1 /* Default target hook functions.
2 Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
5 This file is part of GCC.
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
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
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/>. */
21 /* The migration of target macros to target hooks works as follows:
23 1. Create a target hook that uses the existing target macros to
24 implement the same functionality.
26 2. Convert all the MI files to use the hook instead of the macro.
28 3. Repeat for a majority of the remaining target macros. This will
31 4. Tell target maintainers to start migrating.
33 5. Eventually convert the backends to override the hook instead of
34 defining the macros. This will take some time too.
36 6. TBD when, poison the macros. Unmigrated targets will break at
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.
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.
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. */
52 #include "coretypes.h"
59 #include "diagnostic-core.h"
63 #include "target-def.h"
65 #include "hard-reg-set.h"
72 #include "tree-flow.h"
73 #include "tree-ssa-alias.h"
77 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
78 rtx addr ATTRIBUTE_UNUSED,
79 bool strict ATTRIBUTE_UNUSED)
81 #ifdef GO_IF_LEGITIMATE_ADDRESS
82 /* Defer to the old implementation using a goto. */
84 return strict_memory_address_p (mode, addr);
86 return memory_address_p (mode, addr);
93 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
95 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
96 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
101 default_unspec_may_trap_p (const_rtx x, unsigned flags)
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))
111 for (i = 0; i < XVECLEN (x, 0); ++i)
113 if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
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)
128 return promote_mode (type, mode, punsignedp);
133 default_promote_function_mode_always_promote (const_tree type,
134 enum machine_mode mode,
136 const_tree funtype ATTRIBUTE_UNUSED,
137 int for_return ATTRIBUTE_UNUSED)
139 return promote_mode (type, mode, punsignedp);
144 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
152 default_return_in_memory (const_tree type,
153 const_tree fntype ATTRIBUTE_UNUSED)
155 return (TYPE_MODE (type) == BLKmode);
159 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
160 enum machine_mode mode ATTRIBUTE_UNUSED)
166 default_expand_builtin_saveregs (void)
168 error ("__builtin_saveregs not supported by this target");
173 default_setup_incoming_varargs (CUMULATIVE_ARGS *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)
181 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
184 default_builtin_setjmp_frame_value (void)
186 return virtual_stack_vars_rtx;
189 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
192 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
198 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
200 return (targetm.calls.setup_incoming_varargs
201 != default_setup_incoming_varargs);
205 default_eh_return_filter_mode (void)
207 return targetm.unwind_word_mode ();
211 default_libgcc_cmp_return_mode (void)
217 default_libgcc_shift_count_mode (void)
223 default_unwind_word_mode (void)
228 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
230 unsigned HOST_WIDE_INT
231 default_shift_truncation_mask (enum machine_mode mode)
233 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
236 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
239 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
241 return have_insn_for (DIV, mode) ? 3 : 2;
244 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
247 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
248 enum machine_mode mode_rep ATTRIBUTE_UNUSED)
253 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
256 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
261 /* Return machine mode for non-standard suffix
262 or VOIDmode if non-standard suffixes are unsupported. */
264 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
269 /* The generic C++ ABI specifies this is a 64-bit value. */
271 default_cxx_guard_type (void)
273 return long_long_integer_type_node;
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. */
282 default_cxx_get_cookie_size (tree type)
286 /* We need to allocate an additional max (sizeof (size_t), alignof
287 (true_type)) bytes. */
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;
296 cookie_size = type_align;
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. */
305 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
306 enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
307 bool named_arg ATTRIBUTE_UNUSED)
309 return targetm.calls.must_pass_in_stack (mode, type);
312 /* Return true if a parameter follows callee copies conventions. This
313 version of the hook is true for all named arguments. */
316 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
317 enum machine_mode mode ATTRIBUTE_UNUSED,
318 const_tree type ATTRIBUTE_UNUSED, bool named)
323 /* Emit to STREAM the assembler syntax for insn operand X. */
326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
327 int code ATTRIBUTE_UNUSED)
330 PRINT_OPERAND (stream, x, code);
336 /* Emit to STREAM the assembler syntax for an insn operand whose memory
340 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
341 rtx x ATTRIBUTE_UNUSED)
343 #ifdef PRINT_OPERAND_ADDRESS
344 PRINT_OPERAND_ADDRESS (stream, x);
350 /* Return true if CODE is a valid punctuation character for the
351 `print_operand' hook. */
354 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
356 #ifdef PRINT_OPERAND_PUNCT_VALID_P
357 return PRINT_OPERAND_PUNCT_VALID_P (code);
363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME. */
365 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
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);
374 /* The default implementation of TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA. */
377 default_asm_output_addr_const_extra (FILE *file ATTRIBUTE_UNUSED,
378 rtx x ATTRIBUTE_UNUSED)
380 #ifdef OUTPUT_ADDR_CONST_EXTRA
381 OUTPUT_ADDR_CONST_EXTRA (file, x, fail);
389 /* True if MODE is valid for the target. By "valid", we mean able to
390 be manipulated in non-trivial ways. In particular, this means all
391 the arithmetic is supported.
393 By default we guess this means that any C type is supported. If
394 we can't map the mode back to a type that would be available in C,
395 then reject it. Special case, here, is the double-word arithmetic
396 supported by optabs.c. */
399 default_scalar_mode_supported_p (enum machine_mode mode)
401 int precision = GET_MODE_PRECISION (mode);
403 switch (GET_MODE_CLASS (mode))
405 case MODE_PARTIAL_INT:
407 if (precision == CHAR_TYPE_SIZE)
409 if (precision == SHORT_TYPE_SIZE)
411 if (precision == INT_TYPE_SIZE)
413 if (precision == LONG_TYPE_SIZE)
415 if (precision == LONG_LONG_TYPE_SIZE)
417 if (precision == 2 * BITS_PER_WORD)
422 if (precision == FLOAT_TYPE_SIZE)
424 if (precision == DOUBLE_TYPE_SIZE)
426 if (precision == LONG_DOUBLE_TYPE_SIZE)
430 case MODE_DECIMAL_FLOAT:
442 /* Make some target macros useable by target-independent code. */
444 targhook_words_big_endian (void)
446 return !!WORDS_BIG_ENDIAN;
450 targhook_float_words_big_endian (void)
452 return !!FLOAT_WORDS_BIG_ENDIAN;
455 /* True if the target supports decimal floating point. */
458 default_decimal_float_supported_p (void)
460 return ENABLE_DECIMAL_FLOAT;
463 /* True if the target supports fixed-point arithmetic. */
466 default_fixed_point_supported_p (void)
468 return ENABLE_FIXED_POINT;
471 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
474 This function checks whether a given INSN is valid within a low-overhead
475 loop. If INSN is invalid it returns the reason for that, otherwise it
476 returns NULL. A called function may clobber any special registers required
477 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
478 register for branch on table instructions. We reject the doloop pattern in
482 default_invalid_within_doloop (const_rtx insn)
485 return "Function call in loop.";
487 if (JUMP_TABLE_DATA_P (insn))
488 return "Computed branch in the loop.";
493 /* Mapping of builtin functions to vectorized variants. */
496 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
497 tree type_out ATTRIBUTE_UNUSED,
498 tree type_in ATTRIBUTE_UNUSED)
503 /* Vectorized conversion. */
506 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
507 tree dest_type ATTRIBUTE_UNUSED,
508 tree src_type ATTRIBUTE_UNUSED)
513 /* Default vectorizer cost model values. */
516 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
517 tree vectype ATTRIBUTE_UNUSED,
518 int misalign ATTRIBUTE_UNUSED)
520 switch (type_of_cost)
530 case cond_branch_not_taken:
535 case unaligned_store:
538 case cond_branch_taken:
549 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
550 bool md_fn ATTRIBUTE_UNUSED,
551 bool sqrt ATTRIBUTE_UNUSED)
557 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
558 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
559 enum machine_mode mode ATTRIBUTE_UNUSED,
560 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
566 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
567 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
568 enum machine_mode mode ATTRIBUTE_UNUSED,
569 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
575 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
576 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
577 enum machine_mode mode ATTRIBUTE_UNUSED,
578 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
584 default_function_arg_advance (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
585 enum machine_mode mode ATTRIBUTE_UNUSED,
586 const_tree type ATTRIBUTE_UNUSED,
587 bool named ATTRIBUTE_UNUSED)
593 default_function_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
594 enum machine_mode mode ATTRIBUTE_UNUSED,
595 const_tree type ATTRIBUTE_UNUSED,
596 bool named ATTRIBUTE_UNUSED)
602 default_function_incoming_arg (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
603 enum machine_mode mode ATTRIBUTE_UNUSED,
604 const_tree type ATTRIBUTE_UNUSED,
605 bool named ATTRIBUTE_UNUSED)
611 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
612 const_tree type ATTRIBUTE_UNUSED)
614 return PARM_BOUNDARY;
618 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
623 hook_invalid_arg_for_unprototyped_fn (
624 const_tree typelist ATTRIBUTE_UNUSED,
625 const_tree funcdecl ATTRIBUTE_UNUSED,
626 const_tree val ATTRIBUTE_UNUSED)
631 /* Initialize the stack protection decls. */
633 /* Stack protection related decls living in libgcc. */
634 static GTY(()) tree stack_chk_guard_decl;
637 default_stack_protect_guard (void)
639 tree t = stack_chk_guard_decl;
645 t = build_decl (UNKNOWN_LOCATION,
646 VAR_DECL, get_identifier ("__stack_chk_guard"),
650 DECL_EXTERNAL (t) = 1;
652 TREE_THIS_VOLATILE (t) = 1;
653 DECL_ARTIFICIAL (t) = 1;
654 DECL_IGNORED_P (t) = 1;
656 /* Do not share RTL as the declaration is visible outside of
659 RTX_FLAG (x, used) = 1;
661 stack_chk_guard_decl = t;
667 static GTY(()) tree stack_chk_fail_decl;
670 default_external_stack_protect_fail (void)
672 tree t = stack_chk_fail_decl;
676 t = build_function_type_list (void_type_node, NULL_TREE);
677 t = build_decl (UNKNOWN_LOCATION,
678 FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
681 DECL_EXTERNAL (t) = 1;
683 TREE_THIS_VOLATILE (t) = 1;
684 TREE_NOTHROW (t) = 1;
685 DECL_ARTIFICIAL (t) = 1;
686 DECL_IGNORED_P (t) = 1;
687 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
688 DECL_VISIBILITY_SPECIFIED (t) = 1;
690 stack_chk_fail_decl = t;
693 return build_call_expr (t, 0);
697 default_hidden_stack_protect_fail (void)
699 #ifndef HAVE_GAS_HIDDEN
700 return default_external_stack_protect_fail ();
702 tree t = stack_chk_fail_decl;
705 return default_external_stack_protect_fail ();
709 t = build_function_type_list (void_type_node, NULL_TREE);
710 t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
711 get_identifier ("__stack_chk_fail_local"), t);
714 DECL_EXTERNAL (t) = 1;
716 TREE_THIS_VOLATILE (t) = 1;
717 TREE_NOTHROW (t) = 1;
718 DECL_ARTIFICIAL (t) = 1;
719 DECL_IGNORED_P (t) = 1;
720 DECL_VISIBILITY_SPECIFIED (t) = 1;
721 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
723 stack_chk_fail_decl = t;
726 return build_call_expr (t, 0);
731 hook_bool_const_rtx_commutative_p (const_rtx x,
732 int outer_code ATTRIBUTE_UNUSED)
734 return COMMUTATIVE_P (x);
738 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
739 const_tree fn_decl_or_type,
740 bool outgoing ATTRIBUTE_UNUSED)
742 /* The old interface doesn't handle receiving the function type. */
744 && !DECL_P (fn_decl_or_type))
745 fn_decl_or_type = NULL;
747 #ifdef FUNCTION_VALUE
748 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
755 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
756 const_rtx fun ATTRIBUTE_UNUSED)
759 return LIBCALL_VALUE (mode);
765 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P. */
768 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
770 #ifdef FUNCTION_VALUE_REGNO_P
771 return FUNCTION_VALUE_REGNO_P (regno);
778 default_internal_arg_pointer (void)
780 /* If the reg that the virtual arg pointer will be translated into is
781 not a fixed reg or is the stack pointer, make a copy of the virtual
782 arg pointer, and address parms via the copy. The frame pointer is
783 considered fixed even though it is not marked as such. */
784 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
785 || ! (fixed_regs[ARG_POINTER_REGNUM]
786 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
787 return copy_to_reg (virtual_incoming_args_rtx);
789 return virtual_incoming_args_rtx;
793 default_static_chain (const_tree fndecl, bool incoming_p)
795 if (!DECL_STATIC_CHAIN (fndecl))
800 #ifdef STATIC_CHAIN_INCOMING_REGNUM
801 return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
805 #ifdef STATIC_CHAIN_REGNUM
806 return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
810 static bool issued_error;
814 sorry ("nested functions not supported on this target");
817 /* It really doesn't matter what we return here, so long at it
818 doesn't cause the rest of the compiler to crash. */
819 return gen_rtx_MEM (Pmode, stack_pointer_rtx);
824 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
825 rtx ARG_UNUSED (r_chain))
827 sorry ("nested function trampolines not supported on this target");
831 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
832 tree funtype ATTRIBUTE_UNUSED,
833 int size ATTRIBUTE_UNUSED)
839 default_branch_target_register_class (void)
845 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
846 reg_class_t reload_class_i ATTRIBUTE_UNUSED,
847 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
848 secondary_reload_info *sri)
850 enum reg_class rclass = NO_REGS;
851 enum reg_class reload_class = (enum reg_class) reload_class_i;
853 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
855 sri->icode = sri->prev_sri->t_icode;
858 #ifdef SECONDARY_INPUT_RELOAD_CLASS
860 rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
862 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
864 rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
866 if (rclass != NO_REGS)
869 = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
872 if (icode != CODE_FOR_nothing
873 && !insn_operand_matches (icode, in_p, x))
874 icode = CODE_FOR_nothing;
875 else if (icode != CODE_FOR_nothing)
877 const char *insn_constraint, *scratch_constraint;
878 char insn_letter, scratch_letter;
879 enum reg_class insn_class, scratch_class;
881 gcc_assert (insn_data[(int) icode].n_operands == 3);
882 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
883 if (!*insn_constraint)
884 insn_class = ALL_REGS;
889 gcc_assert (*insn_constraint == '=');
892 insn_letter = *insn_constraint;
894 = (insn_letter == 'r' ? GENERAL_REGS
895 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
897 gcc_assert (insn_class != NO_REGS);
900 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
901 /* The scratch register's constraint must start with "=&",
902 except for an input reload, where only "=" is necessary,
903 and where it might be beneficial to re-use registers from
905 gcc_assert (scratch_constraint[0] == '='
906 && (in_p || scratch_constraint[1] == '&'));
907 scratch_constraint++;
908 if (*scratch_constraint == '&')
909 scratch_constraint++;
910 scratch_letter = *scratch_constraint;
912 = (scratch_letter == 'r' ? GENERAL_REGS
913 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
914 scratch_constraint));
916 if (reg_class_subset_p (reload_class, insn_class))
918 gcc_assert (scratch_class == rclass);
925 if (rclass == NO_REGS)
928 sri->t_icode = icode;
934 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
935 const char *arg ATTRIBUTE_UNUSED,
936 int value ATTRIBUTE_UNUSED)
941 /* By default, if flag_pic is true, then neither local nor global relocs
942 should be placed in readonly memory. */
945 default_reloc_rw_mask (void)
947 return flag_pic ? 3 : 0;
950 /* By default, do no modification. */
951 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
958 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
963 /* Assuming that types whose size is > pointer-size are not guaranteed to be
964 naturally aligned. */
965 if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
968 /* Assuming that types whose size is <= pointer-size
969 are naturally aligned. */
973 /* By default, assume that a target supports any factor of misalignment
974 memory access if it supports movmisalign patten.
975 is_packed is true if the memory access is defined in a packed struct. */
977 default_builtin_support_vector_misalignment (enum machine_mode mode,
985 if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
990 /* By default, only attempt to parallelize bitwise operations, and
991 possibly adds/subtracts using bit-twiddling. */
994 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
999 /* By default only the size derived from the preferred vector mode
1003 default_autovectorize_vector_sizes (void)
1008 /* Determine whether or not a pointer mode is valid. Assume defaults
1009 of ptr_mode or Pmode - can be overridden. */
1011 default_valid_pointer_mode (enum machine_mode mode)
1013 return (mode == ptr_mode || mode == Pmode);
1016 /* Determine whether the memory reference specified by REF may alias
1017 the C libraries errno location. */
1019 default_ref_may_alias_errno (ao_ref *ref)
1021 tree base = ao_ref_base (ref);
1022 /* The default implementation assumes the errno location is
1023 a declaration of type int or is always accessed via a
1024 pointer to int. We assume that accesses to errno are
1025 not deliberately obfuscated (even in conforming ways). */
1026 if (TYPE_UNSIGNED (TREE_TYPE (base))
1027 || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1029 /* The default implementation assumes an errno location
1030 declaration is never defined in the current compilation unit. */
1032 && !TREE_STATIC (base))
1034 else if (TREE_CODE (base) == MEM_REF
1035 && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1037 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1038 return !pi || pi->pt.anything || pi->pt.nonlocal;
1043 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1044 for the generic address space only. */
1047 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1049 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1053 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1054 for the generic address space only. */
1057 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1059 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1063 /* Named address space version of valid_pointer_mode. */
1066 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1068 if (!ADDR_SPACE_GENERIC_P (as))
1069 return (mode == targetm.addr_space.pointer_mode (as)
1070 || mode == targetm.addr_space.address_mode (as));
1072 return targetm.valid_pointer_mode (mode);
1075 /* Some places still assume that all pointer or address modes are the
1076 standard Pmode and ptr_mode. These optimizations become invalid if
1077 the target actually supports multiple different modes. For now,
1078 we disable such optimizations on such targets, using this function. */
1081 target_default_pointer_address_modes_p (void)
1083 if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1085 if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1091 /* Named address space version of legitimate_address_p. */
1094 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1095 bool strict, addr_space_t as)
1097 if (!ADDR_SPACE_GENERIC_P (as))
1100 return targetm.legitimate_address_p (mode, mem, strict);
1103 /* Named address space version of LEGITIMIZE_ADDRESS. */
1106 default_addr_space_legitimize_address (rtx x, rtx oldx,
1107 enum machine_mode mode, addr_space_t as)
1109 if (!ADDR_SPACE_GENERIC_P (as))
1112 return targetm.legitimize_address (x, oldx, mode);
1115 /* The default hook for determining if one named address space is a subset of
1116 another and to return which address space to use as the common address
1120 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1122 return (subset == superset);
1125 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1126 called for targets with only a generic address space. */
1129 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1130 tree from_type ATTRIBUTE_UNUSED,
1131 tree to_type ATTRIBUTE_UNUSED)
1137 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1142 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P. */
1145 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1147 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1149 GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1151 /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS. */
1152 win: ATTRIBUTE_UNUSED_LABEL
1163 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1164 tree ARG_UNUSED (name),
1165 tree ARG_UNUSED (args),
1166 int ARG_UNUSED (flags))
1168 warning (OPT_Wattributes,
1169 "target attribute is not supported on this machine");
1175 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1176 tree ARG_UNUSED (pop_target))
1178 warning (OPT_Wpragmas,
1179 "#pragma GCC target is not supported for this machine");
1185 default_target_can_inline_p (tree caller, tree callee)
1188 tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1189 tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1191 /* If callee has no option attributes, then it is ok to inline */
1195 /* If caller has no option attributes, but callee does then it is not ok to
1197 else if (!caller_opts)
1200 /* If both caller and callee have attributes, assume that if the pointer is
1201 different, the the two functions have different target options since
1202 build_target_option_node uses a hash table for the options. */
1204 ret = (callee_opts == caller_opts);
1210 # define HAVE_casesi 0
1213 /* If the machine does not have a case insn that compares the bounds,
1214 this means extra overhead for dispatch tables, which raises the
1215 threshold for using them. */
1217 unsigned int default_case_values_threshold (void)
1219 return (HAVE_casesi ? 4 : 5);
1223 default_have_conditional_execution (void)
1225 #ifdef HAVE_conditional_execution
1226 return HAVE_conditional_execution;
1232 /* Compute cost of moving registers to/from memory. */
1235 default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1236 reg_class_t rclass ATTRIBUTE_UNUSED,
1237 bool in ATTRIBUTE_UNUSED)
1239 #ifndef MEMORY_MOVE_COST
1240 return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
1242 return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1246 /* Compute cost of moving data from a register of class FROM to one of
1250 default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
1251 reg_class_t from ATTRIBUTE_UNUSED,
1252 reg_class_t to ATTRIBUTE_UNUSED)
1254 #ifndef REGISTER_MOVE_COST
1257 return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1262 default_profile_before_prologue (void)
1264 #ifdef PROFILE_BEFORE_PROLOGUE
1271 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS. */
1274 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1277 #ifdef PREFERRED_RELOAD_CLASS
1278 return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1284 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS. */
1287 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1290 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1291 return PREFERRED_OUTPUT_RELOAD_CLASS (x, (enum reg_class) rclass);
1297 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS. */
1299 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1304 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P. */
1307 default_class_likely_spilled_p (reg_class_t rclass)
1309 return (reg_class_size[(int) rclass] == 1);
1312 /* Determine the debugging unwind mechanism for the target. */
1314 enum unwind_info_type
1315 default_debug_unwind_info (void)
1317 /* If the target wants to force the use of dwarf2 unwind info, let it. */
1318 /* ??? Change all users to the hook, then poison this. */
1319 #ifdef DWARF2_FRAME_INFO
1320 if (DWARF2_FRAME_INFO)
1324 /* Otherwise, only turn it on if dwarf2 debugging is enabled. */
1325 #ifdef DWARF2_DEBUGGING_INFO
1326 if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1333 /* Determine the exception handling mechanism for the target. */
1335 enum unwind_info_type
1336 default_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1338 /* Obey the configure switch to turn on sjlj exceptions. */
1339 #ifdef CONFIG_SJLJ_EXCEPTIONS
1340 if (CONFIG_SJLJ_EXCEPTIONS)
1344 /* ??? Change all users to the hook, then poison this. */
1345 #ifdef DWARF2_UNWIND_INFO
1346 if (DWARF2_UNWIND_INFO)
1353 /* To be used by targets that force dwarf2 unwind enabled. */
1355 enum unwind_info_type
1356 dwarf2_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1358 /* Obey the configure switch to turn on sjlj exceptions. */
1359 #ifdef CONFIG_SJLJ_EXCEPTIONS
1360 if (CONFIG_SJLJ_EXCEPTIONS)
1367 /* To be used by targets that force sjlj unwind enabled. */
1369 enum unwind_info_type
1370 sjlj_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
1375 /* To be used by targets where reg_raw_mode doesn't return the right
1376 mode for registers used in apply_builtin_return and apply_builtin_arg. */
1379 default_get_reg_raw_mode(int regno)
1381 return reg_raw_mode[regno];
1384 /* Return true if the state of option OPTION should be stored in PCH files
1385 and checked by default_pch_valid_p. Store the option's current state
1389 option_affects_pch_p (int option, struct cl_option_state *state)
1391 if ((cl_options[option].flags & CL_TARGET) == 0)
1393 if (option_flag_var (option, &global_options) == &target_flags)
1394 if (targetm.check_pch_target_flags)
1396 return get_option_state (&global_options, option, state);
1399 /* Default version of get_pch_validity.
1400 By default, every flag difference is fatal; that will be mostly right for
1401 most targets, but completely right for very few. */
1404 default_get_pch_validity (size_t *sz)
1406 struct cl_option_state state;
1411 if (targetm.check_pch_target_flags)
1412 *sz += sizeof (target_flags);
1413 for (i = 0; i < cl_options_count; i++)
1414 if (option_affects_pch_p (i, &state))
1417 result = r = XNEWVEC (char, *sz);
1421 if (targetm.check_pch_target_flags)
1423 memcpy (r, &target_flags, sizeof (target_flags));
1424 r += sizeof (target_flags);
1427 for (i = 0; i < cl_options_count; i++)
1428 if (option_affects_pch_p (i, &state))
1430 memcpy (r, state.data, state.size);
1437 /* Return a message which says that a PCH file was created with a different
1438 setting of OPTION. */
1441 pch_option_mismatch (const char *option)
1445 asprintf (&r, _("created and used with differing settings of '%s'"), option);
1447 return _("out of memory");
1451 /* Default version of pch_valid_p. */
1454 default_pch_valid_p (const void *data_p, size_t len)
1456 struct cl_option_state state;
1457 const char *data = (const char *)data_p;
1460 /* -fpic and -fpie also usually make a PCH invalid. */
1461 if (data[0] != flag_pic)
1462 return _("created and used with different settings of -fpic");
1463 if (data[1] != flag_pie)
1464 return _("created and used with different settings of -fpie");
1467 /* Check target_flags. */
1468 if (targetm.check_pch_target_flags)
1473 memcpy (&tf, data, sizeof (target_flags));
1474 data += sizeof (target_flags);
1475 len -= sizeof (target_flags);
1476 r = targetm.check_pch_target_flags (tf);
1481 for (i = 0; i < cl_options_count; i++)
1482 if (option_affects_pch_p (i, &state))
1484 if (memcmp (data, state.data, state.size) != 0)
1485 return pch_option_mismatch (cl_options[i].opt_text);
1493 /* Default version of TARGET_HANDLE_OPTION. */
1496 default_target_handle_option (struct gcc_options *opts ATTRIBUTE_UNUSED,
1497 struct gcc_options *opts_set ATTRIBUTE_UNUSED,
1498 const struct cl_decoded_option *decoded ATTRIBUTE_UNUSED,
1499 location_t loc ATTRIBUTE_UNUSED)
1504 const struct default_options empty_optimization_table[] =
1506 { OPT_LEVELS_NONE, 0, NULL, 0 }
1509 #include "gt-targhooks.h"