gcc/config/i386/sysv4.h

   1 /* Target definitions for GCC for Intel 80386 running System V.4
   2    Copyright (C) 1991, 2001, 2002, 2007 Free Software Foundation, Inc.
   3
   4    Written by Ron Guilmette (rfg@netcom.com).
   5
   6 This file is part of GCC.
   7
   8 GCC 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 3, or (at your option)
  11 any later version.
  12
  13 GCC 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 GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #define TARGET_VERSION fprintf (stderr, " (i386 System V Release 4)");
  24
  25 /* The svr4 ABI for the i386 says that records and unions are returned
  26    in memory.  */
  27
  28 #undef TARGET_RETURN_IN_MEMORY
  29 #define TARGET_RETURN_IN_MEMORY ix86_i386elf_return_in_memory
  30
  31 /* Output at beginning of assembler file.  */
  32 /* The .file command should always begin the output.  */
  33
  34 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
  35 #undef X86_FILE_START_VERSION_DIRECTIVE
  36 #define X86_FILE_START_VERSION_DIRECTIVE true
  37
  38 #undef DBX_REGISTER_NUMBER
  39 #define DBX_REGISTER_NUMBER(n)  svr4_dbx_register_map[n]
  40
  41 /* The routine used to output sequences of byte values.  We use a special
  42    version of this for most svr4 targets because doing so makes the
  43    generated assembly code more compact (and thus faster to assemble)
  44    as well as more readable.  Note that if we find subparts of the
  45    character sequence which end with NUL (and which are shorter than
  46    STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING.  */
  47
  48 #undef ASM_OUTPUT_ASCII
  49 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH)                             \
  50   do                                                                    \
  51     {                                                                   \
  52       const unsigned char *_ascii_bytes =                               \
  53         (const unsigned char *) (STR);                                  \
  54       const unsigned char *limit = _ascii_bytes + (LENGTH);             \
  55       unsigned bytes_in_chunk = 0;                                      \
  56       for (; _ascii_bytes < limit; _ascii_bytes++)                      \
  57         {                                                               \
  58           const unsigned char *p;                                       \
  59           if (bytes_in_chunk >= 64)                                     \
  60             {                                                           \
  61               fputc ('\n', (FILE));                                     \
  62               bytes_in_chunk = 0;                                       \
  63             }                                                           \
  64           for (p = _ascii_bytes; p < limit && *p != '\0'; p++)          \
  65             continue;                                                   \
  66           if (p < limit && (p - _ascii_bytes) <= (long) STRING_LIMIT)   \
  67             {                                                           \
  68               if (bytes_in_chunk > 0)                                   \
  69                 {                                                       \
  70                   fputc ('\n', (FILE));                                 \
  71                   bytes_in_chunk = 0;                                   \
  72                 }                                                       \
  73               ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes);         \
  74               _ascii_bytes = p;                                         \
  75             }                                                           \
  76           else                                                          \
  77             {                                                           \
  78               if (bytes_in_chunk == 0)                                  \
  79                 fprintf ((FILE), "\t.byte\t");                          \
  80               else                                                      \
  81                 fputc (',', (FILE));                                    \
  82               fprintf ((FILE), "0x%02x", *_ascii_bytes);                \
  83               bytes_in_chunk += 5;                                      \
  84             }                                                           \
  85         }                                                               \
  86       if (bytes_in_chunk > 0)                                           \
  87         fprintf ((FILE), "\n");                                         \
  88     }                                                                   \
  89   while (0)
  90
  91 /* A C statement (sans semicolon) to output to the stdio stream
  92    FILE the assembler definition of uninitialized global DECL named
  93    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
  94    Try to use asm_output_aligned_bss to implement this macro.  */
  95
  96 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
  97   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
  98
  99 /* Handle special EH pointer encodings.  Absolute, pc-relative, and
 100    indirect are handled automatically.  */
 101 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
 102   do {                                                                  \
 103     if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel)         \
 104       {                                                                 \
 105         fputs (ASM_LONG, FILE);                                         \
 106         assemble_name (FILE, XSTR (ADDR, 0));                           \
 107         fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \
 108         goto DONE;                                                      \
 109       }                                                                 \
 110   } while (0)
 111
 112 /* Used by crtstuff.c to initialize the base of data-relative relocations.
 113    These are GOT relative on x86, so return the pic register.  */
 114 #ifdef __PIC__
 115 #define CRT_GET_RFIB_DATA(BASE)                 \
 116   {                                             \
 117     register void *ebx_ __asm__("ebx");         \
 118     BASE = ebx_;                                \
 119   }
 120 #else
 121 #define CRT_GET_RFIB_DATA(BASE)                                         \
 122   __asm__ ("call\t.LPR%=\n"                                             \
 123            ".LPR%=:\n\t"                                                \
 124            "pop{l}\t%0\n\t"                                             \
 125            /* Due to a GAS bug, this cannot use EAX.  That encodes      \
 126               smaller than the traditional EBX, which results in the    \
 127               offset being off by one.  */                              \
 128            "add{l}\t{$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0"              \
 129                    "|%0,_GLOBAL_OFFSET_TABLE_+(.-.LPR%=)}"              \
 130            : "=d"(BASE))
 131 #endif