gcc/config/m68k/m68kv4.h

   1 /* Target definitions for GNU compiler for mc680x0 running System V.4
   2    Copyright (C) 1991, 1993, 1994, 1995, 1996, 1998, 1999, 2000
   3    Free Software Foundation, Inc.
   4    Contributed by Ron Guilmette (rfg@monkeys.com) and
   5    Fred Fish (fnf@cygnus.com).
   6
   7 This file is part of GNU CC.
   8
   9 GNU CC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 GNU CC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU CC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 59 Temple Place - Suite 330,
  22 Boston, MA 02111-1307, USA.  */
  23
  24 /* Use SGS_* macros to control compilation in m68k.md */
  25
  26 #define SGS_SWITCH_TABLES       /* Different switch table handling */
  27
  28 /* TODO: convert includes to ${tm_file} list in config.gcc.  */
  29 #include "m68k/sgs.h"           /* The m68k/SVR4 assembler is SGS based */
  30
  31 #include "dbxelf.h"
  32 #include "elfos.h"
  33 #include "svr4.h"               /* Pick up the generic SVR4 macros */
  34
  35 /* See m68k.h.  7 means 68020 with 68881.  */
  36
  37 #ifndef TARGET_DEFAULT
  38 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  39 #endif
  40
  41 /*  Override the definition of NO_DOLLAR_IN_LABEL in svr4.h, for special
  42     g++ assembler names.  When this is defined, g++ uses embedded '.'
  43     characters and some m68k assemblers have problems with this.  The
  44     chances are much greater that any particular assembler will permit
  45     embedded '$' characters.  */
  46
  47 #undef NO_DOLLAR_IN_LABEL
  48
  49 /* Define PCC_STATIC_STRUCT_RETURN if the convention on the target machine
  50    is to use the nonreentrant technique for returning structure and union
  51    values, as commonly implemented by the AT&T Portable C Compiler (PCC).
  52    When defined, the gcc option -fpcc-struct-return can be used to cause
  53    this form to be generated.  When undefined, the option does nothing.
  54    For m68k SVR4, the convention is to use a reentrant technique compatible
  55    with the gcc default, so override the definition of this macro in m68k.h */
  56
  57 #undef PCC_STATIC_STRUCT_RETURN
  58
  59 /* Provide a set of pre-definitions and pre-assertions appropriate for
  60    the m68k running svr4.  __svr4__ is our extension.  */
  61
  62 #define CPP_PREDEFINES \
  63   "-Dm68k -Dunix -D__svr4__ -D__motorola__ \
  64  -Asystem=unix -Asystem=svr4 -Acpu=m68k -Amachine=m68k"
  65
  66 /* Test to see if the target includes a 68881 by default, and use CPP_SPEC
  67    to control whether or not __HAVE_68881__ is defined by default or not.
  68    If a 68881 is the default, gcc will use inline 68881 instructions, by
  69    predefining __HAVE_68881__, unless -msoft-float is specified.
  70    If a 68881 is not the default, gcc will only define __HAVE_68881__ if
  71    -m68881 is specified.  */
  72
  73 #if TARGET_DEFAULT & MASK_68881
  74 #define CPP_SPEC "%{!msoft-float:-D__HAVE_68881__}"
  75 #else
  76 #define CPP_SPEC "%{m68881:-D__HAVE_68881__}"
  77 #endif
  78
  79 /* Output assembler code to FILE to increment profiler label # LABELNO
  80    for profiling a function entry.  We override the definition in m68k.h
  81    and match the way the native m68k/SVR4 compiler does profiling, with the
  82    address of the profile counter in a1, not a0, and using bsr rather
  83    than jsr.  */
  84
  85 #undef FUNCTION_PROFILER
  86 #define FUNCTION_PROFILER(FILE, LABELNO)                                \
  87   asm_fprintf ((FILE), "\tlea.l\t(%LLP%d,%Rpc),%Ra1\n\tbsr\t_mcount\n", \
  88                (LABELNO))
  89
  90 /* Local common symbols are declared to the assembler with ".lcomm" rather
  91    than ".bss", so override the definition in svr4.h */
  92 /* ??? svr4.h no longer defines this, and this is only used by m68k/amix.h.  */
  93
  94 #undef BSS_ASM_OP
  95 #define BSS_ASM_OP      "\t.lcomm\t"
  96
  97 /* Register in which address to store a structure value is passed to a
  98    function.  The default in m68k.h is a1.  For m68k/SVR4 it is a0.  */
  99
 100 #undef STRUCT_VALUE_REGNUM
 101 #define STRUCT_VALUE_REGNUM 8
 102
 103 /* Register in which static-chain is passed to a function.  The
 104    default in m68k.h is a0, but that is already the struct value
 105    regnum.  Make it a1 instead.  */
 106
 107 #undef STATIC_CHAIN_REGNUM
 108 #define STATIC_CHAIN_REGNUM 9
 109
 110 #define ASM_COMMENT_START "#"
 111
 112 #undef TYPE_OPERAND_FMT
 113 #define TYPE_OPERAND_FMT      "@%s"
 114
 115 /* Define how the m68k registers should be numbered for Dwarf output.
 116    The numbering provided here should be compatible with the native
 117    SVR4 SDB debugger in the m68k/SVR4 reference port, where d0-d7
 118    are 0-7, a0-a8 are 8-15, and fp0-fp7 are 16-23.  */
 119
 120 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 121
 122 /* The ASM_OUTPUT_SKIP macro is first defined in m68k.h, using ".skip".
 123    It is then overridden by m68k/sgs.h to use ".space", and again by svr4.h
 124    to use ".zero".  The m68k/SVR4 assembler uses ".space", so repeat the
 125    definition from m68k/sgs.h here.  Note that ASM_NO_SKIP_IN_TEXT is
 126    defined in m68k/sgs.h, so we don't have to repeat it here.  */
 127
 128 #undef ASM_OUTPUT_SKIP
 129 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
 130   fprintf (FILE, "%s%u\n", SPACE_ASM_OP, (SIZE))
 131
 132 /* 1 if N is a possible register number for a function value.
 133    For m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 134    pointer, or floating types, respectively. Reject fp0 if not using a
 135    68881 coprocessor.  */
 136
 137 #undef FUNCTION_VALUE_REGNO_P
 138 #define FUNCTION_VALUE_REGNO_P(N) \
 139   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 140
 141 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 142    more than one register.  */
 143
 144 #undef NEEDS_UNTYPED_CALL
 145 #define NEEDS_UNTYPED_CALL 1
 146
 147 /* Define how to generate (in the callee) the output value of a function
 148    and how to find (in the caller) the value returned by a function.  VALTYPE
 149    is the data type of the value (as a tree).  If the precise function being
 150    called is known, FUNC is its FUNCTION_DECL; otherwise, FUNC is 0.
 151    For m68k/SVR4 generate the result in d0, a0, or fp0 as appropriate.  */
 152
 153 #undef FUNCTION_VALUE
 154 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 155   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 156    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 157    : (POINTER_TYPE_P (VALTYPE)                                          \
 158       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 159       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 160
 161 /* For compatibility with the large body of existing code which does not
 162    always properly declare external functions returning pointer types, the
 163    m68k/SVR4 convention is to copy the value returned for pointer functions
 164    from a0 to d0 in the function epilogue, so that callers that have
 165    neglected to properly declare the callee can still find the correct return
 166    value.  */
 167
 168 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 169 do {                                                                    \
 170   if (current_function_returns_pointer                                  \
 171       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 172     asm_fprintf (FILE, "\tmov.l %Ra0,%Rd0\n");                          \
 173 } while (0);
 174
 175 /* Define how to find the value returned by a library function assuming the
 176    value has mode MODE.
 177    For m68k/SVR4 look for integer values in d0, pointer values in d0
 178    (returned in both d0 and a0), and floating values in fp0.  */
 179
 180 #undef LIBCALL_VALUE
 181 #define LIBCALL_VALUE(MODE)                                             \
 182   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 183     && TARGET_68881)                                                    \
 184    ? gen_rtx_REG ((MODE), 16)                                           \
 185    : gen_rtx_REG ((MODE), 0))
 186
 187 /* Boundary (in *bits*) on which stack pointer should be aligned.
 188    The m68k/SVR4 convention is to keep the stack pointer longword aligned.  */
 189
 190 #undef STACK_BOUNDARY
 191 #define STACK_BOUNDARY 32
 192
 193 /* Alignment of field after `int : 0' in a structure.
 194    For m68k/SVR4, this is the next longword boundary.  */
 195
 196 #undef EMPTY_FIELD_BOUNDARY
 197 #define EMPTY_FIELD_BOUNDARY 32
 198
 199 /* No data type wants to be aligned rounder than this.
 200    For m68k/SVR4, some types (doubles for example) are aligned on 8 byte
 201    boundaries */
 202
 203 #undef BIGGEST_ALIGNMENT
 204 #define BIGGEST_ALIGNMENT 64
 205
 206 /* SVR4 m68k assembler is bitching on the `comm i,1,1' which asks for
 207    1 byte alignment. Don't generate alignment for COMMON seems to be
 208    safer until we the assembler is fixed.  */
 209 #undef ASM_OUTPUT_ALIGNED_COMMON
 210 /* Same problem with this one.  */
 211 #undef ASM_OUTPUT_ALIGNED_LOCAL
 212
 213 /* The `string' directive on m68k svr4 does not handle string with
 214    escape char (ie., `\') right. Use normal way to output ASCII bytes
 215    seems to be safer.  */
 216 #undef ASM_OUTPUT_ASCII
 217 #define ASM_OUTPUT_ASCII(FILE,PTR,LEN)                          \
 218 do {                                                            \
 219   register size_t sp = 0, limit = (LEN);                        \
 220   fputs (integer_asm_op (1, TRUE), (FILE));                     \
 221   do {                                                          \
 222     int ch = (PTR)[sp];                                         \
 223     if (ch > ' ' && ! (ch & 0x80) && ch != '\\')                \
 224       {                                                         \
 225         fprintf ((FILE), "'%c", ch);                            \
 226       }                                                         \
 227     else                                                        \
 228       {                                                         \
 229         fprintf ((FILE), "0x%x", ch);                           \
 230       }                                                         \
 231     if (++sp < limit)                                           \
 232       {                                                         \
 233         if ((sp % 10) == 0)                                     \
 234           {                                                     \
 235             fprintf ((FILE), "\n%s", integer_asm_op (1, TRUE)); \
 236           }                                                     \
 237         else                                                    \
 238           {                                                     \
 239             putc (',', (FILE));                                 \
 240           }                                                     \
 241       }                                                         \
 242   } while (sp < limit);                                         \
 243   putc ('\n', (FILE));                                          \
 244 } while (0)
 245
 246 /* SVR4 m68k assembler is bitching on the syntax `2.b'.
 247    So use the "LLDnnn-LLnnn" format.  Define LLDnnn after the table.  */
 248
 249 #undef ASM_OUTPUT_CASE_END
 250 #define ASM_OUTPUT_CASE_END(FILE,NUM,TABLE)                             \
 251 do {                                                                    \
 252   if (switch_table_difference_label_flag)                               \
 253     asm_fprintf ((FILE), "%s%LLD%d,%LL%d\n", SET_ASM_OP, (NUM), (NUM)); \
 254   switch_table_difference_label_flag = 0;                               \
 255 } while (0)
 256
 257 int switch_table_difference_label_flag;
 258
 259 #undef ASM_OUTPUT_COMMON
 260 #undef ASM_OUTPUT_LOCAL
 261 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
 262 ( fputs (".comm ", (FILE)),                     \
 263   assemble_name ((FILE), (NAME)),               \
 264   fprintf ((FILE), ",%u\n", (SIZE)))
 265
 266 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)  \
 267 ( fputs (".lcomm ", (FILE)),                    \
 268   assemble_name ((FILE), (NAME)),               \
 269   fprintf ((FILE), ",%u\n", (SIZE)))
 270
 271 /* Override the definition in svr4.h. In m68k svr4, using swbeg is the
 272    standard way to do switch table.  */
 273 #undef ASM_OUTPUT_BEFORE_CASE_LABEL
 274 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE)             \
 275   fprintf ((FILE), "%s&%d\n", SWBEG_ASM_OP, XVECLEN (PATTERN (TABLE), 1));
 276
 277 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is an
 278    operand of a function call.  */
 279 #undef LEGITIMATE_PIC_OPERAND_P
 280 #define LEGITIMATE_PIC_OPERAND_P(X) \
 281   ((! symbolic_operand (X, VOIDmode) \
 282     && ! (GET_CODE (X) == CONST_DOUBLE && mem_for_const_double (X) != 0 \
 283           && GET_CODE (mem_for_const_double (X)) == MEM                 \
 284           && symbolic_operand (XEXP (mem_for_const_double (X), 0),      \
 285                                VOIDmode)))                              \
 286    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))               \
 287    || PCREL_GENERAL_OPERAND_OK)
 288
 289 /* Turn off function cse if we are doing PIC. We always want function call
 290    to be done as `bsr foo@PLTPC', so it will force the assembler to create
 291    the PLT entry for `foo'. Doing function cse will cause the address of `foo'
 292    to be loaded into a register, which is exactly what we want to avoid when
 293    we are doing PIC on svr4 m68k.  */
 294 #undef OVERRIDE_OPTIONS
 295 #define OVERRIDE_OPTIONS                \
 296 {                                       \
 297   if (flag_pic) flag_no_function_cse = 1; \
 298   if (! TARGET_68020 && flag_pic == 2)  \
 299     error("-fPIC is not currently supported on the 68000 or 68010\n");  \
 300 }
 301
 302 /* Output assembler code for a block containing the constant parts
 303    of a trampoline, leaving space for the variable parts.  */
 304
 305 /* On m68k svr4, the trampoline is different from the generic version
 306    in that we use a1 as the static call chain.  */
 307
 308 #undef TRAMPOLINE_TEMPLATE
 309 #define TRAMPOLINE_TEMPLATE(FILE)                                       \
 310 {                                                                       \
 311   assemble_aligned_integer (2, GEN_INT (0x227a));                       \
 312   assemble_aligned_integer (2, GEN_INT (8));                            \
 313   assemble_aligned_integer (2, GEN_INT (0x2f3a));                       \
 314   assemble_aligned_integer (2, GEN_INT (8));                            \
 315   assemble_aligned_integer (2, GEN_INT (0x4e75));                       \
 316   assemble_aligned_integer (4, const0_rtx);                             \
 317   assemble_aligned_integer (4, const0_rtx);                             \
 318 }
 319
 320 /* Redefine since we are using a different trampoline */
 321 #undef TRAMPOLINE_SIZE
 322 #define TRAMPOLINE_SIZE 18
 323
 324 /* Emit RTL insns to initialize the variable parts of a trampoline.
 325    FNADDR is an RTX for the address of the function's pure code.
 326    CXT is an RTX for the static chain value for the function.  */
 327
 328 #undef INITIALIZE_TRAMPOLINE
 329 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT)                       \
 330 {                                                                       \
 331   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 10)), CXT); \
 332   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 14)), FNADDR); \
 333 }