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 /* Make some target macros useable by target-independent code.  */
 428 bool
 429 targhook_words_big_endian (void)
 430 {
 431   return !!WORDS_BIG_ENDIAN;
 432 }
 433
 434 bool
 435 targhook_float_words_big_endian (void)
 436 {
 437   return !!FLOAT_WORDS_BIG_ENDIAN;
 438 }
 439
 440 /* True if the target supports floating-point exceptions and rounding
 441    modes.  */
 442
 443 bool
 444 default_float_exceptions_rounding_supported_p (void)
 445 {
 446 #ifdef HAVE_adddf3
 447   return HAVE_adddf3;
 448 #else
 449   return false;
 450 #endif
 451 }
 452
 453 /* True if the target supports decimal floating point.  */
 454
 455 bool
 456 default_decimal_float_supported_p (void)
 457 {
 458   return ENABLE_DECIMAL_FLOAT;
 459 }
 460
 461 /* True if the target supports fixed-point arithmetic.  */
 462
 463 bool
 464 default_fixed_point_supported_p (void)
 465 {
 466   return ENABLE_FIXED_POINT;
 467 }
 468
 469 /* True if the target supports GNU indirect functions.  */
 470
 471 bool
 472 default_has_ifunc_p (void)
 473 {
 474   return HAVE_GNU_INDIRECT_FUNCTION;
 475 }
 476
 477 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 478    an error message.
 479
 480    This function checks whether a given INSN is valid within a low-overhead
 481    loop.  If INSN is invalid it returns the reason for that, otherwise it
 482    returns NULL. A called function may clobber any special registers required
 483    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 484    register for branch on table instructions. We reject the doloop pattern in
 485    these cases.  */
 486
 487 const char *
 488 default_invalid_within_doloop (const_rtx insn)
 489 {
 490   if (CALL_P (insn))
 491     return "Function call in loop.";
 492
 493   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 494     return "Computed branch in the loop.";
 495
 496   return NULL;
 497 }
 498
 499 /* Mapping of builtin functions to vectorized variants.  */
 500
 501 tree
 502 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 503                                      tree type_out ATTRIBUTE_UNUSED,
 504                                      tree type_in ATTRIBUTE_UNUSED)
 505 {
 506   return NULL_TREE;
 507 }
 508
 509 /* Vectorized conversion.  */
 510
 511 tree
 512 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 513                                        tree dest_type ATTRIBUTE_UNUSED,
 514                                        tree src_type ATTRIBUTE_UNUSED)
 515 {
 516   return NULL_TREE;
 517 }
 518
 519 /* Default vectorizer cost model values.  */
 520
 521 int
 522 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 523                                     tree vectype,
 524                                     int misalign ATTRIBUTE_UNUSED)
 525 {
 526   unsigned elements;
 527
 528   switch (type_of_cost)
 529     {
 530       case scalar_stmt:
 531       case scalar_load:
 532       case scalar_store:
 533       case vector_stmt:
 534       case vector_load:
 535       case vector_store:
 536       case vec_to_scalar:
 537       case scalar_to_vec:
 538       case cond_branch_not_taken:
 539       case vec_perm:
 540       case vec_promote_demote:
 541         return 1;
 542
 543       case unaligned_load:
 544       case unaligned_store:
 545         return 2;
 546
 547       case cond_branch_taken:
 548         return 3;
 549
 550       case vec_construct:
 551         elements = TYPE_VECTOR_SUBPARTS (vectype);
 552         return elements / 2 + 1;
 553
 554       default:
 555         gcc_unreachable ();
 556     }
 557 }
 558
 559 /* Reciprocal.  */
 560
 561 tree
 562 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 563                             bool md_fn ATTRIBUTE_UNUSED,
 564                             bool sqrt ATTRIBUTE_UNUSED)
 565 {
 566   return NULL_TREE;
 567 }
 568
 569 bool
 570 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 571         cumulative_args_t ca ATTRIBUTE_UNUSED,
 572         enum machine_mode mode ATTRIBUTE_UNUSED,
 573         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 574 {
 575   return false;
 576 }
 577
 578 bool
 579 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 580         cumulative_args_t ca ATTRIBUTE_UNUSED,
 581         enum machine_mode mode ATTRIBUTE_UNUSED,
 582         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 583 {
 584   return true;
 585 }
 586
 587 int
 588 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 589         cumulative_args_t ca ATTRIBUTE_UNUSED,
 590         enum machine_mode mode ATTRIBUTE_UNUSED,
 591         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 592 {
 593   return 0;
 594 }
 595
 596 void
 597 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 598                               enum machine_mode mode ATTRIBUTE_UNUSED,
 599                               const_tree type ATTRIBUTE_UNUSED,
 600                               bool named ATTRIBUTE_UNUSED)
 601 {
 602   gcc_unreachable ();
 603 }
 604
 605 rtx
 606 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 607                       enum machine_mode mode ATTRIBUTE_UNUSED,
 608                       const_tree type ATTRIBUTE_UNUSED,
 609                       bool named ATTRIBUTE_UNUSED)
 610 {
 611   gcc_unreachable ();
 612 }
 613
 614 rtx
 615 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 616                                enum machine_mode mode ATTRIBUTE_UNUSED,
 617                                const_tree type ATTRIBUTE_UNUSED,
 618                                bool named ATTRIBUTE_UNUSED)
 619 {
 620   gcc_unreachable ();
 621 }
 622
 623 unsigned int
 624 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 625                                const_tree type ATTRIBUTE_UNUSED)
 626 {
 627   return PARM_BOUNDARY;
 628 }
 629
 630 unsigned int
 631 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 632                                      const_tree type ATTRIBUTE_UNUSED)
 633 {
 634   return PARM_BOUNDARY;
 635 }
 636
 637 void
 638 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 639 {
 640 }
 641
 642 const char *
 643 hook_invalid_arg_for_unprototyped_fn (
 644         const_tree typelist ATTRIBUTE_UNUSED,
 645         const_tree funcdecl ATTRIBUTE_UNUSED,
 646         const_tree val ATTRIBUTE_UNUSED)
 647 {
 648   return NULL;
 649 }
 650
 651 /* Initialize the stack protection decls.  */
 652
 653 /* Stack protection related decls living in libgcc.  */
 654 static GTY(()) tree stack_chk_guard_decl;
 655
 656 tree
 657 default_stack_protect_guard (void)
 658 {
 659   tree t = stack_chk_guard_decl;
 660
 661   if (t == NULL)
 662     {
 663       rtx x;
 664
 665       t = build_decl (UNKNOWN_LOCATION,
 666                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 667                       ptr_type_node);
 668       TREE_STATIC (t) = 1;
 669       TREE_PUBLIC (t) = 1;
 670       DECL_EXTERNAL (t) = 1;
 671       TREE_USED (t) = 1;
 672       TREE_THIS_VOLATILE (t) = 1;
 673       DECL_ARTIFICIAL (t) = 1;
 674       DECL_IGNORED_P (t) = 1;
 675
 676       /* Do not share RTL as the declaration is visible outside of
 677          current function.  */
 678       x = DECL_RTL (t);
 679       RTX_FLAG (x, used) = 1;
 680
 681       stack_chk_guard_decl = t;
 682     }
 683
 684   return t;
 685 }
 686
 687 static GTY(()) tree stack_chk_fail_decl;
 688
 689 tree
 690 default_external_stack_protect_fail (void)
 691 {
 692   tree t = stack_chk_fail_decl;
 693
 694   if (t == NULL_TREE)
 695     {
 696       t = build_function_type_list (void_type_node, NULL_TREE);
 697       t = build_decl (UNKNOWN_LOCATION,
 698                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 699       TREE_STATIC (t) = 1;
 700       TREE_PUBLIC (t) = 1;
 701       DECL_EXTERNAL (t) = 1;
 702       TREE_USED (t) = 1;
 703       TREE_THIS_VOLATILE (t) = 1;
 704       TREE_NOTHROW (t) = 1;
 705       DECL_ARTIFICIAL (t) = 1;
 706       DECL_IGNORED_P (t) = 1;
 707       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 708       DECL_VISIBILITY_SPECIFIED (t) = 1;
 709
 710       stack_chk_fail_decl = t;
 711     }
 712
 713   return build_call_expr (t, 0);
 714 }
 715
 716 tree
 717 default_hidden_stack_protect_fail (void)
 718 {
 719 #ifndef HAVE_GAS_HIDDEN
 720   return default_external_stack_protect_fail ();
 721 #else
 722   tree t = stack_chk_fail_decl;
 723
 724   if (!flag_pic)
 725     return default_external_stack_protect_fail ();
 726
 727   if (t == NULL_TREE)
 728     {
 729       t = build_function_type_list (void_type_node, NULL_TREE);
 730       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 731                       get_identifier ("__stack_chk_fail_local"), t);
 732       TREE_STATIC (t) = 1;
 733       TREE_PUBLIC (t) = 1;
 734       DECL_EXTERNAL (t) = 1;
 735       TREE_USED (t) = 1;
 736       TREE_THIS_VOLATILE (t) = 1;
 737       TREE_NOTHROW (t) = 1;
 738       DECL_ARTIFICIAL (t) = 1;
 739       DECL_IGNORED_P (t) = 1;
 740       DECL_VISIBILITY_SPECIFIED (t) = 1;
 741       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 742
 743       stack_chk_fail_decl = t;
 744     }
 745
 746   return build_call_expr (t, 0);
 747 #endif
 748 }
 749
 750 bool
 751 hook_bool_const_rtx_commutative_p (const_rtx x,
 752                                    int outer_code ATTRIBUTE_UNUSED)
 753 {
 754   return COMMUTATIVE_P (x);
 755 }
 756
 757 rtx
 758 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 759                         const_tree fn_decl_or_type,
 760                         bool outgoing ATTRIBUTE_UNUSED)
 761 {
 762   /* The old interface doesn't handle receiving the function type.  */
 763   if (fn_decl_or_type
 764       && !DECL_P (fn_decl_or_type))
 765     fn_decl_or_type = NULL;
 766
 767 #ifdef FUNCTION_VALUE
 768   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 769 #else
 770   gcc_unreachable ();
 771 #endif
 772 }
 773
 774 rtx
 775 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 776                        const_rtx fun ATTRIBUTE_UNUSED)
 777 {
 778 #ifdef LIBCALL_VALUE
 779   return LIBCALL_VALUE (mode);
 780 #else
 781   gcc_unreachable ();
 782 #endif
 783 }
 784
 785 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 786
 787 bool
 788 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 789 {
 790 #ifdef FUNCTION_VALUE_REGNO_P
 791   return FUNCTION_VALUE_REGNO_P (regno);
 792 #else
 793   gcc_unreachable ();
 794 #endif
 795 }
 796
 797 rtx
 798 default_internal_arg_pointer (void)
 799 {
 800   /* If the reg that the virtual arg pointer will be translated into is
 801      not a fixed reg or is the stack pointer, make a copy of the virtual
 802      arg pointer, and address parms via the copy.  The frame pointer is
 803      considered fixed even though it is not marked as such.  */
 804   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 805        || ! (fixed_regs[ARG_POINTER_REGNUM]
 806              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 807     return copy_to_reg (virtual_incoming_args_rtx);
 808   else
 809     return virtual_incoming_args_rtx;
 810 }
 811
 812 rtx
 813 default_static_chain (const_tree fndecl, bool incoming_p)
 814 {
 815   if (!DECL_STATIC_CHAIN (fndecl))
 816     return NULL;
 817
 818   if (incoming_p)
 819     {
 820 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 821       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 822 #endif
 823     }
 824
 825 #ifdef STATIC_CHAIN_REGNUM
 826   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 827 #endif
 828
 829   {
 830     static bool issued_error;
 831     if (!issued_error)
 832       {
 833         issued_error = true;
 834         sorry ("nested functions not supported on this target");
 835       }
 836
 837     /* It really doesn't matter what we return here, so long at it
 838        doesn't cause the rest of the compiler to crash.  */
 839     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 840   }
 841 }
 842
 843 void
 844 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 845                          rtx ARG_UNUSED (r_chain))
 846 {
 847   sorry ("nested function trampolines not supported on this target");
 848 }
 849
 850 int
 851 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 852                           tree funtype ATTRIBUTE_UNUSED,
 853                           int size ATTRIBUTE_UNUSED)
 854 {
 855   return 0;
 856 }
 857
 858 reg_class_t
 859 default_branch_target_register_class (void)
 860 {
 861   return NO_REGS;
 862 }
 863
 864 extern bool
 865 default_lra_p (void)
 866 {
 867   return false;
 868 }
 869
 870 int
 871 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 872 {
 873   return 0;
 874 }
 875
 876 extern bool
 877 default_register_usage_leveling_p (void)
 878 {
 879   return false;
 880 }
 881
 882 extern bool
 883 default_different_addr_displacement_p (void)
 884 {
 885   return false;
 886 }
 887
 888 reg_class_t
 889 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 890                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 891                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 892                           secondary_reload_info *sri)
 893 {
 894   enum reg_class rclass = NO_REGS;
 895   enum reg_class reload_class = (enum reg_class) reload_class_i;
 896
 897   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 898     {
 899       sri->icode = sri->prev_sri->t_icode;
 900       return NO_REGS;
 901     }
 902 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 903   if (in_p)
 904     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 905 #endif
 906 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 907   if (! in_p)
 908     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 909 #endif
 910   if (rclass != NO_REGS)
 911     {
 912       enum insn_code icode
 913         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 914                                 reload_mode);
 915
 916       if (icode != CODE_FOR_nothing
 917           && !insn_operand_matches (icode, in_p, x))
 918         icode = CODE_FOR_nothing;
 919       else if (icode != CODE_FOR_nothing)
 920         {
 921           const char *insn_constraint, *scratch_constraint;
 922           enum reg_class insn_class, scratch_class;
 923
 924           gcc_assert (insn_data[(int) icode].n_operands == 3);
 925           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 926           if (!*insn_constraint)
 927             insn_class = ALL_REGS;
 928           else
 929             {
 930               if (in_p)
 931                 {
 932                   gcc_assert (*insn_constraint == '=');
 933                   insn_constraint++;
 934                 }
 935               insn_class = (reg_class_for_constraint
 936                             (lookup_constraint (insn_constraint)));
 937               gcc_assert (insn_class != NO_REGS);
 938             }
 939
 940           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 941           /* The scratch register's constraint must start with "=&",
 942              except for an input reload, where only "=" is necessary,
 943              and where it might be beneficial to re-use registers from
 944              the input.  */
 945           gcc_assert (scratch_constraint[0] == '='
 946                       && (in_p || scratch_constraint[1] == '&'));
 947           scratch_constraint++;
 948           if (*scratch_constraint == '&')
 949             scratch_constraint++;
 950           scratch_class = (reg_class_for_constraint
 951                            (lookup_constraint (scratch_constraint)));
 952
 953           if (reg_class_subset_p (reload_class, insn_class))
 954             {
 955               gcc_assert (scratch_class == rclass);
 956               rclass = NO_REGS;
 957             }
 958           else
 959             rclass = insn_class;
 960
 961         }
 962       if (rclass == NO_REGS)
 963         sri->icode = icode;
 964       else
 965         sri->t_icode = icode;
 966     }
 967   return rclass;
 968 }
 969
 970 /* By default, if flag_pic is true, then neither local nor global relocs
 971    should be placed in readonly memory.  */
 972
 973 int
 974 default_reloc_rw_mask (void)
 975 {
 976   return flag_pic ? 3 : 0;
 977 }
 978
 979 /* By default, do no modification. */
 980 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 981                                          tree id)
 982 {
 983    return id;
 984 }
 985
 986 /* Default to natural alignment for vector types.  */
 987 HOST_WIDE_INT
 988 default_vector_alignment (const_tree type)
 989 {
 990   return tree_to_shwi (TYPE_SIZE (type));
 991 }
 992
 993 bool
 994 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 995 {
 996   if (is_packed)
 997     return false;
 998
 999   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1000      naturally aligned.  */
1001   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1002     return false;
1003
1004   /* Assuming that types whose size is <= pointer-size
1005      are naturally aligned.  */
1006   return true;
1007 }
1008
1009 /* By default, assume that a target supports any factor of misalignment
1010    memory access if it supports movmisalign patten.
1011    is_packed is true if the memory access is defined in a packed struct.  */
1012 bool
1013 default_builtin_support_vector_misalignment (enum machine_mode mode,
1014                                              const_tree type
1015                                              ATTRIBUTE_UNUSED,
1016                                              int misalignment
1017                                              ATTRIBUTE_UNUSED,
1018                                              bool is_packed
1019                                              ATTRIBUTE_UNUSED)
1020 {
1021   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1022     return true;
1023   return false;
1024 }
1025
1026 /* By default, only attempt to parallelize bitwise operations, and
1027    possibly adds/subtracts using bit-twiddling.  */
1028
1029 enum machine_mode
1030 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1031 {
1032   return word_mode;
1033 }
1034
1035 /* By default only the size derived from the preferred vector mode
1036    is tried.  */
1037
1038 unsigned int
1039 default_autovectorize_vector_sizes (void)
1040 {
1041   return 0;
1042 }
1043
1044 /* By default, the cost model accumulates three separate costs (prologue,
1045    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1046    array of three unsigned ints, set it to zero, and return its address.  */
1047
1048 void *
1049 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1050 {
1051   unsigned *cost = XNEWVEC (unsigned, 3);
1052   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1053   return cost;
1054 }
1055
1056 /* By default, the cost model looks up the cost of the given statement
1057    kind and mode, multiplies it by the occurrence count, accumulates
1058    it into the cost specified by WHERE, and returns the cost added.  */
1059
1060 unsigned
1061 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1062                        struct _stmt_vec_info *stmt_info, int misalign,
1063                        enum vect_cost_model_location where)
1064 {
1065   unsigned *cost = (unsigned *) data;
1066   unsigned retval = 0;
1067
1068   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1069   int stmt_cost = targetm.vectorize.builtin_vectorization_cost (kind, vectype,
1070                                                                 misalign);
1071    /* Statements in an inner loop relative to the loop being
1072       vectorized are weighted more heavily.  The value here is
1073       arbitrary and could potentially be improved with analysis.  */
1074   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1075     count *= 50;  /* FIXME.  */
1076
1077   retval = (unsigned) (count * stmt_cost);
1078   cost[where] += retval;
1079
1080   return retval;
1081 }
1082
1083 /* By default, the cost model just returns the accumulated costs.  */
1084
1085 void
1086 default_finish_cost (void *data, unsigned *prologue_cost,
1087                      unsigned *body_cost, unsigned *epilogue_cost)
1088 {
1089   unsigned *cost = (unsigned *) data;
1090   *prologue_cost = cost[vect_prologue];
1091   *body_cost     = cost[vect_body];
1092   *epilogue_cost = cost[vect_epilogue];
1093 }
1094
1095 /* Free the cost data.  */
1096
1097 void
1098 default_destroy_cost_data (void *data)
1099 {
1100   free (data);
1101 }
1102
1103 /* Determine whether or not a pointer mode is valid. Assume defaults
1104    of ptr_mode or Pmode - can be overridden.  */
1105 bool
1106 default_valid_pointer_mode (enum machine_mode mode)
1107 {
1108   return (mode == ptr_mode || mode == Pmode);
1109 }
1110
1111 /* Determine whether the memory reference specified by REF may alias
1112    the C libraries errno location.  */
1113 bool
1114 default_ref_may_alias_errno (ao_ref *ref)
1115 {
1116   tree base = ao_ref_base (ref);
1117   /* The default implementation assumes the errno location is
1118      a declaration of type int or is always accessed via a
1119      pointer to int.  We assume that accesses to errno are
1120      not deliberately obfuscated (even in conforming ways).  */
1121   if (TYPE_UNSIGNED (TREE_TYPE (base))
1122       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1123     return false;
1124   /* The default implementation assumes an errno location
1125      declaration is never defined in the current compilation unit.  */
1126   if (DECL_P (base)
1127       && !TREE_STATIC (base))
1128     return true;
1129   else if (TREE_CODE (base) == MEM_REF
1130            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1131     {
1132       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1133       return !pi || pi->pt.anything || pi->pt.nonlocal;
1134     }
1135   return false;
1136 }
1137
1138 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1139    for the generic address space only.  */
1140
1141 enum machine_mode
1142 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1143 {
1144   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1145   return ptr_mode;
1146 }
1147
1148 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1149    for the generic address space only.  */
1150
1151 enum machine_mode
1152 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1153 {
1154   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1155   return Pmode;
1156 }
1157
1158 /* Named address space version of valid_pointer_mode.  */
1159
1160 bool
1161 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1162 {
1163   if (!ADDR_SPACE_GENERIC_P (as))
1164     return (mode == targetm.addr_space.pointer_mode (as)
1165             || mode == targetm.addr_space.address_mode (as));
1166
1167   return targetm.valid_pointer_mode (mode);
1168 }
1169
1170 /* Some places still assume that all pointer or address modes are the
1171    standard Pmode and ptr_mode.  These optimizations become invalid if
1172    the target actually supports multiple different modes.  For now,
1173    we disable such optimizations on such targets, using this function.  */
1174
1175 bool
1176 target_default_pointer_address_modes_p (void)
1177 {
1178   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1179     return false;
1180   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1181     return false;
1182
1183   return true;
1184 }
1185
1186 /* Named address space version of legitimate_address_p.  */
1187
1188 bool
1189 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1190                                          bool strict, addr_space_t as)
1191 {
1192   if (!ADDR_SPACE_GENERIC_P (as))
1193     gcc_unreachable ();
1194
1195   return targetm.legitimate_address_p (mode, mem, strict);
1196 }
1197
1198 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1199
1200 rtx
1201 default_addr_space_legitimize_address (rtx x, rtx oldx,
1202                                        enum machine_mode mode, addr_space_t as)
1203 {
1204   if (!ADDR_SPACE_GENERIC_P (as))
1205     return x;
1206
1207   return targetm.legitimize_address (x, oldx, mode);
1208 }
1209
1210 /* The default hook for determining if one named address space is a subset of
1211    another and to return which address space to use as the common address
1212    space.  */
1213
1214 bool
1215 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1216 {
1217   return (subset == superset);
1218 }
1219
1220 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1221    called for targets with only a generic address space.  */
1222
1223 rtx
1224 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1225                             tree from_type ATTRIBUTE_UNUSED,
1226                             tree to_type ATTRIBUTE_UNUSED)
1227 {
1228   gcc_unreachable ();
1229 }
1230
1231 bool
1232 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1233 {
1234   return true;
1235 }
1236
1237 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1238
1239 bool
1240 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1241                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1242 {
1243   return false;
1244 }
1245
1246 bool
1247 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1248                                          tree ARG_UNUSED (name),
1249                                          tree ARG_UNUSED (args),
1250                                          int ARG_UNUSED (flags))
1251 {
1252   warning (OPT_Wattributes,
1253            "target attribute is not supported on this machine");
1254
1255   return false;
1256 }
1257
1258 bool
1259 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1260                                     tree ARG_UNUSED (pop_target))
1261 {
1262   warning (OPT_Wpragmas,
1263            "#pragma GCC target is not supported for this machine");
1264
1265   return false;
1266 }
1267
1268 bool
1269 default_target_can_inline_p (tree caller, tree callee)
1270 {
1271   bool ret = false;
1272   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1273   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1274
1275   /* If callee has no option attributes, then it is ok to inline */
1276   if (!callee_opts)
1277     ret = true;
1278
1279   /* If caller has no option attributes, but callee does then it is not ok to
1280      inline */
1281   else if (!caller_opts)
1282     ret = false;
1283
1284   /* If both caller and callee have attributes, assume that if the
1285      pointer is different, the two functions have different target
1286      options since build_target_option_node uses a hash table for the
1287      options.  */
1288   else
1289     ret = (callee_opts == caller_opts);
1290
1291   return ret;
1292 }
1293
1294 #ifndef HAVE_casesi
1295 # define HAVE_casesi 0
1296 #endif
1297
1298 /* If the machine does not have a case insn that compares the bounds,
1299    this means extra overhead for dispatch tables, which raises the
1300    threshold for using them.  */
1301
1302 unsigned int
1303 default_case_values_threshold (void)
1304 {
1305   return (HAVE_casesi ? 4 : 5);
1306 }
1307
1308 bool
1309 default_have_conditional_execution (void)
1310 {
1311 #ifdef HAVE_conditional_execution
1312   return HAVE_conditional_execution;
1313 #else
1314   return false;
1315 #endif
1316 }
1317
1318 /* By default we assume that c99 functions are present at the runtime,
1319    but sincos is not.  */
1320 bool
1321 default_libc_has_function (enum function_class fn_class)
1322 {
1323   if (fn_class == function_c94
1324       || fn_class == function_c99_misc
1325       || fn_class == function_c99_math_complex)
1326     return true;
1327
1328   return false;
1329 }
1330
1331 bool
1332 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1333 {
1334   return true;
1335 }
1336
1337 bool
1338 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1339 {
1340   return false;
1341 }
1342
1343 tree
1344 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1345 {
1346   return NULL_TREE;
1347 }
1348
1349 /* Compute cost of moving registers to/from memory.  */
1350
1351 int
1352 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1353                           reg_class_t rclass ATTRIBUTE_UNUSED,
1354                           bool in ATTRIBUTE_UNUSED)
1355 {
1356 #ifndef MEMORY_MOVE_COST
1357     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1358 #else
1359     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1360 #endif
1361 }
1362
1363 /* Compute cost of moving data from a register of class FROM to one of
1364    TO, using MODE.  */
1365
1366 int
1367 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1368                             reg_class_t from ATTRIBUTE_UNUSED,
1369                             reg_class_t to ATTRIBUTE_UNUSED)
1370 {
1371 #ifndef REGISTER_MOVE_COST
1372   return 2;
1373 #else
1374   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1375 #endif
1376 }
1377
1378 bool
1379 default_profile_before_prologue (void)
1380 {
1381 #ifdef PROFILE_BEFORE_PROLOGUE
1382   return true;
1383 #else
1384   return false;
1385 #endif
1386 }
1387
1388 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1389
1390 reg_class_t
1391 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1392                                 reg_class_t rclass)
1393 {
1394 #ifdef PREFERRED_RELOAD_CLASS
1395   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1396 #else
1397   return rclass;
1398 #endif
1399 }
1400
1401 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1402
1403 reg_class_t
1404 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1405                                        reg_class_t rclass)
1406 {
1407   return rclass;
1408 }
1409
1410 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1411 reg_class_t
1412 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1413 {
1414   return NO_REGS;
1415 }
1416
1417 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1418
1419 bool
1420 default_class_likely_spilled_p (reg_class_t rclass)
1421 {
1422   return (reg_class_size[(int) rclass] == 1);
1423 }
1424
1425 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1426
1427 unsigned char
1428 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1429                          enum machine_mode mode ATTRIBUTE_UNUSED)
1430 {
1431 #ifdef CLASS_MAX_NREGS
1432   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1433 #else
1434   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1435 #endif
1436 }
1437
1438 /* Determine the debugging unwind mechanism for the target.  */
1439
1440 enum unwind_info_type
1441 default_debug_unwind_info (void)
1442 {
1443   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1444   /* ??? Change all users to the hook, then poison this.  */
1445 #ifdef DWARF2_FRAME_INFO
1446   if (DWARF2_FRAME_INFO)
1447     return UI_DWARF2;
1448 #endif
1449
1450   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1451 #ifdef DWARF2_DEBUGGING_INFO
1452   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1453     return UI_DWARF2;
1454 #endif
1455
1456   return UI_NONE;
1457 }
1458
1459 /* To be used by targets where reg_raw_mode doesn't return the right
1460    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1461
1462 enum machine_mode
1463 default_get_reg_raw_mode (int regno)
1464 {
1465   return reg_raw_mode[regno];
1466 }
1467
1468 /* Return true if a leaf function should stay leaf even with profiling
1469    enabled.  */
1470
1471 bool
1472 default_keep_leaf_when_profiled ()
1473 {
1474   return false;
1475 }
1476
1477 /* Return true if the state of option OPTION should be stored in PCH files
1478    and checked by default_pch_valid_p.  Store the option's current state
1479    in STATE if so.  */
1480
1481 static inline bool
1482 option_affects_pch_p (int option, struct cl_option_state *state)
1483 {
1484   if ((cl_options[option].flags & CL_TARGET) == 0)
1485     return false;
1486   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1487     return false;
1488   if (option_flag_var (option, &global_options) == &target_flags)
1489     if (targetm.check_pch_target_flags)
1490       return false;
1491   return get_option_state (&global_options, option, state);
1492 }
1493
1494 /* Default version of get_pch_validity.
1495    By default, every flag difference is fatal; that will be mostly right for
1496    most targets, but completely right for very few.  */
1497
1498 void *
1499 default_get_pch_validity (size_t *sz)
1500 {
1501   struct cl_option_state state;
1502   size_t i;
1503   char *result, *r;
1504
1505   *sz = 2;
1506   if (targetm.check_pch_target_flags)
1507     *sz += sizeof (target_flags);
1508   for (i = 0; i < cl_options_count; i++)
1509     if (option_affects_pch_p (i, &state))
1510       *sz += state.size;
1511
1512   result = r = XNEWVEC (char, *sz);
1513   r[0] = flag_pic;
1514   r[1] = flag_pie;
1515   r += 2;
1516   if (targetm.check_pch_target_flags)
1517     {
1518       memcpy (r, &target_flags, sizeof (target_flags));
1519       r += sizeof (target_flags);
1520     }
1521
1522   for (i = 0; i < cl_options_count; i++)
1523     if (option_affects_pch_p (i, &state))
1524       {
1525         memcpy (r, state.data, state.size);
1526         r += state.size;
1527       }
1528
1529   return result;
1530 }
1531
1532 /* Return a message which says that a PCH file was created with a different
1533    setting of OPTION.  */
1534
1535 static const char *
1536 pch_option_mismatch (const char *option)
1537 {
1538   char *r;
1539
1540   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1541   if (r == NULL)
1542     return _("out of memory");
1543   return r;
1544 }
1545
1546 /* Default version of pch_valid_p.  */
1547
1548 const char *
1549 default_pch_valid_p (const void *data_p, size_t len)
1550 {
1551   struct cl_option_state state;
1552   const char *data = (const char *)data_p;
1553   size_t i;
1554
1555   /* -fpic and -fpie also usually make a PCH invalid.  */
1556   if (data[0] != flag_pic)
1557     return _("created and used with different settings of -fpic");
1558   if (data[1] != flag_pie)
1559     return _("created and used with different settings of -fpie");
1560   data += 2;
1561
1562   /* Check target_flags.  */
1563   if (targetm.check_pch_target_flags)
1564     {
1565       int tf;
1566       const char *r;
1567
1568       memcpy (&tf, data, sizeof (target_flags));
1569       data += sizeof (target_flags);
1570       len -= sizeof (target_flags);
1571       r = targetm.check_pch_target_flags (tf);
1572       if (r != NULL)
1573         return r;
1574     }
1575
1576   for (i = 0; i < cl_options_count; i++)
1577     if (option_affects_pch_p (i, &state))
1578       {
1579         if (memcmp (data, state.data, state.size) != 0)
1580           return pch_option_mismatch (cl_options[i].opt_text);
1581         data += state.size;
1582         len -= state.size;
1583       }
1584
1585   return NULL;
1586 }
1587
1588 /* Default version of cstore_mode.  */
1589
1590 enum machine_mode
1591 default_cstore_mode (enum insn_code icode)
1592 {
1593   return insn_data[(int) icode].operand[0].mode;
1594 }
1595
1596 /* Default version of member_type_forces_blk.  */
1597
1598 bool
1599 default_member_type_forces_blk (const_tree, enum machine_mode)
1600 {
1601   return false;
1602 }
1603
1604 /* Default version of canonicalize_comparison.  */
1605
1606 void
1607 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1608 {
1609 }
1610
1611 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1612
1613 void
1614 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1615 {
1616 }
1617
1618 #ifndef PAD_VARARGS_DOWN
1619 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1620 #endif
1621
1622 /* Build an indirect-ref expression over the given TREE, which represents a
1623    piece of a va_arg() expansion.  */
1624 tree
1625 build_va_arg_indirect_ref (tree addr)
1626 {
1627   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1628   return addr;
1629 }
1630
1631 /* The "standard" implementation of va_arg: read the value from the
1632    current (padded) address and increment by the (padded) size.  */
1633
1634 tree
1635 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1636                           gimple_seq *post_p)
1637 {
1638   tree addr, t, type_size, rounded_size, valist_tmp;
1639   unsigned HOST_WIDE_INT align, boundary;
1640   bool indirect;
1641
1642 #ifdef ARGS_GROW_DOWNWARD
1643   /* All of the alignment and movement below is for args-grow-up machines.
1644      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1645      implement their own specialized gimplify_va_arg_expr routines.  */
1646   gcc_unreachable ();
1647 #endif
1648
1649   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1650   if (indirect)
1651     type = build_pointer_type (type);
1652
1653   align = PARM_BOUNDARY / BITS_PER_UNIT;
1654   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1655
1656   /* When we align parameter on stack for caller, if the parameter
1657      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1658      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1659      here with caller.  */
1660   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1661     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1662
1663   boundary /= BITS_PER_UNIT;
1664
1665   /* Hoist the valist value into a temporary for the moment.  */
1666   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1667
1668   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1669      requires greater alignment, we must perform dynamic alignment.  */
1670   if (boundary > align
1671       && !integer_zerop (TYPE_SIZE (type)))
1672     {
1673       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1674                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1675       gimplify_and_add (t, pre_p);
1676
1677       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1678                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1679                                valist_tmp,
1680                                build_int_cst (TREE_TYPE (valist), -boundary)));
1681       gimplify_and_add (t, pre_p);
1682     }
1683   else
1684     boundary = align;
1685
1686   /* If the actual alignment is less than the alignment of the type,
1687      adjust the type accordingly so that we don't assume strict alignment
1688      when dereferencing the pointer.  */
1689   boundary *= BITS_PER_UNIT;
1690   if (boundary < TYPE_ALIGN (type))
1691     {
1692       type = build_variant_type_copy (type);
1693       TYPE_ALIGN (type) = boundary;
1694     }
1695
1696   /* Compute the rounded size of the type.  */
1697   type_size = size_in_bytes (type);
1698   rounded_size = round_up (type_size, align);
1699
1700   /* Reduce rounded_size so it's sharable with the postqueue.  */
1701   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1702
1703   /* Get AP.  */
1704   addr = valist_tmp;
1705   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1706     {
1707       /* Small args are padded downward.  */
1708       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1709                        rounded_size, size_int (align));
1710       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1711                        size_binop (MINUS_EXPR, rounded_size, type_size));
1712       addr = fold_build_pointer_plus (addr, t);
1713     }
1714
1715   /* Compute new value for AP.  */
1716   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1717   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1718   gimplify_and_add (t, pre_p);
1719
1720   addr = fold_convert (build_pointer_type (type), addr);
1721
1722   if (indirect)
1723     addr = build_va_arg_indirect_ref (addr);
1724
1725   return build_va_arg_indirect_ref (addr);
1726 }
1727
1728 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1729    not support nested low-overhead loops.  */
1730
1731 bool
1732 can_use_doloop_if_innermost (const widest_int &, const widest_int &,
1733                              unsigned int loop_depth, bool)
1734 {
1735   return loop_depth == 1;
1736 }
1737
1738 #include "gt-targhooks.h"