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)
177 /* The generic C++ ABI specifies this is a 64-bit value. */
179 default_cxx_guard_type (void)
181 return long_long_integer_type_node;
185 /* Returns the size of the cookie to use when allocating an array
186 whose elements have the indicated TYPE. Assumes that it is already
187 known that a cookie is needed. */
190 default_cxx_get_cookie_size (tree type)
194 /* We need to allocate an additional max (sizeof (size_t), alignof
195 (true_type)) bytes. */
199 sizetype_size = size_in_bytes (sizetype);
200 type_align = size_int (TYPE_ALIGN_UNIT (type));
201 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
202 cookie_size = sizetype_size;
204 cookie_size = type_align;
209 /* Return true if a parameter must be passed by reference. This version
210 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
213 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
214 enum machine_mode mode ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED,
215 bool named_arg ATTRIBUTE_UNUSED)
217 return targetm.calls.must_pass_in_stack (mode, type);
220 /* Return true if a parameter follows callee copies conventions. This
221 version of the hook is true for all named arguments. */
224 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
225 enum machine_mode mode ATTRIBUTE_UNUSED,
226 tree type ATTRIBUTE_UNUSED, bool named)
231 /* Emit any directives required to unwind this instruction. */
234 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
235 rtx insn ATTRIBUTE_UNUSED)
237 /* Should never happen. */
241 /* True if MODE is valid for the target. By "valid", we mean able to
242 be manipulated in non-trivial ways. In particular, this means all
243 the arithmetic is supported.
245 By default we guess this means that any C type is supported. If
246 we can't map the mode back to a type that would be available in C,
247 then reject it. Special case, here, is the double-word arithmetic
248 supported by optabs.c. */
251 default_scalar_mode_supported_p (enum machine_mode mode)
253 int precision = GET_MODE_PRECISION (mode);
255 switch (GET_MODE_CLASS (mode))
257 case MODE_PARTIAL_INT:
259 if (precision == CHAR_TYPE_SIZE)
261 if (precision == SHORT_TYPE_SIZE)
263 if (precision == INT_TYPE_SIZE)
265 if (precision == LONG_TYPE_SIZE)
267 if (precision == LONG_LONG_TYPE_SIZE)
269 if (precision == 2 * BITS_PER_WORD)
274 if (precision == FLOAT_TYPE_SIZE)
276 if (precision == DOUBLE_TYPE_SIZE)
278 if (precision == LONG_DOUBLE_TYPE_SIZE)
282 case MODE_DECIMAL_FLOAT:
290 /* True if the target supports decimal floating point. */
293 default_decimal_float_supported_p (void)
295 return ENABLE_DECIMAL_FLOAT;
298 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
301 This function checks whether a given INSN is valid within a low-overhead
302 loop. If INSN is invalid it returns the reason for that, otherwise it
303 returns NULL. A called function may clobber any special registers required
304 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
305 register for branch on table instructions. We reject the doloop pattern in
309 default_invalid_within_doloop (rtx insn)
312 return "Function call in loop.";
315 && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
316 || GET_CODE (PATTERN (insn)) == ADDR_VEC))
317 return "Computed branch in the loop.";
322 /* Mapping of builtin functions to vectorized variants. */
325 default_builtin_vectorized_function (enum built_in_function fn ATTRIBUTE_UNUSED,
326 tree type_out ATTRIBUTE_UNUSED,
327 tree type_in ATTRIBUTE_UNUSED)
332 /* Vectorized conversion. */
335 default_builtin_vectorized_conversion (enum tree_code code ATTRIBUTE_UNUSED,
336 tree type ATTRIBUTE_UNUSED)
344 default_builtin_reciprocal (enum built_in_function fn ATTRIBUTE_UNUSED,
345 bool sqrt ATTRIBUTE_UNUSED)
351 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
352 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
353 enum machine_mode mode ATTRIBUTE_UNUSED,
354 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
360 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
361 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
362 enum machine_mode mode ATTRIBUTE_UNUSED,
363 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
369 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
370 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
371 enum machine_mode mode ATTRIBUTE_UNUSED,
372 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
378 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
383 hook_invalid_arg_for_unprototyped_fn (
384 tree typelist ATTRIBUTE_UNUSED,
385 tree funcdecl ATTRIBUTE_UNUSED,
386 tree val ATTRIBUTE_UNUSED)
391 /* Initialize the stack protection decls. */
393 /* Stack protection related decls living in libgcc. */
394 static GTY(()) tree stack_chk_guard_decl;
397 default_stack_protect_guard (void)
399 tree t = stack_chk_guard_decl;
403 t = build_decl (VAR_DECL, get_identifier ("__stack_chk_guard"),
407 DECL_EXTERNAL (t) = 1;
409 TREE_THIS_VOLATILE (t) = 1;
410 DECL_ARTIFICIAL (t) = 1;
411 DECL_IGNORED_P (t) = 1;
413 stack_chk_guard_decl = t;
419 static GTY(()) tree stack_chk_fail_decl;
422 default_external_stack_protect_fail (void)
424 tree t = stack_chk_fail_decl;
428 t = build_function_type_list (void_type_node, NULL_TREE);
429 t = build_decl (FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
432 DECL_EXTERNAL (t) = 1;
434 TREE_THIS_VOLATILE (t) = 1;
435 TREE_NOTHROW (t) = 1;
436 DECL_ARTIFICIAL (t) = 1;
437 DECL_IGNORED_P (t) = 1;
438 DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
439 DECL_VISIBILITY_SPECIFIED (t) = 1;
441 stack_chk_fail_decl = t;
444 return build_call_expr (t, 0);
448 default_hidden_stack_protect_fail (void)
450 #ifndef HAVE_GAS_HIDDEN
451 return default_external_stack_protect_fail ();
453 tree t = stack_chk_fail_decl;
456 return default_external_stack_protect_fail ();
460 t = build_function_type_list (void_type_node, NULL_TREE);
461 t = build_decl (FUNCTION_DECL,
462 get_identifier ("__stack_chk_fail_local"), t);
465 DECL_EXTERNAL (t) = 1;
467 TREE_THIS_VOLATILE (t) = 1;
468 TREE_NOTHROW (t) = 1;
469 DECL_ARTIFICIAL (t) = 1;
470 DECL_IGNORED_P (t) = 1;
471 DECL_VISIBILITY_SPECIFIED (t) = 1;
472 DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
474 stack_chk_fail_decl = t;
477 return build_call_expr (t, 0);
482 hook_bool_rtx_commutative_p (rtx x, int outer_code ATTRIBUTE_UNUSED)
484 return COMMUTATIVE_P (x);
488 default_function_value (tree ret_type ATTRIBUTE_UNUSED,
489 tree fn_decl_or_type,
490 bool outgoing ATTRIBUTE_UNUSED)
492 /* The old interface doesn't handle receiving the function type. */
494 && !DECL_P (fn_decl_or_type))
495 fn_decl_or_type = NULL;
497 #ifdef FUNCTION_OUTGOING_VALUE
499 return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
502 #ifdef FUNCTION_VALUE
503 return FUNCTION_VALUE (ret_type, fn_decl_or_type);
510 default_internal_arg_pointer (void)
512 /* If the reg that the virtual arg pointer will be translated into is
513 not a fixed reg or is the stack pointer, make a copy of the virtual
514 arg pointer, and address parms via the copy. The frame pointer is
515 considered fixed even though it is not marked as such. */
516 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
517 || ! (fixed_regs[ARG_POINTER_REGNUM]
518 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
519 return copy_to_reg (virtual_incoming_args_rtx);
521 return virtual_incoming_args_rtx;
525 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
526 enum reg_class reload_class ATTRIBUTE_UNUSED,
527 enum machine_mode reload_mode ATTRIBUTE_UNUSED,
528 secondary_reload_info *sri)
530 enum reg_class class = NO_REGS;
532 if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
534 sri->icode = sri->prev_sri->t_icode;
537 #ifdef SECONDARY_INPUT_RELOAD_CLASS
539 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
541 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
543 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
545 if (class != NO_REGS)
547 enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
548 : reload_out_optab[(int) reload_mode]);
550 if (icode != CODE_FOR_nothing
551 && insn_data[(int) icode].operand[in_p].predicate
552 && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
553 icode = CODE_FOR_nothing;
554 else if (icode != CODE_FOR_nothing)
556 const char *insn_constraint, *scratch_constraint;
557 char insn_letter, scratch_letter;
558 enum reg_class insn_class, scratch_class;
560 gcc_assert (insn_data[(int) icode].n_operands == 3);
561 insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
562 if (!*insn_constraint)
563 insn_class = ALL_REGS;
568 gcc_assert (*insn_constraint == '=');
571 insn_letter = *insn_constraint;
573 = (insn_letter == 'r' ? GENERAL_REGS
574 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
576 gcc_assert (insn_class != NO_REGS);
579 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
580 /* The scratch register's constraint must start with "=&",
581 except for an input reload, where only "=" is necessary,
582 and where it might be beneficial to re-use registers from
584 gcc_assert (scratch_constraint[0] == '='
585 && (in_p || scratch_constraint[1] == '&'));
586 scratch_constraint++;
587 if (*scratch_constraint == '&')
588 scratch_constraint++;
589 scratch_letter = *scratch_constraint;
591 = (scratch_letter == 'r' ? GENERAL_REGS
592 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
593 scratch_constraint));
595 if (reg_class_subset_p (reload_class, insn_class))
597 gcc_assert (scratch_class == class);
604 if (class == NO_REGS)
607 sri->t_icode = icode;
613 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
614 const char *arg ATTRIBUTE_UNUSED,
615 int value ATTRIBUTE_UNUSED)
620 /* By default, if flag_pic is true, then neither local nor global relocs
621 should be placed in readonly memory. */
624 default_reloc_rw_mask (void)
626 return flag_pic ? 3 : 0;
629 /* By default, do no modification. */
630 tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
636 #include "gt-targhooks.h"