2011-07-21 François Dumont <francois.cppdevs@free.fr>
[official-gcc.git] / gcc / targhooks.c
blob16d0b189f658fce287049071d859843c3f04582d
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
10 version.
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.
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
29 take some time.
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
37 this point.
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. */
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"
76 bool
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. */
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
92 void
93 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
95 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
96 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
97 #endif
101 default_unspec_may_trap_p (const_rtx x, unsigned flags)
103 int i;
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;
111 for (i = 0; i < XVECLEN (x, 0); ++i)
113 if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
114 return 1;
117 return 0;
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)
127 if (type != NULL_TREE && for_return == 2)
128 return promote_mode (type, mode, punsignedp);
129 return mode;
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)
139 return promote_mode (type, mode, punsignedp);
143 enum machine_mode
144 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
146 if (m1 == m2)
147 return m1;
148 return VOIDmode;
151 bool
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)
162 return x;
166 default_expand_builtin_saveregs (void)
168 error ("__builtin_saveregs not supported by this target");
169 return const0_rtx;
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)
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. */
191 bool
192 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
194 return false;
197 bool
198 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
200 return (targetm.calls.setup_incoming_varargs
201 != default_setup_incoming_varargs);
204 enum machine_mode
205 default_eh_return_filter_mode (void)
207 return targetm.unwind_word_mode ();
210 enum machine_mode
211 default_libgcc_cmp_return_mode (void)
213 return word_mode;
216 enum machine_mode
217 default_libgcc_shift_count_mode (void)
219 return word_mode;
222 enum machine_mode
223 default_unwind_word_mode (void)
225 return word_mode;
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. */
238 unsigned int
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)
250 return UNKNOWN;
253 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
255 bool
256 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
258 return true;
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)
266 return VOIDmode;
269 /* The generic C++ ABI specifies this is a 64-bit value. */
270 tree
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. */
281 tree
282 default_cxx_get_cookie_size (tree type)
284 tree cookie_size;
286 /* We need to allocate an additional max (sizeof (size_t), alignof
287 (true_type)) bytes. */
288 tree sizetype_size;
289 tree type_align;
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;
298 return cookie_size;
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. */
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)
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. */
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)
320 return named;
323 /* Emit to STREAM the assembler syntax for insn operand X. */
325 void
326 default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
327 int code ATTRIBUTE_UNUSED)
329 #ifdef PRINT_OPERAND
330 PRINT_OPERAND (stream, x, code);
331 #else
332 gcc_unreachable ();
333 #endif
336 /* Emit to STREAM the assembler syntax for an insn operand whose memory
337 address is X. */
339 void
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);
345 #else
346 gcc_unreachable ();
347 #endif
350 /* Return true if CODE is a valid punctuation character for the
351 `print_operand' hook. */
353 bool
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);
358 #else
359 return false;
360 #endif
363 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME. */
364 tree
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. */
376 bool
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);
382 return true;
384 fail:
385 #endif
386 return false;
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. */
398 bool
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:
406 case MODE_INT:
407 if (precision == CHAR_TYPE_SIZE)
408 return true;
409 if (precision == SHORT_TYPE_SIZE)
410 return true;
411 if (precision == INT_TYPE_SIZE)
412 return true;
413 if (precision == LONG_TYPE_SIZE)
414 return true;
415 if (precision == LONG_LONG_TYPE_SIZE)
416 return true;
417 if (precision == 2 * BITS_PER_WORD)
418 return true;
419 return false;
421 case MODE_FLOAT:
422 if (precision == FLOAT_TYPE_SIZE)
423 return true;
424 if (precision == DOUBLE_TYPE_SIZE)
425 return true;
426 if (precision == LONG_DOUBLE_TYPE_SIZE)
427 return true;
428 return false;
430 case MODE_DECIMAL_FLOAT:
431 case MODE_FRACT:
432 case MODE_UFRACT:
433 case MODE_ACCUM:
434 case MODE_UACCUM:
435 return false;
437 default:
438 gcc_unreachable ();
442 /* Make some target macros useable by target-independent code. */
443 bool
444 targhook_words_big_endian (void)
446 return !!WORDS_BIG_ENDIAN;
449 bool
450 targhook_float_words_big_endian (void)
452 return !!FLOAT_WORDS_BIG_ENDIAN;
455 /* True if the target supports decimal floating point. */
457 bool
458 default_decimal_float_supported_p (void)
460 return ENABLE_DECIMAL_FLOAT;
463 /* True if the target supports fixed-point arithmetic. */
465 bool
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
472 an error message.
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
479 these cases. */
481 const char *
482 default_invalid_within_doloop (const_rtx insn)
484 if (CALL_P (insn))
485 return "Function call in loop.";
487 if (JUMP_TABLE_DATA_P (insn))
488 return "Computed branch in the loop.";
490 return NULL;
493 /* Mapping of builtin functions to vectorized variants. */
495 tree
496 default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
497 tree type_out ATTRIBUTE_UNUSED,
498 tree type_in ATTRIBUTE_UNUSED)
500 return NULL_TREE;
503 /* Vectorized conversion. */
505 tree
506 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
507 tree dest_type ATTRIBUTE_UNUSED,
508 tree src_type ATTRIBUTE_UNUSED)
510 return NULL_TREE;
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)
522 case scalar_stmt:
523 case scalar_load:
524 case scalar_store:
525 case vector_stmt:
526 case vector_load:
527 case vector_store:
528 case vec_to_scalar:
529 case scalar_to_vec:
530 case cond_branch_not_taken:
531 case vec_perm:
532 return 1;
534 case unaligned_load:
535 case unaligned_store:
536 return 2;
538 case cond_branch_taken:
539 return 3;
541 default:
542 gcc_unreachable ();
546 /* Reciprocal. */
548 tree
549 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
550 bool md_fn ATTRIBUTE_UNUSED,
551 bool sqrt ATTRIBUTE_UNUSED)
553 return NULL_TREE;
556 bool
557 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
558 cumulative_args_t ca ATTRIBUTE_UNUSED,
559 enum machine_mode mode ATTRIBUTE_UNUSED,
560 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
562 return false;
565 bool
566 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
567 cumulative_args_t ca ATTRIBUTE_UNUSED,
568 enum machine_mode mode ATTRIBUTE_UNUSED,
569 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
571 return true;
575 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
576 cumulative_args_t ca ATTRIBUTE_UNUSED,
577 enum machine_mode mode ATTRIBUTE_UNUSED,
578 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
580 return 0;
583 void
584 default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
585 enum machine_mode mode ATTRIBUTE_UNUSED,
586 const_tree type ATTRIBUTE_UNUSED,
587 bool named ATTRIBUTE_UNUSED)
589 gcc_unreachable ();
593 default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
594 enum machine_mode mode ATTRIBUTE_UNUSED,
595 const_tree type ATTRIBUTE_UNUSED,
596 bool named ATTRIBUTE_UNUSED)
598 gcc_unreachable ();
602 default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
603 enum machine_mode mode ATTRIBUTE_UNUSED,
604 const_tree type ATTRIBUTE_UNUSED,
605 bool named ATTRIBUTE_UNUSED)
607 gcc_unreachable ();
610 unsigned int
611 default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
612 const_tree type ATTRIBUTE_UNUSED)
614 return PARM_BOUNDARY;
617 unsigned int
618 default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
619 const_tree type ATTRIBUTE_UNUSED)
621 return PARM_BOUNDARY;
624 void
625 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
629 const char *
630 hook_invalid_arg_for_unprototyped_fn (
631 const_tree typelist ATTRIBUTE_UNUSED,
632 const_tree funcdecl ATTRIBUTE_UNUSED,
633 const_tree val ATTRIBUTE_UNUSED)
635 return NULL;
638 /* Initialize the stack protection decls. */
640 /* Stack protection related decls living in libgcc. */
641 static GTY(()) tree stack_chk_guard_decl;
643 tree
644 default_stack_protect_guard (void)
646 tree t = stack_chk_guard_decl;
648 if (t == NULL)
650 rtx x;
652 t = build_decl (UNKNOWN_LOCATION,
653 VAR_DECL, get_identifier ("__stack_chk_guard"),
654 ptr_type_node);
655 TREE_STATIC (t) = 1;
656 TREE_PUBLIC (t) = 1;
657 DECL_EXTERNAL (t) = 1;
658 TREE_USED (t) = 1;
659 TREE_THIS_VOLATILE (t) = 1;
660 DECL_ARTIFICIAL (t) = 1;
661 DECL_IGNORED_P (t) = 1;
663 /* Do not share RTL as the declaration is visible outside of
664 current function. */
665 x = DECL_RTL (t);
666 RTX_FLAG (x, used) = 1;
668 stack_chk_guard_decl = t;
671 return t;
674 static GTY(()) tree stack_chk_fail_decl;
676 tree
677 default_external_stack_protect_fail (void)
679 tree t = stack_chk_fail_decl;
681 if (t == NULL_TREE)
683 t = build_function_type_list (void_type_node, NULL_TREE);
684 t = build_decl (UNKNOWN_LOCATION,
685 FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
686 TREE_STATIC (t) = 1;
687 TREE_PUBLIC (t) = 1;
688 DECL_EXTERNAL (t) = 1;
689 TREE_USED (t) = 1;
690 TREE_THIS_VOLATILE (t) = 1;
691 TREE_NOTHROW (t) = 1;
692 DECL_ARTIFICIAL (t) = 1;
693 DECL_IGNORED_P (t) = 1;
694 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
695 DECL_VISIBILITY_SPECIFIED (t) = 1;
697 stack_chk_fail_decl = t;
700 return build_call_expr (t, 0);
703 tree
704 default_hidden_stack_protect_fail (void)
706 #ifndef HAVE_GAS_HIDDEN
707 return default_external_stack_protect_fail ();
708 #else
709 tree t = stack_chk_fail_decl;
711 if (!flag_pic)
712 return default_external_stack_protect_fail ();
714 if (t == NULL_TREE)
716 t = build_function_type_list (void_type_node, NULL_TREE);
717 t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
718 get_identifier ("__stack_chk_fail_local"), t);
719 TREE_STATIC (t) = 1;
720 TREE_PUBLIC (t) = 1;
721 DECL_EXTERNAL (t) = 1;
722 TREE_USED (t) = 1;
723 TREE_THIS_VOLATILE (t) = 1;
724 TREE_NOTHROW (t) = 1;
725 DECL_ARTIFICIAL (t) = 1;
726 DECL_IGNORED_P (t) = 1;
727 DECL_VISIBILITY_SPECIFIED (t) = 1;
728 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
730 stack_chk_fail_decl = t;
733 return build_call_expr (t, 0);
734 #endif
737 bool
738 hook_bool_const_rtx_commutative_p (const_rtx x,
739 int outer_code ATTRIBUTE_UNUSED)
741 return COMMUTATIVE_P (x);
745 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
746 const_tree fn_decl_or_type,
747 bool outgoing ATTRIBUTE_UNUSED)
749 /* The old interface doesn't handle receiving the function type. */
750 if (fn_decl_or_type
751 && !DECL_P (fn_decl_or_type))
752 fn_decl_or_type = NULL;
754 #ifdef FUNCTION_VALUE
755 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
756 #else
757 gcc_unreachable ();
758 #endif
762 default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
763 const_rtx fun ATTRIBUTE_UNUSED)
765 #ifdef LIBCALL_VALUE
766 return LIBCALL_VALUE (mode);
767 #else
768 gcc_unreachable ();
769 #endif
772 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P. */
774 bool
775 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
777 #ifdef FUNCTION_VALUE_REGNO_P
778 return FUNCTION_VALUE_REGNO_P (regno);
779 #else
780 gcc_unreachable ();
781 #endif
785 default_internal_arg_pointer (void)
787 /* If the reg that the virtual arg pointer will be translated into is
788 not a fixed reg or is the stack pointer, make a copy of the virtual
789 arg pointer, and address parms via the copy. The frame pointer is
790 considered fixed even though it is not marked as such. */
791 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
792 || ! (fixed_regs[ARG_POINTER_REGNUM]
793 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
794 return copy_to_reg (virtual_incoming_args_rtx);
795 else
796 return virtual_incoming_args_rtx;
800 default_static_chain (const_tree fndecl, bool incoming_p)
802 if (!DECL_STATIC_CHAIN (fndecl))
803 return NULL;
805 if (incoming_p)
807 #ifdef STATIC_CHAIN_INCOMING_REGNUM
808 return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
809 #endif
812 #ifdef STATIC_CHAIN_REGNUM
813 return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
814 #endif
817 static bool issued_error;
818 if (!issued_error)
820 issued_error = true;
821 sorry ("nested functions not supported on this target");
824 /* It really doesn't matter what we return here, so long at it
825 doesn't cause the rest of the compiler to crash. */
826 return gen_rtx_MEM (Pmode, stack_pointer_rtx);
830 void
831 default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
832 rtx ARG_UNUSED (r_chain))
834 sorry ("nested function trampolines not supported on this target");
838 default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
839 tree funtype ATTRIBUTE_UNUSED,
840 int size ATTRIBUTE_UNUSED)
842 return 0;
845 reg_class_t
846 default_branch_target_register_class (void)
848 return NO_REGS;
851 reg_class_t
852 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
853 reg_class_t reload_class_i ATTRIBUTE_UNUSED,
854 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
855 secondary_reload_info *sri)
857 enum reg_class rclass = NO_REGS;
858 enum reg_class reload_class = (enum reg_class) reload_class_i;
860 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
862 sri->icode = sri->prev_sri->t_icode;
863 return NO_REGS;
865 #ifdef SECONDARY_INPUT_RELOAD_CLASS
866 if (in_p)
867 rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
868 #endif
869 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
870 if (! in_p)
871 rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
872 #endif
873 if (rclass != NO_REGS)
875 enum insn_code icode
876 = direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
877 reload_mode);
879 if (icode != CODE_FOR_nothing
880 && !insn_operand_matches (icode, in_p, x))
881 icode = CODE_FOR_nothing;
882 else if (icode != CODE_FOR_nothing)
884 const char *insn_constraint, *scratch_constraint;
885 char insn_letter, scratch_letter;
886 enum reg_class insn_class, scratch_class;
888 gcc_assert (insn_data[(int) icode].n_operands == 3);
889 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
890 if (!*insn_constraint)
891 insn_class = ALL_REGS;
892 else
894 if (in_p)
896 gcc_assert (*insn_constraint == '=');
897 insn_constraint++;
899 insn_letter = *insn_constraint;
900 insn_class
901 = (insn_letter == 'r' ? GENERAL_REGS
902 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
903 insn_constraint));
904 gcc_assert (insn_class != NO_REGS);
907 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
908 /* The scratch register's constraint must start with "=&",
909 except for an input reload, where only "=" is necessary,
910 and where it might be beneficial to re-use registers from
911 the input. */
912 gcc_assert (scratch_constraint[0] == '='
913 && (in_p || scratch_constraint[1] == '&'));
914 scratch_constraint++;
915 if (*scratch_constraint == '&')
916 scratch_constraint++;
917 scratch_letter = *scratch_constraint;
918 scratch_class
919 = (scratch_letter == 'r' ? GENERAL_REGS
920 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
921 scratch_constraint));
923 if (reg_class_subset_p (reload_class, insn_class))
925 gcc_assert (scratch_class == rclass);
926 rclass = NO_REGS;
928 else
929 rclass = insn_class;
932 if (rclass == NO_REGS)
933 sri->icode = icode;
934 else
935 sri->t_icode = icode;
937 return rclass;
940 /* By default, if flag_pic is true, then neither local nor global relocs
941 should be placed in readonly memory. */
944 default_reloc_rw_mask (void)
946 return flag_pic ? 3 : 0;
949 /* By default, do no modification. */
950 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
951 tree id)
953 return id;
956 bool
957 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
959 if (is_packed)
960 return false;
962 /* Assuming that types whose size is > pointer-size are not guaranteed to be
963 naturally aligned. */
964 if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
965 return false;
967 /* Assuming that types whose size is <= pointer-size
968 are naturally aligned. */
969 return true;
972 /* By default, assume that a target supports any factor of misalignment
973 memory access if it supports movmisalign patten.
974 is_packed is true if the memory access is defined in a packed struct. */
975 bool
976 default_builtin_support_vector_misalignment (enum machine_mode mode,
977 const_tree type
978 ATTRIBUTE_UNUSED,
979 int misalignment
980 ATTRIBUTE_UNUSED,
981 bool is_packed
982 ATTRIBUTE_UNUSED)
984 if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
985 return true;
986 return false;
989 /* By default, only attempt to parallelize bitwise operations, and
990 possibly adds/subtracts using bit-twiddling. */
992 enum machine_mode
993 default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
995 return word_mode;
998 /* By default only the size derived from the preferred vector mode
999 is tried. */
1001 unsigned int
1002 default_autovectorize_vector_sizes (void)
1004 return 0;
1007 /* Determine whether or not a pointer mode is valid. Assume defaults
1008 of ptr_mode or Pmode - can be overridden. */
1009 bool
1010 default_valid_pointer_mode (enum machine_mode mode)
1012 return (mode == ptr_mode || mode == Pmode);
1015 /* Determine whether the memory reference specified by REF may alias
1016 the C libraries errno location. */
1017 bool
1018 default_ref_may_alias_errno (ao_ref *ref)
1020 tree base = ao_ref_base (ref);
1021 /* The default implementation assumes the errno location is
1022 a declaration of type int or is always accessed via a
1023 pointer to int. We assume that accesses to errno are
1024 not deliberately obfuscated (even in conforming ways). */
1025 if (TYPE_UNSIGNED (TREE_TYPE (base))
1026 || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
1027 return false;
1028 /* The default implementation assumes an errno location
1029 declaration is never defined in the current compilation unit. */
1030 if (DECL_P (base)
1031 && !TREE_STATIC (base))
1032 return true;
1033 else if (TREE_CODE (base) == MEM_REF
1034 && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1036 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
1037 return !pi || pi->pt.anything || pi->pt.nonlocal;
1039 return false;
1042 /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
1043 for the generic address space only. */
1045 enum machine_mode
1046 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1048 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1049 return ptr_mode;
1052 /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
1053 for the generic address space only. */
1055 enum machine_mode
1056 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
1058 gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
1059 return Pmode;
1062 /* Named address space version of valid_pointer_mode. */
1064 bool
1065 default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
1067 if (!ADDR_SPACE_GENERIC_P (as))
1068 return (mode == targetm.addr_space.pointer_mode (as)
1069 || mode == targetm.addr_space.address_mode (as));
1071 return targetm.valid_pointer_mode (mode);
1074 /* Some places still assume that all pointer or address modes are the
1075 standard Pmode and ptr_mode. These optimizations become invalid if
1076 the target actually supports multiple different modes. For now,
1077 we disable such optimizations on such targets, using this function. */
1079 bool
1080 target_default_pointer_address_modes_p (void)
1082 if (targetm.addr_space.address_mode != default_addr_space_address_mode)
1083 return false;
1084 if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
1085 return false;
1087 return true;
1090 /* Named address space version of legitimate_address_p. */
1092 bool
1093 default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
1094 bool strict, addr_space_t as)
1096 if (!ADDR_SPACE_GENERIC_P (as))
1097 gcc_unreachable ();
1099 return targetm.legitimate_address_p (mode, mem, strict);
1102 /* Named address space version of LEGITIMIZE_ADDRESS. */
1105 default_addr_space_legitimize_address (rtx x, rtx oldx,
1106 enum machine_mode mode, addr_space_t as)
1108 if (!ADDR_SPACE_GENERIC_P (as))
1109 return x;
1111 return targetm.legitimize_address (x, oldx, mode);
1114 /* The default hook for determining if one named address space is a subset of
1115 another and to return which address space to use as the common address
1116 space. */
1118 bool
1119 default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
1121 return (subset == superset);
1124 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1125 called for targets with only a generic address space. */
1128 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
1129 tree from_type ATTRIBUTE_UNUSED,
1130 tree to_type ATTRIBUTE_UNUSED)
1132 gcc_unreachable ();
1135 bool
1136 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
1138 return true;
1141 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P. */
1143 bool
1144 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED)
1146 #ifdef GO_IF_MODE_DEPENDENT_ADDRESS
1148 GO_IF_MODE_DEPENDENT_ADDRESS (CONST_CAST_RTX (addr), win);
1149 return false;
1150 /* Label `win' might (not) be used via GO_IF_MODE_DEPENDENT_ADDRESS. */
1151 win: ATTRIBUTE_UNUSED_LABEL
1152 return true;
1154 #else
1156 return false;
1158 #endif
1161 bool
1162 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
1163 tree ARG_UNUSED (name),
1164 tree ARG_UNUSED (args),
1165 int ARG_UNUSED (flags))
1167 warning (OPT_Wattributes,
1168 "target attribute is not supported on this machine");
1170 return false;
1173 bool
1174 default_target_option_pragma_parse (tree ARG_UNUSED (args),
1175 tree ARG_UNUSED (pop_target))
1177 warning (OPT_Wpragmas,
1178 "#pragma GCC target is not supported for this machine");
1180 return false;
1183 bool
1184 default_target_can_inline_p (tree caller, tree callee)
1186 bool ret = false;
1187 tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
1188 tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
1190 /* If callee has no option attributes, then it is ok to inline */
1191 if (!callee_opts)
1192 ret = true;
1194 /* If caller has no option attributes, but callee does then it is not ok to
1195 inline */
1196 else if (!caller_opts)
1197 ret = false;
1199 /* If both caller and callee have attributes, assume that if the
1200 pointer is different, the two functions have different target
1201 options since build_target_option_node uses a hash table for the
1202 options. */
1203 else
1204 ret = (callee_opts == caller_opts);
1206 return ret;
1209 #ifndef HAVE_casesi
1210 # define HAVE_casesi 0
1211 #endif
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);
1222 bool
1223 default_have_conditional_execution (void)
1225 #ifdef HAVE_conditional_execution
1226 return HAVE_conditional_execution;
1227 #else
1228 return false;
1229 #endif
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));
1241 #else
1242 return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
1243 #endif
1246 /* Compute cost of moving data from a register of class FROM to one of
1247 TO, using MODE. */
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
1255 return 2;
1256 #else
1257 return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
1258 #endif
1261 bool
1262 default_profile_before_prologue (void)
1264 #ifdef PROFILE_BEFORE_PROLOGUE
1265 return true;
1266 #else
1267 return false;
1268 #endif
1271 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS. */
1273 reg_class_t
1274 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
1275 reg_class_t rclass)
1277 #ifdef PREFERRED_RELOAD_CLASS
1278 return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
1279 #else
1280 return rclass;
1281 #endif
1284 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS. */
1286 reg_class_t
1287 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
1288 reg_class_t rclass)
1290 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1291 return PREFERRED_OUTPUT_RELOAD_CLASS (x, (enum reg_class) rclass);
1292 #else
1293 return rclass;
1294 #endif
1297 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS. */
1298 reg_class_t
1299 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
1301 return NO_REGS;
1304 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P. */
1306 bool
1307 default_class_likely_spilled_p (reg_class_t rclass)
1309 return (reg_class_size[(int) rclass] == 1);
1312 /* The default implementation of TARGET_CLASS_MAX_NREGS. */
1314 unsigned char
1315 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
1316 enum machine_mode mode ATTRIBUTE_UNUSED)
1318 #ifdef CLASS_MAX_NREGS
1319 return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
1320 #else
1321 return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
1322 #endif
1325 /* Determine the debugging unwind mechanism for the target. */
1327 enum unwind_info_type
1328 default_debug_unwind_info (void)
1330 /* If the target wants to force the use of dwarf2 unwind info, let it. */
1331 /* ??? Change all users to the hook, then poison this. */
1332 #ifdef DWARF2_FRAME_INFO
1333 if (DWARF2_FRAME_INFO)
1334 return UI_DWARF2;
1335 #endif
1337 /* Otherwise, only turn it on if dwarf2 debugging is enabled. */
1338 #ifdef DWARF2_DEBUGGING_INFO
1339 if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
1340 return UI_DWARF2;
1341 #endif
1343 return UI_NONE;
1346 /* To be used by targets where reg_raw_mode doesn't return the right
1347 mode for registers used in apply_builtin_return and apply_builtin_arg. */
1349 enum machine_mode
1350 default_get_reg_raw_mode(int regno)
1352 return reg_raw_mode[regno];
1355 /* Return true if the state of option OPTION should be stored in PCH files
1356 and checked by default_pch_valid_p. Store the option's current state
1357 in STATE if so. */
1359 static inline bool
1360 option_affects_pch_p (int option, struct cl_option_state *state)
1362 if ((cl_options[option].flags & CL_TARGET) == 0)
1363 return false;
1364 if (option_flag_var (option, &global_options) == &target_flags)
1365 if (targetm.check_pch_target_flags)
1366 return false;
1367 return get_option_state (&global_options, option, state);
1370 /* Default version of get_pch_validity.
1371 By default, every flag difference is fatal; that will be mostly right for
1372 most targets, but completely right for very few. */
1374 void *
1375 default_get_pch_validity (size_t *sz)
1377 struct cl_option_state state;
1378 size_t i;
1379 char *result, *r;
1381 *sz = 2;
1382 if (targetm.check_pch_target_flags)
1383 *sz += sizeof (target_flags);
1384 for (i = 0; i < cl_options_count; i++)
1385 if (option_affects_pch_p (i, &state))
1386 *sz += state.size;
1388 result = r = XNEWVEC (char, *sz);
1389 r[0] = flag_pic;
1390 r[1] = flag_pie;
1391 r += 2;
1392 if (targetm.check_pch_target_flags)
1394 memcpy (r, &target_flags, sizeof (target_flags));
1395 r += sizeof (target_flags);
1398 for (i = 0; i < cl_options_count; i++)
1399 if (option_affects_pch_p (i, &state))
1401 memcpy (r, state.data, state.size);
1402 r += state.size;
1405 return result;
1408 /* Return a message which says that a PCH file was created with a different
1409 setting of OPTION. */
1411 static const char *
1412 pch_option_mismatch (const char *option)
1414 char *r;
1416 asprintf (&r, _("created and used with differing settings of '%s'"), option);
1417 if (r == NULL)
1418 return _("out of memory");
1419 return r;
1422 /* Default version of pch_valid_p. */
1424 const char *
1425 default_pch_valid_p (const void *data_p, size_t len)
1427 struct cl_option_state state;
1428 const char *data = (const char *)data_p;
1429 size_t i;
1431 /* -fpic and -fpie also usually make a PCH invalid. */
1432 if (data[0] != flag_pic)
1433 return _("created and used with different settings of -fpic");
1434 if (data[1] != flag_pie)
1435 return _("created and used with different settings of -fpie");
1436 data += 2;
1438 /* Check target_flags. */
1439 if (targetm.check_pch_target_flags)
1441 int tf;
1442 const char *r;
1444 memcpy (&tf, data, sizeof (target_flags));
1445 data += sizeof (target_flags);
1446 len -= sizeof (target_flags);
1447 r = targetm.check_pch_target_flags (tf);
1448 if (r != NULL)
1449 return r;
1452 for (i = 0; i < cl_options_count; i++)
1453 if (option_affects_pch_p (i, &state))
1455 if (memcmp (data, state.data, state.size) != 0)
1456 return pch_option_mismatch (cl_options[i].opt_text);
1457 data += state.size;
1458 len -= state.size;
1461 return NULL;
1464 #include "gt-targhooks.h"