gcc/config/i386/gas.h

   1 /* Definitions for Intel 386 using GAS.
   2    Copyright (C) 1988-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* Note that i386/seq-gas.h is a GAS configuration that does not use this
  21    file.  */
  22
  23 /* Use the bsd assembler syntax.  */
  24 /* we need to do this because gas is really a bsd style assembler,
  25  * and so doesn't work well this these att-isms:
  26  *
  27  *  ASM_OUTPUT_SKIP is .set .,.+N, which isn't implemented in gas
  28  *  ASM_OUTPUT_LOCAL is done with .set .,.+N, but that can't be
  29  *   used to define bss static space
  30  *
  31  * Next is the question of whether to uses underscores.  RMS didn't
  32  * like this idea at first, but since it is now obvious that we
  33  * need this separate tm file for use with gas, at least to get
  34  * dbx debugging info, I think we should also switch to underscores.
  35  * We can keep i386v for real att style output, and the few
  36  * people who want both form will have to compile twice.
  37  */
  38
  39 /* these come from i386/bsd.h, but are specific to sequent */
  40 #undef DBX_NO_XREFS
  41 #undef DBX_CONTIN_LENGTH
  42
  43 /* Output #ident as a .ident.  */
  44
  45 #undef TARGET_ASM_OUTPUT_IDENT
  46 #define TARGET_ASM_OUTPUT_IDENT default_asm_output_ident_directive
  47
  48 /* In the past there was confusion as to what the argument to .align was
  49    in GAS.  For the last several years the rule has been this: for a.out
  50    file formats that argument is LOG, and for all other file formats the
  51    argument is 1<<LOG.
  52
  53    However, GAS now has .p2align and .balign pseudo-ops so to remove any
  54    doubt or guess work, and since this file is used for both a.out and other
  55    file formats, we use one of them.  */
  56
  57 #ifdef HAVE_GAS_BALIGN_AND_P2ALIGN
  58 #undef ASM_OUTPUT_ALIGN
  59 #define ASM_OUTPUT_ALIGN(FILE,LOG) \
  60   if ((LOG)!=0) fprintf ((FILE), "\t.balign %d\n", 1 << (LOG))
  61 #endif
  62
  63 /* A C statement to output to the stdio stream FILE an assembler
  64    command to advance the location counter to a multiple of 1<<LOG
  65    bytes if it is within MAX_SKIP bytes.
  66
  67    This is used to align code labels according to Intel recommendations.  */
  68
  69 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
  70 #  define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \
  71     if ((LOG) != 0) { \
  72       if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1 << (LOG)) - 1)            \
  73         fprintf ((FILE), "\t.p2align %d\n", (LOG));                     \
  74       else                                                              \
  75         fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));     \
  76     }
  77 #endif
  78 \f
  79 /* A C statement or statements which output an assembler instruction
  80    opcode to the stdio stream STREAM.  The macro-operand PTR is a
  81    variable of type `char *' which points to the opcode name in its
  82    "internal" form--the form that is written in the machine description.
  83
  84    GAS version 1.38.1 doesn't understand the `repz' opcode mnemonic.
  85    So use `repe' instead.  */
  86
  87 #undef ASM_OUTPUT_OPCODE
  88 #define ASM_OUTPUT_OPCODE(STREAM, PTR)  \
  89 {                                                                       \
  90   if ((PTR)[0] == 'r'                                                   \
  91       && (PTR)[1] == 'e'                                                \
  92       && (PTR)[2] == 'p')                                               \
  93     {                                                                   \
  94       if ((PTR)[3] == 'z')                                              \
  95         {                                                               \
  96           fputs ("repe", (STREAM));                                     \
  97           (PTR) += 4;                                                   \
  98         }                                                               \
  99       else if ((PTR)[3] == 'n' && (PTR)[4] == 'z')                      \
 100         {                                                               \
 101           fputs ("repne", (STREAM));                                    \
 102           (PTR) += 5;                                                   \
 103         }                                                               \
 104     }                                                                   \
 105   else                                                                  \
 106     ASM_OUTPUT_AVX_PREFIX ((STREAM), (PTR));                            \
 107 }
 108
 109 /* Define macro used to output shift-double opcodes when the shift
 110    count is in %cl.  Some assemblers require %cl as an argument;
 111    some don't.
 112
 113    GAS requires the %cl argument, so override i386/unix.h.  */
 114
 115 #undef SHIFT_DOUBLE_OMITS_COUNT
 116 #define SHIFT_DOUBLE_OMITS_COUNT 0
 117
 118 /* The comment-starter string as GAS expects it. */
 119 #undef ASM_COMMENT_START
 120 #define ASM_COMMENT_START "#"
 121
 122 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true