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 "toplev.h"
  60 #include "function.h"
  61 #include "target.h"
  62 #include "tm_p.h"
  63 #include "target-def.h"
  64 #include "ggc.h"
  65 #include "hard-reg-set.h"
  66 #include "reload.h"
  67 #include "optabs.h"
  68 #include "recog.h"
  69
  70
  71 bool
  72 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  73                               rtx addr ATTRIBUTE_UNUSED,
  74                               bool strict ATTRIBUTE_UNUSED)
  75 {
  76 #ifdef GO_IF_LEGITIMATE_ADDRESS
  77   /* Defer to the old implementation using a goto.  */
  78   if (strict)
  79     return strict_memory_address_p (mode, addr);
  80   else
  81     return memory_address_p (mode, addr);
  82 #else
  83   gcc_unreachable ();
  84 #endif
  85 }
  86
  87 void
  88 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  89 {
  90 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  91   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  92 #endif
  93 }
  94
  95 int
  96 default_unspec_may_trap_p (const_rtx x, unsigned flags)
  97 {
  98   int i;
  99
 100   if (GET_CODE (x) == UNSPEC_VOLATILE
 101       /* Any floating arithmetic may trap.  */
 102       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
 103           && flag_trapping_math))
 104     return 1;
 105
 106   for (i = 0; i < XVECLEN (x, 0); ++i)
 107     {
 108       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 109         return 1;
 110     }
 111
 112   return 0;
 113 }
 114
 115 enum machine_mode
 116 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 117                                enum machine_mode mode,
 118                                int *punsignedp ATTRIBUTE_UNUSED,
 119                                const_tree funtype ATTRIBUTE_UNUSED,
 120                                int for_return ATTRIBUTE_UNUSED)
 121 {
 122   if (for_return == 2)
 123     return promote_mode (type, mode, punsignedp);
 124   return mode;
 125 }
 126
 127 enum machine_mode
 128 default_promote_function_mode_always_promote (const_tree type,
 129                                               enum machine_mode mode,
 130                                               int *punsignedp,
 131                                               const_tree funtype ATTRIBUTE_UNUSED,
 132                                               int for_return ATTRIBUTE_UNUSED)
 133 {
 134   return promote_mode (type, mode, punsignedp);
 135 }
 136
 137
 138 enum machine_mode
 139 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 140 {
 141   if (m1 == m2)
 142     return m1;
 143   return VOIDmode;
 144 }
 145
 146 bool
 147 default_return_in_memory (const_tree type,
 148                           const_tree fntype ATTRIBUTE_UNUSED)
 149 {
 150   return (TYPE_MODE (type) == BLKmode);
 151 }
 152
 153 rtx
 154 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 155                             enum machine_mode mode ATTRIBUTE_UNUSED)
 156 {
 157   return x;
 158 }
 159
 160 rtx
 161 default_expand_builtin_saveregs (void)
 162 {
 163   error ("__builtin_saveregs not supported by this target");
 164   return const0_rtx;
 165 }
 166
 167 void
 168 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 169                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 170                                 tree type ATTRIBUTE_UNUSED,
 171                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 172                                 int second_time ATTRIBUTE_UNUSED)
 173 {
 174 }
 175
 176 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 177
 178 rtx
 179 default_builtin_setjmp_frame_value (void)
 180 {
 181   return virtual_stack_vars_rtx;
 182 }
 183
 184 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 185
 186 bool
 187 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 188 {
 189   return false;
 190 }
 191
 192 bool
 193 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 194 {
 195   return (targetm.calls.setup_incoming_varargs
 196           != default_setup_incoming_varargs);
 197 }
 198
 199 enum machine_mode
 200 default_eh_return_filter_mode (void)
 201 {
 202   return targetm.unwind_word_mode ();
 203 }
 204
 205 enum machine_mode
 206 default_libgcc_cmp_return_mode (void)
 207 {
 208   return word_mode;
 209 }
 210
 211 enum machine_mode
 212 default_libgcc_shift_count_mode (void)
 213 {
 214   return word_mode;
 215 }
 216
 217 enum machine_mode
 218 default_unwind_word_mode (void)
 219 {
 220   return word_mode;
 221 }
 222
 223 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 224
 225 unsigned HOST_WIDE_INT
 226 default_shift_truncation_mask (enum machine_mode mode)
 227 {
 228   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 229 }
 230
 231 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 232
 233 unsigned int
 234 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 235 {
 236   return have_insn_for (DIV, mode) ? 3 : 2;
 237 }
 238
 239 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 240
 241 int
 242 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 243                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 244 {
 245   return UNKNOWN;
 246 }
 247
 248 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 249
 250 bool
 251 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 252 {
 253   return true;
 254 }
 255
 256 /* Return machine mode for non-standard suffix
 257    or VOIDmode if non-standard suffixes are unsupported.  */
 258 enum machine_mode
 259 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 260 {
 261   return VOIDmode;
 262 }
 263
 264 /* The generic C++ ABI specifies this is a 64-bit value.  */
 265 tree
 266 default_cxx_guard_type (void)
 267 {
 268   return long_long_integer_type_node;
 269 }
 270
 271
 272 /* Returns the size of the cookie to use when allocating an array
 273    whose elements have the indicated TYPE.  Assumes that it is already
 274    known that a cookie is needed.  */
 275
 276 tree
 277 default_cxx_get_cookie_size (tree type)
 278 {
 279   tree cookie_size;
 280
 281   /* We need to allocate an additional max (sizeof (size_t), alignof
 282      (true_type)) bytes.  */
 283   tree sizetype_size;
 284   tree type_align;
 285
 286   sizetype_size = size_in_bytes (sizetype);
 287   type_align = size_int (TYPE_ALIGN_UNIT (type));
 288   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 289     cookie_size = sizetype_size;
 290   else
 291     cookie_size = type_align;
 292
 293   return cookie_size;
 294 }
 295
 296 /* Return true if a parameter must be passed by reference.  This version
 297    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 298
 299 bool
 300 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
 301         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 302         bool named_arg ATTRIBUTE_UNUSED)
 303 {
 304   return targetm.calls.must_pass_in_stack (mode, type);
 305 }
 306
 307 /* Return true if a parameter follows callee copies conventions.  This
 308    version of the hook is true for all named arguments.  */
 309
 310 bool
 311 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 312                           enum machine_mode mode ATTRIBUTE_UNUSED,
 313                           const_tree type ATTRIBUTE_UNUSED, bool named)
 314 {
 315   return named;
 316 }
 317
 318 /* Emit any directives required to unwind this instruction.  */
 319
 320 void
 321 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
 322                      rtx insn ATTRIBUTE_UNUSED)
 323 {
 324   /* Should never happen.  */
 325   gcc_unreachable ();
 326 }
 327
 328 /* Emit to STREAM the assembler syntax for insn operand X.  */
 329
 330 void
 331 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 332                        int code ATTRIBUTE_UNUSED)
 333 {
 334 #ifdef PRINT_OPERAND
 335   PRINT_OPERAND (stream, x, code);
 336 #else
 337   gcc_unreachable ();
 338 #endif
 339 }
 340
 341 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 342    address is X.  */
 343
 344 void
 345 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 346                                rtx x ATTRIBUTE_UNUSED)
 347 {
 348 #ifdef PRINT_OPERAND_ADDRESS
 349   PRINT_OPERAND_ADDRESS (stream, x);
 350 #else
 351   gcc_unreachable ();
 352 #endif
 353 }
 354
 355 /* Return true if CODE is a valid punctuation character for the
 356    `print_operand' hook.  */
 357
 358 bool
 359 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 360 {
 361 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 362   return PRINT_OPERAND_PUNCT_VALID_P (code);
 363 #else
 364   return false;
 365 #endif
 366 }
 367
 368 /* True if MODE is valid for the target.  By "valid", we mean able to
 369    be manipulated in non-trivial ways.  In particular, this means all
 370    the arithmetic is supported.
 371
 372    By default we guess this means that any C type is supported.  If
 373    we can't map the mode back to a type that would be available in C,
 374    then reject it.  Special case, here, is the double-word arithmetic
 375    supported by optabs.c.  */
 376
 377 bool
 378 default_scalar_mode_supported_p (enum machine_mode mode)
 379 {
 380   int precision = GET_MODE_PRECISION (mode);
 381
 382   switch (GET_MODE_CLASS (mode))
 383     {
 384     case MODE_PARTIAL_INT:
 385     case MODE_INT:
 386       if (precision == CHAR_TYPE_SIZE)
 387         return true;
 388       if (precision == SHORT_TYPE_SIZE)
 389         return true;
 390       if (precision == INT_TYPE_SIZE)
 391         return true;
 392       if (precision == LONG_TYPE_SIZE)
 393         return true;
 394       if (precision == LONG_LONG_TYPE_SIZE)
 395         return true;
 396       if (precision == 2 * BITS_PER_WORD)
 397         return true;
 398       return false;
 399
 400     case MODE_FLOAT:
 401       if (precision == FLOAT_TYPE_SIZE)
 402         return true;
 403       if (precision == DOUBLE_TYPE_SIZE)
 404         return true;
 405       if (precision == LONG_DOUBLE_TYPE_SIZE)
 406         return true;
 407       return false;
 408
 409     case MODE_DECIMAL_FLOAT:
 410     case MODE_FRACT:
 411     case MODE_UFRACT:
 412     case MODE_ACCUM:
 413     case MODE_UACCUM:
 414       return false;
 415
 416     default:
 417       gcc_unreachable ();
 418     }
 419 }
 420
 421 /* True if the target supports decimal floating point.  */
 422
 423 bool
 424 default_decimal_float_supported_p (void)
 425 {
 426   return ENABLE_DECIMAL_FLOAT;
 427 }
 428
 429 /* True if the target supports fixed-point arithmetic.  */
 430
 431 bool
 432 default_fixed_point_supported_p (void)
 433 {
 434   return ENABLE_FIXED_POINT;
 435 }
 436
 437 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 438    an error message.
 439
 440    This function checks whether a given INSN is valid within a low-overhead
 441    loop.  If INSN is invalid it returns the reason for that, otherwise it
 442    returns NULL. A called function may clobber any special registers required
 443    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 444    register for branch on table instructions. We reject the doloop pattern in
 445    these cases.  */
 446
 447 const char *
 448 default_invalid_within_doloop (const_rtx insn)
 449 {
 450   if (CALL_P (insn))
 451     return "Function call in loop.";
 452
 453   if (JUMP_TABLE_DATA_P (insn))
 454     return "Computed branch in the loop.";
 455
 456   return NULL;
 457 }
 458
 459 /* Mapping of builtin functions to vectorized variants.  */
 460
 461 tree
 462 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 463                                      tree type_out ATTRIBUTE_UNUSED,
 464                                      tree type_in ATTRIBUTE_UNUSED)
 465 {
 466   return NULL_TREE;
 467 }
 468
 469 /* Vectorized conversion.  */
 470
 471 tree
 472 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 473                                        tree dest_type ATTRIBUTE_UNUSED,
 474                                        tree src_type ATTRIBUTE_UNUSED)
 475 {
 476   return NULL_TREE;
 477 }
 478
 479 /* Default vectorizer cost model values.  */
 480
 481 int
 482 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost)
 483 {
 484   switch (type_of_cost)
 485     {
 486       case scalar_stmt:
 487       case scalar_load:
 488       case scalar_store:
 489       case vector_stmt:
 490       case vector_load:
 491       case vector_store:
 492       case vec_to_scalar:
 493       case scalar_to_vec:
 494       case cond_branch_not_taken:
 495       case vec_perm:
 496         return 1;
 497
 498       case unaligned_load:
 499         return 2;
 500
 501       case cond_branch_taken:
 502         return 3;
 503
 504       default:
 505         gcc_unreachable ();
 506     }
 507 }
 508
 509 /* Reciprocal.  */
 510
 511 tree
 512 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 513                             bool md_fn ATTRIBUTE_UNUSED,
 514                             bool sqrt ATTRIBUTE_UNUSED)
 515 {
 516   return NULL_TREE;
 517 }
 518
 519 bool
 520 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 521         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 522         enum machine_mode mode ATTRIBUTE_UNUSED,
 523         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 524 {
 525   return false;
 526 }
 527
 528 bool
 529 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 530         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 531         enum machine_mode mode ATTRIBUTE_UNUSED,
 532         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 533 {
 534   return true;
 535 }
 536
 537 int
 538 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 539         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 540         enum machine_mode mode ATTRIBUTE_UNUSED,
 541         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 542 {
 543   return 0;
 544 }
 545
 546 void
 547 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 548                               enum machine_mode mode ATTRIBUTE_UNUSED,
 549                               const_tree type ATTRIBUTE_UNUSED,
 550                               bool named ATTRIBUTE_UNUSED)
 551 {
 552 #ifdef FUNCTION_ARG_ADVANCE
 553   CUMULATIVE_ARGS args = *ca;
 554   FUNCTION_ARG_ADVANCE (args, mode, CONST_CAST_TREE (type), named);
 555   *ca = args;
 556 #else
 557   gcc_unreachable ();
 558 #endif
 559 }
 560
 561 rtx
 562 default_function_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 563                       enum machine_mode mode ATTRIBUTE_UNUSED,
 564                       const_tree type ATTRIBUTE_UNUSED,
 565                       bool named ATTRIBUTE_UNUSED)
 566 {
 567 #ifdef FUNCTION_ARG
 568   return FUNCTION_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 569                        CONST_CAST_TREE (type), named);
 570 #else
 571   gcc_unreachable ();
 572 #endif
 573 }
 574
 575 rtx
 576 default_function_incoming_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 577                                enum machine_mode mode ATTRIBUTE_UNUSED,
 578                                const_tree type ATTRIBUTE_UNUSED,
 579                                bool named ATTRIBUTE_UNUSED)
 580 {
 581 #ifdef FUNCTION_INCOMING_ARG
 582   return FUNCTION_INCOMING_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 583                                 CONST_CAST_TREE (type), named);
 584 #else
 585   gcc_unreachable ();
 586 #endif
 587 }
 588
 589 void
 590 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 591 {
 592 }
 593
 594 const char *
 595 hook_invalid_arg_for_unprototyped_fn (
 596         const_tree typelist ATTRIBUTE_UNUSED,
 597         const_tree funcdecl ATTRIBUTE_UNUSED,
 598         const_tree val ATTRIBUTE_UNUSED)
 599 {
 600   return NULL;
 601 }
 602
 603 /* Initialize the stack protection decls.  */
 604
 605 /* Stack protection related decls living in libgcc.  */
 606 static GTY(()) tree stack_chk_guard_decl;
 607
 608 tree
 609 default_stack_protect_guard (void)
 610 {
 611   tree t = stack_chk_guard_decl;
 612
 613   if (t == NULL)
 614     {
 615       rtx x;
 616
 617       t = build_decl (UNKNOWN_LOCATION,
 618                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 619                       ptr_type_node);
 620       TREE_STATIC (t) = 1;
 621       TREE_PUBLIC (t) = 1;
 622       DECL_EXTERNAL (t) = 1;
 623       TREE_USED (t) = 1;
 624       TREE_THIS_VOLATILE (t) = 1;
 625       DECL_ARTIFICIAL (t) = 1;
 626       DECL_IGNORED_P (t) = 1;
 627
 628       /* Do not share RTL as the declaration is visible outside of
 629          current function.  */
 630       x = DECL_RTL (t);
 631       RTX_FLAG (x, used) = 1;
 632
 633       stack_chk_guard_decl = t;
 634     }
 635
 636   return t;
 637 }
 638
 639 static GTY(()) tree stack_chk_fail_decl;
 640
 641 tree
 642 default_external_stack_protect_fail (void)
 643 {
 644   tree t = stack_chk_fail_decl;
 645
 646   if (t == NULL_TREE)
 647     {
 648       t = build_function_type_list (void_type_node, NULL_TREE);
 649       t = build_decl (UNKNOWN_LOCATION,
 650                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 651       TREE_STATIC (t) = 1;
 652       TREE_PUBLIC (t) = 1;
 653       DECL_EXTERNAL (t) = 1;
 654       TREE_USED (t) = 1;
 655       TREE_THIS_VOLATILE (t) = 1;
 656       TREE_NOTHROW (t) = 1;
 657       DECL_ARTIFICIAL (t) = 1;
 658       DECL_IGNORED_P (t) = 1;
 659       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 660       DECL_VISIBILITY_SPECIFIED (t) = 1;
 661
 662       stack_chk_fail_decl = t;
 663     }
 664
 665   return build_call_expr (t, 0);
 666 }
 667
 668 tree
 669 default_hidden_stack_protect_fail (void)
 670 {
 671 #ifndef HAVE_GAS_HIDDEN
 672   return default_external_stack_protect_fail ();
 673 #else
 674   tree t = stack_chk_fail_decl;
 675
 676   if (!flag_pic)
 677     return default_external_stack_protect_fail ();
 678
 679   if (t == NULL_TREE)
 680     {
 681       t = build_function_type_list (void_type_node, NULL_TREE);
 682       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 683                       get_identifier ("__stack_chk_fail_local"), t);
 684       TREE_STATIC (t) = 1;
 685       TREE_PUBLIC (t) = 1;
 686       DECL_EXTERNAL (t) = 1;
 687       TREE_USED (t) = 1;
 688       TREE_THIS_VOLATILE (t) = 1;
 689       TREE_NOTHROW (t) = 1;
 690       DECL_ARTIFICIAL (t) = 1;
 691       DECL_IGNORED_P (t) = 1;
 692       DECL_VISIBILITY_SPECIFIED (t) = 1;
 693       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 694
 695       stack_chk_fail_decl = t;
 696     }
 697
 698   return build_call_expr (t, 0);
 699 #endif
 700 }
 701
 702 bool
 703 hook_bool_const_rtx_commutative_p (const_rtx x,
 704                                    int outer_code ATTRIBUTE_UNUSED)
 705 {
 706   return COMMUTATIVE_P (x);
 707 }
 708
 709 rtx
 710 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 711                         const_tree fn_decl_or_type,
 712                         bool outgoing ATTRIBUTE_UNUSED)
 713 {
 714   /* The old interface doesn't handle receiving the function type.  */
 715   if (fn_decl_or_type
 716       && !DECL_P (fn_decl_or_type))
 717     fn_decl_or_type = NULL;
 718
 719 #ifdef FUNCTION_VALUE
 720   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 721 #else
 722   gcc_unreachable ();
 723 #endif
 724 }
 725
 726 rtx
 727 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 728                        const_rtx fun ATTRIBUTE_UNUSED)
 729 {
 730 #ifdef LIBCALL_VALUE
 731   return LIBCALL_VALUE (mode);
 732 #else
 733   gcc_unreachable ();
 734 #endif
 735 }
 736
 737 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 738
 739 bool
 740 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 741 {
 742 #ifdef FUNCTION_VALUE_REGNO_P
 743   return FUNCTION_VALUE_REGNO_P (regno);
 744 #else
 745   gcc_unreachable ();
 746 #endif
 747 }
 748
 749 rtx
 750 default_internal_arg_pointer (void)
 751 {
 752   /* If the reg that the virtual arg pointer will be translated into is
 753      not a fixed reg or is the stack pointer, make a copy of the virtual
 754      arg pointer, and address parms via the copy.  The frame pointer is
 755      considered fixed even though it is not marked as such.  */
 756   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 757        || ! (fixed_regs[ARG_POINTER_REGNUM]
 758              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 759     return copy_to_reg (virtual_incoming_args_rtx);
 760   else
 761     return virtual_incoming_args_rtx;
 762 }
 763
 764 rtx
 765 default_static_chain (const_tree fndecl, bool incoming_p)
 766 {
 767   if (!DECL_STATIC_CHAIN (fndecl))
 768     return NULL;
 769
 770   if (incoming_p)
 771     {
 772 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 773       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 774 #endif
 775     }
 776
 777 #ifdef STATIC_CHAIN_REGNUM
 778   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 779 #endif
 780
 781   {
 782     static bool issued_error;
 783     if (!issued_error)
 784       {
 785         issued_error = true;
 786         sorry ("nested functions not supported on this target");
 787       }
 788
 789     /* It really doesn't matter what we return here, so long at it
 790        doesn't cause the rest of the compiler to crash.  */
 791     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 792   }
 793 }
 794
 795 void
 796 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 797                          rtx ARG_UNUSED (r_chain))
 798 {
 799   sorry ("nested function trampolines not supported on this target");
 800 }
 801
 802 int
 803 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 804                           tree funtype ATTRIBUTE_UNUSED,
 805                           int size ATTRIBUTE_UNUSED)
 806 {
 807   return 0;
 808 }
 809
 810 reg_class_t
 811 default_branch_target_register_class (void)
 812 {
 813   return NO_REGS;
 814 }
 815
 816 #ifdef IRA_COVER_CLASSES
 817 const reg_class_t *
 818 default_ira_cover_classes (void)
 819 {
 820   static reg_class_t classes[] = IRA_COVER_CLASSES;
 821   return classes;
 822 }
 823 #endif
 824
 825 reg_class_t
 826 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 827                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 828                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 829                           secondary_reload_info *sri)
 830 {
 831   enum reg_class rclass = NO_REGS;
 832   enum reg_class reload_class = (enum reg_class) reload_class_i;
 833
 834   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 835     {
 836       sri->icode = sri->prev_sri->t_icode;
 837       return NO_REGS;
 838     }
 839 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 840   if (in_p)
 841     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 842 #endif
 843 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 844   if (! in_p)
 845     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 846 #endif
 847   if (rclass != NO_REGS)
 848     {
 849       enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
 850                               : reload_out_optab[(int) reload_mode]);
 851
 852       if (icode != CODE_FOR_nothing
 853           && insn_data[(int) icode].operand[in_p].predicate
 854           && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
 855         icode = CODE_FOR_nothing;
 856       else if (icode != CODE_FOR_nothing)
 857         {
 858           const char *insn_constraint, *scratch_constraint;
 859           char insn_letter, scratch_letter;
 860           enum reg_class insn_class, scratch_class;
 861
 862           gcc_assert (insn_data[(int) icode].n_operands == 3);
 863           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 864           if (!*insn_constraint)
 865             insn_class = ALL_REGS;
 866           else
 867             {
 868               if (in_p)
 869                 {
 870                   gcc_assert (*insn_constraint == '=');
 871                   insn_constraint++;
 872                 }
 873               insn_letter = *insn_constraint;
 874               insn_class
 875                 = (insn_letter == 'r' ? GENERAL_REGS
 876                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 877                                                 insn_constraint));
 878               gcc_assert (insn_class != NO_REGS);
 879             }
 880
 881           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 882           /* The scratch register's constraint must start with "=&",
 883              except for an input reload, where only "=" is necessary,
 884              and where it might be beneficial to re-use registers from
 885              the input.  */
 886           gcc_assert (scratch_constraint[0] == '='
 887                       && (in_p || scratch_constraint[1] == '&'));
 888           scratch_constraint++;
 889           if (*scratch_constraint == '&')
 890             scratch_constraint++;
 891           scratch_letter = *scratch_constraint;
 892           scratch_class
 893             = (scratch_letter == 'r' ? GENERAL_REGS
 894                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 895                                             scratch_constraint));
 896
 897           if (reg_class_subset_p (reload_class, insn_class))
 898             {
 899               gcc_assert (scratch_class == rclass);
 900               rclass = NO_REGS;
 901             }
 902           else
 903             rclass = insn_class;
 904
 905         }
 906       if (rclass == NO_REGS)
 907         sri->icode = icode;
 908       else
 909         sri->t_icode = icode;
 910     }
 911   return rclass;
 912 }
 913
 914 void
 915 default_target_option_override (void)
 916 {
 917 #ifdef OVERRIDE_OPTIONS
 918   OVERRIDE_OPTIONS;
 919 #endif
 920 }
 921
 922 bool
 923 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 924                          const char *arg ATTRIBUTE_UNUSED,
 925                          int value ATTRIBUTE_UNUSED)
 926 {
 927   return false;
 928 }
 929
 930 /* By default, if flag_pic is true, then neither local nor global relocs
 931    should be placed in readonly memory.  */
 932
 933 int
 934 default_reloc_rw_mask (void)
 935 {
 936   return flag_pic ? 3 : 0;
 937 }
 938
 939 /* By default, do no modification. */
 940 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 941                                          tree id)
 942 {
 943    return id;
 944 }
 945
 946 bool
 947 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 948 {
 949   if (is_packed)
 950     return false;
 951
 952   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 953      naturally aligned.  */
 954   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 955     return false;
 956
 957   /* Assuming that types whose size is <= pointer-size
 958      are naturally aligned.  */
 959   return true;
 960 }
 961
 962 /* By default, assume that a target supports any factor of misalignment
 963    memory access if it supports movmisalign patten.
 964    is_packed is true if the memory access is defined in a packed struct.  */
 965 bool
 966 default_builtin_support_vector_misalignment (enum machine_mode mode,
 967                                              const_tree type
 968                                              ATTRIBUTE_UNUSED,
 969                                              int misalignment
 970                                              ATTRIBUTE_UNUSED,
 971                                              bool is_packed
 972                                              ATTRIBUTE_UNUSED)
 973 {
 974   if (optab_handler (movmisalign_optab, mode)->insn_code != CODE_FOR_nothing)
 975     return true;
 976   return false;
 977 }
 978
 979 /* Determine whether or not a pointer mode is valid. Assume defaults
 980    of ptr_mode or Pmode - can be overridden.  */
 981 bool
 982 default_valid_pointer_mode (enum machine_mode mode)
 983 {
 984   return (mode == ptr_mode || mode == Pmode);
 985 }
 986
 987 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
 988    for the generic address space only.  */
 989
 990 enum machine_mode
 991 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
 992 {
 993   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
 994   return ptr_mode;
 995 }
 996
 997 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
 998    for the generic address space only.  */
 999
1000 enum machine_mode
1001 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1002 {
1003   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1004   return Pmode;
1005 }
1006
1007 /* Named address space version of valid_pointer_mode.  */
1008
1009 bool
1010 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1011 {
1012   if (!ADDR_SPACE_GENERIC_P (as))
1013     return (mode == targetm.addr_space.pointer_mode (as)
1014             || mode == targetm.addr_space.address_mode (as));
1015
1016   return targetm.valid_pointer_mode (mode);
1017 }
1018
1019 /* Some places still assume that all pointer or address modes are the
1020    standard Pmode and ptr_mode.  These optimizations become invalid if
1021    the target actually supports multiple different modes.  For now,
1022    we disable such optimizations on such targets, using this function.  */
1023
1024 bool
1025 target_default_pointer_address_modes_p (void)
1026 {
1027   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1028     return false;
1029   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1030     return false;
1031
1032   return true;
1033 }
1034
1035 /* Named address space version of legitimate_address_p.  */
1036
1037 bool
1038 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1039                                          bool strict, addr_space_t as)
1040 {
1041   if (!ADDR_SPACE_GENERIC_P (as))
1042     gcc_unreachable ();
1043
1044   return targetm.legitimate_address_p (mode, mem, strict);
1045 }
1046
1047 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1048
1049 rtx
1050 default_addr_space_legitimize_address (rtx x, rtx oldx,
1051                                        enum machine_mode mode, addr_space_t as)
1052 {
1053   if (!ADDR_SPACE_GENERIC_P (as))
1054     return x;
1055
1056   return targetm.legitimize_address (x, oldx, mode);
1057 }
1058
1059 /* The default hook for determining if one named address space is a subset of
1060    another and to return which address space to use as the common address
1061    space.  */
1062
1063 bool
1064 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1065 {
1066   return (subset == superset);
1067 }
1068
1069 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1070    called for targets with only a generic address space.  */
1071
1072 rtx
1073 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1074                             tree from_type ATTRIBUTE_UNUSED,
1075                             tree to_type ATTRIBUTE_UNUSED)
1076 {
1077   gcc_unreachable ();
1078 }
1079
1080 bool
1081 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1082 {
1083   return true;
1084 }
1085
1086 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1087
1088 bool
1089 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1090 {
1091 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1092
1093   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1094   return false;
1095   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1096  win: ATTRIBUTE_UNUSED_LABEL
1097   return true;
1098
1099 #else
1100
1101   return false;
1102
1103 #endif
1104 }
1105
1106 bool
1107 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1108                                          tree ARG_UNUSED (name),
1109                                          tree ARG_UNUSED (args),
1110                                          int ARG_UNUSED (flags))
1111 {
1112   warning (OPT_Wattributes,
1113            "target attribute is not supported on this machine");
1114
1115   return false;
1116 }
1117
1118 bool
1119 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1120                                     tree ARG_UNUSED (pop_target))
1121 {
1122   warning (OPT_Wpragmas,
1123            "#pragma GCC target is not supported for this machine");
1124
1125   return false;
1126 }
1127
1128 bool
1129 default_target_can_inline_p (tree caller, tree callee)
1130 {
1131   bool ret = false;
1132   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1133   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1134
1135   /* If callee has no option attributes, then it is ok to inline */
1136   if (!callee_opts)
1137     ret = true;
1138
1139   /* If caller has no option attributes, but callee does then it is not ok to
1140      inline */
1141   else if (!caller_opts)
1142     ret = false;
1143
1144   /* If both caller and callee have attributes, assume that if the pointer is
1145      different, the the two functions have different target options since
1146      build_target_option_node uses a hash table for the options.  */
1147   else
1148     ret = (callee_opts == caller_opts);
1149
1150   return ret;
1151 }
1152
1153 #ifndef HAVE_casesi
1154 # define HAVE_casesi 0
1155 #endif
1156
1157 /* If the machine does not have a case insn that compares the bounds,
1158    this means extra overhead for dispatch tables, which raises the
1159    threshold for using them.  */
1160
1161 unsigned int default_case_values_threshold (void)
1162 {
1163   return (HAVE_casesi ? 4 : 5);
1164 }
1165
1166 bool
1167 default_have_conditional_execution (void)
1168 {
1169 #ifdef HAVE_conditional_execution
1170   return HAVE_conditional_execution;
1171 #else
1172   return false;
1173 #endif
1174 }
1175
1176 /* Compute cost of moving registers to/from memory.  */
1177
1178 int
1179 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1180                           reg_class_t rclass ATTRIBUTE_UNUSED,
1181                           bool in ATTRIBUTE_UNUSED)
1182 {
1183 #ifndef MEMORY_MOVE_COST
1184     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1185 #else
1186     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1187 #endif
1188 }
1189
1190 /* Compute cost of moving data from a register of class FROM to one of
1191    TO, using MODE.  */
1192
1193 int
1194 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1195                             reg_class_t from ATTRIBUTE_UNUSED,
1196                             reg_class_t to ATTRIBUTE_UNUSED)
1197 {
1198 #ifndef REGISTER_MOVE_COST
1199   return 2;
1200 #else
1201   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1202 #endif
1203 }
1204
1205 #include "gt-targhooks.h"