1 /* Default target hook functions.
2 Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
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"
63 #include "target-def.h"
65 #include "hard-reg-set.h"
72 default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
73 rtx addr ATTRIBUTE_UNUSED,
74 bool strict ATTRIBUTE_UNUSED)
76 #ifdef GO_IF_LEGITIMATE_ADDRESS
77 /* Defer to the old implementation using a goto. */
79 return strict_memory_address_p (mode, addr);
81 return memory_address_p (mode, addr);
88 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
90 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
91 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
96 default_unspec_may_trap_p (const_rtx x, unsigned flags)
100 if (GET_CODE (x) == UNSPEC_VOLATILE
101 /* Any floating arithmetic may trap. */
102 || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
103 && flag_trapping_math))
106 for (i = 0; i < XVECLEN (x, 0); ++i)
108 if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
116 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
124 default_return_in_memory (const_tree type,
125 const_tree fntype ATTRIBUTE_UNUSED)
127 return (TYPE_MODE (type) == BLKmode);
131 default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
132 enum machine_mode mode ATTRIBUTE_UNUSED)
138 default_expand_builtin_saveregs (void)
140 error ("__builtin_saveregs not supported by this target");
145 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
146 enum machine_mode mode ATTRIBUTE_UNUSED,
147 tree type ATTRIBUTE_UNUSED,
148 int *pretend_arg_size ATTRIBUTE_UNUSED,
149 int second_time ATTRIBUTE_UNUSED)
153 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
156 default_builtin_setjmp_frame_value (void)
158 return virtual_stack_vars_rtx;
161 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
164 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
170 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
172 return (targetm.calls.setup_incoming_varargs
173 != default_setup_incoming_varargs);
177 default_eh_return_filter_mode (void)
179 return targetm.unwind_word_mode ();
183 default_libgcc_cmp_return_mode (void)
189 default_libgcc_shift_count_mode (void)
195 default_unwind_word_mode (void)
200 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
202 unsigned HOST_WIDE_INT
203 default_shift_truncation_mask (enum machine_mode mode)
205 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
208 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
211 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
213 return have_insn_for (DIV, mode) ? 3 : 2;
216 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
219 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
220 enum machine_mode mode_rep ATTRIBUTE_UNUSED)
225 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
228 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
233 /* Return machine mode for non-standard suffix
234 or VOIDmode if non-standard suffixes are unsupported. */
236 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
241 /* The generic C++ ABI specifies this is a 64-bit value. */
243 default_cxx_guard_type (void)
245 return long_long_integer_type_node;
249 /* Returns the size of the cookie to use when allocating an array
250 whose elements have the indicated TYPE. Assumes that it is already
251 known that a cookie is needed. */
254 default_cxx_get_cookie_size (tree type)
258 /* We need to allocate an additional max (sizeof (size_t), alignof
259 (true_type)) bytes. */
263 sizetype_size = size_in_bytes (sizetype);
264 type_align = size_int (TYPE_ALIGN_UNIT (type));
265 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
266 cookie_size = sizetype_size;
268 cookie_size = type_align;
273 /* Return true if a parameter must be passed by reference. This version
274 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
277 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
278 enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
279 bool named_arg ATTRIBUTE_UNUSED)
281 return targetm.calls.must_pass_in_stack (mode, type);
284 /* Return true if a parameter follows callee copies conventions. This
285 version of the hook is true for all named arguments. */
288 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
289 enum machine_mode mode ATTRIBUTE_UNUSED,
290 const_tree type ATTRIBUTE_UNUSED, bool named)
295 /* Emit any directives required to unwind this instruction. */
298 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
299 rtx insn ATTRIBUTE_UNUSED)
301 /* Should never happen. */
305 /* True if MODE is valid for the target. By "valid", we mean able to
306 be manipulated in non-trivial ways. In particular, this means all
307 the arithmetic is supported.
309 By default we guess this means that any C type is supported. If
310 we can't map the mode back to a type that would be available in C,
311 then reject it. Special case, here, is the double-word arithmetic
312 supported by optabs.c. */
315 default_scalar_mode_supported_p (enum machine_mode mode)
317 int precision = GET_MODE_PRECISION (mode);
319 switch (GET_MODE_CLASS (mode))
321 case MODE_PARTIAL_INT:
323 if (precision == CHAR_TYPE_SIZE)
325 if (precision == SHORT_TYPE_SIZE)
327 if (precision == INT_TYPE_SIZE)
329 if (precision == LONG_TYPE_SIZE)
331 if (precision == LONG_LONG_TYPE_SIZE)
333 if (precision == 2 * BITS_PER_WORD)
338 if (precision == FLOAT_TYPE_SIZE)
340 if (precision == DOUBLE_TYPE_SIZE)
342 if (precision == LONG_DOUBLE_TYPE_SIZE)
346 case MODE_DECIMAL_FLOAT:
358 /* True if the target supports decimal floating point. */
361 default_decimal_float_supported_p (void)
363 return ENABLE_DECIMAL_FLOAT;
366 /* True if the target supports fixed-point arithmetic. */
369 default_fixed_point_supported_p (void)
371 return ENABLE_FIXED_POINT;
374 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
377 This function checks whether a given INSN is valid within a low-overhead
378 loop. If INSN is invalid it returns the reason for that, otherwise it
379 returns NULL. A called function may clobber any special registers required
380 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
381 register for branch on table instructions. We reject the doloop pattern in
385 default_invalid_within_doloop (const_rtx insn)
388 return "Function call in loop.";
391 && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
392 || GET_CODE (PATTERN (insn)) == ADDR_VEC))
393 return "Computed branch in the loop.";
398 /* Mapping of builtin functions to vectorized variants. */
401 default_builtin_vectorized_function (unsigned int fn ATTRIBUTE_UNUSED,
402 tree type_out ATTRIBUTE_UNUSED,
403 tree type_in ATTRIBUTE_UNUSED)
408 /* Vectorized conversion. */
411 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
412 tree type ATTRIBUTE_UNUSED)
420 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
421 bool md_fn ATTRIBUTE_UNUSED,
422 bool sqrt ATTRIBUTE_UNUSED)
428 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
429 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
430 enum machine_mode mode ATTRIBUTE_UNUSED,
431 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
437 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
438 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
439 enum machine_mode mode ATTRIBUTE_UNUSED,
440 const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
446 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
447 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
448 enum machine_mode mode ATTRIBUTE_UNUSED,
449 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
455 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
460 hook_invalid_arg_for_unprototyped_fn (
461 const_tree typelist ATTRIBUTE_UNUSED,
462 const_tree funcdecl ATTRIBUTE_UNUSED,
463 const_tree val ATTRIBUTE_UNUSED)
468 /* Initialize the stack protection decls. */
470 /* Stack protection related decls living in libgcc. */
471 static GTY(()) tree stack_chk_guard_decl;
474 default_stack_protect_guard (void)
476 tree t = stack_chk_guard_decl;
480 t = build_decl (UNKNOWN_LOCATION,
481 VAR_DECL, get_identifier ("__stack_chk_guard"),
485 DECL_EXTERNAL (t) = 1;
487 TREE_THIS_VOLATILE (t) = 1;
488 DECL_ARTIFICIAL (t) = 1;
489 DECL_IGNORED_P (t) = 1;
491 stack_chk_guard_decl = t;
497 static GTY(()) tree stack_chk_fail_decl;
500 default_external_stack_protect_fail (void)
502 tree t = stack_chk_fail_decl;
506 t = build_function_type_list (void_type_node, NULL_TREE);
507 t = build_decl (UNKNOWN_LOCATION,
508 FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
511 DECL_EXTERNAL (t) = 1;
513 TREE_THIS_VOLATILE (t) = 1;
514 TREE_NOTHROW (t) = 1;
515 DECL_ARTIFICIAL (t) = 1;
516 DECL_IGNORED_P (t) = 1;
517 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
518 DECL_VISIBILITY_SPECIFIED (t) = 1;
520 stack_chk_fail_decl = t;
523 return build_call_expr (t, 0);
527 default_hidden_stack_protect_fail (void)
529 #ifndef HAVE_GAS_HIDDEN
530 return default_external_stack_protect_fail ();
532 tree t = stack_chk_fail_decl;
535 return default_external_stack_protect_fail ();
539 t = build_function_type_list (void_type_node, NULL_TREE);
540 t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
541 get_identifier ("__stack_chk_fail_local"), t);
544 DECL_EXTERNAL (t) = 1;
546 TREE_THIS_VOLATILE (t) = 1;
547 TREE_NOTHROW (t) = 1;
548 DECL_ARTIFICIAL (t) = 1;
549 DECL_IGNORED_P (t) = 1;
550 DECL_VISIBILITY_SPECIFIED (t) = 1;
551 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
553 stack_chk_fail_decl = t;
556 return build_call_expr (t, 0);
561 hook_bool_const_rtx_commutative_p (const_rtx x,
562 int outer_code ATTRIBUTE_UNUSED)
564 return COMMUTATIVE_P (x);
568 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
569 const_tree fn_decl_or_type,
570 bool outgoing ATTRIBUTE_UNUSED)
572 /* The old interface doesn't handle receiving the function type. */
574 && !DECL_P (fn_decl_or_type))
575 fn_decl_or_type = NULL;
577 #ifdef FUNCTION_OUTGOING_VALUE
579 return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
582 #ifdef FUNCTION_VALUE
583 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
590 default_internal_arg_pointer (void)
592 /* If the reg that the virtual arg pointer will be translated into is
593 not a fixed reg or is the stack pointer, make a copy of the virtual
594 arg pointer, and address parms via the copy. The frame pointer is
595 considered fixed even though it is not marked as such. */
596 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
597 || ! (fixed_regs[ARG_POINTER_REGNUM]
598 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
599 return copy_to_reg (virtual_incoming_args_rtx);
601 return virtual_incoming_args_rtx;
605 default_branch_target_register_class (void)
610 #ifdef IRA_COVER_CLASSES
611 const enum reg_class *
612 default_ira_cover_classes (void)
614 static enum reg_class classes[] = IRA_COVER_CLASSES;
620 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
621 enum reg_class reload_class ATTRIBUTE_UNUSED,
622 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
623 secondary_reload_info *sri)
625 enum reg_class rclass = NO_REGS;
627 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
629 sri->icode = sri->prev_sri->t_icode;
632 #ifdef SECONDARY_INPUT_RELOAD_CLASS
634 rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
636 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
638 rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
640 if (rclass != NO_REGS)
642 enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
643 : reload_out_optab[(int) reload_mode]);
645 if (icode != CODE_FOR_nothing
646 && insn_data[(int) icode].operand[in_p].predicate
647 && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
648 icode = CODE_FOR_nothing;
649 else if (icode != CODE_FOR_nothing)
651 const char *insn_constraint, *scratch_constraint;
652 char insn_letter, scratch_letter;
653 enum reg_class insn_class, scratch_class;
655 gcc_assert (insn_data[(int) icode].n_operands == 3);
656 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
657 if (!*insn_constraint)
658 insn_class = ALL_REGS;
663 gcc_assert (*insn_constraint == '=');
666 insn_letter = *insn_constraint;
668 = (insn_letter == 'r' ? GENERAL_REGS
669 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
671 gcc_assert (insn_class != NO_REGS);
674 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
675 /* The scratch register's constraint must start with "=&",
676 except for an input reload, where only "=" is necessary,
677 and where it might be beneficial to re-use registers from
679 gcc_assert (scratch_constraint[0] == '='
680 && (in_p || scratch_constraint[1] == '&'));
681 scratch_constraint++;
682 if (*scratch_constraint == '&')
683 scratch_constraint++;
684 scratch_letter = *scratch_constraint;
686 = (scratch_letter == 'r' ? GENERAL_REGS
687 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
688 scratch_constraint));
690 if (reg_class_subset_p (reload_class, insn_class))
692 gcc_assert (scratch_class == rclass);
699 if (rclass == NO_REGS)
702 sri->t_icode = icode;
708 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
709 const char *arg ATTRIBUTE_UNUSED,
710 int value ATTRIBUTE_UNUSED)
715 /* By default, if flag_pic is true, then neither local nor global relocs
716 should be placed in readonly memory. */
719 default_reloc_rw_mask (void)
721 return flag_pic ? 3 : 0;
724 /* By default, do no modification. */
725 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
732 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
737 /* Assuming that types whose size is > pointer-size are not guaranteed to be
738 naturally aligned. */
739 if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
742 /* Assuming that types whose size is <= pointer-size
743 are naturally aligned. */
748 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
754 default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
755 tree ARG_UNUSED (name),
756 tree ARG_UNUSED (args),
757 int ARG_UNUSED (flags))
759 warning (OPT_Wattributes,
760 "target attribute is not supported on this machine");
766 default_target_option_pragma_parse (tree ARG_UNUSED (args),
767 tree ARG_UNUSED (pop_target))
769 warning (OPT_Wpragmas,
770 "#pragma GCC target is not supported for this machine");
776 default_target_option_can_inline_p (tree caller, tree callee)
779 tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
780 tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
782 /* If callee has no option attributes, then it is ok to inline */
786 /* If caller has no option attributes, but callee does then it is not ok to
788 else if (!caller_opts)
791 /* If both caller and callee have attributes, assume that if the pointer is
792 different, the the two functions have different target options since
793 build_target_option_node uses a hash table for the options. */
795 ret = (callee_opts == caller_opts);
801 # define HAVE_casesi 0
804 /* If the machine does not have a case insn that compares the bounds,
805 this means extra overhead for dispatch tables, which raises the
806 threshold for using them. */
808 unsigned int default_case_values_threshold (void)
810 return (HAVE_casesi ? 4 : 5);
813 #include "gt-targhooks.h"