gcc/config/rs6000/aix.h

   1 // SPDX-License-Identifier: GPL-3.0-or-later
   2 /* Definitions of target machine for GNU compiler,
   3    for IBM RS/6000 POWER running AIX.
   4    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   5
   6    This file is part of GCC.
   7
   8    GCC is free software; you can redistribute it and/or modify it
   9    under the terms of the GNU General Public License as published
  10    by the Free Software Foundation; either version 3, or (at your
  11    option) any later version.
  12
  13    GCC is distributed in the hope that it will be useful, but WITHOUT
  14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  16    License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GCC; see the file COPYING3.  If not see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 /* Yes!  We are AIX!  */
  23 #define DEFAULT_ABI ABI_AIX
  24 #undef  TARGET_AIX
  25 #define TARGET_AIX 1
  26
  27 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
  28    in the #if conditional in options-default.h, so provide another macro.  */
  29 #undef  TARGET_AIX_OS
  30 #define TARGET_AIX_OS 1
  31
  32 /* AIX always has a TOC.  */
  33 #define TARGET_HAS_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 /* Offset within stack frame to start allocating local variables at.
  44    If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
  45    first local allocated.  Otherwise, it is the offset to the BEGINNING
  46    of the first local allocated.
  47
  48    On the RS/6000, the frame pointer is the same as the stack pointer,
  49    except for dynamic allocations.  So we start after the fixed area and
  50    outgoing parameter area.
  51
  52    If the function uses dynamic stack space (CALLS_ALLOCA is set), that
  53    space needs to be aligned to STACK_BOUNDARY, i.e. the sum of the
  54    sizes of the fixed area and the parameter area must be a multiple of
  55    STACK_BOUNDARY.  */
  56
  57 #undef RS6000_STARTING_FRAME_OFFSET
  58 #define RS6000_STARTING_FRAME_OFFSET                                    \
  59   (cfun->calls_alloca                                                   \
  60    ? RS6000_ALIGN (crtl->outgoing_args_size + RS6000_SAVE_AREA, 16)     \
  61    : (RS6000_ALIGN (crtl->outgoing_args_size, 16) + RS6000_SAVE_AREA))
  62
  63 /* Offset from the stack pointer register to an item dynamically
  64    allocated on the stack, e.g., by `alloca'.
  65
  66    The default value for this macro is `STACK_POINTER_OFFSET' plus the
  67    length of the outgoing arguments.  The default is correct for most
  68    machines.  See `function.c' for details.
  69
  70    This value must be a multiple of STACK_BOUNDARY (hard coded in
  71    `emit-rtl.c').  */
  72 #undef STACK_DYNAMIC_OFFSET
  73 #define STACK_DYNAMIC_OFFSET(FUNDECL)                                   \
  74    RS6000_ALIGN (crtl->outgoing_args_size.to_constant ()                \
  75                  + STACK_POINTER_OFFSET, 16)
  76
  77 #undef  TARGET_IEEEQUAD
  78 #define TARGET_IEEEQUAD 0
  79
  80 #undef  TARGET_IEEEQUAD_DEFAULT
  81 #define TARGET_IEEEQUAD_DEFAULT 0
  82
  83 /* The AIX linker will discard static constructors in object files before
  84    collect has a chance to see them, so scan the object files directly.  */
  85 #define COLLECT_EXPORT_LIST
  86
  87 /* On AIX, initialisers specified with -binitfini are called in breadth-first
  88    order.
  89    e.g. if a.out depends on lib1.so, the init function for a.out is called before
  90    the init function for lib1.so.
  91
  92    To ensure global C++ constructors in linked libraries are run before global
  93    C++ constructors from the current module, there is additional symbol scanning
  94    logic in collect2.
  95
  96    The global initialiser/finaliser functions are named __GLOBAL_AIXI_{libname}
  97    and __GLOBAL_AIXD_{libname} and are exported from each shared library.
  98
  99    collect2 will detect these symbols when they exist in shared libraries that
 100    the current program is being linked against.  All such initiliser functions
 101    will be called prior to the constructors of the current program, and
 102    finaliser functions called after destructors.
 103
 104    Reference counting generated by collect2 will ensure that constructors are
 105    only invoked once in the case of multiple dependencies on a library.
 106
 107    -binitfini is still used in parallel to this solution.
 108    This handles the case where a library is loaded through dlopen(), and also
 109    handles the option -blazy.
 110 */
 111 #define COLLECT_SHARED_INIT_FUNC(STREAM, FUNC) \
 112           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_initname, (FUNC))
 113 #define COLLECT_SHARED_FINI_FUNC(STREAM, FUNC) \
 114           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_fininame, (FUNC))
 115
 116 #if HAVE_AS_REF
 117 /* Issue assembly directives that create a reference to the given DWARF table
 118    identifier label from the current function section.  This is defined to
 119    ensure we drag frame tables associated with needed function bodies in
 120    a link with garbage collection activated.  */
 121 #define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
 122 #endif
 123
 124 /* This is the only version of nm that collect2 can work with.  */
 125 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
 126
 127 #define USER_LABEL_PREFIX  ""
 128
 129 /* Don't turn -B into -L if the argument specifies a relative file name.  */
 130 #define RELATIVE_PREFIX_NOT_LINKDIR
 131
 132 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
 133 #define LINK_LIBGCC_SPECIAL_1
 134
 135 /* Names to predefine in the preprocessor for this target machine.  */
 136 #define TARGET_OS_AIX_CPP_BUILTINS()            \
 137   do                                            \
 138     {                                           \
 139       builtin_define ("_IBMR2");                \
 140       builtin_define ("_POWER");                \
 141       builtin_define ("__unix__");              \
 142       builtin_define ("_AIX");                  \
 143       builtin_define ("_AIX32");                \
 144       builtin_define ("_AIX41");                \
 145       builtin_define ("_LONG_LONG");            \
 146       if (TARGET_LONG_DOUBLE_128)               \
 147         builtin_define ("__LONGDOUBLE128");     \
 148       builtin_assert ("system=unix");           \
 149       builtin_assert ("system=aix");            \
 150       if (TARGET_64BIT)                         \
 151         {                                       \
 152           builtin_define ("__PPC__");           \
 153           builtin_define ("__PPC64__");         \
 154           builtin_define ("__powerpc__");       \
 155           builtin_define ("__powerpc64__");     \
 156           builtin_assert ("cpu=powerpc64");     \
 157           builtin_assert ("machine=powerpc64"); \
 158         }                                       \
 159       else                                      \
 160         {                                       \
 161           builtin_define ("__PPC__");           \
 162           builtin_define ("__powerpc__");       \
 163           builtin_assert ("cpu=powerpc");       \
 164           builtin_assert ("machine=powerpc");   \
 165         }                                       \
 166     }                                           \
 167   while (0)
 168
 169 /* Define appropriate architecture macros for preprocessor depending on
 170    target switches.  */
 171
 172 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 173    %{ansi: -D_ANSI_C_SOURCE}"
 174
 175 #define CC1_SPEC "%(cc1_cpu)"
 176
 177 #undef ASM_DEFAULT_SPEC
 178 #define ASM_DEFAULT_SPEC ""
 179
 180 /* Tell the assembler to assume that all undefined names are external.
 181
 182    Don't do this until the fixed IBM assembler is more generally available.
 183    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 184    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 185    longer be needed.  Also, the extern declaration of mcount in
 186    rs6000_xcoff_file_start will no longer be needed.  */
 187
 188 /* #define ASM_SPEC "-u %(asm_cpu)" */
 189
 190 /* Default location of syscalls.exp under AIX */
 191 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
 192
 193 /* Default location of libg.exp under AIX */
 194 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
 195
 196 /* Define the options for the binder: Start text at 512, align all segments
 197    to 512 bytes, and warn if there is text relocation.
 198
 199    The -bhalt:4 option supposedly changes the level at which ld will abort,
 200    but it also suppresses warnings about multiply defined symbols and is
 201    used by the AIX cc command.  So we use it here.
 202
 203    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 204    csects.  See AIX documentation for more information about this.
 205
 206    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 207    that to actually build a shared library you will also need to specify an
 208    export list with the -Wl,-bE option.  */
 209
 210 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 211 %{static:-bnso %(link_syscalls) } \
 212 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 213
 214 /* Profiled library versions are used by linking with special directories.  */
 215 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
 216 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 217
 218 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
 219 #define LIBSTDCXX_STATIC "supc++"
 220
 221 /* This now supports a natural alignment mode.  */
 222 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 223 #define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED) \
 224   (TARGET_ALIGN_NATURAL == 0                                            \
 225    ? rs6000_special_adjust_field_align (TYPE, COMPUTED)                 \
 226    : (COMPUTED))
 227
 228 /* AIX increases natural record alignment to doubleword if the first
 229    field is an FP double while the FP fields remain word aligned.  */
 230 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 231   ((TREE_CODE (STRUCT) == RECORD_TYPE                                   \
 232     || TREE_CODE (STRUCT) == UNION_TYPE                                 \
 233     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                           \
 234    && TARGET_ALIGN_NATURAL == 0                                         \
 235    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 236    : MAX ((COMPUTED), (SPECIFIED)))
 237
 238 /* The AIX ABI isn't explicit on whether aggregates smaller than a
 239    word/doubleword should be padded upward or downward.  One could
 240    reasonably assume that they follow the normal rules for structure
 241    layout treating the parameter area as any other block of memory,
 242    then map the reg param area to registers, i.e., pad upward, which
 243    is the way IBM Compilers for AIX behave.
 244    Setting both of the following defines results in this behavior.  */
 245 #define AGGREGATE_PADDING_FIXED 1
 246 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
 247
 248 /* Specify padding for the last element of a block move between
 249    registers and memory.  FIRST is nonzero if this is the only
 250    element.  */
 251 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 252   (!(FIRST) ? PAD_UPWARD : targetm.calls.function_arg_padding (MODE, TYPE))
 253
 254 /* Indicate that jump tables go in the text section.  */
 255
 256 #define JUMP_TABLES_IN_TEXT_SECTION 1
 257
 258 /* Define any extra SPECS that the compiler needs to generate.  */
 259 #undef  SUBTARGET_EXTRA_SPECS
 260 #define SUBTARGET_EXTRA_SPECS                                           \
 261   { "link_syscalls",            LINK_SYSCALLS_SPEC },                   \
 262   { "link_libg",                LINK_LIBG_SPEC }
 263
 264 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 265
 266 /* No version of AIX fully supports AltiVec or 64-bit instructions in
 267    32-bit mode.  */
 268 #define OS_MISSING_POWERPC64 1
 269 #define OS_MISSING_ALTIVEC 1
 270
 271 /* WINT_TYPE */
 272 #define WINT_TYPE "int"
 273
 274 /* Static stack checking is supported by means of probes.  */
 275 #define STACK_CHECK_STATIC_BUILTIN 1
 276
 277 /* Use standard DWARF numbering for DWARF debugging information.  */
 278 #define RS6000_USE_DWARF_NUMBERING
 279
 280 #define TARGET_PRECOMPUTE_TLS_P rs6000_aix_precompute_tls_p
 281
 282 /* Replace -m64 with -maix64 and -m32 with -maix32.  */
 283 #undef SUBTARGET_DRIVER_SELF_SPECS
 284 #define SUBTARGET_DRIVER_SELF_SPECS     \
 285 "%{m64:-maix64} %<m64",                 \
 286 "%{m32:-maix32} %<m32"