gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* The migration of target macros to target hooks works as follows:
  22
  23    1. Create a target hook that uses the existing target macros to
  24       implement the same functionality.
  25
  26    2. Convert all the MI files to use the hook instead of the macro.
  27
  28    3. Repeat for a majority of the remaining target macros.  This will
  29       take some time.
  30
  31    4. Tell target maintainers to start migrating.
  32
  33    5. Eventually convert the backends to override the hook instead of
  34       defining the macros.  This will take some time too.
  35
  36    6. TBD when, poison the macros.  Unmigrated targets will break at
  37       this point.
  38
  39    Note that we expect steps 1-3 to be done by the people that
  40    understand what the MI does with each macro, and step 5 to be done
  41    by the target maintainers for their respective targets.
  42
  43    Note that steps 1 and 2 don't have to be done together, but no
  44    target can override the new hook until step 2 is complete for it.
  45
  46    Once the macros are poisoned, we will revert to the old migration
  47    rules - migrate the macro, callers, and targets all at once.  This
  48    comment can thus be removed at that point.  */
  49
  50 #include "config.h"
  51 #include "system.h"
  52 #include "coretypes.h"
  53 #include "tm.h"
  54 #include "machmode.h"
  55 #include "rtl.h"
  56 #include "tree.h"
  57 #include "expr.h"
  58 #include "output.h"
  59 #include "diagnostic-core.h"
  60 #include "function.h"
  61 #include "target.h"
  62 #include "tm_p.h"
  63 #include "target-def.h"
  64 #include "ggc.h"
  65 #include "hard-reg-set.h"
  66 #include "regs.h"
  67 #include "reload.h"
  68 #include "optabs.h"
  69 #include "recog.h"
  70 #include "intl.h"
  71 #include "opts.h"
  72 #include "tree-flow.h"
  73 #include "tree-ssa-alias.h"
  74
  75
  76 bool
  77 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  78                               rtx addr ATTRIBUTE_UNUSED,
  79                               bool strict ATTRIBUTE_UNUSED)
  80 {
  81 #ifdef GO_IF_LEGITIMATE_ADDRESS
  82   /* Defer to the old implementation using a goto.  */
  83   if (strict)
  84     return strict_memory_address_p (mode, addr);
  85   else
  86     return memory_address_p (mode, addr);
  87 #else
  88   gcc_unreachable ();
  89 #endif
  90 }
  91
  92 void
  93 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  94 {
  95 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  96   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  97 #endif
  98 }
  99
 100 int
 101 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 102 {
 103   int i;
 104
 105   if (GET_CODE (x) == UNSPEC_VOLATILE
 106       /* Any floating arithmetic may trap.  */
 107       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
 108           && flag_trapping_math))
 109     return 1;
 110
 111   for (i = 0; i < XVECLEN (x, 0); ++i)
 112     {
 113       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 114         return 1;
 115     }
 116
 117   return 0;
 118 }
 119
 120 enum machine_mode
 121 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 122                                enum machine_mode mode,
 123                                int *punsignedp ATTRIBUTE_UNUSED,
 124                                const_tree funtype ATTRIBUTE_UNUSED,
 125                                int for_return ATTRIBUTE_UNUSED)
 126 {
 127   if (type != NULL_TREE && for_return == 2)
 128     return promote_mode (type, mode, punsignedp);
 129   return mode;
 130 }
 131
 132 enum machine_mode
 133 default_promote_function_mode_always_promote (const_tree type,
 134                                               enum machine_mode mode,
 135                                               int *punsignedp,
 136                                               const_tree funtype ATTRIBUTE_UNUSED,
 137                                               int for_return ATTRIBUTE_UNUSED)
 138 {
 139   return promote_mode (type, mode, punsignedp);
 140 }
 141
 142
 143 enum machine_mode
 144 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 145 {
 146   if (m1 == m2)
 147     return m1;
 148   return VOIDmode;
 149 }
 150
 151 bool
 152 default_return_in_memory (const_tree type,
 153                           const_tree fntype ATTRIBUTE_UNUSED)
 154 {
 155   return (TYPE_MODE (type) == BLKmode);
 156 }
 157
 158 rtx
 159 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 160                             enum machine_mode mode ATTRIBUTE_UNUSED)
 161 {
 162   return x;
 163 }
 164
 165 rtx
 166 default_expand_builtin_saveregs (void)
 167 {
 168   error ("__builtin_saveregs not supported by this target");
 169   return const0_rtx;
 170 }
 171
 172 void
 173 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 174                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 175                                 tree type ATTRIBUTE_UNUSED,
 176                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 177                                 int second_time ATTRIBUTE_UNUSED)
 178 {
 179 }
 180
 181 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 182
 183 rtx
 184 default_builtin_setjmp_frame_value (void)
 185 {
 186   return virtual_stack_vars_rtx;
 187 }
 188
 189 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 190
 191 bool
 192 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 193 {
 194   return false;
 195 }
 196
 197 bool
 198 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 199 {
 200   return (targetm.calls.setup_incoming_varargs
 201           != default_setup_incoming_varargs);
 202 }
 203
 204 enum machine_mode
 205 default_eh_return_filter_mode (void)
 206 {
 207   return targetm.unwind_word_mode ();
 208 }
 209
 210 enum machine_mode
 211 default_libgcc_cmp_return_mode (void)
 212 {
 213   return word_mode;
 214 }
 215
 216 enum machine_mode
 217 default_libgcc_shift_count_mode (void)
 218 {
 219   return word_mode;
 220 }
 221
 222 enum machine_mode
 223 default_unwind_word_mode (void)
 224 {
 225   return word_mode;
 226 }
 227
 228 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 229
 230 unsigned HOST_WIDE_INT
 231 default_shift_truncation_mask (enum machine_mode mode)
 232 {
 233   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 234 }
 235
 236 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 237
 238 unsigned int
 239 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 240 {
 241   return have_insn_for (DIV, mode) ? 3 : 2;
 242 }
 243
 244 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 245
 246 int
 247 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 248                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 249 {
 250   return UNKNOWN;
 251 }
 252
 253 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 254
 255 bool
 256 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 257 {
 258   return true;
 259 }
 260
 261 /* Return machine mode for non-standard suffix
 262    or VOIDmode if non-standard suffixes are unsupported.  */
 263 enum machine_mode
 264 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 265 {
 266   return VOIDmode;
 267 }
 268
 269 /* The generic C++ ABI specifies this is a 64-bit value.  */
 270 tree
 271 default_cxx_guard_type (void)
 272 {
 273   return long_long_integer_type_node;
 274 }
 275
 276
 277 /* Returns the size of the cookie to use when allocating an array
 278    whose elements have the indicated TYPE.  Assumes that it is already
 279    known that a cookie is needed.  */
 280
 281 tree
 282 default_cxx_get_cookie_size (tree type)
 283 {
 284   tree cookie_size;
 285
 286   /* We need to allocate an additional max (sizeof (size_t), alignof
 287      (true_type)) bytes.  */
 288   tree sizetype_size;
 289   tree type_align;
 290
 291   sizetype_size = size_in_bytes (sizetype);
 292   type_align = size_int (TYPE_ALIGN_UNIT (type));
 293   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 294     cookie_size = sizetype_size;
 295   else
 296     cookie_size = type_align;
 297
 298   return cookie_size;
 299 }
 300
 301 /* Return true if a parameter must be passed by reference.  This version
 302    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 303
 304 bool
 305 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 306         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 307         bool named_arg ATTRIBUTE_UNUSED)
 308 {
 309   return targetm.calls.must_pass_in_stack (mode, type);
 310 }
 311
 312 /* Return true if a parameter follows callee copies conventions.  This
 313    version of the hook is true for all named arguments.  */
 314
 315 bool
 316 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 317                           enum machine_mode mode ATTRIBUTE_UNUSED,
 318                           const_tree type ATTRIBUTE_UNUSED, bool named)
 319 {
 320   return named;
 321 }
 322
 323 /* Emit to STREAM the assembler syntax for insn operand X.  */
 324
 325 void
 326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 327                        int code ATTRIBUTE_UNUSED)
 328 {
 329 #ifdef PRINT_OPERAND
 330   PRINT_OPERAND (stream, x, code);
 331 #else
 332   gcc_unreachable ();
 333 #endif
 334 }
 335
 336 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 337    address is X.  */
 338
 339 void
 340 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 341                                rtx x ATTRIBUTE_UNUSED)
 342 {
 343 #ifdef PRINT_OPERAND_ADDRESS
 344   PRINT_OPERAND_ADDRESS (stream, x);
 345 #else
 346   gcc_unreachable ();
 347 #endif
 348 }
 349
 350 /* Return true if CODE is a valid punctuation character for the
 351    `print_operand' hook.  */
 352
 353 bool
 354 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 355 {
 356 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 357   return PRINT_OPERAND_PUNCT_VALID_P (code);
 358 #else
 359   return false;
 360 #endif
 361 }
 362
 363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 364 tree
 365 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 366 {
 367   const char *skipped = name + (*name == '*' ? 1 : 0);
 368   const char *stripped = targetm.strip_name_encoding (skipped);
 369   if (*name != '*' && user_label_prefix[0])
 370     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 371   return get_identifier (stripped);
 372 }
 373
 374 /* True if MODE is valid for the target.  By "valid", we mean able to
 375    be manipulated in non-trivial ways.  In particular, this means all
 376    the arithmetic is supported.
 377
 378    By default we guess this means that any C type is supported.  If
 379    we can't map the mode back to a type that would be available in C,
 380    then reject it.  Special case, here, is the double-word arithmetic
 381    supported by optabs.c.  */
 382
 383 bool
 384 default_scalar_mode_supported_p (enum machine_mode mode)
 385 {
 386   int precision = GET_MODE_PRECISION (mode);
 387
 388   switch (GET_MODE_CLASS (mode))
 389     {
 390     case MODE_PARTIAL_INT:
 391     case MODE_INT:
 392       if (precision == CHAR_TYPE_SIZE)
 393         return true;
 394       if (precision == SHORT_TYPE_SIZE)
 395         return true;
 396       if (precision == INT_TYPE_SIZE)
 397         return true;
 398       if (precision == LONG_TYPE_SIZE)
 399         return true;
 400       if (precision == LONG_LONG_TYPE_SIZE)
 401         return true;
 402       if (precision == 2 * BITS_PER_WORD)
 403         return true;
 404       return false;
 405
 406     case MODE_FLOAT:
 407       if (precision == FLOAT_TYPE_SIZE)
 408         return true;
 409       if (precision == DOUBLE_TYPE_SIZE)
 410         return true;
 411       if (precision == LONG_DOUBLE_TYPE_SIZE)
 412         return true;
 413       return false;
 414
 415     case MODE_DECIMAL_FLOAT:
 416     case MODE_FRACT:
 417     case MODE_UFRACT:
 418     case MODE_ACCUM:
 419     case MODE_UACCUM:
 420       return false;
 421
 422     default:
 423       gcc_unreachable ();
 424     }
 425 }
 426
 427 /* Make some target macros useable by target-independent code.  */
 428 bool
 429 targhook_words_big_endian (void)
 430 {
 431   return !!WORDS_BIG_ENDIAN;
 432 }
 433
 434 bool
 435 targhook_float_words_big_endian (void)
 436 {
 437   return !!FLOAT_WORDS_BIG_ENDIAN;
 438 }
 439
 440 /* True if the target supports decimal floating point.  */
 441
 442 bool
 443 default_decimal_float_supported_p (void)
 444 {
 445   return ENABLE_DECIMAL_FLOAT;
 446 }
 447
 448 /* True if the target supports fixed-point arithmetic.  */
 449
 450 bool
 451 default_fixed_point_supported_p (void)
 452 {
 453   return ENABLE_FIXED_POINT;
 454 }
 455
 456 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 457    an error message.
 458
 459    This function checks whether a given INSN is valid within a low-overhead
 460    loop.  If INSN is invalid it returns the reason for that, otherwise it
 461    returns NULL. A called function may clobber any special registers required
 462    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 463    register for branch on table instructions. We reject the doloop pattern in
 464    these cases.  */
 465
 466 const char *
 467 default_invalid_within_doloop (const_rtx insn)
 468 {
 469   if (CALL_P (insn))
 470     return "Function call in loop.";
 471
 472   if (JUMP_TABLE_DATA_P (insn))
 473     return "Computed branch in the loop.";
 474
 475   return NULL;
 476 }
 477
 478 /* Mapping of builtin functions to vectorized variants.  */
 479
 480 tree
 481 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 482                                      tree type_out ATTRIBUTE_UNUSED,
 483                                      tree type_in ATTRIBUTE_UNUSED)
 484 {
 485   return NULL_TREE;
 486 }
 487
 488 /* Vectorized conversion.  */
 489
 490 tree
 491 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 492                                        tree dest_type ATTRIBUTE_UNUSED,
 493                                        tree src_type ATTRIBUTE_UNUSED)
 494 {
 495   return NULL_TREE;
 496 }
 497
 498 /* Default vectorizer cost model values.  */
 499
 500 int
 501 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 502                                     tree vectype,
 503                                     int misalign ATTRIBUTE_UNUSED)
 504 {
 505   unsigned elements;
 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       case vec_promote_demote:
 520         return 1;
 521
 522       case unaligned_load:
 523       case unaligned_store:
 524         return 2;
 525
 526       case cond_branch_taken:
 527         return 3;
 528
 529       case vec_construct:
 530         elements = TYPE_VECTOR_SUBPARTS (vectype);
 531         return elements / 2 + 1;
 532
 533       default:
 534         gcc_unreachable ();
 535     }
 536 }
 537
 538 /* Reciprocal.  */
 539
 540 tree
 541 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 542                             bool md_fn ATTRIBUTE_UNUSED,
 543                             bool sqrt ATTRIBUTE_UNUSED)
 544 {
 545   return NULL_TREE;
 546 }
 547
 548 bool
 549 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 550         cumulative_args_t ca ATTRIBUTE_UNUSED,
 551         enum machine_mode mode ATTRIBUTE_UNUSED,
 552         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 553 {
 554   return false;
 555 }
 556
 557 bool
 558 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 559         cumulative_args_t ca ATTRIBUTE_UNUSED,
 560         enum machine_mode mode ATTRIBUTE_UNUSED,
 561         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 562 {
 563   return true;
 564 }
 565
 566 int
 567 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 568         cumulative_args_t ca ATTRIBUTE_UNUSED,
 569         enum machine_mode mode ATTRIBUTE_UNUSED,
 570         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 571 {
 572   return 0;
 573 }
 574
 575 void
 576 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 577                               enum machine_mode mode ATTRIBUTE_UNUSED,
 578                               const_tree type ATTRIBUTE_UNUSED,
 579                               bool named ATTRIBUTE_UNUSED)
 580 {
 581   gcc_unreachable ();
 582 }
 583
 584 rtx
 585 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 586                       enum machine_mode mode ATTRIBUTE_UNUSED,
 587                       const_tree type ATTRIBUTE_UNUSED,
 588                       bool named ATTRIBUTE_UNUSED)
 589 {
 590   gcc_unreachable ();
 591 }
 592
 593 rtx
 594 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 595                                enum machine_mode mode ATTRIBUTE_UNUSED,
 596                                const_tree type ATTRIBUTE_UNUSED,
 597                                bool named ATTRIBUTE_UNUSED)
 598 {
 599   gcc_unreachable ();
 600 }
 601
 602 unsigned int
 603 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 604                                const_tree type ATTRIBUTE_UNUSED)
 605 {
 606   return PARM_BOUNDARY;
 607 }
 608
 609 unsigned int
 610 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 611                                      const_tree type ATTRIBUTE_UNUSED)
 612 {
 613   return PARM_BOUNDARY;
 614 }
 615
 616 void
 617 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 618 {
 619 }
 620
 621 const char *
 622 hook_invalid_arg_for_unprototyped_fn (
 623         const_tree typelist ATTRIBUTE_UNUSED,
 624         const_tree funcdecl ATTRIBUTE_UNUSED,
 625         const_tree val ATTRIBUTE_UNUSED)
 626 {
 627   return NULL;
 628 }
 629
 630 /* Initialize the stack protection decls.  */
 631
 632 /* Stack protection related decls living in libgcc.  */
 633 static GTY(()) tree stack_chk_guard_decl;
 634
 635 tree
 636 default_stack_protect_guard (void)
 637 {
 638   tree t = stack_chk_guard_decl;
 639
 640   if (t == NULL)
 641     {
 642       rtx x;
 643
 644       t = build_decl (UNKNOWN_LOCATION,
 645                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 646                       ptr_type_node);
 647       TREE_STATIC (t) = 1;
 648       TREE_PUBLIC (t) = 1;
 649       DECL_EXTERNAL (t) = 1;
 650       TREE_USED (t) = 1;
 651       TREE_THIS_VOLATILE (t) = 1;
 652       DECL_ARTIFICIAL (t) = 1;
 653       DECL_IGNORED_P (t) = 1;
 654
 655       /* Do not share RTL as the declaration is visible outside of
 656          current function.  */
 657       x = DECL_RTL (t);
 658       RTX_FLAG (x, used) = 1;
 659
 660       stack_chk_guard_decl = t;
 661     }
 662
 663   return t;
 664 }
 665
 666 static GTY(()) tree stack_chk_fail_decl;
 667
 668 tree
 669 default_external_stack_protect_fail (void)
 670 {
 671   tree t = stack_chk_fail_decl;
 672
 673   if (t == NULL_TREE)
 674     {
 675       t = build_function_type_list (void_type_node, NULL_TREE);
 676       t = build_decl (UNKNOWN_LOCATION,
 677                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 678       TREE_STATIC (t) = 1;
 679       TREE_PUBLIC (t) = 1;
 680       DECL_EXTERNAL (t) = 1;
 681       TREE_USED (t) = 1;
 682       TREE_THIS_VOLATILE (t) = 1;
 683       TREE_NOTHROW (t) = 1;
 684       DECL_ARTIFICIAL (t) = 1;
 685       DECL_IGNORED_P (t) = 1;
 686       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 687       DECL_VISIBILITY_SPECIFIED (t) = 1;
 688
 689       stack_chk_fail_decl = t;
 690     }
 691
 692   return build_call_expr (t, 0);
 693 }
 694
 695 tree
 696 default_hidden_stack_protect_fail (void)
 697 {
 698 #ifndef HAVE_GAS_HIDDEN
 699   return default_external_stack_protect_fail ();
 700 #else
 701   tree t = stack_chk_fail_decl;
 702
 703   if (!flag_pic)
 704     return default_external_stack_protect_fail ();
 705
 706   if (t == NULL_TREE)
 707     {
 708       t = build_function_type_list (void_type_node, NULL_TREE);
 709       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 710                       get_identifier ("__stack_chk_fail_local"), t);
 711       TREE_STATIC (t) = 1;
 712       TREE_PUBLIC (t) = 1;
 713       DECL_EXTERNAL (t) = 1;
 714       TREE_USED (t) = 1;
 715       TREE_THIS_VOLATILE (t) = 1;
 716       TREE_NOTHROW (t) = 1;
 717       DECL_ARTIFICIAL (t) = 1;
 718       DECL_IGNORED_P (t) = 1;
 719       DECL_VISIBILITY_SPECIFIED (t) = 1;
 720       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 721
 722       stack_chk_fail_decl = t;
 723     }
 724
 725   return build_call_expr (t, 0);
 726 #endif
 727 }
 728
 729 bool
 730 hook_bool_const_rtx_commutative_p (const_rtx x,
 731                                    int outer_code ATTRIBUTE_UNUSED)
 732 {
 733   return COMMUTATIVE_P (x);
 734 }
 735
 736 rtx
 737 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 738                         const_tree fn_decl_or_type,
 739                         bool outgoing ATTRIBUTE_UNUSED)
 740 {
 741   /* The old interface doesn't handle receiving the function type.  */
 742   if (fn_decl_or_type
 743       && !DECL_P (fn_decl_or_type))
 744     fn_decl_or_type = NULL;
 745
 746 #ifdef FUNCTION_VALUE
 747   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 748 #else
 749   gcc_unreachable ();
 750 #endif
 751 }
 752
 753 rtx
 754 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 755                        const_rtx fun ATTRIBUTE_UNUSED)
 756 {
 757 #ifdef LIBCALL_VALUE
 758   return LIBCALL_VALUE (mode);
 759 #else
 760   gcc_unreachable ();
 761 #endif
 762 }
 763
 764 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 765
 766 bool
 767 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 768 {
 769 #ifdef FUNCTION_VALUE_REGNO_P
 770   return FUNCTION_VALUE_REGNO_P (regno);
 771 #else
 772   gcc_unreachable ();
 773 #endif
 774 }
 775
 776 rtx
 777 default_internal_arg_pointer (void)
 778 {
 779   /* If the reg that the virtual arg pointer will be translated into is
 780      not a fixed reg or is the stack pointer, make a copy of the virtual
 781      arg pointer, and address parms via the copy.  The frame pointer is
 782      considered fixed even though it is not marked as such.  */
 783   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 784        || ! (fixed_regs[ARG_POINTER_REGNUM]
 785              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 786     return copy_to_reg (virtual_incoming_args_rtx);
 787   else
 788     return virtual_incoming_args_rtx;
 789 }
 790
 791 rtx
 792 default_static_chain (const_tree fndecl, bool incoming_p)
 793 {
 794   if (!DECL_STATIC_CHAIN (fndecl))
 795     return NULL;
 796
 797   if (incoming_p)
 798     {
 799 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 800       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 801 #endif
 802     }
 803
 804 #ifdef STATIC_CHAIN_REGNUM
 805   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 806 #endif
 807
 808   {
 809     static bool issued_error;
 810     if (!issued_error)
 811       {
 812         issued_error = true;
 813         sorry ("nested functions not supported on this target");
 814       }
 815
 816     /* It really doesn't matter what we return here, so long at it
 817        doesn't cause the rest of the compiler to crash.  */
 818     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 819   }
 820 }
 821
 822 void
 823 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 824                          rtx ARG_UNUSED (r_chain))
 825 {
 826   sorry ("nested function trampolines not supported on this target");
 827 }
 828
 829 int
 830 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 831                           tree funtype ATTRIBUTE_UNUSED,
 832                           int size ATTRIBUTE_UNUSED)
 833 {
 834   return 0;
 835 }
 836
 837 reg_class_t
 838 default_branch_target_register_class (void)
 839 {
 840   return NO_REGS;
 841 }
 842
 843 extern bool
 844 default_lra_p (void)
 845 {
 846   return false;
 847 }
 848
 849 int
 850 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 851 {
 852   return 0;
 853 }
 854
 855 extern bool
 856 default_different_addr_displacement_p (void)
 857 {
 858   return false;
 859 }
 860
 861 reg_class_t
 862 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 863                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 864                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 865                           secondary_reload_info *sri)
 866 {
 867   enum reg_class rclass = NO_REGS;
 868   enum reg_class reload_class = (enum reg_class) reload_class_i;
 869
 870   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 871     {
 872       sri->icode = sri->prev_sri->t_icode;
 873       return NO_REGS;
 874     }
 875 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 876   if (in_p)
 877     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 878 #endif
 879 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 880   if (! in_p)
 881     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 882 #endif
 883   if (rclass != NO_REGS)
 884     {
 885       enum insn_code icode
 886         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 887                                 reload_mode);
 888
 889       if (icode != CODE_FOR_nothing
 890           && !insn_operand_matches (icode, in_p, x))
 891         icode = CODE_FOR_nothing;
 892       else if (icode != CODE_FOR_nothing)
 893         {
 894           const char *insn_constraint, *scratch_constraint;
 895           char insn_letter, scratch_letter;
 896           enum reg_class insn_class, scratch_class;
 897
 898           gcc_assert (insn_data[(int) icode].n_operands == 3);
 899           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 900           if (!*insn_constraint)
 901             insn_class = ALL_REGS;
 902           else
 903             {
 904               if (in_p)
 905                 {
 906                   gcc_assert (*insn_constraint == '=');
 907                   insn_constraint++;
 908                 }
 909               insn_letter = *insn_constraint;
 910               insn_class
 911                 = (insn_letter == 'r' ? GENERAL_REGS
 912                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 913                                                 insn_constraint));
 914               gcc_assert (insn_class != NO_REGS);
 915             }
 916
 917           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 918           /* The scratch register's constraint must start with "=&",
 919              except for an input reload, where only "=" is necessary,
 920              and where it might be beneficial to re-use registers from
 921              the input.  */
 922           gcc_assert (scratch_constraint[0] == '='
 923                       && (in_p || scratch_constraint[1] == '&'));
 924           scratch_constraint++;
 925           if (*scratch_constraint == '&')
 926             scratch_constraint++;
 927           scratch_letter = *scratch_constraint;
 928           scratch_class
 929             = (scratch_letter == 'r' ? GENERAL_REGS
 930                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 931                                             scratch_constraint));
 932
 933           if (reg_class_subset_p (reload_class, insn_class))
 934             {
 935               gcc_assert (scratch_class == rclass);
 936               rclass = NO_REGS;
 937             }
 938           else
 939             rclass = insn_class;
 940
 941         }
 942       if (rclass == NO_REGS)
 943         sri->icode = icode;
 944       else
 945         sri->t_icode = icode;
 946     }
 947   return rclass;
 948 }
 949
 950 /* By default, if flag_pic is true, then neither local nor global relocs
 951    should be placed in readonly memory.  */
 952
 953 int
 954 default_reloc_rw_mask (void)
 955 {
 956   return flag_pic ? 3 : 0;
 957 }
 958
 959 /* By default, do no modification. */
 960 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 961                                          tree id)
 962 {
 963    return id;
 964 }
 965
 966 /* Default to natural alignment for vector types.  */
 967 HOST_WIDE_INT
 968 default_vector_alignment (const_tree type)
 969 {
 970   return tree_low_cst (TYPE_SIZE (type), 0);
 971 }
 972
 973 bool
 974 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 975 {
 976   if (is_packed)
 977     return false;
 978
 979   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 980      naturally aligned.  */
 981   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 982     return false;
 983
 984   /* Assuming that types whose size is <= pointer-size
 985      are naturally aligned.  */
 986   return true;
 987 }
 988
 989 /* By default, assume that a target supports any factor of misalignment
 990    memory access if it supports movmisalign patten.
 991    is_packed is true if the memory access is defined in a packed struct.  */
 992 bool
 993 default_builtin_support_vector_misalignment (enum machine_mode mode,
 994                                              const_tree type
 995                                              ATTRIBUTE_UNUSED,
 996                                              int misalignment
 997                                              ATTRIBUTE_UNUSED,
 998                                              bool is_packed
 999                                              ATTRIBUTE_UNUSED)
1000 {
1001   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1002     return true;
1003   return false;
1004 }
1005
1006 /* By default, only attempt to parallelize bitwise operations, and
1007    possibly adds/subtracts using bit-twiddling.  */
1008
1009 enum machine_mode
1010 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1011 {
1012   return word_mode;
1013 }
1014
1015 /* By default only the size derived from the preferred vector mode
1016    is tried.  */
1017
1018 unsigned int
1019 default_autovectorize_vector_sizes (void)
1020 {
1021   return 0;
1022 }
1023
1024 /* By default, the cost model accumulates three separate costs (prologue,
1025    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1026    array of three unsigned ints, set it to zero, and return its address.  */
1027
1028 void *
1029 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1030 {
1031   unsigned *cost = XNEWVEC (unsigned, 3);
1032   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1033   return cost;
1034 }
1035
1036 /* By default, the cost model looks up the cost of the given statement
1037    kind and mode, multiplies it by the occurrence count, accumulates
1038    it into the cost specified by WHERE, and returns the cost added.  */
1039
1040 unsigned
1041 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1042                        struct _stmt_vec_info *stmt_info, int misalign,
1043                        enum vect_cost_model_location where)
1044 {
1045   unsigned *cost = (unsigned *) data;
1046   unsigned retval = 0;
1047
1048   if (flag_vect_cost_model)
1049     {
1050       tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1051       int stmt_cost = default_builtin_vectorization_cost (kind, vectype,
1052                                                           misalign);
1053       /* Statements in an inner loop relative to the loop being
1054          vectorized are weighted more heavily.  The value here is
1055          arbitrary and could potentially be improved with analysis.  */
1056       if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1057         count *= 50;  /* FIXME.  */
1058
1059       retval = (unsigned) (count * stmt_cost);
1060       cost[where] += retval;
1061     }
1062
1063   return retval;
1064 }
1065
1066 /* By default, the cost model just returns the accumulated costs.  */
1067
1068 void
1069 default_finish_cost (void *data, unsigned *prologue_cost,
1070                      unsigned *body_cost, unsigned *epilogue_cost)
1071 {
1072   unsigned *cost = (unsigned *) data;
1073   *prologue_cost = cost[vect_prologue];
1074   *body_cost     = cost[vect_body];
1075   *epilogue_cost = cost[vect_epilogue];
1076 }
1077
1078 /* Free the cost data.  */
1079
1080 void
1081 default_destroy_cost_data (void *data)
1082 {
1083   free (data);
1084 }
1085
1086 /* Determine whether or not a pointer mode is valid. Assume defaults
1087    of ptr_mode or Pmode - can be overridden.  */
1088 bool
1089 default_valid_pointer_mode (enum machine_mode mode)
1090 {
1091   return (mode == ptr_mode || mode == Pmode);
1092 }
1093
1094 /* Determine whether the memory reference specified by REF may alias
1095    the C libraries errno location.  */
1096 bool
1097 default_ref_may_alias_errno (ao_ref *ref)
1098 {
1099   tree base = ao_ref_base (ref);
1100   /* The default implementation assumes the errno location is
1101      a declaration of type int or is always accessed via a
1102      pointer to int.  We assume that accesses to errno are
1103      not deliberately obfuscated (even in conforming ways).  */
1104   if (TYPE_UNSIGNED (TREE_TYPE (base))
1105       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1106     return false;
1107   /* The default implementation assumes an errno location
1108      declaration is never defined in the current compilation unit.  */
1109   if (DECL_P (base)
1110       && !TREE_STATIC (base))
1111     return true;
1112   else if (TREE_CODE (base) == MEM_REF
1113            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1114     {
1115       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1116       return !pi || pi->pt.anything || pi->pt.nonlocal;
1117     }
1118   return false;
1119 }
1120
1121 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1122    for the generic address space only.  */
1123
1124 enum machine_mode
1125 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1126 {
1127   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1128   return ptr_mode;
1129 }
1130
1131 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1132    for the generic address space only.  */
1133
1134 enum machine_mode
1135 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1136 {
1137   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1138   return Pmode;
1139 }
1140
1141 /* Named address space version of valid_pointer_mode.  */
1142
1143 bool
1144 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1145 {
1146   if (!ADDR_SPACE_GENERIC_P (as))
1147     return (mode == targetm.addr_space.pointer_mode (as)
1148             || mode == targetm.addr_space.address_mode (as));
1149
1150   return targetm.valid_pointer_mode (mode);
1151 }
1152
1153 /* Some places still assume that all pointer or address modes are the
1154    standard Pmode and ptr_mode.  These optimizations become invalid if
1155    the target actually supports multiple different modes.  For now,
1156    we disable such optimizations on such targets, using this function.  */
1157
1158 bool
1159 target_default_pointer_address_modes_p (void)
1160 {
1161   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1162     return false;
1163   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1164     return false;
1165
1166   return true;
1167 }
1168
1169 /* Named address space version of legitimate_address_p.  */
1170
1171 bool
1172 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1173                                          bool strict, addr_space_t as)
1174 {
1175   if (!ADDR_SPACE_GENERIC_P (as))
1176     gcc_unreachable ();
1177
1178   return targetm.legitimate_address_p (mode, mem, strict);
1179 }
1180
1181 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1182
1183 rtx
1184 default_addr_space_legitimize_address (rtx x, rtx oldx,
1185                                        enum machine_mode mode, addr_space_t as)
1186 {
1187   if (!ADDR_SPACE_GENERIC_P (as))
1188     return x;
1189
1190   return targetm.legitimize_address (x, oldx, mode);
1191 }
1192
1193 /* The default hook for determining if one named address space is a subset of
1194    another and to return which address space to use as the common address
1195    space.  */
1196
1197 bool
1198 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1199 {
1200   return (subset == superset);
1201 }
1202
1203 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1204    called for targets with only a generic address space.  */
1205
1206 rtx
1207 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1208                             tree from_type ATTRIBUTE_UNUSED,
1209                             tree to_type ATTRIBUTE_UNUSED)
1210 {
1211   gcc_unreachable ();
1212 }
1213
1214 bool
1215 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1216 {
1217   return true;
1218 }
1219
1220 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1221
1222 bool
1223 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1224                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1225 {
1226   return false;
1227 }
1228
1229 bool
1230 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1231                                          tree ARG_UNUSED (name),
1232                                          tree ARG_UNUSED (args),
1233                                          int ARG_UNUSED (flags))
1234 {
1235   warning (OPT_Wattributes,
1236            "target attribute is not supported on this machine");
1237
1238   return false;
1239 }
1240
1241 bool
1242 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1243                                     tree ARG_UNUSED (pop_target))
1244 {
1245   warning (OPT_Wpragmas,
1246            "#pragma GCC target is not supported for this machine");
1247
1248   return false;
1249 }
1250
1251 bool
1252 default_target_can_inline_p (tree caller, tree callee)
1253 {
1254   bool ret = false;
1255   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1256   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1257
1258   /* If callee has no option attributes, then it is ok to inline */
1259   if (!callee_opts)
1260     ret = true;
1261
1262   /* If caller has no option attributes, but callee does then it is not ok to
1263      inline */
1264   else if (!caller_opts)
1265     ret = false;
1266
1267   /* If both caller and callee have attributes, assume that if the
1268      pointer is different, the two functions have different target
1269      options since build_target_option_node uses a hash table for the
1270      options.  */
1271   else
1272     ret = (callee_opts == caller_opts);
1273
1274   return ret;
1275 }
1276
1277 #ifndef HAVE_casesi
1278 # define HAVE_casesi 0
1279 #endif
1280
1281 /* If the machine does not have a case insn that compares the bounds,
1282    this means extra overhead for dispatch tables, which raises the
1283    threshold for using them.  */
1284
1285 unsigned int
1286 default_case_values_threshold (void)
1287 {
1288   return (HAVE_casesi ? 4 : 5);
1289 }
1290
1291 bool
1292 default_have_conditional_execution (void)
1293 {
1294 #ifdef HAVE_conditional_execution
1295   return HAVE_conditional_execution;
1296 #else
1297   return false;
1298 #endif
1299 }
1300
1301 tree
1302 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1303 {
1304   return NULL_TREE;
1305 }
1306
1307 /* Compute cost of moving registers to/from memory.  */
1308
1309 int
1310 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1311                           reg_class_t rclass ATTRIBUTE_UNUSED,
1312                           bool in ATTRIBUTE_UNUSED)
1313 {
1314 #ifndef MEMORY_MOVE_COST
1315     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1316 #else
1317     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1318 #endif
1319 }
1320
1321 /* Compute cost of moving data from a register of class FROM to one of
1322    TO, using MODE.  */
1323
1324 int
1325 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1326                             reg_class_t from ATTRIBUTE_UNUSED,
1327                             reg_class_t to ATTRIBUTE_UNUSED)
1328 {
1329 #ifndef REGISTER_MOVE_COST
1330   return 2;
1331 #else
1332   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1333 #endif
1334 }
1335
1336 bool
1337 default_profile_before_prologue (void)
1338 {
1339 #ifdef PROFILE_BEFORE_PROLOGUE
1340   return true;
1341 #else
1342   return false;
1343 #endif
1344 }
1345
1346 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1347
1348 reg_class_t
1349 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1350                                 reg_class_t rclass)
1351 {
1352 #ifdef PREFERRED_RELOAD_CLASS
1353   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1354 #else
1355   return rclass;
1356 #endif
1357 }
1358
1359 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1360
1361 reg_class_t
1362 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1363                                        reg_class_t rclass)
1364 {
1365   return rclass;
1366 }
1367
1368 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1369 reg_class_t
1370 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1371 {
1372   return NO_REGS;
1373 }
1374
1375 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1376
1377 bool
1378 default_class_likely_spilled_p (reg_class_t rclass)
1379 {
1380   return (reg_class_size[(int) rclass] == 1);
1381 }
1382
1383 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1384
1385 unsigned char
1386 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1387                          enum machine_mode mode ATTRIBUTE_UNUSED)
1388 {
1389 #ifdef CLASS_MAX_NREGS
1390   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1391 #else
1392   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1393 #endif
1394 }
1395
1396 /* Determine the debugging unwind mechanism for the target.  */
1397
1398 enum unwind_info_type
1399 default_debug_unwind_info (void)
1400 {
1401   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1402   /* ??? Change all users to the hook, then poison this.  */
1403 #ifdef DWARF2_FRAME_INFO
1404   if (DWARF2_FRAME_INFO)
1405     return UI_DWARF2;
1406 #endif
1407
1408   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1409 #ifdef DWARF2_DEBUGGING_INFO
1410   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1411     return UI_DWARF2;
1412 #endif
1413
1414   return UI_NONE;
1415 }
1416
1417 /* To be used by targets where reg_raw_mode doesn't return the right
1418    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1419
1420 enum machine_mode
1421 default_get_reg_raw_mode(int regno)
1422 {
1423   return reg_raw_mode[regno];
1424 }
1425
1426 /* Return true if the state of option OPTION should be stored in PCH files
1427    and checked by default_pch_valid_p.  Store the option's current state
1428    in STATE if so.  */
1429
1430 static inline bool
1431 option_affects_pch_p (int option, struct cl_option_state *state)
1432 {
1433   if ((cl_options[option].flags & CL_TARGET) == 0)
1434     return false;
1435   if (option_flag_var (option, &global_options) == &target_flags)
1436     if (targetm.check_pch_target_flags)
1437       return false;
1438   return get_option_state (&global_options, option, state);
1439 }
1440
1441 /* Default version of get_pch_validity.
1442    By default, every flag difference is fatal; that will be mostly right for
1443    most targets, but completely right for very few.  */
1444
1445 void *
1446 default_get_pch_validity (size_t *sz)
1447 {
1448   struct cl_option_state state;
1449   size_t i;
1450   char *result, *r;
1451
1452   *sz = 2;
1453   if (targetm.check_pch_target_flags)
1454     *sz += sizeof (target_flags);
1455   for (i = 0; i < cl_options_count; i++)
1456     if (option_affects_pch_p (i, &state))
1457       *sz += state.size;
1458
1459   result = r = XNEWVEC (char, *sz);
1460   r[0] = flag_pic;
1461   r[1] = flag_pie;
1462   r += 2;
1463   if (targetm.check_pch_target_flags)
1464     {
1465       memcpy (r, &target_flags, sizeof (target_flags));
1466       r += sizeof (target_flags);
1467     }
1468
1469   for (i = 0; i < cl_options_count; i++)
1470     if (option_affects_pch_p (i, &state))
1471       {
1472         memcpy (r, state.data, state.size);
1473         r += state.size;
1474       }
1475
1476   return result;
1477 }
1478
1479 /* Return a message which says that a PCH file was created with a different
1480    setting of OPTION.  */
1481
1482 static const char *
1483 pch_option_mismatch (const char *option)
1484 {
1485   char *r;
1486
1487   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1488   if (r == NULL)
1489     return _("out of memory");
1490   return r;
1491 }
1492
1493 /* Default version of pch_valid_p.  */
1494
1495 const char *
1496 default_pch_valid_p (const void *data_p, size_t len)
1497 {
1498   struct cl_option_state state;
1499   const char *data = (const char *)data_p;
1500   size_t i;
1501
1502   /* -fpic and -fpie also usually make a PCH invalid.  */
1503   if (data[0] != flag_pic)
1504     return _("created and used with different settings of -fpic");
1505   if (data[1] != flag_pie)
1506     return _("created and used with different settings of -fpie");
1507   data += 2;
1508
1509   /* Check target_flags.  */
1510   if (targetm.check_pch_target_flags)
1511     {
1512       int tf;
1513       const char *r;
1514
1515       memcpy (&tf, data, sizeof (target_flags));
1516       data += sizeof (target_flags);
1517       len -= sizeof (target_flags);
1518       r = targetm.check_pch_target_flags (tf);
1519       if (r != NULL)
1520         return r;
1521     }
1522
1523   for (i = 0; i < cl_options_count; i++)
1524     if (option_affects_pch_p (i, &state))
1525       {
1526         if (memcmp (data, state.data, state.size) != 0)
1527           return pch_option_mismatch (cl_options[i].opt_text);
1528         data += state.size;
1529         len -= state.size;
1530       }
1531
1532   return NULL;
1533 }
1534
1535 /* Default version of member_type_forces_blk.  */
1536
1537 bool
1538 default_member_type_forces_blk (const_tree, enum machine_mode)
1539 {
1540   return false;
1541 }
1542
1543 #include "gt-targhooks.h"