gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003-2014 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* The migration of target macros to target hooks works as follows:
  21
  22    1. Create a target hook that uses the existing target macros to
  23       implement the same functionality.
  24
  25    2. Convert all the MI files to use the hook instead of the macro.
  26
  27    3. Repeat for a majority of the remaining target macros.  This will
  28       take some time.
  29
  30    4. Tell target maintainers to start migrating.
  31
  32    5. Eventually convert the backends to override the hook instead of
  33       defining the macros.  This will take some time too.
  34
  35    6. TBD when, poison the macros.  Unmigrated targets will break at
  36       this point.
  37
  38    Note that we expect steps 1-3 to be done by the people that
  39    understand what the MI does with each macro, and step 5 to be done
  40    by the target maintainers for their respective targets.
  41
  42    Note that steps 1 and 2 don't have to be done together, but no
  43    target can override the new hook until step 2 is complete for it.
  44
  45    Once the macros are poisoned, we will revert to the old migration
  46    rules - migrate the macro, callers, and targets all at once.  This
  47    comment can thus be removed at that point.  */
  48
  49 #include "config.h"
  50 #include "system.h"
  51 #include "coretypes.h"
  52 #include "tm.h"
  53 #include "machmode.h"
  54 #include "rtl.h"
  55 #include "tree.h"
  56 #include "stor-layout.h"
  57 #include "varasm.h"
  58 #include "expr.h"
  59 #include "output.h"
  60 #include "diagnostic-core.h"
  61 #include "function.h"
  62 #include "target.h"
  63 #include "tm_p.h"
  64 #include "target-def.h"
  65 #include "hard-reg-set.h"
  66 #include "regs.h"
  67 #include "reload.h"
  68 #include "optabs.h"
  69 #include "recog.h"
  70 #include "intl.h"
  71 #include "opts.h"
  72 #include "tree-ssa-alias.h"
  73 #include "gimple-expr.h"
  74 #include "gimplify.h"
  75 #include "stringpool.h"
  76 #include "tree-ssanames.h"
  77 #include "insn-codes.h"
  78
  79
  80 bool
  81 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  82                               rtx addr ATTRIBUTE_UNUSED,
  83                               bool strict ATTRIBUTE_UNUSED)
  84 {
  85 #ifdef GO_IF_LEGITIMATE_ADDRESS
  86   /* Defer to the old implementation using a goto.  */
  87   if (strict)
  88     return strict_memory_address_p (mode, addr);
  89   else
  90     return memory_address_p (mode, addr);
  91 #else
  92   gcc_unreachable ();
  93 #endif
  94 }
  95
  96 void
  97 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  98 {
  99 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
 100   ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
 101 #endif
 102 }
 103
 104 int
 105 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 106 {
 107   int i;
 108
 109   /* Any floating arithmetic may trap.  */
 110   if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
 111     return 1;
 112
 113   for (i = 0; i < XVECLEN (x, 0); ++i)
 114     {
 115       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 116         return 1;
 117     }
 118
 119   return 0;
 120 }
 121
 122 enum machine_mode
 123 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 124                                enum machine_mode mode,
 125                                int *punsignedp ATTRIBUTE_UNUSED,
 126                                const_tree funtype ATTRIBUTE_UNUSED,
 127                                int for_return ATTRIBUTE_UNUSED)
 128 {
 129   if (type != NULL_TREE && for_return == 2)
 130     return promote_mode (type, mode, punsignedp);
 131   return mode;
 132 }
 133
 134 enum machine_mode
 135 default_promote_function_mode_always_promote (const_tree type,
 136                                               enum machine_mode mode,
 137                                               int *punsignedp,
 138                                               const_tree funtype ATTRIBUTE_UNUSED,
 139                                               int for_return ATTRIBUTE_UNUSED)
 140 {
 141   return promote_mode (type, mode, punsignedp);
 142 }
 143
 144 enum machine_mode
 145 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 146 {
 147   if (m1 == m2)
 148     return m1;
 149   return VOIDmode;
 150 }
 151
 152 bool
 153 default_return_in_memory (const_tree type,
 154                           const_tree fntype ATTRIBUTE_UNUSED)
 155 {
 156   return (TYPE_MODE (type) == BLKmode);
 157 }
 158
 159 rtx
 160 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 161                             enum machine_mode mode ATTRIBUTE_UNUSED)
 162 {
 163   return x;
 164 }
 165
 166 rtx
 167 default_expand_builtin_saveregs (void)
 168 {
 169   error ("__builtin_saveregs not supported by this target");
 170   return const0_rtx;
 171 }
 172
 173 void
 174 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 175                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 176                                 tree type ATTRIBUTE_UNUSED,
 177                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 178                                 int second_time ATTRIBUTE_UNUSED)
 179 {
 180 }
 181
 182 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 183
 184 rtx
 185 default_builtin_setjmp_frame_value (void)
 186 {
 187   return virtual_stack_vars_rtx;
 188 }
 189
 190 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 191
 192 bool
 193 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 194 {
 195   return false;
 196 }
 197
 198 bool
 199 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 200 {
 201   return (targetm.calls.setup_incoming_varargs
 202           != default_setup_incoming_varargs);
 203 }
 204
 205 enum machine_mode
 206 default_eh_return_filter_mode (void)
 207 {
 208   return targetm.unwind_word_mode ();
 209 }
 210
 211 enum machine_mode
 212 default_libgcc_cmp_return_mode (void)
 213 {
 214   return word_mode;
 215 }
 216
 217 enum machine_mode
 218 default_libgcc_shift_count_mode (void)
 219 {
 220   return word_mode;
 221 }
 222
 223 enum machine_mode
 224 default_unwind_word_mode (void)
 225 {
 226   return word_mode;
 227 }
 228
 229 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 230
 231 unsigned HOST_WIDE_INT
 232 default_shift_truncation_mask (enum machine_mode mode)
 233 {
 234   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 235 }
 236
 237 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 238
 239 unsigned int
 240 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 241 {
 242   return have_insn_for (DIV, mode) ? 3 : 2;
 243 }
 244
 245 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 246
 247 int
 248 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 249                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 250 {
 251   return UNKNOWN;
 252 }
 253
 254 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 255
 256 bool
 257 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 258 {
 259   return true;
 260 }
 261
 262 /* Return machine mode for non-standard suffix
 263    or VOIDmode if non-standard suffixes are unsupported.  */
 264 enum machine_mode
 265 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 266 {
 267   return VOIDmode;
 268 }
 269
 270 /* The generic C++ ABI specifies this is a 64-bit value.  */
 271 tree
 272 default_cxx_guard_type (void)
 273 {
 274   return long_long_integer_type_node;
 275 }
 276
 277 /* Returns the size of the cookie to use when allocating an array
 278    whose elements have the indicated TYPE.  Assumes that it is already
 279    known that a cookie is needed.  */
 280
 281 tree
 282 default_cxx_get_cookie_size (tree type)
 283 {
 284   tree cookie_size;
 285
 286   /* We need to allocate an additional max (sizeof (size_t), alignof
 287      (true_type)) bytes.  */
 288   tree sizetype_size;
 289   tree type_align;
 290
 291   sizetype_size = size_in_bytes (sizetype);
 292   type_align = size_int (TYPE_ALIGN_UNIT (type));
 293   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 294     cookie_size = sizetype_size;
 295   else
 296     cookie_size = type_align;
 297
 298   return cookie_size;
 299 }
 300
 301 /* Return true if a parameter must be passed by reference.  This version
 302    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 303
 304 bool
 305 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 306         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 307         bool named_arg ATTRIBUTE_UNUSED)
 308 {
 309   return targetm.calls.must_pass_in_stack (mode, type);
 310 }
 311
 312 /* Return true if a parameter follows callee copies conventions.  This
 313    version of the hook is true for all named arguments.  */
 314
 315 bool
 316 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 317                           enum machine_mode mode ATTRIBUTE_UNUSED,
 318                           const_tree type ATTRIBUTE_UNUSED, bool named)
 319 {
 320   return named;
 321 }
 322
 323 /* Emit to STREAM the assembler syntax for insn operand X.  */
 324
 325 void
 326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 327                        int code ATTRIBUTE_UNUSED)
 328 {
 329 #ifdef PRINT_OPERAND
 330   PRINT_OPERAND (stream, x, code);
 331 #else
 332   gcc_unreachable ();
 333 #endif
 334 }
 335
 336 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 337    address is X.  */
 338
 339 void
 340 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 341                                rtx x ATTRIBUTE_UNUSED)
 342 {
 343 #ifdef PRINT_OPERAND_ADDRESS
 344   PRINT_OPERAND_ADDRESS (stream, x);
 345 #else
 346   gcc_unreachable ();
 347 #endif
 348 }
 349
 350 /* Return true if CODE is a valid punctuation character for the
 351    `print_operand' hook.  */
 352
 353 bool
 354 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 355 {
 356 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 357   return PRINT_OPERAND_PUNCT_VALID_P (code);
 358 #else
 359   return false;
 360 #endif
 361 }
 362
 363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 364 tree
 365 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 366 {
 367   const char *skipped = name + (*name == '*' ? 1 : 0);
 368   const char *stripped = targetm.strip_name_encoding (skipped);
 369   if (*name != '*' && user_label_prefix[0])
 370     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 371   return get_identifier (stripped);
 372 }
 373
 374 /* True if MODE is valid for the target.  By "valid", we mean able to
 375    be manipulated in non-trivial ways.  In particular, this means all
 376    the arithmetic is supported.
 377
 378    By default we guess this means that any C type is supported.  If
 379    we can't map the mode back to a type that would be available in C,
 380    then reject it.  Special case, here, is the double-word arithmetic
 381    supported by optabs.c.  */
 382
 383 bool
 384 default_scalar_mode_supported_p (enum machine_mode mode)
 385 {
 386   int precision = GET_MODE_PRECISION (mode);
 387
 388   switch (GET_MODE_CLASS (mode))
 389     {
 390     case MODE_PARTIAL_INT:
 391     case MODE_INT:
 392       if (precision == CHAR_TYPE_SIZE)
 393         return true;
 394       if (precision == SHORT_TYPE_SIZE)
 395         return true;
 396       if (precision == INT_TYPE_SIZE)
 397         return true;
 398       if (precision == LONG_TYPE_SIZE)
 399         return true;
 400       if (precision == LONG_LONG_TYPE_SIZE)
 401         return true;
 402       if (precision == 2 * BITS_PER_WORD)
 403         return true;
 404       return false;
 405
 406     case MODE_FLOAT:
 407       if (precision == FLOAT_TYPE_SIZE)
 408         return true;
 409       if (precision == DOUBLE_TYPE_SIZE)
 410         return true;
 411       if (precision == LONG_DOUBLE_TYPE_SIZE)
 412         return true;
 413       return false;
 414
 415     case MODE_DECIMAL_FLOAT:
 416     case MODE_FRACT:
 417     case MODE_UFRACT:
 418     case MODE_ACCUM:
 419     case MODE_UACCUM:
 420       return false;
 421
 422     default:
 423       gcc_unreachable ();
 424     }
 425 }
 426
 427 /* Make some target macros useable by target-independent code.  */
 428 bool
 429 targhook_words_big_endian (void)
 430 {
 431   return !!WORDS_BIG_ENDIAN;
 432 }
 433
 434 bool
 435 targhook_float_words_big_endian (void)
 436 {
 437   return !!FLOAT_WORDS_BIG_ENDIAN;
 438 }
 439
 440 /* True if the target supports floating-point exceptions and rounding
 441    modes.  */
 442
 443 bool
 444 default_float_exceptions_rounding_supported_p (void)
 445 {
 446 #ifdef HAVE_adddf3
 447   return HAVE_adddf3;
 448 #else
 449   return false;
 450 #endif
 451 }
 452
 453 /* True if the target supports decimal floating point.  */
 454
 455 bool
 456 default_decimal_float_supported_p (void)
 457 {
 458   return ENABLE_DECIMAL_FLOAT;
 459 }
 460
 461 /* True if the target supports fixed-point arithmetic.  */
 462
 463 bool
 464 default_fixed_point_supported_p (void)
 465 {
 466   return ENABLE_FIXED_POINT;
 467 }
 468
 469 /* True if the target supports GNU indirect functions.  */
 470
 471 bool
 472 default_has_ifunc_p (void)
 473 {
 474   return HAVE_GNU_INDIRECT_FUNCTION;
 475 }
 476
 477 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 478    an error message.
 479
 480    This function checks whether a given INSN is valid within a low-overhead
 481    loop.  If INSN is invalid it returns the reason for that, otherwise it
 482    returns NULL. A called function may clobber any special registers required
 483    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 484    register for branch on table instructions. We reject the doloop pattern in
 485    these cases.  */
 486
 487 const char *
 488 default_invalid_within_doloop (const_rtx insn)
 489 {
 490   if (CALL_P (insn))
 491     return "Function call in loop.";
 492
 493   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 494     return "Computed branch in the loop.";
 495
 496   return NULL;
 497 }
 498
 499 /* Mapping of builtin functions to vectorized variants.  */
 500
 501 tree
 502 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
 503                                      tree type_out ATTRIBUTE_UNUSED,
 504                                      tree type_in ATTRIBUTE_UNUSED)
 505 {
 506   return NULL_TREE;
 507 }
 508
 509 /* Vectorized conversion.  */
 510
 511 tree
 512 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 513                                        tree dest_type ATTRIBUTE_UNUSED,
 514                                        tree src_type ATTRIBUTE_UNUSED)
 515 {
 516   return NULL_TREE;
 517 }
 518
 519 /* Default vectorizer cost model values.  */
 520
 521 int
 522 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 523                                     tree vectype,
 524                                     int misalign ATTRIBUTE_UNUSED)
 525 {
 526   unsigned elements;
 527
 528   switch (type_of_cost)
 529     {
 530       case scalar_stmt:
 531       case scalar_load:
 532       case scalar_store:
 533       case vector_stmt:
 534       case vector_load:
 535       case vector_store:
 536       case vec_to_scalar:
 537       case scalar_to_vec:
 538       case cond_branch_not_taken:
 539       case vec_perm:
 540       case vec_promote_demote:
 541         return 1;
 542
 543       case unaligned_load:
 544       case unaligned_store:
 545         return 2;
 546
 547       case cond_branch_taken:
 548         return 3;
 549
 550       case vec_construct:
 551         elements = TYPE_VECTOR_SUBPARTS (vectype);
 552         return elements / 2 + 1;
 553
 554       default:
 555         gcc_unreachable ();
 556     }
 557 }
 558
 559 /* Reciprocal.  */
 560
 561 tree
 562 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
 563                             bool md_fn ATTRIBUTE_UNUSED,
 564                             bool sqrt ATTRIBUTE_UNUSED)
 565 {
 566   return NULL_TREE;
 567 }
 568
 569 bool
 570 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 571         cumulative_args_t ca ATTRIBUTE_UNUSED,
 572         enum machine_mode mode ATTRIBUTE_UNUSED,
 573         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 574 {
 575   return false;
 576 }
 577
 578 bool
 579 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 580         cumulative_args_t ca ATTRIBUTE_UNUSED,
 581         enum machine_mode mode ATTRIBUTE_UNUSED,
 582         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 583 {
 584   return true;
 585 }
 586
 587 int
 588 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 589         cumulative_args_t ca ATTRIBUTE_UNUSED,
 590         enum machine_mode mode ATTRIBUTE_UNUSED,
 591         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 592 {
 593   return 0;
 594 }
 595
 596 void
 597 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 598                               enum machine_mode mode ATTRIBUTE_UNUSED,
 599                               const_tree type ATTRIBUTE_UNUSED,
 600                               bool named ATTRIBUTE_UNUSED)
 601 {
 602   gcc_unreachable ();
 603 }
 604
 605 rtx
 606 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 607                       enum machine_mode mode ATTRIBUTE_UNUSED,
 608                       const_tree type ATTRIBUTE_UNUSED,
 609                       bool named ATTRIBUTE_UNUSED)
 610 {
 611   gcc_unreachable ();
 612 }
 613
 614 rtx
 615 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 616                                enum machine_mode mode ATTRIBUTE_UNUSED,
 617                                const_tree type ATTRIBUTE_UNUSED,
 618                                bool named ATTRIBUTE_UNUSED)
 619 {
 620   gcc_unreachable ();
 621 }
 622
 623 unsigned int
 624 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 625                                const_tree type ATTRIBUTE_UNUSED)
 626 {
 627   return PARM_BOUNDARY;
 628 }
 629
 630 unsigned int
 631 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
 632                                      const_tree type ATTRIBUTE_UNUSED)
 633 {
 634   return PARM_BOUNDARY;
 635 }
 636
 637 void
 638 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 639 {
 640 }
 641
 642 const char *
 643 hook_invalid_arg_for_unprototyped_fn (
 644         const_tree typelist ATTRIBUTE_UNUSED,
 645         const_tree funcdecl ATTRIBUTE_UNUSED,
 646         const_tree val ATTRIBUTE_UNUSED)
 647 {
 648   return NULL;
 649 }
 650
 651 /* Initialize the stack protection decls.  */
 652
 653 /* Stack protection related decls living in libgcc.  */
 654 static GTY(()) tree stack_chk_guard_decl;
 655
 656 tree
 657 default_stack_protect_guard (void)
 658 {
 659   tree t = stack_chk_guard_decl;
 660
 661   if (t == NULL)
 662     {
 663       rtx x;
 664
 665       t = build_decl (UNKNOWN_LOCATION,
 666                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 667                       ptr_type_node);
 668       TREE_STATIC (t) = 1;
 669       TREE_PUBLIC (t) = 1;
 670       DECL_EXTERNAL (t) = 1;
 671       TREE_USED (t) = 1;
 672       TREE_THIS_VOLATILE (t) = 1;
 673       DECL_ARTIFICIAL (t) = 1;
 674       DECL_IGNORED_P (t) = 1;
 675
 676       /* Do not share RTL as the declaration is visible outside of
 677          current function.  */
 678       x = DECL_RTL (t);
 679       RTX_FLAG (x, used) = 1;
 680
 681       stack_chk_guard_decl = t;
 682     }
 683
 684   return t;
 685 }
 686
 687 static GTY(()) tree stack_chk_fail_decl;
 688
 689 tree
 690 default_external_stack_protect_fail (void)
 691 {
 692   tree t = stack_chk_fail_decl;
 693
 694   if (t == NULL_TREE)
 695     {
 696       t = build_function_type_list (void_type_node, NULL_TREE);
 697       t = build_decl (UNKNOWN_LOCATION,
 698                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 699       TREE_STATIC (t) = 1;
 700       TREE_PUBLIC (t) = 1;
 701       DECL_EXTERNAL (t) = 1;
 702       TREE_USED (t) = 1;
 703       TREE_THIS_VOLATILE (t) = 1;
 704       TREE_NOTHROW (t) = 1;
 705       DECL_ARTIFICIAL (t) = 1;
 706       DECL_IGNORED_P (t) = 1;
 707       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 708       DECL_VISIBILITY_SPECIFIED (t) = 1;
 709
 710       stack_chk_fail_decl = t;
 711     }
 712
 713   return build_call_expr (t, 0);
 714 }
 715
 716 tree
 717 default_hidden_stack_protect_fail (void)
 718 {
 719 #ifndef HAVE_GAS_HIDDEN
 720   return default_external_stack_protect_fail ();
 721 #else
 722   tree t = stack_chk_fail_decl;
 723
 724   if (!flag_pic)
 725     return default_external_stack_protect_fail ();
 726
 727   if (t == NULL_TREE)
 728     {
 729       t = build_function_type_list (void_type_node, NULL_TREE);
 730       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 731                       get_identifier ("__stack_chk_fail_local"), t);
 732       TREE_STATIC (t) = 1;
 733       TREE_PUBLIC (t) = 1;
 734       DECL_EXTERNAL (t) = 1;
 735       TREE_USED (t) = 1;
 736       TREE_THIS_VOLATILE (t) = 1;
 737       TREE_NOTHROW (t) = 1;
 738       DECL_ARTIFICIAL (t) = 1;
 739       DECL_IGNORED_P (t) = 1;
 740       DECL_VISIBILITY_SPECIFIED (t) = 1;
 741       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 742
 743       stack_chk_fail_decl = t;
 744     }
 745
 746   return build_call_expr (t, 0);
 747 #endif
 748 }
 749
 750 bool
 751 hook_bool_const_rtx_commutative_p (const_rtx x,
 752                                    int outer_code ATTRIBUTE_UNUSED)
 753 {
 754   return COMMUTATIVE_P (x);
 755 }
 756
 757 rtx
 758 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 759                         const_tree fn_decl_or_type,
 760                         bool outgoing ATTRIBUTE_UNUSED)
 761 {
 762   /* The old interface doesn't handle receiving the function type.  */
 763   if (fn_decl_or_type
 764       && !DECL_P (fn_decl_or_type))
 765     fn_decl_or_type = NULL;
 766
 767 #ifdef FUNCTION_VALUE
 768   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 769 #else
 770   gcc_unreachable ();
 771 #endif
 772 }
 773
 774 rtx
 775 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
 776                        const_rtx fun ATTRIBUTE_UNUSED)
 777 {
 778 #ifdef LIBCALL_VALUE
 779   return LIBCALL_VALUE (mode);
 780 #else
 781   gcc_unreachable ();
 782 #endif
 783 }
 784
 785 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
 786
 787 bool
 788 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
 789 {
 790 #ifdef FUNCTION_VALUE_REGNO_P
 791   return FUNCTION_VALUE_REGNO_P (regno);
 792 #else
 793   gcc_unreachable ();
 794 #endif
 795 }
 796
 797 rtx
 798 default_internal_arg_pointer (void)
 799 {
 800   /* If the reg that the virtual arg pointer will be translated into is
 801      not a fixed reg or is the stack pointer, make a copy of the virtual
 802      arg pointer, and address parms via the copy.  The frame pointer is
 803      considered fixed even though it is not marked as such.  */
 804   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 805        || ! (fixed_regs[ARG_POINTER_REGNUM]
 806              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 807     return copy_to_reg (virtual_incoming_args_rtx);
 808   else
 809     return virtual_incoming_args_rtx;
 810 }
 811
 812 rtx
 813 default_static_chain (const_tree fndecl, bool incoming_p)
 814 {
 815   if (!DECL_STATIC_CHAIN (fndecl))
 816     return NULL;
 817
 818   if (incoming_p)
 819     {
 820 #ifdef STATIC_CHAIN_INCOMING_REGNUM
 821       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
 822 #endif
 823     }
 824
 825 #ifdef STATIC_CHAIN_REGNUM
 826   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
 827 #endif
 828
 829   {
 830     static bool issued_error;
 831     if (!issued_error)
 832       {
 833         issued_error = true;
 834         sorry ("nested functions not supported on this target");
 835       }
 836
 837     /* It really doesn't matter what we return here, so long at it
 838        doesn't cause the rest of the compiler to crash.  */
 839     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
 840   }
 841 }
 842
 843 void
 844 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
 845                          rtx ARG_UNUSED (r_chain))
 846 {
 847   sorry ("nested function trampolines not supported on this target");
 848 }
 849
 850 int
 851 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
 852                           tree funtype ATTRIBUTE_UNUSED,
 853                           int size ATTRIBUTE_UNUSED)
 854 {
 855   return 0;
 856 }
 857
 858 reg_class_t
 859 default_branch_target_register_class (void)
 860 {
 861   return NO_REGS;
 862 }
 863
 864 extern bool
 865 default_lra_p (void)
 866 {
 867   return false;
 868 }
 869
 870 int
 871 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
 872 {
 873   return 0;
 874 }
 875
 876 extern bool
 877 default_register_usage_leveling_p (void)
 878 {
 879   return false;
 880 }
 881
 882 extern bool
 883 default_different_addr_displacement_p (void)
 884 {
 885   return false;
 886 }
 887
 888 reg_class_t
 889 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 890                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
 891                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 892                           secondary_reload_info *sri)
 893 {
 894   enum reg_class rclass = NO_REGS;
 895   enum reg_class reload_class = (enum reg_class) reload_class_i;
 896
 897   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 898     {
 899       sri->icode = sri->prev_sri->t_icode;
 900       return NO_REGS;
 901     }
 902 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 903   if (in_p)
 904     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 905 #endif
 906 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 907   if (! in_p)
 908     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 909 #endif
 910   if (rclass != NO_REGS)
 911     {
 912       enum insn_code icode
 913         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
 914                                 reload_mode);
 915
 916       if (icode != CODE_FOR_nothing
 917           && !insn_operand_matches (icode, in_p, x))
 918         icode = CODE_FOR_nothing;
 919       else if (icode != CODE_FOR_nothing)
 920         {
 921           const char *insn_constraint, *scratch_constraint;
 922           char insn_letter, scratch_letter;
 923           enum reg_class insn_class, scratch_class;
 924
 925           gcc_assert (insn_data[(int) icode].n_operands == 3);
 926           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 927           if (!*insn_constraint)
 928             insn_class = ALL_REGS;
 929           else
 930             {
 931               if (in_p)
 932                 {
 933                   gcc_assert (*insn_constraint == '=');
 934                   insn_constraint++;
 935                 }
 936               insn_letter = *insn_constraint;
 937               insn_class
 938                 = (insn_letter == 'r' ? GENERAL_REGS
 939                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 940                                                 insn_constraint));
 941               gcc_assert (insn_class != NO_REGS);
 942             }
 943
 944           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 945           /* The scratch register's constraint must start with "=&",
 946              except for an input reload, where only "=" is necessary,
 947              and where it might be beneficial to re-use registers from
 948              the input.  */
 949           gcc_assert (scratch_constraint[0] == '='
 950                       && (in_p || scratch_constraint[1] == '&'));
 951           scratch_constraint++;
 952           if (*scratch_constraint == '&')
 953             scratch_constraint++;
 954           scratch_letter = *scratch_constraint;
 955           scratch_class
 956             = (scratch_letter == 'r' ? GENERAL_REGS
 957                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 958                                             scratch_constraint));
 959
 960           if (reg_class_subset_p (reload_class, insn_class))
 961             {
 962               gcc_assert (scratch_class == rclass);
 963               rclass = NO_REGS;
 964             }
 965           else
 966             rclass = insn_class;
 967
 968         }
 969       if (rclass == NO_REGS)
 970         sri->icode = icode;
 971       else
 972         sri->t_icode = icode;
 973     }
 974   return rclass;
 975 }
 976
 977 /* By default, if flag_pic is true, then neither local nor global relocs
 978    should be placed in readonly memory.  */
 979
 980 int
 981 default_reloc_rw_mask (void)
 982 {
 983   return flag_pic ? 3 : 0;
 984 }
 985
 986 /* By default, do no modification. */
 987 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 988                                          tree id)
 989 {
 990    return id;
 991 }
 992
 993 /* Default to natural alignment for vector types.  */
 994 HOST_WIDE_INT
 995 default_vector_alignment (const_tree type)
 996 {
 997   return tree_to_shwi (TYPE_SIZE (type));
 998 }
 999
1000 bool
1001 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
1002 {
1003   if (is_packed)
1004     return false;
1005
1006   /* Assuming that types whose size is > pointer-size are not guaranteed to be
1007      naturally aligned.  */
1008   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
1009     return false;
1010
1011   /* Assuming that types whose size is <= pointer-size
1012      are naturally aligned.  */
1013   return true;
1014 }
1015
1016 /* By default, assume that a target supports any factor of misalignment
1017    memory access if it supports movmisalign patten.
1018    is_packed is true if the memory access is defined in a packed struct.  */
1019 bool
1020 default_builtin_support_vector_misalignment (enum machine_mode mode,
1021                                              const_tree type
1022                                              ATTRIBUTE_UNUSED,
1023                                              int misalignment
1024                                              ATTRIBUTE_UNUSED,
1025                                              bool is_packed
1026                                              ATTRIBUTE_UNUSED)
1027 {
1028   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1029     return true;
1030   return false;
1031 }
1032
1033 /* By default, only attempt to parallelize bitwise operations, and
1034    possibly adds/subtracts using bit-twiddling.  */
1035
1036 enum machine_mode
1037 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
1038 {
1039   return word_mode;
1040 }
1041
1042 /* By default only the size derived from the preferred vector mode
1043    is tried.  */
1044
1045 unsigned int
1046 default_autovectorize_vector_sizes (void)
1047 {
1048   return 0;
1049 }
1050
1051 /* By default, the cost model accumulates three separate costs (prologue,
1052    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1053    array of three unsigned ints, set it to zero, and return its address.  */
1054
1055 void *
1056 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1057 {
1058   unsigned *cost = XNEWVEC (unsigned, 3);
1059   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1060   return cost;
1061 }
1062
1063 /* By default, the cost model looks up the cost of the given statement
1064    kind and mode, multiplies it by the occurrence count, accumulates
1065    it into the cost specified by WHERE, and returns the cost added.  */
1066
1067 unsigned
1068 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1069                        struct _stmt_vec_info *stmt_info, int misalign,
1070                        enum vect_cost_model_location where)
1071 {
1072   unsigned *cost = (unsigned *) data;
1073   unsigned retval = 0;
1074
1075   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1076   int stmt_cost = default_builtin_vectorization_cost (kind, vectype,
1077                                                           misalign);
1078    /* Statements in an inner loop relative to the loop being
1079       vectorized are weighted more heavily.  The value here is
1080       arbitrary and could potentially be improved with analysis.  */
1081   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1082     count *= 50;  /* FIXME.  */
1083
1084   retval = (unsigned) (count * stmt_cost);
1085   cost[where] += retval;
1086
1087   return retval;
1088 }
1089
1090 /* By default, the cost model just returns the accumulated costs.  */
1091
1092 void
1093 default_finish_cost (void *data, unsigned *prologue_cost,
1094                      unsigned *body_cost, unsigned *epilogue_cost)
1095 {
1096   unsigned *cost = (unsigned *) data;
1097   *prologue_cost = cost[vect_prologue];
1098   *body_cost     = cost[vect_body];
1099   *epilogue_cost = cost[vect_epilogue];
1100 }
1101
1102 /* Free the cost data.  */
1103
1104 void
1105 default_destroy_cost_data (void *data)
1106 {
1107   free (data);
1108 }
1109
1110 /* Determine whether or not a pointer mode is valid. Assume defaults
1111    of ptr_mode or Pmode - can be overridden.  */
1112 bool
1113 default_valid_pointer_mode (enum machine_mode mode)
1114 {
1115   return (mode == ptr_mode || mode == Pmode);
1116 }
1117
1118 /* Determine whether the memory reference specified by REF may alias
1119    the C libraries errno location.  */
1120 bool
1121 default_ref_may_alias_errno (ao_ref *ref)
1122 {
1123   tree base = ao_ref_base (ref);
1124   /* The default implementation assumes the errno location is
1125      a declaration of type int or is always accessed via a
1126      pointer to int.  We assume that accesses to errno are
1127      not deliberately obfuscated (even in conforming ways).  */
1128   if (TYPE_UNSIGNED (TREE_TYPE (base))
1129       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1130     return false;
1131   /* The default implementation assumes an errno location
1132      declaration is never defined in the current compilation unit.  */
1133   if (DECL_P (base)
1134       && !TREE_STATIC (base))
1135     return true;
1136   else if (TREE_CODE (base) == MEM_REF
1137            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1138     {
1139       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1140       return !pi || pi->pt.anything || pi->pt.nonlocal;
1141     }
1142   return false;
1143 }
1144
1145 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1146    for the generic address space only.  */
1147
1148 enum machine_mode
1149 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1150 {
1151   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1152   return ptr_mode;
1153 }
1154
1155 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1156    for the generic address space only.  */
1157
1158 enum machine_mode
1159 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1160 {
1161   gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1162   return Pmode;
1163 }
1164
1165 /* Named address space version of valid_pointer_mode.  */
1166
1167 bool
1168 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1169 {
1170   if (!ADDR_SPACE_GENERIC_P (as))
1171     return (mode == targetm.addr_space.pointer_mode (as)
1172             || mode == targetm.addr_space.address_mode (as));
1173
1174   return targetm.valid_pointer_mode (mode);
1175 }
1176
1177 /* Some places still assume that all pointer or address modes are the
1178    standard Pmode and ptr_mode.  These optimizations become invalid if
1179    the target actually supports multiple different modes.  For now,
1180    we disable such optimizations on such targets, using this function.  */
1181
1182 bool
1183 target_default_pointer_address_modes_p (void)
1184 {
1185   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1186     return false;
1187   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1188     return false;
1189
1190   return true;
1191 }
1192
1193 /* Named address space version of legitimate_address_p.  */
1194
1195 bool
1196 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1197                                          bool strict, addr_space_t as)
1198 {
1199   if (!ADDR_SPACE_GENERIC_P (as))
1200     gcc_unreachable ();
1201
1202   return targetm.legitimate_address_p (mode, mem, strict);
1203 }
1204
1205 /* Named address space version of LEGITIMIZE_ADDRESS.  */
1206
1207 rtx
1208 default_addr_space_legitimize_address (rtx x, rtx oldx,
1209                                        enum machine_mode mode, addr_space_t as)
1210 {
1211   if (!ADDR_SPACE_GENERIC_P (as))
1212     return x;
1213
1214   return targetm.legitimize_address (x, oldx, mode);
1215 }
1216
1217 /* The default hook for determining if one named address space is a subset of
1218    another and to return which address space to use as the common address
1219    space.  */
1220
1221 bool
1222 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1223 {
1224   return (subset == superset);
1225 }
1226
1227 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1228    called for targets with only a generic address space.  */
1229
1230 rtx
1231 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1232                             tree from_type ATTRIBUTE_UNUSED,
1233                             tree to_type ATTRIBUTE_UNUSED)
1234 {
1235   gcc_unreachable ();
1236 }
1237
1238 bool
1239 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1240 {
1241   return true;
1242 }
1243
1244 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1245
1246 bool
1247 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1248                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1249 {
1250   return false;
1251 }
1252
1253 bool
1254 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1255                                          tree ARG_UNUSED (name),
1256                                          tree ARG_UNUSED (args),
1257                                          int ARG_UNUSED (flags))
1258 {
1259   warning (OPT_Wattributes,
1260            "target attribute is not supported on this machine");
1261
1262   return false;
1263 }
1264
1265 bool
1266 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1267                                     tree ARG_UNUSED (pop_target))
1268 {
1269   warning (OPT_Wpragmas,
1270            "#pragma GCC target is not supported for this machine");
1271
1272   return false;
1273 }
1274
1275 bool
1276 default_target_can_inline_p (tree caller, tree callee)
1277 {
1278   bool ret = false;
1279   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1280   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1281
1282   /* If callee has no option attributes, then it is ok to inline */
1283   if (!callee_opts)
1284     ret = true;
1285
1286   /* If caller has no option attributes, but callee does then it is not ok to
1287      inline */
1288   else if (!caller_opts)
1289     ret = false;
1290
1291   /* If both caller and callee have attributes, assume that if the
1292      pointer is different, the two functions have different target
1293      options since build_target_option_node uses a hash table for the
1294      options.  */
1295   else
1296     ret = (callee_opts == caller_opts);
1297
1298   return ret;
1299 }
1300
1301 #ifndef HAVE_casesi
1302 # define HAVE_casesi 0
1303 #endif
1304
1305 /* If the machine does not have a case insn that compares the bounds,
1306    this means extra overhead for dispatch tables, which raises the
1307    threshold for using them.  */
1308
1309 unsigned int
1310 default_case_values_threshold (void)
1311 {
1312   return (HAVE_casesi ? 4 : 5);
1313 }
1314
1315 bool
1316 default_have_conditional_execution (void)
1317 {
1318 #ifdef HAVE_conditional_execution
1319   return HAVE_conditional_execution;
1320 #else
1321   return false;
1322 #endif
1323 }
1324
1325 tree
1326 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1327 {
1328   return NULL_TREE;
1329 }
1330
1331 /* Compute cost of moving registers to/from memory.  */
1332
1333 int
1334 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1335                           reg_class_t rclass ATTRIBUTE_UNUSED,
1336                           bool in ATTRIBUTE_UNUSED)
1337 {
1338 #ifndef MEMORY_MOVE_COST
1339     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1340 #else
1341     return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1342 #endif
1343 }
1344
1345 /* Compute cost of moving data from a register of class FROM to one of
1346    TO, using MODE.  */
1347
1348 int
1349 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1350                             reg_class_t from ATTRIBUTE_UNUSED,
1351                             reg_class_t to ATTRIBUTE_UNUSED)
1352 {
1353 #ifndef REGISTER_MOVE_COST
1354   return 2;
1355 #else
1356   return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1357 #endif
1358 }
1359
1360 bool
1361 default_profile_before_prologue (void)
1362 {
1363 #ifdef PROFILE_BEFORE_PROLOGUE
1364   return true;
1365 #else
1366   return false;
1367 #endif
1368 }
1369
1370 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1371
1372 reg_class_t
1373 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1374                                 reg_class_t rclass)
1375 {
1376 #ifdef PREFERRED_RELOAD_CLASS
1377   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1378 #else
1379   return rclass;
1380 #endif
1381 }
1382
1383 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1384
1385 reg_class_t
1386 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1387                                        reg_class_t rclass)
1388 {
1389   return rclass;
1390 }
1391
1392 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1393 reg_class_t
1394 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1395 {
1396   return NO_REGS;
1397 }
1398
1399 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1400
1401 bool
1402 default_class_likely_spilled_p (reg_class_t rclass)
1403 {
1404   return (reg_class_size[(int) rclass] == 1);
1405 }
1406
1407 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1408
1409 unsigned char
1410 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1411                          enum machine_mode mode ATTRIBUTE_UNUSED)
1412 {
1413 #ifdef CLASS_MAX_NREGS
1414   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1415 #else
1416   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1417 #endif
1418 }
1419
1420 /* Determine the debugging unwind mechanism for the target.  */
1421
1422 enum unwind_info_type
1423 default_debug_unwind_info (void)
1424 {
1425   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1426   /* ??? Change all users to the hook, then poison this.  */
1427 #ifdef DWARF2_FRAME_INFO
1428   if (DWARF2_FRAME_INFO)
1429     return UI_DWARF2;
1430 #endif
1431
1432   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1433 #ifdef DWARF2_DEBUGGING_INFO
1434   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1435     return UI_DWARF2;
1436 #endif
1437
1438   return UI_NONE;
1439 }
1440
1441 /* To be used by targets where reg_raw_mode doesn't return the right
1442    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1443
1444 enum machine_mode
1445 default_get_reg_raw_mode (int regno)
1446 {
1447   return reg_raw_mode[regno];
1448 }
1449
1450 /* Return true if the state of option OPTION should be stored in PCH files
1451    and checked by default_pch_valid_p.  Store the option's current state
1452    in STATE if so.  */
1453
1454 static inline bool
1455 option_affects_pch_p (int option, struct cl_option_state *state)
1456 {
1457   if ((cl_options[option].flags & CL_TARGET) == 0)
1458     return false;
1459   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1460     return false;
1461   if (option_flag_var (option, &global_options) == &target_flags)
1462     if (targetm.check_pch_target_flags)
1463       return false;
1464   return get_option_state (&global_options, option, state);
1465 }
1466
1467 /* Default version of get_pch_validity.
1468    By default, every flag difference is fatal; that will be mostly right for
1469    most targets, but completely right for very few.  */
1470
1471 void *
1472 default_get_pch_validity (size_t *sz)
1473 {
1474   struct cl_option_state state;
1475   size_t i;
1476   char *result, *r;
1477
1478   *sz = 2;
1479   if (targetm.check_pch_target_flags)
1480     *sz += sizeof (target_flags);
1481   for (i = 0; i < cl_options_count; i++)
1482     if (option_affects_pch_p (i, &state))
1483       *sz += state.size;
1484
1485   result = r = XNEWVEC (char, *sz);
1486   r[0] = flag_pic;
1487   r[1] = flag_pie;
1488   r += 2;
1489   if (targetm.check_pch_target_flags)
1490     {
1491       memcpy (r, &target_flags, sizeof (target_flags));
1492       r += sizeof (target_flags);
1493     }
1494
1495   for (i = 0; i < cl_options_count; i++)
1496     if (option_affects_pch_p (i, &state))
1497       {
1498         memcpy (r, state.data, state.size);
1499         r += state.size;
1500       }
1501
1502   return result;
1503 }
1504
1505 /* Return a message which says that a PCH file was created with a different
1506    setting of OPTION.  */
1507
1508 static const char *
1509 pch_option_mismatch (const char *option)
1510 {
1511   char *r;
1512
1513   asprintf (&r, _("created and used with differing settings of '%s'"), option);
1514   if (r == NULL)
1515     return _("out of memory");
1516   return r;
1517 }
1518
1519 /* Default version of pch_valid_p.  */
1520
1521 const char *
1522 default_pch_valid_p (const void *data_p, size_t len)
1523 {
1524   struct cl_option_state state;
1525   const char *data = (const char *)data_p;
1526   size_t i;
1527
1528   /* -fpic and -fpie also usually make a PCH invalid.  */
1529   if (data[0] != flag_pic)
1530     return _("created and used with different settings of -fpic");
1531   if (data[1] != flag_pie)
1532     return _("created and used with different settings of -fpie");
1533   data += 2;
1534
1535   /* Check target_flags.  */
1536   if (targetm.check_pch_target_flags)
1537     {
1538       int tf;
1539       const char *r;
1540
1541       memcpy (&tf, data, sizeof (target_flags));
1542       data += sizeof (target_flags);
1543       len -= sizeof (target_flags);
1544       r = targetm.check_pch_target_flags (tf);
1545       if (r != NULL)
1546         return r;
1547     }
1548
1549   for (i = 0; i < cl_options_count; i++)
1550     if (option_affects_pch_p (i, &state))
1551       {
1552         if (memcmp (data, state.data, state.size) != 0)
1553           return pch_option_mismatch (cl_options[i].opt_text);
1554         data += state.size;
1555         len -= state.size;
1556       }
1557
1558   return NULL;
1559 }
1560
1561 /* Default version of cstore_mode.  */
1562
1563 enum machine_mode
1564 default_cstore_mode (enum insn_code icode)
1565 {
1566   return insn_data[(int) icode].operand[0].mode;
1567 }
1568
1569 /* Default version of member_type_forces_blk.  */
1570
1571 bool
1572 default_member_type_forces_blk (const_tree, enum machine_mode)
1573 {
1574   return false;
1575 }
1576
1577 /* Default version of canonicalize_comparison.  */
1578
1579 void
1580 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
1581 {
1582 }
1583
1584 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
1585
1586 void
1587 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
1588 {
1589 }
1590
1591 #ifndef PAD_VARARGS_DOWN
1592 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
1593 #endif
1594
1595 /* Build an indirect-ref expression over the given TREE, which represents a
1596    piece of a va_arg() expansion.  */
1597 tree
1598 build_va_arg_indirect_ref (tree addr)
1599 {
1600   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
1601   return addr;
1602 }
1603
1604 /* The "standard" implementation of va_arg: read the value from the
1605    current (padded) address and increment by the (padded) size.  */
1606
1607 tree
1608 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
1609                           gimple_seq *post_p)
1610 {
1611   tree addr, t, type_size, rounded_size, valist_tmp;
1612   unsigned HOST_WIDE_INT align, boundary;
1613   bool indirect;
1614
1615 #ifdef ARGS_GROW_DOWNWARD
1616   /* All of the alignment and movement below is for args-grow-up machines.
1617      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
1618      implement their own specialized gimplify_va_arg_expr routines.  */
1619   gcc_unreachable ();
1620 #endif
1621
1622   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
1623   if (indirect)
1624     type = build_pointer_type (type);
1625
1626   align = PARM_BOUNDARY / BITS_PER_UNIT;
1627   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
1628
1629   /* When we align parameter on stack for caller, if the parameter
1630      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
1631      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
1632      here with caller.  */
1633   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
1634     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
1635
1636   boundary /= BITS_PER_UNIT;
1637
1638   /* Hoist the valist value into a temporary for the moment.  */
1639   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
1640
1641   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
1642      requires greater alignment, we must perform dynamic alignment.  */
1643   if (boundary > align
1644       && !integer_zerop (TYPE_SIZE (type)))
1645     {
1646       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1647                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
1648       gimplify_and_add (t, pre_p);
1649
1650       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
1651                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
1652                                valist_tmp,
1653                                build_int_cst (TREE_TYPE (valist), -boundary)));
1654       gimplify_and_add (t, pre_p);
1655     }
1656   else
1657     boundary = align;
1658
1659   /* If the actual alignment is less than the alignment of the type,
1660      adjust the type accordingly so that we don't assume strict alignment
1661      when dereferencing the pointer.  */
1662   boundary *= BITS_PER_UNIT;
1663   if (boundary < TYPE_ALIGN (type))
1664     {
1665       type = build_variant_type_copy (type);
1666       TYPE_ALIGN (type) = boundary;
1667     }
1668
1669   /* Compute the rounded size of the type.  */
1670   type_size = size_in_bytes (type);
1671   rounded_size = round_up (type_size, align);
1672
1673   /* Reduce rounded_size so it's sharable with the postqueue.  */
1674   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
1675
1676   /* Get AP.  */
1677   addr = valist_tmp;
1678   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
1679     {
1680       /* Small args are padded downward.  */
1681       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
1682                        rounded_size, size_int (align));
1683       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
1684                        size_binop (MINUS_EXPR, rounded_size, type_size));
1685       addr = fold_build_pointer_plus (addr, t);
1686     }
1687
1688   /* Compute new value for AP.  */
1689   t = fold_build_pointer_plus (valist_tmp, rounded_size);
1690   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
1691   gimplify_and_add (t, pre_p);
1692
1693   addr = fold_convert (build_pointer_type (type), addr);
1694
1695   if (indirect)
1696     addr = build_va_arg_indirect_ref (addr);
1697
1698   return build_va_arg_indirect_ref (addr);
1699 }
1700
1701 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
1702    not support nested low-overhead loops.  */
1703
1704 bool
1705 can_use_doloop_if_innermost (double_int, double_int,
1706                              unsigned int loop_depth, bool)
1707 {
1708   return loop_depth == 1;
1709 }
1710
1711 #include "gt-targhooks.h"