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 2, 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 COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
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_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
88 default_return_in_memory (tree type,
89 tree fntype ATTRIBUTE_UNUSED)
91 #ifndef RETURN_IN_MEMORY
92 return (TYPE_MODE (type) == BLKmode);
94 return RETURN_IN_MEMORY (type);
99 default_expand_builtin_saveregs (void)
101 error ("__builtin_saveregs not supported by this target");
106 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
107 enum machine_mode mode ATTRIBUTE_UNUSED,
108 tree type ATTRIBUTE_UNUSED,
109 int *pretend_arg_size ATTRIBUTE_UNUSED,
110 int second_time ATTRIBUTE_UNUSED)
114 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
117 default_builtin_setjmp_frame_value (void)
119 return virtual_stack_vars_rtx;
122 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
125 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
131 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
133 return (targetm.calls.setup_incoming_varargs
134 != default_setup_incoming_varargs);
138 default_eh_return_filter_mode (void)
144 default_libgcc_cmp_return_mode (void)
150 default_libgcc_shift_count_mode (void)
155 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
157 unsigned HOST_WIDE_INT
158 default_shift_truncation_mask (enum machine_mode mode)
160 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
163 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
166 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
168 return have_insn_for (DIV, mode) ? 3 : 2;
171 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
174 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
175 enum machine_mode mode_rep ATTRIBUTE_UNUSED)
180 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
183 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
188 /* Return machine mode for non-standard suffix
189 or VOIDmode if non-standard suffixes are unsupported. */
191 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
196 /* The generic C++ ABI specifies this is a 64-bit value. */
198 default_cxx_guard_type (void)
200 return long_long_integer_type_node;
204 /* Returns the size of the cookie to use when allocating an array
205 whose elements have the indicated TYPE. Assumes that it is already
206 known that a cookie is needed. */
209 default_cxx_get_cookie_size (tree type)
213 /* We need to allocate an additional max (sizeof (size_t), alignof
214 (true_type)) bytes. */
218 sizetype_size = size_in_bytes (sizetype);
219 type_align = size_int (TYPE_ALIGN_UNIT (type));
220 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
221 cookie_size = sizetype_size;
223 cookie_size = type_align;
228 /* Return true if a parameter must be passed by reference. This version
229 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
232 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
233 enum machine_mode mode ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED,
234 bool named_arg ATTRIBUTE_UNUSED)
236 return targetm.calls.must_pass_in_stack (mode, type);
239 /* Return true if a parameter follows callee copies conventions. This
240 version of the hook is true for all named arguments. */
243 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
244 enum machine_mode mode ATTRIBUTE_UNUSED,
245 tree type ATTRIBUTE_UNUSED, bool named)
250 /* Emit any directives required to unwind this instruction. */
253 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
254 rtx insn ATTRIBUTE_UNUSED)
256 /* Should never happen. */
260 /* True if MODE is valid for the target. By "valid", we mean able to
261 be manipulated in non-trivial ways. In particular, this means all
262 the arithmetic is supported.
264 By default we guess this means that any C type is supported. If
265 we can't map the mode back to a type that would be available in C,
266 then reject it. Special case, here, is the double-word arithmetic
267 supported by optabs.c. */
270 default_scalar_mode_supported_p (enum machine_mode mode)
272 int precision = GET_MODE_PRECISION (mode);
274 switch (GET_MODE_CLASS (mode))
276 case MODE_PARTIAL_INT:
278 if (precision == CHAR_TYPE_SIZE)
280 if (precision == SHORT_TYPE_SIZE)
282 if (precision == INT_TYPE_SIZE)
284 if (precision == LONG_TYPE_SIZE)
286 if (precision == LONG_LONG_TYPE_SIZE)
288 if (precision == 2 * BITS_PER_WORD)
293 if (precision == FLOAT_TYPE_SIZE)
295 if (precision == DOUBLE_TYPE_SIZE)
297 if (precision == LONG_DOUBLE_TYPE_SIZE)
301 case MODE_DECIMAL_FLOAT:
309 /* True if the target supports decimal floating point. */
312 default_decimal_float_supported_p (void)
314 return ENABLE_DECIMAL_FLOAT;
317 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
320 This function checks whether a given INSN is valid within a low-overhead
321 loop. If INSN is invalid it returns the reason for that, otherwise it
322 returns NULL. A called function may clobber any special registers required
323 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
324 register for branch on table instructions. We reject the doloop pattern in
328 default_invalid_within_doloop (rtx insn)
331 return "Function call in loop.";
334 && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
335 || GET_CODE (PATTERN (insn)) == ADDR_VEC))
336 return "Computed branch in the loop.";
341 /* Mapping of builtin functions to vectorized variants. */
344 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED,
345 tree type_out ATTRIBUTE_UNUSED,
346 tree type_in ATTRIBUTE_UNUSED)
351 /* Vectorized conversion. */
354 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED,
355 tree type ATTRIBUTE_UNUSED)
363 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED,
364 bool md_fn ATTRIBUTE_UNUSED,
365 bool sqrt ATTRIBUTE_UNUSED)
371 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
372 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
373 enum machine_mode mode ATTRIBUTE_UNUSED,
374 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
380 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
381 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
382 enum machine_mode mode ATTRIBUTE_UNUSED,
383 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
389 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
390 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
391 enum machine_mode mode ATTRIBUTE_UNUSED,
392 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
398 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
403 hook_invalid_arg_for_unprototyped_fn (
404 tree typelist ATTRIBUTE_UNUSED,
405 tree funcdecl ATTRIBUTE_UNUSED,
406 tree val ATTRIBUTE_UNUSED)
411 /* Initialize the stack protection decls. */
413 /* Stack protection related decls living in libgcc. */
414 static GTY(()) tree stack_chk_guard_decl;
417 default_stack_protect_guard (void)
419 tree t = stack_chk_guard_decl;
423 t = build_decl (VAR_DECL, get_identifier ("__stack_chk_guard"),
427 DECL_EXTERNAL (t) = 1;
429 TREE_THIS_VOLATILE (t) = 1;
430 DECL_ARTIFICIAL (t) = 1;
431 DECL_IGNORED_P (t) = 1;
433 stack_chk_guard_decl = t;
439 static GTY(()) tree stack_chk_fail_decl;
442 default_external_stack_protect_fail (void)
444 tree t = stack_chk_fail_decl;
448 t = build_function_type_list (void_type_node, NULL_TREE);
449 t = build_decl (FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
452 DECL_EXTERNAL (t) = 1;
454 TREE_THIS_VOLATILE (t) = 1;
455 TREE_NOTHROW (t) = 1;
456 DECL_ARTIFICIAL (t) = 1;
457 DECL_IGNORED_P (t) = 1;
458 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
459 DECL_VISIBILITY_SPECIFIED (t) = 1;
461 stack_chk_fail_decl = t;
464 return build_call_expr (t, 0);
468 default_hidden_stack_protect_fail (void)
470 #ifndef HAVE_GAS_HIDDEN
471 return default_external_stack_protect_fail ();
473 tree t = stack_chk_fail_decl;
476 return default_external_stack_protect_fail ();
480 t = build_function_type_list (void_type_node, NULL_TREE);
481 t = build_decl (FUNCTION_DECL,
482 get_identifier ("__stack_chk_fail_local"), t);
485 DECL_EXTERNAL (t) = 1;
487 TREE_THIS_VOLATILE (t) = 1;
488 TREE_NOTHROW (t) = 1;
489 DECL_ARTIFICIAL (t) = 1;
490 DECL_IGNORED_P (t) = 1;
491 DECL_VISIBILITY_SPECIFIED (t) = 1;
492 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
494 stack_chk_fail_decl = t;
497 return build_call_expr (t, 0);
502 hook_bool_rtx_commutative_p (rtx x, int outer_code ATTRIBUTE_UNUSED)
504 return COMMUTATIVE_P (x);
508 default_function_value (tree ret_type ATTRIBUTE_UNUSED,
509 tree fn_decl_or_type,
510 bool outgoing ATTRIBUTE_UNUSED)
512 /* The old interface doesn't handle receiving the function type. */
514 && !DECL_P (fn_decl_or_type))
515 fn_decl_or_type = NULL;
517 #ifdef FUNCTION_OUTGOING_VALUE
519 return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
522 #ifdef FUNCTION_VALUE
523 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
530 default_internal_arg_pointer (void)
532 /* If the reg that the virtual arg pointer will be translated into is
533 not a fixed reg or is the stack pointer, make a copy of the virtual
534 arg pointer, and address parms via the copy. The frame pointer is
535 considered fixed even though it is not marked as such. */
536 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
537 || ! (fixed_regs[ARG_POINTER_REGNUM]
538 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
539 return copy_to_reg (virtual_incoming_args_rtx);
541 return virtual_incoming_args_rtx;
545 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
546 enum reg_class reload_class ATTRIBUTE_UNUSED,
547 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
548 secondary_reload_info *sri)
550 enum reg_class class = NO_REGS;
552 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
554 sri->icode = sri->prev_sri->t_icode;
557 #ifdef SECONDARY_INPUT_RELOAD_CLASS
559 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
561 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
563 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
565 if (class != NO_REGS)
567 enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
568 : reload_out_optab[(int) reload_mode]);
570 if (icode != CODE_FOR_nothing
571 && insn_data[(int) icode].operand[in_p].predicate
572 && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
573 icode = CODE_FOR_nothing;
574 else if (icode != CODE_FOR_nothing)
576 const char *insn_constraint, *scratch_constraint;
577 char insn_letter, scratch_letter;
578 enum reg_class insn_class, scratch_class;
580 gcc_assert (insn_data[(int) icode].n_operands == 3);
581 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
582 if (!*insn_constraint)
583 insn_class = ALL_REGS;
588 gcc_assert (*insn_constraint == '=');
591 insn_letter = *insn_constraint;
593 = (insn_letter == 'r' ? GENERAL_REGS
594 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
596 gcc_assert (insn_class != NO_REGS);
599 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
600 /* The scratch register's constraint must start with "=&",
601 except for an input reload, where only "=" is necessary,
602 and where it might be beneficial to re-use registers from
604 gcc_assert (scratch_constraint[0] == '='
605 && (in_p || scratch_constraint[1] == '&'));
606 scratch_constraint++;
607 if (*scratch_constraint == '&')
608 scratch_constraint++;
609 scratch_letter = *scratch_constraint;
611 = (scratch_letter == 'r' ? GENERAL_REGS
612 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
613 scratch_constraint));
615 if (reg_class_subset_p (reload_class, insn_class))
617 gcc_assert (scratch_class == class);
624 if (class == NO_REGS)
627 sri->t_icode = icode;
633 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
634 const char *arg ATTRIBUTE_UNUSED,
635 int value ATTRIBUTE_UNUSED)
640 /* By default, if flag_pic is true, then neither local nor global relocs
641 should be placed in readonly memory. */
644 default_reloc_rw_mask (void)
646 return flag_pic ? 3 : 0;
649 /* By default, do no modification. */
650 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
656 #include "gt-targhooks.h"