1 /* Default target hook functions.
2 Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* The migration of target macros to target hooks works as follows:
22 1. Create a target hook that uses the existing target macros to
23 implement the same functionality.
25 2. Convert all the MI files to use the hook instead of the macro.
27 3. Repeat for a majority of the remaining target macros. This will
30 4. Tell target maintainers to start migrating.
32 5. Eventually convert the backends to override the hook instead of
33 defining the macros. This will take some time too.
35 6. TBD when, poison the macros. Unmigrated targets will break at
38 Note that we expect steps 1-3 to be done by the people that
39 understand what the MI does with each macro, and step 5 to be done
40 by the target maintainers for their respective targets.
42 Note that steps 1 and 2 don't have to be done together, but no
43 target can override the new hook until step 2 is complete for it.
45 Once the macros are poisoned, we will revert to the old migration
46 rules - migrate the macro, callers, and targets all at once. This
47 comment can thus be removed at that point. */
51 #include "coretypes.h"
62 #include "target-def.h"
64 #include "hard-reg-set.h"
71 default_external_libcall (rtx fun ATTRIBUTE_UNUSED
)
73 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
74 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file
, fun
);
79 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
87 default_return_in_memory (const_tree type
,
88 const_tree fntype ATTRIBUTE_UNUSED
)
90 #ifndef RETURN_IN_MEMORY
91 return (TYPE_MODE (type
) == BLKmode
);
93 return RETURN_IN_MEMORY (type
);
98 default_expand_builtin_saveregs (void)
100 error ("__builtin_saveregs not supported by this target");
105 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
106 enum machine_mode mode ATTRIBUTE_UNUSED
,
107 tree type ATTRIBUTE_UNUSED
,
108 int *pretend_arg_size ATTRIBUTE_UNUSED
,
109 int second_time ATTRIBUTE_UNUSED
)
113 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
116 default_builtin_setjmp_frame_value (void)
118 return virtual_stack_vars_rtx
;
121 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
124 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
130 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
132 return (targetm
.calls
.setup_incoming_varargs
133 != default_setup_incoming_varargs
);
137 default_eh_return_filter_mode (void)
143 default_libgcc_cmp_return_mode (void)
149 default_libgcc_shift_count_mode (void)
154 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
156 unsigned HOST_WIDE_INT
157 default_shift_truncation_mask (enum machine_mode mode
)
159 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
162 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
165 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED
)
167 return have_insn_for (DIV
, mode
) ? 3 : 2;
170 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
173 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED
,
174 enum machine_mode mode_rep ATTRIBUTE_UNUSED
)
179 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
182 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
187 /* Return machine mode for non-standard suffix
188 or VOIDmode if non-standard suffixes are unsupported. */
190 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED
)
195 /* The generic C++ ABI specifies this is a 64-bit value. */
197 default_cxx_guard_type (void)
199 return long_long_integer_type_node
;
203 /* Returns the size of the cookie to use when allocating an array
204 whose elements have the indicated TYPE. Assumes that it is already
205 known that a cookie is needed. */
208 default_cxx_get_cookie_size (tree type
)
212 /* We need to allocate an additional max (sizeof (size_t), alignof
213 (true_type)) bytes. */
217 sizetype_size
= size_in_bytes (sizetype
);
218 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
219 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
220 cookie_size
= sizetype_size
;
222 cookie_size
= type_align
;
227 /* Return true if a parameter must be passed by reference. This version
228 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
231 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
232 enum machine_mode mode ATTRIBUTE_UNUSED
, const_tree type ATTRIBUTE_UNUSED
,
233 bool named_arg ATTRIBUTE_UNUSED
)
235 return targetm
.calls
.must_pass_in_stack (mode
, type
);
238 /* Return true if a parameter follows callee copies conventions. This
239 version of the hook is true for all named arguments. */
242 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
243 enum machine_mode mode ATTRIBUTE_UNUSED
,
244 const_tree type ATTRIBUTE_UNUSED
, bool named
)
249 /* Emit any directives required to unwind this instruction. */
252 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
253 rtx insn ATTRIBUTE_UNUSED
)
255 /* Should never happen. */
259 /* True if MODE is valid for the target. By "valid", we mean able to
260 be manipulated in non-trivial ways. In particular, this means all
261 the arithmetic is supported.
263 By default we guess this means that any C type is supported. If
264 we can't map the mode back to a type that would be available in C,
265 then reject it. Special case, here, is the double-word arithmetic
266 supported by optabs.c. */
269 default_scalar_mode_supported_p (enum machine_mode mode
)
271 int precision
= GET_MODE_PRECISION (mode
);
273 switch (GET_MODE_CLASS (mode
))
275 case MODE_PARTIAL_INT
:
277 if (precision
== CHAR_TYPE_SIZE
)
279 if (precision
== SHORT_TYPE_SIZE
)
281 if (precision
== INT_TYPE_SIZE
)
283 if (precision
== LONG_TYPE_SIZE
)
285 if (precision
== LONG_LONG_TYPE_SIZE
)
287 if (precision
== 2 * BITS_PER_WORD
)
292 if (precision
== FLOAT_TYPE_SIZE
)
294 if (precision
== DOUBLE_TYPE_SIZE
)
296 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
300 case MODE_DECIMAL_FLOAT
:
312 /* True if the target supports decimal floating point. */
315 default_decimal_float_supported_p (void)
317 return ENABLE_DECIMAL_FLOAT
;
320 /* True if the target supports fixed-point arithmetic. */
323 default_fixed_point_supported_p (void)
325 return ENABLE_FIXED_POINT
;
328 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
331 This function checks whether a given INSN is valid within a low-overhead
332 loop. If INSN is invalid it returns the reason for that, otherwise it
333 returns NULL. A called function may clobber any special registers required
334 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
335 register for branch on table instructions. We reject the doloop pattern in
339 default_invalid_within_doloop (const_rtx insn
)
342 return "Function call in loop.";
345 && (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
346 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
))
347 return "Computed branch in the loop.";
352 /* Mapping of builtin functions to vectorized variants. */
355 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED
,
356 tree type_out ATTRIBUTE_UNUSED
,
357 tree type_in ATTRIBUTE_UNUSED
)
362 /* Vectorized conversion. */
365 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED
,
366 tree type ATTRIBUTE_UNUSED
)
374 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED
,
375 bool md_fn ATTRIBUTE_UNUSED
,
376 bool sqrt ATTRIBUTE_UNUSED
)
382 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
383 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
384 enum machine_mode mode ATTRIBUTE_UNUSED
,
385 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
391 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
392 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
393 enum machine_mode mode ATTRIBUTE_UNUSED
,
394 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
400 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
401 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
402 enum machine_mode mode ATTRIBUTE_UNUSED
,
403 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
409 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED
)
414 hook_invalid_arg_for_unprototyped_fn (
415 const_tree typelist ATTRIBUTE_UNUSED
,
416 const_tree funcdecl ATTRIBUTE_UNUSED
,
417 const_tree val ATTRIBUTE_UNUSED
)
422 /* Initialize the stack protection decls. */
424 /* Stack protection related decls living in libgcc. */
425 static GTY(()) tree stack_chk_guard_decl
;
428 default_stack_protect_guard (void)
430 tree t
= stack_chk_guard_decl
;
434 t
= build_decl (VAR_DECL
, get_identifier ("__stack_chk_guard"),
438 DECL_EXTERNAL (t
) = 1;
440 TREE_THIS_VOLATILE (t
) = 1;
441 DECL_ARTIFICIAL (t
) = 1;
442 DECL_IGNORED_P (t
) = 1;
444 stack_chk_guard_decl
= t
;
450 static GTY(()) tree stack_chk_fail_decl
;
453 default_external_stack_protect_fail (void)
455 tree t
= stack_chk_fail_decl
;
459 t
= build_function_type_list (void_type_node
, NULL_TREE
);
460 t
= build_decl (FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
463 DECL_EXTERNAL (t
) = 1;
465 TREE_THIS_VOLATILE (t
) = 1;
466 TREE_NOTHROW (t
) = 1;
467 DECL_ARTIFICIAL (t
) = 1;
468 DECL_IGNORED_P (t
) = 1;
469 DECL_VISIBILITY (t
) = VISIBILITY_DEFAULT
;
470 DECL_VISIBILITY_SPECIFIED (t
) = 1;
472 stack_chk_fail_decl
= t
;
475 return build_call_expr (t
, 0);
479 default_hidden_stack_protect_fail (void)
481 #ifndef HAVE_GAS_HIDDEN
482 return default_external_stack_protect_fail ();
484 tree t
= stack_chk_fail_decl
;
487 return default_external_stack_protect_fail ();
491 t
= build_function_type_list (void_type_node
, NULL_TREE
);
492 t
= build_decl (FUNCTION_DECL
,
493 get_identifier ("__stack_chk_fail_local"), t
);
496 DECL_EXTERNAL (t
) = 1;
498 TREE_THIS_VOLATILE (t
) = 1;
499 TREE_NOTHROW (t
) = 1;
500 DECL_ARTIFICIAL (t
) = 1;
501 DECL_IGNORED_P (t
) = 1;
502 DECL_VISIBILITY_SPECIFIED (t
) = 1;
503 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
505 stack_chk_fail_decl
= t
;
508 return build_call_expr (t
, 0);
513 hook_bool_const_rtx_commutative_p (const_rtx x
,
514 int outer_code ATTRIBUTE_UNUSED
)
516 return COMMUTATIVE_P (x
);
520 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED
,
521 const_tree fn_decl_or_type
,
522 bool outgoing ATTRIBUTE_UNUSED
)
524 /* The old interface doesn't handle receiving the function type. */
526 && !DECL_P (fn_decl_or_type
))
527 fn_decl_or_type
= NULL
;
529 #ifdef FUNCTION_OUTGOING_VALUE
531 return FUNCTION_OUTGOING_VALUE (ret_type
, fn_decl_or_type
);
534 #ifdef FUNCTION_VALUE
535 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
542 default_internal_arg_pointer (void)
544 /* If the reg that the virtual arg pointer will be translated into is
545 not a fixed reg or is the stack pointer, make a copy of the virtual
546 arg pointer, and address parms via the copy. The frame pointer is
547 considered fixed even though it is not marked as such. */
548 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
549 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
550 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
551 return copy_to_reg (virtual_incoming_args_rtx
);
553 return virtual_incoming_args_rtx
;
557 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
558 enum reg_class reload_class ATTRIBUTE_UNUSED
,
559 enum machine_mode reload_mode ATTRIBUTE_UNUSED
,
560 secondary_reload_info
*sri
)
562 enum reg_class
class = NO_REGS
;
564 if (sri
->prev_sri
&& sri
->prev_sri
->t_icode
!= CODE_FOR_nothing
)
566 sri
->icode
= sri
->prev_sri
->t_icode
;
569 #ifdef SECONDARY_INPUT_RELOAD_CLASS
571 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
573 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
575 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
577 if (class != NO_REGS
)
579 enum insn_code icode
= (in_p
? reload_in_optab
[(int) reload_mode
]
580 : reload_out_optab
[(int) reload_mode
]);
582 if (icode
!= CODE_FOR_nothing
583 && insn_data
[(int) icode
].operand
[in_p
].predicate
584 && ! insn_data
[(int) icode
].operand
[in_p
].predicate (x
, reload_mode
))
585 icode
= CODE_FOR_nothing
;
586 else if (icode
!= CODE_FOR_nothing
)
588 const char *insn_constraint
, *scratch_constraint
;
589 char insn_letter
, scratch_letter
;
590 enum reg_class insn_class
, scratch_class
;
592 gcc_assert (insn_data
[(int) icode
].n_operands
== 3);
593 insn_constraint
= insn_data
[(int) icode
].operand
[!in_p
].constraint
;
594 if (!*insn_constraint
)
595 insn_class
= ALL_REGS
;
600 gcc_assert (*insn_constraint
== '=');
603 insn_letter
= *insn_constraint
;
605 = (insn_letter
== 'r' ? GENERAL_REGS
606 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter
,
608 gcc_assert (insn_class
!= NO_REGS
);
611 scratch_constraint
= insn_data
[(int) icode
].operand
[2].constraint
;
612 /* The scratch register's constraint must start with "=&",
613 except for an input reload, where only "=" is necessary,
614 and where it might be beneficial to re-use registers from
616 gcc_assert (scratch_constraint
[0] == '='
617 && (in_p
|| scratch_constraint
[1] == '&'));
618 scratch_constraint
++;
619 if (*scratch_constraint
== '&')
620 scratch_constraint
++;
621 scratch_letter
= *scratch_constraint
;
623 = (scratch_letter
== 'r' ? GENERAL_REGS
624 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter
,
625 scratch_constraint
));
627 if (reg_class_subset_p (reload_class
, insn_class
))
629 gcc_assert (scratch_class
== class);
636 if (class == NO_REGS
)
639 sri
->t_icode
= icode
;
645 default_handle_c_option (size_t code ATTRIBUTE_UNUSED
,
646 const char *arg ATTRIBUTE_UNUSED
,
647 int value ATTRIBUTE_UNUSED
)
652 /* By default, if flag_pic is true, then neither local nor global relocs
653 should be placed in readonly memory. */
656 default_reloc_rw_mask (void)
658 return flag_pic
? 3 : 0;
661 /* By default, do no modification. */
662 tree
default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED
,
669 default_builtin_vector_alignment_reachable (const_tree type
, bool is_packed
)
674 /* Assuming that types whose size is > pointer-size are not guaranteed to be
675 naturally aligned. */
676 if (tree_int_cst_compare (TYPE_SIZE (type
), bitsize_int (POINTER_SIZE
)) > 0)
679 /* Assuming that types whose size is <= pointer-size
680 are naturally aligned. */
684 #include "gt-targhooks.h"