* flags.h: New variables align_loops, align_loops_log,

[official-gcc.git] / gcc / config / mips / mips.c

/* Subroutines for insn-output.c for MIPS
   Copyright (C) 1989, 90, 91, 93-98, 1999 Free Software Foundation, Inc.
   Contributed by A. Lichnewsky, lich@inria.inria.fr.
   Changes by Michael Meissner, meissner@osf.org.
   64 bit r4000 support by Ian Lance Taylor, ian@cygnus.com, and
   Brendan Eich, brendan@microunity.com.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* ??? The TARGET_FP_CALL_32 macros are intended to simulate a 32 bit
   calling convention in 64 bit mode.  It doesn't work though, and should
   be replaced with something better designed.  */

#include "config.h"
#include "system.h"
#include <signal.h>

#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-flags.h"
#include "insn-attr.h"
#include "insn-codes.h"
#include "recog.h"
#include "toplev.h"
#include "tree.h"
#include "function.h"
#include "expr.h"
#include "flags.h"
#include "reload.h"
#include "output.h"

#if defined(USG) || !defined(HAVE_STAB_H)
#include "gstab.h"  /* If doing DBX on sysV, use our own stab.h.  */
#else
#include <stab.h>  /* On BSD, use the system's stab.h.  */
#endif /* not USG */

#ifdef __GNU_STAB__
#define STAB_CODE_TYPE enum __stab_debug_code
#else
#define STAB_CODE_TYPE int
#endif

extern char  *mktemp ();
extern tree   lookup_name ();

/* Enumeration for all of the relational tests, so that we can build
   arrays indexed by the test type, and not worry about the order
   of EQ, NE, etc. */

enum internal_test {
    ITEST_EQ,
    ITEST_NE,
    ITEST_GT,
    ITEST_GE,
    ITEST_LT,
    ITEST_LE,
    ITEST_GTU,
    ITEST_GEU,
    ITEST_LTU,
    ITEST_LEU,
    ITEST_MAX
  };


struct constant;
static enum internal_test map_test_to_internal_test     PROTO ((enum rtx_code));
static int mips16_simple_memory_operand         PROTO ((rtx, rtx,
                                                        enum machine_mode));
static int m16_check_op                         PROTO ((rtx, int, int, int));
static void block_move_loop                     PROTO ((rtx, rtx, int, int,
                                                        rtx, rtx));
static void block_move_call                     PROTO ((rtx, rtx, rtx));
static FILE *make_temp_file                     PROTO ((void));
static void save_restore_insns                  PROTO ((int, rtx,
                                                        long, FILE *));
static void mips16_output_gp_offset             PROTO ((FILE *, rtx));
static void mips16_fp_args                      PROTO ((FILE *, int, int));
static void build_mips16_function_stub          PROTO ((FILE *));
static void mips16_optimize_gp                  PROTO ((rtx));
static rtx add_constant                         PROTO ((struct constant **,
                                                        rtx,
                                                        enum machine_mode));
static void dump_constants                      PROTO ((struct constant *,
                                                        rtx));
static rtx mips_find_symbol                     PROTO ((rtx));
static void abort_with_insn                     PROTO ((rtx, const char *))
  ATTRIBUTE_NORETURN;
static int symbolic_expression_p                PROTO ((rtx));

/* Global variables for machine-dependent things.  */

/* Threshold for data being put into the small data/bss area, instead
   of the normal data area (references to the small data/bss area take
   1 instruction, and use the global pointer, references to the normal
   data area takes 2 instructions).  */
int mips_section_threshold = -1;

/* Count the number of .file directives, so that .loc is up to date.  */
int num_source_filenames = 0;

/* Count the number of sdb related labels are generated (to find block
   start and end boundaries).  */
int sdb_label_count = 0;

/* Next label # for each statement for Silicon Graphics IRIS systems. */
int sym_lineno = 0;

/* Non-zero if inside of a function, because the stupid MIPS asm can't
   handle .files inside of functions.  */
int inside_function = 0;

/* Files to separate the text and the data output, so that all of the data
   can be emitted before the text, which will mean that the assembler will
   generate smaller code, based on the global pointer.  */
FILE *asm_out_data_file;
FILE *asm_out_text_file;

/* Linked list of all externals that are to be emitted when optimizing
   for the global pointer if they haven't been declared by the end of
   the program with an appropriate .comm or initialization.  */

struct extern_list
{
  struct extern_list *next;     /* next external */
  char *name;                   /* name of the external */
  int size;                     /* size in bytes */
} *extern_head = 0;

/* Name of the file containing the current function.  */
const char *current_function_file = "";

/* Warning given that Mips ECOFF can't support changing files
   within a function.  */
int file_in_function_warning = FALSE;

/* Whether to suppress issuing .loc's because the user attempted
   to change the filename within a function.  */
int ignore_line_number = FALSE;

/* Number of nested .set noreorder, noat, nomacro, and volatile requests.  */
int set_noreorder;
int set_noat;
int set_nomacro;
int set_volatile;

/* The next branch instruction is a branch likely, not branch normal.  */
int mips_branch_likely;

/* Count of delay slots and how many are filled.  */
int dslots_load_total;
int dslots_load_filled;
int dslots_jump_total;
int dslots_jump_filled;

/* # of nops needed by previous insn */
int dslots_number_nops;

/* Number of 1/2/3 word references to data items (ie, not jal's).  */
int num_refs[3];

/* registers to check for load delay */
rtx mips_load_reg, mips_load_reg2, mips_load_reg3, mips_load_reg4;

/* Cached operands, and operator to compare for use in set/branch on
   condition codes.  */
rtx branch_cmp[2];

/* what type of branch to use */
enum cmp_type branch_type;

/* Number of previously seen half-pic pointers and references.  */
static int prev_half_pic_ptrs = 0;
static int prev_half_pic_refs = 0;

/* which cpu are we scheduling for */
enum processor_type mips_cpu;

/* which instruction set architecture to use.  */
int mips_isa;

#ifdef MIPS_ABI_DEFAULT
/* Which ABI to use.  This is defined to a constant in mips.h if the target
   doesn't support multiple ABIs.  */
int mips_abi;
#endif

/* Strings to hold which cpu and instruction set architecture to use.  */
const char *mips_cpu_string;    /* for -mcpu=<xxx> */
const char *mips_isa_string;    /* for -mips{1,2,3,4} */
const char *mips_abi_string;    /* for -mabi={32,n32,64,eabi} */

/* Whether we are generating mips16 code.  This is a synonym for
   TARGET_MIPS16, and exists for use as an attribute.  */
int mips16;

/* This variable is set by -mno-mips16.  We only care whether
   -mno-mips16 appears or not, and using a string in this fashion is
   just a way to avoid using up another bit in target_flags.  */
const char *mips_no_mips16_string;

/* This is only used to determine if an type size setting option was 
   explicitly specified (-mlong64, -mint64, -mlong32).  The specs
   set this option if such an option is used. */
const char *mips_explicit_type_size_string;

/* Whether we are generating mips16 hard float code.  In mips16 mode
   we always set TARGET_SOFT_FLOAT; this variable is nonzero if
   -msoft-float was not specified by the user, which means that we
   should arrange to call mips32 hard floating point code.  */
int mips16_hard_float;

/* This variable is set by -mentry.  We only care whether -mentry
   appears or not, and using a string in this fashion is just a way to
   avoid using up another bit in target_flags.  */
const char *mips_entry_string;

/* Whether we should entry and exit pseudo-ops in mips16 mode.  */
int mips_entry;

/* If TRUE, we split addresses into their high and low parts in the RTL.  */
int mips_split_addresses;

/* Generating calls to position independent functions?  */
enum mips_abicalls_type mips_abicalls;

/* High and low marks for floating point values which we will accept
   as legitimate constants for LEGITIMATE_CONSTANT_P.  These are
   initialized in override_options.  */
REAL_VALUE_TYPE dfhigh, dflow, sfhigh, sflow;

/* Mode used for saving/restoring general purpose registers.  */
static enum machine_mode gpr_mode;

/* Array giving truth value on whether or not a given hard register
   can support a given mode.  */
char mips_hard_regno_mode_ok[(int)MAX_MACHINE_MODE][FIRST_PSEUDO_REGISTER];

/* Current frame information calculated by compute_frame_size.  */
struct mips_frame_info current_frame_info;

/* Zero structure to initialize current_frame_info.  */
struct mips_frame_info zero_frame_info;

/* Temporary filename used to buffer .text until end of program
   for -mgpopt.  */
static char *temp_filename;

/* Pseudo-reg holding the address of the current function when
   generating embedded PIC code.  Created by LEGITIMIZE_ADDRESS, used
   by mips_finalize_pic if it was created.  */
rtx embedded_pic_fnaddr_rtx;

/* The length of all strings seen when compiling for the mips16.  This
   is used to tell how many strings are in the constant pool, so that
   we can see if we may have an overflow.  This is reset each time the
   constant pool is output.  */
int mips_string_length;

/* Pseudo-reg holding the value of $28 in a mips16 function which
   refers to GP relative global variables.  */
rtx mips16_gp_pseudo_rtx;

/* In mips16 mode, we build a list of all the string constants we see
   in a particular function.  */

struct string_constant
{
  struct string_constant *next;
  char *label;
};

static struct string_constant *string_constants;

/* List of all MIPS punctuation characters used by print_operand.  */
char mips_print_operand_punct[256];

/* Map GCC register number to debugger register number.  */
int mips_dbx_regno[FIRST_PSEUDO_REGISTER];

/* Buffer to use to enclose a load/store operation with %{ %} to
   turn on .set volatile.  */
static char volatile_buffer[60];

/* Hardware names for the registers.  If -mrnames is used, this
   will be overwritten with mips_sw_reg_names.  */

char mips_reg_names[][8] =
{
 "$0",   "$1",   "$2",   "$3",   "$4",   "$5",   "$6",   "$7",
 "$8",   "$9",   "$10",  "$11",  "$12",  "$13",  "$14",  "$15",
 "$16",  "$17",  "$18",  "$19",  "$20",  "$21",  "$22",  "$23",
 "$24",  "$25",  "$26",  "$27",  "$28",  "$sp",  "$fp",  "$31",
 "$f0",  "$f1",  "$f2",  "$f3",  "$f4",  "$f5",  "$f6",  "$f7",
 "$f8",  "$f9",  "$f10", "$f11", "$f12", "$f13", "$f14", "$f15",
 "$f16", "$f17", "$f18", "$f19", "$f20", "$f21", "$f22", "$f23",
 "$f24", "$f25", "$f26", "$f27", "$f28", "$f29", "$f30", "$f31",
 "hi",   "lo",   "accum","$fcc0","$fcc1","$fcc2","$fcc3","$fcc4",
 "$fcc5","$fcc6","$fcc7","$rap"
};

/* Mips software names for the registers, used to overwrite the
   mips_reg_names array.  */

char mips_sw_reg_names[][8] =
{
  "$zero","$at",  "$v0",  "$v1",  "$a0",  "$a1",  "$a2",  "$a3",
  "$t0",  "$t1",  "$t2",  "$t3",  "$t4",  "$t5",  "$t6",  "$t7",
  "$s0",  "$s1",  "$s2",  "$s3",  "$s4",  "$s5",  "$s6",  "$s7",
  "$t8",  "$t9",  "$k0",  "$k1",  "$gp",  "$sp",  "$fp",  "$ra",
  "$f0",  "$f1",  "$f2",  "$f3",  "$f4",  "$f5",  "$f6",  "$f7",
  "$f8",  "$f9",  "$f10", "$f11", "$f12", "$f13", "$f14", "$f15",
  "$f16", "$f17", "$f18", "$f19", "$f20", "$f21", "$f22", "$f23",
  "$f24", "$f25", "$f26", "$f27", "$f28", "$f29", "$f30", "$f31",
  "hi",   "lo",   "accum","$fcc0","$fcc1","$fcc2","$fcc3","$fcc4",
  "$fcc5","$fcc6","$fcc7","$rap"
};

/* Map hard register number to register class */
enum reg_class mips_regno_to_class[] =
{
  GR_REGS,      GR_REGS,        M16_NA_REGS,    M16_NA_REGS,
  M16_REGS,     M16_REGS,       M16_REGS,       M16_REGS,
  GR_REGS,      GR_REGS,        GR_REGS,        GR_REGS,
  GR_REGS,      GR_REGS,        GR_REGS,        GR_REGS,
  M16_NA_REGS,  M16_NA_REGS,    GR_REGS,        GR_REGS,
  GR_REGS,      GR_REGS,        GR_REGS,        GR_REGS,
  T_REG,        GR_REGS,        GR_REGS,        GR_REGS,
  GR_REGS,      GR_REGS,        GR_REGS,        GR_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  HI_REG,       LO_REG,         HILO_REG,       ST_REGS,
  ST_REGS,      ST_REGS,        ST_REGS,        ST_REGS,
  ST_REGS,      ST_REGS,        ST_REGS,        GR_REGS
};

/* Map register constraint character to register class.  */
enum reg_class mips_char_to_class[256] =
{
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
  NO_REGS,      NO_REGS,        NO_REGS,        NO_REGS,
};

\f
/* Return truth value of whether OP can be used as an operands
   where a register or 16 bit unsigned integer is needed.  */

int
uns_arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT && SMALL_INT_UNSIGNED (op))
    return 1;

  return register_operand (op, mode);
}

/* Return truth value of whether OP can be used as an operands
   where a 16 bit integer is needed  */

int
arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT && SMALL_INT (op))
    return 1;

  /* On the mips16, a GP relative value is a signed 16 bit offset.  */
  if (TARGET_MIPS16 && GET_CODE (op) == CONST && mips16_gp_offset_p (op))
    return 1;

  return register_operand (op, mode);
}

/* Return truth value of whether OP can be used as an operand in a two
   address arithmetic insn (such as set 123456,%o4) of mode MODE.  */

int
arith32_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT)
    return 1;

  return register_operand (op, mode);
}

/* Return truth value of whether OP is a integer which fits in 16 bits  */

int
small_int (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT && SMALL_INT (op));
}

/* Return truth value of whether OP is a 32 bit integer which is too big to
   be loaded with one instruction.  */

int
large_int (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  HOST_WIDE_INT value;

  if (GET_CODE (op) != CONST_INT)
    return 0;

  value = INTVAL (op);

  /* ior reg,$r0,value */
  if ((value & ~ ((HOST_WIDE_INT) 0x0000ffff)) == 0)
    return 0;

  /* subu reg,$r0,value */
  if (((unsigned HOST_WIDE_INT) (value + 32768)) <= 32767)
    return 0;

  /* lui reg,value>>16 */
  if ((value & 0x0000ffff) == 0)
    return 0;

  return 1;
}

/* Return truth value of whether OP is a register or the constant 0.
   In mips16 mode, we only accept a register, since the mips16 does
   not have $0.  */

int
reg_or_0_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  switch (GET_CODE (op))
    {
    case CONST_INT:
      if (TARGET_MIPS16)
        return 0;
      return INTVAL (op) == 0;

    case CONST_DOUBLE:
      if (TARGET_MIPS16)
        return 0;
      return op == CONST0_RTX (mode);

    case REG:
    case SUBREG:
      return register_operand (op, mode);

    default:
      break;
    }

  return 0;
}

/* Return truth value of whether OP is a register or the constant 0,
   even in mips16 mode. */

int
true_reg_or_0_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  switch (GET_CODE (op))
    {
    case CONST_INT:
      return INTVAL (op) == 0;

    case CONST_DOUBLE:
      return op == CONST0_RTX (mode);

    case REG:
    case SUBREG:
      return register_operand (op, mode);

    default:
      break;
    }

  return 0;
}

/* Return truth value if a CONST_DOUBLE is ok to be a legitimate constant.  */

int
mips_const_double_ok (op, mode)
     rtx op;
     enum machine_mode mode;
{
  REAL_VALUE_TYPE d;

  if (GET_CODE (op) != CONST_DOUBLE)
    return 0;

  if (mode == VOIDmode)
    return 1;

  if (mode != SFmode && mode != DFmode)
    return 0;

  if (op == CONST0_RTX (mode))
    return 1;

  /* ??? li.s does not work right with SGI's Irix 6 assembler.  */
  if (mips_abi != ABI_32 && mips_abi != ABI_O64 && mips_abi != ABI_EABI)
    return 0;

  REAL_VALUE_FROM_CONST_DOUBLE (d, op);

  if (REAL_VALUE_ISNAN (d))
    return FALSE;

  if (REAL_VALUE_NEGATIVE (d))
    d = REAL_VALUE_NEGATE (d);

  if (mode == DFmode)
    {
      if (REAL_VALUES_LESS (d, dfhigh)
          && REAL_VALUES_LESS (dflow, d))
        return 1;
    }
  else
    {
      if (REAL_VALUES_LESS (d, sfhigh)
          && REAL_VALUES_LESS (sflow, d))
        return 1;
    }

  return 0;
}

/* Accept the floating point constant 1 in the appropriate mode.  */

int
const_float_1_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  REAL_VALUE_TYPE d;
  static REAL_VALUE_TYPE onedf;
  static REAL_VALUE_TYPE onesf;
  static int one_initialized;

  if (GET_CODE (op) != CONST_DOUBLE
      || mode != GET_MODE (op)
      || (mode != DFmode && mode != SFmode))
    return 0;

  REAL_VALUE_FROM_CONST_DOUBLE (d, op);

  /* We only initialize these values if we need them, since we will
     never get called unless mips_isa >= 4.  */
  if (! one_initialized)
    {
      onedf = REAL_VALUE_ATOF ("1.0", DFmode);
      onesf = REAL_VALUE_ATOF ("1.0", SFmode);
      one_initialized = 1;
    }

  if (mode == DFmode)
    return REAL_VALUES_EQUAL (d, onedf);
  else
    return REAL_VALUES_EQUAL (d, onesf);
}

/* Return true if a memory load or store of REG plus OFFSET in MODE
   can be represented in a single word on the mips16.  */

static int
mips16_simple_memory_operand (reg, offset, mode)
     rtx reg;
     rtx offset;
     enum machine_mode mode;
{
  int size, off;

  if (mode == BLKmode)
    {
      /* We can't tell, because we don't know how the value will
         eventually be accessed.  Returning 0 here does no great
         harm; it just prevents some possible instruction scheduling.  */
      return 0;
    }

  size = GET_MODE_SIZE (mode);

  if (INTVAL (offset) % size != 0)
    return 0;
  if (REGNO (reg) == STACK_POINTER_REGNUM && GET_MODE_SIZE (mode) == 4)
    off = 0x100;
  else
    off = 0x20;
  if (INTVAL (offset) >= 0 && INTVAL (offset) < off * size)
    return 1;
  return 0;
}

/* Return truth value if a memory operand fits in a single instruction
   (ie, register + small offset).  */

int
simple_memory_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  rtx addr, plus0, plus1;

  /* Eliminate non-memory operations */
  if (GET_CODE (op) != MEM)
    return 0;

  /* dword operations really put out 2 instructions, so eliminate them.  */
  /* ??? This isn't strictly correct.  It is OK to accept multiword modes
     here, since the length attributes are being set correctly, but only
     if the address is offsettable.  LO_SUM is not offsettable.  */
  if (GET_MODE_SIZE (GET_MODE (op)) > UNITS_PER_WORD)
    return 0;

  /* Decode the address now.  */
  addr = XEXP (op, 0);
  switch (GET_CODE (addr))
    {
    case REG:
    case LO_SUM:
      return 1;

    case CONST_INT:
      if (TARGET_MIPS16)
        return 0;
      return SMALL_INT (op);

    case PLUS:
      plus0 = XEXP (addr, 0);
      plus1 = XEXP (addr, 1);
      if (GET_CODE (plus0) == REG
          && GET_CODE (plus1) == CONST_INT && SMALL_INT (plus1)
          && (! TARGET_MIPS16
              || mips16_simple_memory_operand (plus0, plus1, mode)))
        return 1;

      else if (GET_CODE (plus1) == REG
               && GET_CODE (plus0) == CONST_INT && SMALL_INT (plus0)
               && (! TARGET_MIPS16
                   || mips16_simple_memory_operand (plus1, plus0, mode)))
        return 1;

      else
        return 0;

#if 0
      /* We used to allow small symbol refs here (ie, stuff in .sdata
         or .sbss), but this causes some bugs in G++.  Also, it won't
         interfere if the MIPS linker rewrites the store instruction
         because the function is PIC.  */

    case LABEL_REF:             /* never gp relative */
      break;

    case CONST:
      /* If -G 0, we can never have a GP relative memory operation.
         Also, save some time if not optimizing.  */
      if (!TARGET_GP_OPT)
        return 0;

      {
        rtx offset = const0_rtx;
        addr = eliminate_constant_term (XEXP (addr, 0), &offset);
        if (GET_CODE (op) != SYMBOL_REF)
          return 0;

        /* let's be paranoid.... */
        if (! SMALL_INT (offset))
          return 0;
      }

      /* fall through */

    case SYMBOL_REF:
      return SYMBOL_REF_FLAG (addr);
#endif

      /* This SYMBOL_REF case is for the mips16.  If the above case is
         reenabled, this one should be merged in.  */
    case SYMBOL_REF:
      /* References to the constant pool on the mips16 use a small
         offset if the function is small.  The only time we care about
         getting this right is during delayed branch scheduling, so
         don't need to check until then.  The machine_dependent_reorg
         function will set the total length of the instructions used
         in the function in current_frame_info.  If that is small
         enough, we know for sure that this is a small offset.  It
         would be better if we could take into account the location of
         the instruction within the function, but we can't, because we
         don't know where we are.  */
      if (TARGET_MIPS16
          && CONSTANT_POOL_ADDRESS_P (addr)
          && current_frame_info.insns_len > 0)
        {
          long size;

          size = current_frame_info.insns_len + get_pool_size ();
          if (GET_MODE_SIZE (mode) == 4)
            return size < 4 * 0x100;
          else if (GET_MODE_SIZE (mode) == 8)
            return size < 8 * 0x20;
          else
            return 0;
        }

      return 0;

    default:
      break;
    }

  return 0;
}

/* Return nonzero for a memory address that can be used to load or store
   a doubleword.  */

int
double_memory_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  rtx addr;

  if (GET_CODE (op) != MEM
      || ! memory_operand (op, mode))
    {
      /* During reload, we accept a pseudo register if it has an
         appropriate memory address.  If we don't do this, we will
         wind up reloading into a register, and then reloading that
         register from memory, when we could just reload directly from
         memory.  */
      if (reload_in_progress
          && GET_CODE (op) == REG
          && REGNO (op) >= FIRST_PSEUDO_REGISTER
          && reg_renumber[REGNO (op)] < 0
          && reg_equiv_mem[REGNO (op)] != 0
          && double_memory_operand (reg_equiv_mem[REGNO (op)], mode))
        return 1;

      /* All reloaded addresses are valid in TARGET_64BIT mode.  This is
         the same test performed for 'm' in find_reloads.  */

      if (reload_in_progress
          && TARGET_64BIT
          && (GET_CODE (op) == MEM
              || (GET_CODE (op) == REG
                  && REGNO (op) >= FIRST_PSEUDO_REGISTER
                  && reg_renumber[REGNO (op)] < 0)))
        return 1;

      if (reload_in_progress
          && TARGET_MIPS16
          && GET_CODE (op) == MEM)
        {
          rtx addr;

          addr = XEXP (op, 0);

          /* During reload on the mips16, we accept a large offset
             from the frame pointer or the stack pointer.  This large
             address will get reloaded anyhow.  */
          if (GET_CODE (addr) == PLUS
              && GET_CODE (XEXP (addr, 0)) == REG
              && (REGNO (XEXP (addr, 0)) == HARD_FRAME_POINTER_REGNUM
                  || REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM)
              && ((GET_CODE (XEXP (addr, 1)) == CONST_INT
                   && ! SMALL_INT (XEXP (addr, 1)))
                  || (GET_CODE (XEXP (addr, 1)) == SYMBOL_REF
                      && CONSTANT_POOL_ADDRESS_P (XEXP (addr, 1)))))
            return 1;

          /* Similarly, we accept a case where the memory address is
             itself on the stack, and will be reloaded. */
          if (GET_CODE (addr) == MEM)
            {
              rtx maddr;

              maddr = XEXP (addr, 0);
              if (GET_CODE (maddr) == PLUS
                  && GET_CODE (XEXP (maddr, 0)) == REG
                  && (REGNO (XEXP (maddr, 0)) == HARD_FRAME_POINTER_REGNUM
                      || REGNO (XEXP (maddr, 0)) == STACK_POINTER_REGNUM)
                  && ((GET_CODE (XEXP (maddr, 1)) == CONST_INT
                       && ! SMALL_INT (XEXP (maddr, 1)))
                      || (GET_CODE (XEXP (maddr, 1)) == SYMBOL_REF
                          && CONSTANT_POOL_ADDRESS_P (XEXP (maddr, 1)))))
                return 1;
            }

          /* We also accept the same case when we have a 16 bit signed
             offset mixed in as well.  The large address will get
             reloaded, and the 16 bit offset will be OK.  */
          if (GET_CODE (addr) == PLUS
              && GET_CODE (XEXP (addr, 0)) == MEM
              && GET_CODE (XEXP (addr, 1)) == CONST_INT
              && SMALL_INT (XEXP (addr, 1)))
            {
              addr = XEXP (XEXP (addr, 0), 0);
              if (GET_CODE (addr) == PLUS
                  && GET_CODE (XEXP (addr, 0)) == REG
                  && (REGNO (XEXP (addr, 0)) == HARD_FRAME_POINTER_REGNUM
                      || REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM)
                  && ((GET_CODE (XEXP (addr, 1)) == CONST_INT
                       && ! SMALL_INT (XEXP (addr, 1)))
                      || (GET_CODE (XEXP (addr, 1)) == SYMBOL_REF
                          && CONSTANT_POOL_ADDRESS_P (XEXP (addr, 1)))))
                return 1;
            }
        }

      return 0;
    }

  if (TARGET_64BIT)
    {
      /* In this case we can use an instruction like sd.  */
      return 1;
    }

  /* Make sure that 4 added to the address is a valid memory address.
     This essentially just checks for overflow in an added constant.  */

  addr = XEXP (op, 0);

  if (CONSTANT_ADDRESS_P (addr))
    return 1;

  return memory_address_p ((GET_MODE_CLASS (mode) == MODE_INT
                            ? SImode
                            : SFmode),
                           plus_constant_for_output (addr, 4));
}

/* Return nonzero if the code of this rtx pattern is EQ or NE.  */

int
equality_op (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (mode != GET_MODE (op))
    return 0;

  return GET_CODE (op) == EQ || GET_CODE (op) == NE;
}

/* Return nonzero if the code is a relational operations (EQ, LE, etc.) */

int
cmp_op (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (mode != GET_MODE (op))
    return 0;

  return GET_RTX_CLASS (GET_CODE (op)) == '<';
}

/* Return nonzero if the operand is either the PC or a label_ref.  */

int
pc_or_label_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  if (op == pc_rtx)
    return 1;

  if (GET_CODE (op) == LABEL_REF)
    return 1;

  return 0;
}

/* Test for a valid operand for a call instruction.
   Don't allow the arg pointer register or virtual regs
   since they may change into reg + const, which the patterns
   can't handle yet.  */

int
call_insn_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (CONSTANT_ADDRESS_P (op)
          || (GET_CODE (op) == REG && op != arg_pointer_rtx
              && ! (REGNO (op) >= FIRST_PSEUDO_REGISTER
                    && REGNO (op) <= LAST_VIRTUAL_REGISTER)));
}

/* Return nonzero if OPERAND is valid as a source operand for a move
   instruction.  */

int
move_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  /* Accept any general operand after reload has started; doing so
     avoids losing if reload does an in-place replacement of a register
     with a SYMBOL_REF or CONST.  */
  return (general_operand (op, mode)
          && (! (mips_split_addresses && mips_check_split (op, mode))
              || reload_in_progress || reload_completed)
          && ! (TARGET_MIPS16
                && GET_CODE (op) == SYMBOL_REF
                && ! mips16_constant (op, mode, 1, 0)));
}

/* Return nonzero if OPERAND is valid as a source operand for movdi.
   This accepts not only general_operand, but also sign extended
   constants and registers.  We need to accept sign extended constants
   in case a sign extended register which is used in an expression,
   and is equivalent to a constant, is spilled.  */

int
movdi_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && (GET_MODE (XEXP (op, 0)) == SImode
          || (GET_CODE (XEXP (op, 0)) == CONST_INT
              && GET_MODE (XEXP (op, 0)) == VOIDmode))
      && (register_operand (XEXP (op, 0), SImode)
          || immediate_operand (XEXP (op, 0), SImode)))
    return 1;

  return (general_operand (op, mode)
          && ! (TARGET_MIPS16
                && GET_CODE (op) == SYMBOL_REF
                && ! mips16_constant (op, mode, 1, 0)));
}

/* Like register_operand, but when in 64 bit mode also accept a sign
   extend of a 32 bit register, since the value is known to be already
   sign extended.  */

int
se_register_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return register_operand (op, mode);
}

/* Like reg_or_0_operand, but when in 64 bit mode also accept a sign
   extend of a 32 bit register, since the value is known to be already
   sign extended.  */

int
se_reg_or_0_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return reg_or_0_operand (op, mode);
}

/* Like uns_arith_operand, but when in 64 bit mode also accept a sign
   extend of a 32 bit register, since the value is known to be already
   sign extended.  */

int
se_uns_arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return uns_arith_operand (op, mode);
}

/* Like arith_operand, but when in 64 bit mode also accept a sign
   extend of a 32 bit register, since the value is known to be already
   sign extended.  */

int
se_arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return arith_operand (op, mode);
}

/* Like nonmemory_operand, but when in 64 bit mode also accept a sign
   extend of a 32 bit register, since the value is known to be already
   sign extended.  */

int
se_nonmemory_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return nonmemory_operand (op, mode);
}

/* Like nonimmediate_operand, but when in 64 bit mode also accept a
   sign extend of a 32 bit register, since the value is known to be
   already sign extended.  */

int
se_nonimmediate_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (TARGET_64BIT
      && mode == DImode
      && GET_CODE (op) == SIGN_EXTEND
      && GET_MODE (op) == DImode
      && GET_MODE (XEXP (op, 0)) == SImode
      && register_operand (XEXP (op, 0), SImode))
    return 1;

  return nonimmediate_operand (op, mode);
}

/* Accept any operand that can appear in a mips16 constant table
   instruction.  We can't use any of the standard operand functions
   because for these instructions we accept values that are not
   accepted by LEGITIMATE_CONSTANT, such as arbitrary SYMBOL_REFs.  */

int
consttable_operand (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return CONSTANT_P (op);
}

/* Return nonzero if we split the address into high and low parts.  */

/* ??? We should also handle reg+array somewhere.  We get four
   instructions currently, lui %hi/addui %lo/addui reg/lw.  Better is
   lui %hi/addui reg/lw %lo.  Fixing GO_IF_LEGITIMATE_ADDRESS to accept
   (plus (reg) (symbol_ref)) doesn't work because the SYMBOL_REF is broken
   out of the address, then we have 4 instructions to combine.  Perhaps
   add a 3->2 define_split for combine.  */

/* ??? We could also split a CONST_INT here if it is a large_int().
   However, it doesn't seem to be very useful to have %hi(constant).
   We would be better off by doing the masking ourselves and then putting
   the explicit high part of the constant in the RTL.  This will give better
   optimization.  Also, %hi(constant) needs assembler changes to work.
   There is already a define_split that does this.  */

int
mips_check_split (address, mode)
     rtx address;
     enum machine_mode mode;
{     
  /* ??? This is the same check used in simple_memory_operand.
     We use it here because LO_SUM is not offsettable.  */
  if (GET_MODE_SIZE (mode) > UNITS_PER_WORD)
    return 0;

  if ((GET_CODE (address) == SYMBOL_REF && ! SYMBOL_REF_FLAG (address))
      || (GET_CODE (address) == CONST
          && GET_CODE (XEXP (XEXP (address, 0), 0)) == SYMBOL_REF
          && ! SYMBOL_REF_FLAG (XEXP (XEXP (address, 0), 0)))
      || GET_CODE (address) == LABEL_REF)
    return 1;

  return 0;
}
\f
/* We need a lot of little routines to check constant values on the
   mips16.  These are used to figure out how long the instruction will
   be.  It would be much better to do this using constraints, but
   there aren't nearly enough letters available.  */

static int
m16_check_op (op, low, high, mask)
     rtx op;
     int low;
     int high;
     int mask;
{
  return (GET_CODE (op) == CONST_INT
          && INTVAL (op) >= low
          && INTVAL (op) <= high
          && (INTVAL (op) & mask) == 0);
}

int
m16_uimm3_b (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, 0x1, 0x8, 0);
}

int
m16_simm4_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x8, 0x7, 0);
}

int
m16_nsimm4_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x7, 0x8, 0);
}

int
m16_simm5_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x10, 0xf, 0);
}

int
m16_nsimm5_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0xf, 0x10, 0);
}

int
m16_uimm5_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, (- 0x10) << 2, 0xf << 2, 3);
}

int
m16_nuimm5_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, (- 0xf) << 2, 0x10 << 2, 3);
}

int
m16_simm8_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x80, 0x7f, 0);
}

int
m16_nsimm8_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x7f, 0x80, 0);
}

int
m16_uimm8_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, 0x0, 0xff, 0);
}

int
m16_nuimm8_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0xff, 0x0, 0);
}

int
m16_uimm8_m1_1 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, - 0x1, 0xfe, 0);
}

int
m16_uimm8_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, 0x0, 0xff << 2, 3);
}

int
m16_nuimm8_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, (- 0xff) << 2, 0x0, 3);
}

int
m16_simm8_8 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, (- 0x80) << 3, 0x7f << 3, 7);
}

int
m16_nsimm8_8 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return m16_check_op (op, (- 0x7f) << 3, 0x80 << 3, 7);
}

/* References to the string table on the mips16 only use a small
   offset if the function is small.  See the comment in the SYMBOL_REF
   case in simple_memory_operand.  We can't check for LABEL_REF here,
   because the offset is always large if the label is before the
   referencing instruction.  */

int
m16_usym8_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  if (GET_CODE (op) == SYMBOL_REF
      && SYMBOL_REF_FLAG (op)
      && current_frame_info.insns_len > 0
      && XSTR (op, 0)[0] == '*'
      && strncmp (XSTR (op, 0) + 1, LOCAL_LABEL_PREFIX,
                  sizeof LOCAL_LABEL_PREFIX - 1) == 0
      && (current_frame_info.insns_len + get_pool_size () + mips_string_length
          < 4 * 0x100))
    {
      struct string_constant *l;

      /* Make sure this symbol is on thelist of string constants to be
         output for this function.  It is possible that it has already
         been output, in which case this requires a large offset.  */
      for (l = string_constants; l != NULL; l = l->next)
        if (strcmp (l->label, XSTR (op, 0)) == 0)
          return 1;
    }

  return 0;
}

int
m16_usym5_4 (op, mode)
     rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  if (GET_CODE (op) == SYMBOL_REF
      && SYMBOL_REF_FLAG (op)
      && current_frame_info.insns_len > 0
      && XSTR (op, 0)[0] == '*'
      && strncmp (XSTR (op, 0) + 1, LOCAL_LABEL_PREFIX,
                  sizeof LOCAL_LABEL_PREFIX - 1) == 0
      && (current_frame_info.insns_len + get_pool_size () + mips_string_length
          < 4 * 0x20))
    {
      struct string_constant *l;

      /* Make sure this symbol is on thelist of string constants to be
         output for this function.  It is possible that it has already
         been output, in which case this requires a large offset.  */
      for (l = string_constants; l != NULL; l = l->next)
        if (strcmp (l->label, XSTR (op, 0)) == 0)
          return 1;
    }

  return 0;
}
\f
/* Returns an operand string for the given instruction's delay slot,
   after updating filled delay slot statistics.

   We assume that operands[0] is the target register that is set.

   In order to check the next insn, most of this functionality is moved
   to FINAL_PRESCAN_INSN, and we just set the global variables that
   it needs.  */

/* ??? This function no longer does anything useful, because final_prescan_insn
   now will never emit a nop.  */

char *
mips_fill_delay_slot (ret, type, operands, cur_insn)
     char *ret;                 /* normal string to return */
     enum delay_type type;      /* type of delay */
     rtx operands[];            /* operands to use */
     rtx cur_insn;              /* current insn */
{
  register rtx set_reg;
  register enum machine_mode mode;
  register rtx next_insn = cur_insn ? NEXT_INSN (cur_insn) : NULL_RTX;
  register int num_nops;

  if (type == DELAY_LOAD || type == DELAY_FCMP)
    num_nops = 1;

  else if (type == DELAY_HILO)
    num_nops = 2;

  else
    num_nops = 0;

  /* Make sure that we don't put nop's after labels.  */
  next_insn = NEXT_INSN (cur_insn);
  while (next_insn != 0 && GET_CODE (next_insn) == NOTE)
    next_insn = NEXT_INSN (next_insn);

  dslots_load_total += num_nops;
  if (TARGET_DEBUG_F_MODE
      || !optimize
      || type == DELAY_NONE
      || operands == 0
      || cur_insn == 0
      || next_insn == 0
      || GET_CODE (next_insn) == CODE_LABEL
      || (set_reg = operands[0]) == 0)
    {
      dslots_number_nops = 0;
      mips_load_reg  = 0;
      mips_load_reg2 = 0;
      mips_load_reg3 = 0;
      mips_load_reg4 = 0;
      return ret;
    }

  set_reg = operands[0];
  if (set_reg == 0)
    return ret;

  while (GET_CODE (set_reg) == SUBREG)
    set_reg = SUBREG_REG (set_reg);

  mode = GET_MODE (set_reg);
  dslots_number_nops = num_nops;
  mips_load_reg = set_reg;
  if (GET_MODE_SIZE (mode)
      > (FP_REG_P (REGNO (set_reg)) ? UNITS_PER_FPREG : UNITS_PER_WORD))
    mips_load_reg2 = gen_rtx (REG, SImode, REGNO (set_reg) + 1);
  else
    mips_load_reg2 = 0;

  if (type == DELAY_HILO)
    {
      mips_load_reg3 = gen_rtx (REG, SImode, MD_REG_FIRST);
      mips_load_reg4 = gen_rtx (REG, SImode, MD_REG_FIRST+1);
    }
  else
    {
      mips_load_reg3 = 0;
      mips_load_reg4 = 0;
    }

  return ret;
}

\f
/* Determine whether a memory reference takes one (based off of the GP
   pointer), two (normal), or three (label + reg) instructions, and bump the
   appropriate counter for -mstats.  */

void
mips_count_memory_refs (op, num)
     rtx op;
     int num;
{
  int additional = 0;
  int n_words = 0;
  rtx addr, plus0, plus1;
  enum rtx_code code0, code1;
  int looping;

  if (TARGET_DEBUG_B_MODE)
    {
      fprintf (stderr, "\n========== mips_count_memory_refs:\n");
      debug_rtx (op);
    }

  /* Skip MEM if passed, otherwise handle movsi of address.  */
  addr = (GET_CODE (op) != MEM) ? op : XEXP (op, 0);

  /* Loop, going through the address RTL.  */
  do
    {
      looping = FALSE;
      switch (GET_CODE (addr))
        {
        case REG:
        case CONST_INT:
        case LO_SUM:
          break;

        case PLUS:
          plus0 = XEXP (addr, 0);
          plus1 = XEXP (addr, 1);
          code0 = GET_CODE (plus0);
          code1 = GET_CODE (plus1);

          if (code0 == REG)
            {
              additional++;
              addr = plus1;
              looping = 1;
              continue;
            }

          if (code0 == CONST_INT)
            {
              addr = plus1;
              looping = 1;
              continue;
            }

          if (code1 == REG)
            {
              additional++;
              addr = plus0;
              looping = 1;
              continue;
            }

          if (code1 == CONST_INT)
            {
              addr = plus0;
              looping = 1;
              continue;
            }

          if (code0 == SYMBOL_REF || code0 == LABEL_REF || code0 == CONST)
            {
              addr = plus0;
              looping = 1;
              continue;
            }

          if (code1 == SYMBOL_REF || code1 == LABEL_REF || code1 == CONST)
            {
              addr = plus1;
              looping = 1;
              continue;
            }

          break;

        case LABEL_REF:
          n_words = 2;          /* always 2 words */
          break;

        case CONST:
          addr = XEXP (addr, 0);
          looping = 1;
          continue;

        case SYMBOL_REF:
          n_words = SYMBOL_REF_FLAG (addr) ? 1 : 2;
          break;

        default:
          break;
        }
    }
  while (looping);

  if (n_words == 0)
    return;

  n_words += additional;
  if (n_words > 3)
    n_words = 3;

  num_refs[n_words-1] += num;
}

\f
/* Return RTL for the offset from the current function to the argument.

   ??? Which argument is this?  */

rtx
embedded_pic_offset (x)
     rtx x;
{
  if (embedded_pic_fnaddr_rtx == NULL)
    {
      rtx seq;

      embedded_pic_fnaddr_rtx = gen_reg_rtx (Pmode);
      
      /* Output code at function start to initialize the pseudo-reg.  */
      /* ??? We used to do this in FINALIZE_PIC, but that does not work for
         inline functions, because it is called after RTL for the function
         has been copied.  The pseudo-reg in embedded_pic_fnaddr_rtx however
         does not get copied, and ends up not matching the rest of the RTL.
         This solution works, but means that we get unnecessary code to
         initialize this value every time a function is inlined into another
         function.  */
      start_sequence ();
      emit_insn (gen_get_fnaddr (embedded_pic_fnaddr_rtx,
                                 XEXP (DECL_RTL (current_function_decl), 0)));
      seq = gen_sequence ();
      end_sequence ();
      push_topmost_sequence ();
      emit_insn_after (seq, get_insns ());
      pop_topmost_sequence ();
    }

  return gen_rtx (CONST, Pmode,
                  gen_rtx (MINUS, Pmode, x,
                           XEXP (DECL_RTL (current_function_decl), 0)));
}

/* Return the appropriate instructions to move one operand to another.  */

const char *
mips_move_1word (operands, insn, unsignedp)
     rtx operands[];
     rtx insn;
     int unsignedp;
{
  const char *ret = 0;
  rtx op0 = operands[0];
  rtx op1 = operands[1];
  enum rtx_code code0 = GET_CODE (op0);
  enum rtx_code code1 = GET_CODE (op1);
  enum machine_mode mode = GET_MODE (op0);
  int subreg_word0 = 0;
  int subreg_word1 = 0;
  enum delay_type delay = DELAY_NONE;

  while (code0 == SUBREG)
    {
      subreg_word0 += SUBREG_WORD (op0);
      op0 = SUBREG_REG (op0);
      code0 = GET_CODE (op0);
    }

  while (code1 == SUBREG)
    {
      subreg_word1 += SUBREG_WORD (op1);
      op1 = SUBREG_REG (op1);
      code1 = GET_CODE (op1);
    }

  /* For our purposes, a condition code mode is the same as SImode.  */
  if (mode == CCmode)
    mode = SImode;

  if (code0 == REG)
    {
      int regno0 = REGNO (op0) + subreg_word0;

      if (code1 == REG)
        {
          int regno1 = REGNO (op1) + subreg_word1;

          /* Just in case, don't do anything for assigning a register
             to itself, unless we are filling a delay slot.  */
          if (regno0 == regno1 && set_nomacro == 0)
            ret = "";

          else if (GP_REG_P (regno0))
            {
              if (GP_REG_P (regno1))
                ret = "move\t%0,%1";

              else if (MD_REG_P (regno1))
                {
                  delay = DELAY_HILO;
                  if (regno1 != HILO_REGNUM)
                    ret = "mf%1\t%0";
                  else
                    ret = "mflo\t%0";
                }

              else if (ST_REG_P (regno1) && mips_isa >= 4)
                ret = "li\t%0,1\n\tmovf\t%0,%.,%1";

              else
                {
                  delay = DELAY_LOAD;
                  if (FP_REG_P (regno1))
                    ret = "mfc1\t%0,%1";

                  else if (regno1 == FPSW_REGNUM && mips_isa < 4)
                    ret = "cfc1\t%0,$31";
                }
            }

          else if (FP_REG_P (regno0))
            {
              if (GP_REG_P (regno1))
                {
                  delay = DELAY_LOAD;
                  ret = "mtc1\t%1,%0";
                }

              if (FP_REG_P (regno1))
                ret = "mov.s\t%0,%1";
            }

          else if (MD_REG_P (regno0))
            {
              if (GP_REG_P (regno1))
                {
                  delay = DELAY_HILO;
                  if (regno0 != HILO_REGNUM && ! TARGET_MIPS16)
                    ret = "mt%0\t%1";
                }
            }

          else if (regno0 == FPSW_REGNUM && mips_isa < 4)
            {
              if (GP_REG_P (regno1))
                {
                  delay = DELAY_LOAD;
                  ret = "ctc1\t%0,$31";
                }
            }
        }

      else if (code1 == MEM)
        {
          delay = DELAY_LOAD;

          if (TARGET_STATS)
            mips_count_memory_refs (op1, 1);

          if (GP_REG_P (regno0))
            {
              /* For loads, use the mode of the memory item, instead of the
                 target, so zero/sign extend can use this code as well.  */
              switch (GET_MODE (op1))
                {
                default:
                  break;
                case SFmode:
                  ret = "lw\t%0,%1";
                  break;
                case SImode:
                case CCmode:
                  ret = ((unsignedp && TARGET_64BIT)
                         ? "lwu\t%0,%1"
                         : "lw\t%0,%1");
                  break;
                case HImode:
                  ret = (unsignedp) ? "lhu\t%0,%1" : "lh\t%0,%1";
                  break;
                case QImode:
                  ret = (unsignedp) ? "lbu\t%0,%1" : "lb\t%0,%1";
                  break;
                }
            }

          else if (FP_REG_P (regno0) && (mode == SImode || mode == SFmode))
            ret = "l.s\t%0,%1";

          if (ret != (char *)0 && MEM_VOLATILE_P (op1))
            {
              size_t i = strlen (ret);
              if (i > sizeof (volatile_buffer) - sizeof ("%{%}"))
                abort ();

              sprintf (volatile_buffer, "%%{%s%%}", ret);
              ret = volatile_buffer;
            }
        }

      else if (code1 == CONST_INT
               || (code1 == CONST_DOUBLE
                   && GET_MODE (op1) == VOIDmode))
        {
          if (code1 == CONST_DOUBLE)
            {
              /* This can happen when storing constants into long long
                 bitfields.  Just store the least significant word of
                 the value.  */
              operands[1] = op1 = GEN_INT (CONST_DOUBLE_LOW (op1));
            }

          if (INTVAL (op1) == 0 && ! TARGET_MIPS16)
            {
              if (GP_REG_P (regno0))
                ret = "move\t%0,%z1";

              else if (FP_REG_P (regno0))
                {
                  delay = DELAY_LOAD;
                  ret = "mtc1\t%z1,%0";
                }

              else if (MD_REG_P (regno0))
                {
                  delay = DELAY_HILO;
                  ret = "mt%0\t%.";
                }
            }

          else if (GP_REG_P (regno0))
            {
              /* Don't use X format, because that will give out of
                 range numbers for 64 bit host and 32 bit target.  */
              if (! TARGET_MIPS16)
                ret = "li\t%0,%1\t\t\t# %X1";
              else
                {
                  if (INTVAL (op1) >= 0 && INTVAL (op1) <= 0xffff)
                    ret = "li\t%0,%1";
                  else if (INTVAL (op1) < 0 && INTVAL (op1) >= -0xffff)
                    ret = "li\t%0,%n1\n\tneg\t%0";
                }
            }
        }

      else if (code1 == CONST_DOUBLE && mode == SFmode)
        {
          if (op1 == CONST0_RTX (SFmode))
            {
              if (GP_REG_P (regno0))
                ret = "move\t%0,%.";

              else if (FP_REG_P (regno0))
                {
                  delay = DELAY_LOAD;
                  ret = "mtc1\t%.,%0";
                }
            }

          else
            {
              delay = DELAY_LOAD;
              ret = "li.s\t%0,%1";
            }
        }

      else if (code1 == LABEL_REF)
        {
          if (TARGET_STATS)
            mips_count_memory_refs (op1, 1);

          ret = "la\t%0,%a1";
        }

      else if (code1 == SYMBOL_REF || code1 == CONST)
        {
          if (HALF_PIC_P () && CONSTANT_P (op1) && HALF_PIC_ADDRESS_P (op1))
            {
              rtx offset = const0_rtx;

              if (GET_CODE (op1) == CONST)
                op1 = eliminate_constant_term (XEXP (op1, 0), &offset);

              if (GET_CODE (op1) == SYMBOL_REF)
                {
                  operands[2] = HALF_PIC_PTR (op1);

                  if (TARGET_STATS)
                    mips_count_memory_refs (operands[2], 1);

                  if (INTVAL (offset) == 0)
                    {
                      delay = DELAY_LOAD;
                      ret = (unsignedp && TARGET_64BIT
                             ? "lwu\t%0,%2"
                             : "lw\t%0,%2");
                    }
                  else
                    {
                      dslots_load_total++;
                      operands[3] = offset;
                      if (unsignedp && TARGET_64BIT)
                        ret = (SMALL_INT (offset)
                               ? "lwu\t%0,%2%#\n\tadd\t%0,%0,%3"
                               : "lwu\t%0,%2%#\n\t%[li\t%@,%3\n\tadd\t%0,%0,%@%]");
                      else
                        ret = (SMALL_INT (offset)
                               ? "lw\t%0,%2%#\n\tadd\t%0,%0,%3"
                               : "lw\t%0,%2%#\n\t%[li\t%@,%3\n\tadd\t%0,%0,%@%]");
                    }
                }
            }
          else if (TARGET_MIPS16
                   && code1 == CONST
                   && GET_CODE (XEXP (op1, 0)) == REG
                   && REGNO (XEXP (op1, 0)) == GP_REG_FIRST + 28)
            {
              /* This case arises on the mips16; see
                 mips16_gp_pseudo_reg.  */
              ret = "move\t%0,%+";
            }
          else if (TARGET_MIPS16
                   && code1 == SYMBOL_REF
                   && SYMBOL_REF_FLAG (op1)
                   && (XSTR (op1, 0)[0] != '*'
                       || strncmp (XSTR (op1, 0) + 1,
                                   LOCAL_LABEL_PREFIX,
                                   sizeof LOCAL_LABEL_PREFIX - 1) != 0))
            {
              /* This can occur when reloading the address of a GP
                 relative symbol on the mips16.  */
              ret = "move\t%0,%+\n\taddu\t%0,%%gprel(%a1)";
            }
          else
            {
              if (TARGET_STATS)
                mips_count_memory_refs (op1, 1);

              ret = "la\t%0,%a1";
            }
        }

      else if (code1 == PLUS)
        {
          rtx add_op0 = XEXP (op1, 0);
          rtx add_op1 = XEXP (op1, 1);

          if (GET_CODE (XEXP (op1, 1)) == REG
              && GET_CODE (XEXP (op1, 0)) == CONST_INT)
            add_op0 = XEXP (op1, 1), add_op1 = XEXP (op1, 0);

          operands[2] = add_op0;
          operands[3] = add_op1;
          ret = "add%:\t%0,%2,%3";
        }

      else if (code1 == HIGH)
        {
          operands[1] = XEXP (op1, 0);
          ret = "lui\t%0,%%hi(%1)";
        }
    }

  else if (code0 == MEM)
    {
      if (TARGET_STATS)
        mips_count_memory_refs (op0, 1);

      if (code1 == REG)
        {
          int regno1 = REGNO (op1) + subreg_word1;

          if (GP_REG_P (regno1))
            {
              switch (mode)
                {
                case SFmode: ret = "sw\t%1,%0"; break;
                case SImode: ret = "sw\t%1,%0"; break;
                case HImode: ret = "sh\t%1,%0"; break;
                case QImode: ret = "sb\t%1,%0"; break;
                default: break;
                }
            }

          else if (FP_REG_P (regno1) && (mode == SImode || mode == SFmode))
            ret = "s.s\t%1,%0";
        }

      else if (code1 == CONST_INT && INTVAL (op1) == 0)
        {
          switch (mode)
            {
            case SFmode: ret = "sw\t%z1,%0"; break;
            case SImode: ret = "sw\t%z1,%0"; break;
            case HImode: ret = "sh\t%z1,%0"; break;
            case QImode: ret = "sb\t%z1,%0"; break;
            default: break;
            }
        }

      else if (code1 == CONST_DOUBLE && op1 == CONST0_RTX (mode))
        {
          switch (mode)
            {
            case SFmode: ret = "sw\t%.,%0"; break;
            case SImode: ret = "sw\t%.,%0"; break;
            case HImode: ret = "sh\t%.,%0"; break;
            case QImode: ret = "sb\t%.,%0"; break;
            default: break;
            }
        }

      if (ret != 0 && MEM_VOLATILE_P (op0))
        {
          size_t i = strlen (ret);

          if (i > sizeof (volatile_buffer) - sizeof ("%{%}"))
            abort ();
          
          sprintf (volatile_buffer, "%%{%s%%}", ret);
          ret = volatile_buffer;
        }
    }

  if (ret == 0)
    {
      abort_with_insn (insn, "Bad move");
      return 0;
    }

  if (delay != DELAY_NONE)
    return mips_fill_delay_slot (ret, delay, operands, insn);

  return ret;
}

\f
/* Return the appropriate instructions to move 2 words */

const char *
mips_move_2words (operands, insn)
     rtx operands[];
     rtx insn;
{
  const char *ret = 0;
  rtx op0 = operands[0];
  rtx op1 = operands[1];
  enum rtx_code code0 = GET_CODE (operands[0]);
  enum rtx_code code1 = GET_CODE (operands[1]);
  int subreg_word0 = 0;
  int subreg_word1 = 0;
  enum delay_type delay = DELAY_NONE;

  while (code0 == SUBREG)
    {
      subreg_word0 += SUBREG_WORD (op0);
      op0 = SUBREG_REG (op0);
      code0 = GET_CODE (op0);
    }

  if (code1 == SIGN_EXTEND)
    {
      op1 = XEXP (op1, 0);
      code1 = GET_CODE (op1);
    }

  while (code1 == SUBREG)
    {
      subreg_word1 += SUBREG_WORD (op1);
      op1 = SUBREG_REG (op1);
      code1 = GET_CODE (op1);
    }
      
  /* Sanity check.  */
  if (GET_CODE (operands[1]) == SIGN_EXTEND
      && code1 != REG
      && code1 != CONST_INT
      /* The following three can happen as the result of a questionable
         cast.  */
      && code1 != LABEL_REF
      && code1 != SYMBOL_REF
      && code1 != CONST)
    abort ();

  if (code0 == REG)
    {
      int regno0 = REGNO (op0) + subreg_word0;

      if (code1 == REG)
        {
          int regno1 = REGNO (op1) + subreg_word1;

          /* Just in case, don't do anything for assigning a register
             to itself, unless we are filling a delay slot.  */
          if (regno0 == regno1 && set_nomacro == 0)
            ret = "";

          else if (FP_REG_P (regno0))
            {
              if (FP_REG_P (regno1))
                ret = "mov.d\t%0,%1";

              else
                {
                  delay = DELAY_LOAD;
                  if (TARGET_FLOAT64)
                    {
                      if (!TARGET_64BIT)
                        abort_with_insn (insn, "Bad move");

#ifdef TARGET_FP_CALL_32
                      if (FP_CALL_GP_REG_P (regno1))
                        ret = "dsll\t%1,32\n\tor\t%1,%D1\n\tdmtc1\t%1,%0";
                      else
#endif
                        ret = "dmtc1\t%1,%0";
                    }
                  else
                    ret = "mtc1\t%L1,%0\n\tmtc1\t%M1,%D0";
                }
            }

          else if (FP_REG_P (regno1))
            {
              delay = DELAY_LOAD;
              if (TARGET_FLOAT64)
                {
                  if (!TARGET_64BIT)
                    abort_with_insn (insn, "Bad move");

#ifdef TARGET_FP_CALL_32
                  if (FP_CALL_GP_REG_P (regno0))
                    ret = "dmfc1\t%0,%1\n\tmfc1\t%D0,%1\n\tdsrl\t%0,32";
                  else
#endif
                    ret = "dmfc1\t%0,%1";
                }
              else
                ret = "mfc1\t%L0,%1\n\tmfc1\t%M0,%D1";
            }

          else if (MD_REG_P (regno0) && GP_REG_P (regno1) && !TARGET_MIPS16)
            {
              delay = DELAY_HILO;
              if (TARGET_64BIT)
                {
                  if (regno0 != HILO_REGNUM)
                    ret = "mt%0\t%1";
                  else if (regno1 == 0)
                    ret = "mtlo\t%.\n\tmthi\t%.";
                }
              else
                ret = "mthi\t%M1\n\tmtlo\t%L1";
            }

          else if (GP_REG_P (regno0) && MD_REG_P (regno1))
            {
              delay = DELAY_HILO;
              if (TARGET_64BIT)
                {
                  if (regno1 != HILO_REGNUM)
                    ret = "mf%1\t%0";
                }
              else
                ret = "mfhi\t%M0\n\tmflo\t%L0";
            }

          else if (TARGET_64BIT)
            ret = "move\t%0,%1";

          else if (regno0 != (regno1+1))
            ret = "move\t%0,%1\n\tmove\t%D0,%D1";

          else
            ret = "move\t%D0,%D1\n\tmove\t%0,%1";
        }

      else if (code1 == CONST_DOUBLE)
        {
          /* Move zero from $0 unless !TARGET_64BIT and recipient
             is 64-bit fp reg, in which case generate a constant.  */
          if (op1 != CONST0_RTX (GET_MODE (op1))
              || (TARGET_FLOAT64 && !TARGET_64BIT && FP_REG_P (regno0)))
            {
              if (GET_MODE (op1) == DFmode)
                {
                  delay = DELAY_LOAD;

#ifdef TARGET_FP_CALL_32
                  if (FP_CALL_GP_REG_P (regno0))
                    {
                      if (TARGET_FLOAT64 && !TARGET_64BIT)
                        {
                          split_double (op1, operands + 2, operands + 3);
                          ret = "li\t%0,%2\n\tli\t%D0,%3";
                        }
                      else
                        ret = "li.d\t%0,%1\n\tdsll\t%D0,%0,32\n\tdsrl\t%D0,32\n\tdsrl\t%0,32";
                    }
                  else
#endif
                    ret = "li.d\t%0,%1";
                }

              else if (TARGET_64BIT)
                {
                  if (! TARGET_MIPS16)
                    ret = "dli\t%0,%1";
                }

              else
                {
                  split_double (op1, operands + 2, operands + 3);
                  ret = "li\t%0,%2\n\tli\t%D0,%3";
                }
            }

          else
            {
              if (GP_REG_P (regno0))
                ret = (TARGET_64BIT
#ifdef TARGET_FP_CALL_32
                       && ! FP_CALL_GP_REG_P (regno0)
#endif
                       ? "move\t%0,%."
                       : "move\t%0,%.\n\tmove\t%D0,%.");

              else if (FP_REG_P (regno0))
                {
                  delay = DELAY_LOAD;
                  ret = (TARGET_64BIT
                         ? "dmtc1\t%.,%0"
                         : "mtc1\t%.,%0\n\tmtc1\t%.,%D0");
                }
            }
        }

      else if (code1 == CONST_INT && INTVAL (op1) == 0 && ! TARGET_MIPS16)
        {
          if (GP_REG_P (regno0))
            ret = (TARGET_64BIT
                   ? "move\t%0,%."
                   : "move\t%0,%.\n\tmove\t%D0,%.");

          else if (FP_REG_P (regno0))
            {
              delay = DELAY_LOAD;
              ret = (TARGET_64BIT
                     ? "dmtc1\t%.,%0"
                     : (TARGET_FLOAT64
                        ? "li.d\t%0,%1"
                        : "mtc1\t%.,%0\n\tmtc1\t%.,%D0"));
            }
          else if (MD_REG_P (regno0))
            {
              delay = DELAY_HILO;
              ret =  (regno0 == HILO_REGNUM
                      ? "mtlo\t%.\n\tmthi\t%."
                      : "mt%0\t%.\n");
            }
        }
        
      else if (code1 == CONST_INT && GET_MODE (op0) == DImode
               && GP_REG_P (regno0))
        {
          if (TARGET_64BIT)
            {
              if (TARGET_MIPS16)
                {
                  if (INTVAL (op1) >= 0 && INTVAL (op1) <= 0xffff)
                    ret = "li\t%0,%1";
                  else if (INTVAL (op1) < 0 && INTVAL (op1) >= -0xffff)
                    ret = "li\t%0,%n1\n\tneg\t%0";
                }
              else if (GET_CODE (operands[1]) == SIGN_EXTEND)
                ret = "li\t%0,%1\t\t# %X1";
              else if (HOST_BITS_PER_WIDE_INT < 64)
                /* We can't use 'X' for negative numbers, because then we won't
                   get the right value for the upper 32 bits.  */
                ret = (INTVAL (op1) < 0
                       ? "dli\t%0,%1\t\t\t# %X1"
                       : "dli\t%0,%X1\t\t# %1");
              else
                /* We must use 'X', because otherwise LONG_MIN will print as
                   a number that the assembler won't accept.  */
                ret = "dli\t%0,%X1\t\t# %1";
            }
          else if (HOST_BITS_PER_WIDE_INT < 64)
            {
              operands[2] = GEN_INT (INTVAL (operands[1]) >= 0 ? 0 : -1);
              if (TARGET_MIPS16)
                {
                  if (INTVAL (op1) >= 0 && INTVAL (op1) <= 0xffff)
                    ret = "li\t%M0,%2\n\tli\t%L0,%1";
                  else if (INTVAL (op1) < 0 && INTVAL (op1) >= -0xffff)
                    {
                      operands[2] = GEN_INT (1);
                      ret = "li\t%M0,%2\n\tneg\t%M0\n\tli\t%L0,%n1\n\tneg\t%L0";
                    }
                }
              else
                ret = "li\t%M0,%2\n\tli\t%L0,%1";
            }
          else
            {
              /* We use multiple shifts here, to avoid warnings about out
                 of range shifts on 32 bit hosts.  */
              operands[2] = GEN_INT (INTVAL (operands[1]) >> 16 >> 16);
              operands[1]
                = GEN_INT (INTVAL (operands[1]) << 16 << 16 >> 16 >> 16);
              ret = "li\t%M0,%2\n\tli\t%L0,%1";
            }
        }

      else if (code1 == MEM)
        {
          delay = DELAY_LOAD;

          if (TARGET_STATS)
            mips_count_memory_refs (op1, 2);

          if (FP_REG_P (regno0))
            ret = "l.d\t%0,%1";

          else if (TARGET_64BIT)
            {

#ifdef TARGET_FP_CALL_32
              if (FP_CALL_GP_REG_P (regno0))
                ret = (double_memory_operand (op1, GET_MODE (op1))
                       ? "lwu\t%0,%1\n\tlwu\t%D0,4+%1"
                       : "ld\t%0,%1\n\tdsll\t%D0,%0,32\n\tdsrl\t%D0,32\n\tdsrl\t%0,32");
              else
#endif
                ret = "ld\t%0,%1";
            }

          else if (double_memory_operand (op1, GET_MODE (op1)))
            {
              operands[2] = adj_offsettable_operand (op1, 4);
              ret = (reg_mentioned_p (op0, op1)
                     ? "lw\t%D0,%2\n\tlw\t%0,%1"
                     : "lw\t%0,%1\n\tlw\t%D0,%2");
            }

          if (ret != 0 && MEM_VOLATILE_P (op1))
            {
              size_t i = strlen (ret);

              if (i > sizeof (volatile_buffer) - sizeof ("%{%}"))
                abort ();

              sprintf (volatile_buffer, "%%{%s%%}", ret);
              ret = volatile_buffer;
            }
        }

      else if (code1 == LABEL_REF)
        {
          if (TARGET_STATS)
            mips_count_memory_refs (op1, 2);

          if (GET_CODE (operands[1]) == SIGN_EXTEND)
            /* We deliberately remove the 'a' from '%1', so that we don't
               have to add SIGN_EXTEND support to print_operand_address.
               print_operand will just call print_operand_address in this
               case, so there is no problem.  */
            ret = "la\t%0,%1";
          else
            ret = "dla\t%0,%a1";
        }
      else if (code1 == SYMBOL_REF || code1 == CONST)
        {
          if (TARGET_MIPS16
              && code1 == CONST
              && GET_CODE (XEXP (op1, 0)) == REG
              && REGNO (XEXP (op1, 0)) == GP_REG_FIRST + 28)
            {
              /* This case arises on the mips16; see
                 mips16_gp_pseudo_reg.  */
              ret = "move\t%0,%+";
            }
          else if (TARGET_MIPS16
                   && code1 == SYMBOL_REF
                   && SYMBOL_REF_FLAG (op1)
                   && (XSTR (op1, 0)[0] != '*'
                       || strncmp (XSTR (op1, 0) + 1,
                                   LOCAL_LABEL_PREFIX,
                                   sizeof LOCAL_LABEL_PREFIX - 1) != 0))
            {
              /* This can occur when reloading the address of a GP
                 relative symbol on the mips16.  */
              ret = "move\t%0,%+\n\taddu\t%0,%%gprel(%a1)";
            }
          else
            {
              if (TARGET_STATS)
                mips_count_memory_refs (op1, 2);

              if (GET_CODE (operands[1]) == SIGN_EXTEND)
                /* We deliberately remove the 'a' from '%1', so that we don't
                   have to add SIGN_EXTEND support to print_operand_address.
                   print_operand will just call print_operand_address in this
                   case, so there is no problem.  */
                ret = "la\t%0,%1";
              else
                ret = "dla\t%0,%a1";
            }
        }
    }

  else if (code0 == MEM)
    {
      if (code1 == REG)
        {
          int regno1 = REGNO (op1) + subreg_word1;

          if (FP_REG_P (regno1))
            ret = "s.d\t%1,%0";

          else if (TARGET_64BIT)
            {

#ifdef TARGET_FP_CALL_32
              if (FP_CALL_GP_REG_P (regno1))
                ret = "dsll\t%1,32\n\tor\t%1,%D1\n\tsd\t%1,%0";
              else
#endif
                ret = "sd\t%1,%0";
            }

          else if (double_memory_operand (op0, GET_MODE (op0)))
            {
              operands[2] = adj_offsettable_operand (op0, 4);
              ret = "sw\t%1,%0\n\tsw\t%D1,%2";
            }
        }

      else if (((code1 == CONST_INT && INTVAL (op1) == 0)
                || (code1 == CONST_DOUBLE
                    && op1 == CONST0_RTX (GET_MODE (op1))))
               && (TARGET_64BIT
                   || double_memory_operand (op0, GET_MODE (op0))))
        {
          if (TARGET_64BIT)
            ret = "sd\t%.,%0";
          else
            {
              operands[2] = adj_offsettable_operand (op0, 4);
              ret = "sw\t%.,%0\n\tsw\t%.,%2";
            }
        }

      if (TARGET_STATS)
        mips_count_memory_refs (op0, 2);

      if (ret != 0 && MEM_VOLATILE_P (op0))
        {
          size_t i = strlen (ret);

          if (i > sizeof (volatile_buffer) - sizeof ("%{%}"))
            abort ();
          
          sprintf (volatile_buffer, "%%{%s%%}", ret);
          ret = volatile_buffer;
        }
    }

  if (ret == 0)
    {
      abort_with_insn (insn, "Bad move");
      return 0;
    }

  if (delay != DELAY_NONE)
    return mips_fill_delay_slot (ret, delay, operands, insn);

  return ret;
}
\f
/* Provide the costs of an addressing mode that contains ADDR.
   If ADDR is not a valid address, its cost is irrelevant.  */

int
mips_address_cost (addr)
     rtx addr;
{
  switch (GET_CODE (addr))
    {
    case LO_SUM:
      return 1;

    case LABEL_REF:
      return 2;

    case CONST:
      {
        rtx offset = const0_rtx;
        addr = eliminate_constant_term (XEXP (addr, 0), &offset);
        if (GET_CODE (addr) == LABEL_REF)
          return 2;

        if (GET_CODE (addr) != SYMBOL_REF)
          return 4;

        if (! SMALL_INT (offset))
          return 2;
      }

      /* ... fall through ... */

    case SYMBOL_REF:
      return SYMBOL_REF_FLAG (addr) ? 1 : 2;

    case PLUS:
      {
        register rtx plus0 = XEXP (addr, 0);
        register rtx plus1 = XEXP (addr, 1);

        if (GET_CODE (plus0) != REG && GET_CODE (plus1) == REG)
          plus0 = XEXP (addr, 1), plus1 = XEXP (addr, 0);

        if (GET_CODE (plus0) != REG)
          break;

        switch (GET_CODE (plus1))
          {
          case CONST_INT:
            return SMALL_INT (plus1) ? 1 : 2;

          case CONST:
          case SYMBOL_REF:
          case LABEL_REF:
          case HIGH:
          case LO_SUM:
            return mips_address_cost (plus1) + 1;

          default:
            break;
          }
      }

    default:
      break;
    }

  return 4;
}

/* Return nonzero if X is an address which needs a temporary register when 
   reloaded while generating PIC code.  */

int
pic_address_needs_scratch (x)
     rtx x;
{
  /* An address which is a symbolic plus a non SMALL_INT needs a temp reg.  */
  if (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS
      && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
      && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
      && ! SMALL_INT (XEXP (XEXP (x, 0), 1)))
    return 1;

  return 0;
}
\f
/* Make normal rtx_code into something we can index from an array */

static enum internal_test
map_test_to_internal_test (test_code)
     enum rtx_code test_code;
{
  enum internal_test test = ITEST_MAX;

  switch (test_code)
    {
    case EQ:  test = ITEST_EQ;  break;
    case NE:  test = ITEST_NE;  break;
    case GT:  test = ITEST_GT;  break;
    case GE:  test = ITEST_GE;  break;
    case LT:  test = ITEST_LT;  break;
    case LE:  test = ITEST_LE;  break;
    case GTU: test = ITEST_GTU; break;
    case GEU: test = ITEST_GEU; break;
    case LTU: test = ITEST_LTU; break;
    case LEU: test = ITEST_LEU; break;
    default:                    break;
    }

  return test;
}

\f
/* Generate the code to compare two integer values.  The return value is:
   (reg:SI xx)          The pseudo register the comparison is in
   0                    No register, generate a simple branch.

   ??? This is called with result nonzero by the Scond patterns in
   mips.md.  These patterns are called with a target in the mode of
   the Scond instruction pattern.  Since this must be a constant, we
   must use SImode.  This means that if RESULT is non-zero, it will
   always be an SImode register, even if TARGET_64BIT is true.  We
   cope with this by calling convert_move rather than emit_move_insn.
   This will sometimes lead to an unnecessary extension of the result;
   for example:

   long long
   foo (long long i)
   {
     return i < 5;
   }

   */

rtx
gen_int_relational (test_code, result, cmp0, cmp1, p_invert)
     enum rtx_code test_code;   /* relational test (EQ, etc) */
     rtx result;                /* result to store comp. or 0 if branch */
     rtx cmp0;                  /* first operand to compare */
     rtx cmp1;                  /* second operand to compare */
     int *p_invert;             /* NULL or ptr to hold whether branch needs */
                                /* to reverse its test */
{
  struct cmp_info
  {
    enum rtx_code test_code;    /* code to use in instruction (LT vs. LTU) */
    int const_low;              /* low bound of constant we can accept */
    int const_high;             /* high bound of constant we can accept */
    int const_add;              /* constant to add (convert LE -> LT) */
    int reverse_regs;           /* reverse registers in test */
    int invert_const;           /* != 0 if invert value if cmp1 is constant */
    int invert_reg;             /* != 0 if invert value if cmp1 is register */
    int unsignedp;              /* != 0 for unsigned comparisons.  */
  };

  static struct cmp_info info[ (int)ITEST_MAX ] = {

    { XOR,       0,  65535,  0,  0,  0,  0, 0 },        /* EQ  */
    { XOR,       0,  65535,  0,  0,  1,  1, 0 },        /* NE  */
    { LT,   -32769,  32766,  1,  1,  1,  0, 0 },        /* GT  */
    { LT,   -32768,  32767,  0,  0,  1,  1, 0 },        /* GE  */
    { LT,   -32768,  32767,  0,  0,  0,  0, 0 },        /* LT  */
    { LT,   -32769,  32766,  1,  1,  0,  1, 0 },        /* LE  */
    { LTU,  -32769,  32766,  1,  1,  1,  0, 1 },        /* GTU */
    { LTU,  -32768,  32767,  0,  0,  1,  1, 1 },        /* GEU */
    { LTU,  -32768,  32767,  0,  0,  0,  0, 1 },        /* LTU */
    { LTU,  -32769,  32766,  1,  1,  0,  1, 1 },        /* LEU */
  };

  enum internal_test test;
  enum machine_mode mode;
  struct cmp_info *p_info;
  int branch_p;
  int eqne_p;
  int invert;
  rtx reg;
  rtx reg2;

  test = map_test_to_internal_test (test_code);
  if (test == ITEST_MAX)
    abort ();

  p_info = &info[(int) test];
  eqne_p = (p_info->test_code == XOR);

  mode = GET_MODE (cmp0);
  if (mode == VOIDmode)
    mode = GET_MODE (cmp1);

  /* Eliminate simple branches */
  branch_p = (result == 0);
  if (branch_p)
    {
      if (GET_CODE (cmp0) == REG || GET_CODE (cmp0) == SUBREG)
        {
          /* Comparisons against zero are simple branches */
          if (GET_CODE (cmp1) == CONST_INT && INTVAL (cmp1) == 0
              && (! TARGET_MIPS16 || eqne_p))
            return 0;

          /* Test for beq/bne.  */
          if (eqne_p && ! TARGET_MIPS16)
            return 0;
        }

      /* allocate a pseudo to calculate the value in.  */
      result = gen_reg_rtx (mode);
    }

  /* Make sure we can handle any constants given to us.  */
  if (GET_CODE (cmp0) == CONST_INT)
    cmp0 = force_reg (mode, cmp0);

  if (GET_CODE (cmp1) == CONST_INT)
    {
      HOST_WIDE_INT value = INTVAL (cmp1);

      if (value < p_info->const_low
          || value > p_info->const_high
          /* ??? Why?  And why wasn't the similar code below modified too?  */
          || (TARGET_64BIT
              && HOST_BITS_PER_WIDE_INT < 64
              && p_info->const_add != 0
              && ((p_info->unsignedp
                   ? ((unsigned HOST_WIDE_INT) (value + p_info->const_add)
                      > (unsigned HOST_WIDE_INT) INTVAL (cmp1))
                   : (value + p_info->const_add) > INTVAL (cmp1))
                  != (p_info->const_add > 0))))
        cmp1 = force_reg (mode, cmp1);
    }

  /* See if we need to invert the result.  */
  invert = (GET_CODE (cmp1) == CONST_INT
            ? p_info->invert_const : p_info->invert_reg);

  if (p_invert != (int *)0)
    {
      *p_invert = invert;
      invert = 0;
    }

  /* Comparison to constants, may involve adding 1 to change a LT into LE.
     Comparison between two registers, may involve switching operands.  */
  if (GET_CODE (cmp1) == CONST_INT)
    {
      if (p_info->const_add != 0)
        {
          HOST_WIDE_INT new = INTVAL (cmp1) + p_info->const_add;

          /* If modification of cmp1 caused overflow,
             we would get the wrong answer if we follow the usual path;
             thus, x > 0xffffffffU would turn into x > 0U.  */
          if ((p_info->unsignedp
               ? (unsigned HOST_WIDE_INT) new >
               (unsigned HOST_WIDE_INT) INTVAL (cmp1)
               : new > INTVAL (cmp1))
              != (p_info->const_add > 0))
            {
              /* This test is always true, but if INVERT is true then
                 the result of the test needs to be inverted so 0 should
                 be returned instead.  */
              emit_move_insn (result, invert ? const0_rtx : const_true_rtx);
              return result;
            }
          else
            cmp1 = GEN_INT (new);
        }
    }

  else if (p_info->reverse_regs)
    {
      rtx temp = cmp0;
      cmp0 = cmp1;
      cmp1 = temp;
    }

  if (test == ITEST_NE && GET_CODE (cmp1) == CONST_INT && INTVAL (cmp1) == 0)
    reg = cmp0;
  else
    {
      reg = (invert || eqne_p) ? gen_reg_rtx (mode) : result;
      convert_move (reg, gen_rtx (p_info->test_code, mode, cmp0, cmp1), 0);
    }

  if (test == ITEST_NE)
    {
      if (! TARGET_MIPS16)
        {
          convert_move (result, gen_rtx (GTU, mode, reg, const0_rtx), 0);
          invert = 0;
        }
      else
        {
          reg2 = invert ? gen_reg_rtx (mode) : result;
          convert_move (reg2, gen_rtx (LTU, mode, reg, const1_rtx), 0);
          reg = reg2;
        }
    }

  else if (test == ITEST_EQ)
    {
      reg2 = invert ? gen_reg_rtx (mode) : result;
      convert_move (reg2, gen_rtx (LTU, mode, reg, const1_rtx), 0);
      reg = reg2;
    }

  if (invert)
    {
      rtx one;

      if (! TARGET_MIPS16)
        one = const1_rtx;
      else
        {
          /* The value is in $24.  Copy it to another register, so
             that reload doesn't think it needs to store the $24 and
             the input to the XOR in the same location.  */
          reg2 = gen_reg_rtx (mode);
          emit_move_insn (reg2, reg);
          reg = reg2;
          one = force_reg (mode, const1_rtx);
        }
      convert_move (result, gen_rtx (XOR, mode, reg, one), 0);
    }

  return result;
}
\f
/* Emit the common code for doing conditional branches.
   operand[0] is the label to jump to.
   The comparison operands are saved away by cmp{si,di,sf,df}.  */

void
gen_conditional_branch (operands, test_code)
     rtx operands[];
     enum rtx_code test_code;
{
  enum cmp_type type = branch_type;
  rtx cmp0 = branch_cmp[0];
  rtx cmp1 = branch_cmp[1];
  enum machine_mode mode;
  rtx reg;
  int invert;
  rtx label1, label2;

  switch (type)
    {
    case CMP_SI:
    case CMP_DI:
      mode = type == CMP_SI ? SImode : DImode;
      invert = 0;
      reg = gen_int_relational (test_code, NULL_RTX, cmp0, cmp1, &invert);

      if (reg)
        {
          cmp0 = reg;
          cmp1 = const0_rtx;
          test_code = NE;
        }
      else if (GET_CODE (cmp1) == CONST_INT && INTVAL (cmp1) != 0)
        /* We don't want to build a comparison against a non-zero
           constant.  */
        cmp1 = force_reg (mode, cmp1);

      break;

    case CMP_SF:
    case CMP_DF:
      if (mips_isa < 4)
        reg = gen_rtx (REG, CCmode, FPSW_REGNUM);
      else
        reg = gen_reg_rtx (CCmode);

      /* For cmp0 != cmp1, build cmp0 == cmp1, and test for result ==
         0 in the instruction built below.  The MIPS FPU handles
         inequality testing by testing for equality and looking for a
         false result.  */
      emit_insn (gen_rtx (SET, VOIDmode, reg,
                          gen_rtx (test_code == NE ? EQ : test_code,
                                   CCmode, cmp0, cmp1)));

      test_code = test_code == NE ? EQ : NE;
      mode = CCmode;
      cmp0 = reg;
      cmp1 = const0_rtx;
      invert = 0;
      break;

    default:
      abort_with_insn (gen_rtx (test_code, VOIDmode, cmp0, cmp1), "bad test");
    }

  /* Generate the branch.  */

  label1 = gen_rtx (LABEL_REF, VOIDmode, operands[0]);
  label2 = pc_rtx;

  if (invert)
    {
      label2 = label1;
      label1 = pc_rtx;
    }

  emit_jump_insn (gen_rtx (SET, VOIDmode, pc_rtx,
                           gen_rtx (IF_THEN_ELSE, VOIDmode,
                                    gen_rtx (test_code, mode, cmp0, cmp1),
                                    label1, label2)));
}

/* Emit the common code for conditional moves.  OPERANDS is the array
   of operands passed to the conditional move defined_expand.  */

void
gen_conditional_move (operands)
     rtx *operands;
{
  rtx op0 = branch_cmp[0];
  rtx op1 = branch_cmp[1];
  enum machine_mode mode = GET_MODE (branch_cmp[0]);
  enum rtx_code cmp_code = GET_CODE (operands[1]);
  enum rtx_code move_code = NE;
  enum machine_mode op_mode = GET_MODE (operands[0]);
  enum machine_mode cmp_mode;
  rtx cmp_reg;

  if (GET_MODE_CLASS (mode) != MODE_FLOAT)
    {
      switch (cmp_code)
        {
        case EQ:
          cmp_code = XOR;
          move_code = EQ;
          break;
        case NE:
          cmp_code = XOR;
          break;
        case LT:
          break;
        case GE:
          cmp_code = LT;
          move_code = EQ;
          break;
        case GT:
          cmp_code = LT;
          op0 = force_reg (mode, branch_cmp[1]);
          op1 = branch_cmp[0];
          break;
        case LE:
          cmp_code = LT;
          op0 = force_reg (mode, branch_cmp[1]);
          op1 = branch_cmp[0];
          move_code = EQ;
          break;
        case LTU:
          break;
        case GEU:
          cmp_code = LTU;
          move_code = EQ;
          break;
        case GTU:
          cmp_code = LTU;
          op0 = force_reg (mode, branch_cmp[1]);
          op1 = branch_cmp[0];
          break;
        case LEU:
          cmp_code = LTU;
          op0 = force_reg (mode, branch_cmp[1]);
          op1 = branch_cmp[0];
          move_code = EQ;
          break;
        default:
          abort ();
        }
    }
  else if (cmp_code == NE)
    cmp_code = EQ, move_code = EQ;
          
  if (mode == SImode || mode == DImode)
    cmp_mode = mode;
  else if (mode == SFmode || mode == DFmode)
    cmp_mode = CCmode;
  else
    abort ();

  cmp_reg = gen_reg_rtx (cmp_mode);
  emit_insn (gen_rtx (SET, cmp_mode, cmp_reg,
                      gen_rtx (cmp_code, cmp_mode, op0, op1)));

  emit_insn (gen_rtx (SET, op_mode, operands[0],
                      gen_rtx (IF_THEN_ELSE, op_mode,
                               gen_rtx (move_code, VOIDmode,
                                        cmp_reg, CONST0_RTX (SImode)),
                               operands[2], operands[3])));
}
\f
/* Write a loop to move a constant number of bytes.
   Generate load/stores as follows:

   do {
     temp1 = src[0];
     temp2 = src[1];
     ...
     temp<last> = src[MAX_MOVE_REGS-1];
     dest[0] = temp1;
     dest[1] = temp2;
     ...
     dest[MAX_MOVE_REGS-1] = temp<last>;
     src += MAX_MOVE_REGS;
     dest += MAX_MOVE_REGS;
   } while (src != final);

   This way, no NOP's are needed, and only MAX_MOVE_REGS+3 temp
   registers are needed.

   Aligned moves move MAX_MOVE_REGS*4 bytes every (2*MAX_MOVE_REGS)+3
   cycles, unaligned moves move MAX_MOVE_REGS*4 bytes every
   (4*MAX_MOVE_REGS)+3 cycles, assuming no cache misses.  */

#define MAX_MOVE_REGS 4
#define MAX_MOVE_BYTES (MAX_MOVE_REGS * UNITS_PER_WORD)

static void
block_move_loop (dest_reg, src_reg, bytes, align, orig_dest, orig_src)
     rtx dest_reg;              /* register holding destination address */
     rtx src_reg;               /* register holding source address */
     int bytes;                 /* # bytes to move */
     int align;                 /* alignment */
     rtx orig_dest;             /* original dest for change_address */
     rtx orig_src;              /* original source for making a reg note */
{
  rtx dest_mem = change_address (orig_dest, BLKmode, dest_reg);
  rtx src_mem = change_address (orig_src, BLKmode, src_reg);
  rtx align_rtx = GEN_INT (align);
  rtx label;
  rtx final_src;
  rtx bytes_rtx;
  int leftover;

  if (bytes < 2 * MAX_MOVE_BYTES)
    abort ();

  leftover = bytes % MAX_MOVE_BYTES;
  bytes -= leftover;

  label = gen_label_rtx ();
  final_src = gen_reg_rtx (Pmode);
  bytes_rtx = GEN_INT (bytes);

  if (bytes > 0x7fff)
    {
      if (Pmode == DImode)
        {
          emit_insn (gen_movdi (final_src, bytes_rtx));
          emit_insn (gen_adddi3 (final_src, final_src, src_reg));
        }
      else
        {
          emit_insn (gen_movsi (final_src, bytes_rtx));
          emit_insn (gen_addsi3 (final_src, final_src, src_reg));
        }
    }
  else
    {
      if (Pmode == DImode)
        emit_insn (gen_adddi3 (final_src, src_reg, bytes_rtx));
      else
        emit_insn (gen_addsi3 (final_src, src_reg, bytes_rtx));
    }

  emit_label (label);

  bytes_rtx = GEN_INT (MAX_MOVE_BYTES);
  emit_insn (gen_movstrsi_internal (dest_mem, src_mem, bytes_rtx, align_rtx));

  if (Pmode == DImode)
    {
      emit_insn (gen_adddi3 (src_reg, src_reg, bytes_rtx));
      emit_insn (gen_adddi3 (dest_reg, dest_reg, bytes_rtx));
      emit_insn (gen_cmpdi (src_reg, final_src));
    }
  else
    {
      emit_insn (gen_addsi3 (src_reg, src_reg, bytes_rtx));
      emit_insn (gen_addsi3 (dest_reg, dest_reg, bytes_rtx));
      emit_insn (gen_cmpsi (src_reg, final_src));
    }

  emit_jump_insn (gen_bne (label));

  if (leftover)
    emit_insn (gen_movstrsi_internal (dest_mem, src_mem, GEN_INT (leftover),
                                      align_rtx));
}
\f
/* Use a library function to move some bytes.  */

static void
block_move_call (dest_reg, src_reg, bytes_rtx)
     rtx dest_reg;
     rtx src_reg;
     rtx bytes_rtx;
{
  /* We want to pass the size as Pmode, which will normally be SImode
     but will be DImode if we are using 64 bit longs and pointers.  */
  if (GET_MODE (bytes_rtx) != VOIDmode
      && GET_MODE (bytes_rtx) != Pmode)
    bytes_rtx = convert_to_mode (Pmode, bytes_rtx, 1);

#ifdef TARGET_MEM_FUNCTIONS
  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "memcpy"), 0,
                     VOIDmode, 3, dest_reg, Pmode, src_reg, Pmode,
                     convert_to_mode (TYPE_MODE (sizetype), bytes_rtx,
                                      TREE_UNSIGNED (sizetype)),
                     TYPE_MODE (sizetype));
#else
  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "bcopy"), 0,
                     VOIDmode, 3, src_reg, Pmode, dest_reg, Pmode,
                     convert_to_mode (TYPE_MODE (integer_type_node), bytes_rtx,
                                      TREE_UNSIGNED (integer_type_node)),
                     TYPE_MODE (integer_type_node));
#endif
}
\f
/* Expand string/block move operations.

   operands[0] is the pointer to the destination.
   operands[1] is the pointer to the source.
   operands[2] is the number of bytes to move.
   operands[3] is the alignment.  */

void
expand_block_move (operands)
     rtx operands[];
{
  rtx bytes_rtx = operands[2];
  rtx align_rtx = operands[3];
  int constp = GET_CODE (bytes_rtx) == CONST_INT;
  HOST_WIDE_INT bytes = constp ? INTVAL (bytes_rtx) : 0;
  int align = INTVAL (align_rtx);
  rtx orig_src  = operands[1];
  rtx orig_dest = operands[0];
  rtx src_reg;
  rtx dest_reg;

  if (constp && bytes <= 0)
    return;

  if (align > UNITS_PER_WORD)
    align = UNITS_PER_WORD;

  /* Move the address into scratch registers.  */
  dest_reg = copy_addr_to_reg (XEXP (orig_dest, 0));
  src_reg  = copy_addr_to_reg (XEXP (orig_src, 0));

  if (TARGET_MEMCPY)
    block_move_call (dest_reg, src_reg, bytes_rtx);

  else if (constp && bytes <= 2 * MAX_MOVE_BYTES
           && align == UNITS_PER_WORD)
    move_by_pieces (orig_dest, orig_src, bytes, align);
        
  else if (constp && bytes <= 2 * MAX_MOVE_BYTES)
    emit_insn (gen_movstrsi_internal (change_address (orig_dest, BLKmode,
                                                      dest_reg),
                                      change_address (orig_src, BLKmode,
                                                      src_reg),
                                      bytes_rtx, align_rtx));

  else if (constp && align >= UNITS_PER_WORD && optimize)
    block_move_loop (dest_reg, src_reg, bytes, align, orig_dest, orig_src);

  else if (constp && optimize)
    {
      /* If the alignment is not word aligned, generate a test at
         runtime, to see whether things wound up aligned, and we
         can use the faster lw/sw instead ulw/usw.  */

      rtx temp = gen_reg_rtx (Pmode);
      rtx aligned_label = gen_label_rtx ();
      rtx join_label = gen_label_rtx ();
      int leftover = bytes % MAX_MOVE_BYTES;

      bytes -= leftover;

      if (Pmode == DImode)
        {
          emit_insn (gen_iordi3 (temp, src_reg, dest_reg));
          emit_insn (gen_anddi3 (temp, temp, GEN_INT (UNITS_PER_WORD - 1)));
          emit_insn (gen_cmpdi (temp, const0_rtx));
        }
      else
        {
          emit_insn (gen_iorsi3 (temp, src_reg, dest_reg));
          emit_insn (gen_andsi3 (temp, temp, GEN_INT (UNITS_PER_WORD - 1)));
          emit_insn (gen_cmpsi (temp, const0_rtx));
        }

      emit_jump_insn (gen_beq (aligned_label));

      /* Unaligned loop.  */
      block_move_loop (dest_reg, src_reg, bytes, 1, orig_dest, orig_src);
      emit_jump_insn (gen_jump (join_label));
      emit_barrier ();

      /* Aligned loop.  */
      emit_label (aligned_label);
      block_move_loop (dest_reg, src_reg, bytes, UNITS_PER_WORD, orig_dest,
                       orig_src);
      emit_label (join_label);

      /* Bytes at the end of the loop.  */
      if (leftover)
        emit_insn (gen_movstrsi_internal (change_address (orig_dest, BLKmode,
                                                          dest_reg),
                                          change_address (orig_src, BLKmode,
                                                          src_reg),
                                          GEN_INT (leftover),
                                          GEN_INT (align)));
    }

  else
    block_move_call (dest_reg, src_reg, bytes_rtx);
}
\f
/* Emit load/stores for a small constant block_move. 

   operands[0] is the memory address of the destination.
   operands[1] is the memory address of the source.
   operands[2] is the number of bytes to move.
   operands[3] is the alignment.
   operands[4] is a temp register.
   operands[5] is a temp register.
   ...
   operands[3+num_regs] is the last temp register.

   The block move type can be one of the following:
        BLOCK_MOVE_NORMAL       Do all of the block move.
        BLOCK_MOVE_NOT_LAST     Do all but the last store.
        BLOCK_MOVE_LAST         Do just the last store. */

const char *
output_block_move (insn, operands, num_regs, move_type)
     rtx insn;
     rtx operands[];
     int num_regs;
     enum block_move_type move_type;
{
  rtx dest_reg = XEXP (operands[0], 0);
  rtx src_reg = XEXP (operands[1], 0);
  HOST_WIDE_INT bytes = INTVAL (operands[2]);
  int align = INTVAL (operands[3]);
  int num = 0;
  int offset = 0;
  int use_lwl_lwr = 0;
  int last_operand = num_regs + 4;
  int safe_regs = 4;
  int i;
  rtx xoperands[10];

  struct {
    const char *load;           /* load insn without nop */
    const char *load_nop;       /* load insn with trailing nop */
    const char *store;          /* store insn */
    const char *final;          /* if last_store used: NULL or swr */
    const char *last_store;     /* last store instruction */
    int offset;                 /* current offset */
    enum machine_mode mode;     /* mode to use on (MEM) */
  } load_store[4];

  /* ??? Detect a bug in GCC, where it can give us a register
     the same as one of the addressing registers and reduce
     the number of registers available.  */
  for (i = 4;
       i < last_operand
       && safe_regs < (int)(sizeof(xoperands) / sizeof(xoperands[0]));
       i++)
    if (! reg_mentioned_p (operands[i], operands[0])
        && ! reg_mentioned_p (operands[i], operands[1]))
      xoperands[safe_regs++] = operands[i];

  if (safe_regs < last_operand)
    {
      xoperands[0] = operands[0];
      xoperands[1] = operands[1];
      xoperands[2] = operands[2];
      xoperands[3] = operands[3];
      return output_block_move (insn, xoperands, safe_regs - 4, move_type);
    }

  /* If we are given global or static addresses, and we would be
     emitting a few instructions, try to save time by using a
     temporary register for the pointer.  */
  /* ??? The SGI Irix6 assembler fails when a SYMBOL_REF is used in
     an ldl/ldr instruction pair.  We play it safe, and always move
     constant addresses into registers when generating N32/N64 code, just
     in case we might emit an unaligned load instruction.  */
  if (num_regs > 2 && (bytes > 2 * align || move_type != BLOCK_MOVE_NORMAL
                       || mips_abi == ABI_N32 || mips_abi == ABI_64))
    {
      if (CONSTANT_P (src_reg))
        {
          if (TARGET_STATS)
            mips_count_memory_refs (operands[1], 1);

          src_reg = operands[3 + num_regs--];
          if (move_type != BLOCK_MOVE_LAST)
            {
              xoperands[1] = operands[1];
              xoperands[0] = src_reg;
              if (Pmode == DImode)
                output_asm_insn ("dla\t%0,%1", xoperands);
              else
                output_asm_insn ("la\t%0,%1", xoperands);
            }
        }

      if (CONSTANT_P (dest_reg))
        {
          if (TARGET_STATS)
            mips_count_memory_refs (operands[0], 1);

          dest_reg = operands[3 + num_regs--];
          if (move_type != BLOCK_MOVE_LAST)
            {
              xoperands[1] = operands[0];
              xoperands[0] = dest_reg;
              if (Pmode == DImode)
                output_asm_insn ("dla\t%0,%1", xoperands);
              else
                output_asm_insn ("la\t%0,%1", xoperands);
            }
        }
    }

  /* ??? We really shouldn't get any LO_SUM addresses here, because they
     are not offsettable, however, offsettable_address_p says they are
     offsettable. I think this is a bug in offsettable_address_p.
     For expediency, we fix this by just loading the address into a register
     if we happen to get one.  */

  if (GET_CODE (src_reg) == LO_SUM)
    {
      src_reg = operands[3 + num_regs--];
      if (move_type != BLOCK_MOVE_LAST)
        {
          xoperands[2] = XEXP (XEXP (operands[1], 0), 1);
          xoperands[1] = XEXP (XEXP (operands[1], 0), 0);
          xoperands[0] = src_reg;
          if (Pmode == DImode)
            output_asm_insn ("daddiu\t%0,%1,%%lo(%2)", xoperands);
          else
            output_asm_insn ("addiu\t%0,%1,%%lo(%2)", xoperands);
        }
    }

  if (GET_CODE (dest_reg) == LO_SUM)
    {
      dest_reg = operands[3 + num_regs--];
      if (move_type != BLOCK_MOVE_LAST)
        {
          xoperands[2] = XEXP (XEXP (operands[0], 0), 1);
          xoperands[1] = XEXP (XEXP (operands[0], 0), 0);
          xoperands[0] = dest_reg;
          if (Pmode == DImode)
            output_asm_insn ("daddiu\t%0,%1,%%lo(%2)", xoperands);
          else
            output_asm_insn ("addiu\t%0,%1,%%lo(%2)", xoperands);
        }
    }

  if (num_regs > (int)(sizeof (load_store) / sizeof (load_store[0])))
    num_regs = sizeof (load_store) / sizeof (load_store[0]);

  else if (num_regs < 1)
    abort_with_insn (insn,
                     "Cannot do block move, not enough scratch registers");

  while (bytes > 0)
    {
      load_store[num].offset = offset;

      if (TARGET_64BIT && bytes >= 8 && align >= 8)
        {
          load_store[num].load = "ld\t%0,%1";
          load_store[num].load_nop = "ld\t%0,%1%#";
          load_store[num].store = "sd\t%0,%1";
          load_store[num].last_store = "sd\t%0,%1";
          load_store[num].final = 0;
          load_store[num].mode = DImode;
          offset += 8;
          bytes -= 8;
        }

      /* ??? Fails because of a MIPS assembler bug?  */
      else if (TARGET_64BIT && bytes >= 8 && ! TARGET_MIPS16)
        {
          if (BYTES_BIG_ENDIAN)
            {
              load_store[num].load = "ldl\t%0,%1\n\tldr\t%0,%2";
              load_store[num].load_nop = "ldl\t%0,%1\n\tldr\t%0,%2%#";
              load_store[num].store = "sdl\t%0,%1\n\tsdr\t%0,%2";
              load_store[num].last_store = "sdr\t%0,%2";
              load_store[num].final = "sdl\t%0,%1";
            }
          else
            {
              load_store[num].load = "ldl\t%0,%2\n\tldr\t%0,%1";
              load_store[num].load_nop = "ldl\t%0,%2\n\tldr\t%0,%1%#";
              load_store[num].store = "sdl\t%0,%2\n\tsdr\t%0,%1";
              load_store[num].last_store = "sdr\t%0,%1";
              load_store[num].final = "sdl\t%0,%2";
            }

          load_store[num].mode = DImode;
          offset += 8;
          bytes -= 8;
          use_lwl_lwr = 1;
        }

      else if (bytes >= 4 && align >= 4)
        {
          load_store[num].load = "lw\t%0,%1";
          load_store[num].load_nop = "lw\t%0,%1%#";
          load_store[num].store = "sw\t%0,%1";
          load_store[num].last_store = "sw\t%0,%1";
          load_store[num].final = 0;
          load_store[num].mode = SImode;
          offset += 4;
          bytes -= 4;
        }

      else if (bytes >= 4 && ! TARGET_MIPS16)
        {
          if (BYTES_BIG_ENDIAN)
            {
              load_store[num].load = "lwl\t%0,%1\n\tlwr\t%0,%2";
              load_store[num].load_nop = "lwl\t%0,%1\n\tlwr\t%0,%2%#";
              load_store[num].store = "swl\t%0,%1\n\tswr\t%0,%2";
              load_store[num].last_store = "swr\t%0,%2";
              load_store[num].final = "swl\t%0,%1";
            }
          else
            {
              load_store[num].load = "lwl\t%0,%2\n\tlwr\t%0,%1";
              load_store[num].load_nop = "lwl\t%0,%2\n\tlwr\t%0,%1%#";
              load_store[num].store = "swl\t%0,%2\n\tswr\t%0,%1";
              load_store[num].last_store = "swr\t%0,%1";
              load_store[num].final = "swl\t%0,%2";
            }

          load_store[num].mode = SImode;
          offset += 4;
          bytes -= 4;
          use_lwl_lwr = 1;
        }

      else if (bytes >= 2 && align >= 2)
        {
          load_store[num].load = "lh\t%0,%1";
          load_store[num].load_nop = "lh\t%0,%1%#";
          load_store[num].store = "sh\t%0,%1";
          load_store[num].last_store = "sh\t%0,%1";
          load_store[num].final = 0;
          load_store[num].mode = HImode;
          offset += 2;
          bytes -= 2;
        }
      else
        {
          load_store[num].load = "lb\t%0,%1";
          load_store[num].load_nop = "lb\t%0,%1%#";
          load_store[num].store = "sb\t%0,%1";
          load_store[num].last_store = "sb\t%0,%1";
          load_store[num].final = 0;
          load_store[num].mode = QImode;
          offset++;
          bytes--;
        }

      if (TARGET_STATS && move_type != BLOCK_MOVE_LAST)
        {
          dslots_load_total++;
          dslots_load_filled++;

          if (CONSTANT_P (src_reg))
            mips_count_memory_refs (src_reg, 1);

          if (CONSTANT_P (dest_reg))
            mips_count_memory_refs (dest_reg, 1);
        }

      /* Emit load/stores now if we have run out of registers or are
         at the end of the move.  */

      if (++num == num_regs || bytes == 0)
        {
          /* If only load/store, we need a NOP after the load.  */
          if (num == 1)
            {
              load_store[0].load = load_store[0].load_nop;
              if (TARGET_STATS && move_type != BLOCK_MOVE_LAST)
                dslots_load_filled--;
            }

          if (move_type != BLOCK_MOVE_LAST)
            {
              for (i = 0; i < num; i++)
                {
                  int offset;

                  if (!operands[i + 4])
                    abort ();

                  if (GET_MODE (operands[i + 4]) != load_store[i].mode)
                    operands[i + 4] = gen_rtx (REG, load_store[i].mode,
                                               REGNO (operands[i + 4]));

                  offset = load_store[i].offset;
                  xoperands[0] = operands[i + 4];
                  xoperands[1] = gen_rtx (MEM, load_store[i].mode,
                                          plus_constant (src_reg, offset));

                  if (use_lwl_lwr)
                    {
                      int extra_offset
                        = GET_MODE_SIZE (load_store[i].mode) - 1;

                      xoperands[2] = gen_rtx (MEM, load_store[i].mode,
                                              plus_constant (src_reg,
                                                             extra_offset
                                                             + offset));
                    }

                  output_asm_insn (load_store[i].load, xoperands);
                }
            }

          for (i = 0; i < num; i++)
            {
              int last_p = (i == num-1 && bytes == 0);
              int offset = load_store[i].offset;

              xoperands[0] = operands[i + 4];
              xoperands[1] = gen_rtx (MEM, load_store[i].mode,
                                      plus_constant (dest_reg, offset));


              if (use_lwl_lwr)
                {
                  int extra_offset = GET_MODE_SIZE (load_store[i].mode) - 1;
                  xoperands[2] = gen_rtx (MEM, load_store[i].mode,
                                          plus_constant (dest_reg,
                                                         extra_offset
                                                         + offset));
                }

              if (move_type == BLOCK_MOVE_NORMAL)
                output_asm_insn (load_store[i].store, xoperands);

              else if (move_type == BLOCK_MOVE_NOT_LAST)
                {
                  if (!last_p)
                    output_asm_insn (load_store[i].store, xoperands);

                  else if (load_store[i].final != 0)
                    output_asm_insn (load_store[i].final, xoperands);
                }

              else if (last_p)
                output_asm_insn (load_store[i].last_store, xoperands);
            }

          num = 0;              /* reset load_store */
          use_lwl_lwr = 0;
        }
    }

  return "";
}
\f
/* Argument support functions.  */

/* Initialize CUMULATIVE_ARGS for a function.  */

void
init_cumulative_args (cum, fntype, libname)
     CUMULATIVE_ARGS *cum;              /* argument info to initialize */
     tree fntype;                       /* tree ptr for function decl */
     rtx libname ATTRIBUTE_UNUSED;      /* SYMBOL_REF of library name or 0 */
{
  static CUMULATIVE_ARGS zero_cum;
  tree param, next_param;

  if (TARGET_DEBUG_E_MODE)
    {
      fprintf (stderr,
               "\ninit_cumulative_args, fntype = 0x%.8lx", (long)fntype);

      if (!fntype)
        fputc ('\n', stderr);

      else
        {
          tree ret_type = TREE_TYPE (fntype);
          fprintf (stderr, ", fntype code = %s, ret code = %s\n",
                   tree_code_name[(int)TREE_CODE (fntype)],
                   tree_code_name[(int)TREE_CODE (ret_type)]);
        }
    }

  *cum = zero_cum;

  /* Determine if this function has variable arguments.  This is
     indicated by the last argument being 'void_type_mode' if there
     are no variable arguments.  The standard MIPS calling sequence
     passes all arguments in the general purpose registers in this case. */

  for (param = fntype ? TYPE_ARG_TYPES (fntype) : 0;
       param != 0; param = next_param)
    {
      next_param = TREE_CHAIN (param);
      if (next_param == 0 && TREE_VALUE (param) != void_type_node)
        cum->gp_reg_found = 1;
    }
}

/* Advance the argument to the next argument position.  */

void
function_arg_advance (cum, mode, type, named)
     CUMULATIVE_ARGS *cum;      /* current arg information */
     enum machine_mode mode;    /* current arg mode */
     tree type;                 /* type of the argument or 0 if lib support */
     int named;                 /* whether or not the argument was named */
{
  if (TARGET_DEBUG_E_MODE)
    {
      fprintf (stderr,
               "function_adv({gp reg found = %d, arg # = %2d, words = %2d}, %4s, ",
               cum->gp_reg_found, cum->arg_number, cum->arg_words,
               GET_MODE_NAME (mode));
      fprintf (stderr, HOST_PTR_PRINTF, type);
      fprintf (stderr, ", %d )\n\n", named);
    }

  cum->arg_number++;
  switch (mode)
    {
    case VOIDmode:
      break;

    default:
      if (GET_MODE_CLASS (mode) != MODE_COMPLEX_INT
          && GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT)
        abort ();

      cum->gp_reg_found = 1;
      cum->arg_words += ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1)
                         / UNITS_PER_WORD);
      break;

    case BLKmode:
      cum->gp_reg_found = 1;
      cum->arg_words += ((int_size_in_bytes (type) + UNITS_PER_WORD - 1)
                         / UNITS_PER_WORD);
      break;

    case SFmode:
      if (mips_abi == ABI_EABI && ! TARGET_SOFT_FLOAT)
        cum->fp_arg_words++;
      else
        cum->arg_words++;
      if (! cum->gp_reg_found && cum->arg_number <= 2)
        cum->fp_code += 1 << ((cum->arg_number - 1) * 2);
      break;

    case DFmode:
      if (mips_abi == ABI_EABI && ! TARGET_SOFT_FLOAT && ! TARGET_SINGLE_FLOAT)
        cum->fp_arg_words += (TARGET_64BIT ? 1 : 2);
      else
        cum->arg_words += (TARGET_64BIT ? 1 : 2);
      if (! cum->gp_reg_found && ! TARGET_SINGLE_FLOAT && cum->arg_number <= 2)
        cum->fp_code += 2 << ((cum->arg_number - 1) * 2);
      break;

    case DImode:
      cum->gp_reg_found = 1;
      cum->arg_words += (TARGET_64BIT ? 1 : 2);
      break;

    case QImode:
    case HImode:
    case SImode:
      cum->gp_reg_found = 1;
      cum->arg_words++;
      break;
    }
}

/* Return an RTL expression containing the register for the given mode,
   or 0 if the argument is to be passed on the stack.  */

struct rtx_def *
function_arg (cum, mode, type, named)
     CUMULATIVE_ARGS *cum;      /* current arg information */
     enum machine_mode mode;    /* current arg mode */
     tree type;                 /* type of the argument or 0 if lib support */
     int named;                 /* != 0 for normal args, == 0 for ... args */
{
  rtx ret;
  int regbase = -1;
  int bias = 0;
  int *arg_words = &cum->arg_words;
  int struct_p = (type != 0
                  && (TREE_CODE (type) == RECORD_TYPE
                      || TREE_CODE (type) == UNION_TYPE
                      || TREE_CODE (type) == QUAL_UNION_TYPE));

  if (TARGET_DEBUG_E_MODE)
    {
      fprintf (stderr,
               "function_arg( {gp reg found = %d, arg # = %2d, words = %2d}, %4s, ",
               cum->gp_reg_found, cum->arg_number, cum->arg_words,
               GET_MODE_NAME (mode));
      fprintf (stderr, HOST_PTR_PRINTF, type);
      fprintf (stderr, ", %d ) = ", named);
    }
  

  cum->last_arg_fp = 0;
  switch (mode)
    {
    case SFmode:
      if (mips_abi == ABI_32 || mips_abi == ABI_O64)
        {
          if (cum->gp_reg_found || cum->arg_number >= 2 || TARGET_SOFT_FLOAT)
            regbase = GP_ARG_FIRST;
          else
            {
              regbase = FP_ARG_FIRST;

              /* If the first arg was a float in a floating point register,
                 then set bias to align this float arg properly.  */
              if (cum->arg_words == 1)
                bias = 1;
            }
        }
      else if (mips_abi == ABI_EABI && ! TARGET_SOFT_FLOAT)
        {
          if (! TARGET_64BIT)
            cum->fp_arg_words += cum->fp_arg_words & 1;
          cum->last_arg_fp = 1;
          arg_words = &cum->fp_arg_words;
          regbase = FP_ARG_FIRST;
        }
      else
        regbase = (TARGET_SOFT_FLOAT || ! named ? GP_ARG_FIRST : FP_ARG_FIRST);
      break;

    case DFmode:
      if (! TARGET_64BIT)
        {
          if (mips_abi == ABI_EABI
              && ! TARGET_SOFT_FLOAT && ! TARGET_SINGLE_FLOAT)
            cum->fp_arg_words += cum->fp_arg_words & 1;
          else
            cum->arg_words += cum->arg_words & 1;
        }

      if (mips_abi == ABI_32 || mips_abi == ABI_O64)
        regbase = ((cum->gp_reg_found
                    || TARGET_SOFT_FLOAT || TARGET_SINGLE_FLOAT
                    || cum->arg_number >= 2)
                   ? GP_ARG_FIRST : FP_ARG_FIRST);
      else if (mips_abi == ABI_EABI
               && ! TARGET_SOFT_FLOAT && ! TARGET_SINGLE_FLOAT)
        {
          cum->last_arg_fp = 1;
          arg_words = &cum->fp_arg_words;
          regbase = FP_ARG_FIRST;
        }
      else
        regbase = (TARGET_SOFT_FLOAT || TARGET_SINGLE_FLOAT || ! named
                   ? GP_ARG_FIRST : FP_ARG_FIRST);
      break;

    default:
      if (GET_MODE_CLASS (mode) != MODE_COMPLEX_INT
          && GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT)
        abort ();

      /* Drops through.  */
    case BLKmode:
      if (type != (tree)0 && TYPE_ALIGN (type) > (unsigned) BITS_PER_WORD
          && ! TARGET_64BIT && mips_abi != ABI_EABI)
        cum->arg_words += (cum->arg_words & 1);
      regbase = GP_ARG_FIRST;
      break;

    case VOIDmode:
    case QImode:
    case HImode:
    case SImode:
      regbase = GP_ARG_FIRST;
      break;

    case DImode:
      if (! TARGET_64BIT)
        cum->arg_words += (cum->arg_words & 1);
      regbase = GP_ARG_FIRST;
    }

  if (*arg_words >= MAX_ARGS_IN_REGISTERS)
    {
      if (TARGET_DEBUG_E_MODE)
        fprintf (stderr, "<stack>%s\n", struct_p ? ", [struct]" : "");

      ret = 0;
    }
  else
    {
      if (regbase == -1)
        abort ();

      if (! type || TREE_CODE (type) != RECORD_TYPE || mips_abi == ABI_32
          || mips_abi == ABI_EABI || mips_abi == ABI_O64 || ! named)
        ret = gen_rtx (REG, mode, regbase + *arg_words + bias);
      else
        {
          /* The Irix 6 n32/n64 ABIs say that if any 64 bit chunk of the
             structure contains a double in its entirety, then that 64 bit
             chunk is passed in a floating point register.  */
          tree field;

          /* First check to see if there is any such field.  */
          for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
            if (TREE_CODE (field) == FIELD_DECL
                && TREE_CODE (TREE_TYPE (field)) == REAL_TYPE
                && TYPE_PRECISION (TREE_TYPE (field)) == BITS_PER_WORD
                && (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field))
                    % BITS_PER_WORD == 0))
              break;

          /* If the whole struct fits a DFmode register,
             we don't need the PARALLEL.  */
          if (! field || mode == DFmode)
            ret = gen_rtx (REG, mode, regbase + *arg_words + bias);
          else
            {
              /* Now handle the special case by returning a PARALLEL
                 indicating where each 64 bit chunk goes.  */
              int chunks;
              int bitpos;
              int regno;
              int i;

              /* ??? If this is a packed structure, then the last hunk won't
                 be 64 bits.  */

              chunks = TREE_INT_CST_LOW (TYPE_SIZE (type)) / BITS_PER_WORD;
              if (chunks + *arg_words + bias > MAX_ARGS_IN_REGISTERS)
                chunks = MAX_ARGS_IN_REGISTERS - *arg_words - bias;

              /* assign_parms checks the mode of ENTRY_PARM, so we must
                 use the actual mode here.  */
              ret = gen_rtx (PARALLEL, mode, rtvec_alloc (chunks));

              bitpos = 0;
              regno = regbase + *arg_words + bias;
              field = TYPE_FIELDS (type);
              for (i = 0; i < chunks; i++)
                {
                  rtx reg;

                  for (; field; field = TREE_CHAIN (field))
                    if (TREE_CODE (field) == FIELD_DECL
                        && (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field))
                            >= bitpos))
                      break;

                  if (field
                      && TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)) == bitpos
                      && TREE_CODE (TREE_TYPE (field)) == REAL_TYPE
                      && TYPE_PRECISION (TREE_TYPE (field)) == BITS_PER_WORD)
                    reg = gen_rtx (REG, DFmode,
                                   regno + FP_ARG_FIRST - GP_ARG_FIRST);
                  else
                    reg = gen_rtx (REG, word_mode, regno);

                  XVECEXP (ret, 0, i) 
                    = gen_rtx (EXPR_LIST, VOIDmode, reg,
                               GEN_INT (bitpos / BITS_PER_UNIT));

                  bitpos += 64;
                  regno++;
                }
            }
        }

      if (TARGET_DEBUG_E_MODE)
        fprintf (stderr, "%s%s\n", reg_names[regbase + *arg_words + bias],
                 struct_p ? ", [struct]" : "");

      /* The following is a hack in order to pass 1 byte structures
         the same way that the MIPS compiler does (namely by passing
         the structure in the high byte or half word of the register).
         This also makes varargs work.  If we have such a structure,
         we save the adjustment RTL, and the call define expands will
         emit them.  For the VOIDmode argument (argument after the
         last real argument), pass back a parallel vector holding each
         of the adjustments.  */

      /* ??? function_arg can be called more than once for each argument.
         As a result, we compute more adjustments than we need here.
         See the CUMULATIVE_ARGS definition in mips.h.  */

      /* ??? This scheme requires everything smaller than the word size to
         shifted to the left, but when TARGET_64BIT and ! TARGET_INT64,
         that would mean every int needs to be shifted left, which is very
         inefficient.  Let's not carry this compatibility to the 64 bit
         calling convention for now.  */

      if (struct_p && int_size_in_bytes (type) < UNITS_PER_WORD
          && ! TARGET_64BIT && mips_abi != ABI_EABI)
        {
          rtx amount = GEN_INT (BITS_PER_WORD
                                - int_size_in_bytes (type) * BITS_PER_UNIT);
          rtx reg = gen_rtx (REG, word_mode, regbase + *arg_words + bias);

          if (TARGET_64BIT)
            cum->adjust[cum->num_adjusts++] = gen_ashldi3 (reg, reg, amount);
          else
            cum->adjust[cum->num_adjusts++] = gen_ashlsi3 (reg, reg, amount);
        }
    }

  /* We will be called with a mode of VOIDmode after the last argument
     has been seen.  Whatever we return will be passed to the call
     insn.  If we need any shifts for small structures, return them in
     a PARALLEL; in that case, stuff the mips16 fp_code in as the
     mode.  Otherwise, if we have need a mips16 fp_code, return a REG
     with the code stored as the mode.  */
  if (mode == VOIDmode)
    {
      if (cum->num_adjusts > 0)
        ret = gen_rtx (PARALLEL, (enum machine_mode) cum->fp_code,
                       gen_rtvec_v (cum->num_adjusts, cum->adjust));
      else if (TARGET_MIPS16 && cum->fp_code != 0)
        ret = gen_rtx (REG, (enum machine_mode) cum->fp_code, 0);
    }

  return ret;
}

int
function_arg_partial_nregs (cum, mode, type, named)
     CUMULATIVE_ARGS *cum;      /* current arg information */
     enum machine_mode mode;    /* current arg mode */
     tree type;                 /* type of the argument or 0 if lib support */
     int named ATTRIBUTE_UNUSED;/* != 0 for normal args, == 0 for ... args */
{
  if ((mode == BLKmode
       || GET_MODE_CLASS (mode) != MODE_COMPLEX_INT
       || GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT)
      && cum->arg_words < MAX_ARGS_IN_REGISTERS
      && mips_abi != ABI_EABI)
    {
      int words;
      if (mode == BLKmode)
        words = ((int_size_in_bytes (type) + UNITS_PER_WORD - 1)
                 / UNITS_PER_WORD);
      else
        words = (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;

      if (words + cum->arg_words <= MAX_ARGS_IN_REGISTERS)
        return 0;               /* structure fits in registers */

      if (TARGET_DEBUG_E_MODE)
        fprintf (stderr, "function_arg_partial_nregs = %d\n",
                 MAX_ARGS_IN_REGISTERS - cum->arg_words);

      return MAX_ARGS_IN_REGISTERS - cum->arg_words;
    }

  else if (mode == DImode && cum->arg_words == MAX_ARGS_IN_REGISTERS-1
           && ! TARGET_64BIT && mips_abi != ABI_EABI)
    {
      if (TARGET_DEBUG_E_MODE)
        fprintf (stderr, "function_arg_partial_nregs = 1\n");

      return 1;
    }

  return 0;
}
\f
/* Abort after printing out a specific insn.  */

static void
abort_with_insn (insn, reason)
     rtx insn;
     const char *reason;
{
  error (reason);
  debug_rtx (insn);
  abort ();
}

/* Write a message to stderr (for use in macros expanded in files that do not
   include stdio.h).  */

void
trace (s, s1, s2)
     char *s, *s1, *s2;
{
  fprintf (stderr, s, s1, s2);
}
\f
/* Set up the threshold for data to go into the small data area, instead
   of the normal data area, and detect any conflicts in the switches.  */

void
override_options ()
{
  register int i, start;
  register int regno;
  register enum machine_mode mode;

  mips_section_threshold = g_switch_set ? g_switch_value : MIPS_DEFAULT_GVALUE;

  if (mips_section_threshold <= 0)
    target_flags &= ~MASK_GPOPT;
  else if (optimize)
    target_flags |= MASK_GPOPT;

#ifndef MIPS_ISA_DEFAULT
#define MIPS_ISA_DEFAULT 1
#endif

  /* If both single-float and soft-float are set, then clear the one that
     was set by TARGET_DEFAULT, leaving the one that was set by the
     user.  We assume here that the specs prevent both being set by the 
     user. */
#ifdef TARGET_DEFAULT
  if (TARGET_SINGLE_FLOAT && TARGET_SOFT_FLOAT)
    target_flags &= ~(TARGET_DEFAULT&(MASK_SOFT_FLOAT|MASK_SINGLE_FLOAT));
#endif

  /* Get the architectural level.  */
  if (mips_isa_string == 0)
    mips_isa = MIPS_ISA_DEFAULT;

  else if (ISDIGIT (*mips_isa_string))
    {
      mips_isa = atoi (mips_isa_string);
      if (mips_isa == 16)
        {
          /* -mno-mips16 overrides -mips16.  */
          if (mips_no_mips16_string == NULL)
            {
              target_flags |= MASK_MIPS16;
              if (TARGET_64BIT)
                mips_isa = 3;
              else
                mips_isa = MIPS_ISA_DEFAULT;
            }
          else
            {
              mips_isa = MIPS_ISA_DEFAULT;
            }
        }
      else if (mips_isa < 1 || mips_isa > 4)
        {
          error ("-mips%d not supported", mips_isa);
          mips_isa = 1;
        }
    }

  else
    {
      error ("bad value (%s) for -mips switch", mips_isa_string);
      mips_isa = 1;
    }

#ifdef MIPS_ABI_DEFAULT
  /* Get the ABI to use. */
  if (mips_abi_string == (char *) 0)
    mips_abi = MIPS_ABI_DEFAULT;
  else if (! strcmp (mips_abi_string, "32"))
    mips_abi = ABI_32;
  else if (! strcmp (mips_abi_string, "o64"))
    mips_abi = ABI_O64;
  else if (! strcmp (mips_abi_string, "n32"))
    mips_abi = ABI_N32;
  else if (! strcmp (mips_abi_string, "64"))
    mips_abi = ABI_64;
  else if (! strcmp (mips_abi_string, "eabi"))
    mips_abi = ABI_EABI;
  else
    error ("bad value (%s) for -mabi= switch", mips_abi_string);

  /* A specified ISA defaults the ABI if it was not specified.  */
  if (mips_abi_string == 0 && mips_isa_string 
      && mips_abi != ABI_EABI && mips_abi != ABI_O64)
    {
      if (mips_isa <= 2)
        mips_abi = ABI_32;
      else
        mips_abi = ABI_64;
    }

  /* A specified ABI defaults the ISA if it was not specified.  */
  else if (mips_isa_string == 0 && mips_abi_string 
           && mips_abi != ABI_EABI && mips_abi != ABI_O64)
    {
      if (mips_abi == ABI_32)
        mips_isa = 1;
      else if (mips_abi == ABI_N32)
        mips_isa = 3;
      else
        mips_isa = 4;
    }

  /* If both ABI and ISA were specified, check for conflicts.  */
  else if (mips_isa_string && mips_abi_string)
    {
      if ((mips_isa <= 2 && (mips_abi == ABI_N32 || mips_abi == ABI_64
                             || mips_abi == ABI_O64))
          || (mips_isa >= 3 && mips_abi == ABI_32))
        error ("-mabi=%s does not support -mips%d", mips_abi_string, mips_isa);
    }

  /* Override TARGET_DEFAULT if necessary.  */
  if (mips_abi == ABI_32)
    target_flags &= ~ (MASK_FLOAT64|MASK_64BIT);

  /* If no type size setting options (-mlong64,-mint64,-mlong32) were used
     then set the type sizes.  In the EABI in 64 bit mode, longs and
     pointers are 64 bits.  Likewise for the SGI Irix6 N64 ABI.  */
  if (mips_explicit_type_size_string == NULL
      && ((mips_abi == ABI_EABI && TARGET_64BIT)
          || mips_abi == ABI_64))
    target_flags |= MASK_LONG64;

  /* ??? This doesn't work yet, so don't let people try to use it.  */
  if (mips_abi == ABI_32)
    error ("The -mabi=32 support does not work yet.");

#else
  if (mips_abi_string)
    error ("This target does not support the -mabi switch.");
#endif

#ifdef MIPS_CPU_STRING_DEFAULT
  /* ??? There is a minor inconsistency here.  If the user specifies an ISA
     greater than that supported by the default processor, then the user gets
     an error.  Normally, the compiler will just default to the base level cpu
     for the indicated isa.  */
  if (mips_cpu_string == 0)
    mips_cpu_string = MIPS_CPU_STRING_DEFAULT;
#endif

  /* Identify the processor type */
  if (mips_cpu_string == 0
      || !strcmp (mips_cpu_string, "default")
      || !strcmp (mips_cpu_string, "DEFAULT"))
    {
      switch (mips_isa)
        {
        default:
          mips_cpu_string = "3000";
          mips_cpu = PROCESSOR_R3000;
          break;
        case 2:
          mips_cpu_string = "6000";
          mips_cpu = PROCESSOR_R6000;
          break;
        case 3:
          mips_cpu_string = "4000";
          mips_cpu = PROCESSOR_R4000;
          break;
        case 4:
          mips_cpu_string = "8000";
          mips_cpu = PROCESSOR_R8000;
          break;
        }
    }

  else
    {
      const char *p = mips_cpu_string;
      int seen_v = 0;

      /* We need to cope with the various "vr" prefixes for the NEC 4300
         and 4100 processors.  */
      if (*p == 'v' || *p == 'V')
        seen_v = 1, p++;

      if (*p == 'r' || *p == 'R')
        p++;

      /* Since there is no difference between a R2000 and R3000 in
         terms of the scheduler, we collapse them into just an R3000. */

      mips_cpu = PROCESSOR_DEFAULT;
      switch (*p)
        {
        case '2':
          if (!strcmp (p, "2000") || !strcmp (p, "2k") || !strcmp (p, "2K"))
            mips_cpu = PROCESSOR_R3000;
          break;

        case '3':
          if (!strcmp (p, "3000") || !strcmp (p, "3k") || !strcmp (p, "3K"))
            mips_cpu = PROCESSOR_R3000;
          else if (!strcmp (p, "3900"))
            mips_cpu = PROCESSOR_R3900;
          break;

        case '4':
          if (!strcmp (p, "4000") || !strcmp (p, "4k") || !strcmp (p, "4K"))
            mips_cpu = PROCESSOR_R4000;
          /* The vr4100 is a non-FP ISA III processor with some extra
             instructions.  */
          else if (!strcmp (p, "4100"))
            {
              mips_cpu = PROCESSOR_R4100;
              target_flags |= MASK_SOFT_FLOAT ;
            }
          /* The vr4300 is a standard ISA III processor, but with a different
             pipeline.  */
          else if (!strcmp (p, "4300"))
            mips_cpu = PROCESSOR_R4300;
          /* The r4400 is exactly the same as the r4000 from the compiler's
             viewpoint.  */
          else if (!strcmp (p, "4400"))
            mips_cpu = PROCESSOR_R4000;
          else if (!strcmp (p, "4600"))
            mips_cpu = PROCESSOR_R4600;
          else if (!strcmp (p, "4650"))
            mips_cpu = PROCESSOR_R4650;
          break;

        case '5':
          if (!strcmp (p, "5000") || !strcmp (p, "5k") || !strcmp (p, "5K"))
            mips_cpu = PROCESSOR_R5000;
          break;

        case '6':
          if (!strcmp (p, "6000") || !strcmp (p, "6k") || !strcmp (p, "6K"))
            mips_cpu = PROCESSOR_R6000;
          break;

        case '8':
          if (!strcmp (p, "8000"))
            mips_cpu = PROCESSOR_R8000;
          break;

        case 'o':
          if (!strcmp (p, "orion"))
            mips_cpu = PROCESSOR_R4600;
          break;
        }

      if (seen_v
          && mips_cpu != PROCESSOR_R4300
          && mips_cpu != PROCESSOR_R4100
          && mips_cpu != PROCESSOR_R5000)
        mips_cpu = PROCESSOR_DEFAULT;

      if (mips_cpu == PROCESSOR_DEFAULT)
        {
          error ("bad value (%s) for -mcpu= switch", mips_cpu_string);
          mips_cpu_string = "default";
        }
    }

  if ((mips_cpu == PROCESSOR_R3000 && mips_isa > 1)
      || (mips_cpu == PROCESSOR_R6000 && mips_isa > 2)
      || ((mips_cpu == PROCESSOR_R4000
           || mips_cpu == PROCESSOR_R4100
           || mips_cpu == PROCESSOR_R4300
           || mips_cpu == PROCESSOR_R4600
           || mips_cpu == PROCESSOR_R4650)
          && mips_isa > 3))
    error ("-mcpu=%s does not support -mips%d", mips_cpu_string, mips_isa);

  /* make sure sizes of ints/longs/etc. are ok */
  if (mips_isa < 3)
    {
      if (TARGET_FLOAT64)
        fatal ("Only MIPS-III or MIPS-IV CPUs can support 64 bit fp registers");

      else if (TARGET_64BIT)
        fatal ("Only MIPS-III or MIPS-IV CPUs can support 64 bit gp registers");
    }

  if (mips_abi != ABI_32 && mips_abi != ABI_O64)
    flag_pcc_struct_return = 0;

  /* Tell halfpic.c that we have half-pic code if we do.  */
  if (TARGET_HALF_PIC)
    HALF_PIC_INIT ();

  /* -fpic (-KPIC) is the default when TARGET_ABICALLS is defined.  We need
     to set flag_pic so that the LEGITIMATE_PIC_OPERAND_P macro will work.  */
  /* ??? -non_shared turns off pic code generation, but this is not
     implemented.  */
  if (TARGET_ABICALLS)
    {
      mips_abicalls = MIPS_ABICALLS_YES;
      flag_pic = 1;
      if (mips_section_threshold > 0)
        warning ("-G is incompatible with PIC code which is the default");
    }
  else
    mips_abicalls = MIPS_ABICALLS_NO;

  /* -membedded-pic is a form of PIC code suitable for embedded
     systems.  All calls are made using PC relative addressing, and
     all data is addressed using the $gp register.  This requires gas,
     which does most of the work, and GNU ld, which automatically
     expands PC relative calls which are out of range into a longer
     instruction sequence.  All gcc really does differently is
     generate a different sequence for a switch.  */
  if (TARGET_EMBEDDED_PIC)
    {
      flag_pic = 1;
      if (TARGET_ABICALLS)
        warning ("-membedded-pic and -mabicalls are incompatible");

      if (g_switch_set)
        warning ("-G and -membedded-pic are incompatible");

      /* Setting mips_section_threshold is not required, because gas
         will force everything to be GP addressable anyhow, but
         setting it will cause gcc to make better estimates of the
         number of instructions required to access a particular data
         item.  */
      mips_section_threshold = 0x7fffffff;
    }

  /* This optimization requires a linker that can support a R_MIPS_LO16
     relocation which is not immediately preceded by a R_MIPS_HI16 relocation.
     GNU ld has this support, but not all other MIPS linkers do, so we enable
     this optimization only if the user requests it, or if GNU ld is the
     standard linker for this configuration.  */
  /* ??? This does not work when target addresses are DImode.
     This is because we are missing DImode high/lo_sum patterns.  */
  if (TARGET_GAS && ! TARGET_MIPS16 && TARGET_SPLIT_ADDRESSES && optimize && ! flag_pic
      && Pmode == SImode)
    mips_split_addresses = 1;
  else
    mips_split_addresses = 0;

  /* -mrnames says to use the MIPS software convention for register
     names instead of the hardware names (ie, $a0 instead of $4).
     We do this by switching the names in mips_reg_names, which the
     reg_names points into via the REGISTER_NAMES macro.  */

  if (TARGET_NAME_REGS)
    bcopy ((char *) mips_sw_reg_names, (char *) mips_reg_names,
           sizeof (mips_reg_names));

  /* When compiling for the mips16, we can not use floating point.  We
     record the original hard float value in mips16_hard_float.  */
  if (TARGET_MIPS16)
    {
      if (TARGET_SOFT_FLOAT)
        mips16_hard_float = 0;
      else
        mips16_hard_float = 1;
      target_flags |= MASK_SOFT_FLOAT;

      /* Don't run the scheduler before reload, since it tends to
         increase register pressure.  */
      flag_schedule_insns = 0;
    }

  /* We put -mentry in TARGET_OPTIONS rather than TARGET_SWITCHES only
     to avoid using up another bit in target_flags.  */
  if (mips_entry_string != NULL)
    {
      if (*mips_entry_string != '\0')
        error ("Invalid option `entry%s'", mips_entry_string);

      if (! TARGET_MIPS16)
        warning ("-mentry is only meaningful with -mips-16");
      else
        mips_entry = 1;
    }

  /* We copy TARGET_MIPS16 into the mips16 global variable, so that
     attributes can access it.  */
  if (TARGET_MIPS16)
    mips16 = 1;
  else
    mips16 = 0;

  /* Initialize the high and low values for legitimate floating point
     constants.  Rather than trying to get the accuracy down to the
     last bit, just use approximate ranges.  */
  dfhigh = REAL_VALUE_ATOF ("1.0e300", DFmode);
  dflow = REAL_VALUE_ATOF ("1.0e-300", DFmode);
  sfhigh = REAL_VALUE_ATOF ("1.0e38", SFmode);
  sflow = REAL_VALUE_ATOF ("1.0e-38", SFmode);

  mips_print_operand_punct['?'] = 1;
  mips_print_operand_punct['#'] = 1;
  mips_print_operand_punct['&'] = 1;
  mips_print_operand_punct['!'] = 1;
  mips_print_operand_punct['*'] = 1;
  mips_print_operand_punct['@'] = 1;
  mips_print_operand_punct['.'] = 1;
  mips_print_operand_punct['('] = 1;
  mips_print_operand_punct[')'] = 1;
  mips_print_operand_punct['['] = 1;
  mips_print_operand_punct[']'] = 1;
  mips_print_operand_punct['<'] = 1;
  mips_print_operand_punct['>'] = 1;
  mips_print_operand_punct['{'] = 1;
  mips_print_operand_punct['}'] = 1;
  mips_print_operand_punct['^'] = 1;
  mips_print_operand_punct['$'] = 1;
  mips_print_operand_punct['+'] = 1;
  mips_print_operand_punct['~'] = 1;

  mips_char_to_class['d'] = TARGET_MIPS16 ? M16_REGS : GR_REGS;
  mips_char_to_class['e'] = M16_NA_REGS;
  mips_char_to_class['t'] = T_REG;
  mips_char_to_class['f'] = (TARGET_HARD_FLOAT ? FP_REGS : NO_REGS);
  mips_char_to_class['h'] = HI_REG;
  mips_char_to_class['l'] = LO_REG;
  mips_char_to_class['a'] = HILO_REG;
  mips_char_to_class['x'] = MD_REGS;
  mips_char_to_class['b'] = ALL_REGS;
  mips_char_to_class['y'] = GR_REGS;
  mips_char_to_class['z'] = ST_REGS;

  /* Set up array to map GCC register number to debug register number.
     Ignore the special purpose register numbers.  */

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    mips_dbx_regno[i] = -1;

  start = GP_DBX_FIRST - GP_REG_FIRST;
  for (i = GP_REG_FIRST; i <= GP_REG_LAST; i++)
    mips_dbx_regno[i] = i + start;

  start = FP_DBX_FIRST - FP_REG_FIRST;
  for (i = FP_REG_FIRST; i <= FP_REG_LAST; i++)
    mips_dbx_regno[i] = i + start;

  /* Set up array giving whether a given register can hold a given mode.
     At present, restrict ints from being in FP registers, because reload
     is a little enthusiastic about storing extra values in FP registers,
     and this is not good for things like OS kernels.  Also, due to the
     mandatory delay, it is as fast to load from cached memory as to move
     from the FP register.  */

  for (mode = VOIDmode;
       mode != MAX_MACHINE_MODE;
       mode = (enum machine_mode) ((int)mode + 1))
    {
      register int size              = GET_MODE_SIZE (mode);
      register enum mode_class class = GET_MODE_CLASS (mode);

      for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
        {
          register int temp;

          if (mode == CCmode)
            {
              if (mips_isa < 4)
                temp = (regno == FPSW_REGNUM);
              else
                temp = (ST_REG_P (regno) || GP_REG_P (regno)
                        || FP_REG_P (regno));
            }

          else if (GP_REG_P (regno))
            temp = ((regno & 1) == 0 || size <= UNITS_PER_WORD);

          else if (FP_REG_P (regno))
            temp = ((TARGET_FLOAT64 || ((regno & 1) == 0))
                    && (class == MODE_FLOAT
                        || class == MODE_COMPLEX_FLOAT
                        || (TARGET_DEBUG_H_MODE && class == MODE_INT))
                    && (! TARGET_SINGLE_FLOAT || size <= 4));

          else if (MD_REG_P (regno))
            temp = (class == MODE_INT
                    && (size <= UNITS_PER_WORD
                        || (regno == MD_REG_FIRST
                            && size == 2 * UNITS_PER_WORD)));

          else
            temp = 0;

          mips_hard_regno_mode_ok[(int)mode][regno] = temp;
        }
    }

  /* Save GPR registers in word_mode sized hunks.  word_mode hasn't been
     initialized yet, so we can't use that here.  */
  gpr_mode = TARGET_64BIT ? DImode : SImode;

  /* Provide default values for align_* for 64-bit targets.  */
  if (TARGET_64BIT)
    {
      if (align_loops == 0) 
        align_loops = 8;
      if (align_jumps == 0) 
        align_jumps = 8;
      if (align_functions == 0) 
        align_functions = 8;
    }
}

/* On the mips16, we want to allocate $24 (T_REG) before other
   registers for instructions for which it is possible.  This helps
   avoid shuffling registers around in order to set up for an xor,
   encouraging the compiler to use a cmp instead.  */

void
mips_order_regs_for_local_alloc ()
{
  register int i;

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    reg_alloc_order[i] = i;

  if (TARGET_MIPS16)
    {
      /* It really doesn't matter where we put register 0, since it is
         a fixed register anyhow.  */
      reg_alloc_order[0] = 24;
      reg_alloc_order[24] = 0;
    }
}

\f
/* The MIPS debug format wants all automatic variables and arguments
   to be in terms of the virtual frame pointer (stack pointer before
   any adjustment in the function), while the MIPS 3.0 linker wants
   the frame pointer to be the stack pointer after the initial
   adjustment.  So, we do the adjustment here.  The arg pointer (which
   is eliminated) points to the virtual frame pointer, while the frame
   pointer (which may be eliminated) points to the stack pointer after
   the initial adjustments.  */

HOST_WIDE_INT
mips_debugger_offset (addr, offset)
     rtx addr;
     HOST_WIDE_INT offset;
{
  rtx offset2 = const0_rtx;
  rtx reg = eliminate_constant_term (addr, &offset2);

  if (offset == 0)
    offset = INTVAL (offset2);

  if (reg == stack_pointer_rtx || reg == frame_pointer_rtx
      || reg == hard_frame_pointer_rtx)
    {
      HOST_WIDE_INT frame_size = (!current_frame_info.initialized)
                                  ? compute_frame_size (get_frame_size ())
                                  : current_frame_info.total_size;

      /* MIPS16 frame is smaller */
      if (frame_pointer_needed && TARGET_MIPS16)
        frame_size -= current_function_outgoing_args_size;

      offset = offset - frame_size;
    }

  /* sdbout_parms does not want this to crash for unrecognized cases.  */
#if 0
  else if (reg != arg_pointer_rtx)
    abort_with_insn (addr, "mips_debugger_offset called with non stack/frame/arg pointer.");
#endif

  return offset;
}
\f
/* A C compound statement to output to stdio stream STREAM the
   assembler syntax for an instruction operand X.  X is an RTL
   expression.

   CODE is a value that can be used to specify one of several ways
   of printing the operand.  It is used when identical operands
   must be printed differently depending on the context.  CODE
   comes from the `%' specification that was used to request
   printing of the operand.  If the specification was just `%DIGIT'
   then CODE is 0; if the specification was `%LTR DIGIT' then CODE
   is the ASCII code for LTR.

   If X is a register, this macro should print the register's name.
   The names can be found in an array `reg_names' whose type is
   `char *[]'.  `reg_names' is initialized from `REGISTER_NAMES'.

   When the machine description has a specification `%PUNCT' (a `%'
   followed by a punctuation character), this macro is called with
   a null pointer for X and the punctuation character for CODE.

   The MIPS specific codes are:

   'X'  X is CONST_INT, prints 32 bits in hexadecimal format = "0x%08x",
   'x'  X is CONST_INT, prints 16 bits in hexadecimal format = "0x%04x",
   'd'  output integer constant in decimal,
   'z'  if the operand is 0, use $0 instead of normal operand.
   'D'  print second register of double-word register operand.
   'L'  print low-order register of double-word register operand.
   'M'  print high-order register of double-word register operand.
   'C'  print part of opcode for a branch condition.
   'F'  print part of opcode for a floating-point branch condition.
   'N'  print part of opcode for a branch condition, inverted.
   'W'  print part of opcode for a floating-point branch condition, inverted.
   'S'  X is CODE_LABEL, print with prefix of "LS" (for embedded switch).
   'B'  print 'z' for EQ, 'n' for NE
   'b'  print 'n' for EQ, 'z' for NE
   'T'  print 'f' for EQ, 't' for NE
   't'  print 't' for EQ, 'f' for NE
   'Z'  print register and a comma, but print nothing for $fcc0
   '('  Turn on .set noreorder
   ')'  Turn on .set reorder
   '['  Turn on .set noat
   ']'  Turn on .set at
   '<'  Turn on .set nomacro
   '>'  Turn on .set macro
   '{'  Turn on .set volatile (not GAS)
   '}'  Turn on .set novolatile (not GAS)
   '&'  Turn on .set noreorder if filling delay slots
   '*'  Turn on both .set noreorder and .set nomacro if filling delay slots
   '!'  Turn on .set nomacro if filling delay slots
   '#'  Print nop if in a .set noreorder section.
   '?'  Print 'l' if we are to use a branch likely instead of normal branch.
   '@'  Print the name of the assembler temporary register (at or $1).
   '.'  Print the name of the register with a hard-wired zero (zero or $0).
   '^'  Print the name of the pic call-through register (t9 or $25).
   '$'  Print the name of the stack pointer register (sp or $29).
   '+'  Print the name of the gp register (gp or $28).
   '~'  Output an branch alignment to LABEL_ALIGN(NULL).  */

void
print_operand (file, op, letter)
     FILE *file;                /* file to write to */
     rtx op;                    /* operand to print */
     int letter;                /* %<letter> or 0 */
{
  register enum rtx_code code;

  if (PRINT_OPERAND_PUNCT_VALID_P (letter))
    {
      switch (letter)
        {
        case '?':
          if (mips_branch_likely)
            putc ('l', file);
          break;

        case '@':
          fputs (reg_names [GP_REG_FIRST + 1], file);
          break;

        case '^':
          fputs (reg_names [PIC_FUNCTION_ADDR_REGNUM], file);
          break;

        case '.':
          fputs (reg_names [GP_REG_FIRST + 0], file);
          break;

        case '$':
          fputs (reg_names[STACK_POINTER_REGNUM], file);
          break;

        case '+':
          fputs (reg_names[GP_REG_FIRST + 28], file);
          break;

        case '&':
          if (final_sequence != 0 && set_noreorder++ == 0)
            fputs (".set\tnoreorder\n\t", file);
          break;

        case '*':
          if (final_sequence != 0)
            {
              if (set_noreorder++ == 0)
                fputs (".set\tnoreorder\n\t", file);

              if (set_nomacro++ == 0)
                fputs (".set\tnomacro\n\t", file);
            }
          break;

        case '!':
          if (final_sequence != 0 && set_nomacro++ == 0)
            fputs ("\n\t.set\tnomacro", file);
          break;

        case '#':
          if (set_noreorder != 0)
            fputs ("\n\tnop", file);
          else if (TARGET_STATS)
            fputs ("\n\t#nop", file);

          break;

        case '(':
          if (set_noreorder++ == 0)
            fputs (".set\tnoreorder\n\t", file);
          break;

        case ')':
          if (set_noreorder == 0)
            error ("internal error: %%) found without a %%( in assembler pattern");

          else if (--set_noreorder == 0)
            fputs ("\n\t.set\treorder", file);

          break;

        case '[':
          if (set_noat++ == 0)
            fputs (".set\tnoat\n\t", file);
          break;

        case ']': 
          if (set_noat == 0)
            error ("internal error: %%] found without a %%[ in assembler pattern");
          else if (--set_noat == 0)
            fputs ("\n\t.set\tat", file);

          break;

        case '<':
          if (set_nomacro++ == 0)
            fputs (".set\tnomacro\n\t", file);
          break;

        case '>':
          if (set_nomacro == 0)
            error ("internal error: %%> found without a %%< in assembler pattern");
          else if (--set_nomacro == 0)
            fputs ("\n\t.set\tmacro", file);

          break;

        case '{':
          if (set_volatile++ == 0)
            fprintf (file, "%s.set\tvolatile\n\t", TARGET_MIPS_AS ? "" : "#");
          break;

        case '}':
          if (set_volatile == 0)
            error ("internal error: %%} found without a %%{ in assembler pattern");
          else if (--set_volatile == 0)
            fprintf (file, "\n\t%s.set\tnovolatile", (TARGET_MIPS_AS) ? "" : "#");

          break;

        case '~':
          {
            if (align_labels_log > 0)
              ASM_OUTPUT_ALIGN (file, align_labels_log);
          }
        break;

        default:
          error ("PRINT_OPERAND: Unknown punctuation '%c'", letter);
          break;
        }

      return;
    }

  if (! op)
    {
      error ("PRINT_OPERAND null pointer");
      return;
    }

  code = GET_CODE (op);

  if (code == SIGN_EXTEND)
    op = XEXP (op, 0), code = GET_CODE (op);

  if (letter == 'C')
    switch (code)
      {
      case EQ:  fputs ("eq",  file); break;
      case NE:  fputs ("ne",  file); break;
      case GT:  fputs ("gt",  file); break;
      case GE:  fputs ("ge",  file); break;
      case LT:  fputs ("lt",  file); break;
      case LE:  fputs ("le",  file); break;
      case GTU: fputs ("gtu", file); break;
      case GEU: fputs ("geu", file); break;
      case LTU: fputs ("ltu", file); break;
      case LEU: fputs ("leu", file); break;
      default:
        abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%C");
      }

  else if (letter == 'N')
    switch (code)
      {
      case EQ:  fputs ("ne",  file); break;
      case NE:  fputs ("eq",  file); break;
      case GT:  fputs ("le",  file); break;
      case GE:  fputs ("lt",  file); break;
      case LT:  fputs ("ge",  file); break;
      case LE:  fputs ("gt",  file); break;
      case GTU: fputs ("leu", file); break;
      case GEU: fputs ("ltu", file); break;
      case LTU: fputs ("geu", file); break;
      case LEU: fputs ("gtu", file); break;
      default:
        abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%N");
      }

  else if (letter == 'F')
    switch (code)
      {
      case EQ: fputs ("c1f", file); break;
      case NE: fputs ("c1t", file); break;
      default:
        abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%F");
      }

  else if (letter == 'W')
    switch (code)
      {
      case EQ: fputs ("c1t", file); break;
      case NE: fputs ("c1f", file); break;
      default:
        abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%W");
      }

  else if (letter == 'S')
    {
      char buffer[100];

      ASM_GENERATE_INTERNAL_LABEL (buffer, "LS", CODE_LABEL_NUMBER (op));
      assemble_name (file, buffer);
    }

  else if (letter == 'Z')
    {
      register int regnum;

      if (code != REG)
        abort ();

      regnum = REGNO (op);
      if (! ST_REG_P (regnum))
        abort ();

      if (regnum != ST_REG_FIRST)
        fprintf (file, "%s,", reg_names[regnum]);
    }

  else if (code == REG || code == SUBREG)
    {
      register int regnum;

      if (code == REG)
        regnum = REGNO (op);
      else
        regnum = true_regnum (op);

      if ((letter == 'M' && ! WORDS_BIG_ENDIAN)
          || (letter == 'L' && WORDS_BIG_ENDIAN)
          || letter == 'D')
        regnum++;

      fprintf (file, "%s", reg_names[regnum]);
    }

  else if (code == MEM)
    output_address (XEXP (op, 0));

  else if (code == CONST_DOUBLE
           && GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT)
    {
      REAL_VALUE_TYPE d;
      char s[30];

      REAL_VALUE_FROM_CONST_DOUBLE (d, op);
      REAL_VALUE_TO_DECIMAL (d, "%.20e", s);
      fprintf (file, s);
    }

  else if (letter == 'x' && GET_CODE (op) == CONST_INT)
    fprintf (file, HOST_WIDE_INT_PRINT_HEX, 0xffff & INTVAL(op));

  else if (letter == 'X' && GET_CODE(op) == CONST_INT)
    fprintf (file, HOST_WIDE_INT_PRINT_HEX, INTVAL (op));

  else if (letter == 'd' && GET_CODE(op) == CONST_INT)
    fprintf (file, HOST_WIDE_INT_PRINT_DEC, (INTVAL(op)));

  else if (letter == 'z' && GET_CODE (op) == CONST_INT && INTVAL (op) == 0)
    fputs (reg_names[GP_REG_FIRST], file);

  else if (letter == 'd' || letter == 'x' || letter == 'X')
    fatal ("PRINT_OPERAND: letter %c was found & insn was not CONST_INT",
           letter);

  else if (letter == 'B')
    fputs (code == EQ ? "z" : "n", file);
  else if (letter == 'b')
    fputs (code == EQ ? "n" : "z", file);
  else if (letter == 'T')
    fputs (code == EQ ? "f" : "t", file);
  else if (letter == 't')
    fputs (code == EQ ? "t" : "f", file);

  else if (code == CONST && GET_CODE (XEXP (op, 0)) == REG)
    {
      /* This case arises on the mips16; see mips16_gp_pseudo_reg.  */
      print_operand (file, XEXP (op, 0), letter);
    }

  else if (TARGET_MIPS16 && code == CONST && mips16_gp_offset_p (op))
    {
      fputs ("%gprel(", file);
      mips16_output_gp_offset (file, op);
      fputs (")", file);
    }

  else
    output_addr_const (file, op);
}
\f
/* A C compound statement to output to stdio stream STREAM the
   assembler syntax for an instruction operand that is a memory
   reference whose address is ADDR.  ADDR is an RTL expression.

   On some machines, the syntax for a symbolic address depends on
   the section that the address refers to.  On these machines,
   define the macro `ENCODE_SECTION_INFO' to store the information
   into the `symbol_ref', and then check for it here.  */

void
print_operand_address (file, addr)
     FILE *file;
     rtx addr;
{
  if (!addr)
    error ("PRINT_OPERAND_ADDRESS, null pointer");

  else
    switch (GET_CODE (addr))
      {
      case REG:
        if (! TARGET_MIPS16 && REGNO (addr) == ARG_POINTER_REGNUM)
          abort_with_insn (addr, "Arg pointer not eliminated.");

        fprintf (file, "0(%s)", reg_names [REGNO (addr)]);
        break;

      case LO_SUM:
        {
          register rtx arg0 = XEXP (addr, 0);
          register rtx arg1 = XEXP (addr, 1);

          if (! mips_split_addresses)
            abort_with_insn (addr, "PRINT_OPERAND_ADDRESS, Spurious LO_SUM.");

          if (GET_CODE (arg0) != REG)
            abort_with_insn (addr,
                             "PRINT_OPERAND_ADDRESS, LO_SUM with #1 not REG.");

          fprintf (file, "%%lo(");
          print_operand_address (file, arg1);
          fprintf (file, ")(%s)", reg_names [REGNO (arg0)]);
        }
        break;

      case PLUS:
        {
          register rtx reg = 0;
          register rtx offset = 0;
          register rtx arg0 = XEXP (addr, 0);
          register rtx arg1 = XEXP (addr, 1);

          if (GET_CODE (arg0) == REG)
            {
              reg = arg0;
              offset = arg1;
              if (GET_CODE (offset) == REG)
                abort_with_insn (addr, "PRINT_OPERAND_ADDRESS, 2 regs");
            }

          else if (GET_CODE (arg1) == REG)
              reg = arg1, offset = arg0;
          else if (CONSTANT_P (arg0) && CONSTANT_P (arg1))
            {
              output_addr_const (file, addr);
              break;
            }
          else
            abort_with_insn (addr, "PRINT_OPERAND_ADDRESS, no regs");

          if (! CONSTANT_P (offset))
            abort_with_insn (addr, "PRINT_OPERAND_ADDRESS, invalid insn #2");

          if (REGNO (reg) == ARG_POINTER_REGNUM)
            abort_with_insn (addr, "Arg pointer not eliminated.");

          if (TARGET_MIPS16
              && GET_CODE (offset) == CONST
              && mips16_gp_offset_p (offset))
            {
              fputs ("%gprel(", file);
              mips16_output_gp_offset (file, offset);
              fputs (")", file);
            }
          else
            output_addr_const (file, offset);
          fprintf (file, "(%s)", reg_names [REGNO (reg)]);
        }
        break;

      case LABEL_REF:
      case SYMBOL_REF:
      case CONST_INT:
      case CONST:
        output_addr_const (file, addr);
        break;

      default:
        abort_with_insn (addr, "PRINT_OPERAND_ADDRESS, invalid insn #1");
        break;
    }
}

\f
/* If optimizing for the global pointer, keep track of all of the externs, so
   that at the end of the file, we can emit the appropriate .extern
   declaration for them, before writing out the text section.  We assume all
   names passed to us are in the permanent obstack, so they will be valid at
   the end of the compilation.

   If we have -G 0, or the extern size is unknown, or the object is in a user
   specified section that is not .sbss/.sdata, don't bother emitting the
   .externs.  In the case of user specified sections this behaviour is
   required as otherwise GAS will think the object lives in .sbss/.sdata.  */

int
mips_output_external (file, decl, name)
     FILE *file ATTRIBUTE_UNUSED;
     tree decl;
     char *name;
{
  register struct extern_list *p;
  int len;
  tree section_name;

  if (TARGET_GP_OPT
      && TREE_CODE (decl) != FUNCTION_DECL
      && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
      && ((section_name = DECL_SECTION_NAME (decl)) == NULL
          || strcmp (TREE_STRING_POINTER (section_name), ".sbss") == 0
          || strcmp (TREE_STRING_POINTER (section_name), ".sdata") == 0))
    {
      p = (struct extern_list *) permalloc (sizeof (struct extern_list));
      p->next = extern_head;
      p->name = name;
      p->size = len;
      extern_head = p;
    }

#ifdef ASM_OUTPUT_UNDEF_FUNCTION
  if (TREE_CODE (decl) == FUNCTION_DECL
      /* ??? Don't include alloca, since gcc will always expand it
         inline.  If we don't do this, the C++ library fails to build.  */
      && strcmp (name, "alloca")
      /* ??? Don't include __builtin_next_arg, because then gcc will not
         bootstrap under Irix 5.1.  */
      && strcmp (name, "__builtin_next_arg"))
    {
      p = (struct extern_list *) permalloc (sizeof (struct extern_list));
      p->next = extern_head;
      p->name = name;
      p->size = -1;
      extern_head = p;
    }
#endif

  return 0;
}

#ifdef ASM_OUTPUT_UNDEF_FUNCTION
int
mips_output_external_libcall (file, name)
     FILE *file;
     char *name;
{
  register struct extern_list *p;

  p = (struct extern_list *) permalloc (sizeof (struct extern_list));
  p->next = extern_head;
  p->name = name;
  p->size = -1;
  extern_head = p;

  return 0;
}
#endif
\f
/* Compute a string to use as a temporary file name.  */

/* On MSDOS, write temp files in current dir
   because there's no place else we can expect to use.  */
#if __MSDOS__
#ifndef P_tmpdir
#define P_tmpdir "./"
#endif
#endif

static FILE *
make_temp_file ()
{
  FILE *stream;
  const char *base = getenv ("TMPDIR");
  int len;

  if (base == 0)
    {
#ifdef P_tmpdir
      if (access (P_tmpdir, R_OK | W_OK) == 0)
        base = P_tmpdir;
      else
#endif
        if (access ("/usr/tmp", R_OK | W_OK) == 0)
          base = "/usr/tmp/";
        else
          base = "/tmp/";
    }

  len = strlen (base);
  /* temp_filename is global, so we must use malloc, not alloca.  */
  temp_filename = (char *) xmalloc (len + sizeof("/ctXXXXXX"));
  strcpy (temp_filename, base);
  if (len > 0 && temp_filename[len-1] != '/')
    temp_filename[len++] = '/';

  strcpy (temp_filename + len, "ctXXXXXX");
  mktemp (temp_filename);

  stream = fopen (temp_filename, "w+");
  if (!stream)
    pfatal_with_name (temp_filename);

#ifndef __MSDOS__
  /* In MSDOS, we cannot unlink the temporary file until we are finished using
     it.  Otherwise, we delete it now, so that it will be gone even if the
     compiler happens to crash.  */
  unlink (temp_filename);
#endif
  return stream;
}
\f
/* Emit a new filename to a stream.  If this is MIPS ECOFF, watch out
   for .file's that start within a function.  If we are smuggling stabs, try to
   put out a MIPS ECOFF file and a stab.  */

void
mips_output_filename (stream, name)
     FILE *stream;
     char *name;
{
  static int first_time = 1;
  char ltext_label_name[100];

  if (first_time)
    {
      first_time = 0;
      SET_FILE_NUMBER ();
      current_function_file = name;
      ASM_OUTPUT_FILENAME (stream, num_source_filenames, name);
      /* This tells mips-tfile that stabs will follow.  */
      if (!TARGET_GAS && write_symbols == DBX_DEBUG)
        fprintf (stream, "\t#@stabs\n");
    }

  else if (write_symbols == DBX_DEBUG)
    {
      ASM_GENERATE_INTERNAL_LABEL (ltext_label_name, "Ltext", 0);
      fprintf (stream, "%s ", ASM_STABS_OP);
      output_quoted_string (stream, name);
      fprintf (stream, ",%d,0,0,%s\n", N_SOL, &ltext_label_name[1]);
    }

  else if (name != current_function_file
      && strcmp (name, current_function_file) != 0)
    {
      if (inside_function && !TARGET_GAS)
        {
          if (!file_in_function_warning)
            {
              file_in_function_warning = 1;
              ignore_line_number = 1;
              warning ("MIPS ECOFF format does not allow changing filenames within functions with #line");
            }
        }
      else
        {
          SET_FILE_NUMBER ();
          current_function_file = name;
          ASM_OUTPUT_FILENAME (stream, num_source_filenames, name);
        }
    }
}
\f
/* Emit a linenumber.  For encapsulated stabs, we need to put out a stab
   as well as a .loc, since it is possible that MIPS ECOFF might not be
   able to represent the location for inlines that come from a different
   file.  */

void
mips_output_lineno (stream, line)
     FILE *stream;
     int line;
{
  if (write_symbols == DBX_DEBUG)
    {
      ++sym_lineno;
      fprintf (stream, "%sLM%d:\n\t%s %d,0,%d,%sLM%d\n",
               LOCAL_LABEL_PREFIX, sym_lineno, ASM_STABN_OP, N_SLINE, line,
               LOCAL_LABEL_PREFIX, sym_lineno);
    }

  else
    {
      fprintf (stream, "\n\t%s.loc\t%d %d\n",
               (ignore_line_number) ? "#" : "",
               num_source_filenames, line);
  
      LABEL_AFTER_LOC (stream);
    }
}
\f
/* If defined, a C statement to be executed just prior to the output of
   assembler code for INSN, to modify the extracted operands so they will be
   output differently.

   Here the argument OPVEC is the vector containing the operands extracted
   from INSN, and NOPERANDS is the number of elements of the vector which
   contain meaningful data for this insn.  The contents of this vector are
   what will be used to convert the insn template into assembler code, so you
   can change the assembler output by changing the contents of the vector.

   We use it to check if the current insn needs a nop in front of it because
   of load delays, and also to update the delay slot statistics.  */

/* ??? There is no real need for this function, because it never actually
   emits a NOP anymore.  */

void
final_prescan_insn (insn, opvec, noperands)
     rtx insn;
     rtx opvec[] ATTRIBUTE_UNUSED;
     int noperands ATTRIBUTE_UNUSED;
{
  if (dslots_number_nops > 0)
    {
      rtx pattern = PATTERN (insn);
      int length = get_attr_length (insn);

      /* Do we need to emit a NOP? */
      if (length == 0
          || (mips_load_reg != 0 && reg_mentioned_p (mips_load_reg,  pattern))
          || (mips_load_reg2 != 0 && reg_mentioned_p (mips_load_reg2, pattern))
          || (mips_load_reg3 != 0 && reg_mentioned_p (mips_load_reg3, pattern))
          || (mips_load_reg4 != 0
              && reg_mentioned_p (mips_load_reg4, pattern)))
        fputs ("\t#nop\n", asm_out_file);

      else
        dslots_load_filled++;

      while (--dslots_number_nops > 0)
        fputs ("\t#nop\n", asm_out_file);

      mips_load_reg = 0;
      mips_load_reg2 = 0;
      mips_load_reg3 = 0;
      mips_load_reg4 = 0;
    }

  if (TARGET_STATS
      && (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == CALL_INSN))
    dslots_jump_total++;
}
\f
/* Output at beginning of assembler file.

   If we are optimizing to use the global pointer, create a temporary file to
   hold all of the text stuff, and write it out to the end. This is needed
   because the MIPS assembler is evidently one pass, and if it hasn't seen the
   relevant .comm/.lcomm/.extern/.sdata declaration when the code is
   processed, it generates a two instruction sequence.  */

void
mips_asm_file_start (stream)
     FILE *stream;
{
  ASM_OUTPUT_SOURCE_FILENAME (stream, main_input_filename);

  /* Versions of the MIPS assembler before 2.20 generate errors if a branch
     inside of a .set noreorder section jumps to a label outside of the .set
     noreorder section.  Revision 2.20 just set nobopt silently rather than
     fixing the bug.  */

  if (TARGET_MIPS_AS && optimize && flag_delayed_branch)
    fprintf (stream, "\t.set\tnobopt\n");

  /* Generate the pseudo ops that System V.4 wants.  */
#ifndef ABICALLS_ASM_OP
#define ABICALLS_ASM_OP ".abicalls"
#endif
  if (TARGET_ABICALLS)
    /* ??? but do not want this (or want pic0) if -non-shared? */
    fprintf (stream, "\t%s\n", ABICALLS_ASM_OP);

  if (TARGET_MIPS16)
    fprintf (stream, "\t.set\tmips16\n");

  /* Start a section, so that the first .popsection directive is guaranteed
     to have a previously defined section to pop back to.  */
  if (mips_abi != ABI_32 && mips_abi != ABI_O64 && mips_abi != ABI_EABI)
    fprintf (stream, "\t.section\t.text\n");

  /* This code exists so that we can put all externs before all symbol
     references.  This is necessary for the MIPS assembler's global pointer
     optimizations to work.  */
  if (TARGET_FILE_SWITCHING && ! TARGET_MIPS16)
    {
      asm_out_data_file = stream;
      asm_out_text_file = make_temp_file ();
    }

  else
    asm_out_data_file = asm_out_text_file = stream;

  if (flag_verbose_asm)
    fprintf (stream, "\n%s -G value = %d, Cpu = %s, ISA = %d\n",
             ASM_COMMENT_START,
             mips_section_threshold, mips_cpu_string, mips_isa);
}
\f
/* If we are optimizing the global pointer, emit the text section now and any
   small externs which did not have .comm, etc that are needed.  Also, give a
   warning if the data area is more than 32K and -pic because 3 instructions
   are needed to reference the data pointers.  */

void
mips_asm_file_end (file)
     FILE *file;
{
  char buffer[8192];
  tree name_tree;
  struct extern_list *p;
  int len;

  if (HALF_PIC_P ())
    {
      HALF_PIC_FINISH (file);
    }

  if (extern_head)
    {
      fputs ("\n", file);

      for (p = extern_head; p != 0; p = p->next)
        {
          name_tree = get_identifier (p->name);

          /* Positively ensure only one .extern for any given symbol.  */
          if (! TREE_ASM_WRITTEN (name_tree))
            {
              TREE_ASM_WRITTEN (name_tree) = 1;
#ifdef ASM_OUTPUT_UNDEF_FUNCTION
              if (p->size == -1)
                ASM_OUTPUT_UNDEF_FUNCTION (file, p->name);
              else
#endif
                {
                  fputs ("\t.extern\t", file);
                  assemble_name (file, p->name);
                  fprintf (file, ", %d\n", p->size);
                }
            }
        }
    }
      
  if (TARGET_FILE_SWITCHING && ! TARGET_MIPS16)
    {
      fprintf (file, "\n\t.text\n");
      rewind (asm_out_text_file);
      if (ferror (asm_out_text_file))
        fatal_io_error (temp_filename);

      while ((len = fread (buffer, 1, sizeof (buffer), asm_out_text_file)) > 0)
        if ((int) fwrite (buffer, 1, len, file) != len)
          pfatal_with_name (asm_file_name);

      if (len < 0)
        pfatal_with_name (temp_filename);

      if (fclose (asm_out_text_file) != 0)
        pfatal_with_name (temp_filename);

#ifdef __MSDOS__
      unlink (temp_filename);
#endif
    }
}

/* Emit either a label, .comm, or .lcomm directive, and mark that the symbol
   is used, so that we don't emit an .extern for it in mips_asm_file_end.  */

void
mips_declare_object (stream, name, init_string, final_string, size)
     FILE *stream;
     char *name;
     char *init_string;
     char *final_string;
     int size;
{
  fputs (init_string, stream);          /* "", "\t.comm\t", or "\t.lcomm\t" */
  assemble_name (stream, name);
  fprintf (stream, final_string, size); /* ":\n", ",%u\n", ",%u\n" */

  if (TARGET_GP_OPT)
    {
      tree name_tree = get_identifier (name);
      TREE_ASM_WRITTEN (name_tree) = 1;
    }
}
\f
/* Output a double precision value to the assembler.  If both the
   host and target are IEEE, emit the values in hex.  */

void
mips_output_double (stream, value)
     FILE *stream;
     REAL_VALUE_TYPE value;
{
#ifdef REAL_VALUE_TO_TARGET_DOUBLE
  long value_long[2];
  REAL_VALUE_TO_TARGET_DOUBLE (value, value_long);

  fprintf (stream, "\t.word\t0x%08lx\t\t# %.20g\n\t.word\t0x%08lx\n",
           value_long[0], value, value_long[1]);
#else
  fprintf (stream, "\t.double\t%.20g\n", value);
#endif
}

/* Output a single precision value to the assembler.  If both the
   host and target are IEEE, emit the values in hex.  */

void
mips_output_float (stream, value)
     FILE *stream;
     REAL_VALUE_TYPE value;
{
#ifdef REAL_VALUE_TO_TARGET_SINGLE
  long value_long;
  REAL_VALUE_TO_TARGET_SINGLE (value, value_long);

  fprintf (stream, "\t.word\t0x%08lx\t\t# %.12g (float)\n", value_long, value);
#else
  fprintf (stream, "\t.float\t%.12g\n", value);
#endif
}
\f
/* Return the bytes needed to compute the frame pointer from the current
   stack pointer.

   Mips stack frames look like:

             Before call                        After call
        +-----------------------+       +-----------------------+
   high |                       |       |                       |
   mem. |                       |       |                       |
        |  caller's temps.      |       |  caller's temps.      |
        |                       |       |                       |
        +-----------------------+       +-----------------------+
        |                       |       |                       |
        |  arguments on stack.  |       |  arguments on stack.  |
        |                       |       |                       |
        +-----------------------+       +-----------------------+
        |  4 words to save      |       |  4 words to save      |
        |  arguments passed     |       |  arguments passed     |
        |  in registers, even   |       |  in registers, even   |
    SP->|  if not passed.       |  VFP->|  if not passed.       |
        +-----------------------+       +-----------------------+
                                        |                       |
                                        |  fp register save     |
                                        |                       |
                                        +-----------------------+
                                        |                       |
                                        |  gp register save     |
                                        |                       |
                                        +-----------------------+
                                        |                       |
                                        |  local variables      |
                                        |                       |
                                        +-----------------------+
                                        |                       |
                                        |  alloca allocations   |
                                        |                       |
                                        +-----------------------+
                                        |                       |
                                        |  GP save for V.4 abi  |
                                        |                       |
                                        +-----------------------+
                                        |                       |
                                        |  arguments on stack   |
                                        |                       |
                                        +-----------------------+
                                        |  4 words to save      |
                                        |  arguments passed     |
                                        |  in registers, even   |
   low                              SP->|  if not passed.       |
   memory                               +-----------------------+

*/

HOST_WIDE_INT
compute_frame_size (size)
     HOST_WIDE_INT size;        /* # of var. bytes allocated */
{
  int regno;
  HOST_WIDE_INT total_size;     /* # bytes that the entire frame takes up */
  HOST_WIDE_INT var_size;       /* # bytes that variables take up */
  HOST_WIDE_INT args_size;      /* # bytes that outgoing arguments take up */
  HOST_WIDE_INT extra_size;     /* # extra bytes */
  HOST_WIDE_INT gp_reg_rounded; /* # bytes needed to store gp after rounding */
  HOST_WIDE_INT gp_reg_size;    /* # bytes needed to store gp regs */
  HOST_WIDE_INT fp_reg_size;    /* # bytes needed to store fp regs */
  long mask;                    /* mask of saved gp registers */
  long fmask;                   /* mask of saved fp registers */
  int  fp_inc;                  /* 1 or 2 depending on the size of fp regs */
  long fp_bits;                 /* bitmask to use for each fp register */

  gp_reg_size = 0;
  fp_reg_size = 0;
  mask = 0;
  fmask = 0;
  extra_size = MIPS_STACK_ALIGN (((TARGET_ABICALLS) ? UNITS_PER_WORD : 0));
  var_size = MIPS_STACK_ALIGN (size);
  args_size = MIPS_STACK_ALIGN (current_function_outgoing_args_size);

  /* The MIPS 3.0 linker does not like functions that dynamically
     allocate the stack and have 0 for STACK_DYNAMIC_OFFSET, since it
     looks like we are trying to create a second frame pointer to the
     function, so allocate some stack space to make it happy.  */

  if (args_size == 0 && current_function_calls_alloca)
    args_size = 4 * UNITS_PER_WORD;

  total_size = var_size + args_size + extra_size;

  /* Calculate space needed for gp registers.  */
  for (regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++)
    {
      /* $18 is a special case on the mips16.  It may be used to call
         a function which returns a floating point value, but it is
         marked in call_used_regs.  $31 is also a special case.  When
         not using -mentry, it will be used to copy a return value
         into the floating point registers if the return value is
         floating point.  */
      if (MUST_SAVE_REGISTER (regno)
          || (TARGET_MIPS16
              && regno == GP_REG_FIRST + 18
              && regs_ever_live[regno])
          || (TARGET_MIPS16
              && regno == GP_REG_FIRST + 31
              && mips16_hard_float
              && ! mips_entry
              && ! aggregate_value_p (DECL_RESULT (current_function_decl))
              && (GET_MODE_CLASS (DECL_MODE (DECL_RESULT (current_function_decl)))
                  == MODE_FLOAT)
              && (! TARGET_SINGLE_FLOAT
                  || (GET_MODE_SIZE (DECL_MODE (DECL_RESULT (current_function_decl)))
                      <= 4))))
        {
          gp_reg_size += GET_MODE_SIZE (gpr_mode);
          mask |= 1L << (regno - GP_REG_FIRST);

          /* The entry and exit pseudo instructions can not save $17
             without also saving $16.  */
          if (mips_entry
              && regno == GP_REG_FIRST + 17
              && ! MUST_SAVE_REGISTER (GP_REG_FIRST + 16))
            {
              gp_reg_size += UNITS_PER_WORD;
              mask |= 1L << 16;
            }
        }
    }

  /* Calculate space needed for fp registers.  */
  if (TARGET_FLOAT64 || TARGET_SINGLE_FLOAT)
    {
      fp_inc = 1;
      fp_bits = 1;
    }
  else
    {
      fp_inc = 2;
      fp_bits = 3;
    }

  /* This loop must iterate over the same space as its companion in
     save_restore_regs.  */
  for (regno = (FP_REG_LAST - fp_inc + 1);
       regno >= FP_REG_FIRST;
       regno -= fp_inc)
    {
      if (regs_ever_live[regno] && !call_used_regs[regno])
        {
          fp_reg_size += fp_inc * UNITS_PER_FPREG;
          fmask |= fp_bits << (regno - FP_REG_FIRST);
        }
    }

  gp_reg_rounded = MIPS_STACK_ALIGN (gp_reg_size);
  total_size += gp_reg_rounded + MIPS_STACK_ALIGN (fp_reg_size);

  /* The gp reg is caller saved in the 32 bit ABI, so there is no need
     for leaf routines (total_size == extra_size) to save the gp reg.
     The gp reg is callee saved in the 64 bit ABI, so all routines must
     save the gp reg.  This is not a leaf routine if -p, because of the
     call to mcount.  */
  if (total_size == extra_size 
      && (mips_abi == ABI_32 || mips_abi == ABI_O64 || mips_abi == ABI_EABI)
      && ! profile_flag)
    total_size = extra_size = 0;
  else if (TARGET_ABICALLS)
    {
      /* Add the context-pointer to the saved registers.  */
      gp_reg_size += UNITS_PER_WORD;
      mask |= 1L << (PIC_OFFSET_TABLE_REGNUM - GP_REG_FIRST);
      total_size -= gp_reg_rounded;
      gp_reg_rounded = MIPS_STACK_ALIGN (gp_reg_size);
      total_size += gp_reg_rounded;
    }

  /* Add in space reserved on the stack by the callee for storing arguments
     passed in registers.  */
  if (mips_abi != ABI_32 && mips_abi != ABI_O64)
    total_size += MIPS_STACK_ALIGN (current_function_pretend_args_size);

  /* The entry pseudo instruction will allocate 32 bytes on the stack.  */
  if (mips_entry && total_size > 0 && total_size < 32)
    total_size = 32;

  /* Save other computed information.  */
  current_frame_info.total_size = total_size;
  current_frame_info.var_size = var_size;
  current_frame_info.args_size = args_size;
  current_frame_info.extra_size = extra_size;
  current_frame_info.gp_reg_size = gp_reg_size;
  current_frame_info.fp_reg_size = fp_reg_size;
  current_frame_info.mask = mask;
  current_frame_info.fmask = fmask;
  current_frame_info.initialized = reload_completed;
  current_frame_info.num_gp = gp_reg_size / UNITS_PER_WORD;
  current_frame_info.num_fp = fp_reg_size / (fp_inc * UNITS_PER_FPREG);

  if (mask)
    {
      unsigned long offset;

      /* When using mips_entry, the registers are always saved at the
         top of the stack.  */
      if (! mips_entry)
        offset = (args_size + extra_size + var_size
                  + gp_reg_size - GET_MODE_SIZE (gpr_mode));
      else
        offset = total_size - GET_MODE_SIZE (gpr_mode);

      current_frame_info.gp_sp_offset = offset;
      current_frame_info.gp_save_offset = offset - total_size;
    }
  else
    {
      current_frame_info.gp_sp_offset = 0;
      current_frame_info.gp_save_offset = 0;
    }

  if (fmask)
    {
      unsigned long offset = (args_size + extra_size + var_size
                              + gp_reg_rounded + fp_reg_size
                              - fp_inc * UNITS_PER_FPREG);
      current_frame_info.fp_sp_offset = offset;
      current_frame_info.fp_save_offset = offset - total_size;
    }
  else
    {
      current_frame_info.fp_sp_offset = 0;
      current_frame_info.fp_save_offset = 0;
    }

  /* Ok, we're done.  */
  return total_size;
}
\f
/* Common code to emit the insns (or to write the instructions to a file)
   to save/restore registers.

   Other parts of the code assume that MIPS_TEMP1_REGNUM (aka large_reg)
   is not modified within save_restore_insns.  */

#define BITSET_P(VALUE,BIT) (((VALUE) & (1L << (BIT))) != 0)

static void
save_restore_insns (store_p, large_reg, large_offset, file)
     int store_p;       /* true if this is prologue */
     rtx large_reg;     /* register holding large offset constant or NULL */
     long large_offset; /* large constant offset value */
     FILE *file;        /* file to write instructions instead of making RTL */
{
  long mask = current_frame_info.mask;
  long fmask = current_frame_info.fmask;
  int regno;
  rtx base_reg_rtx;
  HOST_WIDE_INT base_offset;
  HOST_WIDE_INT gp_offset;
  HOST_WIDE_INT fp_offset;
  HOST_WIDE_INT end_offset;
  rtx insn;

  if (frame_pointer_needed
      && ! BITSET_P (mask, HARD_FRAME_POINTER_REGNUM - GP_REG_FIRST))
    abort ();

  if (mask == 0 && fmask == 0)
    return;

  /* Save registers starting from high to low.  The debuggers prefer at least
     the return register be stored at func+4, and also it allows us not to
     need a nop in the epilog if at least one register is reloaded in
     addition to return address.  */

  /* Save GP registers if needed.  */
  if (mask)
    {
      /* Pick which pointer to use as a base register.  For small frames, just
         use the stack pointer.  Otherwise, use a temporary register.  Save 2
         cycles if the save area is near the end of a large frame, by reusing
         the constant created in the prologue/epilogue to adjust the stack
         frame.  */

      gp_offset = current_frame_info.gp_sp_offset;
      end_offset
        = gp_offset - (current_frame_info.gp_reg_size
                       - GET_MODE_SIZE (gpr_mode));

      if (gp_offset < 0 || end_offset < 0)
        fatal ("gp_offset (%ld) or end_offset (%ld) is less than zero.",
               (long) gp_offset, (long) end_offset);

      /* If we see a large frame in mips16 mode, we save the registers
         before adjusting the stack pointer, and load them afterward.  */
      else if (TARGET_MIPS16 && large_offset > 32767)
        base_reg_rtx = stack_pointer_rtx, base_offset = large_offset;

      else if (gp_offset < 32768)
        base_reg_rtx = stack_pointer_rtx, base_offset  = 0;

      else if (large_reg != 0
               && (unsigned HOST_WIDE_INT) (large_offset - gp_offset) < 32768
               && (unsigned HOST_WIDE_INT) (large_offset - end_offset) < 32768)
        {
          base_reg_rtx = gen_rtx (REG, Pmode, MIPS_TEMP2_REGNUM);
          base_offset = large_offset;
          if (file == 0)
            {
              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (base_reg_rtx, large_reg,
                                              stack_pointer_rtx));
              else
                insn = emit_insn (gen_addsi3 (base_reg_rtx, large_reg,
                                              stack_pointer_rtx));
              if (store_p)
                RTX_FRAME_RELATED_P (insn) = 1;
            }
          else
            fprintf (file, "\t%s\t%s,%s,%s\n",
                     Pmode == DImode ? "daddu" : "addu",
                     reg_names[MIPS_TEMP2_REGNUM],
                     reg_names[REGNO (large_reg)],
                     reg_names[STACK_POINTER_REGNUM]);
        }

      else
        {
          base_reg_rtx = gen_rtx (REG, Pmode, MIPS_TEMP2_REGNUM);
          base_offset = gp_offset;
          if (file == 0)
            {
              rtx gp_offset_rtx = GEN_INT (gp_offset);

              /* Instruction splitting doesn't preserve the RTX_FRAME_RELATED_P
                 bit, so make sure that we don't emit anything that can be
                 split.  */
              /* ??? There is no DImode ori immediate pattern, so we can only
                 do this for 32 bit code.  */
              if (large_int (gp_offset_rtx)
                  && GET_MODE (base_reg_rtx) == SImode)
                {
                  insn = emit_move_insn (base_reg_rtx,
                                         GEN_INT (gp_offset & 0xffff0000));
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                  insn
                    = emit_insn (gen_iorsi3 (base_reg_rtx, base_reg_rtx,
                                             GEN_INT (gp_offset & 0x0000ffff)));
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                }
              else
                {
                  insn = emit_move_insn (base_reg_rtx, gp_offset_rtx);
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                }

              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (base_reg_rtx, base_reg_rtx,
                                              stack_pointer_rtx));
              else
                insn = emit_insn (gen_addsi3 (base_reg_rtx, base_reg_rtx,
                                              stack_pointer_rtx));
              if (store_p)
                RTX_FRAME_RELATED_P (insn) = 1;
            }
          else
            {
              fprintf (file, "\tli\t%s,0x%.08lx\t# ",
                       reg_names[MIPS_TEMP2_REGNUM], (long) base_offset);
              fprintf (file, HOST_WIDE_INT_PRINT_DEC, base_offset);
              fprintf (file, "\n\t%s\t%s,%s,%s\n",
                       Pmode == DImode ? "daddu" : "addu",
                       reg_names[MIPS_TEMP2_REGNUM],
                       reg_names[MIPS_TEMP2_REGNUM],
                       reg_names[STACK_POINTER_REGNUM]);
            }
        }

      /* When we restore the registers in MIPS16 mode, then if we are
         using a frame pointer, and this is not a large frame, the
         current stack pointer will be offset by
         current_function_outgoing_args_size.  Doing it this way lets
         us avoid offsetting the frame pointer before copying it into
         the stack pointer; there is no instruction to set the stack
         pointer to the sum of a register and a constant.  */
      if (TARGET_MIPS16
          && ! store_p
          && frame_pointer_needed
          && large_offset <= 32767)
        base_offset += current_function_outgoing_args_size;

      for (regno = GP_REG_LAST; regno >= GP_REG_FIRST; regno--)
        if (BITSET_P (mask, regno - GP_REG_FIRST))
          {
            if (file == 0)
              {
                rtx reg_rtx;
                rtx mem_rtx
                  = gen_rtx (MEM, gpr_mode,
                             gen_rtx (PLUS, Pmode, base_reg_rtx,
                                      GEN_INT (gp_offset - base_offset)));

                RTX_UNCHANGING_P (mem_rtx) = 1;

                /* The mips16 does not have an instruction to load
                   $31, so we load $7 instead, and work things out
                   in the caller.  */
                if (TARGET_MIPS16 && ! store_p && regno == GP_REG_FIRST + 31)
                  reg_rtx = gen_rtx (REG, gpr_mode, GP_REG_FIRST + 7);
                /* The mips16 sometimes needs to save $18.  */
                else if (TARGET_MIPS16
                         && regno != GP_REG_FIRST + 31
                         && ! M16_REG_P (regno))
                  {
                    if (! store_p)
                      reg_rtx = gen_rtx (REG, gpr_mode, 6);
                    else
                      {
                        reg_rtx = gen_rtx (REG, gpr_mode, 3);
                        emit_move_insn (reg_rtx,
                                        gen_rtx (REG, gpr_mode, regno));
                      }
                  }
                else
                  reg_rtx = gen_rtx (REG, gpr_mode, regno);

                if (store_p)
                  {
                    insn = emit_move_insn (mem_rtx, reg_rtx);
                    RTX_FRAME_RELATED_P (insn) = 1;
                  }
                else if (!TARGET_ABICALLS 
                         || (mips_abi != ABI_32 && mips_abi != ABI_O64)
                         || regno != (PIC_OFFSET_TABLE_REGNUM - GP_REG_FIRST))
                  {
                    emit_move_insn (reg_rtx, mem_rtx);
                    if (TARGET_MIPS16
                        && regno != GP_REG_FIRST + 31
                        && ! M16_REG_P (regno))
                      emit_move_insn (gen_rtx (REG, gpr_mode, regno),
                                      reg_rtx);
                  }
              }
            else
              {
                if (store_p || !TARGET_ABICALLS 
                    || (mips_abi != ABI_32 && mips_abi != ABI_O64)
                    || regno != (PIC_OFFSET_TABLE_REGNUM - GP_REG_FIRST))
                  {
                    int r = regno;

                    /* The mips16 does not have an instruction to
                       load $31, so we load $7 instead, and work
                       things out in the caller.  */
                    if (TARGET_MIPS16 && ! store_p && r == GP_REG_FIRST + 31)
                      r = GP_REG_FIRST + 7;
                      /* The mips16 sometimes needs to save $18.  */
                    if (TARGET_MIPS16
                        && regno != GP_REG_FIRST + 31
                        && ! M16_REG_P (regno))
                      {
                        if (! store_p)
                          r = GP_REG_FIRST + 6;
                        else
                          {
                            r = GP_REG_FIRST + 3;
                            fprintf (file, "\tmove\t%s,%s\n",
                                     reg_names[r], reg_names[regno]);
                          }
                      }
                    fprintf (file, "\t%s\t%s,",
                             (TARGET_64BIT
                              ? (store_p) ? "sd" : "ld"
                              : (store_p) ? "sw" : "lw"),
                             reg_names[r]);
                    fprintf (file, HOST_WIDE_INT_PRINT_DEC, 
                             gp_offset - base_offset);
                    fprintf (file, "(%s)\n", reg_names[REGNO(base_reg_rtx)]);
                    if (! store_p
                        && TARGET_MIPS16
                        && regno != GP_REG_FIRST + 31
                        && ! M16_REG_P (regno))
                      fprintf (file, "\tmove\t%s,%s\n",
                               reg_names[regno], reg_names[r]);
                  }

              }
            gp_offset -= GET_MODE_SIZE (gpr_mode);
          }
    }
  else
    base_reg_rtx = 0, base_offset  = 0;

  /* Save floating point registers if needed.  */
  if (fmask)
    {
      int fp_inc = (TARGET_FLOAT64 || TARGET_SINGLE_FLOAT) ? 1 : 2;
      int fp_size = fp_inc * UNITS_PER_FPREG;

      /* Pick which pointer to use as a base register.  */
      fp_offset = current_frame_info.fp_sp_offset;
      end_offset = fp_offset - (current_frame_info.fp_reg_size - fp_size);

      if (fp_offset < 0 || end_offset < 0)
        fatal ("fp_offset (%ld) or end_offset (%ld) is less than zero.",
               (long) fp_offset, (long) end_offset);

      else if (fp_offset < 32768)
        base_reg_rtx = stack_pointer_rtx, base_offset  = 0;

      else if (base_reg_rtx != 0
               && (unsigned HOST_WIDE_INT) (base_offset - fp_offset) < 32768
               && (unsigned HOST_WIDE_INT) (base_offset - end_offset) < 32768)
        ;                       /* already set up for gp registers above */

      else if (large_reg != 0
               && (unsigned HOST_WIDE_INT) (large_offset - fp_offset) < 32768
               && (unsigned HOST_WIDE_INT) (large_offset - end_offset) < 32768)
        {
          base_reg_rtx = gen_rtx (REG, Pmode, MIPS_TEMP2_REGNUM);
          base_offset = large_offset;
          if (file == 0)
            {
              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (base_reg_rtx, large_reg,
                                              stack_pointer_rtx));
              else
                insn = emit_insn (gen_addsi3 (base_reg_rtx, large_reg,
                                              stack_pointer_rtx));
              if (store_p)
                RTX_FRAME_RELATED_P (insn) = 1;
            }

          else
            fprintf (file, "\t%s\t%s,%s,%s\n",
                     Pmode == DImode ? "daddu" : "addu",
                     reg_names[MIPS_TEMP2_REGNUM],
                     reg_names[REGNO (large_reg)],
                     reg_names[STACK_POINTER_REGNUM]);
        }

      else
        {
          base_reg_rtx = gen_rtx (REG, Pmode, MIPS_TEMP2_REGNUM);
          base_offset = fp_offset;
          if (file == 0)
            {
              rtx fp_offset_rtx = GEN_INT (fp_offset);

              /* Instruction splitting doesn't preserve the RTX_FRAME_RELATED_P
                 bit, so make sure that we don't emit anything that can be
                 split.  */
              /* ??? There is no DImode ori immediate pattern, so we can only
                 do this for 32 bit code.  */
              if (large_int (fp_offset_rtx)
                  && GET_MODE (base_reg_rtx) == SImode)
                {
                  insn = emit_move_insn (base_reg_rtx,
                                         GEN_INT (fp_offset & 0xffff0000));
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                  insn = emit_insn (gen_iorsi3 (base_reg_rtx, base_reg_rtx,
                                                GEN_INT (fp_offset & 0x0000ffff)));
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                }
              else
                {
                  insn = emit_move_insn (base_reg_rtx, fp_offset_rtx);
                  if (store_p)
                    RTX_FRAME_RELATED_P (insn) = 1;
                }

              if (store_p)
                RTX_FRAME_RELATED_P (insn) = 1;
              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (base_reg_rtx, base_reg_rtx,
                                              stack_pointer_rtx));
              else
                insn = emit_insn (gen_addsi3 (base_reg_rtx, base_reg_rtx,
                                              stack_pointer_rtx));
              if (store_p)
                RTX_FRAME_RELATED_P (insn) = 1;
            }
          else
            {
              fprintf (file, "\tli\t%s,0x%.08lx\t# ",
                       reg_names[MIPS_TEMP2_REGNUM], (long) base_offset);
              fprintf (file, HOST_WIDE_INT_PRINT_DEC, base_offset);
              fprintf (file, "\n\t%s\t%s,%s,%s\n",
                       Pmode == DImode ? "daddu" : "addu",
                       reg_names[MIPS_TEMP2_REGNUM],
                       reg_names[MIPS_TEMP2_REGNUM],
                       reg_names[STACK_POINTER_REGNUM]);
            }
        }

      /* This loop must iterate over the same space as its companion in
         compute_frame_size.  */
      for (regno = (FP_REG_LAST - fp_inc + 1);
           regno >= FP_REG_FIRST;
           regno -= fp_inc)
        if (BITSET_P (fmask, regno - FP_REG_FIRST))
          {
            if (file == 0)
              {
                enum machine_mode sz
                  = TARGET_SINGLE_FLOAT ? SFmode : DFmode;
                rtx reg_rtx = gen_rtx (REG, sz, regno);
                rtx mem_rtx = gen_rtx (MEM, sz,
                                       gen_rtx (PLUS, Pmode, base_reg_rtx,
                                                GEN_INT (fp_offset
                                                         - base_offset)));
                RTX_UNCHANGING_P (mem_rtx) = 1;

                if (store_p)
                  {
                    insn = emit_move_insn (mem_rtx, reg_rtx);
                    RTX_FRAME_RELATED_P (insn) = 1;
                  }
                else
                  emit_move_insn (reg_rtx, mem_rtx);
              }
            else
              {
                fprintf (file, "\t%s\t%s,",
                         (TARGET_SINGLE_FLOAT
                          ? (store_p ? "s.s" : "l.s")
                          : (store_p ? "s.d" : "l.d")),
                         reg_names[regno]);
                fprintf (file, HOST_WIDE_INT_PRINT_DEC,
                         fp_offset - base_offset);
                fprintf (file, "(%s)\n", reg_names[REGNO(base_reg_rtx)]);
              }

            fp_offset -= fp_size;
          }
    }
}
\f
/* Set up the stack and frame (if desired) for the function.  */

void
function_prologue (file, size)
     FILE *file;
     int size ATTRIBUTE_UNUSED;
{
#ifndef FUNCTION_NAME_ALREADY_DECLARED
  char *fnname;
#endif
  long tsize = current_frame_info.total_size;

  ASM_OUTPUT_SOURCE_FILENAME (file, DECL_SOURCE_FILE (current_function_decl));

#ifdef SDB_DEBUGGING_INFO
  if (debug_info_level != DINFO_LEVEL_TERSE && write_symbols == SDB_DEBUG)
    ASM_OUTPUT_SOURCE_LINE (file, DECL_SOURCE_LINE (current_function_decl));
#endif

  /* In mips16 mode, we may need to generate a 32 bit to handle
     floating point arguments.  The linker will arrange for any 32 bit
     functions to call this stub, which will then jump to the 16 bit
     function proper.  */
  if (TARGET_MIPS16 && !TARGET_SOFT_FLOAT
      && current_function_args_info.fp_code != 0)
    build_mips16_function_stub (file);

  inside_function = 1;

#ifndef FUNCTION_NAME_ALREADY_DECLARED
  /* Get the function name the same way that toplev.c does before calling
     assemble_start_function.  This is needed so that the name used here
     exactly matches the name used in ASM_DECLARE_FUNCTION_NAME.  */
  fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);

  if (!flag_inhibit_size_directive)
    {
      fputs ("\t.ent\t", file);
      assemble_name (file, fnname);
      fputs ("\n", file);
    }

  assemble_name (file, fnname);
  fputs (":\n", file);
#endif

  if (!flag_inhibit_size_directive)
    {
      /* .frame FRAMEREG, FRAMESIZE, RETREG */
      fprintf (file,
               "\t.frame\t%s,%ld,%s\t\t# vars= %ld, regs= %d/%d, args= %d, extra= %ld\n",
               (reg_names[(frame_pointer_needed)
                          ? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM]),
               ((frame_pointer_needed && TARGET_MIPS16)
                ? (tsize - current_function_outgoing_args_size)
                : tsize),
               reg_names[31 + GP_REG_FIRST],
               current_frame_info.var_size,
               current_frame_info.num_gp,
               current_frame_info.num_fp,
               current_function_outgoing_args_size,
               current_frame_info.extra_size);

      /* .mask MASK, GPOFFSET; .fmask FPOFFSET */
      fprintf (file, "\t.mask\t0x%08lx,%ld\n\t.fmask\t0x%08lx,%ld\n",
               current_frame_info.mask,
               current_frame_info.gp_save_offset,
               current_frame_info.fmask,
               current_frame_info.fp_save_offset);

      /* Require:
         OLD_SP == *FRAMEREG + FRAMESIZE => can find old_sp from nominated FP reg.
         HIGHEST_GP_SAVED == *FRAMEREG + FRAMESIZE + GPOFFSET => can find saved regs. */
    }

  if (mips_entry && ! mips_can_use_return_insn ())
    {
      int save16 = BITSET_P (current_frame_info.mask, 16);
      int save17 = BITSET_P (current_frame_info.mask, 17);
      int save31 = BITSET_P (current_frame_info.mask, 31);
      int savearg = 0;
      rtx insn;

      /* Look through the initial insns to see if any of them store
         the function parameters into the incoming parameter storage
         area.  If they do, we delete the insn, and save the register
         using the entry pseudo-instruction instead.  We don't try to
         look past a label, jump, or call.  */
      for (insn = get_insns (); insn != NULL_RTX; insn = NEXT_INSN (insn))
        {
          rtx note, set, src, dest, base, offset;
          int hireg;

          if (GET_CODE (insn) == CODE_LABEL
              || GET_CODE (insn) == JUMP_INSN
              || GET_CODE (insn) == CALL_INSN)
            break;
          if (GET_CODE (insn) != INSN)
            continue;
          set = PATTERN (insn);
          if (GET_CODE (set) != SET)
            continue;

          /* An insn storing a function parameter will still have a
             REG_EQUIV note on it mentioning the argument pointer.  */
          note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
          if (note == NULL_RTX)
            continue;
          if (! reg_mentioned_p (arg_pointer_rtx, XEXP (note, 0)))
            continue;

          src = SET_SRC (set);
          if (GET_CODE (src) != REG
              || REGNO (src) < GP_REG_FIRST + 4
              || REGNO (src) > GP_REG_FIRST + 7)
            continue;

          dest = SET_DEST (set);
          if (GET_CODE (dest) != MEM)
            continue;
          if (GET_MODE_SIZE (GET_MODE (dest)) == UNITS_PER_WORD)
            ;
          else if (GET_MODE_SIZE (GET_MODE (dest)) == 2 * UNITS_PER_WORD
                   && REGNO (src) < GP_REG_FIRST + 7)
            ;
          else
            continue;
          offset = const0_rtx;
          base = eliminate_constant_term (XEXP (dest, 0), &offset);
          if (GET_CODE (base) != REG
              || GET_CODE (offset) != CONST_INT)
            continue;
          if (REGNO (base) == STACK_POINTER_REGNUM
              && INTVAL (offset) == tsize + (REGNO (src) - 4) * UNITS_PER_WORD)
            ;
          else if (REGNO (base) == HARD_FRAME_POINTER_REGNUM
                   && (INTVAL (offset)
                       == (tsize
                           + (REGNO (src) - 4) * UNITS_PER_WORD
                           - current_function_outgoing_args_size)))
            ;
          else
            continue;

          /* This insn stores a parameter onto the stack, in the same
             location where the entry pseudo-instruction will put it.
             Delete the insn, and arrange to tell the entry
             instruction to save the register.  */
          PUT_CODE (insn, NOTE);
          NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
          NOTE_SOURCE_FILE (insn) = 0;

          hireg = (REGNO (src)
                   + HARD_REGNO_NREGS (REGNO (src), GET_MODE (dest))
                   - 1);
          if (hireg > savearg)
            savearg = hireg;
        }

      /* If this is a varargs function, we need to save all the
         registers onto the stack anyhow.  */
      if (current_function_stdarg || current_function_varargs)
        savearg = GP_REG_FIRST + 7;

      fprintf (file, "\tentry\t");
      if (savearg > 0)
        {
          if (savearg == GP_REG_FIRST + 4)
            fprintf (file, "%s", reg_names[savearg]);
          else
            fprintf (file, "%s-%s", reg_names[GP_REG_FIRST + 4],
                     reg_names[savearg]);
        }
      if (save16 || save17)
        {
          if (savearg > 0)
            fprintf (file, ",");
          fprintf (file, "%s", reg_names[GP_REG_FIRST + 16]);
          if (save17)
            fprintf (file, "-%s", reg_names[GP_REG_FIRST + 17]);
        }
      if (save31)
        {
          if (savearg > 0 || save16 || save17)
            fprintf (file, ",");
          fprintf (file, "%s", reg_names[GP_REG_FIRST + 31]);
        }
      fprintf (file, "\n");
    }

  if (TARGET_ABICALLS && (mips_abi == ABI_32 || mips_abi == ABI_O64))
    {
      char *sp_str = reg_names[STACK_POINTER_REGNUM];

      fprintf (file, "\t.set\tnoreorder\n\t.cpload\t%s\n\t.set\treorder\n",
               reg_names[PIC_FUNCTION_ADDR_REGNUM]);
      if (tsize > 0)
        {
          fprintf (file, "\t%s\t%s,%s,%ld\n",
                   (Pmode == DImode ? "dsubu" : "subu"),
                   sp_str, sp_str, tsize);
          fprintf (file, "\t.cprestore %ld\n", current_frame_info.args_size);
        }

      if (dwarf2out_do_frame ())
        dwarf2out_def_cfa ("", STACK_POINTER_REGNUM, tsize);
    }
}
\f
/* Expand the prologue into a bunch of separate insns.  */

void
mips_expand_prologue ()
{
  int regno;
  HOST_WIDE_INT tsize;
  rtx tmp_rtx = 0;
  char *arg_name = 0;
  tree fndecl = current_function_decl;
  tree fntype = TREE_TYPE (fndecl);
  tree fnargs = DECL_ARGUMENTS (fndecl);
  rtx next_arg_reg;
  int i;
  tree next_arg;
  tree cur_arg;
  CUMULATIVE_ARGS args_so_far;
  rtx reg_18_save = NULL_RTX;

  /* If struct value address is treated as the first argument, make it so.  */
  if (aggregate_value_p (DECL_RESULT (fndecl))
      && ! current_function_returns_pcc_struct
      && struct_value_incoming_rtx == 0)
    {
      tree type = build_pointer_type (fntype);
      tree function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);

      DECL_ARG_TYPE (function_result_decl) = type;
      TREE_CHAIN (function_result_decl) = fnargs;
      fnargs = function_result_decl;
    }

  /* Determine the last argument, and get its name.  */

  INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
  regno = GP_ARG_FIRST;

  for (cur_arg = fnargs; cur_arg != 0; cur_arg = next_arg)
    {
      tree passed_type = DECL_ARG_TYPE (cur_arg);
      enum machine_mode passed_mode = TYPE_MODE (passed_type);
      rtx entry_parm;

      if (TREE_ADDRESSABLE (passed_type))
        {
          passed_type = build_pointer_type (passed_type);
          passed_mode = Pmode;
        }

      entry_parm = FUNCTION_ARG (args_so_far, passed_mode, passed_type, 1);

      if (entry_parm)
        {
          int words;

          /* passed in a register, so will get homed automatically */
          if (GET_MODE (entry_parm) == BLKmode)
            words = (int_size_in_bytes (passed_type) + 3) / 4;
          else
            words = (GET_MODE_SIZE (GET_MODE (entry_parm)) + 3) / 4;

          regno = REGNO (entry_parm) + words - 1;
        }
      else
        {
          regno = GP_ARG_LAST+1;
          break;
        }

      FUNCTION_ARG_ADVANCE (args_so_far, passed_mode, passed_type, 1);

      next_arg = TREE_CHAIN (cur_arg);
      if (next_arg == 0)
        {
          if (DECL_NAME (cur_arg))
            arg_name = IDENTIFIER_POINTER (DECL_NAME (cur_arg));

          break;
        }
    }

  /* In order to pass small structures by value in registers compatibly with
     the MIPS compiler, we need to shift the value into the high part of the
     register.  Function_arg has encoded a PARALLEL rtx, holding a vector of
     adjustments to be made as the next_arg_reg variable, so we split up the
     insns, and emit them separately.  */

  next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1);
  if (next_arg_reg != 0 && GET_CODE (next_arg_reg) == PARALLEL)
    {
      rtvec adjust = XVEC (next_arg_reg, 0);
      int num = GET_NUM_ELEM (adjust);

      for (i = 0; i < num; i++)
        {
          rtx pattern = RTVEC_ELT (adjust, i);
          if (GET_CODE (pattern) != SET
              || GET_CODE (SET_SRC (pattern)) != ASHIFT)
            abort_with_insn (pattern, "Insn is not a shift");

          PUT_CODE (SET_SRC (pattern), ASHIFTRT);
          emit_insn (pattern);
        }
    }

  tsize = compute_frame_size (get_frame_size ());

  /* If this function is a varargs function, store any registers that
     would normally hold arguments ($4 - $7) on the stack.  */
  if ((mips_abi == ABI_32 || mips_abi == ABI_O64)
      && (! mips_entry || mips_can_use_return_insn ())
      && ((TYPE_ARG_TYPES (fntype) != 0
           && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
               != void_type_node))
          || (arg_name != 0
              && ((arg_name[0] == '_'
                   && strcmp (arg_name, "__builtin_va_alist") == 0)
                  || (arg_name[0] == 'v'
                      && strcmp (arg_name, "va_alist") == 0)))))
    {
      int offset = (regno - GP_ARG_FIRST) * UNITS_PER_WORD;
      rtx ptr = stack_pointer_rtx;

      /* If we are doing svr4-abi, sp has already been decremented by tsize. */
      if (TARGET_ABICALLS)
        offset += tsize;

      for (; regno <= GP_ARG_LAST; regno++)
        {
          if (offset != 0)
            ptr = gen_rtx (PLUS, Pmode, stack_pointer_rtx, GEN_INT (offset));
          emit_move_insn (gen_rtx (MEM, gpr_mode, ptr),
                          gen_rtx (REG, gpr_mode, regno));

          offset += GET_MODE_SIZE (gpr_mode);
        }
    }

  /* If we are using the entry pseudo instruction, it will
     automatically subtract 32 from the stack pointer, so we don't
     need to.  The entry pseudo instruction is emitted by
     function_prologue.  */
  if (mips_entry && ! mips_can_use_return_insn ())
    {
      if (tsize > 0 && tsize <= 32 && frame_pointer_needed)
        {
          rtx insn;

          /* If we are using a frame pointer with a small stack frame,
             we need to initialize it here since it won't be done
             below.  */
          if (TARGET_MIPS16 && current_function_outgoing_args_size != 0)
            {
              rtx incr = GEN_INT (current_function_outgoing_args_size);
              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (hard_frame_pointer_rtx,
                                              stack_pointer_rtx,
                                              incr));
              else
                insn = emit_insn (gen_addsi3 (hard_frame_pointer_rtx,
                                              stack_pointer_rtx,
                                              incr));
            }
          else if (Pmode == DImode)
            insn = emit_insn (gen_movdi (hard_frame_pointer_rtx,
                                         stack_pointer_rtx));
          else
            insn = emit_insn (gen_movsi (hard_frame_pointer_rtx,
                                         stack_pointer_rtx));

          RTX_FRAME_RELATED_P (insn) = 1;
        }

      /* We may need to save $18, if it is used to call a function
         which may return a floating point value.  Set up a sequence
         of instructions to do so.  Later on we emit them at the right
         moment.  */
      if (TARGET_MIPS16 && BITSET_P (current_frame_info.mask, 18))
        {
          rtx reg_rtx = gen_rtx (REG, gpr_mode, GP_REG_FIRST + 3);
          long gp_offset, base_offset;

          gp_offset = current_frame_info.gp_sp_offset;
          if (BITSET_P (current_frame_info.mask, 16))
            gp_offset -= UNITS_PER_WORD;
          if (BITSET_P (current_frame_info.mask, 17))
            gp_offset -= UNITS_PER_WORD;
          if (BITSET_P (current_frame_info.mask, 31))
            gp_offset -= UNITS_PER_WORD;
          if (tsize > 32767)
            base_offset = tsize;
          else
            base_offset = 0;
          start_sequence ();
          emit_move_insn (reg_rtx,
                          gen_rtx (REG, gpr_mode, GP_REG_FIRST + 18));
          emit_move_insn (gen_rtx (MEM, gpr_mode,
                                   gen_rtx (PLUS, Pmode, stack_pointer_rtx,
                                            GEN_INT (gp_offset
                                                     - base_offset))),
                          reg_rtx);
          reg_18_save = gen_sequence ();
          end_sequence ();
        }

      if (tsize > 32)
        tsize -= 32;
      else
        {
          tsize = 0;
          if (reg_18_save != NULL_RTX)
            emit_insn (reg_18_save);
        }
    }

  if (tsize > 0)
    {
      rtx tsize_rtx = GEN_INT (tsize);

      /* If we are doing svr4-abi, sp move is done by
         function_prologue.  In mips16 mode with a large frame, we
         save the registers before adjusting the stack.  */
      if ((!TARGET_ABICALLS || (mips_abi != ABI_32 && mips_abi != ABI_O64))
          && (!TARGET_MIPS16 || tsize <= 32767))
        {
          rtx insn;

          if (tsize > 32767)
            {
              tmp_rtx = gen_rtx (REG, Pmode, MIPS_TEMP1_REGNUM);

              /* Instruction splitting doesn't preserve the RTX_FRAME_RELATED_P
                 bit, so make sure that we don't emit anything that can be
                 split.  */
              /* ??? There is no DImode ori immediate pattern, so we can only
                 do this for 32 bit code.  */
              if (large_int (tsize_rtx) && GET_MODE (tmp_rtx) == SImode)
                {
                  insn = emit_move_insn (tmp_rtx,
                                         GEN_INT (tsize & 0xffff0000));
                  RTX_FRAME_RELATED_P (insn) = 1;
                  insn = emit_insn (gen_iorsi3 (tmp_rtx, tmp_rtx,
                                                GEN_INT (tsize & 0x0000ffff)));
                  RTX_FRAME_RELATED_P (insn) = 1;
                }
              else
                {
                  insn = emit_move_insn (tmp_rtx, tsize_rtx);
                  RTX_FRAME_RELATED_P (insn) = 1;
                }

              tsize_rtx = tmp_rtx;
            }

          if (Pmode == DImode)
            insn = emit_insn (gen_subdi3 (stack_pointer_rtx, stack_pointer_rtx,
                                          tsize_rtx));
          else
            insn = emit_insn (gen_subsi3 (stack_pointer_rtx, stack_pointer_rtx,
                                          tsize_rtx));

          RTX_FRAME_RELATED_P (insn) = 1;
        }

      if (! mips_entry)
        save_restore_insns (1, tmp_rtx, tsize, (FILE *)0);
      else if (reg_18_save != NULL_RTX)
        emit_insn (reg_18_save);

      if ((!TARGET_ABICALLS || (mips_abi != ABI_32 && mips_abi != ABI_O64))
          && TARGET_MIPS16
          && tsize > 32767)
        {
          rtx reg_rtx;

          if (!frame_pointer_needed)
            abort ();

          reg_rtx = gen_rtx (REG, Pmode, 3);
          emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx);
          emit_move_insn (reg_rtx, tsize_rtx);
          if (Pmode == DImode)
            emit_insn (gen_subdi3 (hard_frame_pointer_rtx,
                                   hard_frame_pointer_rtx,
                                   reg_rtx));
          else
            emit_insn (gen_subsi3 (hard_frame_pointer_rtx,
                                   hard_frame_pointer_rtx,
                                   reg_rtx));
          emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
        }

      if (frame_pointer_needed)
        {
          rtx insn = 0;

          /* On the mips16, we encourage the use of unextended
             instructions when using the frame pointer by pointing the
             frame pointer ahead of the argument space allocated on
             the stack.  */
          if ((! TARGET_ABICALLS || (mips_abi != ABI_32 && mips_abi != ABI_O64))
              && TARGET_MIPS16
              && tsize > 32767)
            {
              /* In this case, we have already copied the stack
                 pointer into the frame pointer, above.  We need only
                 adjust for the outgoing argument size.  */
              if (current_function_outgoing_args_size != 0)
                {
                  rtx incr = GEN_INT (current_function_outgoing_args_size);
                  if (Pmode == DImode)
                    insn = emit_insn (gen_adddi3 (hard_frame_pointer_rtx,
                                                  hard_frame_pointer_rtx,
                                                  incr));
                  else
                    insn = emit_insn (gen_addsi3 (hard_frame_pointer_rtx,
                                                  hard_frame_pointer_rtx,
                                                  incr));
                }
            }
          else if (TARGET_MIPS16 && current_function_outgoing_args_size != 0)
            {
              rtx incr = GEN_INT (current_function_outgoing_args_size);
              if (Pmode == DImode)
                insn = emit_insn (gen_adddi3 (hard_frame_pointer_rtx,
                                              stack_pointer_rtx,
                                              incr));
              else
                insn = emit_insn (gen_addsi3 (hard_frame_pointer_rtx,
                                              stack_pointer_rtx,
                                              incr));
            }
          else if (Pmode == DImode)
            insn = emit_insn (gen_movdi (hard_frame_pointer_rtx,
                                         stack_pointer_rtx));
          else
            insn = emit_insn (gen_movsi (hard_frame_pointer_rtx,
                                         stack_pointer_rtx));

          if (insn)
            RTX_FRAME_RELATED_P (insn) = 1;
        }

      if (TARGET_ABICALLS && (mips_abi != ABI_32 && mips_abi != ABI_O64))
        emit_insn (gen_loadgp (XEXP (DECL_RTL (current_function_decl), 0),
                               gen_rtx (REG, DImode, 25)));
    }

  /* If we are profiling, make sure no instructions are scheduled before
     the call to mcount.  */

  if (profile_flag || profile_block_flag)
    emit_insn (gen_blockage ());
}
\f
/* Do any necessary cleanup after a function to restore stack, frame,
   and regs. */

#define RA_MASK ((long) 0x80000000)     /* 1 << 31 */
#define PIC_OFFSET_TABLE_MASK (1 << (PIC_OFFSET_TABLE_REGNUM - GP_REG_FIRST))

void
function_epilogue (file, size)
     FILE *file ATTRIBUTE_UNUSED;
     HOST_WIDE_INT size ATTRIBUTE_UNUSED;
{
  char *fnname;

#ifndef FUNCTION_NAME_ALREADY_DECLARED
  /* Get the function name the same way that toplev.c does before calling
     assemble_start_function.  This is needed so that the name used here
     exactly matches the name used in ASM_DECLARE_FUNCTION_NAME.  */
  fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);

  if (!flag_inhibit_size_directive)
    {
      fputs ("\t.end\t", file);
      assemble_name (file, fnname);
      fputs ("\n", file);
    }
#endif

  if (TARGET_STATS)
    {
      int num_gp_regs = current_frame_info.gp_reg_size / 4;
      int num_fp_regs = current_frame_info.fp_reg_size / 8;
      int num_regs = num_gp_regs + num_fp_regs;
      char *name = fnname;

      if (name[0] == '*')
        name++;

      dslots_load_total += num_regs;

      fprintf (stderr,
               "%-20s fp=%c leaf=%c alloca=%c setjmp=%c stack=%4ld arg=%3d reg=%2d/%d delay=%3d/%3dL %3d/%3dJ refs=%3d/%3d/%3d",
               name, frame_pointer_needed ? 'y' : 'n',
               (current_frame_info.mask & RA_MASK) != 0 ? 'n' : 'y',
               current_function_calls_alloca ? 'y' : 'n',
               current_function_calls_setjmp ? 'y' : 'n',
               current_frame_info.total_size,
               current_function_outgoing_args_size, num_gp_regs, num_fp_regs,
               dslots_load_total, dslots_load_filled,
               dslots_jump_total, dslots_jump_filled,
               num_refs[0], num_refs[1], num_refs[2]);

      if (HALF_PIC_NUMBER_PTRS > prev_half_pic_ptrs)
        {
          fprintf (stderr,
                   " half-pic=%3d", HALF_PIC_NUMBER_PTRS - prev_half_pic_ptrs);
          prev_half_pic_ptrs = HALF_PIC_NUMBER_PTRS;
        }

      if (HALF_PIC_NUMBER_REFS > prev_half_pic_refs)
        {
          fprintf (stderr,
                   " pic-ref=%3d", HALF_PIC_NUMBER_REFS - prev_half_pic_refs);
          prev_half_pic_refs = HALF_PIC_NUMBER_REFS;
        }

      fputc ('\n', stderr);
    }

  /* Reset state info for each function.  */
  inside_function = 0;
  ignore_line_number = 0;
  dslots_load_total = 0;
  dslots_jump_total = 0;
  dslots_load_filled = 0;
  dslots_jump_filled = 0;
  num_refs[0] = 0;
  num_refs[1] = 0;
  num_refs[2] = 0;
  mips_load_reg = 0;
  mips_load_reg2 = 0;
  current_frame_info = zero_frame_info;

  while (string_constants != NULL)
    {
      struct string_constant *next;

      next = string_constants->next;
      free (string_constants);
      string_constants = next;
    }

  /* Restore the output file if optimizing the GP (optimizing the GP causes
     the text to be diverted to a tempfile, so that data decls come before
     references to the data).  */

  if (TARGET_GP_OPT && ! TARGET_MIPS16 && ! TARGET_GAS)
    asm_out_file = asm_out_data_file;
}
\f
/* Expand the epilogue into a bunch of separate insns.  */

void
mips_expand_epilogue ()
{
  HOST_WIDE_INT tsize = current_frame_info.total_size;
  rtx tsize_rtx = GEN_INT (tsize);
  rtx tmp_rtx = (rtx)0;

  if (mips_can_use_return_insn ())
    {
      emit_insn (gen_return ());
      return;
    }

  if (mips_entry && ! mips_can_use_return_insn ())
    tsize -= 32;

  if (tsize > 32767 && ! TARGET_MIPS16)
    {
      tmp_rtx = gen_rtx (REG, Pmode, MIPS_TEMP1_REGNUM);
      emit_move_insn (tmp_rtx, tsize_rtx);
      tsize_rtx = tmp_rtx;
    }

  if (tsize > 0)
    {
      long orig_tsize = tsize;

      if (frame_pointer_needed)
        {
          emit_insn (gen_blockage ());

          /* On the mips16, the frame pointer is offset from the stack
             pointer by current_function_outgoing_args_size.  We
             account for that by changing tsize.  Note that this can
             actually make tsize negative.  */
          if (TARGET_MIPS16)
            {
              tsize -= current_function_outgoing_args_size;

              /* If we have a large frame, it's easier to add to $17
                 than to $sp, since the mips16 has no instruction to
                 add a register to $sp.  */
              if (orig_tsize > 32767)
                {
                  rtx g6_rtx = gen_rtx (REG, Pmode, GP_REG_FIRST + 6);

                  emit_move_insn (g6_rtx, GEN_INT (tsize));
                  if (Pmode == DImode)
                    emit_insn (gen_adddi3 (hard_frame_pointer_rtx,
                                           hard_frame_pointer_rtx,
                                           g6_rtx));
                  else
                    emit_insn (gen_addsi3 (hard_frame_pointer_rtx,
                                           hard_frame_pointer_rtx,
                                           g6_rtx));
                  tsize = 0;
                }
              
              if (tsize && tsize != orig_tsize)
                tsize_rtx = GEN_INT (tsize);
            }

          if (Pmode == DImode)
            emit_insn (gen_movdi (stack_pointer_rtx, hard_frame_pointer_rtx));
          else
            emit_insn (gen_movsi (stack_pointer_rtx, hard_frame_pointer_rtx));
        }

      /* The GP/PIC register is implicitly used by all SYMBOL_REFs, so if we
         are going to restore it, then we must emit a blockage insn to
         prevent the scheduler from moving the restore out of the epilogue.  */
      else if (TARGET_ABICALLS && mips_abi != ABI_32 && mips_abi != ABI_O64
               && (current_frame_info.mask
                   & (1L << (PIC_OFFSET_TABLE_REGNUM - GP_REG_FIRST))))
        emit_insn (gen_blockage ());

      save_restore_insns (0, tmp_rtx, orig_tsize, (FILE *)0);

      /* In mips16 mode with a large frame, we adjust the stack
         pointer before restoring the registers.  In this case, we
         should always be using a frame pointer, so everything should
         have been handled above.  */
      if (tsize > 32767 && TARGET_MIPS16)
        abort ();

      emit_insn (gen_blockage ());
      if (Pmode == DImode && tsize != 0)
        emit_insn (gen_adddi3 (stack_pointer_rtx, stack_pointer_rtx,
                               tsize_rtx));
      else if (tsize != 0)
        emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                               tsize_rtx));
    }

  /* The mips16 loads the return address into $7, not $31.  */
  if (TARGET_MIPS16 && (current_frame_info.mask & RA_MASK) != 0)
    emit_jump_insn (gen_return_internal (gen_rtx (REG, Pmode,
                                                  GP_REG_FIRST + 7)));
  else
    emit_jump_insn (gen_return_internal (gen_rtx (REG, Pmode,
                                                  GP_REG_FIRST + 31)));
}
\f
/* Return nonzero if this function is known to have a null epilogue.
   This allows the optimizer to omit jumps to jumps if no stack
   was created.  */

int
mips_can_use_return_insn ()
{
  if (! reload_completed)
    return 0;

  if (regs_ever_live[31] || profile_flag)
    return 0;

  /* In mips16 mode, a function which returns a floating point value
     needs to arrange to copy the return value into the floating point
     registers.  */
  if (TARGET_MIPS16
      && mips16_hard_float
      && ! aggregate_value_p (DECL_RESULT (current_function_decl))
      && (GET_MODE_CLASS (DECL_MODE (DECL_RESULT (current_function_decl)))
          == MODE_FLOAT)
      && (! TARGET_SINGLE_FLOAT
          || (GET_MODE_SIZE (DECL_MODE (DECL_RESULT (current_function_decl)))
              <= 4)))
    return 0;

  if (current_frame_info.initialized)
    return current_frame_info.total_size == 0;

  return compute_frame_size (get_frame_size ()) == 0;
}
\f
/* Returns non-zero if X contains a SYMBOL_REF.  */

static int
symbolic_expression_p (x)
     rtx x;
{
  if (GET_CODE (x) == SYMBOL_REF)
    return 1;

  if (GET_CODE (x) == CONST)
    return symbolic_expression_p (XEXP (x, 0));
  
  if (GET_RTX_CLASS (GET_CODE (x)) == '1')
    return symbolic_expression_p (XEXP (x, 0));

  if (GET_RTX_CLASS (GET_CODE (x)) == 'c'
      || GET_RTX_CLASS (GET_CODE (x)) == '2')
    return (symbolic_expression_p (XEXP (x, 0))
            || symbolic_expression_p (XEXP (x, 1)));

  return 0;
}

/* Choose the section to use for the constant rtx expression X that has
   mode MODE.  */

void
mips_select_rtx_section (mode, x)
     enum machine_mode mode;
     rtx x ATTRIBUTE_UNUSED;
{
  if (TARGET_MIPS16)
    {
      /* In mips16 mode, the constant table always goes in the same section
         as the function, so that constants can be loaded using PC relative
         addressing.  */
      function_section (current_function_decl);
    }
  else if (TARGET_EMBEDDED_DATA)
    {
      /* For embedded applications, always put constants in read-only data,
         in order to reduce RAM usage.  */
      READONLY_DATA_SECTION ();
    }
  else
    {
      /* For hosted applications, always put constants in small data if
         possible, as this gives the best performance.  */
     
      if (GET_MODE_SIZE (mode) <= mips_section_threshold
          && mips_section_threshold > 0)
        SMALL_DATA_SECTION ();
      else if (flag_pic && symbolic_expression_p (x))
        /* Any expression involving a SYMBOL_REF might need a run-time
           relocation.  (The symbol might be defined in a shared
           library loaded at an unexpected base address.)  So, we must
           put such expressions in the data segment (which is
           writable), rather than the text segment (which is
           read-only).  */
        data_section ();
      else
        READONLY_DATA_SECTION ();
    }
}

/* Choose the section to use for DECL.  RELOC is true if its value contains
   any relocatable expression.

   Some of the logic used here needs to be replicated in
   ENCODE_SECTION_INFO in mips.h so that references to these symbols
   are done correctly.  Specifically, at least all symbols assigned
   here to rom (.text and/or .rodata) must not be referenced via
   ENCODE_SECTION_INFO with %gprel, as the rom might be too far away.

   If you need to make a change here, you probably should check
   ENCODE_SECTION_INFO to see if it needs a similar change.  */

void
mips_select_section (decl, reloc)
     tree decl;
     int reloc;
{
  int size = int_size_in_bytes (TREE_TYPE (decl));

  if ((TARGET_EMBEDDED_PIC || TARGET_MIPS16)
      && TREE_CODE (decl) == STRING_CST
      && !flag_writable_strings)
    /* For embedded position independent code, put constant strings in the
       text section, because the data section is limited to 64K in size.
       For mips16 code, put strings in the text section so that a PC
       relative load instruction can be used to get their address.  */
    text_section ();
  else if (TARGET_EMBEDDED_DATA)
    {
      /* For embedded applications, always put an object in read-only data
         if possible, in order to reduce RAM usage.  */

      if (((TREE_CODE (decl) == VAR_DECL
            && TREE_READONLY (decl) && !TREE_SIDE_EFFECTS (decl)
            && DECL_INITIAL (decl)
            && (DECL_INITIAL (decl) == error_mark_node
                || TREE_CONSTANT (DECL_INITIAL (decl))))
           /* Deal with calls from output_constant_def_contents.  */
           || (TREE_CODE (decl) != VAR_DECL
               && (TREE_CODE (decl) != STRING_CST
                   || !flag_writable_strings)))
          && ! (flag_pic && reloc))
        READONLY_DATA_SECTION ();
      else if (size > 0 && size <= mips_section_threshold)
        SMALL_DATA_SECTION ();
      else
        data_section ();
    }
  else
    {
      /* For hosted applications, always put an object in small data if
         possible, as this gives the best performance.  */

      if (size > 0 && size <= mips_section_threshold)
        SMALL_DATA_SECTION ();
      else if (((TREE_CODE (decl) == VAR_DECL
                 && TREE_READONLY (decl) && !TREE_SIDE_EFFECTS (decl)
                 && DECL_INITIAL (decl)
                 && (DECL_INITIAL (decl) == error_mark_node
                     || TREE_CONSTANT (DECL_INITIAL (decl))))
                /* Deal with calls from output_constant_def_contents.  */
                || (TREE_CODE (decl) != VAR_DECL
                    && (TREE_CODE (decl) != STRING_CST
                        || !flag_writable_strings)))
               && ! (flag_pic && reloc))
        READONLY_DATA_SECTION ();
      else
        data_section ();
    }
}
\f
#ifdef MIPS_ABI_DEFAULT

/* Support functions for the 64 bit ABI.  */

/* Return register to use for a function return value with VALTYPE for function
   FUNC.  */

rtx
mips_function_value (valtype, func)
     tree valtype;
     tree func ATTRIBUTE_UNUSED;
{
  int reg = GP_RETURN;
  enum machine_mode mode = TYPE_MODE (valtype);
  enum mode_class mclass = GET_MODE_CLASS (mode);
  int unsignedp = TREE_UNSIGNED (valtype);

  /* Since we define PROMOTE_FUNCTION_RETURN, we must promote the mode
     just as PROMOTE_MODE does.  */
  mode = promote_mode (valtype, mode, &unsignedp, 1);

  /* ??? How should we return complex float?  */
  if (mclass == MODE_FLOAT || mclass == MODE_COMPLEX_FLOAT)
    {
      if (TARGET_SINGLE_FLOAT
          && (mclass == MODE_FLOAT
              ? GET_MODE_SIZE (mode) > 4 : GET_MODE_SIZE (mode) / 2 > 4))
        reg = GP_RETURN;
      else
        reg = FP_RETURN;
    }

  else if (TREE_CODE (valtype) == RECORD_TYPE
           && mips_abi != ABI_32 
           && mips_abi != ABI_O64 
           && mips_abi != ABI_EABI)
    {
      /* A struct with only one or two floating point fields is returned in
         the floating point registers.  */
      tree field, fields[2];
      int i;

      for (i = 0, field = TYPE_FIELDS (valtype); field;
           field = TREE_CHAIN (field))
        {
          if (TREE_CODE (field) != FIELD_DECL)
            continue;

          if (TREE_CODE (TREE_TYPE (field)) != REAL_TYPE || i >= 2)
            break;

          fields[i++] = field;
        }
          
      /* Must check i, so that we reject structures with no elements.  */
      if (! field)
        {
          if (i == 1)
            {
              /* The structure has DImode, but we don't allow DImode values
                 in FP registers, so we use a PARALLEL even though it isn't
                 strictly necessary.  */
              enum machine_mode field_mode = TYPE_MODE (TREE_TYPE (fields[0]));

              return gen_rtx (PARALLEL, mode,
                              gen_rtvec (1,
                                         gen_rtx (EXPR_LIST, VOIDmode,
                                                  gen_rtx (REG, field_mode,
                                                           FP_RETURN),
                                                  const0_rtx)));
            }

          else if (i == 2)
            {
              enum machine_mode first_mode
                = TYPE_MODE (TREE_TYPE (fields[0]));
              enum machine_mode second_mode
                = TYPE_MODE (TREE_TYPE (fields[1]));
              int first_offset
                = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (fields[0]));
              int second_offset
                = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (fields[1]));

              return gen_rtx (PARALLEL, mode,
                              gen_rtvec (2,
                                         gen_rtx (EXPR_LIST, VOIDmode,
                                                  gen_rtx (REG, first_mode,
                                                           FP_RETURN),
                                                  GEN_INT (first_offset
                                                           / BITS_PER_UNIT)),
                                         gen_rtx (EXPR_LIST, VOIDmode,
                                                  gen_rtx (REG, second_mode,
                                                           FP_RETURN + 2),
                                                  GEN_INT (second_offset
                                                           / BITS_PER_UNIT))));
            }
        }
    }

  return gen_rtx (REG, mode, reg);
}

/* The implementation of FUNCTION_ARG_PASS_BY_REFERENCE.  Return
   nonzero when an argument must be passed by reference.  */

int
function_arg_pass_by_reference (cum, mode, type, named)
     CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED;
     enum machine_mode mode;
     tree type;
     int named ATTRIBUTE_UNUSED;
{
  int size;

  if (mips_abi != ABI_EABI)
    return 0;

  /* ??? How should SCmode be handled?  */
  if (type == NULL_TREE || mode == DImode || mode == DFmode)
    return 0;

  size = int_size_in_bytes (type);
  return size == -1 || size > UNITS_PER_WORD;
}
#endif

/* This function returns the register class required for a secondary
   register when copying between one of the registers in CLASS, and X,
   using MODE.  If IN_P is nonzero, the copy is going from X to the
   register, otherwise the register is the source.  A return value of
   NO_REGS means that no secondary register is required.  */

enum reg_class
mips_secondary_reload_class (class, mode, x, in_p)
     enum reg_class class;
     enum machine_mode mode;
     rtx x;
     int in_p;
{
  enum reg_class gr_regs = TARGET_MIPS16 ? M16_REGS : GR_REGS;
  int regno = -1;
  int gp_reg_p;

  if (GET_CODE (x) == SIGN_EXTEND)
    {
      int off = 0;

      x = XEXP (x, 0);

      /* We may be called with reg_renumber NULL from regclass.
         ??? This is probably a bug.  */
      if (reg_renumber)
        regno = true_regnum (x);
      else
        {
          while (GET_CODE (x) == SUBREG)
            {
              off += SUBREG_WORD (x);
              x = SUBREG_REG (x);
            }

          if (GET_CODE (x) == REG)
            regno = REGNO (x) + off;
        }
    }

  else if (GET_CODE (x) == REG || GET_CODE (x) == SUBREG)
    regno = true_regnum (x);

  gp_reg_p = TARGET_MIPS16 ? M16_REG_P (regno) : GP_REG_P (regno);

  /* We always require a general register when copying anything to
     HILO_REGNUM, except when copying an SImode value from HILO_REGNUM
     to a general register, or when copying from register 0.  */
  if (class == HILO_REG && regno != GP_REG_FIRST + 0)
    return ((! in_p
             && gp_reg_p
             && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (SImode))
            ? NO_REGS : gr_regs);
  else if (regno == HILO_REGNUM)
    return ((in_p
             && class == gr_regs
             && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (SImode))
            ? NO_REGS : gr_regs);

  /* Copying from HI or LO to anywhere other than a general register
     requires a general register.  */
  if (class == HI_REG || class == LO_REG || class == MD_REGS)
    {
      if (TARGET_MIPS16 && in_p)
        {
          /* We can't really copy to HI or LO at all in mips16 mode.  */
          return M16_REGS;
        }
      return gp_reg_p ? NO_REGS : gr_regs;
    }
  if (MD_REG_P (regno))
    {
      if (TARGET_MIPS16 && ! in_p)
        {
          /* We can't really copy to HI or LO at all in mips16 mode.  */
          return M16_REGS;
        }
      return class == gr_regs ? NO_REGS : gr_regs;
    }

  /* We can only copy a value to a condition code register from a
     floating point register, and even then we require a scratch
     floating point register.  We can only copy a value out of a
     condition code register into a general register.  */
  if (class == ST_REGS)
    {
      if (in_p)
        return FP_REGS;
      return GP_REG_P (regno) ? NO_REGS : GR_REGS;
    }
  if (ST_REG_P (regno))
    {
      if (! in_p)
        return FP_REGS;
      return class == GR_REGS ? NO_REGS : GR_REGS;
    }

  /* In mips16 mode, going between memory and anything but M16_REGS
     requires an M16_REG.  */
  if (TARGET_MIPS16)
    {
      if (class != M16_REGS && class != M16_NA_REGS)
        {
          if (gp_reg_p)
            return NO_REGS;
          return M16_REGS;
        }
      if (! gp_reg_p)
        {
          /* The stack pointer isn't a valid operand to an add instruction,
             so we need to load it into M16_REGS first.  This can happen as
             a result of register elimination and form_sum converting
             (plus reg (plus SP CONST)) to (plus (plus reg SP) CONST).  We
             need an extra register if the dest is the same as the other
             register.  In that case, we can't fix the problem by loading SP
             into the dest first.  */
          if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
              && GET_CODE (XEXP (x, 1)) == REG
              && (XEXP (x, 0) == stack_pointer_rtx
                  || XEXP (x, 1) == stack_pointer_rtx))
            return (class == M16_REGS ? M16_NA_REGS : M16_REGS);

          if (class == M16_REGS || class == M16_NA_REGS)
            return NO_REGS;
          return M16_REGS;
        }
    }

  return NO_REGS;
}
\f
/* For each mips16 function which refers to GP relative symbols, we
   use a pseudo register, initialized at the start of the function, to
   hold the $gp value.  */

rtx
mips16_gp_pseudo_reg ()
{
  if (mips16_gp_pseudo_rtx == NULL_RTX)
    {
      rtx const_gp;
      rtx insn, scan;

      mips16_gp_pseudo_rtx = gen_reg_rtx (Pmode);
      RTX_UNCHANGING_P (mips16_gp_pseudo_rtx) = 1;

      /* We want to initialize this to a value which gcc will believe
         is constant.  */
      const_gp = gen_rtx (CONST, Pmode,
                          gen_rtx (REG, Pmode, GP_REG_FIRST + 28));

      start_sequence ();
      emit_move_insn (mips16_gp_pseudo_rtx, const_gp);
      insn = gen_sequence ();
      end_sequence ();

      push_topmost_sequence ();
      /* We need to emit the initialization after the FUNCTION_BEG
         note, so that it will be integrated.  */
      for (scan = get_insns (); scan != NULL_RTX; scan = NEXT_INSN (scan))
        if (GET_CODE (scan) == NOTE
            && NOTE_LINE_NUMBER (scan) == NOTE_INSN_FUNCTION_BEG)
          break;
      if (scan == NULL_RTX)
        scan = get_insns ();
      insn = emit_insn_after (insn, scan);
      pop_topmost_sequence ();
    }

  return mips16_gp_pseudo_rtx;
}

/* Return an RTX which represents the signed 16 bit offset from the
   $gp register for the given symbol.  This is only used on the
   mips16.  */

rtx
mips16_gp_offset (sym)
     rtx sym;
{
  tree gp;

  if (GET_CODE (sym) != SYMBOL_REF
      || ! SYMBOL_REF_FLAG (sym))
    abort ();

  /* We use a special identifier to represent the value of the gp
     register.  */
  gp = get_identifier ("__mips16_gp_value");

  return gen_rtx (CONST, Pmode,
                  gen_rtx (MINUS, Pmode, sym,
                           gen_rtx (SYMBOL_REF, Pmode,
                                    IDENTIFIER_POINTER (gp))));
}

/* Return nonzero if the given RTX represents a signed 16 bit offset
   from the $gp register.  */

int
mips16_gp_offset_p (x)
     rtx x;
{
  if (GET_CODE (x) == CONST)
    x = XEXP (x, 0);

  /* It's OK to add a small integer value to a gp offset.  */
  if (GET_CODE (x) == PLUS)
    {
      if (GET_CODE (XEXP (x, 1)) == CONST_INT
          && SMALL_INT (XEXP (x, 1)))
        return mips16_gp_offset_p (XEXP (x, 0));
      if (GET_CODE (XEXP (x, 0)) == CONST_INT
          && SMALL_INT (XEXP (x, 0)))
        return mips16_gp_offset_p (XEXP (x, 1));
      return 0;
    }

  /* Make sure it is in the form SYM - __mips16_gp_value.  */
  return (GET_CODE (x) == MINUS
          && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
          && SYMBOL_REF_FLAG (XEXP (x, 0))
          && GET_CODE (XEXP (x, 1)) == SYMBOL_REF
          && strcmp (XSTR (XEXP (x, 1), 0), "__mips16_gp_value") == 0);
}

/* Output a GP offset.  We don't want to print the subtraction of
   __mips16_gp_value; it is implicitly represented by the %gprel which
   should have been printed by the caller.  */

static void
mips16_output_gp_offset (file, x)
     FILE *file;
     rtx x;
{
  if (GET_CODE (x) == CONST)
    x = XEXP (x, 0);

  if (GET_CODE (x) == PLUS)
    {
      mips16_output_gp_offset (file, XEXP (x, 0));
      fputs ("+", file);
      mips16_output_gp_offset (file, XEXP (x, 1));
      return;
    }

  if (GET_CODE (x) == MINUS
      && GET_CODE (XEXP (x, 1)) == SYMBOL_REF
      && strcmp (XSTR (XEXP (x, 1), 0), "__mips16_gp_value") == 0)
    {
      mips16_output_gp_offset (file, XEXP (x, 0));
      return;
    }

  output_addr_const (file, x);
}

/* Return nonzero if a constant should not be output until after the
   function.  This is true of most string constants, so that we can
   use a more efficient PC relative reference.  However, a static
   inline function may never call assemble_function_end to write out
   the constant pool, so don't try to postpone the constant in that
   case.

   ??? It's really a bug that a static inline function can put stuff
   in the constant pool even if the function itself is not output.

   We record which string constants we've seen, so that we know which
   ones might use the more efficient reference.  */

int
mips16_constant_after_function_p (x)
     tree x;
{
  if (TREE_CODE (x) == STRING_CST
      && ! flag_writable_strings
      && current_function_decl != 0
      && ! DECL_DEFER_OUTPUT (current_function_decl)
      && ! (DECL_INLINE (current_function_decl)
            && ((! TREE_PUBLIC (current_function_decl)
                 && ! TREE_ADDRESSABLE (current_function_decl)
                 && ! flag_keep_inline_functions)
                || DECL_EXTERNAL (current_function_decl))))
    {
      struct string_constant *n;

      n = (struct string_constant *) xmalloc (sizeof *n);
      n->label = XSTR (XEXP (TREE_CST_RTL (x), 0), 0);
      n->next = string_constants;
      string_constants = n;

      return 1;
    }

  return 0;
}

/* Validate a constant for the mips16.  This rejects general symbolic
   addresses, which must be loaded from memory.  If ADDR is nonzero,
   this should reject anything which is not a legal address.  If
   ADDEND is nonzero, this is being added to something else.  */

int
mips16_constant (x, mode, addr, addend)
     rtx x;
     enum machine_mode mode;
     int addr;
     int addend;
{
  while (GET_CODE (x) == CONST)
    x = XEXP (x, 0);

  switch (GET_CODE (x))
    {
    default:
      return 0;

    case PLUS:
      return (mips16_constant (XEXP (x, 0), mode, addr, 1)
              && mips16_constant (XEXP (x, 1), mode, addr, 1));

    case SYMBOL_REF:
      if (addr && GET_MODE_SIZE (mode) != 4 && GET_MODE_SIZE (mode) != 8)
        return 0;
      if (CONSTANT_POOL_ADDRESS_P (x))
        return 1;

      /* If we aren't looking for a memory address, we can accept a GP
         relative symbol, which will have SYMBOL_REF_FLAG set; movsi
         knows how to handle this.  We can always accept a string
         constant, which is the other case in which SYMBOL_REF_FLAG
         will be set.  */
      if (! addr && ! addend && SYMBOL_REF_FLAG (x) && mode == Pmode)
        return 1;

      /* We can accept a string constant, which will have
         SYMBOL_REF_FLAG set but must be recognized by name to
         distinguish from a GP accessible symbol.  The name of a
         string constant will have been generated by
         ASM_GENERATE_INTERNAL_LABEL as called by output_constant_def.  */
      if (SYMBOL_REF_FLAG (x))
        {
          char *name = XSTR (x, 0);

          return (name[0] == '*'
                  && strncmp (name + 1, LOCAL_LABEL_PREFIX,
                              sizeof LOCAL_LABEL_PREFIX - 1) == 0);
        }

      return 0;

    case LABEL_REF:
      if (addr && GET_MODE_SIZE (mode) != 4 && GET_MODE_SIZE (mode) != 8)
        return 0;
      return 1;

    case CONST_INT:
      if (addr && ! addend)
        return 0;
      return INTVAL (x) > - 0x10000 && INTVAL (x) <= 0xffff;

    case REG:
      /* We need to treat $gp as a legitimate constant, because
         mips16_gp_pseudo_reg assumes that.  */
      return REGNO (x) == GP_REG_FIRST + 28;
    }
}

/* Write out code to move floating point arguments in or out of
   general registers.  Output the instructions to FILE.  FP_CODE is
   the code describing which arguments are present (see the comment at
   the definition of CUMULATIVE_ARGS in mips.h).  FROM_FP_P is non-zero if
   we are copying from the floating point registers.  */

static void
mips16_fp_args (file, fp_code, from_fp_p)
     FILE *file;
     int fp_code;
     int from_fp_p;
{
  const char *s;
  int gparg, fparg;
  unsigned int f;

  /* This code only works for the original 32 bit ABI and the O64 ABI.  */
  if (mips_abi != ABI_32 && mips_abi != ABI_O64)
    abort ();

  if (from_fp_p)
    s = "mfc1";
  else
    s = "mtc1";
  gparg = GP_ARG_FIRST;
  fparg = FP_ARG_FIRST;
  for (f = (unsigned int) fp_code; f != 0; f >>= 2)
    {
      if ((f & 3) == 1)
        {
          if ((fparg & 1) != 0)
            ++fparg;
          fprintf (file, "\t%s\t%s,%s\n", s,
                   reg_names[gparg], reg_names[fparg]);
        }
      else if ((f & 3) == 2)
        {
          if (TARGET_64BIT)
            fprintf (file, "\td%s\t%s,%s\n", s,
                     reg_names[gparg], reg_names[fparg]);
          else
            {
              if ((fparg & 1) != 0)
                ++fparg;
              if (TARGET_BIG_ENDIAN)
                fprintf (file, "\t%s\t%s,%s\n\t%s\t%s,%s\n", s,
                         reg_names[gparg], reg_names[fparg + 1], s,
                         reg_names[gparg + 1], reg_names[fparg]);
              else
                fprintf (file, "\t%s\t%s,%s\n\t%s\t%s,%s\n", s,
                         reg_names[gparg], reg_names[fparg], s,
                         reg_names[gparg + 1], reg_names[fparg + 1]);
              ++gparg;
              ++fparg;
            }
        }
      else
        abort ();

      ++gparg;
      ++fparg;
    }
}

/* Build a mips16 function stub.  This is used for functions which
   take aruments in the floating point registers.  It is 32 bit code
   that moves the floating point args into the general registers, and
   then jumps to the 16 bit code.  */

static void
build_mips16_function_stub (file)
     FILE *file;
{
  char *fnname;
  char *secname, *stubname;
  tree stubid, stubdecl;
  int need_comma;
  unsigned int f;

  fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
  secname = (char *) alloca (strlen (fnname) + 20);
  sprintf (secname, ".mips16.fn.%s", fnname);
  stubname = (char *) alloca (strlen (fnname) + 20);
  sprintf (stubname, "__fn_stub_%s", fnname);
  stubid = get_identifier (stubname);
  stubdecl = build_decl (FUNCTION_DECL, stubid,
                         build_function_type (void_type_node, NULL_TREE));
  DECL_SECTION_NAME (stubdecl) = build_string (strlen (secname), secname);

  fprintf (file, "\t# Stub function for %s (", current_function_name);
  need_comma = 0;
  for (f = (unsigned int) current_function_args_info.fp_code; f != 0; f >>= 2)
    {
      fprintf (file, "%s%s",
               need_comma ? ", " : "",
               (f & 3) == 1 ? "float" : "double");
      need_comma = 1;
    }
  fprintf (file, ")\n");

  fprintf (file, "\t.set\tnomips16\n");
  function_section (stubdecl);
  ASM_OUTPUT_ALIGN (file, floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT));

  /* ??? If FUNCTION_NAME_ALREADY_DECLARED is defined, then we are
     within a .ent, and we can not emit another .ent.  */
#ifndef FUNCTION_NAME_ALREADY_DECLARED
  fputs ("\t.ent\t", file);
  assemble_name (file, stubname);
  fputs ("\n", file);
#endif

  assemble_name (file, stubname);
  fputs (":\n", file);

  /* We don't want the assembler to insert any nops here.  */
  fprintf (file, "\t.set\tnoreorder\n");

  mips16_fp_args (file, current_function_args_info.fp_code, 1);

  fprintf (asm_out_file, "\t.set\tnoat\n");
  fprintf (asm_out_file, "\tla\t%s,", reg_names[GP_REG_FIRST + 1]);
  assemble_name (file, fnname);
  fprintf (file, "\n");
  fprintf (asm_out_file, "\tjr\t%s\n", reg_names[GP_REG_FIRST + 1]);
  fprintf (asm_out_file, "\t.set\tat\n");

  /* Unfortunately, we can't fill the jump delay slot.  We can't fill
     with one of the mfc1 instructions, because the result is not
     available for one instruction, so if the very first instruction
     in the function refers to the register, it will see the wrong
     value.  */
  fprintf (file, "\tnop\n");

  fprintf (file, "\t.set\treorder\n");

#ifndef FUNCTION_NAME_ALREADY_DECLARED
  fputs ("\t.end\t", file);
  assemble_name (file, stubname);
  fputs ("\n", file);
#endif

  fprintf (file, "\t.set\tmips16\n");

  function_section (current_function_decl);
}

/* We keep a list of functions for which we have already built stubs
   in build_mips16_call_stub.  */

struct mips16_stub
{
  struct mips16_stub *next;
  char *name;
  int fpret;
};

static struct mips16_stub *mips16_stubs;

/* Build a call stub for a mips16 call.  A stub is needed if we are
   passing any floating point values which should go into the floating
   point registers.  If we are, and the call turns out to be to a 32
   bit function, the stub will be used to move the values into the
   floating point registers before calling the 32 bit function.  The
   linker will magically adjust the function call to either the 16 bit
   function or the 32 bit stub, depending upon where the function call
   is actually defined.

   Similarly, we need a stub if the return value might come back in a
   floating point register.

   RETVAL, FNMEM, and ARG_SIZE are the values passed to the call insn
   (RETVAL is NULL if this is call rather than call_value).  FP_CODE
   is the code built by function_arg.  This function returns a nonzero
   value if it builds the call instruction itself.  */

int
build_mips16_call_stub (retval, fnmem, arg_size, fp_code)
     rtx retval;
     rtx fnmem;
     rtx arg_size;
     int fp_code;
{
  int fpret;
  rtx fn;
  char *fnname, *secname, *stubname;
  struct mips16_stub *l;
  tree stubid, stubdecl;
  int need_comma;
  unsigned int f;

  /* We don't need to do anything if we aren't in mips16 mode, or if
     we were invoked with the -msoft-float option.  */
  if (! TARGET_MIPS16 || ! mips16_hard_float)
    return 0;

  /* Figure out whether the value might come back in a floating point
     register.  */
  fpret = (retval != 0
           && GET_MODE_CLASS (GET_MODE (retval)) == MODE_FLOAT
           && (! TARGET_SINGLE_FLOAT
               || GET_MODE_SIZE (GET_MODE (retval)) <= 4));

  /* We don't need to do anything if there were no floating point
     arguments and the value will not be returned in a floating point
     register.  */
  if (fp_code == 0 && ! fpret)
    return 0;

  if (GET_CODE (fnmem) != MEM)
    abort ();
  fn = XEXP (fnmem, 0);

  /* We don't need to do anything if this is a call to a special
     mips16 support function.  */
  if (GET_CODE (fn) == SYMBOL_REF
      && strncmp (XSTR (fn, 0), "__mips16_", 9) == 0)
    return 0;

  /* This code will only work for o32 and o64 abis.  The other ABI's 
     require more sophisticated support.  */
  if (mips_abi != ABI_32 && mips_abi != ABI_O64)
    abort ();

  /* We can only handle SFmode and DFmode floating point return
     values.  */
  if (fpret && GET_MODE (retval) != SFmode && GET_MODE (retval) != DFmode)
    abort ();

  /* If we're calling via a function pointer, then we must always call
     via a stub.  There are magic stubs provided in libgcc.a for each
     of the required cases.  Each of them expects the function address
     to arrive in register $2.  */

  if (GET_CODE (fn) != SYMBOL_REF)
    {
      char buf[30];
      tree id;
      rtx stub_fn, stub_mem, insn;

      /* ??? If this code is modified to support other ABI's, we need
         to handle PARALLEL return values here.  */

      sprintf (buf, "__mips16_call_stub_%s%d",
               (fpret
                ? (GET_MODE (retval) == SFmode ? "sf_" : "df_")
                : ""),
               fp_code);
      id = get_identifier (buf);
      stub_fn = gen_rtx (SYMBOL_REF, Pmode, IDENTIFIER_POINTER (id));
      stub_mem = gen_rtx (MEM, Pmode, stub_fn);

      emit_move_insn (gen_rtx (REG, Pmode, 2), fn);

      if (retval == NULL_RTX)
        insn = gen_call_internal0 (stub_mem, arg_size,
                                   gen_rtx (REG, SImode,
                                            GP_REG_FIRST + 31));
      else
        insn = gen_call_value_internal0 (retval, stub_mem, arg_size,
                                         gen_rtx (REG, SImode,
                                                  GP_REG_FIRST + 31));
      insn = emit_call_insn (insn);

      /* Put the register usage information on the CALL.  */
      if (GET_CODE (insn) != CALL_INSN)
        abort ();
      CALL_INSN_FUNCTION_USAGE (insn) =
        gen_rtx (EXPR_LIST, VOIDmode,
                 gen_rtx (USE, VOIDmode, gen_rtx (REG, Pmode, 2)),
                 CALL_INSN_FUNCTION_USAGE (insn));

      /* If we are handling a floating point return value, we need to
         save $18 in the function prologue.  Putting a note on the
         call will mean that regs_ever_live[$18] will be true if the
         call is not eliminated, and we can check that in the prologue
         code.  */
      if (fpret)
        CALL_INSN_FUNCTION_USAGE (insn) =
          gen_rtx (EXPR_LIST, VOIDmode,
                   gen_rtx (USE, VOIDmode, gen_rtx (REG, word_mode, 18)),
                   CALL_INSN_FUNCTION_USAGE (insn));

      /* Return 1 to tell the caller that we've generated the call
         insn.  */
      return 1;
    }

  /* We know the function we are going to call.  If we have already
     built a stub, we don't need to do anything further.  */

  fnname = XSTR (fn, 0);
  for (l = mips16_stubs; l != NULL; l = l->next)
    if (strcmp (l->name, fnname) == 0)
      break;

  if (l == NULL)
    {
      /* Build a special purpose stub.  When the linker sees a
         function call in mips16 code, it will check where the target
         is defined.  If the target is a 32 bit call, the linker will
         search for the section defined here.  It can tell which
         symbol this section is associated with by looking at the
         relocation information (the name is unreliable, since this
         might be a static function).  If such a section is found, the
         linker will redirect the call to the start of the magic
         section.

         If the function does not return a floating point value, the
         special stub section is named
             .mips16.call.FNNAME

         If the function does return a floating point value, the stub
         section is named
             .mips16.call.fp.FNNAME
         */

      secname = (char *) alloca (strlen (fnname) + 40);
      sprintf (secname, ".mips16.call.%s%s",
               fpret ? "fp." : "",
               fnname);
      stubname = (char *) alloca (strlen (fnname) + 20);
      sprintf (stubname, "__call_stub_%s%s",
               fpret ? "fp_" : "",
               fnname);
      stubid = get_identifier (stubname);
      stubdecl = build_decl (FUNCTION_DECL, stubid,
                             build_function_type (void_type_node, NULL_TREE));
      DECL_SECTION_NAME (stubdecl) = build_string (strlen (secname), secname);

      fprintf (asm_out_file, "\t# Stub function to call %s%s (",
               (fpret
                ? (GET_MODE (retval) == SFmode ? "float " : "double ")
                : ""),
               fnname);
      need_comma = 0;
      for (f = (unsigned int) fp_code; f != 0; f >>= 2)
        {
          fprintf (asm_out_file, "%s%s",
                   need_comma ? ", " : "",
                   (f & 3) == 1 ? "float" : "double");
          need_comma = 1;
        }
      fprintf (asm_out_file, ")\n");

      fprintf (asm_out_file, "\t.set\tnomips16\n");
      assemble_start_function (stubdecl, stubname);

#ifndef FUNCTION_NAME_ALREADY_DECLARED
      fputs ("\t.ent\t", asm_out_file);
      assemble_name (asm_out_file, stubname);
      fputs ("\n", asm_out_file);

      assemble_name (asm_out_file, stubname);
      fputs (":\n", asm_out_file);
#endif

      /* We build the stub code by hand.  That's the only way we can
         do it, since we can't generate 32 bit code during a 16 bit
         compilation. */

      /* We don't want the assembler to insert any nops here.  */
      fprintf (asm_out_file, "\t.set\tnoreorder\n");

      mips16_fp_args (asm_out_file, fp_code, 0);

      if (! fpret)
        {
          fprintf (asm_out_file, "\t.set\tnoat\n");
          fprintf (asm_out_file, "\tla\t%s,%s\n", reg_names[GP_REG_FIRST + 1],
                   fnname);
          fprintf (asm_out_file, "\tjr\t%s\n", reg_names[GP_REG_FIRST + 1]);
          fprintf (asm_out_file, "\t.set\tat\n");
          /* Unfortunately, we can't fill the jump delay slot.  We
             can't fill with one of the mtc1 instructions, because the
             result is not available for one instruction, so if the
             very first instruction in the function refers to the
             register, it will see the wrong value.  */
          fprintf (asm_out_file, "\tnop\n");
        }
      else
        {
          fprintf (asm_out_file, "\tmove\t%s,%s\n",
                   reg_names[GP_REG_FIRST + 18], reg_names[GP_REG_FIRST + 31]);
          fprintf (asm_out_file, "\tjal\t%s\n", fnname);
          /* As above, we can't fill the delay slot.  */
          fprintf (asm_out_file, "\tnop\n");
          if (GET_MODE (retval) == SFmode)
            fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                     reg_names[GP_REG_FIRST + 2], reg_names[FP_REG_FIRST + 0]);
          else
            {
              if (TARGET_BIG_ENDIAN)
                {
                  fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                           reg_names[GP_REG_FIRST + 2],
                           reg_names[FP_REG_FIRST + 1]);
                  fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                           reg_names[GP_REG_FIRST + 3],
                           reg_names[FP_REG_FIRST + 0]);
                }
              else
                {
                  fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                           reg_names[GP_REG_FIRST + 2],
                           reg_names[FP_REG_FIRST + 0]);
                  fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                           reg_names[GP_REG_FIRST + 3],
                           reg_names[FP_REG_FIRST + 1]);
                }
            }
          fprintf (asm_out_file, "\tj\t%s\n", reg_names[GP_REG_FIRST + 18]);
          /* As above, we can't fill the delay slot.  */
          fprintf (asm_out_file, "\tnop\n");
        }

      fprintf (asm_out_file, "\t.set\treorder\n");

#ifdef ASM_DECLARE_FUNCTION_SIZE
      ASM_DECLARE_FUNCTION_SIZE (asm_out_file, stubname, stubdecl);
#endif

#ifndef FUNCTION_NAME_ALREADY_DECLARED
      fputs ("\t.end\t", asm_out_file);
      assemble_name (asm_out_file, stubname);
      fputs ("\n", asm_out_file);
#endif

      fprintf (asm_out_file, "\t.set\tmips16\n");

      /* Record this stub.  */
      l = (struct mips16_stub *) xmalloc (sizeof *l);
      l->name = (char *) xmalloc (strlen (fnname) + 1);
      strcpy (l->name, fnname);
      l->fpret = fpret;
      l->next = mips16_stubs;
      mips16_stubs = l;
    }

  /* If we expect a floating point return value, but we've built a
     stub which does not expect one, then we're in trouble.  We can't
     use the existing stub, because it won't handle the floating point
     value.  We can't build a new stub, because the linker won't know
     which stub to use for the various calls in this object file.
     Fortunately, this case is illegal, since it means that a function
     was declared in two different ways in a single compilation.  */
  if (fpret && ! l->fpret)
    error ("can not handle inconsistent calls to `%s'", fnname);

  /* If we are calling a stub which handles a floating point return
     value, we need to arrange to save $18 in the prologue.  We do
     this by marking the function call as using the register.  The
     prologue will later see that it is used, and emit code to save
     it.  */

  if (l->fpret)
    {
      rtx insn;

      if (retval == NULL_RTX)
        insn = gen_call_internal0 (fnmem, arg_size,
                                   gen_rtx (REG, SImode,
                                            GP_REG_FIRST + 31));
      else
        insn = gen_call_value_internal0 (retval, fnmem, arg_size,
                                         gen_rtx (REG, SImode,
                                                  GP_REG_FIRST + 31));
      insn = emit_call_insn (insn);

      if (GET_CODE (insn) != CALL_INSN)
        abort ();

      CALL_INSN_FUNCTION_USAGE (insn) =
        gen_rtx (EXPR_LIST, VOIDmode,
                 gen_rtx (USE, VOIDmode, gen_rtx (REG, word_mode, 18)),
                 CALL_INSN_FUNCTION_USAGE (insn));

      /* Return 1 to tell the caller that we've generated the call
         insn.  */
      return 1;
    }

  /* Return 0 to let the caller generate the call insn.  */
  return 0;
}

/* This function looks through the code for a function, and tries to
   optimize the usage of the $gp register.  We arrange to copy $gp
   into a pseudo-register, and then let gcc's normal reload handling
   deal with the pseudo-register.  Unfortunately, if reload choose to
   put the pseudo-register into a call-clobbered register, it will
   emit saves and restores for that register around any function
   calls.  We don't need the saves, and it's faster to copy $gp than
   to do an actual restore.  ??? This still means that we waste a
   stack slot.

   This is an optimization, and the code which gcc has actually
   generated is correct, so we do not need to catch all cases.  */

static void
mips16_optimize_gp (first)
     rtx first;
{
  rtx gpcopy, slot, insn;

  /* Look through the instructions.  Set GPCOPY to the register which
     holds a copy of $gp.  Set SLOT to the stack slot where it is
     saved.  If we find an instruction which sets GPCOPY to anything
     other than $gp or SLOT, then we can't use it.  If we find an
     instruction which sets SLOT to anything other than GPCOPY, we
     can't use it.  */

  gpcopy = NULL_RTX;
  slot = NULL_RTX;
  for (insn = first; insn != NULL_RTX; insn = next_active_insn (insn))
    {
      rtx set;

      if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
        continue;

      set = PATTERN (insn);

      /* We know that all references to memory will be inside a SET,
         because there is no other way to access memory on the mips16.
         We don't have to worry about a PARALLEL here, because the
         mips.md file will never generate them for memory references.  */
      if (GET_CODE (set) != SET)
        continue;

      if (gpcopy == NULL_RTX
          && GET_CODE (SET_SRC (set)) == CONST
          && GET_CODE (XEXP (SET_SRC (set), 0)) == REG
          && REGNO (XEXP (SET_SRC (set), 0)) == GP_REG_FIRST + 28
          && GET_CODE (SET_DEST (set)) == REG
          && GET_MODE (SET_DEST (set)) == Pmode)
        gpcopy = SET_DEST (set);
      else if (slot == NULL_RTX
               && gpcopy != NULL_RTX
               && GET_CODE (SET_DEST (set)) == MEM
               && GET_CODE (SET_SRC (set)) == REG
               && REGNO (SET_SRC (set)) == REGNO (gpcopy)
               && GET_MODE (SET_DEST (set)) == Pmode)
        {
          rtx base, offset;

          offset = const0_rtx;
          base = eliminate_constant_term (XEXP (SET_DEST (set), 0), &offset);
          if (GET_CODE (base) == REG
              && (REGNO (base) == STACK_POINTER_REGNUM
                  || REGNO (base) == FRAME_POINTER_REGNUM))
            slot = SET_DEST (set);
        }
      else if (gpcopy != NULL_RTX
               && (GET_CODE (SET_DEST (set)) == REG
                   || GET_CODE (SET_DEST (set)) == SUBREG)
               && reg_overlap_mentioned_p (SET_DEST (set), gpcopy)
               && (GET_CODE (SET_DEST (set)) != REG
                   || REGNO (SET_DEST (set)) != REGNO (gpcopy)
                   || GET_MODE (SET_DEST (set)) != Pmode
                   || ((GET_CODE (SET_SRC (set)) != CONST
                        || GET_CODE (XEXP (SET_SRC (set), 0)) != REG
                        || (REGNO (XEXP (SET_SRC (set), 0))
                            != GP_REG_FIRST + 28))
                       && ! rtx_equal_p (SET_SRC (set), slot))))
        break;
      else if (slot != NULL_RTX
               && GET_CODE (SET_DEST (set)) == MEM
               && rtx_equal_p (SET_DEST (set), slot)
               && (GET_CODE (SET_SRC (set)) != REG
                   || REGNO (SET_SRC (set)) != REGNO (gpcopy)))
        break;
    }

  /* If we couldn't find a unique value for GPCOPY or SLOT, then try a
     different optimization.  Any time we find a copy of $28 into a
     register, followed by an add of a symbol_ref to that register, we
     convert it to load the value from the constant table instead.
     The copy and add will take six bytes, just as the load and
     constant table entry will take six bytes.  However, it is
     possible that the constant table entry will be shared.

     This could be a peephole optimization, but I don't know if the
     peephole code can call force_const_mem.

     Using the same register for the copy of $28 and the add of the
     symbol_ref is actually pretty likely, since the add instruction
     requires the destination and the first addend to be the same
     register.  */

  if (insn != NULL_RTX || gpcopy == NULL_RTX || slot == NULL_RTX)
    {
      rtx next;

      /* This optimization is only reasonable if the constant table
         entries are only 4 bytes.  */
      if (Pmode != SImode)
        return;

      for (insn = first; insn != NULL_RTX; insn = next)
        {
          rtx set1, set2;

          next = insn;
          do
            {
              next = NEXT_INSN (next);
            }
          while (next != NULL_RTX
                 && (GET_CODE (next) == NOTE
                     || (GET_CODE (next) == INSN
                         && (GET_CODE (PATTERN (next)) == USE
                             || GET_CODE (PATTERN (next)) == CLOBBER))));

          if (next == NULL_RTX)
            break;

          if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
            continue;

          if (GET_RTX_CLASS (GET_CODE (next)) != 'i')
            continue;

          set1 = PATTERN (insn);
          if (GET_CODE (set1) != SET)
            continue;
          set2 = PATTERN (next);
          if (GET_CODE (set2) != SET)
            continue;

          if (GET_CODE (SET_DEST (set1)) == REG
              && GET_CODE (SET_SRC (set1)) == CONST
              && GET_CODE (XEXP (SET_SRC (set1), 0)) == REG
              && REGNO (XEXP (SET_SRC (set1), 0)) == GP_REG_FIRST + 28
              && rtx_equal_p (SET_DEST (set1), SET_DEST (set2))
              && GET_CODE (SET_SRC (set2)) == PLUS
              && rtx_equal_p (SET_DEST (set1), XEXP (SET_SRC (set2), 0))
              && mips16_gp_offset_p (XEXP (SET_SRC (set2), 1))
              && GET_CODE (XEXP (XEXP (SET_SRC (set2), 1), 0)) == MINUS)
            {
              rtx sym;

              /* We've found a case we can change to load from the
                 constant table.  */

              sym = XEXP (XEXP (XEXP (SET_SRC (set2), 1), 0), 0);
              if (GET_CODE (sym) != SYMBOL_REF)
                abort ();
              emit_insn_after (gen_rtx (SET, VOIDmode, SET_DEST (set1),
                                        force_const_mem (Pmode, sym)),
                               next);
              
              PUT_CODE (insn, NOTE);
              NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
              NOTE_SOURCE_FILE (insn) = 0;

              PUT_CODE (next, NOTE);
              NOTE_LINE_NUMBER (next) = NOTE_INSN_DELETED;
              NOTE_SOURCE_FILE (next) = 0;
            }
        }

      return;
    }

  /* We can safely remove all assignments to SLOT from GPCOPY, and
     replace all assignments from SLOT to GPCOPY with assignments from
     $28.  */

  for (insn = first; insn != NULL_RTX; insn = next_active_insn (insn))
    {
      rtx set;

      if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
        continue;

      set = PATTERN (insn);
      if (GET_CODE (set) != SET
          || GET_MODE (SET_DEST (set)) != Pmode)
        continue;

      if (GET_CODE (SET_DEST (set)) == MEM
          && rtx_equal_p (SET_DEST (set), slot)
          && GET_CODE (SET_SRC (set)) == REG
          && REGNO (SET_SRC (set)) == REGNO (gpcopy))
        {
          PUT_CODE (insn, NOTE);
          NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
          NOTE_SOURCE_FILE (insn) = 0;
        }
      else if (GET_CODE (SET_DEST (set)) == REG
               && REGNO (SET_DEST (set)) == REGNO (gpcopy)
               && GET_CODE (SET_SRC (set)) == MEM
               && rtx_equal_p (SET_SRC (set), slot))
        {
          emit_insn_after (gen_rtx (SET, Pmode, SET_DEST (set),
                                    gen_rtx (CONST, Pmode,
                                             gen_rtx (REG, Pmode,
                                                      GP_REG_FIRST + 28))),
                           insn);
          PUT_CODE (insn, NOTE);
          NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
          NOTE_SOURCE_FILE (insn) = 0;
        }
    }
}

/* We keep a list of constants we which we have to add to internal
   constant tables in the middle of large functions.  */

struct constant
{
  struct constant *next;
  rtx value;
  rtx label;
  enum machine_mode mode;
};

/* Add a constant to the list in *PCONSTANTS.  */

static rtx
add_constant (pconstants, val, mode)
     struct constant **pconstants;
     rtx val;
     enum machine_mode mode;
{
  struct constant *c;

  for (c = *pconstants; c != NULL; c = c->next)
    if (mode == c->mode && rtx_equal_p (val, c->value))
      return c->label;

  c = (struct constant *) xmalloc (sizeof *c);
  c->value = val;
  c->mode = mode;
  c->label = gen_label_rtx ();
  c->next = *pconstants;
  *pconstants = c;
  return c->label;
}

/* Dump out the constants in CONSTANTS after INSN.  */

static void
dump_constants (constants, insn)
     struct constant *constants;
     rtx insn;
{
  struct constant *c;
  int align;

  c = constants;
  align = 0;
  while (c != NULL)
    {
      rtx r;
      struct constant *next;

      switch (GET_MODE_SIZE (c->mode))
        {
        case 1:
          align = 0;
          break;
        case 2:
          if (align < 1)
            insn = emit_insn_after (gen_align_2 (), insn);
          align = 1;
          break;
        case 4:
          if (align < 2)
            insn = emit_insn_after (gen_align_4 (), insn);
          align = 2;
          break;
        default:
          if (align < 3)
            insn = emit_insn_after (gen_align_8 (), insn);
          align = 3;
          break;
        }

      insn = emit_label_after (c->label, insn);

      switch (c->mode)
        {
        case QImode:
          r = gen_consttable_qi (c->value);
          break;
        case HImode:
          r = gen_consttable_hi (c->value);
          break;
        case SImode:
          r = gen_consttable_si (c->value);
          break;
        case SFmode:
          r = gen_consttable_sf (c->value);
          break;
        case DImode:
          r = gen_consttable_di (c->value);
          break;
        case DFmode:
          r = gen_consttable_df (c->value);
          break;
        default:
          abort ();
        }

      insn = emit_insn_after (r, insn);

      next = c->next;
      free (c);
      c = next;
    }

  emit_barrier_after (insn);
}

/* Find the symbol in an address expression.  */

static rtx
mips_find_symbol (addr)
     rtx addr;
{
  if (GET_CODE (addr) == MEM)
    addr = XEXP (addr, 0);
  while (GET_CODE (addr) == CONST)
    addr = XEXP (addr, 0);
  if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF)
    return addr;
  if (GET_CODE (addr) == PLUS)
    {
      rtx l1, l2;

      l1 = mips_find_symbol (XEXP (addr, 0));
      l2 = mips_find_symbol (XEXP (addr, 1));
      if (l1 != NULL_RTX && l2 == NULL_RTX)
        return l1;
      else if (l1 == NULL_RTX && l2 != NULL_RTX)
        return l2;
    }
  return NULL_RTX;
}

/* Exported to toplev.c.

   Do a final pass over the function, just before delayed branch
   scheduling.  */

void
machine_dependent_reorg (first)
     rtx first;
{
  int insns_len, max_internal_pool_size, pool_size, addr, first_constant_ref;
  rtx insn;
  struct constant *constants;

  if (! TARGET_MIPS16)
    return;

  /* If $gp is used, try to remove stores, and replace loads with
     copies from $gp.  */
  if (optimize)
    mips16_optimize_gp (first);

  /* Scan the function looking for PC relative loads which may be out
     of range.  All such loads will either be from the constant table,
     or be getting the address of a constant string.  If the size of
     the function plus the size of the constant table is less than
     0x8000, then all loads are in range.  */

  insns_len = 0;
  for (insn = first; insn; insn = NEXT_INSN (insn))
    {
      insns_len += get_attr_length (insn);

      /* ??? We put switch tables in .text, but we don't define
         JUMP_TABLES_IN_TEXT_SECTION, so get_attr_length will not
         compute their lengths correctly.  */
      if (GET_CODE (insn) == JUMP_INSN)
        {
          rtx body;

          body = PATTERN (insn);
          if (GET_CODE (body) == ADDR_VEC || GET_CODE (body) == ADDR_DIFF_VEC)
            insns_len += (XVECLEN (body, GET_CODE (body) == ADDR_DIFF_VEC)
                          * GET_MODE_SIZE (GET_MODE (body)));
          insns_len += GET_MODE_SIZE (GET_MODE (body)) - 1;
        }
    }

  /* Store the original value of insns_len in current_frame_info, so
     that simple_memory_operand can look at it.  */
  current_frame_info.insns_len = insns_len;

  pool_size = get_pool_size ();
  if (insns_len + pool_size + mips_string_length < 0x8000)
    return;

  /* Loop over the insns and figure out what the maximum internal pool
     size could be.  */
  max_internal_pool_size = 0;
  for (insn = first; insn; insn = NEXT_INSN (insn))
    {
      if (GET_CODE (insn) == INSN
          && GET_CODE (PATTERN (insn)) == SET)
        {
          rtx src;

          src = mips_find_symbol (SET_SRC (PATTERN (insn)));
          if (src == NULL_RTX)
            continue;
          if (CONSTANT_POOL_ADDRESS_P (src))
            max_internal_pool_size += GET_MODE_SIZE (get_pool_mode (src));
          else if (SYMBOL_REF_FLAG (src))
            max_internal_pool_size += GET_MODE_SIZE (Pmode);
        }
    }

  constants = NULL;
  addr = 0;
  first_constant_ref = -1;

  for (insn = first; insn; insn = NEXT_INSN (insn))
    {
      if (GET_CODE (insn) == INSN
          && GET_CODE (PATTERN (insn)) == SET)
        {
          rtx val, src;
          enum machine_mode mode;

          val = NULL_RTX;
          src = mips_find_symbol (SET_SRC (PATTERN (insn)));
          if (src != NULL_RTX && CONSTANT_POOL_ADDRESS_P (src))
            {
              /* ??? This is very conservative, which means that we
                 will generate too many copies of the constant table.
                 The only solution would seem to be some form of
                 relaxing.  */
              if (((insns_len - addr)
                   + max_internal_pool_size
                   + get_pool_offset (src))
                  >= 0x8000)
                {
                  val = get_pool_constant (src);
                  mode = get_pool_mode (src);
                }
              max_internal_pool_size -= GET_MODE_SIZE (get_pool_mode (src));
            }
          else if (src != NULL_RTX && SYMBOL_REF_FLAG (src))
            {
              /* Including all of mips_string_length is conservative,
                 and so is including all of max_internal_pool_size.  */
              if (((insns_len - addr)
                   + max_internal_pool_size
                   + pool_size
                   + mips_string_length)
                  >= 0x8000)
              val = src;
              mode = Pmode;
              max_internal_pool_size -= Pmode;
            }

          if (val != NULL_RTX)
            {
              rtx lab, newsrc;

              /* This PC relative load is out of range.  ??? In the
                 case of a string constant, we are only guessing that
                 it is range, since we don't know the offset of a
                 particular string constant.  */

              lab = add_constant (&constants, val, mode);
              newsrc = gen_rtx (MEM, mode,
                                gen_rtx (LABEL_REF, VOIDmode, lab));
              RTX_UNCHANGING_P (newsrc) = 1;
              PATTERN (insn) = gen_rtx (SET, VOIDmode,
                                        SET_DEST (PATTERN (insn)),
                                        newsrc);
              INSN_CODE (insn) = -1;

              if (first_constant_ref < 0)
                first_constant_ref = addr;
            }
        }

      addr += get_attr_length (insn);

      /* ??? We put switch tables in .text, but we don't define
         JUMP_TABLES_IN_TEXT_SECTION, so get_attr_length will not
         compute their lengths correctly.  */
      if (GET_CODE (insn) == JUMP_INSN)
        {
          rtx body;

          body = PATTERN (insn);
          if (GET_CODE (body) == ADDR_VEC || GET_CODE (body) == ADDR_DIFF_VEC)
            addr += (XVECLEN (body, GET_CODE (body) == ADDR_DIFF_VEC)
                          * GET_MODE_SIZE (GET_MODE (body)));
          addr += GET_MODE_SIZE (GET_MODE (body)) - 1;
        }

      if (GET_CODE (insn) == BARRIER)
        {
          /* Output any constants we have accumulated.  Note that we
             don't need to change ADDR, since its only use is
             subtraction from INSNS_LEN, and both would be changed by
             the same amount.
             ??? If the instructions up to the next barrier reuse a
             constant, it would often be better to continue
             accumulating.  */
          if (constants != NULL)
            dump_constants (constants, insn);
          constants = NULL;
          first_constant_ref = -1;
        }
      
      if (constants != NULL
               && (NEXT_INSN (insn) == NULL 
                   || (first_constant_ref >= 0 
                       && (((addr - first_constant_ref)
                            + 2 /* for alignment */
                            + 2 /* for a short jump insn */
                            + pool_size)
                           >= 0x8000))))
        {
          /* If we haven't had a barrier within 0x8000 bytes of a
             constant reference or we are at the end of the function,
             emit a barrier now. */

          rtx label, jump, barrier;
              
          label = gen_label_rtx ();
          jump = emit_jump_insn_after (gen_jump (label), insn);
          JUMP_LABEL (jump) = label;
          LABEL_NUSES (label) = 1;
          barrier = emit_barrier_after (jump);
          emit_label_after (label, barrier);
          first_constant_ref = -1;
        }
     }

  /* ??? If we output all references to a constant in internal
     constants table, we don't need to output the constant in the real
     constant table, but we have no way to prevent that.  */
}

/* Return nonzero if X is a SIGN or ZERO extend operator.  */
int
extend_operator (x, mode)
     rtx x;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  enum rtx_code code = GET_CODE (x);
  return code == SIGN_EXTEND || code == ZERO_EXTEND;
}

/* Accept any operator that can be used to shift the high half of the
   input value to the lower half, suitable for truncation.  The
   remainder (the lower half of the input, and the upper half of the
   output) will be discarded.  */
int
highpart_shift_operator (x, mode)
     rtx x;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  enum rtx_code code = GET_CODE (x);
  return (code == LSHIFTRT
          || code == ASHIFTRT
          || code == ROTATERT
          || code == ROTATE);
}

/* Return the length of INSN.  LENGTH is the initial length computed by 
   attributes in the machine-description file.  */

int
mips_adjust_insn_length (insn, length)
     rtx insn;
     int length;
{
  /* A unconditional jump has an unfilled delay slot if it is not part
     of a sequence.  A conditional jump normally has a delay slot, but
     does not on MIPS16.  */
  if (simplejump_p (insn)
      || (!TARGET_MIPS16  && (GET_CODE (insn) == JUMP_INSN 
                              || GET_CODE (insn) == CALL_INSN)))
    length += 4;

  /* All MIPS16 instructions are a measly two bytes.  */
  if (TARGET_MIPS16)
    length /= 2;

  return length;
}

/* Output assembly instructions to peform a conditional branch.  

   INSN is the branch instruction.  OPERANDS[0] is the condition.
   OPERANDS[1] is the target of the branch.  OPERANDS[2] is the target
   of the first operand to the condition.  If TWO_OPERANDS_P is
   non-zero the comparison takes two operands; OPERANDS[3] will be the
   second operand.

   If INVERTED_P is non-zero we are to branch if the condition does
   not hold.  If FLOAT_P is non-zero this is a floating-point comparison.

   LENGTH is the length (in bytes) of the sequence we are to generate.
   That tells us whether to generate a simple conditional branch, or a
   reversed conditional branch around a `jr' instruction.  */
char *
mips_output_conditional_branch (insn, 
                                operands, 
                                two_operands_p,
                                float_p,
                                inverted_p,
                                length)
     rtx insn;
     rtx *operands;
     int two_operands_p;
     int float_p;
     int inverted_p;
     int length;
{
  static char buffer[200];
  /* The kind of comparison we are doing.  */
  enum rtx_code code = GET_CODE (operands[0]);
  /* Non-zero if the opcode for the comparison needs a `z' indicating
     that it is a comparision against zero.  */
  int need_z_p;
  /* A string to use in the assembly output to represent the first
     operand.  */
  char *op1 = "%z2";
  /* A string to use in the assembly output to represent the second
     operand.  Use the hard-wired zero register if there's no second
     operand.  */
  char *op2 = (two_operands_p ? ",%z3" : ",%.");
  /* The operand-printing string for the comparison.  */
  char *comp = (float_p ? "%F0" : "%C0");
  /* The operand-printing string for the inverted comparison.  */
  char *inverted_comp = (float_p ? "%W0" : "%N0");

  /* The MIPS processors (for levels of the ISA at least two), have
     "likely" variants of each branch instruction.  These instructions
     annul the instruction in the delay slot if the branch is not
     taken.  */
  mips_branch_likely = (final_sequence && INSN_ANNULLED_BRANCH_P (insn));

  if (!two_operands_p)
    {
      /* To compute whether than A > B, for example, we normally
         subtract B from A and then look at the sign bit.  But, if we
         are doing an unsigned comparison, and B is zero, we don't
         have to do the subtraction.  Instead, we can just check to
         see if A is non-zero.  Thus, we change the CODE here to
         reflect the simpler comparison operation.  */
      switch (code)
        {
        case GTU:
          code = NE;
          break;

        case LEU:
          code = EQ;
          break;

        case GEU:
          /* A condition which will always be true.  */
          code = EQ;
          op1 = "%.";
          break;

        case LTU:
          /* A condition which will always be false. */
          code = NE;
          op1 = "%.";
          break;

        default:
          /* Not a special case.  */
          break;
        }
    }

  /* Relative comparisons are always done against zero.  But
     equality comparisons are done between two operands, and therefore
     do not require a `z' in the assembly language output.  */
  need_z_p = (!float_p && code != EQ && code != NE);
  /* For comparisons against zero, the zero is not provided 
     explicitly.  */
  if (need_z_p)
    op2 = "";

  /* Begin by terminating the buffer.  That way we can always use
     strcat to add to it.  */
  buffer[0] = '\0';

  switch (length) 
    {
    case 4:
    case 8:
      /* Just a simple conditional branch.  */
      if (float_p)
        sprintf (buffer, "%%*b%s%%?\t%%Z2%%1",
                 inverted_p ? inverted_comp : comp);
      else
        sprintf (buffer, "%%*b%s%s%%?\t%s%s,%%1",
                 inverted_p ? inverted_comp : comp,
                 need_z_p ? "z" : "",
                 op1,
                 op2);
      return buffer;

    case 12:
    case 16:
      {
        /* Generate a reversed conditional branch around ` j'
           instruction:

                .set noreorder
                .set nomacro
                bc    l
                nop
                j     target
                .set macro
                .set reorder
             l:

           Because we have to jump four bytes *past* the following
           instruction if this branch was annulled, we can't just use
           a label, as in the picture above; there's no way to put the
           label after the next instruction, as the assembler does not
           accept `.L+4' as the target of a branch.  (We can't just
           wait until the next instruction is output; it might be a
           macro and take up more than four bytes.  Once again, we see
           why we want to eliminate macros.)
           
           If the branch is annulled, we jump four more bytes that we
           would otherwise; that way we skip the annulled instruction
           in the delay slot.  */

        char *target 
          = ((mips_branch_likely || length == 16) ? ".+16" : ".+12");
        char *c;

        strcpy (buffer, "%(%<");
        c = strchr (buffer, '\0');
        /* Generate the reversed comparision.  This takes four 
           bytes.  */
        if (float_p)
          sprintf (c, "%%*b%s\t%%Z2%s",
                   inverted_p ? comp : inverted_comp,
                   target);
        else
          sprintf (c, "%%*b%s%s\t%s%s,%s",
                   inverted_p ? comp : inverted_comp,
                   need_z_p ? "z" : "",
                   op1,
                   op2,
                   target);
        strcat (c, "\n\tnop\n\tj\t%1");
        if (length == 16)
          /* The delay slot was unfilled.  Since we're inside
             .noreorder, the assembler will not fill in the NOP for
             us, so we must do it ourselves.  */
          strcat (buffer, "\n\tnop");
        strcat (buffer, "%>%)");
        return buffer;
      }

    /* We do not currently use this code.  It handles jumps to
       arbitrary locations, using `jr', even across a 256MB boundary.
       We could add a -mhuge switch, and then use this code instead of
       the `j' alternative above when -mhuge was used.  */
#if 0
    case 16:
    case 20:
      {
        /* Generate a reversed conditional branch around a `jr'
           instruction:

                 .set noreorder
                 .set nomacro
                 .set noat
                 bc    l
                 la    $at, target
                 jr    $at
                 .set at
                 .set macro
                 .set reorder
              l:

           Not pretty, but allows a conditional branch anywhere in the
           32-bit address space.  If the original branch is annulled,
           then the instruction in the delay slot should be executed
           only if the branch is taken.  The la instruction is really
           a macro which will usually take eight bytes, but sometimes
           takes only four, if the instruction to which we're jumping
           gets its own entry in the global pointer table, which will
           happen if its a case label.  The assembler will then
           generate only a four-byte sequence, rather than eight, and
           there seems to be no way to tell it not to.  Thus, we can't
           just use a `.+x' addressing form; we don't know what value
           to give for `x'.  

           So, we resort to using the explicit relocation syntax
           available in the assembler and do:

              lw $at,%got_page(target)($gp)
              daddiu $at,$at,%got_ofst(target)

           That way, this always takes up eight bytes, and we can use
           the `.+x' form.  Of course, these explicit machinations
           with relocation will not work with old assemblers.  Then
           again, neither do out-of-range branches, so we haven't lost
           anything.  */

        /* The target of the reversed branch.  */
        char *target 
          = ((mips_branch_likely || length == 20) ? ".+20" : ".+16");
        char *at_register = mips_reg_names[ASSEMBLER_SCRATCH_REGNUM];
        char *gp_register = mips_reg_names[PIC_OFFSET_TABLE_REGNUM];
        char *c;

        strcpy (buffer, "%(%<%[");
        c = strchr (buffer, '\0');
        /* Generate the reversed comparision.  This takes four 
           bytes.  */
        if (float_p)
          sprintf (c, "%%*b%s\t%%Z2%s",
                   inverted_p ? comp : inverted_comp,
                   target);
        else
          sprintf (c, "%%*b%s%s\t%s%s,%s",
                   inverted_p ? comp : inverted_comp,
                   need_z_p ? "z" : "",
                   op1,
                   op2,
                   target);
        c = strchr (buffer, '\0');
        /* Generate the load-address, and jump.  This takes twelve
           bytes, for a total of 16.  */
        sprintf (c,
                 "\n\tlw\t%s,%%%%got_page(%%1)(%s)\n\tdaddiu\t%s,%s,%%%%got_ofst(%%1)\n\tjr\t%s",
                 at_register,
                 gp_register,
                 at_register,
                 at_register,
                 at_register);
        if (length == 20)
          /* The delay slot was unfilled.  Since we're inside
             .noreorder, the assembler will not fill in the NOP for
             us, so we must do it ourselves.  */
          strcat (buffer, "\n\tnop");
        strcat (buffer, "%]%>%)");
        return buffer;
      }
#endif

    default:
      abort ();
    }

  /* NOTREACHED */
  return 0;
}