gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
   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
  73
  74 bool
  75 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  76                               rtx addr ATTRIBUTE_UNUSED,
  77                               bool strict ATTRIBUTE_UNUSED)
  78 {
  79 #ifdef GO_IF_LEGITIMATE_ADDRESS
  80   /* Defer to the old implementation using a goto.  */
  81   if (strict)
  82     return strict_memory_address_p (mode, addr);
  83   else
  84     return memory_address_p (mode, addr);
  85 #else
  86   gcc_unreachable ();
  87 #endif
  88 }
  89
  90 void
  91 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  92 {
  93 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  94   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  95 #endif
  96 }
  97
  98 int
  99 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 100 {
 101   int i;
 102
 103   if (GET_CODE (x) == UNSPEC_VOLATILE
 104       /* Any floating arithmetic may trap.  */
 105       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
 106           && flag_trapping_math))
 107     return 1;
 108
 109   for (i = 0; i < XVECLEN (x, 0); ++i)
 110     {
 111       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 112         return 1;
 113     }
 114
 115   return 0;
 116 }
 117
 118 enum machine_mode
 119 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 120                                enum machine_mode mode,
 121                                int *punsignedp ATTRIBUTE_UNUSED,
 122                                const_tree funtype ATTRIBUTE_UNUSED,
 123                                int for_return ATTRIBUTE_UNUSED)
 124 {
 125   if (for_return == 2)
 126     return promote_mode (type, mode, punsignedp);
 127   return mode;
 128 }
 129
 130 enum machine_mode
 131 default_promote_function_mode_always_promote (const_tree type,
 132                                               enum machine_mode mode,
 133                                               int *punsignedp,
 134                                               const_tree funtype ATTRIBUTE_UNUSED,
 135                                               int for_return ATTRIBUTE_UNUSED)
 136 {
 137   return promote_mode (type, mode, punsignedp);
 138 }
 139
 140
 141 enum machine_mode
 142 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 143 {
 144   if (m1 == m2)
 145     return m1;
 146   return VOIDmode;
 147 }
 148
 149 bool
 150 default_return_in_memory (const_tree type,
 151                           const_tree fntype ATTRIBUTE_UNUSED)
 152 {
 153   return (TYPE_MODE (type) == BLKmode);
 154 }
 155
 156 rtx
 157 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 158                             enum machine_mode mode ATTRIBUTE_UNUSED)
 159 {
 160   return x;
 161 }
 162
 163 rtx
 164 default_expand_builtin_saveregs (void)
 165 {
 166   error ("__builtin_saveregs not supported by this target");
 167   return const0_rtx;
 168 }
 169
 170 void
 171 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 172                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 173                                 tree type ATTRIBUTE_UNUSED,
 174                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 175                                 int second_time ATTRIBUTE_UNUSED)
 176 {
 177 }
 178
 179 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 180
 181 rtx
 182 default_builtin_setjmp_frame_value (void)
 183 {
 184   return virtual_stack_vars_rtx;
 185 }
 186
 187 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 188
 189 bool
 190 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 191 {
 192   return false;
 193 }
 194
 195 bool
 196 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 197 {
 198   return (targetm.calls.setup_incoming_varargs
 199           != default_setup_incoming_varargs);
 200 }
 201
 202 enum machine_mode
 203 default_eh_return_filter_mode (void)
 204 {
 205   return targetm.unwind_word_mode ();
 206 }
 207
 208 enum machine_mode
 209 default_libgcc_cmp_return_mode (void)
 210 {
 211   return word_mode;
 212 }
 213
 214 enum machine_mode
 215 default_libgcc_shift_count_mode (void)
 216 {
 217   return word_mode;
 218 }
 219
 220 enum machine_mode
 221 default_unwind_word_mode (void)
 222 {
 223   return word_mode;
 224 }
 225
 226 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 227
 228 unsigned HOST_WIDE_INT
 229 default_shift_truncation_mask (enum machine_mode mode)
 230 {
 231   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 232 }
 233
 234 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 235
 236 unsigned int
 237 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 238 {
 239   return have_insn_for (DIV, mode) ? 3 : 2;
 240 }
 241
 242 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 243
 244 int
 245 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 246                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 247 {
 248   return UNKNOWN;
 249 }
 250
 251 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 252
 253 bool
 254 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 255 {
 256   return true;
 257 }
 258
 259 /* Return machine mode for non-standard suffix
 260    or VOIDmode if non-standard suffixes are unsupported.  */
 261 enum machine_mode
 262 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 263 {
 264   return VOIDmode;
 265 }
 266
 267 /* The generic C++ ABI specifies this is a 64-bit value.  */
 268 tree
 269 default_cxx_guard_type (void)
 270 {
 271   return long_long_integer_type_node;
 272 }
 273
 274
 275 /* Returns the size of the cookie to use when allocating an array
 276    whose elements have the indicated TYPE.  Assumes that it is already
 277    known that a cookie is needed.  */
 278
 279 tree
 280 default_cxx_get_cookie_size (tree type)
 281 {
 282   tree cookie_size;
 283
 284   /* We need to allocate an additional max (sizeof (size_t), alignof
 285      (true_type)) bytes.  */
 286   tree sizetype_size;
 287   tree type_align;
 288
 289   sizetype_size = size_in_bytes (sizetype);
 290   type_align = size_int (TYPE_ALIGN_UNIT (type));
 291   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 292     cookie_size = sizetype_size;
 293   else
 294     cookie_size = type_align;
 295
 296   return cookie_size;
 297 }
 298
 299 /* Return true if a parameter must be passed by reference.  This version
 300    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 301
 302 bool
 303 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
 304         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 305         bool named_arg ATTRIBUTE_UNUSED)
 306 {
 307   return targetm.calls.must_pass_in_stack (mode, type);
 308 }
 309
 310 /* Return true if a parameter follows callee copies conventions.  This
 311    version of the hook is true for all named arguments.  */
 312
 313 bool
 314 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 315                           enum machine_mode mode ATTRIBUTE_UNUSED,
 316                           const_tree type ATTRIBUTE_UNUSED, bool named)
 317 {
 318   return named;
 319 }
 320
 321 /* Emit to STREAM the assembler syntax for insn operand X.  */
 322
 323 void
 324 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 325                        int code ATTRIBUTE_UNUSED)
 326 {
 327 #ifdef PRINT_OPERAND
 328   PRINT_OPERAND (stream, x, code);
 329 #else
 330   gcc_unreachable ();
 331 #endif
 332 }
 333
 334 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 335    address is X.  */
 336
 337 void
 338 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 339                                rtx x ATTRIBUTE_UNUSED)
 340 {
 341 #ifdef PRINT_OPERAND_ADDRESS
 342   PRINT_OPERAND_ADDRESS (stream, x);
 343 #else
 344   gcc_unreachable ();
 345 #endif
 346 }
 347
 348 /* Return true if CODE is a valid punctuation character for the
 349    `print_operand' hook.  */
 350
 351 bool
 352 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 353 {
 354 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 355   return PRINT_OPERAND_PUNCT_VALID_P (code);
 356 #else
 357   return false;
 358 #endif
 359 }
 360
 361 /* The default implementation of TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA.  */
 362
 363 bool
 364 default_asm_output_addr_const_extra (FILE *file ATTRIBUTE_UNUSED,
 365                                      rtx x ATTRIBUTE_UNUSED)
 366 {
 367 #ifdef OUTPUT_ADDR_CONST_EXTRA
 368   OUTPUT_ADDR_CONST_EXTRA (file, x, fail);
 369   return true;
 370
 371 fail:
 372 #endif
 373   return false;
 374 }
 375
 376 /* True if MODE is valid for the target.  By "valid", we mean able to
 377    be manipulated in non-trivial ways.  In particular, this means all
 378    the arithmetic is supported.
 379
 380    By default we guess this means that any C type is supported.  If
 381    we can't map the mode back to a type that would be available in C,
 382    then reject it.  Special case, here, is the double-word arithmetic
 383    supported by optabs.c.  */
 384
 385 bool
 386 default_scalar_mode_supported_p (enum machine_mode mode)
 387 {
 388   int precision = GET_MODE_PRECISION (mode);
 389
 390   switch (GET_MODE_CLASS (mode))
 391     {
 392     case MODE_PARTIAL_INT:
 393     case MODE_INT:
 394       if (precision == CHAR_TYPE_SIZE)
 395         return true;
 396       if (precision == SHORT_TYPE_SIZE)
 397         return true;
 398       if (precision == INT_TYPE_SIZE)
 399         return true;
 400       if (precision == LONG_TYPE_SIZE)
 401         return true;
 402       if (precision == LONG_LONG_TYPE_SIZE)
 403         return true;
 404       if (precision == 2 * BITS_PER_WORD)
 405         return true;
 406       return false;
 407
 408     case MODE_FLOAT:
 409       if (precision == FLOAT_TYPE_SIZE)
 410         return true;
 411       if (precision == DOUBLE_TYPE_SIZE)
 412         return true;
 413       if (precision == LONG_DOUBLE_TYPE_SIZE)
 414         return true;
 415       return false;
 416
 417     case MODE_DECIMAL_FLOAT:
 418     case MODE_FRACT:
 419     case MODE_UFRACT:
 420     case MODE_ACCUM:
 421     case MODE_UACCUM:
 422       return false;
 423
 424     default:
 425       gcc_unreachable ();
 426     }
 427 }
 428
 429 /* Make some target macros useable by target-independent code.  */
 430 bool
 431 targhook_words_big_endian (void)
 432 {
 433   return !!WORDS_BIG_ENDIAN;
 434 }
 435
 436 bool
 437 targhook_float_words_big_endian (void)
 438 {
 439   return !!FLOAT_WORDS_BIG_ENDIAN;
 440 }
 441
 442 /* True if the target supports decimal floating point.  */
 443
 444 bool
 445 default_decimal_float_supported_p (void)
 446 {
 447   return ENABLE_DECIMAL_FLOAT;
 448 }
 449
 450 /* True if the target supports fixed-point arithmetic.  */
 451
 452 bool
 453 default_fixed_point_supported_p (void)
 454 {
 455   return ENABLE_FIXED_POINT;
 456 }
 457
 458 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 459    an error message.
 460
 461    This function checks whether a given INSN is valid within a low-overhead
 462    loop.  If INSN is invalid it returns the reason for that, otherwise it
 463    returns NULL. A called function may clobber any special registers required
 464    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 465    register for branch on table instructions. We reject the doloop pattern in
 466    these cases.  */
 467
 468 const char *
 469 default_invalid_within_doloop (const_rtx insn)
 470 {
 471   if (CALL_P (insn))
 472     return "Function call in loop.";
 473
 474   if (JUMP_TABLE_DATA_P (insn))
 475     return "Computed branch in the loop.";
 476
 477   return NULL;
 478 }
 479
 480 /* Mapping of builtin functions to vectorized variants.  */
 481
 482 tree
 483 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 484                                      tree type_out ATTRIBUTE_UNUSED,
 485                                      tree type_in ATTRIBUTE_UNUSED)
 486 {
 487   return NULL_TREE;
 488 }
 489
 490 /* Vectorized conversion.  */
 491
 492 tree
 493 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 494                                        tree dest_type ATTRIBUTE_UNUSED,
 495                                        tree src_type ATTRIBUTE_UNUSED)
 496 {
 497   return NULL_TREE;
 498 }
 499
 500 /* Default vectorizer cost model values.  */
 501
 502 int
 503 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 504                                     tree vectype ATTRIBUTE_UNUSED,
 505                                     int misalign ATTRIBUTE_UNUSED)
 506 {
 507   switch (type_of_cost)
 508     {
 509       case scalar_stmt:
 510       case scalar_load:
 511       case scalar_store:
 512       case vector_stmt:
 513       case vector_load:
 514       case vector_store:
 515       case vec_to_scalar:
 516       case scalar_to_vec:
 517       case cond_branch_not_taken:
 518       case vec_perm:
 519         return 1;
 520
 521       case unaligned_load:
 522       case unaligned_store:
 523         return 2;
 524
 525       case cond_branch_taken:
 526         return 3;
 527
 528       default:
 529         gcc_unreachable ();
 530     }
 531 }
 532
 533 /* Reciprocal.  */
 534
 535 tree
 536 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 537                             bool md_fn ATTRIBUTE_UNUSED,
 538                             bool sqrt ATTRIBUTE_UNUSED)
 539 {
 540   return NULL_TREE;
 541 }
 542
 543 bool
 544 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 545         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 546         enum machine_mode mode ATTRIBUTE_UNUSED,
 547         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 548 {
 549   return false;
 550 }
 551
 552 bool
 553 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 554         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 555         enum machine_mode mode ATTRIBUTE_UNUSED,
 556         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 557 {
 558   return true;
 559 }
 560
 561 int
 562 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 563         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 564         enum machine_mode mode ATTRIBUTE_UNUSED,
 565         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 566 {
 567   return 0;
 568 }
 569
 570 void
 571 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 572                               enum machine_mode mode ATTRIBUTE_UNUSED,
 573                               const_tree type ATTRIBUTE_UNUSED,
 574                               bool named ATTRIBUTE_UNUSED)
 575 {
 576 #ifdef FUNCTION_ARG_ADVANCE
 577   CUMULATIVE_ARGS args = *ca;
 578   FUNCTION_ARG_ADVANCE (args, mode, CONST_CAST_TREE (type), named);
 579   *ca = args;
 580 #else
 581   gcc_unreachable ();
 582 #endif
 583 }
 584
 585 rtx
 586 default_function_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 587                       enum machine_mode mode ATTRIBUTE_UNUSED,
 588                       const_tree type ATTRIBUTE_UNUSED,
 589                       bool named ATTRIBUTE_UNUSED)
 590 {
 591 #ifdef FUNCTION_ARG
 592   return FUNCTION_ARG (*ca, mode, CONST_CAST_TREE (type), named);
 593 #else
 594   gcc_unreachable ();
 595 #endif
 596 }
 597
 598 rtx
 599 default_function_incoming_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 600                                enum machine_mode mode ATTRIBUTE_UNUSED,
 601                                const_tree type ATTRIBUTE_UNUSED,
 602                                bool named ATTRIBUTE_UNUSED)
 603 {
 604 #ifdef FUNCTION_INCOMING_ARG
 605   return FUNCTION_INCOMING_ARG (*ca, mode, CONST_CAST_TREE (type), named);
 606 #else
 607   gcc_unreachable ();
 608 #endif
 609 }
 610
 611 unsigned int
 612 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 613                                const_tree type ATTRIBUTE_UNUSED)
 614 {
 615   return PARM_BOUNDARY;
 616 }
 617
 618 void
 619 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 620 {
 621 }
 622
 623 const char *
 624 hook_invalid_arg_for_unprototyped_fn (
 625         const_tree typelist ATTRIBUTE_UNUSED,
 626         const_tree funcdecl ATTRIBUTE_UNUSED,
 627         const_tree val ATTRIBUTE_UNUSED)
 628 {
 629   return NULL;
 630 }
 631
 632 /* Initialize the stack protection decls.  */
 633
 634 /* Stack protection related decls living in libgcc.  */
 635 static GTY(()) tree stack_chk_guard_decl;
 636
 637 tree
 638 default_stack_protect_guard (void)
 639 {
 640   tree t = stack_chk_guard_decl;
 641
 642   if (t == NULL)
 643     {
 644       rtx x;
 645
 646       t = build_decl (UNKNOWN_LOCATION,
 647                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 648                       ptr_type_node);
 649       TREE_STATIC (t) = 1;
 650       TREE_PUBLIC (t) = 1;
 651       DECL_EXTERNAL (t) = 1;
 652       TREE_USED (t) = 1;
 653       TREE_THIS_VOLATILE (t) = 1;
 654       DECL_ARTIFICIAL (t) = 1;
 655       DECL_IGNORED_P (t) = 1;
 656
 657       /* Do not share RTL as the declaration is visible outside of
 658          current function.  */
 659       x = DECL_RTL (t);
 660       RTX_FLAG (x, used) = 1;
 661
 662       stack_chk_guard_decl = t;
 663     }
 664
 665   return t;
 666 }
 667
 668 static GTY(()) tree stack_chk_fail_decl;
 669
 670 tree
 671 default_external_stack_protect_fail (void)
 672 {
 673   tree t = stack_chk_fail_decl;
 674
 675   if (t == NULL_TREE)
 676     {
 677       t = build_function_type_list (void_type_node, NULL_TREE);
 678       t = build_decl (UNKNOWN_LOCATION,
 679                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 680       TREE_STATIC (t) = 1;
 681       TREE_PUBLIC (t) = 1;
 682       DECL_EXTERNAL (t) = 1;
 683       TREE_USED (t) = 1;
 684       TREE_THIS_VOLATILE (t) = 1;
 685       TREE_NOTHROW (t) = 1;
 686       DECL_ARTIFICIAL (t) = 1;
 687       DECL_IGNORED_P (t) = 1;
 688       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 689       DECL_VISIBILITY_SPECIFIED (t) = 1;
 690
 691       stack_chk_fail_decl = t;
 692     }
 693
 694   return build_call_expr (t, 0);
 695 }
 696
 697 tree
 698 default_hidden_stack_protect_fail (void)
 699 {
 700 #ifndef HAVE_GAS_HIDDEN
 701   return default_external_stack_protect_fail ();
 702 #else
 703   tree t = stack_chk_fail_decl;
 704
 705   if (!flag_pic)
 706     return default_external_stack_protect_fail ();
 707
 708   if (t == NULL_TREE)
 709     {
 710       t = build_function_type_list (void_type_node, NULL_TREE);
 711       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 712                       get_identifier ("__stack_chk_fail_local"), t);
 713       TREE_STATIC (t) = 1;
 714       TREE_PUBLIC (t) = 1;
 715       DECL_EXTERNAL (t) = 1;
 716       TREE_USED (t) = 1;
 717       TREE_THIS_VOLATILE (t) = 1;
 718       TREE_NOTHROW (t) = 1;
 719       DECL_ARTIFICIAL (t) = 1;
 720       DECL_IGNORED_P (t) = 1;
 721       DECL_VISIBILITY_SPECIFIED (t) = 1;
 722       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 723
 724       stack_chk_fail_decl = t;
 725     }
 726
 727   return build_call_expr (t, 0);
 728 #endif
 729 }
 730
 731 bool
 732 hook_bool_const_rtx_commutative_p (const_rtx x,
 733                                    int outer_code ATTRIBUTE_UNUSED)
 734 {
 735   return COMMUTATIVE_P (x);
 736 }
 737
 738 rtx
 739 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 740                         const_tree fn_decl_or_type,
 741                         bool outgoing ATTRIBUTE_UNUSED)
 742 {
 743   /* The old interface doesn't handle receiving the function type.  */
 744   if (fn_decl_or_type
 745       && !DECL_P (fn_decl_or_type))
 746     fn_decl_or_type = NULL;
 747
 748 #ifdef FUNCTION_VALUE
 749   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 750 #else
 751   gcc_unreachable ();
 752 #endif
 753 }
 754
 755 rtx
 756 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 757                        const_rtx fun ATTRIBUTE_UNUSED)
 758 {
 759 #ifdef LIBCALL_VALUE
 760   return LIBCALL_VALUE (mode);
 761 #else
 762   gcc_unreachable ();
 763 #endif
 764 }
 765
 766 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 767
 768 bool
 769 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 770 {
 771 #ifdef FUNCTION_VALUE_REGNO_P
 772   return FUNCTION_VALUE_REGNO_P (regno);
 773 #else
 774   gcc_unreachable ();
 775 #endif
 776 }
 777
 778 rtx
 779 default_internal_arg_pointer (void)
 780 {
 781   /* If the reg that the virtual arg pointer will be translated into is
 782      not a fixed reg or is the stack pointer, make a copy of the virtual
 783      arg pointer, and address parms via the copy.  The frame pointer is
 784      considered fixed even though it is not marked as such.  */
 785   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 786        || ! (fixed_regs[ARG_POINTER_REGNUM]
 787              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 788     return copy_to_reg (virtual_incoming_args_rtx);
 789   else
 790     return virtual_incoming_args_rtx;
 791 }
 792
 793 rtx
 794 default_static_chain (const_tree fndecl, bool incoming_p)
 795 {
 796   if (!DECL_STATIC_CHAIN (fndecl))
 797     return NULL;
 798
 799   if (incoming_p)
 800     {
 801 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 802       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 803 #endif
 804     }
 805
 806 #ifdef STATIC_CHAIN_REGNUM
 807   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 808 #endif
 809
 810   {
 811     static bool issued_error;
 812     if (!issued_error)
 813       {
 814         issued_error = true;
 815         sorry ("nested functions not supported on this target");
 816       }
 817
 818     /* It really doesn't matter what we return here, so long at it
 819        doesn't cause the rest of the compiler to crash.  */
 820     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 821   }
 822 }
 823
 824 void
 825 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 826                          rtx ARG_UNUSED (r_chain))
 827 {
 828   sorry ("nested function trampolines not supported on this target");
 829 }
 830
 831 int
 832 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 833                           tree funtype ATTRIBUTE_UNUSED,
 834                           int size ATTRIBUTE_UNUSED)
 835 {
 836   return 0;
 837 }
 838
 839 reg_class_t
 840 default_branch_target_register_class (void)
 841 {
 842   return NO_REGS;
 843 }
 844
 845 #ifdef IRA_COVER_CLASSES
 846 const reg_class_t *
 847 default_ira_cover_classes (void)
 848 {
 849   static reg_class_t classes[] = IRA_COVER_CLASSES;
 850   return classes;
 851 }
 852 #endif
 853
 854 reg_class_t
 855 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 856                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 857                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 858                           secondary_reload_info *sri)
 859 {
 860   enum reg_class rclass = NO_REGS;
 861   enum reg_class reload_class = (enum reg_class) reload_class_i;
 862
 863   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 864     {
 865       sri->icode = sri->prev_sri->t_icode;
 866       return NO_REGS;
 867     }
 868 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 869   if (in_p)
 870     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 871 #endif
 872 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 873   if (! in_p)
 874     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 875 #endif
 876   if (rclass != NO_REGS)
 877     {
 878       enum insn_code icode
 879         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 880                                 reload_mode);
 881
 882       if (icode != CODE_FOR_nothing
 883           && insn_data[(int) icode].operand[in_p].predicate
 884           && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
 885         icode = CODE_FOR_nothing;
 886       else if (icode != CODE_FOR_nothing)
 887         {
 888           const char *insn_constraint, *scratch_constraint;
 889           char insn_letter, scratch_letter;
 890           enum reg_class insn_class, scratch_class;
 891
 892           gcc_assert (insn_data[(int) icode].n_operands == 3);
 893           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 894           if (!*insn_constraint)
 895             insn_class = ALL_REGS;
 896           else
 897             {
 898               if (in_p)
 899                 {
 900                   gcc_assert (*insn_constraint == '=');
 901                   insn_constraint++;
 902                 }
 903               insn_letter = *insn_constraint;
 904               insn_class
 905                 = (insn_letter == 'r' ? GENERAL_REGS
 906                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 907                                                 insn_constraint));
 908               gcc_assert (insn_class != NO_REGS);
 909             }
 910
 911           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 912           /* The scratch register's constraint must start with "=&",
 913              except for an input reload, where only "=" is necessary,
 914              and where it might be beneficial to re-use registers from
 915              the input.  */
 916           gcc_assert (scratch_constraint[0] == '='
 917                       && (in_p || scratch_constraint[1] == '&'));
 918           scratch_constraint++;
 919           if (*scratch_constraint == '&')
 920             scratch_constraint++;
 921           scratch_letter = *scratch_constraint;
 922           scratch_class
 923             = (scratch_letter == 'r' ? GENERAL_REGS
 924                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 925                                             scratch_constraint));
 926
 927           if (reg_class_subset_p (reload_class, insn_class))
 928             {
 929               gcc_assert (scratch_class == rclass);
 930               rclass = NO_REGS;
 931             }
 932           else
 933             rclass = insn_class;
 934
 935         }
 936       if (rclass == NO_REGS)
 937         sri->icode = icode;
 938       else
 939         sri->t_icode = icode;
 940     }
 941   return rclass;
 942 }
 943
 944 bool
 945 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 946                          const char *arg ATTRIBUTE_UNUSED,
 947                          int value ATTRIBUTE_UNUSED)
 948 {
 949   return false;
 950 }
 951
 952 /* By default, if flag_pic is true, then neither local nor global relocs
 953    should be placed in readonly memory.  */
 954
 955 int
 956 default_reloc_rw_mask (void)
 957 {
 958   return flag_pic ? 3 : 0;
 959 }
 960
 961 /* By default, do no modification. */
 962 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 963                                          tree id)
 964 {
 965    return id;
 966 }
 967
 968 bool
 969 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 970 {
 971   if (is_packed)
 972     return false;
 973
 974   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 975      naturally aligned.  */
 976   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 977     return false;
 978
 979   /* Assuming that types whose size is <= pointer-size
 980      are naturally aligned.  */
 981   return true;
 982 }
 983
 984 /* By default, assume that a target supports any factor of misalignment
 985    memory access if it supports movmisalign patten.
 986    is_packed is true if the memory access is defined in a packed struct.  */
 987 bool
 988 default_builtin_support_vector_misalignment (enum machine_mode mode,
 989                                              const_tree type
 990                                              ATTRIBUTE_UNUSED,
 991                                              int misalignment
 992                                              ATTRIBUTE_UNUSED,
 993                                              bool is_packed
 994                                              ATTRIBUTE_UNUSED)
 995 {
 996   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
 997     return true;
 998   return false;
 999 }
1000
1001 /* By default, only attempt to parallelize bitwise operations, and
1002    possibly adds/subtracts using bit-twiddling.  */
1003
1004 enum machine_mode
1005 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1006 {
1007   return word_mode;
1008 }
1009
1010 /* By default only the size derived from the preferred vector mode
1011    is tried.  */
1012
1013 unsigned int
1014 default_autovectorize_vector_sizes (void)
1015 {
1016   return 0;
1017 }
1018
1019 /* Determine whether or not a pointer mode is valid. Assume defaults
1020    of ptr_mode or Pmode - can be overridden.  */
1021 bool
1022 default_valid_pointer_mode (enum machine_mode mode)
1023 {
1024   return (mode == ptr_mode || mode == Pmode);
1025 }
1026
1027 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1028    for the generic address space only.  */
1029
1030 enum machine_mode
1031 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1032 {
1033   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1034   return ptr_mode;
1035 }
1036
1037 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1038    for the generic address space only.  */
1039
1040 enum machine_mode
1041 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1042 {
1043   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1044   return Pmode;
1045 }
1046
1047 /* Named address space version of valid_pointer_mode.  */
1048
1049 bool
1050 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1051 {
1052   if (!ADDR_SPACE_GENERIC_P (as))
1053     return (mode == targetm.addr_space.pointer_mode (as)
1054             || mode == targetm.addr_space.address_mode (as));
1055
1056   return targetm.valid_pointer_mode (mode);
1057 }
1058
1059 /* Some places still assume that all pointer or address modes are the
1060    standard Pmode and ptr_mode.  These optimizations become invalid if
1061    the target actually supports multiple different modes.  For now,
1062    we disable such optimizations on such targets, using this function.  */
1063
1064 bool
1065 target_default_pointer_address_modes_p (void)
1066 {
1067   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1068     return false;
1069   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1070     return false;
1071
1072   return true;
1073 }
1074
1075 /* Named address space version of legitimate_address_p.  */
1076
1077 bool
1078 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1079                                          bool strict, addr_space_t as)
1080 {
1081   if (!ADDR_SPACE_GENERIC_P (as))
1082     gcc_unreachable ();
1083
1084   return targetm.legitimate_address_p (mode, mem, strict);
1085 }
1086
1087 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1088
1089 rtx
1090 default_addr_space_legitimize_address (rtx x, rtx oldx,
1091                                        enum machine_mode mode, addr_space_t as)
1092 {
1093   if (!ADDR_SPACE_GENERIC_P (as))
1094     return x;
1095
1096   return targetm.legitimize_address (x, oldx, mode);
1097 }
1098
1099 /* The default hook for determining if one named address space is a subset of
1100    another and to return which address space to use as the common address
1101    space.  */
1102
1103 bool
1104 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1105 {
1106   return (subset == superset);
1107 }
1108
1109 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1110    called for targets with only a generic address space.  */
1111
1112 rtx
1113 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1114                             tree from_type ATTRIBUTE_UNUSED,
1115                             tree to_type ATTRIBUTE_UNUSED)
1116 {
1117   gcc_unreachable ();
1118 }
1119
1120 bool
1121 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1122 {
1123   return true;
1124 }
1125
1126 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1127
1128 bool
1129 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1130 {
1131 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1132
1133   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1134   return false;
1135   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1136  win: ATTRIBUTE_UNUSED_LABEL
1137   return true;
1138
1139 #else
1140
1141   return false;
1142
1143 #endif
1144 }
1145
1146 bool
1147 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1148                                          tree ARG_UNUSED (name),
1149                                          tree ARG_UNUSED (args),
1150                                          int ARG_UNUSED (flags))
1151 {
1152   warning (OPT_Wattributes,
1153            "target attribute is not supported on this machine");
1154
1155   return false;
1156 }
1157
1158 bool
1159 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1160                                     tree ARG_UNUSED (pop_target))
1161 {
1162   warning (OPT_Wpragmas,
1163            "#pragma GCC target is not supported for this machine");
1164
1165   return false;
1166 }
1167
1168 bool
1169 default_target_can_inline_p (tree caller, tree callee)
1170 {
1171   bool ret = false;
1172   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1173   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1174
1175   /* If callee has no option attributes, then it is ok to inline */
1176   if (!callee_opts)
1177     ret = true;
1178
1179   /* If caller has no option attributes, but callee does then it is not ok to
1180      inline */
1181   else if (!caller_opts)
1182     ret = false;
1183
1184   /* If both caller and callee have attributes, assume that if the pointer is
1185      different, the the two functions have different target options since
1186      build_target_option_node uses a hash table for the options.  */
1187   else
1188     ret = (callee_opts == caller_opts);
1189
1190   return ret;
1191 }
1192
1193 #ifndef HAVE_casesi
1194 # define HAVE_casesi 0
1195 #endif
1196
1197 /* If the machine does not have a case insn that compares the bounds,
1198    this means extra overhead for dispatch tables, which raises the
1199    threshold for using them.  */
1200
1201 unsigned int default_case_values_threshold (void)
1202 {
1203   return (HAVE_casesi ? 4 : 5);
1204 }
1205
1206 bool
1207 default_have_conditional_execution (void)
1208 {
1209 #ifdef HAVE_conditional_execution
1210   return HAVE_conditional_execution;
1211 #else
1212   return false;
1213 #endif
1214 }
1215
1216 /* Compute cost of moving registers to/from memory.  */
1217
1218 int
1219 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1220                           reg_class_t rclass ATTRIBUTE_UNUSED,
1221                           bool in ATTRIBUTE_UNUSED)
1222 {
1223 #ifndef MEMORY_MOVE_COST
1224     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1225 #else
1226     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1227 #endif
1228 }
1229
1230 /* Compute cost of moving data from a register of class FROM to one of
1231    TO, using MODE.  */
1232
1233 int
1234 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1235                             reg_class_t from ATTRIBUTE_UNUSED,
1236                             reg_class_t to ATTRIBUTE_UNUSED)
1237 {
1238 #ifndef REGISTER_MOVE_COST
1239   return 2;
1240 #else
1241   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1242 #endif
1243 }
1244
1245 bool
1246 default_profile_before_prologue (void)
1247 {
1248 #ifdef PROFILE_BEFORE_PROLOGUE
1249   return true;
1250 #else
1251   return false;
1252 #endif
1253 }
1254
1255 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1256
1257 reg_class_t
1258 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1259                                 reg_class_t rclass)
1260 {
1261 #ifdef PREFERRED_RELOAD_CLASS
1262   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1263 #else
1264   return rclass;
1265 #endif
1266 }
1267
1268 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1269
1270 reg_class_t
1271 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1272                                        reg_class_t rclass)
1273 {
1274 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1275   return PREFERRED_OUTPUT_RELOAD_CLASS (x, (enum reg_class) rclass);
1276 #else
1277   return rclass;
1278 #endif
1279 }
1280
1281 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1282 reg_class_t
1283 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1284 {
1285   return NO_REGS;
1286 }
1287
1288 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1289
1290 bool
1291 default_class_likely_spilled_p (reg_class_t rclass)
1292 {
1293   return (reg_class_size[(int) rclass] == 1);
1294 }
1295
1296 /* Determine the debugging unwind mechanism for the target.  */
1297
1298 enum unwind_info_type
1299 default_debug_unwind_info (void)
1300 {
1301   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1302   /* ??? Change all users to the hook, then poison this.  */
1303 #ifdef DWARF2_FRAME_INFO
1304   if (DWARF2_FRAME_INFO)
1305     return UI_DWARF2;
1306 #endif
1307
1308   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1309 #ifdef DWARF2_DEBUGGING_INFO
1310   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1311     return UI_DWARF2;
1312 #endif
1313
1314   return UI_NONE;
1315 }
1316
1317 /* Determine the exception handling mechanism for the target.  */
1318
1319 enum unwind_info_type
1320 default_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1321 {
1322   /* Obey the configure switch to turn on sjlj exceptions.  */
1323 #ifdef CONFIG_SJLJ_EXCEPTIONS
1324   if (CONFIG_SJLJ_EXCEPTIONS)
1325     return UI_SJLJ;
1326 #endif
1327
1328   /* ??? Change all users to the hook, then poison this.  */
1329 #ifdef DWARF2_UNWIND_INFO
1330   if (DWARF2_UNWIND_INFO)
1331     return UI_DWARF2;
1332 #endif
1333
1334   return UI_SJLJ;
1335 }
1336
1337 /* To be used by targets that force dwarf2 unwind enabled.  */
1338
1339 enum unwind_info_type
1340 dwarf2_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1341 {
1342   /* Obey the configure switch to turn on sjlj exceptions.  */
1343 #ifdef CONFIG_SJLJ_EXCEPTIONS
1344   if (CONFIG_SJLJ_EXCEPTIONS)
1345     return UI_SJLJ;
1346 #endif
1347
1348   return UI_DWARF2;
1349 }
1350
1351 /* To be used by targets that force sjlj unwind enabled.  */
1352
1353 enum unwind_info_type
1354 sjlj_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1355 {
1356   return UI_SJLJ;
1357 }
1358
1359 /* To be used by targets where reg_raw_mode doesn't return the right
1360    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1361
1362 enum machine_mode
1363 default_get_reg_raw_mode(int regno)
1364 {
1365   return reg_raw_mode[regno];
1366 }
1367
1368 /* Return true if the state of option OPTION should be stored in PCH files
1369    and checked by default_pch_valid_p.  Store the option's current state
1370    in STATE if so.  */
1371
1372 static inline bool
1373 option_affects_pch_p (int option, struct cl_option_state *state)
1374 {
1375   if ((cl_options[option].flags & CL_TARGET) == 0)
1376     return false;
1377   if (option_flag_var (option, &global_options) == &target_flags)
1378     if (targetm.check_pch_target_flags)
1379       return false;
1380   return get_option_state (&global_options, option, state);
1381 }
1382
1383 /* Default version of get_pch_validity.
1384    By default, every flag difference is fatal; that will be mostly right for
1385    most targets, but completely right for very few.  */
1386
1387 void *
1388 default_get_pch_validity (size_t *sz)
1389 {
1390   struct cl_option_state state;
1391   size_t i;
1392   char *result, *r;
1393
1394   *sz = 2;
1395   if (targetm.check_pch_target_flags)
1396     *sz += sizeof (target_flags);
1397   for (i = 0; i < cl_options_count; i++)
1398     if (option_affects_pch_p (i, &state))
1399       *sz += state.size;
1400
1401   result = r = XNEWVEC (char, *sz);
1402   r[0] = flag_pic;
1403   r[1] = flag_pie;
1404   r += 2;
1405   if (targetm.check_pch_target_flags)
1406     {
1407       memcpy (r, &target_flags, sizeof (target_flags));
1408       r += sizeof (target_flags);
1409     }
1410
1411   for (i = 0; i < cl_options_count; i++)
1412     if (option_affects_pch_p (i, &state))
1413       {
1414         memcpy (r, state.data, state.size);
1415         r += state.size;
1416       }
1417
1418   return result;
1419 }
1420
1421 /* Return a message which says that a PCH file was created with a different
1422    setting of OPTION.  */
1423
1424 static const char *
1425 pch_option_mismatch (const char *option)
1426 {
1427   char *r;
1428
1429   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1430   if (r == NULL)
1431     return _("out of memory");
1432   return r;
1433 }
1434
1435 /* Default version of pch_valid_p.  */
1436
1437 const char *
1438 default_pch_valid_p (const void *data_p, size_t len)
1439 {
1440   struct cl_option_state state;
1441   const char *data = (const char *)data_p;
1442   size_t i;
1443
1444   /* -fpic and -fpie also usually make a PCH invalid.  */
1445   if (data[0] != flag_pic)
1446     return _("created and used with different settings of -fpic");
1447   if (data[1] != flag_pie)
1448     return _("created and used with different settings of -fpie");
1449   data += 2;
1450
1451   /* Check target_flags.  */
1452   if (targetm.check_pch_target_flags)
1453     {
1454       int tf;
1455       const char *r;
1456
1457       memcpy (&tf, data, sizeof (target_flags));
1458       data += sizeof (target_flags);
1459       len -= sizeof (target_flags);
1460       r = targetm.check_pch_target_flags (tf);
1461       if (r != NULL)
1462         return r;
1463     }
1464
1465   for (i = 0; i < cl_options_count; i++)
1466     if (option_affects_pch_p (i, &state))
1467       {
1468         if (memcmp (data, state.data, state.size) != 0)
1469           return pch_option_mismatch (cl_options[i].opt_text);
1470         data += state.size;
1471         len -= state.size;
1472       }
1473
1474   return NULL;
1475 }
1476
1477 const struct default_options empty_optimization_table[] =
1478   {
1479     { OPT_LEVELS_NONE, 0, NULL, 0 }
1480   };
1481
1482 #include "gt-targhooks.h"