gcc/config/mips/elf64.h

   1 /* Definitions of target machine for GNU compiler.  MIPS R4000 version with
   2    GOFAST floating point library.
   3    Copyright (C) 1994, 1995, 1996, 1997, 1999, 2000, 2002
   4    Free Software Foundation, Inc.
   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, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 #define OBJECT_FORMAT_ELF
  24
  25 /* If an embedded ABI is selected, prefer to generate 64-bit code.
  26    Implies -mips3 in such cases.  */
  27 #ifndef TARGET_DEFAULT
  28 #define TARGET_DEFAULT MASK_FLOAT64|MASK_64BIT
  29 #endif
  30
  31 /* This should change to n32 when it is supported in gas.  */
  32 #ifndef MIPS_ABI_DEFAULT
  33 #define MIPS_ABI_DEFAULT ABI_O64
  34 #endif
  35
  36 /* Until we figure out what MIPS ELF targets normally use, just do
  37    stabs in ELF.  */
  38 #ifndef PREFERRED_DEBUGGING_TYPE
  39 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
  40 #endif
  41
  42 /* US Software GOFAST library support.  */
  43 #include "gofast.h"
  44 #define INIT_SUBTARGET_OPTABS INIT_GOFAST_OPTABS
  45
  46 #include "mips/mips.h"
  47
  48 /* Use memcpy, et. al., rather than bcopy.  */
  49 #define TARGET_MEM_FUNCTIONS
  50
  51 /* Biggest alignment supported by the object file format of this
  52    machine.  Use this macro to limit the alignment which can be
  53    specified using the `__attribute__ ((aligned (N)))' construct.  If
  54    not defined, the default value is `BIGGEST_ALIGNMENT'.  */
  55
  56 #undef MAX_OFILE_ALIGNMENT
  57 #define MAX_OFILE_ALIGNMENT (32768*8)
  58
  59 /* We need to use .esize and .etype instead of .size and .type to
  60    avoid conflicting with ELF directives.  */
  61 #undef PUT_SDB_SIZE
  62 #define PUT_SDB_SIZE(a)                                 \
  63 do {                                                    \
  64   extern FILE *asm_out_text_file;                       \
  65   fprintf (asm_out_text_file, "\t.esize\t");            \
  66   fprintf (asm_out_text_file, HOST_WIDE_INT_PRINT_DEC, (HOST_WIDE_INT) (a)); \
  67   fprintf (asm_out_text_file, ";");                     \
  68 } while (0)
  69
  70 #undef PUT_SDB_TYPE
  71 #define PUT_SDB_TYPE(a)                                 \
  72 do {                                                    \
  73   extern FILE *asm_out_text_file;                       \
  74   fprintf (asm_out_text_file, "\t.etype\t0x%x;", (a));  \
  75 } while (0)
  76
  77 /* Switch into a generic section.  */
  78 #undef TARGET_ASM_NAMED_SECTION
  79 #define TARGET_ASM_NAMED_SECTION  default_elf_asm_named_section
  80
  81 /* Given that Irix has it's own headers, not having TARGET_GAS here
  82    seems a mistake.  If we actually need to be prepared for file
  83    switching, then we need a custom TARGET_ASM_NAMED_SECTION too.  */
  84
  85 #undef TEXT_SECTION
  86 #define TEXT_SECTION()                          \
  87 do {                                            \
  88   if (TARGET_FILE_SWITCHING)                    \
  89     abort ();                                   \
  90   fputs (TEXT_SECTION_ASM_OP, asm_out_file);    \
  91   fputc ('\n', asm_out_file);                   \
  92 } while (0)
  93
  94 /* The following macro defines the format used to output the second
  95    operand of the .type assembler directive.  Different svr4 assemblers
  96    expect various different forms for this operand.  The one given here
  97    is just a default.  You may need to override it in your machine-
  98    specific tm.h file (depending upon the particulars of your assembler).  */
  99
 100 #define TYPE_OPERAND_FMT        "@%s"
 101
 102 /* Define the strings used for the special svr4 .type and .size directives.
 103    These strings generally do not vary from one system running svr4 to
 104    another, but if a given system (e.g. m88k running svr) needs to use
 105    different pseudo-op names for these, they may be overridden in the
 106    file which includes this one.  */
 107
 108 #undef TYPE_ASM_OP
 109 #undef SIZE_ASM_OP
 110 #define TYPE_ASM_OP     "\t.type\t"
 111 #define SIZE_ASM_OP     "\t.size\t"
 112
 113 /* These macros generate the special .type and .size directives which
 114    are used to set the corresponding fields of the linker symbol table
 115    entries in an ELF object file under SVR4.  These macros also output
 116    the starting labels for the relevant functions/objects.  */
 117
 118 /* Write the extra assembler code needed to declare an object properly.  */
 119
 120 #undef ASM_DECLARE_OBJECT_NAME
 121 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)                       \
 122   do {                                                                  \
 123     HOST_WIDE_INT size;                                                 \
 124     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");                   \
 125     size_directive_output = 0;                                          \
 126     if (!flag_inhibit_size_directive && DECL_SIZE (DECL))               \
 127       {                                                                 \
 128         size_directive_output = 1;                                      \
 129         size = int_size_in_bytes (TREE_TYPE (DECL));                    \
 130         ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size);                   \
 131       }                                                                 \
 132     mips_declare_object (FILE, NAME, "", ":\n", 0);                     \
 133   } while (0)
 134
 135 /* Output the size directive for a decl in rest_of_decl_compilation
 136    in the case where we did not do so before the initializer.
 137    Once we find the error_mark_node, we know that the value of
 138    size_directive_output was set
 139    by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */
 140
 141 #undef ASM_FINISH_DECLARE_OBJECT
 142 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 143 do {                                                                     \
 144      const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);             \
 145      HOST_WIDE_INT size;                                                 \
 146      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 147          && ! AT_END && TOP_LEVEL                                        \
 148          && DECL_INITIAL (DECL) == error_mark_node                       \
 149          && !size_directive_output)                                      \
 150        {                                                                 \
 151          size_directive_output = 1;                                      \
 152          size = int_size_in_bytes (TREE_TYPE (DECL));                    \
 153          ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size);                   \
 154        }                                                                 \
 155    } while (0)
 156
 157 #define ASM_OUTPUT_DEF(FILE,LABEL1,LABEL2)                            \
 158  do { fputc ( '\t', FILE);                                            \
 159       assemble_name (FILE, LABEL1);                                   \
 160       fputs ( " = ", FILE);                                           \
 161       assemble_name (FILE, LABEL2);                                   \
 162       fputc ( '\n', FILE);                                            \
 163  } while (0)
 164
 165 /* Note about .weak vs. .weakext
 166    The mips native assemblers support .weakext, but not .weak.
 167    mips-elf gas supports .weak, but not .weakext.
 168    mips-elf gas has been changed to support both .weak and .weakext,
 169    but until that support is generally available, the 'if' below
 170    should serve.  */
 171
 172 #undef ASM_WEAKEN_LABEL
 173 #define ASM_WEAKEN_LABEL(FILE,NAME) ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,0)
 174 #define ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,VALUE)  \
 175  do {                                           \
 176   if (TARGET_GAS)                               \
 177       fputs ("\t.weak\t", FILE);                \
 178   else                                          \
 179       fputs ("\t.weakext\t", FILE);             \
 180   assemble_name (FILE, NAME);                   \
 181   if (VALUE)                                    \
 182     {                                           \
 183       fputc (' ', FILE);                        \
 184       assemble_name (FILE, VALUE);              \
 185     }                                           \
 186   fputc ('\n', FILE);                           \
 187  } while (0)
 188
 189 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 190
 191 #define TARGET_ASM_UNIQUE_SECTION mips_unique_section
 192
 193 /* A list of other sections which the compiler might be "in" at any
 194    given time.  */
 195 #undef EXTRA_SECTIONS
 196 #define EXTRA_SECTIONS in_sdata
 197
 198 #undef EXTRA_SECTION_FUNCTIONS
 199 #define EXTRA_SECTION_FUNCTIONS                                         \
 200   SECTION_FUNCTION_TEMPLATE(sdata_section, in_sdata, SDATA_SECTION_ASM_OP)
 201
 202 #define SECTION_FUNCTION_TEMPLATE(FN, ENUM, OP)                               \
 203 void FN ()                                                            \
 204 {                                                                     \
 205   if (in_section != ENUM)                                             \
 206     {                                                                 \
 207       fprintf (asm_out_file, "%s\n", OP);                             \
 208       in_section = ENUM;                                              \
 209     }                                                                 \
 210 }
 211
 212 /* On elf, we *do* have support for the .init and .fini sections, and we
 213    can put stuff in there to be executed before and after `main'.  We let
 214    crtstuff.c and other files know this by defining the following symbols.
 215    The definitions say how to change sections to the .init and .fini
 216    sections.  This is the same for all known elf assemblers.  */
 217
 218 #undef  INIT_SECTION_ASM_OP
 219 #define INIT_SECTION_ASM_OP     "\t.section\t.init"
 220 #undef  FINI_SECTION_ASM_OP
 221 #define FINI_SECTION_ASM_OP     "\t.section\t.fini"
 222
 223 /* Don't set the target flags, this is done by the linker script */
 224 #undef LIB_SPEC
 225 #define LIB_SPEC ""
 226
 227 #undef  STARTFILE_SPEC
 228 #define STARTFILE_SPEC "crti%O%s crtbegin%O%s %{!mno-crt0:crt0%O%s}"
 229
 230 #undef  ENDFILE_SPEC
 231 #define ENDFILE_SPEC "crtend%O%s crtn%O%s"