1 /* Default target hook functions. 2 Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011 3 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 /* The migration of target macros to target hooks works as follows: 22 23 1. Create a target hook that uses the existing target macros to 24 implement the same functionality. 25 26 2. Convert all the MI files to use the hook instead of the macro. 27 28 3. Repeat for a majority of the remaining target macros. This will 29 take some time. 30 31 4. Tell target maintainers to start migrating. 32 33 5. Eventually convert the backends to override the hook instead of 34 defining the macros. This will take some time too. 35 36 6. TBD when, poison the macros. Unmigrated targets will break at 37 this point. 38 39 Note that we expect steps 1-3 to be done by the people that 40 understand what the MI does with each macro, and step 5 to be done 41 by the target maintainers for their respective targets. 42 43 Note that steps 1 and 2 don't have to be done together, but no 44 target can override the new hook until step 2 is complete for it. 45 46 Once the macros are poisoned, we will revert to the old migration 47 rules - migrate the macro, callers, and targets all at once. This 48 comment can thus be removed at that point. */ 49 50 #include "config.h" 51 #include "system.h" 52 #include "coretypes.h" 53 #include "tm.h" 54 #include "machmode.h" 55 #include "rtl.h" 56 #include "tree.h" 57 #include "expr.h" 58 #include "output.h" 59 #include "diagnostic-core.h" 60 #include "function.h" 61 #include "target.h" 62 #include "tm_p.h" 63 #include "target-def.h" 64 #include "ggc.h" 65 #include "hard-reg-set.h" 66 #include "regs.h" 67 #include "reload.h" 68 #include "optabs.h" 69 #include "recog.h" 70 #include "intl.h" 71 #include "opts.h" 72 #include "tree-flow.h" 73 #include "tree-ssa-alias.h" 74 75 76 bool 77 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED, 78 rtx addr ATTRIBUTE_UNUSED, 79 bool strict ATTRIBUTE_UNUSED) 80 { 81 #ifdef GO_IF_LEGITIMATE_ADDRESS 82 /* Defer to the old implementation using a goto. */ 83 if (strict) 84 return strict_memory_address_p (mode, addr); 85 else 86 return memory_address_p (mode, addr); 87 #else 88 gcc_unreachable (); 89 #endif 90 } 91 92 void 93 default_external_libcall (rtx fun ATTRIBUTE_UNUSED) 94 { 95 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL 96 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun); 97 #endif 98 } 99 100 int 101 default_unspec_may_trap_p (const_rtx x, unsigned flags) 102 { 103 int i; 104 105 if (GET_CODE (x) == UNSPEC_VOLATILE 106 /* Any floating arithmetic may trap. */ 107 || (SCALAR_FLOAT_MODE_P (GET_MODE (x)) 108 && flag_trapping_math)) 109 return 1; 110 111 for (i = 0; i < XVECLEN (x, 0); ++i) 112 { 113 if (may_trap_p_1 (XVECEXP (x, 0, i), flags)) 114 return 1; 115 } 116 117 return 0; 118 } 119 120 enum machine_mode 121 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED, 122 enum machine_mode mode, 123 int *punsignedp ATTRIBUTE_UNUSED, 124 const_tree funtype ATTRIBUTE_UNUSED, 125 int for_return ATTRIBUTE_UNUSED) 126 { 127 if (type != NULL_TREE && for_return == 2) 128 return promote_mode (type, mode, punsignedp); 129 return mode; 130 } 131 132 enum machine_mode 133 default_promote_function_mode_always_promote (const_tree type, 134 enum machine_mode mode, 135 int *punsignedp, 136 const_tree funtype ATTRIBUTE_UNUSED, 137 int for_return ATTRIBUTE_UNUSED) 138 { 139 return promote_mode (type, mode, punsignedp); 140 } 141 142 143 enum machine_mode 144 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2) 145 { 146 if (m1 == m2) 147 return m1; 148 return VOIDmode; 149 } 150 151 bool 152 default_return_in_memory (const_tree type, 153 const_tree fntype ATTRIBUTE_UNUSED) 154 { 155 return (TYPE_MODE (type) == BLKmode); 156 } 157 158 rtx 159 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED, 160 enum machine_mode mode ATTRIBUTE_UNUSED) 161 { 162 return x; 163 } 164 165 rtx 166 default_expand_builtin_saveregs (void) 167 { 168 error ("__builtin_saveregs not supported by this target"); 169 return const0_rtx; 170 } 171 172 void 173 default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED, 174 enum machine_mode mode ATTRIBUTE_UNUSED, 175 tree type ATTRIBUTE_UNUSED, 176 int *pretend_arg_size ATTRIBUTE_UNUSED, 177 int second_time ATTRIBUTE_UNUSED) 178 { 179 } 180 181 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */ 182 183 rtx 184 default_builtin_setjmp_frame_value (void) 185 { 186 return virtual_stack_vars_rtx; 187 } 188 189 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */ 190 191 bool 192 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED) 193 { 194 return false; 195 } 196 197 bool 198 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED) 199 { 200 return (targetm.calls.setup_incoming_varargs 201 != default_setup_incoming_varargs); 202 } 203 204 enum machine_mode 205 default_eh_return_filter_mode (void) 206 { 207 return targetm.unwind_word_mode (); 208 } 209 210 enum machine_mode 211 default_libgcc_cmp_return_mode (void) 212 { 213 return word_mode; 214 } 215 216 enum machine_mode 217 default_libgcc_shift_count_mode (void) 218 { 219 return word_mode; 220 } 221 222 enum machine_mode 223 default_unwind_word_mode (void) 224 { 225 return word_mode; 226 } 227 228 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */ 229 230 unsigned HOST_WIDE_INT 231 default_shift_truncation_mask (enum machine_mode mode) 232 { 233 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0; 234 } 235 236 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */ 237 238 unsigned int 239 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED) 240 { 241 return have_insn_for (DIV, mode) ? 3 : 2; 242 } 243 244 /* The default implementation of TARGET_MODE_REP_EXTENDED. */ 245 246 int 247 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED, 248 enum machine_mode mode_rep ATTRIBUTE_UNUSED) 249 { 250 return UNKNOWN; 251 } 252 253 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */ 254 255 bool 256 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED) 257 { 258 return true; 259 } 260 261 /* Return machine mode for non-standard suffix 262 or VOIDmode if non-standard suffixes are unsupported. */ 263 enum machine_mode 264 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED) 265 { 266 return VOIDmode; 267 } 268 269 /* The generic C++ ABI specifies this is a 64-bit value. */ 270 tree 271 default_cxx_guard_type (void) 272 { 273 return long_long_integer_type_node; 274 } 275 276 277 /* Returns the size of the cookie to use when allocating an array 278 whose elements have the indicated TYPE. Assumes that it is already 279 known that a cookie is needed. */ 280 281 tree 282 default_cxx_get_cookie_size (tree type) 283 { 284 tree cookie_size; 285 286 /* We need to allocate an additional max (sizeof (size_t), alignof 287 (true_type)) bytes. */ 288 tree sizetype_size; 289 tree type_align; 290 291 sizetype_size = size_in_bytes (sizetype); 292 type_align = size_int (TYPE_ALIGN_UNIT (type)); 293 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size)) 294 cookie_size = sizetype_size; 295 else 296 cookie_size = type_align; 297 298 return cookie_size; 299 } 300 301 /* Return true if a parameter must be passed by reference. This version 302 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */ 303 304 bool 305 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED, 306 enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED, 307 bool named_arg ATTRIBUTE_UNUSED) 308 { 309 return targetm.calls.must_pass_in_stack (mode, type); 310 } 311 312 /* Return true if a parameter follows callee copies conventions. This 313 version of the hook is true for all named arguments. */ 314 315 bool 316 hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED, 317 enum machine_mode mode ATTRIBUTE_UNUSED, 318 const_tree type ATTRIBUTE_UNUSED, bool named) 319 { 320 return named; 321 } 322 323 /* Emit to STREAM the assembler syntax for insn operand X. */ 324 325 void 326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED, 327 int code ATTRIBUTE_UNUSED) 328 { 329 #ifdef PRINT_OPERAND 330 PRINT_OPERAND (stream, x, code); 331 #else 332 gcc_unreachable (); 333 #endif 334 } 335 336 /* Emit to STREAM the assembler syntax for an insn operand whose memory 337 address is X. */ 338 339 void 340 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED, 341 rtx x ATTRIBUTE_UNUSED) 342 { 343 #ifdef PRINT_OPERAND_ADDRESS 344 PRINT_OPERAND_ADDRESS (stream, x); 345 #else 346 gcc_unreachable (); 347 #endif 348 } 349 350 /* Return true if CODE is a valid punctuation character for the 351 `print_operand' hook. */ 352 353 bool 354 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED) 355 { 356 #ifdef PRINT_OPERAND_PUNCT_VALID_P 357 return PRINT_OPERAND_PUNCT_VALID_P (code); 358 #else 359 return false; 360 #endif 361 } 362 363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME. */ 364 tree 365 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED) 366 { 367 const char *skipped = name + (*name == '*' ? 1 : 0); 368 const char *stripped = targetm.strip_name_encoding (skipped); 369 if (*name != '*' && user_label_prefix[0]) 370 stripped = ACONCAT ((user_label_prefix, stripped, NULL)); 371 return get_identifier (stripped); 372 } 373 374 /* True if MODE is valid for the target. By "valid", we mean able to 375 be manipulated in non-trivial ways. In particular, this means all 376 the arithmetic is supported. 377 378 By default we guess this means that any C type is supported. If 379 we can't map the mode back to a type that would be available in C, 380 then reject it. Special case, here, is the double-word arithmetic 381 supported by optabs.c. */ 382 383 bool 384 default_scalar_mode_supported_p (enum machine_mode mode) 385 { 386 int precision = GET_MODE_PRECISION (mode); 387 388 switch (GET_MODE_CLASS (mode)) 389 { 390 case MODE_PARTIAL_INT: 391 case MODE_INT: 392 if (precision == CHAR_TYPE_SIZE) 393 return true; 394 if (precision == SHORT_TYPE_SIZE) 395 return true; 396 if (precision == INT_TYPE_SIZE) 397 return true; 398 if (precision == LONG_TYPE_SIZE) 399 return true; 400 if (precision == LONG_LONG_TYPE_SIZE) 401 return true; 402 if (precision == 2 * BITS_PER_WORD) 403 return true; 404 return false; 405 406 case MODE_FLOAT: 407 if (precision == FLOAT_TYPE_SIZE) 408 return true; 409 if (precision == DOUBLE_TYPE_SIZE) 410 return true; 411 if (precision == LONG_DOUBLE_TYPE_SIZE) 412 return true; 413 return false; 414 415 case MODE_DECIMAL_FLOAT: 416 case MODE_FRACT: 417 case MODE_UFRACT: 418 case MODE_ACCUM: 419 case MODE_UACCUM: 420 return false; 421 422 default: 423 gcc_unreachable (); 424 } 425 } 426 427 /* Make some target macros useable by target-independent code. */ 428 bool 429 targhook_words_big_endian (void) 430 { 431 return !!WORDS_BIG_ENDIAN; 432 } 433 434 bool 435 targhook_float_words_big_endian (void) 436 { 437 return !!FLOAT_WORDS_BIG_ENDIAN; 438 } 439 440 /* True if the target supports decimal floating point. */ 441 442 bool 443 default_decimal_float_supported_p (void) 444 { 445 return ENABLE_DECIMAL_FLOAT; 446 } 447 448 /* True if the target supports fixed-point arithmetic. */ 449 450 bool 451 default_fixed_point_supported_p (void) 452 { 453 return ENABLE_FIXED_POINT; 454 } 455 456 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns 457 an error message. 458 459 This function checks whether a given INSN is valid within a low-overhead 460 loop. If INSN is invalid it returns the reason for that, otherwise it 461 returns NULL. A called function may clobber any special registers required 462 for low-overhead looping. Additionally, some targets (eg, PPC) use the count 463 register for branch on table instructions. We reject the doloop pattern in 464 these cases. */ 465 466 const char * 467 default_invalid_within_doloop (const_rtx insn) 468 { 469 if (CALL_P (insn)) 470 return "Function call in loop."; 471 472 if (JUMP_TABLE_DATA_P (insn)) 473 return "Computed branch in the loop."; 474 475 return NULL; 476 } 477 478 /* Mapping of builtin functions to vectorized variants. */ 479 480 tree 481 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED, 482 tree type_out ATTRIBUTE_UNUSED, 483 tree type_in ATTRIBUTE_UNUSED) 484 { 485 return NULL_TREE; 486 } 487 488 /* Vectorized conversion. */ 489 490 tree 491 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED, 492 tree dest_type ATTRIBUTE_UNUSED, 493 tree src_type ATTRIBUTE_UNUSED) 494 { 495 return NULL_TREE; 496 } 497 498 /* Default vectorizer cost model values. */ 499 500 int 501 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost, 502 tree vectype ATTRIBUTE_UNUSED, 503 int misalign ATTRIBUTE_UNUSED) 504 { 505 switch (type_of_cost) 506 { 507 case scalar_stmt: 508 case scalar_load: 509 case scalar_store: 510 case vector_stmt: 511 case vector_load: 512 case vector_store: 513 case vec_to_scalar: 514 case scalar_to_vec: 515 case cond_branch_not_taken: 516 case vec_perm: 517 case vec_promote_demote: 518 return 1; 519 520 case unaligned_load: 521 case unaligned_store: 522 return 2; 523 524 case cond_branch_taken: 525 return 3; 526 527 default: 528 gcc_unreachable (); 529 } 530 } 531 532 /* Reciprocal. */ 533 534 tree 535 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED, 536 bool md_fn ATTRIBUTE_UNUSED, 537 bool sqrt ATTRIBUTE_UNUSED) 538 { 539 return NULL_TREE; 540 } 541 542 bool 543 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false ( 544 cumulative_args_t ca ATTRIBUTE_UNUSED, 545 enum machine_mode mode ATTRIBUTE_UNUSED, 546 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED) 547 { 548 return false; 549 } 550 551 bool 552 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true ( 553 cumulative_args_t ca ATTRIBUTE_UNUSED, 554 enum machine_mode mode ATTRIBUTE_UNUSED, 555 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED) 556 { 557 return true; 558 } 559 560 int 561 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 ( 562 cumulative_args_t ca ATTRIBUTE_UNUSED, 563 enum machine_mode mode ATTRIBUTE_UNUSED, 564 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED) 565 { 566 return 0; 567 } 568 569 void 570 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED, 571 enum machine_mode mode ATTRIBUTE_UNUSED, 572 const_tree type ATTRIBUTE_UNUSED, 573 bool named ATTRIBUTE_UNUSED) 574 { 575 gcc_unreachable (); 576 } 577 578 rtx 579 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED, 580 enum machine_mode mode ATTRIBUTE_UNUSED, 581 const_tree type ATTRIBUTE_UNUSED, 582 bool named ATTRIBUTE_UNUSED) 583 { 584 gcc_unreachable (); 585 } 586 587 rtx 588 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED, 589 enum machine_mode mode ATTRIBUTE_UNUSED, 590 const_tree type ATTRIBUTE_UNUSED, 591 bool named ATTRIBUTE_UNUSED) 592 { 593 gcc_unreachable (); 594 } 595 596 unsigned int 597 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED, 598 const_tree type ATTRIBUTE_UNUSED) 599 { 600 return PARM_BOUNDARY; 601 } 602 603 unsigned int 604 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED, 605 const_tree type ATTRIBUTE_UNUSED) 606 { 607 return PARM_BOUNDARY; 608 } 609 610 void 611 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED) 612 { 613 } 614 615 const char * 616 hook_invalid_arg_for_unprototyped_fn ( 617 const_tree typelist ATTRIBUTE_UNUSED, 618 const_tree funcdecl ATTRIBUTE_UNUSED, 619 const_tree val ATTRIBUTE_UNUSED) 620 { 621 return NULL; 622 } 623 624 /* Initialize the stack protection decls. */ 625 626 /* Stack protection related decls living in libgcc. */ 627 static GTY(()) tree stack_chk_guard_decl; 628 629 tree 630 default_stack_protect_guard (void) 631 { 632 tree t = stack_chk_guard_decl; 633 634 if (t == NULL) 635 { 636 rtx x; 637 638 t = build_decl (UNKNOWN_LOCATION, 639 VAR_DECL, get_identifier ("__stack_chk_guard"), 640 ptr_type_node); 641 TREE_STATIC (t) = 1; 642 TREE_PUBLIC (t) = 1; 643 DECL_EXTERNAL (t) = 1; 644 TREE_USED (t) = 1; 645 TREE_THIS_VOLATILE (t) = 1; 646 DECL_ARTIFICIAL (t) = 1; 647 DECL_IGNORED_P (t) = 1; 648 649 /* Do not share RTL as the declaration is visible outside of 650 current function. */ 651 x = DECL_RTL (t); 652 RTX_FLAG (x, used) = 1; 653 654 stack_chk_guard_decl = t; 655 } 656 657 return t; 658 } 659 660 static GTY(()) tree stack_chk_fail_decl; 661 662 tree 663 default_external_stack_protect_fail (void) 664 { 665 tree t = stack_chk_fail_decl; 666 667 if (t == NULL_TREE) 668 { 669 t = build_function_type_list (void_type_node, NULL_TREE); 670 t = build_decl (UNKNOWN_LOCATION, 671 FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t); 672 TREE_STATIC (t) = 1; 673 TREE_PUBLIC (t) = 1; 674 DECL_EXTERNAL (t) = 1; 675 TREE_USED (t) = 1; 676 TREE_THIS_VOLATILE (t) = 1; 677 TREE_NOTHROW (t) = 1; 678 DECL_ARTIFICIAL (t) = 1; 679 DECL_IGNORED_P (t) = 1; 680 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT; 681 DECL_VISIBILITY_SPECIFIED (t) = 1; 682 683 stack_chk_fail_decl = t; 684 } 685 686 return build_call_expr (t, 0); 687 } 688 689 tree 690 default_hidden_stack_protect_fail (void) 691 { 692 #ifndef HAVE_GAS_HIDDEN 693 return default_external_stack_protect_fail (); 694 #else 695 tree t = stack_chk_fail_decl; 696 697 if (!flag_pic) 698 return default_external_stack_protect_fail (); 699 700 if (t == NULL_TREE) 701 { 702 t = build_function_type_list (void_type_node, NULL_TREE); 703 t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, 704 get_identifier ("__stack_chk_fail_local"), t); 705 TREE_STATIC (t) = 1; 706 TREE_PUBLIC (t) = 1; 707 DECL_EXTERNAL (t) = 1; 708 TREE_USED (t) = 1; 709 TREE_THIS_VOLATILE (t) = 1; 710 TREE_NOTHROW (t) = 1; 711 DECL_ARTIFICIAL (t) = 1; 712 DECL_IGNORED_P (t) = 1; 713 DECL_VISIBILITY_SPECIFIED (t) = 1; 714 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN; 715 716 stack_chk_fail_decl = t; 717 } 718 719 return build_call_expr (t, 0); 720 #endif 721 } 722 723 bool 724 hook_bool_const_rtx_commutative_p (const_rtx x, 725 int outer_code ATTRIBUTE_UNUSED) 726 { 727 return COMMUTATIVE_P (x); 728 } 729 730 rtx 731 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED, 732 const_tree fn_decl_or_type, 733 bool outgoing ATTRIBUTE_UNUSED) 734 { 735 /* The old interface doesn't handle receiving the function type. */ 736 if (fn_decl_or_type 737 && !DECL_P (fn_decl_or_type)) 738 fn_decl_or_type = NULL; 739 740 #ifdef FUNCTION_VALUE 741 return FUNCTION_VALUE (ret_type, fn_decl_or_type); 742 #else 743 gcc_unreachable (); 744 #endif 745 } 746 747 rtx 748 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED, 749 const_rtx fun ATTRIBUTE_UNUSED) 750 { 751 #ifdef LIBCALL_VALUE 752 return LIBCALL_VALUE (mode); 753 #else 754 gcc_unreachable (); 755 #endif 756 } 757 758 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P. */ 759 760 bool 761 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED) 762 { 763 #ifdef FUNCTION_VALUE_REGNO_P 764 return FUNCTION_VALUE_REGNO_P (regno); 765 #else 766 gcc_unreachable (); 767 #endif 768 } 769 770 rtx 771 default_internal_arg_pointer (void) 772 { 773 /* If the reg that the virtual arg pointer will be translated into is 774 not a fixed reg or is the stack pointer, make a copy of the virtual 775 arg pointer, and address parms via the copy. The frame pointer is 776 considered fixed even though it is not marked as such. */ 777 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM 778 || ! (fixed_regs[ARG_POINTER_REGNUM] 779 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))) 780 return copy_to_reg (virtual_incoming_args_rtx); 781 else 782 return virtual_incoming_args_rtx; 783 } 784 785 rtx 786 default_static_chain (const_tree fndecl, bool incoming_p) 787 { 788 if (!DECL_STATIC_CHAIN (fndecl)) 789 return NULL; 790 791 if (incoming_p) 792 { 793 #ifdef STATIC_CHAIN_INCOMING_REGNUM 794 return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM); 795 #endif 796 } 797 798 #ifdef STATIC_CHAIN_REGNUM 799 return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM); 800 #endif 801 802 { 803 static bool issued_error; 804 if (!issued_error) 805 { 806 issued_error = true; 807 sorry ("nested functions not supported on this target"); 808 } 809 810 /* It really doesn't matter what we return here, so long at it 811 doesn't cause the rest of the compiler to crash. */ 812 return gen_rtx_MEM (Pmode, stack_pointer_rtx); 813 } 814 } 815 816 void 817 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func), 818 rtx ARG_UNUSED (r_chain)) 819 { 820 sorry ("nested function trampolines not supported on this target"); 821 } 822 823 int 824 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED, 825 tree funtype ATTRIBUTE_UNUSED, 826 int size ATTRIBUTE_UNUSED) 827 { 828 return 0; 829 } 830 831 reg_class_t 832 default_branch_target_register_class (void) 833 { 834 return NO_REGS; 835 } 836 837 reg_class_t 838 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED, 839 reg_class_t reload_class_i ATTRIBUTE_UNUSED, 840 enum machine_mode reload_mode ATTRIBUTE_UNUSED, 841 secondary_reload_info *sri) 842 { 843 enum reg_class rclass = NO_REGS; 844 enum reg_class reload_class = (enum reg_class) reload_class_i; 845 846 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing) 847 { 848 sri->icode = sri->prev_sri->t_icode; 849 return NO_REGS; 850 } 851 #ifdef SECONDARY_INPUT_RELOAD_CLASS 852 if (in_p) 853 rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x); 854 #endif 855 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS 856 if (! in_p) 857 rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x); 858 #endif 859 if (rclass != NO_REGS) 860 { 861 enum insn_code icode 862 = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab, 863 reload_mode); 864 865 if (icode != CODE_FOR_nothing 866 && !insn_operand_matches (icode, in_p, x)) 867 icode = CODE_FOR_nothing; 868 else if (icode != CODE_FOR_nothing) 869 { 870 const char *insn_constraint, *scratch_constraint; 871 char insn_letter, scratch_letter; 872 enum reg_class insn_class, scratch_class; 873 874 gcc_assert (insn_data[(int) icode].n_operands == 3); 875 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint; 876 if (!*insn_constraint) 877 insn_class = ALL_REGS; 878 else 879 { 880 if (in_p) 881 { 882 gcc_assert (*insn_constraint == '='); 883 insn_constraint++; 884 } 885 insn_letter = *insn_constraint; 886 insn_class 887 = (insn_letter == 'r' ? GENERAL_REGS 888 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter, 889 insn_constraint)); 890 gcc_assert (insn_class != NO_REGS); 891 } 892 893 scratch_constraint = insn_data[(int) icode].operand[2].constraint; 894 /* The scratch register's constraint must start with "=&", 895 except for an input reload, where only "=" is necessary, 896 and where it might be beneficial to re-use registers from 897 the input. */ 898 gcc_assert (scratch_constraint[0] == '=' 899 && (in_p || scratch_constraint[1] == '&')); 900 scratch_constraint++; 901 if (*scratch_constraint == '&') 902 scratch_constraint++; 903 scratch_letter = *scratch_constraint; 904 scratch_class 905 = (scratch_letter == 'r' ? GENERAL_REGS 906 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter, 907 scratch_constraint)); 908 909 if (reg_class_subset_p (reload_class, insn_class)) 910 { 911 gcc_assert (scratch_class == rclass); 912 rclass = NO_REGS; 913 } 914 else 915 rclass = insn_class; 916 917 } 918 if (rclass == NO_REGS) 919 sri->icode = icode; 920 else 921 sri->t_icode = icode; 922 } 923 return rclass; 924 } 925 926 /* By default, if flag_pic is true, then neither local nor global relocs 927 should be placed in readonly memory. */ 928 929 int 930 default_reloc_rw_mask (void) 931 { 932 return flag_pic ? 3 : 0; 933 } 934 935 /* By default, do no modification. */ 936 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED, 937 tree id) 938 { 939 return id; 940 } 941 942 /* Default to natural alignment for vector types. */ 943 HOST_WIDE_INT 944 default_vector_alignment (const_tree type) 945 { 946 return tree_low_cst (TYPE_SIZE (type), 0); 947 } 948 949 bool 950 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed) 951 { 952 if (is_packed) 953 return false; 954 955 /* Assuming that types whose size is > pointer-size are not guaranteed to be 956 naturally aligned. */ 957 if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0) 958 return false; 959 960 /* Assuming that types whose size is <= pointer-size 961 are naturally aligned. */ 962 return true; 963 } 964 965 /* By default, assume that a target supports any factor of misalignment 966 memory access if it supports movmisalign patten. 967 is_packed is true if the memory access is defined in a packed struct. */ 968 bool 969 default_builtin_support_vector_misalignment (enum machine_mode mode, 970 const_tree type 971 ATTRIBUTE_UNUSED, 972 int misalignment 973 ATTRIBUTE_UNUSED, 974 bool is_packed 975 ATTRIBUTE_UNUSED) 976 { 977 if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing) 978 return true; 979 return false; 980 } 981 982 /* By default, only attempt to parallelize bitwise operations, and 983 possibly adds/subtracts using bit-twiddling. */ 984 985 enum machine_mode 986 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED) 987 { 988 return word_mode; 989 } 990 991 /* By default only the size derived from the preferred vector mode 992 is tried. */ 993 994 unsigned int 995 default_autovectorize_vector_sizes (void) 996 { 997 return 0; 998 } 999 1000 /* Determine whether or not a pointer mode is valid. Assume defaults 1001 of ptr_mode or Pmode - can be overridden. */ 1002 bool 1003 default_valid_pointer_mode (enum machine_mode mode) 1004 { 1005 return (mode == ptr_mode || mode == Pmode); 1006 } 1007 1008 /* Determine whether the memory reference specified by REF may alias 1009 the C libraries errno location. */ 1010 bool 1011 default_ref_may_alias_errno (ao_ref *ref) 1012 { 1013 tree base = ao_ref_base (ref); 1014 /* The default implementation assumes the errno location is 1015 a declaration of type int or is always accessed via a 1016 pointer to int. We assume that accesses to errno are 1017 not deliberately obfuscated (even in conforming ways). */ 1018 if (TYPE_UNSIGNED (TREE_TYPE (base)) 1019 || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node)) 1020 return false; 1021 /* The default implementation assumes an errno location 1022 declaration is never defined in the current compilation unit. */ 1023 if (DECL_P (base) 1024 && !TREE_STATIC (base)) 1025 return true; 1026 else if (TREE_CODE (base) == MEM_REF 1027 && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) 1028 { 1029 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); 1030 return !pi || pi->pt.anything || pi->pt.nonlocal; 1031 } 1032 return false; 1033 } 1034 1035 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode 1036 for the generic address space only. */ 1037 1038 enum machine_mode 1039 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED) 1040 { 1041 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace)); 1042 return ptr_mode; 1043 } 1044 1045 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode 1046 for the generic address space only. */ 1047 1048 enum machine_mode 1049 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED) 1050 { 1051 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace)); 1052 return Pmode; 1053 } 1054 1055 /* Named address space version of valid_pointer_mode. */ 1056 1057 bool 1058 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as) 1059 { 1060 if (!ADDR_SPACE_GENERIC_P (as)) 1061 return (mode == targetm.addr_space.pointer_mode (as) 1062 || mode == targetm.addr_space.address_mode (as)); 1063 1064 return targetm.valid_pointer_mode (mode); 1065 } 1066 1067 /* Some places still assume that all pointer or address modes are the 1068 standard Pmode and ptr_mode. These optimizations become invalid if 1069 the target actually supports multiple different modes. For now, 1070 we disable such optimizations on such targets, using this function. */ 1071 1072 bool 1073 target_default_pointer_address_modes_p (void) 1074 { 1075 if (targetm.addr_space.address_mode != default_addr_space_address_mode) 1076 return false; 1077 if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode) 1078 return false; 1079 1080 return true; 1081 } 1082 1083 /* Named address space version of legitimate_address_p. */ 1084 1085 bool 1086 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem, 1087 bool strict, addr_space_t as) 1088 { 1089 if (!ADDR_SPACE_GENERIC_P (as)) 1090 gcc_unreachable (); 1091 1092 return targetm.legitimate_address_p (mode, mem, strict); 1093 } 1094 1095 /* Named address space version of LEGITIMIZE_ADDRESS. */ 1096 1097 rtx 1098 default_addr_space_legitimize_address (rtx x, rtx oldx, 1099 enum machine_mode mode, addr_space_t as) 1100 { 1101 if (!ADDR_SPACE_GENERIC_P (as)) 1102 return x; 1103 1104 return targetm.legitimize_address (x, oldx, mode); 1105 } 1106 1107 /* The default hook for determining if one named address space is a subset of 1108 another and to return which address space to use as the common address 1109 space. */ 1110 1111 bool 1112 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset) 1113 { 1114 return (subset == superset); 1115 } 1116 1117 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be 1118 called for targets with only a generic address space. */ 1119 1120 rtx 1121 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED, 1122 tree from_type ATTRIBUTE_UNUSED, 1123 tree to_type ATTRIBUTE_UNUSED) 1124 { 1125 gcc_unreachable (); 1126 } 1127 1128 bool 1129 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED) 1130 { 1131 return true; 1132 } 1133 1134 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P. */ 1135 1136 bool 1137 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED) 1138 { 1139 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS 1140 1141 GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win); 1142 return false; 1143 /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS. */ 1144 win: ATTRIBUTE_UNUSED_LABEL 1145 return true; 1146 1147 #else 1148 1149 return false; 1150 1151 #endif 1152 } 1153 1154 bool 1155 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl), 1156 tree ARG_UNUSED (name), 1157 tree ARG_UNUSED (args), 1158 int ARG_UNUSED (flags)) 1159 { 1160 warning (OPT_Wattributes, 1161 "target attribute is not supported on this machine"); 1162 1163 return false; 1164 } 1165 1166 bool 1167 default_target_option_pragma_parse (tree ARG_UNUSED (args), 1168 tree ARG_UNUSED (pop_target)) 1169 { 1170 warning (OPT_Wpragmas, 1171 "#pragma GCC target is not supported for this machine"); 1172 1173 return false; 1174 } 1175 1176 bool 1177 default_target_can_inline_p (tree caller, tree callee) 1178 { 1179 bool ret = false; 1180 tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee); 1181 tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller); 1182 1183 /* If callee has no option attributes, then it is ok to inline */ 1184 if (!callee_opts) 1185 ret = true; 1186 1187 /* If caller has no option attributes, but callee does then it is not ok to 1188 inline */ 1189 else if (!caller_opts) 1190 ret = false; 1191 1192 /* If both caller and callee have attributes, assume that if the 1193 pointer is different, the two functions have different target 1194 options since build_target_option_node uses a hash table for the 1195 options. */ 1196 else 1197 ret = (callee_opts == caller_opts); 1198 1199 return ret; 1200 } 1201 1202 #ifndef HAVE_casesi 1203 # define HAVE_casesi 0 1204 #endif 1205 1206 /* If the machine does not have a case insn that compares the bounds, 1207 this means extra overhead for dispatch tables, which raises the 1208 threshold for using them. */ 1209 1210 unsigned int default_case_values_threshold (void) 1211 { 1212 return (HAVE_casesi ? 4 : 5); 1213 } 1214 1215 bool 1216 default_have_conditional_execution (void) 1217 { 1218 #ifdef HAVE_conditional_execution 1219 return HAVE_conditional_execution; 1220 #else 1221 return false; 1222 #endif 1223 } 1224 1225 tree 1226 default_builtin_tm_load_store (tree ARG_UNUSED (type)) 1227 { 1228 return NULL_TREE; 1229 } 1230 1231 /* Compute cost of moving registers to/from memory. */ 1232 1233 int 1234 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED, 1235 reg_class_t rclass ATTRIBUTE_UNUSED, 1236 bool in ATTRIBUTE_UNUSED) 1237 { 1238 #ifndef MEMORY_MOVE_COST 1239 return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in)); 1240 #else 1241 return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in); 1242 #endif 1243 } 1244 1245 /* Compute cost of moving data from a register of class FROM to one of 1246 TO, using MODE. */ 1247 1248 int 1249 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED, 1250 reg_class_t from ATTRIBUTE_UNUSED, 1251 reg_class_t to ATTRIBUTE_UNUSED) 1252 { 1253 #ifndef REGISTER_MOVE_COST 1254 return 2; 1255 #else 1256 return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to); 1257 #endif 1258 } 1259 1260 bool 1261 default_profile_before_prologue (void) 1262 { 1263 #ifdef PROFILE_BEFORE_PROLOGUE 1264 return true; 1265 #else 1266 return false; 1267 #endif 1268 } 1269 1270 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS. */ 1271 1272 reg_class_t 1273 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED, 1274 reg_class_t rclass) 1275 { 1276 #ifdef PREFERRED_RELOAD_CLASS 1277 return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass); 1278 #else 1279 return rclass; 1280 #endif 1281 } 1282 1283 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS. */ 1284 1285 reg_class_t 1286 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED, 1287 reg_class_t rclass) 1288 { 1289 return rclass; 1290 } 1291 1292 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS. */ 1293 reg_class_t 1294 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED) 1295 { 1296 return NO_REGS; 1297 } 1298 1299 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P. */ 1300 1301 bool 1302 default_class_likely_spilled_p (reg_class_t rclass) 1303 { 1304 return (reg_class_size[(int) rclass] == 1); 1305 } 1306 1307 /* The default implementation of TARGET_CLASS_MAX_NREGS. */ 1308 1309 unsigned char 1310 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED, 1311 enum machine_mode mode ATTRIBUTE_UNUSED) 1312 { 1313 #ifdef CLASS_MAX_NREGS 1314 return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode); 1315 #else 1316 return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD); 1317 #endif 1318 } 1319 1320 /* Determine the debugging unwind mechanism for the target. */ 1321 1322 enum unwind_info_type 1323 default_debug_unwind_info (void) 1324 { 1325 /* If the target wants to force the use of dwarf2 unwind info, let it. */ 1326 /* ??? Change all users to the hook, then poison this. */ 1327 #ifdef DWARF2_FRAME_INFO 1328 if (DWARF2_FRAME_INFO) 1329 return UI_DWARF2; 1330 #endif 1331 1332 /* Otherwise, only turn it on if dwarf2 debugging is enabled. */ 1333 #ifdef DWARF2_DEBUGGING_INFO 1334 if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG) 1335 return UI_DWARF2; 1336 #endif 1337 1338 return UI_NONE; 1339 } 1340 1341 /* To be used by targets where reg_raw_mode doesn't return the right 1342 mode for registers used in apply_builtin_return and apply_builtin_arg. */ 1343 1344 enum machine_mode 1345 default_get_reg_raw_mode(int regno) 1346 { 1347 return reg_raw_mode[regno]; 1348 } 1349 1350 /* Return true if the state of option OPTION should be stored in PCH files 1351 and checked by default_pch_valid_p. Store the option's current state 1352 in STATE if so. */ 1353 1354 static inline bool 1355 option_affects_pch_p (int option, struct cl_option_state *state) 1356 { 1357 if ((cl_options[option].flags & CL_TARGET) == 0) 1358 return false; 1359 if (option_flag_var (option, &global_options) == &target_flags) 1360 if (targetm.check_pch_target_flags) 1361 return false; 1362 return get_option_state (&global_options, option, state); 1363 } 1364 1365 /* Default version of get_pch_validity. 1366 By default, every flag difference is fatal; that will be mostly right for 1367 most targets, but completely right for very few. */ 1368 1369 void * 1370 default_get_pch_validity (size_t *sz) 1371 { 1372 struct cl_option_state state; 1373 size_t i; 1374 char *result, *r; 1375 1376 *sz = 2; 1377 if (targetm.check_pch_target_flags) 1378 *sz += sizeof (target_flags); 1379 for (i = 0; i < cl_options_count; i++) 1380 if (option_affects_pch_p (i, &state)) 1381 *sz += state.size; 1382 1383 result = r = XNEWVEC (char, *sz); 1384 r[0] = flag_pic; 1385 r[1] = flag_pie; 1386 r += 2; 1387 if (targetm.check_pch_target_flags) 1388 { 1389 memcpy (r, &target_flags, sizeof (target_flags)); 1390 r += sizeof (target_flags); 1391 } 1392 1393 for (i = 0; i < cl_options_count; i++) 1394 if (option_affects_pch_p (i, &state)) 1395 { 1396 memcpy (r, state.data, state.size); 1397 r += state.size; 1398 } 1399 1400 return result; 1401 } 1402 1403 /* Return a message which says that a PCH file was created with a different 1404 setting of OPTION. */ 1405 1406 static const char * 1407 pch_option_mismatch (const char *option) 1408 { 1409 char *r; 1410 1411 asprintf (&r, _("created and used with differing settings of '%s'"), option); 1412 if (r == NULL) 1413 return _("out of memory"); 1414 return r; 1415 } 1416 1417 /* Default version of pch_valid_p. */ 1418 1419 const char * 1420 default_pch_valid_p (const void *data_p, size_t len) 1421 { 1422 struct cl_option_state state; 1423 const char *data = (const char *)data_p; 1424 size_t i; 1425 1426 /* -fpic and -fpie also usually make a PCH invalid. */ 1427 if (data[0] != flag_pic) 1428 return _("created and used with different settings of -fpic"); 1429 if (data[1] != flag_pie) 1430 return _("created and used with different settings of -fpie"); 1431 data += 2; 1432 1433 /* Check target_flags. */ 1434 if (targetm.check_pch_target_flags) 1435 { 1436 int tf; 1437 const char *r; 1438 1439 memcpy (&tf, data, sizeof (target_flags)); 1440 data += sizeof (target_flags); 1441 len -= sizeof (target_flags); 1442 r = targetm.check_pch_target_flags (tf); 1443 if (r != NULL) 1444 return r; 1445 } 1446 1447 for (i = 0; i < cl_options_count; i++) 1448 if (option_affects_pch_p (i, &state)) 1449 { 1450 if (memcmp (data, state.data, state.size) != 0) 1451 return pch_option_mismatch (cl_options[i].opt_text); 1452 data += state.size; 1453 len -= state.size; 1454 } 1455 1456 return NULL; 1457 } 1458 1459 #include "gt-targhooks.h" 1460