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_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), "%s\t0x%x\n", ASM_LONG, value);                \
  60      else                                                               \
  61          fprintf((FILE), "%s\t0x%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), "%s\t0x%x\n", ASM_LONG, value[0]);             \
  76          fprintf((FILE), "%s\t0x%x\n", ASM_LONG, value[1]);             \
  77        }                                                                \
  78      else                                                               \
  79        {                                                                \
  80          fprintf((FILE), "%s\t0x%lx\n", ASM_LONG, value[0]);            \
  81          fprintf((FILE), "%s\t0x%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), "%s\t0x%x\n", ASM_LONG, value[0]);             \
  93          fprintf((FILE), "%s\t0x%x\n", ASM_LONG, value[1]);             \
  94          fprintf((FILE), "%s\t0x%x\n", ASM_LONG, value[2]);             \
  95        }                                                                \
  96      else                                                               \
  97        {                                                                \
  98          fprintf((FILE), "%s\t0x%lx\n", ASM_LONG, value[0]);            \
  99          fprintf((FILE), "%s\t0x%lx\n", ASM_LONG, value[1]);            \
 100          fprintf((FILE), "%s\t0x%lx\n", ASM_LONG, value[2]);            \
 101        }                                                                \
 102    } while (0)
 103
 104 /* Output at beginning of assembler file.  */
 105 /* The .file command should always begin the output.  */
 106
 107 #undef ASM_FILE_START
 108 #define ASM_FILE_START(FILE)                                            \
 109   do {                                                                  \
 110         output_file_directive (FILE, main_input_filename);              \
 111         fprintf (FILE, "\t.version\t\"01.01\"\n");                      \
 112   } while (0)
 113
 114 #undef DBX_REGISTER_NUMBER
 115 #define DBX_REGISTER_NUMBER(n)  svr4_dbx_register_map[n]
 116
 117 /* The routine used to output sequences of byte values.  We use a special
 118    version of this for most svr4 targets because doing so makes the
 119    generated assembly code more compact (and thus faster to assemble)
 120    as well as more readable.  Note that if we find subparts of the
 121    character sequence which end with NUL (and which are shorter than
 122    STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING.  */
 123
 124 #undef ASM_OUTPUT_ASCII
 125 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH)                             \
 126   do                                                                    \
 127     {                                                                   \
 128       register const unsigned char *_ascii_bytes =                      \
 129         (const unsigned char *) (STR);                                  \
 130       register const unsigned char *limit = _ascii_bytes + (LENGTH);    \
 131       register unsigned bytes_in_chunk = 0;                             \
 132       for (; _ascii_bytes < limit; _ascii_bytes++)                      \
 133         {                                                               \
 134           register const unsigned char *p;                              \
 135           if (bytes_in_chunk >= 64)                                     \
 136             {                                                           \
 137               fputc ('\n', (FILE));                                     \
 138               bytes_in_chunk = 0;                                       \
 139             }                                                           \
 140           for (p = _ascii_bytes; p < limit && *p != '\0'; p++)          \
 141             continue;                                                   \
 142           if (p < limit && (p - _ascii_bytes) <= STRING_LIMIT)          \
 143             {                                                           \
 144               if (bytes_in_chunk > 0)                                   \
 145                 {                                                       \
 146                   fputc ('\n', (FILE));                                 \
 147                   bytes_in_chunk = 0;                                   \
 148                 }                                                       \
 149               ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes);         \
 150               _ascii_bytes = p;                                         \
 151             }                                                           \
 152           else                                                          \
 153             {                                                           \
 154               if (bytes_in_chunk == 0)                                  \
 155                 fprintf ((FILE), "\t.byte\t");                          \
 156               else                                                      \
 157                 fputc (',', (FILE));                                    \
 158               fprintf ((FILE), "0x%02x", *_ascii_bytes);                \
 159               bytes_in_chunk += 5;                                      \
 160             }                                                           \
 161         }                                                               \
 162       if (bytes_in_chunk > 0)                                           \
 163         fprintf ((FILE), "\n");                                         \
 164     }                                                                   \
 165   while (0)
 166
 167 /* This is how to output an element of a case-vector that is relative.
 168    This is only used for PIC code.  See comments by the `casesi' insn in
 169    i386.md for an explanation of the expression this outputs. */
 170
 171 #undef ASM_OUTPUT_ADDR_DIFF_ELT
 172 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
 173   fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE)
 174
 175 /* Indicate that jump tables go in the text section.  This is
 176    necessary when compiling PIC code.  */
 177
 178 #define JUMP_TABLES_IN_TEXT_SECTION 1
 179
 180 #define LOCAL_LABEL_PREFIX      "."
 181
 182 /* A C statement to output something to the assembler file to switch to section
 183    NAME for object DECL which is either a FUNCTION_DECL, a VAR_DECL or
 184    NULL_TREE.  Some target formats do not support arbitrary sections.  Do not
 185    define this macro in such cases.  */
 186
 187 #undef  ASM_OUTPUT_SECTION_NAME
 188 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC) \
 189 do {                                                                    \
 190   if ((DECL) && TREE_CODE (DECL) == FUNCTION_DECL)                      \
 191     fprintf (FILE, ".section\t%s,\"ax\"\n", (NAME));                    \
 192   else if ((DECL) && DECL_READONLY_SECTION (DECL, RELOC))               \
 193     fprintf (FILE, ".section\t%s,\"a\"\n", (NAME));                     \
 194   else                                                                  \
 195     fprintf (FILE, ".section\t%s,\"aw\"\n", (NAME));                    \
 196 } while (0)
 197
 198 /* If defined, a C expression whose value is a string containing the
 199    assembler operation to identify the following data as
 200    uninitialized global data.  If not defined, and neither
 201    `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined,
 202    uninitialized global data will be output in the data section if
 203    `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be
 204    used.  */
 205 #undef BSS_SECTION_ASM_OP
 206 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 207
 208 /* Like `ASM_OUTPUT_BSS' except takes the required alignment as a
 209    separate, explicit argument.  If you define this macro, it is used
 210    in place of `ASM_OUTPUT_BSS', and gives you more flexibility in
 211    handling the required alignment of the variable.  The alignment is
 212    specified as the number of bits.
 213
 214    Try to use function `asm_output_aligned_bss' defined in file
 215    `varasm.c' when defining this macro. */
 216 #undef ASM_OUTPUT_ALIGNED_BSS
 217 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 218   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)