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 /* Don't turn -B into -L if the argument specifies a relative file name.  */
  55 #define RELATIVE_PREFIX_NOT_LINKDIR
  56
  57 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
  58 #define LINK_LIBGCC_SPECIAL_1
  59
  60 /* Names to predefine in the preprocessor for this target machine.  */
  61 #define TARGET_OS_AIX_CPP_BUILTINS()            \
  62   do                                            \
  63     {                                           \
  64       builtin_define ("_IBMR2");                \
  65       builtin_define ("_POWER");                \
  66       builtin_define ("_AIX");                  \
  67       builtin_define ("_AIX32");                \
  68       builtin_define ("_AIX41");                \
  69       builtin_define ("_LONG_LONG");            \
  70       if (TARGET_LONG_DOUBLE_128)               \
  71         builtin_define ("__LONGDOUBLE128");     \
  72       builtin_assert ("system=unix");           \
  73       builtin_assert ("system=aix");            \
  74     }                                           \
  75   while (0)
  76
  77 /* Define appropriate architecture macros for preprocessor depending on
  78    target switches.  */
  79
  80 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
  81    %{ansi: -D_ANSI_C_SOURCE}"
  82
  83 #undef ASM_DEFAULT_SPEC
  84 #define ASM_DEFAULT_SPEC ""
  85
  86 /* Tell the assembler to assume that all undefined names are external.
  87
  88    Don't do this until the fixed IBM assembler is more generally available.
  89    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
  90    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
  91    longer be needed.  Also, the extern declaration of mcount in
  92    rs6000_xcoff_file_start will no longer be needed.  */
  93
  94 /* #define ASM_SPEC "-u %(asm_cpu)" */
  95
  96 /* Default location of syscalls.exp under AIX */
  97 #ifndef CROSS_COMPILE
  98 #define LINK_SYSCALLS_SPEC "-bI:/lib/syscalls.exp"
  99 #else
 100 #define LINK_SYSCALLS_SPEC ""
 101 #endif
 102
 103 /* Default location of libg.exp under AIX */
 104 #ifndef CROSS_COMPILE
 105 #define LINK_LIBG_SPEC "-bexport:/usr/lib/libg.exp"
 106 #else
 107 #define LINK_LIBG_SPEC ""
 108 #endif
 109
 110 /* Define the options for the binder: Start text at 512, align all segments
 111    to 512 bytes, and warn if there is text relocation.
 112
 113    The -bhalt:4 option supposedly changes the level at which ld will abort,
 114    but it also suppresses warnings about multiply defined symbols and is
 115    used by the AIX cc command.  So we use it here.
 116
 117    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 118    csects.  See AIX documentation for more information about this.
 119
 120    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 121    that to actually build a shared library you will also need to specify an
 122    export list with the -Wl,-bE option.  */
 123
 124 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 125 %{static:-bnso %(link_syscalls) } \
 126 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 127
 128 /* Profiled library versions are used by linking with special directories.  */
 129 #define LIB_SPEC "%{pg:-L/lib/profiled -L/usr/lib/profiled}\
 130 %{p:-L/lib/profiled -L/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 131
 132 /* This now supports a natural alignment mode.  */
 133 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 134 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 135   (TARGET_ALIGN_NATURAL ? (COMPUTED) : \
 136   (TYPE_MODE (TREE_CODE (TREE_TYPE (FIELD)) == ARRAY_TYPE \
 137               ? get_inner_array_type (FIELD) \
 138               : TREE_TYPE (FIELD)) == DFmode \
 139    ? MIN ((COMPUTED), 32) : (COMPUTED)))
 140
 141 /* AIX increases natural record alignment to doubleword if the first
 142    field is an FP double while the FP fields remain word aligned.  */
 143 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                           \
 144   ((TREE_CODE (STRUCT) == RECORD_TYPE                                           \
 145     || TREE_CODE (STRUCT) == UNION_TYPE                                         \
 146     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                                   \
 147    && TARGET_ALIGN_NATURAL == 0                                                 \
 148    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)              \
 149    : MAX ((COMPUTED), (SPECIFIED)))
 150
 151 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 152    word/doubleword should be padded upward or downward.  One could
 153    reasonably assume that they follow the normal rules for structure
 154    layout treating the parameter area as any other block of memory,
 155    then map the reg param area to registers, i.e., pad upward, which
 156    is the way IBM Compilers for AIX behave.
 157    Setting both of the following defines results in this behavior.  */
 158 #define AGGREGATE_PADDING_FIXED 1
 159 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 160
 161 /* We don't want anything in the reg parm area being passed on the
 162    stack.  */
 163 #define MUST_PASS_IN_STACK(MODE, TYPE)                          \
 164    ((TYPE) != 0                                                 \
 165     && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST             \
 166         || TREE_ADDRESSABLE (TYPE)))
 167
 168 /* Specify padding for the last element of a block move between
 169    registers and memory.  FIRST is nonzero if this is the only
 170    element.  */
 171 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 172   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 173
 174 /* Indicate that jump tables go in the text section.  */
 175
 176 #define JUMP_TABLES_IN_TEXT_SECTION 1
 177
 178 /* Enable AIX XL compiler calling convention breakage compatibility.  */
 179 #undef TARGET_XL_CALL
 180 #define MASK_XL_CALL            0x40000000
 181 #define TARGET_XL_CALL          (target_flags & MASK_XL_CALL)
 182 #undef  SUBTARGET_SWITCHES
 183 #define SUBTARGET_SWITCHES              \
 184   {"xl-call",           MASK_XL_CALL,                                   \
 185    N_("Always pass floating-point arguments in memory") },              \
 186   {"no-xl-call",        - MASK_XL_CALL,                                 \
 187    N_("Don't always pass floating-point arguments in memory") },        \
 188   SUBSUBTARGET_SWITCHES
 189 #define SUBSUBTARGET_SWITCHES
 190
 191 /* Define any extra SPECS that the compiler needs to generate.  */
 192 #undef  SUBTARGET_EXTRA_SPECS
 193 #define SUBTARGET_EXTRA_SPECS                                           \
 194   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 195   { "link_libg",                LINK_LIBG_SPEC }
 196
 197 /* Define cutoff for using external functions to save floating point.  */
 198 #define FP_SAVE_INLINE(FIRST_REG) ((FIRST_REG) == 62 || (FIRST_REG) == 63)
 199
 200 /* __throw will restore its own return address to be the same as the
 201    return address of the function that the throw is being made to.
 202    This is unfortunate, because we want to check the original
 203    return address to see if we need to restore the TOC.
 204    So we have to squirrel it away with this.  */
 205 #define SETUP_FRAME_ADDRESSES() rs6000_aix_emit_builtin_unwind_init ()
 206
 207 /* If the current unwind info (FS) does not contain explicit info
 208    saving R2, then we have to do a minor amount of code reading to
 209    figure out if it was saved.  The big problem here is that the
 210    code that does the save/restore is generated by the linker, so
 211    we have no good way to determine at compile time what to do.  */
 212
 213 #ifdef __powerpc64__
 214 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 215   do {                                                                  \
 216     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 217       {                                                                 \
 218         unsigned int *insn                                              \
 219           = (unsigned int *)                                            \
 220             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 221         if (*insn == 0xE8410028)                                        \
 222           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 40);                 \
 223       }                                                                 \
 224   } while (0)
 225 #else
 226 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 227   do {                                                                  \
 228     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 229       {                                                                 \
 230         unsigned int *insn                                              \
 231           = (unsigned int *)                                            \
 232             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 233         if (*insn == 0x80410014)                                        \
 234           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 20);                 \
 235       }                                                                 \
 236   } while (0)
 237 #endif
 238
 239 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 240
 241 /* Print subsidiary information on the compiler version in use.  */
 242 #define TARGET_VERSION ;
 243
 244 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 245    32-bit mode.  */
 246 #define OS_MISSING_POWERPC64 1
 247 #define OS_MISSING_ALTIVEC 1