gcc/config/rs6000/aix.h

   1 /* Definitions of target machine for GNU compiler,
   2    for IBM RS/6000 POWER running AIX.
   3    Copyright (C) 2000-2016 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 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 ("__unix__");              \
 105       builtin_define ("_AIX");                  \
 106       builtin_define ("_AIX32");                \
 107       builtin_define ("_AIX41");                \
 108       builtin_define ("_LONG_LONG");            \
 109       if (TARGET_LONG_DOUBLE_128)               \
 110         builtin_define ("__LONGDOUBLE128");     \
 111       builtin_assert ("system=unix");           \
 112       builtin_assert ("system=aix");            \
 113       if (TARGET_64BIT)                         \
 114         {                                       \
 115           builtin_define ("__PPC__");           \
 116           builtin_define ("__PPC64__");         \
 117           builtin_define ("__powerpc__");       \
 118           builtin_define ("__powerpc64__");     \
 119           builtin_assert ("cpu=powerpc64");     \
 120           builtin_assert ("machine=powerpc64"); \
 121         }                                       \
 122       else                                      \
 123         {                                       \
 124           builtin_define ("__PPC__");           \
 125           builtin_define ("__powerpc__");       \
 126           builtin_assert ("cpu=powerpc");       \
 127           builtin_assert ("machine=powerpc");   \
 128         }                                       \
 129     }                                           \
 130   while (0)
 131
 132 /* Define appropriate architecture macros for preprocessor depending on
 133    target switches.  */
 134
 135 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 136    %{ansi: -D_ANSI_C_SOURCE}"
 137
 138 #define CC1_SPEC "%(cc1_cpu)"
 139
 140 #undef ASM_DEFAULT_SPEC
 141 #define ASM_DEFAULT_SPEC ""
 142
 143 /* Tell the assembler to assume that all undefined names are external.
 144
 145    Don't do this until the fixed IBM assembler is more generally available.
 146    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 147    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 148    longer be needed.  Also, the extern declaration of mcount in
 149    rs6000_xcoff_file_start will no longer be needed.  */
 150
 151 /* #define ASM_SPEC "-u %(asm_cpu)" */
 152
 153 /* Default location of syscalls.exp under AIX */
 154 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
 155
 156 /* Default location of libg.exp under AIX */
 157 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
 158
 159 /* Define the options for the binder: Start text at 512, align all segments
 160    to 512 bytes, and warn if there is text relocation.
 161
 162    The -bhalt:4 option supposedly changes the level at which ld will abort,
 163    but it also suppresses warnings about multiply defined symbols and is
 164    used by the AIX cc command.  So we use it here.
 165
 166    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 167    csects.  See AIX documentation for more information about this.
 168
 169    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 170    that to actually build a shared library you will also need to specify an
 171    export list with the -Wl,-bE option.  */
 172
 173 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 174 %{static:-bnso %(link_syscalls) } \
 175 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 176
 177 /* Profiled library versions are used by linking with special directories.  */
 178 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
 179 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 180
 181 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
 182 #define LIBSTDCXX_STATIC "supc++"
 183
 184 /* This now supports a natural alignment mode.  */
 185 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 186 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 187   ((TARGET_ALIGN_NATURAL == 0                                           \
 188     && TYPE_MODE (strip_array_types (TREE_TYPE (FIELD))) == DFmode)     \
 189    ? MIN ((COMPUTED), 32)                                               \
 190    : (COMPUTED))
 191
 192 /* AIX increases natural record alignment to doubleword if the first
 193    field is an FP double while the FP fields remain word aligned.  */
 194 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 195   ((TREE_CODE (STRUCT) == RECORD_TYPE                                   \
 196     || TREE_CODE (STRUCT) == UNION_TYPE                                 \
 197     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                           \
 198    && TARGET_ALIGN_NATURAL == 0                                         \
 199    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 200    : MAX ((COMPUTED), (SPECIFIED)))
 201
 202 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 203    word/doubleword should be padded upward or downward.  One could
 204    reasonably assume that they follow the normal rules for structure
 205    layout treating the parameter area as any other block of memory,
 206    then map the reg param area to registers, i.e., pad upward, which
 207    is the way IBM Compilers for AIX behave.
 208    Setting both of the following defines results in this behavior.  */
 209 #define AGGREGATE_PADDING_FIXED 1
 210 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 211
 212 /* Specify padding for the last element of a block move between
 213    registers and memory.  FIRST is nonzero if this is the only
 214    element.  */
 215 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 216   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 217
 218 /* Indicate that jump tables go in the text section.  */
 219
 220 #define JUMP_TABLES_IN_TEXT_SECTION 1
 221
 222 /* Define any extra SPECS that the compiler needs to generate.  */
 223 #undef  SUBTARGET_EXTRA_SPECS
 224 #define SUBTARGET_EXTRA_SPECS                                           \
 225   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 226   { "link_libg",                LINK_LIBG_SPEC }
 227
 228 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 229
 230 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 231    32-bit mode.  */
 232 #define OS_MISSING_POWERPC64 1
 233 #define OS_MISSING_ALTIVEC 1
 234
 235 /* WINT_TYPE */
 236 #define WINT_TYPE "int"
 237
 238 /* Static stack checking is supported by means of probes.  */
 239 #define STACK_CHECK_STATIC_BUILTIN 1
 240
 241 /* Use standard DWARF numbering for DWARF debugging information.  */
 242 #define RS6000_USE_DWARF_NUMBERING
 243