gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
   3    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 under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 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 /* The migration of target macros to target hooks works as follows:
  22
  23    1. Create a target hook that uses the existing target macros to
  24       implement the same functionality.
  25
  26    2. Convert all the MI files to use the hook instead of the macro.
  27
  28    3. Repeat for a majority of the remaining target macros.  This will
  29       take some time.
  30
  31    4. Tell target maintainers to start migrating.
  32
  33    5. Eventually convert the backends to override the hook instead of
  34       defining the macros.  This will take some time too.
  35
  36    6. TBD when, poison the macros.  Unmigrated targets will break at
  37       this point.
  38
  39    Note that we expect steps 1-3 to be done by the people that
  40    understand what the MI does with each macro, and step 5 to be done
  41    by the target maintainers for their respective targets.
  42
  43    Note that steps 1 and 2 don't have to be done together, but no
  44    target can override the new hook until step 2 is complete for it.
  45
  46    Once the macros are poisoned, we will revert to the old migration
  47    rules - migrate the macro, callers, and targets all at once.  This
  48    comment can thus be removed at that point.  */
  49
  50 #include "config.h"
  51 #include "system.h"
  52 #include "coretypes.h"
  53 #include "tm.h"
  54 #include "machmode.h"
  55 #include "rtl.h"
  56 #include "tree.h"
  57 #include "expr.h"
  58 #include "output.h"
  59 #include "diagnostic-core.h"
  60 #include "function.h"
  61 #include "target.h"
  62 #include "tm_p.h"
  63 #include "target-def.h"
  64 #include "ggc.h"
  65 #include "hard-reg-set.h"
  66 #include "regs.h"
  67 #include "reload.h"
  68 #include "optabs.h"
  69 #include "recog.h"
  70 #include "intl.h"
  71 #include "opts.h"
  72 #include "tree-flow.h"
  73 #include "tree-ssa-alias.h"
  74
  75
  76 bool
  77 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  78                               rtx addr ATTRIBUTE_UNUSED,
  79                               bool strict ATTRIBUTE_UNUSED)
  80 {
  81 #ifdef GO_IF_LEGITIMATE_ADDRESS
  82   /* Defer to the old implementation using a goto.  */
  83   if (strict)
  84     return strict_memory_address_p (mode, addr);
  85   else
  86     return memory_address_p (mode, addr);
  87 #else
  88   gcc_unreachable ();
  89 #endif
  90 }
  91
  92 void
  93 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  94 {
  95 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  96   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  97 #endif
  98 }
  99
 100 int
 101 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 102 {
 103   int i;
 104
 105   if (GET_CODE (x) == UNSPEC_VOLATILE
 106       /* Any floating arithmetic may trap.  */
 107       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
 108           && flag_trapping_math))
 109     return 1;
 110
 111   for (i = 0; i < XVECLEN (x, 0); ++i)
 112     {
 113       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 114         return 1;
 115     }
 116
 117   return 0;
 118 }
 119
 120 enum machine_mode
 121 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 122                                enum machine_mode mode,
 123                                int *punsignedp ATTRIBUTE_UNUSED,
 124                                const_tree funtype ATTRIBUTE_UNUSED,
 125                                int for_return ATTRIBUTE_UNUSED)
 126 {
 127   if (type != NULL_TREE && for_return == 2)
 128     return promote_mode (type, mode, punsignedp);
 129   return mode;
 130 }
 131
 132 enum machine_mode
 133 default_promote_function_mode_always_promote (const_tree type,
 134                                               enum machine_mode mode,
 135                                               int *punsignedp,
 136                                               const_tree funtype ATTRIBUTE_UNUSED,
 137                                               int for_return ATTRIBUTE_UNUSED)
 138 {
 139   return promote_mode (type, mode, punsignedp);
 140 }
 141
 142
 143 enum machine_mode
 144 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 145 {
 146   if (m1 == m2)
 147     return m1;
 148   return VOIDmode;
 149 }
 150
 151 bool
 152 default_return_in_memory (const_tree type,
 153                           const_tree fntype ATTRIBUTE_UNUSED)
 154 {
 155   return (TYPE_MODE (type) == BLKmode);
 156 }
 157
 158 rtx
 159 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 160                             enum machine_mode mode ATTRIBUTE_UNUSED)
 161 {
 162   return x;
 163 }
 164
 165 rtx
 166 default_expand_builtin_saveregs (void)
 167 {
 168   error ("__builtin_saveregs not supported by this target");
 169   return const0_rtx;
 170 }
 171
 172 void
 173 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 174                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 175                                 tree type ATTRIBUTE_UNUSED,
 176                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 177                                 int second_time ATTRIBUTE_UNUSED)
 178 {
 179 }
 180
 181 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 182
 183 rtx
 184 default_builtin_setjmp_frame_value (void)
 185 {
 186   return virtual_stack_vars_rtx;
 187 }
 188
 189 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 190
 191 bool
 192 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 193 {
 194   return false;
 195 }
 196
 197 bool
 198 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 199 {
 200   return (targetm.calls.setup_incoming_varargs
 201           != default_setup_incoming_varargs);
 202 }
 203
 204 enum machine_mode
 205 default_eh_return_filter_mode (void)
 206 {
 207   return targetm.unwind_word_mode ();
 208 }
 209
 210 enum machine_mode
 211 default_libgcc_cmp_return_mode (void)
 212 {
 213   return word_mode;
 214 }
 215
 216 enum machine_mode
 217 default_libgcc_shift_count_mode (void)
 218 {
 219   return word_mode;
 220 }
 221
 222 enum machine_mode
 223 default_unwind_word_mode (void)
 224 {
 225   return word_mode;
 226 }
 227
 228 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 229
 230 unsigned HOST_WIDE_INT
 231 default_shift_truncation_mask (enum machine_mode mode)
 232 {
 233   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 234 }
 235
 236 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 237
 238 unsigned int
 239 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 240 {
 241   return have_insn_for (DIV, mode) ? 3 : 2;
 242 }
 243
 244 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 245
 246 int
 247 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 248                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 249 {
 250   return UNKNOWN;
 251 }
 252
 253 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 254
 255 bool
 256 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 257 {
 258   return true;
 259 }
 260
 261 /* Return machine mode for non-standard suffix
 262    or VOIDmode if non-standard suffixes are unsupported.  */
 263 enum machine_mode
 264 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 265 {
 266   return VOIDmode;
 267 }
 268
 269 /* The generic C++ ABI specifies this is a 64-bit value.  */
 270 tree
 271 default_cxx_guard_type (void)
 272 {
 273   return long_long_integer_type_node;
 274 }
 275
 276
 277 /* Returns the size of the cookie to use when allocating an array
 278    whose elements have the indicated TYPE.  Assumes that it is already
 279    known that a cookie is needed.  */
 280
 281 tree
 282 default_cxx_get_cookie_size (tree type)
 283 {
 284   tree cookie_size;
 285
 286   /* We need to allocate an additional max (sizeof (size_t), alignof
 287      (true_type)) bytes.  */
 288   tree sizetype_size;
 289   tree type_align;
 290
 291   sizetype_size = size_in_bytes (sizetype);
 292   type_align = size_int (TYPE_ALIGN_UNIT (type));
 293   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 294     cookie_size = sizetype_size;
 295   else
 296     cookie_size = type_align;
 297
 298   return cookie_size;
 299 }
 300
 301 /* Return true if a parameter must be passed by reference.  This version
 302    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 303
 304 bool
 305 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 306         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 307         bool named_arg ATTRIBUTE_UNUSED)
 308 {
 309   return targetm.calls.must_pass_in_stack (mode, type);
 310 }
 311
 312 /* Return true if a parameter follows callee copies conventions.  This
 313    version of the hook is true for all named arguments.  */
 314
 315 bool
 316 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 317                           enum machine_mode mode ATTRIBUTE_UNUSED,
 318                           const_tree type ATTRIBUTE_UNUSED, bool named)
 319 {
 320   return named;
 321 }
 322
 323 /* Emit to STREAM the assembler syntax for insn operand X.  */
 324
 325 void
 326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 327                        int code ATTRIBUTE_UNUSED)
 328 {
 329 #ifdef PRINT_OPERAND
 330   PRINT_OPERAND (stream, x, code);
 331 #else
 332   gcc_unreachable ();
 333 #endif
 334 }
 335
 336 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 337    address is X.  */
 338
 339 void
 340 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 341                                rtx x ATTRIBUTE_UNUSED)
 342 {
 343 #ifdef PRINT_OPERAND_ADDRESS
 344   PRINT_OPERAND_ADDRESS (stream, x);
 345 #else
 346   gcc_unreachable ();
 347 #endif
 348 }
 349
 350 /* Return true if CODE is a valid punctuation character for the
 351    `print_operand' hook.  */
 352
 353 bool
 354 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 355 {
 356 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 357   return PRINT_OPERAND_PUNCT_VALID_P (code);
 358 #else
 359   return false;
 360 #endif
 361 }
 362
 363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 364 tree
 365 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 366 {
 367   const char *skipped = name + (*name == '*' ? 1 : 0);
 368   const char *stripped = targetm.strip_name_encoding (skipped);
 369   if (*name != '*' && user_label_prefix[0])
 370     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 371   return get_identifier (stripped);
 372 }
 373
 374 /* True if MODE is valid for the target.  By "valid", we mean able to
 375    be manipulated in non-trivial ways.  In particular, this means all
 376    the arithmetic is supported.
 377
 378    By default we guess this means that any C type is supported.  If
 379    we can't map the mode back to a type that would be available in C,
 380    then reject it.  Special case, here, is the double-word arithmetic
 381    supported by optabs.c.  */
 382
 383 bool
 384 default_scalar_mode_supported_p (enum machine_mode mode)
 385 {
 386   int precision = GET_MODE_PRECISION (mode);
 387
 388   switch (GET_MODE_CLASS (mode))
 389     {
 390     case MODE_PARTIAL_INT:
 391     case MODE_INT:
 392       if (precision == CHAR_TYPE_SIZE)
 393         return true;
 394       if (precision == SHORT_TYPE_SIZE)
 395         return true;
 396       if (precision == INT_TYPE_SIZE)
 397         return true;
 398       if (precision == LONG_TYPE_SIZE)
 399         return true;
 400       if (precision == LONG_LONG_TYPE_SIZE)
 401         return true;
 402       if (precision == 2 * BITS_PER_WORD)
 403         return true;
 404       return false;
 405
 406     case MODE_FLOAT:
 407       if (precision == FLOAT_TYPE_SIZE)
 408         return true;
 409       if (precision == DOUBLE_TYPE_SIZE)
 410         return true;
 411       if (precision == LONG_DOUBLE_TYPE_SIZE)
 412         return true;
 413       return false;
 414
 415     case MODE_DECIMAL_FLOAT:
 416     case MODE_FRACT:
 417     case MODE_UFRACT:
 418     case MODE_ACCUM:
 419     case MODE_UACCUM:
 420       return false;
 421
 422     default:
 423       gcc_unreachable ();
 424     }
 425 }
 426
 427 /* Make some target macros useable by target-independent code.  */
 428 bool
 429 targhook_words_big_endian (void)
 430 {
 431   return !!WORDS_BIG_ENDIAN;
 432 }
 433
 434 bool
 435 targhook_float_words_big_endian (void)
 436 {
 437   return !!FLOAT_WORDS_BIG_ENDIAN;
 438 }
 439
 440 /* True if the target supports decimal floating point.  */
 441
 442 bool
 443 default_decimal_float_supported_p (void)
 444 {
 445   return ENABLE_DECIMAL_FLOAT;
 446 }
 447
 448 /* True if the target supports fixed-point arithmetic.  */
 449
 450 bool
 451 default_fixed_point_supported_p (void)
 452 {
 453   return ENABLE_FIXED_POINT;
 454 }
 455
 456 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 457    an error message.
 458
 459    This function checks whether a given INSN is valid within a low-overhead
 460    loop.  If INSN is invalid it returns the reason for that, otherwise it
 461    returns NULL. A called function may clobber any special registers required
 462    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 463    register for branch on table instructions. We reject the doloop pattern in
 464    these cases.  */
 465
 466 const char *
 467 default_invalid_within_doloop (const_rtx insn)
 468 {
 469   if (CALL_P (insn))
 470     return "Function call in loop.";
 471
 472   if (JUMP_TABLE_DATA_P (insn))
 473     return "Computed branch in the loop.";
 474
 475   return NULL;
 476 }
 477
 478 /* Mapping of builtin functions to vectorized variants.  */
 479
 480 tree
 481 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 482                                      tree type_out ATTRIBUTE_UNUSED,
 483                                      tree type_in ATTRIBUTE_UNUSED)
 484 {
 485   return NULL_TREE;
 486 }
 487
 488 /* Vectorized conversion.  */
 489
 490 tree
 491 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 492                                        tree dest_type ATTRIBUTE_UNUSED,
 493                                        tree src_type ATTRIBUTE_UNUSED)
 494 {
 495   return NULL_TREE;
 496 }
 497
 498 /* Default vectorizer cost model values.  */
 499
 500 int
 501 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 502                                     tree vectype ATTRIBUTE_UNUSED,
 503                                     int misalign ATTRIBUTE_UNUSED)
 504 {
 505   switch (type_of_cost)
 506     {
 507       case scalar_stmt:
 508       case scalar_load:
 509       case scalar_store:
 510       case vector_stmt:
 511       case vector_load:
 512       case vector_store:
 513       case vec_to_scalar:
 514       case scalar_to_vec:
 515       case cond_branch_not_taken:
 516       case vec_perm:
 517         return 1;
 518
 519       case unaligned_load:
 520       case unaligned_store:
 521         return 2;
 522
 523       case cond_branch_taken:
 524         return 3;
 525
 526       default:
 527         gcc_unreachable ();
 528     }
 529 }
 530
 531 /* Reciprocal.  */
 532
 533 tree
 534 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 535                             bool md_fn ATTRIBUTE_UNUSED,
 536                             bool sqrt ATTRIBUTE_UNUSED)
 537 {
 538   return NULL_TREE;
 539 }
 540
 541 bool
 542 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 543         cumulative_args_t ca ATTRIBUTE_UNUSED,
 544         enum machine_mode mode ATTRIBUTE_UNUSED,
 545         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 546 {
 547   return false;
 548 }
 549
 550 bool
 551 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 552         cumulative_args_t ca ATTRIBUTE_UNUSED,
 553         enum machine_mode mode ATTRIBUTE_UNUSED,
 554         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 555 {
 556   return true;
 557 }
 558
 559 int
 560 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 561         cumulative_args_t ca ATTRIBUTE_UNUSED,
 562         enum machine_mode mode ATTRIBUTE_UNUSED,
 563         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 564 {
 565   return 0;
 566 }
 567
 568 void
 569 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 570                               enum machine_mode mode ATTRIBUTE_UNUSED,
 571                               const_tree type ATTRIBUTE_UNUSED,
 572                               bool named ATTRIBUTE_UNUSED)
 573 {
 574   gcc_unreachable ();
 575 }
 576
 577 rtx
 578 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 579                       enum machine_mode mode ATTRIBUTE_UNUSED,
 580                       const_tree type ATTRIBUTE_UNUSED,
 581                       bool named ATTRIBUTE_UNUSED)
 582 {
 583   gcc_unreachable ();
 584 }
 585
 586 rtx
 587 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 588                                enum machine_mode mode ATTRIBUTE_UNUSED,
 589                                const_tree type ATTRIBUTE_UNUSED,
 590                                bool named ATTRIBUTE_UNUSED)
 591 {
 592   gcc_unreachable ();
 593 }
 594
 595 unsigned int
 596 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 597                                const_tree type ATTRIBUTE_UNUSED)
 598 {
 599   return PARM_BOUNDARY;
 600 }
 601
 602 unsigned int
 603 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 604                                      const_tree type ATTRIBUTE_UNUSED)
 605 {
 606   return PARM_BOUNDARY;
 607 }
 608
 609 void
 610 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 611 {
 612 }
 613
 614 const char *
 615 hook_invalid_arg_for_unprototyped_fn (
 616         const_tree typelist ATTRIBUTE_UNUSED,
 617         const_tree funcdecl ATTRIBUTE_UNUSED,
 618         const_tree val ATTRIBUTE_UNUSED)
 619 {
 620   return NULL;
 621 }
 622
 623 /* Initialize the stack protection decls.  */
 624
 625 /* Stack protection related decls living in libgcc.  */
 626 static GTY(()) tree stack_chk_guard_decl;
 627
 628 tree
 629 default_stack_protect_guard (void)
 630 {
 631   tree t = stack_chk_guard_decl;
 632
 633   if (t == NULL)
 634     {
 635       rtx x;
 636
 637       t = build_decl (UNKNOWN_LOCATION,
 638                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 639                       ptr_type_node);
 640       TREE_STATIC (t) = 1;
 641       TREE_PUBLIC (t) = 1;
 642       DECL_EXTERNAL (t) = 1;
 643       TREE_USED (t) = 1;
 644       TREE_THIS_VOLATILE (t) = 1;
 645       DECL_ARTIFICIAL (t) = 1;
 646       DECL_IGNORED_P (t) = 1;
 647
 648       /* Do not share RTL as the declaration is visible outside of
 649          current function.  */
 650       x = DECL_RTL (t);
 651       RTX_FLAG (x, used) = 1;
 652
 653       stack_chk_guard_decl = t;
 654     }
 655
 656   return t;
 657 }
 658
 659 static GTY(()) tree stack_chk_fail_decl;
 660
 661 tree
 662 default_external_stack_protect_fail (void)
 663 {
 664   tree t = stack_chk_fail_decl;
 665
 666   if (t == NULL_TREE)
 667     {
 668       t = build_function_type_list (void_type_node, NULL_TREE);
 669       t = build_decl (UNKNOWN_LOCATION,
 670                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 671       TREE_STATIC (t) = 1;
 672       TREE_PUBLIC (t) = 1;
 673       DECL_EXTERNAL (t) = 1;
 674       TREE_USED (t) = 1;
 675       TREE_THIS_VOLATILE (t) = 1;
 676       TREE_NOTHROW (t) = 1;
 677       DECL_ARTIFICIAL (t) = 1;
 678       DECL_IGNORED_P (t) = 1;
 679       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 680       DECL_VISIBILITY_SPECIFIED (t) = 1;
 681
 682       stack_chk_fail_decl = t;
 683     }
 684
 685   return build_call_expr (t, 0);
 686 }
 687
 688 tree
 689 default_hidden_stack_protect_fail (void)
 690 {
 691 #ifndef HAVE_GAS_HIDDEN
 692   return default_external_stack_protect_fail ();
 693 #else
 694   tree t = stack_chk_fail_decl;
 695
 696   if (!flag_pic)
 697     return default_external_stack_protect_fail ();
 698
 699   if (t == NULL_TREE)
 700     {
 701       t = build_function_type_list (void_type_node, NULL_TREE);
 702       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 703                       get_identifier ("__stack_chk_fail_local"), t);
 704       TREE_STATIC (t) = 1;
 705       TREE_PUBLIC (t) = 1;
 706       DECL_EXTERNAL (t) = 1;
 707       TREE_USED (t) = 1;
 708       TREE_THIS_VOLATILE (t) = 1;
 709       TREE_NOTHROW (t) = 1;
 710       DECL_ARTIFICIAL (t) = 1;
 711       DECL_IGNORED_P (t) = 1;
 712       DECL_VISIBILITY_SPECIFIED (t) = 1;
 713       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 714
 715       stack_chk_fail_decl = t;
 716     }
 717
 718   return build_call_expr (t, 0);
 719 #endif
 720 }
 721
 722 bool
 723 hook_bool_const_rtx_commutative_p (const_rtx x,
 724                                    int outer_code ATTRIBUTE_UNUSED)
 725 {
 726   return COMMUTATIVE_P (x);
 727 }
 728
 729 rtx
 730 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 731                         const_tree fn_decl_or_type,
 732                         bool outgoing ATTRIBUTE_UNUSED)
 733 {
 734   /* The old interface doesn't handle receiving the function type.  */
 735   if (fn_decl_or_type
 736       && !DECL_P (fn_decl_or_type))
 737     fn_decl_or_type = NULL;
 738
 739 #ifdef FUNCTION_VALUE
 740   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 741 #else
 742   gcc_unreachable ();
 743 #endif
 744 }
 745
 746 rtx
 747 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 748                        const_rtx fun ATTRIBUTE_UNUSED)
 749 {
 750 #ifdef LIBCALL_VALUE
 751   return LIBCALL_VALUE (mode);
 752 #else
 753   gcc_unreachable ();
 754 #endif
 755 }
 756
 757 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 758
 759 bool
 760 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 761 {
 762 #ifdef FUNCTION_VALUE_REGNO_P
 763   return FUNCTION_VALUE_REGNO_P (regno);
 764 #else
 765   gcc_unreachable ();
 766 #endif
 767 }
 768
 769 rtx
 770 default_internal_arg_pointer (void)
 771 {
 772   /* If the reg that the virtual arg pointer will be translated into is
 773      not a fixed reg or is the stack pointer, make a copy of the virtual
 774      arg pointer, and address parms via the copy.  The frame pointer is
 775      considered fixed even though it is not marked as such.  */
 776   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 777        || ! (fixed_regs[ARG_POINTER_REGNUM]
 778              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 779     return copy_to_reg (virtual_incoming_args_rtx);
 780   else
 781     return virtual_incoming_args_rtx;
 782 }
 783
 784 rtx
 785 default_static_chain (const_tree fndecl, bool incoming_p)
 786 {
 787   if (!DECL_STATIC_CHAIN (fndecl))
 788     return NULL;
 789
 790   if (incoming_p)
 791     {
 792 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 793       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 794 #endif
 795     }
 796
 797 #ifdef STATIC_CHAIN_REGNUM
 798   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 799 #endif
 800
 801   {
 802     static bool issued_error;
 803     if (!issued_error)
 804       {
 805         issued_error = true;
 806         sorry ("nested functions not supported on this target");
 807       }
 808
 809     /* It really doesn't matter what we return here, so long at it
 810        doesn't cause the rest of the compiler to crash.  */
 811     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 812   }
 813 }
 814
 815 void
 816 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 817                          rtx ARG_UNUSED (r_chain))
 818 {
 819   sorry ("nested function trampolines not supported on this target");
 820 }
 821
 822 int
 823 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 824                           tree funtype ATTRIBUTE_UNUSED,
 825                           int size ATTRIBUTE_UNUSED)
 826 {
 827   return 0;
 828 }
 829
 830 reg_class_t
 831 default_branch_target_register_class (void)
 832 {
 833   return NO_REGS;
 834 }
 835
 836 reg_class_t
 837 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 838                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 839                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 840                           secondary_reload_info *sri)
 841 {
 842   enum reg_class rclass = NO_REGS;
 843   enum reg_class reload_class = (enum reg_class) reload_class_i;
 844
 845   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 846     {
 847       sri->icode = sri->prev_sri->t_icode;
 848       return NO_REGS;
 849     }
 850 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 851   if (in_p)
 852     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 853 #endif
 854 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 855   if (! in_p)
 856     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 857 #endif
 858   if (rclass != NO_REGS)
 859     {
 860       enum insn_code icode
 861         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 862                                 reload_mode);
 863
 864       if (icode != CODE_FOR_nothing
 865           && !insn_operand_matches (icode, in_p, x))
 866         icode = CODE_FOR_nothing;
 867       else if (icode != CODE_FOR_nothing)
 868         {
 869           const char *insn_constraint, *scratch_constraint;
 870           char insn_letter, scratch_letter;
 871           enum reg_class insn_class, scratch_class;
 872
 873           gcc_assert (insn_data[(int) icode].n_operands == 3);
 874           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 875           if (!*insn_constraint)
 876             insn_class = ALL_REGS;
 877           else
 878             {
 879               if (in_p)
 880                 {
 881                   gcc_assert (*insn_constraint == '=');
 882                   insn_constraint++;
 883                 }
 884               insn_letter = *insn_constraint;
 885               insn_class
 886                 = (insn_letter == 'r' ? GENERAL_REGS
 887                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 888                                                 insn_constraint));
 889               gcc_assert (insn_class != NO_REGS);
 890             }
 891
 892           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 893           /* The scratch register's constraint must start with "=&",
 894              except for an input reload, where only "=" is necessary,
 895              and where it might be beneficial to re-use registers from
 896              the input.  */
 897           gcc_assert (scratch_constraint[0] == '='
 898                       && (in_p || scratch_constraint[1] == '&'));
 899           scratch_constraint++;
 900           if (*scratch_constraint == '&')
 901             scratch_constraint++;
 902           scratch_letter = *scratch_constraint;
 903           scratch_class
 904             = (scratch_letter == 'r' ? GENERAL_REGS
 905                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 906                                             scratch_constraint));
 907
 908           if (reg_class_subset_p (reload_class, insn_class))
 909             {
 910               gcc_assert (scratch_class == rclass);
 911               rclass = NO_REGS;
 912             }
 913           else
 914             rclass = insn_class;
 915
 916         }
 917       if (rclass == NO_REGS)
 918         sri->icode = icode;
 919       else
 920         sri->t_icode = icode;
 921     }
 922   return rclass;
 923 }
 924
 925 /* By default, if flag_pic is true, then neither local nor global relocs
 926    should be placed in readonly memory.  */
 927
 928 int
 929 default_reloc_rw_mask (void)
 930 {
 931   return flag_pic ? 3 : 0;
 932 }
 933
 934 /* By default, do no modification. */
 935 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 936                                          tree id)
 937 {
 938    return id;
 939 }
 940
 941 bool
 942 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 943 {
 944   if (is_packed)
 945     return false;
 946
 947   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 948      naturally aligned.  */
 949   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 950     return false;
 951
 952   /* Assuming that types whose size is <= pointer-size
 953      are naturally aligned.  */
 954   return true;
 955 }
 956
 957 /* By default, assume that a target supports any factor of misalignment
 958    memory access if it supports movmisalign patten.
 959    is_packed is true if the memory access is defined in a packed struct.  */
 960 bool
 961 default_builtin_support_vector_misalignment (enum machine_mode mode,
 962                                              const_tree type
 963                                              ATTRIBUTE_UNUSED,
 964                                              int misalignment
 965                                              ATTRIBUTE_UNUSED,
 966                                              bool is_packed
 967                                              ATTRIBUTE_UNUSED)
 968 {
 969   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
 970     return true;
 971   return false;
 972 }
 973
 974 /* By default, only attempt to parallelize bitwise operations, and
 975    possibly adds/subtracts using bit-twiddling.  */
 976
 977 enum machine_mode
 978 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
 979 {
 980   return word_mode;
 981 }
 982
 983 /* By default only the size derived from the preferred vector mode
 984    is tried.  */
 985
 986 unsigned int
 987 default_autovectorize_vector_sizes (void)
 988 {
 989   return 0;
 990 }
 991
 992 /* Determine whether or not a pointer mode is valid. Assume defaults
 993    of ptr_mode or Pmode - can be overridden.  */
 994 bool
 995 default_valid_pointer_mode (enum machine_mode mode)
 996 {
 997   return (mode == ptr_mode || mode == Pmode);
 998 }
 999
1000 /* Determine whether the memory reference specified by REF may alias
1001    the C libraries errno location.  */
1002 bool
1003 default_ref_may_alias_errno (ao_ref *ref)
1004 {
1005   tree base = ao_ref_base (ref);
1006   /* The default implementation assumes the errno location is
1007      a declaration of type int or is always accessed via a
1008      pointer to int.  We assume that accesses to errno are
1009      not deliberately obfuscated (even in conforming ways).  */
1010   if (TYPE_UNSIGNED (TREE_TYPE (base))
1011       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1012     return false;
1013   /* The default implementation assumes an errno location
1014      declaration is never defined in the current compilation unit.  */
1015   if (DECL_P (base)
1016       && !TREE_STATIC (base))
1017     return true;
1018   else if (TREE_CODE (base) == MEM_REF
1019            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1020     {
1021       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1022       return !pi || pi->pt.anything || pi->pt.nonlocal;
1023     }
1024   return false;
1025 }
1026
1027 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1028    for the generic address space only.  */
1029
1030 enum machine_mode
1031 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1032 {
1033   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1034   return ptr_mode;
1035 }
1036
1037 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1038    for the generic address space only.  */
1039
1040 enum machine_mode
1041 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1042 {
1043   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1044   return Pmode;
1045 }
1046
1047 /* Named address space version of valid_pointer_mode.  */
1048
1049 bool
1050 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1051 {
1052   if (!ADDR_SPACE_GENERIC_P (as))
1053     return (mode == targetm.addr_space.pointer_mode (as)
1054             || mode == targetm.addr_space.address_mode (as));
1055
1056   return targetm.valid_pointer_mode (mode);
1057 }
1058
1059 /* Some places still assume that all pointer or address modes are the
1060    standard Pmode and ptr_mode.  These optimizations become invalid if
1061    the target actually supports multiple different modes.  For now,
1062    we disable such optimizations on such targets, using this function.  */
1063
1064 bool
1065 target_default_pointer_address_modes_p (void)
1066 {
1067   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1068     return false;
1069   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1070     return false;
1071
1072   return true;
1073 }
1074
1075 /* Named address space version of legitimate_address_p.  */
1076
1077 bool
1078 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1079                                          bool strict, addr_space_t as)
1080 {
1081   if (!ADDR_SPACE_GENERIC_P (as))
1082     gcc_unreachable ();
1083
1084   return targetm.legitimate_address_p (mode, mem, strict);
1085 }
1086
1087 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1088
1089 rtx
1090 default_addr_space_legitimize_address (rtx x, rtx oldx,
1091                                        enum machine_mode mode, addr_space_t as)
1092 {
1093   if (!ADDR_SPACE_GENERIC_P (as))
1094     return x;
1095
1096   return targetm.legitimize_address (x, oldx, mode);
1097 }
1098
1099 /* The default hook for determining if one named address space is a subset of
1100    another and to return which address space to use as the common address
1101    space.  */
1102
1103 bool
1104 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1105 {
1106   return (subset == superset);
1107 }
1108
1109 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1110    called for targets with only a generic address space.  */
1111
1112 rtx
1113 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1114                             tree from_type ATTRIBUTE_UNUSED,
1115                             tree to_type ATTRIBUTE_UNUSED)
1116 {
1117   gcc_unreachable ();
1118 }
1119
1120 bool
1121 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1122 {
1123   return true;
1124 }
1125
1126 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1127
1128 bool
1129 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1130 {
1131 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1132
1133   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1134   return false;
1135   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1136  win: ATTRIBUTE_UNUSED_LABEL
1137   return true;
1138
1139 #else
1140
1141   return false;
1142
1143 #endif
1144 }
1145
1146 bool
1147 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1148                                          tree ARG_UNUSED (name),
1149                                          tree ARG_UNUSED (args),
1150                                          int ARG_UNUSED (flags))
1151 {
1152   warning (OPT_Wattributes,
1153            "target attribute is not supported on this machine");
1154
1155   return false;
1156 }
1157
1158 bool
1159 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1160                                     tree ARG_UNUSED (pop_target))
1161 {
1162   warning (OPT_Wpragmas,
1163            "#pragma GCC target is not supported for this machine");
1164
1165   return false;
1166 }
1167
1168 bool
1169 default_target_can_inline_p (tree caller, tree callee)
1170 {
1171   bool ret = false;
1172   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1173   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1174
1175   /* If callee has no option attributes, then it is ok to inline */
1176   if (!callee_opts)
1177     ret = true;
1178
1179   /* If caller has no option attributes, but callee does then it is not ok to
1180      inline */
1181   else if (!caller_opts)
1182     ret = false;
1183
1184   /* If both caller and callee have attributes, assume that if the
1185      pointer is different, the two functions have different target
1186      options since build_target_option_node uses a hash table for the
1187      options.  */
1188   else
1189     ret = (callee_opts == caller_opts);
1190
1191   return ret;
1192 }
1193
1194 #ifndef HAVE_casesi
1195 # define HAVE_casesi 0
1196 #endif
1197
1198 /* If the machine does not have a case insn that compares the bounds,
1199    this means extra overhead for dispatch tables, which raises the
1200    threshold for using them.  */
1201
1202 unsigned int default_case_values_threshold (void)
1203 {
1204   return (HAVE_casesi ? 4 : 5);
1205 }
1206
1207 bool
1208 default_have_conditional_execution (void)
1209 {
1210 #ifdef HAVE_conditional_execution
1211   return HAVE_conditional_execution;
1212 #else
1213   return false;
1214 #endif
1215 }
1216
1217 /* Compute cost of moving registers to/from memory.  */
1218
1219 int
1220 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1221                           reg_class_t rclass ATTRIBUTE_UNUSED,
1222                           bool in ATTRIBUTE_UNUSED)
1223 {
1224 #ifndef MEMORY_MOVE_COST
1225     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1226 #else
1227     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1228 #endif
1229 }
1230
1231 /* Compute cost of moving data from a register of class FROM to one of
1232    TO, using MODE.  */
1233
1234 int
1235 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1236                             reg_class_t from ATTRIBUTE_UNUSED,
1237                             reg_class_t to ATTRIBUTE_UNUSED)
1238 {
1239 #ifndef REGISTER_MOVE_COST
1240   return 2;
1241 #else
1242   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1243 #endif
1244 }
1245
1246 bool
1247 default_profile_before_prologue (void)
1248 {
1249 #ifdef PROFILE_BEFORE_PROLOGUE
1250   return true;
1251 #else
1252   return false;
1253 #endif
1254 }
1255
1256 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1257
1258 reg_class_t
1259 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1260                                 reg_class_t rclass)
1261 {
1262 #ifdef PREFERRED_RELOAD_CLASS
1263   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1264 #else
1265   return rclass;
1266 #endif
1267 }
1268
1269 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1270
1271 reg_class_t
1272 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1273                                        reg_class_t rclass)
1274 {
1275   return rclass;
1276 }
1277
1278 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1279 reg_class_t
1280 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1281 {
1282   return NO_REGS;
1283 }
1284
1285 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1286
1287 bool
1288 default_class_likely_spilled_p (reg_class_t rclass)
1289 {
1290   return (reg_class_size[(int) rclass] == 1);
1291 }
1292
1293 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1294
1295 unsigned char
1296 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1297                          enum machine_mode mode ATTRIBUTE_UNUSED)
1298 {
1299 #ifdef CLASS_MAX_NREGS
1300   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1301 #else
1302   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1303 #endif
1304 }
1305
1306 /* Determine the debugging unwind mechanism for the target.  */
1307
1308 enum unwind_info_type
1309 default_debug_unwind_info (void)
1310 {
1311   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1312   /* ??? Change all users to the hook, then poison this.  */
1313 #ifdef DWARF2_FRAME_INFO
1314   if (DWARF2_FRAME_INFO)
1315     return UI_DWARF2;
1316 #endif
1317
1318   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1319 #ifdef DWARF2_DEBUGGING_INFO
1320   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1321     return UI_DWARF2;
1322 #endif
1323
1324   return UI_NONE;
1325 }
1326
1327 /* To be used by targets where reg_raw_mode doesn't return the right
1328    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1329
1330 enum machine_mode
1331 default_get_reg_raw_mode(int regno)
1332 {
1333   return reg_raw_mode[regno];
1334 }
1335
1336 /* Return true if the state of option OPTION should be stored in PCH files
1337    and checked by default_pch_valid_p.  Store the option's current state
1338    in STATE if so.  */
1339
1340 static inline bool
1341 option_affects_pch_p (int option, struct cl_option_state *state)
1342 {
1343   if ((cl_options[option].flags & CL_TARGET) == 0)
1344     return false;
1345   if (option_flag_var (option, &global_options) == &target_flags)
1346     if (targetm.check_pch_target_flags)
1347       return false;
1348   return get_option_state (&global_options, option, state);
1349 }
1350
1351 /* Default version of get_pch_validity.
1352    By default, every flag difference is fatal; that will be mostly right for
1353    most targets, but completely right for very few.  */
1354
1355 void *
1356 default_get_pch_validity (size_t *sz)
1357 {
1358   struct cl_option_state state;
1359   size_t i;
1360   char *result, *r;
1361
1362   *sz = 2;
1363   if (targetm.check_pch_target_flags)
1364     *sz += sizeof (target_flags);
1365   for (i = 0; i < cl_options_count; i++)
1366     if (option_affects_pch_p (i, &state))
1367       *sz += state.size;
1368
1369   result = r = XNEWVEC (char, *sz);
1370   r[0] = flag_pic;
1371   r[1] = flag_pie;
1372   r += 2;
1373   if (targetm.check_pch_target_flags)
1374     {
1375       memcpy (r, &target_flags, sizeof (target_flags));
1376       r += sizeof (target_flags);
1377     }
1378
1379   for (i = 0; i < cl_options_count; i++)
1380     if (option_affects_pch_p (i, &state))
1381       {
1382         memcpy (r, state.data, state.size);
1383         r += state.size;
1384       }
1385
1386   return result;
1387 }
1388
1389 /* Return a message which says that a PCH file was created with a different
1390    setting of OPTION.  */
1391
1392 static const char *
1393 pch_option_mismatch (const char *option)
1394 {
1395   char *r;
1396
1397   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1398   if (r == NULL)
1399     return _("out of memory");
1400   return r;
1401 }
1402
1403 /* Default version of pch_valid_p.  */
1404
1405 const char *
1406 default_pch_valid_p (const void *data_p, size_t len)
1407 {
1408   struct cl_option_state state;
1409   const char *data = (const char *)data_p;
1410   size_t i;
1411
1412   /* -fpic and -fpie also usually make a PCH invalid.  */
1413   if (data[0] != flag_pic)
1414     return _("created and used with different settings of -fpic");
1415   if (data[1] != flag_pie)
1416     return _("created and used with different settings of -fpie");
1417   data += 2;
1418
1419   /* Check target_flags.  */
1420   if (targetm.check_pch_target_flags)
1421     {
1422       int tf;
1423       const char *r;
1424
1425       memcpy (&tf, data, sizeof (target_flags));
1426       data += sizeof (target_flags);
1427       len -= sizeof (target_flags);
1428       r = targetm.check_pch_target_flags (tf);
1429       if (r != NULL)
1430         return r;
1431     }
1432
1433   for (i = 0; i < cl_options_count; i++)
1434     if (option_affects_pch_p (i, &state))
1435       {
1436         if (memcmp (data, state.data, state.size) != 0)
1437           return pch_option_mismatch (cl_options[i].opt_text);
1438         data += state.size;
1439         len -= state.size;
1440       }
1441
1442   return NULL;
1443 }
1444
1445 #include "gt-targhooks.h"