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 "optabs.h"
  73 #include "recog.h"
  74 #include "intl.h"
  75 #include "opts.h"
  76 #include "tree-ssa-alias.h"
  77 #include "gimple-expr.h"
  78 #include "gimplify.h"
  79 #include "stringpool.h"
  80 #include "tree-ssanames.h"
  81 #include "insn-codes.h"
  82
  83
  84 bool
  85 default_legitimate_address_p (enum 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 enum machine_mode
 127 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 128                                enum 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 enum machine_mode
 139 default_promote_function_mode_always_promote (const_tree type,
 140                                               enum 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 enum machine_mode
 149 default_cc_modes_compatible (enum machine_mode m1, enum 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                             enum 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                                 enum 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 enum machine_mode
 210 default_eh_return_filter_mode (void)
 211 {
 212   return targetm.unwind_word_mode ();
 213 }
 214
 215 enum machine_mode
 216 default_libgcc_cmp_return_mode (void)
 217 {
 218   return word_mode;
 219 }
 220
 221 enum machine_mode
 222 default_libgcc_shift_count_mode (void)
 223 {
 224   return word_mode;
 225 }
 226
 227 enum 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 (enum 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 (enum 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 (enum machine_mode mode ATTRIBUTE_UNUSED,
 253                            enum 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 enum 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         enum 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                           enum 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 (enum 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 (enum 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         enum 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         enum 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         enum 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                               enum 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                       enum 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                                enum 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 (enum 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 (enum 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 (enum 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 fndecl, bool incoming_p)
 845 {
 846   if (!DECL_STATIC_CHAIN (fndecl))
 847     return NULL;
 848
 849   if (incoming_p)
 850     {
 851 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 852       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 853 #endif
 854     }
 855
 856 #ifdef STATIC_CHAIN_REGNUM
 857   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 858 #endif
 859
 860   {
 861     static bool issued_error;
 862     if (!issued_error)
 863       {
 864         issued_error = true;
 865         sorry ("nested functions not supported on this target");
 866       }
 867
 868     /* It really doesn't matter what we return here, so long at it
 869        doesn't cause the rest of the compiler to crash.  */
 870     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 871   }
 872 }
 873
 874 void
 875 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 876                          rtx ARG_UNUSED (r_chain))
 877 {
 878   sorry ("nested function trampolines not supported on this target");
 879 }
 880
 881 int
 882 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 883                           tree funtype ATTRIBUTE_UNUSED,
 884                           int size ATTRIBUTE_UNUSED)
 885 {
 886   return 0;
 887 }
 888
 889 reg_class_t
 890 default_branch_target_register_class (void)
 891 {
 892   return NO_REGS;
 893 }
 894
 895 extern bool
 896 default_lra_p (void)
 897 {
 898   return false;
 899 }
 900
 901 int
 902 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 903 {
 904   return 0;
 905 }
 906
 907 extern bool
 908 default_register_usage_leveling_p (void)
 909 {
 910   return false;
 911 }
 912
 913 extern bool
 914 default_different_addr_displacement_p (void)
 915 {
 916   return false;
 917 }
 918
 919 reg_class_t
 920 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 921                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 922                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 923                           secondary_reload_info *sri)
 924 {
 925   enum reg_class rclass = NO_REGS;
 926   enum reg_class reload_class = (enum reg_class) reload_class_i;
 927
 928   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 929     {
 930       sri->icode = sri->prev_sri->t_icode;
 931       return NO_REGS;
 932     }
 933 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 934   if (in_p)
 935     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 936 #endif
 937 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 938   if (! in_p)
 939     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 940 #endif
 941   if (rclass != NO_REGS)
 942     {
 943       enum insn_code icode
 944         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 945                                 reload_mode);
 946
 947       if (icode != CODE_FOR_nothing
 948           && !insn_operand_matches (icode, in_p, x))
 949         icode = CODE_FOR_nothing;
 950       else if (icode != CODE_FOR_nothing)
 951         {
 952           const char *insn_constraint, *scratch_constraint;
 953           enum reg_class insn_class, scratch_class;
 954
 955           gcc_assert (insn_data[(int) icode].n_operands == 3);
 956           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 957           if (!*insn_constraint)
 958             insn_class = ALL_REGS;
 959           else
 960             {
 961               if (in_p)
 962                 {
 963                   gcc_assert (*insn_constraint == '=');
 964                   insn_constraint++;
 965                 }
 966               insn_class = (reg_class_for_constraint
 967                             (lookup_constraint (insn_constraint)));
 968               gcc_assert (insn_class != NO_REGS);
 969             }
 970
 971           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 972           /* The scratch register's constraint must start with "=&",
 973              except for an input reload, where only "=" is necessary,
 974              and where it might be beneficial to re-use registers from
 975              the input.  */
 976           gcc_assert (scratch_constraint[0] == '='
 977                       && (in_p || scratch_constraint[1] == '&'));
 978           scratch_constraint++;
 979           if (*scratch_constraint == '&')
 980             scratch_constraint++;
 981           scratch_class = (reg_class_for_constraint
 982                            (lookup_constraint (scratch_constraint)));
 983
 984           if (reg_class_subset_p (reload_class, insn_class))
 985             {
 986               gcc_assert (scratch_class == rclass);
 987               rclass = NO_REGS;
 988             }
 989           else
 990             rclass = insn_class;
 991
 992         }
 993       if (rclass == NO_REGS)
 994         sri->icode = icode;
 995       else
 996         sri->t_icode = icode;
 997     }
 998   return rclass;
 999 }
1000
1001 /* By default, if flag_pic is true, then neither local nor global relocs
1002    should be placed in readonly memory.  */
1003
1004 int
1005 default_reloc_rw_mask (void)
1006 {
1007   return flag_pic ? 3 : 0;
1008 }
1009
1010 /* By default, do no modification. */
1011 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
1012                                          tree id)
1013 {
1014    return id;
1015 }
1016
1017 /* Default to natural alignment for vector types.  */
1018 HOST_WIDE_INT
1019 default_vector_alignment (const_tree type)
1020 {
1021   return tree_to_shwi (TYPE_SIZE (type));
1022 }
1023
1024 bool
1025 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
1026 {
1027   if (is_packed)
1028     return false;
1029
1030   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1031      naturally aligned.  */
1032   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1033     return false;
1034
1035   /* Assuming that types whose size is <= pointer-size
1036      are naturally aligned.  */
1037   return true;
1038 }
1039
1040 /* By default, assume that a target supports any factor of misalignment
1041    memory access if it supports movmisalign patten.
1042    is_packed is true if the memory access is defined in a packed struct.  */
1043 bool
1044 default_builtin_support_vector_misalignment (enum machine_mode mode,
1045                                              const_tree type
1046                                              ATTRIBUTE_UNUSED,
1047                                              int misalignment
1048                                              ATTRIBUTE_UNUSED,
1049                                              bool is_packed
1050                                              ATTRIBUTE_UNUSED)
1051 {
1052   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1053     return true;
1054   return false;
1055 }
1056
1057 /* By default, only attempt to parallelize bitwise operations, and
1058    possibly adds/subtracts using bit-twiddling.  */
1059
1060 enum machine_mode
1061 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1062 {
1063   return word_mode;
1064 }
1065
1066 /* By default only the size derived from the preferred vector mode
1067    is tried.  */
1068
1069 unsigned int
1070 default_autovectorize_vector_sizes (void)
1071 {
1072   return 0;
1073 }
1074
1075 /* By default, the cost model accumulates three separate costs (prologue,
1076    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1077    array of three unsigned ints, set it to zero, and return its address.  */
1078
1079 void *
1080 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1081 {
1082   unsigned *cost = XNEWVEC (unsigned, 3);
1083   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1084   return cost;
1085 }
1086
1087 /* By default, the cost model looks up the cost of the given statement
1088    kind and mode, multiplies it by the occurrence count, accumulates
1089    it into the cost specified by WHERE, and returns the cost added.  */
1090
1091 unsigned
1092 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1093                        struct _stmt_vec_info *stmt_info, int misalign,
1094                        enum vect_cost_model_location where)
1095 {
1096   unsigned *cost = (unsigned *) data;
1097   unsigned retval = 0;
1098
1099   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1100   int stmt_cost = targetm.vectorize.builtin_vectorization_cost (kind, vectype,
1101                                                                 misalign);
1102    /* Statements in an inner loop relative to the loop being
1103       vectorized are weighted more heavily.  The value here is
1104       arbitrary and could potentially be improved with analysis.  */
1105   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1106     count *= 50;  /* FIXME.  */
1107
1108   retval = (unsigned) (count * stmt_cost);
1109   cost[where] += retval;
1110
1111   return retval;
1112 }
1113
1114 /* By default, the cost model just returns the accumulated costs.  */
1115
1116 void
1117 default_finish_cost (void *data, unsigned *prologue_cost,
1118                      unsigned *body_cost, unsigned *epilogue_cost)
1119 {
1120   unsigned *cost = (unsigned *) data;
1121   *prologue_cost = cost[vect_prologue];
1122   *body_cost     = cost[vect_body];
1123   *epilogue_cost = cost[vect_epilogue];
1124 }
1125
1126 /* Free the cost data.  */
1127
1128 void
1129 default_destroy_cost_data (void *data)
1130 {
1131   free (data);
1132 }
1133
1134 /* Determine whether or not a pointer mode is valid. Assume defaults
1135    of ptr_mode or Pmode - can be overridden.  */
1136 bool
1137 default_valid_pointer_mode (enum machine_mode mode)
1138 {
1139   return (mode == ptr_mode || mode == Pmode);
1140 }
1141
1142 /* Determine whether the memory reference specified by REF may alias
1143    the C libraries errno location.  */
1144 bool
1145 default_ref_may_alias_errno (ao_ref *ref)
1146 {
1147   tree base = ao_ref_base (ref);
1148   /* The default implementation assumes the errno location is
1149      a declaration of type int or is always accessed via a
1150      pointer to int.  We assume that accesses to errno are
1151      not deliberately obfuscated (even in conforming ways).  */
1152   if (TYPE_UNSIGNED (TREE_TYPE (base))
1153       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1154     return false;
1155   /* The default implementation assumes an errno location
1156      declaration is never defined in the current compilation unit.  */
1157   if (DECL_P (base)
1158       && !TREE_STATIC (base))
1159     return true;
1160   else if (TREE_CODE (base) == MEM_REF
1161            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1162     {
1163       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1164       return !pi || pi->pt.anything || pi->pt.nonlocal;
1165     }
1166   return false;
1167 }
1168
1169 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1170    for the generic address space only.  */
1171
1172 enum machine_mode
1173 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1174 {
1175   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1176   return ptr_mode;
1177 }
1178
1179 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1180    for the generic address space only.  */
1181
1182 enum machine_mode
1183 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1184 {
1185   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1186   return Pmode;
1187 }
1188
1189 /* Named address space version of valid_pointer_mode.  */
1190
1191 bool
1192 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1193 {
1194   if (!ADDR_SPACE_GENERIC_P (as))
1195     return (mode == targetm.addr_space.pointer_mode (as)
1196             || mode == targetm.addr_space.address_mode (as));
1197
1198   return targetm.valid_pointer_mode (mode);
1199 }
1200
1201 /* Some places still assume that all pointer or address modes are the
1202    standard Pmode and ptr_mode.  These optimizations become invalid if
1203    the target actually supports multiple different modes.  For now,
1204    we disable such optimizations on such targets, using this function.  */
1205
1206 bool
1207 target_default_pointer_address_modes_p (void)
1208 {
1209   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1210     return false;
1211   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1212     return false;
1213
1214   return true;
1215 }
1216
1217 /* Named address space version of legitimate_address_p.  */
1218
1219 bool
1220 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1221                                          bool strict, addr_space_t as)
1222 {
1223   if (!ADDR_SPACE_GENERIC_P (as))
1224     gcc_unreachable ();
1225
1226   return targetm.legitimate_address_p (mode, mem, strict);
1227 }
1228
1229 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1230
1231 rtx
1232 default_addr_space_legitimize_address (rtx x, rtx oldx,
1233                                        enum machine_mode mode, addr_space_t as)
1234 {
1235   if (!ADDR_SPACE_GENERIC_P (as))
1236     return x;
1237
1238   return targetm.legitimize_address (x, oldx, mode);
1239 }
1240
1241 /* The default hook for determining if one named address space is a subset of
1242    another and to return which address space to use as the common address
1243    space.  */
1244
1245 bool
1246 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1247 {
1248   return (subset == superset);
1249 }
1250
1251 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1252    called for targets with only a generic address space.  */
1253
1254 rtx
1255 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1256                             tree from_type ATTRIBUTE_UNUSED,
1257                             tree to_type ATTRIBUTE_UNUSED)
1258 {
1259   gcc_unreachable ();
1260 }
1261
1262 bool
1263 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1264 {
1265   return true;
1266 }
1267
1268 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1269
1270 bool
1271 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1272                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1273 {
1274   return false;
1275 }
1276
1277 bool
1278 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1279                                          tree ARG_UNUSED (name),
1280                                          tree ARG_UNUSED (args),
1281                                          int ARG_UNUSED (flags))
1282 {
1283   warning (OPT_Wattributes,
1284            "target attribute is not supported on this machine");
1285
1286   return false;
1287 }
1288
1289 bool
1290 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1291                                     tree ARG_UNUSED (pop_target))
1292 {
1293   warning (OPT_Wpragmas,
1294            "#pragma GCC target is not supported for this machine");
1295
1296   return false;
1297 }
1298
1299 bool
1300 default_target_can_inline_p (tree caller, tree callee)
1301 {
1302   bool ret = false;
1303   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1304   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1305
1306   /* If callee has no option attributes, then it is ok to inline */
1307   if (!callee_opts)
1308     ret = true;
1309
1310   /* If caller has no option attributes, but callee does then it is not ok to
1311      inline */
1312   else if (!caller_opts)
1313     ret = false;
1314
1315   /* If both caller and callee have attributes, assume that if the
1316      pointer is different, the two functions have different target
1317      options since build_target_option_node uses a hash table for the
1318      options.  */
1319   else
1320     ret = (callee_opts == caller_opts);
1321
1322   return ret;
1323 }
1324
1325 #ifndef HAVE_casesi
1326 # define HAVE_casesi 0
1327 #endif
1328
1329 /* If the machine does not have a case insn that compares the bounds,
1330    this means extra overhead for dispatch tables, which raises the
1331    threshold for using them.  */
1332
1333 unsigned int
1334 default_case_values_threshold (void)
1335 {
1336   return (HAVE_casesi ? 4 : 5);
1337 }
1338
1339 bool
1340 default_have_conditional_execution (void)
1341 {
1342 #ifdef HAVE_conditional_execution
1343   return HAVE_conditional_execution;
1344 #else
1345   return false;
1346 #endif
1347 }
1348
1349 /* By default we assume that c99 functions are present at the runtime,
1350    but sincos is not.  */
1351 bool
1352 default_libc_has_function (enum function_class fn_class)
1353 {
1354   if (fn_class == function_c94
1355       || fn_class == function_c99_misc
1356       || fn_class == function_c99_math_complex)
1357     return true;
1358
1359   return false;
1360 }
1361
1362 bool
1363 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1364 {
1365   return true;
1366 }
1367
1368 bool
1369 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1370 {
1371   return false;
1372 }
1373
1374 tree
1375 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1376 {
1377   return NULL_TREE;
1378 }
1379
1380 /* Compute cost of moving registers to/from memory.  */
1381
1382 int
1383 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1384                           reg_class_t rclass ATTRIBUTE_UNUSED,
1385                           bool in ATTRIBUTE_UNUSED)
1386 {
1387 #ifndef MEMORY_MOVE_COST
1388     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1389 #else
1390     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1391 #endif
1392 }
1393
1394 /* Compute cost of moving data from a register of class FROM to one of
1395    TO, using MODE.  */
1396
1397 int
1398 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1399                             reg_class_t from ATTRIBUTE_UNUSED,
1400                             reg_class_t to ATTRIBUTE_UNUSED)
1401 {
1402 #ifndef REGISTER_MOVE_COST
1403   return 2;
1404 #else
1405   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1406 #endif
1407 }
1408
1409 bool
1410 default_profile_before_prologue (void)
1411 {
1412 #ifdef PROFILE_BEFORE_PROLOGUE
1413   return true;
1414 #else
1415   return false;
1416 #endif
1417 }
1418
1419 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1420
1421 reg_class_t
1422 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1423                                 reg_class_t rclass)
1424 {
1425 #ifdef PREFERRED_RELOAD_CLASS
1426   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1427 #else
1428   return rclass;
1429 #endif
1430 }
1431
1432 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1433
1434 reg_class_t
1435 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1436                                        reg_class_t rclass)
1437 {
1438   return rclass;
1439 }
1440
1441 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1442 reg_class_t
1443 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1444 {
1445   return NO_REGS;
1446 }
1447
1448 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1449
1450 bool
1451 default_class_likely_spilled_p (reg_class_t rclass)
1452 {
1453   return (reg_class_size[(int) rclass] == 1);
1454 }
1455
1456 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1457
1458 unsigned char
1459 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1460                          enum machine_mode mode ATTRIBUTE_UNUSED)
1461 {
1462 #ifdef CLASS_MAX_NREGS
1463   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1464 #else
1465   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1466 #endif
1467 }
1468
1469 /* Determine the debugging unwind mechanism for the target.  */
1470
1471 enum unwind_info_type
1472 default_debug_unwind_info (void)
1473 {
1474   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1475   /* ??? Change all users to the hook, then poison this.  */
1476 #ifdef DWARF2_FRAME_INFO
1477   if (DWARF2_FRAME_INFO)
1478     return UI_DWARF2;
1479 #endif
1480
1481   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1482 #ifdef DWARF2_DEBUGGING_INFO
1483   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1484     return UI_DWARF2;
1485 #endif
1486
1487   return UI_NONE;
1488 }
1489
1490 /* Determine the correct mode for a Dwarf frame register that represents
1491    register REGNO.  */
1492
1493 enum machine_mode
1494 default_dwarf_frame_reg_mode (int regno)
1495 {
1496   enum machine_mode save_mode = reg_raw_mode[regno];
1497
1498   if (HARD_REGNO_CALL_PART_CLOBBERED (regno, save_mode))
1499     save_mode = choose_hard_reg_mode (regno, 1, true);
1500   return save_mode;
1501 }
1502
1503 /* To be used by targets where reg_raw_mode doesn't return the right
1504    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1505
1506 enum machine_mode
1507 default_get_reg_raw_mode (int regno)
1508 {
1509   return reg_raw_mode[regno];
1510 }
1511
1512 /* Return true if a leaf function should stay leaf even with profiling
1513    enabled.  */
1514
1515 bool
1516 default_keep_leaf_when_profiled ()
1517 {
1518   return false;
1519 }
1520
1521 /* Return true if the state of option OPTION should be stored in PCH files
1522    and checked by default_pch_valid_p.  Store the option's current state
1523    in STATE if so.  */
1524
1525 static inline bool
1526 option_affects_pch_p (int option, struct cl_option_state *state)
1527 {
1528   if ((cl_options[option].flags & CL_TARGET) == 0)
1529     return false;
1530   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1531     return false;
1532   if (option_flag_var (option, &global_options) == &target_flags)
1533     if (targetm.check_pch_target_flags)
1534       return false;
1535   return get_option_state (&global_options, option, state);
1536 }
1537
1538 /* Default version of get_pch_validity.
1539    By default, every flag difference is fatal; that will be mostly right for
1540    most targets, but completely right for very few.  */
1541
1542 void *
1543 default_get_pch_validity (size_t *sz)
1544 {
1545   struct cl_option_state state;
1546   size_t i;
1547   char *result, *r;
1548
1549   *sz = 2;
1550   if (targetm.check_pch_target_flags)
1551     *sz += sizeof (target_flags);
1552   for (i = 0; i < cl_options_count; i++)
1553     if (option_affects_pch_p (i, &state))
1554       *sz += state.size;
1555
1556   result = r = XNEWVEC (char, *sz);
1557   r[0] = flag_pic;
1558   r[1] = flag_pie;
1559   r += 2;
1560   if (targetm.check_pch_target_flags)
1561     {
1562       memcpy (r, &target_flags, sizeof (target_flags));
1563       r += sizeof (target_flags);
1564     }
1565
1566   for (i = 0; i < cl_options_count; i++)
1567     if (option_affects_pch_p (i, &state))
1568       {
1569         memcpy (r, state.data, state.size);
1570         r += state.size;
1571       }
1572
1573   return result;
1574 }
1575
1576 /* Return a message which says that a PCH file was created with a different
1577    setting of OPTION.  */
1578
1579 static const char *
1580 pch_option_mismatch (const char *option)
1581 {
1582   char *r;
1583
1584   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1585   if (r == NULL)
1586     return _("out of memory");
1587   return r;
1588 }
1589
1590 /* Default version of pch_valid_p.  */
1591
1592 const char *
1593 default_pch_valid_p (const void *data_p, size_t len)
1594 {
1595   struct cl_option_state state;
1596   const char *data = (const char *)data_p;
1597   size_t i;
1598
1599   /* -fpic and -fpie also usually make a PCH invalid.  */
1600   if (data[0] != flag_pic)
1601     return _("created and used with different settings of -fpic");
1602   if (data[1] != flag_pie)
1603     return _("created and used with different settings of -fpie");
1604   data += 2;
1605
1606   /* Check target_flags.  */
1607   if (targetm.check_pch_target_flags)
1608     {
1609       int tf;
1610       const char *r;
1611
1612       memcpy (&tf, data, sizeof (target_flags));
1613       data += sizeof (target_flags);
1614       len -= sizeof (target_flags);
1615       r = targetm.check_pch_target_flags (tf);
1616       if (r != NULL)
1617         return r;
1618     }
1619
1620   for (i = 0; i < cl_options_count; i++)
1621     if (option_affects_pch_p (i, &state))
1622       {
1623         if (memcmp (data, state.data, state.size) != 0)
1624           return pch_option_mismatch (cl_options[i].opt_text);
1625         data += state.size;
1626         len -= state.size;
1627       }
1628
1629   return NULL;
1630 }
1631
1632 /* Default version of cstore_mode.  */
1633
1634 enum machine_mode
1635 default_cstore_mode (enum insn_code icode)
1636 {
1637   return insn_data[(int) icode].operand[0].mode;
1638 }
1639
1640 /* Default version of member_type_forces_blk.  */
1641
1642 bool
1643 default_member_type_forces_blk (const_tree, enum machine_mode)
1644 {
1645   return false;
1646 }
1647
1648 /* Default version of canonicalize_comparison.  */
1649
1650 void
1651 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1652 {
1653 }
1654
1655 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1656
1657 void
1658 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1659 {
1660 }
1661
1662 #ifndef PAD_VARARGS_DOWN
1663 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1664 #endif
1665
1666 /* Build an indirect-ref expression over the given TREE, which represents a
1667    piece of a va_arg() expansion.  */
1668 tree
1669 build_va_arg_indirect_ref (tree addr)
1670 {
1671   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1672   return addr;
1673 }
1674
1675 /* The "standard" implementation of va_arg: read the value from the
1676    current (padded) address and increment by the (padded) size.  */
1677
1678 tree
1679 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1680                           gimple_seq *post_p)
1681 {
1682   tree addr, t, type_size, rounded_size, valist_tmp;
1683   unsigned HOST_WIDE_INT align, boundary;
1684   bool indirect;
1685
1686 #ifdef ARGS_GROW_DOWNWARD
1687   /* All of the alignment and movement below is for args-grow-up machines.
1688      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1689      implement their own specialized gimplify_va_arg_expr routines.  */
1690   gcc_unreachable ();
1691 #endif
1692
1693   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1694   if (indirect)
1695     type = build_pointer_type (type);
1696
1697   align = PARM_BOUNDARY / BITS_PER_UNIT;
1698   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1699
1700   /* When we align parameter on stack for caller, if the parameter
1701      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1702      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1703      here with caller.  */
1704   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1705     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1706
1707   boundary /= BITS_PER_UNIT;
1708
1709   /* Hoist the valist value into a temporary for the moment.  */
1710   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1711
1712   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1713      requires greater alignment, we must perform dynamic alignment.  */
1714   if (boundary > align
1715       && !integer_zerop (TYPE_SIZE (type)))
1716     {
1717       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1718                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1719       gimplify_and_add (t, pre_p);
1720
1721       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1722                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1723                                valist_tmp,
1724                                build_int_cst (TREE_TYPE (valist), -boundary)));
1725       gimplify_and_add (t, pre_p);
1726     }
1727   else
1728     boundary = align;
1729
1730   /* If the actual alignment is less than the alignment of the type,
1731      adjust the type accordingly so that we don't assume strict alignment
1732      when dereferencing the pointer.  */
1733   boundary *= BITS_PER_UNIT;
1734   if (boundary < TYPE_ALIGN (type))
1735     {
1736       type = build_variant_type_copy (type);
1737       TYPE_ALIGN (type) = boundary;
1738     }
1739
1740   /* Compute the rounded size of the type.  */
1741   type_size = size_in_bytes (type);
1742   rounded_size = round_up (type_size, align);
1743
1744   /* Reduce rounded_size so it's sharable with the postqueue.  */
1745   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1746
1747   /* Get AP.  */
1748   addr = valist_tmp;
1749   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1750     {
1751       /* Small args are padded downward.  */
1752       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1753                        rounded_size, size_int (align));
1754       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1755                        size_binop (MINUS_EXPR, rounded_size, type_size));
1756       addr = fold_build_pointer_plus (addr, t);
1757     }
1758
1759   /* Compute new value for AP.  */
1760   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1761   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1762   gimplify_and_add (t, pre_p);
1763
1764   addr = fold_convert (build_pointer_type (type), addr);
1765
1766   if (indirect)
1767     addr = build_va_arg_indirect_ref (addr);
1768
1769   return build_va_arg_indirect_ref (addr);
1770 }
1771
1772 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1773    not support nested low-overhead loops.  */
1774
1775 bool
1776 can_use_doloop_if_innermost (const widest_int &, const widest_int &,
1777                              unsigned int loop_depth, bool)
1778 {
1779   return loop_depth == 1;
1780 }
1781
1782 #include "gt-targhooks.h"