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