1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2017 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"
31 #include "profile-count.h"
35 #include "diagnostic-core.h"
36 #include "stor-layout.h"
41 #include "common/common-target.h"
44 static rtx
break_out_memory_refs (rtx
);
47 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
50 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
52 int width
= GET_MODE_PRECISION (mode
);
54 /* You want to truncate to a _what_? */
55 gcc_assert (SCALAR_INT_MODE_P (mode
)
56 || POINTER_BOUNDS_MODE_P (mode
));
58 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
60 return c
& 1 ? STORE_FLAG_VALUE
: 0;
62 /* Sign-extend for the requested mode. */
64 if (width
< HOST_BITS_PER_WIDE_INT
)
66 HOST_WIDE_INT sign
= 1;
76 /* Return an rtx for the sum of X and the integer C, given that X has
77 mode MODE. INPLACE is true if X can be modified inplace or false
78 if it must be treated as immutable. */
81 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
89 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
101 CASE_CONST_SCALAR_INT
:
102 return immed_wide_int_const (wi::add (rtx_mode_t (x
, mode
), c
), mode
);
104 /* If this is a reference to the constant pool, try replacing it with
105 a reference to a new constant. If the resulting address isn't
106 valid, don't return it because we have no way to validize it. */
107 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
108 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
110 rtx cst
= get_pool_constant (XEXP (x
, 0));
112 if (GET_CODE (cst
) == CONST_VECTOR
113 && GET_MODE_INNER (GET_MODE (cst
)) == mode
)
115 cst
= gen_lowpart (mode
, cst
);
118 if (GET_MODE (cst
) == VOIDmode
|| GET_MODE (cst
) == mode
)
120 tem
= plus_constant (mode
, cst
, c
);
121 tem
= force_const_mem (GET_MODE (x
), tem
);
122 /* Targets may disallow some constants in the constant pool, thus
123 force_const_mem may return NULL_RTX. */
124 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
131 /* If adding to something entirely constant, set a flag
132 so that we can add a CONST around the result. */
133 if (inplace
&& shared_const_p (x
))
145 /* The interesting case is adding the integer to a sum. Look
146 for constant term in the sum and combine with C. For an
147 integer constant term or a constant term that is not an
148 explicit integer, we combine or group them together anyway.
150 We may not immediately return from the recursive call here, lest
151 all_constant gets lost. */
153 if (CONSTANT_P (XEXP (x
, 1)))
155 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
156 if (term
== const0_rtx
)
161 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
164 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
168 /* We need to be careful since X may be shared and we can't
169 modify it in place. */
171 const_loc
= find_constant_term_loc (&x
);
173 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
183 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
185 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
187 else if (all_constant
)
188 return gen_rtx_CONST (mode
, x
);
193 /* If X is a sum, return a new sum like X but lacking any constant terms.
194 Add all the removed constant terms into *CONSTPTR.
195 X itself is not altered. The result != X if and only if
196 it is not isomorphic to X. */
199 eliminate_constant_term (rtx x
, rtx
*constptr
)
204 if (GET_CODE (x
) != PLUS
)
207 /* First handle constants appearing at this level explicitly. */
208 if (CONST_INT_P (XEXP (x
, 1))
209 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
211 && CONST_INT_P (tem
))
214 return eliminate_constant_term (XEXP (x
, 0), constptr
);
218 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
219 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
220 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
221 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
223 && CONST_INT_P (tem
))
226 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
233 /* Return a copy of X in which all memory references
234 and all constants that involve symbol refs
235 have been replaced with new temporary registers.
236 Also emit code to load the memory locations and constants
237 into those registers.
239 If X contains no such constants or memory references,
240 X itself (not a copy) is returned.
242 If a constant is found in the address that is not a legitimate constant
243 in an insn, it is left alone in the hope that it might be valid in the
246 X may contain no arithmetic except addition, subtraction and multiplication.
247 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
250 break_out_memory_refs (rtx x
)
253 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
254 && GET_MODE (x
) != VOIDmode
))
255 x
= force_reg (GET_MODE (x
), x
);
256 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
257 || GET_CODE (x
) == MULT
)
259 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
260 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
262 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
263 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
269 /* Given X, a memory address in address space AS' pointer mode, convert it to
270 an address in the address space's address mode, or vice versa (TO_MODE says
271 which way). We take advantage of the fact that pointers are not allowed to
272 overflow by commuting arithmetic operations over conversions so that address
273 arithmetic insns can be used. IN_CONST is true if this conversion is inside
274 a CONST. NO_EMIT is true if no insns should be emitted, and instead
275 it should return NULL if it can't be simplified without emitting insns. */
278 convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED
,
279 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
280 bool in_const ATTRIBUTE_UNUSED
,
281 bool no_emit ATTRIBUTE_UNUSED
)
283 #ifndef POINTERS_EXTEND_UNSIGNED
284 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
286 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
287 scalar_int_mode pointer_mode
, address_mode
, from_mode
;
291 /* If X already has the right mode, just return it. */
292 if (GET_MODE (x
) == to_mode
)
295 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
296 address_mode
= targetm
.addr_space
.address_mode (as
);
297 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
299 /* Here we handle some special cases. If none of them apply, fall through
300 to the default case. */
301 switch (GET_CODE (x
))
303 CASE_CONST_SCALAR_INT
:
304 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
306 else if (POINTERS_EXTEND_UNSIGNED
< 0)
308 else if (POINTERS_EXTEND_UNSIGNED
> 0)
312 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
318 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
319 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
320 return SUBREG_REG (x
);
324 temp
= gen_rtx_LABEL_REF (to_mode
, label_ref_label (x
));
325 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
329 temp
= shallow_copy_rtx (x
);
330 PUT_MODE (temp
, to_mode
);
334 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0), as
,
336 return temp
? gen_rtx_CONST (to_mode
, temp
) : temp
;
340 /* For addition we can safely permute the conversion and addition
341 operation if one operand is a constant and converting the constant
342 does not change it or if one operand is a constant and we are
343 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
344 We can always safely permute them if we are making the address
345 narrower. Inside a CONST RTL, this is safe for both pointers
346 zero or sign extended as pointers cannot wrap. */
347 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
348 || (GET_CODE (x
) == PLUS
349 && CONST_INT_P (XEXP (x
, 1))
350 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
351 || XEXP (x
, 1) == convert_memory_address_addr_space_1
352 (to_mode
, XEXP (x
, 1), as
, in_const
,
354 || POINTERS_EXTEND_UNSIGNED
< 0)))
356 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0),
357 as
, in_const
, no_emit
);
358 return (temp
? gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
371 return convert_modes (to_mode
, from_mode
,
372 x
, POINTERS_EXTEND_UNSIGNED
);
373 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
376 /* Given X, a memory address in address space AS' pointer mode, convert it to
377 an address in the address space's address mode, or vice versa (TO_MODE says
378 which way). We take advantage of the fact that pointers are not allowed to
379 overflow by commuting arithmetic operations over conversions so that address
380 arithmetic insns can be used. */
383 convert_memory_address_addr_space (scalar_int_mode to_mode
, rtx x
,
386 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false, false);
390 /* Return something equivalent to X but valid as a memory address for something
391 of mode MODE in the named address space AS. When X is not itself valid,
392 this works by copying X or subexpressions of it into registers. */
395 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
398 scalar_int_mode address_mode
= targetm
.addr_space
.address_mode (as
);
400 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
402 /* By passing constant addresses through registers
403 we get a chance to cse them. */
404 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
405 x
= force_reg (address_mode
, x
);
407 /* We get better cse by rejecting indirect addressing at this stage.
408 Let the combiner create indirect addresses where appropriate.
409 For now, generate the code so that the subexpressions useful to share
410 are visible. But not if cse won't be done! */
413 if (! cse_not_expected
&& !REG_P (x
))
414 x
= break_out_memory_refs (x
);
416 /* At this point, any valid address is accepted. */
417 if (memory_address_addr_space_p (mode
, x
, as
))
420 /* If it was valid before but breaking out memory refs invalidated it,
421 use it the old way. */
422 if (memory_address_addr_space_p (mode
, oldx
, as
))
428 /* Perform machine-dependent transformations on X
429 in certain cases. This is not necessary since the code
430 below can handle all possible cases, but machine-dependent
431 transformations can make better code. */
434 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
435 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
439 /* PLUS and MULT can appear in special ways
440 as the result of attempts to make an address usable for indexing.
441 Usually they are dealt with by calling force_operand, below.
442 But a sum containing constant terms is special
443 if removing them makes the sum a valid address:
444 then we generate that address in a register
445 and index off of it. We do this because it often makes
446 shorter code, and because the addresses thus generated
447 in registers often become common subexpressions. */
448 if (GET_CODE (x
) == PLUS
)
450 rtx constant_term
= const0_rtx
;
451 rtx y
= eliminate_constant_term (x
, &constant_term
);
452 if (constant_term
== const0_rtx
453 || ! memory_address_addr_space_p (mode
, y
, as
))
454 x
= force_operand (x
, NULL_RTX
);
457 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
458 if (! memory_address_addr_space_p (mode
, y
, as
))
459 x
= force_operand (x
, NULL_RTX
);
465 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
466 x
= force_operand (x
, NULL_RTX
);
468 /* If we have a register that's an invalid address,
469 it must be a hard reg of the wrong class. Copy it to a pseudo. */
473 /* Last resort: copy the value to a register, since
474 the register is a valid address. */
476 x
= force_reg (address_mode
, x
);
481 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
482 /* If we didn't change the address, we are done. Otherwise, mark
483 a reg as a pointer if we have REG or REG + CONST_INT. */
487 mark_reg_pointer (x
, BITS_PER_UNIT
);
488 else if (GET_CODE (x
) == PLUS
489 && REG_P (XEXP (x
, 0))
490 && CONST_INT_P (XEXP (x
, 1)))
491 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
493 /* OLDX may have been the address on a temporary. Update the address
494 to indicate that X is now used. */
495 update_temp_slot_address (oldx
, x
);
500 /* Convert a mem ref into one with a valid memory address.
501 Pass through anything else unchanged. */
504 validize_mem (rtx ref
)
508 ref
= use_anchored_address (ref
);
509 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
510 MEM_ADDR_SPACE (ref
)))
513 /* Don't alter REF itself, since that is probably a stack slot. */
514 return replace_equiv_address (ref
, XEXP (ref
, 0));
517 /* If X is a memory reference to a member of an object block, try rewriting
518 it to use an anchor instead. Return the new memory reference on success
519 and the old one on failure. */
522 use_anchored_address (rtx x
)
525 HOST_WIDE_INT offset
;
528 if (!flag_section_anchors
)
534 /* Split the address into a base and offset. */
537 if (GET_CODE (base
) == CONST
538 && GET_CODE (XEXP (base
, 0)) == PLUS
539 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
541 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
542 base
= XEXP (XEXP (base
, 0), 0);
545 /* Check whether BASE is suitable for anchors. */
546 if (GET_CODE (base
) != SYMBOL_REF
547 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
548 || SYMBOL_REF_ANCHOR_P (base
)
549 || SYMBOL_REF_BLOCK (base
) == NULL
550 || !targetm
.use_anchors_for_symbol_p (base
))
553 /* Decide where BASE is going to be. */
554 place_block_symbol (base
);
556 /* Get the anchor we need to use. */
557 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
558 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
559 SYMBOL_REF_TLS_MODEL (base
));
561 /* Work out the offset from the anchor. */
562 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
564 /* If we're going to run a CSE pass, force the anchor into a register.
565 We will then be able to reuse registers for several accesses, if the
566 target costs say that that's worthwhile. */
567 mode
= GET_MODE (base
);
568 if (!cse_not_expected
)
569 base
= force_reg (mode
, base
);
571 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
574 /* Copy the value or contents of X to a new temp reg and return that reg. */
579 rtx temp
= gen_reg_rtx (GET_MODE (x
));
581 /* If not an operand, must be an address with PLUS and MULT so
582 do the computation. */
583 if (! general_operand (x
, VOIDmode
))
584 x
= force_operand (x
, temp
);
587 emit_move_insn (temp
, x
);
592 /* Like copy_to_reg but always give the new register mode Pmode
593 in case X is a constant. */
596 copy_addr_to_reg (rtx x
)
598 return copy_to_mode_reg (Pmode
, x
);
601 /* Like copy_to_reg but always give the new register mode MODE
602 in case X is a constant. */
605 copy_to_mode_reg (machine_mode mode
, rtx x
)
607 rtx temp
= gen_reg_rtx (mode
);
609 /* If not an operand, must be an address with PLUS and MULT so
610 do the computation. */
611 if (! general_operand (x
, VOIDmode
))
612 x
= force_operand (x
, temp
);
614 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
616 emit_move_insn (temp
, x
);
620 /* Load X into a register if it is not already one.
621 Use mode MODE for the register.
622 X should be valid for mode MODE, but it may be a constant which
623 is valid for all integer modes; that's why caller must specify MODE.
625 The caller must not alter the value in the register we return,
626 since we mark it as a "constant" register. */
629 force_reg (machine_mode mode
, rtx x
)
637 if (general_operand (x
, mode
))
639 temp
= gen_reg_rtx (mode
);
640 insn
= emit_move_insn (temp
, x
);
644 temp
= force_operand (x
, NULL_RTX
);
646 insn
= get_last_insn ();
649 rtx temp2
= gen_reg_rtx (mode
);
650 insn
= emit_move_insn (temp2
, temp
);
655 /* Let optimizers know that TEMP's value never changes
656 and that X can be substituted for it. Don't get confused
657 if INSN set something else (such as a SUBREG of TEMP). */
659 && (set
= single_set (insn
)) != 0
660 && SET_DEST (set
) == temp
661 && ! rtx_equal_p (x
, SET_SRC (set
)))
662 set_unique_reg_note (insn
, REG_EQUAL
, x
);
664 /* Let optimizers know that TEMP is a pointer, and if so, the
665 known alignment of that pointer. */
668 if (GET_CODE (x
) == SYMBOL_REF
)
670 align
= BITS_PER_UNIT
;
671 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
672 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
674 else if (GET_CODE (x
) == LABEL_REF
)
675 align
= BITS_PER_UNIT
;
676 else if (GET_CODE (x
) == CONST
677 && GET_CODE (XEXP (x
, 0)) == PLUS
678 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
679 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
681 rtx s
= XEXP (XEXP (x
, 0), 0);
682 rtx c
= XEXP (XEXP (x
, 0), 1);
686 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
687 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
693 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
694 align
= MIN (sa
, ca
);
698 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
699 mark_reg_pointer (temp
, align
);
705 /* If X is a memory ref, copy its contents to a new temp reg and return
706 that reg. Otherwise, return X. */
709 force_not_mem (rtx x
)
713 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
716 temp
= gen_reg_rtx (GET_MODE (x
));
719 REG_POINTER (temp
) = 1;
721 emit_move_insn (temp
, x
);
725 /* Copy X to TARGET (if it's nonzero and a reg)
726 or to a new temp reg and return that reg.
727 MODE is the mode to use for X in case it is a constant. */
730 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
734 if (target
&& REG_P (target
))
737 temp
= gen_reg_rtx (mode
);
739 emit_move_insn (temp
, x
);
743 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
744 PUNSIGNEDP points to the signedness of the type and may be adjusted
745 to show what signedness to use on extension operations.
747 FOR_RETURN is nonzero if the caller is promoting the return value
748 of FNDECL, else it is for promoting args. */
751 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
752 const_tree funtype
, int for_return
)
754 /* Called without a type node for a libcall. */
755 if (type
== NULL_TREE
)
757 if (INTEGRAL_MODE_P (mode
))
758 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
765 switch (TREE_CODE (type
))
767 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
768 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
769 case POINTER_TYPE
: case REFERENCE_TYPE
:
770 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
777 /* Return the mode to use to store a scalar of TYPE and MODE.
778 PUNSIGNEDP points to the signedness of the type and may be adjusted
779 to show what signedness to use on extension operations. */
782 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
783 int *punsignedp ATTRIBUTE_UNUSED
)
790 /* For libcalls this is invoked without TYPE from the backends
791 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
793 if (type
== NULL_TREE
)
796 /* FIXME: this is the same logic that was there until GCC 4.4, but we
797 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
798 is not defined. The affected targets are M32C, S390, SPARC. */
800 code
= TREE_CODE (type
);
801 unsignedp
= *punsignedp
;
805 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
806 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
807 PROMOTE_MODE (mode
, unsignedp
, type
);
808 *punsignedp
= unsignedp
;
811 #ifdef POINTERS_EXTEND_UNSIGNED
814 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
815 return targetm
.addr_space
.address_mode
816 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
828 /* Use one of promote_mode or promote_function_mode to find the promoted
829 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
830 of DECL after promotion. */
833 promote_decl_mode (const_tree decl
, int *punsignedp
)
835 tree type
= TREE_TYPE (decl
);
836 int unsignedp
= TYPE_UNSIGNED (type
);
837 machine_mode mode
= DECL_MODE (decl
);
840 if (TREE_CODE (decl
) == RESULT_DECL
&& !DECL_BY_REFERENCE (decl
))
841 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
842 TREE_TYPE (current_function_decl
), 1);
843 else if (TREE_CODE (decl
) == RESULT_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
844 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
845 TREE_TYPE (current_function_decl
), 2);
847 pmode
= promote_mode (type
, mode
, &unsignedp
);
850 *punsignedp
= unsignedp
;
854 /* Return the promoted mode for name. If it is a named SSA_NAME, it
855 is the same as promote_decl_mode. Otherwise, it is the promoted
856 mode of a temp decl of same type as the SSA_NAME, if we had created
860 promote_ssa_mode (const_tree name
, int *punsignedp
)
862 gcc_assert (TREE_CODE (name
) == SSA_NAME
);
864 /* Partitions holding parms and results must be promoted as expected
866 if (SSA_NAME_VAR (name
)
867 && (TREE_CODE (SSA_NAME_VAR (name
)) == PARM_DECL
868 || TREE_CODE (SSA_NAME_VAR (name
)) == RESULT_DECL
))
870 machine_mode mode
= promote_decl_mode (SSA_NAME_VAR (name
), punsignedp
);
875 tree type
= TREE_TYPE (name
);
876 int unsignedp
= TYPE_UNSIGNED (type
);
877 machine_mode mode
= TYPE_MODE (type
);
879 /* Bypass TYPE_MODE when it maps vector modes to BLKmode. */
882 gcc_assert (VECTOR_TYPE_P (type
));
883 mode
= type
->type_common
.mode
;
886 machine_mode pmode
= promote_mode (type
, mode
, &unsignedp
);
888 *punsignedp
= unsignedp
;
895 /* Controls the behavior of {anti_,}adjust_stack. */
896 static bool suppress_reg_args_size
;
898 /* A helper for adjust_stack and anti_adjust_stack. */
901 adjust_stack_1 (rtx adjust
, bool anti_p
)
906 /* Hereafter anti_p means subtract_p. */
907 if (!STACK_GROWS_DOWNWARD
)
910 temp
= expand_binop (Pmode
,
911 anti_p
? sub_optab
: add_optab
,
912 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
915 if (temp
!= stack_pointer_rtx
)
916 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
919 insn
= get_last_insn ();
920 temp
= single_set (insn
);
921 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
924 if (!suppress_reg_args_size
)
925 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
928 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
929 This pops when ADJUST is positive. ADJUST need not be constant. */
932 adjust_stack (rtx adjust
)
934 if (adjust
== const0_rtx
)
937 /* We expect all variable sized adjustments to be multiple of
938 PREFERRED_STACK_BOUNDARY. */
939 if (CONST_INT_P (adjust
))
940 stack_pointer_delta
-= INTVAL (adjust
);
942 adjust_stack_1 (adjust
, false);
945 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
946 This pushes when ADJUST is positive. ADJUST need not be constant. */
949 anti_adjust_stack (rtx adjust
)
951 if (adjust
== const0_rtx
)
954 /* We expect all variable sized adjustments to be multiple of
955 PREFERRED_STACK_BOUNDARY. */
956 if (CONST_INT_P (adjust
))
957 stack_pointer_delta
+= INTVAL (adjust
);
959 adjust_stack_1 (adjust
, true);
962 /* Round the size of a block to be pushed up to the boundary required
963 by this machine. SIZE is the desired size, which need not be constant. */
966 round_push (rtx size
)
968 rtx align_rtx
, alignm1_rtx
;
970 if (!SUPPORTS_STACK_ALIGNMENT
971 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
973 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
978 if (CONST_INT_P (size
))
980 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
982 if (INTVAL (size
) != new_size
)
983 size
= GEN_INT (new_size
);
987 align_rtx
= GEN_INT (align
);
988 alignm1_rtx
= GEN_INT (align
- 1);
992 /* If crtl->preferred_stack_boundary might still grow, use
993 virtual_preferred_stack_boundary_rtx instead. This will be
994 substituted by the right value in vregs pass and optimized
996 align_rtx
= virtual_preferred_stack_boundary_rtx
;
997 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
1001 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1002 but we know it can't. So add ourselves and then do
1004 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1005 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1006 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1008 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1013 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1014 to a previously-created save area. If no save area has been allocated,
1015 this function will allocate one. If a save area is specified, it
1016 must be of the proper mode. */
1019 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1022 /* The default is that we use a move insn and save in a Pmode object. */
1023 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1024 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1026 /* See if this machine has anything special to do for this kind of save. */
1030 if (targetm
.have_save_stack_block ())
1031 fcn
= targetm
.gen_save_stack_block
;
1034 if (targetm
.have_save_stack_function ())
1035 fcn
= targetm
.gen_save_stack_function
;
1038 if (targetm
.have_save_stack_nonlocal ())
1039 fcn
= targetm
.gen_save_stack_nonlocal
;
1045 /* If there is no save area and we have to allocate one, do so. Otherwise
1046 verify the save area is the proper mode. */
1050 if (mode
!= VOIDmode
)
1052 if (save_level
== SAVE_NONLOCAL
)
1053 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1055 *psave
= sa
= gen_reg_rtx (mode
);
1059 do_pending_stack_adjust ();
1061 sa
= validize_mem (sa
);
1062 emit_insn (fcn (sa
, stack_pointer_rtx
));
1065 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1066 area made by emit_stack_save. If it is zero, we have nothing to do. */
1069 emit_stack_restore (enum save_level save_level
, rtx sa
)
1071 /* The default is that we use a move insn. */
1072 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1074 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1075 STACK_POINTER and HARD_FRAME_POINTER.
1076 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1077 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1078 aligned variables, which is reflected in ix86_can_eliminate.
1079 We normally still have the realigned STACK_POINTER that we can use.
1080 But if there is a stack restore still present at reload, it can trigger
1081 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1082 FRAME_POINTER into a hard reg.
1083 To prevent this situation, we force need_drap if we emit a stack
1085 if (SUPPORTS_STACK_ALIGNMENT
)
1086 crtl
->need_drap
= true;
1088 /* See if this machine has anything special to do for this kind of save. */
1092 if (targetm
.have_restore_stack_block ())
1093 fcn
= targetm
.gen_restore_stack_block
;
1096 if (targetm
.have_restore_stack_function ())
1097 fcn
= targetm
.gen_restore_stack_function
;
1100 if (targetm
.have_restore_stack_nonlocal ())
1101 fcn
= targetm
.gen_restore_stack_nonlocal
;
1109 sa
= validize_mem (sa
);
1110 /* These clobbers prevent the scheduler from moving
1111 references to variable arrays below the code
1112 that deletes (pops) the arrays. */
1113 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1114 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1117 discard_pending_stack_adjust ();
1119 emit_insn (fcn (stack_pointer_rtx
, sa
));
1122 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1123 function. This should be called whenever we allocate or deallocate
1124 dynamic stack space. */
1127 update_nonlocal_goto_save_area (void)
1132 /* The nonlocal_goto_save_area object is an array of N pointers. The
1133 first one is used for the frame pointer save; the rest are sized by
1134 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1135 of the stack save area slots. */
1136 t_save
= build4 (ARRAY_REF
,
1137 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1138 cfun
->nonlocal_goto_save_area
,
1139 integer_one_node
, NULL_TREE
, NULL_TREE
);
1140 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1142 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1145 /* Record a new stack level for the current function. This should be called
1146 whenever we allocate or deallocate dynamic stack space. */
1149 record_new_stack_level (void)
1151 /* Record the new stack level for nonlocal gotos. */
1152 if (cfun
->nonlocal_goto_save_area
)
1153 update_nonlocal_goto_save_area ();
1155 /* Record the new stack level for SJLJ exceptions. */
1156 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1157 update_sjlj_context ();
1160 /* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */
1162 align_dynamic_address (rtx target
, unsigned required_align
)
1164 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1165 but we know it can't. So add ourselves and then do
1167 target
= expand_binop (Pmode
, add_optab
, target
,
1168 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1170 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1171 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1172 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1175 target
= expand_mult (Pmode
, target
,
1176 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1183 /* Return an rtx through *PSIZE, representing the size of an area of memory to
1184 be dynamically pushed on the stack.
1186 *PSIZE is an rtx representing the size of the area.
1188 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1189 parameter may be zero. If so, a proper value will be extracted
1190 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1192 REQUIRED_ALIGN is the alignment (in bits) required for the region
1195 If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for
1196 the additional size returned. */
1198 get_dynamic_stack_size (rtx
*psize
, unsigned size_align
,
1199 unsigned required_align
,
1200 HOST_WIDE_INT
*pstack_usage_size
)
1205 /* Ensure the size is in the proper mode. */
1206 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1207 size
= convert_to_mode (Pmode
, size
, 1);
1209 if (CONST_INT_P (size
))
1211 unsigned HOST_WIDE_INT lsb
;
1213 lsb
= INTVAL (size
);
1216 /* Watch out for overflow truncating to "unsigned". */
1217 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1218 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1220 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1222 else if (size_align
< BITS_PER_UNIT
)
1223 size_align
= BITS_PER_UNIT
;
1225 /* We can't attempt to minimize alignment necessary, because we don't
1226 know the final value of preferred_stack_boundary yet while executing
1228 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1229 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1231 /* We will need to ensure that the address we return is aligned to
1232 REQUIRED_ALIGN. At this point in the compilation, we don't always
1233 know the final value of the STACK_DYNAMIC_OFFSET used in function.c
1234 (it might depend on the size of the outgoing parameter lists, for
1235 example), so we must preventively align the value. We leave space
1236 in SIZE for the hole that might result from the alignment operation. */
1238 extra
= (required_align
- BITS_PER_UNIT
) / BITS_PER_UNIT
;
1239 size
= plus_constant (Pmode
, size
, extra
);
1240 size
= force_operand (size
, NULL_RTX
);
1242 if (flag_stack_usage_info
&& pstack_usage_size
)
1243 *pstack_usage_size
+= extra
;
1245 if (extra
&& size_align
> BITS_PER_UNIT
)
1246 size_align
= BITS_PER_UNIT
;
1248 /* Round the size to a multiple of the required stack alignment.
1249 Since the stack is presumed to be rounded before this allocation,
1250 this will maintain the required alignment.
1252 If the stack grows downward, we could save an insn by subtracting
1253 SIZE from the stack pointer and then aligning the stack pointer.
1254 The problem with this is that the stack pointer may be unaligned
1255 between the execution of the subtraction and alignment insns and
1256 some machines do not allow this. Even on those that do, some
1257 signal handlers malfunction if a signal should occur between those
1258 insns. Since this is an extremely rare event, we have no reliable
1259 way of knowing which systems have this problem. So we avoid even
1260 momentarily mis-aligning the stack. */
1261 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1263 size
= round_push (size
);
1265 if (flag_stack_usage_info
&& pstack_usage_size
)
1267 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1268 *pstack_usage_size
=
1269 (*pstack_usage_size
+ align
- 1) / align
* align
;
1276 /* Return an rtx representing the address of an area of memory dynamically
1277 pushed on the stack.
1279 Any required stack pointer alignment is preserved.
1281 SIZE is an rtx representing the size of the area.
1283 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1284 parameter may be zero. If so, a proper value will be extracted
1285 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1287 REQUIRED_ALIGN is the alignment (in bits) required for the region
1290 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1291 stack space allocated by the generated code cannot be added with itself
1292 in the course of the execution of the function. It is always safe to
1293 pass FALSE here and the following criterion is sufficient in order to
1294 pass TRUE: every path in the CFG that starts at the allocation point and
1295 loops to it executes the associated deallocation code. */
1298 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1299 unsigned required_align
, bool cannot_accumulate
)
1301 HOST_WIDE_INT stack_usage_size
= -1;
1302 rtx_code_label
*final_label
;
1303 rtx final_target
, target
;
1305 /* If we're asking for zero bytes, it doesn't matter what we point
1306 to since we can't dereference it. But return a reasonable
1308 if (size
== const0_rtx
)
1309 return virtual_stack_dynamic_rtx
;
1311 /* Otherwise, show we're calling alloca or equivalent. */
1312 cfun
->calls_alloca
= 1;
1314 /* If stack usage info is requested, look into the size we are passed.
1315 We need to do so this early to avoid the obfuscation that may be
1316 introduced later by the various alignment operations. */
1317 if (flag_stack_usage_info
)
1319 if (CONST_INT_P (size
))
1320 stack_usage_size
= INTVAL (size
);
1321 else if (REG_P (size
))
1323 /* Look into the last emitted insn and see if we can deduce
1324 something for the register. */
1327 insn
= get_last_insn ();
1328 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1330 if (CONST_INT_P (SET_SRC (set
)))
1331 stack_usage_size
= INTVAL (SET_SRC (set
));
1332 else if ((note
= find_reg_equal_equiv_note (insn
))
1333 && CONST_INT_P (XEXP (note
, 0)))
1334 stack_usage_size
= INTVAL (XEXP (note
, 0));
1338 /* If the size is not constant, we can't say anything. */
1339 if (stack_usage_size
== -1)
1341 current_function_has_unbounded_dynamic_stack_size
= 1;
1342 stack_usage_size
= 0;
1346 get_dynamic_stack_size (&size
, size_align
, required_align
, &stack_usage_size
);
1348 target
= gen_reg_rtx (Pmode
);
1350 /* The size is supposed to be fully adjusted at this point so record it
1351 if stack usage info is requested. */
1352 if (flag_stack_usage_info
)
1354 current_function_dynamic_stack_size
+= stack_usage_size
;
1356 /* ??? This is gross but the only safe stance in the absence
1357 of stack usage oriented flow analysis. */
1358 if (!cannot_accumulate
)
1359 current_function_has_unbounded_dynamic_stack_size
= 1;
1362 do_pending_stack_adjust ();
1365 final_target
= NULL_RTX
;
1367 /* If we are splitting the stack, we need to ask the backend whether
1368 there is enough room on the current stack. If there isn't, or if
1369 the backend doesn't know how to tell is, then we need to call a
1370 function to allocate memory in some other way. This memory will
1371 be released when we release the current stack segment. The
1372 effect is that stack allocation becomes less efficient, but at
1373 least it doesn't cause a stack overflow. */
1374 if (flag_split_stack
)
1376 rtx_code_label
*available_label
;
1377 rtx ask
, space
, func
;
1379 available_label
= NULL
;
1381 if (targetm
.have_split_stack_space_check ())
1383 available_label
= gen_label_rtx ();
1385 /* This instruction will branch to AVAILABLE_LABEL if there
1386 are SIZE bytes available on the stack. */
1387 emit_insn (targetm
.gen_split_stack_space_check
1388 (size
, available_label
));
1391 /* The __morestack_allocate_stack_space function will allocate
1392 memory using malloc. If the alignment of the memory returned
1393 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1394 make sure we allocate enough space. */
1395 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1398 ask
= expand_binop (Pmode
, add_optab
, size
,
1399 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1401 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1403 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1405 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1408 if (available_label
== NULL_RTX
)
1411 final_target
= gen_reg_rtx (Pmode
);
1413 emit_move_insn (final_target
, space
);
1415 final_label
= gen_label_rtx ();
1416 emit_jump (final_label
);
1418 emit_label (available_label
);
1421 /* We ought to be called always on the toplevel and stack ought to be aligned
1423 gcc_assert (!(stack_pointer_delta
1424 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1426 /* If needed, check that we have the required amount of stack. Take into
1427 account what has already been checked. */
1428 if (STACK_CHECK_MOVING_SP
)
1430 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1431 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1433 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1434 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1436 /* Don't let anti_adjust_stack emit notes. */
1437 suppress_reg_args_size
= true;
1439 /* Perform the required allocation from the stack. Some systems do
1440 this differently than simply incrementing/decrementing from the
1441 stack pointer, such as acquiring the space by calling malloc(). */
1442 if (targetm
.have_allocate_stack ())
1444 struct expand_operand ops
[2];
1445 /* We don't have to check against the predicate for operand 0 since
1446 TARGET is known to be a pseudo of the proper mode, which must
1447 be valid for the operand. */
1448 create_fixed_operand (&ops
[0], target
);
1449 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1450 expand_insn (targetm
.code_for_allocate_stack
, 2, ops
);
1454 int saved_stack_pointer_delta
;
1456 if (!STACK_GROWS_DOWNWARD
)
1457 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1459 /* Check stack bounds if necessary. */
1460 if (crtl
->limit_stack
)
1463 rtx_code_label
*space_available
= gen_label_rtx ();
1464 if (STACK_GROWS_DOWNWARD
)
1465 available
= expand_binop (Pmode
, sub_optab
,
1466 stack_pointer_rtx
, stack_limit_rtx
,
1467 NULL_RTX
, 1, OPTAB_WIDEN
);
1469 available
= expand_binop (Pmode
, sub_optab
,
1470 stack_limit_rtx
, stack_pointer_rtx
,
1471 NULL_RTX
, 1, OPTAB_WIDEN
);
1473 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1475 if (targetm
.have_trap ())
1476 emit_insn (targetm
.gen_trap ());
1478 error ("stack limits not supported on this target");
1480 emit_label (space_available
);
1483 saved_stack_pointer_delta
= stack_pointer_delta
;
1485 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1486 anti_adjust_stack_and_probe (size
, false);
1488 anti_adjust_stack (size
);
1490 /* Even if size is constant, don't modify stack_pointer_delta.
1491 The constant size alloca should preserve
1492 crtl->preferred_stack_boundary alignment. */
1493 stack_pointer_delta
= saved_stack_pointer_delta
;
1495 if (STACK_GROWS_DOWNWARD
)
1496 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1499 suppress_reg_args_size
= false;
1501 /* Finish up the split stack handling. */
1502 if (final_label
!= NULL_RTX
)
1504 gcc_assert (flag_split_stack
);
1505 emit_move_insn (final_target
, target
);
1506 emit_label (final_label
);
1507 target
= final_target
;
1510 target
= align_dynamic_address (target
, required_align
);
1512 /* Now that we've committed to a return value, mark its alignment. */
1513 mark_reg_pointer (target
, required_align
);
1515 /* Record the new stack level. */
1516 record_new_stack_level ();
1521 /* Return an rtx representing the address of an area of memory already
1522 statically pushed onto the stack in the virtual stack vars area. (It is
1523 assumed that the area is allocated in the function prologue.)
1525 Any required stack pointer alignment is preserved.
1527 OFFSET is the offset of the area into the virtual stack vars area.
1529 REQUIRED_ALIGN is the alignment (in bits) required for the region
1533 get_dynamic_stack_base (HOST_WIDE_INT offset
, unsigned required_align
)
1537 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1538 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1540 target
= gen_reg_rtx (Pmode
);
1541 emit_move_insn (target
, virtual_stack_vars_rtx
);
1542 target
= expand_binop (Pmode
, add_optab
, target
,
1543 gen_int_mode (offset
, Pmode
),
1544 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1545 target
= align_dynamic_address (target
, required_align
);
1547 /* Now that we've committed to a return value, mark its alignment. */
1548 mark_reg_pointer (target
, required_align
);
1553 /* A front end may want to override GCC's stack checking by providing a
1554 run-time routine to call to check the stack, so provide a mechanism for
1555 calling that routine. */
1557 static GTY(()) rtx stack_check_libfunc
;
1560 set_stack_check_libfunc (const char *libfunc_name
)
1562 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1563 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1566 /* Emit one stack probe at ADDRESS, an address within the stack. */
1569 emit_stack_probe (rtx address
)
1571 if (targetm
.have_probe_stack_address ())
1572 emit_insn (targetm
.gen_probe_stack_address (address
));
1575 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1577 MEM_VOLATILE_P (memref
) = 1;
1579 /* See if we have an insn to probe the stack. */
1580 if (targetm
.have_probe_stack ())
1581 emit_insn (targetm
.gen_probe_stack (memref
));
1583 emit_move_insn (memref
, const0_rtx
);
1587 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1588 FIRST is a constant and size is a Pmode RTX. These are offsets from
1589 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1590 or subtract them from the stack pointer. */
1592 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1594 #if STACK_GROWS_DOWNWARD
1595 #define STACK_GROW_OP MINUS
1596 #define STACK_GROW_OPTAB sub_optab
1597 #define STACK_GROW_OFF(off) -(off)
1599 #define STACK_GROW_OP PLUS
1600 #define STACK_GROW_OPTAB add_optab
1601 #define STACK_GROW_OFF(off) (off)
1605 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1607 /* First ensure SIZE is Pmode. */
1608 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1609 size
= convert_to_mode (Pmode
, size
, 1);
1611 /* Next see if we have a function to check the stack. */
1612 if (stack_check_libfunc
)
1614 rtx addr
= memory_address (Pmode
,
1615 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1617 plus_constant (Pmode
,
1619 emit_library_call (stack_check_libfunc
, LCT_THROW
, VOIDmode
, 1, addr
,
1623 /* Next see if we have an insn to check the stack. */
1624 else if (targetm
.have_check_stack ())
1626 struct expand_operand ops
[1];
1627 rtx addr
= memory_address (Pmode
,
1628 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1630 plus_constant (Pmode
,
1633 create_input_operand (&ops
[0], addr
, Pmode
);
1634 success
= maybe_expand_insn (targetm
.code_for_check_stack
, 1, ops
);
1635 gcc_assert (success
);
1638 /* Otherwise we have to generate explicit probes. If we have a constant
1639 small number of them to generate, that's the easy case. */
1640 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1642 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1645 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1646 it exceeds SIZE. If only one probe is needed, this will not
1647 generate any code. Then probe at FIRST + SIZE. */
1648 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1650 addr
= memory_address (Pmode
,
1651 plus_constant (Pmode
, stack_pointer_rtx
,
1652 STACK_GROW_OFF (first
+ i
)));
1653 emit_stack_probe (addr
);
1656 addr
= memory_address (Pmode
,
1657 plus_constant (Pmode
, stack_pointer_rtx
,
1658 STACK_GROW_OFF (first
+ isize
)));
1659 emit_stack_probe (addr
);
1662 /* In the variable case, do the same as above, but in a loop. Note that we
1663 must be extra careful with variables wrapping around because we might be
1664 at the very top (or the very bottom) of the address space and we have to
1665 be able to handle this case properly; in particular, we use an equality
1666 test for the loop condition. */
1669 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1670 rtx_code_label
*loop_lab
= gen_label_rtx ();
1671 rtx_code_label
*end_lab
= gen_label_rtx ();
1673 /* Step 1: round SIZE to the previous multiple of the interval. */
1675 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1677 = simplify_gen_binary (AND
, Pmode
, size
,
1678 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1679 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1682 /* Step 2: compute initial and final value of the loop counter. */
1684 /* TEST_ADDR = SP + FIRST. */
1685 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1687 gen_int_mode (first
, Pmode
)),
1690 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1691 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1693 rounded_size_op
), NULL_RTX
);
1698 while (TEST_ADDR != LAST_ADDR)
1700 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1704 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1705 until it is equal to ROUNDED_SIZE. */
1707 emit_label (loop_lab
);
1709 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1710 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1713 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1714 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1715 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1718 gcc_assert (temp
== test_addr
);
1720 /* Probe at TEST_ADDR. */
1721 emit_stack_probe (test_addr
);
1723 emit_jump (loop_lab
);
1725 emit_label (end_lab
);
1728 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1729 that SIZE is equal to ROUNDED_SIZE. */
1731 /* TEMP = SIZE - ROUNDED_SIZE. */
1732 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1733 if (temp
!= const0_rtx
)
1737 if (CONST_INT_P (temp
))
1739 /* Use [base + disp} addressing mode if supported. */
1740 HOST_WIDE_INT offset
= INTVAL (temp
);
1741 addr
= memory_address (Pmode
,
1742 plus_constant (Pmode
, last_addr
,
1743 STACK_GROW_OFF (offset
)));
1747 /* Manual CSE if the difference is not known at compile-time. */
1748 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1749 addr
= memory_address (Pmode
,
1750 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1754 emit_stack_probe (addr
);
1758 /* Make sure nothing is scheduled before we are done. */
1759 emit_insn (gen_blockage ());
1762 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1763 while probing it. This pushes when SIZE is positive. SIZE need not
1764 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1765 by plus SIZE at the end. */
1768 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1770 /* We skip the probe for the first interval + a small dope of 4 words and
1771 probe that many bytes past the specified size to maintain a protection
1772 area at the botton of the stack. */
1773 const int dope
= 4 * UNITS_PER_WORD
;
1775 /* First ensure SIZE is Pmode. */
1776 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1777 size
= convert_to_mode (Pmode
, size
, 1);
1779 /* If we have a constant small number of probes to generate, that's the
1781 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1783 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1784 bool first_probe
= true;
1786 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1787 values of N from 1 until it exceeds SIZE. If only one probe is
1788 needed, this will not generate any code. Then adjust and probe
1789 to PROBE_INTERVAL + SIZE. */
1790 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1794 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1795 first_probe
= false;
1798 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1799 emit_stack_probe (stack_pointer_rtx
);
1803 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1805 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1806 emit_stack_probe (stack_pointer_rtx
);
1809 /* In the variable case, do the same as above, but in a loop. Note that we
1810 must be extra careful with variables wrapping around because we might be
1811 at the very top (or the very bottom) of the address space and we have to
1812 be able to handle this case properly; in particular, we use an equality
1813 test for the loop condition. */
1816 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1817 rtx_code_label
*loop_lab
= gen_label_rtx ();
1818 rtx_code_label
*end_lab
= gen_label_rtx ();
1821 /* Step 1: round SIZE to the previous multiple of the interval. */
1823 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1825 = simplify_gen_binary (AND
, Pmode
, size
,
1826 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1827 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1830 /* Step 2: compute initial and final value of the loop counter. */
1832 /* SP = SP_0 + PROBE_INTERVAL. */
1833 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1835 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1836 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1838 rounded_size_op
), NULL_RTX
);
1843 while (SP != LAST_ADDR)
1845 SP = SP + PROBE_INTERVAL
1849 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1850 values of N from 1 until it is equal to ROUNDED_SIZE. */
1852 emit_label (loop_lab
);
1854 /* Jump to END_LAB if SP == LAST_ADDR. */
1855 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1858 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1859 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1860 emit_stack_probe (stack_pointer_rtx
);
1862 emit_jump (loop_lab
);
1864 emit_label (end_lab
);
1867 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1868 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1870 /* TEMP = SIZE - ROUNDED_SIZE. */
1871 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1872 if (temp
!= const0_rtx
)
1874 /* Manual CSE if the difference is not known at compile-time. */
1875 if (GET_CODE (temp
) != CONST_INT
)
1876 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1877 anti_adjust_stack (temp
);
1878 emit_stack_probe (stack_pointer_rtx
);
1882 /* Adjust back and account for the additional first interval. */
1884 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1886 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1889 /* Return an rtx representing the register or memory location
1890 in which a scalar value of data type VALTYPE
1891 was returned by a function call to function FUNC.
1892 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1893 function is known, otherwise 0.
1894 OUTGOING is 1 if on a machine with register windows this function
1895 should return the register in which the function will put its result
1899 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1900 int outgoing ATTRIBUTE_UNUSED
)
1904 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1907 && GET_MODE (val
) == BLKmode
)
1909 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1910 opt_scalar_int_mode tmpmode
;
1912 /* int_size_in_bytes can return -1. We don't need a check here
1913 since the value of bytes will then be large enough that no
1914 mode will match anyway. */
1916 FOR_EACH_MODE_IN_CLASS (tmpmode
, MODE_INT
)
1918 /* Have we found a large enough mode? */
1919 if (GET_MODE_SIZE (tmpmode
.require ()) >= bytes
)
1923 PUT_MODE (val
, tmpmode
.require ());
1928 /* Return an rtx representing the register or memory location
1929 in which a scalar value of mode MODE was returned by a library call. */
1932 hard_libcall_value (machine_mode mode
, rtx fun
)
1934 return targetm
.calls
.libcall_value (mode
, fun
);
1937 /* Look up the tree code for a given rtx code
1938 to provide the arithmetic operation for real_arithmetic.
1939 The function returns an int because the caller may not know
1940 what `enum tree_code' means. */
1943 rtx_to_tree_code (enum rtx_code code
)
1945 enum tree_code tcode
;
1968 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1971 return ((int) tcode
);
1974 #include "gt-explow.h"