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)
143 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
145 unsigned HOST_WIDE_INT
146 default_shift_truncation_mask (enum machine_mode mode)
148 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
151 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
154 default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
156 return have_insn_for (DIV, mode) ? 3 : 2;
159 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
162 default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
163 enum machine_mode mode_rep ATTRIBUTE_UNUSED)
168 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
171 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
176 /* Return machine mode for non-standard suffix
177 or VOIDmode if non-standard suffixes are unsupported. */
179 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
184 /* The generic C++ ABI specifies this is a 64-bit value. */
186 default_cxx_guard_type (void)
188 return long_long_integer_type_node;
192 /* Returns the size of the cookie to use when allocating an array
193 whose elements have the indicated TYPE. Assumes that it is already
194 known that a cookie is needed. */
197 default_cxx_get_cookie_size (tree type)
201 /* We need to allocate an additional max (sizeof (size_t), alignof
202 (true_type)) bytes. */
206 sizetype_size = size_in_bytes (sizetype);
207 type_align = size_int (TYPE_ALIGN_UNIT (type));
208 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
209 cookie_size = sizetype_size;
211 cookie_size = type_align;
216 /* Return true if a parameter must be passed by reference. This version
217 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
220 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
221 enum machine_mode mode ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED,
222 bool named_arg ATTRIBUTE_UNUSED)
224 return targetm.calls.must_pass_in_stack (mode, type);
227 /* Return true if a parameter follows callee copies conventions. This
228 version of the hook is true for all named arguments. */
231 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
232 enum machine_mode mode ATTRIBUTE_UNUSED,
233 tree type ATTRIBUTE_UNUSED, bool named)
238 /* Emit any directives required to unwind this instruction. */
241 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
242 rtx insn ATTRIBUTE_UNUSED)
244 /* Should never happen. */
248 /* True if MODE is valid for the target. By "valid", we mean able to
249 be manipulated in non-trivial ways. In particular, this means all
250 the arithmetic is supported.
252 By default we guess this means that any C type is supported. If
253 we can't map the mode back to a type that would be available in C,
254 then reject it. Special case, here, is the double-word arithmetic
255 supported by optabs.c. */
258 default_scalar_mode_supported_p (enum machine_mode mode)
260 int precision = GET_MODE_PRECISION (mode);
262 switch (GET_MODE_CLASS (mode))
264 case MODE_PARTIAL_INT:
266 if (precision == CHAR_TYPE_SIZE)
268 if (precision == SHORT_TYPE_SIZE)
270 if (precision == INT_TYPE_SIZE)
272 if (precision == LONG_TYPE_SIZE)
274 if (precision == LONG_LONG_TYPE_SIZE)
276 if (precision == 2 * BITS_PER_WORD)
281 if (precision == FLOAT_TYPE_SIZE)
283 if (precision == DOUBLE_TYPE_SIZE)
285 if (precision == LONG_DOUBLE_TYPE_SIZE)
289 case MODE_DECIMAL_FLOAT:
297 /* True if the target supports decimal floating point. */
300 default_decimal_float_supported_p (void)
302 return ENABLE_DECIMAL_FLOAT;
305 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
308 This function checks whether a given INSN is valid within a low-overhead
309 loop. If INSN is invalid it returns the reason for that, otherwise it
310 returns NULL. A called function may clobber any special registers required
311 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
312 register for branch on table instructions. We reject the doloop pattern in
316 default_invalid_within_doloop (rtx insn)
319 return "Function call in loop.";
322 && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
323 || GET_CODE (PATTERN (insn)) == ADDR_VEC))
324 return "Computed branch in the loop.";
329 /* Mapping of builtin functions to vectorized variants. */
332 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED,
333 tree type_out ATTRIBUTE_UNUSED,
334 tree type_in ATTRIBUTE_UNUSED)
339 /* Vectorized conversion. */
342 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED,
343 tree type ATTRIBUTE_UNUSED)
351 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED,
352 bool md_fn ATTRIBUTE_UNUSED,
353 bool sqrt ATTRIBUTE_UNUSED)
359 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
360 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
361 enum machine_mode mode ATTRIBUTE_UNUSED,
362 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
368 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
369 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
370 enum machine_mode mode ATTRIBUTE_UNUSED,
371 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
377 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
378 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
379 enum machine_mode mode ATTRIBUTE_UNUSED,
380 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
386 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
391 hook_invalid_arg_for_unprototyped_fn (
392 tree typelist ATTRIBUTE_UNUSED,
393 tree funcdecl ATTRIBUTE_UNUSED,
394 tree val ATTRIBUTE_UNUSED)
399 /* Initialize the stack protection decls. */
401 /* Stack protection related decls living in libgcc. */
402 static GTY(()) tree stack_chk_guard_decl;
405 default_stack_protect_guard (void)
407 tree t = stack_chk_guard_decl;
411 t = build_decl (VAR_DECL, get_identifier ("__stack_chk_guard"),
415 DECL_EXTERNAL (t) = 1;
417 TREE_THIS_VOLATILE (t) = 1;
418 DECL_ARTIFICIAL (t) = 1;
419 DECL_IGNORED_P (t) = 1;
421 stack_chk_guard_decl = t;
427 static GTY(()) tree stack_chk_fail_decl;
430 default_external_stack_protect_fail (void)
432 tree t = stack_chk_fail_decl;
436 t = build_function_type_list (void_type_node, NULL_TREE);
437 t = build_decl (FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
440 DECL_EXTERNAL (t) = 1;
442 TREE_THIS_VOLATILE (t) = 1;
443 TREE_NOTHROW (t) = 1;
444 DECL_ARTIFICIAL (t) = 1;
445 DECL_IGNORED_P (t) = 1;
446 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
447 DECL_VISIBILITY_SPECIFIED (t) = 1;
449 stack_chk_fail_decl = t;
452 return build_call_expr (t, 0);
456 default_hidden_stack_protect_fail (void)
458 #ifndef HAVE_GAS_HIDDEN
459 return default_external_stack_protect_fail ();
461 tree t = stack_chk_fail_decl;
464 return default_external_stack_protect_fail ();
468 t = build_function_type_list (void_type_node, NULL_TREE);
469 t = build_decl (FUNCTION_DECL,
470 get_identifier ("__stack_chk_fail_local"), t);
473 DECL_EXTERNAL (t) = 1;
475 TREE_THIS_VOLATILE (t) = 1;
476 TREE_NOTHROW (t) = 1;
477 DECL_ARTIFICIAL (t) = 1;
478 DECL_IGNORED_P (t) = 1;
479 DECL_VISIBILITY_SPECIFIED (t) = 1;
480 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
482 stack_chk_fail_decl = t;
485 return build_call_expr (t, 0);
490 hook_bool_rtx_commutative_p (rtx x, int outer_code ATTRIBUTE_UNUSED)
492 return COMMUTATIVE_P (x);
496 default_function_value (tree ret_type ATTRIBUTE_UNUSED,
497 tree fn_decl_or_type,
498 bool outgoing ATTRIBUTE_UNUSED)
500 /* The old interface doesn't handle receiving the function type. */
502 && !DECL_P (fn_decl_or_type))
503 fn_decl_or_type = NULL;
505 #ifdef FUNCTION_OUTGOING_VALUE
507 return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
510 #ifdef FUNCTION_VALUE
511 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
518 default_internal_arg_pointer (void)
520 /* If the reg that the virtual arg pointer will be translated into is
521 not a fixed reg or is the stack pointer, make a copy of the virtual
522 arg pointer, and address parms via the copy. The frame pointer is
523 considered fixed even though it is not marked as such. */
524 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
525 || ! (fixed_regs[ARG_POINTER_REGNUM]
526 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
527 return copy_to_reg (virtual_incoming_args_rtx);
529 return virtual_incoming_args_rtx;
533 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
534 enum reg_class reload_class ATTRIBUTE_UNUSED,
535 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
536 secondary_reload_info *sri)
538 enum reg_class class = NO_REGS;
540 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
542 sri->icode = sri->prev_sri->t_icode;
545 #ifdef SECONDARY_INPUT_RELOAD_CLASS
547 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
549 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
551 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
553 if (class != NO_REGS)
555 enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
556 : reload_out_optab[(int) reload_mode]);
558 if (icode != CODE_FOR_nothing
559 && insn_data[(int) icode].operand[in_p].predicate
560 && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
561 icode = CODE_FOR_nothing;
562 else if (icode != CODE_FOR_nothing)
564 const char *insn_constraint, *scratch_constraint;
565 char insn_letter, scratch_letter;
566 enum reg_class insn_class, scratch_class;
568 gcc_assert (insn_data[(int) icode].n_operands == 3);
569 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
570 if (!*insn_constraint)
571 insn_class = ALL_REGS;
576 gcc_assert (*insn_constraint == '=');
579 insn_letter = *insn_constraint;
581 = (insn_letter == 'r' ? GENERAL_REGS
582 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
584 gcc_assert (insn_class != NO_REGS);
587 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
588 /* The scratch register's constraint must start with "=&",
589 except for an input reload, where only "=" is necessary,
590 and where it might be beneficial to re-use registers from
592 gcc_assert (scratch_constraint[0] == '='
593 && (in_p || scratch_constraint[1] == '&'));
594 scratch_constraint++;
595 if (*scratch_constraint == '&')
596 scratch_constraint++;
597 scratch_letter = *scratch_constraint;
599 = (scratch_letter == 'r' ? GENERAL_REGS
600 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
601 scratch_constraint));
603 if (reg_class_subset_p (reload_class, insn_class))
605 gcc_assert (scratch_class == class);
612 if (class == NO_REGS)
615 sri->t_icode = icode;
621 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
622 const char *arg ATTRIBUTE_UNUSED,
623 int value ATTRIBUTE_UNUSED)
628 /* By default, if flag_pic is true, then neither local nor global relocs
629 should be placed in readonly memory. */
632 default_reloc_rw_mask (void)
634 return flag_pic ? 3 : 0;
637 /* By default, do no modification. */
638 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
644 #include "gt-targhooks.h"