gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003-2019 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 "target.h"
  53 #include "function.h"
  54 #include "rtl.h"
  55 #include "tree.h"
  56 #include "tree-ssa-alias.h"
  57 #include "gimple-expr.h"
  58 #include "memmodel.h"
  59 #include "tm_p.h"
  60 #include "stringpool.h"
  61 #include "tree-vrp.h"
  62 #include "tree-ssanames.h"
  63 #include "profile-count.h"
  64 #include "optabs.h"
  65 #include "regs.h"
  66 #include "recog.h"
  67 #include "diagnostic-core.h"
  68 #include "fold-const.h"
  69 #include "stor-layout.h"
  70 #include "varasm.h"
  71 #include "flags.h"
  72 #include "explow.h"
  73 #include "calls.h"
  74 #include "expr.h"
  75 #include "output.h"
  76 #include "common/common-target.h"
  77 #include "reload.h"
  78 #include "intl.h"
  79 #include "opts.h"
  80 #include "gimplify.h"
  81 #include "predict.h"
  82 #include "params.h"
  83 #include "real.h"
  84 #include "langhooks.h"
  85 #include "sbitmap.h"
  86
  87 bool
  88 default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
  89                               rtx addr ATTRIBUTE_UNUSED,
  90                               bool strict ATTRIBUTE_UNUSED)
  91 {
  92 #ifdef GO_IF_LEGITIMATE_ADDRESS
  93   /* Defer to the old implementation using a goto.  */
  94   if (strict)
  95     return strict_memory_address_p (mode, addr);
  96   else
  97     return memory_address_p (mode, addr);
  98 #else
  99   gcc_unreachable ();
 100 #endif
 101 }
 102
 103 void
 104 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
 105 {
 106 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
 107   ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
 108 #endif
 109 }
 110
 111 int
 112 default_unspec_may_trap_p (const_rtx x, unsigned flags)
 113 {
 114   int i;
 115
 116   /* Any floating arithmetic may trap.  */
 117   if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
 118     return 1;
 119
 120   for (i = 0; i < XVECLEN (x, 0); ++i)
 121     {
 122       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
 123         return 1;
 124     }
 125
 126   return 0;
 127 }
 128
 129 machine_mode
 130 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 131                                machine_mode mode,
 132                                int *punsignedp ATTRIBUTE_UNUSED,
 133                                const_tree funtype ATTRIBUTE_UNUSED,
 134                                int for_return ATTRIBUTE_UNUSED)
 135 {
 136   if (type != NULL_TREE && for_return == 2)
 137     return promote_mode (type, mode, punsignedp);
 138   return mode;
 139 }
 140
 141 machine_mode
 142 default_promote_function_mode_always_promote (const_tree type,
 143                                               machine_mode mode,
 144                                               int *punsignedp,
 145                                               const_tree funtype ATTRIBUTE_UNUSED,
 146                                               int for_return ATTRIBUTE_UNUSED)
 147 {
 148   return promote_mode (type, mode, punsignedp);
 149 }
 150
 151 machine_mode
 152 default_cc_modes_compatible (machine_mode m1, machine_mode m2)
 153 {
 154   if (m1 == m2)
 155     return m1;
 156   return VOIDmode;
 157 }
 158
 159 bool
 160 default_return_in_memory (const_tree type,
 161                           const_tree fntype ATTRIBUTE_UNUSED)
 162 {
 163   return (TYPE_MODE (type) == BLKmode);
 164 }
 165
 166 rtx
 167 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
 168                             machine_mode mode ATTRIBUTE_UNUSED)
 169 {
 170   return x;
 171 }
 172
 173 bool
 174 default_legitimize_address_displacement (rtx *, rtx *, poly_int64,
 175                                          machine_mode)
 176 {
 177   return false;
 178 }
 179
 180 bool
 181 default_const_not_ok_for_debug_p (rtx x)
 182 {
 183   if (GET_CODE (x) == UNSPEC)
 184     return true;
 185   return false;
 186 }
 187
 188 rtx
 189 default_expand_builtin_saveregs (void)
 190 {
 191   error ("%<__builtin_saveregs%> not supported by this target");
 192   return const0_rtx;
 193 }
 194
 195 void
 196 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
 197                                 machine_mode mode ATTRIBUTE_UNUSED,
 198                                 tree type ATTRIBUTE_UNUSED,
 199                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 200                                 int second_time ATTRIBUTE_UNUSED)
 201 {
 202 }
 203
 204 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 205
 206 rtx
 207 default_builtin_setjmp_frame_value (void)
 208 {
 209   return virtual_stack_vars_rtx;
 210 }
 211
 212 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 213
 214 bool
 215 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
 216 {
 217   return false;
 218 }
 219
 220 bool
 221 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
 222 {
 223   return (targetm.calls.setup_incoming_varargs
 224           != default_setup_incoming_varargs);
 225 }
 226
 227 scalar_int_mode
 228 default_eh_return_filter_mode (void)
 229 {
 230   return targetm.unwind_word_mode ();
 231 }
 232
 233 scalar_int_mode
 234 default_libgcc_cmp_return_mode (void)
 235 {
 236   return word_mode;
 237 }
 238
 239 scalar_int_mode
 240 default_libgcc_shift_count_mode (void)
 241 {
 242   return word_mode;
 243 }
 244
 245 scalar_int_mode
 246 default_unwind_word_mode (void)
 247 {
 248   return word_mode;
 249 }
 250
 251 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 252
 253 unsigned HOST_WIDE_INT
 254 default_shift_truncation_mask (machine_mode mode)
 255 {
 256   return SHIFT_COUNT_TRUNCATED ? GET_MODE_UNIT_BITSIZE (mode) - 1 : 0;
 257 }
 258
 259 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 260
 261 unsigned int
 262 default_min_divisions_for_recip_mul (machine_mode mode ATTRIBUTE_UNUSED)
 263 {
 264   return have_insn_for (DIV, mode) ? 3 : 2;
 265 }
 266
 267 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 268
 269 int
 270 default_mode_rep_extended (scalar_int_mode, scalar_int_mode)
 271 {
 272   return UNKNOWN;
 273 }
 274
 275 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 276
 277 bool
 278 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
 279 {
 280   return true;
 281 }
 282
 283 /* Return machine mode for non-standard suffix
 284    or VOIDmode if non-standard suffixes are unsupported.  */
 285 machine_mode
 286 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 287 {
 288   return VOIDmode;
 289 }
 290
 291 /* The generic C++ ABI specifies this is a 64-bit value.  */
 292 tree
 293 default_cxx_guard_type (void)
 294 {
 295   return long_long_integer_type_node;
 296 }
 297
 298 /* Returns the size of the cookie to use when allocating an array
 299    whose elements have the indicated TYPE.  Assumes that it is already
 300    known that a cookie is needed.  */
 301
 302 tree
 303 default_cxx_get_cookie_size (tree type)
 304 {
 305   tree cookie_size;
 306
 307   /* We need to allocate an additional max (sizeof (size_t), alignof
 308      (true_type)) bytes.  */
 309   tree sizetype_size;
 310   tree type_align;
 311
 312   sizetype_size = size_in_bytes (sizetype);
 313   type_align = size_int (TYPE_ALIGN_UNIT (type));
 314   if (tree_int_cst_lt (type_align, sizetype_size))
 315     cookie_size = sizetype_size;
 316   else
 317     cookie_size = type_align;
 318
 319   return cookie_size;
 320 }
 321
 322 /* Return true if a parameter must be passed by reference.  This version
 323    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 324
 325 bool
 326 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
 327         machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 328         bool named_arg ATTRIBUTE_UNUSED)
 329 {
 330   return targetm.calls.must_pass_in_stack (mode, type);
 331 }
 332
 333 /* Return true if a parameter follows callee copies conventions.  This
 334    version of the hook is true for all named arguments.  */
 335
 336 bool
 337 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
 338                           machine_mode mode ATTRIBUTE_UNUSED,
 339                           const_tree type ATTRIBUTE_UNUSED, bool named)
 340 {
 341   return named;
 342 }
 343
 344 /* Emit to STREAM the assembler syntax for insn operand X.  */
 345
 346 void
 347 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 348                        int code ATTRIBUTE_UNUSED)
 349 {
 350 #ifdef PRINT_OPERAND
 351   PRINT_OPERAND (stream, x, code);
 352 #else
 353   gcc_unreachable ();
 354 #endif
 355 }
 356
 357 /* Emit to STREAM the assembler syntax for an insn operand whose memory
 358    address is X.  */
 359
 360 void
 361 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
 362                                machine_mode /*mode*/,
 363                                rtx x ATTRIBUTE_UNUSED)
 364 {
 365 #ifdef PRINT_OPERAND_ADDRESS
 366   PRINT_OPERAND_ADDRESS (stream, x);
 367 #else
 368   gcc_unreachable ();
 369 #endif
 370 }
 371
 372 /* Return true if CODE is a valid punctuation character for the
 373    `print_operand' hook.  */
 374
 375 bool
 376 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
 377 {
 378 #ifdef PRINT_OPERAND_PUNCT_VALID_P
 379   return PRINT_OPERAND_PUNCT_VALID_P (code);
 380 #else
 381   return false;
 382 #endif
 383 }
 384
 385 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
 386 tree
 387 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
 388 {
 389   const char *skipped = name + (*name == '*' ? 1 : 0);
 390   const char *stripped = targetm.strip_name_encoding (skipped);
 391   if (*name != '*' && user_label_prefix[0])
 392     stripped = ACONCAT ((user_label_prefix, stripped, NULL));
 393   return get_identifier (stripped);
 394 }
 395
 396 /* The default implementation of TARGET_TRANSLATE_MODE_ATTRIBUTE.  */
 397
 398 machine_mode
 399 default_translate_mode_attribute (machine_mode mode)
 400 {
 401   return mode;
 402 }
 403
 404 /* True if MODE is valid for the target.  By "valid", we mean able to
 405    be manipulated in non-trivial ways.  In particular, this means all
 406    the arithmetic is supported.
 407
 408    By default we guess this means that any C type is supported.  If
 409    we can't map the mode back to a type that would be available in C,
 410    then reject it.  Special case, here, is the double-word arithmetic
 411    supported by optabs.c.  */
 412
 413 bool
 414 default_scalar_mode_supported_p (scalar_mode mode)
 415 {
 416   int precision = GET_MODE_PRECISION (mode);
 417
 418   switch (GET_MODE_CLASS (mode))
 419     {
 420     case MODE_PARTIAL_INT:
 421     case MODE_INT:
 422       if (precision == CHAR_TYPE_SIZE)
 423         return true;
 424       if (precision == SHORT_TYPE_SIZE)
 425         return true;
 426       if (precision == INT_TYPE_SIZE)
 427         return true;
 428       if (precision == LONG_TYPE_SIZE)
 429         return true;
 430       if (precision == LONG_LONG_TYPE_SIZE)
 431         return true;
 432       if (precision == 2 * BITS_PER_WORD)
 433         return true;
 434       return false;
 435
 436     case MODE_FLOAT:
 437       if (precision == FLOAT_TYPE_SIZE)
 438         return true;
 439       if (precision == DOUBLE_TYPE_SIZE)
 440         return true;
 441       if (precision == LONG_DOUBLE_TYPE_SIZE)
 442         return true;
 443       return false;
 444
 445     case MODE_DECIMAL_FLOAT:
 446     case MODE_FRACT:
 447     case MODE_UFRACT:
 448     case MODE_ACCUM:
 449     case MODE_UACCUM:
 450       return false;
 451
 452     default:
 453       gcc_unreachable ();
 454     }
 455 }
 456
 457 /* Return true if libgcc supports floating-point mode MODE (known to
 458    be supported as a scalar mode).  */
 459
 460 bool
 461 default_libgcc_floating_mode_supported_p (scalar_float_mode mode)
 462 {
 463   switch (mode)
 464     {
 465 #ifdef HAVE_SFmode
 466     case E_SFmode:
 467 #endif
 468 #ifdef HAVE_DFmode
 469     case E_DFmode:
 470 #endif
 471 #ifdef HAVE_XFmode
 472     case E_XFmode:
 473 #endif
 474 #ifdef HAVE_TFmode
 475     case E_TFmode:
 476 #endif
 477       return true;
 478
 479     default:
 480       return false;
 481     }
 482 }
 483
 484 /* Return the machine mode to use for the type _FloatN, if EXTENDED is
 485    false, or _FloatNx, if EXTENDED is true, or VOIDmode if not
 486    supported.  */
 487 opt_scalar_float_mode
 488 default_floatn_mode (int n, bool extended)
 489 {
 490   if (extended)
 491     {
 492       opt_scalar_float_mode cand1, cand2;
 493       scalar_float_mode mode;
 494       switch (n)
 495         {
 496         case 32:
 497 #ifdef HAVE_DFmode
 498           cand1 = DFmode;
 499 #endif
 500           break;
 501
 502         case 64:
 503 #ifdef HAVE_XFmode
 504           cand1 = XFmode;
 505 #endif
 506 #ifdef HAVE_TFmode
 507           cand2 = TFmode;
 508 #endif
 509           break;
 510
 511         case 128:
 512           break;
 513
 514         default:
 515           /* Those are the only valid _FloatNx types.  */
 516           gcc_unreachable ();
 517         }
 518       if (cand1.exists (&mode)
 519           && REAL_MODE_FORMAT (mode)->ieee_bits > n
 520           && targetm.scalar_mode_supported_p (mode)
 521           && targetm.libgcc_floating_mode_supported_p (mode))
 522         return cand1;
 523       if (cand2.exists (&mode)
 524           && REAL_MODE_FORMAT (mode)->ieee_bits > n
 525           && targetm.scalar_mode_supported_p (mode)
 526           && targetm.libgcc_floating_mode_supported_p (mode))
 527         return cand2;
 528     }
 529   else
 530     {
 531       opt_scalar_float_mode cand;
 532       scalar_float_mode mode;
 533       switch (n)
 534         {
 535         case 16:
 536           /* Always enable _Float16 if we have basic support for the mode.
 537              Targets can control the range and precision of operations on
 538              the _Float16 type using TARGET_C_EXCESS_PRECISION.  */
 539 #ifdef HAVE_HFmode
 540           cand = HFmode;
 541 #endif
 542           break;
 543
 544         case 32:
 545 #ifdef HAVE_SFmode
 546           cand = SFmode;
 547 #endif
 548           break;
 549
 550         case 64:
 551 #ifdef HAVE_DFmode
 552           cand = DFmode;
 553 #endif
 554           break;
 555
 556         case 128:
 557 #ifdef HAVE_TFmode
 558           cand = TFmode;
 559 #endif
 560           break;
 561
 562         default:
 563           break;
 564         }
 565       if (cand.exists (&mode)
 566           && REAL_MODE_FORMAT (mode)->ieee_bits == n
 567           && targetm.scalar_mode_supported_p (mode)
 568           && targetm.libgcc_floating_mode_supported_p (mode))
 569         return cand;
 570     }
 571   return opt_scalar_float_mode ();
 572 }
 573
 574 /* Define this to return true if the _Floatn and _Floatnx built-in functions
 575    should implicitly enable the built-in function without the __builtin_ prefix
 576    in addition to the normal built-in function with the __builtin_ prefix.  The
 577    default is to only enable built-in functions without the __builtin_ prefix
 578    for the GNU C langauge.  The argument FUNC is the enum builtin_in_function
 579    id of the function to be enabled.  */
 580
 581 bool
 582 default_floatn_builtin_p (int func ATTRIBUTE_UNUSED)
 583 {
 584   static bool first_time_p = true;
 585   static bool c_or_objective_c;
 586
 587   if (first_time_p)
 588     {
 589       first_time_p = false;
 590       c_or_objective_c = lang_GNU_C () || lang_GNU_OBJC ();
 591     }
 592
 593   return c_or_objective_c;
 594 }
 595
 596 /* Make some target macros useable by target-independent code.  */
 597 bool
 598 targhook_words_big_endian (void)
 599 {
 600   return !!WORDS_BIG_ENDIAN;
 601 }
 602
 603 bool
 604 targhook_float_words_big_endian (void)
 605 {
 606   return !!FLOAT_WORDS_BIG_ENDIAN;
 607 }
 608
 609 /* True if the target supports floating-point exceptions and rounding
 610    modes.  */
 611
 612 bool
 613 default_float_exceptions_rounding_supported_p (void)
 614 {
 615 #ifdef HAVE_adddf3
 616   return HAVE_adddf3;
 617 #else
 618   return false;
 619 #endif
 620 }
 621
 622 /* True if the target supports decimal floating point.  */
 623
 624 bool
 625 default_decimal_float_supported_p (void)
 626 {
 627   return ENABLE_DECIMAL_FLOAT;
 628 }
 629
 630 /* True if the target supports fixed-point arithmetic.  */
 631
 632 bool
 633 default_fixed_point_supported_p (void)
 634 {
 635   return ENABLE_FIXED_POINT;
 636 }
 637
 638 /* True if the target supports GNU indirect functions.  */
 639
 640 bool
 641 default_has_ifunc_p (void)
 642 {
 643   return HAVE_GNU_INDIRECT_FUNCTION;
 644 }
 645
 646 /* Return true if we predict the loop LOOP will be transformed to a
 647    low-overhead loop, otherwise return false.
 648
 649    By default, false is returned, as this hook's applicability should be
 650    verified for each target.  Target maintainers should re-define the hook
 651    if the target can take advantage of it.  */
 652
 653 bool
 654 default_predict_doloop_p (struct loop *loop ATTRIBUTE_UNUSED)
 655 {
 656   return false;
 657 }
 658
 659 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 660    an error message.
 661
 662    This function checks whether a given INSN is valid within a low-overhead
 663    loop.  If INSN is invalid it returns the reason for that, otherwise it
 664    returns NULL. A called function may clobber any special registers required
 665    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 666    register for branch on table instructions. We reject the doloop pattern in
 667    these cases.  */
 668
 669 const char *
 670 default_invalid_within_doloop (const rtx_insn *insn)
 671 {
 672   if (CALL_P (insn))
 673     return "Function call in loop.";
 674
 675   if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
 676     return "Computed branch in the loop.";
 677
 678   return NULL;
 679 }
 680
 681 /* Mapping of builtin functions to vectorized variants.  */
 682
 683 tree
 684 default_builtin_vectorized_function (unsigned int, tree, tree)
 685 {
 686   return NULL_TREE;
 687 }
 688
 689 /* Mapping of target builtin functions to vectorized variants.  */
 690
 691 tree
 692 default_builtin_md_vectorized_function (tree, tree, tree)
 693 {
 694   return NULL_TREE;
 695 }
 696
 697 /* Vectorized conversion.  */
 698
 699 tree
 700 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
 701                                        tree dest_type ATTRIBUTE_UNUSED,
 702                                        tree src_type ATTRIBUTE_UNUSED)
 703 {
 704   return NULL_TREE;
 705 }
 706
 707 /* Default vectorizer cost model values.  */
 708
 709 int
 710 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
 711                                     tree vectype,
 712                                     int misalign ATTRIBUTE_UNUSED)
 713 {
 714   switch (type_of_cost)
 715     {
 716       case scalar_stmt:
 717       case scalar_load:
 718       case scalar_store:
 719       case vector_stmt:
 720       case vector_load:
 721       case vector_store:
 722       case vec_to_scalar:
 723       case scalar_to_vec:
 724       case cond_branch_not_taken:
 725       case vec_perm:
 726       case vec_promote_demote:
 727         return 1;
 728
 729       case unaligned_load:
 730       case unaligned_store:
 731         return 2;
 732
 733       case cond_branch_taken:
 734         return 3;
 735
 736       case vec_construct:
 737         return estimated_poly_value (TYPE_VECTOR_SUBPARTS (vectype)) - 1;
 738
 739       default:
 740         gcc_unreachable ();
 741     }
 742 }
 743
 744 /* Reciprocal.  */
 745
 746 tree
 747 default_builtin_reciprocal (tree)
 748 {
 749   return NULL_TREE;
 750 }
 751
 752 bool
 753 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 754         cumulative_args_t ca ATTRIBUTE_UNUSED,
 755         machine_mode mode ATTRIBUTE_UNUSED,
 756         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 757 {
 758   return false;
 759 }
 760
 761 bool
 762 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 763         cumulative_args_t ca ATTRIBUTE_UNUSED,
 764         machine_mode mode ATTRIBUTE_UNUSED,
 765         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 766 {
 767   return true;
 768 }
 769
 770 int
 771 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 772         cumulative_args_t ca ATTRIBUTE_UNUSED,
 773         machine_mode mode ATTRIBUTE_UNUSED,
 774         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 775 {
 776   return 0;
 777 }
 778
 779 void
 780 hook_void_CUMULATIVE_ARGS_tree (cumulative_args_t ca ATTRIBUTE_UNUSED,
 781                                 tree ATTRIBUTE_UNUSED)
 782 {
 783 }
 784
 785 void
 786 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
 787                               machine_mode mode ATTRIBUTE_UNUSED,
 788                               const_tree type ATTRIBUTE_UNUSED,
 789                               bool named ATTRIBUTE_UNUSED)
 790 {
 791   gcc_unreachable ();
 792 }
 793
 794 /* Default implementation of TARGET_FUNCTION_ARG_OFFSET.  */
 795
 796 HOST_WIDE_INT
 797 default_function_arg_offset (machine_mode, const_tree)
 798 {
 799   return 0;
 800 }
 801
 802 /* Default implementation of TARGET_FUNCTION_ARG_PADDING: usually pad
 803    upward, but pad short args downward on big-endian machines.  */
 804
 805 pad_direction
 806 default_function_arg_padding (machine_mode mode, const_tree type)
 807 {
 808   if (!BYTES_BIG_ENDIAN)
 809     return PAD_UPWARD;
 810
 811   unsigned HOST_WIDE_INT size;
 812   if (mode == BLKmode)
 813     {
 814       if (!type || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
 815         return PAD_UPWARD;
 816       size = int_size_in_bytes (type);
 817     }
 818   else
 819     /* Targets with variable-sized modes must override this hook
 820        and handle variable-sized modes explicitly.  */
 821     size = GET_MODE_SIZE (mode).to_constant ();
 822
 823   if (size < (PARM_BOUNDARY / BITS_PER_UNIT))
 824     return PAD_DOWNWARD;
 825
 826   return PAD_UPWARD;
 827 }
 828
 829 rtx
 830 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 831                       machine_mode mode ATTRIBUTE_UNUSED,
 832                       const_tree type ATTRIBUTE_UNUSED,
 833                       bool named ATTRIBUTE_UNUSED)
 834 {
 835   gcc_unreachable ();
 836 }
 837
 838 rtx
 839 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
 840                                machine_mode mode ATTRIBUTE_UNUSED,
 841                                const_tree type ATTRIBUTE_UNUSED,
 842                                bool named ATTRIBUTE_UNUSED)
 843 {
 844   gcc_unreachable ();
 845 }
 846
 847 unsigned int
 848 default_function_arg_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 849                                const_tree type ATTRIBUTE_UNUSED)
 850 {
 851   return PARM_BOUNDARY;
 852 }
 853
 854 unsigned int
 855 default_function_arg_round_boundary (machine_mode mode ATTRIBUTE_UNUSED,
 856                                      const_tree type ATTRIBUTE_UNUSED)
 857 {
 858   return PARM_BOUNDARY;
 859 }
 860
 861 void
 862 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 863 {
 864 }
 865
 866 const char *
 867 hook_invalid_arg_for_unprototyped_fn (
 868         const_tree typelist ATTRIBUTE_UNUSED,
 869         const_tree funcdecl ATTRIBUTE_UNUSED,
 870         const_tree val ATTRIBUTE_UNUSED)
 871 {
 872   return NULL;
 873 }
 874
 875 /* Initialize the stack protection decls.  */
 876
 877 /* Stack protection related decls living in libgcc.  */
 878 static GTY(()) tree stack_chk_guard_decl;
 879
 880 tree
 881 default_stack_protect_guard (void)
 882 {
 883   tree t = stack_chk_guard_decl;
 884
 885   if (t == NULL)
 886     {
 887       rtx x;
 888
 889       t = build_decl (UNKNOWN_LOCATION,
 890                       VAR_DECL, get_identifier ("__stack_chk_guard"),
 891                       ptr_type_node);
 892       TREE_STATIC (t) = 1;
 893       TREE_PUBLIC (t) = 1;
 894       DECL_EXTERNAL (t) = 1;
 895       TREE_USED (t) = 1;
 896       TREE_THIS_VOLATILE (t) = 1;
 897       DECL_ARTIFICIAL (t) = 1;
 898       DECL_IGNORED_P (t) = 1;
 899
 900       /* Do not share RTL as the declaration is visible outside of
 901          current function.  */
 902       x = DECL_RTL (t);
 903       RTX_FLAG (x, used) = 1;
 904
 905       stack_chk_guard_decl = t;
 906     }
 907
 908   return t;
 909 }
 910
 911 static GTY(()) tree stack_chk_fail_decl;
 912
 913 tree
 914 default_external_stack_protect_fail (void)
 915 {
 916   tree t = stack_chk_fail_decl;
 917
 918   if (t == NULL_TREE)
 919     {
 920       t = build_function_type_list (void_type_node, NULL_TREE);
 921       t = build_decl (UNKNOWN_LOCATION,
 922                       FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 923       TREE_STATIC (t) = 1;
 924       TREE_PUBLIC (t) = 1;
 925       DECL_EXTERNAL (t) = 1;
 926       TREE_USED (t) = 1;
 927       TREE_THIS_VOLATILE (t) = 1;
 928       TREE_NOTHROW (t) = 1;
 929       DECL_ARTIFICIAL (t) = 1;
 930       DECL_IGNORED_P (t) = 1;
 931       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 932       DECL_VISIBILITY_SPECIFIED (t) = 1;
 933
 934       stack_chk_fail_decl = t;
 935     }
 936
 937   return build_call_expr (t, 0);
 938 }
 939
 940 tree
 941 default_hidden_stack_protect_fail (void)
 942 {
 943 #ifndef HAVE_GAS_HIDDEN
 944   return default_external_stack_protect_fail ();
 945 #else
 946   tree t = stack_chk_fail_decl;
 947
 948   if (!flag_pic)
 949     return default_external_stack_protect_fail ();
 950
 951   if (t == NULL_TREE)
 952     {
 953       t = build_function_type_list (void_type_node, NULL_TREE);
 954       t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
 955                       get_identifier ("__stack_chk_fail_local"), t);
 956       TREE_STATIC (t) = 1;
 957       TREE_PUBLIC (t) = 1;
 958       DECL_EXTERNAL (t) = 1;
 959       TREE_USED (t) = 1;
 960       TREE_THIS_VOLATILE (t) = 1;
 961       TREE_NOTHROW (t) = 1;
 962       DECL_ARTIFICIAL (t) = 1;
 963       DECL_IGNORED_P (t) = 1;
 964       DECL_VISIBILITY_SPECIFIED (t) = 1;
 965       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 966
 967       stack_chk_fail_decl = t;
 968     }
 969
 970   return build_call_expr (t, 0);
 971 #endif
 972 }
 973
 974 bool
 975 hook_bool_const_rtx_commutative_p (const_rtx x,
 976                                    int outer_code ATTRIBUTE_UNUSED)
 977 {
 978   return COMMUTATIVE_P (x);
 979 }
 980
 981 rtx
 982 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 983                         const_tree fn_decl_or_type,
 984                         bool outgoing ATTRIBUTE_UNUSED)
 985 {
 986   /* The old interface doesn't handle receiving the function type.  */
 987   if (fn_decl_or_type
 988       && !DECL_P (fn_decl_or_type))
 989     fn_decl_or_type = NULL;
 990
 991 #ifdef FUNCTION_VALUE
 992   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 993 #else
 994   gcc_unreachable ();
 995 #endif
 996 }
 997
 998 rtx
 999 default_libcall_value (machine_mode mode ATTRIBUTE_UNUSED,
1000                        const_rtx fun ATTRIBUTE_UNUSED)
1001 {
1002 #ifdef LIBCALL_VALUE
1003   return LIBCALL_VALUE (MACRO_MODE (mode));
1004 #else
1005   gcc_unreachable ();
1006 #endif
1007 }
1008
1009 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */
1010
1011 bool
1012 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
1013 {
1014 #ifdef FUNCTION_VALUE_REGNO_P
1015   return FUNCTION_VALUE_REGNO_P (regno);
1016 #else
1017   gcc_unreachable ();
1018 #endif
1019 }
1020
1021 rtx
1022 default_internal_arg_pointer (void)
1023 {
1024   /* If the reg that the virtual arg pointer will be translated into is
1025      not a fixed reg or is the stack pointer, make a copy of the virtual
1026      arg pointer, and address parms via the copy.  The frame pointer is
1027      considered fixed even though it is not marked as such.  */
1028   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
1029        || ! (fixed_regs[ARG_POINTER_REGNUM]
1030              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
1031     return copy_to_reg (virtual_incoming_args_rtx);
1032   else
1033     return virtual_incoming_args_rtx;
1034 }
1035
1036 rtx
1037 default_static_chain (const_tree ARG_UNUSED (fndecl_or_type), bool incoming_p)
1038 {
1039   if (incoming_p)
1040     {
1041 #ifdef STATIC_CHAIN_INCOMING_REGNUM
1042       return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
1043 #endif
1044     }
1045
1046 #ifdef STATIC_CHAIN_REGNUM
1047   return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
1048 #endif
1049
1050   {
1051     static bool issued_error;
1052     if (!issued_error)
1053       {
1054         issued_error = true;
1055         sorry ("nested functions not supported on this target");
1056       }
1057
1058     /* It really doesn't matter what we return here, so long at it
1059        doesn't cause the rest of the compiler to crash.  */
1060     return gen_rtx_MEM (Pmode, stack_pointer_rtx);
1061   }
1062 }
1063
1064 void
1065 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
1066                          rtx ARG_UNUSED (r_chain))
1067 {
1068   sorry ("nested function trampolines not supported on this target");
1069 }
1070
1071 poly_int64
1072 default_return_pops_args (tree, tree, poly_int64)
1073 {
1074   return 0;
1075 }
1076
1077 reg_class_t
1078 default_branch_target_register_class (void)
1079 {
1080   return NO_REGS;
1081 }
1082
1083 reg_class_t
1084 default_ira_change_pseudo_allocno_class (int regno ATTRIBUTE_UNUSED,
1085                                          reg_class_t cl,
1086                                          reg_class_t best_cl ATTRIBUTE_UNUSED)
1087 {
1088   return cl;
1089 }
1090
1091 extern bool
1092 default_lra_p (void)
1093 {
1094   return true;
1095 }
1096
1097 int
1098 default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
1099 {
1100   return 0;
1101 }
1102
1103 extern bool
1104 default_register_usage_leveling_p (void)
1105 {
1106   return false;
1107 }
1108
1109 extern bool
1110 default_different_addr_displacement_p (void)
1111 {
1112   return false;
1113 }
1114
1115 reg_class_t
1116 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
1117                           reg_class_t reload_class_i ATTRIBUTE_UNUSED,
1118                           machine_mode reload_mode ATTRIBUTE_UNUSED,
1119                           secondary_reload_info *sri)
1120 {
1121   enum reg_class rclass = NO_REGS;
1122   enum reg_class reload_class = (enum reg_class) reload_class_i;
1123
1124   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
1125     {
1126       sri->icode = sri->prev_sri->t_icode;
1127       return NO_REGS;
1128     }
1129 #ifdef SECONDARY_INPUT_RELOAD_CLASS
1130   if (in_p)
1131     rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class,
1132                                            MACRO_MODE (reload_mode), x);
1133 #endif
1134 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
1135   if (! in_p)
1136     rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class,
1137                                             MACRO_MODE (reload_mode), x);
1138 #endif
1139   if (rclass != NO_REGS)
1140     {
1141       enum insn_code icode
1142         = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
1143                                 reload_mode);
1144
1145       if (icode != CODE_FOR_nothing
1146           && !insn_operand_matches (icode, in_p, x))
1147         icode = CODE_FOR_nothing;
1148       else if (icode != CODE_FOR_nothing)
1149         {
1150           const char *insn_constraint, *scratch_constraint;
1151           enum reg_class insn_class, scratch_class;
1152
1153           gcc_assert (insn_data[(int) icode].n_operands == 3);
1154           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
1155           if (!*insn_constraint)
1156             insn_class = ALL_REGS;
1157           else
1158             {
1159               if (in_p)
1160                 {
1161                   gcc_assert (*insn_constraint == '=');
1162                   insn_constraint++;
1163                 }
1164               insn_class = (reg_class_for_constraint
1165                             (lookup_constraint (insn_constraint)));
1166               gcc_assert (insn_class != NO_REGS);
1167             }
1168
1169           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
1170           /* The scratch register's constraint must start with "=&",
1171              except for an input reload, where only "=" is necessary,
1172              and where it might be beneficial to re-use registers from
1173              the input.  */
1174           gcc_assert (scratch_constraint[0] == '='
1175                       && (in_p || scratch_constraint[1] == '&'));
1176           scratch_constraint++;
1177           if (*scratch_constraint == '&')
1178             scratch_constraint++;
1179           scratch_class = (reg_class_for_constraint
1180                            (lookup_constraint (scratch_constraint)));
1181
1182           if (reg_class_subset_p (reload_class, insn_class))
1183             {
1184               gcc_assert (scratch_class == rclass);
1185               rclass = NO_REGS;
1186             }
1187           else
1188             rclass = insn_class;
1189
1190         }
1191       if (rclass == NO_REGS)
1192         sri->icode = icode;
1193       else
1194         sri->t_icode = icode;
1195     }
1196   return rclass;
1197 }
1198
1199 /* The default implementation of TARGET_SECONDARY_MEMORY_NEEDED_MODE.  */
1200
1201 machine_mode
1202 default_secondary_memory_needed_mode (machine_mode mode)
1203 {
1204   if (!targetm.lra_p ()
1205       && known_lt (GET_MODE_BITSIZE (mode), BITS_PER_WORD)
1206       && INTEGRAL_MODE_P (mode))
1207     return mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0).require ();
1208   return mode;
1209 }
1210
1211 /* By default, if flag_pic is true, then neither local nor global relocs
1212    should be placed in readonly memory.  */
1213
1214 int
1215 default_reloc_rw_mask (void)
1216 {
1217   return flag_pic ? 3 : 0;
1218 }
1219
1220 /* By default, address diff vectors are generated
1221 for jump tables when flag_pic is true.  */
1222
1223 bool
1224 default_generate_pic_addr_diff_vec (void)
1225 {
1226   return flag_pic;
1227 }
1228
1229 /* By default, do no modification. */
1230 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
1231                                          tree id)
1232 {
1233    return id;
1234 }
1235
1236 /* The default implementation of TARGET_STATIC_RTX_ALIGNMENT.  */
1237
1238 HOST_WIDE_INT
1239 default_static_rtx_alignment (machine_mode mode)
1240 {
1241   return GET_MODE_ALIGNMENT (mode);
1242 }
1243
1244 /* The default implementation of TARGET_CONSTANT_ALIGNMENT.  */
1245
1246 HOST_WIDE_INT
1247 default_constant_alignment (const_tree, HOST_WIDE_INT align)
1248 {
1249   return align;
1250 }
1251
1252 /* An implementation of TARGET_CONSTANT_ALIGNMENT that aligns strings
1253    to at least BITS_PER_WORD but otherwise makes no changes.  */
1254
1255 HOST_WIDE_INT
1256 constant_alignment_word_strings (const_tree exp, HOST_WIDE_INT align)
1257 {
1258   if (TREE_CODE (exp) == STRING_CST)
1259     return MAX (align, BITS_PER_WORD);
1260   return align;
1261 }
1262
1263 /* Default to natural alignment for vector types, bounded by
1264    MAX_OFILE_ALIGNMENT.  */
1265
1266 HOST_WIDE_INT
1267 default_vector_alignment (const_tree type)
1268 {
1269   unsigned HOST_WIDE_INT align = MAX_OFILE_ALIGNMENT;
1270   tree size = TYPE_SIZE (type);
1271   if (tree_fits_uhwi_p (size))
1272     align = tree_to_uhwi (size);
1273
1274   return align < MAX_OFILE_ALIGNMENT ? align : MAX_OFILE_ALIGNMENT;
1275 }
1276
1277 /* The default implementation of
1278    TARGET_VECTORIZE_PREFERRED_VECTOR_ALIGNMENT.  */
1279
1280 poly_uint64
1281 default_preferred_vector_alignment (const_tree type)
1282 {
1283   return TYPE_ALIGN (type);
1284 }
1285
1286 /* By default assume vectors of element TYPE require a multiple of the natural
1287    alignment of TYPE.  TYPE is naturally aligned if IS_PACKED is false.  */
1288 bool
1289 default_builtin_vector_alignment_reachable (const_tree /*type*/, bool is_packed)
1290 {
1291   return ! is_packed;
1292 }
1293
1294 /* By default, assume that a target supports any factor of misalignment
1295    memory access if it supports movmisalign patten.
1296    is_packed is true if the memory access is defined in a packed struct.  */
1297 bool
1298 default_builtin_support_vector_misalignment (machine_mode mode,
1299                                              const_tree type
1300                                              ATTRIBUTE_UNUSED,
1301                                              int misalignment
1302                                              ATTRIBUTE_UNUSED,
1303                                              bool is_packed
1304                                              ATTRIBUTE_UNUSED)
1305 {
1306   if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
1307     return true;
1308   return false;
1309 }
1310
1311 /* By default, only attempt to parallelize bitwise operations, and
1312    possibly adds/subtracts using bit-twiddling.  */
1313
1314 machine_mode
1315 default_preferred_simd_mode (scalar_mode)
1316 {
1317   return word_mode;
1318 }
1319
1320 /* By default do not split reductions further.  */
1321
1322 machine_mode
1323 default_split_reduction (machine_mode mode)
1324 {
1325   return mode;
1326 }
1327
1328 /* By default only the size derived from the preferred vector mode
1329    is tried.  */
1330
1331 void
1332 default_autovectorize_vector_sizes (vector_sizes *, bool)
1333 {
1334 }
1335
1336 /* By default a vector of integers is used as a mask.  */
1337
1338 opt_machine_mode
1339 default_get_mask_mode (poly_uint64 nunits, poly_uint64 vector_size)
1340 {
1341   unsigned int elem_size = vector_element_size (vector_size, nunits);
1342   scalar_int_mode elem_mode
1343     = smallest_int_mode_for_size (elem_size * BITS_PER_UNIT);
1344   machine_mode vector_mode;
1345
1346   gcc_assert (known_eq (elem_size * nunits, vector_size));
1347
1348   if (mode_for_vector (elem_mode, nunits).exists (&vector_mode)
1349       && VECTOR_MODE_P (vector_mode)
1350       && targetm.vector_mode_supported_p (vector_mode))
1351     return vector_mode;
1352
1353   return opt_machine_mode ();
1354 }
1355
1356 /* By default consider masked stores to be expensive.  */
1357
1358 bool
1359 default_empty_mask_is_expensive (unsigned ifn)
1360 {
1361   return ifn == IFN_MASK_STORE;
1362 }
1363
1364 /* By default, the cost model accumulates three separate costs (prologue,
1365    loop body, and epilogue) for a vectorized loop or block.  So allocate an
1366    array of three unsigned ints, set it to zero, and return its address.  */
1367
1368 void *
1369 default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
1370 {
1371   unsigned *cost = XNEWVEC (unsigned, 3);
1372   cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
1373   return cost;
1374 }
1375
1376 /* By default, the cost model looks up the cost of the given statement
1377    kind and mode, multiplies it by the occurrence count, accumulates
1378    it into the cost specified by WHERE, and returns the cost added.  */
1379
1380 unsigned
1381 default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
1382                        struct _stmt_vec_info *stmt_info, int misalign,
1383                        enum vect_cost_model_location where)
1384 {
1385   unsigned *cost = (unsigned *) data;
1386   unsigned retval = 0;
1387
1388   tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
1389   int stmt_cost = targetm.vectorize.builtin_vectorization_cost (kind, vectype,
1390                                                                 misalign);
1391    /* Statements in an inner loop relative to the loop being
1392       vectorized are weighted more heavily.  The value here is
1393       arbitrary and could potentially be improved with analysis.  */
1394   if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
1395     count *= 50;  /* FIXME.  */
1396
1397   retval = (unsigned) (count * stmt_cost);
1398   cost[where] += retval;
1399
1400   return retval;
1401 }
1402
1403 /* By default, the cost model just returns the accumulated costs.  */
1404
1405 void
1406 default_finish_cost (void *data, unsigned *prologue_cost,
1407                      unsigned *body_cost, unsigned *epilogue_cost)
1408 {
1409   unsigned *cost = (unsigned *) data;
1410   *prologue_cost = cost[vect_prologue];
1411   *body_cost     = cost[vect_body];
1412   *epilogue_cost = cost[vect_epilogue];
1413 }
1414
1415 /* Free the cost data.  */
1416
1417 void
1418 default_destroy_cost_data (void *data)
1419 {
1420   free (data);
1421 }
1422
1423 /* Determine whether or not a pointer mode is valid. Assume defaults
1424    of ptr_mode or Pmode - can be overridden.  */
1425 bool
1426 default_valid_pointer_mode (scalar_int_mode mode)
1427 {
1428   return (mode == ptr_mode || mode == Pmode);
1429 }
1430
1431 /* Determine whether the memory reference specified by REF may alias
1432    the C libraries errno location.  */
1433 bool
1434 default_ref_may_alias_errno (ao_ref *ref)
1435 {
1436   tree base = ao_ref_base (ref);
1437   /* The default implementation assumes the errno location is
1438      a declaration of type int or is always accessed via a
1439      pointer to int.  We assume that accesses to errno are
1440      not deliberately obfuscated (even in conforming ways).  */
1441   if (TYPE_UNSIGNED (TREE_TYPE (base))
1442       || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1443     return false;
1444   /* The default implementation assumes an errno location
1445      declaration is never defined in the current compilation unit.  */
1446   if (DECL_P (base)
1447       && !TREE_STATIC (base))
1448     return true;
1449   else if (TREE_CODE (base) == MEM_REF
1450            && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1451     {
1452       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1453       return !pi || pi->pt.anything || pi->pt.nonlocal;
1454     }
1455   return false;
1456 }
1457
1458 /* Return the mode for a pointer to a given ADDRSPACE,
1459    defaulting to ptr_mode for all address spaces.  */
1460
1461 scalar_int_mode
1462 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1463 {
1464   return ptr_mode;
1465 }
1466
1467 /* Return the mode for an address in a given ADDRSPACE,
1468    defaulting to Pmode for all address spaces.  */
1469
1470 scalar_int_mode
1471 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1472 {
1473   return Pmode;
1474 }
1475
1476 /* Named address space version of valid_pointer_mode.
1477    To match the above, the same modes apply to all address spaces.  */
1478
1479 bool
1480 default_addr_space_valid_pointer_mode (scalar_int_mode mode,
1481                                        addr_space_t as ATTRIBUTE_UNUSED)
1482 {
1483   return targetm.valid_pointer_mode (mode);
1484 }
1485
1486 /* Some places still assume that all pointer or address modes are the
1487    standard Pmode and ptr_mode.  These optimizations become invalid if
1488    the target actually supports multiple different modes.  For now,
1489    we disable such optimizations on such targets, using this function.  */
1490
1491 bool
1492 target_default_pointer_address_modes_p (void)
1493 {
1494   if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1495     return false;
1496   if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1497     return false;
1498
1499   return true;
1500 }
1501
1502 /* Named address space version of legitimate_address_p.
1503    By default, all address spaces have the same form.  */
1504
1505 bool
1506 default_addr_space_legitimate_address_p (machine_mode mode, rtx mem,
1507                                          bool strict,
1508                                          addr_space_t as ATTRIBUTE_UNUSED)
1509 {
1510   return targetm.legitimate_address_p (mode, mem, strict);
1511 }
1512
1513 /* Named address space version of LEGITIMIZE_ADDRESS.
1514    By default, all address spaces have the same form.  */
1515
1516 rtx
1517 default_addr_space_legitimize_address (rtx x, rtx oldx, machine_mode mode,
1518                                        addr_space_t as ATTRIBUTE_UNUSED)
1519 {
1520   return targetm.legitimize_address (x, oldx, mode);
1521 }
1522
1523 /* The default hook for determining if one named address space is a subset of
1524    another and to return which address space to use as the common address
1525    space.  */
1526
1527 bool
1528 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1529 {
1530   return (subset == superset);
1531 }
1532
1533 /* The default hook for determining if 0 within a named address
1534    space is a valid address.  */
1535
1536 bool
1537 default_addr_space_zero_address_valid (addr_space_t as ATTRIBUTE_UNUSED)
1538 {
1539   return false;
1540 }
1541
1542 /* The default hook for debugging the address space is to return the
1543    address space number to indicate DW_AT_address_class.  */
1544 int
1545 default_addr_space_debug (addr_space_t as)
1546 {
1547   return as;
1548 }
1549
1550 /* The default hook implementation for TARGET_ADDR_SPACE_DIAGNOSE_USAGE.
1551    Don't complain about any address space.  */
1552
1553 void
1554 default_addr_space_diagnose_usage (addr_space_t, location_t)
1555 {
1556 }
1557
1558
1559 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1560    called for targets with only a generic address space.  */
1561
1562 rtx
1563 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1564                             tree from_type ATTRIBUTE_UNUSED,
1565                             tree to_type ATTRIBUTE_UNUSED)
1566 {
1567   gcc_unreachable ();
1568 }
1569
1570 /* The defualt implementation of TARGET_HARD_REGNO_NREGS.  */
1571
1572 unsigned int
1573 default_hard_regno_nregs (unsigned int, machine_mode mode)
1574 {
1575   /* Targets with variable-sized modes must provide their own definition
1576      of this hook.  */
1577   return CEIL (GET_MODE_SIZE (mode).to_constant (), UNITS_PER_WORD);
1578 }
1579
1580 bool
1581 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1582 {
1583   return true;
1584 }
1585
1586 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */
1587
1588 bool
1589 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
1590                                   addr_space_t addrspace ATTRIBUTE_UNUSED)
1591 {
1592   return false;
1593 }
1594
1595 bool
1596 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1597                                          tree ARG_UNUSED (name),
1598                                          tree ARG_UNUSED (args),
1599                                          int ARG_UNUSED (flags))
1600 {
1601   warning (OPT_Wattributes,
1602            "target attribute is not supported on this machine");
1603
1604   return false;
1605 }
1606
1607 bool
1608 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1609                                     tree ARG_UNUSED (pop_target))
1610 {
1611   /* If args is NULL the caller is handle_pragma_pop_options ().  In that case,
1612      emit no warning because "#pragma GCC pop_target" is valid on targets that
1613      do not have the "target" pragma.  */
1614   if (args)
1615     warning (OPT_Wpragmas,
1616              "%<#pragma GCC target%> is not supported for this machine");
1617
1618   return false;
1619 }
1620
1621 bool
1622 default_target_can_inline_p (tree caller, tree callee)
1623 {
1624   tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1625   tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1626   if (! callee_opts)
1627     callee_opts = target_option_default_node;
1628   if (! caller_opts)
1629     caller_opts = target_option_default_node;
1630
1631   /* If both caller and callee have attributes, assume that if the
1632      pointer is different, the two functions have different target
1633      options since build_target_option_node uses a hash table for the
1634      options.  */
1635   return callee_opts == caller_opts;
1636 }
1637
1638 /* If the machine does not have a case insn that compares the bounds,
1639    this means extra overhead for dispatch tables, which raises the
1640    threshold for using them.  */
1641
1642 unsigned int
1643 default_case_values_threshold (void)
1644 {
1645   return (targetm.have_casesi () ? 4 : 5);
1646 }
1647
1648 bool
1649 default_have_conditional_execution (void)
1650 {
1651   return HAVE_conditional_execution;
1652 }
1653
1654 /* By default we assume that c99 functions are present at the runtime,
1655    but sincos is not.  */
1656 bool
1657 default_libc_has_function (enum function_class fn_class)
1658 {
1659   if (fn_class == function_c94
1660       || fn_class == function_c99_misc
1661       || fn_class == function_c99_math_complex)
1662     return true;
1663
1664   return false;
1665 }
1666
1667 /* By default assume that libc has not a fast implementation.  */
1668
1669 bool
1670 default_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
1671 {
1672   return false;
1673 }
1674
1675 bool
1676 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1677 {
1678   return true;
1679 }
1680
1681 bool
1682 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED)
1683 {
1684   return false;
1685 }
1686
1687 tree
1688 default_builtin_tm_load_store (tree ARG_UNUSED (type))
1689 {
1690   return NULL_TREE;
1691 }
1692
1693 /* Compute cost of moving registers to/from memory.  */
1694
1695 int
1696 default_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1697                           reg_class_t rclass ATTRIBUTE_UNUSED,
1698                           bool in ATTRIBUTE_UNUSED)
1699 {
1700 #ifndef MEMORY_MOVE_COST
1701     return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1702 #else
1703     return MEMORY_MOVE_COST (MACRO_MODE (mode), (enum reg_class) rclass, in);
1704 #endif
1705 }
1706
1707 /* Compute cost of moving data from a register of class FROM to one of
1708    TO, using MODE.  */
1709
1710 int
1711 default_register_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
1712                             reg_class_t from ATTRIBUTE_UNUSED,
1713                             reg_class_t to ATTRIBUTE_UNUSED)
1714 {
1715 #ifndef REGISTER_MOVE_COST
1716   return 2;
1717 #else
1718   return REGISTER_MOVE_COST (MACRO_MODE (mode),
1719                              (enum reg_class) from, (enum reg_class) to);
1720 #endif
1721 }
1722
1723 /* The default implementation of TARGET_SLOW_UNALIGNED_ACCESS.  */
1724
1725 bool
1726 default_slow_unaligned_access (machine_mode, unsigned int)
1727 {
1728   return STRICT_ALIGNMENT;
1729 }
1730
1731 /* The default implementation of TARGET_ESTIMATED_POLY_VALUE.  */
1732
1733 HOST_WIDE_INT
1734 default_estimated_poly_value (poly_int64 x)
1735 {
1736   return x.coeffs[0];
1737 }
1738
1739 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
1740    behavior.  SPEED_P is true if we are compiling for speed.  */
1741
1742 unsigned int
1743 get_move_ratio (bool speed_p ATTRIBUTE_UNUSED)
1744 {
1745   unsigned int move_ratio;
1746 #ifdef MOVE_RATIO
1747   move_ratio = (unsigned int) MOVE_RATIO (speed_p);
1748 #else
1749 #if defined (HAVE_cpymemqi) || defined (HAVE_cpymemhi) || defined (HAVE_cpymemsi) || defined (HAVE_cpymemdi) || defined (HAVE_cpymemti)
1750   move_ratio = 2;
1751 #else /* No cpymem patterns, pick a default.  */
1752   move_ratio = ((speed_p) ? 15 : 3);
1753 #endif
1754 #endif
1755   return move_ratio;
1756 }
1757
1758 /* Return TRUE if the move_by_pieces/set_by_pieces infrastructure should be
1759    used; return FALSE if the cpymem/setmem optab should be expanded, or
1760    a call to memcpy emitted.  */
1761
1762 bool
1763 default_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
1764                                         unsigned int alignment,
1765                                         enum by_pieces_operation op,
1766                                         bool speed_p)
1767 {
1768   unsigned int max_size = 0;
1769   unsigned int ratio = 0;
1770
1771   switch (op)
1772     {
1773     case CLEAR_BY_PIECES:
1774       max_size = STORE_MAX_PIECES;
1775       ratio = CLEAR_RATIO (speed_p);
1776       break;
1777     case MOVE_BY_PIECES:
1778       max_size = MOVE_MAX_PIECES;
1779       ratio = get_move_ratio (speed_p);
1780       break;
1781     case SET_BY_PIECES:
1782       max_size = STORE_MAX_PIECES;
1783       ratio = SET_RATIO (speed_p);
1784       break;
1785     case STORE_BY_PIECES:
1786       max_size = STORE_MAX_PIECES;
1787       ratio = get_move_ratio (speed_p);
1788       break;
1789     case COMPARE_BY_PIECES:
1790       max_size = COMPARE_MAX_PIECES;
1791       /* Pick a likely default, just as in get_move_ratio.  */
1792       ratio = speed_p ? 15 : 3;
1793       break;
1794     }
1795
1796   return by_pieces_ninsns (size, alignment, max_size + 1, op) < ratio;
1797 }
1798
1799 /* This hook controls code generation for expanding a memcmp operation by
1800    pieces.  Return 1 for the normal pattern of compare/jump after each pair
1801    of loads, or a higher number to reduce the number of branches.  */
1802
1803 int
1804 default_compare_by_pieces_branch_ratio (machine_mode)
1805 {
1806   return 1;
1807 }
1808
1809 /* Write PATCH_AREA_SIZE NOPs into the asm outfile FILE around a function
1810    entry.  If RECORD_P is true and the target supports named sections,
1811    the location of the NOPs will be recorded in a special object section
1812    called "__patchable_function_entries".  This routine may be called
1813    twice per function to put NOPs before and after the function
1814    entry.  */
1815
1816 void
1817 default_print_patchable_function_entry (FILE *file,
1818                                         unsigned HOST_WIDE_INT patch_area_size,
1819                                         bool record_p)
1820 {
1821   const char *nop_templ = 0;
1822   int code_num;
1823   rtx_insn *my_nop = make_insn_raw (gen_nop ());
1824
1825   /* We use the template alone, relying on the (currently sane) assumption
1826      that the NOP template does not have variable operands.  */
1827   code_num = recog_memoized (my_nop);
1828   nop_templ = get_insn_template (code_num, my_nop);
1829
1830   if (record_p && targetm_common.have_named_sections)
1831     {
1832       char buf[256];
1833       static int patch_area_number;
1834       section *previous_section = in_section;
1835       const char *asm_op = integer_asm_op (POINTER_SIZE_UNITS, false);
1836
1837       gcc_assert (asm_op != NULL);
1838       patch_area_number++;
1839       ASM_GENERATE_INTERNAL_LABEL (buf, "LPFE", patch_area_number);
1840
1841       switch_to_section (get_section ("__patchable_function_entries",
1842                                       SECTION_WRITE | SECTION_RELRO, NULL));
1843       fputs (asm_op, file);
1844       assemble_name_raw (file, buf);
1845       fputc ('\n', file);
1846
1847       switch_to_section (previous_section);
1848       ASM_OUTPUT_LABEL (file, buf);
1849     }
1850
1851   unsigned i;
1852   for (i = 0; i < patch_area_size; ++i)
1853     fprintf (file, "\t%s\n", nop_templ);
1854 }
1855
1856 bool
1857 default_profile_before_prologue (void)
1858 {
1859 #ifdef PROFILE_BEFORE_PROLOGUE
1860   return true;
1861 #else
1862   return false;
1863 #endif
1864 }
1865
1866 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */
1867
1868 reg_class_t
1869 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1870                                 reg_class_t rclass)
1871 {
1872 #ifdef PREFERRED_RELOAD_CLASS
1873   return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1874 #else
1875   return rclass;
1876 #endif
1877 }
1878
1879 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */
1880
1881 reg_class_t
1882 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1883                                        reg_class_t rclass)
1884 {
1885   return rclass;
1886 }
1887
1888 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
1889 reg_class_t
1890 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1891 {
1892   return NO_REGS;
1893 }
1894
1895 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */
1896
1897 bool
1898 default_class_likely_spilled_p (reg_class_t rclass)
1899 {
1900   return (reg_class_size[(int) rclass] == 1);
1901 }
1902
1903 /* The default implementation of TARGET_CLASS_MAX_NREGS.  */
1904
1905 unsigned char
1906 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1907                          machine_mode mode ATTRIBUTE_UNUSED)
1908 {
1909 #ifdef CLASS_MAX_NREGS
1910   return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass,
1911                                           MACRO_MODE (mode));
1912 #else
1913   /* Targets with variable-sized modes must provide their own definition
1914      of this hook.  */
1915   unsigned int size = GET_MODE_SIZE (mode).to_constant ();
1916   return (size + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1917 #endif
1918 }
1919
1920 /* Determine the debugging unwind mechanism for the target.  */
1921
1922 enum unwind_info_type
1923 default_debug_unwind_info (void)
1924 {
1925   /* If the target wants to force the use of dwarf2 unwind info, let it.  */
1926   /* ??? Change all users to the hook, then poison this.  */
1927 #ifdef DWARF2_FRAME_INFO
1928   if (DWARF2_FRAME_INFO)
1929     return UI_DWARF2;
1930 #endif
1931
1932   /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
1933 #ifdef DWARF2_DEBUGGING_INFO
1934   if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1935     return UI_DWARF2;
1936 #endif
1937
1938   return UI_NONE;
1939 }
1940
1941 /* Targets that set NUM_POLY_INT_COEFFS to something greater than 1
1942    must define this hook.  */
1943
1944 unsigned int
1945 default_dwarf_poly_indeterminate_value (unsigned int, unsigned int *, int *)
1946 {
1947   gcc_unreachable ();
1948 }
1949
1950 /* Determine the correct mode for a Dwarf frame register that represents
1951    register REGNO.  */
1952
1953 machine_mode
1954 default_dwarf_frame_reg_mode (int regno)
1955 {
1956   machine_mode save_mode = reg_raw_mode[regno];
1957
1958   if (targetm.hard_regno_call_part_clobbered (NULL, regno, save_mode))
1959     save_mode = choose_hard_reg_mode (regno, 1, true);
1960   return save_mode;
1961 }
1962
1963 /* To be used by targets where reg_raw_mode doesn't return the right
1964    mode for registers used in apply_builtin_return and apply_builtin_arg.  */
1965
1966 fixed_size_mode
1967 default_get_reg_raw_mode (int regno)
1968 {
1969   /* Targets must override this hook if the underlying register is
1970      variable-sized.  */
1971   return as_a <fixed_size_mode> (reg_raw_mode[regno]);
1972 }
1973
1974 /* Return true if a leaf function should stay leaf even with profiling
1975    enabled.  */
1976
1977 bool
1978 default_keep_leaf_when_profiled ()
1979 {
1980   return false;
1981 }
1982
1983 /* Return true if the state of option OPTION should be stored in PCH files
1984    and checked by default_pch_valid_p.  Store the option's current state
1985    in STATE if so.  */
1986
1987 static inline bool
1988 option_affects_pch_p (int option, struct cl_option_state *state)
1989 {
1990   if ((cl_options[option].flags & CL_TARGET) == 0)
1991     return false;
1992   if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
1993     return false;
1994   if (option_flag_var (option, &global_options) == &target_flags)
1995     if (targetm.check_pch_target_flags)
1996       return false;
1997   return get_option_state (&global_options, option, state);
1998 }
1999
2000 /* Default version of get_pch_validity.
2001    By default, every flag difference is fatal; that will be mostly right for
2002    most targets, but completely right for very few.  */
2003
2004 void *
2005 default_get_pch_validity (size_t *sz)
2006 {
2007   struct cl_option_state state;
2008   size_t i;
2009   char *result, *r;
2010
2011   *sz = 2;
2012   if (targetm.check_pch_target_flags)
2013     *sz += sizeof (target_flags);
2014   for (i = 0; i < cl_options_count; i++)
2015     if (option_affects_pch_p (i, &state))
2016       *sz += state.size;
2017
2018   result = r = XNEWVEC (char, *sz);
2019   r[0] = flag_pic;
2020   r[1] = flag_pie;
2021   r += 2;
2022   if (targetm.check_pch_target_flags)
2023     {
2024       memcpy (r, &target_flags, sizeof (target_flags));
2025       r += sizeof (target_flags);
2026     }
2027
2028   for (i = 0; i < cl_options_count; i++)
2029     if (option_affects_pch_p (i, &state))
2030       {
2031         memcpy (r, state.data, state.size);
2032         r += state.size;
2033       }
2034
2035   return result;
2036 }
2037
2038 /* Return a message which says that a PCH file was created with a different
2039    setting of OPTION.  */
2040
2041 static const char *
2042 pch_option_mismatch (const char *option)
2043 {
2044   return xasprintf (_("created and used with differing settings of '%s'"),
2045                     option);
2046 }
2047
2048 /* Default version of pch_valid_p.  */
2049
2050 const char *
2051 default_pch_valid_p (const void *data_p, size_t len)
2052 {
2053   struct cl_option_state state;
2054   const char *data = (const char *)data_p;
2055   size_t i;
2056
2057   /* -fpic and -fpie also usually make a PCH invalid.  */
2058   if (data[0] != flag_pic)
2059     return _("created and used with different settings of %<-fpic%>");
2060   if (data[1] != flag_pie)
2061     return _("created and used with different settings of %<-fpie%>");
2062   data += 2;
2063
2064   /* Check target_flags.  */
2065   if (targetm.check_pch_target_flags)
2066     {
2067       int tf;
2068       const char *r;
2069
2070       memcpy (&tf, data, sizeof (target_flags));
2071       data += sizeof (target_flags);
2072       len -= sizeof (target_flags);
2073       r = targetm.check_pch_target_flags (tf);
2074       if (r != NULL)
2075         return r;
2076     }
2077
2078   for (i = 0; i < cl_options_count; i++)
2079     if (option_affects_pch_p (i, &state))
2080       {
2081         if (memcmp (data, state.data, state.size) != 0)
2082           return pch_option_mismatch (cl_options[i].opt_text);
2083         data += state.size;
2084         len -= state.size;
2085       }
2086
2087   return NULL;
2088 }
2089
2090 /* Default version of cstore_mode.  */
2091
2092 scalar_int_mode
2093 default_cstore_mode (enum insn_code icode)
2094 {
2095   return as_a <scalar_int_mode> (insn_data[(int) icode].operand[0].mode);
2096 }
2097
2098 /* Default version of member_type_forces_blk.  */
2099
2100 bool
2101 default_member_type_forces_blk (const_tree, machine_mode)
2102 {
2103   return false;
2104 }
2105
2106 rtx
2107 default_load_bounds_for_arg (rtx addr ATTRIBUTE_UNUSED,
2108                              rtx ptr ATTRIBUTE_UNUSED,
2109                              rtx bnd ATTRIBUTE_UNUSED)
2110 {
2111   gcc_unreachable ();
2112 }
2113
2114 void
2115 default_store_bounds_for_arg (rtx val ATTRIBUTE_UNUSED,
2116                               rtx addr ATTRIBUTE_UNUSED,
2117                               rtx bounds ATTRIBUTE_UNUSED,
2118                               rtx to ATTRIBUTE_UNUSED)
2119 {
2120   gcc_unreachable ();
2121 }
2122
2123 rtx
2124 default_load_returned_bounds (rtx slot ATTRIBUTE_UNUSED)
2125 {
2126   gcc_unreachable ();
2127 }
2128
2129 void
2130 default_store_returned_bounds (rtx slot ATTRIBUTE_UNUSED,
2131                                rtx bounds ATTRIBUTE_UNUSED)
2132 {
2133   gcc_unreachable ();
2134 }
2135
2136 /* Default version of canonicalize_comparison.  */
2137
2138 void
2139 default_canonicalize_comparison (int *, rtx *, rtx *, bool)
2140 {
2141 }
2142
2143 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */
2144
2145 void
2146 default_atomic_assign_expand_fenv (tree *, tree *, tree *)
2147 {
2148 }
2149
2150 #ifndef PAD_VARARGS_DOWN
2151 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
2152 #endif
2153
2154 /* Build an indirect-ref expression over the given TREE, which represents a
2155    piece of a va_arg() expansion.  */
2156 tree
2157 build_va_arg_indirect_ref (tree addr)
2158 {
2159   addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
2160   return addr;
2161 }
2162
2163 /* The "standard" implementation of va_arg: read the value from the
2164    current (padded) address and increment by the (padded) size.  */
2165
2166 tree
2167 std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
2168                           gimple_seq *post_p)
2169 {
2170   tree addr, t, type_size, rounded_size, valist_tmp;
2171   unsigned HOST_WIDE_INT align, boundary;
2172   bool indirect;
2173
2174   /* All of the alignment and movement below is for args-grow-up machines.
2175      As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
2176      implement their own specialized gimplify_va_arg_expr routines.  */
2177   if (ARGS_GROW_DOWNWARD)
2178     gcc_unreachable ();
2179
2180   indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
2181   if (indirect)
2182     type = build_pointer_type (type);
2183
2184   if (targetm.calls.split_complex_arg
2185       && TREE_CODE (type) == COMPLEX_TYPE
2186       && targetm.calls.split_complex_arg (type))
2187     {
2188       tree real_part, imag_part;
2189
2190       real_part = std_gimplify_va_arg_expr (valist,
2191                                             TREE_TYPE (type), pre_p, NULL);
2192       real_part = get_initialized_tmp_var (real_part, pre_p, NULL);
2193
2194       imag_part = std_gimplify_va_arg_expr (unshare_expr (valist),
2195                                             TREE_TYPE (type), pre_p, NULL);
2196       imag_part = get_initialized_tmp_var (imag_part, pre_p, NULL);
2197
2198       return build2 (COMPLEX_EXPR, type, real_part, imag_part);
2199    }
2200
2201   align = PARM_BOUNDARY / BITS_PER_UNIT;
2202   boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);
2203
2204   /* When we align parameter on stack for caller, if the parameter
2205      alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
2206      aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
2207      here with caller.  */
2208   if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
2209     boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
2210
2211   boundary /= BITS_PER_UNIT;
2212
2213   /* Hoist the valist value into a temporary for the moment.  */
2214   valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);
2215
2216   /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
2217      requires greater alignment, we must perform dynamic alignment.  */
2218   if (boundary > align
2219       && !TYPE_EMPTY_P (type)
2220       && !integer_zerop (TYPE_SIZE (type)))
2221     {
2222       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
2223                   fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
2224       gimplify_and_add (t, pre_p);
2225
2226       t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
2227                   fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
2228                                valist_tmp,
2229                                build_int_cst (TREE_TYPE (valist), -boundary)));
2230       gimplify_and_add (t, pre_p);
2231     }
2232   else
2233     boundary = align;
2234
2235   /* If the actual alignment is less than the alignment of the type,
2236      adjust the type accordingly so that we don't assume strict alignment
2237      when dereferencing the pointer.  */
2238   boundary *= BITS_PER_UNIT;
2239   if (boundary < TYPE_ALIGN (type))
2240     {
2241       type = build_variant_type_copy (type);
2242       SET_TYPE_ALIGN (type, boundary);
2243     }
2244
2245   /* Compute the rounded size of the type.  */
2246   type_size = arg_size_in_bytes (type);
2247   rounded_size = round_up (type_size, align);
2248
2249   /* Reduce rounded_size so it's sharable with the postqueue.  */
2250   gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);
2251
2252   /* Get AP.  */
2253   addr = valist_tmp;
2254   if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
2255     {
2256       /* Small args are padded downward.  */
2257       t = fold_build2_loc (input_location, GT_EXPR, sizetype,
2258                        rounded_size, size_int (align));
2259       t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
2260                        size_binop (MINUS_EXPR, rounded_size, type_size));
2261       addr = fold_build_pointer_plus (addr, t);
2262     }
2263
2264   /* Compute new value for AP.  */
2265   t = fold_build_pointer_plus (valist_tmp, rounded_size);
2266   t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
2267   gimplify_and_add (t, pre_p);
2268
2269   addr = fold_convert (build_pointer_type (type), addr);
2270
2271   if (indirect)
2272     addr = build_va_arg_indirect_ref (addr);
2273
2274   return build_va_arg_indirect_ref (addr);
2275 }
2276
2277 void
2278 default_setup_incoming_vararg_bounds (cumulative_args_t ca ATTRIBUTE_UNUSED,
2279                                       machine_mode mode ATTRIBUTE_UNUSED,
2280                                       tree type ATTRIBUTE_UNUSED,
2281                                       int *pretend_arg_size ATTRIBUTE_UNUSED,
2282                                       int second_time ATTRIBUTE_UNUSED)
2283 {
2284 }
2285
2286 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
2287    not support nested low-overhead loops.  */
2288
2289 bool
2290 can_use_doloop_if_innermost (const widest_int &, const widest_int &,
2291                              unsigned int loop_depth, bool)
2292 {
2293   return loop_depth == 1;
2294 }
2295
2296 /* Default implementation of TARGET_OPTAB_SUPPORTED_P.  */
2297
2298 bool
2299 default_optab_supported_p (int, machine_mode, machine_mode, optimization_type)
2300 {
2301   return true;
2302 }
2303
2304 /* Default implementation of TARGET_MAX_NOCE_IFCVT_SEQ_COST.  */
2305
2306 unsigned int
2307 default_max_noce_ifcvt_seq_cost (edge e)
2308 {
2309   bool predictable_p = predictable_edge_p (e);
2310
2311   enum compiler_param param
2312     = (predictable_p
2313        ? PARAM_MAX_RTL_IF_CONVERSION_PREDICTABLE_COST
2314        : PARAM_MAX_RTL_IF_CONVERSION_UNPREDICTABLE_COST);
2315
2316   /* If we have a parameter set, use that, otherwise take a guess using
2317      BRANCH_COST.  */
2318   if (global_options_set.x_param_values[param])
2319     return PARAM_VALUE (param);
2320   else
2321     return BRANCH_COST (true, predictable_p) * COSTS_N_INSNS (3);
2322 }
2323
2324 /* Default implementation of TARGET_MIN_ARITHMETIC_PRECISION.  */
2325
2326 unsigned int
2327 default_min_arithmetic_precision (void)
2328 {
2329   return WORD_REGISTER_OPERATIONS ? BITS_PER_WORD : BITS_PER_UNIT;
2330 }
2331
2332 /* Default implementation of TARGET_C_EXCESS_PRECISION.  */
2333
2334 enum flt_eval_method
2335 default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED)
2336 {
2337   return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT;
2338 }
2339
2340 /* Default implementation for
2341   TARGET_STACK_CLASH_PROTECTION_ALLOCA_PROBE_RANGE.  */
2342 HOST_WIDE_INT
2343 default_stack_clash_protection_alloca_probe_range (void)
2344 {
2345   return 0;
2346 }
2347
2348 /* The default implementation of TARGET_EARLY_REMAT_MODES.  */
2349
2350 void
2351 default_select_early_remat_modes (sbitmap)
2352 {
2353 }
2354
2355 /* The default implementation of TARGET_PREFERRED_ELSE_VALUE.  */
2356
2357 tree
2358 default_preferred_else_value (unsigned, tree type, unsigned, tree *)
2359 {
2360   return build_zero_cst (type);
2361 }
2362
2363 /* Default implementation of TARGET_HAVE_SPECULATION_SAFE_VALUE.  */
2364 bool
2365 default_have_speculation_safe_value (bool active ATTRIBUTE_UNUSED)
2366 {
2367 #ifdef HAVE_speculation_barrier
2368   return active ? HAVE_speculation_barrier : true;
2369 #else
2370   return false;
2371 #endif
2372 }
2373 /* Alternative implementation of TARGET_HAVE_SPECULATION_SAFE_VALUE
2374    that can be used on targets that never have speculative execution.  */
2375 bool
2376 speculation_safe_value_not_needed (bool active)
2377 {
2378   return !active;
2379 }
2380
2381 /* Default implementation of the speculation-safe-load builtin.  This
2382    implementation simply copies val to result and generates a
2383    speculation_barrier insn, if such a pattern is defined.  */
2384 rtx
2385 default_speculation_safe_value (machine_mode mode ATTRIBUTE_UNUSED,
2386                                 rtx result, rtx val,
2387                                 rtx failval ATTRIBUTE_UNUSED)
2388 {
2389   emit_move_insn (result, val);
2390
2391 #ifdef HAVE_speculation_barrier
2392   /* Assume the target knows what it is doing: if it defines a
2393      speculation barrier, but it is not enabled, then assume that one
2394      isn't needed.  */
2395   if (HAVE_speculation_barrier)
2396     emit_insn (gen_speculation_barrier ());
2397 #endif
2398
2399   return result;
2400 }
2401
2402 void
2403 default_remove_extra_call_preserved_regs (rtx_insn *, HARD_REG_SET *)
2404 {
2405 }
2406
2407 #include "gt-targhooks.h"