1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2014 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/>. */
23 #include "coretypes.h"
25 #include "diagnostic-core.h"
28 #include "stor-layout.h"
36 #include "hard-reg-set.h"
42 #include "insn-config.h"
45 #include "langhooks.h"
47 #include "common/common-target.h"
50 static rtx
break_out_memory_refs (rtx
);
53 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
56 trunc_int_for_mode (HOST_WIDE_INT c
, enum machine_mode mode
)
58 int width
= GET_MODE_PRECISION (mode
);
60 /* You want to truncate to a _what_? */
61 gcc_assert (SCALAR_INT_MODE_P (mode
));
63 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
65 return c
& 1 ? STORE_FLAG_VALUE
: 0;
67 /* Sign-extend for the requested mode. */
69 if (width
< HOST_BITS_PER_WIDE_INT
)
71 HOST_WIDE_INT sign
= 1;
81 /* Return an rtx for the sum of X and the integer C, given that X has
82 mode MODE. INPLACE is true if X can be modified inplace or false
83 if it must be treated as immutable. */
86 plus_constant (enum machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
94 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
106 CASE_CONST_SCALAR_INT
:
107 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
110 /* If this is a reference to the constant pool, try replacing it with
111 a reference to a new constant. If the resulting address isn't
112 valid, don't return it because we have no way to validize it. */
113 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
114 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
116 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
117 tem
= force_const_mem (GET_MODE (x
), tem
);
118 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
124 /* If adding to something entirely constant, set a flag
125 so that we can add a CONST around the result. */
126 if (inplace
&& shared_const_p (x
))
138 /* The interesting case is adding the integer to a sum. Look
139 for constant term in the sum and combine with C. For an
140 integer constant term or a constant term that is not an
141 explicit integer, we combine or group them together anyway.
143 We may not immediately return from the recursive call here, lest
144 all_constant gets lost. */
146 if (CONSTANT_P (XEXP (x
, 1)))
148 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
149 if (term
== const0_rtx
)
154 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
157 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
161 /* We need to be careful since X may be shared and we can't
162 modify it in place. */
164 const_loc
= find_constant_term_loc (&x
);
166 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
176 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
178 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
180 else if (all_constant
)
181 return gen_rtx_CONST (mode
, x
);
186 /* If X is a sum, return a new sum like X but lacking any constant terms.
187 Add all the removed constant terms into *CONSTPTR.
188 X itself is not altered. The result != X if and only if
189 it is not isomorphic to X. */
192 eliminate_constant_term (rtx x
, rtx
*constptr
)
197 if (GET_CODE (x
) != PLUS
)
200 /* First handle constants appearing at this level explicitly. */
201 if (CONST_INT_P (XEXP (x
, 1))
202 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
204 && CONST_INT_P (tem
))
207 return eliminate_constant_term (XEXP (x
, 0), constptr
);
211 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
212 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
213 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
214 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
216 && CONST_INT_P (tem
))
219 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
225 /* Returns a tree for the size of EXP in bytes. */
228 tree_expr_size (const_tree exp
)
231 && DECL_SIZE_UNIT (exp
) != 0)
232 return DECL_SIZE_UNIT (exp
);
234 return size_in_bytes (TREE_TYPE (exp
));
237 /* Return an rtx for the size in bytes of the value of EXP. */
244 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
245 size
= TREE_OPERAND (exp
, 1);
248 size
= tree_expr_size (exp
);
250 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
253 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
256 /* Return a wide integer for the size in bytes of the value of EXP, or -1
257 if the size can vary or is larger than an integer. */
260 int_expr_size (tree exp
)
264 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
265 size
= TREE_OPERAND (exp
, 1);
268 size
= tree_expr_size (exp
);
272 if (size
== 0 || !tree_fits_shwi_p (size
))
275 return tree_to_shwi (size
);
278 /* Return a copy of X in which all memory references
279 and all constants that involve symbol refs
280 have been replaced with new temporary registers.
281 Also emit code to load the memory locations and constants
282 into those registers.
284 If X contains no such constants or memory references,
285 X itself (not a copy) is returned.
287 If a constant is found in the address that is not a legitimate constant
288 in an insn, it is left alone in the hope that it might be valid in the
291 X may contain no arithmetic except addition, subtraction and multiplication.
292 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
295 break_out_memory_refs (rtx x
)
298 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
299 && GET_MODE (x
) != VOIDmode
))
300 x
= force_reg (GET_MODE (x
), x
);
301 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
302 || GET_CODE (x
) == MULT
)
304 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
305 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
307 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
308 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
314 /* Given X, a memory address in address space AS' pointer mode, convert it to
315 an address in the address space's address mode, or vice versa (TO_MODE says
316 which way). We take advantage of the fact that pointers are not allowed to
317 overflow by commuting arithmetic operations over conversions so that address
318 arithmetic insns can be used. IN_CONST is true if this conversion is inside
322 convert_memory_address_addr_space_1 (enum machine_mode to_mode ATTRIBUTE_UNUSED
,
323 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
324 bool in_const ATTRIBUTE_UNUSED
)
326 #ifndef POINTERS_EXTEND_UNSIGNED
327 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
329 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
330 enum machine_mode pointer_mode
, address_mode
, from_mode
;
334 /* If X already has the right mode, just return it. */
335 if (GET_MODE (x
) == to_mode
)
338 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
339 address_mode
= targetm
.addr_space
.address_mode (as
);
340 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
342 /* Here we handle some special cases. If none of them apply, fall through
343 to the default case. */
344 switch (GET_CODE (x
))
346 CASE_CONST_SCALAR_INT
:
347 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
349 else if (POINTERS_EXTEND_UNSIGNED
< 0)
351 else if (POINTERS_EXTEND_UNSIGNED
> 0)
355 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
361 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
362 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
363 return SUBREG_REG (x
);
367 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
368 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
373 temp
= shallow_copy_rtx (x
);
374 PUT_MODE (temp
, to_mode
);
379 return gen_rtx_CONST (to_mode
,
380 convert_memory_address_addr_space_1
381 (to_mode
, XEXP (x
, 0), as
, true));
386 /* For addition we can safely permute the conversion and addition
387 operation if one operand is a constant and converting the constant
388 does not change it or if one operand is a constant and we are
389 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
390 We can always safely permute them if we are making the address
391 narrower. Inside a CONST RTL, this is safe for both pointers
392 zero or sign extended as pointers cannot wrap. */
393 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
394 || (GET_CODE (x
) == PLUS
395 && CONST_INT_P (XEXP (x
, 1))
396 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
397 || XEXP (x
, 1) == convert_memory_address_addr_space_1
398 (to_mode
, XEXP (x
, 1), as
, in_const
)
399 || POINTERS_EXTEND_UNSIGNED
< 0)))
400 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
401 convert_memory_address_addr_space_1
402 (to_mode
, XEXP (x
, 0), as
, in_const
),
410 return convert_modes (to_mode
, from_mode
,
411 x
, POINTERS_EXTEND_UNSIGNED
);
412 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
415 /* Given X, a memory address in address space AS' pointer mode, convert it to
416 an address in the address space's address mode, or vice versa (TO_MODE says
417 which way). We take advantage of the fact that pointers are not allowed to
418 overflow by commuting arithmetic operations over conversions so that address
419 arithmetic insns can be used. */
422 convert_memory_address_addr_space (enum machine_mode to_mode
, rtx x
, addr_space_t as
)
424 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false);
427 /* Return something equivalent to X but valid as a memory address for something
428 of mode MODE in the named address space AS. When X is not itself valid,
429 this works by copying X or subexpressions of it into registers. */
432 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
435 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
437 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
439 /* By passing constant addresses through registers
440 we get a chance to cse them. */
441 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
442 x
= force_reg (address_mode
, x
);
444 /* We get better cse by rejecting indirect addressing at this stage.
445 Let the combiner create indirect addresses where appropriate.
446 For now, generate the code so that the subexpressions useful to share
447 are visible. But not if cse won't be done! */
450 if (! cse_not_expected
&& !REG_P (x
))
451 x
= break_out_memory_refs (x
);
453 /* At this point, any valid address is accepted. */
454 if (memory_address_addr_space_p (mode
, x
, as
))
457 /* If it was valid before but breaking out memory refs invalidated it,
458 use it the old way. */
459 if (memory_address_addr_space_p (mode
, oldx
, as
))
465 /* Perform machine-dependent transformations on X
466 in certain cases. This is not necessary since the code
467 below can handle all possible cases, but machine-dependent
468 transformations can make better code. */
471 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
472 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
476 /* PLUS and MULT can appear in special ways
477 as the result of attempts to make an address usable for indexing.
478 Usually they are dealt with by calling force_operand, below.
479 But a sum containing constant terms is special
480 if removing them makes the sum a valid address:
481 then we generate that address in a register
482 and index off of it. We do this because it often makes
483 shorter code, and because the addresses thus generated
484 in registers often become common subexpressions. */
485 if (GET_CODE (x
) == PLUS
)
487 rtx constant_term
= const0_rtx
;
488 rtx y
= eliminate_constant_term (x
, &constant_term
);
489 if (constant_term
== const0_rtx
490 || ! memory_address_addr_space_p (mode
, y
, as
))
491 x
= force_operand (x
, NULL_RTX
);
494 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
495 if (! memory_address_addr_space_p (mode
, y
, as
))
496 x
= force_operand (x
, NULL_RTX
);
502 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
503 x
= force_operand (x
, NULL_RTX
);
505 /* If we have a register that's an invalid address,
506 it must be a hard reg of the wrong class. Copy it to a pseudo. */
510 /* Last resort: copy the value to a register, since
511 the register is a valid address. */
513 x
= force_reg (address_mode
, x
);
518 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
519 /* If we didn't change the address, we are done. Otherwise, mark
520 a reg as a pointer if we have REG or REG + CONST_INT. */
524 mark_reg_pointer (x
, BITS_PER_UNIT
);
525 else if (GET_CODE (x
) == PLUS
526 && REG_P (XEXP (x
, 0))
527 && CONST_INT_P (XEXP (x
, 1)))
528 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
530 /* OLDX may have been the address on a temporary. Update the address
531 to indicate that X is now used. */
532 update_temp_slot_address (oldx
, x
);
537 /* If REF is a MEM with an invalid address, change it into a valid address.
538 Pass through anything else unchanged. REF must be an unshared rtx and
539 the function may modify it in-place. */
542 validize_mem (rtx ref
)
546 ref
= use_anchored_address (ref
);
547 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
548 MEM_ADDR_SPACE (ref
)))
551 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
554 /* If X is a memory reference to a member of an object block, try rewriting
555 it to use an anchor instead. Return the new memory reference on success
556 and the old one on failure. */
559 use_anchored_address (rtx x
)
562 HOST_WIDE_INT offset
;
563 enum machine_mode mode
;
565 if (!flag_section_anchors
)
571 /* Split the address into a base and offset. */
574 if (GET_CODE (base
) == CONST
575 && GET_CODE (XEXP (base
, 0)) == PLUS
576 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
578 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
579 base
= XEXP (XEXP (base
, 0), 0);
582 /* Check whether BASE is suitable for anchors. */
583 if (GET_CODE (base
) != SYMBOL_REF
584 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
585 || SYMBOL_REF_ANCHOR_P (base
)
586 || SYMBOL_REF_BLOCK (base
) == NULL
587 || !targetm
.use_anchors_for_symbol_p (base
))
590 /* Decide where BASE is going to be. */
591 place_block_symbol (base
);
593 /* Get the anchor we need to use. */
594 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
595 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
596 SYMBOL_REF_TLS_MODEL (base
));
598 /* Work out the offset from the anchor. */
599 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
601 /* If we're going to run a CSE pass, force the anchor into a register.
602 We will then be able to reuse registers for several accesses, if the
603 target costs say that that's worthwhile. */
604 mode
= GET_MODE (base
);
605 if (!cse_not_expected
)
606 base
= force_reg (mode
, base
);
608 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
611 /* Copy the value or contents of X to a new temp reg and return that reg. */
616 rtx temp
= gen_reg_rtx (GET_MODE (x
));
618 /* If not an operand, must be an address with PLUS and MULT so
619 do the computation. */
620 if (! general_operand (x
, VOIDmode
))
621 x
= force_operand (x
, temp
);
624 emit_move_insn (temp
, x
);
629 /* Like copy_to_reg but always give the new register mode Pmode
630 in case X is a constant. */
633 copy_addr_to_reg (rtx x
)
635 return copy_to_mode_reg (Pmode
, x
);
638 /* Like copy_to_reg but always give the new register mode MODE
639 in case X is a constant. */
642 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
644 rtx temp
= gen_reg_rtx (mode
);
646 /* If not an operand, must be an address with PLUS and MULT so
647 do the computation. */
648 if (! general_operand (x
, VOIDmode
))
649 x
= force_operand (x
, temp
);
651 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
653 emit_move_insn (temp
, x
);
657 /* Load X into a register if it is not already one.
658 Use mode MODE for the register.
659 X should be valid for mode MODE, but it may be a constant which
660 is valid for all integer modes; that's why caller must specify MODE.
662 The caller must not alter the value in the register we return,
663 since we mark it as a "constant" register. */
666 force_reg (enum machine_mode mode
, rtx x
)
674 if (general_operand (x
, mode
))
676 temp
= gen_reg_rtx (mode
);
677 insn
= emit_move_insn (temp
, x
);
681 temp
= force_operand (x
, NULL_RTX
);
683 insn
= get_last_insn ();
686 rtx temp2
= gen_reg_rtx (mode
);
687 insn
= emit_move_insn (temp2
, temp
);
692 /* Let optimizers know that TEMP's value never changes
693 and that X can be substituted for it. Don't get confused
694 if INSN set something else (such as a SUBREG of TEMP). */
696 && (set
= single_set (insn
)) != 0
697 && SET_DEST (set
) == temp
698 && ! rtx_equal_p (x
, SET_SRC (set
)))
699 set_unique_reg_note (insn
, REG_EQUAL
, x
);
701 /* Let optimizers know that TEMP is a pointer, and if so, the
702 known alignment of that pointer. */
705 if (GET_CODE (x
) == SYMBOL_REF
)
707 align
= BITS_PER_UNIT
;
708 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
709 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
711 else if (GET_CODE (x
) == LABEL_REF
)
712 align
= BITS_PER_UNIT
;
713 else if (GET_CODE (x
) == CONST
714 && GET_CODE (XEXP (x
, 0)) == PLUS
715 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
716 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
718 rtx s
= XEXP (XEXP (x
, 0), 0);
719 rtx c
= XEXP (XEXP (x
, 0), 1);
723 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
724 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
730 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
731 align
= MIN (sa
, ca
);
735 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
736 mark_reg_pointer (temp
, align
);
742 /* If X is a memory ref, copy its contents to a new temp reg and return
743 that reg. Otherwise, return X. */
746 force_not_mem (rtx x
)
750 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
753 temp
= gen_reg_rtx (GET_MODE (x
));
756 REG_POINTER (temp
) = 1;
758 emit_move_insn (temp
, x
);
762 /* Copy X to TARGET (if it's nonzero and a reg)
763 or to a new temp reg and return that reg.
764 MODE is the mode to use for X in case it is a constant. */
767 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
771 if (target
&& REG_P (target
))
774 temp
= gen_reg_rtx (mode
);
776 emit_move_insn (temp
, x
);
780 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
781 PUNSIGNEDP points to the signedness of the type and may be adjusted
782 to show what signedness to use on extension operations.
784 FOR_RETURN is nonzero if the caller is promoting the return value
785 of FNDECL, else it is for promoting args. */
788 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
789 const_tree funtype
, int for_return
)
791 /* Called without a type node for a libcall. */
792 if (type
== NULL_TREE
)
794 if (INTEGRAL_MODE_P (mode
))
795 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
802 switch (TREE_CODE (type
))
804 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
805 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
806 case POINTER_TYPE
: case REFERENCE_TYPE
:
807 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
814 /* Return the mode to use to store a scalar of TYPE and MODE.
815 PUNSIGNEDP points to the signedness of the type and may be adjusted
816 to show what signedness to use on extension operations. */
819 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
820 int *punsignedp ATTRIBUTE_UNUSED
)
827 /* For libcalls this is invoked without TYPE from the backends
828 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
830 if (type
== NULL_TREE
)
833 /* FIXME: this is the same logic that was there until GCC 4.4, but we
834 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
835 is not defined. The affected targets are M32C, S390, SPARC. */
837 code
= TREE_CODE (type
);
838 unsignedp
= *punsignedp
;
842 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
843 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
844 PROMOTE_MODE (mode
, unsignedp
, type
);
845 *punsignedp
= unsignedp
;
849 #ifdef POINTERS_EXTEND_UNSIGNED
852 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
853 return targetm
.addr_space
.address_mode
854 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
867 /* Use one of promote_mode or promote_function_mode to find the promoted
868 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
869 of DECL after promotion. */
872 promote_decl_mode (const_tree decl
, int *punsignedp
)
874 tree type
= TREE_TYPE (decl
);
875 int unsignedp
= TYPE_UNSIGNED (type
);
876 enum machine_mode mode
= DECL_MODE (decl
);
877 enum machine_mode pmode
;
879 if (TREE_CODE (decl
) == RESULT_DECL
880 || TREE_CODE (decl
) == PARM_DECL
)
881 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
882 TREE_TYPE (current_function_decl
), 2);
884 pmode
= promote_mode (type
, mode
, &unsignedp
);
887 *punsignedp
= unsignedp
;
892 /* Controls the behaviour of {anti_,}adjust_stack. */
893 static bool suppress_reg_args_size
;
895 /* A helper for adjust_stack and anti_adjust_stack. */
898 adjust_stack_1 (rtx adjust
, bool anti_p
)
903 #ifndef STACK_GROWS_DOWNWARD
904 /* Hereafter anti_p means subtract_p. */
908 temp
= expand_binop (Pmode
,
909 anti_p
? sub_optab
: add_optab
,
910 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
913 if (temp
!= stack_pointer_rtx
)
914 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
917 insn
= get_last_insn ();
918 temp
= single_set (insn
);
919 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
922 if (!suppress_reg_args_size
)
923 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
926 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
927 This pops when ADJUST is positive. ADJUST need not be constant. */
930 adjust_stack (rtx adjust
)
932 if (adjust
== const0_rtx
)
935 /* We expect all variable sized adjustments to be multiple of
936 PREFERRED_STACK_BOUNDARY. */
937 if (CONST_INT_P (adjust
))
938 stack_pointer_delta
-= INTVAL (adjust
);
940 adjust_stack_1 (adjust
, false);
943 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
944 This pushes when ADJUST is positive. ADJUST need not be constant. */
947 anti_adjust_stack (rtx adjust
)
949 if (adjust
== const0_rtx
)
952 /* We expect all variable sized adjustments to be multiple of
953 PREFERRED_STACK_BOUNDARY. */
954 if (CONST_INT_P (adjust
))
955 stack_pointer_delta
+= INTVAL (adjust
);
957 adjust_stack_1 (adjust
, true);
960 /* Round the size of a block to be pushed up to the boundary required
961 by this machine. SIZE is the desired size, which need not be constant. */
964 round_push (rtx size
)
966 rtx align_rtx
, alignm1_rtx
;
968 if (!SUPPORTS_STACK_ALIGNMENT
969 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
971 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
976 if (CONST_INT_P (size
))
978 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
980 if (INTVAL (size
) != new_size
)
981 size
= GEN_INT (new_size
);
985 align_rtx
= GEN_INT (align
);
986 alignm1_rtx
= GEN_INT (align
- 1);
990 /* If crtl->preferred_stack_boundary might still grow, use
991 virtual_preferred_stack_boundary_rtx instead. This will be
992 substituted by the right value in vregs pass and optimized
994 align_rtx
= virtual_preferred_stack_boundary_rtx
;
995 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
999 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1000 but we know it can't. So add ourselves and then do
1002 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1003 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1004 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1006 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1011 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1012 to a previously-created save area. If no save area has been allocated,
1013 this function will allocate one. If a save area is specified, it
1014 must be of the proper mode. */
1017 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1020 /* The default is that we use a move insn and save in a Pmode object. */
1021 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1022 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1024 /* See if this machine has anything special to do for this kind of save. */
1027 #ifdef HAVE_save_stack_block
1029 if (HAVE_save_stack_block
)
1030 fcn
= gen_save_stack_block
;
1033 #ifdef HAVE_save_stack_function
1035 if (HAVE_save_stack_function
)
1036 fcn
= gen_save_stack_function
;
1039 #ifdef HAVE_save_stack_nonlocal
1041 if (HAVE_save_stack_nonlocal
)
1042 fcn
= gen_save_stack_nonlocal
;
1049 /* If there is no save area and we have to allocate one, do so. Otherwise
1050 verify the save area is the proper mode. */
1054 if (mode
!= VOIDmode
)
1056 if (save_level
== SAVE_NONLOCAL
)
1057 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1059 *psave
= sa
= gen_reg_rtx (mode
);
1063 do_pending_stack_adjust ();
1065 sa
= validize_mem (sa
);
1066 emit_insn (fcn (sa
, stack_pointer_rtx
));
1069 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1070 area made by emit_stack_save. If it is zero, we have nothing to do. */
1073 emit_stack_restore (enum save_level save_level
, rtx sa
)
1075 /* The default is that we use a move insn. */
1076 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1078 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1079 STACK_POINTER and HARD_FRAME_POINTER.
1080 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1081 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1082 aligned variables, which is reflected in ix86_can_eliminate.
1083 We normally still have the realigned STACK_POINTER that we can use.
1084 But if there is a stack restore still present at reload, it can trigger
1085 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1086 FRAME_POINTER into a hard reg.
1087 To prevent this situation, we force need_drap if we emit a stack
1089 if (SUPPORTS_STACK_ALIGNMENT
)
1090 crtl
->need_drap
= true;
1092 /* See if this machine has anything special to do for this kind of save. */
1095 #ifdef HAVE_restore_stack_block
1097 if (HAVE_restore_stack_block
)
1098 fcn
= gen_restore_stack_block
;
1101 #ifdef HAVE_restore_stack_function
1103 if (HAVE_restore_stack_function
)
1104 fcn
= gen_restore_stack_function
;
1107 #ifdef HAVE_restore_stack_nonlocal
1109 if (HAVE_restore_stack_nonlocal
)
1110 fcn
= gen_restore_stack_nonlocal
;
1119 sa
= validize_mem (sa
);
1120 /* These clobbers prevent the scheduler from moving
1121 references to variable arrays below the code
1122 that deletes (pops) the arrays. */
1123 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1124 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1127 discard_pending_stack_adjust ();
1129 emit_insn (fcn (stack_pointer_rtx
, sa
));
1132 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1133 function. This function should be called whenever we allocate or
1134 deallocate dynamic stack space. */
1137 update_nonlocal_goto_save_area (void)
1142 /* The nonlocal_goto_save_area object is an array of N pointers. The
1143 first one is used for the frame pointer save; the rest are sized by
1144 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1145 of the stack save area slots. */
1146 t_save
= build4 (ARRAY_REF
,
1147 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1148 cfun
->nonlocal_goto_save_area
,
1149 integer_one_node
, NULL_TREE
, NULL_TREE
);
1150 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1152 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1155 /* Return an rtx representing the address of an area of memory dynamically
1156 pushed on the stack.
1158 Any required stack pointer alignment is preserved.
1160 SIZE is an rtx representing the size of the area.
1162 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1163 parameter may be zero. If so, a proper value will be extracted
1164 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1166 REQUIRED_ALIGN is the alignment (in bits) required for the region
1169 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1170 stack space allocated by the generated code cannot be added with itself
1171 in the course of the execution of the function. It is always safe to
1172 pass FALSE here and the following criterion is sufficient in order to
1173 pass TRUE: every path in the CFG that starts at the allocation point and
1174 loops to it executes the associated deallocation code. */
1177 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1178 unsigned required_align
, bool cannot_accumulate
)
1180 HOST_WIDE_INT stack_usage_size
= -1;
1181 rtx_code_label
*final_label
;
1182 rtx final_target
, target
;
1183 unsigned extra_align
= 0;
1186 /* If we're asking for zero bytes, it doesn't matter what we point
1187 to since we can't dereference it. But return a reasonable
1189 if (size
== const0_rtx
)
1190 return virtual_stack_dynamic_rtx
;
1192 /* Otherwise, show we're calling alloca or equivalent. */
1193 cfun
->calls_alloca
= 1;
1195 /* If stack usage info is requested, look into the size we are passed.
1196 We need to do so this early to avoid the obfuscation that may be
1197 introduced later by the various alignment operations. */
1198 if (flag_stack_usage_info
)
1200 if (CONST_INT_P (size
))
1201 stack_usage_size
= INTVAL (size
);
1202 else if (REG_P (size
))
1204 /* Look into the last emitted insn and see if we can deduce
1205 something for the register. */
1208 insn
= get_last_insn ();
1209 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1211 if (CONST_INT_P (SET_SRC (set
)))
1212 stack_usage_size
= INTVAL (SET_SRC (set
));
1213 else if ((note
= find_reg_equal_equiv_note (insn
))
1214 && CONST_INT_P (XEXP (note
, 0)))
1215 stack_usage_size
= INTVAL (XEXP (note
, 0));
1219 /* If the size is not constant, we can't say anything. */
1220 if (stack_usage_size
== -1)
1222 current_function_has_unbounded_dynamic_stack_size
= 1;
1223 stack_usage_size
= 0;
1227 /* Ensure the size is in the proper mode. */
1228 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1229 size
= convert_to_mode (Pmode
, size
, 1);
1231 /* Adjust SIZE_ALIGN, if needed. */
1232 if (CONST_INT_P (size
))
1234 unsigned HOST_WIDE_INT lsb
;
1236 lsb
= INTVAL (size
);
1239 /* Watch out for overflow truncating to "unsigned". */
1240 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1241 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1243 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1245 else if (size_align
< BITS_PER_UNIT
)
1246 size_align
= BITS_PER_UNIT
;
1248 /* We can't attempt to minimize alignment necessary, because we don't
1249 know the final value of preferred_stack_boundary yet while executing
1251 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1252 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1254 /* We will need to ensure that the address we return is aligned to
1255 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1256 always know its final value at this point in the compilation (it
1257 might depend on the size of the outgoing parameter lists, for
1258 example), so we must align the value to be returned in that case.
1259 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1260 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1261 We must also do an alignment operation on the returned value if
1262 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1264 If we have to align, we must leave space in SIZE for the hole
1265 that might result from the alignment operation. */
1267 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1270 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1271 extra_align
= PREFERRED_STACK_BOUNDARY
;
1272 else if (required_align
> STACK_BOUNDARY
)
1273 extra_align
= STACK_BOUNDARY
;
1275 extra_align
= BITS_PER_UNIT
;
1278 /* ??? STACK_POINTER_OFFSET is always defined now. */
1279 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1281 extra_align
= BITS_PER_UNIT
;
1286 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1288 size
= plus_constant (Pmode
, size
, extra
);
1289 size
= force_operand (size
, NULL_RTX
);
1291 if (flag_stack_usage_info
)
1292 stack_usage_size
+= extra
;
1294 if (extra
&& size_align
> extra_align
)
1295 size_align
= extra_align
;
1298 /* Round the size to a multiple of the required stack alignment.
1299 Since the stack if presumed to be rounded before this allocation,
1300 this will maintain the required alignment.
1302 If the stack grows downward, we could save an insn by subtracting
1303 SIZE from the stack pointer and then aligning the stack pointer.
1304 The problem with this is that the stack pointer may be unaligned
1305 between the execution of the subtraction and alignment insns and
1306 some machines do not allow this. Even on those that do, some
1307 signal handlers malfunction if a signal should occur between those
1308 insns. Since this is an extremely rare event, we have no reliable
1309 way of knowing which systems have this problem. So we avoid even
1310 momentarily mis-aligning the stack. */
1311 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1313 size
= round_push (size
);
1315 if (flag_stack_usage_info
)
1317 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1318 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1322 target
= gen_reg_rtx (Pmode
);
1324 /* The size is supposed to be fully adjusted at this point so record it
1325 if stack usage info is requested. */
1326 if (flag_stack_usage_info
)
1328 current_function_dynamic_stack_size
+= stack_usage_size
;
1330 /* ??? This is gross but the only safe stance in the absence
1331 of stack usage oriented flow analysis. */
1332 if (!cannot_accumulate
)
1333 current_function_has_unbounded_dynamic_stack_size
= 1;
1337 final_target
= NULL_RTX
;
1339 /* If we are splitting the stack, we need to ask the backend whether
1340 there is enough room on the current stack. If there isn't, or if
1341 the backend doesn't know how to tell is, then we need to call a
1342 function to allocate memory in some other way. This memory will
1343 be released when we release the current stack segment. The
1344 effect is that stack allocation becomes less efficient, but at
1345 least it doesn't cause a stack overflow. */
1346 if (flag_split_stack
)
1348 rtx_code_label
*available_label
;
1349 rtx ask
, space
, func
;
1351 available_label
= NULL
;
1353 #ifdef HAVE_split_stack_space_check
1354 if (HAVE_split_stack_space_check
)
1356 available_label
= gen_label_rtx ();
1358 /* This instruction will branch to AVAILABLE_LABEL if there
1359 are SIZE bytes available on the stack. */
1360 emit_insn (gen_split_stack_space_check (size
, available_label
));
1364 /* The __morestack_allocate_stack_space function will allocate
1365 memory using malloc. If the alignment of the memory returned
1366 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1367 make sure we allocate enough space. */
1368 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1372 ask
= expand_binop (Pmode
, add_optab
, size
,
1373 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1375 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1379 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1381 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1384 if (available_label
== NULL_RTX
)
1387 final_target
= gen_reg_rtx (Pmode
);
1389 emit_move_insn (final_target
, space
);
1391 final_label
= gen_label_rtx ();
1392 emit_jump (final_label
);
1394 emit_label (available_label
);
1397 do_pending_stack_adjust ();
1399 /* We ought to be called always on the toplevel and stack ought to be aligned
1401 gcc_assert (!(stack_pointer_delta
1402 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1404 /* If needed, check that we have the required amount of stack. Take into
1405 account what has already been checked. */
1406 if (STACK_CHECK_MOVING_SP
)
1408 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1409 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1411 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1412 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1414 /* Don't let anti_adjust_stack emit notes. */
1415 suppress_reg_args_size
= true;
1417 /* Perform the required allocation from the stack. Some systems do
1418 this differently than simply incrementing/decrementing from the
1419 stack pointer, such as acquiring the space by calling malloc(). */
1420 #ifdef HAVE_allocate_stack
1421 if (HAVE_allocate_stack
)
1423 struct expand_operand ops
[2];
1424 /* We don't have to check against the predicate for operand 0 since
1425 TARGET is known to be a pseudo of the proper mode, which must
1426 be valid for the operand. */
1427 create_fixed_operand (&ops
[0], target
);
1428 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1429 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1434 int saved_stack_pointer_delta
;
1436 #ifndef STACK_GROWS_DOWNWARD
1437 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1440 /* Check stack bounds if necessary. */
1441 if (crtl
->limit_stack
)
1444 rtx_code_label
*space_available
= gen_label_rtx ();
1445 #ifdef STACK_GROWS_DOWNWARD
1446 available
= expand_binop (Pmode
, sub_optab
,
1447 stack_pointer_rtx
, stack_limit_rtx
,
1448 NULL_RTX
, 1, OPTAB_WIDEN
);
1450 available
= expand_binop (Pmode
, sub_optab
,
1451 stack_limit_rtx
, stack_pointer_rtx
,
1452 NULL_RTX
, 1, OPTAB_WIDEN
);
1454 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1458 emit_insn (gen_trap ());
1461 error ("stack limits not supported on this target");
1463 emit_label (space_available
);
1466 saved_stack_pointer_delta
= stack_pointer_delta
;
1468 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1469 anti_adjust_stack_and_probe (size
, false);
1471 anti_adjust_stack (size
);
1473 /* Even if size is constant, don't modify stack_pointer_delta.
1474 The constant size alloca should preserve
1475 crtl->preferred_stack_boundary alignment. */
1476 stack_pointer_delta
= saved_stack_pointer_delta
;
1478 #ifdef STACK_GROWS_DOWNWARD
1479 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1483 suppress_reg_args_size
= false;
1485 /* Finish up the split stack handling. */
1486 if (final_label
!= NULL_RTX
)
1488 gcc_assert (flag_split_stack
);
1489 emit_move_insn (final_target
, target
);
1490 emit_label (final_label
);
1491 target
= final_target
;
1496 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1497 but we know it can't. So add ourselves and then do
1499 target
= expand_binop (Pmode
, add_optab
, target
,
1500 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1502 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1503 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1504 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1507 target
= expand_mult (Pmode
, target
,
1508 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1513 /* Now that we've committed to a return value, mark its alignment. */
1514 mark_reg_pointer (target
, required_align
);
1516 /* Record the new stack level for nonlocal gotos. */
1517 if (cfun
->nonlocal_goto_save_area
!= 0)
1518 update_nonlocal_goto_save_area ();
1523 /* A front end may want to override GCC's stack checking by providing a
1524 run-time routine to call to check the stack, so provide a mechanism for
1525 calling that routine. */
1527 static GTY(()) rtx stack_check_libfunc
;
1530 set_stack_check_libfunc (const char *libfunc_name
)
1532 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1533 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1536 /* Emit one stack probe at ADDRESS, an address within the stack. */
1539 emit_stack_probe (rtx address
)
1541 #ifdef HAVE_probe_stack_address
1542 if (HAVE_probe_stack_address
)
1543 emit_insn (gen_probe_stack_address (address
));
1547 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1549 MEM_VOLATILE_P (memref
) = 1;
1551 /* See if we have an insn to probe the stack. */
1552 #ifdef HAVE_probe_stack
1553 if (HAVE_probe_stack
)
1554 emit_insn (gen_probe_stack (memref
));
1557 emit_move_insn (memref
, const0_rtx
);
1561 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1562 FIRST is a constant and size is a Pmode RTX. These are offsets from
1563 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1564 or subtract them from the stack pointer. */
1566 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1568 #ifdef STACK_GROWS_DOWNWARD
1569 #define STACK_GROW_OP MINUS
1570 #define STACK_GROW_OPTAB sub_optab
1571 #define STACK_GROW_OFF(off) -(off)
1573 #define STACK_GROW_OP PLUS
1574 #define STACK_GROW_OPTAB add_optab
1575 #define STACK_GROW_OFF(off) (off)
1579 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1581 /* First ensure SIZE is Pmode. */
1582 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1583 size
= convert_to_mode (Pmode
, size
, 1);
1585 /* Next see if we have a function to check the stack. */
1586 if (stack_check_libfunc
)
1588 rtx addr
= memory_address (Pmode
,
1589 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1591 plus_constant (Pmode
,
1593 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1597 /* Next see if we have an insn to check the stack. */
1598 #ifdef HAVE_check_stack
1599 else if (HAVE_check_stack
)
1601 struct expand_operand ops
[1];
1602 rtx addr
= memory_address (Pmode
,
1603 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1605 plus_constant (Pmode
,
1608 create_input_operand (&ops
[0], addr
, Pmode
);
1609 success
= maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
);
1610 gcc_assert (success
);
1614 /* Otherwise we have to generate explicit probes. If we have a constant
1615 small number of them to generate, that's the easy case. */
1616 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1618 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1621 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1622 it exceeds SIZE. If only one probe is needed, this will not
1623 generate any code. Then probe at FIRST + SIZE. */
1624 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1626 addr
= memory_address (Pmode
,
1627 plus_constant (Pmode
, stack_pointer_rtx
,
1628 STACK_GROW_OFF (first
+ i
)));
1629 emit_stack_probe (addr
);
1632 addr
= memory_address (Pmode
,
1633 plus_constant (Pmode
, stack_pointer_rtx
,
1634 STACK_GROW_OFF (first
+ isize
)));
1635 emit_stack_probe (addr
);
1638 /* In the variable case, do the same as above, but in a loop. Note that we
1639 must be extra careful with variables wrapping around because we might be
1640 at the very top (or the very bottom) of the address space and we have to
1641 be able to handle this case properly; in particular, we use an equality
1642 test for the loop condition. */
1645 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1646 rtx_code_label
*loop_lab
= gen_label_rtx ();
1647 rtx_code_label
*end_lab
= gen_label_rtx ();
1649 /* Step 1: round SIZE to the previous multiple of the interval. */
1651 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1653 = simplify_gen_binary (AND
, Pmode
, size
,
1654 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1655 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1658 /* Step 2: compute initial and final value of the loop counter. */
1660 /* TEST_ADDR = SP + FIRST. */
1661 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1663 gen_int_mode (first
, Pmode
)),
1666 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1667 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1669 rounded_size_op
), NULL_RTX
);
1674 while (TEST_ADDR != LAST_ADDR)
1676 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1680 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1681 until it is equal to ROUNDED_SIZE. */
1683 emit_label (loop_lab
);
1685 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1686 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1689 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1690 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1691 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1694 gcc_assert (temp
== test_addr
);
1696 /* Probe at TEST_ADDR. */
1697 emit_stack_probe (test_addr
);
1699 emit_jump (loop_lab
);
1701 emit_label (end_lab
);
1704 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1705 that SIZE is equal to ROUNDED_SIZE. */
1707 /* TEMP = SIZE - ROUNDED_SIZE. */
1708 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1709 if (temp
!= const0_rtx
)
1713 if (CONST_INT_P (temp
))
1715 /* Use [base + disp} addressing mode if supported. */
1716 HOST_WIDE_INT offset
= INTVAL (temp
);
1717 addr
= memory_address (Pmode
,
1718 plus_constant (Pmode
, last_addr
,
1719 STACK_GROW_OFF (offset
)));
1723 /* Manual CSE if the difference is not known at compile-time. */
1724 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1725 addr
= memory_address (Pmode
,
1726 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1730 emit_stack_probe (addr
);
1734 /* Make sure nothing is scheduled before we are done. */
1735 emit_insn (gen_blockage ());
1738 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1739 while probing it. This pushes when SIZE is positive. SIZE need not
1740 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1741 by plus SIZE at the end. */
1744 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1746 /* We skip the probe for the first interval + a small dope of 4 words and
1747 probe that many bytes past the specified size to maintain a protection
1748 area at the botton of the stack. */
1749 const int dope
= 4 * UNITS_PER_WORD
;
1751 /* First ensure SIZE is Pmode. */
1752 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1753 size
= convert_to_mode (Pmode
, size
, 1);
1755 /* If we have a constant small number of probes to generate, that's the
1757 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1759 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1760 bool first_probe
= true;
1762 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1763 values of N from 1 until it exceeds SIZE. If only one probe is
1764 needed, this will not generate any code. Then adjust and probe
1765 to PROBE_INTERVAL + SIZE. */
1766 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1770 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1771 first_probe
= false;
1774 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1775 emit_stack_probe (stack_pointer_rtx
);
1779 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1781 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1782 emit_stack_probe (stack_pointer_rtx
);
1785 /* In the variable case, do the same as above, but in a loop. Note that we
1786 must be extra careful with variables wrapping around because we might be
1787 at the very top (or the very bottom) of the address space and we have to
1788 be able to handle this case properly; in particular, we use an equality
1789 test for the loop condition. */
1792 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1793 rtx_code_label
*loop_lab
= gen_label_rtx ();
1794 rtx_code_label
*end_lab
= gen_label_rtx ();
1797 /* Step 1: round SIZE to the previous multiple of the interval. */
1799 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1801 = simplify_gen_binary (AND
, Pmode
, size
,
1802 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1803 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1806 /* Step 2: compute initial and final value of the loop counter. */
1808 /* SP = SP_0 + PROBE_INTERVAL. */
1809 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1811 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1812 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1814 rounded_size_op
), NULL_RTX
);
1819 while (SP != LAST_ADDR)
1821 SP = SP + PROBE_INTERVAL
1825 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1826 values of N from 1 until it is equal to ROUNDED_SIZE. */
1828 emit_label (loop_lab
);
1830 /* Jump to END_LAB if SP == LAST_ADDR. */
1831 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1834 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1835 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1836 emit_stack_probe (stack_pointer_rtx
);
1838 emit_jump (loop_lab
);
1840 emit_label (end_lab
);
1843 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1844 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1846 /* TEMP = SIZE - ROUNDED_SIZE. */
1847 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1848 if (temp
!= const0_rtx
)
1850 /* Manual CSE if the difference is not known at compile-time. */
1851 if (GET_CODE (temp
) != CONST_INT
)
1852 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1853 anti_adjust_stack (temp
);
1854 emit_stack_probe (stack_pointer_rtx
);
1858 /* Adjust back and account for the additional first interval. */
1860 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1862 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1865 /* Return an rtx representing the register or memory location
1866 in which a scalar value of data type VALTYPE
1867 was returned by a function call to function FUNC.
1868 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1869 function is known, otherwise 0.
1870 OUTGOING is 1 if on a machine with register windows this function
1871 should return the register in which the function will put its result
1875 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1876 int outgoing ATTRIBUTE_UNUSED
)
1880 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1883 && GET_MODE (val
) == BLKmode
)
1885 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1886 enum machine_mode tmpmode
;
1888 /* int_size_in_bytes can return -1. We don't need a check here
1889 since the value of bytes will then be large enough that no
1890 mode will match anyway. */
1892 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1893 tmpmode
!= VOIDmode
;
1894 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1896 /* Have we found a large enough mode? */
1897 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1901 /* No suitable mode found. */
1902 gcc_assert (tmpmode
!= VOIDmode
);
1904 PUT_MODE (val
, tmpmode
);
1909 /* Return an rtx representing the register or memory location
1910 in which a scalar value of mode MODE was returned by a library call. */
1913 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1915 return targetm
.calls
.libcall_value (mode
, fun
);
1918 /* Look up the tree code for a given rtx code
1919 to provide the arithmetic operation for REAL_ARITHMETIC.
1920 The function returns an int because the caller may not know
1921 what `enum tree_code' means. */
1924 rtx_to_tree_code (enum rtx_code code
)
1926 enum tree_code tcode
;
1949 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1952 return ((int) tcode
);
1955 #include "gt-explow.h"