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  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_POWER6
  77 #undef  PROCESSOR_DEFAULT64
  78 #define PROCESSOR_DEFAULT64 PROCESSOR_POWER6
  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 /* FIXME: This will quite possibly choose the wrong dynamic linker.  */
 176 #undef  LINK_OS_GNU_SPEC
 177 #define LINK_OS_GNU_SPEC LINK_OS_LINUX_SPEC
 178
 179 #ifndef RS6000_BI_ARCH
 180 #define ASM_DEFAULT_SPEC "-mppc64"
 181 #define ASM_SPEC         "%(asm_spec64) %(asm_spec_common)"
 182 #define LINK_OS_LINUX_SPEC "%(link_os_linux_spec64)"
 183 #else
 184 #if DEFAULT_ARCH64_P
 185 #define ASM_DEFAULT_SPEC "-mppc%{!m32:64}"
 186 #define ASM_SPEC         "%{m32:%(asm_spec32)}%{!m32:%(asm_spec64)} %(asm_spec_common)"
 187 #define LINK_OS_LINUX_SPEC "%{m32:%(link_os_linux_spec32)}%{!m32:%(link_os_linux_spec64)}"
 188 #else
 189 #define ASM_DEFAULT_SPEC "-mppc%{m64:64}"
 190 #define ASM_SPEC         "%{!m64:%(asm_spec32)}%{m64:%(asm_spec64)} %(asm_spec_common)"
 191 #define LINK_OS_LINUX_SPEC "%{!m64:%(link_os_linux_spec32)}%{m64:%(link_os_linux_spec64)}"
 192 #endif
 193 #endif
 194
 195 #define ASM_SPEC32 "-a32 %{Ym,*} %{Yd,*} \
 196 %{mrelocatable} %{mrelocatable-lib} %{fpic:-K PIC} %{fPIC:-K PIC} \
 197 %{memb} %{!memb: %{msdata=eabi: -memb}} \
 198 %{!mlittle: %{!mlittle-endian: %{!mbig: %{!mbig-endian: \
 199     %{mcall-freebsd: -mbig} \
 200     %{mcall-i960-old: -mlittle} \
 201     %{mcall-linux: -mbig} \
 202     %{mcall-gnu: -mbig} \
 203     %{mcall-netbsd: -mbig} \
 204 }}}}"
 205
 206 #define ASM_SPEC64 "-a64"
 207
 208 #define ASM_SPEC_COMMON "%(asm_cpu) \
 209 %{,assembler|,assembler-with-cpp: %{mregnames} %{mno-regnames}} \
 210 %{Qy:} %{!Qn:-Qy} \
 211 %{mlittle} %{mlittle-endian} %{mbig} %{mbig-endian}"
 212
 213 #undef  SUBSUBTARGET_EXTRA_SPECS
 214 #define SUBSUBTARGET_EXTRA_SPECS \
 215   { "asm_spec_common",          ASM_SPEC_COMMON },                      \
 216   { "asm_spec32",               ASM_SPEC32 },                           \
 217   { "asm_spec64",               ASM_SPEC64 },                           \
 218   { "link_os_linux_spec32",     LINK_OS_LINUX_SPEC32 },                 \
 219   { "link_os_linux_spec64",     LINK_OS_LINUX_SPEC64 },
 220
 221 #undef  MULTILIB_DEFAULTS
 222 #if DEFAULT_ARCH64_P
 223 #define MULTILIB_DEFAULTS { "m64" }
 224 #else
 225 #define MULTILIB_DEFAULTS { "m32" }
 226 #endif
 227
 228 #ifndef RS6000_BI_ARCH
 229
 230 /* 64-bit PowerPC Linux is always big-endian.  */
 231 #undef  TARGET_LITTLE_ENDIAN
 232 #define TARGET_LITTLE_ENDIAN    0
 233
 234 /* 64-bit PowerPC Linux always has a TOC.  */
 235 #undef  TARGET_TOC
 236 #define TARGET_TOC              1
 237
 238 /* Some things from sysv4.h we don't do when 64 bit.  */
 239 #undef  TARGET_RELOCATABLE
 240 #define TARGET_RELOCATABLE      0
 241 #undef  TARGET_EABI
 242 #define TARGET_EABI             0
 243 #undef  TARGET_PROTOTYPE
 244 #define TARGET_PROTOTYPE        0
 245 #undef RELOCATABLE_NEEDS_FIXUP
 246 #define RELOCATABLE_NEEDS_FIXUP 0
 247
 248 #endif
 249
 250 /* We use glibc _mcount for profiling.  */
 251 #define NO_PROFILE_COUNTERS 1
 252 #define PROFILE_HOOK(LABEL) \
 253   do { if (TARGET_64BIT) output_profile_hook (LABEL); } while (0)
 254
 255 /* PowerPC64 Linux word-aligns FP doubles when -malign-power is given.  */
 256 #undef  ADJUST_FIELD_ALIGN
 257 #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
 258   ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE)     \
 259    ? 128                                                                \
 260    : (TARGET_64BIT                                                      \
 261       && TARGET_ALIGN_NATURAL == 0                                      \
 262       && TYPE_MODE (strip_array_types (TREE_TYPE (FIELD))) == DFmode)   \
 263    ? MIN ((COMPUTED), 32)                                               \
 264    : (COMPUTED))
 265
 266 /* PowerPC64 Linux increases natural record alignment to doubleword if
 267    the first field is an FP double, only if in power alignment mode.  */
 268 #undef  ROUND_TYPE_ALIGN
 269 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)                   \
 270   ((TARGET_64BIT                                                        \
 271     && (TREE_CODE (STRUCT) == RECORD_TYPE                               \
 272         || TREE_CODE (STRUCT) == UNION_TYPE                             \
 273         || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)                       \
 274     && TARGET_ALIGN_NATURAL == 0)                                       \
 275    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)      \
 276    : MAX ((COMPUTED), (SPECIFIED)))
 277
 278 /* Use the default for compiling target libs.  */
 279 #ifdef IN_TARGET_LIBS
 280 #undef TARGET_ALIGN_NATURAL
 281 #define TARGET_ALIGN_NATURAL 1
 282 #endif
 283
 284 /* Indicate that jump tables go in the text section.  */
 285 #undef  JUMP_TABLES_IN_TEXT_SECTION
 286 #define JUMP_TABLES_IN_TEXT_SECTION TARGET_64BIT
 287
 288 /* The linux ppc64 ABI isn't explicit on whether aggregates smaller
 289    than a doubleword should be padded upward or downward.  You could
 290    reasonably assume that they follow the normal rules for structure
 291    layout treating the parameter area as any other block of memory,
 292    then map the reg param area to registers.  i.e. pad upward.
 293    Setting both of the following defines results in this behavior.
 294    Setting just the first one will result in aggregates that fit in a
 295    doubleword being padded downward, and others being padded upward.
 296    Not a bad idea as this results in struct { int x; } being passed
 297    the same way as an int.  */
 298 #define AGGREGATE_PADDING_FIXED TARGET_64BIT
 299 #define AGGREGATES_PAD_UPWARD_ALWAYS 0
 300
 301 /* Specify padding for the last element of a block move between
 302    registers and memory.  FIRST is nonzero if this is the only
 303    element.  */
 304 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 305   (!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
 306
 307 /* Linux doesn't support saving and restoring 64-bit regs in a 32-bit
 308    process.  */
 309 #define OS_MISSING_POWERPC64 !TARGET_64BIT
 310
 311 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
 312
 313 /* glibc has float and long double forms of math functions.  */
 314 #undef  TARGET_C99_FUNCTIONS
 315 #define TARGET_C99_FUNCTIONS (OPTION_GLIBC)
 316
 317 /* Whether we have sincos that follows the GNU extension.  */
 318 #undef  TARGET_HAS_SINCOS
 319 #define TARGET_HAS_SINCOS (OPTION_GLIBC)
 320
 321 #undef  TARGET_OS_CPP_BUILTINS
 322 #define TARGET_OS_CPP_BUILTINS()                        \
 323   do                                                    \
 324     {                                                   \
 325       if (TARGET_64BIT)                                 \
 326         {                                               \
 327           builtin_define ("__PPC__");                   \
 328           builtin_define ("__PPC64__");                 \
 329           builtin_define ("__powerpc__");               \
 330           builtin_define ("__powerpc64__");             \
 331           builtin_assert ("cpu=powerpc64");             \
 332           builtin_assert ("machine=powerpc64");         \
 333         }                                               \
 334       else                                              \
 335         {                                               \
 336           builtin_define_std ("PPC");                   \
 337           builtin_define_std ("powerpc");               \
 338           builtin_assert ("cpu=powerpc");               \
 339           builtin_assert ("machine=powerpc");           \
 340           TARGET_OS_SYSV_CPP_BUILTINS ();               \
 341         }                                               \
 342     }                                                   \
 343   while (0)
 344
 345 #undef  CPP_OS_DEFAULT_SPEC
 346 #define CPP_OS_DEFAULT_SPEC "%(cpp_os_linux)"
 347
 348 /* The GNU C++ standard library currently requires _GNU_SOURCE being
 349    defined on glibc-based systems. This temporary hack accomplishes this,
 350    it should go away as soon as libstdc++-v3 has a real fix.  */
 351 #undef  CPLUSPLUS_CPP_SPEC
 352 #define CPLUSPLUS_CPP_SPEC "-D_GNU_SOURCE %(cpp)"
 353
 354 #undef  LINK_SHLIB_SPEC
 355 #define LINK_SHLIB_SPEC "%{shared:-shared} %{!shared: %{static:-static}}"
 356
 357 #undef  LIB_DEFAULT_SPEC
 358 #define LIB_DEFAULT_SPEC "%(lib_linux)"
 359
 360 #undef  STARTFILE_DEFAULT_SPEC
 361 #define STARTFILE_DEFAULT_SPEC "%(startfile_linux)"
 362
 363 #undef  ENDFILE_DEFAULT_SPEC
 364 #define ENDFILE_DEFAULT_SPEC "%(endfile_linux)"
 365
 366 #undef  LINK_START_DEFAULT_SPEC
 367 #define LINK_START_DEFAULT_SPEC "%(link_start_linux)"
 368
 369 #undef  LINK_OS_DEFAULT_SPEC
 370 #define LINK_OS_DEFAULT_SPEC "%(link_os_linux)"
 371
 372 #define GLIBC_DYNAMIC_LINKER32 "/lib/ld.so.1"
 373 #define GLIBC_DYNAMIC_LINKER64 "/lib64/ld64.so.1"
 374 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 375 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 376 #if DEFAULT_LIBC == LIBC_UCLIBC
 377 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{mglibc:" G ";:" U "}"
 378 #elif DEFAULT_LIBC == LIBC_GLIBC
 379 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{muclibc:" U ";:" G "}"
 380 #else
 381 #error "Unsupported DEFAULT_LIBC"
 382 #endif
 383 #define LINUX_DYNAMIC_LINKER32 \
 384   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32)
 385 #define LINUX_DYNAMIC_LINKER64 \
 386   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64)
 387
 388
 389 #define LINK_OS_LINUX_SPEC32 "-m elf32ppclinux %{!shared: %{!static: \
 390   %{rdynamic:-export-dynamic} \
 391   -dynamic-linker " LINUX_DYNAMIC_LINKER32 "}}"
 392
 393 #define LINK_OS_LINUX_SPEC64 "-m elf64ppc %{!shared: %{!static: \
 394   %{rdynamic:-export-dynamic} \
 395   -dynamic-linker " LINUX_DYNAMIC_LINKER64 "}}"
 396
 397 #undef  TOC_SECTION_ASM_OP
 398 #define TOC_SECTION_ASM_OP \
 399   (TARGET_64BIT                                         \
 400    ? "\t.section\t\".toc\",\"aw\""                      \
 401    : "\t.section\t\".got\",\"aw\"")
 402
 403 #undef  MINIMAL_TOC_SECTION_ASM_OP
 404 #define MINIMAL_TOC_SECTION_ASM_OP \
 405   (TARGET_64BIT                                         \
 406    ? "\t.section\t\".toc1\",\"aw\""                     \
 407    : ((TARGET_RELOCATABLE || flag_pic)                  \
 408       ? "\t.section\t\".got2\",\"aw\""                  \
 409       : "\t.section\t\".got1\",\"aw\""))
 410
 411 #undef  TARGET_VERSION
 412 #define TARGET_VERSION fprintf (stderr, " (PowerPC64 GNU/Linux)");
 413
 414 /* Must be at least as big as our pointer type.  */
 415 #undef  SIZE_TYPE
 416 #define SIZE_TYPE (TARGET_64BIT ? "long unsigned int" : "unsigned int")
 417
 418 #undef  PTRDIFF_TYPE
 419 #define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
 420
 421 #undef  WCHAR_TYPE
 422 #define WCHAR_TYPE (TARGET_64BIT ? "int" : "long int")
 423 #undef  WCHAR_TYPE_SIZE
 424 #define WCHAR_TYPE_SIZE 32
 425
 426 /* Override rs6000.h definition.  */
 427 #undef  ASM_APP_ON
 428 #define ASM_APP_ON "#APP\n"
 429
 430 /* Override rs6000.h definition.  */
 431 #undef  ASM_APP_OFF
 432 #define ASM_APP_OFF "#NO_APP\n"
 433
 434 /* PowerPC no-op instruction.  */
 435 #undef  RS6000_CALL_GLUE
 436 #define RS6000_CALL_GLUE (TARGET_64BIT ? "nop" : "cror 31,31,31")
 437
 438 #undef  RS6000_MCOUNT
 439 #define RS6000_MCOUNT "_mcount"
 440
 441 #ifdef __powerpc64__
 442 /* _init and _fini functions are built from bits spread across many
 443    object files, each potentially with a different TOC pointer.  For
 444    that reason, place a nop after the call so that the linker can
 445    restore the TOC pointer if a TOC adjusting call stub is needed.  */
 446 #if DOT_SYMBOLS
 447 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)      \
 448   asm (SECTION_OP "\n"                                  \
 449 "       bl ." #FUNC "\n"                                \
 450 "       nop\n"                                          \
 451 "       .previous");
 452 #else
 453 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)      \
 454   asm (SECTION_OP "\n"                                  \
 455 "       bl " #FUNC "\n"                                 \
 456 "       nop\n"                                          \
 457 "       .previous");
 458 #endif
 459 #endif
 460
 461 /* FP save and restore routines.  */
 462 #undef  SAVE_FP_PREFIX
 463 #define SAVE_FP_PREFIX (TARGET_64BIT ? "._savef" : "_savefpr_")
 464 #undef  SAVE_FP_SUFFIX
 465 #define SAVE_FP_SUFFIX ""
 466 #undef  RESTORE_FP_PREFIX
 467 #define RESTORE_FP_PREFIX (TARGET_64BIT ? "._restf" : "_restfpr_")
 468 #undef  RESTORE_FP_SUFFIX
 469 #define RESTORE_FP_SUFFIX ""
 470
 471 /* Dwarf2 debugging.  */
 472 #undef  PREFERRED_DEBUGGING_TYPE
 473 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
 474
 475 /* This is how to declare the size of a function.  */
 476 #undef  ASM_DECLARE_FUNCTION_SIZE
 477 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)                    \
 478   do                                                                    \
 479     {                                                                   \
 480       if (!flag_inhibit_size_directive)                                 \
 481         {                                                               \
 482           fputs ("\t.size\t", (FILE));                                  \
 483           if (TARGET_64BIT && DOT_SYMBOLS)                              \
 484             putc ('.', (FILE));                                         \
 485           assemble_name ((FILE), (FNAME));                              \
 486           fputs (",.-", (FILE));                                        \
 487           rs6000_output_function_entry (FILE, FNAME);                   \
 488           putc ('\n', (FILE));                                          \
 489         }                                                               \
 490     }                                                                   \
 491   while (0)
 492
 493 /* Return nonzero if this entry is to be written into the constant
 494    pool in a special way.  We do so if this is a SYMBOL_REF, LABEL_REF
 495    or a CONST containing one of them.  If -mfp-in-toc (the default),
 496    we also do this for floating-point constants.  We actually can only
 497    do this if the FP formats of the target and host machines are the
 498    same, but we can't check that since not every file that uses
 499    the macros includes real.h.  We also do this when we can write the
 500    entry into the TOC and the entry is not larger than a TOC entry.  */
 501
 502 #undef  ASM_OUTPUT_SPECIAL_POOL_ENTRY_P
 503 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY_P(X, MODE)                        \
 504   (TARGET_TOC                                                           \
 505    && (GET_CODE (X) == SYMBOL_REF                                       \
 506        || (GET_CODE (X) == CONST && GET_CODE (XEXP (X, 0)) == PLUS      \
 507            && GET_CODE (XEXP (XEXP (X, 0), 0)) == SYMBOL_REF)           \
 508        || GET_CODE (X) == LABEL_REF                                     \
 509        || (GET_CODE (X) == CONST_INT                                    \
 510            && GET_MODE_BITSIZE (MODE) <= GET_MODE_BITSIZE (Pmode))      \
 511        || (GET_CODE (X) == CONST_DOUBLE                                 \
 512            && ((TARGET_64BIT                                            \
 513                 && (TARGET_MINIMAL_TOC                                  \
 514                     || (SCALAR_FLOAT_MODE_P (GET_MODE (X))              \
 515                         && ! TARGET_NO_FP_IN_TOC)))                     \
 516                || (!TARGET_64BIT                                        \
 517                    && !TARGET_NO_FP_IN_TOC                              \
 518                    && !TARGET_RELOCATABLE                               \
 519                    && SCALAR_FLOAT_MODE_P (GET_MODE (X))                \
 520                    && BITS_PER_WORD == HOST_BITS_PER_INT)))))
 521
 522 /* Select a format to encode pointers in exception handling data.  CODE
 523    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
 524    true if the symbol may be affected by dynamic relocations.  */
 525 #undef  ASM_PREFERRED_EH_DATA_FORMAT
 526 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
 527   ((TARGET_64BIT || flag_pic || TARGET_RELOCATABLE)                     \
 528    ? (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel               \
 529       | (TARGET_64BIT ? DW_EH_PE_udata8 : DW_EH_PE_sdata4))             \
 530    : DW_EH_PE_absptr)
 531
 532 /* For backward compatibility, we must continue to use the AIX
 533    structure return convention.  */
 534 #undef DRAFT_V4_STRUCT_RET
 535 #define DRAFT_V4_STRUCT_RET (!TARGET_64BIT)
 536
 537 #define TARGET_ASM_FILE_END rs6000_elf_end_indicate_exec_stack
 538
 539 #define TARGET_POSIX_IO
 540
 541 #define LINK_GCC_C_SEQUENCE_SPEC \
 542   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
 543
 544 /* Use --as-needed -lgcc_s for eh support.  */
 545 #ifdef HAVE_LD_AS_NEEDED
 546 #define USE_LD_AS_NEEDED 1
 547 #endif
 548
 549 #define MD_UNWIND_SUPPORT "config/rs6000/linux-unwind.h"
 550
 551 #ifdef TARGET_LIBC_PROVIDES_SSP
 552 /* ppc32 glibc provides __stack_chk_guard in -0x7008(2),
 553    ppc64 glibc provides it at -0x7010(13).  */
 554 #define TARGET_THREAD_SSP_OFFSET        (TARGET_64BIT ? -0x7010 : -0x7008)
 555 #endif
 556
 557 #define POWERPC_LINUX
 558
 559 /* ppc{32,64} linux has 128-bit long double support in glibc 2.4 and later.  */
 560 #ifdef TARGET_DEFAULT_LONG_DOUBLE_128
 561 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 128
 562 #endif
 563
 564 /* Static stack checking is supported by means of probes.  */
 565 #define STACK_CHECK_STATIC_BUILTIN 1
 566
 567 /* The default value isn't sufficient in 64-bit mode.  */
 568 #define STACK_CHECK_PROTECT (TARGET_64BIT ? 16 * 1024 : 12 * 1024)