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_unspec_may_trap_p (const_rtx x
, unsigned flags
)
83 if (GET_CODE (x
) == UNSPEC_VOLATILE
84 /* Any floating arithmetic may trap. */
85 || (SCALAR_FLOAT_MODE_P (GET_MODE (x
))
86 && flag_trapping_math
))
89 for (i
= 0; i
< XVECLEN (x
, 0); ++i
)
91 if (may_trap_p_1 (XVECEXP (x
, 0, i
), flags
))
99 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
107 default_return_in_memory (const_tree type
,
108 const_tree fntype ATTRIBUTE_UNUSED
)
110 return (TYPE_MODE (type
) == BLKmode
);
114 default_expand_builtin_saveregs (void)
116 error ("__builtin_saveregs not supported by this target");
121 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
122 enum machine_mode mode ATTRIBUTE_UNUSED
,
123 tree type ATTRIBUTE_UNUSED
,
124 int *pretend_arg_size ATTRIBUTE_UNUSED
,
125 int second_time ATTRIBUTE_UNUSED
)
129 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
132 default_builtin_setjmp_frame_value (void)
134 return virtual_stack_vars_rtx
;
137 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
140 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
146 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
148 return (targetm
.calls
.setup_incoming_varargs
149 != default_setup_incoming_varargs
);
153 default_eh_return_filter_mode (void)
159 default_libgcc_cmp_return_mode (void)
165 default_libgcc_shift_count_mode (void)
170 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
172 unsigned HOST_WIDE_INT
173 default_shift_truncation_mask (enum machine_mode mode
)
175 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
178 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
181 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED
)
183 return have_insn_for (DIV
, mode
) ? 3 : 2;
186 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
189 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED
,
190 enum machine_mode mode_rep ATTRIBUTE_UNUSED
)
195 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
198 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
203 /* Return machine mode for non-standard suffix
204 or VOIDmode if non-standard suffixes are unsupported. */
206 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED
)
211 /* The generic C++ ABI specifies this is a 64-bit value. */
213 default_cxx_guard_type (void)
215 return long_long_integer_type_node
;
219 /* Returns the size of the cookie to use when allocating an array
220 whose elements have the indicated TYPE. Assumes that it is already
221 known that a cookie is needed. */
224 default_cxx_get_cookie_size (tree type
)
228 /* We need to allocate an additional max (sizeof (size_t), alignof
229 (true_type)) bytes. */
233 sizetype_size
= size_in_bytes (sizetype
);
234 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
235 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
236 cookie_size
= sizetype_size
;
238 cookie_size
= type_align
;
243 /* Return true if a parameter must be passed by reference. This version
244 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
247 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
248 enum machine_mode mode ATTRIBUTE_UNUSED
, const_tree type ATTRIBUTE_UNUSED
,
249 bool named_arg ATTRIBUTE_UNUSED
)
251 return targetm
.calls
.must_pass_in_stack (mode
, type
);
254 /* Return true if a parameter follows callee copies conventions. This
255 version of the hook is true for all named arguments. */
258 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
259 enum machine_mode mode ATTRIBUTE_UNUSED
,
260 const_tree type ATTRIBUTE_UNUSED
, bool named
)
265 /* Emit any directives required to unwind this instruction. */
268 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
269 rtx insn ATTRIBUTE_UNUSED
)
271 /* Should never happen. */
275 /* True if MODE is valid for the target. By "valid", we mean able to
276 be manipulated in non-trivial ways. In particular, this means all
277 the arithmetic is supported.
279 By default we guess this means that any C type is supported. If
280 we can't map the mode back to a type that would be available in C,
281 then reject it. Special case, here, is the double-word arithmetic
282 supported by optabs.c. */
285 default_scalar_mode_supported_p (enum machine_mode mode
)
287 int precision
= GET_MODE_PRECISION (mode
);
289 switch (GET_MODE_CLASS (mode
))
291 case MODE_PARTIAL_INT
:
293 if (precision
== CHAR_TYPE_SIZE
)
295 if (precision
== SHORT_TYPE_SIZE
)
297 if (precision
== INT_TYPE_SIZE
)
299 if (precision
== LONG_TYPE_SIZE
)
301 if (precision
== LONG_LONG_TYPE_SIZE
)
303 if (precision
== 2 * BITS_PER_WORD
)
308 if (precision
== FLOAT_TYPE_SIZE
)
310 if (precision
== DOUBLE_TYPE_SIZE
)
312 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
316 case MODE_DECIMAL_FLOAT
:
328 /* True if the target supports decimal floating point. */
331 default_decimal_float_supported_p (void)
333 return ENABLE_DECIMAL_FLOAT
;
336 /* True if the target supports fixed-point arithmetic. */
339 default_fixed_point_supported_p (void)
341 return ENABLE_FIXED_POINT
;
344 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
347 This function checks whether a given INSN is valid within a low-overhead
348 loop. If INSN is invalid it returns the reason for that, otherwise it
349 returns NULL. A called function may clobber any special registers required
350 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
351 register for branch on table instructions. We reject the doloop pattern in
355 default_invalid_within_doloop (const_rtx insn
)
358 return "Function call in loop.";
361 && (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
362 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
))
363 return "Computed branch in the loop.";
368 /* Mapping of builtin functions to vectorized variants. */
371 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED
,
372 tree type_out ATTRIBUTE_UNUSED
,
373 tree type_in ATTRIBUTE_UNUSED
)
378 /* Vectorized conversion. */
381 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED
,
382 tree type ATTRIBUTE_UNUSED
)
390 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED
,
391 bool md_fn ATTRIBUTE_UNUSED
,
392 bool sqrt ATTRIBUTE_UNUSED
)
398 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
399 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
400 enum machine_mode mode ATTRIBUTE_UNUSED
,
401 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
407 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
408 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
409 enum machine_mode mode ATTRIBUTE_UNUSED
,
410 const_tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
416 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
417 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
418 enum machine_mode mode ATTRIBUTE_UNUSED
,
419 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
425 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED
)
430 hook_invalid_arg_for_unprototyped_fn (
431 const_tree typelist ATTRIBUTE_UNUSED
,
432 const_tree funcdecl ATTRIBUTE_UNUSED
,
433 const_tree val ATTRIBUTE_UNUSED
)
438 /* Initialize the stack protection decls. */
440 /* Stack protection related decls living in libgcc. */
441 static GTY(()) tree stack_chk_guard_decl
;
444 default_stack_protect_guard (void)
446 tree t
= stack_chk_guard_decl
;
450 t
= build_decl (VAR_DECL
, get_identifier ("__stack_chk_guard"),
454 DECL_EXTERNAL (t
) = 1;
456 TREE_THIS_VOLATILE (t
) = 1;
457 DECL_ARTIFICIAL (t
) = 1;
458 DECL_IGNORED_P (t
) = 1;
460 stack_chk_guard_decl
= t
;
466 static GTY(()) tree stack_chk_fail_decl
;
469 default_external_stack_protect_fail (void)
471 tree t
= stack_chk_fail_decl
;
475 t
= build_function_type_list (void_type_node
, NULL_TREE
);
476 t
= build_decl (FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
479 DECL_EXTERNAL (t
) = 1;
481 TREE_THIS_VOLATILE (t
) = 1;
482 TREE_NOTHROW (t
) = 1;
483 DECL_ARTIFICIAL (t
) = 1;
484 DECL_IGNORED_P (t
) = 1;
485 DECL_VISIBILITY (t
) = VISIBILITY_DEFAULT
;
486 DECL_VISIBILITY_SPECIFIED (t
) = 1;
488 stack_chk_fail_decl
= t
;
491 return build_call_expr (t
, 0);
495 default_hidden_stack_protect_fail (void)
497 #ifndef HAVE_GAS_HIDDEN
498 return default_external_stack_protect_fail ();
500 tree t
= stack_chk_fail_decl
;
503 return default_external_stack_protect_fail ();
507 t
= build_function_type_list (void_type_node
, NULL_TREE
);
508 t
= build_decl (FUNCTION_DECL
,
509 get_identifier ("__stack_chk_fail_local"), t
);
512 DECL_EXTERNAL (t
) = 1;
514 TREE_THIS_VOLATILE (t
) = 1;
515 TREE_NOTHROW (t
) = 1;
516 DECL_ARTIFICIAL (t
) = 1;
517 DECL_IGNORED_P (t
) = 1;
518 DECL_VISIBILITY_SPECIFIED (t
) = 1;
519 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
521 stack_chk_fail_decl
= t
;
524 return build_call_expr (t
, 0);
529 hook_bool_const_rtx_commutative_p (const_rtx x
,
530 int outer_code ATTRIBUTE_UNUSED
)
532 return COMMUTATIVE_P (x
);
536 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED
,
537 const_tree fn_decl_or_type
,
538 bool outgoing ATTRIBUTE_UNUSED
)
540 /* The old interface doesn't handle receiving the function type. */
542 && !DECL_P (fn_decl_or_type
))
543 fn_decl_or_type
= NULL
;
545 #ifdef FUNCTION_OUTGOING_VALUE
547 return FUNCTION_OUTGOING_VALUE (ret_type
, fn_decl_or_type
);
550 #ifdef FUNCTION_VALUE
551 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
558 default_internal_arg_pointer (void)
560 /* If the reg that the virtual arg pointer will be translated into is
561 not a fixed reg or is the stack pointer, make a copy of the virtual
562 arg pointer, and address parms via the copy. The frame pointer is
563 considered fixed even though it is not marked as such. */
564 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
565 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
566 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
567 return copy_to_reg (virtual_incoming_args_rtx
);
569 return virtual_incoming_args_rtx
;
573 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
574 enum reg_class reload_class ATTRIBUTE_UNUSED
,
575 enum machine_mode reload_mode ATTRIBUTE_UNUSED
,
576 secondary_reload_info
*sri
)
578 enum reg_class
class = NO_REGS
;
580 if (sri
->prev_sri
&& sri
->prev_sri
->t_icode
!= CODE_FOR_nothing
)
582 sri
->icode
= sri
->prev_sri
->t_icode
;
585 #ifdef SECONDARY_INPUT_RELOAD_CLASS
587 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
589 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
591 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class
, reload_mode
, x
);
593 if (class != NO_REGS
)
595 enum insn_code icode
= (in_p
? reload_in_optab
[(int) reload_mode
]
596 : reload_out_optab
[(int) reload_mode
]);
598 if (icode
!= CODE_FOR_nothing
599 && insn_data
[(int) icode
].operand
[in_p
].predicate
600 && ! insn_data
[(int) icode
].operand
[in_p
].predicate (x
, reload_mode
))
601 icode
= CODE_FOR_nothing
;
602 else if (icode
!= CODE_FOR_nothing
)
604 const char *insn_constraint
, *scratch_constraint
;
605 char insn_letter
, scratch_letter
;
606 enum reg_class insn_class
, scratch_class
;
608 gcc_assert (insn_data
[(int) icode
].n_operands
== 3);
609 insn_constraint
= insn_data
[(int) icode
].operand
[!in_p
].constraint
;
610 if (!*insn_constraint
)
611 insn_class
= ALL_REGS
;
616 gcc_assert (*insn_constraint
== '=');
619 insn_letter
= *insn_constraint
;
621 = (insn_letter
== 'r' ? GENERAL_REGS
622 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter
,
624 gcc_assert (insn_class
!= NO_REGS
);
627 scratch_constraint
= insn_data
[(int) icode
].operand
[2].constraint
;
628 /* The scratch register's constraint must start with "=&",
629 except for an input reload, where only "=" is necessary,
630 and where it might be beneficial to re-use registers from
632 gcc_assert (scratch_constraint
[0] == '='
633 && (in_p
|| scratch_constraint
[1] == '&'));
634 scratch_constraint
++;
635 if (*scratch_constraint
== '&')
636 scratch_constraint
++;
637 scratch_letter
= *scratch_constraint
;
639 = (scratch_letter
== 'r' ? GENERAL_REGS
640 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter
,
641 scratch_constraint
));
643 if (reg_class_subset_p (reload_class
, insn_class
))
645 gcc_assert (scratch_class
== class);
652 if (class == NO_REGS
)
655 sri
->t_icode
= icode
;
661 default_handle_c_option (size_t code ATTRIBUTE_UNUSED
,
662 const char *arg ATTRIBUTE_UNUSED
,
663 int value ATTRIBUTE_UNUSED
)
668 /* By default, if flag_pic is true, then neither local nor global relocs
669 should be placed in readonly memory. */
672 default_reloc_rw_mask (void)
674 return flag_pic
? 3 : 0;
677 /* By default, do no modification. */
678 tree
default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED
,
685 default_builtin_vector_alignment_reachable (const_tree type
, bool is_packed
)
690 /* Assuming that types whose size is > pointer-size are not guaranteed to be
691 naturally aligned. */
692 if (tree_int_cst_compare (TYPE_SIZE (type
), bitsize_int (POINTER_SIZE
)) > 0)
695 /* Assuming that types whose size is <= pointer-size
696 are naturally aligned. */
700 #include "gt-targhooks.h"