gcc/config/rs6000/linux64.h

   1 /* Definitions of target machine for GNU compiler,
   2    for 64 bit PowerPC linux.
   3    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
   4    2009, 2010, 2011  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    Under Section 7 of GPL version 3, you are granted additional
  19    permissions described in the GCC Runtime Library Exception, version
  20    3.1, as published by the Free Software Foundation.
  21
  22    You should have received a copy of the GNU General Public License and
  23    a copy of the GCC Runtime Library Exception along with this program;
  24    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25    <http://www.gnu.org/licenses/>.  */
  26
  27 #ifndef RS6000_BI_ARCH
  28
  29 #undef  DEFAULT_ABI
  30 #define DEFAULT_ABI ABI_AIX
  31
  32 #undef  TARGET_64BIT
  33 #define TARGET_64BIT 1
  34
  35 #define DEFAULT_ARCH64_P 1
  36 #define RS6000_BI_ARCH_P 0
  37
  38 #else
  39
  40 #define DEFAULT_ARCH64_P (TARGET_DEFAULT & MASK_64BIT)
  41 #define RS6000_BI_ARCH_P 1
  42
  43 #endif
  44
  45 #ifdef IN_LIBGCC2
  46 #undef TARGET_64BIT
  47 #ifdef __powerpc64__
  48 #define TARGET_64BIT 1
  49 #else
  50 #define TARGET_64BIT 0
  51 #endif
  52 #endif
  53
  54 #undef  TARGET_AIX
  55 #define TARGET_AIX TARGET_64BIT
  56
  57 #ifdef HAVE_LD_NO_DOT_SYMS
  58 /* New ABI uses a local sym for the function entry point.  */
  59 extern int dot_symbols;
  60 #undef DOT_SYMBOLS
  61 #define DOT_SYMBOLS dot_symbols
  62 #endif
  63
  64 #define TARGET_PROFILE_KERNEL profile_kernel
  65
  66 #define TARGET_USES_LINUX64_OPT 1
  67 #ifdef HAVE_LD_LARGE_TOC
  68 #undef TARGET_CMODEL
  69 #define TARGET_CMODEL rs6000_current_cmodel
  70 #define SET_CMODEL(opt) rs6000_current_cmodel = opt
  71 #else
  72 #define SET_CMODEL(opt) do {} while (0)
  73 #endif
  74
  75 #undef  PROCESSOR_DEFAULT
  76 #define PROCESSOR_DEFAULT PROCESSOR_POWER7
  77 #undef  PROCESSOR_DEFAULT64
  78 #define PROCESSOR_DEFAULT64 PROCESSOR_POWER7
  79
  80 /* We don't need to generate entries in .fixup, except when
  81    -mrelocatable or -mrelocatable-lib is given.  */
  82 #undef RELOCATABLE_NEEDS_FIXUP
  83 #define RELOCATABLE_NEEDS_FIXUP \
  84   (target_flags & target_flags_explicit & MASK_RELOCATABLE)
  85
  86 #undef  RS6000_ABI_NAME
  87 #define RS6000_ABI_NAME "linux"
  88
  89 #define INVALID_64BIT "-m%s not supported in this configuration"
  90 #define INVALID_32BIT INVALID_64BIT
  91
  92 #undef  SUBSUBTARGET_OVERRIDE_OPTIONS
  93 #define SUBSUBTARGET_OVERRIDE_OPTIONS                           \
  94   do                                                            \
  95     {                                                           \
  96       if (!rs6000_explicit_options.alignment)                   \
  97         rs6000_alignment_flags = MASK_ALIGN_NATURAL;            \
  98       if (TARGET_64BIT)                                         \
  99         {                                                       \
 100           if (DEFAULT_ABI != ABI_AIX)                           \
 101             {                                                   \
 102               rs6000_current_abi = ABI_AIX;                     \
 103               error (INVALID_64BIT, "call");                    \
 104             }                                                   \
 105           dot_symbols = !strcmp (rs6000_abi_name, "aixdesc");   \
 106           if (target_flags & MASK_RELOCATABLE)                  \
 107             {                                                   \
 108               target_flags &= ~MASK_RELOCATABLE;                \
 109               error (INVALID_64BIT, "relocatable");             \
 110             }                                                   \
 111           if (target_flags & MASK_EABI)                         \
 112             {                                                   \
 113               target_flags &= ~MASK_EABI;                       \
 114               error (INVALID_64BIT, "eabi");                    \
 115             }                                                   \
 116           if (TARGET_PROTOTYPE)                                 \
 117             {                                                   \
 118               target_prototype = 0;                             \
 119               error (INVALID_64BIT, "prototype");               \
 120             }                                                   \
 121           if ((target_flags & MASK_POWERPC64) == 0)             \
 122             {                                                   \
 123               target_flags |= MASK_POWERPC64;                   \
 124               error ("-m64 requires a PowerPC64 cpu");          \
 125             }                                                   \
 126           if ((target_flags_explicit & MASK_MINIMAL_TOC) != 0)  \
 127             {                                                   \
 128               if (rs6000_explicit_options.cmodel                \
 129                   && rs6000_current_cmodel != CMODEL_SMALL)     \
 130                 error ("-mcmodel incompatible with other toc options"); \
 131               SET_CMODEL (CMODEL_SMALL);                        \
 132             }                                                   \
 133           else                                                  \
 134             {                                                   \
 135               if (!rs6000_explicit_options.cmodel)              \
 136                 SET_CMODEL (CMODEL_MEDIUM);                     \
 137               if (rs6000_current_cmodel != CMODEL_SMALL)        \
 138                 {                                               \
 139                   TARGET_NO_FP_IN_TOC = 0;                      \
 140                   TARGET_NO_SUM_IN_TOC = 0;                     \
 141                 }                                               \
 142             }                                                   \
 143         }                                                       \
 144       else                                                      \
 145         {                                                       \
 146           if (!RS6000_BI_ARCH_P)                                \
 147             error (INVALID_32BIT, "32");                        \
 148           if (TARGET_PROFILE_KERNEL)                            \
 149             {                                                   \
 150               TARGET_PROFILE_KERNEL = 0;                        \
 151               error (INVALID_32BIT, "profile-kernel");          \
 152             }                                                   \
 153           if (rs6000_explicit_options.cmodel)                   \
 154             {                                                   \
 155               SET_CMODEL (CMODEL_SMALL);                        \
 156               error (INVALID_32BIT, "cmodel");                  \
 157             }                                                   \
 158         }                                                       \
 159     }                                                           \
 160   while (0)
 161
 162 #ifdef  RS6000_BI_ARCH
 163
 164 #undef  OPTION_TARGET_CPU_DEFAULT
 165 #define OPTION_TARGET_CPU_DEFAULT \
 166   (((TARGET_DEFAULT ^ target_flags) & MASK_64BIT) \
 167    ? (char *) 0 : TARGET_CPU_DEFAULT)
 168
 169 #endif
 170
 171 #undef  ASM_DEFAULT_SPEC
 172 #undef  ASM_SPEC
 173 #undef  LINK_OS_LINUX_SPEC
 174
 175 #ifndef RS6000_BI_ARCH
 176 #define ASM_DEFAULT_SPEC "-mppc64"
 177 #define ASM_SPEC         "%(asm_spec64) %(asm_spec_common)"
 178 #define LINK_OS_LINUX_SPEC "%(link_os_linux_spec64)"
 179 #else
 180 #if DEFAULT_ARCH64_P
 181 #define ASM_DEFAULT_SPEC "-mppc%{!m32:64}"
 182 #define ASM_SPEC         "%{m32:%(asm_spec32)}%{!m32:%(asm_spec64)} %(asm_spec_common)"
 183 #define LINK_OS_LINUX_SPEC "%{m32:%(link_os_linux_spec32)}%{!m32:%(link_os_linux_spec64)}"
 184 #else
 185 #define ASM_DEFAULT_SPEC "-mppc%{m64:64}"
 186 #define ASM_SPEC         "%{!m64:%(asm_spec32)}%{m64:%(asm_spec64)} %(asm_spec_common)"
 187 #define LINK_OS_LINUX_SPEC "%{!m64:%(link_os_linux_spec32)}%{m64:%(link_os_linux_spec64)}"
 188 #endif
 189 #endif
 190
 191 #define ASM_SPEC32 "-a32 \
 192 %{mrelocatable} %{mrelocatable-lib} %{fpic:-K PIC} %{fPIC:-K PIC} \
 193 %{memb} %{!memb: %{msdata=eabi: -memb}} \
 194 %{!mlittle: %{!mlittle-endian: %{!mbig: %{!mbig-endian: \
 195     %{mcall-freebsd: -mbig} \
 196     %{mcall-i960-old: -mlittle} \
 197     %{mcall-linux: -mbig} \
 198     %{mcall-netbsd: -mbig} \
 199 }}}}"
 200
 201 #define ASM_SPEC64 "-a64"
 202
 203 #define ASM_SPEC_COMMON "%(asm_cpu) \
 204 %{,assembler|,assembler-with-cpp: %{mregnames} %{mno-regnames}} \
 205 %{mlittle} %{mlittle-endian} %{mbig} %{mbig-endian}"
 206
 207 #undef  SUBSUBTARGET_EXTRA_SPECS
 208 #define SUBSUBTARGET_EXTRA_SPECS \
 209   { "asm_spec_common",          ASM_SPEC_COMMON },                      \
 210   { "asm_spec32",               ASM_SPEC32 },                           \
 211   { "asm_spec64",               ASM_SPEC64 },                           \
 212   { "link_os_linux_spec32",     LINK_OS_LINUX_SPEC32 },                 \
 213   { "link_os_linux_spec64",     LINK_OS_LINUX_SPEC64 },
 214
 215 #undef  MULTILIB_DEFAULTS
 216 #if DEFAULT_ARCH64_P
 217 #define MULTILIB_DEFAULTS { "m64" }
 218 #else
 219 #define MULTILIB_DEFAULTS { "m32" }
 220 #endif
 221
 222 #ifndef RS6000_BI_ARCH
 223
 224 /* 64-bit PowerPC Linux is always big-endian.  */
 225 #undef  TARGET_LITTLE_ENDIAN
 226 #define TARGET_LITTLE_ENDIAN    0
 227
 228 /* 64-bit PowerPC Linux always has a TOC.  */
 229 #undef  TARGET_TOC
 230 #define TARGET_TOC              1
 231
 232 /* Some things from sysv4.h we don't do when 64 bit.  */
 233 #undef  TARGET_RELOCATABLE
 234 #define TARGET_RELOCATABLE      0
 235 #undef  TARGET_EABI
 236 #define TARGET_EABI             0
 237 #undef  TARGET_PROTOTYPE
 238 #define TARGET_PROTOTYPE        0
 239 #undef RELOCATABLE_NEEDS_FIXUP
 240 #define RELOCATABLE_NEEDS_FIXUP 0
 241
 242 #endif
 243
 244 /* We use glibc _mcount for profiling.  */
 245 #define NO_PROFILE_COUNTERS 1
 246 #define PROFILE_HOOK(LABEL) \
 247   do { if (TARGET_64BIT) output_profile_hook (LABEL); } while (0)
 248
 249 /* PowerPC64 Linux word-aligns FP doubles when -malign-power is given.  */
 250 #undef  ADJUST_FIELD_ALIGN
 251 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 252   ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE)     \
 253    ? 128                                                                \
 254    : (TARGET_64BIT                                                      \
 255       && TARGET_ALIGN_NATURAL == 0                                      \
 256       && TYPE_MODE (strip_array_types (TREE_TYPE (FIELD))) == DFmode)   \
 257    ? MIN ((COMPUTED), 32)                                               \
 258    : (COMPUTED))
 259
 260 /* PowerPC64 Linux increases natural record alignment to doubleword if
 261    the first field is an FP double, only if in power alignment mode.  */
 262 #undef  ROUND_TYPE_ALIGN
 263 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 264   ((TARGET_64BIT                                                        \
 265     && (TREE_CODE (STRUCT) == RECORD_TYPE                               \
 266         || TREE_CODE (STRUCT) == UNION_TYPE                             \
 267         || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                       \
 268     && TARGET_ALIGN_NATURAL == 0)                                       \
 269    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 270    : MAX ((COMPUTED), (SPECIFIED)))
 271
 272 /* Use the default for compiling target libs.  */
 273 #ifdef IN_TARGET_LIBS
 274 #undef TARGET_ALIGN_NATURAL
 275 #define TARGET_ALIGN_NATURAL 1
 276 #endif
 277
 278 /* Indicate that jump tables go in the text section.  */
 279 #undef  JUMP_TABLES_IN_TEXT_SECTION
 280 #define JUMP_TABLES_IN_TEXT_SECTION TARGET_64BIT
 281
 282 /* The linux ppc64 ABI isn't explicit on whether aggregates smaller
 283    than a doubleword should be padded upward or downward.  You could
 284    reasonably assume that they follow the normal rules for structure
 285    layout treating the parameter area as any other block of memory,
 286    then map the reg param area to registers.  i.e. pad upward.
 287    Setting both of the following defines results in this behavior.
 288    Setting just the first one will result in aggregates that fit in a
 289    doubleword being padded downward, and others being padded upward.
 290    Not a bad idea as this results in struct { int x; } being passed
 291    the same way as an int.  */
 292 #define AGGREGATE_PADDING_FIXED TARGET_64BIT
 293 #define AGGREGATES_PAD_UPWARD_ALWAYS 0
 294
 295 /* Specify padding for the last element of a block move between
 296    registers and memory.  FIRST is nonzero if this is the only
 297    element.  */
 298 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 299   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 300
 301 /* Linux doesn't support saving and restoring 64-bit regs in a 32-bit
 302    process.  */
 303 #define OS_MISSING_POWERPC64 !TARGET_64BIT
 304
 305 #ifdef SINGLE_LIBC
 306 #define OPTION_GLIBC  (DEFAULT_LIBC == LIBC_GLIBC)
 307 #else
 308 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
 309 #endif
 310
 311 /* glibc has float and long double forms of math functions.  */
 312 #undef  TARGET_C99_FUNCTIONS
 313 #define TARGET_C99_FUNCTIONS (OPTION_GLIBC)
 314
 315 /* Whether we have sincos that follows the GNU extension.  */
 316 #undef  TARGET_HAS_SINCOS
 317 #define TARGET_HAS_SINCOS (OPTION_GLIBC)
 318
 319 #undef  TARGET_OS_CPP_BUILTINS
 320 #define TARGET_OS_CPP_BUILTINS()                        \
 321   do                                                    \
 322     {                                                   \
 323       if (TARGET_64BIT)                                 \
 324         {                                               \
 325           builtin_define ("__PPC__");                   \
 326           builtin_define ("__PPC64__");                 \
 327           builtin_define ("__powerpc__");               \
 328           builtin_define ("__powerpc64__");             \
 329           builtin_assert ("cpu=powerpc64");             \
 330           builtin_assert ("machine=powerpc64");         \
 331         }                                               \
 332       else                                              \
 333         {                                               \
 334           builtin_define_std ("PPC");                   \
 335           builtin_define_std ("powerpc");               \
 336           builtin_assert ("cpu=powerpc");               \
 337           builtin_assert ("machine=powerpc");           \
 338           TARGET_OS_SYSV_CPP_BUILTINS ();               \
 339         }                                               \
 340     }                                                   \
 341   while (0)
 342
 343 #undef  CPP_OS_DEFAULT_SPEC
 344 #define CPP_OS_DEFAULT_SPEC "%(cpp_os_linux)"
 345
 346 /* The GNU C++ standard library currently requires _GNU_SOURCE being
 347    defined on glibc-based systems. This temporary hack accomplishes this,
 348    it should go away as soon as libstdc++-v3 has a real fix.  */
 349 #undef  CPLUSPLUS_CPP_SPEC
 350 #define CPLUSPLUS_CPP_SPEC "-D_GNU_SOURCE %(cpp)"
 351
 352 #undef  LINK_SHLIB_SPEC
 353 #define LINK_SHLIB_SPEC "%{shared:-shared} %{!shared: %{static:-static}}"
 354
 355 #undef  LIB_DEFAULT_SPEC
 356 #define LIB_DEFAULT_SPEC "%(lib_linux)"
 357
 358 #undef  STARTFILE_DEFAULT_SPEC
 359 #define STARTFILE_DEFAULT_SPEC "%(startfile_linux)"
 360
 361 #undef  ENDFILE_DEFAULT_SPEC
 362 #define ENDFILE_DEFAULT_SPEC "%(endfile_linux)"
 363
 364 #undef  LINK_START_DEFAULT_SPEC
 365 #define LINK_START_DEFAULT_SPEC "%(link_start_linux)"
 366
 367 #undef  LINK_OS_DEFAULT_SPEC
 368 #define LINK_OS_DEFAULT_SPEC "%(link_os_linux)"
 369
 370 #define GLIBC_DYNAMIC_LINKER32 "/lib/ld.so.1"
 371 #define GLIBC_DYNAMIC_LINKER64 "/lib64/ld64.so.1"
 372 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 373 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 374 #if DEFAULT_LIBC == LIBC_UCLIBC
 375 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{mglibc:" G ";:" U "}"
 376 #elif DEFAULT_LIBC == LIBC_GLIBC
 377 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{muclibc:" U ";:" G "}"
 378 #else
 379 #error "Unsupported DEFAULT_LIBC"
 380 #endif
 381 #define LINUX_DYNAMIC_LINKER32 \
 382   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32)
 383 #define LINUX_DYNAMIC_LINKER64 \
 384   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64)
 385
 386
 387 #define LINK_OS_LINUX_SPEC32 "-m elf32ppclinux %{!shared: %{!static: \
 388   %{rdynamic:-export-dynamic} \
 389   -dynamic-linker " LINUX_DYNAMIC_LINKER32 "}}"
 390
 391 #define LINK_OS_LINUX_SPEC64 "-m elf64ppc %{!shared: %{!static: \
 392   %{rdynamic:-export-dynamic} \
 393   -dynamic-linker " LINUX_DYNAMIC_LINKER64 "}}"
 394
 395 #undef  TOC_SECTION_ASM_OP
 396 #define TOC_SECTION_ASM_OP \
 397   (TARGET_64BIT                                         \
 398    ? "\t.section\t\".toc\",\"aw\""                      \
 399    : "\t.section\t\".got\",\"aw\"")
 400
 401 #undef  MINIMAL_TOC_SECTION_ASM_OP
 402 #define MINIMAL_TOC_SECTION_ASM_OP \
 403   (TARGET_64BIT                                         \
 404    ? "\t.section\t\".toc1\",\"aw\""                     \
 405    : ((TARGET_RELOCATABLE || flag_pic)                  \
 406       ? "\t.section\t\".got2\",\"aw\""                  \
 407       : "\t.section\t\".got1\",\"aw\""))
 408
 409 #undef  TARGET_VERSION
 410 #define TARGET_VERSION fprintf (stderr, " (PowerPC64 GNU/Linux)");
 411
 412 /* Must be at least as big as our pointer type.  */
 413 #undef  SIZE_TYPE
 414 #define SIZE_TYPE (TARGET_64BIT ? "long unsigned int" : "unsigned int")
 415
 416 #undef  PTRDIFF_TYPE
 417 #define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
 418
 419 #undef  WCHAR_TYPE
 420 #define WCHAR_TYPE (TARGET_64BIT ? "int" : "long int")
 421 #undef  WCHAR_TYPE_SIZE
 422 #define WCHAR_TYPE_SIZE 32
 423
 424 /* Override rs6000.h definition.  */
 425 #undef  ASM_APP_ON
 426 #define ASM_APP_ON "#APP\n"
 427
 428 /* Override rs6000.h definition.  */
 429 #undef  ASM_APP_OFF
 430 #define ASM_APP_OFF "#NO_APP\n"
 431
 432 /* PowerPC no-op instruction.  */
 433 #undef  RS6000_CALL_GLUE
 434 #define RS6000_CALL_GLUE (TARGET_64BIT ? "nop" : "cror 31,31,31")
 435
 436 #undef  RS6000_MCOUNT
 437 #define RS6000_MCOUNT "_mcount"
 438
 439 #ifdef __powerpc64__
 440 /* _init and _fini functions are built from bits spread across many
 441    object files, each potentially with a different TOC pointer.  For
 442    that reason, place a nop after the call so that the linker can
 443    restore the TOC pointer if a TOC adjusting call stub is needed.  */
 444 #if DOT_SYMBOLS
 445 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)      \
 446   asm (SECTION_OP "\n"                                  \
 447 "       bl ." #FUNC "\n"                                \
 448 "       nop\n"                                          \
 449 "       .previous");
 450 #else
 451 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)      \
 452   asm (SECTION_OP "\n"                                  \
 453 "       bl " #FUNC "\n"                                 \
 454 "       nop\n"                                          \
 455 "       .previous");
 456 #endif
 457 #endif
 458
 459 /* FP save and restore routines.  */
 460 #undef  SAVE_FP_PREFIX
 461 #define SAVE_FP_PREFIX (TARGET_64BIT ? "._savef" : "_savefpr_")
 462 #undef  SAVE_FP_SUFFIX
 463 #define SAVE_FP_SUFFIX ""
 464 #undef  RESTORE_FP_PREFIX
 465 #define RESTORE_FP_PREFIX (TARGET_64BIT ? "._restf" : "_restfpr_")
 466 #undef  RESTORE_FP_SUFFIX
 467 #define RESTORE_FP_SUFFIX ""
 468
 469 /* Dwarf2 debugging.  */
 470 #undef  PREFERRED_DEBUGGING_TYPE
 471 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
 472
 473 /* This is how to declare the size of a function.  */
 474 #undef  ASM_DECLARE_FUNCTION_SIZE
 475 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)                    \
 476   do                                                                    \
 477     {                                                                   \
 478       if (!flag_inhibit_size_directive)                                 \
 479         {                                                               \
 480           fputs ("\t.size\t", (FILE));                                  \
 481           if (TARGET_64BIT && DOT_SYMBOLS)                              \
 482             putc ('.', (FILE));                                         \
 483           assemble_name ((FILE), (FNAME));                              \
 484           fputs (",.-", (FILE));                                        \
 485           rs6000_output_function_entry (FILE, FNAME);                   \
 486           putc ('\n', (FILE));                                          \
 487         }                                                               \
 488     }                                                                   \
 489   while (0)
 490
 491 /* Return nonzero if this entry is to be written into the constant
 492    pool in a special way.  We do so if this is a SYMBOL_REF, LABEL_REF
 493    or a CONST containing one of them.  If -mfp-in-toc (the default),
 494    we also do this for floating-point constants.  We actually can only
 495    do this if the FP formats of the target and host machines are the
 496    same, but we can't check that since not every file that uses
 497    the macros includes real.h.  We also do this when we can write the
 498    entry into the TOC and the entry is not larger than a TOC entry.  */
 499
 500 #undef  ASM_OUTPUT_SPECIAL_POOL_ENTRY_P
 501 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY_P(X, MODE)                        \
 502   (TARGET_TOC                                                           \
 503    && (GET_CODE (X) == SYMBOL_REF                                       \
 504        || (GET_CODE (X) == CONST && GET_CODE (XEXP (X, 0)) == PLUS      \
 505            && GET_CODE (XEXP (XEXP (X, 0), 0)) == SYMBOL_REF)           \
 506        || GET_CODE (X) == LABEL_REF                                     \
 507        || (GET_CODE (X) == CONST_INT                                    \
 508            && GET_MODE_BITSIZE (MODE) <= GET_MODE_BITSIZE (Pmode))      \
 509        || (GET_CODE (X) == CONST_DOUBLE                                 \
 510            && ((TARGET_64BIT                                            \
 511                 && (TARGET_MINIMAL_TOC                                  \
 512                     || (SCALAR_FLOAT_MODE_P (GET_MODE (X))              \
 513                         && ! TARGET_NO_FP_IN_TOC)))                     \
 514                || (!TARGET_64BIT                                        \
 515                    && !TARGET_NO_FP_IN_TOC                              \
 516                    && !TARGET_RELOCATABLE                               \
 517                    && SCALAR_FLOAT_MODE_P (GET_MODE (X))                \
 518                    && BITS_PER_WORD == HOST_BITS_PER_INT)))))
 519
 520 /* Select a format to encode pointers in exception handling data.  CODE
 521    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
 522    true if the symbol may be affected by dynamic relocations.  */
 523 #undef  ASM_PREFERRED_EH_DATA_FORMAT
 524 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
 525   ((TARGET_64BIT || flag_pic || TARGET_RELOCATABLE)                     \
 526    ? (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel               \
 527       | (TARGET_64BIT ? DW_EH_PE_udata8 : DW_EH_PE_sdata4))             \
 528    : DW_EH_PE_absptr)
 529
 530 /* For backward compatibility, we must continue to use the AIX
 531    structure return convention.  */
 532 #undef DRAFT_V4_STRUCT_RET
 533 #define DRAFT_V4_STRUCT_RET (!TARGET_64BIT)
 534
 535 #define TARGET_POSIX_IO
 536
 537 #define LINK_GCC_C_SEQUENCE_SPEC \
 538   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
 539
 540 /* Use --as-needed -lgcc_s for eh support.  */
 541 #ifdef HAVE_LD_AS_NEEDED
 542 #define USE_LD_AS_NEEDED 1
 543 #endif
 544
 545 #define MD_UNWIND_SUPPORT "config/rs6000/linux-unwind.h"
 546
 547 #ifdef TARGET_LIBC_PROVIDES_SSP
 548 /* ppc32 glibc provides __stack_chk_guard in -0x7008(2),
 549    ppc64 glibc provides it at -0x7010(13).  */
 550 #define TARGET_THREAD_SSP_OFFSET        (TARGET_64BIT ? -0x7010 : -0x7008)
 551 #endif
 552
 553 #define POWERPC_LINUX
 554
 555 /* ppc{32,64} linux has 128-bit long double support in glibc 2.4 and later.  */
 556 #ifdef TARGET_DEFAULT_LONG_DOUBLE_128
 557 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 128
 558 #endif
 559
 560 /* Static stack checking is supported by means of probes.  */
 561 #define STACK_CHECK_STATIC_BUILTIN 1
 562
 563 /* The default value isn't sufficient in 64-bit mode.  */
 564 #define STACK_CHECK_PROTECT (TARGET_64BIT ? 16 * 1024 : 12 * 1024)