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 (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 *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 *ca ATTRIBUTE_UNUSED)
 193 {
 194   return false;
 195 }
 196
 197 bool
 198 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *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 * 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 *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 *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 /* The default implementation of TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA.  */
 375
 376 bool
 377 default_asm_output_addr_const_extra (FILE *file ATTRIBUTE_UNUSED,
 378                                      rtx x ATTRIBUTE_UNUSED)
 379 {
 380 #ifdef OUTPUT_ADDR_CONST_EXTRA
 381   OUTPUT_ADDR_CONST_EXTRA (file, x, fail);
 382   return true;
 383
 384 fail:
 385 #endif
 386   return false;
 387 }
 388
 389 /* True if MODE is valid for the target.  By "valid", we mean able to
 390    be manipulated in non-trivial ways.  In particular, this means all
 391    the arithmetic is supported.
 392
 393    By default we guess this means that any C type is supported.  If
 394    we can't map the mode back to a type that would be available in C,
 395    then reject it.  Special case, here, is the double-word arithmetic
 396    supported by optabs.c.  */
 397
 398 bool
 399 default_scalar_mode_supported_p (enum machine_mode mode)
 400 {
 401   int precision = GET_MODE_PRECISION (mode);
 402
 403   switch (GET_MODE_CLASS (mode))
 404     {
 405     case MODE_PARTIAL_INT:
 406     case MODE_INT:
 407       if (precision == CHAR_TYPE_SIZE)
 408         return true;
 409       if (precision == SHORT_TYPE_SIZE)
 410         return true;
 411       if (precision == INT_TYPE_SIZE)
 412         return true;
 413       if (precision == LONG_TYPE_SIZE)
 414         return true;
 415       if (precision == LONG_LONG_TYPE_SIZE)
 416         return true;
 417       if (precision == 2 * BITS_PER_WORD)
 418         return true;
 419       return false;
 420
 421     case MODE_FLOAT:
 422       if (precision == FLOAT_TYPE_SIZE)
 423         return true;
 424       if (precision == DOUBLE_TYPE_SIZE)
 425         return true;
 426       if (precision == LONG_DOUBLE_TYPE_SIZE)
 427         return true;
 428       return false;
 429
 430     case MODE_DECIMAL_FLOAT:
 431     case MODE_FRACT:
 432     case MODE_UFRACT:
 433     case MODE_ACCUM:
 434     case MODE_UACCUM:
 435       return false;
 436
 437     default:
 438       gcc_unreachable ();
 439     }
 440 }
 441
 442 /* Make some target macros useable by target-independent code.  */
 443 bool
 444 targhook_words_big_endian (void)
 445 {
 446   return !!WORDS_BIG_ENDIAN;
 447 }
 448
 449 bool
 450 targhook_float_words_big_endian (void)
 451 {
 452   return !!FLOAT_WORDS_BIG_ENDIAN;
 453 }
 454
 455 /* True if the target supports decimal floating point.  */
 456
 457 bool
 458 default_decimal_float_supported_p (void)
 459 {
 460   return ENABLE_DECIMAL_FLOAT;
 461 }
 462
 463 /* True if the target supports fixed-point arithmetic.  */
 464
 465 bool
 466 default_fixed_point_supported_p (void)
 467 {
 468   return ENABLE_FIXED_POINT;
 469 }
 470
 471 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 472    an error message.
 473
 474    This function checks whether a given INSN is valid within a low-overhead
 475    loop.  If INSN is invalid it returns the reason for that, otherwise it
 476    returns NULL. A called function may clobber any special registers required
 477    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 478    register for branch on table instructions. We reject the doloop pattern in
 479    these cases.  */
 480
 481 const char *
 482 default_invalid_within_doloop (const_rtx insn)
 483 {
 484   if (CALL_P (insn))
 485     return "Function call in loop.";
 486
 487   if (JUMP_TABLE_DATA_P (insn))
 488     return "Computed branch in the loop.";
 489
 490   return NULL;
 491 }
 492
 493 /* Mapping of builtin functions to vectorized variants.  */
 494
 495 tree
 496 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 497                                      tree type_out ATTRIBUTE_UNUSED,
 498                                      tree type_in ATTRIBUTE_UNUSED)
 499 {
 500   return NULL_TREE;
 501 }
 502
 503 /* Vectorized conversion.  */
 504
 505 tree
 506 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 507                                        tree dest_type ATTRIBUTE_UNUSED,
 508                                        tree src_type ATTRIBUTE_UNUSED)
 509 {
 510   return NULL_TREE;
 511 }
 512
 513 /* Default vectorizer cost model values.  */
 514
 515 int
 516 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 517                                     tree vectype ATTRIBUTE_UNUSED,
 518                                     int misalign ATTRIBUTE_UNUSED)
 519 {
 520   switch (type_of_cost)
 521     {
 522       case scalar_stmt:
 523       case scalar_load:
 524       case scalar_store:
 525       case vector_stmt:
 526       case vector_load:
 527       case vector_store:
 528       case vec_to_scalar:
 529       case scalar_to_vec:
 530       case cond_branch_not_taken:
 531       case vec_perm:
 532         return 1;
 533
 534       case unaligned_load:
 535       case unaligned_store:
 536         return 2;
 537
 538       case cond_branch_taken:
 539         return 3;
 540
 541       default:
 542         gcc_unreachable ();
 543     }
 544 }
 545
 546 /* Reciprocal.  */
 547
 548 tree
 549 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 550                             bool md_fn ATTRIBUTE_UNUSED,
 551                             bool sqrt ATTRIBUTE_UNUSED)
 552 {
 553   return NULL_TREE;
 554 }
 555
 556 bool
 557 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 558         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 559         enum machine_mode mode ATTRIBUTE_UNUSED,
 560         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 561 {
 562   return false;
 563 }
 564
 565 bool
 566 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 567         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 568         enum machine_mode mode ATTRIBUTE_UNUSED,
 569         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 570 {
 571   return true;
 572 }
 573
 574 int
 575 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 576         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 577         enum machine_mode mode ATTRIBUTE_UNUSED,
 578         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 579 {
 580   return 0;
 581 }
 582
 583 void
 584 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 585                               enum machine_mode mode ATTRIBUTE_UNUSED,
 586                               const_tree type ATTRIBUTE_UNUSED,
 587                               bool named ATTRIBUTE_UNUSED)
 588 {
 589   gcc_unreachable ();
 590 }
 591
 592 rtx
 593 default_function_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 594                       enum machine_mode mode ATTRIBUTE_UNUSED,
 595                       const_tree type ATTRIBUTE_UNUSED,
 596                       bool named ATTRIBUTE_UNUSED)
 597 {
 598   gcc_unreachable ();
 599 }
 600
 601 rtx
 602 default_function_incoming_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 603                                enum machine_mode mode ATTRIBUTE_UNUSED,
 604                                const_tree type ATTRIBUTE_UNUSED,
 605                                bool named ATTRIBUTE_UNUSED)
 606 {
 607   gcc_unreachable ();
 608 }
 609
 610 unsigned int
 611 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 612                                const_tree type ATTRIBUTE_UNUSED)
 613 {
 614   return PARM_BOUNDARY;
 615 }
 616
 617 void
 618 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 619 {
 620 }
 621
 622 const char *
 623 hook_invalid_arg_for_unprototyped_fn (
 624         const_tree typelist ATTRIBUTE_UNUSED,
 625         const_tree funcdecl ATTRIBUTE_UNUSED,
 626         const_tree val ATTRIBUTE_UNUSED)
 627 {
 628   return NULL;
 629 }
 630
 631 /* Initialize the stack protection decls.  */
 632
 633 /* Stack protection related decls living in libgcc.  */
 634 static GTY(()) tree stack_chk_guard_decl;
 635
 636 tree
 637 default_stack_protect_guard (void)
 638 {
 639   tree t = stack_chk_guard_decl;
 640
 641   if (t == NULL)
 642     {
 643       rtx x;
 644
 645       t = build_decl (UNKNOWN_LOCATION,
 646                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 647                       ptr_type_node);
 648       TREE_STATIC (t) = 1;
 649       TREE_PUBLIC (t) = 1;
 650       DECL_EXTERNAL (t) = 1;
 651       TREE_USED (t) = 1;
 652       TREE_THIS_VOLATILE (t) = 1;
 653       DECL_ARTIFICIAL (t) = 1;
 654       DECL_IGNORED_P (t) = 1;
 655
 656       /* Do not share RTL as the declaration is visible outside of
 657          current function.  */
 658       x = DECL_RTL (t);
 659       RTX_FLAG (x, used) = 1;
 660
 661       stack_chk_guard_decl = t;
 662     }
 663
 664   return t;
 665 }
 666
 667 static GTY(()) tree stack_chk_fail_decl;
 668
 669 tree
 670 default_external_stack_protect_fail (void)
 671 {
 672   tree t = stack_chk_fail_decl;
 673
 674   if (t == NULL_TREE)
 675     {
 676       t = build_function_type_list (void_type_node, NULL_TREE);
 677       t = build_decl (UNKNOWN_LOCATION,
 678                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 679       TREE_STATIC (t) = 1;
 680       TREE_PUBLIC (t) = 1;
 681       DECL_EXTERNAL (t) = 1;
 682       TREE_USED (t) = 1;
 683       TREE_THIS_VOLATILE (t) = 1;
 684       TREE_NOTHROW (t) = 1;
 685       DECL_ARTIFICIAL (t) = 1;
 686       DECL_IGNORED_P (t) = 1;
 687       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 688       DECL_VISIBILITY_SPECIFIED (t) = 1;
 689
 690       stack_chk_fail_decl = t;
 691     }
 692
 693   return build_call_expr (t, 0);
 694 }
 695
 696 tree
 697 default_hidden_stack_protect_fail (void)
 698 {
 699 #ifndef HAVE_GAS_HIDDEN
 700   return default_external_stack_protect_fail ();
 701 #else
 702   tree t = stack_chk_fail_decl;
 703
 704   if (!flag_pic)
 705     return default_external_stack_protect_fail ();
 706
 707   if (t == NULL_TREE)
 708     {
 709       t = build_function_type_list (void_type_node, NULL_TREE);
 710       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 711                       get_identifier ("__stack_chk_fail_local"), t);
 712       TREE_STATIC (t) = 1;
 713       TREE_PUBLIC (t) = 1;
 714       DECL_EXTERNAL (t) = 1;
 715       TREE_USED (t) = 1;
 716       TREE_THIS_VOLATILE (t) = 1;
 717       TREE_NOTHROW (t) = 1;
 718       DECL_ARTIFICIAL (t) = 1;
 719       DECL_IGNORED_P (t) = 1;
 720       DECL_VISIBILITY_SPECIFIED (t) = 1;
 721       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 722
 723       stack_chk_fail_decl = t;
 724     }
 725
 726   return build_call_expr (t, 0);
 727 #endif
 728 }
 729
 730 bool
 731 hook_bool_const_rtx_commutative_p (const_rtx x,
 732                                    int outer_code ATTRIBUTE_UNUSED)
 733 {
 734   return COMMUTATIVE_P (x);
 735 }
 736
 737 rtx
 738 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 739                         const_tree fn_decl_or_type,
 740                         bool outgoing ATTRIBUTE_UNUSED)
 741 {
 742   /* The old interface doesn't handle receiving the function type.  */
 743   if (fn_decl_or_type
 744       && !DECL_P (fn_decl_or_type))
 745     fn_decl_or_type = NULL;
 746
 747 #ifdef FUNCTION_VALUE
 748   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 749 #else
 750   gcc_unreachable ();
 751 #endif
 752 }
 753
 754 rtx
 755 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 756                        const_rtx fun ATTRIBUTE_UNUSED)
 757 {
 758 #ifdef LIBCALL_VALUE
 759   return LIBCALL_VALUE (mode);
 760 #else
 761   gcc_unreachable ();
 762 #endif
 763 }
 764
 765 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 766
 767 bool
 768 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 769 {
 770 #ifdef FUNCTION_VALUE_REGNO_P
 771   return FUNCTION_VALUE_REGNO_P (regno);
 772 #else
 773   gcc_unreachable ();
 774 #endif
 775 }
 776
 777 rtx
 778 default_internal_arg_pointer (void)
 779 {
 780   /* If the reg that the virtual arg pointer will be translated into is
 781      not a fixed reg or is the stack pointer, make a copy of the virtual
 782      arg pointer, and address parms via the copy.  The frame pointer is
 783      considered fixed even though it is not marked as such.  */
 784   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 785        || ! (fixed_regs[ARG_POINTER_REGNUM]
 786              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 787     return copy_to_reg (virtual_incoming_args_rtx);
 788   else
 789     return virtual_incoming_args_rtx;
 790 }
 791
 792 rtx
 793 default_static_chain (const_tree fndecl, bool incoming_p)
 794 {
 795   if (!DECL_STATIC_CHAIN (fndecl))
 796     return NULL;
 797
 798   if (incoming_p)
 799     {
 800 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 801       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 802 #endif
 803     }
 804
 805 #ifdef STATIC_CHAIN_REGNUM
 806   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 807 #endif
 808
 809   {
 810     static bool issued_error;
 811     if (!issued_error)
 812       {
 813         issued_error = true;
 814         sorry ("nested functions not supported on this target");
 815       }
 816
 817     /* It really doesn't matter what we return here, so long at it
 818        doesn't cause the rest of the compiler to crash.  */
 819     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 820   }
 821 }
 822
 823 void
 824 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 825                          rtx ARG_UNUSED (r_chain))
 826 {
 827   sorry ("nested function trampolines not supported on this target");
 828 }
 829
 830 int
 831 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 832                           tree funtype ATTRIBUTE_UNUSED,
 833                           int size ATTRIBUTE_UNUSED)
 834 {
 835   return 0;
 836 }
 837
 838 reg_class_t
 839 default_branch_target_register_class (void)
 840 {
 841   return NO_REGS;
 842 }
 843
 844 reg_class_t
 845 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 846                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 847                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 848                           secondary_reload_info *sri)
 849 {
 850   enum reg_class rclass = NO_REGS;
 851   enum reg_class reload_class = (enum reg_class) reload_class_i;
 852
 853   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 854     {
 855       sri->icode = sri->prev_sri->t_icode;
 856       return NO_REGS;
 857     }
 858 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 859   if (in_p)
 860     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 861 #endif
 862 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 863   if (! in_p)
 864     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 865 #endif
 866   if (rclass != NO_REGS)
 867     {
 868       enum insn_code icode
 869         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 870                                 reload_mode);
 871
 872       if (icode != CODE_FOR_nothing
 873           && !insn_operand_matches (icode, in_p, x))
 874         icode = CODE_FOR_nothing;
 875       else if (icode != CODE_FOR_nothing)
 876         {
 877           const char *insn_constraint, *scratch_constraint;
 878           char insn_letter, scratch_letter;
 879           enum reg_class insn_class, scratch_class;
 880
 881           gcc_assert (insn_data[(int) icode].n_operands == 3);
 882           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 883           if (!*insn_constraint)
 884             insn_class = ALL_REGS;
 885           else
 886             {
 887               if (in_p)
 888                 {
 889                   gcc_assert (*insn_constraint == '=');
 890                   insn_constraint++;
 891                 }
 892               insn_letter = *insn_constraint;
 893               insn_class
 894                 = (insn_letter == 'r' ? GENERAL_REGS
 895                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 896                                                 insn_constraint));
 897               gcc_assert (insn_class != NO_REGS);
 898             }
 899
 900           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 901           /* The scratch register's constraint must start with "=&",
 902              except for an input reload, where only "=" is necessary,
 903              and where it might be beneficial to re-use registers from
 904              the input.  */
 905           gcc_assert (scratch_constraint[0] == '='
 906                       && (in_p || scratch_constraint[1] == '&'));
 907           scratch_constraint++;
 908           if (*scratch_constraint == '&')
 909             scratch_constraint++;
 910           scratch_letter = *scratch_constraint;
 911           scratch_class
 912             = (scratch_letter == 'r' ? GENERAL_REGS
 913                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 914                                             scratch_constraint));
 915
 916           if (reg_class_subset_p (reload_class, insn_class))
 917             {
 918               gcc_assert (scratch_class == rclass);
 919               rclass = NO_REGS;
 920             }
 921           else
 922             rclass = insn_class;
 923
 924         }
 925       if (rclass == NO_REGS)
 926         sri->icode = icode;
 927       else
 928         sri->t_icode = icode;
 929     }
 930   return rclass;
 931 }
 932
 933 /* By default, if flag_pic is true, then neither local nor global relocs
 934    should be placed in readonly memory.  */
 935
 936 int
 937 default_reloc_rw_mask (void)
 938 {
 939   return flag_pic ? 3 : 0;
 940 }
 941
 942 /* By default, do no modification. */
 943 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 944                                          tree id)
 945 {
 946    return id;
 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 /* Compute cost of moving registers to/from memory.  */
1226
1227 int
1228 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1229                           reg_class_t rclass ATTRIBUTE_UNUSED,
1230                           bool in ATTRIBUTE_UNUSED)
1231 {
1232 #ifndef MEMORY_MOVE_COST
1233     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1234 #else
1235     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1236 #endif
1237 }
1238
1239 /* Compute cost of moving data from a register of class FROM to one of
1240    TO, using MODE.  */
1241
1242 int
1243 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1244                             reg_class_t from ATTRIBUTE_UNUSED,
1245                             reg_class_t to ATTRIBUTE_UNUSED)
1246 {
1247 #ifndef REGISTER_MOVE_COST
1248   return 2;
1249 #else
1250   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1251 #endif
1252 }
1253
1254 bool
1255 default_profile_before_prologue (void)
1256 {
1257 #ifdef PROFILE_BEFORE_PROLOGUE
1258   return true;
1259 #else
1260   return false;
1261 #endif
1262 }
1263
1264 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1265
1266 reg_class_t
1267 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1268                                 reg_class_t rclass)
1269 {
1270 #ifdef PREFERRED_RELOAD_CLASS
1271   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1272 #else
1273   return rclass;
1274 #endif
1275 }
1276
1277 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1278
1279 reg_class_t
1280 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1281                                        reg_class_t rclass)
1282 {
1283 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1284   return PREFERRED_OUTPUT_RELOAD_CLASS (x, (enum reg_class) rclass);
1285 #else
1286   return rclass;
1287 #endif
1288 }
1289
1290 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1291 reg_class_t
1292 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1293 {
1294   return NO_REGS;
1295 }
1296
1297 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1298
1299 bool
1300 default_class_likely_spilled_p (reg_class_t rclass)
1301 {
1302   return (reg_class_size[(int) rclass] == 1);
1303 }
1304
1305 /* Determine the debugging unwind mechanism for the target.  */
1306
1307 enum unwind_info_type
1308 default_debug_unwind_info (void)
1309 {
1310   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1311   /* ??? Change all users to the hook, then poison this.  */
1312 #ifdef DWARF2_FRAME_INFO
1313   if (DWARF2_FRAME_INFO)
1314     return UI_DWARF2;
1315 #endif
1316
1317   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1318 #ifdef DWARF2_DEBUGGING_INFO
1319   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1320     return UI_DWARF2;
1321 #endif
1322
1323   return UI_NONE;
1324 }
1325
1326 /* Determine the exception handling mechanism for the target.  */
1327
1328 enum unwind_info_type
1329 default_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1330 {
1331   /* Obey the configure switch to turn on sjlj exceptions.  */
1332 #ifdef CONFIG_SJLJ_EXCEPTIONS
1333   if (CONFIG_SJLJ_EXCEPTIONS)
1334     return UI_SJLJ;
1335 #endif
1336
1337   /* ??? Change all users to the hook, then poison this.  */
1338 #ifdef DWARF2_UNWIND_INFO
1339   if (DWARF2_UNWIND_INFO)
1340     return UI_DWARF2;
1341 #endif
1342
1343   return UI_SJLJ;
1344 }
1345
1346 /* To be used by targets that force dwarf2 unwind enabled.  */
1347
1348 enum unwind_info_type
1349 dwarf2_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1350 {
1351   /* Obey the configure switch to turn on sjlj exceptions.  */
1352 #ifdef CONFIG_SJLJ_EXCEPTIONS
1353   if (CONFIG_SJLJ_EXCEPTIONS)
1354     return UI_SJLJ;
1355 #endif
1356
1357   return UI_DWARF2;
1358 }
1359
1360 /* To be used by targets that force sjlj unwind enabled.  */
1361
1362 enum unwind_info_type
1363 sjlj_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1364 {
1365   return UI_SJLJ;
1366 }
1367
1368 /* To be used by targets where reg_raw_mode doesn't return the right
1369    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1370
1371 enum machine_mode
1372 default_get_reg_raw_mode(int regno)
1373 {
1374   return reg_raw_mode[regno];
1375 }
1376
1377 /* Return true if the state of option OPTION should be stored in PCH files
1378    and checked by default_pch_valid_p.  Store the option's current state
1379    in STATE if so.  */
1380
1381 static inline bool
1382 option_affects_pch_p (int option, struct cl_option_state *state)
1383 {
1384   if ((cl_options[option].flags & CL_TARGET) == 0)
1385     return false;
1386   if (option_flag_var (option, &global_options) == &target_flags)
1387     if (targetm.check_pch_target_flags)
1388       return false;
1389   return get_option_state (&global_options, option, state);
1390 }
1391
1392 /* Default version of get_pch_validity.
1393    By default, every flag difference is fatal; that will be mostly right for
1394    most targets, but completely right for very few.  */
1395
1396 void *
1397 default_get_pch_validity (size_t *sz)
1398 {
1399   struct cl_option_state state;
1400   size_t i;
1401   char *result, *r;
1402
1403   *sz = 2;
1404   if (targetm.check_pch_target_flags)
1405     *sz += sizeof (target_flags);
1406   for (i = 0; i < cl_options_count; i++)
1407     if (option_affects_pch_p (i, &state))
1408       *sz += state.size;
1409
1410   result = r = XNEWVEC (char, *sz);
1411   r[0] = flag_pic;
1412   r[1] = flag_pie;
1413   r += 2;
1414   if (targetm.check_pch_target_flags)
1415     {
1416       memcpy (r, &target_flags, sizeof (target_flags));
1417       r += sizeof (target_flags);
1418     }
1419
1420   for (i = 0; i < cl_options_count; i++)
1421     if (option_affects_pch_p (i, &state))
1422       {
1423         memcpy (r, state.data, state.size);
1424         r += state.size;
1425       }
1426
1427   return result;
1428 }
1429
1430 /* Return a message which says that a PCH file was created with a different
1431    setting of OPTION.  */
1432
1433 static const char *
1434 pch_option_mismatch (const char *option)
1435 {
1436   char *r;
1437
1438   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1439   if (r == NULL)
1440     return _("out of memory");
1441   return r;
1442 }
1443
1444 /* Default version of pch_valid_p.  */
1445
1446 const char *
1447 default_pch_valid_p (const void *data_p, size_t len)
1448 {
1449   struct cl_option_state state;
1450   const char *data = (const char *)data_p;
1451   size_t i;
1452
1453   /* -fpic and -fpie also usually make a PCH invalid.  */
1454   if (data[0] != flag_pic)
1455     return _("created and used with different settings of -fpic");
1456   if (data[1] != flag_pie)
1457     return _("created and used with different settings of -fpie");
1458   data += 2;
1459
1460   /* Check target_flags.  */
1461   if (targetm.check_pch_target_flags)
1462     {
1463       int tf;
1464       const char *r;
1465
1466       memcpy (&tf, data, sizeof (target_flags));
1467       data += sizeof (target_flags);
1468       len -= sizeof (target_flags);
1469       r = targetm.check_pch_target_flags (tf);
1470       if (r != NULL)
1471         return r;
1472     }
1473
1474   for (i = 0; i < cl_options_count; i++)
1475     if (option_affects_pch_p (i, &state))
1476       {
1477         if (memcmp (data, state.data, state.size) != 0)
1478           return pch_option_mismatch (cl_options[i].opt_text);
1479         data += state.size;
1480         len -= state.size;
1481       }
1482
1483   return NULL;
1484 }
1485
1486 /* Default version of TARGET_HANDLE_OPTION.  */
1487
1488 bool
1489 default_target_handle_option (struct gcc_options *opts ATTRIBUTE_UNUSED,
1490                               struct gcc_options *opts_set ATTRIBUTE_UNUSED,
1491                               const struct cl_decoded_option *decoded ATTRIBUTE_UNUSED,
1492                               location_t loc ATTRIBUTE_UNUSED)
1493 {
1494   return true;
1495 }
1496
1497 const struct default_options empty_optimization_table[] =
1498   {
1499     { OPT_LEVELS_NONE, 0, NULL, 0 }
1500   };
1501
1502 #include "gt-targhooks.h"