gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003-2013 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* The migration of target macros to target hooks works as follows:
  21
  22    1. Create a target hook that uses the existing target macros to
  23       implement the same functionality.
  24
  25    2. Convert all the MI files to use the hook instead of the macro.
  26
  27    3. Repeat for a majority of the remaining target macros.  This will
  28       take some time.
  29
  30    4. Tell target maintainers to start migrating.
  31
  32    5. Eventually convert the backends to override the hook instead of
  33       defining the macros.  This will take some time too.
  34
  35    6. TBD when, poison the macros.  Unmigrated targets will break at
  36       this point.
  37
  38    Note that we expect steps 1-3 to be done by the people that
  39    understand what the MI does with each macro, and step 5 to be done
  40    by the target maintainers for their respective targets.
  41
  42    Note that steps 1 and 2 don't have to be done together, but no
  43    target can override the new hook until step 2 is complete for it.
  44
  45    Once the macros are poisoned, we will revert to the old migration
  46    rules - migrate the macro, callers, and targets all at once.  This
  47    comment can thus be removed at that point.  */
  48
  49 #include "config.h"
  50 #include "system.h"
  51 #include "coretypes.h"
  52 #include "tm.h"
  53 #include "machmode.h"
  54 #include "rtl.h"
  55 #include "tree.h"
  56 #include "stor-layout.h"
  57 #include "varasm.h"
  58 #include "expr.h"
  59 #include "output.h"
  60 #include "diagnostic-core.h"
  61 #include "function.h"
  62 #include "target.h"
  63 #include "tm_p.h"
  64 #include "target-def.h"
  65 #include "ggc.h"
  66 #include "hard-reg-set.h"
  67 #include "regs.h"
  68 #include "reload.h"
  69 #include "optabs.h"
  70 #include "recog.h"
  71 #include "intl.h"
  72 #include "opts.h"
  73 #include "gimple.h"
  74 #include "gimplify.h"
  75 #include "stringpool.h"
  76 #include "tree-ssanames.h"
  77 #include "tree-ssa-alias.h"
  78 #include "insn-codes.h"
  79
  80
  81 bool
  82 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  83                               rtx addr ATTRIBUTE_UNUSED,
  84                               bool strict ATTRIBUTE_UNUSED)
  85 {
  86 #ifdef GO_IF_LEGITIMATE_ADDRESS
  87   /* Defer to the old implementation using a goto.  */
  88   if (strict)
  89     return strict_memory_address_p (mode, addr);
  90   else
  91     return memory_address_p (mode, addr);
  92 #else
  93   gcc_unreachable ();
  94 #endif
  95 }
  96
  97 void
  98 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  99 {
 100 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
 101   ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
 102 #endif
 103 }
 104
 105 int
 106 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 107 {
 108   int i;
 109
 110   /* Any floating arithmetic may trap.  */
 111   if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
 112     return 1;
 113
 114   for (i = 0; i < XVECLEN (x, 0); ++i)
 115     {
 116       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 117         return 1;
 118     }
 119
 120   return 0;
 121 }
 122
 123 enum machine_mode
 124 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 125                                enum machine_mode mode,
 126                                int *punsignedp ATTRIBUTE_UNUSED,
 127                                const_tree funtype ATTRIBUTE_UNUSED,
 128                                int for_return ATTRIBUTE_UNUSED)
 129 {
 130   if (type != NULL_TREE && for_return == 2)
 131     return promote_mode (type, mode, punsignedp);
 132   return mode;
 133 }
 134
 135 enum machine_mode
 136 default_promote_function_mode_always_promote (const_tree type,
 137                                               enum machine_mode mode,
 138                                               int *punsignedp,
 139                                               const_tree funtype ATTRIBUTE_UNUSED,
 140                                               int for_return ATTRIBUTE_UNUSED)
 141 {
 142   return promote_mode (type, mode, punsignedp);
 143 }
 144
 145 enum machine_mode
 146 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 147 {
 148   if (m1 == m2)
 149     return m1;
 150   return VOIDmode;
 151 }
 152
 153 bool
 154 default_return_in_memory (const_tree type,
 155                           const_tree fntype ATTRIBUTE_UNUSED)
 156 {
 157   return (TYPE_MODE (type) == BLKmode);
 158 }
 159
 160 rtx
 161 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 162                             enum machine_mode mode ATTRIBUTE_UNUSED)
 163 {
 164   return x;
 165 }
 166
 167 rtx
 168 default_expand_builtin_saveregs (void)
 169 {
 170   error ("__builtin_saveregs not supported by this target");
 171   return const0_rtx;
 172 }
 173
 174 void
 175 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 176                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 177                                 tree type ATTRIBUTE_UNUSED,
 178                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 179                                 int second_time ATTRIBUTE_UNUSED)
 180 {
 181 }
 182
 183 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 184
 185 rtx
 186 default_builtin_setjmp_frame_value (void)
 187 {
 188   return virtual_stack_vars_rtx;
 189 }
 190
 191 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 192
 193 bool
 194 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 195 {
 196   return false;
 197 }
 198
 199 bool
 200 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 201 {
 202   return (targetm.calls.setup_incoming_varargs
 203           != default_setup_incoming_varargs);
 204 }
 205
 206 enum machine_mode
 207 default_eh_return_filter_mode (void)
 208 {
 209   return targetm.unwind_word_mode ();
 210 }
 211
 212 enum machine_mode
 213 default_libgcc_cmp_return_mode (void)
 214 {
 215   return word_mode;
 216 }
 217
 218 enum machine_mode
 219 default_libgcc_shift_count_mode (void)
 220 {
 221   return word_mode;
 222 }
 223
 224 enum machine_mode
 225 default_unwind_word_mode (void)
 226 {
 227   return word_mode;
 228 }
 229
 230 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 231
 232 unsigned HOST_WIDE_INT
 233 default_shift_truncation_mask (enum machine_mode mode)
 234 {
 235   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 236 }
 237
 238 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 239
 240 unsigned int
 241 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 242 {
 243   return have_insn_for (DIV, mode) ? 3 : 2;
 244 }
 245
 246 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 247
 248 int
 249 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 250                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 251 {
 252   return UNKNOWN;
 253 }
 254
 255 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 256
 257 bool
 258 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 259 {
 260   return true;
 261 }
 262
 263 /* Return machine mode for non-standard suffix
 264    or VOIDmode if non-standard suffixes are unsupported.  */
 265 enum machine_mode
 266 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 267 {
 268   return VOIDmode;
 269 }
 270
 271 /* The generic C++ ABI specifies this is a 64-bit value.  */
 272 tree
 273 default_cxx_guard_type (void)
 274 {
 275   return long_long_integer_type_node;
 276 }
 277
 278 /* Returns the size of the cookie to use when allocating an array
 279    whose elements have the indicated TYPE.  Assumes that it is already
 280    known that a cookie is needed.  */
 281
 282 tree
 283 default_cxx_get_cookie_size (tree type)
 284 {
 285   tree cookie_size;
 286
 287   /* We need to allocate an additional max (sizeof (size_t), alignof
 288      (true_type)) bytes.  */
 289   tree sizetype_size;
 290   tree type_align;
 291
 292   sizetype_size = size_in_bytes (sizetype);
 293   type_align = size_int (TYPE_ALIGN_UNIT (type));
 294   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 295     cookie_size = sizetype_size;
 296   else
 297     cookie_size = type_align;
 298
 299   return cookie_size;
 300 }
 301
 302 /* Return true if a parameter must be passed by reference.  This version
 303    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 304
 305 bool
 306 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 307         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 308         bool named_arg ATTRIBUTE_UNUSED)
 309 {
 310   return targetm.calls.must_pass_in_stack (mode, type);
 311 }
 312
 313 /* Return true if a parameter follows callee copies conventions.  This
 314    version of the hook is true for all named arguments.  */
 315
 316 bool
 317 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 318                           enum machine_mode mode ATTRIBUTE_UNUSED,
 319                           const_tree type ATTRIBUTE_UNUSED, bool named)
 320 {
 321   return named;
 322 }
 323
 324 /* Emit to STREAM the assembler syntax for insn operand X.  */
 325
 326 void
 327 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 328                        int code ATTRIBUTE_UNUSED)
 329 {
 330 #ifdef PRINT_OPERAND
 331   PRINT_OPERAND (stream, x, code);
 332 #else
 333   gcc_unreachable ();
 334 #endif
 335 }
 336
 337 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 338    address is X.  */
 339
 340 void
 341 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 342                                rtx x ATTRIBUTE_UNUSED)
 343 {
 344 #ifdef PRINT_OPERAND_ADDRESS
 345   PRINT_OPERAND_ADDRESS (stream, x);
 346 #else
 347   gcc_unreachable ();
 348 #endif
 349 }
 350
 351 /* Return true if CODE is a valid punctuation character for the
 352    `print_operand' hook.  */
 353
 354 bool
 355 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 356 {
 357 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 358   return PRINT_OPERAND_PUNCT_VALID_P (code);
 359 #else
 360   return false;
 361 #endif
 362 }
 363
 364 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 365 tree
 366 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 367 {
 368   const char *skipped = name + (*name == '*' ? 1 : 0);
 369   const char *stripped = targetm.strip_name_encoding (skipped);
 370   if (*name != '*' && user_label_prefix[0])
 371     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 372   return get_identifier (stripped);
 373 }
 374
 375 /* True if MODE is valid for the target.  By "valid", we mean able to
 376    be manipulated in non-trivial ways.  In particular, this means all
 377    the arithmetic is supported.
 378
 379    By default we guess this means that any C type is supported.  If
 380    we can't map the mode back to a type that would be available in C,
 381    then reject it.  Special case, here, is the double-word arithmetic
 382    supported by optabs.c.  */
 383
 384 bool
 385 default_scalar_mode_supported_p (enum machine_mode mode)
 386 {
 387   int precision = GET_MODE_PRECISION (mode);
 388
 389   switch (GET_MODE_CLASS (mode))
 390     {
 391     case MODE_PARTIAL_INT:
 392     case MODE_INT:
 393       if (precision == CHAR_TYPE_SIZE)
 394         return true;
 395       if (precision == SHORT_TYPE_SIZE)
 396         return true;
 397       if (precision == INT_TYPE_SIZE)
 398         return true;
 399       if (precision == LONG_TYPE_SIZE)
 400         return true;
 401       if (precision == LONG_LONG_TYPE_SIZE)
 402         return true;
 403       if (precision == 2 * BITS_PER_WORD)
 404         return true;
 405       return false;
 406
 407     case MODE_FLOAT:
 408       if (precision == FLOAT_TYPE_SIZE)
 409         return true;
 410       if (precision == DOUBLE_TYPE_SIZE)
 411         return true;
 412       if (precision == LONG_DOUBLE_TYPE_SIZE)
 413         return true;
 414       return false;
 415
 416     case MODE_DECIMAL_FLOAT:
 417     case MODE_FRACT:
 418     case MODE_UFRACT:
 419     case MODE_ACCUM:
 420     case MODE_UACCUM:
 421       return false;
 422
 423     default:
 424       gcc_unreachable ();
 425     }
 426 }
 427
 428 /* Make some target macros useable by target-independent code.  */
 429 bool
 430 targhook_words_big_endian (void)
 431 {
 432   return !!WORDS_BIG_ENDIAN;
 433 }
 434
 435 bool
 436 targhook_float_words_big_endian (void)
 437 {
 438   return !!FLOAT_WORDS_BIG_ENDIAN;
 439 }
 440
 441 /* True if the target supports floating-point exceptions and rounding
 442    modes.  */
 443
 444 bool
 445 default_float_exceptions_rounding_supported_p (void)
 446 {
 447 #ifdef HAVE_adddf3
 448   return HAVE_adddf3;
 449 #else
 450   return false;
 451 #endif
 452 }
 453
 454 /* True if the target supports decimal floating point.  */
 455
 456 bool
 457 default_decimal_float_supported_p (void)
 458 {
 459   return ENABLE_DECIMAL_FLOAT;
 460 }
 461
 462 /* True if the target supports fixed-point arithmetic.  */
 463
 464 bool
 465 default_fixed_point_supported_p (void)
 466 {
 467   return ENABLE_FIXED_POINT;
 468 }
 469
 470 /* True if the target supports GNU indirect functions.  */
 471
 472 bool
 473 default_has_ifunc_p (void)
 474 {
 475   return HAVE_GNU_INDIRECT_FUNCTION;
 476 }
 477
 478 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 479    an error message.
 480
 481    This function checks whether a given INSN is valid within a low-overhead
 482    loop.  If INSN is invalid it returns the reason for that, otherwise it
 483    returns NULL. A called function may clobber any special registers required
 484    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 485    register for branch on table instructions. We reject the doloop pattern in
 486    these cases.  */
 487
 488 const char *
 489 default_invalid_within_doloop (const_rtx insn)
 490 {
 491   if (CALL_P (insn))
 492     return "Function call in loop.";
 493
 494   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 495     return "Computed branch in the loop.";
 496
 497   return NULL;
 498 }
 499
 500 /* Mapping of builtin functions to vectorized variants.  */
 501
 502 tree
 503 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 504                                      tree type_out ATTRIBUTE_UNUSED,
 505                                      tree type_in ATTRIBUTE_UNUSED)
 506 {
 507   return NULL_TREE;
 508 }
 509
 510 /* Vectorized conversion.  */
 511
 512 tree
 513 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 514                                        tree dest_type ATTRIBUTE_UNUSED,
 515                                        tree src_type ATTRIBUTE_UNUSED)
 516 {
 517   return NULL_TREE;
 518 }
 519
 520 /* Default vectorizer cost model values.  */
 521
 522 int
 523 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 524                                     tree vectype,
 525                                     int misalign ATTRIBUTE_UNUSED)
 526 {
 527   unsigned elements;
 528
 529   switch (type_of_cost)
 530     {
 531       case scalar_stmt:
 532       case scalar_load:
 533       case scalar_store:
 534       case vector_stmt:
 535       case vector_load:
 536       case vector_store:
 537       case vec_to_scalar:
 538       case scalar_to_vec:
 539       case cond_branch_not_taken:
 540       case vec_perm:
 541       case vec_promote_demote:
 542         return 1;
 543
 544       case unaligned_load:
 545       case unaligned_store:
 546         return 2;
 547
 548       case cond_branch_taken:
 549         return 3;
 550
 551       case vec_construct:
 552         elements = TYPE_VECTOR_SUBPARTS (vectype);
 553         return elements / 2 + 1;
 554
 555       default:
 556         gcc_unreachable ();
 557     }
 558 }
 559
 560 /* Reciprocal.  */
 561
 562 tree
 563 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 564                             bool md_fn ATTRIBUTE_UNUSED,
 565                             bool sqrt ATTRIBUTE_UNUSED)
 566 {
 567   return NULL_TREE;
 568 }
 569
 570 bool
 571 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 572         cumulative_args_t ca ATTRIBUTE_UNUSED,
 573         enum machine_mode mode ATTRIBUTE_UNUSED,
 574         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 575 {
 576   return false;
 577 }
 578
 579 bool
 580 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 581         cumulative_args_t ca ATTRIBUTE_UNUSED,
 582         enum machine_mode mode ATTRIBUTE_UNUSED,
 583         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 584 {
 585   return true;
 586 }
 587
 588 int
 589 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 590         cumulative_args_t ca ATTRIBUTE_UNUSED,
 591         enum machine_mode mode ATTRIBUTE_UNUSED,
 592         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 593 {
 594   return 0;
 595 }
 596
 597 void
 598 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 599                               enum machine_mode mode ATTRIBUTE_UNUSED,
 600                               const_tree type ATTRIBUTE_UNUSED,
 601                               bool named ATTRIBUTE_UNUSED)
 602 {
 603   gcc_unreachable ();
 604 }
 605
 606 rtx
 607 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 608                       enum machine_mode mode ATTRIBUTE_UNUSED,
 609                       const_tree type ATTRIBUTE_UNUSED,
 610                       bool named ATTRIBUTE_UNUSED)
 611 {
 612   gcc_unreachable ();
 613 }
 614
 615 rtx
 616 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 617                                enum machine_mode mode ATTRIBUTE_UNUSED,
 618                                const_tree type ATTRIBUTE_UNUSED,
 619                                bool named ATTRIBUTE_UNUSED)
 620 {
 621   gcc_unreachable ();
 622 }
 623
 624 unsigned int
 625 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 626                                const_tree type ATTRIBUTE_UNUSED)
 627 {
 628   return PARM_BOUNDARY;
 629 }
 630
 631 unsigned int
 632 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 633                                      const_tree type ATTRIBUTE_UNUSED)
 634 {
 635   return PARM_BOUNDARY;
 636 }
 637
 638 void
 639 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 640 {
 641 }
 642
 643 const char *
 644 hook_invalid_arg_for_unprototyped_fn (
 645         const_tree typelist ATTRIBUTE_UNUSED,
 646         const_tree funcdecl ATTRIBUTE_UNUSED,
 647         const_tree val ATTRIBUTE_UNUSED)
 648 {
 649   return NULL;
 650 }
 651
 652 /* Initialize the stack protection decls.  */
 653
 654 /* Stack protection related decls living in libgcc.  */
 655 static GTY(()) tree stack_chk_guard_decl;
 656
 657 tree
 658 default_stack_protect_guard (void)
 659 {
 660   tree t = stack_chk_guard_decl;
 661
 662   if (t == NULL)
 663     {
 664       rtx x;
 665
 666       t = build_decl (UNKNOWN_LOCATION,
 667                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 668                       ptr_type_node);
 669       TREE_STATIC (t) = 1;
 670       TREE_PUBLIC (t) = 1;
 671       DECL_EXTERNAL (t) = 1;
 672       TREE_USED (t) = 1;
 673       TREE_THIS_VOLATILE (t) = 1;
 674       DECL_ARTIFICIAL (t) = 1;
 675       DECL_IGNORED_P (t) = 1;
 676
 677       /* Do not share RTL as the declaration is visible outside of
 678          current function.  */
 679       x = DECL_RTL (t);
 680       RTX_FLAG (x, used) = 1;
 681
 682       stack_chk_guard_decl = t;
 683     }
 684
 685   return t;
 686 }
 687
 688 static GTY(()) tree stack_chk_fail_decl;
 689
 690 tree
 691 default_external_stack_protect_fail (void)
 692 {
 693   tree t = stack_chk_fail_decl;
 694
 695   if (t == NULL_TREE)
 696     {
 697       t = build_function_type_list (void_type_node, NULL_TREE);
 698       t = build_decl (UNKNOWN_LOCATION,
 699                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 700       TREE_STATIC (t) = 1;
 701       TREE_PUBLIC (t) = 1;
 702       DECL_EXTERNAL (t) = 1;
 703       TREE_USED (t) = 1;
 704       TREE_THIS_VOLATILE (t) = 1;
 705       TREE_NOTHROW (t) = 1;
 706       DECL_ARTIFICIAL (t) = 1;
 707       DECL_IGNORED_P (t) = 1;
 708       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 709       DECL_VISIBILITY_SPECIFIED (t) = 1;
 710
 711       stack_chk_fail_decl = t;
 712     }
 713
 714   return build_call_expr (t, 0);
 715 }
 716
 717 tree
 718 default_hidden_stack_protect_fail (void)
 719 {
 720 #ifndef HAVE_GAS_HIDDEN
 721   return default_external_stack_protect_fail ();
 722 #else
 723   tree t = stack_chk_fail_decl;
 724
 725   if (!flag_pic)
 726     return default_external_stack_protect_fail ();
 727
 728   if (t == NULL_TREE)
 729     {
 730       t = build_function_type_list (void_type_node, NULL_TREE);
 731       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 732                       get_identifier ("__stack_chk_fail_local"), t);
 733       TREE_STATIC (t) = 1;
 734       TREE_PUBLIC (t) = 1;
 735       DECL_EXTERNAL (t) = 1;
 736       TREE_USED (t) = 1;
 737       TREE_THIS_VOLATILE (t) = 1;
 738       TREE_NOTHROW (t) = 1;
 739       DECL_ARTIFICIAL (t) = 1;
 740       DECL_IGNORED_P (t) = 1;
 741       DECL_VISIBILITY_SPECIFIED (t) = 1;
 742       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 743
 744       stack_chk_fail_decl = t;
 745     }
 746
 747   return build_call_expr (t, 0);
 748 #endif
 749 }
 750
 751 bool
 752 hook_bool_const_rtx_commutative_p (const_rtx x,
 753                                    int outer_code ATTRIBUTE_UNUSED)
 754 {
 755   return COMMUTATIVE_P (x);
 756 }
 757
 758 rtx
 759 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 760                         const_tree fn_decl_or_type,
 761                         bool outgoing ATTRIBUTE_UNUSED)
 762 {
 763   /* The old interface doesn't handle receiving the function type.  */
 764   if (fn_decl_or_type
 765       && !DECL_P (fn_decl_or_type))
 766     fn_decl_or_type = NULL;
 767
 768 #ifdef FUNCTION_VALUE
 769   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 770 #else
 771   gcc_unreachable ();
 772 #endif
 773 }
 774
 775 rtx
 776 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 777                        const_rtx fun ATTRIBUTE_UNUSED)
 778 {
 779 #ifdef LIBCALL_VALUE
 780   return LIBCALL_VALUE (mode);
 781 #else
 782   gcc_unreachable ();
 783 #endif
 784 }
 785
 786 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 787
 788 bool
 789 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 790 {
 791 #ifdef FUNCTION_VALUE_REGNO_P
 792   return FUNCTION_VALUE_REGNO_P (regno);
 793 #else
 794   gcc_unreachable ();
 795 #endif
 796 }
 797
 798 rtx
 799 default_internal_arg_pointer (void)
 800 {
 801   /* If the reg that the virtual arg pointer will be translated into is
 802      not a fixed reg or is the stack pointer, make a copy of the virtual
 803      arg pointer, and address parms via the copy.  The frame pointer is
 804      considered fixed even though it is not marked as such.  */
 805   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 806        || ! (fixed_regs[ARG_POINTER_REGNUM]
 807              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 808     return copy_to_reg (virtual_incoming_args_rtx);
 809   else
 810     return virtual_incoming_args_rtx;
 811 }
 812
 813 rtx
 814 default_static_chain (const_tree fndecl, bool incoming_p)
 815 {
 816   if (!DECL_STATIC_CHAIN (fndecl))
 817     return NULL;
 818
 819   if (incoming_p)
 820     {
 821 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 822       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 823 #endif
 824     }
 825
 826 #ifdef STATIC_CHAIN_REGNUM
 827   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 828 #endif
 829
 830   {
 831     static bool issued_error;
 832     if (!issued_error)
 833       {
 834         issued_error = true;
 835         sorry ("nested functions not supported on this target");
 836       }
 837
 838     /* It really doesn't matter what we return here, so long at it
 839        doesn't cause the rest of the compiler to crash.  */
 840     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 841   }
 842 }
 843
 844 void
 845 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 846                          rtx ARG_UNUSED (r_chain))
 847 {
 848   sorry ("nested function trampolines not supported on this target");
 849 }
 850
 851 int
 852 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 853                           tree funtype ATTRIBUTE_UNUSED,
 854                           int size ATTRIBUTE_UNUSED)
 855 {
 856   return 0;
 857 }
 858
 859 reg_class_t
 860 default_branch_target_register_class (void)
 861 {
 862   return NO_REGS;
 863 }
 864
 865 extern bool
 866 default_lra_p (void)
 867 {
 868   return false;
 869 }
 870
 871 int
 872 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 873 {
 874   return 0;
 875 }
 876
 877 extern bool
 878 default_register_usage_leveling_p (void)
 879 {
 880   return false;
 881 }
 882
 883 extern bool
 884 default_different_addr_displacement_p (void)
 885 {
 886   return false;
 887 }
 888
 889 reg_class_t
 890 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 891                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 892                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 893                           secondary_reload_info *sri)
 894 {
 895   enum reg_class rclass = NO_REGS;
 896   enum reg_class reload_class = (enum reg_class) reload_class_i;
 897
 898   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 899     {
 900       sri->icode = sri->prev_sri->t_icode;
 901       return NO_REGS;
 902     }
 903 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 904   if (in_p)
 905     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 906 #endif
 907 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 908   if (! in_p)
 909     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 910 #endif
 911   if (rclass != NO_REGS)
 912     {
 913       enum insn_code icode
 914         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 915                                 reload_mode);
 916
 917       if (icode != CODE_FOR_nothing
 918           && !insn_operand_matches (icode, in_p, x))
 919         icode = CODE_FOR_nothing;
 920       else if (icode != CODE_FOR_nothing)
 921         {
 922           const char *insn_constraint, *scratch_constraint;
 923           char insn_letter, scratch_letter;
 924           enum reg_class insn_class, scratch_class;
 925
 926           gcc_assert (insn_data[(int) icode].n_operands == 3);
 927           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 928           if (!*insn_constraint)
 929             insn_class = ALL_REGS;
 930           else
 931             {
 932               if (in_p)
 933                 {
 934                   gcc_assert (*insn_constraint == '=');
 935                   insn_constraint++;
 936                 }
 937               insn_letter = *insn_constraint;
 938               insn_class
 939                 = (insn_letter == 'r' ? GENERAL_REGS
 940                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 941                                                 insn_constraint));
 942               gcc_assert (insn_class != NO_REGS);
 943             }
 944
 945           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 946           /* The scratch register's constraint must start with "=&",
 947              except for an input reload, where only "=" is necessary,
 948              and where it might be beneficial to re-use registers from
 949              the input.  */
 950           gcc_assert (scratch_constraint[0] == '='
 951                       && (in_p || scratch_constraint[1] == '&'));
 952           scratch_constraint++;
 953           if (*scratch_constraint == '&')
 954             scratch_constraint++;
 955           scratch_letter = *scratch_constraint;
 956           scratch_class
 957             = (scratch_letter == 'r' ? GENERAL_REGS
 958                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 959                                             scratch_constraint));
 960
 961           if (reg_class_subset_p (reload_class, insn_class))
 962             {
 963               gcc_assert (scratch_class == rclass);
 964               rclass = NO_REGS;
 965             }
 966           else
 967             rclass = insn_class;
 968
 969         }
 970       if (rclass == NO_REGS)
 971         sri->icode = icode;
 972       else
 973         sri->t_icode = icode;
 974     }
 975   return rclass;
 976 }
 977
 978 /* By default, if flag_pic is true, then neither local nor global relocs
 979    should be placed in readonly memory.  */
 980
 981 int
 982 default_reloc_rw_mask (void)
 983 {
 984   return flag_pic ? 3 : 0;
 985 }
 986
 987 /* By default, do no modification. */
 988 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 989                                          tree id)
 990 {
 991    return id;
 992 }
 993
 994 /* Default to natural alignment for vector types.  */
 995 HOST_WIDE_INT
 996 default_vector_alignment (const_tree type)
 997 {
 998   return tree_to_shwi (TYPE_SIZE (type));
 999 }
1000
1001 bool
1002 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
1003 {
1004   if (is_packed)
1005     return false;
1006
1007   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1008      naturally aligned.  */
1009   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1010     return false;
1011
1012   /* Assuming that types whose size is <= pointer-size
1013      are naturally aligned.  */
1014   return true;
1015 }
1016
1017 /* By default, assume that a target supports any factor of misalignment
1018    memory access if it supports movmisalign patten.
1019    is_packed is true if the memory access is defined in a packed struct.  */
1020 bool
1021 default_builtin_support_vector_misalignment (enum machine_mode mode,
1022                                              const_tree type
1023                                              ATTRIBUTE_UNUSED,
1024                                              int misalignment
1025                                              ATTRIBUTE_UNUSED,
1026                                              bool is_packed
1027                                              ATTRIBUTE_UNUSED)
1028 {
1029   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1030     return true;
1031   return false;
1032 }
1033
1034 /* By default, only attempt to parallelize bitwise operations, and
1035    possibly adds/subtracts using bit-twiddling.  */
1036
1037 enum machine_mode
1038 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1039 {
1040   return word_mode;
1041 }
1042
1043 /* By default only the size derived from the preferred vector mode
1044    is tried.  */
1045
1046 unsigned int
1047 default_autovectorize_vector_sizes (void)
1048 {
1049   return 0;
1050 }
1051
1052 /* By default, the cost model accumulates three separate costs (prologue,
1053    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1054    array of three unsigned ints, set it to zero, and return its address.  */
1055
1056 void *
1057 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1058 {
1059   unsigned *cost = XNEWVEC (unsigned, 3);
1060   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1061   return cost;
1062 }
1063
1064 /* By default, the cost model looks up the cost of the given statement
1065    kind and mode, multiplies it by the occurrence count, accumulates
1066    it into the cost specified by WHERE, and returns the cost added.  */
1067
1068 unsigned
1069 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1070                        struct _stmt_vec_info *stmt_info, int misalign,
1071                        enum vect_cost_model_location where)
1072 {
1073   unsigned *cost = (unsigned *) data;
1074   unsigned retval = 0;
1075
1076   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1077   int stmt_cost = default_builtin_vectorization_cost (kind, vectype,
1078                                                           misalign);
1079    /* Statements in an inner loop relative to the loop being
1080       vectorized are weighted more heavily.  The value here is
1081       arbitrary and could potentially be improved with analysis.  */
1082   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1083     count *= 50;  /* FIXME.  */
1084
1085   retval = (unsigned) (count * stmt_cost);
1086   cost[where] += retval;
1087
1088   return retval;
1089 }
1090
1091 /* By default, the cost model just returns the accumulated costs.  */
1092
1093 void
1094 default_finish_cost (void *data, unsigned *prologue_cost,
1095                      unsigned *body_cost, unsigned *epilogue_cost)
1096 {
1097   unsigned *cost = (unsigned *) data;
1098   *prologue_cost = cost[vect_prologue];
1099   *body_cost     = cost[vect_body];
1100   *epilogue_cost = cost[vect_epilogue];
1101 }
1102
1103 /* Free the cost data.  */
1104
1105 void
1106 default_destroy_cost_data (void *data)
1107 {
1108   free (data);
1109 }
1110
1111 /* Determine whether or not a pointer mode is valid. Assume defaults
1112    of ptr_mode or Pmode - can be overridden.  */
1113 bool
1114 default_valid_pointer_mode (enum machine_mode mode)
1115 {
1116   return (mode == ptr_mode || mode == Pmode);
1117 }
1118
1119 /* Determine whether the memory reference specified by REF may alias
1120    the C libraries errno location.  */
1121 bool
1122 default_ref_may_alias_errno (ao_ref *ref)
1123 {
1124   tree base = ao_ref_base (ref);
1125   /* The default implementation assumes the errno location is
1126      a declaration of type int or is always accessed via a
1127      pointer to int.  We assume that accesses to errno are
1128      not deliberately obfuscated (even in conforming ways).  */
1129   if (TYPE_UNSIGNED (TREE_TYPE (base))
1130       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1131     return false;
1132   /* The default implementation assumes an errno location
1133      declaration is never defined in the current compilation unit.  */
1134   if (DECL_P (base)
1135       && !TREE_STATIC (base))
1136     return true;
1137   else if (TREE_CODE (base) == MEM_REF
1138            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1139     {
1140       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1141       return !pi || pi->pt.anything || pi->pt.nonlocal;
1142     }
1143   return false;
1144 }
1145
1146 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1147    for the generic address space only.  */
1148
1149 enum machine_mode
1150 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1151 {
1152   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1153   return ptr_mode;
1154 }
1155
1156 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1157    for the generic address space only.  */
1158
1159 enum machine_mode
1160 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1161 {
1162   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1163   return Pmode;
1164 }
1165
1166 /* Named address space version of valid_pointer_mode.  */
1167
1168 bool
1169 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1170 {
1171   if (!ADDR_SPACE_GENERIC_P (as))
1172     return (mode == targetm.addr_space.pointer_mode (as)
1173             || mode == targetm.addr_space.address_mode (as));
1174
1175   return targetm.valid_pointer_mode (mode);
1176 }
1177
1178 /* Some places still assume that all pointer or address modes are the
1179    standard Pmode and ptr_mode.  These optimizations become invalid if
1180    the target actually supports multiple different modes.  For now,
1181    we disable such optimizations on such targets, using this function.  */
1182
1183 bool
1184 target_default_pointer_address_modes_p (void)
1185 {
1186   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1187     return false;
1188   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1189     return false;
1190
1191   return true;
1192 }
1193
1194 /* Named address space version of legitimate_address_p.  */
1195
1196 bool
1197 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1198                                          bool strict, addr_space_t as)
1199 {
1200   if (!ADDR_SPACE_GENERIC_P (as))
1201     gcc_unreachable ();
1202
1203   return targetm.legitimate_address_p (mode, mem, strict);
1204 }
1205
1206 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1207
1208 rtx
1209 default_addr_space_legitimize_address (rtx x, rtx oldx,
1210                                        enum machine_mode mode, addr_space_t as)
1211 {
1212   if (!ADDR_SPACE_GENERIC_P (as))
1213     return x;
1214
1215   return targetm.legitimize_address (x, oldx, mode);
1216 }
1217
1218 /* The default hook for determining if one named address space is a subset of
1219    another and to return which address space to use as the common address
1220    space.  */
1221
1222 bool
1223 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1224 {
1225   return (subset == superset);
1226 }
1227
1228 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1229    called for targets with only a generic address space.  */
1230
1231 rtx
1232 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1233                             tree from_type ATTRIBUTE_UNUSED,
1234                             tree to_type ATTRIBUTE_UNUSED)
1235 {
1236   gcc_unreachable ();
1237 }
1238
1239 bool
1240 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1241 {
1242   return true;
1243 }
1244
1245 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1246
1247 bool
1248 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1249                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1250 {
1251   return false;
1252 }
1253
1254 bool
1255 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1256                                          tree ARG_UNUSED (name),
1257                                          tree ARG_UNUSED (args),
1258                                          int ARG_UNUSED (flags))
1259 {
1260   warning (OPT_Wattributes,
1261            "target attribute is not supported on this machine");
1262
1263   return false;
1264 }
1265
1266 bool
1267 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1268                                     tree ARG_UNUSED (pop_target))
1269 {
1270   warning (OPT_Wpragmas,
1271            "#pragma GCC target is not supported for this machine");
1272
1273   return false;
1274 }
1275
1276 bool
1277 default_target_can_inline_p (tree caller, tree callee)
1278 {
1279   bool ret = false;
1280   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1281   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1282
1283   /* If callee has no option attributes, then it is ok to inline */
1284   if (!callee_opts)
1285     ret = true;
1286
1287   /* If caller has no option attributes, but callee does then it is not ok to
1288      inline */
1289   else if (!caller_opts)
1290     ret = false;
1291
1292   /* If both caller and callee have attributes, assume that if the
1293      pointer is different, the two functions have different target
1294      options since build_target_option_node uses a hash table for the
1295      options.  */
1296   else
1297     ret = (callee_opts == caller_opts);
1298
1299   return ret;
1300 }
1301
1302 #ifndef HAVE_casesi
1303 # define HAVE_casesi 0
1304 #endif
1305
1306 /* If the machine does not have a case insn that compares the bounds,
1307    this means extra overhead for dispatch tables, which raises the
1308    threshold for using them.  */
1309
1310 unsigned int
1311 default_case_values_threshold (void)
1312 {
1313   return (HAVE_casesi ? 4 : 5);
1314 }
1315
1316 bool
1317 default_have_conditional_execution (void)
1318 {
1319 #ifdef HAVE_conditional_execution
1320   return HAVE_conditional_execution;
1321 #else
1322   return false;
1323 #endif
1324 }
1325
1326 tree
1327 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1328 {
1329   return NULL_TREE;
1330 }
1331
1332 /* Compute cost of moving registers to/from memory.  */
1333
1334 int
1335 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1336                           reg_class_t rclass ATTRIBUTE_UNUSED,
1337                           bool in ATTRIBUTE_UNUSED)
1338 {
1339 #ifndef MEMORY_MOVE_COST
1340     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1341 #else
1342     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1343 #endif
1344 }
1345
1346 /* Compute cost of moving data from a register of class FROM to one of
1347    TO, using MODE.  */
1348
1349 int
1350 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1351                             reg_class_t from ATTRIBUTE_UNUSED,
1352                             reg_class_t to ATTRIBUTE_UNUSED)
1353 {
1354 #ifndef REGISTER_MOVE_COST
1355   return 2;
1356 #else
1357   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1358 #endif
1359 }
1360
1361 bool
1362 default_profile_before_prologue (void)
1363 {
1364 #ifdef PROFILE_BEFORE_PROLOGUE
1365   return true;
1366 #else
1367   return false;
1368 #endif
1369 }
1370
1371 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1372
1373 reg_class_t
1374 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1375                                 reg_class_t rclass)
1376 {
1377 #ifdef PREFERRED_RELOAD_CLASS
1378   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1379 #else
1380   return rclass;
1381 #endif
1382 }
1383
1384 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1385
1386 reg_class_t
1387 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1388                                        reg_class_t rclass)
1389 {
1390   return rclass;
1391 }
1392
1393 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1394 reg_class_t
1395 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1396 {
1397   return NO_REGS;
1398 }
1399
1400 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1401
1402 bool
1403 default_class_likely_spilled_p (reg_class_t rclass)
1404 {
1405   return (reg_class_size[(int) rclass] == 1);
1406 }
1407
1408 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1409
1410 unsigned char
1411 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1412                          enum machine_mode mode ATTRIBUTE_UNUSED)
1413 {
1414 #ifdef CLASS_MAX_NREGS
1415   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1416 #else
1417   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1418 #endif
1419 }
1420
1421 /* Determine the debugging unwind mechanism for the target.  */
1422
1423 enum unwind_info_type
1424 default_debug_unwind_info (void)
1425 {
1426   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1427   /* ??? Change all users to the hook, then poison this.  */
1428 #ifdef DWARF2_FRAME_INFO
1429   if (DWARF2_FRAME_INFO)
1430     return UI_DWARF2;
1431 #endif
1432
1433   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1434 #ifdef DWARF2_DEBUGGING_INFO
1435   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1436     return UI_DWARF2;
1437 #endif
1438
1439   return UI_NONE;
1440 }
1441
1442 /* To be used by targets where reg_raw_mode doesn't return the right
1443    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1444
1445 enum machine_mode
1446 default_get_reg_raw_mode (int regno)
1447 {
1448   return reg_raw_mode[regno];
1449 }
1450
1451 /* Return true if the state of option OPTION should be stored in PCH files
1452    and checked by default_pch_valid_p.  Store the option's current state
1453    in STATE if so.  */
1454
1455 static inline bool
1456 option_affects_pch_p (int option, struct cl_option_state *state)
1457 {
1458   if ((cl_options[option].flags & CL_TARGET) == 0)
1459     return false;
1460   if (option_flag_var (option, &global_options) == &target_flags)
1461     if (targetm.check_pch_target_flags)
1462       return false;
1463   return get_option_state (&global_options, option, state);
1464 }
1465
1466 /* Default version of get_pch_validity.
1467    By default, every flag difference is fatal; that will be mostly right for
1468    most targets, but completely right for very few.  */
1469
1470 void *
1471 default_get_pch_validity (size_t *sz)
1472 {
1473   struct cl_option_state state;
1474   size_t i;
1475   char *result, *r;
1476
1477   *sz = 2;
1478   if (targetm.check_pch_target_flags)
1479     *sz += sizeof (target_flags);
1480   for (i = 0; i < cl_options_count; i++)
1481     if (option_affects_pch_p (i, &state))
1482       *sz += state.size;
1483
1484   result = r = XNEWVEC (char, *sz);
1485   r[0] = flag_pic;
1486   r[1] = flag_pie;
1487   r += 2;
1488   if (targetm.check_pch_target_flags)
1489     {
1490       memcpy (r, &target_flags, sizeof (target_flags));
1491       r += sizeof (target_flags);
1492     }
1493
1494   for (i = 0; i < cl_options_count; i++)
1495     if (option_affects_pch_p (i, &state))
1496       {
1497         memcpy (r, state.data, state.size);
1498         r += state.size;
1499       }
1500
1501   return result;
1502 }
1503
1504 /* Return a message which says that a PCH file was created with a different
1505    setting of OPTION.  */
1506
1507 static const char *
1508 pch_option_mismatch (const char *option)
1509 {
1510   char *r;
1511
1512   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1513   if (r == NULL)
1514     return _("out of memory");
1515   return r;
1516 }
1517
1518 /* Default version of pch_valid_p.  */
1519
1520 const char *
1521 default_pch_valid_p (const void *data_p, size_t len)
1522 {
1523   struct cl_option_state state;
1524   const char *data = (const char *)data_p;
1525   size_t i;
1526
1527   /* -fpic and -fpie also usually make a PCH invalid.  */
1528   if (data[0] != flag_pic)
1529     return _("created and used with different settings of -fpic");
1530   if (data[1] != flag_pie)
1531     return _("created and used with different settings of -fpie");
1532   data += 2;
1533
1534   /* Check target_flags.  */
1535   if (targetm.check_pch_target_flags)
1536     {
1537       int tf;
1538       const char *r;
1539
1540       memcpy (&tf, data, sizeof (target_flags));
1541       data += sizeof (target_flags);
1542       len -= sizeof (target_flags);
1543       r = targetm.check_pch_target_flags (tf);
1544       if (r != NULL)
1545         return r;
1546     }
1547
1548   for (i = 0; i < cl_options_count; i++)
1549     if (option_affects_pch_p (i, &state))
1550       {
1551         if (memcmp (data, state.data, state.size) != 0)
1552           return pch_option_mismatch (cl_options[i].opt_text);
1553         data += state.size;
1554         len -= state.size;
1555       }
1556
1557   return NULL;
1558 }
1559
1560 /* Default version of cstore_mode.  */
1561
1562 enum machine_mode
1563 default_cstore_mode (enum insn_code icode)
1564 {
1565   return insn_data[(int) icode].operand[0].mode;
1566 }
1567
1568 /* Default version of member_type_forces_blk.  */
1569
1570 bool
1571 default_member_type_forces_blk (const_tree, enum machine_mode)
1572 {
1573   return false;
1574 }
1575 rtx
1576 default_load_bounds_for_arg (rtx addr ATTRIBUTE_UNUSED,
1577                              rtx ptr ATTRIBUTE_UNUSED,
1578                              rtx bnd ATTRIBUTE_UNUSED)
1579 {
1580   gcc_unreachable ();
1581 }
1582
1583 void
1584 default_store_bounds_for_arg (rtx val ATTRIBUTE_UNUSED,
1585                               rtx addr ATTRIBUTE_UNUSED,
1586                               rtx bounds ATTRIBUTE_UNUSED,
1587                               rtx to ATTRIBUTE_UNUSED)
1588 {
1589   gcc_unreachable ();
1590 }
1591
1592 tree
1593 default_fn_abi_va_list_bounds_size (tree fndecl ATTRIBUTE_UNUSED)
1594 {
1595   return integer_zero_node;
1596 }
1597
1598 /* Default version of canonicalize_comparison.  */
1599
1600 void
1601 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1602 {
1603 }
1604
1605 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1606
1607 void
1608 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1609 {
1610 }
1611
1612 #ifndef PAD_VARARGS_DOWN
1613 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1614 #endif
1615
1616 /* Build an indirect-ref expression over the given TREE, which represents a
1617    piece of a va_arg() expansion.  */
1618 tree
1619 build_va_arg_indirect_ref (tree addr)
1620 {
1621   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1622   return addr;
1623 }
1624
1625 /* The "standard" implementation of va_arg: read the value from the
1626    current (padded) address and increment by the (padded) size.  */
1627
1628 tree
1629 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1630                           gimple_seq *post_p)
1631 {
1632   tree addr, t, type_size, rounded_size, valist_tmp;
1633   unsigned HOST_WIDE_INT align, boundary;
1634   bool indirect;
1635
1636 #ifdef ARGS_GROW_DOWNWARD
1637   /* All of the alignment and movement below is for args-grow-up machines.
1638      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1639      implement their own specialized gimplify_va_arg_expr routines.  */
1640   gcc_unreachable ();
1641 #endif
1642
1643   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1644   if (indirect)
1645     type = build_pointer_type (type);
1646
1647   align = PARM_BOUNDARY / BITS_PER_UNIT;
1648   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1649
1650   /* When we align parameter on stack for caller, if the parameter
1651      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1652      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1653      here with caller.  */
1654   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1655     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1656
1657   boundary /= BITS_PER_UNIT;
1658
1659   /* Hoist the valist value into a temporary for the moment.  */
1660   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1661
1662   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1663      requires greater alignment, we must perform dynamic alignment.  */
1664   if (boundary > align
1665       && !integer_zerop (TYPE_SIZE (type)))
1666     {
1667       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1668                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1669       gimplify_and_add (t, pre_p);
1670
1671       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1672                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1673                                valist_tmp,
1674                                build_int_cst (TREE_TYPE (valist), -boundary)));
1675       gimplify_and_add (t, pre_p);
1676     }
1677   else
1678     boundary = align;
1679
1680   /* If the actual alignment is less than the alignment of the type,
1681      adjust the type accordingly so that we don't assume strict alignment
1682      when dereferencing the pointer.  */
1683   boundary *= BITS_PER_UNIT;
1684   if (boundary < TYPE_ALIGN (type))
1685     {
1686       type = build_variant_type_copy (type);
1687       TYPE_ALIGN (type) = boundary;
1688     }
1689
1690   /* Compute the rounded size of the type.  */
1691   type_size = size_in_bytes (type);
1692   rounded_size = round_up (type_size, align);
1693
1694   /* Reduce rounded_size so it's sharable with the postqueue.  */
1695   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1696
1697   /* Get AP.  */
1698   addr = valist_tmp;
1699   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1700     {
1701       /* Small args are padded downward.  */
1702       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1703                        rounded_size, size_int (align));
1704       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1705                        size_binop (MINUS_EXPR, rounded_size, type_size));
1706       addr = fold_build_pointer_plus (addr, t);
1707     }
1708
1709   /* Compute new value for AP.  */
1710   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1711   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1712   gimplify_and_add (t, pre_p);
1713
1714   addr = fold_convert (build_pointer_type (type), addr);
1715
1716   if (indirect)
1717     addr = build_va_arg_indirect_ref (addr);
1718
1719   return build_va_arg_indirect_ref (addr);
1720 }
1721
1722 tree
1723 default_chkp_bound_type (void)
1724 {
1725   tree res = make_node (POINTER_BOUNDS_TYPE);
1726   TYPE_PRECISION (res) = TYPE_PRECISION (size_type_node) * 2;
1727   layout_type (res);
1728   return res;
1729 }
1730
1731 enum machine_mode
1732 default_chkp_bound_mode (void)
1733 {
1734   return VOIDmode;
1735 }
1736
1737 tree
1738 default_builtin_chkp_function (unsigned int fcode ATTRIBUTE_UNUSED)
1739 {
1740   return NULL_TREE;
1741 }
1742
1743 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1744    not support nested low-overhead loops.  */
1745
1746 bool
1747 can_use_doloop_if_innermost (double_int, double_int,
1748                              unsigned int loop_depth, bool)
1749 {
1750   return loop_depth == 1;
1751 }
1752
1753 #include "gt-targhooks.h"