gcc/config/rs6000/darwin.h

   1 /* Target definitions for PowerPC running Darwin (Mac OS X).
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3    Contributed by Apple Computer 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 #undef DARWIN_PPC
  22 #define DARWIN_PPC 1
  23
  24 /* The "Darwin ABI" is mostly like AIX, but with some key differences.  */
  25
  26 #define DEFAULT_ABI ABI_DARWIN
  27
  28 #ifdef IN_LIBGCC2
  29 #undef TARGET_64BIT
  30 #ifdef __powerpc64__
  31 #define TARGET_64BIT 1
  32 #else
  33 #define TARGET_64BIT 0
  34 #endif
  35 #endif
  36
  37 /* The object file format is Mach-O.  */
  38
  39 #define TARGET_OBJECT_FORMAT OBJECT_MACHO
  40
  41 /* Size of the Obj-C jump buffer.  */
  42 #define OBJC_JBLEN ((TARGET_64BIT) ? (26*2 + 18*2 + 129 + 1) : (26 + 18*2 + 129 + 1))
  43
  44 /* We're not ever going to do TOCs.  */
  45
  46 #define TARGET_HAS_TOC 0
  47
  48 /* Override the default rs6000 definition.  */
  49 #undef  PTRDIFF_TYPE
  50 #define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
  51
  52 #define TARGET_OS_CPP_BUILTINS()                        \
  53   do                                                    \
  54     {                                                   \
  55       builtin_define ("__POWERPC__");                   \
  56       builtin_define ("__PPC__");                       \
  57       if (TARGET_64BIT)                                 \
  58         {                                               \
  59           builtin_define ("__ppc64__");                 \
  60           builtin_define ("__PPC64__");                 \
  61           builtin_define ("__powerpc64__");             \
  62           builtin_assert ("cpu=powerpc64");             \
  63           builtin_assert ("machine=powerpc64");         \
  64         }                                               \
  65       else                                              \
  66         {                                               \
  67           builtin_define ("__ppc__");                   \
  68           builtin_define_std ("PPC");                   \
  69           builtin_assert ("cpu=powerpc");               \
  70           builtin_assert ("machine=powerpc");           \
  71         }                                               \
  72       builtin_define ("__NATURAL_ALIGNMENT__");         \
  73       darwin_cpp_builtins (pfile);                      \
  74     }                                                   \
  75   while (0)
  76
  77 #define SUBTARGET_OVERRIDE_OPTIONS darwin_rs6000_override_options ()
  78
  79 #define C_COMMON_OVERRIDE_OPTIONS do {                                  \
  80   /* On powerpc, __cxa_get_exception_ptr is available starting in the   \
  81      10.4.6 libstdc++.dylib.  */                                        \
  82   if (strverscmp (darwin_macosx_version_min, "10.4.6") < 0              \
  83       && flag_use_cxa_get_exception_ptr == 2)                           \
  84     flag_use_cxa_get_exception_ptr = 0;                                 \
  85   if (flag_mkernel)                                                     \
  86     flag_no_builtin = 1;                                                \
  87   SUBTARGET_C_COMMON_OVERRIDE_OPTIONS;                                  \
  88 } while (0)
  89
  90 /* Darwin has 128-bit long double support in libc in 10.4 and later.
  91    Default to 128-bit long doubles even on earlier platforms for ABI
  92    consistency; arithmetic will work even if libc and libm support is
  93    not available.  */
  94
  95 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 128
  96
  97 /* Machine dependent libraries.
  98    Include libmx when targeting Darwin 7.0 and above, but before libSystem,
  99    since the functions are actually in libSystem but for 7.x compatibility
 100    we want them to be looked for in libmx first.
 101    Include libSystemStubs when compiling against 10.3 - 10.6 SDKs (we assume
 102    this is the case when targetting these) - but not for 64-bit long double.
 103    Don't do either for m64, the library is either a dummy or non-existent.
 104 */
 105
 106 #undef LIB_SPEC
 107 #define LIB_SPEC \
 108 "%{!static:                                                             \
 109   %{!m64:%{!mlong-double-64:                                            \
 110     %{pg:%:version-compare(>< 10.3 10.7 mmacosx-version-min= -lSystemStubs_profile)} \
 111     %{!pg:%:version-compare(>< 10.3 10.7 mmacosx-version-min= -lSystemStubs)} \
 112      %:version-compare(>< 10.3 10.4 mmacosx-version-min= -lmx)}}        \
 113   -lSystem                                                              \
 114 }"
 115
 116 #undef DARWIN_HEAP_T_LIB
 117 #define DARWIN_HEAP_T_LIB " "
 118
 119 /* We want -fPIC by default, unless we're using -static to compile for
 120    the kernel or some such.  The "-faltivec" option should have been
 121    called "-maltivec" all along.  */
 122
 123 #define CC1_SPEC "\
 124   %(cc1_cpu) \
 125   %{g: %{!fno-eliminate-unused-debug-symbols: -feliminate-unused-debug-symbols }} \
 126   %{static: %{Zdynamic: %e conflicting code gen style switches are used}}\
 127   %{!mkernel:%{!static:%{!mdynamic-no-pic:-fPIC}}} \
 128   %{faltivec:-maltivec -include altivec.h} %{fno-altivec:-mno-altivec} \
 129   %<faltivec %<fno-altivec " \
 130   DARWIN_CC1_SPEC
 131
 132 /* Default to PPC for single arch builds.  */
 133 #define DARWIN_ARCH_SPEC "ppc"
 134
 135 #define DARWIN_SUBARCH_SPEC "                   \
 136  %{mcpu=601:ppc601;                             \
 137    mcpu=603:ppc603;                             \
 138    mcpu=603e:ppc603;                            \
 139    mcpu=604:ppc604;                             \
 140    mcpu=604e:ppc604e;                           \
 141    mcpu=740:ppc750;                             \
 142    mcpu=750:ppc750;                             \
 143    mcpu=G3:ppc750;                              \
 144    mcpu=7400:ppc7400;                           \
 145    mcpu=G4:ppc7400;                             \
 146    mcpu=7450:ppc7450;                           \
 147    mcpu=970:ppc970;                             \
 148    mcpu=power4:ppc970;                          \
 149    mcpu=G5:ppc970;                              \
 150    :ppc}"
 151
 152 /* We need to jam the crt to 10.5 for 10.6 (Rosetta) use.  */
 153 #undef DARWIN_CRT1_SPEC
 154 #define DARWIN_CRT1_SPEC                                                \
 155   "%:version-compare(!> 10.5 mmacosx-version-min= -lcrt1.o)             \
 156    %:version-compare(>< 10.5 10.7 mmacosx-version-min= -lcrt1.10.5.o)   \
 157    %{fgnu-tm: -lcrttms.o}"
 158
 159 /* crt2.o is at least partially required for 10.3.x and earlier.
 160    It deals with registration of the unwind frames, where this is not
 161    automatically provided by the system.  So we need it for any case that
 162    might use exceptions.  */
 163 #undef DARWIN_CRT2_SPEC
 164 #define DARWIN_CRT2_SPEC \
 165 "%{!m64:%{shared-libgcc|static-libstdc++|fexceptions|fobjc-exceptions|fgnu-runtime: \
 166    %:version-compare(!> 10.4 mmacosx-version-min= crt2.o%s) \
 167   }}"
 168
 169 /* crt3 deals with providing cxa_atexit on earlier systems (or fixing it up,
 170    for broken versions).  It's only needed for c++ code, so we can make it
 171    conditional on shared-libgcc since that's forced on for c++.  */
 172 #undef DARWIN_CRT3_SPEC
 173 #define DARWIN_CRT3_SPEC \
 174 "%{!m64:%{shared-libgcc|static-libstdc++:                                                       \
 175    %:version-compare(>< 10.4 10.5 mmacosx-version-min= crt3.o%s) \
 176    %:version-compare(!> 10.4 mmacosx-version-min= crt3_2.o%s) \
 177   }}"
 178
 179 /* As for crt1, we need to force the dylib crt for 10.6.  */
 180 #undef DARWIN_DYLIB1_SPEC
 181 #define DARWIN_DYLIB1_SPEC                                              \
 182   "%:version-compare(!> 10.5 mmacosx-version-min= -ldylib1.o)           \
 183    %:version-compare(>< 10.5 10.7 mmacosx-version-min= -ldylib1.10.5.o)"
 184
 185 /* Likewise, the bundle crt.  */
 186 #undef DARWIN_BUNDLE1_SPEC
 187 #define DARWIN_BUNDLE1_SPEC \
 188 "%{!static:%:version-compare(< 10.7 mmacosx-version-min= -lbundle1.o)   \
 189            %{fgnu-tm: -lcrttms.o}}"
 190
 191 /* The PPC regs save/restore functions are leaves and could, conceivably
 192    be used by the tm destructor.  */
 193 #undef ENDFILE_SPEC
 194 #define ENDFILE_SPEC TM_DESTRUCTOR " -lef_ppc"
 195
 196 #undef SUBTARGET_EXTRA_SPECS
 197 #define SUBTARGET_EXTRA_SPECS                   \
 198   DARWIN_EXTRA_SPECS                            \
 199   { "darwin_arch", DARWIN_ARCH_SPEC },          \
 200   { "darwin_crt2", DARWIN_CRT2_SPEC },          \
 201   { "darwin_subarch", DARWIN_SUBARCH_SPEC },
 202
 203 /* Output a .machine directive.  */
 204 #undef TARGET_ASM_FILE_START
 205 #define TARGET_ASM_FILE_START rs6000_darwin_file_start
 206
 207 /* Make both r2 and r13 available for allocation.  */
 208 #define FIXED_R2 0
 209 #define FIXED_R13 TARGET_64BIT
 210
 211 /* Base register for access to local variables of the function.  */
 212
 213 #undef  HARD_FRAME_POINTER_REGNUM
 214 #define HARD_FRAME_POINTER_REGNUM 30
 215
 216 #undef  RS6000_PIC_OFFSET_TABLE_REGNUM
 217 #define RS6000_PIC_OFFSET_TABLE_REGNUM 31
 218
 219 #undef FIRST_SAVED_GP_REGNO
 220 #define FIRST_SAVED_GP_REGNO 13
 221
 222 /* Darwin's stack must remain 16-byte aligned for both 32 and 64 bit
 223    ABIs.  */
 224
 225 #undef  STACK_BOUNDARY
 226 #define STACK_BOUNDARY 128
 227
 228 /* Offset within stack frame to start allocating local variables at.
 229    For supported Darwin versions, FRAME_GROWS_DOWNWARD is true, therefore
 230    this value is the offset to the END of the first local allocated.
 231
 232    On the RS/6000, the frame pointer is the same as the stack pointer,
 233    except for dynamic allocations.  So we start after the fixed area and
 234    outgoing parameter area.
 235
 236    If the function uses dynamic stack space (CALLS_ALLOCA is set), that
 237    space needs to be aligned to STACK_BOUNDARY, i.e. the sum of the
 238    sizes of the fixed area and the parameter area must be a multiple of
 239    STACK_BOUNDARY.  */
 240
 241 #undef RS6000_STARTING_FRAME_OFFSET
 242 #define RS6000_STARTING_FRAME_OFFSET                                    \
 243   (cfun->calls_alloca                                                   \
 244    ? RS6000_ALIGN (crtl->outgoing_args_size + RS6000_SAVE_AREA, 16)     \
 245    : (RS6000_ALIGN (crtl->outgoing_args_size, 16) + RS6000_SAVE_AREA))
 246
 247 /* Offset from the stack pointer register to an item dynamically
 248    allocated on the stack, e.g., by `alloca'.
 249
 250    The default value for this macro is `STACK_POINTER_OFFSET' plus the
 251    length of the outgoing arguments.  The default is correct for most
 252    machines.  See `function.cc' for details.
 253
 254    This value must be a multiple of STACK_BOUNDARY (hard coded in
 255    `emit-rtl.cc').  */
 256
 257 #undef STACK_DYNAMIC_OFFSET
 258 #define STACK_DYNAMIC_OFFSET(FUNDECL)                                   \
 259   RS6000_ALIGN (crtl->outgoing_args_size.to_constant()                  \
 260                 + STACK_POINTER_OFFSET, 16)
 261
 262 /* Darwin uses a function call if everything needs to be saved/restored.  */
 263
 264 #undef WORLD_SAVE_P
 265 #define WORLD_SAVE_P(INFO) ((INFO)->world_save_p)
 266
 267 /* We don't use these on Darwin, they are just place-holders.  */
 268 #define SAVE_FP_PREFIX ""
 269 #define SAVE_FP_SUFFIX ""
 270 #define RESTORE_FP_PREFIX ""
 271 #define RESTORE_FP_SUFFIX ""
 272
 273 /* The assembler wants the alternate register names, but without
 274    leading percent sign.  */
 275 #undef REGISTER_NAMES
 276 #define REGISTER_NAMES                                                  \
 277 {                                                                       \
 278   /* GPRs */                                                            \
 279      "r0",  "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",             \
 280      "r8",  "r9", "r10", "r11", "r12", "r13", "r14", "r15",             \
 281     "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",             \
 282     "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",             \
 283   /* FPRs */                                                            \
 284      "f0",  "f1",  "f2",  "f3",  "f4",  "f5",  "f6",  "f7",             \
 285      "f8",  "f9", "f10", "f11", "f12", "f13", "f14", "f15",             \
 286     "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",             \
 287     "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",             \
 288   /* VRs */                                                             \
 289      "v0",  "v1",  "v2",  "v3",  "v4",  "v5",  "v6",  "v7",             \
 290      "v8",  "v9", "v10", "v11", "v12", "v13", "v14", "v15",             \
 291     "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23",             \
 292     "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31",             \
 293   /* lr ctr ca ap */                                                    \
 294      "lr", "ctr", "xer",  "ap",                                         \
 295   /* cr0..cr7 */                                                        \
 296     "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7",             \
 297   /* vrsave vscr sfp */                                                 \
 298     "vrsave", "vscr", "sfp"                                             \
 299 }
 300
 301 /* This outputs NAME to FILE.  */
 302
 303 #undef  RS6000_OUTPUT_BASENAME
 304 #define RS6000_OUTPUT_BASENAME(FILE, NAME)      \
 305     assemble_name (FILE, NAME)
 306
 307 /* Globalizing directive for a label.  */
 308 #undef GLOBAL_ASM_OP
 309 #define GLOBAL_ASM_OP "\t.globl "
 310 #undef TARGET_ASM_GLOBALIZE_LABEL
 311
 312 /* This is how to output an internal label prefix.  rs6000.cc uses this
 313    when generating traceback tables.  */
 314 /* Not really used for Darwin?  */
 315
 316 #undef ASM_OUTPUT_INTERNAL_LABEL_PREFIX
 317 #define ASM_OUTPUT_INTERNAL_LABEL_PREFIX(FILE,PREFIX)   \
 318   fprintf (FILE, "%s", PREFIX)
 319
 320 /* Override the standard rs6000 definition.  */
 321
 322 #undef ASM_COMMENT_START
 323 #define ASM_COMMENT_START ";"
 324
 325 /* This is how to output an assembler line that says to advance
 326    the location counter to a multiple of 2**LOG bytes using the
 327    "nop" instruction as padding.  */
 328
 329 #define ASM_OUTPUT_ALIGN_WITH_NOP(FILE,LOG)                   \
 330   do                                                          \
 331     {                                                         \
 332       if ((LOG) < 3)                                          \
 333         {                                                     \
 334           ASM_OUTPUT_ALIGN (FILE,LOG);                        \
 335         }                                                     \
 336       else /* nop == ori r0,r0,0 */                           \
 337         fprintf (FILE, "\t.align32 %d,0x60000000\n", (LOG));  \
 338     } while (0)
 339
 340 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
 341 /* This is supported in cctools 465 and later.  The macro test
 342    above prevents using it in earlier build environments.  */
 343 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP)          \
 344   if ((LOG) > 0)                                             \
 345     {                                                         \
 346       if ((MAX_SKIP) <= 0)                                    \
 347         fprintf ((FILE), "\t.p2align %d\n", (LOG));           \
 348       else                                                    \
 349         fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \
 350     }
 351 #endif
 352
 353 /* Generate insns to call the profiler.  */
 354
 355 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
 356
 357 /* Function name to call to do profiling.  */
 358
 359 #define RS6000_MCOUNT "*mcount"
 360
 361 /* Default processor: G4, and G5 for 64-bit.  */
 362
 363 #undef PROCESSOR_DEFAULT
 364 #define PROCESSOR_DEFAULT  PROCESSOR_PPC7400
 365 #undef PROCESSOR_DEFAULT64
 366 #define PROCESSOR_DEFAULT64  PROCESSOR_POWER4
 367
 368 /* Default target flag settings.  Despite the fact that STMW/LMW
 369    serializes, it's still a big code size win to use them.  Use FSEL by
 370    default as well.  */
 371
 372 #undef  TARGET_DEFAULT
 373 #define TARGET_DEFAULT (OPTION_MASK_MULTIPLE | OPTION_MASK_PPC_GFXOPT)
 374
 375 /* Darwin always uses IBM long double, never IEEE long double.  */
 376 #undef  TARGET_IEEEQUAD
 377 #define TARGET_IEEEQUAD 0
 378
 379 #undef  TARGET_IEEEQUAD_DEFAULT
 380 #define TARGET_IEEEQUAD_DEFAULT 0
 381
 382 /* Since Darwin doesn't do TOCs, stub this out.  */
 383
 384 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY_P(X, MODE)  ((void)X, (void)MODE, 0)
 385
 386 /* Unlike most other PowerPC targets, chars are signed, for
 387    consistency with other Darwin architectures.  */
 388
 389 #undef DEFAULT_SIGNED_CHAR
 390 #define DEFAULT_SIGNED_CHAR (1)
 391
 392 /* Given an rtx X being reloaded into a reg required to be
 393    in class CLASS, return the class of reg to actually use.
 394    In general this is just CLASS; but on some machines
 395    in some cases it is preferable to use a more restrictive class.
 396
 397    On the RS/6000, we have to return NO_REGS when we want to reload a
 398    floating-point CONST_DOUBLE to force it to be copied to memory.
 399
 400    Don't allow R0 when loading the address of, or otherwise furtling with,
 401    a SYMBOL_REF.  */
 402
 403 #undef PREFERRED_RELOAD_CLASS
 404 #define PREFERRED_RELOAD_CLASS(X,CLASS)                         \
 405   ((CONSTANT_P (X)                                              \
 406     && reg_classes_intersect_p ((CLASS), FLOAT_REGS))           \
 407    ? NO_REGS                                                    \
 408    : ((SYMBOL_REF_P (X) || GET_CODE (X) == HIGH)                \
 409       && reg_class_subset_p (BASE_REGS, (CLASS)))               \
 410    ? BASE_REGS                                                  \
 411    : (GET_MODE_CLASS (GET_MODE (X)) == MODE_INT                 \
 412       && (CLASS) == GEN_OR_FLOAT_REGS)                          \
 413    ? GENERAL_REGS                                               \
 414    : (CLASS))
 415
 416 /* Compute field alignment.
 417    This implements the 'power' alignment rule by pegging the alignment of
 418    items (beyond the first aggregate field) to 32 bits.  The pegging is
 419    suppressed for vector and long double items (both 128 in size).
 420    There is a dummy use of the FIELD argument to avoid an unused variable
 421    warning (see PR59496).  */
 422 #define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED)               \
 423   ((void) (FIELD),                                              \
 424     (TARGET_ALIGN_NATURAL                                       \
 425      ? (COMPUTED)                                               \
 426      : (COMPUTED) == 128                                        \
 427         ? 128                                                   \
 428         : MIN ((COMPUTED), 32)))
 429
 430 /* Darwin increases natural record alignment to doubleword if the first
 431    field is an FP double while the FP fields remain word aligned.  */
 432 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                     \
 433   (RECORD_OR_UNION_TYPE_P (STRUCT)                                \
 434    && TARGET_ALIGN_NATURAL == 0                                           \
 435    ? darwin_rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED) \
 436    : (VECTOR_TYPE_P (STRUCT)                                      \
 437       && ALTIVEC_VECTOR_MODE (TYPE_MODE (STRUCT)))                        \
 438    ? MAX (MAX ((COMPUTED), (SPECIFIED)), 128)                             \
 439    : MAX ((COMPUTED), (SPECIFIED)))
 440
 441 /* Specify padding for the last element of a block move between
 442    registers and memory.  FIRST is nonzero if this is the only
 443    element.  */
 444 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 445   (!(FIRST) ? PAD_UPWARD : targetm.calls.function_arg_padding (MODE, TYPE))
 446
 447 #define DOUBLE_INT_ASM_OP "\t.quad\t"
 448
 449 /* For binary compatibility with 2.95; Darwin C APIs use bool from
 450    stdbool.h, which was an int-sized enum in 2.95.  Users can explicitly
 451    choose to have sizeof(bool)==1 with the -mone-byte-bool switch. */
 452 #define BOOL_TYPE_SIZE (darwin_one_byte_bool ? CHAR_TYPE_SIZE : INT_TYPE_SIZE)
 453
 454 #undef REGISTER_TARGET_PRAGMAS
 455 #define REGISTER_TARGET_PRAGMAS() \
 456   do \
 457     { \
 458       DARWIN_REGISTER_TARGET_PRAGMAS(); \
 459       targetm.target_option.pragma_parse = rs6000_pragma_target_parse; \
 460       targetm.resolve_overloaded_builtin = altivec_resolve_overloaded_builtin; \
 461     } \
 462   while (0)
 463
 464 #ifdef IN_LIBGCC2
 465 #include <stdbool.h>
 466 #endif
 467
 468 /* True, iff we're generating fast turn around debugging code.  When
 469    true, we arrange for function prologues to start with 5 nops so
 470    that gdb may insert code to redirect them, and for data to be
 471    accessed indirectly.  The runtime uses this indirection to forward
 472    references for data to the original instance of that data.  */
 473
 474 #define TARGET_FIX_AND_CONTINUE (darwin_fix_and_continue)
 475
 476 /* This is the reserved direct dispatch address for Objective-C.  */
 477 #define OFFS_MSGSEND_FAST               0xFFFEFF00
 478
 479 /* This is the reserved ivar address Objective-C.  */
 480 #define OFFS_ASSIGNIVAR_FAST            0xFFFEFEC0
 481
 482 /* Old versions of Mac OS/Darwin don't have C99 functions available.  */
 483 #undef TARGET_LIBC_HAS_FUNCTION
 484 #define TARGET_LIBC_HAS_FUNCTION darwin_libc_has_function
 485
 486 /* When generating kernel code or kexts, we don't use Altivec by
 487    default, as kernel code doesn't save/restore those registers.  */
 488 #define OS_MISSING_ALTIVEC (flag_mkernel || flag_apple_kext)
 489
 490 /* Darwin has support for section anchors on powerpc*.
 491    It is disabled for any section containing a "zero-sized item" (because these
 492    are re-written as size=1 to be compatible with the OSX ld64).
 493    The re-writing would interfere with the computation of anchor offsets.
 494    Therefore, we place zero-sized items in their own sections and make such
 495    sections unavailable to section anchoring.  */
 496
 497 #undef TARGET_ASM_OUTPUT_ANCHOR
 498 #define TARGET_ASM_OUTPUT_ANCHOR darwin_asm_output_anchor
 499
 500 #undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
 501 #define TARGET_USE_ANCHORS_FOR_SYMBOL_P darwin_use_anchors_for_symbol_p
 502
 503 #undef DARWIN_SECTION_ANCHORS
 504 #define DARWIN_SECTION_ANCHORS 1
 505
 506 /* PPC Darwin has to rename some of the long double builtins.  */
 507 #undef  SUBTARGET_INIT_BUILTINS
 508 #define SUBTARGET_INIT_BUILTINS                                         \
 509 do {                                                                    \
 510   darwin_patch_builtins ();                                             \
 511   rs6000_builtin_decls[(unsigned) (RS6000_BIF_CFSTRING)]                \
 512     = darwin_init_cfstring_builtins ((unsigned) (RS6000_BIF_CFSTRING)); \
 513 } while(0)
 514
 515 /* So far, there is no rs6000_fold_builtin, if one is introduced, then
 516    this will need to be modified similar to the x86 case.  */
 517 #define TARGET_FOLD_BUILTIN SUBTARGET_FOLD_BUILTIN
 518
 519 /* First available SYMBOL flag bit for use by subtargets.  */
 520 #define SYMBOL_FLAG_SUBT_DEP (SYMBOL_FLAG_MACH_DEP)
 521
 522 /* Use standard DWARF numbering for DWARF debugging information.  */
 523 #define RS6000_USE_DWARF_NUMBERING
 524