gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003-2015 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 "rtl.h"
  54 #include "input.h"
  55 #include "alias.h"
  56 #include "symtab.h"
  57 #include "tree.h"
  58 #include "fold-const.h"
  59 #include "stor-layout.h"
  60 #include "varasm.h"
  61 #include "hard-reg-set.h"
  62 #include "function.h"
  63 #include "flags.h"
  64 #include "insn-config.h"
  65 #include "expmed.h"
  66 #include "dojump.h"
  67 #include "explow.h"
  68 #include "calls.h"
  69 #include "emit-rtl.h"
  70 #include "stmt.h"
  71 #include "expr.h"
  72 #include "output.h"
  73 #include "diagnostic-core.h"
  74 #include "target.h"
  75 #include "tm_p.h"
  76 #include "target-def.h"
  77 #include "regs.h"
  78 #include "reload.h"
  79 #include "insn-codes.h"
  80 #include "optabs.h"
  81 #include "recog.h"
  82 #include "intl.h"
  83 #include "opts.h"
  84 #include "tree-ssa-alias.h"
  85 #include "gimple-expr.h"
  86 #include "gimplify.h"
  87 #include "stringpool.h"
  88 #include "tree-ssanames.h"
  89
  90
  91 bool
  92 default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
  93                               rtx addr ATTRIBUTE_UNUSED,
  94                               bool strict ATTRIBUTE_UNUSED)
  95 {
  96 #ifdef GO_IF_LEGITIMATE_ADDRESS
  97   /* Defer to the old implementation using a goto.  */
  98   if (strict)
  99     return strict_memory_address_p (mode, addr);
 100   else
 101     return memory_address_p (mode, addr);
 102 #else
 103   gcc_unreachable ();
 104 #endif
 105 }
 106
 107 void
 108 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
 109 {
 110 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
 111   ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
 112 #endif
 113 }
 114
 115 int
 116 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 117 {
 118   int i;
 119
 120   /* Any floating arithmetic may trap.  */
 121   if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
 122     return 1;
 123
 124   for (i = 0; i < XVECLEN (x, 0); ++i)
 125     {
 126       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 127         return 1;
 128     }
 129
 130   return 0;
 131 }
 132
 133 machine_mode
 134 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 135                                machine_mode mode,
 136                                int *punsignedp ATTRIBUTE_UNUSED,
 137                                const_tree funtype ATTRIBUTE_UNUSED,
 138                                int for_return ATTRIBUTE_UNUSED)
 139 {
 140   if (type != NULL_TREE && for_return == 2)
 141     return promote_mode (type, mode, punsignedp);
 142   return mode;
 143 }
 144
 145 machine_mode
 146 default_promote_function_mode_always_promote (const_tree type,
 147                                               machine_mode mode,
 148                                               int *punsignedp,
 149                                               const_tree funtype ATTRIBUTE_UNUSED,
 150                                               int for_return ATTRIBUTE_UNUSED)
 151 {
 152   return promote_mode (type, mode, punsignedp);
 153 }
 154
 155 machine_mode
 156 default_cc_modes_compatible (machine_mode m1, machine_mode m2)
 157 {
 158   if (m1 == m2)
 159     return m1;
 160   return VOIDmode;
 161 }
 162
 163 bool
 164 default_return_in_memory (const_tree type,
 165                           const_tree fntype ATTRIBUTE_UNUSED)
 166 {
 167   return (TYPE_MODE (type) == BLKmode);
 168 }
 169
 170 rtx
 171 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 172                             machine_mode mode ATTRIBUTE_UNUSED)
 173 {
 174   return x;
 175 }
 176
 177 bool
 178 default_legitimize_address_displacement (rtx *disp ATTRIBUTE_UNUSED,
 179                                          rtx *offset ATTRIBUTE_UNUSED,
 180                                          machine_mode mode ATTRIBUTE_UNUSED)
 181 {
 182   return false;
 183 }
 184
 185 rtx
 186 default_expand_builtin_saveregs (void)
 187 {
 188   error ("__builtin_saveregs not supported by this target");
 189   return const0_rtx;
 190 }
 191
 192 void
 193 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 194                                 machine_mode mode ATTRIBUTE_UNUSED,
 195                                 tree type ATTRIBUTE_UNUSED,
 196                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 197                                 int second_time ATTRIBUTE_UNUSED)
 198 {
 199 }
 200
 201 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 202
 203 rtx
 204 default_builtin_setjmp_frame_value (void)
 205 {
 206   return virtual_stack_vars_rtx;
 207 }
 208
 209 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 210
 211 bool
 212 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 213 {
 214   return false;
 215 }
 216
 217 bool
 218 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 219 {
 220   return (targetm.calls.setup_incoming_varargs
 221           != default_setup_incoming_varargs);
 222 }
 223
 224 machine_mode
 225 default_eh_return_filter_mode (void)
 226 {
 227   return targetm.unwind_word_mode ();
 228 }
 229
 230 machine_mode
 231 default_libgcc_cmp_return_mode (void)
 232 {
 233   return word_mode;
 234 }
 235
 236 machine_mode
 237 default_libgcc_shift_count_mode (void)
 238 {
 239   return word_mode;
 240 }
 241
 242 machine_mode
 243 default_unwind_word_mode (void)
 244 {
 245   return word_mode;
 246 }
 247
 248 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 249
 250 unsigned HOST_WIDE_INT
 251 default_shift_truncation_mask (machine_mode mode)
 252 {
 253   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 254 }
 255
 256 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 257
 258 unsigned int
 259 default_min_divisions_for_recip_mul (machine_mode mode ATTRIBUTE_UNUSED)
 260 {
 261   return have_insn_for (DIV, mode) ? 3 : 2;
 262 }
 263
 264 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 265
 266 int
 267 default_mode_rep_extended (machine_mode mode ATTRIBUTE_UNUSED,
 268                            machine_mode mode_rep ATTRIBUTE_UNUSED)
 269 {
 270   return UNKNOWN;
 271 }
 272
 273 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 274
 275 bool
 276 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 277 {
 278   return true;
 279 }
 280
 281 /* Return machine mode for non-standard suffix
 282    or VOIDmode if non-standard suffixes are unsupported.  */
 283 machine_mode
 284 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 285 {
 286   return VOIDmode;
 287 }
 288
 289 /* The generic C++ ABI specifies this is a 64-bit value.  */
 290 tree
 291 default_cxx_guard_type (void)
 292 {
 293   return long_long_integer_type_node;
 294 }
 295
 296 /* Returns the size of the cookie to use when allocating an array
 297    whose elements have the indicated TYPE.  Assumes that it is already
 298    known that a cookie is needed.  */
 299
 300 tree
 301 default_cxx_get_cookie_size (tree type)
 302 {
 303   tree cookie_size;
 304
 305   /* We need to allocate an additional max (sizeof (size_t), alignof
 306      (true_type)) bytes.  */
 307   tree sizetype_size;
 308   tree type_align;
 309
 310   sizetype_size = size_in_bytes (sizetype);
 311   type_align = size_int (TYPE_ALIGN_UNIT (type));
 312   if (tree_int_cst_lt (type_align, sizetype_size))
 313     cookie_size = sizetype_size;
 314   else
 315     cookie_size = type_align;
 316
 317   return cookie_size;
 318 }
 319
 320 /* Return true if a parameter must be passed by reference.  This version
 321    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 322
 323 bool
 324 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 325         machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 326         bool named_arg ATTRIBUTE_UNUSED)
 327 {
 328   return targetm.calls.must_pass_in_stack (mode, type);
 329 }
 330
 331 /* Return true if a parameter follows callee copies conventions.  This
 332    version of the hook is true for all named arguments.  */
 333
 334 bool
 335 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 336                           machine_mode mode ATTRIBUTE_UNUSED,
 337                           const_tree type ATTRIBUTE_UNUSED, bool named)
 338 {
 339   return named;
 340 }
 341
 342 /* Emit to STREAM the assembler syntax for insn operand X.  */
 343
 344 void
 345 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 346                        int code ATTRIBUTE_UNUSED)
 347 {
 348 #ifdef PRINT_OPERAND
 349   PRINT_OPERAND (stream, x, code);
 350 #else
 351   gcc_unreachable ();
 352 #endif
 353 }
 354
 355 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 356    address is X.  */
 357
 358 void
 359 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 360                                rtx x ATTRIBUTE_UNUSED)
 361 {
 362 #ifdef PRINT_OPERAND_ADDRESS
 363   PRINT_OPERAND_ADDRESS (stream, x);
 364 #else
 365   gcc_unreachable ();
 366 #endif
 367 }
 368
 369 /* Return true if CODE is a valid punctuation character for the
 370    `print_operand' hook.  */
 371
 372 bool
 373 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 374 {
 375 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 376   return PRINT_OPERAND_PUNCT_VALID_P (code);
 377 #else
 378   return false;
 379 #endif
 380 }
 381
 382 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 383 tree
 384 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 385 {
 386   const char *skipped = name + (*name == '*' ? 1 : 0);
 387   const char *stripped = targetm.strip_name_encoding (skipped);
 388   if (*name != '*' && user_label_prefix[0])
 389     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 390   return get_identifier (stripped);
 391 }
 392
 393 /* True if MODE is valid for the target.  By "valid", we mean able to
 394    be manipulated in non-trivial ways.  In particular, this means all
 395    the arithmetic is supported.
 396
 397    By default we guess this means that any C type is supported.  If
 398    we can't map the mode back to a type that would be available in C,
 399    then reject it.  Special case, here, is the double-word arithmetic
 400    supported by optabs.c.  */
 401
 402 bool
 403 default_scalar_mode_supported_p (machine_mode mode)
 404 {
 405   int precision = GET_MODE_PRECISION (mode);
 406
 407   switch (GET_MODE_CLASS (mode))
 408     {
 409     case MODE_PARTIAL_INT:
 410     case MODE_INT:
 411       if (precision == CHAR_TYPE_SIZE)
 412         return true;
 413       if (precision == SHORT_TYPE_SIZE)
 414         return true;
 415       if (precision == INT_TYPE_SIZE)
 416         return true;
 417       if (precision == LONG_TYPE_SIZE)
 418         return true;
 419       if (precision == LONG_LONG_TYPE_SIZE)
 420         return true;
 421       if (precision == 2 * BITS_PER_WORD)
 422         return true;
 423       return false;
 424
 425     case MODE_FLOAT:
 426       if (precision == FLOAT_TYPE_SIZE)
 427         return true;
 428       if (precision == DOUBLE_TYPE_SIZE)
 429         return true;
 430       if (precision == LONG_DOUBLE_TYPE_SIZE)
 431         return true;
 432       return false;
 433
 434     case MODE_DECIMAL_FLOAT:
 435     case MODE_FRACT:
 436     case MODE_UFRACT:
 437     case MODE_ACCUM:
 438     case MODE_UACCUM:
 439       return false;
 440
 441     default:
 442       gcc_unreachable ();
 443     }
 444 }
 445
 446 /* Return true if libgcc supports floating-point mode MODE (known to
 447    be supported as a scalar mode).  */
 448
 449 bool
 450 default_libgcc_floating_mode_supported_p (machine_mode mode)
 451 {
 452   switch (mode)
 453     {
 454 #ifdef HAVE_SFmode
 455     case SFmode:
 456 #endif
 457 #ifdef HAVE_DFmode
 458     case DFmode:
 459 #endif
 460 #ifdef HAVE_XFmode
 461     case XFmode:
 462 #endif
 463 #ifdef HAVE_TFmode
 464     case TFmode:
 465 #endif
 466       return true;
 467
 468     default:
 469       return false;
 470     }
 471 }
 472
 473 /* Make some target macros useable by target-independent code.  */
 474 bool
 475 targhook_words_big_endian (void)
 476 {
 477   return !!WORDS_BIG_ENDIAN;
 478 }
 479
 480 bool
 481 targhook_float_words_big_endian (void)
 482 {
 483   return !!FLOAT_WORDS_BIG_ENDIAN;
 484 }
 485
 486 /* True if the target supports floating-point exceptions and rounding
 487    modes.  */
 488
 489 bool
 490 default_float_exceptions_rounding_supported_p (void)
 491 {
 492 #ifdef HAVE_adddf3
 493   return HAVE_adddf3;
 494 #else
 495   return false;
 496 #endif
 497 }
 498
 499 /* True if the target supports decimal floating point.  */
 500
 501 bool
 502 default_decimal_float_supported_p (void)
 503 {
 504   return ENABLE_DECIMAL_FLOAT;
 505 }
 506
 507 /* True if the target supports fixed-point arithmetic.  */
 508
 509 bool
 510 default_fixed_point_supported_p (void)
 511 {
 512   return ENABLE_FIXED_POINT;
 513 }
 514
 515 /* True if the target supports GNU indirect functions.  */
 516
 517 bool
 518 default_has_ifunc_p (void)
 519 {
 520   return HAVE_GNU_INDIRECT_FUNCTION;
 521 }
 522
 523 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 524    an error message.
 525
 526    This function checks whether a given INSN is valid within a low-overhead
 527    loop.  If INSN is invalid it returns the reason for that, otherwise it
 528    returns NULL. A called function may clobber any special registers required
 529    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 530    register for branch on table instructions. We reject the doloop pattern in
 531    these cases.  */
 532
 533 const char *
 534 default_invalid_within_doloop (const rtx_insn *insn)
 535 {
 536   if (CALL_P (insn))
 537     return "Function call in loop.";
 538
 539   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 540     return "Computed branch in the loop.";
 541
 542   return NULL;
 543 }
 544
 545 /* Mapping of builtin functions to vectorized variants.  */
 546
 547 tree
 548 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 549                                      tree type_out ATTRIBUTE_UNUSED,
 550                                      tree type_in ATTRIBUTE_UNUSED)
 551 {
 552   return NULL_TREE;
 553 }
 554
 555 /* Vectorized conversion.  */
 556
 557 tree
 558 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 559                                        tree dest_type ATTRIBUTE_UNUSED,
 560                                        tree src_type ATTRIBUTE_UNUSED)
 561 {
 562   return NULL_TREE;
 563 }
 564
 565 /* Default vectorizer cost model values.  */
 566
 567 int
 568 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 569                                     tree vectype,
 570                                     int misalign ATTRIBUTE_UNUSED)
 571 {
 572   unsigned elements;
 573
 574   switch (type_of_cost)
 575     {
 576       case scalar_stmt:
 577       case scalar_load:
 578       case scalar_store:
 579       case vector_stmt:
 580       case vector_load:
 581       case vector_store:
 582       case vec_to_scalar:
 583       case scalar_to_vec:
 584       case cond_branch_not_taken:
 585       case vec_perm:
 586       case vec_promote_demote:
 587         return 1;
 588
 589       case unaligned_load:
 590       case unaligned_store:
 591         return 2;
 592
 593       case cond_branch_taken:
 594         return 3;
 595
 596       case vec_construct:
 597         elements = TYPE_VECTOR_SUBPARTS (vectype);
 598         return elements / 2 + 1;
 599
 600       default:
 601         gcc_unreachable ();
 602     }
 603 }
 604
 605 /* Reciprocal.  */
 606
 607 tree
 608 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 609                             bool md_fn ATTRIBUTE_UNUSED,
 610                             bool sqrt ATTRIBUTE_UNUSED)
 611 {
 612   return NULL_TREE;
 613 }
 614
 615 bool
 616 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 617         cumulative_args_t ca ATTRIBUTE_UNUSED,
 618         machine_mode mode ATTRIBUTE_UNUSED,
 619         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 620 {
 621   return false;
 622 }
 623
 624 bool
 625 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 626         cumulative_args_t ca ATTRIBUTE_UNUSED,
 627         machine_mode mode ATTRIBUTE_UNUSED,
 628         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 629 {
 630   return true;
 631 }
 632
 633 int
 634 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 635         cumulative_args_t ca ATTRIBUTE_UNUSED,
 636         machine_mode mode ATTRIBUTE_UNUSED,
 637         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 638 {
 639   return 0;
 640 }
 641
 642 void
 643 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 644                               machine_mode mode ATTRIBUTE_UNUSED,
 645                               const_tree type ATTRIBUTE_UNUSED,
 646                               bool named ATTRIBUTE_UNUSED)
 647 {
 648   gcc_unreachable ();
 649 }
 650
 651 rtx
 652 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 653                       machine_mode mode ATTRIBUTE_UNUSED,
 654                       const_tree type ATTRIBUTE_UNUSED,
 655                       bool named ATTRIBUTE_UNUSED)
 656 {
 657   gcc_unreachable ();
 658 }
 659
 660 rtx
 661 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 662                                machine_mode mode ATTRIBUTE_UNUSED,
 663                                const_tree type ATTRIBUTE_UNUSED,
 664                                bool named ATTRIBUTE_UNUSED)
 665 {
 666   gcc_unreachable ();
 667 }
 668
 669 unsigned int
 670 default_function_arg_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 671                                const_tree type ATTRIBUTE_UNUSED)
 672 {
 673   return PARM_BOUNDARY;
 674 }
 675
 676 unsigned int
 677 default_function_arg_round_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 678                                      const_tree type ATTRIBUTE_UNUSED)
 679 {
 680   return PARM_BOUNDARY;
 681 }
 682
 683 void
 684 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 685 {
 686 }
 687
 688 const char *
 689 hook_invalid_arg_for_unprototyped_fn (
 690         const_tree typelist ATTRIBUTE_UNUSED,
 691         const_tree funcdecl ATTRIBUTE_UNUSED,
 692         const_tree val ATTRIBUTE_UNUSED)
 693 {
 694   return NULL;
 695 }
 696
 697 /* Initialize the stack protection decls.  */
 698
 699 /* Stack protection related decls living in libgcc.  */
 700 static GTY(()) tree stack_chk_guard_decl;
 701
 702 tree
 703 default_stack_protect_guard (void)
 704 {
 705   tree t = stack_chk_guard_decl;
 706
 707   if (t == NULL)
 708     {
 709       rtx x;
 710
 711       t = build_decl (UNKNOWN_LOCATION,
 712                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 713                       ptr_type_node);
 714       TREE_STATIC (t) = 1;
 715       TREE_PUBLIC (t) = 1;
 716       DECL_EXTERNAL (t) = 1;
 717       TREE_USED (t) = 1;
 718       TREE_THIS_VOLATILE (t) = 1;
 719       DECL_ARTIFICIAL (t) = 1;
 720       DECL_IGNORED_P (t) = 1;
 721
 722       /* Do not share RTL as the declaration is visible outside of
 723          current function.  */
 724       x = DECL_RTL (t);
 725       RTX_FLAG (x, used) = 1;
 726
 727       stack_chk_guard_decl = t;
 728     }
 729
 730   return t;
 731 }
 732
 733 static GTY(()) tree stack_chk_fail_decl;
 734
 735 tree
 736 default_external_stack_protect_fail (void)
 737 {
 738   tree t = stack_chk_fail_decl;
 739
 740   if (t == NULL_TREE)
 741     {
 742       t = build_function_type_list (void_type_node, NULL_TREE);
 743       t = build_decl (UNKNOWN_LOCATION,
 744                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 745       TREE_STATIC (t) = 1;
 746       TREE_PUBLIC (t) = 1;
 747       DECL_EXTERNAL (t) = 1;
 748       TREE_USED (t) = 1;
 749       TREE_THIS_VOLATILE (t) = 1;
 750       TREE_NOTHROW (t) = 1;
 751       DECL_ARTIFICIAL (t) = 1;
 752       DECL_IGNORED_P (t) = 1;
 753       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 754       DECL_VISIBILITY_SPECIFIED (t) = 1;
 755
 756       stack_chk_fail_decl = t;
 757     }
 758
 759   return build_call_expr (t, 0);
 760 }
 761
 762 tree
 763 default_hidden_stack_protect_fail (void)
 764 {
 765 #ifndef HAVE_GAS_HIDDEN
 766   return default_external_stack_protect_fail ();
 767 #else
 768   tree t = stack_chk_fail_decl;
 769
 770   if (!flag_pic)
 771     return default_external_stack_protect_fail ();
 772
 773   if (t == NULL_TREE)
 774     {
 775       t = build_function_type_list (void_type_node, NULL_TREE);
 776       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 777                       get_identifier ("__stack_chk_fail_local"), t);
 778       TREE_STATIC (t) = 1;
 779       TREE_PUBLIC (t) = 1;
 780       DECL_EXTERNAL (t) = 1;
 781       TREE_USED (t) = 1;
 782       TREE_THIS_VOLATILE (t) = 1;
 783       TREE_NOTHROW (t) = 1;
 784       DECL_ARTIFICIAL (t) = 1;
 785       DECL_IGNORED_P (t) = 1;
 786       DECL_VISIBILITY_SPECIFIED (t) = 1;
 787       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 788
 789       stack_chk_fail_decl = t;
 790     }
 791
 792   return build_call_expr (t, 0);
 793 #endif
 794 }
 795
 796 bool
 797 hook_bool_const_rtx_commutative_p (const_rtx x,
 798                                    int outer_code ATTRIBUTE_UNUSED)
 799 {
 800   return COMMUTATIVE_P (x);
 801 }
 802
 803 rtx
 804 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 805                         const_tree fn_decl_or_type,
 806                         bool outgoing ATTRIBUTE_UNUSED)
 807 {
 808   /* The old interface doesn't handle receiving the function type.  */
 809   if (fn_decl_or_type
 810       && !DECL_P (fn_decl_or_type))
 811     fn_decl_or_type = NULL;
 812
 813 #ifdef FUNCTION_VALUE
 814   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 815 #else
 816   gcc_unreachable ();
 817 #endif
 818 }
 819
 820 rtx
 821 default_libcall_value (machine_mode mode ATTRIBUTE_UNUSED,
 822                        const_rtx fun ATTRIBUTE_UNUSED)
 823 {
 824 #ifdef LIBCALL_VALUE
 825   return LIBCALL_VALUE (mode);
 826 #else
 827   gcc_unreachable ();
 828 #endif
 829 }
 830
 831 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 832
 833 bool
 834 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 835 {
 836 #ifdef FUNCTION_VALUE_REGNO_P
 837   return FUNCTION_VALUE_REGNO_P (regno);
 838 #else
 839   gcc_unreachable ();
 840 #endif
 841 }
 842
 843 rtx
 844 default_internal_arg_pointer (void)
 845 {
 846   /* If the reg that the virtual arg pointer will be translated into is
 847      not a fixed reg or is the stack pointer, make a copy of the virtual
 848      arg pointer, and address parms via the copy.  The frame pointer is
 849      considered fixed even though it is not marked as such.  */
 850   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 851        || ! (fixed_regs[ARG_POINTER_REGNUM]
 852              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 853     return copy_to_reg (virtual_incoming_args_rtx);
 854   else
 855     return virtual_incoming_args_rtx;
 856 }
 857
 858 rtx
 859 default_static_chain (const_tree ARG_UNUSED (fndecl_or_type), bool incoming_p)
 860 {
 861   if (incoming_p)
 862     {
 863 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 864       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 865 #endif
 866     }
 867
 868 #ifdef STATIC_CHAIN_REGNUM
 869   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 870 #endif
 871
 872   {
 873     static bool issued_error;
 874     if (!issued_error)
 875       {
 876         issued_error = true;
 877         sorry ("nested functions not supported on this target");
 878       }
 879
 880     /* It really doesn't matter what we return here, so long at it
 881        doesn't cause the rest of the compiler to crash.  */
 882     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 883   }
 884 }
 885
 886 void
 887 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 888                          rtx ARG_UNUSED (r_chain))
 889 {
 890   sorry ("nested function trampolines not supported on this target");
 891 }
 892
 893 int
 894 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 895                           tree funtype ATTRIBUTE_UNUSED,
 896                           int size ATTRIBUTE_UNUSED)
 897 {
 898   return 0;
 899 }
 900
 901 reg_class_t
 902 default_branch_target_register_class (void)
 903 {
 904   return NO_REGS;
 905 }
 906
 907 reg_class_t
 908 default_ira_change_pseudo_allocno_class (int regno ATTRIBUTE_UNUSED,
 909                                          reg_class_t cl)
 910 {
 911   return cl;
 912 }
 913
 914 extern bool
 915 default_lra_p (void)
 916 {
 917   return false;
 918 }
 919
 920 int
 921 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 922 {
 923   return 0;
 924 }
 925
 926 extern bool
 927 default_register_usage_leveling_p (void)
 928 {
 929   return false;
 930 }
 931
 932 extern bool
 933 default_different_addr_displacement_p (void)
 934 {
 935   return false;
 936 }
 937
 938 reg_class_t
 939 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 940                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 941                           machine_mode reload_mode ATTRIBUTE_UNUSED,
 942                           secondary_reload_info *sri)
 943 {
 944   enum reg_class rclass = NO_REGS;
 945   enum reg_class reload_class = (enum reg_class) reload_class_i;
 946
 947   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 948     {
 949       sri->icode = sri->prev_sri->t_icode;
 950       return NO_REGS;
 951     }
 952 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 953   if (in_p)
 954     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 955 #endif
 956 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 957   if (! in_p)
 958     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 959 #endif
 960   if (rclass != NO_REGS)
 961     {
 962       enum insn_code icode
 963         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 964                                 reload_mode);
 965
 966       if (icode != CODE_FOR_nothing
 967           && !insn_operand_matches (icode, in_p, x))
 968         icode = CODE_FOR_nothing;
 969       else if (icode != CODE_FOR_nothing)
 970         {
 971           const char *insn_constraint, *scratch_constraint;
 972           enum reg_class insn_class, scratch_class;
 973
 974           gcc_assert (insn_data[(int) icode].n_operands == 3);
 975           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 976           if (!*insn_constraint)
 977             insn_class = ALL_REGS;
 978           else
 979             {
 980               if (in_p)
 981                 {
 982                   gcc_assert (*insn_constraint == '=');
 983                   insn_constraint++;
 984                 }
 985               insn_class = (reg_class_for_constraint
 986                             (lookup_constraint (insn_constraint)));
 987               gcc_assert (insn_class != NO_REGS);
 988             }
 989
 990           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 991           /* The scratch register's constraint must start with "=&",
 992              except for an input reload, where only "=" is necessary,
 993              and where it might be beneficial to re-use registers from
 994              the input.  */
 995           gcc_assert (scratch_constraint[0] == '='
 996                       && (in_p || scratch_constraint[1] == '&'));
 997           scratch_constraint++;
 998           if (*scratch_constraint == '&')
 999             scratch_constraint++;
1000           scratch_class = (reg_class_for_constraint
1001                            (lookup_constraint (scratch_constraint)));
1002
1003           if (reg_class_subset_p (reload_class, insn_class))
1004             {
1005               gcc_assert (scratch_class == rclass);
1006               rclass = NO_REGS;
1007             }
1008           else
1009             rclass = insn_class;
1010
1011         }
1012       if (rclass == NO_REGS)
1013         sri->icode = icode;
1014       else
1015         sri->t_icode = icode;
1016     }
1017   return rclass;
1018 }
1019
1020 /* By default, if flag_pic is true, then neither local nor global relocs
1021    should be placed in readonly memory.  */
1022
1023 int
1024 default_reloc_rw_mask (void)
1025 {
1026   return flag_pic ? 3 : 0;
1027 }
1028
1029 /* By default, do no modification. */
1030 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
1031                                          tree id)
1032 {
1033    return id;
1034 }
1035
1036 /* Default to natural alignment for vector types.  */
1037 HOST_WIDE_INT
1038 default_vector_alignment (const_tree type)
1039 {
1040   return tree_to_shwi (TYPE_SIZE (type));
1041 }
1042
1043 bool
1044 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
1045 {
1046   if (is_packed)
1047     return false;
1048
1049   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1050      naturally aligned.  */
1051   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1052     return false;
1053
1054   /* Assuming that types whose size is <= pointer-size
1055      are naturally aligned.  */
1056   return true;
1057 }
1058
1059 /* By default, assume that a target supports any factor of misalignment
1060    memory access if it supports movmisalign patten.
1061    is_packed is true if the memory access is defined in a packed struct.  */
1062 bool
1063 default_builtin_support_vector_misalignment (machine_mode mode,
1064                                              const_tree type
1065                                              ATTRIBUTE_UNUSED,
1066                                              int misalignment
1067                                              ATTRIBUTE_UNUSED,
1068                                              bool is_packed
1069                                              ATTRIBUTE_UNUSED)
1070 {
1071   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1072     return true;
1073   return false;
1074 }
1075
1076 /* By default, only attempt to parallelize bitwise operations, and
1077    possibly adds/subtracts using bit-twiddling.  */
1078
1079 machine_mode
1080 default_preferred_simd_mode (machine_mode mode ATTRIBUTE_UNUSED)
1081 {
1082   return word_mode;
1083 }
1084
1085 /* By default only the size derived from the preferred vector mode
1086    is tried.  */
1087
1088 unsigned int
1089 default_autovectorize_vector_sizes (void)
1090 {
1091   return 0;
1092 }
1093
1094 /* By default, the cost model accumulates three separate costs (prologue,
1095    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1096    array of three unsigned ints, set it to zero, and return its address.  */
1097
1098 void *
1099 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1100 {
1101   unsigned *cost = XNEWVEC (unsigned, 3);
1102   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1103   return cost;
1104 }
1105
1106 /* By default, the cost model looks up the cost of the given statement
1107    kind and mode, multiplies it by the occurrence count, accumulates
1108    it into the cost specified by WHERE, and returns the cost added.  */
1109
1110 unsigned
1111 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1112                        struct _stmt_vec_info *stmt_info, int misalign,
1113                        enum vect_cost_model_location where)
1114 {
1115   unsigned *cost = (unsigned *) data;
1116   unsigned retval = 0;
1117
1118   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1119   int stmt_cost = targetm.vectorize.builtin_vectorization_cost (kind, vectype,
1120                                                                 misalign);
1121    /* Statements in an inner loop relative to the loop being
1122       vectorized are weighted more heavily.  The value here is
1123       arbitrary and could potentially be improved with analysis.  */
1124   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1125     count *= 50;  /* FIXME.  */
1126
1127   retval = (unsigned) (count * stmt_cost);
1128   cost[where] += retval;
1129
1130   return retval;
1131 }
1132
1133 /* By default, the cost model just returns the accumulated costs.  */
1134
1135 void
1136 default_finish_cost (void *data, unsigned *prologue_cost,
1137                      unsigned *body_cost, unsigned *epilogue_cost)
1138 {
1139   unsigned *cost = (unsigned *) data;
1140   *prologue_cost = cost[vect_prologue];
1141   *body_cost     = cost[vect_body];
1142   *epilogue_cost = cost[vect_epilogue];
1143 }
1144
1145 /* Free the cost data.  */
1146
1147 void
1148 default_destroy_cost_data (void *data)
1149 {
1150   free (data);
1151 }
1152
1153 /* Determine whether or not a pointer mode is valid. Assume defaults
1154    of ptr_mode or Pmode - can be overridden.  */
1155 bool
1156 default_valid_pointer_mode (machine_mode mode)
1157 {
1158   return (mode == ptr_mode || mode == Pmode);
1159 }
1160
1161 /* Determine whether the memory reference specified by REF may alias
1162    the C libraries errno location.  */
1163 bool
1164 default_ref_may_alias_errno (ao_ref *ref)
1165 {
1166   tree base = ao_ref_base (ref);
1167   /* The default implementation assumes the errno location is
1168      a declaration of type int or is always accessed via a
1169      pointer to int.  We assume that accesses to errno are
1170      not deliberately obfuscated (even in conforming ways).  */
1171   if (TYPE_UNSIGNED (TREE_TYPE (base))
1172       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1173     return false;
1174   /* The default implementation assumes an errno location
1175      declaration is never defined in the current compilation unit.  */
1176   if (DECL_P (base)
1177       && !TREE_STATIC (base))
1178     return true;
1179   else if (TREE_CODE (base) == MEM_REF
1180            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1181     {
1182       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1183       return !pi || pi->pt.anything || pi->pt.nonlocal;
1184     }
1185   return false;
1186 }
1187
1188 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1189    for the generic address space only.  */
1190
1191 machine_mode
1192 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1193 {
1194   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1195   return ptr_mode;
1196 }
1197
1198 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1199    for the generic address space only.  */
1200
1201 machine_mode
1202 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1203 {
1204   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1205   return Pmode;
1206 }
1207
1208 /* Named address space version of valid_pointer_mode.  */
1209
1210 bool
1211 default_addr_space_valid_pointer_mode (machine_mode mode, addr_space_t as)
1212 {
1213   if (!ADDR_SPACE_GENERIC_P (as))
1214     return (mode == targetm.addr_space.pointer_mode (as)
1215             || mode == targetm.addr_space.address_mode (as));
1216
1217   return targetm.valid_pointer_mode (mode);
1218 }
1219
1220 /* Some places still assume that all pointer or address modes are the
1221    standard Pmode and ptr_mode.  These optimizations become invalid if
1222    the target actually supports multiple different modes.  For now,
1223    we disable such optimizations on such targets, using this function.  */
1224
1225 bool
1226 target_default_pointer_address_modes_p (void)
1227 {
1228   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1229     return false;
1230   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1231     return false;
1232
1233   return true;
1234 }
1235
1236 /* Named address space version of legitimate_address_p.  */
1237
1238 bool
1239 default_addr_space_legitimate_address_p (machine_mode mode, rtx mem,
1240                                          bool strict, addr_space_t as)
1241 {
1242   if (!ADDR_SPACE_GENERIC_P (as))
1243     gcc_unreachable ();
1244
1245   return targetm.legitimate_address_p (mode, mem, strict);
1246 }
1247
1248 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1249
1250 rtx
1251 default_addr_space_legitimize_address (rtx x, rtx oldx,
1252                                        machine_mode mode, addr_space_t as)
1253 {
1254   if (!ADDR_SPACE_GENERIC_P (as))
1255     return x;
1256
1257   return targetm.legitimize_address (x, oldx, mode);
1258 }
1259
1260 /* The default hook for determining if one named address space is a subset of
1261    another and to return which address space to use as the common address
1262    space.  */
1263
1264 bool
1265 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1266 {
1267   return (subset == superset);
1268 }
1269
1270 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1271    called for targets with only a generic address space.  */
1272
1273 rtx
1274 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1275                             tree from_type ATTRIBUTE_UNUSED,
1276                             tree to_type ATTRIBUTE_UNUSED)
1277 {
1278   gcc_unreachable ();
1279 }
1280
1281 bool
1282 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1283 {
1284   return true;
1285 }
1286
1287 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1288
1289 bool
1290 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1291                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1292 {
1293   return false;
1294 }
1295
1296 bool
1297 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1298                                          tree ARG_UNUSED (name),
1299                                          tree ARG_UNUSED (args),
1300                                          int ARG_UNUSED (flags))
1301 {
1302   warning (OPT_Wattributes,
1303            "target attribute is not supported on this machine");
1304
1305   return false;
1306 }
1307
1308 bool
1309 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1310                                     tree ARG_UNUSED (pop_target))
1311 {
1312   warning (OPT_Wpragmas,
1313            "#pragma GCC target is not supported for this machine");
1314
1315   return false;
1316 }
1317
1318 bool
1319 default_target_can_inline_p (tree caller, tree callee)
1320 {
1321   bool ret = false;
1322   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1323   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1324
1325   /* If callee has no option attributes, then it is ok to inline */
1326   if (!callee_opts)
1327     ret = true;
1328
1329   /* If caller has no option attributes, but callee does then it is not ok to
1330      inline */
1331   else if (!caller_opts)
1332     ret = false;
1333
1334   /* If both caller and callee have attributes, assume that if the
1335      pointer is different, the two functions have different target
1336      options since build_target_option_node uses a hash table for the
1337      options.  */
1338   else
1339     ret = (callee_opts == caller_opts);
1340
1341   return ret;
1342 }
1343
1344 #ifndef HAVE_casesi
1345 # define HAVE_casesi 0
1346 #endif
1347
1348 /* If the machine does not have a case insn that compares the bounds,
1349    this means extra overhead for dispatch tables, which raises the
1350    threshold for using them.  */
1351
1352 unsigned int
1353 default_case_values_threshold (void)
1354 {
1355   return (HAVE_casesi ? 4 : 5);
1356 }
1357
1358 bool
1359 default_have_conditional_execution (void)
1360 {
1361 #ifdef HAVE_conditional_execution
1362   return HAVE_conditional_execution;
1363 #else
1364   return false;
1365 #endif
1366 }
1367
1368 /* By default we assume that c99 functions are present at the runtime,
1369    but sincos is not.  */
1370 bool
1371 default_libc_has_function (enum function_class fn_class)
1372 {
1373   if (fn_class == function_c94
1374       || fn_class == function_c99_misc
1375       || fn_class == function_c99_math_complex)
1376     return true;
1377
1378   return false;
1379 }
1380
1381 bool
1382 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1383 {
1384   return true;
1385 }
1386
1387 bool
1388 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1389 {
1390   return false;
1391 }
1392
1393 tree
1394 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1395 {
1396   return NULL_TREE;
1397 }
1398
1399 /* Compute cost of moving registers to/from memory.  */
1400
1401 int
1402 default_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1403                           reg_class_t rclass ATTRIBUTE_UNUSED,
1404                           bool in ATTRIBUTE_UNUSED)
1405 {
1406 #ifndef MEMORY_MOVE_COST
1407     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1408 #else
1409     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1410 #endif
1411 }
1412
1413 /* Compute cost of moving data from a register of class FROM to one of
1414    TO, using MODE.  */
1415
1416 int
1417 default_register_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1418                             reg_class_t from ATTRIBUTE_UNUSED,
1419                             reg_class_t to ATTRIBUTE_UNUSED)
1420 {
1421 #ifndef REGISTER_MOVE_COST
1422   return 2;
1423 #else
1424   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1425 #endif
1426 }
1427
1428 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
1429    behaviour.  SPEED_P is true if we are compiling for speed.  */
1430
1431 unsigned int
1432 get_move_ratio (bool speed_p ATTRIBUTE_UNUSED)
1433 {
1434   unsigned int move_ratio;
1435 #ifdef MOVE_RATIO
1436   move_ratio = (unsigned int) MOVE_RATIO (speed_p);
1437 #else
1438 #if defined (HAVE_movmemqi) || defined (HAVE_movmemhi) || defined (HAVE_movmemsi) || defined (HAVE_movmemdi) || defined (HAVE_movmemti)
1439   move_ratio = 2;
1440 #else /* No movmem patterns, pick a default.  */
1441   move_ratio = ((speed_p) ? 15 : 3);
1442 #endif
1443 #endif
1444   return move_ratio;
1445 }
1446
1447 /* Return TRUE if the move_by_pieces/set_by_pieces infrastructure should be
1448    used; return FALSE if the movmem/setmem optab should be expanded, or
1449    a call to memcpy emitted.  */
1450
1451 bool
1452 default_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
1453                                         unsigned int alignment,
1454                                         enum by_pieces_operation op,
1455                                         bool speed_p)
1456 {
1457   unsigned int max_size = 0;
1458   unsigned int ratio = 0;
1459
1460   switch (op)
1461     {
1462       case CLEAR_BY_PIECES:
1463         max_size = STORE_MAX_PIECES;
1464         ratio = CLEAR_RATIO (speed_p);
1465         break;
1466       case MOVE_BY_PIECES:
1467         max_size = MOVE_MAX_PIECES;
1468         ratio = get_move_ratio (speed_p);
1469         break;
1470       case SET_BY_PIECES:
1471         max_size = STORE_MAX_PIECES;
1472         ratio = SET_RATIO (speed_p);
1473         break;
1474       case STORE_BY_PIECES:
1475         max_size = STORE_MAX_PIECES;
1476         ratio = get_move_ratio (speed_p);
1477         break;
1478     }
1479
1480   return move_by_pieces_ninsns (size, alignment, max_size + 1) < ratio;
1481 }
1482
1483 bool
1484 default_profile_before_prologue (void)
1485 {
1486 #ifdef PROFILE_BEFORE_PROLOGUE
1487   return true;
1488 #else
1489   return false;
1490 #endif
1491 }
1492
1493 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1494
1495 reg_class_t
1496 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1497                                 reg_class_t rclass)
1498 {
1499 #ifdef PREFERRED_RELOAD_CLASS
1500   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1501 #else
1502   return rclass;
1503 #endif
1504 }
1505
1506 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1507
1508 reg_class_t
1509 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1510                                        reg_class_t rclass)
1511 {
1512   return rclass;
1513 }
1514
1515 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1516 reg_class_t
1517 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1518 {
1519   return NO_REGS;
1520 }
1521
1522 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1523
1524 bool
1525 default_class_likely_spilled_p (reg_class_t rclass)
1526 {
1527   return (reg_class_size[(int) rclass] == 1);
1528 }
1529
1530 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1531
1532 unsigned char
1533 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1534                          machine_mode mode ATTRIBUTE_UNUSED)
1535 {
1536 #ifdef CLASS_MAX_NREGS
1537   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1538 #else
1539   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1540 #endif
1541 }
1542
1543 /* Determine the debugging unwind mechanism for the target.  */
1544
1545 enum unwind_info_type
1546 default_debug_unwind_info (void)
1547 {
1548   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1549   /* ??? Change all users to the hook, then poison this.  */
1550 #ifdef DWARF2_FRAME_INFO
1551   if (DWARF2_FRAME_INFO)
1552     return UI_DWARF2;
1553 #endif
1554
1555   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1556 #ifdef DWARF2_DEBUGGING_INFO
1557   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1558     return UI_DWARF2;
1559 #endif
1560
1561   return UI_NONE;
1562 }
1563
1564 /* Determine the correct mode for a Dwarf frame register that represents
1565    register REGNO.  */
1566
1567 machine_mode
1568 default_dwarf_frame_reg_mode (int regno)
1569 {
1570   machine_mode save_mode = reg_raw_mode[regno];
1571
1572   if (HARD_REGNO_CALL_PART_CLOBBERED (regno, save_mode))
1573     save_mode = choose_hard_reg_mode (regno, 1, true);
1574   return save_mode;
1575 }
1576
1577 /* To be used by targets where reg_raw_mode doesn't return the right
1578    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1579
1580 machine_mode
1581 default_get_reg_raw_mode (int regno)
1582 {
1583   return reg_raw_mode[regno];
1584 }
1585
1586 /* Return true if a leaf function should stay leaf even with profiling
1587    enabled.  */
1588
1589 bool
1590 default_keep_leaf_when_profiled ()
1591 {
1592   return false;
1593 }
1594
1595 /* Return true if the state of option OPTION should be stored in PCH files
1596    and checked by default_pch_valid_p.  Store the option's current state
1597    in STATE if so.  */
1598
1599 static inline bool
1600 option_affects_pch_p (int option, struct cl_option_state *state)
1601 {
1602   if ((cl_options[option].flags & CL_TARGET) == 0)
1603     return false;
1604   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1605     return false;
1606   if (option_flag_var (option, &global_options) == &target_flags)
1607     if (targetm.check_pch_target_flags)
1608       return false;
1609   return get_option_state (&global_options, option, state);
1610 }
1611
1612 /* Default version of get_pch_validity.
1613    By default, every flag difference is fatal; that will be mostly right for
1614    most targets, but completely right for very few.  */
1615
1616 void *
1617 default_get_pch_validity (size_t *sz)
1618 {
1619   struct cl_option_state state;
1620   size_t i;
1621   char *result, *r;
1622
1623   *sz = 2;
1624   if (targetm.check_pch_target_flags)
1625     *sz += sizeof (target_flags);
1626   for (i = 0; i < cl_options_count; i++)
1627     if (option_affects_pch_p (i, &state))
1628       *sz += state.size;
1629
1630   result = r = XNEWVEC (char, *sz);
1631   r[0] = flag_pic;
1632   r[1] = flag_pie;
1633   r += 2;
1634   if (targetm.check_pch_target_flags)
1635     {
1636       memcpy (r, &target_flags, sizeof (target_flags));
1637       r += sizeof (target_flags);
1638     }
1639
1640   for (i = 0; i < cl_options_count; i++)
1641     if (option_affects_pch_p (i, &state))
1642       {
1643         memcpy (r, state.data, state.size);
1644         r += state.size;
1645       }
1646
1647   return result;
1648 }
1649
1650 /* Return a message which says that a PCH file was created with a different
1651    setting of OPTION.  */
1652
1653 static const char *
1654 pch_option_mismatch (const char *option)
1655 {
1656   return xasprintf (_("created and used with differing settings of '%s'"),
1657                     option);
1658 }
1659
1660 /* Default version of pch_valid_p.  */
1661
1662 const char *
1663 default_pch_valid_p (const void *data_p, size_t len)
1664 {
1665   struct cl_option_state state;
1666   const char *data = (const char *)data_p;
1667   size_t i;
1668
1669   /* -fpic and -fpie also usually make a PCH invalid.  */
1670   if (data[0] != flag_pic)
1671     return _("created and used with different settings of -fpic");
1672   if (data[1] != flag_pie)
1673     return _("created and used with different settings of -fpie");
1674   data += 2;
1675
1676   /* Check target_flags.  */
1677   if (targetm.check_pch_target_flags)
1678     {
1679       int tf;
1680       const char *r;
1681
1682       memcpy (&tf, data, sizeof (target_flags));
1683       data += sizeof (target_flags);
1684       len -= sizeof (target_flags);
1685       r = targetm.check_pch_target_flags (tf);
1686       if (r != NULL)
1687         return r;
1688     }
1689
1690   for (i = 0; i < cl_options_count; i++)
1691     if (option_affects_pch_p (i, &state))
1692       {
1693         if (memcmp (data, state.data, state.size) != 0)
1694           return pch_option_mismatch (cl_options[i].opt_text);
1695         data += state.size;
1696         len -= state.size;
1697       }
1698
1699   return NULL;
1700 }
1701
1702 /* Default version of cstore_mode.  */
1703
1704 machine_mode
1705 default_cstore_mode (enum insn_code icode)
1706 {
1707   return insn_data[(int) icode].operand[0].mode;
1708 }
1709
1710 /* Default version of member_type_forces_blk.  */
1711
1712 bool
1713 default_member_type_forces_blk (const_tree, machine_mode)
1714 {
1715   return false;
1716 }
1717
1718 rtx
1719 default_load_bounds_for_arg (rtx addr ATTRIBUTE_UNUSED,
1720                              rtx ptr ATTRIBUTE_UNUSED,
1721                              rtx bnd ATTRIBUTE_UNUSED)
1722 {
1723   gcc_unreachable ();
1724 }
1725
1726 void
1727 default_store_bounds_for_arg (rtx val ATTRIBUTE_UNUSED,
1728                               rtx addr ATTRIBUTE_UNUSED,
1729                               rtx bounds ATTRIBUTE_UNUSED,
1730                               rtx to ATTRIBUTE_UNUSED)
1731 {
1732   gcc_unreachable ();
1733 }
1734
1735 rtx
1736 default_load_returned_bounds (rtx slot ATTRIBUTE_UNUSED)
1737 {
1738   gcc_unreachable ();
1739 }
1740
1741 void
1742 default_store_returned_bounds (rtx slot ATTRIBUTE_UNUSED,
1743                                rtx bounds ATTRIBUTE_UNUSED)
1744 {
1745   gcc_unreachable ();
1746 }
1747
1748 /* Default version of canonicalize_comparison.  */
1749
1750 void
1751 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1752 {
1753 }
1754
1755 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1756
1757 void
1758 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1759 {
1760 }
1761
1762 #ifndef PAD_VARARGS_DOWN
1763 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1764 #endif
1765
1766 /* Build an indirect-ref expression over the given TREE, which represents a
1767    piece of a va_arg() expansion.  */
1768 tree
1769 build_va_arg_indirect_ref (tree addr)
1770 {
1771   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1772   return addr;
1773 }
1774
1775 /* The "standard" implementation of va_arg: read the value from the
1776    current (padded) address and increment by the (padded) size.  */
1777
1778 tree
1779 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1780                           gimple_seq *post_p)
1781 {
1782   tree addr, t, type_size, rounded_size, valist_tmp;
1783   unsigned HOST_WIDE_INT align, boundary;
1784   bool indirect;
1785
1786   /* All of the alignment and movement below is for args-grow-up machines.
1787      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1788      implement their own specialized gimplify_va_arg_expr routines.  */
1789   if (ARGS_GROW_DOWNWARD)
1790     gcc_unreachable ();
1791
1792   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1793   if (indirect)
1794     type = build_pointer_type (type);
1795
1796   align = PARM_BOUNDARY / BITS_PER_UNIT;
1797   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1798
1799   /* When we align parameter on stack for caller, if the parameter
1800      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1801      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1802      here with caller.  */
1803   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1804     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1805
1806   boundary /= BITS_PER_UNIT;
1807
1808   /* Hoist the valist value into a temporary for the moment.  */
1809   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1810
1811   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1812      requires greater alignment, we must perform dynamic alignment.  */
1813   if (boundary > align
1814       && !integer_zerop (TYPE_SIZE (type)))
1815     {
1816       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1817                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1818       gimplify_and_add (t, pre_p);
1819
1820       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1821                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1822                                valist_tmp,
1823                                build_int_cst (TREE_TYPE (valist), -boundary)));
1824       gimplify_and_add (t, pre_p);
1825     }
1826   else
1827     boundary = align;
1828
1829   /* If the actual alignment is less than the alignment of the type,
1830      adjust the type accordingly so that we don't assume strict alignment
1831      when dereferencing the pointer.  */
1832   boundary *= BITS_PER_UNIT;
1833   if (boundary < TYPE_ALIGN (type))
1834     {
1835       type = build_variant_type_copy (type);
1836       TYPE_ALIGN (type) = boundary;
1837     }
1838
1839   /* Compute the rounded size of the type.  */
1840   type_size = size_in_bytes (type);
1841   rounded_size = round_up (type_size, align);
1842
1843   /* Reduce rounded_size so it's sharable with the postqueue.  */
1844   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1845
1846   /* Get AP.  */
1847   addr = valist_tmp;
1848   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1849     {
1850       /* Small args are padded downward.  */
1851       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1852                        rounded_size, size_int (align));
1853       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1854                        size_binop (MINUS_EXPR, rounded_size, type_size));
1855       addr = fold_build_pointer_plus (addr, t);
1856     }
1857
1858   /* Compute new value for AP.  */
1859   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1860   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1861   gimplify_and_add (t, pre_p);
1862
1863   addr = fold_convert (build_pointer_type (type), addr);
1864
1865   if (indirect)
1866     addr = build_va_arg_indirect_ref (addr);
1867
1868   return build_va_arg_indirect_ref (addr);
1869 }
1870
1871 tree
1872 default_chkp_bound_type (void)
1873 {
1874   tree res = make_node (POINTER_BOUNDS_TYPE);
1875   TYPE_PRECISION (res) = TYPE_PRECISION (size_type_node) * 2;
1876   TYPE_NAME (res) = get_identifier ("__bounds_type");
1877   SET_TYPE_MODE (res, targetm.chkp_bound_mode ());
1878   layout_type (res);
1879   return res;
1880 }
1881
1882 enum machine_mode
1883 default_chkp_bound_mode (void)
1884 {
1885   return VOIDmode;
1886 }
1887
1888 tree
1889 default_builtin_chkp_function (unsigned int fcode ATTRIBUTE_UNUSED)
1890 {
1891   return NULL_TREE;
1892 }
1893
1894 rtx
1895 default_chkp_function_value_bounds (const_tree ret_type ATTRIBUTE_UNUSED,
1896                                     const_tree fn_decl_or_type ATTRIBUTE_UNUSED,
1897                                     bool outgoing ATTRIBUTE_UNUSED)
1898 {
1899   gcc_unreachable ();
1900 }
1901
1902 tree
1903 default_chkp_make_bounds_constant (HOST_WIDE_INT lb ATTRIBUTE_UNUSED,
1904                                    HOST_WIDE_INT ub ATTRIBUTE_UNUSED)
1905 {
1906   return NULL_TREE;
1907 }
1908
1909 int
1910 default_chkp_initialize_bounds (tree var ATTRIBUTE_UNUSED,
1911                                 tree lb ATTRIBUTE_UNUSED,
1912                                 tree ub ATTRIBUTE_UNUSED,
1913                                 tree *stmts ATTRIBUTE_UNUSED)
1914 {
1915   return 0;
1916 }
1917
1918 void
1919 default_setup_incoming_vararg_bounds (cumulative_args_t ca ATTRIBUTE_UNUSED,
1920                                       enum machine_mode mode ATTRIBUTE_UNUSED,
1921                                       tree type ATTRIBUTE_UNUSED,
1922                                       int *pretend_arg_size ATTRIBUTE_UNUSED,
1923                                       int second_time ATTRIBUTE_UNUSED)
1924 {
1925 }
1926
1927 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1928    not support nested low-overhead loops.  */
1929
1930 bool
1931 can_use_doloop_if_innermost (const widest_int &, const widest_int &,
1932                              unsigned int loop_depth, bool)
1933 {
1934   return loop_depth == 1;
1935 }
1936
1937 #include "gt-targhooks.h"