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_promote_function_mode (const_tree type ATTRIBUTE_UNUSED
,
117 enum machine_mode mode
,
118 int *punsignedp ATTRIBUTE_UNUSED
,
119 const_tree funtype ATTRIBUTE_UNUSED
,
120 int for_return ATTRIBUTE_UNUSED
)
123 return promote_mode (type
, mode
, punsignedp
);
128 default_promote_function_mode_always_promote (const_tree type
,
129 enum machine_mode mode
,
131 const_tree funtype ATTRIBUTE_UNUSED
,
132 int for_return ATTRIBUTE_UNUSED
)
134 return promote_mode (type
, mode
, punsignedp
);
139 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
147 default_return_in_memory (const_tree type
,
148 const_tree fntype ATTRIBUTE_UNUSED
)
150 return (TYPE_MODE (type
) == BLKmode
);
154 default_legitimize_address (rtx x
, rtx orig_x ATTRIBUTE_UNUSED
,
155 enum machine_mode mode ATTRIBUTE_UNUSED
)
161 default_expand_builtin_saveregs (void)
163 error ("__builtin_saveregs not supported by this target");
168 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
169 enum machine_mode mode ATTRIBUTE_UNUSED
,
170 tree type ATTRIBUTE_UNUSED
,
171 int *pretend_arg_size ATTRIBUTE_UNUSED
,
172 int second_time ATTRIBUTE_UNUSED
)
176 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
179 default_builtin_setjmp_frame_value (void)
181 return virtual_stack_vars_rtx
;
184 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
187 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
193 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
195 return (targetm
.calls
.setup_incoming_varargs
196 != default_setup_incoming_varargs
);
200 default_eh_return_filter_mode (void)
202 return targetm
.unwind_word_mode ();
206 default_libgcc_cmp_return_mode (void)
212 default_libgcc_shift_count_mode (void)
218 default_unwind_word_mode (void)
223 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
225 unsigned HOST_WIDE_INT
226 default_shift_truncation_mask (enum machine_mode mode
)
228 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
231 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
234 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED
)
236 return have_insn_for (DIV
, mode
) ? 3 : 2;
239 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
242 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED
,
243 enum machine_mode mode_rep ATTRIBUTE_UNUSED
)
248 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
251 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
256 /* Return machine mode for non-standard suffix
257 or VOIDmode if non-standard suffixes are unsupported. */
259 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED
)
264 /* The generic C++ ABI specifies this is a 64-bit value. */
266 default_cxx_guard_type (void)
268 return long_long_integer_type_node
;
272 /* Returns the size of the cookie to use when allocating an array
273 whose elements have the indicated TYPE. Assumes that it is already
274 known that a cookie is needed. */
277 default_cxx_get_cookie_size (tree type
)
281 /* We need to allocate an additional max (sizeof (size_t), alignof
282 (true_type)) bytes. */
286 sizetype_size
= size_in_bytes (sizetype
);
287 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
288 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
289 cookie_size
= sizetype_size
;
291 cookie_size
= type_align
;
296 /* Return true if a parameter must be passed by reference. This version
297 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
300 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
301 enum machine_mode mode ATTRIBUTE_UNUSED
, const_tree type ATTRIBUTE_UNUSED
,
302 bool named_arg ATTRIBUTE_UNUSED
)
304 return targetm
.calls
.must_pass_in_stack (mode
, type
);
307 /* Return true if a parameter follows callee copies conventions. This
308 version of the hook is true for all named arguments. */
311 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
312 enum machine_mode mode ATTRIBUTE_UNUSED
,
313 const_tree type ATTRIBUTE_UNUSED
, bool named
)
318 /* Emit any directives required to unwind this instruction. */
321 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
322 rtx insn ATTRIBUTE_UNUSED
)
324 /* Should never happen. */
328 /* True if MODE is valid for the target. By "valid", we mean able to
329 be manipulated in non-trivial ways. In particular, this means all
330 the arithmetic is supported.
332 By default we guess this means that any C type is supported. If
333 we can't map the mode back to a type that would be available in C,
334 then reject it. Special case, here, is the double-word arithmetic
335 supported by optabs.c. */
338 default_scalar_mode_supported_p (enum machine_mode mode
)
340 int precision
= GET_MODE_PRECISION (mode
);
342 switch (GET_MODE_CLASS (mode
))
344 case MODE_PARTIAL_INT
:
346 if (precision
== CHAR_TYPE_SIZE
)
348 if (precision
== SHORT_TYPE_SIZE
)
350 if (precision
== INT_TYPE_SIZE
)
352 if (precision
== LONG_TYPE_SIZE
)
354 if (precision
== LONG_LONG_TYPE_SIZE
)
356 if (precision
== 2 * BITS_PER_WORD
)
361 if (precision
== FLOAT_TYPE_SIZE
)
363 if (precision
== DOUBLE_TYPE_SIZE
)
365 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
369 case MODE_DECIMAL_FLOAT
:
381 /* True if the target supports decimal floating point. */
384 default_decimal_float_supported_p (void)
386 return ENABLE_DECIMAL_FLOAT
;
389 /* True if the target supports fixed-point arithmetic. */
392 default_fixed_point_supported_p (void)
394 return ENABLE_FIXED_POINT
;
397 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
400 This function checks whether a given INSN is valid within a low-overhead
401 loop. If INSN is invalid it returns the reason for that, otherwise it
402 returns NULL. A called function may clobber any special registers required
403 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
404 register for branch on table instructions. We reject the doloop pattern in
408 default_invalid_within_doloop (const_rtx insn
)
411 return "Function call in loop.";
413 if (JUMP_TABLE_DATA_P (insn
))
414 return "Computed branch in the loop.";
419 /* Mapping of builtin functions to vectorized variants. */
422 default_builtin_vectorized_function (unsigned int fn ATTRIBUTE_UNUSED
,
423 tree type_out ATTRIBUTE_UNUSED
,
424 tree type_in ATTRIBUTE_UNUSED
)
429 /* Vectorized conversion. */
432 default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED
,
433 tree type ATTRIBUTE_UNUSED
)
441 default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED
,
442 bool md_fn ATTRIBUTE_UNUSED
,
443 bool sqrt ATTRIBUTE_UNUSED
)
449 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
450 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
451 enum machine_mode mode ATTRIBUTE_UNUSED
,
452 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
458 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
459 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
460 enum machine_mode mode ATTRIBUTE_UNUSED
,
461 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
467 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
468 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
469 enum machine_mode mode ATTRIBUTE_UNUSED
,
470 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
476 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED
)
481 hook_invalid_arg_for_unprototyped_fn (
482 const_tree typelist ATTRIBUTE_UNUSED
,
483 const_tree funcdecl ATTRIBUTE_UNUSED
,
484 const_tree val ATTRIBUTE_UNUSED
)
489 /* Initialize the stack protection decls. */
491 /* Stack protection related decls living in libgcc. */
492 static GTY(()) tree stack_chk_guard_decl
;
495 default_stack_protect_guard (void)
497 tree t
= stack_chk_guard_decl
;
501 t
= build_decl (UNKNOWN_LOCATION
,
502 VAR_DECL
, get_identifier ("__stack_chk_guard"),
506 DECL_EXTERNAL (t
) = 1;
508 TREE_THIS_VOLATILE (t
) = 1;
509 DECL_ARTIFICIAL (t
) = 1;
510 DECL_IGNORED_P (t
) = 1;
512 stack_chk_guard_decl
= t
;
518 static GTY(()) tree stack_chk_fail_decl
;
521 default_external_stack_protect_fail (void)
523 tree t
= stack_chk_fail_decl
;
527 t
= build_function_type_list (void_type_node
, NULL_TREE
);
528 t
= build_decl (UNKNOWN_LOCATION
,
529 FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
532 DECL_EXTERNAL (t
) = 1;
534 TREE_THIS_VOLATILE (t
) = 1;
535 TREE_NOTHROW (t
) = 1;
536 DECL_ARTIFICIAL (t
) = 1;
537 DECL_IGNORED_P (t
) = 1;
538 DECL_VISIBILITY (t
) = VISIBILITY_DEFAULT
;
539 DECL_VISIBILITY_SPECIFIED (t
) = 1;
541 stack_chk_fail_decl
= t
;
544 return build_call_expr (t
, 0);
548 default_hidden_stack_protect_fail (void)
550 #ifndef HAVE_GAS_HIDDEN
551 return default_external_stack_protect_fail ();
553 tree t
= stack_chk_fail_decl
;
556 return default_external_stack_protect_fail ();
560 t
= build_function_type_list (void_type_node
, NULL_TREE
);
561 t
= build_decl (UNKNOWN_LOCATION
, FUNCTION_DECL
,
562 get_identifier ("__stack_chk_fail_local"), t
);
565 DECL_EXTERNAL (t
) = 1;
567 TREE_THIS_VOLATILE (t
) = 1;
568 TREE_NOTHROW (t
) = 1;
569 DECL_ARTIFICIAL (t
) = 1;
570 DECL_IGNORED_P (t
) = 1;
571 DECL_VISIBILITY_SPECIFIED (t
) = 1;
572 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
574 stack_chk_fail_decl
= t
;
577 return build_call_expr (t
, 0);
582 hook_bool_const_rtx_commutative_p (const_rtx x
,
583 int outer_code ATTRIBUTE_UNUSED
)
585 return COMMUTATIVE_P (x
);
589 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED
,
590 const_tree fn_decl_or_type
,
591 bool outgoing ATTRIBUTE_UNUSED
)
593 /* The old interface doesn't handle receiving the function type. */
595 && !DECL_P (fn_decl_or_type
))
596 fn_decl_or_type
= NULL
;
598 #ifdef FUNCTION_OUTGOING_VALUE
600 return FUNCTION_OUTGOING_VALUE (ret_type
, fn_decl_or_type
);
603 #ifdef FUNCTION_VALUE
604 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
611 default_libcall_value (enum machine_mode mode
, rtx fun ATTRIBUTE_UNUSED
)
613 return LIBCALL_VALUE (mode
);
617 default_internal_arg_pointer (void)
619 /* If the reg that the virtual arg pointer will be translated into is
620 not a fixed reg or is the stack pointer, make a copy of the virtual
621 arg pointer, and address parms via the copy. The frame pointer is
622 considered fixed even though it is not marked as such. */
623 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
624 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
625 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
626 return copy_to_reg (virtual_incoming_args_rtx
);
628 return virtual_incoming_args_rtx
;
632 default_static_chain (const_tree fndecl
, bool incoming_p
)
634 if (!DECL_STATIC_CHAIN (fndecl
))
639 #ifdef STATIC_CHAIN_INCOMING_REGNUM
640 return gen_rtx_REG (Pmode
, STATIC_CHAIN_INCOMING_REGNUM
);
644 #ifdef STATIC_CHAIN_REGNUM
645 return gen_rtx_REG (Pmode
, STATIC_CHAIN_REGNUM
);
649 static bool issued_error
;
653 sorry ("nested functions not supported on this target");
656 /* It really doesn't matter what we return here, so long at it
657 doesn't cause the rest of the compiler to crash. */
658 return gen_rtx_MEM (Pmode
, stack_pointer_rtx
);
663 default_trampoline_init (rtx
ARG_UNUSED (m_tramp
), tree
ARG_UNUSED (t_func
),
664 rtx
ARG_UNUSED (r_chain
))
666 sorry ("nested function trampolines not supported on this target");
670 default_branch_target_register_class (void)
675 #ifdef IRA_COVER_CLASSES
676 const enum reg_class
*
677 default_ira_cover_classes (void)
679 static enum reg_class classes
[] = IRA_COVER_CLASSES
;
685 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
686 enum reg_class reload_class ATTRIBUTE_UNUSED
,
687 enum machine_mode reload_mode ATTRIBUTE_UNUSED
,
688 secondary_reload_info
*sri
)
690 enum reg_class rclass
= NO_REGS
;
692 if (sri
->prev_sri
&& sri
->prev_sri
->t_icode
!= CODE_FOR_nothing
)
694 sri
->icode
= sri
->prev_sri
->t_icode
;
697 #ifdef SECONDARY_INPUT_RELOAD_CLASS
699 rclass
= SECONDARY_INPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
701 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
703 rclass
= SECONDARY_OUTPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
705 if (rclass
!= NO_REGS
)
707 enum insn_code icode
= (in_p
? reload_in_optab
[(int) reload_mode
]
708 : reload_out_optab
[(int) reload_mode
]);
710 if (icode
!= CODE_FOR_nothing
711 && insn_data
[(int) icode
].operand
[in_p
].predicate
712 && ! insn_data
[(int) icode
].operand
[in_p
].predicate (x
, reload_mode
))
713 icode
= CODE_FOR_nothing
;
714 else if (icode
!= CODE_FOR_nothing
)
716 const char *insn_constraint
, *scratch_constraint
;
717 char insn_letter
, scratch_letter
;
718 enum reg_class insn_class
, scratch_class
;
720 gcc_assert (insn_data
[(int) icode
].n_operands
== 3);
721 insn_constraint
= insn_data
[(int) icode
].operand
[!in_p
].constraint
;
722 if (!*insn_constraint
)
723 insn_class
= ALL_REGS
;
728 gcc_assert (*insn_constraint
== '=');
731 insn_letter
= *insn_constraint
;
733 = (insn_letter
== 'r' ? GENERAL_REGS
734 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter
,
736 gcc_assert (insn_class
!= NO_REGS
);
739 scratch_constraint
= insn_data
[(int) icode
].operand
[2].constraint
;
740 /* The scratch register's constraint must start with "=&",
741 except for an input reload, where only "=" is necessary,
742 and where it might be beneficial to re-use registers from
744 gcc_assert (scratch_constraint
[0] == '='
745 && (in_p
|| scratch_constraint
[1] == '&'));
746 scratch_constraint
++;
747 if (*scratch_constraint
== '&')
748 scratch_constraint
++;
749 scratch_letter
= *scratch_constraint
;
751 = (scratch_letter
== 'r' ? GENERAL_REGS
752 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter
,
753 scratch_constraint
));
755 if (reg_class_subset_p (reload_class
, insn_class
))
757 gcc_assert (scratch_class
== rclass
);
764 if (rclass
== NO_REGS
)
767 sri
->t_icode
= icode
;
773 default_handle_c_option (size_t code ATTRIBUTE_UNUSED
,
774 const char *arg ATTRIBUTE_UNUSED
,
775 int value ATTRIBUTE_UNUSED
)
780 /* By default, if flag_pic is true, then neither local nor global relocs
781 should be placed in readonly memory. */
784 default_reloc_rw_mask (void)
786 return flag_pic
? 3 : 0;
789 /* By default, do no modification. */
790 tree
default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED
,
797 default_builtin_vector_alignment_reachable (const_tree type
, bool is_packed
)
802 /* Assuming that types whose size is > pointer-size are not guaranteed to be
803 naturally aligned. */
804 if (tree_int_cst_compare (TYPE_SIZE (type
), bitsize_int (POINTER_SIZE
)) > 0)
807 /* Assuming that types whose size is <= pointer-size
808 are naturally aligned. */
812 /* By default, assume that a target supports any factor of misalignment
813 memory access if it supports movmisalign patten.
814 is_packed is true if the memory access is defined in a packed struct. */
816 default_builtin_support_vector_misalignment (enum machine_mode mode
,
824 if (optab_handler (movmisalign_optab
, mode
)->insn_code
!= CODE_FOR_nothing
)
830 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED
)
836 default_target_option_valid_attribute_p (tree
ARG_UNUSED (fndecl
),
837 tree
ARG_UNUSED (name
),
838 tree
ARG_UNUSED (args
),
839 int ARG_UNUSED (flags
))
841 warning (OPT_Wattributes
,
842 "target attribute is not supported on this machine");
848 default_target_option_pragma_parse (tree
ARG_UNUSED (args
),
849 tree
ARG_UNUSED (pop_target
))
851 warning (OPT_Wpragmas
,
852 "#pragma GCC target is not supported for this machine");
858 default_target_can_inline_p (tree caller
, tree callee
)
861 tree callee_opts
= DECL_FUNCTION_SPECIFIC_TARGET (callee
);
862 tree caller_opts
= DECL_FUNCTION_SPECIFIC_TARGET (caller
);
864 /* If callee has no option attributes, then it is ok to inline */
868 /* If caller has no option attributes, but callee does then it is not ok to
870 else if (!caller_opts
)
873 /* If both caller and callee have attributes, assume that if the pointer is
874 different, the the two functions have different target options since
875 build_target_option_node uses a hash table for the options. */
877 ret
= (callee_opts
== caller_opts
);
883 # define HAVE_casesi 0
886 /* If the machine does not have a case insn that compares the bounds,
887 this means extra overhead for dispatch tables, which raises the
888 threshold for using them. */
890 unsigned int default_case_values_threshold (void)
892 return (HAVE_casesi
? 4 : 5);
895 #include "gt-targhooks.h"