gcc/config/rs6000/aix.h

   1 /* Definitions of target machine for GNU compiler,
   2    for IBM RS/6000 POWER running AIX.
   3    Copyright (C) 2000-2021 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 /* System headers are not C++-aware.  */
  27 #define SYSTEM_IMPLICIT_EXTERN_C 1
  28
  29 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
  30    in the #if conditional in options-default.h, so provide another macro.  */
  31 #undef  TARGET_AIX_OS
  32 #define TARGET_AIX_OS 1
  33
  34 /* AIX always has a TOC.  */
  35 #define TARGET_HAS_TOC 1
  36 #define FIXED_R2 1
  37
  38 /* AIX allows r13 to be used in 32-bit mode.  */
  39 #define FIXED_R13 0
  40
  41 /* 32-bit and 64-bit AIX stack boundary is 128.  */
  42 #undef  STACK_BOUNDARY
  43 #define STACK_BOUNDARY 128
  44
  45 /* Offset within stack frame to start allocating local variables at.
  46    If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
  47    first local allocated.  Otherwise, it is the offset to the BEGINNING
  48    of the first local allocated.
  49
  50    On the RS/6000, the frame pointer is the same as the stack pointer,
  51    except for dynamic allocations.  So we start after the fixed area and
  52    outgoing parameter area.
  53
  54    If the function uses dynamic stack space (CALLS_ALLOCA is set), that
  55    space needs to be aligned to STACK_BOUNDARY, i.e. the sum of the
  56    sizes of the fixed area and the parameter area must be a multiple of
  57    STACK_BOUNDARY.  */
  58
  59 #undef RS6000_STARTING_FRAME_OFFSET
  60 #define RS6000_STARTING_FRAME_OFFSET                                    \
  61   (cfun->calls_alloca                                                   \
  62    ? RS6000_ALIGN (crtl->outgoing_args_size + RS6000_SAVE_AREA, 16)     \
  63    : (RS6000_ALIGN (crtl->outgoing_args_size, 16) + RS6000_SAVE_AREA))
  64
  65 /* Offset from the stack pointer register to an item dynamically
  66    allocated on the stack, e.g., by `alloca'.
  67
  68    The default value for this macro is `STACK_POINTER_OFFSET' plus the
  69    length of the outgoing arguments.  The default is correct for most
  70    machines.  See `function.c' for details.
  71
  72    This value must be a multiple of STACK_BOUNDARY (hard coded in
  73    `emit-rtl.c').  */
  74 #undef STACK_DYNAMIC_OFFSET
  75 #define STACK_DYNAMIC_OFFSET(FUNDECL)                                   \
  76    RS6000_ALIGN (crtl->outgoing_args_size.to_constant ()                \
  77                  + STACK_POINTER_OFFSET, 16)
  78
  79 #undef  TARGET_IEEEQUAD
  80 #define TARGET_IEEEQUAD 0
  81
  82 #undef  TARGET_IEEEQUAD_DEFAULT
  83 #define TARGET_IEEEQUAD_DEFAULT 0
  84
  85 /* The AIX linker will discard static constructors in object files before
  86    collect has a chance to see them, so scan the object files directly.  */
  87 #define COLLECT_EXPORT_LIST
  88
  89 /* On AIX, initialisers specified with -binitfini are called in breadth-first
  90    order.
  91    e.g. if a.out depends on lib1.so, the init function for a.out is called before
  92    the init function for lib1.so.
  93
  94    To ensure global C++ constructors in linked libraries are run before global
  95    C++ constructors from the current module, there is additional symbol scanning
  96    logic in collect2.
  97
  98    The global initialiser/finaliser functions are named __GLOBAL_AIXI_{libname}
  99    and __GLOBAL_AIXD_{libname} and are exported from each shared library.
 100
 101    collect2 will detect these symbols when they exist in shared libraries that
 102    the current program is being linked against.  All such initiliser functions
 103    will be called prior to the constructors of the current program, and
 104    finaliser functions called after destructors.
 105
 106    Reference counting generated by collect2 will ensure that constructors are
 107    only invoked once in the case of multiple dependencies on a library.
 108
 109    -binitfini is still used in parallel to this solution.
 110    This handles the case where a library is loaded through dlopen(), and also
 111    handles the option -blazy.
 112 */
 113 #define COLLECT_SHARED_INIT_FUNC(STREAM, FUNC) \
 114           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_initname, (FUNC))
 115 #define COLLECT_SHARED_FINI_FUNC(STREAM, FUNC) \
 116           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_fininame, (FUNC))
 117
 118 #if HAVE_AS_REF
 119 /* Issue assembly directives that create a reference to the given DWARF table
 120    identifier label from the current function section.  This is defined to
 121    ensure we drag frame tables associated with needed function bodies in
 122    a link with garbage collection activated.  */
 123 #define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
 124 #endif
 125
 126 /* This is the only version of nm that collect2 can work with.  */
 127 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
 128
 129 #define USER_LABEL_PREFIX  ""
 130
 131 /* Don't turn -B into -L if the argument specifies a relative file name.  */
 132 #define RELATIVE_PREFIX_NOT_LINKDIR
 133
 134 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
 135 #define LINK_LIBGCC_SPECIAL_1
 136
 137 /* Names to predefine in the preprocessor for this target machine.  */
 138 #define TARGET_OS_AIX_CPP_BUILTINS()            \
 139   do                                            \
 140     {                                           \
 141       builtin_define ("_IBMR2");                \
 142       builtin_define ("_POWER");                \
 143       builtin_define ("__unix__");              \
 144       builtin_define ("_AIX");                  \
 145       builtin_define ("_AIX32");                \
 146       builtin_define ("_AIX41");                \
 147       builtin_define ("_LONG_LONG");            \
 148       if (TARGET_LONG_DOUBLE_128)               \
 149         builtin_define ("__LONGDOUBLE128");     \
 150       builtin_assert ("system=unix");           \
 151       builtin_assert ("system=aix");            \
 152       if (TARGET_64BIT)                         \
 153         {                                       \
 154           builtin_define ("__PPC__");           \
 155           builtin_define ("__PPC64__");         \
 156           builtin_define ("__powerpc__");       \
 157           builtin_define ("__powerpc64__");     \
 158           builtin_assert ("cpu=powerpc64");     \
 159           builtin_assert ("machine=powerpc64"); \
 160         }                                       \
 161       else                                      \
 162         {                                       \
 163           builtin_define ("__PPC__");           \
 164           builtin_define ("__powerpc__");       \
 165           builtin_assert ("cpu=powerpc");       \
 166           builtin_assert ("machine=powerpc");   \
 167         }                                       \
 168     }                                           \
 169   while (0)
 170
 171 /* Define appropriate architecture macros for preprocessor depending on
 172    target switches.  */
 173
 174 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 175    %{ansi: -D_ANSI_C_SOURCE}"
 176
 177 #define CC1_SPEC "%(cc1_cpu)"
 178
 179 #undef ASM_DEFAULT_SPEC
 180 #define ASM_DEFAULT_SPEC ""
 181
 182 /* Tell the assembler to assume that all undefined names are external.
 183
 184    Don't do this until the fixed IBM assembler is more generally available.
 185    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 186    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 187    longer be needed.  Also, the extern declaration of mcount in
 188    rs6000_xcoff_file_start will no longer be needed.  */
 189
 190 /* #define ASM_SPEC "-u %(asm_cpu)" */
 191
 192 /* Default location of syscalls.exp under AIX */
 193 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
 194
 195 /* Default location of libg.exp under AIX */
 196 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
 197
 198 /* Define the options for the binder: Start text at 512, align all segments
 199    to 512 bytes, and warn if there is text relocation.
 200
 201    The -bhalt:4 option supposedly changes the level at which ld will abort,
 202    but it also suppresses warnings about multiply defined symbols and is
 203    used by the AIX cc command.  So we use it here.
 204
 205    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 206    csects.  See AIX documentation for more information about this.
 207
 208    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 209    that to actually build a shared library you will also need to specify an
 210    export list with the -Wl,-bE option.  */
 211
 212 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 213 %{static:-bnso %(link_syscalls) } \
 214 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 215
 216 /* Profiled library versions are used by linking with special directories.  */
 217 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
 218 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 219
 220 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
 221 #define LIBSTDCXX_STATIC "supc++"
 222
 223 /* This now supports a natural alignment mode.  */
 224 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 225 #define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED) \
 226   (TARGET_ALIGN_NATURAL == 0                                            \
 227    ? rs6000_special_adjust_field_align (TYPE, COMPUTED)                 \
 228    : (COMPUTED))
 229
 230 /* AIX increases natural record alignment to doubleword if the first
 231    field is an FP double while the FP fields remain word aligned.  */
 232 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 233   ((TREE_CODE (STRUCT) == RECORD_TYPE                                   \
 234     || TREE_CODE (STRUCT) == UNION_TYPE                                 \
 235     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                           \
 236    && TARGET_ALIGN_NATURAL == 0                                         \
 237    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 238    : MAX ((COMPUTED), (SPECIFIED)))
 239
 240 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 241    word/doubleword should be padded upward or downward.  One could
 242    reasonably assume that they follow the normal rules for structure
 243    layout treating the parameter area as any other block of memory,
 244    then map the reg param area to registers, i.e., pad upward, which
 245    is the way IBM Compilers for AIX behave.
 246    Setting both of the following defines results in this behavior.  */
 247 #define AGGREGATE_PADDING_FIXED 1
 248 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 249
 250 /* Specify padding for the last element of a block move between
 251    registers and memory.  FIRST is nonzero if this is the only
 252    element.  */
 253 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 254   (!(FIRST) ? PAD_UPWARD : targetm.calls.function_arg_padding (MODE, TYPE))
 255
 256 /* Indicate that jump tables go in the text section.  */
 257
 258 #define JUMP_TABLES_IN_TEXT_SECTION 1
 259
 260 /* Define any extra SPECS that the compiler needs to generate.  */
 261 #undef  SUBTARGET_EXTRA_SPECS
 262 #define SUBTARGET_EXTRA_SPECS                                           \
 263   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 264   { "link_libg",                LINK_LIBG_SPEC }
 265
 266 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 267
 268 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 269    32-bit mode.  */
 270 #define OS_MISSING_POWERPC64 1
 271 #define OS_MISSING_ALTIVEC 1
 272
 273 /* WINT_TYPE */
 274 #define WINT_TYPE "int"
 275
 276 /* Static stack checking is supported by means of probes.  */
 277 #define STACK_CHECK_STATIC_BUILTIN 1
 278
 279 /* Use standard DWARF numbering for DWARF debugging information.  */
 280 #define RS6000_USE_DWARF_NUMBERING
 281
 282 #define TARGET_PRECOMPUTE_TLS_P rs6000_aix_precompute_tls_p
 283
 284 /* Replace -m64 with -maix64 and -m32 with -maix32.  */
 285 #undef SUBTARGET_DRIVER_SELF_SPECS
 286 #define SUBTARGET_DRIVER_SELF_SPECS     \
 287 "%{m64:-maix64} %<m64",                 \
 288 "%{m32:-maix32} %<m32"