gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* The migration of target macros to target hooks works as follows:
  22
  23    1. Create a target hook that uses the existing target macros to
  24       implement the same functionality.
  25
  26    2. Convert all the MI files to use the hook instead of the macro.
  27
  28    3. Repeat for a majority of the remaining target macros.  This will
  29       take some time.
  30
  31    4. Tell target maintainers to start migrating.
  32
  33    5. Eventually convert the backends to override the hook instead of
  34       defining the macros.  This will take some time too.
  35
  36    6. TBD when, poison the macros.  Unmigrated targets will break at
  37       this point.
  38
  39    Note that we expect steps 1-3 to be done by the people that
  40    understand what the MI does with each macro, and step 5 to be done
  41    by the target maintainers for their respective targets.
  42
  43    Note that steps 1 and 2 don't have to be done together, but no
  44    target can override the new hook until step 2 is complete for it.
  45
  46    Once the macros are poisoned, we will revert to the old migration
  47    rules - migrate the macro, callers, and targets all at once.  This
  48    comment can thus be removed at that point.  */
  49
  50 #include "config.h"
  51 #include "system.h"
  52 #include "coretypes.h"
  53 #include "tm.h"
  54 #include "machmode.h"
  55 #include "rtl.h"
  56 #include "tree.h"
  57 #include "expr.h"
  58 #include "output.h"
  59 #include "diagnostic-core.h"
  60 #include "toplev.h"
  61 #include "function.h"
  62 #include "target.h"
  63 #include "tm_p.h"
  64 #include "target-def.h"
  65 #include "ggc.h"
  66 #include "hard-reg-set.h"
  67 #include "reload.h"
  68 #include "optabs.h"
  69 #include "recog.h"
  70
  71
  72 bool
  73 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  74                               rtx addr ATTRIBUTE_UNUSED,
  75                               bool strict ATTRIBUTE_UNUSED)
  76 {
  77 #ifdef GO_IF_LEGITIMATE_ADDRESS
  78   /* Defer to the old implementation using a goto.  */
  79   if (strict)
  80     return strict_memory_address_p (mode, addr);
  81   else
  82     return memory_address_p (mode, addr);
  83 #else
  84   gcc_unreachable ();
  85 #endif
  86 }
  87
  88 void
  89 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  90 {
  91 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  92   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  93 #endif
  94 }
  95
  96 int
  97 default_unspec_may_trap_p (const_rtx x, unsigned flags)
  98 {
  99   int i;
 100
 101   if (GET_CODE (x) == UNSPEC_VOLATILE
 102       /* Any floating arithmetic may trap.  */
 103       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
 104           && flag_trapping_math))
 105     return 1;
 106
 107   for (i = 0; i < XVECLEN (x, 0); ++i)
 108     {
 109       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 110         return 1;
 111     }
 112
 113   return 0;
 114 }
 115
 116 enum machine_mode
 117 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 118                                enum machine_mode mode,
 119                                int *punsignedp ATTRIBUTE_UNUSED,
 120                                const_tree funtype ATTRIBUTE_UNUSED,
 121                                int for_return ATTRIBUTE_UNUSED)
 122 {
 123   if (for_return == 2)
 124     return promote_mode (type, mode, punsignedp);
 125   return mode;
 126 }
 127
 128 enum machine_mode
 129 default_promote_function_mode_always_promote (const_tree type,
 130                                               enum machine_mode mode,
 131                                               int *punsignedp,
 132                                               const_tree funtype ATTRIBUTE_UNUSED,
 133                                               int for_return ATTRIBUTE_UNUSED)
 134 {
 135   return promote_mode (type, mode, punsignedp);
 136 }
 137
 138
 139 enum machine_mode
 140 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 141 {
 142   if (m1 == m2)
 143     return m1;
 144   return VOIDmode;
 145 }
 146
 147 bool
 148 default_return_in_memory (const_tree type,
 149                           const_tree fntype ATTRIBUTE_UNUSED)
 150 {
 151   return (TYPE_MODE (type) == BLKmode);
 152 }
 153
 154 rtx
 155 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 156                             enum machine_mode mode ATTRIBUTE_UNUSED)
 157 {
 158   return x;
 159 }
 160
 161 rtx
 162 default_expand_builtin_saveregs (void)
 163 {
 164   error ("__builtin_saveregs not supported by this target");
 165   return const0_rtx;
 166 }
 167
 168 void
 169 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 170                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 171                                 tree type ATTRIBUTE_UNUSED,
 172                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 173                                 int second_time ATTRIBUTE_UNUSED)
 174 {
 175 }
 176
 177 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 178
 179 rtx
 180 default_builtin_setjmp_frame_value (void)
 181 {
 182   return virtual_stack_vars_rtx;
 183 }
 184
 185 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 186
 187 bool
 188 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 189 {
 190   return false;
 191 }
 192
 193 bool
 194 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 195 {
 196   return (targetm.calls.setup_incoming_varargs
 197           != default_setup_incoming_varargs);
 198 }
 199
 200 enum machine_mode
 201 default_eh_return_filter_mode (void)
 202 {
 203   return targetm.unwind_word_mode ();
 204 }
 205
 206 enum machine_mode
 207 default_libgcc_cmp_return_mode (void)
 208 {
 209   return word_mode;
 210 }
 211
 212 enum machine_mode
 213 default_libgcc_shift_count_mode (void)
 214 {
 215   return word_mode;
 216 }
 217
 218 enum machine_mode
 219 default_unwind_word_mode (void)
 220 {
 221   return word_mode;
 222 }
 223
 224 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 225
 226 unsigned HOST_WIDE_INT
 227 default_shift_truncation_mask (enum machine_mode mode)
 228 {
 229   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 230 }
 231
 232 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 233
 234 unsigned int
 235 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 236 {
 237   return have_insn_for (DIV, mode) ? 3 : 2;
 238 }
 239
 240 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 241
 242 int
 243 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 244                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 245 {
 246   return UNKNOWN;
 247 }
 248
 249 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 250
 251 bool
 252 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 253 {
 254   return true;
 255 }
 256
 257 /* Return machine mode for non-standard suffix
 258    or VOIDmode if non-standard suffixes are unsupported.  */
 259 enum machine_mode
 260 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 261 {
 262   return VOIDmode;
 263 }
 264
 265 /* The generic C++ ABI specifies this is a 64-bit value.  */
 266 tree
 267 default_cxx_guard_type (void)
 268 {
 269   return long_long_integer_type_node;
 270 }
 271
 272
 273 /* Returns the size of the cookie to use when allocating an array
 274    whose elements have the indicated TYPE.  Assumes that it is already
 275    known that a cookie is needed.  */
 276
 277 tree
 278 default_cxx_get_cookie_size (tree type)
 279 {
 280   tree cookie_size;
 281
 282   /* We need to allocate an additional max (sizeof (size_t), alignof
 283      (true_type)) bytes.  */
 284   tree sizetype_size;
 285   tree type_align;
 286
 287   sizetype_size = size_in_bytes (sizetype);
 288   type_align = size_int (TYPE_ALIGN_UNIT (type));
 289   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 290     cookie_size = sizetype_size;
 291   else
 292     cookie_size = type_align;
 293
 294   return cookie_size;
 295 }
 296
 297 /* Return true if a parameter must be passed by reference.  This version
 298    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 299
 300 bool
 301 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
 302         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 303         bool named_arg ATTRIBUTE_UNUSED)
 304 {
 305   return targetm.calls.must_pass_in_stack (mode, type);
 306 }
 307
 308 /* Return true if a parameter follows callee copies conventions.  This
 309    version of the hook is true for all named arguments.  */
 310
 311 bool
 312 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 313                           enum machine_mode mode ATTRIBUTE_UNUSED,
 314                           const_tree type ATTRIBUTE_UNUSED, bool named)
 315 {
 316   return named;
 317 }
 318
 319 /* Emit to STREAM the assembler syntax for insn operand X.  */
 320
 321 void
 322 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 323                        int code ATTRIBUTE_UNUSED)
 324 {
 325 #ifdef PRINT_OPERAND
 326   PRINT_OPERAND (stream, x, code);
 327 #else
 328   gcc_unreachable ();
 329 #endif
 330 }
 331
 332 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 333    address is X.  */
 334
 335 void
 336 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 337                                rtx x ATTRIBUTE_UNUSED)
 338 {
 339 #ifdef PRINT_OPERAND_ADDRESS
 340   PRINT_OPERAND_ADDRESS (stream, x);
 341 #else
 342   gcc_unreachable ();
 343 #endif
 344 }
 345
 346 /* Return true if CODE is a valid punctuation character for the
 347    `print_operand' hook.  */
 348
 349 bool
 350 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 351 {
 352 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 353   return PRINT_OPERAND_PUNCT_VALID_P (code);
 354 #else
 355   return false;
 356 #endif
 357 }
 358
 359 /* True if MODE is valid for the target.  By "valid", we mean able to
 360    be manipulated in non-trivial ways.  In particular, this means all
 361    the arithmetic is supported.
 362
 363    By default we guess this means that any C type is supported.  If
 364    we can't map the mode back to a type that would be available in C,
 365    then reject it.  Special case, here, is the double-word arithmetic
 366    supported by optabs.c.  */
 367
 368 bool
 369 default_scalar_mode_supported_p (enum machine_mode mode)
 370 {
 371   int precision = GET_MODE_PRECISION (mode);
 372
 373   switch (GET_MODE_CLASS (mode))
 374     {
 375     case MODE_PARTIAL_INT:
 376     case MODE_INT:
 377       if (precision == CHAR_TYPE_SIZE)
 378         return true;
 379       if (precision == SHORT_TYPE_SIZE)
 380         return true;
 381       if (precision == INT_TYPE_SIZE)
 382         return true;
 383       if (precision == LONG_TYPE_SIZE)
 384         return true;
 385       if (precision == LONG_LONG_TYPE_SIZE)
 386         return true;
 387       if (precision == 2 * BITS_PER_WORD)
 388         return true;
 389       return false;
 390
 391     case MODE_FLOAT:
 392       if (precision == FLOAT_TYPE_SIZE)
 393         return true;
 394       if (precision == DOUBLE_TYPE_SIZE)
 395         return true;
 396       if (precision == LONG_DOUBLE_TYPE_SIZE)
 397         return true;
 398       return false;
 399
 400     case MODE_DECIMAL_FLOAT:
 401     case MODE_FRACT:
 402     case MODE_UFRACT:
 403     case MODE_ACCUM:
 404     case MODE_UACCUM:
 405       return false;
 406
 407     default:
 408       gcc_unreachable ();
 409     }
 410 }
 411
 412 /* True if the target supports decimal floating point.  */
 413
 414 bool
 415 default_decimal_float_supported_p (void)
 416 {
 417   return ENABLE_DECIMAL_FLOAT;
 418 }
 419
 420 /* True if the target supports fixed-point arithmetic.  */
 421
 422 bool
 423 default_fixed_point_supported_p (void)
 424 {
 425   return ENABLE_FIXED_POINT;
 426 }
 427
 428 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 429    an error message.
 430
 431    This function checks whether a given INSN is valid within a low-overhead
 432    loop.  If INSN is invalid it returns the reason for that, otherwise it
 433    returns NULL. A called function may clobber any special registers required
 434    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 435    register for branch on table instructions. We reject the doloop pattern in
 436    these cases.  */
 437
 438 const char *
 439 default_invalid_within_doloop (const_rtx insn)
 440 {
 441   if (CALL_P (insn))
 442     return "Function call in loop.";
 443
 444   if (JUMP_TABLE_DATA_P (insn))
 445     return "Computed branch in the loop.";
 446
 447   return NULL;
 448 }
 449
 450 /* Mapping of builtin functions to vectorized variants.  */
 451
 452 tree
 453 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 454                                      tree type_out ATTRIBUTE_UNUSED,
 455                                      tree type_in ATTRIBUTE_UNUSED)
 456 {
 457   return NULL_TREE;
 458 }
 459
 460 /* Vectorized conversion.  */
 461
 462 tree
 463 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 464                                        tree dest_type ATTRIBUTE_UNUSED,
 465                                        tree src_type ATTRIBUTE_UNUSED)
 466 {
 467   return NULL_TREE;
 468 }
 469
 470 /* Default vectorizer cost model values.  */
 471
 472 int
 473 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 474                                     tree vectype ATTRIBUTE_UNUSED,
 475                                     int misalign ATTRIBUTE_UNUSED)
 476 {
 477   switch (type_of_cost)
 478     {
 479       case scalar_stmt:
 480       case scalar_load:
 481       case scalar_store:
 482       case vector_stmt:
 483       case vector_load:
 484       case vector_store:
 485       case vec_to_scalar:
 486       case scalar_to_vec:
 487       case cond_branch_not_taken:
 488       case vec_perm:
 489         return 1;
 490
 491       case unaligned_load:
 492       case unaligned_store:
 493         return 2;
 494
 495       case cond_branch_taken:
 496         return 3;
 497
 498       default:
 499         gcc_unreachable ();
 500     }
 501 }
 502
 503 /* Reciprocal.  */
 504
 505 tree
 506 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 507                             bool md_fn ATTRIBUTE_UNUSED,
 508                             bool sqrt ATTRIBUTE_UNUSED)
 509 {
 510   return NULL_TREE;
 511 }
 512
 513 bool
 514 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 515         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 516         enum machine_mode mode ATTRIBUTE_UNUSED,
 517         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 518 {
 519   return false;
 520 }
 521
 522 bool
 523 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 524         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 525         enum machine_mode mode ATTRIBUTE_UNUSED,
 526         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 527 {
 528   return true;
 529 }
 530
 531 int
 532 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 533         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 534         enum machine_mode mode ATTRIBUTE_UNUSED,
 535         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 536 {
 537   return 0;
 538 }
 539
 540 void
 541 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 542                               enum machine_mode mode ATTRIBUTE_UNUSED,
 543                               const_tree type ATTRIBUTE_UNUSED,
 544                               bool named ATTRIBUTE_UNUSED)
 545 {
 546 #ifdef FUNCTION_ARG_ADVANCE
 547   CUMULATIVE_ARGS args = *ca;
 548   FUNCTION_ARG_ADVANCE (args, mode, CONST_CAST_TREE (type), named);
 549   *ca = args;
 550 #else
 551   gcc_unreachable ();
 552 #endif
 553 }
 554
 555 rtx
 556 default_function_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 557                       enum machine_mode mode ATTRIBUTE_UNUSED,
 558                       const_tree type ATTRIBUTE_UNUSED,
 559                       bool named ATTRIBUTE_UNUSED)
 560 {
 561 #ifdef FUNCTION_ARG
 562   return FUNCTION_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 563                        CONST_CAST_TREE (type), named);
 564 #else
 565   gcc_unreachable ();
 566 #endif
 567 }
 568
 569 rtx
 570 default_function_incoming_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 571                                enum machine_mode mode ATTRIBUTE_UNUSED,
 572                                const_tree type ATTRIBUTE_UNUSED,
 573                                bool named ATTRIBUTE_UNUSED)
 574 {
 575 #ifdef FUNCTION_INCOMING_ARG
 576   return FUNCTION_INCOMING_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 577                                 CONST_CAST_TREE (type), named);
 578 #else
 579   gcc_unreachable ();
 580 #endif
 581 }
 582
 583 void
 584 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 585 {
 586 }
 587
 588 const char *
 589 hook_invalid_arg_for_unprototyped_fn (
 590         const_tree typelist ATTRIBUTE_UNUSED,
 591         const_tree funcdecl ATTRIBUTE_UNUSED,
 592         const_tree val ATTRIBUTE_UNUSED)
 593 {
 594   return NULL;
 595 }
 596
 597 /* Initialize the stack protection decls.  */
 598
 599 /* Stack protection related decls living in libgcc.  */
 600 static GTY(()) tree stack_chk_guard_decl;
 601
 602 tree
 603 default_stack_protect_guard (void)
 604 {
 605   tree t = stack_chk_guard_decl;
 606
 607   if (t == NULL)
 608     {
 609       rtx x;
 610
 611       t = build_decl (UNKNOWN_LOCATION,
 612                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 613                       ptr_type_node);
 614       TREE_STATIC (t) = 1;
 615       TREE_PUBLIC (t) = 1;
 616       DECL_EXTERNAL (t) = 1;
 617       TREE_USED (t) = 1;
 618       TREE_THIS_VOLATILE (t) = 1;
 619       DECL_ARTIFICIAL (t) = 1;
 620       DECL_IGNORED_P (t) = 1;
 621
 622       /* Do not share RTL as the declaration is visible outside of
 623          current function.  */
 624       x = DECL_RTL (t);
 625       RTX_FLAG (x, used) = 1;
 626
 627       stack_chk_guard_decl = t;
 628     }
 629
 630   return t;
 631 }
 632
 633 static GTY(()) tree stack_chk_fail_decl;
 634
 635 tree
 636 default_external_stack_protect_fail (void)
 637 {
 638   tree t = stack_chk_fail_decl;
 639
 640   if (t == NULL_TREE)
 641     {
 642       t = build_function_type_list (void_type_node, NULL_TREE);
 643       t = build_decl (UNKNOWN_LOCATION,
 644                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 645       TREE_STATIC (t) = 1;
 646       TREE_PUBLIC (t) = 1;
 647       DECL_EXTERNAL (t) = 1;
 648       TREE_USED (t) = 1;
 649       TREE_THIS_VOLATILE (t) = 1;
 650       TREE_NOTHROW (t) = 1;
 651       DECL_ARTIFICIAL (t) = 1;
 652       DECL_IGNORED_P (t) = 1;
 653       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 654       DECL_VISIBILITY_SPECIFIED (t) = 1;
 655
 656       stack_chk_fail_decl = t;
 657     }
 658
 659   return build_call_expr (t, 0);
 660 }
 661
 662 tree
 663 default_hidden_stack_protect_fail (void)
 664 {
 665 #ifndef HAVE_GAS_HIDDEN
 666   return default_external_stack_protect_fail ();
 667 #else
 668   tree t = stack_chk_fail_decl;
 669
 670   if (!flag_pic)
 671     return default_external_stack_protect_fail ();
 672
 673   if (t == NULL_TREE)
 674     {
 675       t = build_function_type_list (void_type_node, NULL_TREE);
 676       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 677                       get_identifier ("__stack_chk_fail_local"), t);
 678       TREE_STATIC (t) = 1;
 679       TREE_PUBLIC (t) = 1;
 680       DECL_EXTERNAL (t) = 1;
 681       TREE_USED (t) = 1;
 682       TREE_THIS_VOLATILE (t) = 1;
 683       TREE_NOTHROW (t) = 1;
 684       DECL_ARTIFICIAL (t) = 1;
 685       DECL_IGNORED_P (t) = 1;
 686       DECL_VISIBILITY_SPECIFIED (t) = 1;
 687       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 688
 689       stack_chk_fail_decl = t;
 690     }
 691
 692   return build_call_expr (t, 0);
 693 #endif
 694 }
 695
 696 bool
 697 hook_bool_const_rtx_commutative_p (const_rtx x,
 698                                    int outer_code ATTRIBUTE_UNUSED)
 699 {
 700   return COMMUTATIVE_P (x);
 701 }
 702
 703 rtx
 704 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 705                         const_tree fn_decl_or_type,
 706                         bool outgoing ATTRIBUTE_UNUSED)
 707 {
 708   /* The old interface doesn't handle receiving the function type.  */
 709   if (fn_decl_or_type
 710       && !DECL_P (fn_decl_or_type))
 711     fn_decl_or_type = NULL;
 712
 713 #ifdef FUNCTION_VALUE
 714   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 715 #else
 716   gcc_unreachable ();
 717 #endif
 718 }
 719
 720 rtx
 721 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 722                        const_rtx fun ATTRIBUTE_UNUSED)
 723 {
 724 #ifdef LIBCALL_VALUE
 725   return LIBCALL_VALUE (mode);
 726 #else
 727   gcc_unreachable ();
 728 #endif
 729 }
 730
 731 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 732
 733 bool
 734 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 735 {
 736 #ifdef FUNCTION_VALUE_REGNO_P
 737   return FUNCTION_VALUE_REGNO_P (regno);
 738 #else
 739   gcc_unreachable ();
 740 #endif
 741 }
 742
 743 rtx
 744 default_internal_arg_pointer (void)
 745 {
 746   /* If the reg that the virtual arg pointer will be translated into is
 747      not a fixed reg or is the stack pointer, make a copy of the virtual
 748      arg pointer, and address parms via the copy.  The frame pointer is
 749      considered fixed even though it is not marked as such.  */
 750   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 751        || ! (fixed_regs[ARG_POINTER_REGNUM]
 752              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 753     return copy_to_reg (virtual_incoming_args_rtx);
 754   else
 755     return virtual_incoming_args_rtx;
 756 }
 757
 758 rtx
 759 default_static_chain (const_tree fndecl, bool incoming_p)
 760 {
 761   if (!DECL_STATIC_CHAIN (fndecl))
 762     return NULL;
 763
 764   if (incoming_p)
 765     {
 766 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 767       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 768 #endif
 769     }
 770
 771 #ifdef STATIC_CHAIN_REGNUM
 772   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 773 #endif
 774
 775   {
 776     static bool issued_error;
 777     if (!issued_error)
 778       {
 779         issued_error = true;
 780         sorry ("nested functions not supported on this target");
 781       }
 782
 783     /* It really doesn't matter what we return here, so long at it
 784        doesn't cause the rest of the compiler to crash.  */
 785     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 786   }
 787 }
 788
 789 void
 790 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 791                          rtx ARG_UNUSED (r_chain))
 792 {
 793   sorry ("nested function trampolines not supported on this target");
 794 }
 795
 796 int
 797 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 798                           tree funtype ATTRIBUTE_UNUSED,
 799                           int size ATTRIBUTE_UNUSED)
 800 {
 801   return 0;
 802 }
 803
 804 reg_class_t
 805 default_branch_target_register_class (void)
 806 {
 807   return NO_REGS;
 808 }
 809
 810 #ifdef IRA_COVER_CLASSES
 811 const reg_class_t *
 812 default_ira_cover_classes (void)
 813 {
 814   static reg_class_t classes[] = IRA_COVER_CLASSES;
 815   return classes;
 816 }
 817 #endif
 818
 819 reg_class_t
 820 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 821                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 822                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 823                           secondary_reload_info *sri)
 824 {
 825   enum reg_class rclass = NO_REGS;
 826   enum reg_class reload_class = (enum reg_class) reload_class_i;
 827
 828   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 829     {
 830       sri->icode = sri->prev_sri->t_icode;
 831       return NO_REGS;
 832     }
 833 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 834   if (in_p)
 835     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 836 #endif
 837 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 838   if (! in_p)
 839     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 840 #endif
 841   if (rclass != NO_REGS)
 842     {
 843       enum insn_code icode
 844         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 845                                 reload_mode);
 846
 847       if (icode != CODE_FOR_nothing
 848           && insn_data[(int) icode].operand[in_p].predicate
 849           && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
 850         icode = CODE_FOR_nothing;
 851       else if (icode != CODE_FOR_nothing)
 852         {
 853           const char *insn_constraint, *scratch_constraint;
 854           char insn_letter, scratch_letter;
 855           enum reg_class insn_class, scratch_class;
 856
 857           gcc_assert (insn_data[(int) icode].n_operands == 3);
 858           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 859           if (!*insn_constraint)
 860             insn_class = ALL_REGS;
 861           else
 862             {
 863               if (in_p)
 864                 {
 865                   gcc_assert (*insn_constraint == '=');
 866                   insn_constraint++;
 867                 }
 868               insn_letter = *insn_constraint;
 869               insn_class
 870                 = (insn_letter == 'r' ? GENERAL_REGS
 871                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 872                                                 insn_constraint));
 873               gcc_assert (insn_class != NO_REGS);
 874             }
 875
 876           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 877           /* The scratch register's constraint must start with "=&",
 878              except for an input reload, where only "=" is necessary,
 879              and where it might be beneficial to re-use registers from
 880              the input.  */
 881           gcc_assert (scratch_constraint[0] == '='
 882                       && (in_p || scratch_constraint[1] == '&'));
 883           scratch_constraint++;
 884           if (*scratch_constraint == '&')
 885             scratch_constraint++;
 886           scratch_letter = *scratch_constraint;
 887           scratch_class
 888             = (scratch_letter == 'r' ? GENERAL_REGS
 889                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 890                                             scratch_constraint));
 891
 892           if (reg_class_subset_p (reload_class, insn_class))
 893             {
 894               gcc_assert (scratch_class == rclass);
 895               rclass = NO_REGS;
 896             }
 897           else
 898             rclass = insn_class;
 899
 900         }
 901       if (rclass == NO_REGS)
 902         sri->icode = icode;
 903       else
 904         sri->t_icode = icode;
 905     }
 906   return rclass;
 907 }
 908
 909 void
 910 default_target_option_override (void)
 911 {
 912 #ifdef OVERRIDE_OPTIONS
 913   OVERRIDE_OPTIONS;
 914 #endif
 915 }
 916
 917 bool
 918 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 919                          const char *arg ATTRIBUTE_UNUSED,
 920                          int value ATTRIBUTE_UNUSED)
 921 {
 922   return false;
 923 }
 924
 925 /* By default, if flag_pic is true, then neither local nor global relocs
 926    should be placed in readonly memory.  */
 927
 928 int
 929 default_reloc_rw_mask (void)
 930 {
 931   return flag_pic ? 3 : 0;
 932 }
 933
 934 /* By default, do no modification. */
 935 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 936                                          tree id)
 937 {
 938    return id;
 939 }
 940
 941 bool
 942 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 943 {
 944   if (is_packed)
 945     return false;
 946
 947   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 948      naturally aligned.  */
 949   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 950     return false;
 951
 952   /* Assuming that types whose size is <= pointer-size
 953      are naturally aligned.  */
 954   return true;
 955 }
 956
 957 /* By default, assume that a target supports any factor of misalignment
 958    memory access if it supports movmisalign patten.
 959    is_packed is true if the memory access is defined in a packed struct.  */
 960 bool
 961 default_builtin_support_vector_misalignment (enum machine_mode mode,
 962                                              const_tree type
 963                                              ATTRIBUTE_UNUSED,
 964                                              int misalignment
 965                                              ATTRIBUTE_UNUSED,
 966                                              bool is_packed
 967                                              ATTRIBUTE_UNUSED)
 968 {
 969   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
 970     return true;
 971   return false;
 972 }
 973
 974 /* Determine whether or not a pointer mode is valid. Assume defaults
 975    of ptr_mode or Pmode - can be overridden.  */
 976 bool
 977 default_valid_pointer_mode (enum machine_mode mode)
 978 {
 979   return (mode == ptr_mode || mode == Pmode);
 980 }
 981
 982 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
 983    for the generic address space only.  */
 984
 985 enum machine_mode
 986 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
 987 {
 988   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
 989   return ptr_mode;
 990 }
 991
 992 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
 993    for the generic address space only.  */
 994
 995 enum machine_mode
 996 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
 997 {
 998   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
 999   return Pmode;
1000 }
1001
1002 /* Named address space version of valid_pointer_mode.  */
1003
1004 bool
1005 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1006 {
1007   if (!ADDR_SPACE_GENERIC_P (as))
1008     return (mode == targetm.addr_space.pointer_mode (as)
1009             || mode == targetm.addr_space.address_mode (as));
1010
1011   return targetm.valid_pointer_mode (mode);
1012 }
1013
1014 /* Some places still assume that all pointer or address modes are the
1015    standard Pmode and ptr_mode.  These optimizations become invalid if
1016    the target actually supports multiple different modes.  For now,
1017    we disable such optimizations on such targets, using this function.  */
1018
1019 bool
1020 target_default_pointer_address_modes_p (void)
1021 {
1022   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1023     return false;
1024   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1025     return false;
1026
1027   return true;
1028 }
1029
1030 /* Named address space version of legitimate_address_p.  */
1031
1032 bool
1033 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1034                                          bool strict, addr_space_t as)
1035 {
1036   if (!ADDR_SPACE_GENERIC_P (as))
1037     gcc_unreachable ();
1038
1039   return targetm.legitimate_address_p (mode, mem, strict);
1040 }
1041
1042 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1043
1044 rtx
1045 default_addr_space_legitimize_address (rtx x, rtx oldx,
1046                                        enum machine_mode mode, addr_space_t as)
1047 {
1048   if (!ADDR_SPACE_GENERIC_P (as))
1049     return x;
1050
1051   return targetm.legitimize_address (x, oldx, mode);
1052 }
1053
1054 /* The default hook for determining if one named address space is a subset of
1055    another and to return which address space to use as the common address
1056    space.  */
1057
1058 bool
1059 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1060 {
1061   return (subset == superset);
1062 }
1063
1064 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1065    called for targets with only a generic address space.  */
1066
1067 rtx
1068 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1069                             tree from_type ATTRIBUTE_UNUSED,
1070                             tree to_type ATTRIBUTE_UNUSED)
1071 {
1072   gcc_unreachable ();
1073 }
1074
1075 bool
1076 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1077 {
1078   return true;
1079 }
1080
1081 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1082
1083 bool
1084 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1085 {
1086 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1087
1088   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1089   return false;
1090   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1091  win: ATTRIBUTE_UNUSED_LABEL
1092   return true;
1093
1094 #else
1095
1096   return false;
1097
1098 #endif
1099 }
1100
1101 bool
1102 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1103                                          tree ARG_UNUSED (name),
1104                                          tree ARG_UNUSED (args),
1105                                          int ARG_UNUSED (flags))
1106 {
1107   warning (OPT_Wattributes,
1108            "target attribute is not supported on this machine");
1109
1110   return false;
1111 }
1112
1113 bool
1114 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1115                                     tree ARG_UNUSED (pop_target))
1116 {
1117   warning (OPT_Wpragmas,
1118            "#pragma GCC target is not supported for this machine");
1119
1120   return false;
1121 }
1122
1123 bool
1124 default_target_can_inline_p (tree caller, tree callee)
1125 {
1126   bool ret = false;
1127   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1128   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1129
1130   /* If callee has no option attributes, then it is ok to inline */
1131   if (!callee_opts)
1132     ret = true;
1133
1134   /* If caller has no option attributes, but callee does then it is not ok to
1135      inline */
1136   else if (!caller_opts)
1137     ret = false;
1138
1139   /* If both caller and callee have attributes, assume that if the pointer is
1140      different, the the two functions have different target options since
1141      build_target_option_node uses a hash table for the options.  */
1142   else
1143     ret = (callee_opts == caller_opts);
1144
1145   return ret;
1146 }
1147
1148 #ifndef HAVE_casesi
1149 # define HAVE_casesi 0
1150 #endif
1151
1152 /* If the machine does not have a case insn that compares the bounds,
1153    this means extra overhead for dispatch tables, which raises the
1154    threshold for using them.  */
1155
1156 unsigned int default_case_values_threshold (void)
1157 {
1158   return (HAVE_casesi ? 4 : 5);
1159 }
1160
1161 bool
1162 default_have_conditional_execution (void)
1163 {
1164 #ifdef HAVE_conditional_execution
1165   return HAVE_conditional_execution;
1166 #else
1167   return false;
1168 #endif
1169 }
1170
1171 /* Compute cost of moving registers to/from memory.  */
1172
1173 int
1174 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1175                           reg_class_t rclass ATTRIBUTE_UNUSED,
1176                           bool in ATTRIBUTE_UNUSED)
1177 {
1178 #ifndef MEMORY_MOVE_COST
1179     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1180 #else
1181     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1182 #endif
1183 }
1184
1185 /* Compute cost of moving data from a register of class FROM to one of
1186    TO, using MODE.  */
1187
1188 int
1189 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1190                             reg_class_t from ATTRIBUTE_UNUSED,
1191                             reg_class_t to ATTRIBUTE_UNUSED)
1192 {
1193 #ifndef REGISTER_MOVE_COST
1194   return 2;
1195 #else
1196   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1197 #endif
1198 }
1199
1200 #include "gt-targhooks.h"