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                                     tree vectype ATTRIBUTE_UNUSED,
 484                                     int misalign ATTRIBUTE_UNUSED)
 485 {
 486   switch (type_of_cost)
 487     {
 488       case scalar_stmt:
 489       case scalar_load:
 490       case scalar_store:
 491       case vector_stmt:
 492       case vector_load:
 493       case vector_store:
 494       case vec_to_scalar:
 495       case scalar_to_vec:
 496       case cond_branch_not_taken:
 497       case vec_perm:
 498         return 1;
 499
 500       case unaligned_load:
 501       case unaligned_store:
 502         return 2;
 503
 504       case cond_branch_taken:
 505         return 3;
 506
 507       default:
 508         gcc_unreachable ();
 509     }
 510 }
 511
 512 /* Reciprocal.  */
 513
 514 tree
 515 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 516                             bool md_fn ATTRIBUTE_UNUSED,
 517                             bool sqrt ATTRIBUTE_UNUSED)
 518 {
 519   return NULL_TREE;
 520 }
 521
 522 bool
 523 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 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 false;
 529 }
 530
 531 bool
 532 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 533         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 534         enum machine_mode mode ATTRIBUTE_UNUSED,
 535         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 536 {
 537   return true;
 538 }
 539
 540 int
 541 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 542         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 543         enum machine_mode mode ATTRIBUTE_UNUSED,
 544         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 545 {
 546   return 0;
 547 }
 548
 549 void
 550 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 551                               enum machine_mode mode ATTRIBUTE_UNUSED,
 552                               const_tree type ATTRIBUTE_UNUSED,
 553                               bool named ATTRIBUTE_UNUSED)
 554 {
 555 #ifdef FUNCTION_ARG_ADVANCE
 556   CUMULATIVE_ARGS args = *ca;
 557   FUNCTION_ARG_ADVANCE (args, mode, CONST_CAST_TREE (type), named);
 558   *ca = args;
 559 #else
 560   gcc_unreachable ();
 561 #endif
 562 }
 563
 564 rtx
 565 default_function_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 566                       enum machine_mode mode ATTRIBUTE_UNUSED,
 567                       const_tree type ATTRIBUTE_UNUSED,
 568                       bool named ATTRIBUTE_UNUSED)
 569 {
 570 #ifdef FUNCTION_ARG
 571   return FUNCTION_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 572                        CONST_CAST_TREE (type), named);
 573 #else
 574   gcc_unreachable ();
 575 #endif
 576 }
 577
 578 rtx
 579 default_function_incoming_arg (const CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 580                                enum machine_mode mode ATTRIBUTE_UNUSED,
 581                                const_tree type ATTRIBUTE_UNUSED,
 582                                bool named ATTRIBUTE_UNUSED)
 583 {
 584 #ifdef FUNCTION_INCOMING_ARG
 585   return FUNCTION_INCOMING_ARG (*(CONST_CAST (CUMULATIVE_ARGS *, ca)), mode,
 586                                 CONST_CAST_TREE (type), named);
 587 #else
 588   gcc_unreachable ();
 589 #endif
 590 }
 591
 592 void
 593 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 594 {
 595 }
 596
 597 const char *
 598 hook_invalid_arg_for_unprototyped_fn (
 599         const_tree typelist ATTRIBUTE_UNUSED,
 600         const_tree funcdecl ATTRIBUTE_UNUSED,
 601         const_tree val ATTRIBUTE_UNUSED)
 602 {
 603   return NULL;
 604 }
 605
 606 /* Initialize the stack protection decls.  */
 607
 608 /* Stack protection related decls living in libgcc.  */
 609 static GTY(()) tree stack_chk_guard_decl;
 610
 611 tree
 612 default_stack_protect_guard (void)
 613 {
 614   tree t = stack_chk_guard_decl;
 615
 616   if (t == NULL)
 617     {
 618       rtx x;
 619
 620       t = build_decl (UNKNOWN_LOCATION,
 621                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 622                       ptr_type_node);
 623       TREE_STATIC (t) = 1;
 624       TREE_PUBLIC (t) = 1;
 625       DECL_EXTERNAL (t) = 1;
 626       TREE_USED (t) = 1;
 627       TREE_THIS_VOLATILE (t) = 1;
 628       DECL_ARTIFICIAL (t) = 1;
 629       DECL_IGNORED_P (t) = 1;
 630
 631       /* Do not share RTL as the declaration is visible outside of
 632          current function.  */
 633       x = DECL_RTL (t);
 634       RTX_FLAG (x, used) = 1;
 635
 636       stack_chk_guard_decl = t;
 637     }
 638
 639   return t;
 640 }
 641
 642 static GTY(()) tree stack_chk_fail_decl;
 643
 644 tree
 645 default_external_stack_protect_fail (void)
 646 {
 647   tree t = stack_chk_fail_decl;
 648
 649   if (t == NULL_TREE)
 650     {
 651       t = build_function_type_list (void_type_node, NULL_TREE);
 652       t = build_decl (UNKNOWN_LOCATION,
 653                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 654       TREE_STATIC (t) = 1;
 655       TREE_PUBLIC (t) = 1;
 656       DECL_EXTERNAL (t) = 1;
 657       TREE_USED (t) = 1;
 658       TREE_THIS_VOLATILE (t) = 1;
 659       TREE_NOTHROW (t) = 1;
 660       DECL_ARTIFICIAL (t) = 1;
 661       DECL_IGNORED_P (t) = 1;
 662       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 663       DECL_VISIBILITY_SPECIFIED (t) = 1;
 664
 665       stack_chk_fail_decl = t;
 666     }
 667
 668   return build_call_expr (t, 0);
 669 }
 670
 671 tree
 672 default_hidden_stack_protect_fail (void)
 673 {
 674 #ifndef HAVE_GAS_HIDDEN
 675   return default_external_stack_protect_fail ();
 676 #else
 677   tree t = stack_chk_fail_decl;
 678
 679   if (!flag_pic)
 680     return default_external_stack_protect_fail ();
 681
 682   if (t == NULL_TREE)
 683     {
 684       t = build_function_type_list (void_type_node, NULL_TREE);
 685       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 686                       get_identifier ("__stack_chk_fail_local"), t);
 687       TREE_STATIC (t) = 1;
 688       TREE_PUBLIC (t) = 1;
 689       DECL_EXTERNAL (t) = 1;
 690       TREE_USED (t) = 1;
 691       TREE_THIS_VOLATILE (t) = 1;
 692       TREE_NOTHROW (t) = 1;
 693       DECL_ARTIFICIAL (t) = 1;
 694       DECL_IGNORED_P (t) = 1;
 695       DECL_VISIBILITY_SPECIFIED (t) = 1;
 696       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 697
 698       stack_chk_fail_decl = t;
 699     }
 700
 701   return build_call_expr (t, 0);
 702 #endif
 703 }
 704
 705 bool
 706 hook_bool_const_rtx_commutative_p (const_rtx x,
 707                                    int outer_code ATTRIBUTE_UNUSED)
 708 {
 709   return COMMUTATIVE_P (x);
 710 }
 711
 712 rtx
 713 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 714                         const_tree fn_decl_or_type,
 715                         bool outgoing ATTRIBUTE_UNUSED)
 716 {
 717   /* The old interface doesn't handle receiving the function type.  */
 718   if (fn_decl_or_type
 719       && !DECL_P (fn_decl_or_type))
 720     fn_decl_or_type = NULL;
 721
 722 #ifdef FUNCTION_VALUE
 723   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 724 #else
 725   gcc_unreachable ();
 726 #endif
 727 }
 728
 729 rtx
 730 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 731                        const_rtx fun ATTRIBUTE_UNUSED)
 732 {
 733 #ifdef LIBCALL_VALUE
 734   return LIBCALL_VALUE (mode);
 735 #else
 736   gcc_unreachable ();
 737 #endif
 738 }
 739
 740 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 741
 742 bool
 743 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 744 {
 745 #ifdef FUNCTION_VALUE_REGNO_P
 746   return FUNCTION_VALUE_REGNO_P (regno);
 747 #else
 748   gcc_unreachable ();
 749 #endif
 750 }
 751
 752 rtx
 753 default_internal_arg_pointer (void)
 754 {
 755   /* If the reg that the virtual arg pointer will be translated into is
 756      not a fixed reg or is the stack pointer, make a copy of the virtual
 757      arg pointer, and address parms via the copy.  The frame pointer is
 758      considered fixed even though it is not marked as such.  */
 759   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 760        || ! (fixed_regs[ARG_POINTER_REGNUM]
 761              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 762     return copy_to_reg (virtual_incoming_args_rtx);
 763   else
 764     return virtual_incoming_args_rtx;
 765 }
 766
 767 rtx
 768 default_static_chain (const_tree fndecl, bool incoming_p)
 769 {
 770   if (!DECL_STATIC_CHAIN (fndecl))
 771     return NULL;
 772
 773   if (incoming_p)
 774     {
 775 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 776       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 777 #endif
 778     }
 779
 780 #ifdef STATIC_CHAIN_REGNUM
 781   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 782 #endif
 783
 784   {
 785     static bool issued_error;
 786     if (!issued_error)
 787       {
 788         issued_error = true;
 789         sorry ("nested functions not supported on this target");
 790       }
 791
 792     /* It really doesn't matter what we return here, so long at it
 793        doesn't cause the rest of the compiler to crash.  */
 794     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 795   }
 796 }
 797
 798 void
 799 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 800                          rtx ARG_UNUSED (r_chain))
 801 {
 802   sorry ("nested function trampolines not supported on this target");
 803 }
 804
 805 int
 806 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 807                           tree funtype ATTRIBUTE_UNUSED,
 808                           int size ATTRIBUTE_UNUSED)
 809 {
 810   return 0;
 811 }
 812
 813 reg_class_t
 814 default_branch_target_register_class (void)
 815 {
 816   return NO_REGS;
 817 }
 818
 819 #ifdef IRA_COVER_CLASSES
 820 const reg_class_t *
 821 default_ira_cover_classes (void)
 822 {
 823   static reg_class_t classes[] = IRA_COVER_CLASSES;
 824   return classes;
 825 }
 826 #endif
 827
 828 reg_class_t
 829 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 830                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 831                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 832                           secondary_reload_info *sri)
 833 {
 834   enum reg_class rclass = NO_REGS;
 835   enum reg_class reload_class = (enum reg_class) reload_class_i;
 836
 837   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 838     {
 839       sri->icode = sri->prev_sri->t_icode;
 840       return NO_REGS;
 841     }
 842 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 843   if (in_p)
 844     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 845 #endif
 846 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 847   if (! in_p)
 848     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 849 #endif
 850   if (rclass != NO_REGS)
 851     {
 852       enum insn_code icode
 853         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 854                                 reload_mode);
 855
 856       if (icode != CODE_FOR_nothing
 857           && insn_data[(int) icode].operand[in_p].predicate
 858           && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
 859         icode = CODE_FOR_nothing;
 860       else if (icode != CODE_FOR_nothing)
 861         {
 862           const char *insn_constraint, *scratch_constraint;
 863           char insn_letter, scratch_letter;
 864           enum reg_class insn_class, scratch_class;
 865
 866           gcc_assert (insn_data[(int) icode].n_operands == 3);
 867           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 868           if (!*insn_constraint)
 869             insn_class = ALL_REGS;
 870           else
 871             {
 872               if (in_p)
 873                 {
 874                   gcc_assert (*insn_constraint == '=');
 875                   insn_constraint++;
 876                 }
 877               insn_letter = *insn_constraint;
 878               insn_class
 879                 = (insn_letter == 'r' ? GENERAL_REGS
 880                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 881                                                 insn_constraint));
 882               gcc_assert (insn_class != NO_REGS);
 883             }
 884
 885           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 886           /* The scratch register's constraint must start with "=&",
 887              except for an input reload, where only "=" is necessary,
 888              and where it might be beneficial to re-use registers from
 889              the input.  */
 890           gcc_assert (scratch_constraint[0] == '='
 891                       && (in_p || scratch_constraint[1] == '&'));
 892           scratch_constraint++;
 893           if (*scratch_constraint == '&')
 894             scratch_constraint++;
 895           scratch_letter = *scratch_constraint;
 896           scratch_class
 897             = (scratch_letter == 'r' ? GENERAL_REGS
 898                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 899                                             scratch_constraint));
 900
 901           if (reg_class_subset_p (reload_class, insn_class))
 902             {
 903               gcc_assert (scratch_class == rclass);
 904               rclass = NO_REGS;
 905             }
 906           else
 907             rclass = insn_class;
 908
 909         }
 910       if (rclass == NO_REGS)
 911         sri->icode = icode;
 912       else
 913         sri->t_icode = icode;
 914     }
 915   return rclass;
 916 }
 917
 918 void
 919 default_target_option_override (void)
 920 {
 921 #ifdef OVERRIDE_OPTIONS
 922   OVERRIDE_OPTIONS;
 923 #endif
 924 }
 925
 926 bool
 927 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 928                          const char *arg ATTRIBUTE_UNUSED,
 929                          int value ATTRIBUTE_UNUSED)
 930 {
 931   return false;
 932 }
 933
 934 /* By default, if flag_pic is true, then neither local nor global relocs
 935    should be placed in readonly memory.  */
 936
 937 int
 938 default_reloc_rw_mask (void)
 939 {
 940   return flag_pic ? 3 : 0;
 941 }
 942
 943 /* By default, do no modification. */
 944 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 945                                          tree id)
 946 {
 947    return id;
 948 }
 949
 950 bool
 951 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 952 {
 953   if (is_packed)
 954     return false;
 955
 956   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 957      naturally aligned.  */
 958   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 959     return false;
 960
 961   /* Assuming that types whose size is <= pointer-size
 962      are naturally aligned.  */
 963   return true;
 964 }
 965
 966 /* By default, assume that a target supports any factor of misalignment
 967    memory access if it supports movmisalign patten.
 968    is_packed is true if the memory access is defined in a packed struct.  */
 969 bool
 970 default_builtin_support_vector_misalignment (enum machine_mode mode,
 971                                              const_tree type
 972                                              ATTRIBUTE_UNUSED,
 973                                              int misalignment
 974                                              ATTRIBUTE_UNUSED,
 975                                              bool is_packed
 976                                              ATTRIBUTE_UNUSED)
 977 {
 978   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
 979     return true;
 980   return false;
 981 }
 982
 983 /* Determine whether or not a pointer mode is valid. Assume defaults
 984    of ptr_mode or Pmode - can be overridden.  */
 985 bool
 986 default_valid_pointer_mode (enum machine_mode mode)
 987 {
 988   return (mode == ptr_mode || mode == Pmode);
 989 }
 990
 991 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
 992    for the generic address space only.  */
 993
 994 enum machine_mode
 995 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
 996 {
 997   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
 998   return ptr_mode;
 999 }
1000
1001 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1002    for the generic address space only.  */
1003
1004 enum machine_mode
1005 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1006 {
1007   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1008   return Pmode;
1009 }
1010
1011 /* Named address space version of valid_pointer_mode.  */
1012
1013 bool
1014 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1015 {
1016   if (!ADDR_SPACE_GENERIC_P (as))
1017     return (mode == targetm.addr_space.pointer_mode (as)
1018             || mode == targetm.addr_space.address_mode (as));
1019
1020   return targetm.valid_pointer_mode (mode);
1021 }
1022
1023 /* Some places still assume that all pointer or address modes are the
1024    standard Pmode and ptr_mode.  These optimizations become invalid if
1025    the target actually supports multiple different modes.  For now,
1026    we disable such optimizations on such targets, using this function.  */
1027
1028 bool
1029 target_default_pointer_address_modes_p (void)
1030 {
1031   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1032     return false;
1033   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1034     return false;
1035
1036   return true;
1037 }
1038
1039 /* Named address space version of legitimate_address_p.  */
1040
1041 bool
1042 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1043                                          bool strict, addr_space_t as)
1044 {
1045   if (!ADDR_SPACE_GENERIC_P (as))
1046     gcc_unreachable ();
1047
1048   return targetm.legitimate_address_p (mode, mem, strict);
1049 }
1050
1051 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1052
1053 rtx
1054 default_addr_space_legitimize_address (rtx x, rtx oldx,
1055                                        enum machine_mode mode, addr_space_t as)
1056 {
1057   if (!ADDR_SPACE_GENERIC_P (as))
1058     return x;
1059
1060   return targetm.legitimize_address (x, oldx, mode);
1061 }
1062
1063 /* The default hook for determining if one named address space is a subset of
1064    another and to return which address space to use as the common address
1065    space.  */
1066
1067 bool
1068 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1069 {
1070   return (subset == superset);
1071 }
1072
1073 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1074    called for targets with only a generic address space.  */
1075
1076 rtx
1077 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1078                             tree from_type ATTRIBUTE_UNUSED,
1079                             tree to_type ATTRIBUTE_UNUSED)
1080 {
1081   gcc_unreachable ();
1082 }
1083
1084 bool
1085 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1086 {
1087   return true;
1088 }
1089
1090 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1091
1092 bool
1093 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1094 {
1095 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1096
1097   GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1098   return false;
1099   /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS.  */
1100  win: ATTRIBUTE_UNUSED_LABEL
1101   return true;
1102
1103 #else
1104
1105   return false;
1106
1107 #endif
1108 }
1109
1110 bool
1111 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1112                                          tree ARG_UNUSED (name),
1113                                          tree ARG_UNUSED (args),
1114                                          int ARG_UNUSED (flags))
1115 {
1116   warning (OPT_Wattributes,
1117            "target attribute is not supported on this machine");
1118
1119   return false;
1120 }
1121
1122 bool
1123 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1124                                     tree ARG_UNUSED (pop_target))
1125 {
1126   warning (OPT_Wpragmas,
1127            "#pragma GCC target is not supported for this machine");
1128
1129   return false;
1130 }
1131
1132 bool
1133 default_target_can_inline_p (tree caller, tree callee)
1134 {
1135   bool ret = false;
1136   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1137   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1138
1139   /* If callee has no option attributes, then it is ok to inline */
1140   if (!callee_opts)
1141     ret = true;
1142
1143   /* If caller has no option attributes, but callee does then it is not ok to
1144      inline */
1145   else if (!caller_opts)
1146     ret = false;
1147
1148   /* If both caller and callee have attributes, assume that if the pointer is
1149      different, the the two functions have different target options since
1150      build_target_option_node uses a hash table for the options.  */
1151   else
1152     ret = (callee_opts == caller_opts);
1153
1154   return ret;
1155 }
1156
1157 #ifndef HAVE_casesi
1158 # define HAVE_casesi 0
1159 #endif
1160
1161 /* If the machine does not have a case insn that compares the bounds,
1162    this means extra overhead for dispatch tables, which raises the
1163    threshold for using them.  */
1164
1165 unsigned int default_case_values_threshold (void)
1166 {
1167   return (HAVE_casesi ? 4 : 5);
1168 }
1169
1170 bool
1171 default_have_conditional_execution (void)
1172 {
1173 #ifdef HAVE_conditional_execution
1174   return HAVE_conditional_execution;
1175 #else
1176   return false;
1177 #endif
1178 }
1179
1180 /* Compute cost of moving registers to/from memory.  */
1181
1182 int
1183 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1184                           reg_class_t rclass ATTRIBUTE_UNUSED,
1185                           bool in ATTRIBUTE_UNUSED)
1186 {
1187 #ifndef MEMORY_MOVE_COST
1188     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1189 #else
1190     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1191 #endif
1192 }
1193
1194 /* Compute cost of moving data from a register of class FROM to one of
1195    TO, using MODE.  */
1196
1197 int
1198 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1199                             reg_class_t from ATTRIBUTE_UNUSED,
1200                             reg_class_t to ATTRIBUTE_UNUSED)
1201 {
1202 #ifndef REGISTER_MOVE_COST
1203   return 2;
1204 #else
1205   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1206 #endif
1207 }
1208
1209 #include "gt-targhooks.h"