gcc/config/rs6000/aix.h

   1 /* Definitions of target machine for GNU compiler,
   2    for IBM RS/6000 POWER running AIX.
   3    Copyright (C) 2000-2017 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 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
  27    in the #if conditional in options-default.h, so provide another macro.  */
  28 #undef  TARGET_AIX_OS
  29 #define TARGET_AIX_OS 1
  30
  31 /* AIX always has a TOC.  */
  32 #define TARGET_NO_TOC 0
  33 #define TARGET_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 + STACK_POINTER_OFFSET, 16)
  75
  76 #undef  TARGET_IEEEQUAD
  77 #define TARGET_IEEEQUAD 0
  78
  79 #undef  TARGET_IEEEQUAD_DEFAULT
  80 #define TARGET_IEEEQUAD_DEFAULT 0
  81
  82 /* The AIX linker will discard static constructors in object files before
  83    collect has a chance to see them, so scan the object files directly.  */
  84 #define COLLECT_EXPORT_LIST
  85
  86 /* On AIX, initialisers specified with -binitfini are called in breadth-first
  87    order.
  88    e.g. if a.out depends on lib1.so, the init function for a.out is called before
  89    the init function for lib1.so.
  90
  91    To ensure global C++ constructors in linked libraries are run before global
  92    C++ constructors from the current module, there is additional symbol scanning
  93    logic in collect2.
  94
  95    The global initialiser/finaliser functions are named __GLOBAL_AIXI_{libname}
  96    and __GLOBAL_AIXD_{libname} and are exported from each shared library.
  97
  98    collect2 will detect these symbols when they exist in shared libraries that
  99    the current program is being linked against.  All such initiliser functions
 100    will be called prior to the constructors of the current program, and
 101    finaliser functions called after destructors.
 102
 103    Reference counting generated by collect2 will ensure that constructors are
 104    only invoked once in the case of multiple dependencies on a library.
 105
 106    -binitfini is still used in parallel to this solution.
 107    This handles the case where a library is loaded through dlopen(), and also
 108    handles the option -blazy.
 109 */
 110 #define COLLECT_SHARED_INIT_FUNC(STREAM, FUNC) \
 111           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_initname, (FUNC))
 112 #define COLLECT_SHARED_FINI_FUNC(STREAM, FUNC) \
 113           fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_fininame, (FUNC))
 114
 115 #if HAVE_AS_REF
 116 /* Issue assembly directives that create a reference to the given DWARF table
 117    identifier label from the current function section.  This is defined to
 118    ensure we drag frame tables associated with needed function bodies in
 119    a link with garbage collection activated.  */
 120 #define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
 121 #endif
 122
 123 /* This is the only version of nm that collect2 can work with.  */
 124 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
 125
 126 #define USER_LABEL_PREFIX  ""
 127
 128 /* Don't turn -B into -L if the argument specifies a relative file name.  */
 129 #define RELATIVE_PREFIX_NOT_LINKDIR
 130
 131 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
 132 #define LINK_LIBGCC_SPECIAL_1
 133
 134 /* Names to predefine in the preprocessor for this target machine.  */
 135 #define TARGET_OS_AIX_CPP_BUILTINS()            \
 136   do                                            \
 137     {                                           \
 138       builtin_define ("_IBMR2");                \
 139       builtin_define ("_POWER");                \
 140       builtin_define ("__unix__");              \
 141       builtin_define ("_AIX");                  \
 142       builtin_define ("_AIX32");                \
 143       builtin_define ("_AIX41");                \
 144       builtin_define ("_LONG_LONG");            \
 145       if (TARGET_LONG_DOUBLE_128)               \
 146         builtin_define ("__LONGDOUBLE128");     \
 147       builtin_assert ("system=unix");           \
 148       builtin_assert ("system=aix");            \
 149       if (TARGET_64BIT)                         \
 150         {                                       \
 151           builtin_define ("__PPC__");           \
 152           builtin_define ("__PPC64__");         \
 153           builtin_define ("__powerpc__");       \
 154           builtin_define ("__powerpc64__");     \
 155           builtin_assert ("cpu=powerpc64");     \
 156           builtin_assert ("machine=powerpc64"); \
 157         }                                       \
 158       else                                      \
 159         {                                       \
 160           builtin_define ("__PPC__");           \
 161           builtin_define ("__powerpc__");       \
 162           builtin_assert ("cpu=powerpc");       \
 163           builtin_assert ("machine=powerpc");   \
 164         }                                       \
 165     }                                           \
 166   while (0)
 167
 168 /* Define appropriate architecture macros for preprocessor depending on
 169    target switches.  */
 170
 171 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
 172    %{ansi: -D_ANSI_C_SOURCE}"
 173
 174 #define CC1_SPEC "%(cc1_cpu)"
 175
 176 #undef ASM_DEFAULT_SPEC
 177 #define ASM_DEFAULT_SPEC ""
 178
 179 /* Tell the assembler to assume that all undefined names are external.
 180
 181    Don't do this until the fixed IBM assembler is more generally available.
 182    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
 183    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
 184    longer be needed.  Also, the extern declaration of mcount in
 185    rs6000_xcoff_file_start will no longer be needed.  */
 186
 187 /* #define ASM_SPEC "-u %(asm_cpu)" */
 188
 189 /* Default location of syscalls.exp under AIX */
 190 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
 191
 192 /* Default location of libg.exp under AIX */
 193 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
 194
 195 /* Define the options for the binder: Start text at 512, align all segments
 196    to 512 bytes, and warn if there is text relocation.
 197
 198    The -bhalt:4 option supposedly changes the level at which ld will abort,
 199    but it also suppresses warnings about multiply defined symbols and is
 200    used by the AIX cc command.  So we use it here.
 201
 202    -bnodelcsect undoes a poor choice of default relating to multiply-defined
 203    csects.  See AIX documentation for more information about this.
 204
 205    -bM:SRE tells the linker that the output file is Shared REusable.  Note
 206    that to actually build a shared library you will also need to specify an
 207    export list with the -Wl,-bE option.  */
 208
 209 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
 210 %{static:-bnso %(link_syscalls) } \
 211 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
 212
 213 /* Profiled library versions are used by linking with special directories.  */
 214 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
 215 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
 216
 217 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
 218 #define LIBSTDCXX_STATIC "supc++"
 219
 220 /* This now supports a natural alignment mode.  */
 221 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
 222 #define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED) \
 223   ((TARGET_ALIGN_NATURAL == 0                                           \
 224     && TYPE_MODE (strip_array_types (TYPE)) == DFmode)                  \
 225    ? MIN ((COMPUTED), 32)                                               \
 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