, assignment_expr(state)));
                break;
        case TOK_MINUSEQ:
                lvalue(state, left);
                eat(state, TOK_MINUSEQ);
                def = write_expr(state, left,
                        mk_sub_expr(state, left, assignment_expr(state)));
                break;
        case TOK_SLEQ:
        case TOK_SREQ:
        case TOK_ANDEQ:
        case TOK_XOREQ:
        case TOK_OREQ:
                lvalue(state, left);
                integral(state, left);
                eat(state, tok);
                right = read_expr(state, assignment_expr(state));
                integral(state, right);
                right = integral_promotion(state, right);
                sign = is_signed(left->type);
                op = -1;
                switch(tok) {
                case TOK_SLEQ:  op = OP_SL; break;
                case TOK_SREQ:  op = sign? OP_SSR: OP_USR; break;
                case TOK_ANDEQ: op = OP_AND; break;
                case TOK_XOREQ: op = OP_XOR; break;
                case TOK_OREQ:  op = OP_OR; break;
                }
                def = write_expr(state, left,
                        triple(state, op, left->type,
                                read_expr(state, left), right));
                break;
        }
        return def;
}

static struct triple *expr(struct compile_state *state)
{
        struct triple *def;
        def = assignment_expr(state);
        while(peek(state) == TOK_COMMA) {
                eat(state, TOK_COMMA);
                def = mkprog(state, def, assignment_expr(state), 0UL);
        }
        return def;
}

static void expr_statement(struct compile_state *state, struct triple *first)
{
        if (peek(state) != TOK_SEMI) {
                /* lvalue conversions always apply except when certian operators
                 * are applied.  I apply the lvalue conversions here
                 * as I know no more operators will be applied.
                 */
                flatten(state, first, lvalue_conversion(state, expr(state)));
        }
        eat(state, TOK_SEMI);
}

static void if_statement(struct compile_state *state, struct triple *first)
{
        struct triple *test, *jmp1, *jmp2, *middle, *end;

        jmp1 = jmp2 = middle = 0;
        eat(state, TOK_IF);
        eat(state, TOK_LPAREN);
        test = expr(state);
        bool(state, test);
        /* Cleanup and invert the test */
        test = lfalse_expr(state, read_expr(state, test));
        eat(state, TOK_RPAREN);
        /* Generate the needed pieces */
        middle = label(state);
        jmp1 = branch(state, middle, test);
        /* Thread the pieces together */
        flatten(state, first, test);
        flatten(state, first, jmp1);
        flatten(state, first, label(state));
        statement(state, first);
        if (peek(state) == TOK_ELSE) {
                eat(state, TOK_ELSE);
                /* Generate the rest of the pieces */
                end = label(state);
                jmp2 = branch(state, end, 0);
                /* Thread them together */
                flatten(state, first, jmp2);
                flatten(state, first, middle);
                statement(state, first);
                flatten(state, first, end);
        }
        else {
                flatten(state, first, middle);
        }
}

static void for_statement(struct compile_state *state, struct triple *first)
{
        struct triple *head, *test, *tail, *jmp1, *jmp2, *end;
        struct triple *label1, *label2, *label3;
        struct hash_entry *ident;

        eat(state, TOK_FOR);
        eat(state, TOK_LPAREN);
        head = test = tail = jmp1 = jmp2 = 0;
        if (peek(state) != TOK_SEMI) {
                head = expr(state);
        }
        eat(state, TOK_SEMI);
        if (peek(state) != TOK_SEMI) {
                test = expr(state);
                bool(state, test);
                test = ltrue_expr(state, read_expr(state, test));
        }
        eat(state, TOK_SEMI);
        if (peek(state) != TOK_RPAREN) {
                tail = expr(state);
        }
        eat(state, TOK_RPAREN);
        /* Generate the needed pieces */
        label1 = label(state);
        label2 = label(state);
        label3 = label(state);
        if (test) {
                jmp1 = branch(state, label3, 0);
                jmp2 = branch(state, label1, test);
        }
        else {
                jmp2 = branch(state, label1, 0);
        }
        end = label(state);
        /* Remember where break and continue go */
        start_scope(state);
        ident = state->i_break;
        symbol(state, ident, &ident->sym_ident, end, end->type);
        ident = state->i_continue;
        symbol(state, ident, &ident->sym_ident, label2, label2->type);
        /* Now include the body */
        flatten(state, first, head);
        flatten(state, first, jmp1);
        flatten(state, first, label1);
        statement(state, first);
        flatten(state, first, label2);
        flatten(state, first, tail);
        flatten(state, first, label3);
        flatten(state, first, test);
        flatten(state, first, jmp2);
        flatten(state, first, end);
        /* Cleanup the break/continue scope */
        end_scope(state);
}

static void while_statement(struct compile_state *state, struct triple *first)
{
        struct triple *label1, *test, *label2, *jmp1, *jmp2, *end;
        struct hash_entry *ident;
        eat(state, TOK_WHILE);
        eat(state, TOK_LPAREN);
        test = expr(state);
        bool(state, test);
        test = ltrue_expr(state, read_expr(state, test));
        eat(state, TOK_RPAREN);
        /* Generate the needed pieces */
        label1 = label(state);
        label2 = label(state);
        jmp1 = branch(state, label2, 0);
        jmp2 = branch(state, label1, test);
        end = label(state);
        /* Remember where break and continue go */
        start_scope(state);
        ident = state->i_break;
        symbol(state, ident, &ident->sym_ident, end, end->type);
        ident = state->i_continue;
        symbol(state, ident, &ident->sym_ident, label2, label2->type);
        /* Thread them together */
        flatten(state, first, jmp1);
        flatten(state, first, label1);
        statement(state, first);
        flatten(state, first, label2);
        flatten(state, first, test);
        flatten(state, first, jmp2);
        flatten(state, first, end);
        /* Cleanup the break/continue scope */
        end_scope(state);
}

static void do_statement(struct compile_state *state, struct triple *first)
{
        struct triple *label1, *label2, *test, *end;
        struct hash_entry *ident;
        eat(state, TOK_DO);
        /* Generate the needed pieces */
        label1 = label(state);
        label2 = label(state);
        end = label(state);
        /* Remember where break and continue go */
        start_scope(state);
        ident = state->i_break;
        symbol(state, ident, &ident->sym_ident, end, end->type);
        ident = state->i_continue;
        symbol(state, ident, &ident->sym_ident, label2, label2->type);
        /* Now include the body */
        flatten(state, first, label1);
        statement(state, first);
        /* Cleanup the break/continue scope */
        end_scope(state);
        /* Eat the rest of the loop */
        eat(state, TOK_WHILE);
        eat(state, TOK_LPAREN);
        test = read_expr(state, expr(state));
        bool(state, test);
        eat(state, TOK_RPAREN);
        eat(state, TOK_SEMI);
        /* Thread the pieces together */
        test = ltrue_expr(state, test);
        flatten(state, first, label2);
        flatten(state, first, test);
        flatten(state, first, branch(state, label1, test));
        flatten(state, first, end);
}


static void return_statement(struct compile_state *state, struct triple *first)
{
        struct triple *jmp, *mv, *dest, *var, *val;
        int last;
        eat(state, TOK_RETURN);

#if DEBUG_ROMCC_WARNINGS
#warning "FIXME implement a more general excess branch elimination"
#endif
        val = 0;
        /* If we have a return value do some more work */
        if (peek(state) != TOK_SEMI) {
                val = read_expr(state, expr(state));
        }
        eat(state, TOK_SEMI);

        /* See if this last statement in a function */
        last = ((peek(state) == TOK_RBRACE) &&
                (state->scope_depth == GLOBAL_SCOPE_DEPTH +2));

        /* Find the return variable */
        var = fresult(state, state->main_function);

        /* Find the return destination */
        dest = state->i_return->sym_ident->def;
        mv = jmp = 0;
        /* If needed generate a jump instruction */
        if (!last) {
                jmp = branch(state, dest, 0);
        }
        /* If needed generate an assignment instruction */
        if (val) {
                mv = write_expr(state, deref_index(state, var, 1), val);
        }
        /* Now put the code together */
        if (mv) {
                flatten(state, first, mv);
                flatten(state, first, jmp);
        }
        else if (jmp) {
                flatten(state, first, jmp);
        }
}

static void break_statement(struct compile_state *state, struct triple *first)
{
        struct triple *dest;
        eat(state, TOK_BREAK);
        eat(state, TOK_SEMI);
        if (!state->i_break->sym_ident) {
                error(state, 0, "break statement not within loop or switch");
        }
        dest = state->i_break->sym_ident->def;
        flatten(state, first, branch(state, dest, 0));
}

static void continue_statement(struct compile_state *state, struct triple *first)
{
        struct triple *dest;
        eat(state, TOK_CONTINUE);
        eat(state, TOK_SEMI);
        if (!state->i_continue->sym_ident) {
                error(state, 0, "continue statement outside of a loop");
        }
        dest = state->i_continue->sym_ident->def;
        flatten(state, first, branch(state, dest, 0));
}

static void goto_statement(struct compile_state *state, struct triple *first)
{
        struct hash_entry *ident;
        eat(state, TOK_GOTO);
        ident = eat(state, TOK_IDENT)->ident;
        if (!ident->sym_label) {
                /* If this is a forward branch allocate the label now,
                 * it will be flattend in the appropriate location later.
                 */
                struct triple *ins;
                ins = label(state);
                label_symbol(state, ident, ins, FUNCTION_SCOPE_DEPTH);
        }
        eat(state, TOK_SEMI);

        flatten(state, first, branch(state, ident->sym_label->def, 0));
}

static void labeled_statement(struct compile_state *state, struct triple *first)
{
        struct triple *ins;
        struct hash_entry *ident;

        ident = eat(state, TOK_IDENT)->ident;
        if (ident->sym_label && ident->sym_label->def) {
                ins = ident->sym_label->def;
                put_occurrence(ins->occurrence);
                ins->occurrence = new_occurrence(state);
        }
        else {
                ins = label(state);
                label_symbol(state, ident, ins, FUNCTION_SCOPE_DEPTH);
        }
        if (ins->id & TRIPLE_FLAG_FLATTENED) {
                error(state, 0, "label %s already defined", ident->name);
        }
        flatten(state, first, ins);

        eat(state, TOK_COLON);
        statement(state, first);
}

static void switch_statement(struct compile_state *state, struct triple *first)
{
        struct triple *value, *top, *end, *dbranch;
        struct hash_entry *ident;

        /* See if we have a valid switch statement */
        eat(state, TOK_SWITCH);
        eat(state, TOK_LPAREN);
        value = expr(state);
        integral(state, value);
        value = read_expr(state, value);
        eat(state, TOK_RPAREN);
        /* Generate the needed pieces */
        top = label(state);
        end = label(state);
        dbranch = branch(state, end, 0);
        /* Remember where case branches and break goes */
        start_scope(state);
        ident = state->i_switch;
        symbol(state, ident, &ident->sym_ident, value, value->type);
        ident = state->i_case;
        symbol(state, ident, &ident->sym_ident, top, top->type);
        ident = state->i_break;
        symbol(state, ident, &ident->sym_ident, end, end->type);
        ident = state->i_default;
        symbol(state, ident, &ident->sym_ident, dbranch, dbranch->type);
        /* Thread them together */
        flatten(state, first, value);
        flatten(state, first, top);
        flatten(state, first, dbranch);
        statement(state, first);
        flatten(state, first, end);
        /* Cleanup the switch scope */
        end_scope(state);
}

static void case_statement(struct compile_state *state, struct triple *first)
{
        struct triple *cvalue, *dest, *test, *jmp;
        struct triple *ptr, *value, *top, *dbranch;

        /* See if w have a valid case statement */
        eat(state, TOK_CASE);
        cvalue = constant_expr(state);
        integral(state, cvalue);
        if (cvalue->op != OP_INTCONST) {
                error(state, 0, "integer constant expected");
        }
        eat(state, TOK_COLON);
        if (!state->i_case->sym_ident) {
                error(state, 0, "case statement not within a switch");
        }

        /* Lookup the interesting pieces */
        top = state->i_case->sym_ident->def;
        value = state->i_switch->sym_ident->def;
        dbranch = state->i_default->sym_ident->def;

        /* See if this case label has already been used */
        for(ptr = top; ptr != dbranch; ptr = ptr->next) {
                if (ptr->op != OP_EQ) {
                        continue;
                }
                if (RHS(ptr, 1)->u.cval == cvalue->u.cval) {
                        error(state, 0, "duplicate case %d statement",
                                cvalue->u.cval);
                }
        }
        /* Generate the needed pieces */
        dest = label(state);
        test = triple(state, OP_EQ, &int_type, value, cvalue);
        jmp = branch(state, dest, test);
        /* Thread the pieces together */
        flatten(state, dbranch, test);
        flatten(state, dbranch, jmp);
        flatten(state, dbranch, label(state));
        flatten(state, first, dest);
        statement(state, first);
}

static void default_statement(struct compile_state *state, struct triple *first)
{
        struct triple *dest;
        struct triple *dbranch, *end;

        /* See if we have a valid default statement */
        eat(state, TOK_DEFAULT);
        eat(state, TOK_COLON);

        if (!state->i_case->sym_ident) {
                error(state, 0, "default statement not within a switch");
        }

        /* Lookup the interesting pieces */
        dbranch = state->i_default->sym_ident->def;
        end = state->i_break->sym_ident->def;

        /* See if a default statement has already happened */
        if (TARG(dbranch, 0) != end) {
                error(state, 0, "duplicate default statement");
        }

        /* Generate the needed pieces */
        dest = label(state);

        /* Blame the branch on the default statement */
        put_occurrence(dbranch->occurrence);
        dbranch->occurrence = new_occurrence(state);

        /* Thread the pieces together */
        TARG(dbranch, 0) = dest;
        use_triple(dest, dbranch);
        flatten(state, first, dest);
        statement(state, first);
}

static void asm_statement(struct compile_state *state, struct triple *first)
{
        struct asm_info *info;
        struct {
                struct triple *constraint;
                struct triple *expr;
        } out_param[MAX_LHS], in_param[MAX_RHS], clob_param[MAX_LHS];
        struct triple *def, *asm_str;
        int out, in, clobbers, more, colons, i;
        int flags;

        flags = 0;
        eat(state, TOK_ASM);
        /* For now ignore the qualifiers */
        switch(peek(state)) {
        case TOK_CONST:
                eat(state, TOK_CONST);
                break;
        case TOK_VOLATILE:
                eat(state, TOK_VOLATILE);
                flags |= TRIPLE_FLAG_VOLATILE;
                break;
        }
        eat(state, TOK_LPAREN);
        asm_str = string_constant(state);

        colons = 0;
        out = in = clobbers = 0;
        /* Outputs */
        if ((colons == 0) && (peek(state) == TOK_COLON)) {
                eat(state, TOK_COLON);
                colons++;
                more = (peek(state) == TOK_LIT_STRING);
                while(more) {
                        struct triple *var;
                        struct triple *constraint;
                        char *str;
                        more = 0;
                        if (out > MAX_LHS) {
                                error(state, 0, "Maximum output count exceeded.");
                        }
                        constraint = string_constant(state);
                        str = constraint->u.blob;
                        if (str[0] != '=') {
                                error(state, 0, "Output constraint does not start with =");
                        }
                        constraint->u.blob = str + 1;
                        eat(state, TOK_LPAREN);
                        var = conditional_expr(state);
                        eat(state, TOK_RPAREN);

                        lvalue(state, var);
                        out_param[out].constraint = constraint;
                        out_param[out].expr       = var;
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                                more = 1;
                        }
                        out++;
                }
        }
        /* Inputs */
        if ((colons == 1) && (peek(state) == TOK_COLON)) {
                eat(state, TOK_COLON);
                colons++;
                more = (peek(state) == TOK_LIT_STRING);
                while(more) {
                        struct triple *val;
                        struct triple *constraint;
                        char *str;
                        more = 0;
                        if (in > MAX_RHS) {
                                error(state, 0, "Maximum input count exceeded.");
                        }
                        constraint = string_constant(state);
                        str = constraint->u.blob;
                        if (digitp(str[0] && str[1] == '\0')) {
                                int val;
                                val = digval(str[0]);
                                if ((val < 0) || (val >= out)) {
                                        error(state, 0, "Invalid input constraint %d", val);
                                }
                        }
                        eat(state, TOK_LPAREN);
                        val = conditional_expr(state);
                        eat(state, TOK_RPAREN);

                        in_param[in].constraint = constraint;
                        in_param[in].expr       = val;
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                                more = 1;
                        }
                        in++;
                }
        }

        /* Clobber */
        if ((colons == 2) && (peek(state) == TOK_COLON)) {
                eat(state, TOK_COLON);
                colons++;
                more = (peek(state) == TOK_LIT_STRING);
                while(more) {
                        struct triple *clobber;
                        more = 0;
                        if ((clobbers + out) > MAX_LHS) {
                                error(state, 0, "Maximum clobber limit exceeded.");
                        }
                        clobber = string_constant(state);

                        clob_param[clobbers].constraint = clobber;
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                                more = 1;
                        }
                        clobbers++;
                }
        }
        eat(state, TOK_RPAREN);
        eat(state, TOK_SEMI);


        info = xcmalloc(sizeof(*info), "asm_info");
        info->str = asm_str->u.blob;
        free_triple(state, asm_str);

        def = new_triple(state, OP_ASM, &void_type, clobbers + out, in);
        def->u.ainfo = info;
        def->id |= flags;

        /* Find the register constraints */
        for(i = 0; i < out; i++) {
                struct triple *constraint;
                constraint = out_param[i].constraint;
                info->tmpl.lhs[i] = arch_reg_constraint(state,
                        out_param[i].expr->type, constraint->u.blob);
                free_triple(state, constraint);
        }
        for(; i - out < clobbers; i++) {
                struct triple *constraint;
                constraint = clob_param[i - out].constraint;
                info->tmpl.lhs[i] = arch_reg_clobber(state, constraint->u.blob);
                free_triple(state, constraint);
        }
        for(i = 0; i < in; i++) {
                struct triple *constraint;
                const char *str;
                constraint = in_param[i].constraint;
                str = constraint->u.blob;
                if (digitp(str[0]) && str[1] == '\0') {
                        struct reg_info cinfo;
                        int val;
                        val = digval(str[0]);
                        cinfo.reg = info->tmpl.lhs[val].reg;
                        cinfo.regcm = arch_type_to_regcm(state, in_param[i].expr->type);
                        cinfo.regcm &= info->tmpl.lhs[val].regcm;
                        if (cinfo.reg == REG_UNSET) {
                                cinfo.reg = REG_VIRT0 + val;
                        }
                        if (cinfo.regcm == 0) {
                                error(state, 0, "No registers for %d", val);
                        }
                        info->tmpl.lhs[val] = cinfo;
                        info->tmpl.rhs[i]   = cinfo;

                } else {
                        info->tmpl.rhs[i] = arch_reg_constraint(state,
                                in_param[i].expr->type, str);
                }
                free_triple(state, constraint);
        }

        /* Now build the helper expressions */
        for(i = 0; i < in; i++) {
                RHS(def, i) = read_expr(state, in_param[i].expr);
        }
        flatten(state, first, def);
        for(i = 0; i < (out + clobbers); i++) {
                struct type *type;
                struct triple *piece;
                if (i < out) {
                        type = out_param[i].expr->type;
                } else {
                        size_t size = arch_reg_size(info->tmpl.lhs[i].reg);
                        if (size >= SIZEOF_LONG) {
                                type = &ulong_type;
                        }
                        else if (size >= SIZEOF_INT) {
                                type = &uint_type;
                        }
                        else if (size >= SIZEOF_SHORT) {
                                type = &ushort_type;
                        }
                        else {
                                type = &uchar_type;
                        }
                }
                piece = triple(state, OP_PIECE, type, def, 0);
                piece->u.cval = i;
                LHS(def, i) = piece;
                flatten(state, first, piece);
        }
        /* And write the helpers to their destinations */
        for(i = 0; i < out; i++) {
                struct triple *piece;
                piece = LHS(def, i);
                flatten(state, first,
                        write_expr(state, out_param[i].expr, piece));
        }
}


static int isdecl(int tok)
{
        switch(tok) {
        case TOK_AUTO:
        case TOK_REGISTER:
        case TOK_STATIC:
        case TOK_EXTERN:
        case TOK_TYPEDEF:
        case TOK_CONST:
        case TOK_RESTRICT:
        case TOK_VOLATILE:
        case TOK_VOID:
        case TOK_CHAR:
        case TOK_SHORT:
        case TOK_INT:
        case TOK_LONG:
        case TOK_FLOAT:
        case TOK_DOUBLE:
        case TOK_SIGNED:
        case TOK_UNSIGNED:
        case TOK_STRUCT:
        case TOK_UNION:
        case TOK_ENUM:
        case TOK_TYPE_NAME: /* typedef name */
                return 1;
        default:
                return 0;
        }
}

static void compound_statement(struct compile_state *state, struct triple *first)
{
        eat(state, TOK_LBRACE);
        start_scope(state);

        /* statement-list opt */
        while (peek(state) != TOK_RBRACE) {
                statement(state, first);
        }
        end_scope(state);
        eat(state, TOK_RBRACE);
}

static void statement(struct compile_state *state, struct triple *first)
{
        int tok;
        tok = peek(state);
        if (tok == TOK_LBRACE) {
                compound_statement(state, first);
        }
        else if (tok == TOK_IF) {
                if_statement(state, first);
        }
        else if (tok == TOK_FOR) {
                for_statement(state, first);
        }
        else if (tok == TOK_WHILE) {
                while_statement(state, first);
        }
        else if (tok == TOK_DO) {
                do_statement(state, first);
        }
        else if (tok == TOK_RETURN) {
                return_statement(state, first);
        }
        else if (tok == TOK_BREAK) {
                break_statement(state, first);
        }
        else if (tok == TOK_CONTINUE) {
                continue_statement(state, first);
        }
        else if (tok == TOK_GOTO) {
                goto_statement(state, first);
        }
        else if (tok == TOK_SWITCH) {
                switch_statement(state, first);
        }
        else if (tok == TOK_ASM) {
                asm_statement(state, first);
        }
        else if ((tok == TOK_IDENT) && (peek2(state) == TOK_COLON)) {
                labeled_statement(state, first);
        }
        else if (tok == TOK_CASE) {
                case_statement(state, first);
        }
        else if (tok == TOK_DEFAULT) {
                default_statement(state, first);
        }
        else if (isdecl(tok)) {
                /* This handles C99 intermixing of statements and decls */
                decl(state, first);
        }
        else {
                expr_statement(state, first);
        }
}

static struct type *param_decl(struct compile_state *state)
{
        struct type *type;
        struct hash_entry *ident;
        /* Cheat so the declarator will know we are not global */
        start_scope(state);
        ident = 0;
        type = decl_specifiers(state);
        type = declarator(state, type, &ident, 0);
        type->field_ident = ident;
        end_scope(state);
        return type;
}

static struct type *param_type_list(struct compile_state *state, struct type *type)
{
        struct type *ftype, **next;
        ftype = new_type(TYPE_FUNCTION | (type->type & STOR_MASK), type, param_decl(state));
        next = &ftype->right;
        ftype->elements = 1;
        while(peek(state) == TOK_COMMA) {
                eat(state, TOK_COMMA);
                if (peek(state) == TOK_DOTS) {
                        eat(state, TOK_DOTS);
                        error(state, 0, "variadic functions not supported");
                }
                else {
                        *next = new_type(TYPE_PRODUCT, *next, param_decl(state));
                        next = &((*next)->right);
                        ftype->elements++;
                }
        }
        return ftype;
}

static struct type *type_name(struct compile_state *state)
{
        struct type *type;
        type = specifier_qualifier_list(state);
        /* abstract-declarator (may consume no tokens) */
        type = declarator(state, type, 0, 0);
        return type;
}

static struct type *direct_declarator(
        struct compile_state *state, struct type *type,
        struct hash_entry **pident, int need_ident)
{
        struct hash_entry *ident;
        struct type *outer;
        int op;
        outer = 0;
        arrays_complete(state, type);
        switch(peek(state)) {
        case TOK_IDENT:
                ident = eat(state, TOK_IDENT)->ident;
                if (!ident) {
                        error(state, 0, "Unexpected identifier found");
                }
                /* The name of what we are declaring */
                *pident = ident;
                break;
        case TOK_LPAREN:
                eat(state, TOK_LPAREN);
                outer = declarator(state, type, pident, need_ident);
                eat(state, TOK_RPAREN);
                break;
        default:
                if (need_ident) {
                        error(state, 0, "Identifier expected");
                }
                break;
        }
        do {
                op = 1;
                arrays_complete(state, type);
                switch(peek(state)) {
                case TOK_LPAREN:
                        eat(state, TOK_LPAREN);
                        type = param_type_list(state, type);
                        eat(state, TOK_RPAREN);
                        break;
                case TOK_LBRACKET:
                {
                        unsigned int qualifiers;
                        struct triple *value;
                        value = 0;
                        eat(state, TOK_LBRACKET);
                        if (peek(state) != TOK_RBRACKET) {
                                value = constant_expr(state);
                                integral(state, value);
                        }
                        eat(state, TOK_RBRACKET);

                        qualifiers = type->type & (QUAL_MASK | STOR_MASK);
                        type = new_type(TYPE_ARRAY | qualifiers, type, 0);
                        if (value) {
                                type->elements = value->u.cval;
                                free_triple(state, value);
                        } else {
                                type->elements = ELEMENT_COUNT_UNSPECIFIED;
                                op = 0;
                        }
                }
                        break;
                default:
                        op = 0;
                        break;
                }
        } while(op);
        if (outer) {
                struct type *inner;
                arrays_complete(state, type);
                FINISHME();
                for(inner = outer; inner->left; inner = inner->left)
                        ;
                inner->left = type;
                type = outer;
        }
        return type;
}

static struct type *declarator(
        struct compile_state *state, struct type *type,
        struct hash_entry **pident, int need_ident)
{
        while(peek(state) == TOK_STAR) {
                eat(state, TOK_STAR);
                type = new_type(TYPE_POINTER | (type->type & STOR_MASK), type, 0);
        }
        type = direct_declarator(state, type, pident, need_ident);
        return type;
}

static struct type *typedef_name(
        struct compile_state *state, unsigned int specifiers)
{
        struct hash_entry *ident;
        struct type *type;
        ident = eat(state, TOK_TYPE_NAME)->ident;
        type = ident->sym_ident->type;
        specifiers |= type->type & QUAL_MASK;
        if ((specifiers & (STOR_MASK | QUAL_MASK)) !=
                (type->type & (STOR_MASK | QUAL_MASK))) {
                type = clone_type(specifiers, type);
        }
        return type;
}

static struct type *enum_specifier(
        struct compile_state *state, unsigned int spec)
{
        struct hash_entry *ident;
        ulong_t base;
        int tok;
        struct type *enum_type;
        enum_type = 0;
        ident = 0;
        eat(state, TOK_ENUM);
        tok = peek(state);
        if ((tok == TOK_IDENT) || (tok == TOK_ENUM_CONST) || (tok == TOK_TYPE_NAME)) {
                ident = eat(state, tok)->ident;
        }
        base = 0;
        if (!ident || (peek(state) == TOK_LBRACE)) {
                struct type **next;
                eat(state, TOK_LBRACE);
                enum_type = new_type(TYPE_ENUM | spec, 0, 0);
                enum_type->type_ident = ident;
                next = &enum_type->right;
                do {
                        struct hash_entry *eident;
                        struct triple *value;
                        struct type *entry;
                        eident = eat(state, TOK_IDENT)->ident;
                        if (eident->sym_ident) {
                                error(state, 0, "%s already declared",
                                        eident->name);
                        }
                        eident->tok = TOK_ENUM_CONST;
                        if (peek(state) == TOK_EQ) {
                                struct triple *val;
                                eat(state, TOK_EQ);
                                val = constant_expr(state);
                                integral(state, val);
                                base = val->u.cval;
                        }
                        value = int_const(state, &int_type, base);
                        symbol(state, eident, &eident->sym_ident, value, &int_type);
                        entry = new_type(TYPE_LIST, 0, 0);
                        entry->field_ident = eident;
                        *next = entry;
                        next = &entry->right;
                        base += 1;
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                        }
                } while(peek(state) != TOK_RBRACE);
                eat(state, TOK_RBRACE);
                if (ident) {
                        symbol(state, ident, &ident->sym_tag, 0, enum_type);
                }
        }
        if (ident && ident->sym_tag &&
                ident->sym_tag->type &&
                ((ident->sym_tag->type->type & TYPE_MASK) == TYPE_ENUM)) {
                enum_type = clone_type(spec, ident->sym_tag->type);
        }
        else if (ident && !enum_type) {
                error(state, 0, "enum %s undeclared", ident->name);
        }
        return enum_type;
}

static struct type *struct_declarator(
        struct compile_state *state, struct type *type, struct hash_entry **ident)
{
        if (peek(state) != TOK_COLON) {
                type = declarator(state, type, ident, 1);
        }
        if (peek(state) == TOK_COLON) {
                struct triple *value;
                eat(state, TOK_COLON);
                value = constant_expr(state);
                if (value->op != OP_INTCONST) {
                        error(state, 0, "Invalid constant expression");
                }
                if (value->u.cval > size_of(state, type)) {
                        error(state, 0, "bitfield larger than base type");
                }
                if (!TYPE_INTEGER(type->type) || ((type->type & TYPE_MASK) == TYPE_BITFIELD)) {
                        error(state, 0, "bitfield base not an integer type");
                }
                type = new_type(TYPE_BITFIELD, type, 0);
                type->elements = value->u.cval;
        } else
                type = clone_type(0, type);

        return type;
}

static struct type *struct_or_union_specifier(
        struct compile_state *state, unsigned int spec)
{
        struct type *struct_type;
        struct hash_entry *ident;
        unsigned int type_main;
        unsigned int type_join;
        int tok;
        struct_type = 0;
        ident = 0;
        switch(peek(state)) {
        case TOK_STRUCT:
                eat(state, TOK_STRUCT);
                type_main = TYPE_STRUCT;
                type_join = TYPE_PRODUCT;
                break;
        case TOK_UNION:
                eat(state, TOK_UNION);
                type_main = TYPE_UNION;
                type_join = TYPE_OVERLAP;
                break;
        default:
                eat(state, TOK_STRUCT);
                type_main = TYPE_STRUCT;
                type_join = TYPE_PRODUCT;
                break;
        }
        tok = peek(state);
        if ((tok == TOK_IDENT) || (tok == TOK_ENUM_CONST) || (tok == TOK_TYPE_NAME)) {
                ident = eat(state, tok)->ident;
        }
        if (!ident || (peek(state) == TOK_LBRACE)) {
                ulong_t elements;
                struct type **next;
                elements = 0;
                eat(state, TOK_LBRACE);
                next = &struct_type;
                do {
                        struct type *base_type;
                        int done;
                        base_type = specifier_qualifier_list(state);
                        do {
                                struct type *type;
                                struct hash_entry *fident;
                                done = 1;
                                type = struct_declarator(state, base_type, &fident);
                                elements++;
                                if (peek(state) == TOK_COMMA) {
                                        done = 0;
                                        eat(state, TOK_COMMA);
                                }
                                type->field_ident = fident;
                                if (*next) {
                                        *next = new_type(type_join, *next, type);
                                        next = &((*next)->right);
                                } else {
                                        *next = type;
                                }
                        } while(!done);
                        eat(state, TOK_SEMI);
                } while(peek(state) != TOK_RBRACE);
                eat(state, TOK_RBRACE);
                struct_type = new_type(type_main | spec, struct_type, 0);
                struct_type->type_ident = ident;
                struct_type->elements = elements;
                if (ident) {
                        symbol(state, ident, &ident->sym_tag, 0, struct_type);
                }
        }
        if (ident && ident->sym_tag &&
                ident->sym_tag->type &&
                ((ident->sym_tag->type->type & TYPE_MASK) == type_main)) {
                struct_type = clone_type(spec, ident->sym_tag->type);
        }
        else if (ident && !struct_type) {
                error(state, 0, "%s %s undeclared",
                        (type_main == TYPE_STRUCT)?"struct" : "union",
                        ident->name);
        }
        return struct_type;
}

static unsigned int storage_class_specifier_opt(struct compile_state *state)
{
        unsigned int specifiers;
        switch(peek(state)) {
        case TOK_AUTO:
                eat(state, TOK_AUTO);
                specifiers = STOR_AUTO;
                break;
        case TOK_REGISTER:
                eat(state, TOK_REGISTER);
                specifiers = STOR_REGISTER;
                break;
        case TOK_STATIC:
                eat(state, TOK_STATIC);
                specifiers = STOR_STATIC;
                break;
        case TOK_EXTERN:
                eat(state, TOK_EXTERN);
                specifiers = STOR_EXTERN;
                break;
        case TOK_TYPEDEF:
                eat(state, TOK_TYPEDEF);
                specifiers = STOR_TYPEDEF;
                break;
        default:
                if (state->scope_depth <= GLOBAL_SCOPE_DEPTH) {
                        specifiers = STOR_LOCAL;
                }
                else {
                        specifiers = STOR_AUTO;
                }
        }
        return specifiers;
}

static unsigned int function_specifier_opt(struct compile_state *state)
{
        /* Ignore the inline keyword */
        unsigned int specifiers;
        specifiers = 0;
        switch(peek(state)) {
        case TOK_INLINE:
                eat(state, TOK_INLINE);
                specifiers = STOR_INLINE;
        }
        return specifiers;
}

static unsigned int attrib(struct compile_state *state, unsigned int attributes)
{
        int tok = peek(state);
        switch(tok) {
        case TOK_COMMA:
        case TOK_LPAREN:
                /* The empty attribute ignore it */
                break;
        case TOK_IDENT:
        case TOK_ENUM_CONST:
        case TOK_TYPE_NAME:
        {
                struct hash_entry *ident;
                ident = eat(state, TOK_IDENT)->ident;

                if (ident == state->i_noinline) {
                        if (attributes & ATTRIB_ALWAYS_INLINE) {
                                error(state, 0, "both always_inline and noinline attribtes");
                        }
                        attributes |= ATTRIB_NOINLINE;
                }
                else if (ident == state->i_always_inline) {
                        if (attributes & ATTRIB_NOINLINE) {
                                error(state, 0, "both noinline and always_inline attribtes");
                        }
                        attributes |= ATTRIB_ALWAYS_INLINE;
                }
                else if (ident == state->i_noreturn) {
                        // attribute((noreturn)) does nothing (yet?)
                }
                else if (ident == state->i_unused) {
                        // attribute((unused)) does nothing (yet?)
                }
                else if (ident == state->i_packed) {
                        // attribute((packed)) does nothing (yet?)
                }
                else {
                        error(state, 0, "Unknown attribute:%s", ident->name);
                }
                break;
        }
        default:
                error(state, 0, "Unexpected token: %s\n", tokens[tok]);
                break;
        }
        return attributes;
}

static unsigned int attribute_list(struct compile_state *state, unsigned type)
{
        type = attrib(state, type);
        while(peek(state) == TOK_COMMA) {
                eat(state, TOK_COMMA);
                type = attrib(state, type);
        }
        return type;
}

static unsigned int attributes_opt(struct compile_state *state, unsigned type)
{
        if (peek(state) == TOK_ATTRIBUTE) {
                eat(state, TOK_ATTRIBUTE);
                eat(state, TOK_LPAREN);
                eat(state, TOK_LPAREN);
                type = attribute_list(state, type);
                eat(state, TOK_RPAREN);
                eat(state, TOK_RPAREN);
        }
        return type;
}

static unsigned int type_qualifiers(struct compile_state *state)
{
        unsigned int specifiers;
        int done;
        done = 0;
        specifiers = QUAL_NONE;
        do {
                switch(peek(state)) {
                case TOK_CONST:
                        eat(state, TOK_CONST);
                        specifiers |= QUAL_CONST;
                        break;
                case TOK_VOLATILE:
                        eat(state, TOK_VOLATILE);
                        specifiers |= QUAL_VOLATILE;
                        break;
                case TOK_RESTRICT:
                        eat(state, TOK_RESTRICT);
                        specifiers |= QUAL_RESTRICT;
                        break;
                default:
                        done = 1;
                        break;
                }
        } while(!done);
        return specifiers;
}

static struct type *type_specifier(
        struct compile_state *state, unsigned int spec)
{
        struct type *type;
        int tok;
        type = 0;
        switch((tok = peek(state))) {
        case TOK_VOID:
                eat(state, TOK_VOID);
                type = new_type(TYPE_VOID | spec, 0, 0);
                break;
        case TOK_CHAR:
                eat(state, TOK_CHAR);
                type = new_type(TYPE_CHAR | spec, 0, 0);
                break;
        case TOK_SHORT:
                eat(state, TOK_SHORT);
                if (peek(state) == TOK_INT) {
                        eat(state, TOK_INT);
                }
                type = new_type(TYPE_SHORT | spec, 0, 0);
                break;
        case TOK_INT:
                eat(state, TOK_INT);
                type = new_type(TYPE_INT | spec, 0, 0);
                break;
        case TOK_LONG:
                eat(state, TOK_LONG);
                switch(peek(state)) {
                case TOK_LONG:
                        eat(state, TOK_LONG);
                        error(state, 0, "long long not supported");
                        break;
                case TOK_DOUBLE:
                        eat(state, TOK_DOUBLE);
                        error(state, 0, "long double not supported");
                        break;
                case TOK_INT:
                        eat(state, TOK_INT);
                        type = new_type(TYPE_LONG | spec, 0, 0);
                        break;
                default:
                        type = new_type(TYPE_LONG | spec, 0, 0);
                        break;
                }
                break;
        case TOK_FLOAT:
                eat(state, TOK_FLOAT);
                error(state, 0, "type float not supported");
                break;
        case TOK_DOUBLE:
                eat(state, TOK_DOUBLE);
                error(state, 0, "type double not supported");
                break;
        case TOK_SIGNED:
                eat(state, TOK_SIGNED);
                switch(peek(state)) {
                case TOK_LONG:
                        eat(state, TOK_LONG);
                        switch(peek(state)) {
                        case TOK_LONG:
                                eat(state, TOK_LONG);
                                error(state, 0, "type long long not supported");
                                break;
                        case TOK_INT:
                                eat(state, TOK_INT);
                                type = new_type(TYPE_LONG | spec, 0, 0);
                                break;
                        default:
                                type = new_type(TYPE_LONG | spec, 0, 0);
                                break;
                        }
                        break;
                case TOK_INT:
                        eat(state, TOK_INT);
                        type = new_type(TYPE_INT | spec, 0, 0);
                        break;
                case TOK_SHORT:
                        eat(state, TOK_SHORT);
                        type = new_type(TYPE_SHORT | spec, 0, 0);
                        break;
                case TOK_CHAR:
                        eat(state, TOK_CHAR);
                        type = new_type(TYPE_CHAR | spec, 0, 0);
                        break;
                default:
                        type = new_type(TYPE_INT | spec, 0, 0);
                        break;
                }
                break;
        case TOK_UNSIGNED:
                eat(state, TOK_UNSIGNED);
                switch(peek(state)) {
                case TOK_LONG:
                        eat(state, TOK_LONG);
                        switch(peek(state)) {
                        case TOK_LONG:
                                eat(state, TOK_LONG);
                                error(state, 0, "unsigned long long not supported");
                                break;
                        case TOK_INT:
                                eat(state, TOK_INT);
                                type = new_type(TYPE_ULONG | spec, 0, 0);
                                break;
                        default:
                                type = new_type(TYPE_ULONG | spec, 0, 0);
                                break;
                        }
                        break;
                case TOK_INT:
                        eat(state, TOK_INT);
                        type = new_type(TYPE_UINT | spec, 0, 0);
                        break;
                case TOK_SHORT:
                        eat(state, TOK_SHORT);
                        type = new_type(TYPE_USHORT | spec, 0, 0);
                        break;
                case TOK_CHAR:
                        eat(state, TOK_CHAR);
                        type = new_type(TYPE_UCHAR | spec, 0, 0);
                        break;
                default:
                        type = new_type(TYPE_UINT | spec, 0, 0);
                        break;
                }
                break;
                /* struct or union specifier */
        case TOK_STRUCT:
        case TOK_UNION:
                type = struct_or_union_specifier(state, spec);
                break;
                /* enum-spefifier */
        case TOK_ENUM:
                type = enum_specifier(state, spec);
                break;
                /* typedef name */
        case TOK_TYPE_NAME:
                type = typedef_name(state, spec);
                break;
        default:
                error(state, 0, "bad type specifier %s",
                        tokens[tok]);
                break;
        }
        return type;
}

static int istype(int tok)
{
        switch(tok) {
        case TOK_CONST:
        case TOK_RESTRICT:
        case TOK_VOLATILE:
        case TOK_VOID:
        case TOK_CHAR:
        case TOK_SHORT:
        case TOK_INT:
        case TOK_LONG:
        case TOK_FLOAT:
        case TOK_DOUBLE:
        case TOK_SIGNED:
        case TOK_UNSIGNED:
        case TOK_STRUCT:
        case TOK_UNION:
        case TOK_ENUM:
        case TOK_TYPE_NAME:
                return 1;
        default:
                return 0;
        }
}


static struct type *specifier_qualifier_list(struct compile_state *state)
{
        struct type *type;
        unsigned int specifiers = 0;

        /* type qualifiers */
        specifiers |= type_qualifiers(state);

        /* type specifier */
        type = type_specifier(state, specifiers);

        return type;
}

#if DEBUG_ROMCC_WARNING
static int isdecl_specifier(int tok)
{
        switch(tok) {
                /* storage class specifier */
        case TOK_AUTO:
        case TOK_REGISTER:
        case TOK_STATIC:
        case TOK_EXTERN:
        case TOK_TYPEDEF:
                /* type qualifier */
        case TOK_CONST:
        case TOK_RESTRICT:
        case TOK_VOLATILE:
                /* type specifiers */
        case TOK_VOID:
        case TOK_CHAR:
        case TOK_SHORT:
        case TOK_INT:
        case TOK_LONG:
        case TOK_FLOAT:
        case TOK_DOUBLE:
        case TOK_SIGNED:
        case TOK_UNSIGNED:
                /* struct or union specifier */
        case TOK_STRUCT:
        case TOK_UNION:
                /* enum-spefifier */
        case TOK_ENUM:
                /* typedef name */
        case TOK_TYPE_NAME:
                /* function specifiers */
        case TOK_INLINE:
                return 1;
        default:
                return 0;
        }
}
#endif

static struct type *decl_specifiers(struct compile_state *state)
{
        struct type *type;
        unsigned int specifiers;
        /* I am overly restrictive in the arragement of specifiers supported.
         * C is overly flexible in this department it makes interpreting
         * the parse tree difficult.
         */
        specifiers = 0;

        /* storage class specifier */
        specifiers |= storage_class_specifier_opt(state);

        /* function-specifier */
        specifiers |= function_specifier_opt(state);

        /* attributes */
        specifiers |= attributes_opt(state, 0);

        /* type qualifier */
        specifiers |= type_qualifiers(state);

        /* type specifier */
        type = type_specifier(state, specifiers);
        return type;
}

struct field_info {
        struct type *type;
        size_t offset;
};

static struct field_info designator(struct compile_state *state, struct type *type)
{
        int tok;
        struct field_info info;
        info.offset = ~0U;
        info.type = 0;
        do {
                switch(peek(state)) {
                case TOK_LBRACKET:
                {
                        struct triple *value;
                        if ((type->type & TYPE_MASK) != TYPE_ARRAY) {
                                error(state, 0, "Array designator not in array initializer");
                        }
                        eat(state, TOK_LBRACKET);
                        value = constant_expr(state);
                        eat(state, TOK_RBRACKET);

                        info.type = type->left;
                        info.offset = value->u.cval * size_of(state, info.type);
                        break;
                }
                case TOK_DOT:
                {
                        struct hash_entry *field;
                        if (((type->type & TYPE_MASK) != TYPE_STRUCT) &&
                                ((type->type & TYPE_MASK) != TYPE_UNION))
                        {
                                error(state, 0, "Struct designator not in struct initializer");
                        }
                        eat(state, TOK_DOT);
                        field = eat(state, TOK_IDENT)->ident;
                        info.offset = field_offset(state, type, field);
                        info.type   = field_type(state, type, field);
                        break;
                }
                default:
                        error(state, 0, "Invalid designator");
                }
                tok = peek(state);
        } while((tok == TOK_LBRACKET) || (tok == TOK_DOT));
        eat(state, TOK_EQ);
        return info;
}

static struct triple *initializer(
        struct compile_state *state, struct type *type)
{
        struct triple *result;
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME more consistent initializer handling (where should eval_const_expr go?"
#endif
        if (peek(state) != TOK_LBRACE) {
                result = assignment_expr(state);
                if (((type->type & TYPE_MASK) == TYPE_ARRAY) &&
                        (type->elements == ELEMENT_COUNT_UNSPECIFIED) &&
                        ((result->type->type & TYPE_MASK) == TYPE_ARRAY) &&
                        (result->type->elements != ELEMENT_COUNT_UNSPECIFIED) &&
                        (equiv_types(type->left, result->type->left))) {
                        type->elements = result->type->elements;
                }
                if (is_lvalue(state, result) &&
                        ((result->type->type & TYPE_MASK) == TYPE_ARRAY) &&
                        (type->type & TYPE_MASK) != TYPE_ARRAY)
                {
                        result = lvalue_conversion(state, result);
                }
                if (!is_init_compatible(state, type, result->type)) {
                        error(state, 0, "Incompatible types in initializer");
                }
                if (!equiv_types(type, result->type)) {
                        result = mk_cast_expr(state, type, result);
                }
        }
        else {
                int comma;
                size_t max_offset;
                struct field_info info;
                void *buf;
                if (((type->type & TYPE_MASK) != TYPE_ARRAY) &&
                        ((type->type & TYPE_MASK) != TYPE_STRUCT)) {
                        internal_error(state, 0, "unknown initializer type");
                }
                info.offset = 0;
                info.type = type->left;
                if ((type->type & TYPE_MASK) == TYPE_STRUCT) {
                        info.type = next_field(state, type, 0);
                }
                if (type->elements == ELEMENT_COUNT_UNSPECIFIED) {
                        max_offset = 0;
                } else {
                        max_offset = size_of(state, type);
                }
                buf = xcmalloc(bits_to_bytes(max_offset), "initializer");
                eat(state, TOK_LBRACE);
                do {
                        struct triple *value;
                        struct type *value_type;
                        size_t value_size;
                        void *dest;
                        int tok;
                        comma = 0;
                        tok = peek(state);
                        if ((tok == TOK_LBRACKET) || (tok == TOK_DOT)) {
                                info = designator(state, type);
                        }
                        if ((type->elements != ELEMENT_COUNT_UNSPECIFIED) &&
                                (info.offset >= max_offset)) {
                                error(state, 0, "element beyond bounds");
                        }
                        value_type = info.type;
                        value = eval_const_expr(state, initializer(state, value_type));
                        value_size = size_of(state, value_type);
                        if (((type->type & TYPE_MASK) == TYPE_ARRAY) &&
                                (type->elements == ELEMENT_COUNT_UNSPECIFIED) &&
                                (max_offset <= info.offset)) {
                                void *old_buf;
                                size_t old_size;
                                old_buf = buf;
                                old_size = max_offset;
                                max_offset = info.offset + value_size;
                                buf = xmalloc(bits_to_bytes(max_offset), "initializer");
                                memcpy(buf, old_buf, bits_to_bytes(old_size));
                                xfree(old_buf);
                        }
                        dest = ((char *)buf) + bits_to_bytes(info.offset);
#if DEBUG_INITIALIZER
                        fprintf(state->errout, "dest = buf + %d max_offset: %d value_size: %d op: %d\n",
                                dest - buf,
                                bits_to_bytes(max_offset),
                                bits_to_bytes(value_size),
                                value->op);
#endif
                        if (value->op == OP_BLOBCONST) {
                                memcpy(dest, value->u.blob, bits_to_bytes(value_size));
                        }
                        else if ((value->op == OP_INTCONST) && (value_size == SIZEOF_I8)) {
#if DEBUG_INITIALIZER
                                fprintf(state->errout, "byte: %02x\n", value->u.cval & 0xff);
#endif
                                *((uint8_t *)dest) = value->u.cval & 0xff;
                        }
                        else if ((value->op == OP_INTCONST) && (value_size == SIZEOF_I16)) {
                                *((uint16_t *)dest) = value->u.cval & 0xffff;
                        }
                        else if ((value->op == OP_INTCONST) && (value_size == SIZEOF_I32)) {
                                *((uint32_t *)dest) = value->u.cval & 0xffffffff;
                        }
                        else {
                                internal_error(state, 0, "unhandled constant initializer");
                        }
                        free_triple(state, value);
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                                comma = 1;
                        }
                        info.offset += value_size;
                        if ((type->type & TYPE_MASK) == TYPE_STRUCT) {
                                info.type = next_field(state, type, info.type);
                                info.offset = field_offset(state, type,
                                        info.type->field_ident);
                        }
                } while(comma && (peek(state) != TOK_RBRACE));
                if ((type->elements == ELEMENT_COUNT_UNSPECIFIED) &&
                        ((type->type & TYPE_MASK) == TYPE_ARRAY)) {
                        type->elements = max_offset / size_of(state, type->left);
                }
                eat(state, TOK_RBRACE);
                result = triple(state, OP_BLOBCONST, type, 0, 0);
                result->u.blob = buf;
        }
        return result;
}

static void resolve_branches(struct compile_state *state, struct triple *first)
{
        /* Make a second pass and finish anything outstanding
         * with respect to branches.  The only outstanding item
         * is to see if there are goto to labels that have not
         * been defined and to error about them.
         */
        int i;
        struct triple *ins;
        /* Also error on branches that do not use their targets */
        ins = first;
        do {
                if (!triple_is_ret(state, ins)) {
                        struct triple **expr ;
                        struct triple_set *set;
                        expr = triple_targ(state, ins, 0);
                        for(; expr; expr = triple_targ(state, ins, expr)) {
                                struct triple *targ;
                                targ = *expr;
                                for(set = targ?targ->use:0; set; set = set->next) {
                                        if (set->member == ins) {
                                                break;
                                        }
                                }
                                if (!set) {
                                        internal_error(state, ins, "targ not used");
                                }
                        }
                }
                ins = ins->next;
        } while(ins != first);
        /* See if there are goto to labels that have not been defined */
        for(i = 0; i < HASH_TABLE_SIZE; i++) {
                struct hash_entry *entry;
                for(entry = state->hash_table[i]; entry; entry = entry->next) {
                        struct triple *ins;
                        if (!entry->sym_label) {
                                continue;
                        }
                        ins = entry->sym_label->def;
                        if (!(ins->id & TRIPLE_FLAG_FLATTENED)) {
                                error(state, ins, "label `%s' used but not defined",
                                        entry->name);
                        }
                }
        }
}

static struct triple *function_definition(
        struct compile_state *state, struct type *type)
{
        struct triple *def, *tmp, *first, *end, *retvar, *ret;
        struct triple *fname;
        struct type *fname_type;
        struct hash_entry *ident;
        struct type *param, *crtype, *ctype;
        int i;
        if ((type->type &TYPE_MASK) != TYPE_FUNCTION) {
                error(state, 0, "Invalid function header");
        }

        /* Verify the function type */
        if (((type->right->type & TYPE_MASK) != TYPE_VOID)  &&
                ((type->right->type & TYPE_MASK) != TYPE_PRODUCT) &&
                (type->right->field_ident == 0)) {
                error(state, 0, "Invalid function parameters");
        }
        param = type->right;
        i = 0;
        while((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                i++;
                if (!param->left->field_ident) {
                        error(state, 0, "No identifier for parameter %d\n", i);
                }
                param = param->right;
        }
        i++;
        if (((param->type & TYPE_MASK) != TYPE_VOID) && !param->field_ident) {
                error(state, 0, "No identifier for parameter %d\n", i);
        }

        /* Get a list of statements for this function. */
        def = triple(state, OP_LIST, type, 0, 0);

        /* Start a new scope for the passed parameters */
        start_scope(state);

        /* Put a label at the very start of a function */
        first = label(state);
        RHS(def, 0) = first;

        /* Put a label at the very end of a function */
        end = label(state);
        flatten(state, first, end);
        /* Remember where return goes */
        ident = state->i_return;
        symbol(state, ident, &ident->sym_ident, end, end->type);

        /* Get the initial closure type */
        ctype = new_type(TYPE_JOIN, &void_type, 0);
        ctype->elements = 1;

        /* Add a variable for the return value */
        crtype = new_type(TYPE_TUPLE,
                /* Remove all type qualifiers from the return type */
                new_type(TYPE_PRODUCT, ctype, clone_type(0, type->left)), 0);
        crtype->elements = 2;
        flatten(state, end, variable(state, crtype));

        /* Allocate a variable for the return address */
        retvar = flatten(state, end, variable(state, &void_ptr_type));

        /* Add in the return instruction */
        ret = triple(state, OP_RET, &void_type, read_expr(state, retvar), 0);
        flatten(state, first, ret);

        /* Walk through the parameters and create symbol table entries
         * for them.
         */
        param = type->right;
        while((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                ident = param->left->field_ident;
                tmp = variable(state, param->left);
                var_symbol(state, ident, tmp);
                flatten(state, end, tmp);
                param = param->right;
        }
        if ((param->type & TYPE_MASK) != TYPE_VOID) {
                /* And don't forget the last parameter */
                ident = param->field_ident;
                tmp = variable(state, param);
                symbol(state, ident, &ident->sym_ident, tmp, tmp->type);
                flatten(state, end, tmp);
        }

        /* Add the declaration static const char __func__ [] = "func-name"  */
        fname_type = new_type(TYPE_ARRAY,
                clone_type(QUAL_CONST | STOR_STATIC, &char_type), 0);
        fname_type->type |= QUAL_CONST | STOR_STATIC;
        fname_type->elements = strlen(state->function) + 1;

        fname = triple(state, OP_BLOBCONST, fname_type, 0, 0);
        fname->u.blob = (void *)state->function;
        fname = flatten(state, end, fname);

        ident = state->i___func__;
        symbol(state, ident, &ident->sym_ident, fname, fname_type);

        /* Remember which function I am compiling.
         * Also assume the last defined function is the main function.
         */
        state->main_function = def;

        /* Now get the actual function definition */
        compound_statement(state, end);

        /* Finish anything unfinished with branches */
        resolve_branches(state, first);

        /* Remove the parameter scope */
        end_scope(state);


        /* Remember I have defined a function */
        if (!state->functions) {
                state->functions = def;
        } else {
                insert_triple(state, state->functions, def);
        }
        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->dbgout;
                fprintf(fp, "\n");
                loc(fp, state, 0);
                fprintf(fp, "\n__________ %s _________\n", __FUNCTION__);
                display_func(state, fp, def);
                fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
        }

        return def;
}

static struct triple *do_decl(struct compile_state *state,
        struct type *type, struct hash_entry *ident)
{
        struct triple *def;
        def = 0;
        /* Clean up the storage types used */
        switch (type->type & STOR_MASK) {
        case STOR_AUTO:
        case STOR_STATIC:
                /* These are the good types I am aiming for */
                break;
        case STOR_REGISTER:
                type->type &= ~STOR_MASK;
                type->type |= STOR_AUTO;
                break;
        case STOR_LOCAL:
        case STOR_EXTERN:
                type->type &= ~STOR_MASK;
                type->type |= STOR_STATIC;
                break;
        case STOR_TYPEDEF:
                if (!ident) {
                        error(state, 0, "typedef without name");
                }
                symbol(state, ident, &ident->sym_ident, 0, type);
                ident->tok = TOK_TYPE_NAME;
                return 0;
                break;
        default:
                internal_error(state, 0, "Undefined storage class");
        }
        if ((type->type & TYPE_MASK) == TYPE_FUNCTION) {
                // ignore function prototypes
                return def;
        }
        if (ident &&
                ((type->type & TYPE_MASK) == TYPE_ARRAY) &&
                ((type->type & STOR_MASK) != STOR_STATIC))
                error(state, 0, "non static arrays not supported");
        if (ident &&
                ((type->type & STOR_MASK) == STOR_STATIC) &&
                ((type->type & QUAL_CONST) == 0)) {
                error(state, 0, "non const static variables not supported");
        }
        if (ident) {
                def = variable(state, type);
                var_symbol(state, ident, def);
        }
        return def;
}

static void decl(struct compile_state *state, struct triple *first)
{
        struct type *base_type, *type;
        struct hash_entry *ident;
        struct triple *def;
        int global;
        global = (state->scope_depth <= GLOBAL_SCOPE_DEPTH);
        base_type = decl_specifiers(state);
        ident = 0;
        type = declarator(state, base_type, &ident, 0);
        type->type = attributes_opt(state, type->type);
        if (global && ident && (peek(state) == TOK_LBRACE)) {
                /* function */
                type->type_ident = ident;
                state->function = ident->name;
                def = function_definition(state, type);
                symbol(state, ident, &ident->sym_ident, def, type);
                state->function = 0;
        }
        else {
                int done;
                flatten(state, first, do_decl(state, type, ident));
                /* type or variable definition */
                do {
                        done = 1;
                        if (peek(state) == TOK_EQ) {
                                if (!ident) {
                                        error(state, 0, "cannot assign to a type");
                                }
                                eat(state, TOK_EQ);
                                flatten(state, first,
                                        init_expr(state,
                                                ident->sym_ident->def,
                                                initializer(state, type)));
                        }
                        arrays_complete(state, type);
                        if (peek(state) == TOK_COMMA) {
                                eat(state, TOK_COMMA);
                                ident = 0;
                                type = declarator(state, base_type, &ident, 0);
                                flatten(state, first, do_decl(state, type, ident));
                                done = 0;
                        }
                } while(!done);
                eat(state, TOK_SEMI);
        }
}

static void decls(struct compile_state *state)
{
        struct triple *list;
        int tok;
        list = label(state);
        while(1) {
                tok = peek(state);
                if (tok == TOK_EOF) {
                        return;
                }
                if (tok == TOK_SPACE) {
                        eat(state, TOK_SPACE);
                }
                decl(state, list);
                if (list->next != list) {
                        error(state, 0, "global variables not supported");
                }
        }
}

/*
 * Function inlining
 */
struct triple_reg_set {
        struct triple_reg_set *next;
        struct triple *member;
        struct triple *new;
};
struct reg_block {
        struct block *block;
        struct triple_reg_set *in;
        struct triple_reg_set *out;
        int vertex;
};
static void setup_basic_blocks(struct compile_state *, struct basic_blocks *bb);
static void analyze_basic_blocks(struct compile_state *state, struct basic_blocks *bb);
static void free_basic_blocks(struct compile_state *, struct basic_blocks *bb);
static int tdominates(struct compile_state *state, struct triple *dom, struct triple *sub);
static void walk_blocks(struct compile_state *state, struct basic_blocks *bb,
        void (*cb)(struct compile_state *state, struct block *block, void *arg),
        void *arg);
static void print_block(
        struct compile_state *state, struct block *block, void *arg);
static int do_triple_set(struct triple_reg_set **head,
        struct triple *member, struct triple *new_member);
static void do_triple_unset(struct triple_reg_set **head, struct triple *member);
static struct reg_block *compute_variable_lifetimes(
        struct compile_state *state, struct basic_blocks *bb);
static void free_variable_lifetimes(struct compile_state *state,
        struct basic_blocks *bb, struct reg_block *blocks);
#if DEBUG_EXPLICIT_CLOSURES
static void print_live_variables(struct compile_state *state,
        struct basic_blocks *bb, struct reg_block *rb, FILE *fp);
#endif


static struct triple *call(struct compile_state *state,
        struct triple *retvar, struct triple *ret_addr,
        struct triple *targ, struct triple *ret)
{
        struct triple *call;

        if (!retvar || !is_lvalue(state, retvar)) {
                internal_error(state, 0, "writing to a non lvalue?");
        }
        write_compatible(state, retvar->type, &void_ptr_type);

        call = new_triple(state, OP_CALL, &void_type, 1, 0);
        TARG(call, 0) = targ;
        MISC(call, 0) = ret;
        if (!targ || (targ->op != OP_LABEL)) {
                internal_error(state, 0, "call not to a label");
        }
        if (!ret || (ret->op != OP_RET)) {
                internal_error(state, 0, "call not matched with return");
        }
        return call;
}

static void walk_functions(struct compile_state *state,
        void (*cb)(struct compile_state *state, struct triple *func, void *arg),
        void *arg)
{
        struct triple *func, *first;
        func = first = state->functions;
        do {
                cb(state, func, arg);
                func = func->next;
        } while(func != first);
}

static void reverse_walk_functions(struct compile_state *state,
        void (*cb)(struct compile_state *state, struct triple *func, void *arg),
        void *arg)
{
        struct triple *func, *first;
        func = first = state->functions;
        do {
                func = func->prev;
                cb(state, func, arg);
        } while(func != first);
}


static void mark_live(struct compile_state *state, struct triple *func, void *arg)
{
        struct triple *ptr, *first;
        if (func->u.cval == 0) {
                return;
        }
        ptr = first = RHS(func, 0);
        do {
                if (ptr->op == OP_FCALL) {
                        struct triple *called_func;
                        called_func = MISC(ptr, 0);
                        /* Mark the called function as used */
                        if (!(func->id & TRIPLE_FLAG_FLATTENED)) {
                                called_func->u.cval++;
                        }
                        /* Remove the called function from the list */
                        called_func->prev->next = called_func->next;
                        called_func->next->prev = called_func->prev;

                        /* Place the called function before me on the list */
                        called_func->next       = func;
                        called_func->prev       = func->prev;
                        called_func->prev->next = called_func;
                        called_func->next->prev = called_func;
                }
                ptr = ptr->next;
        } while(ptr != first);
        func->id |= TRIPLE_FLAG_FLATTENED;
}

static void mark_live_functions(struct compile_state *state)
{
        /* Ensure state->main_function is the last function in
         * the list of functions.
         */
        if ((state->main_function->next != state->functions) ||
                (state->functions->prev != state->main_function)) {
                internal_error(state, 0,
                        "state->main_function is not at the end of the function list ");
        }
        state->main_function->u.cval = 1;
        reverse_walk_functions(state, mark_live, 0);
}

static int local_triple(struct compile_state *state,
        struct triple *func, struct triple *ins)
{
        int local = (ins->id & TRIPLE_FLAG_LOCAL);
#if 0
        if (!local) {
                FILE *fp = state->errout;
                fprintf(fp, "global: ");
                display_triple(fp, ins);
        }
#endif
        return local;
}

struct triple *copy_func(struct compile_state *state, struct triple *ofunc,
        struct occurrence *base_occurrence)
{
        struct triple *nfunc;
        struct triple *nfirst, *ofirst;
        struct triple *new, *old;

        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->dbgout;
                fprintf(fp, "\n");
                loc(fp, state, 0);
                fprintf(fp, "\n__________ %s _________\n", __FUNCTION__);
                display_func(state, fp, ofunc);
                fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
        }

        /* Make a new copy of the old function */
        nfunc = triple(state, OP_LIST, ofunc->type, 0, 0);
        nfirst = 0;
        ofirst = old = RHS(ofunc, 0);
        do {
                struct triple *new;
                struct occurrence *occurrence;
                int old_lhs, old_rhs;
                old_lhs = old->lhs;
                old_rhs = old->rhs;
                occurrence = inline_occurrence(state, base_occurrence, old->occurrence);
                if (ofunc->u.cval && (old->op == OP_FCALL)) {
                        MISC(old, 0)->u.cval += 1;
                }
                new = alloc_triple(state, old->op, old->type, old_lhs, old_rhs,
                        occurrence);
                if (!triple_stores_block(state, new)) {
                        memcpy(&new->u, &old->u, sizeof(new->u));
                }
                if (!nfirst) {
                        RHS(nfunc, 0) = nfirst = new;
                }
                else {
                        insert_triple(state, nfirst, new);
                }
                new->id |= TRIPLE_FLAG_FLATTENED;
                new->id |= old->id & TRIPLE_FLAG_COPY;

                /* During the copy remember new as user of old */
                use_triple(old, new);

                /* Remember which instructions are local */
                old->id |= TRIPLE_FLAG_LOCAL;
                old = old->next;
        } while(old != ofirst);

        /* Make a second pass to fix up any unresolved references */
        old = ofirst;
        new = nfirst;
        do {
                struct triple **oexpr, **nexpr;
                int count, i;
                /* Lookup where the copy is, to join pointers */
                count = TRIPLE_SIZE(old);
                for(i = 0; i < count; i++) {
                        oexpr = &old->param[i];
                        nexpr = &new->param[i];
                        if (*oexpr && !*nexpr) {
                                if (!local_triple(state, ofunc, *oexpr)) {
                                        *nexpr = *oexpr;
                                }
                                else if ((*oexpr)->use) {
                                        *nexpr = (*oexpr)->use->member;
                                }
                                if (*nexpr == old) {
                                        internal_error(state, 0, "new == old?");
                                }
                                use_triple(*nexpr, new);
                        }
                        if (!*nexpr && *oexpr) {
                                internal_error(state, 0, "Could not copy %d", i);
                        }
                }
                old = old->next;
                new = new->next;
        } while((old != ofirst) && (new != nfirst));

        /* Make a third pass to cleanup the extra useses */
        old = ofirst;
        new = nfirst;
        do {
                unuse_triple(old, new);
                /* Forget which instructions are local */
                old->id &= ~TRIPLE_FLAG_LOCAL;
                old = old->next;
                new = new->next;
        } while ((old != ofirst) && (new != nfirst));
        return nfunc;
}

static void expand_inline_call(
        struct compile_state *state, struct triple *me, struct triple *fcall)
{
        /* Inline the function call */
        struct type *ptype;
        struct triple *ofunc, *nfunc, *nfirst, *result, *retvar, *ins;
        struct triple *end, *nend;
        int pvals, i;

        /* Find the triples */
        ofunc = MISC(fcall, 0);
        if (ofunc->op != OP_LIST) {
                internal_error(state, 0, "improper function");
        }
        nfunc = copy_func(state, ofunc, fcall->occurrence);
        /* Prepend the parameter reading into the new function list */
        ptype = nfunc->type->right;
        pvals = fcall->rhs;
        for(i = 0; i < pvals; i++) {
                struct type *atype;
                struct triple *arg, *param;
                atype = ptype;
                if ((ptype->type & TYPE_MASK) == TYPE_PRODUCT) {
                        atype = ptype->left;
                }
                param = farg(state, nfunc, i);
                if ((param->type->type & TYPE_MASK) != (atype->type & TYPE_MASK)) {
                        internal_error(state, fcall, "param %d type mismatch", i);
                }
                arg = RHS(fcall, i);
                flatten(state, fcall, write_expr(state, param, arg));
                ptype = ptype->right;
        }
        result = 0;
        if ((nfunc->type->left->type & TYPE_MASK) != TYPE_VOID) {
                result = read_expr(state,
                        deref_index(state, fresult(state, nfunc), 1));
        }
        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->dbgout;
                fprintf(fp, "\n");
                loc(fp, state, 0);
                fprintf(fp, "\n__________ %s _________\n", __FUNCTION__);
                display_func(state, fp, nfunc);
                fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
        }

        /*
         * Get rid of the extra triples
         */
        /* Remove the read of the return address */
        ins = RHS(nfunc, 0)->prev->prev;
        if ((ins->op != OP_READ) || (RHS(ins, 0) != fretaddr(state, nfunc))) {
                internal_error(state, ins, "Not return address read?");
        }
        release_triple(state, ins);
        /* Remove the return instruction */
        ins = RHS(nfunc, 0)->prev;
        if (ins->op != OP_RET) {
                internal_error(state, ins, "Not return?");
        }
        release_triple(state, ins);
        /* Remove the retaddres variable */
        retvar = fretaddr(state, nfunc);
        if ((retvar->lhs != 1) ||
                (retvar->op != OP_ADECL) ||
                (retvar->next->op != OP_PIECE) ||
                (MISC(retvar->next, 0) != retvar)) {
                internal_error(state, retvar, "Not the return address?");
        }
        release_triple(state, retvar->next);
        release_triple(state, retvar);

        /* Remove the label at the start of the function */
        ins = RHS(nfunc, 0);
        if (ins->op != OP_LABEL) {
                internal_error(state, ins, "Not label?");
        }
        nfirst = ins->next;
        free_triple(state, ins);
        /* Release the new function header */
        RHS(nfunc, 0) = 0;
        free_triple(state, nfunc);

        /* Append the new function list onto the return list */
        end = fcall->prev;
        nend = nfirst->prev;
        end->next    = nfirst;
        nfirst->prev = end;
        nend->next   = fcall;
        fcall->prev  = nend;

        /* Now the result reading code */
        if (result) {
                result = flatten(state, fcall, result);
                propagate_use(state, fcall, result);
        }

        /* Release the original fcall instruction */
        release_triple(state, fcall);

        return;
}

/*
 *
 * Type of the result variable.
 *
 *                                     result
 *                                        |
 *                             +----------+------------+
 *                             |                       |
 *                     union of closures         result_type
 *                             |
 *          +------------------+---------------+
 *          |                                  |
 *       closure1                    ...   closuerN
 *          |                                  |
 *  +----+--+-+--------+-----+       +----+----+---+-----+
 *  |    |    |        |     |       |    |        |     |
 * var1 var2 var3 ... varN result   var1 var2 ... varN result
 *                           |
 *                  +--------+---------+
 *                  |                  |
 *          union of closures     result_type
 *                  |
 *            +-----+-------------------+
 *            |                         |
 *         closure1            ...  closureN
 *            |                         |
 *  +-----+---+----+----+      +----+---+----+-----+
 *  |     |        |    |      |    |        |     |
 * var1 var2 ... varN result  var1 var2 ... varN result
 */

static int add_closure_type(struct compile_state *state,
        struct triple *func, struct type *closure_type)
{
        struct type *type, *ctype, **next;
        struct triple *var, *new_var;
        int i;

#if 0
        FILE *fp = state->errout;
        fprintf(fp, "original_type: ");
        name_of(fp, fresult(state, func)->type);
        fprintf(fp, "\n");
#endif
        /* find the original type */
        var = fresult(state, func);
        type = var->type;
        if (type->elements != 2) {
                internal_error(state, var, "bad return type");
        }

        /* Find the complete closure type and update it */
        ctype = type->left->left;
        next = &ctype->left;
        while(((*next)->type & TYPE_MASK) == TYPE_OVERLAP) {
                next = &(*next)->right;
        }
        *next = new_type(TYPE_OVERLAP, *next, dup_type(state, closure_type));
        ctype->elements += 1;

#if 0
        fprintf(fp, "new_type: ");
        name_of(fp, type);
        fprintf(fp, "\n");
        fprintf(fp, "ctype: %p %d bits: %d ",
                ctype, ctype->elements, reg_size_of(state, ctype));
        name_of(fp, ctype);
        fprintf(fp, "\n");
#endif

        /* Regenerate the variable with the new type definition */
        new_var = pre_triple(state, var, OP_ADECL, type, 0, 0);
        new_var->id |= TRIPLE_FLAG_FLATTENED;
        for(i = 0; i < new_var->lhs; i++) {
                LHS(new_var, i)->id |= TRIPLE_FLAG_FLATTENED;
        }

        /* Point everyone at the new variable */
        propagate_use(state, var, new_var);

        /* Release the original variable */
        for(i = 0; i < var->lhs; i++) {
                release_triple(state, LHS(var, i));
        }
        release_triple(state, var);

        /* Return the index of the added closure type */
        return ctype->elements - 1;
}

static struct triple *closure_expr(struct compile_state *state,
        struct triple *func, int closure_idx, int var_idx)
{
        return deref_index(state,
                deref_index(state,
                        deref_index(state, fresult(state, func), 0),
                        closure_idx),
                var_idx);
}


static void insert_triple_set(
        struct triple_reg_set **head, struct triple *member)
{
        struct triple_reg_set *new;
        new = xcmalloc(sizeof(*new), "triple_set");
        new->member = member;
        new->new    = 0;
        new->next   = *head;
        *head       = new;
}

static int ordered_triple_set(
        struct triple_reg_set **head, struct triple *member)
{
        struct triple_reg_set **ptr;
        if (!member)
                return 0;
        ptr = head;
        while(*ptr) {
                if (member == (*ptr)->member) {
                        return 0;
                }
                /* keep the list ordered */
                if (member->id < (*ptr)->member->id) {
                        break;
                }
                ptr = &(*ptr)->next;
        }
        insert_triple_set(ptr, member);
        return 1;
}


static void free_closure_variables(struct compile_state *state,
        struct triple_reg_set **enclose)
{
        struct triple_reg_set *entry, *next;
        for(entry = *enclose; entry; entry = next) {
                next = entry->next;
                do_triple_unset(enclose, entry->member);
        }
}

static int lookup_closure_index(struct compile_state *state,
        struct triple *me, struct triple *val)
{
        struct triple *first, *ins, *next;
        first = RHS(me, 0);
        next = first;
        do {
                struct triple *result;
                struct triple *index0, *index1, *index2, *read, *write;
                ins = next;
                next = ins->next;
                if (ins->op != OP_CALL) {
                        continue;
                }
                /* I am at a previous call point examine it closely */
                if (ins->next->op != OP_LABEL) {
                        internal_error(state, ins, "call not followed by label");
                }
                /* Does this call does not enclose any variables? */
                if ((ins->next->next->op != OP_INDEX) ||
                        (ins->next->next->u.cval != 0) ||
                        (result = MISC(ins->next->next, 0)) ||
                        (result->id & TRIPLE_FLAG_LOCAL)) {
                        continue;
                }
                /* The pattern is:
                 * 0 index result < 0 >
                 * 1 index 0 < ? >
                 * 2 index 1 < ? >
                 * 3 read  2
                 * 4 write 3 var
                 */
                for(index0 = ins->next->next;
                        (index0->op == OP_INDEX) &&
                                (MISC(index0, 0) == result) &&
                                (index0->u.cval == 0) ;
                        index0 = write->next)
                {
                        index1 = index0->next;
                        index2 = index1->next;
                        read   = index2->next;
                        write  = read->next;
                        if ((index0->op != OP_INDEX) ||
                                (index1->op != OP_INDEX) ||
                                (index2->op != OP_INDEX) ||
                                (read->op != OP_READ) ||
                                (write->op != OP_WRITE) ||
                                (MISC(index1, 0) != index0) ||
                                (MISC(index2, 0) != index1) ||
                                (RHS(read, 0) != index2) ||
                                (RHS(write, 0) != read)) {
                                internal_error(state, index0, "bad var read");
                        }
                        if (MISC(write, 0) == val) {
                                return index2->u.cval;
                        }
                }
        } while(next != first);
        return -1;
}

static inline int enclose_triple(struct triple *ins)
{
        return (ins && ((ins->type->type & TYPE_MASK) != TYPE_VOID));
}

static void compute_closure_variables(struct compile_state *state,
        struct triple *me, struct triple *fcall, struct triple_reg_set **enclose)
{
        struct triple_reg_set *set, *vars, **last_var;
        struct basic_blocks bb;
        struct reg_block *rb;
        struct block *block;
        struct triple *old_result, *first, *ins;
        size_t count, idx;
        uint64_t used_indices;
        int i, max_index;
#define MAX_INDICES (sizeof(used_indices)*CHAR_BIT)
#define ID_BITS(X) ((X) & (TRIPLE_FLAG_LOCAL -1))
        struct {
                unsigned id;
                int index;
        } *info;


        /* Find the basic blocks of this function */
        bb.func = me;
        bb.first = RHS(me, 0);
        old_result = 0;
        if (!triple_is_ret(state, bb.first->prev)) {
                bb.func = 0;
        } else {
                old_result = fresult(state, me);
        }
        analyze_basic_blocks(state, &bb);

        /* Find which variables are currently alive in a given block */
        rb = compute_variable_lifetimes(state, &bb);

        /* Find the variables that are currently alive */
        block = block_of_triple(state, fcall);
        if (!block || (block->vertex <= 0) || (block->vertex > bb.last_vertex)) {
                internal_error(state, fcall, "No reg block? block: %p", block);
        }

#if DEBUG_EXPLICIT_CLOSURES
        print_live_variables(state, &bb, rb, state->dbgout);
        fflush(state->dbgout);
#endif

        /* Count the number of triples in the function */
        first = RHS(me, 0);
        ins = first;
        count = 0;
        do {
                count++;
                ins = ins->next;
        } while(ins != first);

        /* Allocate some memory to temporary hold the id info */
        info = xcmalloc(sizeof(*info) * (count +1), "info");

        /* Mark the local function */
        first = RHS(me, 0);
        ins = first;
        idx = 1;
        do {
                info[idx].id = ins->id;
                ins->id = TRIPLE_FLAG_LOCAL | idx;
                idx++;
                ins = ins->next;
        } while(ins != first);

        /*
         * Build the list of variables to enclose.
         *
         * A target it to put the same variable in the
         * same slot for ever call of a given function.
         * After coloring this removes all of the variable
         * manipulation code.
         *
         * The list of variables to enclose is built ordered
         * program order because except in corner cases this
         * gives me the stability of assignment I need.
         *
         * To gurantee that stability I lookup the variables
         * to see where they have been used before and
         * I build my final list with the assigned indices.
         */
        vars = 0;
        if (enclose_triple(old_result)) {
                ordered_triple_set(&vars, old_result);
        }
        for(set = rb[block->vertex].out; set; set = set->next) {
                if (!enclose_triple(set->member)) {
                        continue;
                }
                if ((set->member == fcall) || (set->member == old_result)) {
                        continue;
                }
                if (!local_triple(state, me, set->member)) {
                        internal_error(state, set->member, "not local?");
                }
                ordered_triple_set(&vars, set->member);
        }

        /* Lookup the current indices of the live varialbe */
        used_indices = 0;
        max_index = -1;
        for(set = vars; set ; set = set->next) {
                struct triple *ins;
                int index;
                ins = set->member;
                index  = lookup_closure_index(state, me, ins);
                info[ID_BITS(ins->id)].index = index;
                if (index < 0) {
                        continue;
                }
                if (index >= MAX_INDICES) {
                        internal_error(state, ins, "index unexpectedly large");
                }
                if (used_indices & ((uint64_t)1 << index)) {
                        internal_error(state, ins, "index previously used?");
                }
                /* Remember which indices have been used */
                used_indices |= ((uint64_t)1 << index);
                if (index > max_index) {
                        max_index = index;
                }
        }

        /* Walk through the live variables and make certain
         * everything is assigned an index.
         */
        for(set = vars; set; set = set->next) {
                struct triple *ins;
                int index;
                ins = set->member;
                index = info[ID_BITS(ins->id)].index;
                if (index >= 0) {
                        continue;
                }
                /* Find the lowest unused index value */
                for(index = 0; index < MAX_INDICES; index++) {
                        if (!(used_indices & ((uint64_t)1 << index))) {
                                break;
                        }
                }
                if (index == MAX_INDICES) {
                        internal_error(state, ins, "no free indices?");
                }
                info[ID_BITS(ins->id)].index = index;
                /* Remember which indices have been used */
                used_indices |= ((uint64_t)1 << index);
                if (index > max_index) {
                        max_index = index;
                }
        }

        /* Build the return list of variables with positions matching
         * their indices.
         */
        *enclose = 0;
        last_var = enclose;
        for(i = 0; i <= max_index; i++) {
                struct triple *var;
                var = 0;
                if (used_indices & ((uint64_t)1 << i)) {
                        for(set = vars; set; set = set->next) {
                                int index;
                                index = info[ID_BITS(set->member->id)].index;
                                if (index == i) {
                                        var = set->member;
                                        break;
                                }
                        }
                        if (!var) {
                                internal_error(state, me, "missing variable");
                        }
                }
                insert_triple_set(last_var, var);
                last_var = &(*last_var)->next;
        }

#if DEBUG_EXPLICIT_CLOSURES
        /* Print out the variables to be enclosed */
        loc(state->dbgout, state, fcall);
        fprintf(state->dbgout, "Alive:\n");
        for(set = *enclose; set; set = set->next) {
                display_triple(state->dbgout, set->member);
        }
        fflush(state->dbgout);
#endif

        /* Clear the marks */
        ins = first;
        do {
                ins->id = info[ID_BITS(ins->id)].id;
                ins = ins->next;
        } while(ins != first);

        /* Release the ordered list of live variables */
        free_closure_variables(state, &vars);

        /* Release the storage of the old ids */
        xfree(info);

        /* Release the variable lifetime information */
        free_variable_lifetimes(state, &bb, rb);

        /* Release the basic blocks of this function */
        free_basic_blocks(state, &bb);
}

static void expand_function_call(
        struct compile_state *state, struct triple *me, struct triple *fcall)
{
        /* Generate an ordinary function call */
        struct type *closure_type, **closure_next;
        struct triple *func, *func_first, *func_last, *retvar;
        struct triple *first;
        struct type *ptype, *rtype;
        struct triple *ret_addr, *ret_loc;
        struct triple_reg_set *enclose, *set;
        int closure_idx, pvals, i;

#if DEBUG_EXPLICIT_CLOSURES
        FILE *fp = state->dbgout;
        fprintf(fp, "\ndisplay_func(me) ptr: %p\n", fcall);
        display_func(state, fp, MISC(fcall, 0));
        display_func(state, fp, me);
        fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
#endif

        /* Find the triples */
        func = MISC(fcall, 0);
        func_first = RHS(func, 0);
        retvar = fretaddr(state, func);
        func_last  = func_first->prev;
        first = fcall->next;

        /* Find what I need to enclose */
        compute_closure_variables(state, me, fcall, &enclose);

        /* Compute the closure type */
        closure_type = new_type(TYPE_TUPLE, 0, 0);
        closure_type->elements = 0;
        closure_next = &closure_type->left;
        for(set = enclose; set ; set = set->next) {
                struct type *type;
                type = &void_type;
                if (set->member) {
                        type = set->member->type;
                }
                if (!*closure_next) {
                        *closure_next = type;
                } else {
                        *closure_next = new_type(TYPE_PRODUCT, *closure_next,
                                type);
                        closure_next = &(*closure_next)->right;
                }
                closure_type->elements += 1;
        }
        if (closure_type->elements == 0) {
                closure_type->type = TYPE_VOID;
        }


#if DEBUG_EXPLICIT_CLOSURES
        fprintf(state->dbgout, "closure type: ");
        name_of(state->dbgout, closure_type);
        fprintf(state->dbgout, "\n");
#endif

        /* Update the called functions closure variable */
        closure_idx = add_closure_type(state, func, closure_type);
        free(closure_type);
        closure_type = NULL;

        /* Generate some needed triples */
        ret_loc = label(state);
        ret_addr = triple(state, OP_ADDRCONST, &void_ptr_type, ret_loc, 0);

        /* Pass the parameters to the new function */
        ptype = func->type->right;
        pvals = fcall->rhs;
        for(i = 0; i < pvals; i++) {
                struct type *atype;
                struct triple *arg, *param;
                atype = ptype;
                if ((ptype->type & TYPE_MASK) == TYPE_PRODUCT) {
                        atype = ptype->left;
                }
                param = farg(state, func, i);
                if ((param->type->type & TYPE_MASK) != (atype->type & TYPE_MASK)) {
                        internal_error(state, fcall, "param type mismatch");
                }
                arg = RHS(fcall, i);
                flatten(state, first, write_expr(state, param, arg));
                ptype = ptype->right;
        }
        rtype = func->type->left;

        /* Thread the triples together */
        ret_loc       = flatten(state, first, ret_loc);

        /* Save the active variables in the result variable */
        for(i = 0, set = enclose; set ; set = set->next, i++) {
                if (!set->member) {
                        continue;
                }
                flatten(state, ret_loc,
                        write_expr(state,
                                closure_expr(state, func, closure_idx, i),
                                read_expr(state, set->member)));
        }

        /* Initialize the return value */
        if ((rtype->type & TYPE_MASK) != TYPE_VOID) {
                flatten(state, ret_loc,
                        write_expr(state,
                                deref_index(state, fresult(state, func), 1),
                                new_triple(state, OP_UNKNOWNVAL, rtype,  0, 0)));
        }

        ret_addr      = flatten(state, ret_loc, ret_addr);
        flatten(state, ret_loc, write_expr(state, retvar, ret_addr));
        flatten(state, ret_loc,
                call(state, retvar, ret_addr, func_first, func_last));

        /* Find the result */
        if ((rtype->type & TYPE_MASK) != TYPE_VOID) {
                struct triple * result;
                result = flatten(state, first,
                        read_expr(state,
                                deref_index(state, fresult(state, func), 1)));

                propagate_use(state, fcall, result);
        }

        /* Release the original fcall instruction */
        release_triple(state, fcall);

        /* Restore the active variables from the result variable */
        for(i = 0, set = enclose; set ; set = set->next, i++) {
                struct triple_set *use, *next;
                struct triple *new;
                struct basic_blocks bb;
                if (!set->member || (set->member == fcall)) {
                        continue;
                }
                /* Generate an expression for the value */
                new = flatten(state, first,
                        read_expr(state,
                                closure_expr(state, func, closure_idx, i)));


                /* If the original is an lvalue restore the preserved value */
                if (is_lvalue(state, set->member)) {
                        flatten(state, first,
                                write_expr(state, set->member, new));
                        continue;
                }
                /*
                 * If the original is a value update the dominated uses.
                 */

                /* Analyze the basic blocks so I can see who dominates whom */
                bb.func = me;
                bb.first = RHS(me, 0);
                if (!triple_is_ret(state, bb.first->prev)) {
                        bb.func = 0;
                }
                analyze_basic_blocks(state, &bb);


#if DEBUG_EXPLICIT_CLOSURES
                fprintf(state->errout, "Updating domindated uses: %p -> %p\n",
                        set->member, new);
#endif
                /* If fcall dominates the use update the expression */
                for(use = set->member->use; use; use = next) {
                        /* Replace use modifies the use chain and
                         * removes use, so I must take a copy of the
                         * next entry early.
                         */
                        next = use->next;
                        if (!tdominates(state, fcall, use->member)) {
                                continue;
                        }
                        replace_use(state, set->member, new, use->member);
                }

                /* Release the basic blocks, the instructions will be
                 * different next time, and flatten/insert_triple does
                 * not update the block values so I can't cache the analysis.
                 */
                free_basic_blocks(state, &bb);
        }

        /* Release the closure variable list */
        free_closure_variables(state, &enclose);

        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->dbgout;
                fprintf(fp, "\n");
                loc(fp, state, 0);
                fprintf(fp, "\n__________ %s _________\n", __FUNCTION__);
                display_func(state, fp, func);
                display_func(state, fp, me);
                fprintf(fp, "__________ %s _________ done\n\n", __FUNCTION__);
        }

        return;
}

static int do_inline(struct compile_state *state, struct triple *func)
{
        int do_inline;
        int policy;

        policy = state->compiler->flags & COMPILER_INLINE_MASK;
        switch(policy) {
        case COMPILER_INLINE_ALWAYS:
                do_inline = 1;
                if (func->type->type & ATTRIB_NOINLINE) {
                        error(state, func, "noinline with always_inline compiler option");
                }
                break;
        case COMPILER_INLINE_NEVER:
                do_inline = 0;
                if (func->type->type & ATTRIB_ALWAYS_INLINE) {
                        error(state, func, "always_inline with noinline compiler option");
                }
                break;
        case COMPILER_INLINE_DEFAULTON:
                switch(func->type->type & STOR_MASK) {
                case STOR_STATIC | STOR_INLINE:
                case STOR_LOCAL  | STOR_INLINE:
                case STOR_EXTERN | STOR_INLINE:
                        do_inline = 1;
                        break;
                default:
                        do_inline = 1;
                        break;
                }
                break;
        case COMPILER_INLINE_DEFAULTOFF:
                switch(func->type->type & STOR_MASK) {
                case STOR_STATIC | STOR_INLINE:
                case STOR_LOCAL  | STOR_INLINE:
                case STOR_EXTERN | STOR_INLINE:
                        do_inline = 1;
                        break;
                default:
                        do_inline = 0;
                        break;
                }
                break;
        case COMPILER_INLINE_NOPENALTY:
                switch(func->type->type & STOR_MASK) {
                case STOR_STATIC | STOR_INLINE:
                case STOR_LOCAL  | STOR_INLINE:
                case STOR_EXTERN | STOR_INLINE:
                        do_inline = 1;
                        break;
                default:
                        do_inline = (func->u.cval == 1);
                        break;
                }
                break;
        default:
                internal_error(state, 0, "Unimplemented inline policy");
                break;
        }
        /* Force inlining */
        if (func->type->type & ATTRIB_NOINLINE) {
                do_inline = 0;
        }
        if (func->type->type & ATTRIB_ALWAYS_INLINE) {
                do_inline = 1;
        }
        return do_inline;
}

static void inline_function(struct compile_state *state, struct triple *me, void *arg)
{
        struct triple *first, *ptr, *next;
        /* If the function is not used don't bother */
        if (me->u.cval <= 0) {
                return;
        }
        if (state->compiler->debug & DEBUG_CALLS2) {
                FILE *fp = state->dbgout;
                fprintf(fp, "in: %s\n",
                        me->type->type_ident->name);
        }

        first = RHS(me, 0);
        next = first;
        do {
                struct triple *func, *prev;
                ptr = next;
                prev = ptr->prev;
                next = ptr->next;
                if (ptr->op != OP_FCALL) {
                        continue;
                }
                func = MISC(ptr, 0);
                /* See if the function should be inlined */
                if (!do_inline(state, func)) {
                        /* Put a label after the fcall */
                        post_triple(state, ptr, OP_LABEL, &void_type, 0, 0);
                        continue;
                }
                if (state->compiler->debug & DEBUG_CALLS) {
                        FILE *fp = state->dbgout;
                        if (state->compiler->debug & DEBUG_CALLS2) {
                                loc(fp, state, ptr);
                        }
                        fprintf(fp, "inlining %s\n",
                                func->type->type_ident->name);
                        fflush(fp);
                }

                /* Update the function use counts */
                func->u.cval -= 1;

                /* Replace the fcall with the called function */
                expand_inline_call(state, me, ptr);

                next = prev->next;
        } while (next != first);

        next = first;
        do {
                struct triple *prev, *func;
                ptr = next;
                prev = ptr->prev;
                next = ptr->next;
                if (ptr->op != OP_FCALL) {
                        continue;
                }
                func = MISC(ptr, 0);
                if (state->compiler->debug & DEBUG_CALLS) {
                        FILE *fp = state->dbgout;
                        if (state->compiler->debug & DEBUG_CALLS2) {
                                loc(fp, state, ptr);
                        }
                        fprintf(fp, "calling %s\n",
                                func->type->type_ident->name);
                        fflush(fp);
                }
                /* Replace the fcall with the instruction sequence
                 * needed to make the call.
                 */
                expand_function_call(state, me, ptr);
                next = prev->next;
        } while(next != first);
}

static void inline_functions(struct compile_state *state, struct triple *func)
{
        inline_function(state, func, 0);
        reverse_walk_functions(state, inline_function, 0);
}

static void insert_function(struct compile_state *state,
        struct triple *func, void *arg)
{
        struct triple *first, *end, *ffirst, *fend;

        if (state->compiler->debug & DEBUG_INLINE) {
                FILE *fp = state->errout;
                fprintf(fp, "%s func count: %d\n",
                        func->type->type_ident->name, func->u.cval);
        }
        if (func->u.cval == 0) {
                return;
        }

        /* Find the end points of the lists */
        first  = arg;
        end    = first->prev;
        ffirst = RHS(func, 0);
        fend   = ffirst->prev;

        /* splice the lists together */
        end->next    = ffirst;
        ffirst->prev = end;
        fend->next   = first;
        first->prev  = fend;
}

struct triple *input_asm(struct compile_state *state)
{
        struct asm_info *info;
        struct triple *def;
        int i, out;

        info = xcmalloc(sizeof(*info), "asm_info");
        info->str = "";

        out = sizeof(arch_input_regs)/sizeof(arch_input_regs[0]);
        memcpy(&info->tmpl.lhs, arch_input_regs, sizeof(arch_input_regs));

        def = new_triple(state, OP_ASM, &void_type, out, 0);
        def->u.ainfo = info;
        def->id |= TRIPLE_FLAG_VOLATILE;

        for(i = 0; i < out; i++) {
                struct triple *piece;
                piece = triple(state, OP_PIECE, &int_type, def, 0);
                piece->u.cval = i;
                LHS(def, i) = piece;
        }

        return def;
}

struct triple *output_asm(struct compile_state *state)
{
        struct asm_info *info;
        struct triple *def;
        int in;

        info = xcmalloc(sizeof(*info), "asm_info");
        info->str = "";

        in = sizeof(arch_output_regs)/sizeof(arch_output_regs[0]);
        memcpy(&info->tmpl.rhs, arch_output_regs, sizeof(arch_output_regs));

        def = new_triple(state, OP_ASM, &void_type, 0, in);
        def->u.ainfo = info;
        def->id |= TRIPLE_FLAG_VOLATILE;

        return def;
}

static void join_functions(struct compile_state *state)
{
        struct triple *start, *end, *call, *in, *out, *func;
        struct file_state file;
        struct type *pnext, *param;
        struct type *result_type, *args_type;
        int idx;

        /* Be clear the functions have not been joined yet */
        state->functions_joined = 0;

        /* Dummy file state to get debug handing right */
        memset(&file, 0, sizeof(file));
        file.basename = "";
        file.line = 0;
        file.report_line = 0;
        file.report_name = file.basename;
        file.prev = state->file;
        state->file = &file;
        state->function = "";

        if (!state->main_function) {
                error(state, 0, "No functions to compile\n");
        }

        /* The type of arguments */
        args_type   = state->main_function->type->right;
        /* The return type without any specifiers */
        result_type = clone_type(0, state->main_function->type->left);


        /* Verify the external arguments */
        if (registers_of(state, args_type) > ARCH_INPUT_REGS) {
                error(state, state->main_function,
                        "Too many external input arguments");
        }
        if (registers_of(state, result_type) > ARCH_OUTPUT_REGS) {
                error(state, state->main_function,
                        "Too many external output arguments");
        }

        /* Lay down the basic program structure */
        end           = label(state);
        start         = label(state);
        start         = flatten(state, state->first, start);
        end           = flatten(state, state->first, end);
        in            = input_asm(state);
        out           = output_asm(state);
        call          = new_triple(state, OP_FCALL, result_type, -1, registers_of(state, args_type));
        MISC(call, 0) = state->main_function;
        in            = flatten(state, state->first, in);
        call          = flatten(state, state->first, call);
        out           = flatten(state, state->first, out);


        /* Read the external input arguments */
        pnext = args_type;
        idx = 0;
        while(pnext && ((pnext->type & TYPE_MASK) != TYPE_VOID)) {
                struct triple *expr;
                param = pnext;
                pnext = 0;
                if ((param->type & TYPE_MASK) == TYPE_PRODUCT) {
                        pnext = param->right;
                        param = param->left;
                }
                if (registers_of(state, param) != 1) {
                        error(state, state->main_function,
                                "Arg: %d %s requires multiple registers",
                                idx + 1, param->field_ident->name);
                }
                expr = read_expr(state, LHS(in, idx));
                RHS(call, idx) = expr;
                expr = flatten(state, call, expr);
                use_triple(expr, call);

                idx++;
        }


        /* Write the external output arguments */
        pnext = result_type;
        if ((pnext->type & TYPE_MASK) == TYPE_STRUCT) {
                pnext = result_type->left;
        }
        for(idx = 0; idx < out->rhs; idx++) {
                struct triple *expr;
                param = pnext;
                pnext = 0;
                if (param && ((param->type & TYPE_MASK) == TYPE_PRODUCT)) {
                        pnext = param->right;
                        param = param->left;
                }
                if (param && ((param->type & TYPE_MASK) == TYPE_VOID)) {
                        param = 0;
                }
                if (param) {
                        if (registers_of(state, param) != 1) {
                                error(state, state->main_function,
                                        "Result: %d %s requires multiple registers",
                                        idx, param->field_ident->name);
                        }
                        expr = read_expr(state, call);
                        if ((result_type->type & TYPE_MASK) == TYPE_STRUCT) {
                                expr = deref_field(state, expr, param->field_ident);
                        }
                } else {
                        expr = triple(state, OP_UNKNOWNVAL, &int_type, 0, 0);
                }
                flatten(state, out, expr);
                RHS(out, idx) = expr;
                use_triple(expr, out);
        }

        /* Allocate a dummy containing function */
        func = triple(state, OP_LIST,
                new_type(TYPE_FUNCTION, &void_type, &void_type), 0, 0);
        func->type->type_ident = lookup(state, "", 0);
        RHS(func, 0) = state->first;
        func->u.cval = 1;

        /* See which functions are called, and how often */
        mark_live_functions(state);
        inline_functions(state, func);
        walk_functions(state, insert_function, end);

        if (start->next != end) {
                flatten(state, start, branch(state, end, 0));
        }

        /* OK now the functions have been joined. */
        state->functions_joined = 1;

        /* Done now cleanup */
        state->file = file.prev;
        state->function = 0;
}

/*
 * Data structurs for optimation.
 */


static int do_use_block(
        struct block *used, struct block_set **head, struct block *user,
        int front)
{
        struct block_set **ptr, *new;
        if (!used)
                return 0;
        if (!user)
                return 0;
        ptr = head;
        while(*ptr) {
                if ((*ptr)->member == user) {
                        return 0;
                }
                ptr = &(*ptr)->next;
        }
        new = xcmalloc(sizeof(*new), "block_set");
        new->member = user;
        if (front) {
                new->next = *head;
                *head = new;
        }
        else {
                new->next = 0;
                *ptr = new;
        }
        return 1;
}
static int do_unuse_block(
        struct block *used, struct block_set **head, struct block *unuser)
{
        struct block_set *use, **ptr;
        int count;
        count = 0;
        ptr = head;
        while(*ptr) {
                use = *ptr;
                if (use->member == unuser) {
                        *ptr = use->next;
                        memset(use, -1, sizeof(*use));
                        xfree(use);
                        count += 1;
                }
                else {
                        ptr = &use->next;
                }
        }
        return count;
}

static void use_block(struct block *used, struct block *user)
{
        int count;
        /* Append new to the head of the list, print_block
         * depends on this.
         */
        count = do_use_block(used, &used->use, user, 1);
        used->users += count;
}
static void unuse_block(struct block *used, struct block *unuser)
{
        int count;
        count = do_unuse_block(used, &used->use, unuser);
        used->users -= count;
}

static void add_block_edge(struct block *block, struct block *edge, int front)
{
        int count;
        count = do_use_block(block, &block->edges, edge, front);
        block->edge_count += count;
}

static void remove_block_edge(struct block *block, struct block *edge)
{
        int count;
        count = do_unuse_block(block, &block->edges, edge);
        block->edge_count -= count;
}

static void idom_block(struct block *idom, struct block *user)
{
        do_use_block(idom, &idom->idominates, user, 0);
}

static void unidom_block(struct block *idom, struct block *unuser)
{
        do_unuse_block(idom, &idom->idominates, unuser);
}

static void domf_block(struct block *block, struct block *domf)
{
        do_use_block(block, &block->domfrontier, domf, 0);
}

static void undomf_block(struct block *block, struct block *undomf)
{
        do_unuse_block(block, &block->domfrontier, undomf);
}

static void ipdom_block(struct block *ipdom, struct block *user)
{
        do_use_block(ipdom, &ipdom->ipdominates, user, 0);
}

static void unipdom_block(struct block *ipdom, struct block *unuser)
{
        do_unuse_block(ipdom, &ipdom->ipdominates, unuser);
}

static void ipdomf_block(struct block *block, struct block *ipdomf)
{
        do_use_block(block, &block->ipdomfrontier, ipdomf, 0);
}

static void unipdomf_block(struct block *block, struct block *unipdomf)
{
        do_unuse_block(block, &block->ipdomfrontier, unipdomf);
}

static int walk_triples(
        struct compile_state *state,
        int (*cb)(struct compile_state *state, struct triple *ptr, void *arg),
        void *arg)
{
        struct triple *ptr;
        int result;
        ptr = state->first;
        do {
                result = cb(state, ptr, arg);
                if (ptr->next->prev != ptr) {
                        internal_error(state, ptr->next, "bad prev");
                }
                ptr = ptr->next;
        } while((result == 0) && (ptr != state->first));
        return result;
}

#define PRINT_LIST 1
static int do_print_triple(struct compile_state *state, struct triple *ins, void *arg)
{
        FILE *fp = arg;
        int op;
        op = ins->op;
        if (op == OP_LIST) {
#if !PRINT_LIST
                return 0;
#endif
        }
        if ((op == OP_LABEL) && (ins->use)) {
                fprintf(fp, "\n%p:\n", ins);
        }
        display_triple(fp, ins);

        if (triple_is_branch(state, ins) && ins->use &&
                (ins->op != OP_RET) && (ins->op != OP_FCALL)) {
                internal_error(state, ins, "branch used?");
        }
        if (triple_is_branch(state, ins)) {
                fprintf(fp, "\n");
        }
        return 0;
}

static void print_triples(struct compile_state *state)
{
        if (state->compiler->debug & DEBUG_TRIPLES) {
                FILE *fp = state->dbgout;
                fprintf(fp, "--------------- triples ---------------\n");
                walk_triples(state, do_print_triple, fp);
                fprintf(fp, "\n");
        }
}

struct cf_block {
        struct block *block;
};
static void find_cf_blocks(struct cf_block *cf, struct block *block)
{
        struct block_set *edge;
        if (!block || (cf[block->vertex].block == block)) {
                return;
        }
        cf[block->vertex].block = block;
        for(edge = block->edges; edge; edge = edge->next) {
                find_cf_blocks(cf, edge->member);
        }
}

static void print_control_flow(struct compile_state *state,
        FILE *fp, struct basic_blocks *bb)
{
        struct cf_block *cf;
        int i;
        fprintf(fp, "\ncontrol flow\n");
        cf = xcmalloc(sizeof(*cf) * (bb->last_vertex + 1), "cf_block");
        find_cf_blocks(cf, bb->first_block);

        for(i = 1; i <= bb->last_vertex; i++) {
                struct block *block;
                struct block_set *edge;
                block = cf[i].block;
                if (!block)
                        continue;
                fprintf(fp, "(%p) %d:", block, block->vertex);
                for(edge = block->edges; edge; edge = edge->next) {
                        fprintf(fp, " %d", edge->member->vertex);
                }
                fprintf(fp, "\n");
        }

        xfree(cf);
}

static void free_basic_block(struct compile_state *state, struct block *block)
{
        struct block_set *edge, *entry;
        struct block *child;
        if (!block) {
                return;
        }
        if (block->vertex == -1) {
                return;
        }
        block->vertex = -1;
        for(edge = block->edges; edge; edge = edge->next) {
                if (edge->member) {
                        unuse_block(edge->member, block);
                }
        }
        if (block->idom) {
                unidom_block(block->idom, block);
        }
        block->idom = 0;
        if (block->ipdom) {
                unipdom_block(block->ipdom, block);
        }
        block->ipdom = 0;
        while((entry = block->use)) {
                child = entry->member;
                unuse_block(block, child);
                if (child && (child->vertex != -1)) {
                        for(edge = child->edges; edge; edge = edge->next) {
                                edge->member = 0;
                        }
                }
        }
        while((entry = block->idominates)) {
                child = entry->member;
                unidom_block(block, child);
                if (child && (child->vertex != -1)) {
                        child->idom = 0;
                }
        }
        while((entry = block->domfrontier)) {
                child = entry->member;
                undomf_block(block, child);
        }
        while((entry = block->ipdominates)) {
                child = entry->member;
                unipdom_block(block, child);
                if (child && (child->vertex != -1)) {
                        child->ipdom = 0;
                }
        }
        while((entry = block->ipdomfrontier)) {
                child = entry->member;
                unipdomf_block(block, child);
        }
        if (block->users != 0) {
                internal_error(state, 0, "block still has users");
        }
        while((edge = block->edges)) {
                child = edge->member;
                remove_block_edge(block, child);

                if (child && (child->vertex != -1)) {
                        free_basic_block(state, child);
                }
        }
        memset(block, -1, sizeof(*block));
}

static void free_basic_blocks(struct compile_state *state,
        struct basic_blocks *bb)
{
        struct triple *first, *ins;
        free_basic_block(state, bb->first_block);
        bb->last_vertex = 0;
        bb->first_block = bb->last_block = 0;
        first = bb->first;
        ins = first;
        do {
                if (triple_stores_block(state, ins)) {
                        ins->u.block = 0;
                }
                ins = ins->next;
        } while(ins != first);

}

static struct block *basic_block(struct compile_state *state,
        struct basic_blocks *bb, struct triple *first)
{
        struct block *block;
        struct triple *ptr;
        if (!triple_is_label(state, first)) {
                internal_error(state, first, "block does not start with a label");
        }
        /* See if this basic block has already been setup */
        if (first->u.block != 0) {
                return first->u.block;
        }
        /* Allocate another basic block structure */
        bb->last_vertex += 1;
        block = xcmalloc(sizeof(*block), "block");
        block->first = block->last = first;
        block->vertex = bb->last_vertex;
        ptr = first;
        do {
                if ((ptr != first) && triple_is_label(state, ptr) && (ptr->use)) {
                        break;
                }
                block->last = ptr;
                /* If ptr->u is not used remember where the baic block is */
                if (triple_stores_block(state, ptr)) {
                        ptr->u.block = block;
                }
                if (triple_is_branch(state, ptr)) {
                        break;
                }
                ptr = ptr->next;
        } while (ptr != bb->first);
        if ((ptr == bb->first) ||
                ((ptr->next == bb->first) && (
                        triple_is_end(state, ptr) ||
                        triple_is_ret(state, ptr))))
        {
                /* The block has no outflowing edges */
        }
        else if (triple_is_label(state, ptr)) {
                struct block *next;
                next = basic_block(state, bb, ptr);
                add_block_edge(block, next, 0);
                use_block(next, block);
        }
        else if (triple_is_branch(state, ptr)) {
                struct triple **expr, *first;
                struct block *child;
                /* Find the branch targets.
                 * I special case the first branch as that magically
                 * avoids some difficult cases for the register allocator.
                 */
                expr = triple_edge_targ(state, ptr, 0);
                if (!expr) {
                        internal_error(state, ptr, "branch without targets");
                }
                first = *expr;
                expr = triple_edge_targ(state, ptr, expr);
                for(; expr; expr = triple_edge_targ(state, ptr, expr)) {
                        if (!*expr) continue;
                        child = basic_block(state, bb, *expr);
                        use_block(child, block);
                        add_block_edge(block, child, 0);
                }
                if (first) {
                        child = basic_block(state, bb, first);
                        use_block(child, block);
                        add_block_edge(block, child, 1);

                        /* Be certain the return block of a call is
                         * in a basic block.  When it is not find
                         * start of the block, insert a label if
                         * necessary and build the basic block.
                         * Then add a fake edge from the start block
                         * to the return block of the function.
                         */
                        if (state->functions_joined && triple_is_call(state, ptr)
                                && !block_of_triple(state, MISC(ptr, 0))) {
                                struct block *tail;
                                struct triple *start;
                                start = triple_to_block_start(state, MISC(ptr, 0));
                                if (!triple_is_label(state, start)) {
                                        start = pre_triple(state,
                                                start, OP_LABEL, &void_type, 0, 0);
                                }
                                tail = basic_block(state, bb, start);
                                add_block_edge(child, tail, 0);
                                use_block(tail, child);
                        }
                }
        }
        else {
                internal_error(state, 0, "Bad basic block split");
        }
#if 0
{
        struct block_set *edge;
        FILE *fp = state->errout;
        fprintf(fp, "basic_block: %10p [%2d] ( %10p - %10p )",
                block, block->vertex,
                block->first, block->last);
        for(edge = block->edges; edge; edge = edge->next) {
                fprintf(fp, " %10p [%2d]",
                        edge->member ? edge->member->first : 0,
                        edge->member ? edge->member->vertex : -1);
        }
        fprintf(fp, "\n");
}
#endif
        return block;
}


static void walk_blocks(struct compile_state *state, struct basic_blocks *bb,
        void (*cb)(struct compile_state *state, struct block *block, void *arg),
        void *arg)
{
        struct triple *ptr, *first;
        struct block *last_block;
        last_block = 0;
        first = bb->first;
        ptr = first;
        do {
                if (triple_stores_block(state, ptr)) {
                        struct block *block;
                        block = ptr->u.block;
                        if (block && (block != last_block)) {
                                cb(state, block, arg);
                        }
                        last_block = block;
                }
                ptr = ptr->next;
        } while(ptr != first);
}

static void print_block(
        struct compile_state *state, struct block *block, void *arg)
{
        struct block_set *user, *edge;
        struct triple *ptr;
        FILE *fp = arg;

        fprintf(fp, "\nblock: %p (%d) ",
                block,
                block->vertex);

        for(edge = block->edges; edge; edge = edge->next) {
                fprintf(fp, " %p<-%p",
                        edge->member,
                        (edge->member && edge->member->use)?
                        edge->member->use->member : 0);
        }
        fprintf(fp, "\n");
        if (block->first->op == OP_LABEL) {
                fprintf(fp, "%p:\n", block->first);
        }
        for(ptr = block->first; ; ) {
                display_triple(fp, ptr);
                if (ptr == block->last)
                        break;
                ptr = ptr->next;
                if (ptr == block->first) {
                        internal_error(state, 0, "missing block last?");
                }
        }
        fprintf(fp, "users %d: ", block->users);
        for(user = block->use; user; user = user->next) {
                fprintf(fp, "%p (%d) ",
                        user->member,
                        user->member->vertex);
        }
        fprintf(fp,"\n\n");
}


static void romcc_print_blocks(struct compile_state *state, FILE *fp)
{
        fprintf(fp, "--------------- blocks ---------------\n");
        walk_blocks(state, &state->bb, print_block, fp);
}
static void print_blocks(struct compile_state *state, const char *func, FILE *fp)
{
        if (state->compiler->debug & DEBUG_BASIC_BLOCKS) {
                fprintf(fp, "After %s\n", func);
                romcc_print_blocks(state, fp);
                if (state->compiler->debug & DEBUG_FDOMINATORS) {
                        print_dominators(state, fp, &state->bb);
                        print_dominance_frontiers(state, fp, &state->bb);
                }
                print_control_flow(state, fp, &state->bb);
        }
}

static void prune_nonblock_triples(struct compile_state *state,
        struct basic_blocks *bb)
{
        struct block *block;
        struct triple *first, *ins, *next;
        /* Delete the triples not in a basic block */
        block = 0;
        first = bb->first;
        ins = first;
        do {
                next = ins->next;
                if (ins->op == OP_LABEL) {
                        block = ins->u.block;
                }
                if (!block) {
                        struct triple_set *use;
                        for(use = ins->use; use; use = use->next) {
                                struct block *block;
                                block = block_of_triple(state, use->member);
                                if (block != 0) {
                                        internal_error(state, ins, "pruning used ins?");
                                }
                        }
                        release_triple(state, ins);
                }
                if (block && block->last == ins) {
                        block = 0;
                }
                ins = next;
        } while(ins != first);
}

static void setup_basic_blocks(struct compile_state *state,
        struct basic_blocks *bb)
{
        if (!triple_stores_block(state, bb->first)) {
                internal_error(state, 0, "ins will not store block?");
        }
        /* Initialize the state */
        bb->first_block = bb->last_block = 0;
        bb->last_vertex = 0;
        free_basic_blocks(state, bb);

        /* Find the basic blocks */
        bb->first_block = basic_block(state, bb, bb->first);

        /* Be certain the last instruction of a function, or the
         * entire program is in a basic block.  When it is not find
         * the start of the block, insert a label if necessary and build
         * basic block.  Then add a fake edge from the start block
         * to the final block.
         */
        if (!block_of_triple(state, bb->first->prev)) {
                struct triple *start;
                struct block *tail;
                start = triple_to_block_start(state, bb->first->prev);
                if (!triple_is_label(state, start)) {
                        start = pre_triple(state,
                                start, OP_LABEL, &void_type, 0, 0);
                }
                tail = basic_block(state, bb, start);
                add_block_edge(bb->first_block, tail, 0);
                use_block(tail, bb->first_block);
        }

        /* Find the last basic block.
         */
        bb->last_block = block_of_triple(state, bb->first->prev);

        /* Delete the triples not in a basic block */
        prune_nonblock_triples(state, bb);

#if 0
        /* If we are debugging print what I have just done */
        if (state->compiler->debug & DEBUG_BASIC_BLOCKS) {
                print_blocks(state, state->dbgout);
                print_control_flow(state, bb);
        }
#endif
}


struct sdom_block {
        struct block *block;
        struct sdom_block *sdominates;
        struct sdom_block *sdom_next;
        struct sdom_block *sdom;
        struct sdom_block *label;
        struct sdom_block *parent;
        struct sdom_block *ancestor;
        int vertex;
};


static void unsdom_block(struct sdom_block *block)
{
        struct sdom_block **ptr;
        if (!block->sdom_next) {
                return;
        }
        ptr = &block->sdom->sdominates;
        while(*ptr) {
                if ((*ptr) == block) {
                        *ptr = block->sdom_next;
                        return;
                }
                ptr = &(*ptr)->sdom_next;
        }
}

static void sdom_block(struct sdom_block *sdom, struct sdom_block *block)
{
        unsdom_block(block);
        block->sdom = sdom;
        block->sdom_next = sdom->sdominates;
        sdom->sdominates = block;
}



static int initialize_sdblock(struct sdom_block *sd,
        struct block *parent, struct block *block, int vertex)
{
        struct block_set *edge;
        if (!block || (sd[block->vertex].block == block)) {
                return vertex;
        }
        vertex += 1;
        /* Renumber the blocks in a convenient fashion */
        block->vertex = vertex;
        sd[vertex].block    = block;
        sd[vertex].sdom     = &sd[vertex];
        sd[vertex].label    = &sd[vertex];
        sd[vertex].parent   = parent? &sd[parent->vertex] : 0;
        sd[vertex].ancestor = 0;
        sd[vertex].vertex   = vertex;
        for(edge = block->edges; edge; edge = edge->next) {
                vertex = initialize_sdblock(sd, block, edge->member, vertex);
        }
        return vertex;
}

static int initialize_spdblock(
        struct compile_state *state, struct sdom_block *sd,
        struct block *parent, struct block *block, int vertex)
{
        struct block_set *user;
        if (!block || (sd[block->vertex].block == block)) {
                return vertex;
        }
        vertex += 1;
        /* Renumber the blocks in a convenient fashion */
        block->vertex = vertex;
        sd[vertex].block    = block;
        sd[vertex].sdom     = &sd[vertex];
        sd[vertex].label    = &sd[vertex];
        sd[vertex].parent   = parent? &sd[parent->vertex] : 0;
        sd[vertex].ancestor = 0;
        sd[vertex].vertex   = vertex;
        for(user = block->use; user; user = user->next) {
                vertex = initialize_spdblock(state, sd, block, user->member, vertex);
        }
        return vertex;
}

static int setup_spdblocks(struct compile_state *state,
        struct basic_blocks *bb, struct sdom_block *sd)
{
        struct block *block;
        int vertex;
        /* Setup as many sdpblocks as possible without using fake edges */
        vertex = initialize_spdblock(state, sd, 0, bb->last_block, 0);

        /* Walk through the graph and find unconnected blocks.  Add a
         * fake edge from the unconnected blocks to the end of the
         * graph.
         */
        block = bb->first_block->last->next->u.block;
        for(; block && block != bb->first_block; block = block->last->next->u.block) {
                if (sd[block->vertex].block == block) {
                        continue;
                }
#if DEBUG_SDP_BLOCKS
                {
                        FILE *fp = state->errout;
                        fprintf(fp, "Adding %d\n", vertex +1);
                }
#endif
                add_block_edge(block, bb->last_block, 0);
                use_block(bb->last_block, block);

                vertex = initialize_spdblock(state, sd, bb->last_block, block, vertex);
        }
        return vertex;
}

static void compress_ancestors(struct sdom_block *v)
{
        /* This procedure assumes ancestor(v) != 0 */
        /* if (ancestor(ancestor(v)) != 0) {
         *      compress(ancestor(ancestor(v)));
         *      if (semi(label(ancestor(v))) < semi(label(v))) {
         *              label(v) = label(ancestor(v));
         *      }
         *      ancestor(v) = ancestor(ancestor(v));
         * }
         */
        if (!v->ancestor) {
                return;
        }
        if (v->ancestor->ancestor) {
                compress_ancestors(v->ancestor->ancestor);
                if (v->ancestor->label->sdom->vertex < v->label->sdom->vertex) {
                        v->label = v->ancestor->label;
                }
                v->ancestor = v->ancestor->ancestor;
        }
}

static void compute_sdom(struct compile_state *state,
        struct basic_blocks *bb, struct sdom_block *sd)
{
        int i;
        /* // step 2
         *  for each v <= pred(w) {
         *      u = EVAL(v);
         *      if (semi[u] < semi[w] {
         *              semi[w] = semi[u];
         *      }
         * }
         * add w to bucket(vertex(semi[w]));
         * LINK(parent(w), w);
         *
         * // step 3
         * for each v <= bucket(parent(w)) {
         *      delete v from bucket(parent(w));
         *      u = EVAL(v);
         *      dom(v) = (semi[u] < semi[v]) ? u : parent(w);
         * }
         */
        for(i = bb->last_vertex; i >= 2; i--) {
                struct sdom_block *v, *parent, *next;
                struct block_set *user;
                struct block *block;
                block = sd[i].block;
                parent = sd[i].parent;
                /* Step 2 */
                for(user = block->use; user; user = user->next) {
                        struct sdom_block *v, *u;
                        v = &sd[user->member->vertex];
                        u = !(v->ancestor)? v : (compress_ancestors(v), v->label);
                        if (u->sdom->vertex < sd[i].sdom->vertex) {
                                sd[i].sdom = u->sdom;
                        }
                }
                sdom_block(sd[i].sdom, &sd[i]);
                sd[i].ancestor = parent;
                /* Step 3 */
                for(v = parent->sdominates; v; v = next) {
                        struct sdom_block *u;
                        next = v->sdom_next;
                        unsdom_block(v);
                        u = (!v->ancestor) ? v : (compress_ancestors(v), v->label);
                        v->block->idom = (u->sdom->vertex < v->sdom->vertex)?
                                u->block : parent->block;
                }
        }
}

static void compute_spdom(struct compile_state *state,
        struct basic_blocks *bb, struct sdom_block *sd)
{
        int i;
        /* // step 2
         *  for each v <= pred(w) {
         *      u = EVAL(v);
         *      if (semi[u] < semi[w] {
         *              semi[w] = semi[u];
         *      }
         * }
         * add w to bucket(vertex(semi[w]));
         * LINK(parent(w), w);
         *
         * // step 3
         * for each v <= bucket(parent(w)) {
         *      delete v from bucket(parent(w));
         *      u = EVAL(v);
         *      dom(v) = (semi[u] < semi[v]) ? u : parent(w);
         * }
         */
        for(i = bb->last_vertex; i >= 2; i--) {
                struct sdom_block *u, *v, *parent, *next;
                struct block_set *edge;
                struct block *block;
                block = sd[i].block;
                parent = sd[i].parent;
                /* Step 2 */
                for(edge = block->edges; edge; edge = edge->next) {
                        v = &sd[edge->member->vertex];
                        u = !(v->ancestor)? v : (compress_ancestors(v), v->label);
                        if (u->sdom->vertex < sd[i].sdom->vertex) {
                                sd[i].sdom = u->sdom;
                        }
                }
                sdom_block(sd[i].sdom, &sd[i]);
                sd[i].ancestor = parent;
                /* Step 3 */
                for(v = parent->sdominates; v; v = next) {
                        struct sdom_block *u;
                        next = v->sdom_next;
                        unsdom_block(v);
                        u = (!v->ancestor) ? v : (compress_ancestors(v), v->label);
                        v->block->ipdom = (u->sdom->vertex < v->sdom->vertex)?
                                u->block : parent->block;
                }
        }
}

static void compute_idom(struct compile_state *state,
        struct basic_blocks *bb, struct sdom_block *sd)
{
        int i;
        for(i = 2; i <= bb->last_vertex; i++) {
                struct block *block;
                block = sd[i].block;
                if (block->idom->vertex != sd[i].sdom->vertex) {
                        block->idom = block->idom->idom;
                }
                idom_block(block->idom, block);
        }
        sd[1].block->idom = 0;
}

static void compute_ipdom(struct compile_state *state,
        struct basic_blocks *bb, struct sdom_block *sd)
{
        int i;
        for(i = 2; i <= bb->last_vertex; i++) {
                struct block *block;
                block = sd[i].block;
                if (block->ipdom->vertex != sd[i].sdom->vertex) {
                        block->ipdom = block->ipdom->ipdom;
                }
                ipdom_block(block->ipdom, block);
        }
        sd[1].block->ipdom = 0;
}

        /* Theorem 1:
         *   Every vertex of a flowgraph G = (V, E, r) except r has
         *   a unique immediate dominator.
         *   The edges {(idom(w), w) |w <= V - {r}} form a directed tree
         *   rooted at r, called the dominator tree of G, such that
         *   v dominates w if and only if v is a proper ancestor of w in
         *   the dominator tree.
         */
        /* Lemma 1:
         *   If v and w are vertices of G such that v <= w,
         *   than any path from v to w must contain a common ancestor
         *   of v and w in T.
         */
        /* Lemma 2:  For any vertex w != r, idom(w) -> w */
        /* Lemma 3:  For any vertex w != r, sdom(w) -> w */
        /* Lemma 4:  For any vertex w != r, idom(w) -> sdom(w) */
        /* Theorem 2:
         *   Let w != r.  Suppose every u for which sdom(w) -> u -> w satisfies
         *   sdom(u) >= sdom(w).  Then idom(w) = sdom(w).
         */
        /* Theorem 3:
         *   Let w != r and let u be a vertex for which sdom(u) is
         *   minimum among vertices u satisfying sdom(w) -> u -> w.
         *   Then sdom(u) <= sdom(w) and idom(u) = idom(w).
         */
        /* Lemma 5:  Let vertices v,w satisfy v -> w.
         *           Then v -> idom(w) or idom(w) -> idom(v)
         */

static void find_immediate_dominators(struct compile_state *state,
        struct basic_blocks *bb)
{
        struct sdom_block *sd;
        /* w->sdom = min{v| there is a path v = v0,v1,...,vk = w such that:
         *           vi > w for (1 <= i <= k - 1}
         */
        /* Theorem 4:
         *   For any vertex w != r.
         *   sdom(w) = min(
         *                 {v|(v,w) <= E  and v < w } U
         *                 {sdom(u) | u > w and there is an edge (v, w) such that u -> v})
         */
        /* Corollary 1:
         *   Let w != r and let u be a vertex for which sdom(u) is
         *   minimum among vertices u satisfying sdom(w) -> u -> w.
         *   Then:
         *                   { sdom(w) if sdom(w) = sdom(u),
         *        idom(w) = {
         *                   { idom(u) otherwise
         */
        /* The algorithm consists of the following 4 steps.
         * Step 1.  Carry out a depth-first search of the problem graph.
         *    Number the vertices from 1 to N as they are reached during
         *    the search.  Initialize the variables used in succeeding steps.
         * Step 2.  Compute the semidominators of all vertices by applying
         *    theorem 4.   Carry out the computation vertex by vertex in
         *    decreasing order by number.
         * Step 3.  Implicitly define the immediate dominator of each vertex
         *    by applying Corollary 1.
         * Step 4.  Explicitly define the immediate dominator of each vertex,
         *    carrying out the computation vertex by vertex in increasing order
         *    by number.
         */
        /* Step 1 initialize the basic block information */
        sd = xcmalloc(sizeof(*sd) * (bb->last_vertex + 1), "sdom_state");
        initialize_sdblock(sd, 0, bb->first_block, 0);
#if 0
        sd[1].size  = 0;
        sd[1].label = 0;
        sd[1].sdom  = 0;
#endif
        /* Step 2 compute the semidominators */
        /* Step 3 implicitly define the immediate dominator of each vertex */
        compute_sdom(state, bb, sd);
        /* Step 4 explicitly define the immediate dominator of each vertex */
        compute_idom(state, bb, sd);
        xfree(sd);
}

static void find_post_dominators(struct compile_state *state,
        struct basic_blocks *bb)
{
        struct sdom_block *sd;
        int vertex;
        /* Step 1 initialize the basic block information */
        sd = xcmalloc(sizeof(*sd) * (bb->last_vertex + 1), "sdom_state");

        vertex = setup_spdblocks(state, bb, sd);
        if (vertex != bb->last_vertex) {
                internal_error(state, 0, "missing %d blocks",
                        bb->last_vertex - vertex);
        }

        /* Step 2 compute the semidominators */
        /* Step 3 implicitly define the immediate dominator of each vertex */
        compute_spdom(state, bb, sd);
        /* Step 4 explicitly define the immediate dominator of each vertex */
        compute_ipdom(state, bb, sd);
        xfree(sd);
}



static void find_block_domf(struct compile_state *state, struct block *block)
{
        struct block *child;
        struct block_set *user, *edge;
        if (block->domfrontier != 0) {
                internal_error(state, block->first, "domfrontier present?");
        }
        for(user = block->idominates; user; user = user->next) {
                child = user->member;
                if (child->idom != block) {
                        internal_error(state, block->first, "bad idom");
                }
                find_block_domf(state, child);
        }
        for(edge = block->edges; edge; edge = edge->next) {
                if (edge->member->idom != block) {
                        domf_block(block, edge->member);
                }
        }
        for(user = block->idominates; user; user = user->next) {
                struct block_set *frontier;
                child = user->member;
                for(frontier = child->domfrontier; frontier; frontier = frontier->next) {
                        if (frontier->member->idom != block) {
                                domf_block(block, frontier->member);
                        }
                }
        }
}

static void find_block_ipdomf(struct compile_state *state, struct block *block)
{
        struct block *child;
        struct block_set *user;
        if (block->ipdomfrontier != 0) {
                internal_error(state, block->first, "ipdomfrontier present?");
        }
        for(user = block->ipdominates; user; user = user->next) {
                child = user->member;
                if (child->ipdom != block) {
                        internal_error(state, block->first, "bad ipdom");
                }
                find_block_ipdomf(state, child);
        }
        for(user = block->use; user; user = user->next) {
                if (user->member->ipdom != block) {
                        ipdomf_block(block, user->member);
                }
        }
        for(user = block->ipdominates; user; user = user->next) {
                struct block_set *frontier;
                child = user->member;
                for(frontier = child->ipdomfrontier; frontier; frontier = frontier->next) {
                        if (frontier->member->ipdom != block) {
                                ipdomf_block(block, frontier->member);
                        }
                }
        }
}

static void print_dominated(
        struct compile_state *state, struct block *block, void *arg)
{
        struct block_set *user;
        FILE *fp = arg;

        fprintf(fp, "%d:", block->vertex);
        for(user = block->idominates; user; user = user->next) {
                fprintf(fp, " %d", user->member->vertex);
                if (user->member->idom != block) {
                        internal_error(state, user->member->first, "bad idom");
                }
        }
        fprintf(fp,"\n");
}

static void print_dominated2(
        struct compile_state *state, FILE *fp, int depth, struct block *block)
{
        struct block_set *user;
        struct triple *ins;
        struct occurrence *ptr, *ptr2;
        const char *filename1, *filename2;
        int equal_filenames;
        int i;
        for(i = 0; i < depth; i++) {
                fprintf(fp, "   ");
        }
        fprintf(fp, "%3d: %p (%p - %p) @",
                block->vertex, block, block->first, block->last);
        ins = block->first;
        while(ins != block->last && (ins->occurrence->line == 0)) {
                ins = ins->next;
        }
        ptr = ins->occurrence;
        ptr2 = block->last->occurrence;
        filename1 = ptr->filename? ptr->filename : "";
        filename2 = ptr2->filename? ptr2->filename : "";
        equal_filenames = (strcmp(filename1, filename2) == 0);
        if ((ptr == ptr2) || (equal_filenames && ptr->line == ptr2->line)) {
                fprintf(fp, " %s:%d", ptr->filename, ptr->line);
        } else if (equal_filenames) {
                fprintf(fp, " %s:(%d - %d)",
                        ptr->filename, ptr->line, ptr2->line);
        } else {
                fprintf(fp, " (%s:%d - %s:%d)",
                        ptr->filename, ptr->line,
                        ptr2->filename, ptr2->line);
        }
        fprintf(fp, "\n");
        for(user = block->idominates; user; user = user->next) {
                print_dominated2(state, fp, depth + 1, user->member);
        }
}

static void print_dominators(struct compile_state *state, FILE *fp, struct basic_blocks *bb)
{
        fprintf(fp, "\ndominates\n");
        walk_blocks(state, bb, print_dominated, fp);
        fprintf(fp, "dominates\n");
        print_dominated2(state, fp, 0, bb->first_block);
}


static int print_frontiers(
        struct compile_state *state, FILE *fp, struct block *block, int vertex)
{
        struct block_set *user, *edge;

        if (!block || (block->vertex != vertex + 1)) {
                return vertex;
        }
        vertex += 1;

        fprintf(fp, "%d:", block->vertex);
        for(user = block->domfrontier; user; user = user->next) {
                fprintf(fp, " %d", user->member->vertex);
        }
        fprintf(fp, "\n");

        for(edge = block->edges; edge; edge = edge->next) {
                vertex = print_frontiers(state, fp, edge->member, vertex);
        }
        return vertex;
}
static void print_dominance_frontiers(struct compile_state *state,
        FILE *fp, struct basic_blocks *bb)
{
        fprintf(fp, "\ndominance frontiers\n");
        print_frontiers(state, fp, bb->first_block, 0);

}

static void analyze_idominators(struct compile_state *state, struct basic_blocks *bb)
{
        /* Find the immediate dominators */
        find_immediate_dominators(state, bb);
        /* Find the dominance frontiers */
        find_block_domf(state, bb->first_block);
        /* If debuging print the print what I have just found */
        if (state->compiler->debug & DEBUG_FDOMINATORS) {
                print_dominators(state, state->dbgout, bb);
                print_dominance_frontiers(state, state->dbgout, bb);
                print_control_flow(state, state->dbgout, bb);
        }
}


static void print_ipdominated(
        struct compile_state *state, struct block *block, void *arg)
{
        struct block_set *user;
        FILE *fp = arg;

        fprintf(fp, "%d:", block->vertex);
        for(user = block->ipdominates; user; user = user->next) {
                fprintf(fp, " %d", user->member->vertex);
                if (user->member->ipdom != block) {
                        internal_error(state, user->member->first, "bad ipdom");
                }
        }
        fprintf(fp, "\n");
}

static void print_ipdominators(struct compile_state *state, FILE *fp,
        struct basic_blocks *bb)
{
        fprintf(fp, "\nipdominates\n");
        walk_blocks(state, bb, print_ipdominated, fp);
}

static int print_pfrontiers(
        struct compile_state *state, FILE *fp, struct block *block, int vertex)
{
        struct block_set *user;

        if (!block || (block->vertex != vertex + 1)) {
                return vertex;
        }
        vertex += 1;

        fprintf(fp, "%d:", block->vertex);
        for(user = block->ipdomfrontier; user; user = user->next) {
                fprintf(fp, " %d", user->member->vertex);
        }
        fprintf(fp, "\n");
        for(user = block->use; user; user = user->next) {
                vertex = print_pfrontiers(state, fp, user->member, vertex);
        }
        return vertex;
}
static void print_ipdominance_frontiers(struct compile_state *state,
        FILE *fp, struct basic_blocks *bb)
{
        fprintf(fp, "\nipdominance frontiers\n");
        print_pfrontiers(state, fp, bb->last_block, 0);

}

static void analyze_ipdominators(struct compile_state *state,
        struct basic_blocks *bb)
{
        /* Find the post dominators */
        find_post_dominators(state, bb);
        /* Find the control dependencies (post dominance frontiers) */
        find_block_ipdomf(state, bb->last_block);
        /* If debuging print the print what I have just found */
        if (state->compiler->debug & DEBUG_RDOMINATORS) {
                print_ipdominators(state, state->dbgout, bb);
                print_ipdominance_frontiers(state, state->dbgout, bb);
                print_control_flow(state, state->dbgout, bb);
        }
}

static int bdominates(struct compile_state *state,
        struct block *dom, struct block *sub)
{
        while(sub && (sub != dom)) {
                sub = sub->idom;
        }
        return sub == dom;
}

static int tdominates(struct compile_state *state,
        struct triple *dom, struct triple *sub)
{
        struct block *bdom, *bsub;
        int result;
        bdom = block_of_triple(state, dom);
        bsub = block_of_triple(state, sub);
        if (bdom != bsub) {
                result = bdominates(state, bdom, bsub);
        }
        else {
                struct triple *ins;
                if (!bdom || !bsub) {
                        internal_error(state, dom, "huh?");
                }
                ins = sub;
                while((ins != bsub->first) && (ins != dom)) {
                        ins = ins->prev;
                }
                result = (ins == dom);
        }
        return result;
}

static void analyze_basic_blocks(
        struct compile_state *state, struct basic_blocks *bb)
{
        setup_basic_blocks(state, bb);
        analyze_idominators(state, bb);
        analyze_ipdominators(state, bb);
}

static void insert_phi_operations(struct compile_state *state)
{
        size_t size;
        struct triple *first;
        int *has_already, *work;
        struct block *work_list, **work_list_tail;
        int iter;
        struct triple *var, *vnext;

        size = sizeof(int) * (state->bb.last_vertex + 1);
        has_already = xcmalloc(size, "has_already");
        work =        xcmalloc(size, "work");
        iter = 0;

        first = state->first;
        for(var = first->next; var != first ; var = vnext) {
                struct block *block;
                struct triple_set *user, *unext;
                vnext = var->next;

                if (!triple_is_auto_var(state, var) || !var->use) {
                        continue;
                }

                iter += 1;
                work_list = 0;
                work_list_tail = &work_list;
                for(user = var->use; user; user = unext) {
                        unext = user->next;
                        if (MISC(var, 0) == user->member) {
                                continue;
                        }
                        if (user->member->op == OP_READ) {
                                continue;
                        }
                        if (user->member->op != OP_WRITE) {
                                internal_error(state, user->member,
                                        "bad variable access");
                        }
                        block = user->member->u.block;
                        if (!block) {
                                warning(state, user->member, "dead code");
                                release_triple(state, user->member);
                                continue;
                        }
                        if (work[block->vertex] >= iter) {
                                continue;
                        }
                        work[block->vertex] = iter;
                        *work_list_tail = block;
                        block->work_next = 0;
                        work_list_tail = &block->work_next;
                }
                for(block = work_list; block; block = block->work_next) {
                        struct block_set *df;
                        for(df = block->domfrontier; df; df = df->next) {
                                struct triple *phi;
                                struct block *front;
                                int in_edges;
                                front = df->member;

                                if (has_already[front->vertex] >= iter) {
                                        continue;
                                }
                                /* Count how many edges flow into this block */
                                in_edges = front->users;
                                /* Insert a phi function for this variable */
                                get_occurrence(var->occurrence);
                                phi = alloc_triple(
                                        state, OP_PHI, var->type, -1, in_edges,
                                        var->occurrence);
                                phi->u.block = front;
                                MISC(phi, 0) = var;
                                use_triple(var, phi);
#if 1
                                if (phi->rhs != in_edges) {
                                        internal_error(state, phi, "phi->rhs: %d != in_edges: %d",
                                                phi->rhs, in_edges);
                                }
#endif
                                /* Insert the phi functions immediately after the label */
                                insert_triple(state, front->first->next, phi);
                                if (front->first == front->last) {
                                        front->last = front->first->next;
                                }
                                has_already[front->vertex] = iter;
                                transform_to_arch_instruction(state, phi);

                                /* If necessary plan to visit the basic block */
                                if (work[front->vertex] >= iter) {
                                        continue;
                                }
                                work[front->vertex] = iter;
                                *work_list_tail = front;
                                front->work_next = 0;
                                work_list_tail = &front->work_next;
                        }
                }
        }
        xfree(has_already);
        xfree(work);
}


struct stack {
        struct triple_set *top;
        unsigned orig_id;
};

static int count_auto_vars(struct compile_state *state)
{
        struct triple *first, *ins;
        int auto_vars = 0;
        first = state->first;
        ins = first;
        do {
                if (triple_is_auto_var(state, ins)) {
                        auto_vars += 1;
                }
                ins = ins->next;
        } while(ins != first);
        return auto_vars;
}

static void number_auto_vars(struct compile_state *state, struct stack *stacks)
{
        struct triple *first, *ins;
        int auto_vars = 0;
        first = state->first;
        ins = first;
        do {
                if (triple_is_auto_var(state, ins)) {
                        auto_vars += 1;
                        stacks[auto_vars].orig_id = ins->id;
                        ins->id = auto_vars;
                }
                ins = ins->next;
        } while(ins != first);
}

static void restore_auto_vars(struct compile_state *state, struct stack *stacks)
{
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                if (triple_is_auto_var(state, ins)) {
                        ins->id = stacks[ins->id].orig_id;
                }
                ins = ins->next;
        } while(ins != first);
}

static struct triple *peek_triple(struct stack *stacks, struct triple *var)
{
        struct triple_set *head;
        struct triple *top_val;
        top_val = 0;
        head = stacks[var->id].top;
        if (head) {
                top_val = head->member;
        }
        return top_val;
}

static void push_triple(struct stack *stacks, struct triple *var, struct triple *val)
{
        struct triple_set *new;
        /* Append new to the head of the list,
         * it's the only sensible behavoir for a stack.
         */
        new = xcmalloc(sizeof(*new), "triple_set");
        new->member = val;
        new->next   = stacks[var->id].top;
        stacks[var->id].top = new;
}

static void pop_triple(struct stack *stacks, struct triple *var, struct triple *oldval)
{
        struct triple_set *set, **ptr;
        ptr = &stacks[var->id].top;
        while(*ptr) {
                set = *ptr;
                if (set->member == oldval) {
                        *ptr = set->next;
                        xfree(set);
                        /* Only free one occurrence from the stack */
                        return;
                }
                else {
                        ptr = &set->next;
                }
        }
}

/*
 * C(V)
 * S(V)
 */
static void fixup_block_phi_variables(
        struct compile_state *state, struct stack *stacks, struct block *parent, struct block *block)
{
        struct block_set *set;
        struct triple *ptr;
        int edge;
        if (!parent || !block)
                return;
        /* Find the edge I am coming in on */
        edge = 0;
        for(set = block->use; set; set = set->next, edge++) {
                if (set->member == parent) {
                        break;
                }
        }
        if (!set) {
                internal_error(state, 0, "phi input is not on a control predecessor");
        }
        for(ptr = block->first; ; ptr = ptr->next) {
                if (ptr->op == OP_PHI) {
                        struct triple *var, *val, **slot;
                        var = MISC(ptr, 0);
                        if (!var) {
                                internal_error(state, ptr, "no var???");
                        }
                        /* Find the current value of the variable */
                        val = peek_triple(stacks, var);
                        if (val && ((val->op == OP_WRITE) || (val->op == OP_READ))) {
                                internal_error(state, val, "bad value in phi");
                        }
                        if (edge >= ptr->rhs) {
                                internal_error(state, ptr, "edges > phi rhs");
                        }
                        slot = &RHS(ptr, edge);
                        if ((*slot != 0) && (*slot != val)) {
                                internal_error(state, ptr, "phi already bound on this edge");
                        }
                        *slot = val;
                        use_triple(val, ptr);
                }
                if (ptr == block->last) {
                        break;
                }
        }
}


static void rename_block_variables(
        struct compile_state *state, struct stack *stacks, struct block *block)
{
        struct block_set *user, *edge;
        struct triple *ptr, *next, *last;
        int done;
        if (!block)
                return;
        last = block->first;
        done = 0;
        for(ptr = block->first; !done; ptr = next) {
                next = ptr->next;
                if (ptr == block->last) {
                        done = 1;
                }
                /* RHS(A) */
                if (ptr->op == OP_READ) {
                        struct triple *var, *val;
                        var = RHS(ptr, 0);
                        if (!triple_is_auto_var(state, var)) {
                                internal_error(state, ptr, "read of non auto var!");
                        }
                        unuse_triple(var, ptr);
                        /* Find the current value of the variable */
                        val = peek_triple(stacks, var);
                        if (!val) {
                                /* Let the optimizer at variables that are not initially
                                 * set.  But give it a bogus value so things seem to
                                 * work by accident.  This is useful for bitfields because
                                 * setting them always involves a read-modify-write.
                                 */
                                if (TYPE_ARITHMETIC(ptr->type->type)) {
                                        val = pre_triple(state, ptr, OP_INTCONST, ptr->type, 0, 0);
                                        val->u.cval = 0xdeadbeaf;
                                } else {
                                        val = pre_triple(state, ptr, OP_UNKNOWNVAL, ptr->type, 0, 0);
                                }
                        }
                        if (!val) {
                                error(state, ptr, "variable used without being set");
                        }
                        if ((val->op == OP_WRITE) || (val->op == OP_READ)) {
                                internal_error(state, val, "bad value in read");
                        }
                        propagate_use(state, ptr, val);
                        release_triple(state, ptr);
                        continue;
                }
                /* LHS(A) */
                if (ptr->op == OP_WRITE) {
                        struct triple *var, *val, *tval;
                        var = MISC(ptr, 0);
                        if (!triple_is_auto_var(state, var)) {
                                internal_error(state, ptr, "write to non auto var!");
                        }
                        tval = val = RHS(ptr, 0);
                        if ((val->op == OP_WRITE) || (val->op == OP_READ) ||
                                triple_is_auto_var(state, val)) {
                                internal_error(state, ptr, "bad value in write");
                        }
                        /* Insert a cast if the types differ */
                        if (!is_subset_type(ptr->type, val->type)) {
                                if (val->op == OP_INTCONST) {
                                        tval = pre_triple(state, ptr, OP_INTCONST, ptr->type, 0, 0);
                                        tval->u.cval = val->u.cval;
                                }
                                else {
                                        tval = pre_triple(state, ptr, OP_CONVERT, ptr->type, val, 0);
                                        use_triple(val, tval);
                                }
                                transform_to_arch_instruction(state, tval);
                                unuse_triple(val, ptr);
                                RHS(ptr, 0) = tval;
                                use_triple(tval, ptr);
                        }
                        propagate_use(state, ptr, tval);
                        unuse_triple(var, ptr);
                        /* Push OP_WRITE ptr->right onto a stack of variable uses */
                        push_triple(stacks, var, tval);
                }
                if (ptr->op == OP_PHI) {
                        struct triple *var;
                        var = MISC(ptr, 0);
                        if (!triple_is_auto_var(state, var)) {
                                internal_error(state, ptr, "phi references non auto var!");
                        }
                        /* Push OP_PHI onto a stack of variable uses */
                        push_triple(stacks, var, ptr);
                }
                last = ptr;
        }
        block->last = last;

        /* Fixup PHI functions in the cf successors */
        for(edge = block->edges; edge; edge = edge->next) {
                fixup_block_phi_variables(state, stacks, block, edge->member);
        }
        /* rename variables in the dominated nodes */
        for(user = block->idominates; user; user = user->next) {
                rename_block_variables(state, stacks, user->member);
        }
        /* pop the renamed variable stack */
        last = block->first;
        done = 0;
        for(ptr = block->first; !done ; ptr = next) {
                next = ptr->next;
                if (ptr == block->last) {
                        done = 1;
                }
                if (ptr->op == OP_WRITE) {
                        struct triple *var;
                        var = MISC(ptr, 0);
                        /* Pop OP_WRITE ptr->right from the stack of variable uses */
                        pop_triple(stacks, var, RHS(ptr, 0));
                        release_triple(state, ptr);
                        continue;
                }
                if (ptr->op == OP_PHI) {
                        struct triple *var;
                        var = MISC(ptr, 0);
                        /* Pop OP_WRITE ptr->right from the stack of variable uses */
                        pop_triple(stacks, var, ptr);
                }
                last = ptr;
        }
        block->last = last;
}

static void rename_variables(struct compile_state *state)
{
        struct stack *stacks;
        int auto_vars;

        /* Allocate stacks for the Variables */
        auto_vars = count_auto_vars(state);
        stacks = xcmalloc(sizeof(stacks[0])*(auto_vars + 1), "auto var stacks");

        /* Give each auto_var a stack */
        number_auto_vars(state, stacks);

        /* Rename the variables */
        rename_block_variables(state, stacks, state->bb.first_block);

        /* Remove the stacks from the auto_vars */
        restore_auto_vars(state, stacks);
        xfree(stacks);
}

static void prune_block_variables(struct compile_state *state,
        struct block *block)
{
        struct block_set *user;
        struct triple *next, *ptr;
        int done;

        done = 0;
        for(ptr = block->first; !done; ptr = next) {
                /* Be extremely careful I am deleting the list
                 * as I walk trhough it.
                 */
                next = ptr->next;
                if (ptr == block->last) {
                        done = 1;
                }
                if (triple_is_auto_var(state, ptr)) {
                        struct triple_set *user, *next;
                        for(user = ptr->use; user; user = next) {
                                struct triple *use;
                                next = user->next;
                                use = user->member;
                                if (MISC(ptr, 0) == user->member) {
                                        continue;
                                }
                                if (use->op != OP_PHI) {
                                        internal_error(state, use, "decl still used");
                                }
                                if (MISC(use, 0) != ptr) {
                                        internal_error(state, use, "bad phi use of decl");
                                }
                                unuse_triple(ptr, use);
                                MISC(use, 0) = 0;
                        }
                        if ((ptr->u.cval == 0) && (MISC(ptr, 0)->lhs == 1)) {
                                /* Delete the adecl */
                                release_triple(state, MISC(ptr, 0));
                                /* And the piece */
                                release_triple(state, ptr);
                        }
                        continue;
                }
        }
        for(user = block->idominates; user; user = user->next) {
                prune_block_variables(state, user->member);
        }
}

struct phi_triple {
        struct triple *phi;
        unsigned orig_id;
        int alive;
};

static void keep_phi(struct compile_state *state, struct phi_triple *live, struct triple *phi)
{
        struct triple **slot;
        int zrhs, i;
        if (live[phi->id].alive) {
                return;
        }
        live[phi->id].alive = 1;
        zrhs = phi->rhs;
        slot = &RHS(phi, 0);
        for(i = 0; i < zrhs; i++) {
                struct triple *used;
                used = slot[i];
                if (used && (used->op == OP_PHI)) {
                        keep_phi(state, live, used);
                }
        }
}

static void prune_unused_phis(struct compile_state *state)
{
        struct triple *first, *phi;
        struct phi_triple *live;
        int phis, i;

        /* Find the first instruction */
        first = state->first;

        /* Count how many phi functions I need to process */
        phis = 0;
        for(phi = first->next; phi != first; phi = phi->next) {
                if (phi->op == OP_PHI) {
                        phis += 1;
                }
        }

        /* Mark them all dead */
        live = xcmalloc(sizeof(*live) * (phis + 1), "phi_triple");
        phis = 0;
        for(phi = first->next; phi != first; phi = phi->next) {
                if (phi->op != OP_PHI) {
                        continue;
                }
                live[phis].alive   = 0;
                live[phis].orig_id = phi->id;
                live[phis].phi     = phi;
                phi->id = phis;
                phis += 1;
        }

        /* Mark phis alive that are used by non phis */
        for(i = 0; i < phis; i++) {
                struct triple_set *set;
                for(set = live[i].phi->use; !live[i].alive && set; set = set->next) {
                        if (set->member->op != OP_PHI) {
                                keep_phi(state, live, live[i].phi);
                                break;
                        }
                }
        }

        /* Delete the extraneous phis */
        for(i = 0; i < phis; i++) {
                struct triple **slot;
                int zrhs, j;
                if (!live[i].alive) {
                        release_triple(state, live[i].phi);
                        continue;
                }
                phi = live[i].phi;
                slot = &RHS(phi, 0);
                zrhs = phi->rhs;
                for(j = 0; j < zrhs; j++) {
                        if(!slot[j]) {
                                struct triple *unknown;
                                get_occurrence(phi->occurrence);
                                unknown = flatten(state, state->global_pool,
                                        alloc_triple(state, OP_UNKNOWNVAL,
                                                phi->type, 0, 0, phi->occurrence));
                                slot[j] = unknown;
                                use_triple(unknown, phi);
                                transform_to_arch_instruction(state, unknown);
#if 0
                                warning(state, phi, "variable not set at index %d on all paths to use", j);
#endif
                        }
                }
        }
        xfree(live);
}

static void transform_to_ssa_form(struct compile_state *state)
{
        insert_phi_operations(state);
        rename_variables(state);

        prune_block_variables(state, state->bb.first_block);
        prune_unused_phis(state);

        print_blocks(state, __func__, state->dbgout);
}


static void clear_vertex(
        struct compile_state *state, struct block *block, void *arg)
{
        /* Clear the current blocks vertex and the vertex of all
         * of the current blocks neighbors in case there are malformed
         * blocks with now instructions at this point.
         */
        struct block_set *user, *edge;
        block->vertex = 0;
        for(edge = block->edges; edge; edge = edge->next) {
                edge->member->vertex = 0;
        }
        for(user = block->use; user; user = user->next) {
                user->member->vertex = 0;
        }
}

static void mark_live_block(
        struct compile_state *state, struct block *block, int *next_vertex)
{
        /* See if this is a block that has not been marked */
        if (block->vertex != 0) {
                return;
        }
        block->vertex = *next_vertex;
        *next_vertex += 1;
        if (triple_is_branch(state, block->last)) {
                struct triple **targ;
                targ = triple_edge_targ(state, block->last, 0);
                for(; targ; targ = triple_edge_targ(state, block->last, targ)) {
                        if (!*targ) {
                                continue;
                        }
                        if (!triple_stores_block(state, *targ)) {
                                internal_error(state, 0, "bad targ");
                        }
                        mark_live_block(state, (*targ)->u.block, next_vertex);
                }
                /* Ensure the last block of a function remains alive */
                if (triple_is_call(state, block->last)) {
                        mark_live_block(state, MISC(block->last, 0)->u.block, next_vertex);
                }
        }
        else if (block->last->next != state->first) {
                struct triple *ins;
                ins = block->last->next;
                if (!triple_stores_block(state, ins)) {
                        internal_error(state, 0, "bad block start");
                }
                mark_live_block(state, ins->u.block, next_vertex);
        }
}

static void transform_from_ssa_form(struct compile_state *state)
{
        /* To get out of ssa form we insert moves on the incoming
         * edges to blocks containting phi functions.
         */
        struct triple *first;
        struct triple *phi, *var, *next;
        int next_vertex;

        /* Walk the control flow to see which blocks remain alive */
        walk_blocks(state, &state->bb, clear_vertex, 0);
        next_vertex = 1;
        mark_live_block(state, state->bb.first_block, &next_vertex);

        /* Walk all of the operations to find the phi functions */
        first = state->first;
        for(phi = first->next; phi != first ; phi = next) {
                struct block_set *set;
                struct block *block;
                struct triple **slot;
                struct triple *var;
                struct triple_set *use, *use_next;
                int edge, writers, readers;
                next = phi->next;
                if (phi->op != OP_PHI) {
                        continue;
                }

                block = phi->u.block;
                slot  = &RHS(phi, 0);

                /* If this phi is in a dead block just forget it */
                if (block->vertex == 0) {
                        release_triple(state, phi);
                        continue;
                }

                /* Forget uses from code in dead blocks */
                for(use = phi->use; use; use = use_next) {
                        struct block *ublock;
                        struct triple **expr;
                        use_next = use->next;
                        ublock = block_of_triple(state, use->member);
                        if ((use->member == phi) || (ublock->vertex != 0)) {
                                continue;
                        }
                        expr = triple_rhs(state, use->member, 0);
                        for(; expr; expr = triple_rhs(state, use->member, expr)) {
                                if (*expr == phi) {
                                        *expr = 0;
                                }
                        }
                        unuse_triple(phi, use->member);
                }
                /* A variable to replace the phi function */
                if (registers_of(state, phi->type) != 1) {
                        internal_error(state, phi, "phi->type does not fit in a single register!");
                }
                var = post_triple(state, phi, OP_ADECL, phi->type, 0, 0);
                var = var->next; /* point at the var */

                /* Replaces use of phi with var */
                propagate_use(state, phi, var);

                /* Count the readers */
                readers = 0;
                for(use = var->use; use; use = use->next) {
                        if (use->member != MISC(var, 0)) {
                                readers++;
                        }
                }

                /* Walk all of the incoming edges/blocks and insert moves.
                 */
                writers = 0;
                for(edge = 0, set = block->use; set; set = set->next, edge++) {
                        struct block *eblock, *vblock;
                        struct triple *move;
                        struct triple *val, *base;
                        eblock = set->member;
                        val = slot[edge];
                        slot[edge] = 0;
                        unuse_triple(val, phi);
                        vblock = block_of_triple(state, val);

                        /* If we don't have a value that belongs in an OP_WRITE
                         * continue on.
                         */
                        if (!val || (val == &unknown_triple) || (val == phi)
                                || (vblock && (vblock->vertex == 0))) {
                                continue;
                        }
                        /* If the value should never occur error */
                        if (!vblock) {
                                internal_error(state, val, "no vblock?");
                                continue;
                        }

                        /* If the value occurs in a dead block see if a replacement
                         * block can be found.
                         */
                        while(eblock && (eblock->vertex == 0)) {
                                eblock = eblock->idom;
                        }
                        /* If not continue on with the next value. */
                        if (!eblock || (eblock->vertex == 0)) {
                                continue;
                        }

                        /* If we have an empty incoming block ignore it. */
                        if (!eblock->first) {
                                internal_error(state, 0, "empty block?");
                        }

                        /* Make certain the write is placed in the edge block... */
                        /* Walk through the edge block backwards to find an
                         * appropriate location for the OP_WRITE.
                         */
                        for(base = eblock->last; base != eblock->first; base = base->prev) {
                                struct triple **expr;
                                if (base->op == OP_PIECE) {
                                        base = MISC(base, 0);
                                }
                                if ((base == var) || (base == val)) {
                                        goto out;
                                }
                                expr = triple_lhs(state, base, 0);
                                for(; expr; expr = triple_lhs(state, base, expr)) {
                                        if ((*expr) == val) {
                                                goto out;
                                        }
                                }
                                expr = triple_rhs(state, base, 0);
                                for(; expr; expr = triple_rhs(state, base, expr)) {
                                        if ((*expr) == var) {
                                                goto out;
                                        }
                                }
                        }
                out:
                        if (triple_is_branch(state, base)) {
                                internal_error(state, base,
                                        "Could not insert write to phi");
                        }
                        move = post_triple(state, base, OP_WRITE, var->type, val, var);
                        use_triple(val, move);
                        use_triple(var, move);
                        writers++;
                }
                if (!writers && readers) {
                        internal_error(state, var, "no value written to in use phi?");
                }
                /* If var is not used free it */
                if (!writers) {
                        release_triple(state, MISC(var, 0));
                        release_triple(state, var);
                }
                /* Release the phi function */
                release_triple(state, phi);
        }

        /* Walk all of the operations to find the adecls */
        for(var = first->next; var != first ; var = var->next) {
                struct triple_set *use, *use_next;
                if (!triple_is_auto_var(state, var)) {
                        continue;
                }

                /* Walk through all of the rhs uses of var and
                 * replace them with read of var.
                 */
                for(use = var->use; use; use = use_next) {
                        struct triple *read, *user;
                        struct triple **slot;
                        int zrhs, i, used;
                        use_next = use->next;
                        user = use->member;

                        /* Generate a read of var */
                        read = pre_triple(state, user, OP_READ, var->type, var, 0);
                        use_triple(var, read);

                        /* Find the rhs uses and see if they need to be replaced */
                        used = 0;
                        zrhs = user->rhs;
                        slot = &RHS(user, 0);
                        for(i = 0; i < zrhs; i++) {
                                if (slot[i] == var) {
                                        slot[i] = read;
                                        used = 1;
                                }
                        }
                        /* If we did use it cleanup the uses */
                        if (used) {
                                unuse_triple(var, user);
                                use_triple(read, user);
                        }
                        /* If we didn't use it release the extra triple */
                        else {
                                release_triple(state, read);
                        }
                }
        }
}

#define HI() if (state->compiler->debug & DEBUG_REBUILD_SSA_FORM) { \
        FILE *fp = state->dbgout; \
        fprintf(fp, "@ %s:%d\n", __FILE__, __LINE__); romcc_print_blocks(state, fp); \
        }

static void rebuild_ssa_form(struct compile_state *state)
{
HI();
        transform_from_ssa_form(state);
HI();
        state->bb.first = state->first;
        free_basic_blocks(state, &state->bb);
        analyze_basic_blocks(state, &state->bb);
HI();
        insert_phi_operations(state);
HI();
        rename_variables(state);
HI();

        prune_block_variables(state, state->bb.first_block);
HI();
        prune_unused_phis(state);
HI();
}
#undef HI

/*
 * Register conflict resolution
 * =========================================================
 */

static struct reg_info find_def_color(
        struct compile_state *state, struct triple *def)
{
        struct triple_set *set;
        struct reg_info info;
        info.reg = REG_UNSET;
        info.regcm = 0;
        if (!triple_is_def(state, def)) {
                return info;
        }
        info = arch_reg_lhs(state, def, 0);
        if (info.reg >= MAX_REGISTERS) {
                info.reg = REG_UNSET;
        }
        for(set = def->use; set; set = set->next) {
                struct reg_info tinfo;
                int i;
                i = find_rhs_use(state, set->member, def);
                if (i < 0) {
                        continue;
                }
                tinfo = arch_reg_rhs(state, set->member, i);
                if (tinfo.reg >= MAX_REGISTERS) {
                        tinfo.reg = REG_UNSET;
                }
                if ((tinfo.reg != REG_UNSET) &&
                        (info.reg != REG_UNSET) &&
                        (tinfo.reg != info.reg)) {
                        internal_error(state, def, "register conflict");
                }
                if ((info.regcm & tinfo.regcm) == 0) {
                        internal_error(state, def, "regcm conflict %x & %x == 0",
                                info.regcm, tinfo.regcm);
                }
                if (info.reg == REG_UNSET) {
                        info.reg = tinfo.reg;
                }
                info.regcm &= tinfo.regcm;
        }
        if (info.reg >= MAX_REGISTERS) {
                internal_error(state, def, "register out of range");
        }
        return info;
}

static struct reg_info find_lhs_pre_color(
        struct compile_state *state, struct triple *ins, int index)
{
        struct reg_info info;
        int zlhs, zrhs, i;
        zrhs = ins->rhs;
        zlhs = ins->lhs;
        if (!zlhs && triple_is_def(state, ins)) {
                zlhs = 1;
        }
        if (index >= zlhs) {
                internal_error(state, ins, "Bad lhs %d", index);
        }
        info = arch_reg_lhs(state, ins, index);
        for(i = 0; i < zrhs; i++) {
                struct reg_info rinfo;
                rinfo = arch_reg_rhs(state, ins, i);
                if ((info.reg == rinfo.reg) &&
                        (rinfo.reg >= MAX_REGISTERS)) {
                        struct reg_info tinfo;
                        tinfo = find_lhs_pre_color(state, RHS(ins, index), 0);
                        info.reg = tinfo.reg;
                        info.regcm &= tinfo.regcm;
                        break;
                }
        }
        if (info.reg >= MAX_REGISTERS) {
                info.reg = REG_UNSET;
        }
        return info;
}

static struct reg_info find_rhs_post_color(
        struct compile_state *state, struct triple *ins, int index);

static struct reg_info find_lhs_post_color(
        struct compile_state *state, struct triple *ins, int index)
{
        struct triple_set *set;
        struct reg_info info;
        struct triple *lhs;
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_lhs_post_color(%p, %d)\n",
                ins, index);
#endif
        if ((index == 0) && triple_is_def(state, ins)) {
                lhs = ins;
        }
        else if (index < ins->lhs) {
                lhs = LHS(ins, index);
        }
        else {
                internal_error(state, ins, "Bad lhs %d", index);
                lhs = 0;
        }
        info = arch_reg_lhs(state, ins, index);
        if (info.reg >= MAX_REGISTERS) {
                info.reg = REG_UNSET;
        }
        for(set = lhs->use; set; set = set->next) {
                struct reg_info rinfo;
                struct triple *user;
                int zrhs, i;
                user = set->member;
                zrhs = user->rhs;
                for(i = 0; i < zrhs; i++) {
                        if (RHS(user, i) != lhs) {
                                continue;
                        }
                        rinfo = find_rhs_post_color(state, user, i);
                        if ((info.reg != REG_UNSET) &&
                                (rinfo.reg != REG_UNSET) &&
                                (info.reg != rinfo.reg)) {
                                internal_error(state, ins, "register conflict");
                        }
                        if ((info.regcm & rinfo.regcm) == 0) {
                                internal_error(state, ins, "regcm conflict %x & %x == 0",
                                        info.regcm, rinfo.regcm);
                        }
                        if (info.reg == REG_UNSET) {
                                info.reg = rinfo.reg;
                        }
                        info.regcm &= rinfo.regcm;
                }
        }
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_lhs_post_color(%p, %d) -> ( %d, %x)\n",
                ins, index, info.reg, info.regcm);
#endif
        return info;
}

static struct reg_info find_rhs_post_color(
        struct compile_state *state, struct triple *ins, int index)
{
        struct reg_info info, rinfo;
        int zlhs, i;
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_rhs_post_color(%p, %d)\n",
                ins, index);
#endif
        rinfo = arch_reg_rhs(state, ins, index);
        zlhs = ins->lhs;
        if (!zlhs && triple_is_def(state, ins)) {
                zlhs = 1;
        }
        info = rinfo;
        if (info.reg >= MAX_REGISTERS) {
                info.reg = REG_UNSET;
        }
        for(i = 0; i < zlhs; i++) {
                struct reg_info linfo;
                linfo = arch_reg_lhs(state, ins, i);
                if ((linfo.reg == rinfo.reg) &&
                        (linfo.reg >= MAX_REGISTERS)) {
                        struct reg_info tinfo;
                        tinfo = find_lhs_post_color(state, ins, i);
                        if (tinfo.reg >= MAX_REGISTERS) {
                                tinfo.reg = REG_UNSET;
                        }
                        info.regcm &= linfo.regcm;
                        info.regcm &= tinfo.regcm;
                        if (info.reg != REG_UNSET) {
                                internal_error(state, ins, "register conflict");
                        }
                        if (info.regcm == 0) {
                                internal_error(state, ins, "regcm conflict");
                        }
                        info.reg = tinfo.reg;
                }
        }
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_rhs_post_color(%p, %d) -> ( %d, %x)\n",
                ins, index, info.reg, info.regcm);
#endif
        return info;
}

static struct reg_info find_lhs_color(
        struct compile_state *state, struct triple *ins, int index)
{
        struct reg_info pre, post, info;
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_lhs_color(%p, %d)\n",
                ins, index);
#endif
        pre = find_lhs_pre_color(state, ins, index);
        post = find_lhs_post_color(state, ins, index);
        if ((pre.reg != post.reg) &&
                (pre.reg != REG_UNSET) &&
                (post.reg != REG_UNSET)) {
                internal_error(state, ins, "register conflict");
        }
        info.regcm = pre.regcm & post.regcm;
        info.reg = pre.reg;
        if (info.reg == REG_UNSET) {
                info.reg = post.reg;
        }
#if DEBUG_TRIPLE_COLOR
        fprintf(state->errout, "find_lhs_color(%p, %d) -> ( %d, %x) ... (%d, %x) (%d, %x)\n",
                ins, index, info.reg, info.regcm,
                pre.reg, pre.regcm, post.reg, post.regcm);
#endif
        return info;
}

static struct triple *post_copy(struct compile_state *state, struct triple *ins)
{
        struct triple_set *entry, *next;
        struct triple *out;
        struct reg_info info, rinfo;

        info = arch_reg_lhs(state, ins, 0);
        out = post_triple(state, ins, OP_COPY, ins->type, ins, 0);
        use_triple(RHS(out, 0), out);
        /* Get the users of ins to use out instead */
        for(entry = ins->use; entry; entry = next) {
                int i;
                next = entry->next;
                if (entry->member == out) {
                        continue;
                }
                i = find_rhs_use(state, entry->member, ins);
                if (i < 0) {
                        continue;
                }
                rinfo = arch_reg_rhs(state, entry->member, i);
                if ((info.reg == REG_UNNEEDED) && (rinfo.reg == REG_UNNEEDED)) {
                        continue;
                }
                replace_rhs_use(state, ins, out, entry->member);
        }
        transform_to_arch_instruction(state, out);
        return out;
}

static struct triple *typed_pre_copy(
        struct compile_state *state, struct type *type, struct triple *ins, int index)
{
        /* Carefully insert enough operations so that I can
         * enter any operation with a GPR32.
         */
        struct triple *in;
        struct triple **expr;
        unsigned classes;
        struct reg_info info;
        int op;
        if (ins->op == OP_PHI) {
                internal_error(state, ins, "pre_copy on a phi?");
        }
        classes = arch_type_to_regcm(state, type);
        info = arch_reg_rhs(state, ins, index);
        expr = &RHS(ins, index);
        if ((info.regcm & classes) == 0) {
                FILE *fp = state->errout;
                fprintf(fp, "src_type: ");
                name_of(fp, ins->type);
                fprintf(fp, "\ndst_type: ");
                name_of(fp, type);
                fprintf(fp, "\n");
                internal_error(state, ins, "pre_copy with no register classes");
        }
        op = OP_COPY;
        if (!equiv_types(type, (*expr)->type)) {
                op = OP_CONVERT;
        }
        in = pre_triple(state, ins, op, type, *expr, 0);
        unuse_triple(*expr, ins);
        *expr = in;
        use_triple(RHS(in, 0), in);
        use_triple(in, ins);
        transform_to_arch_instruction(state, in);
        return in;

}
static struct triple *pre_copy(
        struct compile_state *state, struct triple *ins, int index)
{
        return typed_pre_copy(state, RHS(ins, index)->type, ins, index);
}


static void insert_copies_to_phi(struct compile_state *state)
{
        /* To get out of ssa form we insert moves on the incoming
         * edges to blocks containting phi functions.
         */
        struct triple *first;
        struct triple *phi;

        /* Walk all of the operations to find the phi functions */
        first = state->first;
        for(phi = first->next; phi != first ; phi = phi->next) {
                struct block_set *set;
                struct block *block;
                struct triple **slot, *copy;
                int edge;
                if (phi->op != OP_PHI) {
                        continue;
                }
                phi->id |= TRIPLE_FLAG_POST_SPLIT;
                block = phi->u.block;
                slot  = &RHS(phi, 0);
                /* Phi's that feed into mandatory live range joins
                 * cause nasty complications.  Insert a copy of
                 * the phi value so I never have to deal with
                 * that in the rest of the code.
                 */
                copy = post_copy(state, phi);
                copy->id |= TRIPLE_FLAG_PRE_SPLIT;
                /* Walk all of the incoming edges/blocks and insert moves.
                 */
                for(edge = 0, set = block->use; set; set = set->next, edge++) {
                        struct block *eblock;
                        struct triple *move;
                        struct triple *val;
                        struct triple *ptr;
                        eblock = set->member;
                        val = slot[edge];

                        if (val == phi) {
                                continue;
                        }

                        get_occurrence(val->occurrence);
                        move = build_triple(state, OP_COPY, val->type, val, 0,
                                val->occurrence);
                        move->u.block = eblock;
                        move->id |= TRIPLE_FLAG_PRE_SPLIT;
                        use_triple(val, move);

                        slot[edge] = move;
                        unuse_triple(val, phi);
                        use_triple(move, phi);

                        /* Walk up the dominator tree until I have found the appropriate block */
                        while(eblock && !tdominates(state, val, eblock->last)) {
                                eblock = eblock->idom;
                        }
                        if (!eblock) {
                                internal_error(state, phi, "Cannot find block dominated by %p",
                                        val);
                        }

                        /* Walk through the block backwards to find
                         * an appropriate location for the OP_COPY.
                         */
                        for(ptr = eblock->last; ptr != eblock->first; ptr = ptr->prev) {
                                struct triple **expr;
                                if (ptr->op == OP_PIECE) {
                                        ptr = MISC(ptr, 0);
                                }
                                if ((ptr == phi) || (ptr == val)) {
                                        goto out;
                                }
                                expr = triple_lhs(state, ptr, 0);
                                for(;expr; expr = triple_lhs(state, ptr, expr)) {
                                        if ((*expr) == val) {
                                                goto out;
                                        }
                                }
                                expr = triple_rhs(state, ptr, 0);
                                for(;expr; expr = triple_rhs(state, ptr, expr)) {
                                        if ((*expr) == phi) {
                                                goto out;
                                        }
                                }
                        }
                out:
                        if (triple_is_branch(state, ptr)) {
                                internal_error(state, ptr,
                                        "Could not insert write to phi");
                        }
                        insert_triple(state, after_lhs(state, ptr), move);
                        if (eblock->last == after_lhs(state, ptr)->prev) {
                                eblock->last = move;
                        }
                        transform_to_arch_instruction(state, move);
                }
        }
        print_blocks(state, __func__, state->dbgout);
}

struct triple_reg_set;
struct reg_block;


static int do_triple_set(struct triple_reg_set **head,
        struct triple *member, struct triple *new_member)
{
        struct triple_reg_set **ptr, *new;
        if (!member)
                return 0;
        ptr = head;
        while(*ptr) {
                if ((*ptr)->member == member) {
                        return 0;
                }
                ptr = &(*ptr)->next;
        }
        new = xcmalloc(sizeof(*new), "triple_set");
        new->member = member;
        new->new    = new_member;
        new->next   = *head;
        *head       = new;
        return 1;
}

static void do_triple_unset(struct triple_reg_set **head, struct triple *member)
{
        struct triple_reg_set *entry, **ptr;
        ptr = head;
        while(*ptr) {
                entry = *ptr;
                if (entry->member == member) {
                        *ptr = entry->next;
                        xfree(entry);
                        return;
                }
                else {
                        ptr = &entry->next;
                }
        }
}

static int in_triple(struct reg_block *rb, struct triple *in)
{
        return do_triple_set(&rb->in, in, 0);
}

#if DEBUG_ROMCC_WARNING
static void unin_triple(struct reg_block *rb, struct triple *unin)
{
        do_triple_unset(&rb->in, unin);
}
#endif

static int out_triple(struct reg_block *rb, struct triple *out)
{
        return do_triple_set(&rb->out, out, 0);
}
#if DEBUG_ROMCC_WARNING
static void unout_triple(struct reg_block *rb, struct triple *unout)
{
        do_triple_unset(&rb->out, unout);
}
#endif

static int initialize_regblock(struct reg_block *blocks,
        struct block *block, int vertex)
{
        struct block_set *user;
        if (!block || (blocks[block->vertex].block == block)) {
                return vertex;
        }
        vertex += 1;
        /* Renumber the blocks in a convenient fashion */
        block->vertex = vertex;
        blocks[vertex].block    = block;
        blocks[vertex].vertex   = vertex;
        for(user = block->use; user; user = user->next) {
                vertex = initialize_regblock(blocks, user->member, vertex);
        }
        return vertex;
}

static struct triple *part_to_piece(struct compile_state *state, struct triple *ins)
{
/* Part to piece is a best attempt and it cannot be correct all by
 * itself.  If various values are read as different sizes in different
 * parts of the code this function cannot work.  Or rather it cannot
 * work in conjunction with compute_variable_liftimes.  As the
 * analysis will get confused.
 */
        struct triple *base;
        unsigned reg;
        if (!is_lvalue(state, ins)) {
                return ins;
        }
        base = 0;
        reg = 0;
        while(ins && triple_is_part(state, ins) && (ins->op != OP_PIECE)) {
                base = MISC(ins, 0);
                switch(ins->op) {
                case OP_INDEX:
                        reg += index_reg_offset(state, base->type, ins->u.cval)/REG_SIZEOF_REG;
                        break;
                case OP_DOT:
                        reg += field_reg_offset(state, base->type, ins->u.field)/REG_SIZEOF_REG;
                        break;
                default:
                        internal_error(state, ins, "unhandled part");
                        break;
                }
                ins = base;
        }
        if (base) {
                if (reg > base->lhs) {
                        internal_error(state, base, "part out of range?");
                }
                ins = LHS(base, reg);
        }
        return ins;
}

static int this_def(struct compile_state *state,
        struct triple *ins, struct triple *other)
{
        if (ins == other) {
                return 1;
        }
        if (ins->op == OP_WRITE) {
                ins = part_to_piece(state, MISC(ins, 0));
        }
        return ins == other;
}

static int phi_in(struct compile_state *state, struct reg_block *blocks,
        struct reg_block *rb, struct block *suc)
{
        /* Read the conditional input set of a successor block
         * (i.e. the input to the phi nodes) and place it in the
         * current blocks output set.
         */
        struct block_set *set;
        struct triple *ptr;
        int edge;
        int done, change;
        change = 0;
        /* Find the edge I am coming in on */
        for(edge = 0, set = suc->use; set; set = set->next, edge++) {
                if (set->member == rb->block) {
                        break;
                }
        }
        if (!set) {
                internal_error(state, 0, "Not coming on a control edge?");
        }
        for(done = 0, ptr = suc->first; !done; ptr = ptr->next) {
                struct triple **slot, *expr, *ptr2;
                int out_change, done2;
                done = (ptr == suc->last);
                if (ptr->op != OP_PHI) {
                        continue;
                }
                slot = &RHS(ptr, 0);
                expr = slot[edge];
                out_change = out_triple(rb, expr);
                if (!out_change) {
                        continue;
                }
                /* If we don't define the variable also plast it
                 * in the current blocks input set.
                 */
                ptr2 = rb->block->first;
                for(done2 = 0; !done2; ptr2 = ptr2->next) {
                        if (this_def(state, ptr2, expr)) {
                                break;
                        }
                        done2 = (ptr2 == rb->block->last);
                }
                if (!done2) {
                        continue;
                }
                change |= in_triple(rb, expr);
        }
        return change;
}

static int reg_in(struct compile_state *state, struct reg_block *blocks,
        struct reg_block *rb, struct block *suc)
{
        struct triple_reg_set *in_set;
        int change;
        change = 0;
        /* Read the input set of a successor block
         * and place it in the current blocks output set.
         */
        in_set = blocks[suc->vertex].in;
        for(; in_set; in_set = in_set->next) {
                int out_change, done;
                struct triple *first, *last, *ptr;
                out_change = out_triple(rb, in_set->member);
                if (!out_change) {
                        continue;
                }
                /* If we don't define the variable also place it
                 * in the current blocks input set.
                 */
                first = rb->block->first;
                last = rb->block->last;
                done = 0;
                for(ptr = first; !done; ptr = ptr->next) {
                        if (this_def(state, ptr, in_set->member)) {
                                break;
                        }
                        done = (ptr == last);
                }
                if (!done) {
                        continue;
                }
                change |= in_triple(rb, in_set->member);
        }
        change |= phi_in(state, blocks, rb, suc);
        return change;
}

static int use_in(struct compile_state *state, struct reg_block *rb)
{
        /* Find the variables we use but don't define and add
         * it to the current blocks input set.
         */
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME is this O(N^2) algorithm bad?"
#endif
        struct block *block;
        struct triple *ptr;
        int done;
        int change;
        block = rb->block;
        change = 0;
        for(done = 0, ptr = block->last; !done; ptr = ptr->prev) {
                struct triple **expr;
                done = (ptr == block->first);
                /* The variable a phi function uses depends on the
                 * control flow, and is handled in phi_in, not
                 * here.
                 */
                if (ptr->op == OP_PHI) {
                        continue;
                }
                expr = triple_rhs(state, ptr, 0);
                for(;expr; expr = triple_rhs(state, ptr, expr)) {
                        struct triple *rhs, *test;
                        int tdone;
                        rhs = part_to_piece(state, *expr);
                        if (!rhs) {
                                continue;
                        }

                        /* See if rhs is defined in this block.
                         * A write counts as a definition.
                         */
                        for(tdone = 0, test = ptr; !tdone; test = test->prev) {
                                tdone = (test == block->first);
                                if (this_def(state, test, rhs)) {
                                        rhs = 0;
                                        break;
                                }
                        }
                        /* If I still have a valid rhs add it to in */
                        change |= in_triple(rb, rhs);
                }
        }
        return change;
}

static struct reg_block *compute_variable_lifetimes(
        struct compile_state *state, struct basic_blocks *bb)
{
        struct reg_block *blocks;
        int change;
        blocks = xcmalloc(
                sizeof(*blocks)*(bb->last_vertex + 1), "reg_block");
        initialize_regblock(blocks, bb->last_block, 0);
        do {
                int i;
                change = 0;
                for(i = 1; i <= bb->last_vertex; i++) {
                        struct block_set *edge;
                        struct reg_block *rb;
                        rb = &blocks[i];
                        /* Add the all successor's input set to in */
                        for(edge = rb->block->edges; edge; edge = edge->next) {
                                change |= reg_in(state, blocks, rb, edge->member);
                        }
                        /* Add use to in... */
                        change |= use_in(state, rb);
                }
        } while(change);
        return blocks;
}

static void free_variable_lifetimes(struct compile_state *state,
        struct basic_blocks *bb, struct reg_block *blocks)
{
        int i;
        /* free in_set && out_set on each block */
        for(i = 1; i <= bb->last_vertex; i++) {
                struct triple_reg_set *entry, *next;
                struct reg_block *rb;
                rb = &blocks[i];
                for(entry = rb->in; entry ; entry = next) {
                        next = entry->next;
                        do_triple_unset(&rb->in, entry->member);
                }
                for(entry = rb->out; entry; entry = next) {
                        next = entry->next;
                        do_triple_unset(&rb->out, entry->member);
                }
        }
        xfree(blocks);

}

typedef void (*wvl_cb_t)(
        struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg);

static void walk_variable_lifetimes(struct compile_state *state,
        struct basic_blocks *bb, struct reg_block *blocks,
        wvl_cb_t cb, void *arg)
{
        int i;

        for(i = 1; i <= state->bb.last_vertex; i++) {
                struct triple_reg_set *live;
                struct triple_reg_set *entry, *next;
                struct triple *ptr, *prev;
                struct reg_block *rb;
                struct block *block;
                int done;

                /* Get the blocks */
                rb = &blocks[i];
                block = rb->block;

                /* Copy out into live */
                live = 0;
                for(entry = rb->out; entry; entry = next) {
                        next = entry->next;
                        do_triple_set(&live, entry->member, entry->new);
                }
                /* Walk through the basic block calculating live */
                for(done = 0, ptr = block->last; !done; ptr = prev) {
                        struct triple **expr;

                        prev = ptr->prev;
                        done = (ptr == block->first);

                        /* Ensure the current definition is in live */
                        if (triple_is_def(state, ptr)) {
                                do_triple_set(&live, ptr, 0);
                        }

                        /* Inform the callback function of what is
                         * going on.
                         */
                         cb(state, blocks, live, rb, ptr, arg);

                        /* Remove the current definition from live */
                        do_triple_unset(&live, ptr);

                        /* Add the current uses to live.
                         *
                         * It is safe to skip phi functions because they do
                         * not have any block local uses, and the block
                         * output sets already properly account for what
                         * control flow depedent uses phi functions do have.
                         */
                        if (ptr->op == OP_PHI) {
                                continue;
                        }
                        expr = triple_rhs(state, ptr, 0);
                        for(;expr; expr = triple_rhs(state, ptr, expr)) {
                                /* If the triple is not a definition skip it. */
                                if (!*expr || !triple_is_def(state, *expr)) {
                                        continue;
                                }
                                do_triple_set(&live, *expr, 0);
                        }
                }
                /* Free live */
                for(entry = live; entry; entry = next) {
                        next = entry->next;
                        do_triple_unset(&live, entry->member);
                }
        }
}

struct print_live_variable_info {
        struct reg_block *rb;
        FILE *fp;
};
#if DEBUG_EXPLICIT_CLOSURES
static void print_live_variables_block(
        struct compile_state *state, struct block *block, void *arg)

{
        struct print_live_variable_info *info = arg;
        struct block_set *edge;
        FILE *fp = info->fp;
        struct reg_block *rb;
        struct triple *ptr;
        int phi_present;
        int done;
        rb = &info->rb[block->vertex];

        fprintf(fp, "\nblock: %p (%d),",
                block,  block->vertex);
        for(edge = block->edges; edge; edge = edge->next) {
                fprintf(fp, " %p<-%p",
                        edge->member,
                        edge->member && edge->member->use?edge->member->use->member : 0);
        }
        fprintf(fp, "\n");
        if (rb->in) {
                struct triple_reg_set *in_set;
                fprintf(fp, "        in:");
                for(in_set = rb->in; in_set; in_set = in_set->next) {
                        fprintf(fp, " %-10p", in_set->member);
                }
                fprintf(fp, "\n");
        }
        phi_present = 0;
        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                done = (ptr == block->last);
                if (ptr->op == OP_PHI) {
                        phi_present = 1;
                        break;
                }
        }
        if (phi_present) {
                int edge;
                for(edge = 0; edge < block->users; edge++) {
                        fprintf(fp, "     in(%d):", edge);
                        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                                struct triple **slot;
                                done = (ptr == block->last);
                                if (ptr->op != OP_PHI) {
                                        continue;
                                }
                                slot = &RHS(ptr, 0);
                                fprintf(fp, " %-10p", slot[edge]);
                        }
                        fprintf(fp, "\n");
                }
        }
        if (block->first->op == OP_LABEL) {
                fprintf(fp, "%p:\n", block->first);
        }
        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                done = (ptr == block->last);
                display_triple(fp, ptr);
        }
        if (rb->out) {
                struct triple_reg_set *out_set;
                fprintf(fp, "       out:");
                for(out_set = rb->out; out_set; out_set = out_set->next) {
                        fprintf(fp, " %-10p", out_set->member);
                }
                fprintf(fp, "\n");
        }
        fprintf(fp, "\n");
}

static void print_live_variables(struct compile_state *state,
        struct basic_blocks *bb, struct reg_block *rb, FILE *fp)
{
        struct print_live_variable_info info;
        info.rb = rb;
        info.fp = fp;
        fprintf(fp, "\nlive variables by block\n");
        walk_blocks(state, bb, print_live_variables_block, &info);

}
#endif

static int count_triples(struct compile_state *state)
{
        struct triple *first, *ins;
        int triples = 0;
        first = state->first;
        ins = first;
        do {
                triples++;
                ins = ins->next;
        } while (ins != first);
        return triples;
}


struct dead_triple {
        struct triple *triple;
        struct dead_triple *work_next;
        struct block *block;
        int old_id;
        int flags;
#define TRIPLE_FLAG_ALIVE 1
#define TRIPLE_FLAG_FREE  1
};

static void print_dead_triples(struct compile_state *state,
        struct dead_triple *dtriple)
{
        struct triple *first, *ins;
        struct dead_triple *dt;
        FILE *fp;
        if (!(state->compiler->debug & DEBUG_TRIPLES)) {
                return;
        }
        fp = state->dbgout;
        fprintf(fp, "--------------- dtriples ---------------\n");
        first = state->first;
        ins = first;
        do {
                dt = &dtriple[ins->id];
                if ((ins->op == OP_LABEL) && (ins->use)) {
                        fprintf(fp, "\n%p:\n", ins);
                }
                fprintf(fp, "%c",
                        (dt->flags & TRIPLE_FLAG_ALIVE)?' ': '-');
                display_triple(fp, ins);
                if (triple_is_branch(state, ins)) {
                        fprintf(fp, "\n");
                }
                ins = ins->next;
        } while(ins != first);
        fprintf(fp, "\n");
}


static void awaken(
        struct compile_state *state,
        struct dead_triple *dtriple, struct triple **expr,
        struct dead_triple ***work_list_tail)
{
        struct triple *triple;
        struct dead_triple *dt;
        if (!expr) {
                return;
        }
        triple = *expr;
        if (!triple) {
                return;
        }
        if (triple->id <= 0)  {
                internal_error(state, triple, "bad triple id: %d",
                        triple->id);
        }
        if (triple->op == OP_NOOP) {
                internal_error(state, triple, "awakening noop?");
                return;
        }
        dt = &dtriple[triple->id];
        if (!(dt->flags & TRIPLE_FLAG_ALIVE)) {
                dt->flags |= TRIPLE_FLAG_ALIVE;
                if (!dt->work_next) {
                        **work_list_tail = dt;
                        *work_list_tail = &dt->work_next;
                }
        }
}

static void eliminate_inefectual_code(struct compile_state *state)
{
        struct dead_triple *dtriple, *work_list, **work_list_tail, *dt;
        int triples, i;
        struct triple *first, *ins;

        if (!(state->compiler->flags & COMPILER_ELIMINATE_INEFECTUAL_CODE)) {
                return;
        }

        /* Setup the work list */
        work_list = 0;
        work_list_tail = &work_list;

        first = state->first;

        /* Count how many triples I have */
        triples = count_triples(state);

        /* Now put then in an array and mark all of the triples dead */
        dtriple = xcmalloc(sizeof(*dtriple) * (triples + 1), "dtriples");

        ins = first;
        i = 1;
        do {
                dtriple[i].triple = ins;
                dtriple[i].block  = block_of_triple(state, ins);
                dtriple[i].flags  = 0;
                dtriple[i].old_id = ins->id;
                ins->id = i;
                /* See if it is an operation we always keep */
                if (!triple_is_pure(state, ins, dtriple[i].old_id)) {
                        awaken(state, dtriple, &ins, &work_list_tail);
                }
                i++;
                ins = ins->next;
        } while(ins != first);
        while(work_list) {
                struct block *block;
                struct dead_triple *dt;
                struct block_set *user;
                struct triple **expr;
                dt = work_list;
                work_list = dt->work_next;
                if (!work_list) {
                        work_list_tail = &work_list;
                }
                /* Make certain the block the current instruction is in lives */
                block = block_of_triple(state, dt->triple);
                awaken(state, dtriple, &block->first, &work_list_tail);
                if (triple_is_branch(state, block->last)) {
                        awaken(state, dtriple, &block->last, &work_list_tail);
                } else {
                        awaken(state, dtriple, &block->last->next, &work_list_tail);
                }

                /* Wake up the data depencencies of this triple */
                expr = 0;
                do {
                        expr = triple_rhs(state, dt->triple, expr);
                        awaken(state, dtriple, expr, &work_list_tail);
                } while(expr);
                do {
                        expr = triple_lhs(state, dt->triple, expr);
                        awaken(state, dtriple, expr, &work_list_tail);
                } while(expr);
                do {
                        expr = triple_misc(state, dt->triple, expr);
                        awaken(state, dtriple, expr, &work_list_tail);
                } while(expr);
                /* Wake up the forward control dependencies */
                do {
                        expr = triple_targ(state, dt->triple, expr);
                        awaken(state, dtriple, expr, &work_list_tail);
                } while(expr);
                /* Wake up the reverse control dependencies of this triple */
                for(user = dt->block->ipdomfrontier; user; user = user->next) {
                        struct triple *last;
                        last = user->member->last;
                        while((last->op == OP_NOOP) && (last != user->member->first)) {
#if DEBUG_ROMCC_WARNINGS
#warning "Should we bring the awakening noops back?"
#endif
                                // internal_warning(state, last, "awakening noop?");
                                last = last->prev;
                        }
                        awaken(state, dtriple, &last, &work_list_tail);
                }
        }
        print_dead_triples(state, dtriple);
        for(dt = &dtriple[1]; dt <= &dtriple[triples]; dt++) {
                if ((dt->triple->op == OP_NOOP) &&
                        (dt->flags & TRIPLE_FLAG_ALIVE)) {
                        internal_error(state, dt->triple, "noop effective?");
                }
                dt->triple->id = dt->old_id;    /* Restore the color */
                if (!(dt->flags & TRIPLE_FLAG_ALIVE)) {
                        release_triple(state, dt->triple);
                }
        }
        xfree(dtriple);

        rebuild_ssa_form(state);

        print_blocks(state, __func__, state->dbgout);
}


static void insert_mandatory_copies(struct compile_state *state)
{
        struct triple *ins, *first;

        /* The object is with a minimum of inserted copies,
         * to resolve in fundamental register conflicts between
         * register value producers and consumers.
         * Theoretically we may be greater than minimal when we
         * are inserting copies before instructions but that
         * case should be rare.
         */
        first = state->first;
        ins = first;
        do {
                struct triple_set *entry, *next;
                struct triple *tmp;
                struct reg_info info;
                unsigned reg, regcm;
                int do_post_copy, do_pre_copy;
                tmp = 0;
                if (!triple_is_def(state, ins)) {
                        goto next;
                }
                /* Find the architecture specific color information */
                info = find_lhs_pre_color(state, ins, 0);
                if (info.reg >= MAX_REGISTERS) {
                        info.reg = REG_UNSET;
                }

                reg = REG_UNSET;
                regcm = arch_type_to_regcm(state, ins->type);
                do_pre_copy = 0;

                /* Walk through the uses of ins and check for conflicts */
                for(entry = ins->use; entry; entry = next) {
                        struct reg_info rinfo;
                        int i;
                        next = entry->next;
                        i = find_rhs_use(state, entry->member, ins);
                        if (i < 0) {
                                continue;
                        }

                        /* Find the users color requirements */
                        rinfo = arch_reg_rhs(state, entry->member, i);
                        if (rinfo.reg >= MAX_REGISTERS) {
                                rinfo.reg = REG_UNSET;
                        }

                        /* See if I need a pre_copy */
                        if (rinfo.reg != REG_UNSET) {
                                if ((reg != REG_UNSET) && (reg != rinfo.reg)) {
                                        do_pre_copy = 1;
                                }
                                reg = rinfo.reg;
                        }
                        regcm &= rinfo.regcm;
                        regcm = arch_regcm_normalize(state, regcm);
                        if (regcm == 0) {
                                do_pre_copy = 1;
                        }
                        /* Always use pre_copies for constants.
                         * They do not take up any registers until a
                         * copy places them in one.
                         */
                        if ((info.reg == REG_UNNEEDED) &&
                                (rinfo.reg != REG_UNNEEDED)) {
                                do_pre_copy = 1;
                        }
                }
                do_post_copy =
                        !do_pre_copy &&
                        (((info.reg != REG_UNSET) &&
                                (reg != REG_UNSET) &&
                                (info.reg != reg)) ||
                        ((info.regcm & regcm) == 0));

                reg = info.reg;
                regcm = info.regcm;
                /* Walk through the uses of ins and do a pre_copy or see if a post_copy is warranted */
                for(entry = ins->use; entry; entry = next) {
                        struct reg_info rinfo;
                        int i;
                        next = entry->next;
                        i = find_rhs_use(state, entry->member, ins);
                        if (i < 0) {
                                continue;
                        }

                        /* Find the users color requirements */
                        rinfo = arch_reg_rhs(state, entry->member, i);
                        if (rinfo.reg >= MAX_REGISTERS) {
                                rinfo.reg = REG_UNSET;
                        }

                        /* Now see if it is time to do the pre_copy */
                        if (rinfo.reg != REG_UNSET) {
                                if (((reg != REG_UNSET) && (reg != rinfo.reg)) ||
                                        ((regcm & rinfo.regcm) == 0) ||
                                        /* Don't let a mandatory coalesce sneak
                                         * into a operation that is marked to prevent
                                         * coalescing.
                                         */
                                        ((reg != REG_UNNEEDED) &&
                                        ((ins->id & TRIPLE_FLAG_POST_SPLIT) ||
                                        (entry->member->id & TRIPLE_FLAG_PRE_SPLIT)))
                                        ) {
                                        if (do_pre_copy) {
                                                struct triple *user;
                                                user = entry->member;
                                                if (RHS(user, i) != ins) {
                                                        internal_error(state, user, "bad rhs");
                                                }
                                                tmp = pre_copy(state, user, i);
                                                tmp->id |= TRIPLE_FLAG_PRE_SPLIT;
                                                continue;
                                        } else {
                                                do_post_copy = 1;
                                        }
                                }
                                reg = rinfo.reg;
                        }
                        if ((regcm & rinfo.regcm) == 0) {
                                if (do_pre_copy) {
                                        struct triple *user;
                                        user = entry->member;
                                        if (RHS(user, i) != ins) {
                                                internal_error(state, user, "bad rhs");
                                        }
                                        tmp = pre_copy(state, user, i);
                                        tmp->id |= TRIPLE_FLAG_PRE_SPLIT;
                                        continue;
                                } else {
                                        do_post_copy = 1;
                                }
                        }
                        regcm &= rinfo.regcm;

                }
                if (do_post_copy) {
                        struct reg_info pre, post;
                        tmp = post_copy(state, ins);
                        tmp->id |= TRIPLE_FLAG_PRE_SPLIT;
                        pre = arch_reg_lhs(state, ins, 0);
                        post = arch_reg_lhs(state, tmp, 0);
                        if ((pre.reg == post.reg) && (pre.regcm == post.regcm)) {
                                internal_error(state, tmp, "useless copy");
                        }
                }
        next:
                ins = ins->next;
        } while(ins != first);

        print_blocks(state, __func__, state->dbgout);
}


struct live_range_edge;
struct live_range_def;
struct live_range {
        struct live_range_edge *edges;
        struct live_range_def *defs;
/* Note. The list pointed to by defs is kept in order.
 * That is baring splits in the flow control
 * defs dominates defs->next wich dominates defs->next->next
 * etc.
 */
        unsigned color;
        unsigned classes;
        unsigned degree;
        unsigned length;
        struct live_range *group_next, **group_prev;
};

struct live_range_edge {
        struct live_range_edge *next;
        struct live_range *node;
};

struct live_range_def {
        struct live_range_def *next;
        struct live_range_def *prev;
        struct live_range *lr;
        struct triple *def;
        unsigned orig_id;
};

#define LRE_HASH_SIZE 2048
struct lre_hash {
        struct lre_hash *next;
        struct live_range *left;
        struct live_range *right;
};


struct reg_state {
        struct lre_hash *hash[LRE_HASH_SIZE];
        struct reg_block *blocks;
        struct live_range_def *lrd;
        struct live_range *lr;
        struct live_range *low, **low_tail;
        struct live_range *high, **high_tail;
        unsigned defs;
        unsigned ranges;
        int passes, max_passes;
};


struct print_interference_block_info {
        struct reg_state *rstate;
        FILE *fp;
        int need_edges;
};
static void print_interference_block(
        struct compile_state *state, struct block *block, void *arg)

{
        struct print_interference_block_info *info = arg;
        struct reg_state *rstate = info->rstate;
        struct block_set *edge;
        FILE *fp = info->fp;
        struct reg_block *rb;
        struct triple *ptr;
        int phi_present;
        int done;
        rb = &rstate->blocks[block->vertex];

        fprintf(fp, "\nblock: %p (%d),",
                block,  block->vertex);
        for(edge = block->edges; edge; edge = edge->next) {
                fprintf(fp, " %p<-%p",
                        edge->member,
                        edge->member && edge->member->use?edge->member->use->member : 0);
        }
        fprintf(fp, "\n");
        if (rb->in) {
                struct triple_reg_set *in_set;
                fprintf(fp, "        in:");
                for(in_set = rb->in; in_set; in_set = in_set->next) {
                        fprintf(fp, " %-10p", in_set->member);
                }
                fprintf(fp, "\n");
        }
        phi_present = 0;
        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                done = (ptr == block->last);
                if (ptr->op == OP_PHI) {
                        phi_present = 1;
                        break;
                }
        }
        if (phi_present) {
                int edge;
                for(edge = 0; edge < block->users; edge++) {
                        fprintf(fp, "     in(%d):", edge);
                        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                                struct triple **slot;
                                done = (ptr == block->last);
                                if (ptr->op != OP_PHI) {
                                        continue;
                                }
                                slot = &RHS(ptr, 0);
                                fprintf(fp, " %-10p", slot[edge]);
                        }
                        fprintf(fp, "\n");
                }
        }
        if (block->first->op == OP_LABEL) {
                fprintf(fp, "%p:\n", block->first);
        }
        for(done = 0, ptr = block->first; !done; ptr = ptr->next) {
                struct live_range *lr;
                unsigned id;
                done = (ptr == block->last);
                lr = rstate->lrd[ptr->id].lr;

                id = ptr->id;
                ptr->id = rstate->lrd[id].orig_id;
                SET_REG(ptr->id, lr->color);
                display_triple(fp, ptr);
                ptr->id = id;

                if (triple_is_def(state, ptr) && (lr->defs == 0)) {
                        internal_error(state, ptr, "lr has no defs!");
                }
                if (info->need_edges) {
                        if (lr->defs) {
                                struct live_range_def *lrd;
                                fprintf(fp, "       range:");
                                lrd = lr->defs;
                                do {
                                        fprintf(fp, " %-10p", lrd->def);
                                        lrd = lrd->next;
                                } while(lrd != lr->defs);
                                fprintf(fp, "\n");
                        }
                        if (lr->edges > 0) {
                                struct live_range_edge *edge;
                                fprintf(fp, "       edges:");
                                for(edge = lr->edges; edge; edge = edge->next) {
                                        struct live_range_def *lrd;
                                        lrd = edge->node->defs;
                                        do {
                                                fprintf(fp, " %-10p", lrd->def);
                                                lrd = lrd->next;
                                        } while(lrd != edge->node->defs);
                                        fprintf(fp, "|");
                                }
                                fprintf(fp, "\n");
                        }
                }
                /* Do a bunch of sanity checks */
                valid_ins(state, ptr);
                if (ptr->id > rstate->defs) {
                        internal_error(state, ptr, "Invalid triple id: %d",
                                ptr->id);
                }
        }
        if (rb->out) {
                struct triple_reg_set *out_set;
                fprintf(fp, "       out:");
                for(out_set = rb->out; out_set; out_set = out_set->next) {
                        fprintf(fp, " %-10p", out_set->member);
                }
                fprintf(fp, "\n");
        }
        fprintf(fp, "\n");
}

static void print_interference_blocks(
        struct compile_state *state, struct reg_state *rstate, FILE *fp, int need_edges)
{
        struct print_interference_block_info info;
        info.rstate = rstate;
        info.fp = fp;
        info.need_edges = need_edges;
        fprintf(fp, "\nlive variables by block\n");
        walk_blocks(state, &state->bb, print_interference_block, &info);

}

static unsigned regc_max_size(struct compile_state *state, int classes)
{
        unsigned max_size;
        int i;
        max_size = 0;
        for(i = 0; i < MAX_REGC; i++) {
                if (classes & (1 << i)) {
                        unsigned size;
                        size = arch_regc_size(state, i);
                        if (size > max_size) {
                                max_size = size;
                        }
                }
        }
        return max_size;
}

static int reg_is_reg(struct compile_state *state, int reg1, int reg2)
{
        unsigned equivs[MAX_REG_EQUIVS];
        int i;
        if ((reg1 < 0) || (reg1 >= MAX_REGISTERS)) {
                internal_error(state, 0, "invalid register");
        }
        if ((reg2 < 0) || (reg2 >= MAX_REGISTERS)) {
                internal_error(state, 0, "invalid register");
        }
        arch_reg_equivs(state, equivs, reg1);
        for(i = 0; (i < MAX_REG_EQUIVS) && equivs[i] != REG_UNSET; i++) {
                if (equivs[i] == reg2) {
                        return 1;
                }
        }
        return 0;
}

static void reg_fill_used(struct compile_state *state, char *used, int reg)
{
        unsigned equivs[MAX_REG_EQUIVS];
        int i;
        if (reg == REG_UNNEEDED) {
                return;
        }
        arch_reg_equivs(state, equivs, reg);
        for(i = 0; (i < MAX_REG_EQUIVS) && equivs[i] != REG_UNSET; i++) {
                used[equivs[i]] = 1;
        }
        return;
}

static void reg_inc_used(struct compile_state *state, char *used, int reg)
{
        unsigned equivs[MAX_REG_EQUIVS];
        int i;
        if (reg == REG_UNNEEDED) {
                return;
        }
        arch_reg_equivs(state, equivs, reg);
        for(i = 0; (i < MAX_REG_EQUIVS) && equivs[i] != REG_UNSET; i++) {
                used[equivs[i]] += 1;
        }
        return;
}

static unsigned int hash_live_edge(
        struct live_range *left, struct live_range *right)
{
        unsigned int hash, val;
        unsigned long lval, rval;
        lval = ((unsigned long)left)/sizeof(struct live_range);
        rval = ((unsigned long)right)/sizeof(struct live_range);
        hash = 0;
        while(lval) {
                val = lval & 0xff;
                lval >>= 8;
                hash = (hash *263) + val;
        }
        while(rval) {
                val = rval & 0xff;
                rval >>= 8;
                hash = (hash *263) + val;
        }
        hash = hash & (LRE_HASH_SIZE - 1);
        return hash;
}

static struct lre_hash **lre_probe(struct reg_state *rstate,
        struct live_range *left, struct live_range *right)
{
        struct lre_hash **ptr;
        unsigned int index;
        /* Ensure left <= right */
        if (left > right) {
                struct live_range *tmp;
                tmp = left;
                left = right;
                right = tmp;
        }
        index = hash_live_edge(left, right);

        ptr = &rstate->hash[index];
        while(*ptr) {
                if (((*ptr)->left == left) && ((*ptr)->right == right)) {
                        break;
                }
                ptr = &(*ptr)->next;
        }
        return ptr;
}

static int interfere(struct reg_state *rstate,
        struct live_range *left, struct live_range *right)
{
        struct lre_hash **ptr;
        ptr = lre_probe(rstate, left, right);
        return ptr && *ptr;
}

static void add_live_edge(struct reg_state *rstate,
        struct live_range *left, struct live_range *right)
{
        /* FIXME the memory allocation overhead is noticeable here... */
        struct lre_hash **ptr, *new_hash;
        struct live_range_edge *edge;

        if (left == right) {
                return;
        }
        if ((left == &rstate->lr[0]) || (right == &rstate->lr[0])) {
                return;
        }
        /* Ensure left <= right */
        if (left > right) {
                struct live_range *tmp;
                tmp = left;
                left = right;
                right = tmp;
        }
        ptr = lre_probe(rstate, left, right);
        if (*ptr) {
                return;
        }
#if 0
        fprintf(state->errout, "new_live_edge(%p, %p)\n",
                left, right);
#endif
        new_hash = xmalloc(sizeof(*new_hash), "lre_hash");
        new_hash->next  = *ptr;
        new_hash->left  = left;
        new_hash->right = right;
        *ptr = new_hash;

        edge = xmalloc(sizeof(*edge), "live_range_edge");
        edge->next   = left->edges;
        edge->node   = right;
        left->edges  = edge;
        left->degree += 1;

        edge = xmalloc(sizeof(*edge), "live_range_edge");
        edge->next    = right->edges;
        edge->node    = left;
        right->edges  = edge;
        right->degree += 1;
}

static void remove_live_edge(struct reg_state *rstate,
        struct live_range *left, struct live_range *right)
{
        struct live_range_edge *edge, **ptr;
        struct lre_hash **hptr, *entry;
        hptr = lre_probe(rstate, left, right);
        if (!hptr || !*hptr) {
                return;
        }
        entry = *hptr;
        *hptr = entry->next;
        xfree(entry);

        for(ptr = &left->edges; *ptr; ptr = &(*ptr)->next) {
                edge = *ptr;
                if (edge->node == right) {
                        *ptr = edge->next;
                        memset(edge, 0, sizeof(*edge));
                        xfree(edge);
                        right->degree--;
                        break;
                }
        }
        for(ptr = &right->edges; *ptr; ptr = &(*ptr)->next) {
                edge = *ptr;
                if (edge->node == left) {
                        *ptr = edge->next;
                        memset(edge, 0, sizeof(*edge));
                        xfree(edge);
                        left->degree--;
                        break;
                }
        }
}

static void remove_live_edges(struct reg_state *rstate, struct live_range *range)
{
        struct live_range_edge *edge, *next;
        for(edge = range->edges; edge; edge = next) {
                next = edge->next;
                remove_live_edge(rstate, range, edge->node);
        }
}

static void transfer_live_edges(struct reg_state *rstate,
        struct live_range *dest, struct live_range *src)
{
        struct live_range_edge *edge, *next;
        for(edge = src->edges; edge; edge = next) {
                struct live_range *other;
                next = edge->next;
                other = edge->node;
                remove_live_edge(rstate, src, other);
                add_live_edge(rstate, dest, other);
        }
}


/* Interference graph...
 *
 * new(n) --- Return a graph with n nodes but no edges.
 * add(g,x,y) --- Return a graph including g with an between x and y
 * interfere(g, x, y) --- Return true if there exists an edge between the nodes
 *                x and y in the graph g
 * degree(g, x) --- Return the degree of the node x in the graph g
 * neighbors(g, x, f) --- Apply function f to each neighbor of node x in the graph g
 *
 * Implement with a hash table && a set of adjcency vectors.
 * The hash table supports constant time implementations of add and interfere.
 * The adjacency vectors support an efficient implementation of neighbors.
 */

/*
 *     +---------------------------------------------------+
 *     |         +--------------+                          |
 *     v         v              |                          |
 * renumber -> build graph -> colalesce -> spill_costs -> simplify -> select
 *
 * -- In simplify implment optimistic coloring... (No backtracking)
 * -- Implement Rematerialization it is the only form of spilling we can perform
 *    Essentially this means dropping a constant from a register because
 *    we can regenerate it later.
 *
 * --- Very conservative colalescing (don't colalesce just mark the opportunities)
 *     coalesce at phi points...
 * --- Bias coloring if at all possible do the coalesing a compile time.
 *
 *
 */

#if DEBUG_ROMCC_WARNING
static void different_colored(
        struct compile_state *state, struct reg_state *rstate,
        struct triple *parent, struct triple *ins)
{
        struct live_range *lr;
        struct triple **expr;
        lr = rstate->lrd[ins->id].lr;
        expr = triple_rhs(state, ins, 0);
        for(;expr; expr = triple_rhs(state, ins, expr)) {
                struct live_range *lr2;
                if (!*expr || (*expr == parent) || (*expr == ins)) {
                        continue;
                }
                lr2 = rstate->lrd[(*expr)->id].lr;
                if (lr->color == lr2->color) {
                        internal_error(state, ins, "live range too big");
                }
        }
}
#endif

static struct live_range *coalesce_ranges(
        struct compile_state *state, struct reg_state *rstate,
        struct live_range *lr1, struct live_range *lr2)
{
        struct live_range_def *head, *mid1, *mid2, *end, *lrd;
        unsigned color;
        unsigned classes;
        if (lr1 == lr2) {
                return lr1;
        }
        if (!lr1->defs || !lr2->defs) {
                internal_error(state, 0,
                        "cannot coalese dead live ranges");
        }
        if ((lr1->color == REG_UNNEEDED) ||
                (lr2->color == REG_UNNEEDED)) {
                internal_error(state, 0,
                        "cannot coalesce live ranges without a possible color");
        }
        if ((lr1->color != lr2->color) &&
                (lr1->color != REG_UNSET) &&
                (lr2->color != REG_UNSET)) {
                internal_error(state, lr1->defs->def,
                        "cannot coalesce live ranges of different colors");
        }
        color = lr1->color;
        if (color == REG_UNSET) {
                color = lr2->color;
        }
        classes = lr1->classes & lr2->classes;
        if (!classes) {
                internal_error(state, lr1->defs->def,
                        "cannot coalesce live ranges with dissimilar register classes");
        }
        if (state->compiler->debug & DEBUG_COALESCING) {
                FILE *fp = state->errout;
                fprintf(fp, "coalescing:");
                lrd = lr1->defs;
                do {
                        fprintf(fp, " %p", lrd->def);
                        lrd = lrd->next;
                } while(lrd != lr1->defs);
                fprintf(fp, " |");
                lrd = lr2->defs;
                do {
                        fprintf(fp, " %p", lrd->def);
                        lrd = lrd->next;
                } while(lrd != lr2->defs);
                fprintf(fp, "\n");
        }
        /* If there is a clear dominate live range put it in lr1,
         * For purposes of this test phi functions are
         * considered dominated by the definitions that feed into
         * them.
         */
        if ((lr1->defs->prev->def->op == OP_PHI) ||
                ((lr2->defs->prev->def->op != OP_PHI) &&
                tdominates(state, lr2->defs->def, lr1->defs->def))) {
                struct live_range *tmp;
                tmp = lr1;
                lr1 = lr2;
                lr2 = tmp;
        }
#if 0
        if (lr1->defs->orig_id  & TRIPLE_FLAG_POST_SPLIT) {
                fprintf(state->errout, "lr1 post\n");
        }
        if (lr1->defs->orig_id & TRIPLE_FLAG_PRE_SPLIT) {
                fprintf(state->errout, "lr1 pre\n");
        }
        if (lr2->defs->orig_id  & TRIPLE_FLAG_POST_SPLIT) {
                fprintf(state->errout, "lr2 post\n");
        }
        if (lr2->defs->orig_id & TRIPLE_FLAG_PRE_SPLIT) {
                fprintf(state->errout, "lr2 pre\n");
        }
#endif
#if 0
        fprintf(state->errout, "coalesce color1(%p): %3d color2(%p) %3d\n",
                lr1->defs->def,
                lr1->color,
                lr2->defs->def,
                lr2->color);
#endif

        /* Append lr2 onto lr1 */
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME should this be a merge instead of a splice?"
#endif
        /* This FIXME item applies to the correctness of live_range_end
         * and to the necessity of making multiple passes of coalesce_live_ranges.
         * A failure to find some coalesce opportunities in coaleace_live_ranges
         * does not impact the correct of the compiler just the efficiency with
         * which registers are allocated.
         */
        head = lr1->defs;
        mid1 = lr1->defs->prev;
        mid2 = lr2->defs;
        end  = lr2->defs->prev;

        head->prev = end;
        end->next  = head;

        mid1->next = mid2;
        mid2->prev = mid1;

        /* Fixup the live range in the added live range defs */
        lrd = head;
        do {
                lrd->lr = lr1;
                lrd = lrd->next;
        } while(lrd != head);

        /* Mark lr2 as free. */
        lr2->defs = 0;
        lr2->color = REG_UNNEEDED;
        lr2->classes = 0;

        if (!lr1->defs) {
                internal_error(state, 0, "lr1->defs == 0 ?");
        }

        lr1->color   = color;
        lr1->classes = classes;

        /* Keep the graph in sync by transferring the edges from lr2 to lr1 */
        transfer_live_edges(rstate, lr1, lr2);

        return lr1;
}

static struct live_range_def *live_range_head(
        struct compile_state *state, struct live_range *lr,
        struct live_range_def *last)
{
        struct live_range_def *result;
        result = 0;
        if (last == 0) {
                result = lr->defs;
        }
        else if (!tdominates(state, lr->defs->def, last->next->def)) {
                result = last->next;
        }
        return result;
}

static struct live_range_def *live_range_end(
        struct compile_state *state, struct live_range *lr,
        struct live_range_def *last)
{
        struct live_range_def *result;
        result = 0;
        if (last == 0) {
                result = lr->defs->prev;
        }
        else if (!tdominates(state, last->prev->def, lr->defs->prev->def)) {
                result = last->prev;
        }
        return result;
}


static void initialize_live_ranges(
        struct compile_state *state, struct reg_state *rstate)
{
        struct triple *ins, *first;
        size_t count, size;
        int i, j;

        first = state->first;
        /* First count how many instructions I have.
         */
        count = count_triples(state);
        /* Potentially I need one live range definitions for each
         * instruction.
         */
        rstate->defs = count;
        /* Potentially I need one live range for each instruction
         * plus an extra for the dummy live range.
         */
        rstate->ranges = count + 1;
        size = sizeof(rstate->lrd[0]) * rstate->defs;
        rstate->lrd = xcmalloc(size, "live_range_def");
        size = sizeof(rstate->lr[0]) * rstate->ranges;
        rstate->lr  = xcmalloc(size, "live_range");

        /* Setup the dummy live range */
        rstate->lr[0].classes = 0;
        rstate->lr[0].color = REG_UNSET;
        rstate->lr[0].defs = 0;
        i = j = 0;
        ins = first;
        do {
                /* If the triple is a variable give it a live range */
                if (triple_is_def(state, ins)) {
                        struct reg_info info;
                        /* Find the architecture specific color information */
                        info = find_def_color(state, ins);
                        i++;
                        rstate->lr[i].defs    = &rstate->lrd[j];
                        rstate->lr[i].color   = info.reg;
                        rstate->lr[i].classes = info.regcm;
                        rstate->lr[i].degree  = 0;
                        rstate->lrd[j].lr = &rstate->lr[i];
                }
                /* Otherwise give the triple the dummy live range. */
                else {
                        rstate->lrd[j].lr = &rstate->lr[0];
                }

                /* Initialize the live_range_def */
                rstate->lrd[j].next    = &rstate->lrd[j];
                rstate->lrd[j].prev    = &rstate->lrd[j];
                rstate->lrd[j].def     = ins;
                rstate->lrd[j].orig_id = ins->id;
                ins->id = j;

                j++;
                ins = ins->next;
        } while(ins != first);
        rstate->ranges = i;

        /* Make a second pass to handle architecture specific register
         * constraints.
         */
        ins = first;
        do {
                int zlhs, zrhs, i, j;
                if (ins->id > rstate->defs) {
                        internal_error(state, ins, "bad id");
                }

                /* Walk through the template of ins and coalesce live ranges */
                zlhs = ins->lhs;
                if ((zlhs == 0) && triple_is_def(state, ins)) {
                        zlhs = 1;
                }
                zrhs = ins->rhs;

                if (state->compiler->debug & DEBUG_COALESCING2) {
                        fprintf(state->errout, "mandatory coalesce: %p %d %d\n",
                                ins, zlhs, zrhs);
                }

                for(i = 0; i < zlhs; i++) {
                        struct reg_info linfo;
                        struct live_range_def *lhs;
                        linfo = arch_reg_lhs(state, ins, i);
                        if (linfo.reg < MAX_REGISTERS) {
                                continue;
                        }
                        if (triple_is_def(state, ins)) {
                                lhs = &rstate->lrd[ins->id];
                        } else {
                                lhs = &rstate->lrd[LHS(ins, i)->id];
                        }

                        if (state->compiler->debug & DEBUG_COALESCING2) {
                                fprintf(state->errout, "coalesce lhs(%d): %p %d\n",
                                        i, lhs, linfo.reg);
                        }

                        for(j = 0; j < zrhs; j++) {
                                struct reg_info rinfo;
                                struct live_range_def *rhs;
                                rinfo = arch_reg_rhs(state, ins, j);
                                if (rinfo.reg < MAX_REGISTERS) {
                                        continue;
                                }
                                rhs = &rstate->lrd[RHS(ins, j)->id];

                                if (state->compiler->debug & DEBUG_COALESCING2) {
                                        fprintf(state->errout, "coalesce rhs(%d): %p %d\n",
                                                j, rhs, rinfo.reg);
                                }

                                if (rinfo.reg == linfo.reg) {
                                        coalesce_ranges(state, rstate,
                                                lhs->lr, rhs->lr);
                                }
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void graph_ins(
        struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg)
{
        struct reg_state *rstate = arg;
        struct live_range *def;
        struct triple_reg_set *entry;

        /* If the triple is not a definition
         * we do not have a definition to add to
         * the interference graph.
         */
        if (!triple_is_def(state, ins)) {
                return;
        }
        def = rstate->lrd[ins->id].lr;

        /* Create an edge between ins and everything that is
         * alive, unless the live_range cannot share
         * a physical register with ins.
         */
        for(entry = live; entry; entry = entry->next) {
                struct live_range *lr;
                if (entry->member->id > rstate->defs) {
                        internal_error(state, 0, "bad entry?");
                }
                lr = rstate->lrd[entry->member->id].lr;
                if (def == lr) {
                        continue;
                }
                if (!arch_regcm_intersect(def->classes, lr->classes)) {
                        continue;
                }
                add_live_edge(rstate, def, lr);
        }
        return;
}

#if DEBUG_CONSISTENCY > 1
static struct live_range *get_verify_live_range(
        struct compile_state *state, struct reg_state *rstate, struct triple *ins)
{
        struct live_range *lr;
        struct live_range_def *lrd;
        int ins_found;
        if ((ins->id < 0) || (ins->id > rstate->defs)) {
                internal_error(state, ins, "bad ins?");
        }
        lr = rstate->lrd[ins->id].lr;
        ins_found = 0;
        lrd = lr->defs;
        do {
                if (lrd->def == ins) {
                        ins_found = 1;
                }
                lrd = lrd->next;
        } while(lrd != lr->defs);
        if (!ins_found) {
                internal_error(state, ins, "ins not in live range");
        }
        return lr;
}

static void verify_graph_ins(
        struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg)
{
        struct reg_state *rstate = arg;
        struct triple_reg_set *entry1, *entry2;


        /* Compare live against edges and make certain the code is working */
        for(entry1 = live; entry1; entry1 = entry1->next) {
                struct live_range *lr1;
                lr1 = get_verify_live_range(state, rstate, entry1->member);
                for(entry2 = live; entry2; entry2 = entry2->next) {
                        struct live_range *lr2;
                        struct live_range_edge *edge2;
                        int lr1_found;
                        int lr2_degree;
                        if (entry2 == entry1) {
                                continue;
                        }
                        lr2 = get_verify_live_range(state, rstate, entry2->member);
                        if (lr1 == lr2) {
                                internal_error(state, entry2->member,
                                        "live range with 2 values simultaneously alive");
                        }
                        if (!arch_regcm_intersect(lr1->classes, lr2->classes)) {
                                continue;
                        }
                        if (!interfere(rstate, lr1, lr2)) {
                                internal_error(state, entry2->member,
                                        "edges don't interfere?");
                        }

                        lr1_found = 0;
                        lr2_degree = 0;
                        for(edge2 = lr2->edges; edge2; edge2 = edge2->next) {
                                lr2_degree++;
                                if (edge2->node == lr1) {
                                        lr1_found = 1;
                                }
                        }
                        if (lr2_degree != lr2->degree) {
                                internal_error(state, entry2->member,
                                        "computed degree: %d does not match reported degree: %d\n",
                                        lr2_degree, lr2->degree);
                        }
                        if (!lr1_found) {
                                internal_error(state, entry2->member, "missing edge");
                        }
                }
        }
        return;
}
#endif

static void print_interference_ins(
        struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg)
{
        struct reg_state *rstate = arg;
        struct live_range *lr;
        unsigned id;
        FILE *fp = state->dbgout;

        lr = rstate->lrd[ins->id].lr;
        id = ins->id;
        ins->id = rstate->lrd[id].orig_id;
        SET_REG(ins->id, lr->color);
        display_triple(state->dbgout, ins);
        ins->id = id;

        if (lr->defs) {
                struct live_range_def *lrd;
                fprintf(fp, "       range:");
                lrd = lr->defs;
                do {
                        fprintf(fp, " %-10p", lrd->def);
                        lrd = lrd->next;
                } while(lrd != lr->defs);
                fprintf(fp, "\n");
        }
        if (live) {
                struct triple_reg_set *entry;
                fprintf(fp, "        live:");
                for(entry = live; entry; entry = entry->next) {
                        fprintf(fp, " %-10p", entry->member);
                }
                fprintf(fp, "\n");
        }
        if (lr->edges) {
                struct live_range_edge *entry;
                fprintf(fp, "       edges:");
                for(entry = lr->edges; entry; entry = entry->next) {
                        struct live_range_def *lrd;
                        lrd = entry->node->defs;
                        do {
                                fprintf(fp, " %-10p", lrd->def);
                                lrd = lrd->next;
                        } while(lrd != entry->node->defs);
                        fprintf(fp, "|");
                }
                fprintf(fp, "\n");
        }
        if (triple_is_branch(state, ins)) {
                fprintf(fp, "\n");
        }
        return;
}

static int coalesce_live_ranges(
        struct compile_state *state, struct reg_state *rstate)
{
        /* At the point where a value is moved from one
         * register to another that value requires two
         * registers, thus increasing register pressure.
         * Live range coaleescing reduces the register
         * pressure by keeping a value in one register
         * longer.
         *
         * In the case of a phi function all paths leading
         * into it must be allocated to the same register
         * otherwise the phi function may not be removed.
         *
         * Forcing a value to stay in a single register
         * for an extended period of time does have
         * limitations when applied to non homogenous
         * register pool.
         *
         * The two cases I have identified are:
         * 1) Two forced register assignments may
         *    collide.
         * 2) Registers may go unused because they
         *    are only good for storing the value
         *    and not manipulating it.
         *
         * Because of this I need to split live ranges,
         * even outside of the context of coalesced live
         * ranges.  The need to split live ranges does
         * impose some constraints on live range coalescing.
         *
         * - Live ranges may not be coalesced across phi
         *   functions.  This creates a 2 headed live
         *   range that cannot be sanely split.
         *
         * - phi functions (coalesced in initialize_live_ranges)
         *   are handled as pre split live ranges so we will
         *   never attempt to split them.
         */
        int coalesced;
        int i;

        coalesced = 0;
        for(i = 0; i <= rstate->ranges; i++) {
                struct live_range *lr1;
                struct live_range_def *lrd1;
                lr1 = &rstate->lr[i];
                if (!lr1->defs) {
                        continue;
                }
                lrd1 = live_range_end(state, lr1, 0);
                for(; lrd1; lrd1 = live_range_end(state, lr1, lrd1)) {
                        struct triple_set *set;
                        if (lrd1->def->op != OP_COPY) {
                                continue;
                        }
                        /* Skip copies that are the result of a live range split. */
                        if (lrd1->orig_id & TRIPLE_FLAG_POST_SPLIT) {
                                continue;
                        }
                        for(set = lrd1->def->use; set; set = set->next) {
                                struct live_range_def *lrd2;
                                struct live_range *lr2, *res;

                                lrd2 = &rstate->lrd[set->member->id];

                                /* Don't coalesce with instructions
                                 * that are the result of a live range
                                 * split.
                                 */
                                if (lrd2->orig_id & TRIPLE_FLAG_PRE_SPLIT) {
                                        continue;
                                }
                                lr2 = rstate->lrd[set->member->id].lr;
                                if (lr1 == lr2) {
                                        continue;
                                }
                                if ((lr1->color != lr2->color) &&
                                        (lr1->color != REG_UNSET) &&
                                        (lr2->color != REG_UNSET)) {
                                        continue;
                                }
                                if ((lr1->classes & lr2->classes) == 0) {
                                        continue;
                                }

                                if (interfere(rstate, lr1, lr2)) {
                                        continue;
                                }

                                res = coalesce_ranges(state, rstate, lr1, lr2);
                                coalesced += 1;
                                if (res != lr1) {
                                        goto next;
                                }
                        }
                }
        next:
                ;
        }
        return coalesced;
}


static void fix_coalesce_conflicts(struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg)
{
        int *conflicts = arg;
        int zlhs, zrhs, i, j;

        /* See if we have a mandatory coalesce operation between
         * a lhs and a rhs value.  If so and the rhs value is also
         * alive then this triple needs to be pre copied.  Otherwise
         * we would have two definitions in the same live range simultaneously
         * alive.
         */
        zlhs = ins->lhs;
        if ((zlhs == 0) && triple_is_def(state, ins)) {
                zlhs = 1;
        }
        zrhs = ins->rhs;
        for(i = 0; i < zlhs; i++) {
                struct reg_info linfo;
                linfo = arch_reg_lhs(state, ins, i);
                if (linfo.reg < MAX_REGISTERS) {
                        continue;
                }
                for(j = 0; j < zrhs; j++) {
                        struct reg_info rinfo;
                        struct triple *rhs;
                        struct triple_reg_set *set;
                        int found;
                        found = 0;
                        rinfo = arch_reg_rhs(state, ins, j);
                        if (rinfo.reg != linfo.reg) {
                                continue;
                        }
                        rhs = RHS(ins, j);
                        for(set = live; set && !found; set = set->next) {
                                if (set->member == rhs) {
                                        found = 1;
                                }
                        }
                        if (found) {
                                struct triple *copy;
                                copy = pre_copy(state, ins, j);
                                copy->id |= TRIPLE_FLAG_PRE_SPLIT;
                                (*conflicts)++;
                        }
                }
        }
        return;
}

static int correct_coalesce_conflicts(
        struct compile_state *state, struct reg_block *blocks)
{
        int conflicts;
        conflicts = 0;
        walk_variable_lifetimes(state, &state->bb, blocks,
                fix_coalesce_conflicts, &conflicts);
        return conflicts;
}

static void replace_set_use(struct compile_state *state,
        struct triple_reg_set *head, struct triple *orig, struct triple *new)
{
        struct triple_reg_set *set;
        for(set = head; set; set = set->next) {
                if (set->member == orig) {
                        set->member = new;
                }
        }
}

static void replace_block_use(struct compile_state *state,
        struct reg_block *blocks, struct triple *orig, struct triple *new)
{
        int i;
#if DEBUG_ROMCC_WARNINGS
#warning "WISHLIST visit just those blocks that need it *"
#endif
        for(i = 1; i <= state->bb.last_vertex; i++) {
                struct reg_block *rb;
                rb = &blocks[i];
                replace_set_use(state, rb->in, orig, new);
                replace_set_use(state, rb->out, orig, new);
        }
}

static void color_instructions(struct compile_state *state)
{
        struct triple *ins, *first;
        first = state->first;
        ins = first;
        do {
                if (triple_is_def(state, ins)) {
                        struct reg_info info;
                        info = find_lhs_color(state, ins, 0);
                        if (info.reg >= MAX_REGISTERS) {
                                info.reg = REG_UNSET;
                        }
                        SET_INFO(ins->id, info);
                }
                ins = ins->next;
        } while(ins != first);
}

static struct reg_info read_lhs_color(
        struct compile_state *state, struct triple *ins, int index)
{
        struct reg_info info;
        if ((index == 0) && triple_is_def(state, ins)) {
                info.reg   = ID_REG(ins->id);
                info.regcm = ID_REGCM(ins->id);
        }
        else if (index < ins->lhs) {
                info = read_lhs_color(state, LHS(ins, index), 0);
        }
        else {
                internal_error(state, ins, "Bad lhs %d", index);
                info.reg = REG_UNSET;
                info.regcm = 0;
        }
        return info;
}

static struct triple *resolve_tangle(
        struct compile_state *state, struct triple *tangle)
{
        struct reg_info info, uinfo;
        struct triple_set *set, *next;
        struct triple *copy;

#if DEBUG_ROMCC_WARNINGS
#warning "WISHLIST recalculate all affected instructions colors"
#endif
        info = find_lhs_color(state, tangle, 0);
        for(set = tangle->use; set; set = next) {
                struct triple *user;
                int i, zrhs;
                next = set->next;
                user = set->member;
                zrhs = user->rhs;
                for(i = 0; i < zrhs; i++) {
                        if (RHS(user, i) != tangle) {
                                continue;
                        }
                        uinfo = find_rhs_post_color(state, user, i);
                        if (uinfo.reg == info.reg) {
                                copy = pre_copy(state, user, i);
                                copy->id |= TRIPLE_FLAG_PRE_SPLIT;
                                SET_INFO(copy->id, uinfo);
                        }
                }
        }
        copy = 0;
        uinfo = find_lhs_pre_color(state, tangle, 0);
        if (uinfo.reg == info.reg) {
                struct reg_info linfo;
                copy = post_copy(state, tangle);
                copy->id |= TRIPLE_FLAG_PRE_SPLIT;
                linfo = find_lhs_color(state, copy, 0);
                SET_INFO(copy->id, linfo);
        }
        info = find_lhs_color(state, tangle, 0);
        SET_INFO(tangle->id, info);

        return copy;
}


static void fix_tangles(struct compile_state *state,
        struct reg_block *blocks, struct triple_reg_set *live,
        struct reg_block *rb, struct triple *ins, void *arg)
{
        int *tangles = arg;
        struct triple *tangle;
        do {
                char used[MAX_REGISTERS];
                struct triple_reg_set *set;
                tangle = 0;

                /* Find out which registers have multiple uses at this point */
                memset(used, 0, sizeof(used));
                for(set = live; set; set = set->next) {
                        struct reg_info info;
                        info = read_lhs_color(state, set->member, 0);
                        if (info.reg == REG_UNSET) {
                                continue;
                        }
                        reg_inc_used(state, used, info.reg);
                }

                /* Now find the least dominated definition of a register in
                 * conflict I have seen so far.
                 */
                for(set = live; set; set = set->next) {
                        struct reg_info info;
                        info = read_lhs_color(state, set->member, 0);
                        if (used[info.reg] < 2) {
                                continue;
                        }
                        /* Changing copies that feed into phi functions
                         * is incorrect.
                         */
                        if (set->member->use &&
                                (set->member->use->member->op == OP_PHI)) {
                                continue;
                        }
                        if (!tangle || tdominates(state, set->member, tangle)) {
                                tangle = set->member;
                        }
                }
                /* If I have found a tangle resolve it */
                if (tangle) {
                        struct triple *post_copy;
                        (*tangles)++;
                        post_copy = resolve_tangle(state, tangle);
                        if (post_copy) {
                                replace_block_use(state, blocks, tangle, post_copy);
                        }
                        if (post_copy && (tangle != ins)) {
                                replace_set_use(state, live, tangle, post_copy);
                        }
                }
        } while(tangle);
        return;
}

static int correct_tangles(
        struct compile_state *state, struct reg_block *blocks)
{
        int tangles;
        tangles = 0;
        color_instructions(state);
        walk_variable_lifetimes(state, &state->bb, blocks,
                fix_tangles, &tangles);
        return tangles;
}


static void ids_from_rstate(struct compile_state *state, struct reg_state *rstate);
static void cleanup_rstate(struct compile_state *state, struct reg_state *rstate);

struct triple *find_constrained_def(
        struct compile_state *state, struct live_range *range, struct triple *constrained)
{
        struct live_range_def *lrd, *lrd_next;
        lrd_next = range->defs;
        do {
                struct reg_info info;
                unsigned regcm;

                lrd = lrd_next;
                lrd_next = lrd->next;

                regcm = arch_type_to_regcm(state, lrd->def->type);
                info = find_lhs_color(state, lrd->def, 0);
                regcm      = arch_regcm_reg_normalize(state, regcm);
                info.regcm = arch_regcm_reg_normalize(state, info.regcm);
                /* If the 2 register class masks are equal then
                 * the current register class is not constrained.
                 */
                if (regcm == info.regcm) {
                        continue;
                }

                /* If there is just one use.
                 * That use cannot accept a larger register class.
                 * There are no intervening definitions except
                 * definitions that feed into that use.
                 * Then a triple is not constrained.
                 * FIXME handle this case!
                 */
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME ignore cases that cannot be fixed (a definition followed by a use)"
#endif


                /* Of the constrained live ranges deal with the
                 * least dominated one first.
                 */
                if (state->compiler->debug & DEBUG_RANGE_CONFLICTS) {
                        fprintf(state->errout, "canidate: %p %-8s regcm: %x %x\n",
                                lrd->def, tops(lrd->def->op), regcm, info.regcm);
                }
                if (!constrained ||
                        tdominates(state, lrd->def, constrained))
                {
                        constrained = lrd->def;
                }
        } while(lrd_next != range->defs);
        return constrained;
}

static int split_constrained_ranges(
        struct compile_state *state, struct reg_state *rstate,
        struct live_range *range)
{
        /* Walk through the edges in conflict and our current live
         * range, and find definitions that are more severly constrained
         * than they type of data they contain require.
         *
         * Then pick one of those ranges and relax the constraints.
         */
        struct live_range_edge *edge;
        struct triple *constrained;

        constrained = 0;
        for(edge = range->edges; edge; edge = edge->next) {
                constrained = find_constrained_def(state, edge->node, constrained);
        }
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME should I call find_constrained_def here only if no previous constrained def was found?"
#endif
        if (!constrained) {
                constrained = find_constrained_def(state, range, constrained);
        }

        if (state->compiler->debug & DEBUG_RANGE_CONFLICTS) {
                fprintf(state->errout, "constrained: ");
                display_triple(state->errout, constrained);
        }
        if (constrained) {
                ids_from_rstate(state, rstate);
                cleanup_rstate(state, rstate);
                resolve_tangle(state, constrained);
        }
        return !!constrained;
}

static int split_ranges(
        struct compile_state *state, struct reg_state *rstate,
        char *used, struct live_range *range)
{
        int split;
        if (state->compiler->debug & DEBUG_RANGE_CONFLICTS) {
                fprintf(state->errout, "split_ranges %d %s %p\n",
                        rstate->passes, tops(range->defs->def->op), range->defs->def);
        }
        if ((range->color == REG_UNNEEDED) ||
                (rstate->passes >= rstate->max_passes)) {
                return 0;
        }
        split = split_constrained_ranges(state, rstate, range);

        /* Ideally I would split the live range that will not be used
         * for the longest period of time in hopes that this will
         * (a) allow me to spill a register or
         * (b) allow me to place a value in another register.
         *
         * So far I don't have a test case for this, the resolving
         * of mandatory constraints has solved all of my
         * know issues.  So I have chosen not to write any
         * code until I cat get a better feel for cases where
         * it would be useful to have.
         *
         */
#if DEBUG_ROMCC_WARNINGS
#warning "WISHLIST implement live range splitting..."
#endif

        if (!split && (state->compiler->debug & DEBUG_RANGE_CONFLICTS2)) {
                FILE *fp = state->errout;
                print_interference_blocks(state, rstate, fp, 0);
                print_dominators(state, fp, &state->bb);
        }
        return split;
}

static FILE *cgdebug_fp(struct compile_state *state)
{
        FILE *fp;
        fp = 0;
        if (!fp && (state->compiler->debug & DEBUG_COLOR_GRAPH2)) {
                fp = state->errout;
        }
        if (!fp && (state->compiler->debug & DEBUG_COLOR_GRAPH)) {
                fp = state->dbgout;
        }
        return fp;
}

static void cgdebug_printf(struct compile_state *state, const char *fmt, ...)
{
        FILE *fp;
        fp = cgdebug_fp(state);
        if (fp) {
                va_list args;
                va_start(args, fmt);
                vfprintf(fp, fmt, args);
                va_end(args);
        }
}

static void cgdebug_flush(struct compile_state *state)
{
        FILE *fp;
        fp = cgdebug_fp(state);
        if (fp) {
                fflush(fp);
        }
}

static void cgdebug_loc(struct compile_state *state, struct triple *ins)
{
        FILE *fp;
        fp = cgdebug_fp(state);
        if (fp) {
                loc(fp, state, ins);
        }
}

static int select_free_color(struct compile_state *state,
        struct reg_state *rstate, struct live_range *range)
{
        struct triple_set *entry;
        struct live_range_def *lrd;
        struct live_range_def *phi;
        struct live_range_edge *edge;
        char used[MAX_REGISTERS];
        struct triple **expr;

        /* Instead of doing just the trivial color select here I try
         * a few extra things because a good color selection will help reduce
         * copies.
         */

        /* Find the registers currently in use */
        memset(used, 0, sizeof(used));
        for(edge = range->edges; edge; edge = edge->next) {
                if (edge->node->color == REG_UNSET) {
                        continue;
                }
                reg_fill_used(state, used, edge->node->color);
        }

        if (state->compiler->debug & DEBUG_COLOR_GRAPH2) {
                int i;
                i = 0;
                for(edge = range->edges; edge; edge = edge->next) {
                        i++;
                }
                cgdebug_printf(state, "\n%s edges: %d",
                        tops(range->defs->def->op), i);
                cgdebug_loc(state, range->defs->def);
                cgdebug_printf(state, "\n");
                for(i = 0; i < MAX_REGISTERS; i++) {
                        if (used[i]) {
                                cgdebug_printf(state, "used: %s\n",
                                        arch_reg_str(i));
                        }
                }
        }

        /* If a color is already assigned see if it will work */
        if (range->color != REG_UNSET) {
                struct live_range_def *lrd;
                if (!used[range->color]) {
                        return 1;
                }
                for(edge = range->edges; edge; edge = edge->next) {
                        if (edge->node->color != range->color) {
                                continue;
                        }
                        warning(state, edge->node->defs->def, "edge: ");
                        lrd = edge->node->defs;
                        do {
                                warning(state, lrd->def, " %p %s",
                                        lrd->def, tops(lrd->def->op));
                                lrd = lrd->next;
                        } while(lrd != edge->node->defs);
                }
                lrd = range->defs;
                warning(state, range->defs->def, "def: ");
                do {
                        warning(state, lrd->def, " %p %s",
                                lrd->def, tops(lrd->def->op));
                        lrd = lrd->next;
                } while(lrd != range->defs);
                internal_error(state, range->defs->def,
                        "live range with already used color %s",
                        arch_reg_str(range->color));
        }

        /* If I feed into an expression reuse it's color.
         * This should help remove copies in the case of 2 register instructions
         * and phi functions.
         */
        phi = 0;
        lrd = live_range_end(state, range, 0);
        for(; (range->color == REG_UNSET) && lrd ; lrd = live_range_end(state, range, lrd)) {
                entry = lrd->def->use;
                for(;(range->color == REG_UNSET) && entry; entry = entry->next) {
                        struct live_range_def *insd;
                        unsigned regcm;
                        insd = &rstate->lrd[entry->member->id];
                        if (insd->lr->defs == 0) {
                                continue;
                        }
                        if (!phi && (insd->def->op == OP_PHI) &&
                                !interfere(rstate, range, insd->lr)) {
                                phi = insd;
                        }
                        if (insd->lr->color == REG_UNSET) {
                                continue;
                        }
                        regcm = insd->lr->classes;
                        if (((regcm & range->classes) == 0) ||
                                (used[insd->lr->color])) {
                                continue;
                        }
                        if (interfere(rstate, range, insd->lr)) {
                                continue;
                        }
                        range->color = insd->lr->color;
                }
        }
        /* If I feed into a phi function reuse it's color or the color
         * of something else that feeds into the phi function.
         */
        if (phi) {
                if (phi->lr->color != REG_UNSET) {
                        if (used[phi->lr->color]) {
                                range->color = phi->lr->color;
                        }
                }
                else {
                        expr = triple_rhs(state, phi->def, 0);
                        for(; expr; expr = triple_rhs(state, phi->def, expr)) {
                                struct live_range *lr;
                                unsigned regcm;
                                if (!*expr) {
                                        continue;
                                }
                                lr = rstate->lrd[(*expr)->id].lr;
                                if (lr->color == REG_UNSET) {
                                        continue;
                                }
                                regcm = lr->classes;
                                if (((regcm & range->classes) == 0) ||
                                        (used[lr->color])) {
                                        continue;
                                }
                                if (interfere(rstate, range, lr)) {
                                        continue;
                                }
                                range->color = lr->color;
                        }
                }
        }
        /* If I don't interfere with a rhs node reuse it's color */
        lrd = live_range_head(state, range, 0);
        for(; (range->color == REG_UNSET) && lrd ; lrd = live_range_head(state, range, lrd)) {
                expr = triple_rhs(state, lrd->def, 0);
                for(; expr; expr = triple_rhs(state, lrd->def, expr)) {
                        struct live_range *lr;
                        unsigned regcm;
                        if (!*expr) {
                                continue;
                        }
                        lr = rstate->lrd[(*expr)->id].lr;
                        if (lr->color == REG_UNSET) {
                                continue;
                        }
                        regcm = lr->classes;
                        if (((regcm & range->classes) == 0) ||
                                (used[lr->color])) {
                                continue;
                        }
                        if (interfere(rstate, range, lr)) {
                                continue;
                        }
                        range->color = lr->color;
                        break;
                }
        }
        /* If I have not opportunitically picked a useful color
         * pick the first color that is free.
         */
        if (range->color == REG_UNSET) {
                range->color =
                        arch_select_free_register(state, used, range->classes);
        }
        if (range->color == REG_UNSET) {
                struct live_range_def *lrd;
                int i;
                if (split_ranges(state, rstate, used, range)) {
                        return 0;
                }
                for(edge = range->edges; edge; edge = edge->next) {
                        warning(state, edge->node->defs->def, "edge reg %s",
                                arch_reg_str(edge->node->color));
                        lrd = edge->node->defs;
                        do {
                                warning(state, lrd->def, " %s %p",
                                        tops(lrd->def->op), lrd->def);
                                lrd = lrd->next;
                        } while(lrd != edge->node->defs);
                }
                warning(state, range->defs->def, "range: ");
                lrd = range->defs;
                do {
                        warning(state, lrd->def, " %s %p",
                                tops(lrd->def->op), lrd->def);
                        lrd = lrd->next;
                } while(lrd != range->defs);

                warning(state, range->defs->def, "classes: %x",
                        range->classes);
                for(i = 0; i < MAX_REGISTERS; i++) {
                        if (used[i]) {
                                warning(state, range->defs->def, "used: %s",
                                        arch_reg_str(i));
                        }
                }
                error(state, range->defs->def, "too few registers");
        }
        range->classes &= arch_reg_regcm(state, range->color);
        if ((range->color == REG_UNSET) || (range->classes == 0)) {
                internal_error(state, range->defs->def, "select_free_color did not?");
        }
        return 1;
}

static int color_graph(struct compile_state *state, struct reg_state *rstate)
{
        int colored;
        struct live_range_edge *edge;
        struct live_range *range;
        if (rstate->low) {
                cgdebug_printf(state, "Lo: ");
                range = rstate->low;
                if (*range->group_prev != range) {
                        internal_error(state, 0, "lo: *prev != range?");
                }
                *range->group_prev = range->group_next;
                if (range->group_next) {
                        range->group_next->group_prev = range->group_prev;
                }
                if (&range->group_next == rstate->low_tail) {
                        rstate->low_tail = range->group_prev;
                }
                if (rstate->low == range) {
                        internal_error(state, 0, "low: next != prev?");
                }
        }
        else if (rstate->high) {
                cgdebug_printf(state, "Hi: ");
                range = rstate->high;
                if (*range->group_prev != range) {
                        internal_error(state, 0, "hi: *prev != range?");
                }
                *range->group_prev = range->group_next;
                if (range->group_next) {
                        range->group_next->group_prev = range->group_prev;
                }
                if (&range->group_next == rstate->high_tail) {
                        rstate->high_tail = range->group_prev;
                }
                if (rstate->high == range) {
                        internal_error(state, 0, "high: next != prev?");
                }
        }
        else {
                return 1;
        }
        cgdebug_printf(state, " %td\n", range - rstate->lr);
        range->group_prev = 0;
        for(edge = range->edges; edge; edge = edge->next) {
                struct live_range *node;
                node = edge->node;
                /* Move nodes from the high to the low list */
                if (node->group_prev && (node->color == REG_UNSET) &&
                        (node->degree == regc_max_size(state, node->classes))) {
                        if (*node->group_prev != node) {
                                internal_error(state, 0, "move: *prev != node?");
                        }
                        *node->group_prev = node->group_next;
                        if (node->group_next) {
                                node->group_next->group_prev = node->group_prev;
                        }
                        if (&node->group_next == rstate->high_tail) {
                                rstate->high_tail = node->group_prev;
                        }
                        cgdebug_printf(state, "Moving...%td to low\n", node - rstate->lr);
                        node->group_prev  = rstate->low_tail;
                        node->group_next  = 0;
                        *rstate->low_tail = node;
                        rstate->low_tail  = &node->group_next;
                        if (*node->group_prev != node) {
                                internal_error(state, 0, "move2: *prev != node?");
                        }
                }
                node->degree -= 1;
        }
        colored = color_graph(state, rstate);
        if (colored) {
                cgdebug_printf(state, "Coloring %td @", range - rstate->lr);
                cgdebug_loc(state, range->defs->def);
                cgdebug_flush(state);
                colored = select_free_color(state, rstate, range);
                if (colored) {
                        cgdebug_printf(state, " %s\n", arch_reg_str(range->color));
                }
        }
        return colored;
}

static void verify_colors(struct compile_state *state, struct reg_state *rstate)
{
        struct live_range *lr;
        struct live_range_edge *edge;
        struct triple *ins, *first;
        char used[MAX_REGISTERS];
        first = state->first;
        ins = first;
        do {
                if (triple_is_def(state, ins)) {
                        if (ins->id > rstate->defs) {
                                internal_error(state, ins,
                                        "triple without a live range def");
                        }
                        lr = rstate->lrd[ins->id].lr;
                        if (lr->color == REG_UNSET) {
                                internal_error(state, ins,
                                        "triple without a color");
                        }
                        /* Find the registers used by the edges */
                        memset(used, 0, sizeof(used));
                        for(edge = lr->edges; edge; edge = edge->next) {
                                if (edge->node->color == REG_UNSET) {
                                        internal_error(state, 0,
                                                "live range without a color");
                        }
                                reg_fill_used(state, used, edge->node->color);
                        }
                        if (used[lr->color]) {
                                internal_error(state, ins,
                                        "triple with already used color");
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void color_triples(struct compile_state *state, struct reg_state *rstate)
{
        struct live_range_def *lrd;
        struct live_range *lr;
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                if (ins->id > rstate->defs) {
                        internal_error(state, ins,
                                "triple without a live range");
                }
                lrd = &rstate->lrd[ins->id];
                lr = lrd->lr;
                ins->id = lrd->orig_id;
                SET_REG(ins->id, lr->color);
                ins = ins->next;
        } while (ins != first);
}

static struct live_range *merge_sort_lr(
        struct live_range *first, struct live_range *last)
{
        struct live_range *mid, *join, **join_tail, *pick;
        size_t size;
        size = (last - first) + 1;
        if (size >= 2) {
                mid = first + size/2;
                first = merge_sort_lr(first, mid -1);
                mid   = merge_sort_lr(mid, last);

                join = 0;
                join_tail = &join;
                /* merge the two lists */
                while(first && mid) {
                        if ((first->degree < mid->degree) ||
                                ((first->degree == mid->degree) &&
                                        (first->length < mid->length))) {
                                pick = first;
                                first = first->group_next;
                                if (first) {
                                        first->group_prev = 0;
                                }
                        }
                        else {
                                pick = mid;
                                mid = mid->group_next;
                                if (mid) {
                                        mid->group_prev = 0;
                                }
                        }
                        pick->group_next = 0;
                        pick->group_prev = join_tail;
                        *join_tail = pick;
                        join_tail = &pick->group_next;
                }
                /* Splice the remaining list */
                pick = (first)? first : mid;
                *join_tail = pick;
                if (pick) {
                        pick->group_prev = join_tail;
                }
        }
        else {
                if (!first->defs) {
                        first = 0;
                }
                join = first;
        }
        return join;
}

static void ids_from_rstate(struct compile_state *state,
        struct reg_state *rstate)
{
        struct triple *ins, *first;
        if (!rstate->defs) {
                return;
        }
        /* Display the graph if desired */
        if (state->compiler->debug & DEBUG_INTERFERENCE) {
                FILE *fp = state->dbgout;
                print_interference_blocks(state, rstate, fp, 0);
                print_control_flow(state, fp, &state->bb);
                fflush(fp);
        }
        first = state->first;
        ins = first;
        do {
                if (ins->id) {
                        struct live_range_def *lrd;
                        lrd = &rstate->lrd[ins->id];
                        ins->id = lrd->orig_id;
                }
                ins = ins->next;
        } while(ins != first);
}

static void cleanup_live_edges(struct reg_state *rstate)
{
        int i;
        /* Free the edges on each node */
        for(i = 1; i <= rstate->ranges; i++) {
                remove_live_edges(rstate, &rstate->lr[i]);
        }
}

static void cleanup_rstate(struct compile_state *state, struct reg_state *rstate)
{
        cleanup_live_edges(rstate);
        xfree(rstate->lrd);
        xfree(rstate->lr);

        /* Free the variable lifetime information */
        if (rstate->blocks) {
                free_variable_lifetimes(state, &state->bb, rstate->blocks);
        }
        rstate->defs = 0;
        rstate->ranges = 0;
        rstate->lrd = 0;
        rstate->lr = 0;
        rstate->blocks = 0;
}

static void verify_consistency(struct compile_state *state);
static void allocate_registers(struct compile_state *state)
{
        struct reg_state rstate;
        int colored;

        /* Clear out the reg_state */
        memset(&rstate, 0, sizeof(rstate));
        rstate.max_passes = state->compiler->max_allocation_passes;

        do {
                struct live_range **point, **next;
                int tangles;
                int coalesced;

                if (state->compiler->debug & DEBUG_RANGE_CONFLICTS) {
                        FILE *fp = state->errout;
                        fprintf(fp, "pass: %d\n", rstate.passes);
                        fflush(fp);
                }

                /* Restore ids */
                ids_from_rstate(state, &rstate);

                /* Cleanup the temporary data structures */
                cleanup_rstate(state, &rstate);

                /* Compute the variable lifetimes */
                rstate.blocks = compute_variable_lifetimes(state, &state->bb);

                /* Fix invalid mandatory live range coalesce conflicts */
                correct_coalesce_conflicts(state, rstate.blocks);

                /* Fix two simultaneous uses of the same register.
                 * In a few pathlogical cases a partial untangle moves
                 * the tangle to a part of the graph we won't revisit.
                 * So we keep looping until we have no more tangle fixes
                 * to apply.
                 */
                do {
                        tangles = correct_tangles(state, rstate.blocks);
                } while(tangles);


                print_blocks(state, "resolve_tangles", state->dbgout);
                verify_consistency(state);

                /* Allocate and initialize the live ranges */
                initialize_live_ranges(state, &rstate);

                /* Note currently doing coalescing in a loop appears to
                 * buys me nothing.  The code is left this way in case
                 * there is some value in it.  Or if a future bugfix
                 * yields some benefit.
                 */
                do {
                        if (state->compiler->debug & DEBUG_COALESCING) {
                                fprintf(state->errout, "coalescing\n");
                        }

                        /* Remove any previous live edge calculations */
                        cleanup_live_edges(&rstate);

                        /* Compute the interference graph */
                        walk_variable_lifetimes(
                                state, &state->bb, rstate.blocks,
                                graph_ins, &rstate);

                        /* Display the interference graph if desired */
                        if (state->compiler->debug & DEBUG_INTERFERENCE) {
                                print_interference_blocks(state, &rstate, state->dbgout, 1);
                                fprintf(state->dbgout, "\nlive variables by instruction\n");
                                walk_variable_lifetimes(
                                        state, &state->bb, rstate.blocks,
                                        print_interference_ins, &rstate);
                        }

                        coalesced = coalesce_live_ranges(state, &rstate);

                        if (state->compiler->debug & DEBUG_COALESCING) {
                                fprintf(state->errout, "coalesced: %d\n", coalesced);
                        }
                } while(coalesced);

#if DEBUG_CONSISTENCY > 1
# if 0
                fprintf(state->errout, "verify_graph_ins...\n");
# endif
                /* Verify the interference graph */
                walk_variable_lifetimes(
                        state, &state->bb, rstate.blocks,
                        verify_graph_ins, &rstate);
# if 0
                fprintf(state->errout, "verify_graph_ins done\n");
#endif
#endif

                /* Build the groups low and high.  But with the nodes
                 * first sorted by degree order.
                 */
                rstate.low_tail  = &rstate.low;
                rstate.high_tail = &rstate.high;
                rstate.high = merge_sort_lr(&rstate.lr[1], &rstate.lr[rstate.ranges]);
                if (rstate.high) {
                        rstate.high->group_prev = &rstate.high;
                }
                for(point = &rstate.high; *point; point = &(*point)->group_next)
                        ;
                rstate.high_tail = point;
                /* Walk through the high list and move everything that needs
                 * to be onto low.
                 */
                for(point = &rstate.high; *point; point = next) {
                        struct live_range *range;
                        next = &(*point)->group_next;
                        range = *point;

                        /* If it has a low degree or it already has a color
                         * place the node in low.
                         */
                        if ((range->degree < regc_max_size(state, range->classes)) ||
                                (range->color != REG_UNSET)) {
                                cgdebug_printf(state, "Lo: %5td degree %5d%s\n",
                                        range - rstate.lr, range->degree,
                                        (range->color != REG_UNSET) ? " (colored)": "");
                                *range->group_prev = range->group_next;
                                if (range->group_next) {
                                        range->group_next->group_prev = range->group_prev;
                                }
                                if (&range->group_next == rstate.high_tail) {
                                        rstate.high_tail = range->group_prev;
                                }
                                range->group_prev  = rstate.low_tail;
                                range->group_next  = 0;
                                *rstate.low_tail   = range;
                                rstate.low_tail    = &range->group_next;
                                next = point;
                        }
                        else {
                                cgdebug_printf(state, "hi: %5td degree %5d%s\n",
                                        range - rstate.lr, range->degree,
                                        (range->color != REG_UNSET) ? " (colored)": "");
                        }
                }
                /* Color the live_ranges */
                colored = color_graph(state, &rstate);
                rstate.passes++;
        } while (!colored);

        /* Verify the graph was properly colored */
        verify_colors(state, &rstate);

        /* Move the colors from the graph to the triples */
        color_triples(state, &rstate);

        /* Cleanup the temporary data structures */
        cleanup_rstate(state, &rstate);

        /* Display the new graph */
        print_blocks(state, __func__, state->dbgout);
}

/* Sparce Conditional Constant Propogation
 * =========================================
 */
struct ssa_edge;
struct flow_block;
struct lattice_node {
        unsigned old_id;
        struct triple *def;
        struct ssa_edge *out;
        struct flow_block *fblock;
        struct triple *val;
        /* lattice high   val == def
         * lattice const  is_const(val)
         * lattice low    other
         */
};
struct ssa_edge {
        struct lattice_node *src;
        struct lattice_node *dst;
        struct ssa_edge *work_next;
        struct ssa_edge *work_prev;
        struct ssa_edge *out_next;
};
struct flow_edge {
        struct flow_block *src;
        struct flow_block *dst;
        struct flow_edge *work_next;
        struct flow_edge *work_prev;
        struct flow_edge *in_next;
        struct flow_edge *out_next;
        int executable;
};
#define MAX_FLOW_BLOCK_EDGES 3
struct flow_block {
        struct block *block;
        struct flow_edge *in;
        struct flow_edge *out;
        struct flow_edge *edges;
};

struct scc_state {
        int ins_count;
        struct lattice_node *lattice;
        struct ssa_edge     *ssa_edges;
        struct flow_block   *flow_blocks;
        struct flow_edge    *flow_work_list;
        struct ssa_edge     *ssa_work_list;
};


static int is_scc_const(struct compile_state *state, struct triple *ins)
{
        return ins && (triple_is_ubranch(state, ins) || is_const(ins));
}

static int is_lattice_hi(struct compile_state *state, struct lattice_node *lnode)
{
        return !is_scc_const(state, lnode->val) && (lnode->val == lnode->def);
}

static int is_lattice_const(struct compile_state *state, struct lattice_node *lnode)
{
        return is_scc_const(state, lnode->val);
}

static int is_lattice_lo(struct compile_state *state, struct lattice_node *lnode)
{
        return (lnode->val != lnode->def) && !is_scc_const(state, lnode->val);
}

static void scc_add_fedge(struct compile_state *state, struct scc_state *scc,
        struct flow_edge *fedge)
{
        if (state->compiler->debug & DEBUG_SCC_TRANSFORM2) {
                fprintf(state->errout, "adding fedge: %p (%4d -> %5d)\n",
                        fedge,
                        fedge->src->block?fedge->src->block->last->id: 0,
                        fedge->dst->block?fedge->dst->block->first->id: 0);
        }
        if ((fedge == scc->flow_work_list) ||
                (fedge->work_next != fedge) ||
                (fedge->work_prev != fedge)) {

                if (state->compiler->debug & DEBUG_SCC_TRANSFORM2) {
                        fprintf(state->errout, "dupped fedge: %p\n",
                                fedge);
                }
                return;
        }
        if (!scc->flow_work_list) {
                scc->flow_work_list = fedge;
                fedge->work_next = fedge->work_prev = fedge;
        }
        else {
                struct flow_edge *ftail;
                ftail = scc->flow_work_list->work_prev;
                fedge->work_next = ftail->work_next;
                fedge->work_prev = ftail;
                fedge->work_next->work_prev = fedge;
                fedge->work_prev->work_next = fedge;
        }
}

static struct flow_edge *scc_next_fedge(
        struct compile_state *state, struct scc_state *scc)
{
        struct flow_edge *fedge;
        fedge = scc->flow_work_list;
        if (fedge) {
                fedge->work_next->work_prev = fedge->work_prev;
                fedge->work_prev->work_next = fedge->work_next;
                if (fedge->work_next != fedge) {
                        scc->flow_work_list = fedge->work_next;
                } else {
                        scc->flow_work_list = 0;
                }
                fedge->work_next = fedge->work_prev = fedge;
        }
        return fedge;
}

static void scc_add_sedge(struct compile_state *state, struct scc_state *scc,
        struct ssa_edge *sedge)
{
        if (state->compiler->debug & DEBUG_SCC_TRANSFORM2) {
                fprintf(state->errout, "adding sedge: %5ld (%4d -> %5d)\n",
                        (long)(sedge - scc->ssa_edges),
                        sedge->src->def->id,
                        sedge->dst->def->id);
        }
        if ((sedge == scc->ssa_work_list) ||
                (sedge->work_next != sedge) ||
                (sedge->work_prev != sedge)) {

                if (state->compiler->debug & DEBUG_SCC_TRANSFORM2) {
                        fprintf(state->errout, "dupped sedge: %5ld\n",
                                (long)(sedge - scc->ssa_edges));
                }
                return;
        }
        if (!scc->ssa_work_list) {
                scc->ssa_work_list = sedge;
                sedge->work_next = sedge->work_prev = sedge;
        }
        else {
                struct ssa_edge *stail;
                stail = scc->ssa_work_list->work_prev;
                sedge->work_next = stail->work_next;
                sedge->work_prev = stail;
                sedge->work_next->work_prev = sedge;
                sedge->work_prev->work_next = sedge;
        }
}

static struct ssa_edge *scc_next_sedge(
        struct compile_state *state, struct scc_state *scc)
{
        struct ssa_edge *sedge;
        sedge = scc->ssa_work_list;
        if (sedge) {
                sedge->work_next->work_prev = sedge->work_prev;
                sedge->work_prev->work_next = sedge->work_next;
                if (sedge->work_next != sedge) {
                        scc->ssa_work_list = sedge->work_next;
                } else {
                        scc->ssa_work_list = 0;
                }
                sedge->work_next = sedge->work_prev = sedge;
        }
        return sedge;
}

static void initialize_scc_state(
        struct compile_state *state, struct scc_state *scc)
{
        int ins_count, ssa_edge_count;
        int ins_index, ssa_edge_index, fblock_index;
        struct triple *first, *ins;
        struct block *block;
        struct flow_block *fblock;

        memset(scc, 0, sizeof(*scc));

        /* Inialize pass zero find out how much memory we need */
        first = state->first;
        ins = first;
        ins_count = ssa_edge_count = 0;
        do {
                struct triple_set *edge;
                ins_count += 1;
                for(edge = ins->use; edge; edge = edge->next) {
                        ssa_edge_count++;
                }
                ins = ins->next;
        } while(ins != first);
        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                fprintf(state->errout, "ins_count: %d ssa_edge_count: %d vertex_count: %d\n",
                        ins_count, ssa_edge_count, state->bb.last_vertex);
        }
        scc->ins_count   = ins_count;
        scc->lattice     =
                xcmalloc(sizeof(*scc->lattice)*(ins_count + 1), "lattice");
        scc->ssa_edges   =
                xcmalloc(sizeof(*scc->ssa_edges)*(ssa_edge_count + 1), "ssa_edges");
        scc->flow_blocks =
                xcmalloc(sizeof(*scc->flow_blocks)*(state->bb.last_vertex + 1),
                        "flow_blocks");

        /* Initialize pass one collect up the nodes */
        fblock = 0;
        block = 0;
        ins_index = ssa_edge_index = fblock_index = 0;
        ins = first;
        do {
                if ((ins->op == OP_LABEL) && (block != ins->u.block)) {
                        block = ins->u.block;
                        if (!block) {
                                internal_error(state, ins, "label without block");
                        }
                        fblock_index += 1;
                        block->vertex = fblock_index;
                        fblock = &scc->flow_blocks[fblock_index];
                        fblock->block = block;
                        fblock->edges = xcmalloc(sizeof(*fblock->edges)*block->edge_count,
                                "flow_edges");
                }
                {
                        struct lattice_node *lnode;
                        ins_index += 1;
                        lnode = &scc->lattice[ins_index];
                        lnode->def = ins;
                        lnode->out = 0;
                        lnode->fblock = fblock;
                        lnode->val = ins; /* LATTICE HIGH */
                        if (lnode->val->op == OP_UNKNOWNVAL) {
                                lnode->val = 0; /* LATTICE LOW by definition */
                        }
                        lnode->old_id = ins->id;
                        ins->id = ins_index;
                }
                ins = ins->next;
        } while(ins != first);
        /* Initialize pass two collect up the edges */
        block = 0;
        fblock = 0;
        ins = first;
        do {
                {
                        struct triple_set *edge;
                        struct ssa_edge **stail;
                        struct lattice_node *lnode;
                        lnode = &scc->lattice[ins->id];
                        lnode->out = 0;
                        stail = &lnode->out;
                        for(edge = ins->use; edge; edge = edge->next) {
                                struct ssa_edge *sedge;
                                ssa_edge_index += 1;
                                sedge = &scc->ssa_edges[ssa_edge_index];
                                *stail = sedge;
                                stail = &sedge->out_next;
                                sedge->src = lnode;
                                sedge->dst = &scc->lattice[edge->member->id];
                                sedge->work_next = sedge->work_prev = sedge;
                                sedge->out_next = 0;
                        }
                }
                if ((ins->op == OP_LABEL) && (block != ins->u.block)) {
                        struct flow_edge *fedge, **ftail;
                        struct block_set *bedge;
                        block = ins->u.block;
                        fblock = &scc->flow_blocks[block->vertex];
                        fblock->in = 0;
                        fblock->out = 0;
                        ftail = &fblock->out;

                        fedge = fblock->edges;
                        bedge = block->edges;
                        for(; bedge; bedge = bedge->next, fedge++) {
                                fedge->dst = &scc->flow_blocks[bedge->member->vertex];
                                if (fedge->dst->block != bedge->member) {
                                        internal_error(state, 0, "block mismatch");
                                }
                                *ftail = fedge;
                                ftail = &fedge->out_next;
                                fedge->out_next = 0;
                        }
                        for(fedge = fblock->out; fedge; fedge = fedge->out_next) {
                                fedge->src = fblock;
                                fedge->work_next = fedge->work_prev = fedge;
                                fedge->executable = 0;
                        }
                }
                ins = ins->next;
        } while (ins != first);
        block = 0;
        fblock = 0;
        ins = first;
        do {
                if ((ins->op  == OP_LABEL) && (block != ins->u.block)) {
                        struct flow_edge **ftail;
                        struct block_set *bedge;
                        block = ins->u.block;
                        fblock = &scc->flow_blocks[block->vertex];
                        ftail = &fblock->in;
                        for(bedge = block->use; bedge; bedge = bedge->next) {
                                struct block *src_block;
                                struct flow_block *sfblock;
                                struct flow_edge *sfedge;
                                src_block = bedge->member;
                                sfblock = &scc->flow_blocks[src_block->vertex];
                                for(sfedge = sfblock->out; sfedge; sfedge = sfedge->out_next) {
                                        if (sfedge->dst == fblock) {
                                                break;
                                        }
                                }
                                if (!sfedge) {
                                        internal_error(state, 0, "edge mismatch");
                                }
                                *ftail = sfedge;
                                ftail = &sfedge->in_next;
                                sfedge->in_next = 0;
                        }
                }
                ins = ins->next;
        } while(ins != first);
        /* Setup a dummy block 0 as a node above the start node */
        {
                struct flow_block *fblock, *dst;
                struct flow_edge *fedge;
                fblock = &scc->flow_blocks[0];
                fblock->block = 0;
                fblock->edges = xcmalloc(sizeof(*fblock->edges)*1, "flow_edges");
                fblock->in = 0;
                fblock->out = fblock->edges;
                dst = &scc->flow_blocks[state->bb.first_block->vertex];
                fedge = fblock->edges;
                fedge->src        = fblock;
                fedge->dst        = dst;
                fedge->work_next  = fedge;
                fedge->work_prev  = fedge;
                fedge->in_next    = fedge->dst->in;
                fedge->out_next   = 0;
                fedge->executable = 0;
                fedge->dst->in = fedge;

                /* Initialize the work lists */
                scc->flow_work_list = 0;
                scc->ssa_work_list  = 0;
                scc_add_fedge(state, scc, fedge);
        }
        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                fprintf(state->errout, "ins_index: %d ssa_edge_index: %d fblock_index: %d\n",
                        ins_index, ssa_edge_index, fblock_index);
        }
}


static void free_scc_state(
        struct compile_state *state, struct scc_state *scc)
{
        int i;
        for(i = 0; i < state->bb.last_vertex + 1; i++) {
                struct flow_block *fblock;
                fblock = &scc->flow_blocks[i];
                if (fblock->edges) {
                        xfree(fblock->edges);
                        fblock->edges = 0;
                }
        }
        xfree(scc->flow_blocks);
        xfree(scc->ssa_edges);
        xfree(scc->lattice);

}

static struct lattice_node *triple_to_lattice(
        struct compile_state *state, struct scc_state *scc, struct triple *ins)
{
        if (ins->id <= 0) {
                internal_error(state, ins, "bad id");
        }
        return &scc->lattice[ins->id];
}

static struct triple *preserve_lval(
        struct compile_state *state, struct lattice_node *lnode)
{
        struct triple *old;
        /* Preserve the original value */
        if (lnode->val) {
                old = dup_triple(state, lnode->val);
                if (lnode->val != lnode->def) {
                        xfree(lnode->val);
                }
                lnode->val = 0;
        } else {
                old = 0;
        }
        return old;
}

static int lval_changed(struct compile_state *state,
        struct triple *old, struct lattice_node *lnode)
{
        int changed;
        /* See if the lattice value has changed */
        changed = 1;
        if (!old && !lnode->val) {
                changed = 0;
        }
        if (changed &&
                lnode->val && old &&
                (memcmp(lnode->val->param, old->param,
                        TRIPLE_SIZE(lnode->val) * sizeof(lnode->val->param[0])) == 0) &&
                (memcmp(&lnode->val->u, &old->u, sizeof(old->u)) == 0)) {
                changed = 0;
        }
        if (old) {
                xfree(old);
        }
        return changed;

}

static void scc_debug_lnode(
        struct compile_state *state, struct scc_state *scc,
        struct lattice_node *lnode, int changed)
{
        if ((state->compiler->debug & DEBUG_SCC_TRANSFORM2) && lnode->val) {
                display_triple_changes(state->errout, lnode->val, lnode->def);
        }
        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                FILE *fp = state->errout;
                struct triple *val, **expr;
                val = lnode->val? lnode->val : lnode->def;
                fprintf(fp, "%p %s %3d %10s (",
                        lnode->def,
                        ((lnode->def->op == OP_PHI)? "phi: ": "expr:"),
                        lnode->def->id,
                        tops(lnode->def->op));
                expr = triple_rhs(state, lnode->def, 0);
                for(;expr;expr = triple_rhs(state, lnode->def, expr)) {
                        if (*expr) {
                                fprintf(fp, " %d", (*expr)->id);
                        }
                }
                if (val->op == OP_INTCONST) {
                        fprintf(fp, " <0x%08lx>", (unsigned long)(val->u.cval));
                }
                fprintf(fp, " ) -> %s %s\n",
                        (is_lattice_hi(state, lnode)? "hi":
                                is_lattice_const(state, lnode)? "const" : "lo"),
                        changed? "changed" : ""
                        );
        }
}

static int compute_lnode_val(struct compile_state *state, struct scc_state *scc,
        struct lattice_node *lnode)
{
        int changed;
        struct triple *old, *scratch;
        struct triple **dexpr, **vexpr;
        int count, i;

        /* Store the original value */
        old = preserve_lval(state, lnode);

        /* Reinitialize the value */
        lnode->val = scratch = dup_triple(state, lnode->def);
        scratch->id = lnode->old_id;
        scratch->next     = scratch;
        scratch->prev     = scratch;
        scratch->use      = 0;

        count = TRIPLE_SIZE(scratch);
        for(i = 0; i < count; i++) {
                dexpr = &lnode->def->param[i];
                vexpr = &scratch->param[i];
                *vexpr = *dexpr;
                if (((i < TRIPLE_MISC_OFF(scratch)) ||
                        (i >= TRIPLE_TARG_OFF(scratch))) &&
                        *dexpr) {
                        struct lattice_node *tmp;
                        tmp = triple_to_lattice(state, scc, *dexpr);
                        *vexpr = (tmp->val)? tmp->val : tmp->def;
                }
        }
        if (triple_is_branch(state, scratch)) {
                scratch->next = lnode->def->next;
        }
        /* Recompute the value */
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME see if simplify does anything bad"
#endif
        /* So far it looks like only the strength reduction
         * optimization are things I need to worry about.
         */
        simplify(state, scratch);
        /* Cleanup my value */
        if (scratch->use) {
                internal_error(state, lnode->def, "scratch used?");
        }
        if ((scratch->prev != scratch) ||
                ((scratch->next != scratch) &&
                        (!triple_is_branch(state, lnode->def) ||
                                (scratch->next != lnode->def->next)))) {
                internal_error(state, lnode->def, "scratch in list?");
        }
        /* undo any uses... */
        count = TRIPLE_SIZE(scratch);
        for(i = 0; i < count; i++) {
                vexpr = &scratch->param[i];
                if (*vexpr) {
                        unuse_triple(*vexpr, scratch);
                }
        }
        if (lnode->val->op == OP_UNKNOWNVAL) {
                lnode->val = 0; /* Lattice low by definition */
        }
        /* Find the case when I am lattice high */
        if (lnode->val &&
                (lnode->val->op == lnode->def->op) &&
                (memcmp(lnode->val->param, lnode->def->param,
                        count * sizeof(lnode->val->param[0])) == 0) &&
                (memcmp(&lnode->val->u, &lnode->def->u, sizeof(lnode->def->u)) == 0)) {
                lnode->val = lnode->def;
        }
        /* Only allow lattice high when all of my inputs
         * are also lattice high.  Occasionally I can
         * have constants with a lattice low input, so
         * I do not need to check that case.
         */
        if (is_lattice_hi(state, lnode)) {
                struct lattice_node *tmp;
                int rhs;
                rhs = lnode->val->rhs;
                for(i = 0; i < rhs; i++) {
                        tmp = triple_to_lattice(state, scc, RHS(lnode->val, i));
                        if (!is_lattice_hi(state, tmp)) {
                                lnode->val = 0;
                                break;
                        }
                }
        }
        /* Find the cases that are always lattice lo */
        if (lnode->val &&
                triple_is_def(state, lnode->val) &&
                !triple_is_pure(state, lnode->val, lnode->old_id)) {
                lnode->val = 0;
        }
        /* See if the lattice value has changed */
        changed = lval_changed(state, old, lnode);
        /* See if this value should not change */
        if ((lnode->val != lnode->def) &&
                ((      !triple_is_def(state, lnode->def)  &&
                        !triple_is_cbranch(state, lnode->def)) ||
                        (lnode->def->op == OP_PIECE))) {
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME constant propagate through expressions with multiple left hand sides"
#endif
                if (changed) {
                        internal_warning(state, lnode->def, "non def changes value?");
                }
                lnode->val = 0;
        }

        /* See if we need to free the scratch value */
        if (lnode->val != scratch) {
                xfree(scratch);
        }

        return changed;
}


static void scc_visit_cbranch(struct compile_state *state, struct scc_state *scc,
        struct lattice_node *lnode)
{
        struct lattice_node *cond;
        struct flow_edge *left, *right;
        int changed;

        /* Update the branch value */
        changed = compute_lnode_val(state, scc, lnode);
        scc_debug_lnode(state, scc, lnode, changed);

        /* This only applies to conditional branches */
        if (!triple_is_cbranch(state, lnode->def)) {
                internal_error(state, lnode->def, "not a conditional branch");
        }

        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                struct flow_edge *fedge;
                FILE *fp = state->errout;
                fprintf(fp, "%s: %d (",
                        tops(lnode->def->op),
                        lnode->def->id);

                for(fedge = lnode->fblock->out; fedge; fedge = fedge->out_next) {
                        fprintf(fp, " %d", fedge->dst->block->vertex);
                }
                fprintf(fp, " )");
                if (lnode->def->rhs > 0) {
                        fprintf(fp, " <- %d",
                                RHS(lnode->def, 0)->id);
                }
                fprintf(fp, "\n");
        }
        cond = triple_to_lattice(state, scc, RHS(lnode->def,0));
        for(left = cond->fblock->out; left; left = left->out_next) {
                if (left->dst->block->first == lnode->def->next) {
                        break;
                }
        }
        if (!left) {
                internal_error(state, lnode->def, "Cannot find left branch edge");
        }
        for(right = cond->fblock->out; right; right = right->out_next) {
                if (right->dst->block->first == TARG(lnode->def, 0)) {
                        break;
                }
        }
        if (!right) {
                internal_error(state, lnode->def, "Cannot find right branch edge");
        }
        /* I should only come here if the controlling expressions value
         * has changed, which means it must be either a constant or lo.
         */
        if (is_lattice_hi(state, cond)) {
                internal_error(state, cond->def, "condition high?");
                return;
        }
        if (is_lattice_lo(state, cond)) {
                scc_add_fedge(state, scc, left);
                scc_add_fedge(state, scc, right);
        }
        else if (cond->val->u.cval) {
                scc_add_fedge(state, scc, right);
        } else {
                scc_add_fedge(state, scc, left);
        }

}


static void scc_add_sedge_dst(struct compile_state *state,
        struct scc_state *scc, struct ssa_edge *sedge)
{
        if (triple_is_cbranch(state, sedge->dst->def)) {
                scc_visit_cbranch(state, scc, sedge->dst);
        }
        else if (triple_is_def(state, sedge->dst->def)) {
                scc_add_sedge(state, scc, sedge);
        }
}

static void scc_visit_phi(struct compile_state *state, struct scc_state *scc,
        struct lattice_node *lnode)
{
        struct lattice_node *tmp;
        struct triple **slot, *old;
        struct flow_edge *fedge;
        int changed;
        int index;
        if (lnode->def->op != OP_PHI) {
                internal_error(state, lnode->def, "not phi");
        }
        /* Store the original value */
        old = preserve_lval(state, lnode);

        /* default to lattice high */
        lnode->val = lnode->def;
        slot = &RHS(lnode->def, 0);
        index = 0;
        for(fedge = lnode->fblock->in; fedge; index++, fedge = fedge->in_next) {
                if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                        fprintf(state->errout, "Examining edge: %d vertex: %d executable: %d\n",
                                index,
                                fedge->dst->block->vertex,
                                fedge->executable
                                );
                }
                if (!fedge->executable) {
                        continue;
                }
                if (!slot[index]) {
                        internal_error(state, lnode->def, "no phi value");
                }
                tmp = triple_to_lattice(state, scc, slot[index]);
                /* meet(X, lattice low) = lattice low */
                if (is_lattice_lo(state, tmp)) {
                        lnode->val = 0;
                }
                /* meet(X, lattice high) = X */
                else if (is_lattice_hi(state, tmp)) {
                }
                /* meet(lattice high, X) = X */
                else if (is_lattice_hi(state, lnode)) {
                        lnode->val = dup_triple(state, tmp->val);
                        /* Only change the type if necessary */
                        if (!is_subset_type(lnode->def->type, tmp->val->type)) {
                                lnode->val->type = lnode->def->type;
                        }
                }
                /* meet(const, const) = const or lattice low */
                else if (lnode->val != 0 &&
                                !constants_equal(state, lnode->val, tmp->val)) {
                        lnode->val = 0;
                }

                /* meet(lattice low, X) = lattice low */
                if (is_lattice_lo(state, lnode)) {
                        lnode->val = 0;
                        break;
                }
        }
        changed = lval_changed(state, old, lnode);
        scc_debug_lnode(state, scc, lnode, changed);

        /* If the lattice value has changed update the work lists. */
        if (changed) {
                struct ssa_edge *sedge;
                for(sedge = lnode->out; sedge; sedge = sedge->out_next) {
                        scc_add_sedge_dst(state, scc, sedge);
                }
        }
}


static void scc_visit_expr(struct compile_state *state, struct scc_state *scc,
        struct lattice_node *lnode)
{
        int changed;

        if (!triple_is_def(state, lnode->def)) {
                internal_warning(state, lnode->def, "not visiting an expression?");
        }
        changed = compute_lnode_val(state, scc, lnode);
        scc_debug_lnode(state, scc, lnode, changed);

        if (changed) {
                struct ssa_edge *sedge;
                for(sedge = lnode->out; sedge; sedge = sedge->out_next) {
                        scc_add_sedge_dst(state, scc, sedge);
                }
        }
}

static void scc_writeback_values(
        struct compile_state *state, struct scc_state *scc)
{
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                struct lattice_node *lnode;
                lnode = triple_to_lattice(state, scc, ins);
                if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                        if (is_lattice_hi(state, lnode) &&
                                (lnode->val->op != OP_NOOP))
                        {
                                struct flow_edge *fedge;
                                int executable;
                                executable = 0;
                                for(fedge = lnode->fblock->in;
                                    !executable && fedge; fedge = fedge->in_next) {
                                        executable |= fedge->executable;
                                }
                                if (executable) {
                                        internal_warning(state, lnode->def,
                                                "lattice node %d %s->%s still high?",
                                                ins->id,
                                                tops(lnode->def->op),
                                                tops(lnode->val->op));
                                }
                        }
                }

                /* Restore id */
                ins->id = lnode->old_id;
                if (lnode->val && (lnode->val != ins)) {
                        /* See if it something I know how to write back */
                        switch(lnode->val->op) {
                        case OP_INTCONST:
                                mkconst(state, ins, lnode->val->u.cval);
                                break;
                        case OP_ADDRCONST:
                                mkaddr_const(state, ins,
                                        MISC(lnode->val, 0), lnode->val->u.cval);
                                break;
                        default:
                                /* By default don't copy the changes,
                                 * recompute them in place instead.
                                 */
                                simplify(state, ins);
                                break;
                        }
                        if (is_const(lnode->val) &&
                                !constants_equal(state, lnode->val, ins)) {
                                internal_error(state, 0, "constants not equal");
                        }
                        /* Free the lattice nodes */
                        xfree(lnode->val);
                        lnode->val = 0;
                }
                ins = ins->next;
        } while(ins != first);
}

static void scc_transform(struct compile_state *state)
{
        struct scc_state scc;
        if (!(state->compiler->flags & COMPILER_SCC_TRANSFORM)) {
                return;
        }

        initialize_scc_state(state, &scc);

        while(scc.flow_work_list || scc.ssa_work_list) {
                struct flow_edge *fedge;
                struct ssa_edge *sedge;
                struct flow_edge *fptr;
                while((fedge = scc_next_fedge(state, &scc))) {
                        struct block *block;
                        struct triple *ptr;
                        struct flow_block *fblock;
                        int reps;
                        int done;
                        if (fedge->executable) {
                                continue;
                        }
                        if (!fedge->dst) {
                                internal_error(state, 0, "fedge without dst");
                        }
                        if (!fedge->src) {
                                internal_error(state, 0, "fedge without src");
                        }
                        fedge->executable = 1;
                        fblock = fedge->dst;
                        block = fblock->block;
                        reps = 0;
                        for(fptr = fblock->in; fptr; fptr = fptr->in_next) {
                                if (fptr->executable) {
                                        reps++;
                                }
                        }

                        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                                fprintf(state->errout, "vertex: %d reps: %d\n",
                                        block->vertex, reps);
                        }

                        done = 0;
                        for(ptr = block->first; !done; ptr = ptr->next) {
                                struct lattice_node *lnode;
                                done = (ptr == block->last);
                                lnode = &scc.lattice[ptr->id];
                                if (ptr->op == OP_PHI) {
                                        scc_visit_phi(state, &scc, lnode);
                                }
                                else if ((reps == 1) && triple_is_def(state, ptr))
                                {
                                        scc_visit_expr(state, &scc, lnode);
                                }
                        }
                        /* Add unconditional branch edges */
                        if (!triple_is_cbranch(state, fblock->block->last)) {
                                struct flow_edge *out;
                                for(out = fblock->out; out; out = out->out_next) {
                                        scc_add_fedge(state, &scc, out);
                                }
                        }
                }
                while((sedge = scc_next_sedge(state, &scc))) {
                        struct lattice_node *lnode;
                        struct flow_block *fblock;
                        lnode = sedge->dst;
                        fblock = lnode->fblock;

                        if (state->compiler->debug & DEBUG_SCC_TRANSFORM) {
                                fprintf(state->errout, "sedge: %5ld (%5d -> %5d)\n",
                                        (unsigned long)sedge - (unsigned long)scc.ssa_edges,
                                        sedge->src->def->id,
                                        sedge->dst->def->id);
                        }

                        if (lnode->def->op == OP_PHI) {
                                scc_visit_phi(state, &scc, lnode);
                        }
                        else {
                                for(fptr = fblock->in; fptr; fptr = fptr->in_next) {
                                        if (fptr->executable) {
                                                break;
                                        }
                                }
                                if (fptr) {
                                        scc_visit_expr(state, &scc, lnode);
                                }
                        }
                }
        }

        scc_writeback_values(state, &scc);
        free_scc_state(state, &scc);
        rebuild_ssa_form(state);

        print_blocks(state, __func__, state->dbgout);
}


static void transform_to_arch_instructions(struct compile_state *state)
{
        struct triple *ins, *first;
        first = state->first;
        ins = first;
        do {
                ins = transform_to_arch_instruction(state, ins);
        } while(ins != first);

        print_blocks(state, __func__, state->dbgout);
}

#if DEBUG_CONSISTENCY
static void verify_uses(struct compile_state *state)
{
        struct triple *first, *ins;
        struct triple_set *set;
        first = state->first;
        ins = first;
        do {
                struct triple **expr;
                expr = triple_rhs(state, ins, 0);
                for(; expr; expr = triple_rhs(state, ins, expr)) {
                        struct triple *rhs;
                        rhs = *expr;
                        for(set = rhs?rhs->use:0; set; set = set->next) {
                                if (set->member == ins) {
                                        break;
                                }
                        }
                        if (!set) {
                                internal_error(state, ins, "rhs not used");
                        }
                }
                expr = triple_lhs(state, ins, 0);
                for(; expr; expr = triple_lhs(state, ins, expr)) {
                        struct triple *lhs;
                        lhs = *expr;
                        for(set =  lhs?lhs->use:0; set; set = set->next) {
                                if (set->member == ins) {
                                        break;
                                }
                        }
                        if (!set) {
                                internal_error(state, ins, "lhs not used");
                        }
                }
                expr = triple_misc(state, ins, 0);
                if (ins->op != OP_PHI) {
                        for(; expr; expr = triple_targ(state, ins, expr)) {
                                struct triple *misc;
                                misc = *expr;
                                for(set = misc?misc->use:0; set; set = set->next) {
                                        if (set->member == ins) {
                                                break;
                                        }
                                }
                                if (!set) {
                                        internal_error(state, ins, "misc not used");
                                }
                        }
                }
                if (!triple_is_ret(state, ins)) {
                        expr = triple_targ(state, ins, 0);
                        for(; expr; expr = triple_targ(state, ins, expr)) {
                                struct triple *targ;
                                targ = *expr;
                                for(set = targ?targ->use:0; set; set = set->next) {
                                        if (set->member == ins) {
                                                break;
                                        }
                                }
                                if (!set) {
                                        internal_error(state, ins, "targ not used");
                                }
                        }
                }
                ins = ins->next;
        } while(ins != first);

}
static void verify_blocks_present(struct compile_state *state)
{
        struct triple *first, *ins;
        if (!state->bb.first_block) {
                return;
        }
        first = state->first;
        ins = first;
        do {
                valid_ins(state, ins);
                if (triple_stores_block(state, ins)) {
                        if (!ins->u.block) {
                                internal_error(state, ins,
                                        "%p not in a block?", ins);
                        }
                }
                ins = ins->next;
        } while(ins != first);


}

static int edge_present(struct compile_state *state, struct block *block, struct triple *edge)
{
        struct block_set *bedge;
        struct block *targ;
        targ = block_of_triple(state, edge);
        for(bedge = block->edges; bedge; bedge = bedge->next) {
                if (bedge->member == targ) {
                        return 1;
                }
        }
        return 0;
}

static void verify_blocks(struct compile_state *state)
{
        struct triple *ins;
        struct block *block;
        int blocks;
        block = state->bb.first_block;
        if (!block) {
                return;
        }
        blocks = 0;
        do {
                int users;
                struct block_set *user, *edge;
                blocks++;
                for(ins = block->first; ins != block->last->next; ins = ins->next) {
                        if (triple_stores_block(state, ins) && (ins->u.block != block)) {
                                internal_error(state, ins, "inconsitent block specified");
                        }
                        valid_ins(state, ins);
                }
                users = 0;
                for(user = block->use; user; user = user->next) {
                        users++;
                        if (!user->member->first) {
                                internal_error(state, block->first, "user is empty");
                        }
                        if ((block == state->bb.last_block) &&
                                (user->member == state->bb.first_block)) {
                                continue;
                        }
                        for(edge = user->member->edges; edge; edge = edge->next) {
                                if (edge->member == block) {
                                        break;
                                }
                        }
                        if (!edge) {
                                internal_error(state, user->member->first,
                                        "user does not use block");
                        }
                }
                if (triple_is_branch(state, block->last)) {
                        struct triple **expr;
                        expr = triple_edge_targ(state, block->last, 0);
                        for(;expr; expr = triple_edge_targ(state, block->last, expr)) {
                                if (*expr && !edge_present(state, block, *expr)) {
                                        internal_error(state, block->last, "no edge to targ");
                                }
                        }
                }
                if (!triple_is_ubranch(state, block->last) &&
                        (block != state->bb.last_block) &&
                        !edge_present(state, block, block->last->next)) {
                        internal_error(state, block->last, "no edge to block->last->next");
                }
                for(edge = block->edges; edge; edge = edge->next) {
                        for(user = edge->member->use; user; user = user->next) {
                                if (user->member == block) {
                                        break;
                                }
                        }
                        if (!user || user->member != block) {
                                internal_error(state, block->first,
                                        "block does not use edge");
                        }
                        if (!edge->member->first) {
                                internal_error(state, block->first, "edge block is empty");
                        }
                }
                if (block->users != users) {
                        internal_error(state, block->first,
                                "computed users %d != stored users %d",
                                users, block->users);
                }
                if (!(block->last->next) || !(block->last->next->u.block)) {
                        internal_error(state, block->last,
                                "bad next block");
                }
                if (!triple_stores_block(state, block->last->next)) {
                        internal_error(state, block->last->next,
                                "cannot find next block");
                }
                block = block->last->next->u.block;
        } while(block != state->bb.first_block);
        if (blocks != state->bb.last_vertex) {
                internal_error(state, 0, "computed blocks: %d != stored blocks %d",
                        blocks, state->bb.last_vertex);
        }
}

static void verify_domination(struct compile_state *state)
{
        struct triple *first, *ins;
        struct triple_set *set;
        if (!state->bb.first_block) {
                return;
        }

        first = state->first;
        ins = first;
        do {
                for(set = ins->use; set; set = set->next) {
                        struct triple **slot;
                        struct triple *use_point;
                        int i, zrhs;
                        use_point = 0;
                        zrhs = set->member->rhs;
                        slot = &RHS(set->member, 0);
                        /* See if the use is on the right hand side */
                        for(i = 0; i < zrhs; i++) {
                                if (slot[i] == ins) {
                                        break;
                                }
                        }
                        if (i < zrhs) {
                                use_point = set->member;
                                if (set->member->op == OP_PHI) {
                                        struct block_set *bset;
                                        int edge;
                                        bset = set->member->u.block->use;
                                        for(edge = 0; bset && (edge < i); edge++) {
                                                bset = bset->next;
                                        }
                                        if (!bset) {
                                                internal_error(state, set->member,
                                                        "no edge for phi rhs %d", i);
                                        }
                                        use_point = bset->member->last;
                                }
                        }
                        if (use_point &&
                                !tdominates(state, ins, use_point)) {
                                if (is_const(ins)) {
                                        internal_warning(state, ins,
                                        "non dominated rhs use point %p?", use_point);
                                }
                                else {
                                        internal_error(state, ins,
                                                "non dominated rhs use point %p?", use_point);
                                }
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void verify_rhs(struct compile_state *state)
{
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                struct triple **slot;
                int zrhs, i;
                zrhs = ins->rhs;
                slot = &RHS(ins, 0);
                for(i = 0; i < zrhs; i++) {
                        if (slot[i] == 0) {
                                internal_error(state, ins,
                                        "missing rhs %d on %s",
                                        i, tops(ins->op));
                        }
                        if ((ins->op != OP_PHI) && (slot[i] == ins)) {
                                internal_error(state, ins,
                                        "ins == rhs[%d] on %s",
                                        i, tops(ins->op));
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void verify_piece(struct compile_state *state)
{
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                struct triple *ptr;
                int lhs, i;
                lhs = ins->lhs;
                for(ptr = ins->next, i = 0; i < lhs; i++, ptr = ptr->next) {
                        if (ptr != LHS(ins, i)) {
                                internal_error(state, ins, "malformed lhs on %s",
                                        tops(ins->op));
                        }
                        if (ptr->op != OP_PIECE) {
                                internal_error(state, ins, "bad lhs op %s at %d on %s",
                                        tops(ptr->op), i, tops(ins->op));
                        }
                        if (ptr->u.cval != i) {
                                internal_error(state, ins, "bad u.cval of %d %d expected",
                                        ptr->u.cval, i);
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void verify_ins_colors(struct compile_state *state)
{
        struct triple *first, *ins;

        first = state->first;
        ins = first;
        do {
                ins = ins->next;
        } while(ins != first);
}

static void verify_unknown(struct compile_state *state)
{
        struct triple *first, *ins;
        if (    (unknown_triple.next != &unknown_triple) ||
                (unknown_triple.prev != &unknown_triple) ||
#if 0
                (unknown_triple.use != 0) ||
#endif
                (unknown_triple.op != OP_UNKNOWNVAL) ||
                (unknown_triple.lhs != 0) ||
                (unknown_triple.rhs != 0) ||
                (unknown_triple.misc != 0) ||
                (unknown_triple.targ != 0) ||
                (unknown_triple.template_id != 0) ||
                (unknown_triple.id != -1) ||
                (unknown_triple.type != &unknown_type) ||
                (unknown_triple.occurrence != &dummy_occurrence) ||
                (unknown_triple.param[0] != 0) ||
                (unknown_triple.param[1] != 0)) {
                internal_error(state, &unknown_triple, "unknown_triple corrupted!");
        }
        if (    (dummy_occurrence.count != 2) ||
                (strcmp(dummy_occurrence.filename, __FILE__) != 0) ||
                (strcmp(dummy_occurrence.function, "") != 0) ||
                (dummy_occurrence.col != 0) ||
                (dummy_occurrence.parent != 0)) {
                internal_error(state, &unknown_triple, "dummy_occurrence corrupted!");
        }
        if (    (unknown_type.type != TYPE_UNKNOWN)) {
                internal_error(state, &unknown_triple, "unknown_type corrupted!");
        }
        first = state->first;
        ins = first;
        do {
                int params, i;
                if (ins == &unknown_triple) {
                        internal_error(state, ins, "unknown triple in list");
                }
                params = TRIPLE_SIZE(ins);
                for(i = 0; i < params; i++) {
                        if (ins->param[i] == &unknown_triple) {
                                internal_error(state, ins, "unknown triple used!");
                        }
                }
                ins = ins->next;
        } while(ins != first);
}

static void verify_types(struct compile_state *state)
{
        struct triple *first, *ins;
        first = state->first;
        ins = first;
        do {
                struct type *invalid;
                invalid = invalid_type(state, ins->type);
                if (invalid) {
                        FILE *fp = state->errout;
                        fprintf(fp, "type: ");
                        name_of(fp, ins->type);
                        fprintf(fp, "\n");
                        fprintf(fp, "invalid type: ");
                        name_of(fp, invalid);
                        fprintf(fp, "\n");
                        internal_error(state, ins, "invalid ins type");
                }
        } while(ins != first);
}

static void verify_copy(struct compile_state *state)
{
        struct triple *first, *ins, *next;
        first = state->first;
        next = ins = first;
        do {
                ins = next;
                next = ins->next;
                if (ins->op != OP_COPY) {
                        continue;
                }
                if (!equiv_types(ins->type, RHS(ins, 0)->type)) {
                        FILE *fp = state->errout;
                        fprintf(fp, "src type: ");
                        name_of(fp, RHS(ins, 0)->type);
                        fprintf(fp, "\n");
                        fprintf(fp, "dst type: ");
                        name_of(fp, ins->type);
                        fprintf(fp, "\n");
                        internal_error(state, ins, "type mismatch in copy");
                }
        } while(next != first);
}

static void verify_consistency(struct compile_state *state)
{
        verify_unknown(state);
        verify_uses(state);
        verify_blocks_present(state);
        verify_blocks(state);
        verify_domination(state);
        verify_rhs(state);
        verify_piece(state);
        verify_ins_colors(state);
        verify_types(state);
        verify_copy(state);
        if (state->compiler->debug & DEBUG_VERIFICATION) {
                fprintf(state->dbgout, "consistency verified\n");
        }
}
#else
static void verify_consistency(struct compile_state *state) {}
#endif /* DEBUG_CONSISTENCY */

static void optimize(struct compile_state *state)
{
        /* Join all of the functions into one giant function */
        join_functions(state);

        /* Dump what the instruction graph intially looks like */
        print_triples(state);

        /* Replace structures with simpler data types */
        decompose_compound_types(state);
        print_triples(state);

        verify_consistency(state);
        /* Analyze the intermediate code */
        state->bb.first = state->first;
        analyze_basic_blocks(state, &state->bb);

        /* Transform the code to ssa form. */
        /*
         * The transformation to ssa form puts a phi function
         * on each of edge of a dominance frontier where that
         * phi function might be needed.  At -O2 if we don't
         * eleminate the excess phi functions we can get an
         * exponential code size growth.  So I kill the extra
         * phi functions early and I kill them often.
         */
        transform_to_ssa_form(state);
        verify_consistency(state);

        /* Remove dead code */
        eliminate_inefectual_code(state);
        verify_consistency(state);

        /* Do strength reduction and simple constant optimizations */
        simplify_all(state);
        verify_consistency(state);
        /* Propagate constants throughout the code */
        scc_transform(state);
        verify_consistency(state);
#if DEBUG_ROMCC_WARNINGS
#warning "WISHLIST implement single use constants (least possible register pressure)"
#warning "WISHLIST implement induction variable elimination"
#endif
        /* Select architecture instructions and an initial partial
         * coloring based on architecture constraints.
         */
        transform_to_arch_instructions(state);
        verify_consistency(state);

        /* Remove dead code */
        eliminate_inefectual_code(state);
        verify_consistency(state);

        /* Color all of the variables to see if they will fit in registers */
        insert_copies_to_phi(state);
        verify_consistency(state);

        insert_mandatory_copies(state);
        verify_consistency(state);

        allocate_registers(state);
        verify_consistency(state);

        /* Remove the optimization information.
         * This is more to check for memory consistency than to free memory.
         */
        free_basic_blocks(state, &state->bb);
}

static void print_op_asm(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        struct asm_info *info;
        const char *ptr;
        unsigned lhs, rhs, i;
        info = ins->u.ainfo;
        lhs = ins->lhs;
        rhs = ins->rhs;
        /* Don't count the clobbers in lhs */
        for(i = 0; i < lhs; i++) {
                if (LHS(ins, i)->type == &void_type) {
                        break;
                }
        }
        lhs = i;
        fprintf(fp, "#ASM\n");
        fputc('\t', fp);
        for(ptr = info->str; *ptr; ptr++) {
                char *next;
                unsigned long param;
                struct triple *piece;
                if (*ptr != '%') {
                        fputc(*ptr, fp);
                        continue;
                }
                ptr++;
                if (*ptr == '%') {
                        fputc('%', fp);
                        continue;
                }
                param = strtoul(ptr, &next, 10);
                if (ptr == next) {
                        error(state, ins, "Invalid asm template");
                }
                if (param >= (lhs + rhs)) {
                        error(state, ins, "Invalid param %%%u in asm template",
                                param);
                }
                piece = (param < lhs)? LHS(ins, param) : RHS(ins, param - lhs);
                fprintf(fp, "%s",
                        arch_reg_str(ID_REG(piece->id)));
                ptr = next -1;
        }
        fprintf(fp, "\n#NOT ASM\n");
}


/* Only use the low x86 byte registers.  This allows me
 * allocate the entire register when a byte register is used.
 */
#define X86_4_8BIT_GPRS 1

/* x86 featrues */
#define X86_MMX_REGS  (1<<0)
#define X86_XMM_REGS  (1<<1)
#define X86_NOOP_COPY (1<<2)

/* The x86 register classes */
#define REGC_FLAGS       0
#define REGC_GPR8        1
#define REGC_GPR16       2
#define REGC_GPR32       3
#define REGC_DIVIDEND64  4
#define REGC_DIVIDEND32  5
#define REGC_MMX         6
#define REGC_XMM         7
#define REGC_GPR32_8     8
#define REGC_GPR16_8     9
#define REGC_GPR8_LO    10
#define REGC_IMM32      11
#define REGC_IMM16      12
#define REGC_IMM8       13
#define LAST_REGC  REGC_IMM8
#if LAST_REGC >= MAX_REGC
#error "MAX_REGC is to low"
#endif

/* Register class masks */
#define REGCM_FLAGS      (1 << REGC_FLAGS)
#define REGCM_GPR8       (1 << REGC_GPR8)
#define REGCM_GPR16      (1 << REGC_GPR16)
#define REGCM_GPR32      (1 << REGC_GPR32)
#define REGCM_DIVIDEND64 (1 << REGC_DIVIDEND64)
#define REGCM_DIVIDEND32 (1 << REGC_DIVIDEND32)
#define REGCM_MMX        (1 << REGC_MMX)
#define REGCM_XMM        (1 << REGC_XMM)
#define REGCM_GPR32_8    (1 << REGC_GPR32_8)
#define REGCM_GPR16_8    (1 << REGC_GPR16_8)
#define REGCM_GPR8_LO    (1 << REGC_GPR8_LO)
#define REGCM_IMM32      (1 << REGC_IMM32)
#define REGCM_IMM16      (1 << REGC_IMM16)
#define REGCM_IMM8       (1 << REGC_IMM8)
#define REGCM_ALL        ((1 << (LAST_REGC + 1)) - 1)
#define REGCM_IMMALL    (REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8)

/* The x86 registers */
#define REG_EFLAGS  2
#define REGC_FLAGS_FIRST REG_EFLAGS
#define REGC_FLAGS_LAST  REG_EFLAGS
#define REG_AL      3
#define REG_BL      4
#define REG_CL      5
#define REG_DL      6
#define REG_AH      7
#define REG_BH      8
#define REG_CH      9
#define REG_DH      10
#define REGC_GPR8_LO_FIRST REG_AL
#define REGC_GPR8_LO_LAST  REG_DL
#define REGC_GPR8_FIRST  REG_AL
#define REGC_GPR8_LAST   REG_DH
#define REG_AX     11
#define REG_BX     12
#define REG_CX     13
#define REG_DX     14
#define REG_SI     15
#define REG_DI     16
#define REG_BP     17
#define REG_SP     18
#define REGC_GPR16_FIRST REG_AX
#define REGC_GPR16_LAST  REG_SP
#define REG_EAX    19
#define REG_EBX    20
#define REG_ECX    21
#define REG_EDX    22
#define REG_ESI    23
#define REG_EDI    24
#define REG_EBP    25
#define REG_ESP    26
#define REGC_GPR32_FIRST REG_EAX
#define REGC_GPR32_LAST  REG_ESP
#define REG_EDXEAX 27
#define REGC_DIVIDEND64_FIRST REG_EDXEAX
#define REGC_DIVIDEND64_LAST  REG_EDXEAX
#define REG_DXAX   28
#define REGC_DIVIDEND32_FIRST REG_DXAX
#define REGC_DIVIDEND32_LAST  REG_DXAX
#define REG_MMX0   29
#define REG_MMX1   30
#define REG_MMX2   31
#define REG_MMX3   32
#define REG_MMX4   33
#define REG_MMX5   34
#define REG_MMX6   35
#define REG_MMX7   36
#define REGC_MMX_FIRST REG_MMX0
#define REGC_MMX_LAST  REG_MMX7
#define REG_XMM0   37
#define REG_XMM1   38
#define REG_XMM2   39
#define REG_XMM3   40
#define REG_XMM4   41
#define REG_XMM5   42
#define REG_XMM6   43
#define REG_XMM7   44
#define REGC_XMM_FIRST REG_XMM0
#define REGC_XMM_LAST  REG_XMM7

#if DEBUG_ROMCC_WARNINGS
#warning "WISHLIST figure out how to use pinsrw and pextrw to better use extended regs"
#endif

#define LAST_REG   REG_XMM7

#define REGC_GPR32_8_FIRST REG_EAX
#define REGC_GPR32_8_LAST  REG_EDX
#define REGC_GPR16_8_FIRST REG_AX
#define REGC_GPR16_8_LAST  REG_DX

#define REGC_IMM8_FIRST    -1
#define REGC_IMM8_LAST     -1
#define REGC_IMM16_FIRST   -2
#define REGC_IMM16_LAST    -1
#define REGC_IMM32_FIRST   -4
#define REGC_IMM32_LAST    -1

#if LAST_REG >= MAX_REGISTERS
#error "MAX_REGISTERS to low"
#endif


static unsigned regc_size[LAST_REGC +1] = {
        [REGC_FLAGS]      = REGC_FLAGS_LAST      - REGC_FLAGS_FIRST + 1,
        [REGC_GPR8]       = REGC_GPR8_LAST       - REGC_GPR8_FIRST + 1,
        [REGC_GPR16]      = REGC_GPR16_LAST      - REGC_GPR16_FIRST + 1,
        [REGC_GPR32]      = REGC_GPR32_LAST      - REGC_GPR32_FIRST + 1,
        [REGC_DIVIDEND64] = REGC_DIVIDEND64_LAST - REGC_DIVIDEND64_FIRST + 1,
        [REGC_DIVIDEND32] = REGC_DIVIDEND32_LAST - REGC_DIVIDEND32_FIRST + 1,
        [REGC_MMX]        = REGC_MMX_LAST        - REGC_MMX_FIRST + 1,
        [REGC_XMM]        = REGC_XMM_LAST        - REGC_XMM_FIRST + 1,
        [REGC_GPR32_8]    = REGC_GPR32_8_LAST    - REGC_GPR32_8_FIRST + 1,
        [REGC_GPR16_8]    = REGC_GPR16_8_LAST    - REGC_GPR16_8_FIRST + 1,
        [REGC_GPR8_LO]    = REGC_GPR8_LO_LAST    - REGC_GPR8_LO_FIRST + 1,
        [REGC_IMM32]      = 0,
        [REGC_IMM16]      = 0,
        [REGC_IMM8]       = 0,
};

static const struct {
        int first, last;
} regcm_bound[LAST_REGC + 1] = {
        [REGC_FLAGS]      = { REGC_FLAGS_FIRST,      REGC_FLAGS_LAST },
        [REGC_GPR8]       = { REGC_GPR8_FIRST,       REGC_GPR8_LAST },
        [REGC_GPR16]      = { REGC_GPR16_FIRST,      REGC_GPR16_LAST },
        [REGC_GPR32]      = { REGC_GPR32_FIRST,      REGC_GPR32_LAST },
        [REGC_DIVIDEND64] = { REGC_DIVIDEND64_FIRST, REGC_DIVIDEND64_LAST },
        [REGC_DIVIDEND32] = { REGC_DIVIDEND32_FIRST, REGC_DIVIDEND32_LAST },
        [REGC_MMX]        = { REGC_MMX_FIRST,        REGC_MMX_LAST },
        [REGC_XMM]        = { REGC_XMM_FIRST,        REGC_XMM_LAST },
        [REGC_GPR32_8]    = { REGC_GPR32_8_FIRST,    REGC_GPR32_8_LAST },
        [REGC_GPR16_8]    = { REGC_GPR16_8_FIRST,    REGC_GPR16_8_LAST },
        [REGC_GPR8_LO]    = { REGC_GPR8_LO_FIRST,    REGC_GPR8_LO_LAST },
        [REGC_IMM32]      = { REGC_IMM32_FIRST,      REGC_IMM32_LAST },
        [REGC_IMM16]      = { REGC_IMM16_FIRST,      REGC_IMM16_LAST },
        [REGC_IMM8]       = { REGC_IMM8_FIRST,       REGC_IMM8_LAST },
};

#if ARCH_INPUT_REGS != 4
#error ARCH_INPUT_REGS size mismatch
#endif
static const struct reg_info arch_input_regs[ARCH_INPUT_REGS] = {
        { .reg = REG_EAX, .regcm = REGCM_GPR32 },
        { .reg = REG_EBX, .regcm = REGCM_GPR32 },
        { .reg = REG_ECX, .regcm = REGCM_GPR32 },
        { .reg = REG_EDX, .regcm = REGCM_GPR32 },
};

#if ARCH_OUTPUT_REGS != 4
#error ARCH_INPUT_REGS size mismatch
#endif
static const struct reg_info arch_output_regs[ARCH_OUTPUT_REGS] = {
        { .reg = REG_EAX, .regcm = REGCM_GPR32 },
        { .reg = REG_EBX, .regcm = REGCM_GPR32 },
        { .reg = REG_ECX, .regcm = REGCM_GPR32 },
        { .reg = REG_EDX, .regcm = REGCM_GPR32 },
};

static void init_arch_state(struct arch_state *arch)
{
        memset(arch, 0, sizeof(*arch));
        arch->features = 0;
}

static const struct compiler_flag arch_flags[] = {
        { "mmx",       X86_MMX_REGS },
        { "sse",       X86_XMM_REGS },
        { "noop-copy", X86_NOOP_COPY },
        { 0,     0 },
};
static const struct compiler_flag arch_cpus[] = {
        { "i386", 0 },
        { "p2",   X86_MMX_REGS },
        { "p3",   X86_MMX_REGS | X86_XMM_REGS },
        { "p4",   X86_MMX_REGS | X86_XMM_REGS },
        { "k7",   X86_MMX_REGS },
        { "k8",   X86_MMX_REGS | X86_XMM_REGS },
        { "c3",   X86_MMX_REGS },
        { "c3-2", X86_MMX_REGS | X86_XMM_REGS }, /* Nehemiah */
        {  0,     0 }
};
static int arch_encode_flag(struct arch_state *arch, const char *flag)
{
        int result;
        int act;

        act = 1;
        if (strncmp(flag, "no-", 3) == 0) {
                flag += 3;
                act = 0;
        }
        if (act && strncmp(flag, "cpu=", 4) == 0) {
                flag += 4;
                result = set_flag(arch_cpus, &arch->features, 1, flag);
        }
        else {
                result = set_flag(arch_flags, &arch->features, act, flag);
        }
        return result;
}

static void arch_usage(FILE *fp)
{
        flag_usage(fp, arch_flags, "-m", "-mno-");
        flag_usage(fp, arch_cpus, "-mcpu=", 0);
}

static unsigned arch_regc_size(struct compile_state *state, int class)
{
        if ((class < 0) || (class > LAST_REGC)) {
                return 0;
        }
        return regc_size[class];
}

static int arch_regcm_intersect(unsigned regcm1, unsigned regcm2)
{
        /* See if two register classes may have overlapping registers */
        unsigned gpr_mask = REGCM_GPR8 | REGCM_GPR8_LO | REGCM_GPR16_8 | REGCM_GPR16 |
                REGCM_GPR32_8 | REGCM_GPR32 |
                REGCM_DIVIDEND32 | REGCM_DIVIDEND64;

        /* Special case for the immediates */
        if ((regcm1 & (REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8)) &&
                ((regcm1 & ~(REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8)) == 0) &&
                (regcm2 & (REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8)) &&
                ((regcm2 & ~(REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8)) == 0)) {
                return 0;
        }
        return (regcm1 & regcm2) ||
                ((regcm1 & gpr_mask) && (regcm2 & gpr_mask));
}

static void arch_reg_equivs(
        struct compile_state *state, unsigned *equiv, int reg)
{
        if ((reg < 0) || (reg > LAST_REG)) {
                internal_error(state, 0, "invalid register");
        }
        *equiv++ = reg;
        switch(reg) {
        case REG_AL:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_AH;
#endif
                *equiv++ = REG_AX;
                *equiv++ = REG_EAX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_AH:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_AL;
#endif
                *equiv++ = REG_AX;
                *equiv++ = REG_EAX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_BL:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_BH;
#endif
                *equiv++ = REG_BX;
                *equiv++ = REG_EBX;
                break;

        case REG_BH:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_BL;
#endif
                *equiv++ = REG_BX;
                *equiv++ = REG_EBX;
                break;
        case REG_CL:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_CH;
#endif
                *equiv++ = REG_CX;
                *equiv++ = REG_ECX;
                break;

        case REG_CH:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_CL;
#endif
                *equiv++ = REG_CX;
                *equiv++ = REG_ECX;
                break;
        case REG_DL:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_DH;
#endif
                *equiv++ = REG_DX;
                *equiv++ = REG_EDX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_DH:
#if X86_4_8BIT_GPRS
                *equiv++ = REG_DL;
#endif
                *equiv++ = REG_DX;
                *equiv++ = REG_EDX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_AX:
                *equiv++ = REG_AL;
                *equiv++ = REG_AH;
                *equiv++ = REG_EAX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_BX:
                *equiv++ = REG_BL;
                *equiv++ = REG_BH;
                *equiv++ = REG_EBX;
                break;
        case REG_CX:
                *equiv++ = REG_CL;
                *equiv++ = REG_CH;
                *equiv++ = REG_ECX;
                break;
        case REG_DX:
                *equiv++ = REG_DL;
                *equiv++ = REG_DH;
                *equiv++ = REG_EDX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_SI:
                *equiv++ = REG_ESI;
                break;
        case REG_DI:
                *equiv++ = REG_EDI;
                break;
        case REG_BP:
                *equiv++ = REG_EBP;
                break;
        case REG_SP:
                *equiv++ = REG_ESP;
                break;
        case REG_EAX:
                *equiv++ = REG_AL;
                *equiv++ = REG_AH;
                *equiv++ = REG_AX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_EBX:
                *equiv++ = REG_BL;
                *equiv++ = REG_BH;
                *equiv++ = REG_BX;
                break;
        case REG_ECX:
                *equiv++ = REG_CL;
                *equiv++ = REG_CH;
                *equiv++ = REG_CX;
                break;
        case REG_EDX:
                *equiv++ = REG_DL;
                *equiv++ = REG_DH;
                *equiv++ = REG_DX;
                *equiv++ = REG_DXAX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_ESI:
                *equiv++ = REG_SI;
                break;
        case REG_EDI:
                *equiv++ = REG_DI;
                break;
        case REG_EBP:
                *equiv++ = REG_BP;
                break;
        case REG_ESP:
                *equiv++ = REG_SP;
                break;
        case REG_DXAX:
                *equiv++ = REG_AL;
                *equiv++ = REG_AH;
                *equiv++ = REG_DL;
                *equiv++ = REG_DH;
                *equiv++ = REG_AX;
                *equiv++ = REG_DX;
                *equiv++ = REG_EAX;
                *equiv++ = REG_EDX;
                *equiv++ = REG_EDXEAX;
                break;
        case REG_EDXEAX:
                *equiv++ = REG_AL;
                *equiv++ = REG_AH;
                *equiv++ = REG_DL;
                *equiv++ = REG_DH;
                *equiv++ = REG_AX;
                *equiv++ = REG_DX;
                *equiv++ = REG_EAX;
                *equiv++ = REG_EDX;
                *equiv++ = REG_DXAX;
                break;
        }
        *equiv++ = REG_UNSET;
}

static unsigned arch_avail_mask(struct compile_state *state)
{
        unsigned avail_mask;
        /* REGCM_GPR8 is not available */
        avail_mask = REGCM_GPR8_LO | REGCM_GPR16_8 | REGCM_GPR16 |
                REGCM_GPR32 | REGCM_GPR32_8 |
                REGCM_DIVIDEND32 | REGCM_DIVIDEND64 |
                REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8 | REGCM_FLAGS;
        if (state->arch->features & X86_MMX_REGS) {
                avail_mask |= REGCM_MMX;
        }
        if (state->arch->features & X86_XMM_REGS) {
                avail_mask |= REGCM_XMM;
        }
        return avail_mask;
}

static unsigned arch_regcm_normalize(struct compile_state *state, unsigned regcm)
{
        unsigned mask, result;
        int class, class2;
        result = regcm;

        for(class = 0, mask = 1; mask; mask <<= 1, class++) {
                if ((result & mask) == 0) {
                        continue;
                }
                if (class > LAST_REGC) {
                        result &= ~mask;
                        continue;
                }
                for(class2 = 0; class2 <= LAST_REGC; class2++) {
                        if ((regcm_bound[class2].first >= regcm_bound[class].first) &&
                                (regcm_bound[class2].last <= regcm_bound[class].last)) {
                                result |= (1 << class2);
                        }
                }
        }
        result &= arch_avail_mask(state);
        return result;
}

static unsigned arch_regcm_reg_normalize(struct compile_state *state, unsigned regcm)
{
        /* Like arch_regcm_normalize except immediate register classes are excluded */
        regcm = arch_regcm_normalize(state, regcm);
        /* Remove the immediate register classes */
        regcm &= ~(REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8);
        return regcm;

}

static unsigned arch_reg_regcm(struct compile_state *state, int reg)
{
        unsigned mask;
        int class;
        mask = 0;
        for(class = 0; class <= LAST_REGC; class++) {
                if ((reg >= regcm_bound[class].first) &&
                        (reg <= regcm_bound[class].last)) {
                        mask |= (1 << class);
                }
        }
        if (!mask) {
                internal_error(state, 0, "reg %d not in any class", reg);
        }
        return mask;
}

static struct reg_info arch_reg_constraint(
        struct compile_state *state, struct type *type, const char *constraint)
{
        static const struct {
                char class;
                unsigned int mask;
                unsigned int reg;
        } constraints[] = {
                { 'r', REGCM_GPR32,   REG_UNSET },
                { 'g', REGCM_GPR32,   REG_UNSET },
                { 'p', REGCM_GPR32,   REG_UNSET },
                { 'q', REGCM_GPR8_LO, REG_UNSET },
                { 'Q', REGCM_GPR32_8, REG_UNSET },
                { 'x', REGCM_XMM,     REG_UNSET },
                { 'y', REGCM_MMX,     REG_UNSET },
                { 'a', REGCM_GPR32,   REG_EAX },
                { 'b', REGCM_GPR32,   REG_EBX },
                { 'c', REGCM_GPR32,   REG_ECX },
                { 'd', REGCM_GPR32,   REG_EDX },
                { 'D', REGCM_GPR32,   REG_EDI },
                { 'S', REGCM_GPR32,   REG_ESI },
                { '\0', 0, REG_UNSET },
        };
        unsigned int regcm;
        unsigned int mask, reg;
        struct reg_info result;
        const char *ptr;
        regcm = arch_type_to_regcm(state, type);
        reg = REG_UNSET;
        mask = 0;
        for(ptr = constraint; *ptr; ptr++) {
                int i;
                if (*ptr ==  ' ') {
                        continue;
                }
                for(i = 0; constraints[i].class != '\0'; i++) {
                        if (constraints[i].class == *ptr) {
                                break;
                        }
                }
                if (constraints[i].class == '\0') {
                        error(state, 0, "invalid register constraint ``%c''", *ptr);
                        break;
                }
                if ((constraints[i].mask & regcm) == 0) {
                        error(state, 0, "invalid register class %c specified",
                                *ptr);
                }
                mask |= constraints[i].mask;
                if (constraints[i].reg != REG_UNSET) {
                        if ((reg != REG_UNSET) && (reg != constraints[i].reg)) {
                                error(state, 0, "Only one register may be specified");
                        }
                        reg = constraints[i].reg;
                }
        }
        result.reg = reg;
        result.regcm = mask;
        return result;
}

static struct reg_info arch_reg_clobber(
        struct compile_state *state, const char *clobber)
{
        struct reg_info result;
        if (strcmp(clobber, "memory") == 0) {
                result.reg = REG_UNSET;
                result.regcm = 0;
        }
        else if (strcmp(clobber, "eax") == 0) {
                result.reg = REG_EAX;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "ebx") == 0) {
                result.reg = REG_EBX;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "ecx") == 0) {
                result.reg = REG_ECX;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "edx") == 0) {
                result.reg = REG_EDX;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "esi") == 0) {
                result.reg = REG_ESI;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "edi") == 0) {
                result.reg = REG_EDI;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "ebp") == 0) {
                result.reg = REG_EBP;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "esp") == 0) {
                result.reg = REG_ESP;
                result.regcm = REGCM_GPR32;
        }
        else if (strcmp(clobber, "cc") == 0) {
                result.reg = REG_EFLAGS;
                result.regcm = REGCM_FLAGS;
        }
        else if ((strncmp(clobber, "xmm", 3) == 0)  &&
                octdigitp(clobber[3]) && (clobber[4] == '\0')) {
                result.reg = REG_XMM0 + octdigval(clobber[3]);
                result.regcm = REGCM_XMM;
        }
        else if ((strncmp(clobber, "mm", 2) == 0) &&
                octdigitp(clobber[3]) && (clobber[4] == '\0')) {
                result.reg = REG_MMX0 + octdigval(clobber[3]);
                result.regcm = REGCM_MMX;
        }
        else {
                error(state, 0, "unknown register name `%s' in asm",
                        clobber);
                result.reg = REG_UNSET;
                result.regcm = 0;
        }
        return result;
}

static int do_select_reg(struct compile_state *state,
        char *used, int reg, unsigned classes)
{
        unsigned mask;
        if (used[reg]) {
                return REG_UNSET;
        }
        mask = arch_reg_regcm(state, reg);
        return (classes & mask) ? reg : REG_UNSET;
}

static int arch_select_free_register(
        struct compile_state *state, char *used, int classes)
{
        /* Live ranges with the most neighbors are colored first.
         *
         * Generally it does not matter which colors are given
         * as the register allocator attempts to color live ranges
         * in an order where you are guaranteed not to run out of colors.
         *
         * Occasionally the register allocator cannot find an order
         * of register selection that will find a free color.  To
         * increase the odds the register allocator will work when
         * it guesses first give out registers from register classes
         * least likely to run out of registers.
         *
         */
        int i, reg;
        reg = REG_UNSET;
        for(i = REGC_XMM_FIRST; (reg == REG_UNSET) && (i <= REGC_XMM_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_MMX_FIRST; (reg == REG_UNSET) && (i <= REGC_MMX_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_GPR32_LAST; (reg == REG_UNSET) && (i >= REGC_GPR32_FIRST); i--) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_GPR16_FIRST; (reg == REG_UNSET) && (i <= REGC_GPR16_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_GPR8_FIRST; (reg == REG_UNSET) && (i <= REGC_GPR8_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_GPR8_LO_FIRST; (reg == REG_UNSET) && (i <= REGC_GPR8_LO_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_DIVIDEND32_FIRST; (reg == REG_UNSET) && (i <= REGC_DIVIDEND32_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_DIVIDEND64_FIRST; (reg == REG_UNSET) && (i <= REGC_DIVIDEND64_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        for(i = REGC_FLAGS_FIRST; (reg == REG_UNSET) && (i <= REGC_FLAGS_LAST); i++) {
                reg = do_select_reg(state, used, i, classes);
        }
        return reg;
}


static unsigned arch_type_to_regcm(struct compile_state *state, struct type *type)
{

#if DEBUG_ROMCC_WARNINGS
#warning "FIXME force types smaller (if legal) before I get here"
#endif
        unsigned mask;
        switch(type->type & TYPE_MASK) {
        case TYPE_ARRAY:
        case TYPE_VOID:
                mask = 0;
                break;
        case TYPE_CHAR:
        case TYPE_UCHAR:
                mask = REGCM_GPR8 | REGCM_GPR8_LO |
                        REGCM_GPR16 | REGCM_GPR16_8 |
                        REGCM_GPR32 | REGCM_GPR32_8 |
                        REGCM_DIVIDEND32 | REGCM_DIVIDEND64 |
                        REGCM_MMX | REGCM_XMM |
                        REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8;
                break;
        case TYPE_SHORT:
        case TYPE_USHORT:
                mask =  REGCM_GPR16 | REGCM_GPR16_8 |
                        REGCM_GPR32 | REGCM_GPR32_8 |
                        REGCM_DIVIDEND32 | REGCM_DIVIDEND64 |
                        REGCM_MMX | REGCM_XMM |
                        REGCM_IMM32 | REGCM_IMM16;
                break;
        case TYPE_ENUM:
        case TYPE_INT:
        case TYPE_UINT:
        case TYPE_LONG:
        case TYPE_ULONG:
        case TYPE_POINTER:
                mask =  REGCM_GPR32 | REGCM_GPR32_8 |
                        REGCM_DIVIDEND32 | REGCM_DIVIDEND64 |
                        REGCM_MMX | REGCM_XMM |
                        REGCM_IMM32;
                break;
        case TYPE_JOIN:
        case TYPE_UNION:
                mask = arch_type_to_regcm(state, type->left);
                break;
        case TYPE_OVERLAP:
                mask = arch_type_to_regcm(state, type->left) &
                        arch_type_to_regcm(state, type->right);
                break;
        case TYPE_BITFIELD:
                mask = arch_type_to_regcm(state, type->left);
                break;
        default:
                fprintf(state->errout, "type: ");
                name_of(state->errout, type);
                fprintf(state->errout, "\n");
                internal_error(state, 0, "no register class for type");
                break;
        }
        mask = arch_regcm_normalize(state, mask);
        return mask;
}

static int is_imm32(struct triple *imm)
{
        // second condition commented out to prevent compiler warning:
        // imm->u.cval is always 32bit unsigned, so the comparison is
        // always true.
        return ((imm->op == OP_INTCONST) /* && (imm->u.cval <= 0xffffffffUL) */ ) ||
                (imm->op == OP_ADDRCONST);

}
static int is_imm16(struct triple *imm)
{
        return ((imm->op == OP_INTCONST) && (imm->u.cval <= 0xffff));
}
static int is_imm8(struct triple *imm)
{
        return ((imm->op == OP_INTCONST) && (imm->u.cval <= 0xff));
}

static int get_imm32(struct triple *ins, struct triple **expr)
{
        struct triple *imm;
        imm = *expr;
        while(imm->op == OP_COPY) {
                imm = RHS(imm, 0);
        }
        if (!is_imm32(imm)) {
                return 0;
        }
        unuse_triple(*expr, ins);
        use_triple(imm, ins);
        *expr = imm;
        return 1;
}

static int get_imm8(struct triple *ins, struct triple **expr)
{
        struct triple *imm;
        imm = *expr;
        while(imm->op == OP_COPY) {
                imm = RHS(imm, 0);
        }
        if (!is_imm8(imm)) {
                return 0;
        }
        unuse_triple(*expr, ins);
        use_triple(imm, ins);
        *expr = imm;
        return 1;
}

#define TEMPLATE_NOP           0
#define TEMPLATE_INTCONST8     1
#define TEMPLATE_INTCONST32    2
#define TEMPLATE_UNKNOWNVAL    3
#define TEMPLATE_COPY8_REG     5
#define TEMPLATE_COPY16_REG    6
#define TEMPLATE_COPY32_REG    7
#define TEMPLATE_COPY_IMM8     8
#define TEMPLATE_COPY_IMM16    9
#define TEMPLATE_COPY_IMM32   10
#define TEMPLATE_PHI8         11
#define TEMPLATE_PHI16        12
#define TEMPLATE_PHI32        13
#define TEMPLATE_STORE8       14
#define TEMPLATE_STORE16      15
#define TEMPLATE_STORE32      16
#define TEMPLATE_LOAD8        17
#define TEMPLATE_LOAD16       18
#define TEMPLATE_LOAD32       19
#define TEMPLATE_BINARY8_REG  20
#define TEMPLATE_BINARY16_REG 21
#define TEMPLATE_BINARY32_REG 22
#define TEMPLATE_BINARY8_IMM  23
#define TEMPLATE_BINARY16_IMM 24
#define TEMPLATE_BINARY32_IMM 25
#define TEMPLATE_SL8_CL       26
#define TEMPLATE_SL16_CL      27
#define TEMPLATE_SL32_CL      28
#define TEMPLATE_SL8_IMM      29
#define TEMPLATE_SL16_IMM     30
#define TEMPLATE_SL32_IMM     31
#define TEMPLATE_UNARY8       32
#define TEMPLATE_UNARY16      33
#define TEMPLATE_UNARY32      34
#define TEMPLATE_CMP8_REG     35
#define TEMPLATE_CMP16_REG    36
#define TEMPLATE_CMP32_REG    37
#define TEMPLATE_CMP8_IMM     38
#define TEMPLATE_CMP16_IMM    39
#define TEMPLATE_CMP32_IMM    40
#define TEMPLATE_TEST8        41
#define TEMPLATE_TEST16       42
#define TEMPLATE_TEST32       43
#define TEMPLATE_SET          44
#define TEMPLATE_JMP          45
#define TEMPLATE_RET          46
#define TEMPLATE_INB_DX       47
#define TEMPLATE_INB_IMM      48
#define TEMPLATE_INW_DX       49
#define TEMPLATE_INW_IMM      50
#define TEMPLATE_INL_DX       51
#define TEMPLATE_INL_IMM      52
#define TEMPLATE_OUTB_DX      53
#define TEMPLATE_OUTB_IMM     54
#define TEMPLATE_OUTW_DX      55
#define TEMPLATE_OUTW_IMM     56
#define TEMPLATE_OUTL_DX      57
#define TEMPLATE_OUTL_IMM     58
#define TEMPLATE_BSF          59
#define TEMPLATE_RDMSR        60
#define TEMPLATE_WRMSR        61
#define TEMPLATE_UMUL8        62
#define TEMPLATE_UMUL16       63
#define TEMPLATE_UMUL32       64
#define TEMPLATE_DIV8         65
#define TEMPLATE_DIV16        66
#define TEMPLATE_DIV32        67
#define LAST_TEMPLATE       TEMPLATE_DIV32
#if LAST_TEMPLATE >= MAX_TEMPLATES
#error "MAX_TEMPLATES to low"
#endif

#define COPY8_REGCM     (REGCM_DIVIDEND64 | REGCM_DIVIDEND32 | REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO | REGCM_MMX | REGCM_XMM)
#define COPY16_REGCM    (REGCM_DIVIDEND64 | REGCM_DIVIDEND32 | REGCM_GPR32 | REGCM_GPR16 | REGCM_MMX | REGCM_XMM)
#define COPY32_REGCM    (REGCM_DIVIDEND64 | REGCM_DIVIDEND32 | REGCM_GPR32 | REGCM_MMX | REGCM_XMM)


static struct ins_template templates[] = {
        [TEMPLATE_NOP]      = {
                .lhs = {
                        [ 0] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 1] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 2] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 3] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 4] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 5] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 6] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 7] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 8] = { REG_UNNEEDED, REGCM_IMMALL },
                        [ 9] = { REG_UNNEEDED, REGCM_IMMALL },
                        [10] = { REG_UNNEEDED, REGCM_IMMALL },
                        [11] = { REG_UNNEEDED, REGCM_IMMALL },
                        [12] = { REG_UNNEEDED, REGCM_IMMALL },
                        [13] = { REG_UNNEEDED, REGCM_IMMALL },
                        [14] = { REG_UNNEEDED, REGCM_IMMALL },
                        [15] = { REG_UNNEEDED, REGCM_IMMALL },
                        [16] = { REG_UNNEEDED, REGCM_IMMALL },
                        [17] = { REG_UNNEEDED, REGCM_IMMALL },
                        [18] = { REG_UNNEEDED, REGCM_IMMALL },
                        [19] = { REG_UNNEEDED, REGCM_IMMALL },
                        [20] = { REG_UNNEEDED, REGCM_IMMALL },
                        [21] = { REG_UNNEEDED, REGCM_IMMALL },
                        [22] = { REG_UNNEEDED, REGCM_IMMALL },
                        [23] = { REG_UNNEEDED, REGCM_IMMALL },
                        [24] = { REG_UNNEEDED, REGCM_IMMALL },
                        [25] = { REG_UNNEEDED, REGCM_IMMALL },
                        [26] = { REG_UNNEEDED, REGCM_IMMALL },
                        [27] = { REG_UNNEEDED, REGCM_IMMALL },
                        [28] = { REG_UNNEEDED, REGCM_IMMALL },
                        [29] = { REG_UNNEEDED, REGCM_IMMALL },
                        [30] = { REG_UNNEEDED, REGCM_IMMALL },
                        [31] = { REG_UNNEEDED, REGCM_IMMALL },
                        [32] = { REG_UNNEEDED, REGCM_IMMALL },
                        [33] = { REG_UNNEEDED, REGCM_IMMALL },
                        [34] = { REG_UNNEEDED, REGCM_IMMALL },
                        [35] = { REG_UNNEEDED, REGCM_IMMALL },
                        [36] = { REG_UNNEEDED, REGCM_IMMALL },
                        [37] = { REG_UNNEEDED, REGCM_IMMALL },
                        [38] = { REG_UNNEEDED, REGCM_IMMALL },
                        [39] = { REG_UNNEEDED, REGCM_IMMALL },
                        [40] = { REG_UNNEEDED, REGCM_IMMALL },
                        [41] = { REG_UNNEEDED, REGCM_IMMALL },
                        [42] = { REG_UNNEEDED, REGCM_IMMALL },
                        [43] = { REG_UNNEEDED, REGCM_IMMALL },
                        [44] = { REG_UNNEEDED, REGCM_IMMALL },
                        [45] = { REG_UNNEEDED, REGCM_IMMALL },
                        [46] = { REG_UNNEEDED, REGCM_IMMALL },
                        [47] = { REG_UNNEEDED, REGCM_IMMALL },
                        [48] = { REG_UNNEEDED, REGCM_IMMALL },
                        [49] = { REG_UNNEEDED, REGCM_IMMALL },
                        [50] = { REG_UNNEEDED, REGCM_IMMALL },
                        [51] = { REG_UNNEEDED, REGCM_IMMALL },
                        [52] = { REG_UNNEEDED, REGCM_IMMALL },
                        [53] = { REG_UNNEEDED, REGCM_IMMALL },
                        [54] = { REG_UNNEEDED, REGCM_IMMALL },
                        [55] = { REG_UNNEEDED, REGCM_IMMALL },
                        [56] = { REG_UNNEEDED, REGCM_IMMALL },
                        [57] = { REG_UNNEEDED, REGCM_IMMALL },
                        [58] = { REG_UNNEEDED, REGCM_IMMALL },
                        [59] = { REG_UNNEEDED, REGCM_IMMALL },
                        [60] = { REG_UNNEEDED, REGCM_IMMALL },
                        [61] = { REG_UNNEEDED, REGCM_IMMALL },
                        [62] = { REG_UNNEEDED, REGCM_IMMALL },
                        [63] = { REG_UNNEEDED, REGCM_IMMALL },
                },
        },
        [TEMPLATE_INTCONST8] = {
                .lhs = { [0] = { REG_UNNEEDED, REGCM_IMM8 } },
        },
        [TEMPLATE_INTCONST32] = {
                .lhs = { [0] = { REG_UNNEEDED, REGCM_IMM32 } },
        },
        [TEMPLATE_UNKNOWNVAL] = {
                .lhs = { [0] = { REG_UNSET, COPY32_REGCM } },
        },
        [TEMPLATE_COPY8_REG] = {
                .lhs = { [0] = { REG_UNSET, COPY8_REGCM } },
                .rhs = { [0] = { REG_UNSET, COPY8_REGCM }  },
        },
        [TEMPLATE_COPY16_REG] = {
                .lhs = { [0] = { REG_UNSET, COPY16_REGCM } },
                .rhs = { [0] = { REG_UNSET, COPY16_REGCM }  },
        },
        [TEMPLATE_COPY32_REG] = {
                .lhs = { [0] = { REG_UNSET, COPY32_REGCM } },
                .rhs = { [0] = { REG_UNSET, COPY32_REGCM }  },
        },
        [TEMPLATE_COPY_IMM8] = {
                .lhs = { [0] = { REG_UNSET, COPY8_REGCM } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM8 } },
        },
        [TEMPLATE_COPY_IMM16] = {
                .lhs = { [0] = { REG_UNSET, COPY16_REGCM } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM16 | REGCM_IMM8 } },
        },
        [TEMPLATE_COPY_IMM32] = {
                .lhs = { [0] = { REG_UNSET, COPY32_REGCM } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8 } },
        },
        [TEMPLATE_PHI8] = {
                .lhs = { [0] = { REG_VIRT0, COPY8_REGCM } },
                .rhs = { [0] = { REG_VIRT0, COPY8_REGCM } },
        },
        [TEMPLATE_PHI16] = {
                .lhs = { [0] = { REG_VIRT0, COPY16_REGCM } },
                .rhs = { [0] = { REG_VIRT0, COPY16_REGCM } },
        },
        [TEMPLATE_PHI32] = {
                .lhs = { [0] = { REG_VIRT0, COPY32_REGCM } },
                .rhs = { [0] = { REG_VIRT0, COPY32_REGCM } },
        },
        [TEMPLATE_STORE8] = {
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_STORE16] = {
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR16 },
                },
        },
        [TEMPLATE_STORE32] = {
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR32 },
                },
        },
        [TEMPLATE_LOAD8] = {
                .lhs = { [0] = { REG_UNSET, REGCM_GPR8_LO } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_LOAD16] = {
                .lhs = { [0] = { REG_UNSET, REGCM_GPR16 } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_LOAD32] = {
                .lhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_BINARY8_REG] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR8_LO },
                        [1] = { REG_UNSET, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_BINARY16_REG] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR16 },
                        [1] = { REG_UNSET, REGCM_GPR16 },
                },
        },
        [TEMPLATE_BINARY32_REG] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR32 },
                },
        },
        [TEMPLATE_BINARY8_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR8_LO },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_BINARY16_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR16 },
                        [1] = { REG_UNNEEDED, REGCM_IMM16 },
                },
        },
        [TEMPLATE_BINARY32_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR32 },
                        [1] = { REG_UNNEEDED, REGCM_IMM32 },
                },
        },
        [TEMPLATE_SL8_CL] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR8_LO },
                        [1] = { REG_CL, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_SL16_CL] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR16 },
                        [1] = { REG_CL, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_SL32_CL] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
                .rhs = {
                        [0] = { REG_VIRT0, REGCM_GPR32 },
                        [1] = { REG_CL, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_SL8_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR8_LO },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_SL16_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR16 },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_SL32_IMM] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
                .rhs = {
                        [0] = { REG_VIRT0,    REGCM_GPR32 },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_UNARY8] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
                .rhs = { [0] = { REG_VIRT0, REGCM_GPR8_LO } },
        },
        [TEMPLATE_UNARY16] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
                .rhs = { [0] = { REG_VIRT0, REGCM_GPR16 } },
        },
        [TEMPLATE_UNARY32] = {
                .lhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
                .rhs = { [0] = { REG_VIRT0, REGCM_GPR32 } },
        },
        [TEMPLATE_CMP8_REG] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR8_LO },
                        [1] = { REG_UNSET, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_CMP16_REG] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR16 },
                        [1] = { REG_UNSET, REGCM_GPR16 },
                },
        },
        [TEMPLATE_CMP32_REG] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR32 },
                },
        },
        [TEMPLATE_CMP8_IMM] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR8_LO },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_CMP16_IMM] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR16 },
                        [1] = { REG_UNNEEDED, REGCM_IMM16 },
                },
        },
        [TEMPLATE_CMP32_IMM] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = {
                        [0] = { REG_UNSET, REGCM_GPR32 },
                        [1] = { REG_UNNEEDED, REGCM_IMM32 },
                },
        },
        [TEMPLATE_TEST8] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR8_LO } },
        },
        [TEMPLATE_TEST16] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR16 } },
        },
        [TEMPLATE_TEST32] = {
                .lhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_SET] = {
                .lhs = { [0] = { REG_UNSET, REGCM_GPR8_LO } },
                .rhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
        },
        [TEMPLATE_JMP] = {
                .rhs = { [0] = { REG_EFLAGS, REGCM_FLAGS } },
        },
        [TEMPLATE_RET] = {
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_INB_DX] = {
                .lhs = { [0] = { REG_AL,  REGCM_GPR8_LO } },
                .rhs = { [0] = { REG_DX, REGCM_GPR16 } },
        },
        [TEMPLATE_INB_IMM] = {
                .lhs = { [0] = { REG_AL,  REGCM_GPR8_LO } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM8 } },
        },
        [TEMPLATE_INW_DX]  = {
                .lhs = { [0] = { REG_AX,  REGCM_GPR16 } },
                .rhs = { [0] = { REG_DX, REGCM_GPR16 } },
        },
        [TEMPLATE_INW_IMM] = {
                .lhs = { [0] = { REG_AX,  REGCM_GPR16 } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM8 } },
        },
        [TEMPLATE_INL_DX]  = {
                .lhs = { [0] = { REG_EAX, REGCM_GPR32 } },
                .rhs = { [0] = { REG_DX, REGCM_GPR16 } },
        },
        [TEMPLATE_INL_IMM] = {
                .lhs = { [0] = { REG_EAX, REGCM_GPR32 } },
                .rhs = { [0] = { REG_UNNEEDED, REGCM_IMM8 } },
        },
        [TEMPLATE_OUTB_DX] = {
                .rhs = {
                        [0] = { REG_AL,  REGCM_GPR8_LO },
                        [1] = { REG_DX, REGCM_GPR16 },
                },
        },
        [TEMPLATE_OUTB_IMM] = {
                .rhs = {
                        [0] = { REG_AL,  REGCM_GPR8_LO },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_OUTW_DX] = {
                .rhs = {
                        [0] = { REG_AX,  REGCM_GPR16 },
                        [1] = { REG_DX, REGCM_GPR16 },
                },
        },
        [TEMPLATE_OUTW_IMM] = {
                .rhs = {
                        [0] = { REG_AX,  REGCM_GPR16 },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_OUTL_DX] = {
                .rhs = {
                        [0] = { REG_EAX, REGCM_GPR32 },
                        [1] = { REG_DX, REGCM_GPR16 },
                },
        },
        [TEMPLATE_OUTL_IMM] = {
                .rhs = {
                        [0] = { REG_EAX, REGCM_GPR32 },
                        [1] = { REG_UNNEEDED, REGCM_IMM8 },
                },
        },
        [TEMPLATE_BSF] = {
                .lhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
                .rhs = { [0] = { REG_UNSET, REGCM_GPR32 } },
        },
        [TEMPLATE_RDMSR] = {
                .lhs = {
                        [0] = { REG_EAX, REGCM_GPR32 },
                        [1] = { REG_EDX, REGCM_GPR32 },
                },
                .rhs = { [0] = { REG_ECX, REGCM_GPR32 } },
        },
        [TEMPLATE_WRMSR] = {
                .rhs = {
                        [0] = { REG_ECX, REGCM_GPR32 },
                        [1] = { REG_EAX, REGCM_GPR32 },
                        [2] = { REG_EDX, REGCM_GPR32 },
                },
        },
        [TEMPLATE_UMUL8] = {
                .lhs = { [0] = { REG_AX, REGCM_GPR16 } },
                .rhs = {
                        [0] = { REG_AL, REGCM_GPR8_LO },
                        [1] = { REG_UNSET, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_UMUL16] = {
                .lhs = { [0] = { REG_DXAX, REGCM_DIVIDEND32 } },
                .rhs = {
                        [0] = { REG_AX, REGCM_GPR16 },
                        [1] = { REG_UNSET, REGCM_GPR16 },
                },
        },
        [TEMPLATE_UMUL32] = {
                .lhs = { [0] = { REG_EDXEAX, REGCM_DIVIDEND64 } },
                .rhs = {
                        [0] = { REG_EAX, REGCM_GPR32 },
                        [1] = { REG_UNSET, REGCM_GPR32 },
                },
        },
        [TEMPLATE_DIV8] = {
                .lhs = {
                        [0] = { REG_AL, REGCM_GPR8_LO },
                        [1] = { REG_AH, REGCM_GPR8 },
                },
                .rhs = {
                        [0] = { REG_AX, REGCM_GPR16 },
                        [1] = { REG_UNSET, REGCM_GPR8_LO },
                },
        },
        [TEMPLATE_DIV16] = {
                .lhs = {
                        [0] = { REG_AX, REGCM_GPR16 },
                        [1] = { REG_DX, REGCM_GPR16 },
                },
                .rhs = {
                        [0] = { REG_DXAX, REGCM_DIVIDEND32 },
                        [1] = { REG_UNSET, REGCM_GPR16 },
                },
        },
        [TEMPLATE_DIV32] = {
                .lhs = {
                        [0] = { REG_EAX, REGCM_GPR32 },
                        [1] = { REG_EDX, REGCM_GPR32 },
                },
                .rhs = {
                        [0] = { REG_EDXEAX, REGCM_DIVIDEND64 },
                        [1] = { REG_UNSET, REGCM_GPR32 },
                },
        },
};

static void fixup_branch(struct compile_state *state,
        struct triple *branch, int jmp_op, int cmp_op, struct type *cmp_type,
        struct triple *left, struct triple *right)
{
        struct triple *test;
        if (!left) {
                internal_error(state, branch, "no branch test?");
        }
        test = pre_triple(state, branch,
                cmp_op, cmp_type, left, right);
        test->template_id = TEMPLATE_TEST32;
        if (cmp_op == OP_CMP) {
                test->template_id = TEMPLATE_CMP32_REG;
                if (get_imm32(test, &RHS(test, 1))) {
                        test->template_id = TEMPLATE_CMP32_IMM;
                }
        }
        use_triple(RHS(test, 0), test);
        use_triple(RHS(test, 1), test);
        unuse_triple(RHS(branch, 0), branch);
        RHS(branch, 0) = test;
        branch->op = jmp_op;
        branch->template_id = TEMPLATE_JMP;
        use_triple(RHS(branch, 0), branch);
}

static void fixup_branches(struct compile_state *state,
        struct triple *cmp, struct triple *use, int jmp_op)
{
        struct triple_set *entry, *next;
        for(entry = use->use; entry; entry = next) {
                next = entry->next;
                if (entry->member->op == OP_COPY) {
                        fixup_branches(state, cmp, entry->member, jmp_op);
                }
                else if (entry->member->op == OP_CBRANCH) {
                        struct triple *branch;
                        struct triple *left, *right;
                        left = right = 0;
                        left = RHS(cmp, 0);
                        if (cmp->rhs > 1) {
                                right = RHS(cmp, 1);
                        }
                        branch = entry->member;
                        fixup_branch(state, branch, jmp_op,
                                cmp->op, cmp->type, left, right);
                }
        }
}

static void bool_cmp(struct compile_state *state,
        struct triple *ins, int cmp_op, int jmp_op, int set_op)
{
        struct triple_set *entry, *next;
        struct triple *set, *convert;

        /* Put a barrier up before the cmp which preceeds the
         * copy instruction.  If a set actually occurs this gives
         * us a chance to move variables in registers out of the way.
         */

        /* Modify the comparison operator */
        ins->op = cmp_op;
        ins->template_id = TEMPLATE_TEST32;
        if (cmp_op == OP_CMP) {
                ins->template_id = TEMPLATE_CMP32_REG;
                if (get_imm32(ins, &RHS(ins, 1))) {
                        ins->template_id =  TEMPLATE_CMP32_IMM;
                }
        }
        /* Generate the instruction sequence that will transform the
         * result of the comparison into a logical value.
         */
        set = post_triple(state, ins, set_op, &uchar_type, ins, 0);
        use_triple(ins, set);
        set->template_id = TEMPLATE_SET;

        convert = set;
        if (!equiv_types(ins->type, set->type)) {
                convert = post_triple(state, set, OP_CONVERT, ins->type, set, 0);
                use_triple(set, convert);
                convert->template_id = TEMPLATE_COPY32_REG;
        }

        for(entry = ins->use; entry; entry = next) {
                next = entry->next;
                if (entry->member == set) {
                        continue;
                }
                replace_rhs_use(state, ins, convert, entry->member);
        }
        fixup_branches(state, ins, convert, jmp_op);
}

struct reg_info arch_reg_lhs(struct compile_state *state, struct triple *ins, int index)
{
        struct ins_template *template;
        struct reg_info result;
        int zlhs;
        if (ins->op == OP_PIECE) {
                index = ins->u.cval;
                ins = MISC(ins, 0);
        }
        zlhs = ins->lhs;
        if (triple_is_def(state, ins)) {
                zlhs = 1;
        }
        if (index >= zlhs) {
                internal_error(state, ins, "index %d out of range for %s",
                        index, tops(ins->op));
        }
        switch(ins->op) {
        case OP_ASM:
                template = &ins->u.ainfo->tmpl;
                break;
        default:
                if (ins->template_id > LAST_TEMPLATE) {
                        internal_error(state, ins, "bad template number %d",
                                ins->template_id);
                }
                template = &templates[ins->template_id];
                break;
        }
        result = template->lhs[index];
        result.regcm = arch_regcm_normalize(state, result.regcm);
        if (result.reg != REG_UNNEEDED) {
                result.regcm &= ~(REGCM_IMM32 | REGCM_IMM16 | REGCM_IMM8);
        }
        if (result.regcm == 0) {
                internal_error(state, ins, "lhs %d regcm == 0", index);
        }
        return result;
}

struct reg_info arch_reg_rhs(struct compile_state *state, struct triple *ins, int index)
{
        struct reg_info result;
        struct ins_template *template;
        if ((index > ins->rhs) ||
                (ins->op == OP_PIECE)) {
                internal_error(state, ins, "index %d out of range for %s\n",
                        index, tops(ins->op));
        }
        switch(ins->op) {
        case OP_ASM:
                template = &ins->u.ainfo->tmpl;
                break;
        case OP_PHI:
                index = 0;
                /* Fall through */
        default:
                if (ins->template_id > LAST_TEMPLATE) {
                        internal_error(state, ins, "bad template number %d",
                                ins->template_id);
                }
                template = &templates[ins->template_id];
                break;
        }
        result = template->rhs[index];
        result.regcm = arch_regcm_normalize(state, result.regcm);
        if (result.regcm == 0) {
                internal_error(state, ins, "rhs %d regcm == 0", index);
        }
        return result;
}

static struct triple *mod_div(struct compile_state *state,
        struct triple *ins, int div_op, int index)
{
        struct triple *div, *piece1;

        /* Generate the appropriate division instruction */
        div = post_triple(state, ins, div_op, ins->type, 0, 0);
        RHS(div, 0) = RHS(ins, 0);
        RHS(div, 1) = RHS(ins, 1);
        piece1 = LHS(div, 1);
        div->template_id  = TEMPLATE_DIV32;
        use_triple(RHS(div, 0), div);
        use_triple(RHS(div, 1), div);
        use_triple(LHS(div, 0), div);
        use_triple(LHS(div, 1), div);

        /* Replate uses of ins with the appropriate piece of the div */
        propagate_use(state, ins, LHS(div, index));
        release_triple(state, ins);

        /* Return the address of the next instruction */
        return piece1->next;
}

static int noop_adecl(struct triple *adecl)
{
        struct triple_set *use;
        /* It's a noop if it doesn't specify stoorage */
        if (adecl->lhs == 0) {
                return 1;
        }
        /* Is the adecl used? If not it's a noop */
        for(use = adecl->use; use ; use = use->next) {
                if ((use->member->op != OP_PIECE) ||
                        (MISC(use->member, 0) != adecl)) {
                        return 0;
                }
        }
        return 1;
}

static struct triple *x86_deposit(struct compile_state *state, struct triple *ins)
{
        struct triple *mask, *nmask, *shift;
        struct triple *val, *val_mask, *val_shift;
        struct triple *targ, *targ_mask;
        struct triple *new;
        ulong_t the_mask, the_nmask;

        targ = RHS(ins, 0);
        val = RHS(ins, 1);

        /* Get constant for the mask value */
        the_mask = 1;
        the_mask <<= ins->u.bitfield.size;
        the_mask -= 1;
        the_mask <<= ins->u.bitfield.offset;
        mask = pre_triple(state, ins, OP_INTCONST, &uint_type, 0, 0);
        mask->u.cval = the_mask;

        /* Get the inverted mask value */
        the_nmask = ~the_mask;
        nmask = pre_triple(state, ins, OP_INTCONST, &uint_type, 0, 0);
        nmask->u.cval = the_nmask;

        /* Get constant for the shift value */
        shift = pre_triple(state, ins, OP_INTCONST, &uint_type, 0, 0);
        shift->u.cval = ins->u.bitfield.offset;

        /* Shift and mask the source value */
        val_shift = val;
        if (shift->u.cval != 0) {
                val_shift = pre_triple(state, ins, OP_SL, val->type, val, shift);
                use_triple(val, val_shift);
                use_triple(shift, val_shift);
        }
        val_mask = val_shift;
        if (is_signed(val->type)) {
                val_mask = pre_triple(state, ins, OP_AND, val->type, val_shift, mask);
                use_triple(val_shift, val_mask);
                use_triple(mask, val_mask);
        }

        /* Mask the target value */
        targ_mask = pre_triple(state, ins, OP_AND, targ->type, targ, nmask);
        use_triple(targ, targ_mask);
        use_triple(nmask, targ_mask);

        /* Now combined them together */
        new = pre_triple(state, ins, OP_OR, targ->type, targ_mask, val_mask);
        use_triple(targ_mask, new);
        use_triple(val_mask, new);

        /* Move all of the users over to the new expression */
        propagate_use(state, ins, new);

        /* Delete the original triple */
        release_triple(state, ins);

        /* Restart the transformation at mask */
        return mask;
}

static struct triple *x86_extract(struct compile_state *state, struct triple *ins)
{
        struct triple *mask, *shift;
        struct triple *val, *val_mask, *val_shift;
        ulong_t the_mask;

        val = RHS(ins, 0);

        /* Get constant for the mask value */
        the_mask = 1;
        the_mask <<= ins->u.bitfield.size;
        the_mask -= 1;
        mask = pre_triple(state, ins, OP_INTCONST, &int_type, 0, 0);
        mask->u.cval = the_mask;

        /* Get constant for the right shift value */
        shift = pre_triple(state, ins, OP_INTCONST, &int_type, 0, 0);
        shift->u.cval = ins->u.bitfield.offset;

        /* Shift arithmetic right, to correct the sign */
        val_shift = val;
        if (shift->u.cval != 0) {
                int op;
                if (ins->op == OP_SEXTRACT) {
                        op = OP_SSR;
                } else {
                        op = OP_USR;
                }
                val_shift = pre_triple(state, ins, op, val->type, val, shift);
                use_triple(val, val_shift);
                use_triple(shift, val_shift);
        }

        /* Finally mask the value */
        val_mask = pre_triple(state, ins, OP_AND, ins->type, val_shift, mask);
        use_triple(val_shift, val_mask);
        use_triple(mask,      val_mask);

        /* Move all of the users over to the new expression */
        propagate_use(state, ins, val_mask);

        /* Release the original instruction */
        release_triple(state, ins);

        return mask;

}

static struct triple *transform_to_arch_instruction(
        struct compile_state *state, struct triple *ins)
{
        /* Transform from generic 3 address instructions
         * to archtecture specific instructions.
         * And apply architecture specific constraints to instructions.
         * Copies are inserted to preserve the register flexibility
         * of 3 address instructions.
         */
        struct triple *next, *value;
        size_t size;
        next = ins->next;
        switch(ins->op) {
        case OP_INTCONST:
                ins->template_id = TEMPLATE_INTCONST32;
                if (ins->u.cval < 256) {
                        ins->template_id = TEMPLATE_INTCONST8;
                }
                break;
        case OP_ADDRCONST:
                ins->template_id = TEMPLATE_INTCONST32;
                break;
        case OP_UNKNOWNVAL:
                ins->template_id = TEMPLATE_UNKNOWNVAL;
                break;
        case OP_NOOP:
        case OP_SDECL:
        case OP_BLOBCONST:
        case OP_LABEL:
                ins->template_id = TEMPLATE_NOP;
                break;
        case OP_COPY:
        case OP_CONVERT:
                size = size_of(state, ins->type);
                value = RHS(ins, 0);
                if (is_imm8(value) && (size <= SIZEOF_I8)) {
                        ins->template_id = TEMPLATE_COPY_IMM8;
                }
                else if (is_imm16(value) && (size <= SIZEOF_I16)) {
                        ins->template_id = TEMPLATE_COPY_IMM16;
                }
                else if (is_imm32(value) && (size <= SIZEOF_I32)) {
                        ins->template_id = TEMPLATE_COPY_IMM32;
                }
                else if (is_const(value)) {
                        internal_error(state, ins, "bad constant passed to copy");
                }
                else if (size <= SIZEOF_I8) {
                        ins->template_id = TEMPLATE_COPY8_REG;
                }
                else if (size <= SIZEOF_I16) {
                        ins->template_id = TEMPLATE_COPY16_REG;
                }
                else if (size <= SIZEOF_I32) {
                        ins->template_id = TEMPLATE_COPY32_REG;
                }
                else {
                        internal_error(state, ins, "bad type passed to copy");
                }
                break;
        case OP_PHI:
                size = size_of(state, ins->type);
                if (size <= SIZEOF_I8) {
                        ins->template_id = TEMPLATE_PHI8;
                }
                else if (size <= SIZEOF_I16) {
                        ins->template_id = TEMPLATE_PHI16;
                }
                else if (size <= SIZEOF_I32) {
                        ins->template_id = TEMPLATE_PHI32;
                }
                else {
                        internal_error(state, ins, "bad type passed to phi");
                }
                break;
        case OP_ADECL:
                /* Adecls should always be treated as dead code and
                 * removed.  If we are not optimizing they may linger.
                 */
                if (!noop_adecl(ins)) {
                        internal_error(state, ins, "adecl remains?");
                }
                ins->template_id = TEMPLATE_NOP;
                next = after_lhs(state, ins);
                break;
        case OP_STORE:
                switch(ins->type->type & TYPE_MASK) {
                case TYPE_CHAR:    case TYPE_UCHAR:
                        ins->template_id = TEMPLATE_STORE8;
                        break;
                case TYPE_SHORT:   case TYPE_USHORT:
                        ins->template_id = TEMPLATE_STORE16;
                        break;
                case TYPE_INT:     case TYPE_UINT:
                case TYPE_LONG:    case TYPE_ULONG:
                case TYPE_POINTER:
                        ins->template_id = TEMPLATE_STORE32;
                        break;
                default:
                        internal_error(state, ins, "unknown type in store");
                        break;
                }
                break;
        case OP_LOAD:
                switch(ins->type->type & TYPE_MASK) {
                case TYPE_CHAR:   case TYPE_UCHAR:
                case TYPE_SHORT:  case TYPE_USHORT:
                case TYPE_INT:    case TYPE_UINT:
                case TYPE_LONG:   case TYPE_ULONG:
                case TYPE_POINTER:
                        break;
                default:
                        internal_error(state, ins, "unknown type in load");
                        break;
                }
                ins->template_id = TEMPLATE_LOAD32;
                break;
        case OP_ADD:
        case OP_SUB:
        case OP_AND:
        case OP_XOR:
        case OP_OR:
        case OP_SMUL:
                ins->template_id = TEMPLATE_BINARY32_REG;
                if (get_imm32(ins, &RHS(ins, 1))) {
                        ins->template_id = TEMPLATE_BINARY32_IMM;
                }
                break;
        case OP_SDIVT:
        case OP_UDIVT:
                ins->template_id = TEMPLATE_DIV32;
                next = after_lhs(state, ins);
                break;
        case OP_UMUL:
                ins->template_id = TEMPLATE_UMUL32;
                break;
        case OP_UDIV:
                next = mod_div(state, ins, OP_UDIVT, 0);
                break;
        case OP_SDIV:
                next = mod_div(state, ins, OP_SDIVT, 0);
                break;
        case OP_UMOD:
                next = mod_div(state, ins, OP_UDIVT, 1);
                break;
        case OP_SMOD:
                next = mod_div(state, ins, OP_SDIVT, 1);
                break;
        case OP_SL:
        case OP_SSR:
        case OP_USR:
                ins->template_id = TEMPLATE_SL32_CL;
                if (get_imm8(ins, &RHS(ins, 1))) {
                        ins->template_id = TEMPLATE_SL32_IMM;
                } else if (size_of(state, RHS(ins, 1)->type) > SIZEOF_CHAR) {
                        typed_pre_copy(state, &uchar_type, ins, 1);
                }
                break;
        case OP_INVERT:
        case OP_NEG:
                ins->template_id = TEMPLATE_UNARY32;
                break;
        case OP_EQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_EQ, OP_SET_EQ);
                break;
        case OP_NOTEQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_NOTEQ, OP_SET_NOTEQ);
                break;
        case OP_SLESS:
                bool_cmp(state, ins, OP_CMP, OP_JMP_SLESS, OP_SET_SLESS);
                break;
        case OP_ULESS:
                bool_cmp(state, ins, OP_CMP, OP_JMP_ULESS, OP_SET_ULESS);
                break;
        case OP_SMORE:
                bool_cmp(state, ins, OP_CMP, OP_JMP_SMORE, OP_SET_SMORE);
                break;
        case OP_UMORE:
                bool_cmp(state, ins, OP_CMP, OP_JMP_UMORE, OP_SET_UMORE);
                break;
        case OP_SLESSEQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_SLESSEQ, OP_SET_SLESSEQ);
                break;
        case OP_ULESSEQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_ULESSEQ, OP_SET_ULESSEQ);
                break;
        case OP_SMOREEQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_SMOREEQ, OP_SET_SMOREEQ);
                break;
        case OP_UMOREEQ:
                bool_cmp(state, ins, OP_CMP, OP_JMP_UMOREEQ, OP_SET_UMOREEQ);
                break;
        case OP_LTRUE:
                bool_cmp(state, ins, OP_TEST, OP_JMP_NOTEQ, OP_SET_NOTEQ);
                break;
        case OP_LFALSE:
                bool_cmp(state, ins, OP_TEST, OP_JMP_EQ, OP_SET_EQ);
                break;
        case OP_BRANCH:
                ins->op = OP_JMP;
                ins->template_id = TEMPLATE_NOP;
                break;
        case OP_CBRANCH:
                fixup_branch(state, ins, OP_JMP_NOTEQ, OP_TEST,
                        RHS(ins, 0)->type, RHS(ins, 0), 0);
                break;
        case OP_CALL:
                ins->template_id = TEMPLATE_NOP;
                break;
        case OP_RET:
                ins->template_id = TEMPLATE_RET;
                break;
        case OP_INB:
        case OP_INW:
        case OP_INL:
                switch(ins->op) {
                case OP_INB: ins->template_id = TEMPLATE_INB_DX; break;
                case OP_INW: ins->template_id = TEMPLATE_INW_DX; break;
                case OP_INL: ins->template_id = TEMPLATE_INL_DX; break;
                }
                if (get_imm8(ins, &RHS(ins, 0))) {
                        ins->template_id += 1;
                }
                break;
        case OP_OUTB:
        case OP_OUTW:
        case OP_OUTL:
                switch(ins->op) {
                case OP_OUTB: ins->template_id = TEMPLATE_OUTB_DX; break;
                case OP_OUTW: ins->template_id = TEMPLATE_OUTW_DX; break;
                case OP_OUTL: ins->template_id = TEMPLATE_OUTL_DX; break;
                }
                if (get_imm8(ins, &RHS(ins, 1))) {
                        ins->template_id += 1;
                }
                break;
        case OP_BSF:
        case OP_BSR:
                ins->template_id = TEMPLATE_BSF;
                break;
        case OP_RDMSR:
                ins->template_id = TEMPLATE_RDMSR;
                next = after_lhs(state, ins);
                break;
        case OP_WRMSR:
                ins->template_id = TEMPLATE_WRMSR;
                break;
        case OP_HLT:
                ins->template_id = TEMPLATE_NOP;
                break;
        case OP_ASM:
                ins->template_id = TEMPLATE_NOP;
                next = after_lhs(state, ins);
                break;
                /* Already transformed instructions */
        case OP_TEST:
                ins->template_id = TEMPLATE_TEST32;
                break;
        case OP_CMP:
                ins->template_id = TEMPLATE_CMP32_REG;
                if (get_imm32(ins, &RHS(ins, 1))) {
                        ins->template_id = TEMPLATE_CMP32_IMM;
                }
                break;
        case OP_JMP:
                ins->template_id = TEMPLATE_NOP;
                break;
        case OP_JMP_EQ:      case OP_JMP_NOTEQ:
        case OP_JMP_SLESS:   case OP_JMP_ULESS:
        case OP_JMP_SMORE:   case OP_JMP_UMORE:
        case OP_JMP_SLESSEQ: case OP_JMP_ULESSEQ:
        case OP_JMP_SMOREEQ: case OP_JMP_UMOREEQ:
                ins->template_id = TEMPLATE_JMP;
                break;
        case OP_SET_EQ:      case OP_SET_NOTEQ:
        case OP_SET_SLESS:   case OP_SET_ULESS:
        case OP_SET_SMORE:   case OP_SET_UMORE:
        case OP_SET_SLESSEQ: case OP_SET_ULESSEQ:
        case OP_SET_SMOREEQ: case OP_SET_UMOREEQ:
                ins->template_id = TEMPLATE_SET;
                break;
        case OP_DEPOSIT:
                next = x86_deposit(state, ins);
                break;
        case OP_SEXTRACT:
        case OP_UEXTRACT:
                next = x86_extract(state, ins);
                break;
                /* Unhandled instructions */
        case OP_PIECE:
        default:
                internal_error(state, ins, "unhandled ins: %d %s",
                        ins->op, tops(ins->op));
                break;
        }
        return next;
}

static long next_label(struct compile_state *state)
{
        static long label_counter = 1000;
        return ++label_counter;
}
static void generate_local_labels(struct compile_state *state)
{
        struct triple *first, *label;
        first = state->first;
        label = first;
        do {
                if ((label->op == OP_LABEL) ||
                        (label->op == OP_SDECL)) {
                        if (label->use) {
                                label->u.cval = next_label(state);
                        } else {
                                label->u.cval = 0;
                        }

                }
                label = label->next;
        } while(label != first);
}

static int check_reg(struct compile_state *state,
        struct triple *triple, int classes)
{
        unsigned mask;
        int reg;
        reg = ID_REG(triple->id);
        if (reg == REG_UNSET) {
                internal_error(state, triple, "register not set");
        }
        mask = arch_reg_regcm(state, reg);
        if (!(classes & mask)) {
                internal_error(state, triple, "reg %d in wrong class",
                        reg);
        }
        return reg;
}


#if REG_XMM7 != 44
#error "Registers have renumberd fix arch_reg_str"
#endif
static const char *arch_regs[] = {
        "%unset",
        "%unneeded",
        "%eflags",
        "%al", "%bl", "%cl", "%dl", "%ah", "%bh", "%ch", "%dh",
        "%ax", "%bx", "%cx", "%dx", "%si", "%di", "%bp", "%sp",
        "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi", "%ebp", "%esp",
        "%edx:%eax",
        "%dx:%ax",
        "%mm0", "%mm1", "%mm2", "%mm3", "%mm4", "%mm5", "%mm6", "%mm7",
        "%xmm0", "%xmm1", "%xmm2", "%xmm3",
        "%xmm4", "%xmm5", "%xmm6", "%xmm7",
};
static const char *arch_reg_str(int reg)
{
        if (!((reg >= REG_EFLAGS) && (reg <= REG_XMM7))) {
                reg = 0;
        }
        return arch_regs[reg];
}

static const char *reg(struct compile_state *state, struct triple *triple,
        int classes)
{
        int reg;
        reg = check_reg(state, triple, classes);
        return arch_reg_str(reg);
}

static int arch_reg_size(int reg)
{
        int size;
        size = 0;
        if (reg == REG_EFLAGS) {
                size = 32;
        }
        else if ((reg >= REG_AL) && (reg <= REG_DH)) {
                size = 8;
        }
        else if ((reg >= REG_AX) && (reg <= REG_SP)) {
                size = 16;
        }
        else if ((reg >= REG_EAX) && (reg <= REG_ESP)) {
                size = 32;
        }
        else if (reg == REG_EDXEAX) {
                size = 64;
        }
        else if (reg == REG_DXAX) {
                size = 32;
        }
        else if ((reg >= REG_MMX0) && (reg <= REG_MMX7)) {
                size = 64;
        }
        else if ((reg >= REG_XMM0) && (reg <= REG_XMM7)) {
                size = 128;
        }
        return size;
}

static int reg_size(struct compile_state *state, struct triple *ins)
{
        int reg;
        reg = ID_REG(ins->id);
        if (reg == REG_UNSET) {
                internal_error(state, ins, "register not set");
        }
        return arch_reg_size(reg);
}



const char *type_suffix(struct compile_state *state, struct type *type)
{
        const char *suffix;
        switch(size_of(state, type)) {
        case SIZEOF_I8:  suffix = "b"; break;
        case SIZEOF_I16: suffix = "w"; break;
        case SIZEOF_I32: suffix = "l"; break;
        default:
                internal_error(state, 0, "unknown suffix");
                suffix = 0;
                break;
        }
        return suffix;
}

static void print_const_val(
        struct compile_state *state, struct triple *ins, FILE *fp)
{
        switch(ins->op) {
        case OP_INTCONST:
                fprintf(fp, " $%ld ",
                        (long)(ins->u.cval));
                break;
        case OP_ADDRCONST:
                if ((MISC(ins, 0)->op != OP_SDECL) &&
                        (MISC(ins, 0)->op != OP_LABEL))
                {
                        internal_error(state, ins, "bad base for addrconst");
                }
                if (MISC(ins, 0)->u.cval <= 0) {
                        internal_error(state, ins, "unlabeled constant");
                }
                fprintf(fp, " $L%s%lu+%lu ",
                        state->compiler->label_prefix,
                        (unsigned long)(MISC(ins, 0)->u.cval),
                        (unsigned long)(ins->u.cval));
                break;
        default:
                internal_error(state, ins, "unknown constant type");
                break;
        }
}

static void print_const(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        switch(ins->op) {
        case OP_INTCONST:
                switch(ins->type->type & TYPE_MASK) {
                case TYPE_CHAR:
                case TYPE_UCHAR:
                        fprintf(fp, ".byte 0x%02lx\n",
                                (unsigned long)(ins->u.cval));
                        break;
                case TYPE_SHORT:
                case TYPE_USHORT:
                        fprintf(fp, ".short 0x%04lx\n",
                                (unsigned long)(ins->u.cval));
                        break;
                case TYPE_INT:
                case TYPE_UINT:
                case TYPE_LONG:
                case TYPE_ULONG:
                case TYPE_POINTER:
                        fprintf(fp, ".int %lu\n",
                                (unsigned long)(ins->u.cval));
                        break;
                default:
                        fprintf(state->errout, "type: ");
                        name_of(state->errout, ins->type);
                        fprintf(state->errout, "\n");
                        internal_error(state, ins, "Unknown constant type. Val: %lu",
                                (unsigned long)(ins->u.cval));
                }

                break;
        case OP_ADDRCONST:
                if ((MISC(ins, 0)->op != OP_SDECL) &&
                        (MISC(ins, 0)->op != OP_LABEL)) {
                        internal_error(state, ins, "bad base for addrconst");
                }
                if (MISC(ins, 0)->u.cval <= 0) {
                        internal_error(state, ins, "unlabeled constant");
                }
                fprintf(fp, ".int L%s%lu+%lu\n",
                        state->compiler->label_prefix,
                        (unsigned long)(MISC(ins, 0)->u.cval),
                        (unsigned long)(ins->u.cval));
                break;
        case OP_BLOBCONST:
        {
                unsigned char *blob;
                size_t size, i;
                size = size_of_in_bytes(state, ins->type);
                blob = ins->u.blob;
                for(i = 0; i < size; i++) {
                        fprintf(fp, ".byte 0x%02x\n",
                                blob[i]);
                }
                break;
        }
        default:
                internal_error(state, ins, "Unknown constant type");
                break;
        }
}

#define TEXT_SECTION ".rom.text"
#define DATA_SECTION ".rom.data"

static long get_const_pool_ref(
        struct compile_state *state, struct triple *ins, size_t size, FILE *fp)
{
        size_t fill_bytes;
        long ref;
        ref = next_label(state);
        fprintf(fp, ".section \"" DATA_SECTION "\"\n");
        fprintf(fp, ".balign %ld\n", (long int)align_of_in_bytes(state, ins->type));
        fprintf(fp, "L%s%lu:\n", state->compiler->label_prefix, ref);
        print_const(state, ins, fp);
        fill_bytes = bits_to_bytes(size - size_of(state, ins->type));
        if (fill_bytes) {
                fprintf(fp, ".fill %ld, 1, 0\n", (long int)fill_bytes);
        }
        fprintf(fp, ".section \"" TEXT_SECTION "\"\n");
        return ref;
}

static long get_mask_pool_ref(
        struct compile_state *state, struct triple *ins, unsigned long mask, FILE *fp)
{
        long ref;
        if (mask == 0xff) {
                ref = 1;
        }
        else if (mask == 0xffff) {
                ref = 2;
        }
        else {
                internal_error(state, ins, "unhandled mask value");
        }
        return ref;
}

static void print_binary_op(struct compile_state *state,
        const char *op, struct triple *ins, FILE *fp)
{
        unsigned mask;
        mask = REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO;
        if (ID_REG(RHS(ins, 0)->id) != ID_REG(ins->id)) {
                internal_error(state, ins, "invalid register assignment");
        }
        if (is_const(RHS(ins, 1))) {
                fprintf(fp, "\t%s ", op);
                print_const_val(state, RHS(ins, 1), fp);
                fprintf(fp, ", %s\n",
                        reg(state, RHS(ins, 0), mask));
        }
        else {
                unsigned lmask, rmask;
                int lreg, rreg;
                lreg = check_reg(state, RHS(ins, 0), mask);
                rreg = check_reg(state, RHS(ins, 1), mask);
                lmask = arch_reg_regcm(state, lreg);
                rmask = arch_reg_regcm(state, rreg);
                mask = lmask & rmask;
                fprintf(fp, "\t%s %s, %s\n",
                        op,
                        reg(state, RHS(ins, 1), mask),
                        reg(state, RHS(ins, 0), mask));
        }
}
static void print_unary_op(struct compile_state *state,
        const char *op, struct triple *ins, FILE *fp)
{
        unsigned mask;
        mask = REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO;
        fprintf(fp, "\t%s %s\n",
                op,
                reg(state, RHS(ins, 0), mask));
}

static void print_op_shift(struct compile_state *state,
        const char *op, struct triple *ins, FILE *fp)
{
        unsigned mask;
        mask = REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO;
        if (ID_REG(RHS(ins, 0)->id) != ID_REG(ins->id)) {
                internal_error(state, ins, "invalid register assignment");
        }
        if (is_const(RHS(ins, 1))) {
                fprintf(fp, "\t%s ", op);
                print_const_val(state, RHS(ins, 1), fp);
                fprintf(fp, ", %s\n",
                        reg(state, RHS(ins, 0), mask));
        }
        else {
                fprintf(fp, "\t%s %s, %s\n",
                        op,
                        reg(state, RHS(ins, 1), REGCM_GPR8_LO),
                        reg(state, RHS(ins, 0), mask));
        }
}

static void print_op_in(struct compile_state *state, struct triple *ins, FILE *fp)
{
        const char *op;
        int mask;
        int dreg;
        switch(ins->op) {
        case OP_INB: op = "inb", mask = REGCM_GPR8_LO; break;
        case OP_INW: op = "inw", mask = REGCM_GPR16; break;
        case OP_INL: op = "inl", mask = REGCM_GPR32; break;
        default:
                internal_error(state, ins, "not an in operation");
                op = 0;
                break;
        }
        dreg = check_reg(state, ins, mask);
        if (!reg_is_reg(state, dreg, REG_EAX)) {
                internal_error(state, ins, "dst != %%eax");
        }
        if (is_const(RHS(ins, 0))) {
                fprintf(fp, "\t%s ", op);
                print_const_val(state, RHS(ins, 0), fp);
                fprintf(fp, ", %s\n",
                        reg(state, ins, mask));
        }
        else {
                int addr_reg;
                addr_reg = check_reg(state, RHS(ins, 0), REGCM_GPR16);
                if (!reg_is_reg(state, addr_reg, REG_DX)) {
                        internal_error(state, ins, "src != %%dx");
                }
                fprintf(fp, "\t%s %s, %s\n",
                        op,
                        reg(state, RHS(ins, 0), REGCM_GPR16),
                        reg(state, ins, mask));
        }
}

static void print_op_out(struct compile_state *state, struct triple *ins, FILE *fp)
{
        const char *op;
        int mask;
        int lreg;
        switch(ins->op) {
        case OP_OUTB: op = "outb", mask = REGCM_GPR8_LO; break;
        case OP_OUTW: op = "outw", mask = REGCM_GPR16; break;
        case OP_OUTL: op = "outl", mask = REGCM_GPR32; break;
        default:
                internal_error(state, ins, "not an out operation");
                op = 0;
                break;
        }
        lreg = check_reg(state, RHS(ins, 0), mask);
        if (!reg_is_reg(state, lreg, REG_EAX)) {
                internal_error(state, ins, "src != %%eax");
        }
        if (is_const(RHS(ins, 1))) {
                fprintf(fp, "\t%s %s,",
                        op, reg(state, RHS(ins, 0), mask));
                print_const_val(state, RHS(ins, 1), fp);
                fprintf(fp, "\n");
        }
        else {
                int addr_reg;
                addr_reg = check_reg(state, RHS(ins, 1), REGCM_GPR16);
                if (!reg_is_reg(state, addr_reg, REG_DX)) {
                        internal_error(state, ins, "dst != %%dx");
                }
                fprintf(fp, "\t%s %s, %s\n",
                        op,
                        reg(state, RHS(ins, 0), mask),
                        reg(state, RHS(ins, 1), REGCM_GPR16));
        }
}

static void print_op_move(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        /* op_move is complex because there are many types
         * of registers we can move between.
         * Because OP_COPY will be introduced in arbitrary locations
         * OP_COPY must not affect flags.
         * OP_CONVERT can change the flags and it is the only operation
         * where it is expected the types in the registers can change.
         */
        int omit_copy = 1; /* Is it o.k. to omit a noop copy? */
        struct triple *dst, *src;
        if (state->arch->features & X86_NOOP_COPY) {
                omit_copy = 0;
        }
        if ((ins->op == OP_COPY) || (ins->op == OP_CONVERT)) {
                src = RHS(ins, 0);
                dst = ins;
        }
        else {
                internal_error(state, ins, "unknown move operation");
                src = dst = 0;
        }
        if (reg_size(state, dst) < size_of(state, dst->type)) {
                internal_error(state, ins, "Invalid destination register");
        }
        if (!equiv_types(src->type, dst->type) && (dst->op == OP_COPY)) {
                fprintf(state->errout, "src type: ");
                name_of(state->errout, src->type);
                fprintf(state->errout, "\n");
                fprintf(state->errout, "dst type: ");
                name_of(state->errout, dst->type);
                fprintf(state->errout, "\n");
                internal_error(state, ins, "Type mismatch for OP_COPY");
        }

        if (!is_const(src)) {
                int src_reg, dst_reg;
                int src_regcm, dst_regcm;
                src_reg   = ID_REG(src->id);
                dst_reg   = ID_REG(dst->id);
                src_regcm = arch_reg_regcm(state, src_reg);
                dst_regcm = arch_reg_regcm(state, dst_reg);
                /* If the class is the same just move the register */
                if (src_regcm & dst_regcm &
                        (REGCM_GPR8_LO | REGCM_GPR16 | REGCM_GPR32)) {
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmov %s, %s\n",
                                        reg(state, src, src_regcm),
                                        reg(state, dst, dst_regcm));
                        }
                }
                /* Move 32bit to 16bit */
                else if ((src_regcm & REGCM_GPR32) &&
                        (dst_regcm & REGCM_GPR16)) {
                        src_reg = (src_reg - REGC_GPR32_FIRST) + REGC_GPR16_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmovw %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                /* Move from 32bit gprs to 16bit gprs */
                else if ((src_regcm & REGCM_GPR32) &&
                        (dst_regcm & REGCM_GPR16)) {
                        dst_reg = (dst_reg - REGC_GPR16_FIRST) + REGC_GPR32_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmov %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                /* Move 32bit to 8bit */
                else if ((src_regcm & REGCM_GPR32_8) &&
                        (dst_regcm & REGCM_GPR8_LO))
                {
                        src_reg = (src_reg - REGC_GPR32_8_FIRST) + REGC_GPR8_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmovb %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                /* Move 16bit to 8bit */
                else if ((src_regcm & REGCM_GPR16_8) &&
                        (dst_regcm & REGCM_GPR8_LO))
                {
                        src_reg = (src_reg - REGC_GPR16_8_FIRST) + REGC_GPR8_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmovb %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                /* Move 8/16bit to 16/32bit */
                else if ((src_regcm & (REGCM_GPR8_LO | REGCM_GPR16)) &&
                        (dst_regcm & (REGCM_GPR16 | REGCM_GPR32))) {
                        const char *op;
                        op = is_signed(src->type)? "movsx": "movzx";
                        fprintf(fp, "\t%s %s, %s\n",
                                op,
                                reg(state, src, src_regcm),
                                reg(state, dst, dst_regcm));
                }
                /* Move between sse registers */
                else if ((src_regcm & dst_regcm & REGCM_XMM)) {
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmovdqa %s, %s\n",
                                        reg(state, src, src_regcm),
                                        reg(state, dst, dst_regcm));
                        }
                }
                /* Move between mmx registers */
                else if ((src_regcm & dst_regcm & REGCM_MMX)) {
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmovq %s, %s\n",
                                        reg(state, src, src_regcm),
                                        reg(state, dst, dst_regcm));
                        }
                }
                /* Move from sse to mmx registers */
                else if ((src_regcm & REGCM_XMM) && (dst_regcm & REGCM_MMX)) {
                        fprintf(fp, "\tmovdq2q %s, %s\n",
                                reg(state, src, src_regcm),
                                reg(state, dst, dst_regcm));
                }
                /* Move from mmx to sse registers */
                else if ((src_regcm & REGCM_MMX) && (dst_regcm & REGCM_XMM)) {
                        fprintf(fp, "\tmovq2dq %s, %s\n",
                                reg(state, src, src_regcm),
                                reg(state, dst, dst_regcm));
                }
                /* Move between 32bit gprs & mmx/sse registers */
                else if ((src_regcm & (REGCM_GPR32 | REGCM_MMX | REGCM_XMM)) &&
                        (dst_regcm & (REGCM_GPR32 | REGCM_MMX | REGCM_XMM))) {
                        fprintf(fp, "\tmovd %s, %s\n",
                                reg(state, src, src_regcm),
                                reg(state, dst, dst_regcm));
                }
                /* Move from 16bit gprs &  mmx/sse registers */
                else if ((src_regcm & REGCM_GPR16) &&
                        (dst_regcm & (REGCM_MMX | REGCM_XMM))) {
                        const char *op;
                        int mid_reg;
                        op = is_signed(src->type)? "movsx":"movzx";
                        mid_reg = (src_reg - REGC_GPR16_FIRST) + REGC_GPR32_FIRST;
                        fprintf(fp, "\t%s %s, %s\n\tmovd %s, %s\n",
                                op,
                                arch_reg_str(src_reg),
                                arch_reg_str(mid_reg),
                                arch_reg_str(mid_reg),
                                arch_reg_str(dst_reg));
                }
                /* Move from mmx/sse registers to 16bit gprs */
                else if ((src_regcm & (REGCM_MMX | REGCM_XMM)) &&
                        (dst_regcm & REGCM_GPR16)) {
                        dst_reg = (dst_reg - REGC_GPR16_FIRST) + REGC_GPR32_FIRST;
                        fprintf(fp, "\tmovd %s, %s\n",
                                arch_reg_str(src_reg),
                                arch_reg_str(dst_reg));
                }
                /* Move from gpr to 64bit dividend */
                else if ((src_regcm & (REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO))  &&
                        (dst_regcm & REGCM_DIVIDEND64)) {
                        const char *extend;
                        extend = is_signed(src->type)? "cltd":"movl $0, %edx";
                        fprintf(fp, "\tmov %s, %%eax\n\t%s\n",
                                arch_reg_str(src_reg),
                                extend);
                }
                /* Move from 64bit gpr to gpr */
                else if ((src_regcm & REGCM_DIVIDEND64) &&
                        (dst_regcm & (REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO))) {
                        if (dst_regcm & REGCM_GPR32) {
                                src_reg = REG_EAX;
                        }
                        else if (dst_regcm & REGCM_GPR16) {
                                src_reg = REG_AX;
                        }
                        else if (dst_regcm & REGCM_GPR8_LO) {
                                src_reg = REG_AL;
                        }
                        fprintf(fp, "\tmov %s, %s\n",
                                arch_reg_str(src_reg),
                                arch_reg_str(dst_reg));
                }
                /* Move from mmx/sse registers to 64bit gpr */
                else if ((src_regcm & (REGCM_MMX | REGCM_XMM)) &&
                        (dst_regcm & REGCM_DIVIDEND64)) {
                        const char *extend;
                        extend = is_signed(src->type)? "cltd": "movl $0, %edx";
                        fprintf(fp, "\tmovd %s, %%eax\n\t%s\n",
                                arch_reg_str(src_reg),
                                extend);
                }
                /* Move from 64bit gpr to mmx/sse register */
                else if ((src_regcm & REGCM_DIVIDEND64) &&
                        (dst_regcm & (REGCM_XMM | REGCM_MMX))) {
                        fprintf(fp, "\tmovd %%eax, %s\n",
                                arch_reg_str(dst_reg));
                }
#if X86_4_8BIT_GPRS
                /* Move from 8bit gprs to  mmx/sse registers */
                else if ((src_regcm & REGCM_GPR8_LO) && (src_reg <= REG_DL) &&
                        (dst_regcm & (REGCM_MMX | REGCM_XMM))) {
                        const char *op;
                        int mid_reg;
                        op = is_signed(src->type)? "movsx":"movzx";
                        mid_reg = (src_reg - REGC_GPR8_FIRST) + REGC_GPR32_FIRST;
                        fprintf(fp, "\t%s %s, %s\n\tmovd %s, %s\n",
                                op,
                                reg(state, src, src_regcm),
                                arch_reg_str(mid_reg),
                                arch_reg_str(mid_reg),
                                reg(state, dst, dst_regcm));
                }
                /* Move from mmx/sse registers and 8bit gprs */
                else if ((src_regcm & (REGCM_MMX | REGCM_XMM)) &&
                        (dst_regcm & REGCM_GPR8_LO) && (dst_reg <= REG_DL)) {
                        int mid_reg;
                        mid_reg = (dst_reg - REGC_GPR8_FIRST) + REGC_GPR32_FIRST;
                        fprintf(fp, "\tmovd %s, %s\n",
                                reg(state, src, src_regcm),
                                arch_reg_str(mid_reg));
                }
                /* Move from 32bit gprs to 8bit gprs */
                else if ((src_regcm & REGCM_GPR32) &&
                        (dst_regcm & REGCM_GPR8_LO)) {
                        dst_reg = (dst_reg - REGC_GPR8_FIRST) + REGC_GPR32_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmov %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                /* Move from 16bit gprs to 8bit gprs */
                else if ((src_regcm & REGCM_GPR16) &&
                        (dst_regcm & REGCM_GPR8_LO)) {
                        dst_reg = (dst_reg - REGC_GPR8_FIRST) + REGC_GPR16_FIRST;
                        if ((src_reg != dst_reg) || !omit_copy) {
                                fprintf(fp, "\tmov %s, %s\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
#endif /* X86_4_8BIT_GPRS */
                /* Move from %eax:%edx to %eax:%edx */
                else if ((src_regcm & REGCM_DIVIDEND64) &&
                        (dst_regcm & REGCM_DIVIDEND64) &&
                        (src_reg == dst_reg)) {
                        if (!omit_copy) {
                                fprintf(fp, "\t/*mov %s, %s*/\n",
                                        arch_reg_str(src_reg),
                                        arch_reg_str(dst_reg));
                        }
                }
                else {
                        if ((src_regcm & ~REGCM_FLAGS) == 0) {
                                internal_error(state, ins, "attempt to copy from %%eflags!");
                        }
                        internal_error(state, ins, "unknown copy type");
                }
        }
        else {
                size_t dst_size;
                int dst_reg;
                int dst_regcm;
                dst_size = size_of(state, dst->type);
                dst_reg = ID_REG(dst->id);
                dst_regcm = arch_reg_regcm(state, dst_reg);
                if (dst_regcm & (REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO)) {
                        fprintf(fp, "\tmov ");
                        print_const_val(state, src, fp);
                        fprintf(fp, ", %s\n",
                                reg(state, dst, REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO));
                }
                else if (dst_regcm & REGCM_DIVIDEND64) {
                        if (dst_size > SIZEOF_I32) {
                                internal_error(state, ins, "%dbit constant...", dst_size);
                        }
                        fprintf(fp, "\tmov $0, %%edx\n");
                        fprintf(fp, "\tmov ");
                        print_const_val(state, src, fp);
                        fprintf(fp, ", %%eax\n");
                }
                else if (dst_regcm & REGCM_DIVIDEND32) {
                        if (dst_size > SIZEOF_I16) {
                                internal_error(state, ins, "%dbit constant...", dst_size);
                        }
                        fprintf(fp, "\tmov $0, %%dx\n");
                        fprintf(fp, "\tmov ");
                        print_const_val(state, src, fp);
                        fprintf(fp, ", %%ax");
                }
                else if (dst_regcm & (REGCM_XMM | REGCM_MMX)) {
                        long ref;
                        if (dst_size > SIZEOF_I32) {
                                internal_error(state, ins, "%d bit constant...", dst_size);
                        }
                        ref = get_const_pool_ref(state, src, SIZEOF_I32, fp);
                        fprintf(fp, "\tmovd L%s%lu, %s\n",
                                state->compiler->label_prefix, ref,
                                reg(state, dst, (REGCM_XMM | REGCM_MMX)));
                }
                else {
                        internal_error(state, ins, "unknown copy immediate type");
                }
        }
        /* Leave now if this is not a type conversion */
        if (ins->op != OP_CONVERT) {
                return;
        }
        /* Now make certain I have not logically overflowed the destination */
        if ((size_of(state, src->type) > size_of(state, dst->type)) &&
                (size_of(state, dst->type) < reg_size(state, dst)))
        {
                unsigned long mask;
                int dst_reg;
                int dst_regcm;
                if (size_of(state, dst->type) >= 32) {
                        fprintf(state->errout, "dst type: ");
                        name_of(state->errout, dst->type);
                        fprintf(state->errout, "\n");
                        internal_error(state, dst, "unhandled dst type size");
                }
                mask = 1;
                mask <<= size_of(state, dst->type);
                mask -= 1;

                dst_reg = ID_REG(dst->id);
                dst_regcm = arch_reg_regcm(state, dst_reg);

                if (dst_regcm & (REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO)) {
                        fprintf(fp, "\tand $0x%lx, %s\n",
                                mask, reg(state, dst, REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO));
                }
                else if (dst_regcm & REGCM_MMX) {
                        long ref;
                        ref = get_mask_pool_ref(state, dst, mask, fp);
                        fprintf(fp, "\tpand L%s%lu, %s\n",
                                state->compiler->label_prefix, ref,
                                reg(state, dst, REGCM_MMX));
                }
                else if (dst_regcm & REGCM_XMM) {
                        long ref;
                        ref = get_mask_pool_ref(state, dst, mask, fp);
                        fprintf(fp, "\tpand L%s%lu, %s\n",
                                state->compiler->label_prefix, ref,
                                reg(state, dst, REGCM_XMM));
                }
                else {
                        fprintf(state->errout, "dst type: ");
                        name_of(state->errout, dst->type);
                        fprintf(state->errout, "\n");
                        fprintf(state->errout, "dst: %s\n", reg(state, dst, REGCM_ALL));
                        internal_error(state, dst, "failed to trunc value: mask %lx", mask);
                }
        }
        /* Make certain I am properly sign extended */
        if ((size_of(state, src->type) < size_of(state, dst->type)) &&
                (is_signed(src->type)))
        {
                int reg_bits, shift_bits;
                int dst_reg;
                int dst_regcm;

                reg_bits = reg_size(state, dst);
                if (reg_bits > 32) {
                        reg_bits = 32;
                }
                shift_bits = reg_bits - size_of(state, src->type);
                dst_reg = ID_REG(dst->id);
                dst_regcm = arch_reg_regcm(state, dst_reg);

                if (shift_bits < 0) {
                        internal_error(state, dst, "negative shift?");
                }

                if (dst_regcm & (REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO)) {
                        fprintf(fp, "\tshl $%d, %s\n",
                                shift_bits,
                                reg(state, dst, REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO));
                        fprintf(fp, "\tsar $%d, %s\n",
                                shift_bits,
                                reg(state, dst, REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO));
                }
                else if (dst_regcm & (REGCM_MMX | REGCM_XMM)) {
                        fprintf(fp, "\tpslld $%d, %s\n",
                                shift_bits,
                                reg(state, dst, REGCM_MMX | REGCM_XMM));
                        fprintf(fp, "\tpsrad $%d, %s\n",
                                shift_bits,
                                reg(state, dst, REGCM_MMX | REGCM_XMM));
                }
                else {
                        fprintf(state->errout, "dst type: ");
                        name_of(state->errout, dst->type);
                        fprintf(state->errout, "\n");
                        fprintf(state->errout, "dst: %s\n", reg(state, dst, REGCM_ALL));
                        internal_error(state, dst, "failed to signed extend value");
                }
        }
}

static void print_op_load(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        struct triple *dst, *src;
        const char *op;
        dst = ins;
        src = RHS(ins, 0);
        if (is_const(src) || is_const(dst)) {
                internal_error(state, ins, "unknown load operation");
        }
        switch(ins->type->type & TYPE_MASK) {
        case TYPE_CHAR:   op = "movsbl"; break;
        case TYPE_UCHAR:  op = "movzbl"; break;
        case TYPE_SHORT:  op = "movswl"; break;
        case TYPE_USHORT: op = "movzwl"; break;
        case TYPE_INT:    case TYPE_UINT:
        case TYPE_LONG:   case TYPE_ULONG:
        case TYPE_POINTER:
                op = "movl";
                break;
        default:
                internal_error(state, ins, "unknown type in load");
                op = "<invalid opcode>";
                break;
        }
        fprintf(fp, "\t%s (%s), %s\n",
                op,
                reg(state, src, REGCM_GPR32),
                reg(state, dst, REGCM_GPR32));
}


static void print_op_store(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        struct triple *dst, *src;
        dst = RHS(ins, 0);
        src = RHS(ins, 1);
        if (is_const(src) && (src->op == OP_INTCONST)) {
                long_t value;
                value = (long_t)(src->u.cval);
                fprintf(fp, "\tmov%s $%ld, (%s)\n",
                        type_suffix(state, src->type),
                        (long)(value),
                        reg(state, dst, REGCM_GPR32));
        }
        else if (is_const(dst) && (dst->op == OP_INTCONST)) {
                fprintf(fp, "\tmov%s %s, 0x%08lx\n",
                        type_suffix(state, src->type),
                        reg(state, src, REGCM_GPR8_LO | REGCM_GPR16 | REGCM_GPR32),
                        (unsigned long)(dst->u.cval));
        }
        else {
                if (is_const(src) || is_const(dst)) {
                        internal_error(state, ins, "unknown store operation");
                }
                fprintf(fp, "\tmov%s %s, (%s)\n",
                        type_suffix(state, src->type),
                        reg(state, src, REGCM_GPR8_LO | REGCM_GPR16 | REGCM_GPR32),
                        reg(state, dst, REGCM_GPR32));
        }


}

static void print_op_smul(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        if (!is_const(RHS(ins, 1))) {
                fprintf(fp, "\timul %s, %s\n",
                        reg(state, RHS(ins, 1), REGCM_GPR32),
                        reg(state, RHS(ins, 0), REGCM_GPR32));
        }
        else {
                fprintf(fp, "\timul ");
                print_const_val(state, RHS(ins, 1), fp);
                fprintf(fp, ", %s\n", reg(state, RHS(ins, 0), REGCM_GPR32));
        }
}

static void print_op_cmp(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        unsigned mask;
        int dreg;
        mask = REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO;
        dreg = check_reg(state, ins, REGCM_FLAGS);
        if (!reg_is_reg(state, dreg, REG_EFLAGS)) {
                internal_error(state, ins, "bad dest register for cmp");
        }
        if (is_const(RHS(ins, 1))) {
                fprintf(fp, "\tcmp ");
                print_const_val(state, RHS(ins, 1), fp);
                fprintf(fp, ", %s\n", reg(state, RHS(ins, 0), mask));
        }
        else {
                unsigned lmask, rmask;
                int lreg, rreg;
                lreg = check_reg(state, RHS(ins, 0), mask);
                rreg = check_reg(state, RHS(ins, 1), mask);
                lmask = arch_reg_regcm(state, lreg);
                rmask = arch_reg_regcm(state, rreg);
                mask = lmask & rmask;
                fprintf(fp, "\tcmp %s, %s\n",
                        reg(state, RHS(ins, 1), mask),
                        reg(state, RHS(ins, 0), mask));
        }
}

static void print_op_test(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        unsigned mask;
        mask = REGCM_GPR32 | REGCM_GPR16 | REGCM_GPR8_LO;
        fprintf(fp, "\ttest %s, %s\n",
                reg(state, RHS(ins, 0), mask),
                reg(state, RHS(ins, 0), mask));
}

static void print_op_branch(struct compile_state *state,
        struct triple *branch, FILE *fp)
{
        const char *bop = "j";
        if ((branch->op == OP_JMP) || (branch->op == OP_CALL)) {
                if (branch->rhs != 0) {
                        internal_error(state, branch, "jmp with condition?");
                }
                bop = "jmp";
        }
        else {
                struct triple *ptr;
                if (branch->rhs != 1) {
                        internal_error(state, branch, "jmpcc without condition?");
                }
                check_reg(state, RHS(branch, 0), REGCM_FLAGS);
                if ((RHS(branch, 0)->op != OP_CMP) &&
                        (RHS(branch, 0)->op != OP_TEST)) {
                        internal_error(state, branch, "bad branch test");
                }
#if DEBUG_ROMCC_WARNINGS
#warning "FIXME I have observed instructions between the test and branch instructions"
#endif
                for(ptr = RHS(branch, 0)->next; ptr != branch; ptr = ptr->next) {
                        if (ptr->op != OP_COPY) {
                                internal_error(state, branch, "branch does not follow test");
                        }
                }
                switch(branch->op) {
                case OP_JMP_EQ:       bop = "jz";  break;
                case OP_JMP_NOTEQ:    bop = "jnz"; break;
                case OP_JMP_SLESS:    bop = "jl";  break;
                case OP_JMP_ULESS:    bop = "jb";  break;
                case OP_JMP_SMORE:    bop = "jg";  break;
                case OP_JMP_UMORE:    bop = "ja";  break;
                case OP_JMP_SLESSEQ:  bop = "jle"; break;
                case OP_JMP_ULESSEQ:  bop = "jbe"; break;
                case OP_JMP_SMOREEQ:  bop = "jge"; break;
                case OP_JMP_UMOREEQ:  bop = "jae"; break;
                default:
                        internal_error(state, branch, "Invalid branch op");
                        break;
                }

        }
#if 1
        if (branch->op == OP_CALL) {
                fprintf(fp, "\t/* call */\n");
        }
#endif
        fprintf(fp, "\t%s L%s%lu\n",
                bop,
                state->compiler->label_prefix,
                (unsigned long)(TARG(branch, 0)->u.cval));
}

static void print_op_ret(struct compile_state *state,
        struct triple *branch, FILE *fp)
{
        fprintf(fp, "\tjmp *%s\n",
                reg(state, RHS(branch, 0), REGCM_GPR32));
}

static void print_op_set(struct compile_state *state,
        struct triple *set, FILE *fp)
{
        const char *sop = "set";
        if (set->rhs != 1) {
                internal_error(state, set, "setcc without condition?");
        }
        check_reg(state, RHS(set, 0), REGCM_FLAGS);
        if ((RHS(set, 0)->op != OP_CMP) &&
                (RHS(set, 0)->op != OP_TEST)) {
                internal_error(state, set, "bad set test");
        }
        if (RHS(set, 0)->next != set) {
                internal_error(state, set, "set does not follow test");
        }
        switch(set->op) {
        case OP_SET_EQ:       sop = "setz";  break;
        case OP_SET_NOTEQ:    sop = "setnz"; break;
        case OP_SET_SLESS:    sop = "setl";  break;
        case OP_SET_ULESS:    sop = "setb";  break;
        case OP_SET_SMORE:    sop = "setg";  break;
        case OP_SET_UMORE:    sop = "seta";  break;
        case OP_SET_SLESSEQ:  sop = "setle"; break;
        case OP_SET_ULESSEQ:  sop = "setbe"; break;
        case OP_SET_SMOREEQ:  sop = "setge"; break;
        case OP_SET_UMOREEQ:  sop = "setae"; break;
        default:
                internal_error(state, set, "Invalid set op");
                break;
        }
        fprintf(fp, "\t%s %s\n",
                sop, reg(state, set, REGCM_GPR8_LO));
}

static void print_op_bit_scan(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        const char *op;
        switch(ins->op) {
        case OP_BSF: op = "bsf"; break;
        case OP_BSR: op = "bsr"; break;
        default:
                internal_error(state, ins, "unknown bit scan");
                op = 0;
                break;
        }
        fprintf(fp,
                "\t%s %s, %s\n"
                "\tjnz 1f\n"
                "\tmovl $-1, %s\n"
                "1:\n",
                op,
                reg(state, RHS(ins, 0), REGCM_GPR32),
                reg(state, ins, REGCM_GPR32),
                reg(state, ins, REGCM_GPR32));
}


static void print_sdecl(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        fprintf(fp, ".section \"" DATA_SECTION "\"\n");
        fprintf(fp, ".balign %ld\n", (long int)align_of_in_bytes(state, ins->type));
        fprintf(fp, "L%s%lu:\n",
                state->compiler->label_prefix, (unsigned long)(ins->u.cval));
        print_const(state, MISC(ins, 0), fp);
        fprintf(fp, ".section \"" TEXT_SECTION "\"\n");

}

static void print_instruction(struct compile_state *state,
        struct triple *ins, FILE *fp)
{
        /* Assumption: after I have exted the register allocator
         * everything is in a valid register.
         */
        switch(ins->op) {
        case OP_ASM:
                print_op_asm(state, ins, fp);
                break;
        case OP_ADD:    print_binary_op(state, "add", ins, fp); break;
        case OP_SUB:    print_binary_op(state, "sub", ins, fp); break;
        case OP_AND:    print_binary_op(state, "and", ins, fp); break;
        case OP_XOR:    print_binary_op(state, "xor", ins, fp); break;
        case OP_OR:     print_binary_op(state, "or",  ins, fp); break;
        case OP_SL:     print_op_shift(state, "shl", ins, fp); break;
        case OP_USR:    print_op_shift(state, "shr", ins, fp); break;
        case OP_SSR:    print_op_shift(state, "sar", ins, fp); break;
        case OP_POS:    break;
        case OP_NEG:    print_unary_op(state, "neg", ins, fp); break;
        case OP_INVERT: print_unary_op(state, "not", ins, fp); break;
        case OP_NOOP:
        case OP_INTCONST:
        case OP_ADDRCONST:
        case OP_BLOBCONST:
                /* Don't generate anything here for constants */
        case OP_PHI:
                /* Don't generate anything for variable declarations. */
                break;
        case OP_UNKNOWNVAL:
                fprintf(fp, " /* unknown %s */\n",
                        reg(state, ins, REGCM_ALL));
                break;
        case OP_SDECL:
                print_sdecl(state, ins, fp);
                break;
        case OP_COPY:
        case OP_CONVERT:
                print_op_move(state, ins, fp);
                break;
        case OP_LOAD:
                print_op_load(state, ins, fp);
                break;
        case OP_STORE:
                print_op_store(state, ins, fp);
                break;
        case OP_SMUL:
                print_op_smul(state, ins, fp);
                break;
        case OP_CMP:    print_op_cmp(state, ins, fp); break;
        case OP_TEST:   print_op_test(state, ins, fp); break;
        case OP_JMP:
        case OP_JMP_EQ:      case OP_JMP_NOTEQ:
        case OP_JMP_SLESS:   case OP_JMP_ULESS:
        case OP_JMP_SMORE:   case OP_JMP_UMORE:
        case OP_JMP_SLESSEQ: case OP_JMP_ULESSEQ:
        case OP_JMP_SMOREEQ: case OP_JMP_UMOREEQ:
        case OP_CALL:
                print_op_branch(state, ins, fp);
                break;
        case OP_RET:
                print_op_ret(state, ins, fp);
                break;
        case OP_SET_EQ:      case OP_SET_NOTEQ:
        case OP_SET_SLESS:   case OP_SET_ULESS:
        case OP_SET_SMORE:   case OP_SET_UMORE:
        case OP_SET_SLESSEQ: case OP_SET_ULESSEQ:
        case OP_SET_SMOREEQ: case OP_SET_UMOREEQ:
                print_op_set(state, ins, fp);
                break;
        case OP_INB:  case OP_INW:  case OP_INL:
                print_op_in(state, ins, fp);
                break;
        case OP_OUTB: case OP_OUTW: case OP_OUTL:
                print_op_out(state, ins, fp);
                break;
        case OP_BSF:
        case OP_BSR:
                print_op_bit_scan(state, ins, fp);
                break;
        case OP_RDMSR:
                after_lhs(state, ins);
                fprintf(fp, "\trdmsr\n");
                break;
        case OP_WRMSR:
                fprintf(fp, "\twrmsr\n");
                break;
        case OP_HLT:
                fprintf(fp, "\thlt\n");
                break;
        case OP_SDIVT:
                fprintf(fp, "\tidiv %s\n", reg(state, RHS(ins, 1), REGCM_GPR32));
                break;
        case OP_UDIVT:
                fprintf(fp, "\tdiv %s\n", reg(state, RHS(ins, 1), REGCM_GPR32));
                break;
        case OP_UMUL:
                fprintf(fp, "\tmul %s\n", reg(state, RHS(ins, 1), REGCM_GPR32));
                break;
        case OP_LABEL:
                if (!ins->use) {
                        return;
                }
                fprintf(fp, "L%s%lu:\n",
                        state->compiler->label_prefix, (unsigned long)(ins->u.cval));
                break;
        case OP_ADECL:
                /* Ignore adecls with no registers error otherwise */
                if (!noop_adecl(ins)) {
                        internal_error(state, ins, "adecl remains?");
                }
                break;
                /* Ignore OP_PIECE */
        case OP_PIECE:
                break;
                /* Operations that should never get here */
        case OP_SDIV: case OP_UDIV:
        case OP_SMOD: case OP_UMOD:
        case OP_LTRUE:   case OP_LFALSE:  case OP_EQ:      case OP_NOTEQ:
        case OP_SLESS:   case OP_ULESS:   case OP_SMORE:   case OP_UMORE:
        case OP_SLESSEQ: case OP_ULESSEQ: case OP_SMOREEQ: case OP_UMOREEQ:
        default:
                internal_error(state, ins, "unknown op: %d %s",
                        ins->op, tops(ins->op));
                break;
        }
}

static void print_instructions(struct compile_state *state)
{
        struct triple *first, *ins;
        int print_location;
        struct occurrence *last_occurrence;
        FILE *fp;
        int max_inline_depth;
        max_inline_depth = 0;
        print_location = 1;
        last_occurrence = 0;
        fp = state->output;
        /* Masks for common sizes */
        fprintf(fp, ".section \"" DATA_SECTION "\"\n");
        fprintf(fp, ".balign 16\n");
        fprintf(fp, "L%s1:\n", state->compiler->label_prefix);
        fprintf(fp, ".int 0xff, 0, 0, 0\n");
        fprintf(fp, "L%s2:\n", state->compiler->label_prefix);
        fprintf(fp, ".int 0xffff, 0, 0, 0\n");
        fprintf(fp, ".section \"" TEXT_SECTION "\"\n");
        first = state->first;
        ins = first;
        do {
                if (print_location &&
                        last_occurrence != ins->occurrence) {
                        if (!ins->occurrence->parent) {
                                fprintf(fp, "\t/* %s,%s:%d.%d */\n",
                                        ins->occurrence->function?ins->occurrence->function:"(null)",
                                        ins->occurrence->filename?ins->occurrence->filename:"(null)",
                                        ins->occurrence->line,
                                        ins->occurrence->col);
                        }
                        else {
                                struct occurrence *ptr;
                                int inline_depth;
                                fprintf(fp, "\t/*\n");
                                inline_depth = 0;
                                for(ptr = ins->occurrence; ptr; ptr = ptr->parent) {
                                        inline_depth++;
                                        fprintf(fp, "\t * %s,%s:%d.%d\n",
                                                ptr->function,
                                                ptr->filename,
                                                ptr->line,
                                                ptr->col);
                                }
                                fprintf(fp, "\t */\n");
                                if (inline_depth > max_inline_depth) {
                                        max_inline_depth = inline_depth;
                                }
                        }
                        if (last_occurrence) {
                                put_occurrence(last_occurrence);
                        }
                        get_occurrence(ins->occurrence);
                        last_occurrence = ins->occurrence;
                }

                print_instruction(state, ins, fp);
                ins = ins->next;
        } while(ins != first);
        if (print_location) {
                fprintf(fp, "/* max inline depth %d */\n",
                        max_inline_depth);
        }
}

static void generate_code(struct compile_state *state)
{
        generate_local_labels(state);
        print_instructions(state);

}

static void print_preprocessed_tokens(struct compile_state *state)
{
        int tok;
        FILE *fp;
        int line;
        const char *filename;
        fp = state->output;
        filename = 0;
        line = 0;
        for(;;) {
                struct file_state *file;
                struct token *tk;
                const char *token_str;
                tok = peek(state);
                if (tok == TOK_EOF) {
                        break;
                }
                tk = eat(state, tok);
                token_str =
                        tk->ident ? tk->ident->name :
                        tk->str_len ? tk->val.str :
                        tokens[tk->tok];

                file = state->file;
                while(file->macro && file->prev) {
                        file = file->prev;
                }
                if (!file->macro &&
                        ((file->line != line) || (file->basename != filename)))
                {
                        int i, col;
                        if ((file->basename == filename) &&
                                (line < file->line)) {
                                while(line < file->line) {
                                        fprintf(fp, "\n");
                                        line++;
                                }
                        }
                        else {
                                fprintf(fp, "\n#line %d \"%s\"\n",
                                        file->line, file->basename);
                        }
                        line = file->line;
                        filename = file->basename;
                        col = get_col(file) - strlen(token_str);
                        for(i = 0; i < col; i++) {
                                fprintf(fp, " ");
                        }
                }

                fprintf(fp, "%s ", token_str);

                if (state->compiler->debug & DEBUG_TOKENS) {
                        loc(state->dbgout, state, 0);
                        fprintf(state->dbgout, "%s <- `%s'\n",
                                tokens[tok], token_str);
                }
        }
}

static void compile(const char *filename,
        struct compiler_state *compiler, struct arch_state *arch)
{
        int i;
        struct compile_state state;
        struct triple *ptr;
        struct filelist *includes = include_filelist;
        memset(&state, 0, sizeof(state));
        state.compiler = compiler;
        state.arch     = arch;
        state.file = 0;
        for(i = 0; i < sizeof(state.token)/sizeof(state.token[0]); i++) {
                memset(&state.token[i], 0, sizeof(state.token[i]));
                state.token[i].tok = -1;
        }
        /* Remember the output descriptors */
        state.errout = stderr;
        state.dbgout = stdout;
        /* Remember the output filename */
        if ((state.compiler->flags & COMPILER_PP_ONLY) && (strcmp("auto.inc",state.compiler->ofilename) == 0)) {
                state.output    = stdout;
        } else {
                state.output    = fopen(state.compiler->ofilename, "w");
                if (!state.output) {
                        error(&state, 0, "Cannot open output file %s\n",
                                state.compiler->ofilename);
                }
        }
        /* Make certain a good cleanup happens */
        exit_state = &state;
        atexit(exit_cleanup);

        /* Prep the preprocessor */
        state.if_depth = 0;
        memset(state.if_bytes, 0, sizeof(state.if_bytes));
        /* register the C keywords */
        register_keywords(&state);
        /* register the keywords the macro preprocessor knows */
        register_macro_keywords(&state);
        /* generate some builtin macros */
        register_builtin_macros(&state);
        /* Memorize where some special keywords are. */
        state.i_switch        = lookup(&state, "switch", 6);
        state.i_case          = lookup(&state, "case", 4);
        state.i_continue      = lookup(&state, "continue", 8);
        state.i_break         = lookup(&state, "break", 5);
        state.i_default       = lookup(&state, "default", 7);
        state.i_return        = lookup(&state, "return", 6);
        /* Memorize where predefined macros are. */
        state.i___VA_ARGS__   = lookup(&state, "__VA_ARGS__", 11);
        state.i___FILE__      = lookup(&state, "__FILE__", 8);
        state.i___LINE__      = lookup(&state, "__LINE__", 8);
        /* Memorize where predefined identifiers are. */
        state.i___func__      = lookup(&state, "__func__", 8);
        /* Memorize where some attribute keywords are. */
        state.i_noinline      = lookup(&state, "noinline", 8);
        state.i_always_inline = lookup(&state, "always_inline", 13);
        state.i_noreturn      = lookup(&state, "noreturn", 8);
        state.i_unused        = lookup(&state, "unused", 6);
        state.i_packed        = lookup(&state, "packed", 6);

        /* Process the command line macros */
        process_cmdline_macros(&state);

        /* Allocate beginning bounding labels for the function list */
        state.first = label(&state);
        state.first->id |= TRIPLE_FLAG_VOLATILE;
        use_triple(state.first, state.first);
        ptr = label(&state);
        ptr->id |= TRIPLE_FLAG_VOLATILE;
        use_triple(ptr, ptr);
        flatten(&state, state.first, ptr);

        /* Allocate a label for the pool of global variables */
        state.global_pool = label(&state);
        state.global_pool->id |= TRIPLE_FLAG_VOLATILE;
        flatten(&state, state.first, state.global_pool);

        /* Enter the globl definition scope */
        start_scope(&state);
        register_builtins(&state);

        compile_file(&state, filename, 1);

        while (includes) {
                compile_file(&state, includes->filename, 1);
                includes=includes->next;
        }

        /* Stop if all we want is preprocessor output */
        if (state.compiler->flags & COMPILER_PP_ONLY) {
                print_preprocessed_tokens(&state);
                return;
        }

        decls(&state);

        /* Exit the global definition scope */
        end_scope(&state);

        /* Now that basic compilation has happened
         * optimize the intermediate code
         */
        optimize(&state);

        generate_code(&state);
        if (state.compiler->debug) {
                fprintf(state.errout, "done\n");
        }
        exit_state = 0;
}

static void version(FILE *fp)
{
        fprintf(fp, "romcc " VERSION " released " RELEASE_DATE "\n");
}

static void usage(void)
{
        FILE *fp = stdout;
        version(fp);
        fprintf(fp,
                "\nUsage: romcc [options] <source>.c\n"
                "Compile a C source file generating a binary that does not implicilty use RAM\n"
                "Options:\n"
                "-o <output file name>\n"
                "-f<option>            Specify a generic compiler option\n"
                "-m<option>            Specify a arch dependent option\n"
                "--                    Specify this is the last option\n"
                "\nGeneric compiler options:\n"
        );
        compiler_usage(fp);
        fprintf(fp,
                "\nArchitecture compiler options:\n"
        );
        arch_usage(fp);
        fprintf(fp,
                "\n"
        );
}

static void arg_error(char *fmt, ...)
{
        va_list args;
        va_start(args, fmt);
        vfprintf(stderr, fmt, args);
        va_end(args);
        usage();
        exit(1);
}

static void arg_warning(char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        vfprintf(stderr, fmt, args);
        va_end(args);
}

int main(int argc, char **argv)
{
        const char *filename;
        struct compiler_state compiler;
        struct arch_state arch;
        int all_opts;


        /* I don't want any surprises */
        setlocale(LC_ALL, "C");

        init_compiler_state(&compiler);
        init_arch_state(&arch);
        filename = 0;
        all_opts = 0;
        while(argc > 1) {
                if (!all_opts && (strcmp(argv[1], "-o") == 0) && (argc > 2)) {
                        compiler.ofilename = argv[2];
                        argv += 2;
                        argc -= 2;
                }
                else if (!all_opts && argv[1][0] == '-') {
                        int result;
                        result = -1;
                        if (strcmp(argv[1], "--") == 0) {
                                result = 0;
                                all_opts = 1;
                        }
                        else if (strncmp(argv[1], "-E", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]);
                        }
                        else if (strncmp(argv[1], "-O", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]);
                        }
                        else if (strncmp(argv[1], "-I", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]);
                        }
                        else if (strncmp(argv[1], "-D", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]);
                        }
                        else if (strncmp(argv[1], "-U", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]);
                        }
                        else if (strncmp(argv[1], "--label-prefix=", 15) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]+2);
                        }
                        else if (strncmp(argv[1], "-f", 2) == 0) {
                                result = compiler_encode_flag(&compiler, argv[1]+2);
                        }
                        else if (strncmp(argv[1], "-m", 2) == 0) {
                                result = arch_encode_flag(&arch, argv[1]+2);
                        }
                        else if (strncmp(argv[1], "-c", 2) == 0) {
                                result = 0;
                        }
                        else if (strncmp(argv[1], "-S", 2) == 0) {
                                result = 0;
                        }
                        else if (strncmp(argv[1], "-include", 10) == 0) {
                                struct filelist *old_head = include_filelist;
                                include_filelist = malloc(sizeof(struct filelist));
                                if (!include_filelist) {
                                        die("Out of memory.\n");
                                }
                                argv++;
                                argc--;
                                include_filelist->filename = strdup(argv[1]);
                                include_filelist->next = old_head;
                                result = 0;
                        }
                        if (result < 0) {
                                arg_error("Invalid option specified: %s\n",
                                        argv[1]);
                        }
                        argv++;
                        argc--;
                }
                else {
                        if (filename) {
                                arg_error("Only one filename may be specified\n");
                        }
                        filename = argv[1];
                        argv++;
                        argc--;
                }
        }
        if (!filename) {
                arg_error("No filename specified\n");
        }
        compile(filename, &compiler, &arch);

        return 0;
}