gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003-2014 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 "hashtab.h"
  62 #include "hash-set.h"
  63 #include "vec.h"
  64 #include "hard-reg-set.h"
  65 #include "input.h"
  66 #include "function.h"
  67 #include "target.h"
  68 #include "tm_p.h"
  69 #include "target-def.h"
  70 #include "regs.h"
  71 #include "reload.h"
  72 #include "insn-codes.h"
  73 #include "optabs.h"
  74 #include "recog.h"
  75 #include "intl.h"
  76 #include "opts.h"
  77 #include "tree-ssa-alias.h"
  78 #include "gimple-expr.h"
  79 #include "gimplify.h"
  80 #include "stringpool.h"
  81 #include "tree-ssanames.h"
  82
  83
  84 bool
  85 default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
  86                               rtx addr ATTRIBUTE_UNUSED,
  87                               bool strict ATTRIBUTE_UNUSED)
  88 {
  89 #ifdef GO_IF_LEGITIMATE_ADDRESS
  90   /* Defer to the old implementation using a goto.  */
  91   if (strict)
  92     return strict_memory_address_p (mode, addr);
  93   else
  94     return memory_address_p (mode, addr);
  95 #else
  96   gcc_unreachable ();
  97 #endif
  98 }
  99
 100 void
 101 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
 102 {
 103 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
 104   ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
 105 #endif
 106 }
 107
 108 int
 109 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 110 {
 111   int i;
 112
 113   /* Any floating arithmetic may trap.  */
 114   if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
 115     return 1;
 116
 117   for (i = 0; i < XVECLEN (x, 0); ++i)
 118     {
 119       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 120         return 1;
 121     }
 122
 123   return 0;
 124 }
 125
 126 machine_mode
 127 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 128                                machine_mode mode,
 129                                int *punsignedp ATTRIBUTE_UNUSED,
 130                                const_tree funtype ATTRIBUTE_UNUSED,
 131                                int for_return ATTRIBUTE_UNUSED)
 132 {
 133   if (type != NULL_TREE && for_return == 2)
 134     return promote_mode (type, mode, punsignedp);
 135   return mode;
 136 }
 137
 138 machine_mode
 139 default_promote_function_mode_always_promote (const_tree type,
 140                                               machine_mode mode,
 141                                               int *punsignedp,
 142                                               const_tree funtype ATTRIBUTE_UNUSED,
 143                                               int for_return ATTRIBUTE_UNUSED)
 144 {
 145   return promote_mode (type, mode, punsignedp);
 146 }
 147
 148 machine_mode
 149 default_cc_modes_compatible (machine_mode m1, machine_mode m2)
 150 {
 151   if (m1 == m2)
 152     return m1;
 153   return VOIDmode;
 154 }
 155
 156 bool
 157 default_return_in_memory (const_tree type,
 158                           const_tree fntype ATTRIBUTE_UNUSED)
 159 {
 160   return (TYPE_MODE (type) == BLKmode);
 161 }
 162
 163 rtx
 164 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 165                             machine_mode mode ATTRIBUTE_UNUSED)
 166 {
 167   return x;
 168 }
 169
 170 rtx
 171 default_expand_builtin_saveregs (void)
 172 {
 173   error ("__builtin_saveregs not supported by this target");
 174   return const0_rtx;
 175 }
 176
 177 void
 178 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 179                                 machine_mode mode ATTRIBUTE_UNUSED,
 180                                 tree type ATTRIBUTE_UNUSED,
 181                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 182                                 int second_time ATTRIBUTE_UNUSED)
 183 {
 184 }
 185
 186 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 187
 188 rtx
 189 default_builtin_setjmp_frame_value (void)
 190 {
 191   return virtual_stack_vars_rtx;
 192 }
 193
 194 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 195
 196 bool
 197 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 198 {
 199   return false;
 200 }
 201
 202 bool
 203 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 204 {
 205   return (targetm.calls.setup_incoming_varargs
 206           != default_setup_incoming_varargs);
 207 }
 208
 209 machine_mode
 210 default_eh_return_filter_mode (void)
 211 {
 212   return targetm.unwind_word_mode ();
 213 }
 214
 215 machine_mode
 216 default_libgcc_cmp_return_mode (void)
 217 {
 218   return word_mode;
 219 }
 220
 221 machine_mode
 222 default_libgcc_shift_count_mode (void)
 223 {
 224   return word_mode;
 225 }
 226
 227 machine_mode
 228 default_unwind_word_mode (void)
 229 {
 230   return word_mode;
 231 }
 232
 233 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 234
 235 unsigned HOST_WIDE_INT
 236 default_shift_truncation_mask (machine_mode mode)
 237 {
 238   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 239 }
 240
 241 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 242
 243 unsigned int
 244 default_min_divisions_for_recip_mul (machine_mode mode ATTRIBUTE_UNUSED)
 245 {
 246   return have_insn_for (DIV, mode) ? 3 : 2;
 247 }
 248
 249 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 250
 251 int
 252 default_mode_rep_extended (machine_mode mode ATTRIBUTE_UNUSED,
 253                            machine_mode mode_rep ATTRIBUTE_UNUSED)
 254 {
 255   return UNKNOWN;
 256 }
 257
 258 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 259
 260 bool
 261 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 262 {
 263   return true;
 264 }
 265
 266 /* Return machine mode for non-standard suffix
 267    or VOIDmode if non-standard suffixes are unsupported.  */
 268 machine_mode
 269 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 270 {
 271   return VOIDmode;
 272 }
 273
 274 /* The generic C++ ABI specifies this is a 64-bit value.  */
 275 tree
 276 default_cxx_guard_type (void)
 277 {
 278   return long_long_integer_type_node;
 279 }
 280
 281 /* Returns the size of the cookie to use when allocating an array
 282    whose elements have the indicated TYPE.  Assumes that it is already
 283    known that a cookie is needed.  */
 284
 285 tree
 286 default_cxx_get_cookie_size (tree type)
 287 {
 288   tree cookie_size;
 289
 290   /* We need to allocate an additional max (sizeof (size_t), alignof
 291      (true_type)) bytes.  */
 292   tree sizetype_size;
 293   tree type_align;
 294
 295   sizetype_size = size_in_bytes (sizetype);
 296   type_align = size_int (TYPE_ALIGN_UNIT (type));
 297   if (tree_int_cst_lt (type_align, sizetype_size))
 298     cookie_size = sizetype_size;
 299   else
 300     cookie_size = type_align;
 301
 302   return cookie_size;
 303 }
 304
 305 /* Return true if a parameter must be passed by reference.  This version
 306    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 307
 308 bool
 309 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 310         machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 311         bool named_arg ATTRIBUTE_UNUSED)
 312 {
 313   return targetm.calls.must_pass_in_stack (mode, type);
 314 }
 315
 316 /* Return true if a parameter follows callee copies conventions.  This
 317    version of the hook is true for all named arguments.  */
 318
 319 bool
 320 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 321                           machine_mode mode ATTRIBUTE_UNUSED,
 322                           const_tree type ATTRIBUTE_UNUSED, bool named)
 323 {
 324   return named;
 325 }
 326
 327 /* Emit to STREAM the assembler syntax for insn operand X.  */
 328
 329 void
 330 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 331                        int code ATTRIBUTE_UNUSED)
 332 {
 333 #ifdef PRINT_OPERAND
 334   PRINT_OPERAND (stream, x, code);
 335 #else
 336   gcc_unreachable ();
 337 #endif
 338 }
 339
 340 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 341    address is X.  */
 342
 343 void
 344 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 345                                rtx x ATTRIBUTE_UNUSED)
 346 {
 347 #ifdef PRINT_OPERAND_ADDRESS
 348   PRINT_OPERAND_ADDRESS (stream, x);
 349 #else
 350   gcc_unreachable ();
 351 #endif
 352 }
 353
 354 /* Return true if CODE is a valid punctuation character for the
 355    `print_operand' hook.  */
 356
 357 bool
 358 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 359 {
 360 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 361   return PRINT_OPERAND_PUNCT_VALID_P (code);
 362 #else
 363   return false;
 364 #endif
 365 }
 366
 367 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 368 tree
 369 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 370 {
 371   const char *skipped = name + (*name == '*' ? 1 : 0);
 372   const char *stripped = targetm.strip_name_encoding (skipped);
 373   if (*name != '*' && user_label_prefix[0])
 374     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 375   return get_identifier (stripped);
 376 }
 377
 378 /* True if MODE is valid for the target.  By "valid", we mean able to
 379    be manipulated in non-trivial ways.  In particular, this means all
 380    the arithmetic is supported.
 381
 382    By default we guess this means that any C type is supported.  If
 383    we can't map the mode back to a type that would be available in C,
 384    then reject it.  Special case, here, is the double-word arithmetic
 385    supported by optabs.c.  */
 386
 387 bool
 388 default_scalar_mode_supported_p (machine_mode mode)
 389 {
 390   int precision = GET_MODE_PRECISION (mode);
 391
 392   switch (GET_MODE_CLASS (mode))
 393     {
 394     case MODE_PARTIAL_INT:
 395     case MODE_INT:
 396       if (precision == CHAR_TYPE_SIZE)
 397         return true;
 398       if (precision == SHORT_TYPE_SIZE)
 399         return true;
 400       if (precision == INT_TYPE_SIZE)
 401         return true;
 402       if (precision == LONG_TYPE_SIZE)
 403         return true;
 404       if (precision == LONG_LONG_TYPE_SIZE)
 405         return true;
 406       if (precision == 2 * BITS_PER_WORD)
 407         return true;
 408       return false;
 409
 410     case MODE_FLOAT:
 411       if (precision == FLOAT_TYPE_SIZE)
 412         return true;
 413       if (precision == DOUBLE_TYPE_SIZE)
 414         return true;
 415       if (precision == LONG_DOUBLE_TYPE_SIZE)
 416         return true;
 417       return false;
 418
 419     case MODE_DECIMAL_FLOAT:
 420     case MODE_FRACT:
 421     case MODE_UFRACT:
 422     case MODE_ACCUM:
 423     case MODE_UACCUM:
 424       return false;
 425
 426     default:
 427       gcc_unreachable ();
 428     }
 429 }
 430
 431 /* Return true if libgcc supports floating-point mode MODE (known to
 432    be supported as a scalar mode).  */
 433
 434 bool
 435 default_libgcc_floating_mode_supported_p (machine_mode mode)
 436 {
 437   switch (mode)
 438     {
 439 #ifdef HAVE_SFmode
 440     case SFmode:
 441 #endif
 442 #ifdef HAVE_DFmode
 443     case DFmode:
 444 #endif
 445 #ifdef HAVE_XFmode
 446     case XFmode:
 447 #endif
 448 #ifdef HAVE_TFmode
 449     case TFmode:
 450 #endif
 451       return true;
 452
 453     default:
 454       return false;
 455     }
 456 }
 457
 458 /* Make some target macros useable by target-independent code.  */
 459 bool
 460 targhook_words_big_endian (void)
 461 {
 462   return !!WORDS_BIG_ENDIAN;
 463 }
 464
 465 bool
 466 targhook_float_words_big_endian (void)
 467 {
 468   return !!FLOAT_WORDS_BIG_ENDIAN;
 469 }
 470
 471 /* True if the target supports floating-point exceptions and rounding
 472    modes.  */
 473
 474 bool
 475 default_float_exceptions_rounding_supported_p (void)
 476 {
 477 #ifdef HAVE_adddf3
 478   return HAVE_adddf3;
 479 #else
 480   return false;
 481 #endif
 482 }
 483
 484 /* True if the target supports decimal floating point.  */
 485
 486 bool
 487 default_decimal_float_supported_p (void)
 488 {
 489   return ENABLE_DECIMAL_FLOAT;
 490 }
 491
 492 /* True if the target supports fixed-point arithmetic.  */
 493
 494 bool
 495 default_fixed_point_supported_p (void)
 496 {
 497   return ENABLE_FIXED_POINT;
 498 }
 499
 500 /* True if the target supports GNU indirect functions.  */
 501
 502 bool
 503 default_has_ifunc_p (void)
 504 {
 505   return HAVE_GNU_INDIRECT_FUNCTION;
 506 }
 507
 508 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 509    an error message.
 510
 511    This function checks whether a given INSN is valid within a low-overhead
 512    loop.  If INSN is invalid it returns the reason for that, otherwise it
 513    returns NULL. A called function may clobber any special registers required
 514    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 515    register for branch on table instructions. We reject the doloop pattern in
 516    these cases.  */
 517
 518 const char *
 519 default_invalid_within_doloop (const rtx_insn *insn)
 520 {
 521   if (CALL_P (insn))
 522     return "Function call in loop.";
 523
 524   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 525     return "Computed branch in the loop.";
 526
 527   return NULL;
 528 }
 529
 530 /* Mapping of builtin functions to vectorized variants.  */
 531
 532 tree
 533 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 534                                      tree type_out ATTRIBUTE_UNUSED,
 535                                      tree type_in ATTRIBUTE_UNUSED)
 536 {
 537   return NULL_TREE;
 538 }
 539
 540 /* Vectorized conversion.  */
 541
 542 tree
 543 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 544                                        tree dest_type ATTRIBUTE_UNUSED,
 545                                        tree src_type ATTRIBUTE_UNUSED)
 546 {
 547   return NULL_TREE;
 548 }
 549
 550 /* Default vectorizer cost model values.  */
 551
 552 int
 553 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 554                                     tree vectype,
 555                                     int misalign ATTRIBUTE_UNUSED)
 556 {
 557   unsigned elements;
 558
 559   switch (type_of_cost)
 560     {
 561       case scalar_stmt:
 562       case scalar_load:
 563       case scalar_store:
 564       case vector_stmt:
 565       case vector_load:
 566       case vector_store:
 567       case vec_to_scalar:
 568       case scalar_to_vec:
 569       case cond_branch_not_taken:
 570       case vec_perm:
 571       case vec_promote_demote:
 572         return 1;
 573
 574       case unaligned_load:
 575       case unaligned_store:
 576         return 2;
 577
 578       case cond_branch_taken:
 579         return 3;
 580
 581       case vec_construct:
 582         elements = TYPE_VECTOR_SUBPARTS (vectype);
 583         return elements / 2 + 1;
 584
 585       default:
 586         gcc_unreachable ();
 587     }
 588 }
 589
 590 /* Reciprocal.  */
 591
 592 tree
 593 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 594                             bool md_fn ATTRIBUTE_UNUSED,
 595                             bool sqrt ATTRIBUTE_UNUSED)
 596 {
 597   return NULL_TREE;
 598 }
 599
 600 bool
 601 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 602         cumulative_args_t ca ATTRIBUTE_UNUSED,
 603         machine_mode mode ATTRIBUTE_UNUSED,
 604         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 605 {
 606   return false;
 607 }
 608
 609 bool
 610 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 611         cumulative_args_t ca ATTRIBUTE_UNUSED,
 612         machine_mode mode ATTRIBUTE_UNUSED,
 613         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 614 {
 615   return true;
 616 }
 617
 618 int
 619 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 620         cumulative_args_t ca ATTRIBUTE_UNUSED,
 621         machine_mode mode ATTRIBUTE_UNUSED,
 622         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 623 {
 624   return 0;
 625 }
 626
 627 void
 628 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 629                               machine_mode mode ATTRIBUTE_UNUSED,
 630                               const_tree type ATTRIBUTE_UNUSED,
 631                               bool named ATTRIBUTE_UNUSED)
 632 {
 633   gcc_unreachable ();
 634 }
 635
 636 rtx
 637 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 638                       machine_mode mode ATTRIBUTE_UNUSED,
 639                       const_tree type ATTRIBUTE_UNUSED,
 640                       bool named ATTRIBUTE_UNUSED)
 641 {
 642   gcc_unreachable ();
 643 }
 644
 645 rtx
 646 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 647                                machine_mode mode ATTRIBUTE_UNUSED,
 648                                const_tree type ATTRIBUTE_UNUSED,
 649                                bool named ATTRIBUTE_UNUSED)
 650 {
 651   gcc_unreachable ();
 652 }
 653
 654 unsigned int
 655 default_function_arg_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 656                                const_tree type ATTRIBUTE_UNUSED)
 657 {
 658   return PARM_BOUNDARY;
 659 }
 660
 661 unsigned int
 662 default_function_arg_round_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 663                                      const_tree type ATTRIBUTE_UNUSED)
 664 {
 665   return PARM_BOUNDARY;
 666 }
 667
 668 void
 669 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 670 {
 671 }
 672
 673 const char *
 674 hook_invalid_arg_for_unprototyped_fn (
 675         const_tree typelist ATTRIBUTE_UNUSED,
 676         const_tree funcdecl ATTRIBUTE_UNUSED,
 677         const_tree val ATTRIBUTE_UNUSED)
 678 {
 679   return NULL;
 680 }
 681
 682 /* Initialize the stack protection decls.  */
 683
 684 /* Stack protection related decls living in libgcc.  */
 685 static GTY(()) tree stack_chk_guard_decl;
 686
 687 tree
 688 default_stack_protect_guard (void)
 689 {
 690   tree t = stack_chk_guard_decl;
 691
 692   if (t == NULL)
 693     {
 694       rtx x;
 695
 696       t = build_decl (UNKNOWN_LOCATION,
 697                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 698                       ptr_type_node);
 699       TREE_STATIC (t) = 1;
 700       TREE_PUBLIC (t) = 1;
 701       DECL_EXTERNAL (t) = 1;
 702       TREE_USED (t) = 1;
 703       TREE_THIS_VOLATILE (t) = 1;
 704       DECL_ARTIFICIAL (t) = 1;
 705       DECL_IGNORED_P (t) = 1;
 706
 707       /* Do not share RTL as the declaration is visible outside of
 708          current function.  */
 709       x = DECL_RTL (t);
 710       RTX_FLAG (x, used) = 1;
 711
 712       stack_chk_guard_decl = t;
 713     }
 714
 715   return t;
 716 }
 717
 718 static GTY(()) tree stack_chk_fail_decl;
 719
 720 tree
 721 default_external_stack_protect_fail (void)
 722 {
 723   tree t = stack_chk_fail_decl;
 724
 725   if (t == NULL_TREE)
 726     {
 727       t = build_function_type_list (void_type_node, NULL_TREE);
 728       t = build_decl (UNKNOWN_LOCATION,
 729                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 730       TREE_STATIC (t) = 1;
 731       TREE_PUBLIC (t) = 1;
 732       DECL_EXTERNAL (t) = 1;
 733       TREE_USED (t) = 1;
 734       TREE_THIS_VOLATILE (t) = 1;
 735       TREE_NOTHROW (t) = 1;
 736       DECL_ARTIFICIAL (t) = 1;
 737       DECL_IGNORED_P (t) = 1;
 738       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 739       DECL_VISIBILITY_SPECIFIED (t) = 1;
 740
 741       stack_chk_fail_decl = t;
 742     }
 743
 744   return build_call_expr (t, 0);
 745 }
 746
 747 tree
 748 default_hidden_stack_protect_fail (void)
 749 {
 750 #ifndef HAVE_GAS_HIDDEN
 751   return default_external_stack_protect_fail ();
 752 #else
 753   tree t = stack_chk_fail_decl;
 754
 755   if (!flag_pic)
 756     return default_external_stack_protect_fail ();
 757
 758   if (t == NULL_TREE)
 759     {
 760       t = build_function_type_list (void_type_node, NULL_TREE);
 761       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 762                       get_identifier ("__stack_chk_fail_local"), t);
 763       TREE_STATIC (t) = 1;
 764       TREE_PUBLIC (t) = 1;
 765       DECL_EXTERNAL (t) = 1;
 766       TREE_USED (t) = 1;
 767       TREE_THIS_VOLATILE (t) = 1;
 768       TREE_NOTHROW (t) = 1;
 769       DECL_ARTIFICIAL (t) = 1;
 770       DECL_IGNORED_P (t) = 1;
 771       DECL_VISIBILITY_SPECIFIED (t) = 1;
 772       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 773
 774       stack_chk_fail_decl = t;
 775     }
 776
 777   return build_call_expr (t, 0);
 778 #endif
 779 }
 780
 781 bool
 782 hook_bool_const_rtx_commutative_p (const_rtx x,
 783                                    int outer_code ATTRIBUTE_UNUSED)
 784 {
 785   return COMMUTATIVE_P (x);
 786 }
 787
 788 rtx
 789 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 790                         const_tree fn_decl_or_type,
 791                         bool outgoing ATTRIBUTE_UNUSED)
 792 {
 793   /* The old interface doesn't handle receiving the function type.  */
 794   if (fn_decl_or_type
 795       && !DECL_P (fn_decl_or_type))
 796     fn_decl_or_type = NULL;
 797
 798 #ifdef FUNCTION_VALUE
 799   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 800 #else
 801   gcc_unreachable ();
 802 #endif
 803 }
 804
 805 rtx
 806 default_libcall_value (machine_mode mode ATTRIBUTE_UNUSED,
 807                        const_rtx fun ATTRIBUTE_UNUSED)
 808 {
 809 #ifdef LIBCALL_VALUE
 810   return LIBCALL_VALUE (mode);
 811 #else
 812   gcc_unreachable ();
 813 #endif
 814 }
 815
 816 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 817
 818 bool
 819 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 820 {
 821 #ifdef FUNCTION_VALUE_REGNO_P
 822   return FUNCTION_VALUE_REGNO_P (regno);
 823 #else
 824   gcc_unreachable ();
 825 #endif
 826 }
 827
 828 rtx
 829 default_internal_arg_pointer (void)
 830 {
 831   /* If the reg that the virtual arg pointer will be translated into is
 832      not a fixed reg or is the stack pointer, make a copy of the virtual
 833      arg pointer, and address parms via the copy.  The frame pointer is
 834      considered fixed even though it is not marked as such.  */
 835   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 836        || ! (fixed_regs[ARG_POINTER_REGNUM]
 837              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 838     return copy_to_reg (virtual_incoming_args_rtx);
 839   else
 840     return virtual_incoming_args_rtx;
 841 }
 842
 843 rtx
 844 default_static_chain (const_tree ARG_UNUSED (fndecl_or_type), bool incoming_p)
 845 {
 846   if (incoming_p)
 847     {
 848 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 849       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 850 #endif
 851     }
 852
 853 #ifdef STATIC_CHAIN_REGNUM
 854   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 855 #endif
 856
 857   {
 858     static bool issued_error;
 859     if (!issued_error)
 860       {
 861         issued_error = true;
 862         sorry ("nested functions not supported on this target");
 863       }
 864
 865     /* It really doesn't matter what we return here, so long at it
 866        doesn't cause the rest of the compiler to crash.  */
 867     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 868   }
 869 }
 870
 871 void
 872 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 873                          rtx ARG_UNUSED (r_chain))
 874 {
 875   sorry ("nested function trampolines not supported on this target");
 876 }
 877
 878 int
 879 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 880                           tree funtype ATTRIBUTE_UNUSED,
 881                           int size ATTRIBUTE_UNUSED)
 882 {
 883   return 0;
 884 }
 885
 886 reg_class_t
 887 default_branch_target_register_class (void)
 888 {
 889   return NO_REGS;
 890 }
 891
 892 extern bool
 893 default_lra_p (void)
 894 {
 895   return false;
 896 }
 897
 898 int
 899 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 900 {
 901   return 0;
 902 }
 903
 904 extern bool
 905 default_register_usage_leveling_p (void)
 906 {
 907   return false;
 908 }
 909
 910 extern bool
 911 default_different_addr_displacement_p (void)
 912 {
 913   return false;
 914 }
 915
 916 reg_class_t
 917 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 918                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 919                           machine_mode reload_mode ATTRIBUTE_UNUSED,
 920                           secondary_reload_info *sri)
 921 {
 922   enum reg_class rclass = NO_REGS;
 923   enum reg_class reload_class = (enum reg_class) reload_class_i;
 924
 925   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 926     {
 927       sri->icode = sri->prev_sri->t_icode;
 928       return NO_REGS;
 929     }
 930 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 931   if (in_p)
 932     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 933 #endif
 934 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 935   if (! in_p)
 936     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 937 #endif
 938   if (rclass != NO_REGS)
 939     {
 940       enum insn_code icode
 941         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 942                                 reload_mode);
 943
 944       if (icode != CODE_FOR_nothing
 945           && !insn_operand_matches (icode, in_p, x))
 946         icode = CODE_FOR_nothing;
 947       else if (icode != CODE_FOR_nothing)
 948         {
 949           const char *insn_constraint, *scratch_constraint;
 950           enum reg_class insn_class, scratch_class;
 951
 952           gcc_assert (insn_data[(int) icode].n_operands == 3);
 953           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 954           if (!*insn_constraint)
 955             insn_class = ALL_REGS;
 956           else
 957             {
 958               if (in_p)
 959                 {
 960                   gcc_assert (*insn_constraint == '=');
 961                   insn_constraint++;
 962                 }
 963               insn_class = (reg_class_for_constraint
 964                             (lookup_constraint (insn_constraint)));
 965               gcc_assert (insn_class != NO_REGS);
 966             }
 967
 968           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 969           /* The scratch register's constraint must start with "=&",
 970              except for an input reload, where only "=" is necessary,
 971              and where it might be beneficial to re-use registers from
 972              the input.  */
 973           gcc_assert (scratch_constraint[0] == '='
 974                       && (in_p || scratch_constraint[1] == '&'));
 975           scratch_constraint++;
 976           if (*scratch_constraint == '&')
 977             scratch_constraint++;
 978           scratch_class = (reg_class_for_constraint
 979                            (lookup_constraint (scratch_constraint)));
 980
 981           if (reg_class_subset_p (reload_class, insn_class))
 982             {
 983               gcc_assert (scratch_class == rclass);
 984               rclass = NO_REGS;
 985             }
 986           else
 987             rclass = insn_class;
 988
 989         }
 990       if (rclass == NO_REGS)
 991         sri->icode = icode;
 992       else
 993         sri->t_icode = icode;
 994     }
 995   return rclass;
 996 }
 997
 998 /* By default, if flag_pic is true, then neither local nor global relocs
 999    should be placed in readonly memory.  */
1000
1001 int
1002 default_reloc_rw_mask (void)
1003 {
1004   return flag_pic ? 3 : 0;
1005 }
1006
1007 /* By default, do no modification. */
1008 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
1009                                          tree id)
1010 {
1011    return id;
1012 }
1013
1014 /* Default to natural alignment for vector types.  */
1015 HOST_WIDE_INT
1016 default_vector_alignment (const_tree type)
1017 {
1018   return tree_to_shwi (TYPE_SIZE (type));
1019 }
1020
1021 bool
1022 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
1023 {
1024   if (is_packed)
1025     return false;
1026
1027   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1028      naturally aligned.  */
1029   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1030     return false;
1031
1032   /* Assuming that types whose size is <= pointer-size
1033      are naturally aligned.  */
1034   return true;
1035 }
1036
1037 /* By default, assume that a target supports any factor of misalignment
1038    memory access if it supports movmisalign patten.
1039    is_packed is true if the memory access is defined in a packed struct.  */
1040 bool
1041 default_builtin_support_vector_misalignment (machine_mode mode,
1042                                              const_tree type
1043                                              ATTRIBUTE_UNUSED,
1044                                              int misalignment
1045                                              ATTRIBUTE_UNUSED,
1046                                              bool is_packed
1047                                              ATTRIBUTE_UNUSED)
1048 {
1049   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1050     return true;
1051   return false;
1052 }
1053
1054 /* By default, only attempt to parallelize bitwise operations, and
1055    possibly adds/subtracts using bit-twiddling.  */
1056
1057 machine_mode
1058 default_preferred_simd_mode (machine_mode mode ATTRIBUTE_UNUSED)
1059 {
1060   return word_mode;
1061 }
1062
1063 /* By default only the size derived from the preferred vector mode
1064    is tried.  */
1065
1066 unsigned int
1067 default_autovectorize_vector_sizes (void)
1068 {
1069   return 0;
1070 }
1071
1072 /* By default, the cost model accumulates three separate costs (prologue,
1073    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1074    array of three unsigned ints, set it to zero, and return its address.  */
1075
1076 void *
1077 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1078 {
1079   unsigned *cost = XNEWVEC (unsigned, 3);
1080   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1081   return cost;
1082 }
1083
1084 /* By default, the cost model looks up the cost of the given statement
1085    kind and mode, multiplies it by the occurrence count, accumulates
1086    it into the cost specified by WHERE, and returns the cost added.  */
1087
1088 unsigned
1089 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1090                        struct _stmt_vec_info *stmt_info, int misalign,
1091                        enum vect_cost_model_location where)
1092 {
1093   unsigned *cost = (unsigned *) data;
1094   unsigned retval = 0;
1095
1096   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1097   int stmt_cost = targetm.vectorize.builtin_vectorization_cost (kind, vectype,
1098                                                                 misalign);
1099    /* Statements in an inner loop relative to the loop being
1100       vectorized are weighted more heavily.  The value here is
1101       arbitrary and could potentially be improved with analysis.  */
1102   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1103     count *= 50;  /* FIXME.  */
1104
1105   retval = (unsigned) (count * stmt_cost);
1106   cost[where] += retval;
1107
1108   return retval;
1109 }
1110
1111 /* By default, the cost model just returns the accumulated costs.  */
1112
1113 void
1114 default_finish_cost (void *data, unsigned *prologue_cost,
1115                      unsigned *body_cost, unsigned *epilogue_cost)
1116 {
1117   unsigned *cost = (unsigned *) data;
1118   *prologue_cost = cost[vect_prologue];
1119   *body_cost     = cost[vect_body];
1120   *epilogue_cost = cost[vect_epilogue];
1121 }
1122
1123 /* Free the cost data.  */
1124
1125 void
1126 default_destroy_cost_data (void *data)
1127 {
1128   free (data);
1129 }
1130
1131 /* Determine whether or not a pointer mode is valid. Assume defaults
1132    of ptr_mode or Pmode - can be overridden.  */
1133 bool
1134 default_valid_pointer_mode (machine_mode mode)
1135 {
1136   return (mode == ptr_mode || mode == Pmode);
1137 }
1138
1139 /* Determine whether the memory reference specified by REF may alias
1140    the C libraries errno location.  */
1141 bool
1142 default_ref_may_alias_errno (ao_ref *ref)
1143 {
1144   tree base = ao_ref_base (ref);
1145   /* The default implementation assumes the errno location is
1146      a declaration of type int or is always accessed via a
1147      pointer to int.  We assume that accesses to errno are
1148      not deliberately obfuscated (even in conforming ways).  */
1149   if (TYPE_UNSIGNED (TREE_TYPE (base))
1150       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1151     return false;
1152   /* The default implementation assumes an errno location
1153      declaration is never defined in the current compilation unit.  */
1154   if (DECL_P (base)
1155       && !TREE_STATIC (base))
1156     return true;
1157   else if (TREE_CODE (base) == MEM_REF
1158            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1159     {
1160       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1161       return !pi || pi->pt.anything || pi->pt.nonlocal;
1162     }
1163   return false;
1164 }
1165
1166 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1167    for the generic address space only.  */
1168
1169 machine_mode
1170 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1171 {
1172   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1173   return ptr_mode;
1174 }
1175
1176 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1177    for the generic address space only.  */
1178
1179 machine_mode
1180 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1181 {
1182   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1183   return Pmode;
1184 }
1185
1186 /* Named address space version of valid_pointer_mode.  */
1187
1188 bool
1189 default_addr_space_valid_pointer_mode (machine_mode mode, addr_space_t as)
1190 {
1191   if (!ADDR_SPACE_GENERIC_P (as))
1192     return (mode == targetm.addr_space.pointer_mode (as)
1193             || mode == targetm.addr_space.address_mode (as));
1194
1195   return targetm.valid_pointer_mode (mode);
1196 }
1197
1198 /* Some places still assume that all pointer or address modes are the
1199    standard Pmode and ptr_mode.  These optimizations become invalid if
1200    the target actually supports multiple different modes.  For now,
1201    we disable such optimizations on such targets, using this function.  */
1202
1203 bool
1204 target_default_pointer_address_modes_p (void)
1205 {
1206   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1207     return false;
1208   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1209     return false;
1210
1211   return true;
1212 }
1213
1214 /* Named address space version of legitimate_address_p.  */
1215
1216 bool
1217 default_addr_space_legitimate_address_p (machine_mode mode, rtx mem,
1218                                          bool strict, addr_space_t as)
1219 {
1220   if (!ADDR_SPACE_GENERIC_P (as))
1221     gcc_unreachable ();
1222
1223   return targetm.legitimate_address_p (mode, mem, strict);
1224 }
1225
1226 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1227
1228 rtx
1229 default_addr_space_legitimize_address (rtx x, rtx oldx,
1230                                        machine_mode mode, addr_space_t as)
1231 {
1232   if (!ADDR_SPACE_GENERIC_P (as))
1233     return x;
1234
1235   return targetm.legitimize_address (x, oldx, mode);
1236 }
1237
1238 /* The default hook for determining if one named address space is a subset of
1239    another and to return which address space to use as the common address
1240    space.  */
1241
1242 bool
1243 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1244 {
1245   return (subset == superset);
1246 }
1247
1248 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1249    called for targets with only a generic address space.  */
1250
1251 rtx
1252 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1253                             tree from_type ATTRIBUTE_UNUSED,
1254                             tree to_type ATTRIBUTE_UNUSED)
1255 {
1256   gcc_unreachable ();
1257 }
1258
1259 bool
1260 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1261 {
1262   return true;
1263 }
1264
1265 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1266
1267 bool
1268 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1269                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1270 {
1271   return false;
1272 }
1273
1274 bool
1275 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1276                                          tree ARG_UNUSED (name),
1277                                          tree ARG_UNUSED (args),
1278                                          int ARG_UNUSED (flags))
1279 {
1280   warning (OPT_Wattributes,
1281            "target attribute is not supported on this machine");
1282
1283   return false;
1284 }
1285
1286 bool
1287 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1288                                     tree ARG_UNUSED (pop_target))
1289 {
1290   warning (OPT_Wpragmas,
1291            "#pragma GCC target is not supported for this machine");
1292
1293   return false;
1294 }
1295
1296 bool
1297 default_target_can_inline_p (tree caller, tree callee)
1298 {
1299   bool ret = false;
1300   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1301   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1302
1303   /* If callee has no option attributes, then it is ok to inline */
1304   if (!callee_opts)
1305     ret = true;
1306
1307   /* If caller has no option attributes, but callee does then it is not ok to
1308      inline */
1309   else if (!caller_opts)
1310     ret = false;
1311
1312   /* If both caller and callee have attributes, assume that if the
1313      pointer is different, the two functions have different target
1314      options since build_target_option_node uses a hash table for the
1315      options.  */
1316   else
1317     ret = (callee_opts == caller_opts);
1318
1319   return ret;
1320 }
1321
1322 #ifndef HAVE_casesi
1323 # define HAVE_casesi 0
1324 #endif
1325
1326 /* If the machine does not have a case insn that compares the bounds,
1327    this means extra overhead for dispatch tables, which raises the
1328    threshold for using them.  */
1329
1330 unsigned int
1331 default_case_values_threshold (void)
1332 {
1333   return (HAVE_casesi ? 4 : 5);
1334 }
1335
1336 bool
1337 default_have_conditional_execution (void)
1338 {
1339 #ifdef HAVE_conditional_execution
1340   return HAVE_conditional_execution;
1341 #else
1342   return false;
1343 #endif
1344 }
1345
1346 /* By default we assume that c99 functions are present at the runtime,
1347    but sincos is not.  */
1348 bool
1349 default_libc_has_function (enum function_class fn_class)
1350 {
1351   if (fn_class == function_c94
1352       || fn_class == function_c99_misc
1353       || fn_class == function_c99_math_complex)
1354     return true;
1355
1356   return false;
1357 }
1358
1359 bool
1360 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1361 {
1362   return true;
1363 }
1364
1365 bool
1366 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1367 {
1368   return false;
1369 }
1370
1371 tree
1372 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1373 {
1374   return NULL_TREE;
1375 }
1376
1377 /* Compute cost of moving registers to/from memory.  */
1378
1379 int
1380 default_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1381                           reg_class_t rclass ATTRIBUTE_UNUSED,
1382                           bool in ATTRIBUTE_UNUSED)
1383 {
1384 #ifndef MEMORY_MOVE_COST
1385     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1386 #else
1387     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1388 #endif
1389 }
1390
1391 /* Compute cost of moving data from a register of class FROM to one of
1392    TO, using MODE.  */
1393
1394 int
1395 default_register_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1396                             reg_class_t from ATTRIBUTE_UNUSED,
1397                             reg_class_t to ATTRIBUTE_UNUSED)
1398 {
1399 #ifndef REGISTER_MOVE_COST
1400   return 2;
1401 #else
1402   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1403 #endif
1404 }
1405
1406 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
1407    behaviour.  SPEED_P is true if we are compiling for speed.  */
1408
1409 unsigned int
1410 get_move_ratio (bool speed_p ATTRIBUTE_UNUSED)
1411 {
1412   unsigned int move_ratio;
1413 #ifdef MOVE_RATIO
1414   move_ratio = (unsigned int) MOVE_RATIO (speed_p);
1415 #else
1416 #if defined (HAVE_movmemqi) || defined (HAVE_movmemhi) || defined (HAVE_movmemsi) || defined (HAVE_movmemdi) || defined (HAVE_movmemti)
1417   move_ratio = 2;
1418 #else /* No movmem patterns, pick a default.  */
1419   move_ratio = ((speed_p) ? 15 : 3);
1420 #endif
1421 #endif
1422   return move_ratio;
1423 }
1424
1425 /* Return TRUE if the move_by_pieces/set_by_pieces infrastructure should be
1426    used; return FALSE if the movmem/setmem optab should be expanded, or
1427    a call to memcpy emitted.  */
1428
1429 bool
1430 default_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
1431                                         unsigned int alignment,
1432                                         enum by_pieces_operation op,
1433                                         bool speed_p)
1434 {
1435   unsigned int max_size = 0;
1436   unsigned int ratio = 0;
1437
1438   switch (op)
1439     {
1440       case CLEAR_BY_PIECES:
1441         max_size = STORE_MAX_PIECES;
1442         ratio = CLEAR_RATIO (speed_p);
1443         break;
1444       case MOVE_BY_PIECES:
1445         max_size = MOVE_MAX_PIECES;
1446         ratio = get_move_ratio (speed_p);
1447         break;
1448       case SET_BY_PIECES:
1449         max_size = STORE_MAX_PIECES;
1450         ratio = SET_RATIO (speed_p);
1451         break;
1452       case STORE_BY_PIECES:
1453         max_size = STORE_MAX_PIECES;
1454         ratio = get_move_ratio (speed_p);
1455         break;
1456     }
1457
1458   return move_by_pieces_ninsns (size, alignment, max_size + 1) < ratio;
1459 }
1460
1461 bool
1462 default_profile_before_prologue (void)
1463 {
1464 #ifdef PROFILE_BEFORE_PROLOGUE
1465   return true;
1466 #else
1467   return false;
1468 #endif
1469 }
1470
1471 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1472
1473 reg_class_t
1474 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1475                                 reg_class_t rclass)
1476 {
1477 #ifdef PREFERRED_RELOAD_CLASS
1478   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1479 #else
1480   return rclass;
1481 #endif
1482 }
1483
1484 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1485
1486 reg_class_t
1487 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1488                                        reg_class_t rclass)
1489 {
1490   return rclass;
1491 }
1492
1493 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1494 reg_class_t
1495 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1496 {
1497   return NO_REGS;
1498 }
1499
1500 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1501
1502 bool
1503 default_class_likely_spilled_p (reg_class_t rclass)
1504 {
1505   return (reg_class_size[(int) rclass] == 1);
1506 }
1507
1508 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1509
1510 unsigned char
1511 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1512                          machine_mode mode ATTRIBUTE_UNUSED)
1513 {
1514 #ifdef CLASS_MAX_NREGS
1515   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1516 #else
1517   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1518 #endif
1519 }
1520
1521 /* Determine the debugging unwind mechanism for the target.  */
1522
1523 enum unwind_info_type
1524 default_debug_unwind_info (void)
1525 {
1526   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1527   /* ??? Change all users to the hook, then poison this.  */
1528 #ifdef DWARF2_FRAME_INFO
1529   if (DWARF2_FRAME_INFO)
1530     return UI_DWARF2;
1531 #endif
1532
1533   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1534 #ifdef DWARF2_DEBUGGING_INFO
1535   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1536     return UI_DWARF2;
1537 #endif
1538
1539   return UI_NONE;
1540 }
1541
1542 /* Determine the correct mode for a Dwarf frame register that represents
1543    register REGNO.  */
1544
1545 machine_mode
1546 default_dwarf_frame_reg_mode (int regno)
1547 {
1548   machine_mode save_mode = reg_raw_mode[regno];
1549
1550   if (HARD_REGNO_CALL_PART_CLOBBERED (regno, save_mode))
1551     save_mode = choose_hard_reg_mode (regno, 1, true);
1552   return save_mode;
1553 }
1554
1555 /* To be used by targets where reg_raw_mode doesn't return the right
1556    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1557
1558 machine_mode
1559 default_get_reg_raw_mode (int regno)
1560 {
1561   return reg_raw_mode[regno];
1562 }
1563
1564 /* Return true if a leaf function should stay leaf even with profiling
1565    enabled.  */
1566
1567 bool
1568 default_keep_leaf_when_profiled ()
1569 {
1570   return false;
1571 }
1572
1573 /* Return true if the state of option OPTION should be stored in PCH files
1574    and checked by default_pch_valid_p.  Store the option's current state
1575    in STATE if so.  */
1576
1577 static inline bool
1578 option_affects_pch_p (int option, struct cl_option_state *state)
1579 {
1580   if ((cl_options[option].flags & CL_TARGET) == 0)
1581     return false;
1582   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1583     return false;
1584   if (option_flag_var (option, &global_options) == &target_flags)
1585     if (targetm.check_pch_target_flags)
1586       return false;
1587   return get_option_state (&global_options, option, state);
1588 }
1589
1590 /* Default version of get_pch_validity.
1591    By default, every flag difference is fatal; that will be mostly right for
1592    most targets, but completely right for very few.  */
1593
1594 void *
1595 default_get_pch_validity (size_t *sz)
1596 {
1597   struct cl_option_state state;
1598   size_t i;
1599   char *result, *r;
1600
1601   *sz = 2;
1602   if (targetm.check_pch_target_flags)
1603     *sz += sizeof (target_flags);
1604   for (i = 0; i < cl_options_count; i++)
1605     if (option_affects_pch_p (i, &state))
1606       *sz += state.size;
1607
1608   result = r = XNEWVEC (char, *sz);
1609   r[0] = flag_pic;
1610   r[1] = flag_pie;
1611   r += 2;
1612   if (targetm.check_pch_target_flags)
1613     {
1614       memcpy (r, &target_flags, sizeof (target_flags));
1615       r += sizeof (target_flags);
1616     }
1617
1618   for (i = 0; i < cl_options_count; i++)
1619     if (option_affects_pch_p (i, &state))
1620       {
1621         memcpy (r, state.data, state.size);
1622         r += state.size;
1623       }
1624
1625   return result;
1626 }
1627
1628 /* Return a message which says that a PCH file was created with a different
1629    setting of OPTION.  */
1630
1631 static const char *
1632 pch_option_mismatch (const char *option)
1633 {
1634   char *r;
1635
1636   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1637   if (r == NULL)
1638     return _("out of memory");
1639   return r;
1640 }
1641
1642 /* Default version of pch_valid_p.  */
1643
1644 const char *
1645 default_pch_valid_p (const void *data_p, size_t len)
1646 {
1647   struct cl_option_state state;
1648   const char *data = (const char *)data_p;
1649   size_t i;
1650
1651   /* -fpic and -fpie also usually make a PCH invalid.  */
1652   if (data[0] != flag_pic)
1653     return _("created and used with different settings of -fpic");
1654   if (data[1] != flag_pie)
1655     return _("created and used with different settings of -fpie");
1656   data += 2;
1657
1658   /* Check target_flags.  */
1659   if (targetm.check_pch_target_flags)
1660     {
1661       int tf;
1662       const char *r;
1663
1664       memcpy (&tf, data, sizeof (target_flags));
1665       data += sizeof (target_flags);
1666       len -= sizeof (target_flags);
1667       r = targetm.check_pch_target_flags (tf);
1668       if (r != NULL)
1669         return r;
1670     }
1671
1672   for (i = 0; i < cl_options_count; i++)
1673     if (option_affects_pch_p (i, &state))
1674       {
1675         if (memcmp (data, state.data, state.size) != 0)
1676           return pch_option_mismatch (cl_options[i].opt_text);
1677         data += state.size;
1678         len -= state.size;
1679       }
1680
1681   return NULL;
1682 }
1683
1684 /* Default version of cstore_mode.  */
1685
1686 machine_mode
1687 default_cstore_mode (enum insn_code icode)
1688 {
1689   return insn_data[(int) icode].operand[0].mode;
1690 }
1691
1692 /* Default version of member_type_forces_blk.  */
1693
1694 bool
1695 default_member_type_forces_blk (const_tree, machine_mode)
1696 {
1697   return false;
1698 }
1699
1700 rtx
1701 default_load_bounds_for_arg (rtx addr ATTRIBUTE_UNUSED,
1702                              rtx ptr ATTRIBUTE_UNUSED,
1703                              rtx bnd ATTRIBUTE_UNUSED)
1704 {
1705   gcc_unreachable ();
1706 }
1707
1708 void
1709 default_store_bounds_for_arg (rtx val ATTRIBUTE_UNUSED,
1710                               rtx addr ATTRIBUTE_UNUSED,
1711                               rtx bounds ATTRIBUTE_UNUSED,
1712                               rtx to ATTRIBUTE_UNUSED)
1713 {
1714   gcc_unreachable ();
1715 }
1716
1717 rtx
1718 default_load_returned_bounds (rtx slot ATTRIBUTE_UNUSED)
1719 {
1720   gcc_unreachable ();
1721 }
1722
1723 void
1724 default_store_returned_bounds (rtx slot ATTRIBUTE_UNUSED,
1725                                rtx bounds ATTRIBUTE_UNUSED)
1726 {
1727   gcc_unreachable ();
1728 }
1729
1730 /* Default version of canonicalize_comparison.  */
1731
1732 void
1733 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1734 {
1735 }
1736
1737 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1738
1739 void
1740 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1741 {
1742 }
1743
1744 #ifndef PAD_VARARGS_DOWN
1745 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1746 #endif
1747
1748 /* Build an indirect-ref expression over the given TREE, which represents a
1749    piece of a va_arg() expansion.  */
1750 tree
1751 build_va_arg_indirect_ref (tree addr)
1752 {
1753   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1754   return addr;
1755 }
1756
1757 /* The "standard" implementation of va_arg: read the value from the
1758    current (padded) address and increment by the (padded) size.  */
1759
1760 tree
1761 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1762                           gimple_seq *post_p)
1763 {
1764   tree addr, t, type_size, rounded_size, valist_tmp;
1765   unsigned HOST_WIDE_INT align, boundary;
1766   bool indirect;
1767
1768 #ifdef ARGS_GROW_DOWNWARD
1769   /* All of the alignment and movement below is for args-grow-up machines.
1770      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1771      implement their own specialized gimplify_va_arg_expr routines.  */
1772   gcc_unreachable ();
1773 #endif
1774
1775   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1776   if (indirect)
1777     type = build_pointer_type (type);
1778
1779   align = PARM_BOUNDARY / BITS_PER_UNIT;
1780   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1781
1782   /* When we align parameter on stack for caller, if the parameter
1783      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1784      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1785      here with caller.  */
1786   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1787     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1788
1789   boundary /= BITS_PER_UNIT;
1790
1791   /* Hoist the valist value into a temporary for the moment.  */
1792   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1793
1794   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1795      requires greater alignment, we must perform dynamic alignment.  */
1796   if (boundary > align
1797       && !integer_zerop (TYPE_SIZE (type)))
1798     {
1799       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1800                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1801       gimplify_and_add (t, pre_p);
1802
1803       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1804                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1805                                valist_tmp,
1806                                build_int_cst (TREE_TYPE (valist), -boundary)));
1807       gimplify_and_add (t, pre_p);
1808     }
1809   else
1810     boundary = align;
1811
1812   /* If the actual alignment is less than the alignment of the type,
1813      adjust the type accordingly so that we don't assume strict alignment
1814      when dereferencing the pointer.  */
1815   boundary *= BITS_PER_UNIT;
1816   if (boundary < TYPE_ALIGN (type))
1817     {
1818       type = build_variant_type_copy (type);
1819       TYPE_ALIGN (type) = boundary;
1820     }
1821
1822   /* Compute the rounded size of the type.  */
1823   type_size = size_in_bytes (type);
1824   rounded_size = round_up (type_size, align);
1825
1826   /* Reduce rounded_size so it's sharable with the postqueue.  */
1827   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1828
1829   /* Get AP.  */
1830   addr = valist_tmp;
1831   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1832     {
1833       /* Small args are padded downward.  */
1834       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1835                        rounded_size, size_int (align));
1836       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1837                        size_binop (MINUS_EXPR, rounded_size, type_size));
1838       addr = fold_build_pointer_plus (addr, t);
1839     }
1840
1841   /* Compute new value for AP.  */
1842   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1843   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1844   gimplify_and_add (t, pre_p);
1845
1846   addr = fold_convert (build_pointer_type (type), addr);
1847
1848   if (indirect)
1849     addr = build_va_arg_indirect_ref (addr);
1850
1851   return build_va_arg_indirect_ref (addr);
1852 }
1853
1854 tree
1855 default_chkp_bound_type (void)
1856 {
1857   tree res = make_node (POINTER_BOUNDS_TYPE);
1858   TYPE_PRECISION (res) = TYPE_PRECISION (size_type_node) * 2;
1859   TYPE_NAME (res) = get_identifier ("__bounds_type");
1860   SET_TYPE_MODE (res, targetm.chkp_bound_mode ());
1861   layout_type (res);
1862   return res;
1863 }
1864
1865 enum machine_mode
1866 default_chkp_bound_mode (void)
1867 {
1868   return VOIDmode;
1869 }
1870
1871 tree
1872 default_builtin_chkp_function (unsigned int fcode ATTRIBUTE_UNUSED)
1873 {
1874   return NULL_TREE;
1875 }
1876
1877 rtx
1878 default_chkp_function_value_bounds (const_tree ret_type ATTRIBUTE_UNUSED,
1879                                     const_tree fn_decl_or_type ATTRIBUTE_UNUSED,
1880                                     bool outgoing ATTRIBUTE_UNUSED)
1881 {
1882   gcc_unreachable ();
1883 }
1884
1885 tree
1886 default_chkp_make_bounds_constant (HOST_WIDE_INT lb ATTRIBUTE_UNUSED,
1887                                    HOST_WIDE_INT ub ATTRIBUTE_UNUSED)
1888 {
1889   return NULL_TREE;
1890 }
1891
1892 int
1893 default_chkp_initialize_bounds (tree var ATTRIBUTE_UNUSED,
1894                                 tree lb ATTRIBUTE_UNUSED,
1895                                 tree ub ATTRIBUTE_UNUSED,
1896                                 tree *stmts ATTRIBUTE_UNUSED)
1897 {
1898   return 0;
1899 }
1900
1901 void
1902 default_setup_incoming_vararg_bounds (cumulative_args_t ca ATTRIBUTE_UNUSED,
1903                                       enum machine_mode mode ATTRIBUTE_UNUSED,
1904                                       tree type ATTRIBUTE_UNUSED,
1905                                       int *pretend_arg_size ATTRIBUTE_UNUSED,
1906                                       int second_time ATTRIBUTE_UNUSED)
1907 {
1908 }
1909
1910 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1911    not support nested low-overhead loops.  */
1912
1913 bool
1914 can_use_doloop_if_innermost (const widest_int &, const widest_int &,
1915                              unsigned int loop_depth, bool)
1916 {
1917   return loop_depth == 1;
1918 }
1919
1920 #include "gt-targhooks.h"