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       case vec_promote_demote:
 518         return 1;
 519
 520       case unaligned_load:
 521       case unaligned_store:
 522         return 2;
 523
 524       case cond_branch_taken:
 525         return 3;
 526
 527       default:
 528         gcc_unreachable ();
 529     }
 530 }
 531
 532 /* Reciprocal.  */
 533
 534 tree
 535 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 536                             bool md_fn ATTRIBUTE_UNUSED,
 537                             bool sqrt ATTRIBUTE_UNUSED)
 538 {
 539   return NULL_TREE;
 540 }
 541
 542 bool
 543 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 544         cumulative_args_t ca ATTRIBUTE_UNUSED,
 545         enum machine_mode mode ATTRIBUTE_UNUSED,
 546         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 547 {
 548   return false;
 549 }
 550
 551 bool
 552 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 553         cumulative_args_t ca ATTRIBUTE_UNUSED,
 554         enum machine_mode mode ATTRIBUTE_UNUSED,
 555         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 556 {
 557   return true;
 558 }
 559
 560 int
 561 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 562         cumulative_args_t ca ATTRIBUTE_UNUSED,
 563         enum machine_mode mode ATTRIBUTE_UNUSED,
 564         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 565 {
 566   return 0;
 567 }
 568
 569 void
 570 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 571                               enum machine_mode mode ATTRIBUTE_UNUSED,
 572                               const_tree type ATTRIBUTE_UNUSED,
 573                               bool named ATTRIBUTE_UNUSED)
 574 {
 575   gcc_unreachable ();
 576 }
 577
 578 rtx
 579 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 580                       enum machine_mode mode ATTRIBUTE_UNUSED,
 581                       const_tree type ATTRIBUTE_UNUSED,
 582                       bool named ATTRIBUTE_UNUSED)
 583 {
 584   gcc_unreachable ();
 585 }
 586
 587 rtx
 588 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 589                                enum machine_mode mode ATTRIBUTE_UNUSED,
 590                                const_tree type ATTRIBUTE_UNUSED,
 591                                bool named ATTRIBUTE_UNUSED)
 592 {
 593   gcc_unreachable ();
 594 }
 595
 596 unsigned int
 597 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 598                                const_tree type ATTRIBUTE_UNUSED)
 599 {
 600   return PARM_BOUNDARY;
 601 }
 602
 603 unsigned int
 604 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 605                                      const_tree type ATTRIBUTE_UNUSED)
 606 {
 607   return PARM_BOUNDARY;
 608 }
 609
 610 void
 611 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 612 {
 613 }
 614
 615 const char *
 616 hook_invalid_arg_for_unprototyped_fn (
 617         const_tree typelist ATTRIBUTE_UNUSED,
 618         const_tree funcdecl ATTRIBUTE_UNUSED,
 619         const_tree val ATTRIBUTE_UNUSED)
 620 {
 621   return NULL;
 622 }
 623
 624 /* Initialize the stack protection decls.  */
 625
 626 /* Stack protection related decls living in libgcc.  */
 627 static GTY(()) tree stack_chk_guard_decl;
 628
 629 tree
 630 default_stack_protect_guard (void)
 631 {
 632   tree t = stack_chk_guard_decl;
 633
 634   if (t == NULL)
 635     {
 636       rtx x;
 637
 638       t = build_decl (UNKNOWN_LOCATION,
 639                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 640                       ptr_type_node);
 641       TREE_STATIC (t) = 1;
 642       TREE_PUBLIC (t) = 1;
 643       DECL_EXTERNAL (t) = 1;
 644       TREE_USED (t) = 1;
 645       TREE_THIS_VOLATILE (t) = 1;
 646       DECL_ARTIFICIAL (t) = 1;
 647       DECL_IGNORED_P (t) = 1;
 648
 649       /* Do not share RTL as the declaration is visible outside of
 650          current function.  */
 651       x = DECL_RTL (t);
 652       RTX_FLAG (x, used) = 1;
 653
 654       stack_chk_guard_decl = t;
 655     }
 656
 657   return t;
 658 }
 659
 660 static GTY(()) tree stack_chk_fail_decl;
 661
 662 tree
 663 default_external_stack_protect_fail (void)
 664 {
 665   tree t = stack_chk_fail_decl;
 666
 667   if (t == NULL_TREE)
 668     {
 669       t = build_function_type_list (void_type_node, NULL_TREE);
 670       t = build_decl (UNKNOWN_LOCATION,
 671                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 672       TREE_STATIC (t) = 1;
 673       TREE_PUBLIC (t) = 1;
 674       DECL_EXTERNAL (t) = 1;
 675       TREE_USED (t) = 1;
 676       TREE_THIS_VOLATILE (t) = 1;
 677       TREE_NOTHROW (t) = 1;
 678       DECL_ARTIFICIAL (t) = 1;
 679       DECL_IGNORED_P (t) = 1;
 680       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 681       DECL_VISIBILITY_SPECIFIED (t) = 1;
 682
 683       stack_chk_fail_decl = t;
 684     }
 685
 686   return build_call_expr (t, 0);
 687 }
 688
 689 tree
 690 default_hidden_stack_protect_fail (void)
 691 {
 692 #ifndef HAVE_GAS_HIDDEN
 693   return default_external_stack_protect_fail ();
 694 #else
 695   tree t = stack_chk_fail_decl;
 696
 697   if (!flag_pic)
 698     return default_external_stack_protect_fail ();
 699
 700   if (t == NULL_TREE)
 701     {
 702       t = build_function_type_list (void_type_node, NULL_TREE);
 703       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 704                       get_identifier ("__stack_chk_fail_local"), t);
 705       TREE_STATIC (t) = 1;
 706       TREE_PUBLIC (t) = 1;
 707       DECL_EXTERNAL (t) = 1;
 708       TREE_USED (t) = 1;
 709       TREE_THIS_VOLATILE (t) = 1;
 710       TREE_NOTHROW (t) = 1;
 711       DECL_ARTIFICIAL (t) = 1;
 712       DECL_IGNORED_P (t) = 1;
 713       DECL_VISIBILITY_SPECIFIED (t) = 1;
 714       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 715
 716       stack_chk_fail_decl = t;
 717     }
 718
 719   return build_call_expr (t, 0);
 720 #endif
 721 }
 722
 723 bool
 724 hook_bool_const_rtx_commutative_p (const_rtx x,
 725                                    int outer_code ATTRIBUTE_UNUSED)
 726 {
 727   return COMMUTATIVE_P (x);
 728 }
 729
 730 rtx
 731 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 732                         const_tree fn_decl_or_type,
 733                         bool outgoing ATTRIBUTE_UNUSED)
 734 {
 735   /* The old interface doesn't handle receiving the function type.  */
 736   if (fn_decl_or_type
 737       && !DECL_P (fn_decl_or_type))
 738     fn_decl_or_type = NULL;
 739
 740 #ifdef FUNCTION_VALUE
 741   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 742 #else
 743   gcc_unreachable ();
 744 #endif
 745 }
 746
 747 rtx
 748 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 749                        const_rtx fun ATTRIBUTE_UNUSED)
 750 {
 751 #ifdef LIBCALL_VALUE
 752   return LIBCALL_VALUE (mode);
 753 #else
 754   gcc_unreachable ();
 755 #endif
 756 }
 757
 758 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 759
 760 bool
 761 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 762 {
 763 #ifdef FUNCTION_VALUE_REGNO_P
 764   return FUNCTION_VALUE_REGNO_P (regno);
 765 #else
 766   gcc_unreachable ();
 767 #endif
 768 }
 769
 770 rtx
 771 default_internal_arg_pointer (void)
 772 {
 773   /* If the reg that the virtual arg pointer will be translated into is
 774      not a fixed reg or is the stack pointer, make a copy of the virtual
 775      arg pointer, and address parms via the copy.  The frame pointer is
 776      considered fixed even though it is not marked as such.  */
 777   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 778        || ! (fixed_regs[ARG_POINTER_REGNUM]
 779              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 780     return copy_to_reg (virtual_incoming_args_rtx);
 781   else
 782     return virtual_incoming_args_rtx;
 783 }
 784
 785 rtx
 786 default_static_chain (const_tree fndecl, bool incoming_p)
 787 {
 788   if (!DECL_STATIC_CHAIN (fndecl))
 789     return NULL;
 790
 791   if (incoming_p)
 792     {
 793 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 794       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 795 #endif
 796     }
 797
 798 #ifdef STATIC_CHAIN_REGNUM
 799   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 800 #endif
 801
 802   {
 803     static bool issued_error;
 804     if (!issued_error)
 805       {
 806         issued_error = true;
 807         sorry ("nested functions not supported on this target");
 808       }
 809
 810     /* It really doesn't matter what we return here, so long at it
 811        doesn't cause the rest of the compiler to crash.  */
 812     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 813   }
 814 }
 815
 816 void
 817 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 818                          rtx ARG_UNUSED (r_chain))
 819 {
 820   sorry ("nested function trampolines not supported on this target");
 821 }
 822
 823 int
 824 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 825                           tree funtype ATTRIBUTE_UNUSED,
 826                           int size ATTRIBUTE_UNUSED)
 827 {
 828   return 0;
 829 }
 830
 831 reg_class_t
 832 default_branch_target_register_class (void)
 833 {
 834   return NO_REGS;
 835 }
 836
 837 reg_class_t
 838 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 839                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 840                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 841                           secondary_reload_info *sri)
 842 {
 843   enum reg_class rclass = NO_REGS;
 844   enum reg_class reload_class = (enum reg_class) reload_class_i;
 845
 846   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 847     {
 848       sri->icode = sri->prev_sri->t_icode;
 849       return NO_REGS;
 850     }
 851 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 852   if (in_p)
 853     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 854 #endif
 855 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 856   if (! in_p)
 857     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 858 #endif
 859   if (rclass != NO_REGS)
 860     {
 861       enum insn_code icode
 862         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 863                                 reload_mode);
 864
 865       if (icode != CODE_FOR_nothing
 866           && !insn_operand_matches (icode, in_p, x))
 867         icode = CODE_FOR_nothing;
 868       else if (icode != CODE_FOR_nothing)
 869         {
 870           const char *insn_constraint, *scratch_constraint;
 871           char insn_letter, scratch_letter;
 872           enum reg_class insn_class, scratch_class;
 873
 874           gcc_assert (insn_data[(int) icode].n_operands == 3);
 875           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 876           if (!*insn_constraint)
 877             insn_class = ALL_REGS;
 878           else
 879             {
 880               if (in_p)
 881                 {
 882                   gcc_assert (*insn_constraint == '=');
 883                   insn_constraint++;
 884                 }
 885               insn_letter = *insn_constraint;
 886               insn_class
 887                 = (insn_letter == 'r' ? GENERAL_REGS
 888                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 889                                                 insn_constraint));
 890               gcc_assert (insn_class != NO_REGS);
 891             }
 892
 893           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 894           /* The scratch register's constraint must start with "=&",
 895              except for an input reload, where only "=" is necessary,
 896              and where it might be beneficial to re-use registers from
 897              the input.  */
 898           gcc_assert (scratch_constraint[0] == '='
 899                       && (in_p || scratch_constraint[1] == '&'));
 900           scratch_constraint++;
 901           if (*scratch_constraint == '&')
 902             scratch_constraint++;
 903           scratch_letter = *scratch_constraint;
 904           scratch_class
 905             = (scratch_letter == 'r' ? GENERAL_REGS
 906                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 907                                             scratch_constraint));
 908
 909           if (reg_class_subset_p (reload_class, insn_class))
 910             {
 911               gcc_assert (scratch_class == rclass);
 912               rclass = NO_REGS;
 913             }
 914           else
 915             rclass = insn_class;
 916
 917         }
 918       if (rclass == NO_REGS)
 919         sri->icode = icode;
 920       else
 921         sri->t_icode = icode;
 922     }
 923   return rclass;
 924 }
 925
 926 /* By default, if flag_pic is true, then neither local nor global relocs
 927    should be placed in readonly memory.  */
 928
 929 int
 930 default_reloc_rw_mask (void)
 931 {
 932   return flag_pic ? 3 : 0;
 933 }
 934
 935 /* By default, do no modification. */
 936 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 937                                          tree id)
 938 {
 939    return id;
 940 }
 941
 942 /* Default to natural alignment for vector types.  */
 943 HOST_WIDE_INT
 944 default_vector_alignment (const_tree type)
 945 {
 946   return tree_low_cst (TYPE_SIZE (type), 0);
 947 }
 948
 949 bool
 950 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 951 {
 952   if (is_packed)
 953     return false;
 954
 955   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 956      naturally aligned.  */
 957   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 958     return false;
 959
 960   /* Assuming that types whose size is <= pointer-size
 961      are naturally aligned.  */
 962   return true;
 963 }
 964
 965 /* By default, assume that a target supports any factor of misalignment
 966    memory access if it supports movmisalign patten.
 967    is_packed is true if the memory access is defined in a packed struct.  */
 968 bool
 969 default_builtin_support_vector_misalignment (enum machine_mode mode,
 970                                              const_tree type
 971                                              ATTRIBUTE_UNUSED,
 972                                              int misalignment
 973                                              ATTRIBUTE_UNUSED,
 974                                              bool is_packed
 975                                              ATTRIBUTE_UNUSED)
 976 {
 977   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
 978     return true;
 979   return false;
 980 }
 981
 982 /* By default, only attempt to parallelize bitwise operations, and
 983    possibly adds/subtracts using bit-twiddling.  */
 984
 985 enum machine_mode
 986 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
 987 {
 988   return word_mode;
 989 }
 990
 991 /* By default only the size derived from the preferred vector mode
 992    is tried.  */
 993
 994 unsigned int
 995 default_autovectorize_vector_sizes (void)
 996 {
 997   return 0;
 998 }
 999
1000 /* Determine whether or not a pointer mode is valid. Assume defaults
1001    of ptr_mode or Pmode - can be overridden.  */
1002 bool
1003 default_valid_pointer_mode (enum machine_mode mode)
1004 {
1005   return (mode == ptr_mode || mode == Pmode);
1006 }
1007
1008 /* Determine whether the memory reference specified by REF may alias
1009    the C libraries errno location.  */
1010 bool
1011 default_ref_may_alias_errno (ao_ref *ref)
1012 {
1013   tree base = ao_ref_base (ref);
1014   /* The default implementation assumes the errno location is
1015      a declaration of type int or is always accessed via a
1016      pointer to int.  We assume that accesses to errno are
1017      not deliberately obfuscated (even in conforming ways).  */
1018   if (TYPE_UNSIGNED (TREE_TYPE (base))
1019       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1020     return false;
1021   /* The default implementation assumes an errno location
1022      declaration is never defined in the current compilation unit.  */
1023   if (DECL_P (base)
1024       && !TREE_STATIC (base))
1025     return true;
1026   else if (TREE_CODE (base) == MEM_REF
1027            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1028     {
1029       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1030       return !pi || pi->pt.anything || pi->pt.nonlocal;
1031     }
1032   return false;
1033 }
1034
1035 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1036    for the generic address space only.  */
1037
1038 enum machine_mode
1039 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1040 {
1041   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1042   return ptr_mode;
1043 }
1044
1045 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1046    for the generic address space only.  */
1047
1048 enum machine_mode
1049 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1050 {
1051   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1052   return Pmode;
1053 }
1054
1055 /* Named address space version of valid_pointer_mode.  */
1056
1057 bool
1058 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1059 {
1060   if (!ADDR_SPACE_GENERIC_P (as))
1061     return (mode == targetm.addr_space.pointer_mode (as)
1062             || mode == targetm.addr_space.address_mode (as));
1063
1064   return targetm.valid_pointer_mode (mode);
1065 }
1066
1067 /* Some places still assume that all pointer or address modes are the
1068    standard Pmode and ptr_mode.  These optimizations become invalid if
1069    the target actually supports multiple different modes.  For now,
1070    we disable such optimizations on such targets, using this function.  */
1071
1072 bool
1073 target_default_pointer_address_modes_p (void)
1074 {
1075   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1076     return false;
1077   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1078     return false;
1079
1080   return true;
1081 }
1082
1083 /* Named address space version of legitimate_address_p.  */
1084
1085 bool
1086 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1087                                          bool strict, addr_space_t as)
1088 {
1089   if (!ADDR_SPACE_GENERIC_P (as))
1090     gcc_unreachable ();
1091
1092   return targetm.legitimate_address_p (mode, mem, strict);
1093 }
1094
1095 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1096
1097 rtx
1098 default_addr_space_legitimize_address (rtx x, rtx oldx,
1099                                        enum machine_mode mode, addr_space_t as)
1100 {
1101   if (!ADDR_SPACE_GENERIC_P (as))
1102     return x;
1103
1104   return targetm.legitimize_address (x, oldx, mode);
1105 }
1106
1107 /* The default hook for determining if one named address space is a subset of
1108    another and to return which address space to use as the common address
1109    space.  */
1110
1111 bool
1112 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1113 {
1114   return (subset == superset);
1115 }
1116
1117 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1118    called for targets with only a generic address space.  */
1119
1120 rtx
1121 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1122                             tree from_type ATTRIBUTE_UNUSED,
1123                             tree to_type ATTRIBUTE_UNUSED)
1124 {
1125   gcc_unreachable ();
1126 }
1127
1128 bool
1129 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1130 {
1131   return true;
1132 }
1133
1134 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1135
1136 bool
1137 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1138 {
1139 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1140
1141   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1142   return false;
1143   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1144  win: ATTRIBUTE_UNUSED_LABEL
1145   return true;
1146
1147 #else
1148
1149   return false;
1150
1151 #endif
1152 }
1153
1154 bool
1155 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1156                                          tree ARG_UNUSED (name),
1157                                          tree ARG_UNUSED (args),
1158                                          int ARG_UNUSED (flags))
1159 {
1160   warning (OPT_Wattributes,
1161            "target attribute is not supported on this machine");
1162
1163   return false;
1164 }
1165
1166 bool
1167 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1168                                     tree ARG_UNUSED (pop_target))
1169 {
1170   warning (OPT_Wpragmas,
1171            "#pragma GCC target is not supported for this machine");
1172
1173   return false;
1174 }
1175
1176 bool
1177 default_target_can_inline_p (tree caller, tree callee)
1178 {
1179   bool ret = false;
1180   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1181   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1182
1183   /* If callee has no option attributes, then it is ok to inline */
1184   if (!callee_opts)
1185     ret = true;
1186
1187   /* If caller has no option attributes, but callee does then it is not ok to
1188      inline */
1189   else if (!caller_opts)
1190     ret = false;
1191
1192   /* If both caller and callee have attributes, assume that if the
1193      pointer is different, the two functions have different target
1194      options since build_target_option_node uses a hash table for the
1195      options.  */
1196   else
1197     ret = (callee_opts == caller_opts);
1198
1199   return ret;
1200 }
1201
1202 #ifndef HAVE_casesi
1203 # define HAVE_casesi 0
1204 #endif
1205
1206 /* If the machine does not have a case insn that compares the bounds,
1207    this means extra overhead for dispatch tables, which raises the
1208    threshold for using them.  */
1209
1210 unsigned int default_case_values_threshold (void)
1211 {
1212   return (HAVE_casesi ? 4 : 5);
1213 }
1214
1215 bool
1216 default_have_conditional_execution (void)
1217 {
1218 #ifdef HAVE_conditional_execution
1219   return HAVE_conditional_execution;
1220 #else
1221   return false;
1222 #endif
1223 }
1224
1225 tree
1226 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1227 {
1228   return NULL_TREE;
1229 }
1230
1231 /* Compute cost of moving registers to/from memory.  */
1232
1233 int
1234 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1235                           reg_class_t rclass ATTRIBUTE_UNUSED,
1236                           bool in ATTRIBUTE_UNUSED)
1237 {
1238 #ifndef MEMORY_MOVE_COST
1239     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1240 #else
1241     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1242 #endif
1243 }
1244
1245 /* Compute cost of moving data from a register of class FROM to one of
1246    TO, using MODE.  */
1247
1248 int
1249 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1250                             reg_class_t from ATTRIBUTE_UNUSED,
1251                             reg_class_t to ATTRIBUTE_UNUSED)
1252 {
1253 #ifndef REGISTER_MOVE_COST
1254   return 2;
1255 #else
1256   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1257 #endif
1258 }
1259
1260 bool
1261 default_profile_before_prologue (void)
1262 {
1263 #ifdef PROFILE_BEFORE_PROLOGUE
1264   return true;
1265 #else
1266   return false;
1267 #endif
1268 }
1269
1270 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1271
1272 reg_class_t
1273 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1274                                 reg_class_t rclass)
1275 {
1276 #ifdef PREFERRED_RELOAD_CLASS
1277   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1278 #else
1279   return rclass;
1280 #endif
1281 }
1282
1283 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1284
1285 reg_class_t
1286 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1287                                        reg_class_t rclass)
1288 {
1289   return rclass;
1290 }
1291
1292 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1293 reg_class_t
1294 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1295 {
1296   return NO_REGS;
1297 }
1298
1299 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1300
1301 bool
1302 default_class_likely_spilled_p (reg_class_t rclass)
1303 {
1304   return (reg_class_size[(int) rclass] == 1);
1305 }
1306
1307 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1308
1309 unsigned char
1310 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1311                          enum machine_mode mode ATTRIBUTE_UNUSED)
1312 {
1313 #ifdef CLASS_MAX_NREGS
1314   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1315 #else
1316   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1317 #endif
1318 }
1319
1320 /* Determine the debugging unwind mechanism for the target.  */
1321
1322 enum unwind_info_type
1323 default_debug_unwind_info (void)
1324 {
1325   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1326   /* ??? Change all users to the hook, then poison this.  */
1327 #ifdef DWARF2_FRAME_INFO
1328   if (DWARF2_FRAME_INFO)
1329     return UI_DWARF2;
1330 #endif
1331
1332   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1333 #ifdef DWARF2_DEBUGGING_INFO
1334   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1335     return UI_DWARF2;
1336 #endif
1337
1338   return UI_NONE;
1339 }
1340
1341 /* To be used by targets where reg_raw_mode doesn't return the right
1342    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1343
1344 enum machine_mode
1345 default_get_reg_raw_mode(int regno)
1346 {
1347   return reg_raw_mode[regno];
1348 }
1349
1350 /* Return true if the state of option OPTION should be stored in PCH files
1351    and checked by default_pch_valid_p.  Store the option's current state
1352    in STATE if so.  */
1353
1354 static inline bool
1355 option_affects_pch_p (int option, struct cl_option_state *state)
1356 {
1357   if ((cl_options[option].flags & CL_TARGET) == 0)
1358     return false;
1359   if (option_flag_var (option, &global_options) == &target_flags)
1360     if (targetm.check_pch_target_flags)
1361       return false;
1362   return get_option_state (&global_options, option, state);
1363 }
1364
1365 /* Default version of get_pch_validity.
1366    By default, every flag difference is fatal; that will be mostly right for
1367    most targets, but completely right for very few.  */
1368
1369 void *
1370 default_get_pch_validity (size_t *sz)
1371 {
1372   struct cl_option_state state;
1373   size_t i;
1374   char *result, *r;
1375
1376   *sz = 2;
1377   if (targetm.check_pch_target_flags)
1378     *sz += sizeof (target_flags);
1379   for (i = 0; i < cl_options_count; i++)
1380     if (option_affects_pch_p (i, &state))
1381       *sz += state.size;
1382
1383   result = r = XNEWVEC (char, *sz);
1384   r[0] = flag_pic;
1385   r[1] = flag_pie;
1386   r += 2;
1387   if (targetm.check_pch_target_flags)
1388     {
1389       memcpy (r, &target_flags, sizeof (target_flags));
1390       r += sizeof (target_flags);
1391     }
1392
1393   for (i = 0; i < cl_options_count; i++)
1394     if (option_affects_pch_p (i, &state))
1395       {
1396         memcpy (r, state.data, state.size);
1397         r += state.size;
1398       }
1399
1400   return result;
1401 }
1402
1403 /* Return a message which says that a PCH file was created with a different
1404    setting of OPTION.  */
1405
1406 static const char *
1407 pch_option_mismatch (const char *option)
1408 {
1409   char *r;
1410
1411   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1412   if (r == NULL)
1413     return _("out of memory");
1414   return r;
1415 }
1416
1417 /* Default version of pch_valid_p.  */
1418
1419 const char *
1420 default_pch_valid_p (const void *data_p, size_t len)
1421 {
1422   struct cl_option_state state;
1423   const char *data = (const char *)data_p;
1424   size_t i;
1425
1426   /* -fpic and -fpie also usually make a PCH invalid.  */
1427   if (data[0] != flag_pic)
1428     return _("created and used with different settings of -fpic");
1429   if (data[1] != flag_pie)
1430     return _("created and used with different settings of -fpie");
1431   data += 2;
1432
1433   /* Check target_flags.  */
1434   if (targetm.check_pch_target_flags)
1435     {
1436       int tf;
1437       const char *r;
1438
1439       memcpy (&tf, data, sizeof (target_flags));
1440       data += sizeof (target_flags);
1441       len -= sizeof (target_flags);
1442       r = targetm.check_pch_target_flags (tf);
1443       if (r != NULL)
1444         return r;
1445     }
1446
1447   for (i = 0; i < cl_options_count; i++)
1448     if (option_affects_pch_p (i, &state))
1449       {
1450         if (memcmp (data, state.data, state.size) != 0)
1451           return pch_option_mismatch (cl_options[i].opt_text);
1452         data += state.size;
1453         len -= state.size;
1454       }
1455
1456   return NULL;
1457 }
1458
1459 #include "gt-targhooks.h"