gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004, 2005, 2007 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 "expr.h"
  57 #include "output.h"
  58 #include "toplev.h"
  59 #include "function.h"
  60 #include "target.h"
  61 #include "tm_p.h"
  62 #include "target-def.h"
  63 #include "ggc.h"
  64 #include "hard-reg-set.h"
  65 #include "reload.h"
  66 #include "optabs.h"
  67 #include "recog.h"
  68
  69
  70 void
  71 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  72 {
  73 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  74   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  75 #endif
  76 }
  77
  78 int
  79 default_unspec_may_trap_p (const_rtx x, unsigned flags)
  80 {
  81   int i;
  82
  83   if (GET_CODE (x) == UNSPEC_VOLATILE
  84       /* Any floating arithmetic may trap.  */
  85       || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
  86           && flag_trapping_math))
  87     return 1;
  88
  89   for (i = 0; i < XVECLEN (x, 0); ++i)
  90     {
  91       if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
  92         return 1;
  93     }
  94
  95   return 0;
  96 }
  97
  98 enum machine_mode
  99 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
 100 {
 101   if (m1 == m2)
 102     return m1;
 103   return VOIDmode;
 104 }
 105
 106 bool
 107 default_return_in_memory (const_tree type,
 108                           const_tree fntype ATTRIBUTE_UNUSED)
 109 {
 110   return (TYPE_MODE (type) == BLKmode);
 111 }
 112
 113 rtx
 114 default_expand_builtin_saveregs (void)
 115 {
 116   error ("__builtin_saveregs not supported by this target");
 117   return const0_rtx;
 118 }
 119
 120 void
 121 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 122                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 123                                 tree type ATTRIBUTE_UNUSED,
 124                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 125                                 int second_time ATTRIBUTE_UNUSED)
 126 {
 127 }
 128
 129 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
 130
 131 rtx
 132 default_builtin_setjmp_frame_value (void)
 133 {
 134   return virtual_stack_vars_rtx;
 135 }
 136
 137 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
 138
 139 bool
 140 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 141 {
 142   return false;
 143 }
 144
 145 bool
 146 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 147 {
 148   return (targetm.calls.setup_incoming_varargs
 149           != default_setup_incoming_varargs);
 150 }
 151
 152 enum machine_mode
 153 default_eh_return_filter_mode (void)
 154 {
 155   return word_mode;
 156 }
 157
 158 enum machine_mode
 159 default_libgcc_cmp_return_mode (void)
 160 {
 161   return word_mode;
 162 }
 163
 164 enum machine_mode
 165 default_libgcc_shift_count_mode (void)
 166 {
 167   return word_mode;
 168 }
 169
 170 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
 171
 172 unsigned HOST_WIDE_INT
 173 default_shift_truncation_mask (enum machine_mode mode)
 174 {
 175   return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
 176 }
 177
 178 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
 179
 180 unsigned int
 181 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
 182 {
 183   return have_insn_for (DIV, mode) ? 3 : 2;
 184 }
 185
 186 /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
 187
 188 int
 189 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
 190                            enum machine_mode mode_rep ATTRIBUTE_UNUSED)
 191 {
 192   return UNKNOWN;
 193 }
 194
 195 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 196
 197 bool
 198 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 199 {
 200   return true;
 201 }
 202
 203 /* Return machine mode for non-standard suffix
 204    or VOIDmode if non-standard suffixes are unsupported.  */
 205 enum machine_mode
 206 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
 207 {
 208   return VOIDmode;
 209 }
 210
 211 /* The generic C++ ABI specifies this is a 64-bit value.  */
 212 tree
 213 default_cxx_guard_type (void)
 214 {
 215   return long_long_integer_type_node;
 216 }
 217
 218
 219 /* Returns the size of the cookie to use when allocating an array
 220    whose elements have the indicated TYPE.  Assumes that it is already
 221    known that a cookie is needed.  */
 222
 223 tree
 224 default_cxx_get_cookie_size (tree type)
 225 {
 226   tree cookie_size;
 227
 228   /* We need to allocate an additional max (sizeof (size_t), alignof
 229      (true_type)) bytes.  */
 230   tree sizetype_size;
 231   tree type_align;
 232
 233   sizetype_size = size_in_bytes (sizetype);
 234   type_align = size_int (TYPE_ALIGN_UNIT (type));
 235   if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
 236     cookie_size = sizetype_size;
 237   else
 238     cookie_size = type_align;
 239
 240   return cookie_size;
 241 }
 242
 243 /* Return true if a parameter must be passed by reference.  This version
 244    of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
 245
 246 bool
 247 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
 248         enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
 249         bool named_arg ATTRIBUTE_UNUSED)
 250 {
 251   return targetm.calls.must_pass_in_stack (mode, type);
 252 }
 253
 254 /* Return true if a parameter follows callee copies conventions.  This
 255    version of the hook is true for all named arguments.  */
 256
 257 bool
 258 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 259                           enum machine_mode mode ATTRIBUTE_UNUSED,
 260                           const_tree type ATTRIBUTE_UNUSED, bool named)
 261 {
 262   return named;
 263 }
 264
 265 /* Emit any directives required to unwind this instruction.  */
 266
 267 void
 268 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
 269                      rtx insn ATTRIBUTE_UNUSED)
 270 {
 271   /* Should never happen.  */
 272   gcc_unreachable ();
 273 }
 274
 275 /* True if MODE is valid for the target.  By "valid", we mean able to
 276    be manipulated in non-trivial ways.  In particular, this means all
 277    the arithmetic is supported.
 278
 279    By default we guess this means that any C type is supported.  If
 280    we can't map the mode back to a type that would be available in C,
 281    then reject it.  Special case, here, is the double-word arithmetic
 282    supported by optabs.c.  */
 283
 284 bool
 285 default_scalar_mode_supported_p (enum machine_mode mode)
 286 {
 287   int precision = GET_MODE_PRECISION (mode);
 288
 289   switch (GET_MODE_CLASS (mode))
 290     {
 291     case MODE_PARTIAL_INT:
 292     case MODE_INT:
 293       if (precision == CHAR_TYPE_SIZE)
 294         return true;
 295       if (precision == SHORT_TYPE_SIZE)
 296         return true;
 297       if (precision == INT_TYPE_SIZE)
 298         return true;
 299       if (precision == LONG_TYPE_SIZE)
 300         return true;
 301       if (precision == LONG_LONG_TYPE_SIZE)
 302         return true;
 303       if (precision == 2 * BITS_PER_WORD)
 304         return true;
 305       return false;
 306
 307     case MODE_FLOAT:
 308       if (precision == FLOAT_TYPE_SIZE)
 309         return true;
 310       if (precision == DOUBLE_TYPE_SIZE)
 311         return true;
 312       if (precision == LONG_DOUBLE_TYPE_SIZE)
 313         return true;
 314       return false;
 315
 316     case MODE_DECIMAL_FLOAT:
 317     case MODE_FRACT:
 318     case MODE_UFRACT:
 319     case MODE_ACCUM:
 320     case MODE_UACCUM:
 321       return false;
 322
 323     default:
 324       gcc_unreachable ();
 325     }
 326 }
 327
 328 /* True if the target supports decimal floating point.  */
 329
 330 bool
 331 default_decimal_float_supported_p (void)
 332 {
 333   return ENABLE_DECIMAL_FLOAT;
 334 }
 335
 336 /* True if the target supports fixed-point arithmetic.  */
 337
 338 bool
 339 default_fixed_point_supported_p (void)
 340 {
 341   return ENABLE_FIXED_POINT;
 342 }
 343
 344 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
 345    an error message.
 346
 347    This function checks whether a given INSN is valid within a low-overhead
 348    loop.  If INSN is invalid it returns the reason for that, otherwise it
 349    returns NULL. A called function may clobber any special registers required
 350    for low-overhead looping. Additionally, some targets (eg, PPC) use the count
 351    register for branch on table instructions. We reject the doloop pattern in
 352    these cases.  */
 353
 354 const char *
 355 default_invalid_within_doloop (const_rtx insn)
 356 {
 357   if (CALL_P (insn))
 358     return "Function call in loop.";
 359
 360   if (JUMP_P (insn)
 361       && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
 362           || GET_CODE (PATTERN (insn)) == ADDR_VEC))
 363     return "Computed branch in the loop.";
 364
 365   return NULL;
 366 }
 367
 368 /* Mapping of builtin functions to vectorized variants.  */
 369
 370 tree
 371 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED,
 372                                      tree type_out ATTRIBUTE_UNUSED,
 373                                      tree type_in ATTRIBUTE_UNUSED)
 374 {
 375   return NULL_TREE;
 376 }
 377
 378 /* Vectorized conversion.  */
 379
 380 tree
 381 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED,
 382                                        tree type ATTRIBUTE_UNUSED)
 383 {
 384   return NULL_TREE;
 385 }
 386
 387 /* Reciprocal.  */
 388
 389 tree
 390 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED,
 391                             bool md_fn ATTRIBUTE_UNUSED,
 392                             bool sqrt ATTRIBUTE_UNUSED)
 393 {
 394   return NULL_TREE;
 395 }
 396
 397 bool
 398 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
 399         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 400         enum machine_mode mode ATTRIBUTE_UNUSED,
 401         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 402 {
 403   return false;
 404 }
 405
 406 bool
 407 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
 408         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 409         enum machine_mode mode ATTRIBUTE_UNUSED,
 410         const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 411 {
 412   return true;
 413 }
 414
 415 int
 416 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
 417         CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 418         enum machine_mode mode ATTRIBUTE_UNUSED,
 419         tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
 420 {
 421   return 0;
 422 }
 423
 424 void
 425 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
 426 {
 427 }
 428
 429 const char *
 430 hook_invalid_arg_for_unprototyped_fn (
 431         const_tree typelist ATTRIBUTE_UNUSED,
 432         const_tree funcdecl ATTRIBUTE_UNUSED,
 433         const_tree val ATTRIBUTE_UNUSED)
 434 {
 435   return NULL;
 436 }
 437
 438 /* Initialize the stack protection decls.  */
 439
 440 /* Stack protection related decls living in libgcc.  */
 441 static GTY(()) tree stack_chk_guard_decl;
 442
 443 tree
 444 default_stack_protect_guard (void)
 445 {
 446   tree t = stack_chk_guard_decl;
 447
 448   if (t == NULL)
 449     {
 450       t = build_decl (VAR_DECL, get_identifier ("__stack_chk_guard"),
 451                       ptr_type_node);
 452       TREE_STATIC (t) = 1;
 453       TREE_PUBLIC (t) = 1;
 454       DECL_EXTERNAL (t) = 1;
 455       TREE_USED (t) = 1;
 456       TREE_THIS_VOLATILE (t) = 1;
 457       DECL_ARTIFICIAL (t) = 1;
 458       DECL_IGNORED_P (t) = 1;
 459
 460       stack_chk_guard_decl = t;
 461     }
 462
 463   return t;
 464 }
 465
 466 static GTY(()) tree stack_chk_fail_decl;
 467
 468 tree
 469 default_external_stack_protect_fail (void)
 470 {
 471   tree t = stack_chk_fail_decl;
 472
 473   if (t == NULL_TREE)
 474     {
 475       t = build_function_type_list (void_type_node, NULL_TREE);
 476       t = build_decl (FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
 477       TREE_STATIC (t) = 1;
 478       TREE_PUBLIC (t) = 1;
 479       DECL_EXTERNAL (t) = 1;
 480       TREE_USED (t) = 1;
 481       TREE_THIS_VOLATILE (t) = 1;
 482       TREE_NOTHROW (t) = 1;
 483       DECL_ARTIFICIAL (t) = 1;
 484       DECL_IGNORED_P (t) = 1;
 485       DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
 486       DECL_VISIBILITY_SPECIFIED (t) = 1;
 487
 488       stack_chk_fail_decl = t;
 489     }
 490
 491   return build_call_expr (t, 0);
 492 }
 493
 494 tree
 495 default_hidden_stack_protect_fail (void)
 496 {
 497 #ifndef HAVE_GAS_HIDDEN
 498   return default_external_stack_protect_fail ();
 499 #else
 500   tree t = stack_chk_fail_decl;
 501
 502   if (!flag_pic)
 503     return default_external_stack_protect_fail ();
 504
 505   if (t == NULL_TREE)
 506     {
 507       t = build_function_type_list (void_type_node, NULL_TREE);
 508       t = build_decl (FUNCTION_DECL,
 509                       get_identifier ("__stack_chk_fail_local"), t);
 510       TREE_STATIC (t) = 1;
 511       TREE_PUBLIC (t) = 1;
 512       DECL_EXTERNAL (t) = 1;
 513       TREE_USED (t) = 1;
 514       TREE_THIS_VOLATILE (t) = 1;
 515       TREE_NOTHROW (t) = 1;
 516       DECL_ARTIFICIAL (t) = 1;
 517       DECL_IGNORED_P (t) = 1;
 518       DECL_VISIBILITY_SPECIFIED (t) = 1;
 519       DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
 520
 521       stack_chk_fail_decl = t;
 522     }
 523
 524   return build_call_expr (t, 0);
 525 #endif
 526 }
 527
 528 bool
 529 hook_bool_const_rtx_commutative_p (const_rtx x,
 530                                    int outer_code ATTRIBUTE_UNUSED)
 531 {
 532   return COMMUTATIVE_P (x);
 533 }
 534
 535 rtx
 536 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
 537                         const_tree fn_decl_or_type,
 538                         bool outgoing ATTRIBUTE_UNUSED)
 539 {
 540   /* The old interface doesn't handle receiving the function type.  */
 541   if (fn_decl_or_type
 542       && !DECL_P (fn_decl_or_type))
 543     fn_decl_or_type = NULL;
 544
 545 #ifdef FUNCTION_OUTGOING_VALUE
 546   if (outgoing)
 547     return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
 548 #endif
 549
 550 #ifdef FUNCTION_VALUE
 551   return FUNCTION_VALUE (ret_type, fn_decl_or_type);
 552 #else
 553   return NULL_RTX;
 554 #endif
 555 }
 556
 557 rtx
 558 default_internal_arg_pointer (void)
 559 {
 560   /* If the reg that the virtual arg pointer will be translated into is
 561      not a fixed reg or is the stack pointer, make a copy of the virtual
 562      arg pointer, and address parms via the copy.  The frame pointer is
 563      considered fixed even though it is not marked as such.  */
 564   if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
 565        || ! (fixed_regs[ARG_POINTER_REGNUM]
 566              || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
 567     return copy_to_reg (virtual_incoming_args_rtx);
 568   else
 569     return virtual_incoming_args_rtx;
 570 }
 571
 572 enum reg_class
 573 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
 574                           enum reg_class reload_class ATTRIBUTE_UNUSED,
 575                           enum machine_mode reload_mode ATTRIBUTE_UNUSED,
 576                           secondary_reload_info *sri)
 577 {
 578   enum reg_class class = NO_REGS;
 579
 580   if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
 581     {
 582       sri->icode = sri->prev_sri->t_icode;
 583       return NO_REGS;
 584     }
 585 #ifdef SECONDARY_INPUT_RELOAD_CLASS
 586   if (in_p)
 587     class = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 588 #endif
 589 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
 590   if (! in_p)
 591     class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
 592 #endif
 593   if (class != NO_REGS)
 594     {
 595       enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
 596                               : reload_out_optab[(int) reload_mode]);
 597
 598       if (icode != CODE_FOR_nothing
 599           && insn_data[(int) icode].operand[in_p].predicate
 600           && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
 601         icode = CODE_FOR_nothing;
 602       else if (icode != CODE_FOR_nothing)
 603         {
 604           const char *insn_constraint, *scratch_constraint;
 605           char insn_letter, scratch_letter;
 606           enum reg_class insn_class, scratch_class;
 607
 608           gcc_assert (insn_data[(int) icode].n_operands == 3);
 609           insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
 610           if (!*insn_constraint)
 611             insn_class = ALL_REGS;
 612           else
 613             {
 614               if (in_p)
 615                 {
 616                   gcc_assert (*insn_constraint == '=');
 617                   insn_constraint++;
 618                 }
 619               insn_letter = *insn_constraint;
 620               insn_class
 621                 = (insn_letter == 'r' ? GENERAL_REGS
 622                    : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
 623                                                 insn_constraint));
 624               gcc_assert (insn_class != NO_REGS);
 625             }
 626
 627           scratch_constraint = insn_data[(int) icode].operand[2].constraint;
 628           /* The scratch register's constraint must start with "=&",
 629              except for an input reload, where only "=" is necessary,
 630              and where it might be beneficial to re-use registers from
 631              the input.  */
 632           gcc_assert (scratch_constraint[0] == '='
 633                       && (in_p || scratch_constraint[1] == '&'));
 634           scratch_constraint++;
 635           if (*scratch_constraint == '&')
 636             scratch_constraint++;
 637           scratch_letter = *scratch_constraint;
 638           scratch_class
 639             = (scratch_letter == 'r' ? GENERAL_REGS
 640                : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
 641                                             scratch_constraint));
 642
 643           if (reg_class_subset_p (reload_class, insn_class))
 644             {
 645               gcc_assert (scratch_class == class);
 646               class = NO_REGS;
 647             }
 648           else
 649             class = insn_class;
 650
 651         }
 652       if (class == NO_REGS)
 653         sri->icode = icode;
 654       else
 655         sri->t_icode = icode;
 656     }
 657   return class;
 658 }
 659
 660 bool
 661 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 662                          const char *arg ATTRIBUTE_UNUSED,
 663                          int value ATTRIBUTE_UNUSED)
 664 {
 665   return false;
 666 }
 667
 668 /* By default, if flag_pic is true, then neither local nor global relocs
 669    should be placed in readonly memory.  */
 670
 671 int
 672 default_reloc_rw_mask (void)
 673 {
 674   return flag_pic ? 3 : 0;
 675 }
 676
 677 /* By default, do no modification. */
 678 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
 679                                          tree id)
 680 {
 681    return id;
 682 }
 683
 684 bool
 685 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 686 {
 687   if (is_packed)
 688     return false;
 689
 690   /* Assuming that types whose size is > pointer-size are not guaranteed to be
 691      naturally aligned.  */
 692   if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
 693     return false;
 694
 695   /* Assuming that types whose size is <= pointer-size
 696      are naturally aligned.  */
 697   return true;
 698 }
 699
 700 #include "gt-targhooks.h"