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 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_CPP_BUILTINS()         \
  62   do                                     \
  63     {                                    \
  64       builtin_define ("_IBMR2");         \
  65       builtin_define ("_POWER");         \
  66       builtin_define ("_AIX");           \
  67       builtin_define ("_AIX32");         \
  68       builtin_define ("_LONG_LONG");     \
  69       builtin_assert ("system=unix");    \
  70       builtin_assert ("system=aix");     \
  71       builtin_assert ("cpu=rs6000");     \
  72       builtin_assert ("machine=rs6000"); \
  73     }                                    \
  74   while (0)
  75
  76 /* Define appropriate architecture macros for preprocessor depending on
  77    target switches.  */
  78
  79 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
  80    %{ansi: -D_ANSI_C_SOURCE}"
  81
  82 #undef ASM_DEFAULT_SPEC
  83 #define ASM_DEFAULT_SPEC ""
  84
  85 /* Tell the assembler to assume that all undefined names are external.
  86
  87    Don't do this until the fixed IBM assembler is more generally available.
  88    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
  89    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
  90    longer be needed.  Also, the extern declaration of mcount in
  91    rs6000_xcoff_file_start will no longer be needed.  */
  92
  93 /* #define ASM_SPEC "-u %(asm_cpu)" */
  94
  95 /* Default location of syscalls.exp under AIX */
  96 #ifndef CROSS_COMPILE
  97 #define LINK_SYSCALLS_SPEC "-bI:/lib/syscalls.exp"
  98 #else
  99 #define LINK_SYSCALLS_SPEC ""
 100 #endif
 101
 102 /* Default location of libg.exp under AIX */
 103 #ifndef CROSS_COMPILE
 104 #define LINK_LIBG_SPEC "-bexport:/usr/lib/libg.exp"
 105 #else
 106 #define LINK_LIBG_SPEC ""
 107 #endif
 108
 109 /* Define the options for the binder: Start text at 512, align all segments
 110    to 512 bytes, and warn if there is text relocation.
 111
 112    The -bhalt:4 option supposedly changes the level at which ld will abort,
 113    but it also suppresses warnings about multiply defined symbols and is
 114    used by the AIX cc command.  So we use it here.
 115
 116    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 117    csects.  See AIX documentation for more information about this.
 118
 119    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 120    that to actually build a shared library you will also need to specify an
 121    export list with the -Wl,-bE option.  */
 122
 123 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 124 %{static:-bnso %(link_syscalls) } \
 125 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 126
 127 /* Profiled library versions are used by linking with special directories.  */
 128 #define LIB_SPEC "%{pg:-L/lib/profiled -L/usr/lib/profiled}\
 129 %{p:-L/lib/profiled -L/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 130
 131 /* This now supports a natural alignment mode. */
 132 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 133 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 134   (TARGET_ALIGN_NATURAL ? (COMPUTED) : \
 135   (TYPE_MODE (TREE_CODE (TREE_TYPE (FIELD)) == ARRAY_TYPE \
 136               ? get_inner_array_type (FIELD) \
 137               : TREE_TYPE (FIELD)) == DFmode \
 138    ? MIN ((COMPUTED), 32) : (COMPUTED)))
 139
 140 /* AIX increases natural record alignment to doubleword if the first
 141    field is an FP double while the FP fields remain word aligned.  */
 142 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)   \
 143   ((TREE_CODE (STRUCT) == RECORD_TYPE                   \
 144     || TREE_CODE (STRUCT) == UNION_TYPE                 \
 145     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)           \
 146    && TYPE_FIELDS (STRUCT) != 0                         \
 147    && TARGET_ALIGN_NATURAL == 0                         \
 148    && DECL_MODE (TYPE_FIELDS (STRUCT)) == DFmode        \
 149    ? MAX (MAX ((COMPUTED), (SPECIFIED)), 64)            \
 150    : MAX ((COMPUTED), (SPECIFIED)))
 151
 152 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 153    word/doubleword should be padded upward or downward.  One could
 154    reasonably assume that they follow the normal rules for structure
 155    layout treating the parameter area as any other block of memory,
 156    then map the reg param area to registers, i.e., pad upward, which
 157    is the way IBM Compilers for AIX behave.
 158    Setting both of the following defines results in this behavior.  */
 159 #define AGGREGATE_PADDING_FIXED 1
 160 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 161
 162 /* We don't want anything in the reg parm area being passed on the
 163    stack.  */
 164 #define MUST_PASS_IN_STACK(MODE, TYPE)                          \
 165    ((TYPE) != 0                                                 \
 166     && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST             \
 167         || TREE_ADDRESSABLE (TYPE)))
 168
 169 /* Specify padding for the last element of a block move between
 170    registers and memory.  FIRST is nonzero if this is the only
 171    element.  */
 172 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 173   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 174
 175 /* Indicate that jump tables go in the text section.  */
 176
 177 #define JUMP_TABLES_IN_TEXT_SECTION 1
 178
 179 /* Enable AIX XL compiler calling convention breakage compatibility.  */
 180 #undef TARGET_XL_CALL
 181 #define MASK_XL_CALL            0x40000000
 182 #define TARGET_XL_CALL          (target_flags & MASK_XL_CALL)
 183 #undef  SUBTARGET_SWITCHES
 184 #define SUBTARGET_SWITCHES              \
 185   {"xl-call",           MASK_XL_CALL,                                   \
 186    N_("Always pass floating-point arguments in memory") },              \
 187   {"no-xl-call",        - MASK_XL_CALL,                                 \
 188    N_("Don't always pass floating-point arguments in memory") },        \
 189   SUBSUBTARGET_SWITCHES
 190 #define SUBSUBTARGET_SWITCHES
 191
 192 /* Define any extra SPECS that the compiler needs to generate.  */
 193 #undef  SUBTARGET_EXTRA_SPECS
 194 #define SUBTARGET_EXTRA_SPECS                                           \
 195   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 196   { "link_libg",                LINK_LIBG_SPEC }
 197
 198 /* Define cutoff for using external functions to save floating point.  */
 199 #define FP_SAVE_INLINE(FIRST_REG) ((FIRST_REG) == 62 || (FIRST_REG) == 63)
 200
 201 /* __throw will restore its own return address to be the same as the
 202    return address of the function that the throw is being made to.
 203    This is unfortunate, because we want to check the original
 204    return address to see if we need to restore the TOC.
 205    So we have to squirrel it away with this.  */
 206 #define SETUP_FRAME_ADDRESSES() rs6000_aix_emit_builtin_unwind_init ()
 207
 208 /* If the current unwind info (FS) does not contain explicit info
 209    saving R2, then we have to do a minor amount of code reading to
 210    figure out if it was saved.  The big problem here is that the
 211    code that does the save/restore is generated by the linker, so
 212    we have no good way to determine at compile time what to do.  */
 213
 214 #ifdef __powerpc64__
 215 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 216   do {                                                                  \
 217     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 218       {                                                                 \
 219         unsigned int *insn                                              \
 220           = (unsigned int *)                                            \
 221             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 222         if (*insn == 0xE8410028)                                        \
 223           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 40);                 \
 224       }                                                                 \
 225   } while (0)
 226 #else
 227 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)                                 \
 228   do {                                                                  \
 229     if ((FS)->regs.reg[2].how == REG_UNSAVED)                           \
 230       {                                                                 \
 231         unsigned int *insn                                              \
 232           = (unsigned int *)                                            \
 233             _Unwind_GetGR ((CTX), LINK_REGISTER_REGNUM);                \
 234         if (*insn == 0x80410014)                                        \
 235           _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 20);                 \
 236       }                                                                 \
 237   } while (0)
 238 #endif
 239
 240 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 241
 242 /* Print subsidiary information on the compiler version in use.  */
 243 #define TARGET_VERSION ;