gcc/config/rs6000/aix.h

   1 /* Definitions of target machine for GNU compiler,
   2    for IBM RS/6000 POWER running AIX.
   3    Copyright (C) 2000-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published
   9    by the Free Software Foundation; either version 3, or (at your
  10    option) any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GCC; see the file COPYING3.  If not see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 /* Yes!  We are AIX!  */
  22 #define DEFAULT_ABI ABI_AIX
  23 #undef  TARGET_AIX
  24 #define TARGET_AIX 1
  25
  26 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
  27    in the #if conditional in options-default.h, so provide another macro.  */
  28 #undef  TARGET_AIX_OS
  29 #define TARGET_AIX_OS 1
  30
  31 /* AIX always has a TOC.  */
  32 #define TARGET_NO_TOC 0
  33 #define TARGET_TOC 1
  34 #define FIXED_R2 1
  35
  36 /* AIX allows r13 to be used in 32-bit mode.  */
  37 #define FIXED_R13 0
  38
  39 /* 32-bit and 64-bit AIX stack boundary is 128.  */
  40 #undef  STACK_BOUNDARY
  41 #define STACK_BOUNDARY 128
  42
  43 #undef  TARGET_IEEEQUAD
  44 #define TARGET_IEEEQUAD 0
  45
  46 /* The AIX linker will discard static constructors in object files before
  47    collect has a chance to see them, so scan the object files directly.  */
  48 #define COLLECT_EXPORT_LIST
  49
  50 /* On AIX, initialisers specified with -binitfini are called in breadth-first
  51    order.
  52    e.g. if a.out depends on lib1.so, the init function for a.out is called before
  53    the init function for lib1.so.
  54
  55    To ensure global C++ constructors in linked libraries are run before global
  56    C++ constructors from the current module, there is additional symbol scanning
  57    logic in collect2.
  58
  59    The global initialiser/finaliser functions are named __GLOBAL_AIXI_{libname}
  60    and __GLOBAL_AIXD_{libname} and are exported from each shared library.
  61
  62    collect2 will detect these symbols when they exist in shared libraries that
  63    the current program is being linked against.  All such initiliser functions
  64    will be called prior to the constructors of the current program, and
  65    finaliser functions called after destructors.
  66
  67    Reference counting generated by collect2 will ensure that constructors are
  68    only invoked once in the case of multiple dependencies on a library.
  69
  70    -binitfini is still used in parallel to this solution.
  71    This handles the case where a library is loaded through dlopen(), and also
  72    handles the option -blazy.
  73 */
  74 #define COLLECT_SHARED_INIT_FUNC(STREAM, FUNC) \
  75           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_initname, (FUNC))
  76 #define COLLECT_SHARED_FINI_FUNC(STREAM, FUNC) \
  77           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_fininame, (FUNC))
  78
  79 #if HAVE_AS_REF
  80 /* Issue assembly directives that create a reference to the given DWARF table
  81    identifier label from the current function section.  This is defined to
  82    ensure we drag frame frame tables associated with needed function bodies in
  83    a link with garbage collection activated.  */
  84 #define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
  85 #endif
  86
  87 /* This is the only version of nm that collect2 can work with.  */
  88 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
  89
  90 #define USER_LABEL_PREFIX  ""
  91
  92 /* Don't turn -B into -L if the argument specifies a relative file name.  */
  93 #define RELATIVE_PREFIX_NOT_LINKDIR
  94
  95 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
  96 #define LINK_LIBGCC_SPECIAL_1
  97
  98 /* Names to predefine in the preprocessor for this target machine.  */
  99 #define TARGET_OS_AIX_CPP_BUILTINS()            \
 100   do                                            \
 101     {                                           \
 102       builtin_define ("_IBMR2");                \
 103       builtin_define ("_POWER");                \
 104       builtin_define ("__powerpc__");           \
 105       builtin_define ("__PPC__");               \
 106       builtin_define ("__unix__");              \
 107       builtin_define ("_AIX");                  \
 108       builtin_define ("_AIX32");                \
 109       builtin_define ("_AIX41");                \
 110       builtin_define ("_LONG_LONG");            \
 111       if (TARGET_LONG_DOUBLE_128)               \
 112         builtin_define ("__LONGDOUBLE128");     \
 113       builtin_assert ("system=unix");           \
 114       builtin_assert ("system=aix");            \
 115     }                                           \
 116   while (0)
 117
 118 /* Define appropriate architecture macros for preprocessor depending on
 119    target switches.  */
 120
 121 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 122    %{ansi: -D_ANSI_C_SOURCE}"
 123
 124 #define CC1_SPEC "%(cc1_cpu)"
 125
 126 #undef ASM_DEFAULT_SPEC
 127 #define ASM_DEFAULT_SPEC ""
 128
 129 /* Tell the assembler to assume that all undefined names are external.
 130
 131    Don't do this until the fixed IBM assembler is more generally available.
 132    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 133    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 134    longer be needed.  Also, the extern declaration of mcount in
 135    rs6000_xcoff_file_start will no longer be needed.  */
 136
 137 /* #define ASM_SPEC "-u %(asm_cpu)" */
 138
 139 /* Default location of syscalls.exp under AIX */
 140 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
 141
 142 /* Default location of libg.exp under AIX */
 143 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
 144
 145 /* Define the options for the binder: Start text at 512, align all segments
 146    to 512 bytes, and warn if there is text relocation.
 147
 148    The -bhalt:4 option supposedly changes the level at which ld will abort,
 149    but it also suppresses warnings about multiply defined symbols and is
 150    used by the AIX cc command.  So we use it here.
 151
 152    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 153    csects.  See AIX documentation for more information about this.
 154
 155    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 156    that to actually build a shared library you will also need to specify an
 157    export list with the -Wl,-bE option.  */
 158
 159 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 160 %{static:-bnso %(link_syscalls) } \
 161 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 162
 163 /* Profiled library versions are used by linking with special directories.  */
 164 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
 165 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 166
 167 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
 168 #define LIBSTDCXX_STATIC "supc++"
 169
 170 /* This now supports a natural alignment mode.  */
 171 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 172 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 173   ((TARGET_ALIGN_NATURAL == 0                                           \
 174     && TYPE_MODE (strip_array_types (TREE_TYPE (FIELD))) == DFmode)     \
 175    ? MIN ((COMPUTED), 32)                                               \
 176    : (COMPUTED))
 177
 178 /* AIX increases natural record alignment to doubleword if the first
 179    field is an FP double while the FP fields remain word aligned.  */
 180 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 181   ((TREE_CODE (STRUCT) == RECORD_TYPE                                   \
 182     || TREE_CODE (STRUCT) == UNION_TYPE                                 \
 183     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                           \
 184    && TARGET_ALIGN_NATURAL == 0                                         \
 185    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 186    : MAX ((COMPUTED), (SPECIFIED)))
 187
 188 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 189    word/doubleword should be padded upward or downward.  One could
 190    reasonably assume that they follow the normal rules for structure
 191    layout treating the parameter area as any other block of memory,
 192    then map the reg param area to registers, i.e., pad upward, which
 193    is the way IBM Compilers for AIX behave.
 194    Setting both of the following defines results in this behavior.  */
 195 #define AGGREGATE_PADDING_FIXED 1
 196 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 197
 198 /* Specify padding for the last element of a block move between
 199    registers and memory.  FIRST is nonzero if this is the only
 200    element.  */
 201 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 202   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 203
 204 /* Indicate that jump tables go in the text section.  */
 205
 206 #define JUMP_TABLES_IN_TEXT_SECTION 1
 207
 208 /* Define any extra SPECS that the compiler needs to generate.  */
 209 #undef  SUBTARGET_EXTRA_SPECS
 210 #define SUBTARGET_EXTRA_SPECS                                           \
 211   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 212   { "link_libg",                LINK_LIBG_SPEC }
 213
 214 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 215
 216 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 217    32-bit mode.  */
 218 #define OS_MISSING_POWERPC64 1
 219 #define OS_MISSING_ALTIVEC 1
 220
 221 /* WINT_TYPE */
 222 #define WINT_TYPE "int"
 223
 224 /* Static stack checking is supported by means of probes.  */
 225 #define STACK_CHECK_STATIC_BUILTIN 1