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_external_libcall (rtx fun ATTRIBUTE_UNUSED
)
74 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
75 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file
, fun
);
80 default_unspec_may_trap_p (const_rtx x
, unsigned flags
)
84 if (GET_CODE (x
) == UNSPEC_VOLATILE
85 /* Any floating arithmetic may trap. */
86 || (SCALAR_FLOAT_MODE_P (GET_MODE (x
))
87 && flag_trapping_math
))
90 for (i
= 0; i
< XVECLEN (x
, 0); ++i
)
92 if (may_trap_p_1 (XVECEXP (x
, 0, i
), flags
))
100 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
108 default_return_in_memory (const_tree type
,
109 const_tree fntype ATTRIBUTE_UNUSED
)
111 return (TYPE_MODE (type
) == BLKmode
);
115 default_legitimize_address (rtx x
, rtx orig_x ATTRIBUTE_UNUSED
,
116 enum machine_mode mode ATTRIBUTE_UNUSED
)
122 default_expand_builtin_saveregs (void)
124 error ("__builtin_saveregs not supported by this target");
129 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
130 enum machine_mode mode ATTRIBUTE_UNUSED
,
131 tree type ATTRIBUTE_UNUSED
,
132 int *pretend_arg_size ATTRIBUTE_UNUSED
,
133 int second_time ATTRIBUTE_UNUSED
)
137 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
140 default_builtin_setjmp_frame_value (void)
142 return virtual_stack_vars_rtx
;
145 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
148 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
154 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
156 return (targetm
.calls
.setup_incoming_varargs
157 != default_setup_incoming_varargs
);
161 default_eh_return_filter_mode (void)
163 return targetm
.unwind_word_mode ();
167 default_libgcc_cmp_return_mode (void)
173 default_libgcc_shift_count_mode (void)
179 default_unwind_word_mode (void)
184 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
186 unsigned HOST_WIDE_INT
187 default_shift_truncation_mask (enum machine_mode mode
)
189 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
192 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
195 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED
)
197 return have_insn_for (DIV
, mode
) ? 3 : 2;
200 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
203 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED
,
204 enum machine_mode mode_rep ATTRIBUTE_UNUSED
)
209 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
212 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
217 /* Return machine mode for non-standard suffix
218 or VOIDmode if non-standard suffixes are unsupported. */
220 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED
)
225 /* The generic C++ ABI specifies this is a 64-bit value. */
227 default_cxx_guard_type (void)
229 return long_long_integer_type_node
;
233 /* Returns the size of the cookie to use when allocating an array
234 whose elements have the indicated TYPE. Assumes that it is already
235 known that a cookie is needed. */
238 default_cxx_get_cookie_size (tree type
)
242 /* We need to allocate an additional max (sizeof (size_t), alignof
243 (true_type)) bytes. */
247 sizetype_size
= size_in_bytes (sizetype
);
248 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
249 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
250 cookie_size
= sizetype_size
;
252 cookie_size
= type_align
;
257 /* Return true if a parameter must be passed by reference. This version
258 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
261 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
262 enum machine_mode mode ATTRIBUTE_UNUSED
, const_tree type ATTRIBUTE_UNUSED
,
263 bool named_arg ATTRIBUTE_UNUSED
)
265 return targetm
.calls
.must_pass_in_stack (mode
, type
);
268 /* Return true if a parameter follows callee copies conventions. This
269 version of the hook is true for all named arguments. */
272 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
273 enum machine_mode mode ATTRIBUTE_UNUSED
,
274 const_tree type ATTRIBUTE_UNUSED
, bool named
)
279 /* Emit any directives required to unwind this instruction. */
282 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
283 rtx insn ATTRIBUTE_UNUSED
)
285 /* Should never happen. */
289 /* True if MODE is valid for the target. By "valid", we mean able to
290 be manipulated in non-trivial ways. In particular, this means all
291 the arithmetic is supported.
293 By default we guess this means that any C type is supported. If
294 we can't map the mode back to a type that would be available in C,
295 then reject it. Special case, here, is the double-word arithmetic
296 supported by optabs.c. */
299 default_scalar_mode_supported_p (enum machine_mode mode
)
301 int precision
= GET_MODE_PRECISION (mode
);
303 switch (GET_MODE_CLASS (mode
))
305 case MODE_PARTIAL_INT
:
307 if (precision
== CHAR_TYPE_SIZE
)
309 if (precision
== SHORT_TYPE_SIZE
)
311 if (precision
== INT_TYPE_SIZE
)
313 if (precision
== LONG_TYPE_SIZE
)
315 if (precision
== LONG_LONG_TYPE_SIZE
)
317 if (precision
== 2 * BITS_PER_WORD
)
322 if (precision
== FLOAT_TYPE_SIZE
)
324 if (precision
== DOUBLE_TYPE_SIZE
)
326 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
330 case MODE_DECIMAL_FLOAT
:
342 /* True if the target supports decimal floating point. */
345 default_decimal_float_supported_p (void)
347 return ENABLE_DECIMAL_FLOAT
;
350 /* True if the target supports fixed-point arithmetic. */
353 default_fixed_point_supported_p (void)
355 return ENABLE_FIXED_POINT
;
358 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
361 This function checks whether a given INSN is valid within a low-overhead
362 loop. If INSN is invalid it returns the reason for that, otherwise it
363 returns NULL. A called function may clobber any special registers required
364 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
365 register for branch on table instructions. We reject the doloop pattern in
369 default_invalid_within_doloop (const_rtx insn
)
372 return "Function call in loop.";
375 && (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
376 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
))
377 return "Computed branch in the loop.";
382 /* Mapping of builtin functions to vectorized variants. */
385 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED
,
386 tree type_out ATTRIBUTE_UNUSED
,
387 tree type_in ATTRIBUTE_UNUSED
)
392 /* Vectorized conversion. */
395 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED
,
396 tree type ATTRIBUTE_UNUSED
)
404 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED
,
405 bool md_fn ATTRIBUTE_UNUSED
,
406 bool sqrt ATTRIBUTE_UNUSED
)
412 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
413 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
414 enum machine_mode mode ATTRIBUTE_UNUSED
,
415 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
421 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
422 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
423 enum machine_mode mode ATTRIBUTE_UNUSED
,
424 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
430 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
431 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
432 enum machine_mode mode ATTRIBUTE_UNUSED
,
433 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
439 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED
)
444 hook_invalid_arg_for_unprototyped_fn (
445 const_tree typelist ATTRIBUTE_UNUSED
,
446 const_tree funcdecl ATTRIBUTE_UNUSED
,
447 const_tree val ATTRIBUTE_UNUSED
)
452 /* Initialize the stack protection decls. */
454 /* Stack protection related decls living in libgcc. */
455 static GTY(()) tree stack_chk_guard_decl
;
458 default_stack_protect_guard (void)
460 tree t
= stack_chk_guard_decl
;
464 t
= build_decl (VAR_DECL
, get_identifier ("__stack_chk_guard"),
468 DECL_EXTERNAL (t
) = 1;
470 TREE_THIS_VOLATILE (t
) = 1;
471 DECL_ARTIFICIAL (t
) = 1;
472 DECL_IGNORED_P (t
) = 1;
474 stack_chk_guard_decl
= t
;
480 static GTY(()) tree stack_chk_fail_decl
;
483 default_external_stack_protect_fail (void)
485 tree t
= stack_chk_fail_decl
;
489 t
= build_function_type_list (void_type_node
, NULL_TREE
);
490 t
= build_decl (FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
493 DECL_EXTERNAL (t
) = 1;
495 TREE_THIS_VOLATILE (t
) = 1;
496 TREE_NOTHROW (t
) = 1;
497 DECL_ARTIFICIAL (t
) = 1;
498 DECL_IGNORED_P (t
) = 1;
499 DECL_VISIBILITY (t
) = VISIBILITY_DEFAULT
;
500 DECL_VISIBILITY_SPECIFIED (t
) = 1;
502 stack_chk_fail_decl
= t
;
505 return build_call_expr (t
, 0);
509 default_hidden_stack_protect_fail (void)
511 #ifndef HAVE_GAS_HIDDEN
512 return default_external_stack_protect_fail ();
514 tree t
= stack_chk_fail_decl
;
517 return default_external_stack_protect_fail ();
521 t
= build_function_type_list (void_type_node
, NULL_TREE
);
522 t
= build_decl (FUNCTION_DECL
,
523 get_identifier ("__stack_chk_fail_local"), t
);
526 DECL_EXTERNAL (t
) = 1;
528 TREE_THIS_VOLATILE (t
) = 1;
529 TREE_NOTHROW (t
) = 1;
530 DECL_ARTIFICIAL (t
) = 1;
531 DECL_IGNORED_P (t
) = 1;
532 DECL_VISIBILITY_SPECIFIED (t
) = 1;
533 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
535 stack_chk_fail_decl
= t
;
538 return build_call_expr (t
, 0);
543 hook_bool_const_rtx_commutative_p (const_rtx x
,
544 int outer_code ATTRIBUTE_UNUSED
)
546 return COMMUTATIVE_P (x
);
550 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED
,
551 const_tree fn_decl_or_type
,
552 bool outgoing ATTRIBUTE_UNUSED
)
554 /* The old interface doesn't handle receiving the function type. */
556 && !DECL_P (fn_decl_or_type
))
557 fn_decl_or_type
= NULL
;
559 #ifdef FUNCTION_OUTGOING_VALUE
561 return FUNCTION_OUTGOING_VALUE (ret_type
, fn_decl_or_type
);
564 #ifdef FUNCTION_VALUE
565 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
572 default_internal_arg_pointer (void)
574 /* If the reg that the virtual arg pointer will be translated into is
575 not a fixed reg or is the stack pointer, make a copy of the virtual
576 arg pointer, and address parms via the copy. The frame pointer is
577 considered fixed even though it is not marked as such. */
578 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
579 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
580 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
581 return copy_to_reg (virtual_incoming_args_rtx
);
583 return virtual_incoming_args_rtx
;
587 default_branch_target_register_class (void)
592 #ifdef IRA_COVER_CLASSES
593 const enum reg_class
*
594 default_ira_cover_classes (void)
596 static enum reg_class classes
[] = IRA_COVER_CLASSES
;
602 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
603 enum reg_class reload_class ATTRIBUTE_UNUSED
,
604 enum machine_mode reload_mode ATTRIBUTE_UNUSED
,
605 secondary_reload_info
*sri
)
607 enum reg_class rclass
= NO_REGS
;
609 if (sri
->prev_sri
&& sri
->prev_sri
->t_icode
!= CODE_FOR_nothing
)
611 sri
->icode
= sri
->prev_sri
->t_icode
;
614 #ifdef SECONDARY_INPUT_RELOAD_CLASS
616 rclass
= SECONDARY_INPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
618 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
620 rclass
= SECONDARY_OUTPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
622 if (rclass
!= NO_REGS
)
624 enum insn_code icode
= (in_p
? reload_in_optab
[(int) reload_mode
]
625 : reload_out_optab
[(int) reload_mode
]);
627 if (icode
!= CODE_FOR_nothing
628 && insn_data
[(int) icode
].operand
[in_p
].predicate
629 && ! insn_data
[(int) icode
].operand
[in_p
].predicate (x
, reload_mode
))
630 icode
= CODE_FOR_nothing
;
631 else if (icode
!= CODE_FOR_nothing
)
633 const char *insn_constraint
, *scratch_constraint
;
634 char insn_letter
, scratch_letter
;
635 enum reg_class insn_class
, scratch_class
;
637 gcc_assert (insn_data
[(int) icode
].n_operands
== 3);
638 insn_constraint
= insn_data
[(int) icode
].operand
[!in_p
].constraint
;
639 if (!*insn_constraint
)
640 insn_class
= ALL_REGS
;
645 gcc_assert (*insn_constraint
== '=');
648 insn_letter
= *insn_constraint
;
650 = (insn_letter
== 'r' ? GENERAL_REGS
651 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter
,
653 gcc_assert (insn_class
!= NO_REGS
);
656 scratch_constraint
= insn_data
[(int) icode
].operand
[2].constraint
;
657 /* The scratch register's constraint must start with "=&",
658 except for an input reload, where only "=" is necessary,
659 and where it might be beneficial to re-use registers from
661 gcc_assert (scratch_constraint
[0] == '='
662 && (in_p
|| scratch_constraint
[1] == '&'));
663 scratch_constraint
++;
664 if (*scratch_constraint
== '&')
665 scratch_constraint
++;
666 scratch_letter
= *scratch_constraint
;
668 = (scratch_letter
== 'r' ? GENERAL_REGS
669 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter
,
670 scratch_constraint
));
672 if (reg_class_subset_p (reload_class
, insn_class
))
674 gcc_assert (scratch_class
== rclass
);
681 if (rclass
== NO_REGS
)
684 sri
->t_icode
= icode
;
690 default_handle_c_option (size_t code ATTRIBUTE_UNUSED
,
691 const char *arg ATTRIBUTE_UNUSED
,
692 int value ATTRIBUTE_UNUSED
)
697 /* By default, if flag_pic is true, then neither local nor global relocs
698 should be placed in readonly memory. */
701 default_reloc_rw_mask (void)
703 return flag_pic
? 3 : 0;
706 /* By default, do no modification. */
707 tree
default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED
,
714 default_builtin_vector_alignment_reachable (const_tree type
, bool is_packed
)
719 /* Assuming that types whose size is > pointer-size are not guaranteed to be
720 naturally aligned. */
721 if (tree_int_cst_compare (TYPE_SIZE (type
), bitsize_int (POINTER_SIZE
)) > 0)
724 /* Assuming that types whose size is <= pointer-size
725 are naturally aligned. */
730 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED
)
736 default_target_option_valid_attribute_p (tree
ARG_UNUSED (fndecl
),
737 tree
ARG_UNUSED (name
),
738 tree
ARG_UNUSED (args
),
739 int ARG_UNUSED (flags
))
741 warning (OPT_Wattributes
,
742 "target attribute is not supported on this machine");
748 default_target_option_pragma_parse (tree
ARG_UNUSED (args
),
749 tree
ARG_UNUSED (pop_target
))
751 warning (OPT_Wpragmas
,
752 "#pragma GCC target is not supported for this machine");
758 default_target_option_can_inline_p (tree caller
, tree callee
)
761 tree callee_opts
= DECL_FUNCTION_SPECIFIC_TARGET (callee
);
762 tree caller_opts
= DECL_FUNCTION_SPECIFIC_TARGET (caller
);
764 /* If callee has no option attributes, then it is ok to inline */
768 /* If caller has no option attributes, but callee does then it is not ok to
770 else if (!caller_opts
)
773 /* If both caller and callee have attributes, assume that if the pointer is
774 different, the the two functions have different target options since
775 build_target_option_node uses a hash table for the options. */
777 ret
= (callee_opts
== caller_opts
);
783 # define HAVE_casesi 0
786 /* If the machine does not have a case insn that compares the bounds,
787 this means extra overhead for dispatch tables, which raises the
788 threshold for using them. */
790 unsigned int default_case_values_threshold (void)
792 return (HAVE_casesi
? 4 : 5);
795 #include "gt-targhooks.h"