gcc/config/i386/gnu-user.h

   1 /* Definitions for Intel 386 systems using GNU userspace.
   2    Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2004, 2005,
   3    2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
   4    Contributed by Eric Youngdale.
   5    Modified for stabs-in-ELF by H.J. Lu.
   6
   7 This file is part of GCC.
   8
   9 GCC 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 3, or (at your option)
  12 any later version.
  13
  14 GCC 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 GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 /* Output at beginning of assembler file.  */
  24 /* The .file command should always begin the output.  */
  25 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
  26
  27 #undef ASM_COMMENT_START
  28 #define ASM_COMMENT_START "#"
  29
  30 #undef DBX_REGISTER_NUMBER
  31 #define DBX_REGISTER_NUMBER(n) \
  32   (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
  33
  34 /* Output assembler code to FILE to call the profiler.
  35    To the best of my knowledge, no GNU userspace libc has required the label
  36    argument to mcount.  */
  37
  38 #define NO_PROFILE_COUNTERS     1
  39
  40 #undef MCOUNT_NAME
  41 #define MCOUNT_NAME "mcount"
  42
  43 /* The GLIBC version of mcount for the x86 assumes that there is a
  44    frame, so we cannot allow profiling without a frame pointer.  */
  45
  46 #undef SUBTARGET_FRAME_POINTER_REQUIRED
  47 #define SUBTARGET_FRAME_POINTER_REQUIRED crtl->profile
  48
  49 #undef SIZE_TYPE
  50 #define SIZE_TYPE "unsigned int"
  51
  52 #undef PTRDIFF_TYPE
  53 #define PTRDIFF_TYPE "int"
  54
  55 #undef WCHAR_TYPE
  56 #define WCHAR_TYPE "long int"
  57
  58 #undef WCHAR_TYPE_SIZE
  59 #define WCHAR_TYPE_SIZE BITS_PER_WORD
  60
  61 /* Provide a LINK_SPEC appropriate for GNU userspace.  Here we provide support
  62    for the special GCC options -static and -shared, which allow us to
  63    link things in one of these three modes by applying the appropriate
  64    combinations of options at link-time.
  65
  66    When the -shared link option is used a final link is not being
  67    done.  */
  68
  69 #undef  ASM_SPEC
  70 #define ASM_SPEC \
  71   "--32 %{!mno-sse2avx:%{mavx:-msse2avx}} %{msse2avx:%{!mavx:-msse2avx}}"
  72
  73 #undef  SUBTARGET_EXTRA_SPECS
  74 #define SUBTARGET_EXTRA_SPECS \
  75   { "link_emulation", GNU_USER_LINK_EMULATION },\
  76   { "dynamic_linker", GNU_USER_DYNAMIC_LINKER }
  77
  78 #define GNU_USER_TARGET_LINK_SPEC "-m %(link_emulation) %{shared:-shared} \
  79   %{!shared: \
  80     %{!static: \
  81       %{rdynamic:-export-dynamic} \
  82       -dynamic-linker %(dynamic_linker)} \
  83       %{static:-static}}"
  84
  85 #undef  LINK_SPEC
  86 #define LINK_SPEC GNU_USER_TARGET_LINK_SPEC
  87
  88 /* A C statement (sans semicolon) to output to the stdio stream
  89    FILE the assembler definition of uninitialized global DECL named
  90    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
  91    Try to use asm_output_aligned_bss to implement this macro.  */
  92
  93 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
  94   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
  95
  96 /* A C statement to output to the stdio stream FILE an assembler
  97    command to advance the location counter to a multiple of 1<<LOG
  98    bytes if it is within MAX_SKIP bytes.
  99
 100    This is used to align code labels according to Intel recommendations.  */
 101
 102 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
 103 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP)                    \
 104   do {                                                                  \
 105     if ((LOG) != 0) {                                                   \
 106       if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG));  \
 107       else {                                                            \
 108         fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));     \
 109         /* Make sure that we have at least 8 byte alignment if > 8 byte \
 110            alignment is preferred.  */                                  \
 111         if ((LOG) > 3                                                   \
 112             && (1 << (LOG)) > ((MAX_SKIP) + 1)                          \
 113             && (MAX_SKIP) >= 7)                                         \
 114           fputs ("\t.p2align 3\n", (FILE));                             \
 115       }                                                                 \
 116     }                                                                   \
 117   } while (0)
 118 #endif
 119
 120 /* Handle special EH pointer encodings.  Absolute, pc-relative, and
 121    indirect are handled automatically.  */
 122 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
 123   do {                                                                  \
 124     if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel)         \
 125       {                                                                 \
 126         fputs (ASM_LONG, FILE);                 \
 127         assemble_name (FILE, XSTR (ADDR, 0));                           \
 128         fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \
 129         goto DONE;                                                      \
 130       }                                                                 \
 131   } while (0)
 132
 133 /* Used by crtstuff.c to initialize the base of data-relative relocations.
 134    These are GOT relative on x86, so return the pic register.  */
 135 #ifdef __PIC__
 136 #define CRT_GET_RFIB_DATA(BASE)                 \
 137   {                                             \
 138     register void *ebx_ __asm__("ebx");         \
 139     BASE = ebx_;                                \
 140   }
 141 #else
 142 #define CRT_GET_RFIB_DATA(BASE)                                         \
 143   __asm__ ("call\t.LPR%=\n"                                             \
 144            ".LPR%=:\n\t"                                                \
 145            "pop{l}\t%0\n\t"                                             \
 146            /* Due to a GAS bug, this cannot use EAX.  That encodes      \
 147               smaller than the traditional EBX, which results in the    \
 148               offset being off by one.  */                              \
 149            "add{l}\t{$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0"              \
 150                    "|%0,_GLOBAL_OFFSET_TABLE_+(.-.LPR%=)}"              \
 151            : "=d"(BASE))
 152 #endif
 153
 154 #ifdef TARGET_LIBC_PROVIDES_SSP
 155 /* i386 glibc provides __stack_chk_guard in %gs:0x14.  */
 156 #define TARGET_THREAD_SSP_OFFSET        0x14
 157
 158 /* We steal the last transactional memory word.  */
 159 #define TARGET_CAN_SPLIT_STACK
 160 #define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30
 161 #endif