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, 2001, 2002, 2003, 2004 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 2, 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 COPYING.  If not, write to the
  19    Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  20    MA 02111-1307, USA.  */
  21
  22 /* Yes!  We are AIX!  */
  23 #define DEFAULT_ABI ABI_AIX
  24 #undef  TARGET_AIX
  25 #define TARGET_AIX 1
  26
  27 /* AIX always has a TOC.  */
  28 #define TARGET_NO_TOC 0
  29 #define TARGET_TOC 1
  30 #define FIXED_R2 1
  31
  32 /* AIX allows r13 to be used in 32-bit mode.  */
  33 #define FIXED_R13 0
  34
  35 /* AIX does not support Altivec.  */
  36 #undef  TARGET_ALTIVEC
  37 #define TARGET_ALTIVEC 0
  38 #undef  TARGET_ALTIVEC_ABI
  39 #define TARGET_ALTIVEC_ABI 0
  40 #undef  TARGET_ALTIVEC_VRSAVE
  41 #define TARGET_ALTIVEC_VRSAVE 0
  42
  43 /* The AIX linker will discard static constructors in object files before
  44    collect has a chance to see them, so scan the object files directly.  */
  45 #define COLLECT_EXPORT_LIST
  46
  47 /* Handle #pragma weak and #pragma pack.  */
  48 #define HANDLE_SYSV_PRAGMA 1
  49
  50 /* This is the only version of nm that collect2 can work with.  */
  51 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
  52
  53 #define USER_LABEL_PREFIX  ""
  54
  55 /* Don't turn -B into -L if the argument specifies a relative file name.  */
  56 #define RELATIVE_PREFIX_NOT_LINKDIR
  57
  58 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
  59 #define LINK_LIBGCC_SPECIAL_1
  60
  61 #define MFWRAP_SPEC " %{static: %{fmudflap|fmudflapth: \
  62  -brename:malloc,__wrap_malloc -brename:__real_malloc,malloc \
  63  -brename:free,__wrap_free -brename:__real_free,free \
  64  -brename:calloc,__wrap_calloc -brename:__real_calloc,calloc \
  65  -brename:realloc,__wrap_realloc -brename:__real_realloc,realloc \
  66  -brename:mmap,__wrap_mmap -brename:__real_mmap,mmap \
  67  -brename:munmap,__wrap_munmap -brename:__real_munmap,munmap \
  68  -brename:alloca,__wrap_alloca -brename:__real_alloca,alloca \
  69 } %{fmudflapth: \
  70  -brename:pthread_create,__wrap_pthread_create \
  71  -brename:__real_pthread_create,pthread_create \
  72  -brename:pthread_join,__wrap_pthread_join \
  73  -brename:__real_pthread_join,pthread_join \
  74  -brename:pthread_exit,__wrap_pthread_exit \
  75  -brename:__real_pthread_exit,pthread_exit \
  76 }} %{fmudflap|fmudflapth: \
  77  -brename:main,__wrap_main -brename:__real_main,main \
  78 }"
  79
  80 #define MFLIB_SPEC " %{fmudflap: -lmudflap \
  81  %{static:%(link_gcc_c_sequence) -lmudflap}} \
  82  %{fmudflapth: -lmudflapth -lpthread \
  83  %{static:%(link_gcc_c_sequence) -lmudflapth}} "
  84
  85 /* Names to predefine in the preprocessor for this target machine.  */
  86 #define TARGET_OS_AIX_CPP_BUILTINS()            \
  87   do                                            \
  88     {                                           \
  89       builtin_define ("_IBMR2");                \
  90       builtin_define ("_POWER");                \
  91       builtin_define ("_AIX");                  \
  92       builtin_define ("_AIX32");                \
  93       builtin_define ("_AIX41");                \
  94       builtin_define ("_LONG_LONG");            \
  95       if (TARGET_LONG_DOUBLE_128)               \
  96         builtin_define ("__LONGDOUBLE128");     \
  97       builtin_assert ("system=unix");           \
  98       builtin_assert ("system=aix");            \
  99     }                                           \
 100   while (0)
 101
 102 /* Define appropriate architecture macros for preprocessor depending on
 103    target switches.  */
 104
 105 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 106    %{ansi: -D_ANSI_C_SOURCE}"
 107
 108 #undef ASM_DEFAULT_SPEC
 109 #define ASM_DEFAULT_SPEC ""
 110
 111 /* Tell the assembler to assume that all undefined names are external.
 112
 113    Don't do this until the fixed IBM assembler is more generally available.
 114    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 115    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 116    longer be needed.  Also, the extern declaration of mcount in
 117    rs6000_xcoff_file_start will no longer be needed.  */
 118
 119 /* #define ASM_SPEC "-u %(asm_cpu)" */
 120
 121 /* Default location of syscalls.exp under AIX */
 122 #ifndef CROSS_COMPILE
 123 #define LINK_SYSCALLS_SPEC "-bI:/lib/syscalls.exp"
 124 #else
 125 #define LINK_SYSCALLS_SPEC ""
 126 #endif
 127
 128 /* Default location of libg.exp under AIX */
 129 #ifndef CROSS_COMPILE
 130 #define LINK_LIBG_SPEC "-bexport:/usr/lib/libg.exp"
 131 #else
 132 #define LINK_LIBG_SPEC ""
 133 #endif
 134
 135 /* Define the options for the binder: Start text at 512, align all segments
 136    to 512 bytes, and warn if there is text relocation.
 137
 138    The -bhalt:4 option supposedly changes the level at which ld will abort,
 139    but it also suppresses warnings about multiply defined symbols and is
 140    used by the AIX cc command.  So we use it here.
 141
 142    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 143    csects.  See AIX documentation for more information about this.
 144
 145    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 146    that to actually build a shared library you will also need to specify an
 147    export list with the -Wl,-bE option.  */
 148
 149 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 150 %{static:-bnso %(link_syscalls) } \
 151 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 152
 153 /* Profiled library versions are used by linking with special directories.  */
 154 #define LIB_SPEC "%{pg:-L/lib/profiled -L/usr/lib/profiled}\
 155 %{p:-L/lib/profiled -L/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 156
 157 /* This now supports a natural alignment mode.  */
 158 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 159 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 160   (TARGET_ALIGN_NATURAL ? (COMPUTED) : \
 161   (TYPE_MODE (TREE_CODE (TREE_TYPE (FIELD)) == ARRAY_TYPE \
 162               ? get_inner_array_type (FIELD) \
 163               : TREE_TYPE (FIELD)) == DFmode \
 164    ? MIN ((COMPUTED), 32) : (COMPUTED)))
 165
 166 /* AIX increases natural record alignment to doubleword if the first
 167    field is an FP double while the FP fields remain word aligned.  */
 168 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                           \
 169   ((TREE_CODE (STRUCT) == RECORD_TYPE                                           \
 170     || TREE_CODE (STRUCT) == UNION_TYPE                                         \
 171     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                                   \
 172    && TARGET_ALIGN_NATURAL == 0                                                 \
 173    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)              \
 174    : MAX ((COMPUTED), (SPECIFIED)))
 175
 176 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 177    word/doubleword should be padded upward or downward.  One could
 178    reasonably assume that they follow the normal rules for structure
 179    layout treating the parameter area as any other block of memory,
 180    then map the reg param area to registers, i.e., pad upward, which
 181    is the way IBM Compilers for AIX behave.
 182    Setting both of the following defines results in this behavior.  */
 183 #define AGGREGATE_PADDING_FIXED 1
 184 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 185
 186 /* Specify padding for the last element of a block move between
 187    registers and memory.  FIRST is nonzero if this is the only
 188    element.  */
 189 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 190   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 191
 192 /* Indicate that jump tables go in the text section.  */
 193
 194 #define JUMP_TABLES_IN_TEXT_SECTION 1
 195
 196 /* Enable AIX XL compiler calling convention breakage compatibility.  */
 197 #undef TARGET_XL_CALL
 198 #define MASK_XL_CALL            0x40000000
 199 #define TARGET_XL_CALL          (target_flags & MASK_XL_CALL)
 200 #undef  SUBTARGET_SWITCHES
 201 #define SUBTARGET_SWITCHES              \
 202   {"xl-call",           MASK_XL_CALL,                                   \
 203    N_("Always pass floating-point arguments in memory") },              \
 204   {"no-xl-call",        - MASK_XL_CALL,                                 \
 205    N_("Don't always pass floating-point arguments in memory") },        \
 206   SUBSUBTARGET_SWITCHES
 207 #define SUBSUBTARGET_SWITCHES
 208
 209 /* Define any extra SPECS that the compiler needs to generate.  */
 210 #undef  SUBTARGET_EXTRA_SPECS
 211 #define SUBTARGET_EXTRA_SPECS                                           \
 212   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 213   { "link_libg",                LINK_LIBG_SPEC }
 214
 215 /* Define cutoff for using external functions to save floating point.  */
 216 #define FP_SAVE_INLINE(FIRST_REG) ((FIRST_REG) == 62 || (FIRST_REG) == 63)
 217
 218 /* __throw will restore its own return address to be the same as the
 219    return address of the function that the throw is being made to.
 220    This is unfortunate, because we want to check the original
 221    return address to see if we need to restore the TOC.
 222    So we have to squirrel it away with this.  */
 223 #define SETUP_FRAME_ADDRESSES() rs6000_aix_emit_builtin_unwind_init ()
 224
 225 /* If the current unwind info (FS) does not contain explicit info
 226    saving R2, then we have to do a minor amount of code reading to
 227    figure out if it was saved.  The big problem here is that the
 228    code that does the save/restore is generated by the linker, so
 229    we have no good way to determine at compile time what to do.  */
 230
 231 #ifdef __64BIT__
 232 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 233   do {                                                                  \
 234     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 235       {                                                                 \
 236         unsigned int *insn                                              \
 237           = (unsigned int *)                                            \
 238             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 239         if (*insn == 0xE8410028)                                        \
 240           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 40);                 \
 241       }                                                                 \
 242   } while (0)
 243 #else
 244 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 245   do {                                                                  \
 246     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 247       {                                                                 \
 248         unsigned int *insn                                              \
 249           = (unsigned int *)                                            \
 250             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 251         if (*insn == 0x80410014)                                        \
 252           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 20);                 \
 253       }                                                                 \
 254   } while (0)
 255 #endif
 256
 257 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 258
 259 /* Print subsidiary information on the compiler version in use.  */
 260 #define TARGET_VERSION ;
 261
 262 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 263    32-bit mode.  */
 264 #define OS_MISSING_POWERPC64 1
 265 #define OS_MISSING_ALTIVEC 1