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