gcc/config/i386/i386elf.h

   1 /* Target definitions for GNU compiler for Intel 80386 using ELF
   2    Copyright (C) 1988, 1991, 1995, 2000, 2001 Free Software Foundation, Inc.
   3
   4    Derived from sysv4.h written by Ron Guilmette (rfg@netcom.com).
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU CC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU CC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 /* Use stabs instead of DWARF debug format.  */
  23 #undef  PREFERRED_DEBUGGING_TYPE
  24 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
  25
  26 #undef TARGET_VERSION
  27 #define TARGET_VERSION fprintf (stderr, " (i386 bare ELF target)");
  28
  29 /* By default, target has a 80387, uses IEEE compatible arithmetic,
  30    and returns float values in the 387.  */
  31
  32 #define TARGET_SUBTARGET_DEFAULT (MASK_80387 | MASK_IEEE_FP | MASK_FLOAT_RETURNS)
  33
  34 /* The ELF ABI for the i386 says that records and unions are returned
  35    in memory.  */
  36
  37 #undef RETURN_IN_MEMORY
  38 #define RETURN_IN_MEMORY(TYPE) \
  39   (TYPE_MODE (TYPE) == BLKmode \
  40    || (VECTOR_MODE_P (TYPE_MODE (TYPE)) && int_size_in_bytes (TYPE) == 8))
  41
  42 /* This used to define X86, but james@bigtex.cactus.org says that
  43    is supposed to be defined optionally by user programs--not by default.  */
  44 #define CPP_PREDEFINES ""
  45
  46 #undef CPP_SPEC
  47 #define CPP_SPEC "%(cpp_cpu)"
  48
  49 /* This is how to output assembly code to define a `float' constant.
  50    We always have to use a .long pseudo-op to do this because the native
  51    SVR4 ELF assembler is buggy and it generates incorrect values when we
  52    try to use the .float pseudo-op instead.  */
  53
  54 #undef ASM_OUTPUT_FLOAT
  55 #define ASM_OUTPUT_FLOAT(FILE,VALUE)                                    \
  56 do { long value;                                                        \
  57      REAL_VALUE_TO_TARGET_SINGLE ((VALUE), value);                      \
  58      if (sizeof (int) == sizeof (long))                                 \
  59          fprintf((FILE), "%s0x%x\n", ASM_LONG, value);                  \
  60      else                                                               \
  61          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value);                 \
  62    } while (0)
  63
  64 /* This is how to output assembly code to define a `double' constant.
  65    We always have to use a pair of .long pseudo-ops to do this because
  66    the native SVR4 ELF assembler is buggy and it generates incorrect
  67    values when we try to use the the .double pseudo-op instead.  */
  68
  69 #undef ASM_OUTPUT_DOUBLE
  70 #define ASM_OUTPUT_DOUBLE(FILE,VALUE)                                   \
  71 do { long value[2];                                                     \
  72      REAL_VALUE_TO_TARGET_DOUBLE ((VALUE), value);                      \
  73      if (sizeof (int) == sizeof (long))                                 \
  74        {                                                                \
  75          fprintf((FILE), "%s0x%x\n", ASM_LONG, value[0]);               \
  76          fprintf((FILE), "%s0x%x\n", ASM_LONG, value[1]);               \
  77        }                                                                \
  78      else                                                               \
  79        {                                                                \
  80          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value[0]);              \
  81          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value[1]);              \
  82        }                                                                \
  83    } while (0)
  84
  85
  86 #undef ASM_OUTPUT_LONG_DOUBLE
  87 #define ASM_OUTPUT_LONG_DOUBLE(FILE,VALUE)                              \
  88 do { long value[3];                                                     \
  89      REAL_VALUE_TO_TARGET_LONG_DOUBLE ((VALUE), value);                 \
  90      if (sizeof (int) == sizeof (long))                                 \
  91        {                                                                \
  92          fprintf((FILE), "%s0x%x\n", ASM_LONG, value[0]);               \
  93          fprintf((FILE), "%s0x%x\n", ASM_LONG, value[1]);               \
  94          fprintf((FILE), "%s0x%x\n", ASM_LONG, value[2]);               \
  95        }                                                                \
  96      else                                                               \
  97        {                                                                \
  98          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value[0]);              \
  99          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value[1]);              \
 100          fprintf((FILE), "%s0x%lx\n", ASM_LONG, value[2]);              \
 101        }                                                                \
 102    } while (0)
 103
 104 #undef DBX_REGISTER_NUMBER
 105 #define DBX_REGISTER_NUMBER(n) \
 106   (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
 107
 108 /* The routine used to output sequences of byte values.  We use a special
 109    version of this for most svr4 targets because doing so makes the
 110    generated assembly code more compact (and thus faster to assemble)
 111    as well as more readable.  Note that if we find subparts of the
 112    character sequence which end with NUL (and which are shorter than
 113    STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING.  */
 114
 115 #undef ASM_OUTPUT_ASCII
 116 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH)                             \
 117   do                                                                    \
 118     {                                                                   \
 119       register const unsigned char *_ascii_bytes =                      \
 120         (const unsigned char *) (STR);                                  \
 121       register const unsigned char *limit = _ascii_bytes + (LENGTH);    \
 122       register unsigned bytes_in_chunk = 0;                             \
 123       for (; _ascii_bytes < limit; _ascii_bytes++)                      \
 124         {                                                               \
 125           register const unsigned char *p;                              \
 126           if (bytes_in_chunk >= 64)                                     \
 127             {                                                           \
 128               fputc ('\n', (FILE));                                     \
 129               bytes_in_chunk = 0;                                       \
 130             }                                                           \
 131           for (p = _ascii_bytes; p < limit && *p != '\0'; p++)          \
 132             continue;                                                   \
 133           if (p < limit && (p - _ascii_bytes) <= STRING_LIMIT)          \
 134             {                                                           \
 135               if (bytes_in_chunk > 0)                                   \
 136                 {                                                       \
 137                   fputc ('\n', (FILE));                                 \
 138                   bytes_in_chunk = 0;                                   \
 139                 }                                                       \
 140               ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes);         \
 141               _ascii_bytes = p;                                         \
 142             }                                                           \
 143           else                                                          \
 144             {                                                           \
 145               if (bytes_in_chunk == 0)                                  \
 146                 fprintf ((FILE), "\t.byte\t");                          \
 147               else                                                      \
 148                 fputc (',', (FILE));                                    \
 149               fprintf ((FILE), "0x%02x", *_ascii_bytes);                \
 150               bytes_in_chunk += 5;                                      \
 151             }                                                           \
 152         }                                                               \
 153       if (bytes_in_chunk > 0)                                           \
 154         fprintf ((FILE), "\n");                                         \
 155     }                                                                   \
 156   while (0)
 157
 158 /* This is how to output an element of a case-vector that is relative.
 159    This is only used for PIC code.  See comments by the `casesi' insn in
 160    i386.md for an explanation of the expression this outputs. */
 161
 162 #undef ASM_OUTPUT_ADDR_DIFF_ELT
 163 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
 164   fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE)
 165
 166 /* Indicate that jump tables go in the text section.  This is
 167    necessary when compiling PIC code.  */
 168
 169 #define JUMP_TABLES_IN_TEXT_SECTION 1
 170
 171 #define LOCAL_LABEL_PREFIX      "."
 172
 173 /* A C statement to output something to the assembler file to switch to section
 174    NAME for object DECL which is either a FUNCTION_DECL, a VAR_DECL or
 175    NULL_TREE.  Some target formats do not support arbitrary sections.  Do not
 176    define this macro in such cases.  */
 177
 178 #undef  ASM_OUTPUT_SECTION_NAME
 179 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC) \
 180 do {                                                                    \
 181   if ((DECL) && TREE_CODE (DECL) == FUNCTION_DECL)                      \
 182     fprintf (FILE, ".section\t%s,\"ax\"\n", (NAME));                    \
 183   else if ((DECL) && DECL_READONLY_SECTION (DECL, RELOC))               \
 184     fprintf (FILE, ".section\t%s,\"a\"\n", (NAME));                     \
 185   else                                                                  \
 186     fprintf (FILE, ".section\t%s,\"aw\"\n", (NAME));                    \
 187 } while (0)
 188
 189 /* If defined, a C expression whose value is a string containing the
 190    assembler operation to identify the following data as
 191    uninitialized global data.  If not defined, and neither
 192    `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined,
 193    uninitialized global data will be output in the data section if
 194    `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be
 195    used.  */
 196 #undef BSS_SECTION_ASM_OP
 197 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 198
 199 /* Like `ASM_OUTPUT_BSS' except takes the required alignment as a
 200    separate, explicit argument.  If you define this macro, it is used
 201    in place of `ASM_OUTPUT_BSS', and gives you more flexibility in
 202    handling the required alignment of the variable.  The alignment is
 203    specified as the number of bits.
 204
 205    Try to use function `asm_output_aligned_bss' defined in file
 206    `varasm.c' when defining this macro. */
 207 #undef ASM_OUTPUT_ALIGNED_BSS
 208 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 209   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)