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"
37 #include "insn-config.h"
40 #include "langhooks.h"
42 #include "common/common-target.h"
45 static rtx
break_out_memory_refs (rtx
);
48 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
51 trunc_int_for_mode (HOST_WIDE_INT c
, enum machine_mode mode
)
53 int width
= GET_MODE_PRECISION (mode
);
55 /* You want to truncate to a _what_? */
56 gcc_assert (SCALAR_INT_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
80 plus_constant (enum machine_mode mode
, rtx x
, HOST_WIDE_INT c
)
87 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
100 if (GET_MODE_BITSIZE (mode
) > HOST_BITS_PER_WIDE_INT
)
102 double_int di_x
= double_int::from_shwi (INTVAL (x
));
103 double_int di_c
= double_int::from_shwi (c
);
106 double_int v
= di_x
.add_with_sign (di_c
, false, &overflow
);
110 return immed_double_int_const (v
, mode
);
113 return gen_int_mode (UINTVAL (x
) + c
, mode
);
117 double_int di_x
= double_int::from_pair (CONST_DOUBLE_HIGH (x
),
118 CONST_DOUBLE_LOW (x
));
119 double_int di_c
= double_int::from_shwi (c
);
122 double_int v
= di_x
.add_with_sign (di_c
, false, &overflow
);
124 /* Sorry, we have no way to represent overflows this wide.
125 To fix, add constant support wider than CONST_DOUBLE. */
126 gcc_assert (GET_MODE_BITSIZE (mode
) <= HOST_BITS_PER_DOUBLE_INT
);
128 return immed_double_int_const (v
, mode
);
132 /* If this is a reference to the constant pool, try replacing it with
133 a reference to a new constant. If the resulting address isn't
134 valid, don't return it because we have no way to validize it. */
135 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
136 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
138 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
139 tem
= force_const_mem (GET_MODE (x
), tem
);
140 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
146 /* If adding to something entirely constant, set a flag
147 so that we can add a CONST around the result. */
158 /* The interesting case is adding the integer to a sum. Look
159 for constant term in the sum and combine with C. For an
160 integer constant term or a constant term that is not an
161 explicit integer, we combine or group them together anyway.
163 We may not immediately return from the recursive call here, lest
164 all_constant gets lost. */
166 if (CONSTANT_P (XEXP (x
, 1)))
168 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0),
169 plus_constant (mode
, XEXP (x
, 1), c
));
172 else if (find_constant_term_loc (&y
))
174 /* We need to be careful since X may be shared and we can't
175 modify it in place. */
176 rtx copy
= copy_rtx (x
);
177 rtx
*const_loc
= find_constant_term_loc (©
);
179 *const_loc
= plus_constant (mode
, *const_loc
, c
);
190 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
192 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
194 else if (all_constant
)
195 return gen_rtx_CONST (mode
, x
);
200 /* If X is a sum, return a new sum like X but lacking any constant terms.
201 Add all the removed constant terms into *CONSTPTR.
202 X itself is not altered. The result != X if and only if
203 it is not isomorphic to X. */
206 eliminate_constant_term (rtx x
, rtx
*constptr
)
211 if (GET_CODE (x
) != PLUS
)
214 /* First handle constants appearing at this level explicitly. */
215 if (CONST_INT_P (XEXP (x
, 1))
216 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
218 && CONST_INT_P (tem
))
221 return eliminate_constant_term (XEXP (x
, 0), constptr
);
225 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
226 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
227 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
228 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
230 && CONST_INT_P (tem
))
233 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
239 /* Return an rtx for the size in bytes of the value of EXP. */
246 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
247 size
= TREE_OPERAND (exp
, 1);
250 size
= tree_expr_size (exp
);
252 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
255 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
258 /* Return a wide integer for the size in bytes of the value of EXP, or -1
259 if the size can vary or is larger than an integer. */
262 int_expr_size (tree exp
)
266 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
267 size
= TREE_OPERAND (exp
, 1);
270 size
= tree_expr_size (exp
);
274 if (size
== 0 || !tree_fits_shwi_p (size
))
277 return tree_to_shwi (size
);
280 /* Return a copy of X in which all memory references
281 and all constants that involve symbol refs
282 have been replaced with new temporary registers.
283 Also emit code to load the memory locations and constants
284 into those registers.
286 If X contains no such constants or memory references,
287 X itself (not a copy) is returned.
289 If a constant is found in the address that is not a legitimate constant
290 in an insn, it is left alone in the hope that it might be valid in the
293 X may contain no arithmetic except addition, subtraction and multiplication.
294 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
297 break_out_memory_refs (rtx x
)
300 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
301 && GET_MODE (x
) != VOIDmode
))
302 x
= force_reg (GET_MODE (x
), x
);
303 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
304 || GET_CODE (x
) == MULT
)
306 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
307 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
309 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
310 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
316 /* Given X, a memory address in address space AS' pointer mode, convert it to
317 an address in the address space's address mode, or vice versa (TO_MODE says
318 which way). We take advantage of the fact that pointers are not allowed to
319 overflow by commuting arithmetic operations over conversions so that address
320 arithmetic insns can be used. */
323 convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED
,
324 rtx x
, addr_space_t as 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
, XEXP (x
, 0));
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
381 (to_mode
, XEXP (x
, 0), as
));
386 /* FIXME: For addition, we used to permute the conversion and
387 addition operation only if one operand is a constant and
388 converting the constant does not change it or if one operand
389 is a constant and we are using a ptr_extend instruction
390 (POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
391 may overflow/underflow. We relax the condition to include
392 zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
393 parts of the compiler depend on it. See PR 49721.
395 We can always safely permute them if we are making the address
397 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
398 || (GET_CODE (x
) == PLUS
399 && CONST_INT_P (XEXP (x
, 1))
400 && (POINTERS_EXTEND_UNSIGNED
!= 0
401 || XEXP (x
, 1) == convert_memory_address_addr_space
402 (to_mode
, XEXP (x
, 1), as
))))
403 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
404 convert_memory_address_addr_space
405 (to_mode
, XEXP (x
, 0), as
),
413 return convert_modes (to_mode
, from_mode
,
414 x
, POINTERS_EXTEND_UNSIGNED
);
415 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
418 /* Return something equivalent to X but valid as a memory address for something
419 of mode MODE in the named address space AS. When X is not itself valid,
420 this works by copying X or subexpressions of it into registers. */
423 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
426 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
428 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
430 /* By passing constant addresses through registers
431 we get a chance to cse them. */
432 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
433 x
= force_reg (address_mode
, x
);
435 /* We get better cse by rejecting indirect addressing at this stage.
436 Let the combiner create indirect addresses where appropriate.
437 For now, generate the code so that the subexpressions useful to share
438 are visible. But not if cse won't be done! */
441 if (! cse_not_expected
&& !REG_P (x
))
442 x
= break_out_memory_refs (x
);
444 /* At this point, any valid address is accepted. */
445 if (memory_address_addr_space_p (mode
, x
, as
))
448 /* If it was valid before but breaking out memory refs invalidated it,
449 use it the old way. */
450 if (memory_address_addr_space_p (mode
, oldx
, as
))
456 /* Perform machine-dependent transformations on X
457 in certain cases. This is not necessary since the code
458 below can handle all possible cases, but machine-dependent
459 transformations can make better code. */
462 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
463 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
467 /* PLUS and MULT can appear in special ways
468 as the result of attempts to make an address usable for indexing.
469 Usually they are dealt with by calling force_operand, below.
470 But a sum containing constant terms is special
471 if removing them makes the sum a valid address:
472 then we generate that address in a register
473 and index off of it. We do this because it often makes
474 shorter code, and because the addresses thus generated
475 in registers often become common subexpressions. */
476 if (GET_CODE (x
) == PLUS
)
478 rtx constant_term
= const0_rtx
;
479 rtx y
= eliminate_constant_term (x
, &constant_term
);
480 if (constant_term
== const0_rtx
481 || ! memory_address_addr_space_p (mode
, y
, as
))
482 x
= force_operand (x
, NULL_RTX
);
485 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
486 if (! memory_address_addr_space_p (mode
, y
, as
))
487 x
= force_operand (x
, NULL_RTX
);
493 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
494 x
= force_operand (x
, NULL_RTX
);
496 /* If we have a register that's an invalid address,
497 it must be a hard reg of the wrong class. Copy it to a pseudo. */
501 /* Last resort: copy the value to a register, since
502 the register is a valid address. */
504 x
= force_reg (address_mode
, x
);
509 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
510 /* If we didn't change the address, we are done. Otherwise, mark
511 a reg as a pointer if we have REG or REG + CONST_INT. */
515 mark_reg_pointer (x
, BITS_PER_UNIT
);
516 else if (GET_CODE (x
) == PLUS
517 && REG_P (XEXP (x
, 0))
518 && CONST_INT_P (XEXP (x
, 1)))
519 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
521 /* OLDX may have been the address on a temporary. Update the address
522 to indicate that X is now used. */
523 update_temp_slot_address (oldx
, x
);
528 /* Convert a mem ref into one with a valid memory address.
529 Pass through anything else unchanged. */
532 validize_mem (rtx ref
)
536 ref
= use_anchored_address (ref
);
537 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
538 MEM_ADDR_SPACE (ref
)))
541 /* Don't alter REF itself, since that is probably a stack slot. */
542 return replace_equiv_address (ref
, XEXP (ref
, 0));
545 /* If X is a memory reference to a member of an object block, try rewriting
546 it to use an anchor instead. Return the new memory reference on success
547 and the old one on failure. */
550 use_anchored_address (rtx x
)
553 HOST_WIDE_INT offset
;
554 enum machine_mode mode
;
556 if (!flag_section_anchors
)
562 /* Split the address into a base and offset. */
565 if (GET_CODE (base
) == CONST
566 && GET_CODE (XEXP (base
, 0)) == PLUS
567 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
569 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
570 base
= XEXP (XEXP (base
, 0), 0);
573 /* Check whether BASE is suitable for anchors. */
574 if (GET_CODE (base
) != SYMBOL_REF
575 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
576 || SYMBOL_REF_ANCHOR_P (base
)
577 || SYMBOL_REF_BLOCK (base
) == NULL
578 || !targetm
.use_anchors_for_symbol_p (base
))
581 /* Decide where BASE is going to be. */
582 place_block_symbol (base
);
584 /* Get the anchor we need to use. */
585 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
586 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
587 SYMBOL_REF_TLS_MODEL (base
));
589 /* Work out the offset from the anchor. */
590 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
592 /* If we're going to run a CSE pass, force the anchor into a register.
593 We will then be able to reuse registers for several accesses, if the
594 target costs say that that's worthwhile. */
595 mode
= GET_MODE (base
);
596 if (!cse_not_expected
)
597 base
= force_reg (mode
, base
);
599 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
602 /* Copy the value or contents of X to a new temp reg and return that reg. */
607 rtx temp
= gen_reg_rtx (GET_MODE (x
));
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
);
615 emit_move_insn (temp
, x
);
620 /* Like copy_to_reg but always give the new register mode Pmode
621 in case X is a constant. */
624 copy_addr_to_reg (rtx x
)
626 return copy_to_mode_reg (Pmode
, x
);
629 /* Like copy_to_reg but always give the new register mode MODE
630 in case X is a constant. */
633 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
635 rtx temp
= gen_reg_rtx (mode
);
637 /* If not an operand, must be an address with PLUS and MULT so
638 do the computation. */
639 if (! general_operand (x
, VOIDmode
))
640 x
= force_operand (x
, temp
);
642 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
644 emit_move_insn (temp
, x
);
648 /* Load X into a register if it is not already one.
649 Use mode MODE for the register.
650 X should be valid for mode MODE, but it may be a constant which
651 is valid for all integer modes; that's why caller must specify MODE.
653 The caller must not alter the value in the register we return,
654 since we mark it as a "constant" register. */
657 force_reg (enum machine_mode mode
, rtx x
)
664 if (general_operand (x
, mode
))
666 temp
= gen_reg_rtx (mode
);
667 insn
= emit_move_insn (temp
, x
);
671 temp
= force_operand (x
, NULL_RTX
);
673 insn
= get_last_insn ();
676 rtx temp2
= gen_reg_rtx (mode
);
677 insn
= emit_move_insn (temp2
, temp
);
682 /* Let optimizers know that TEMP's value never changes
683 and that X can be substituted for it. Don't get confused
684 if INSN set something else (such as a SUBREG of TEMP). */
686 && (set
= single_set (insn
)) != 0
687 && SET_DEST (set
) == temp
688 && ! rtx_equal_p (x
, SET_SRC (set
)))
689 set_unique_reg_note (insn
, REG_EQUAL
, x
);
691 /* Let optimizers know that TEMP is a pointer, and if so, the
692 known alignment of that pointer. */
695 if (GET_CODE (x
) == SYMBOL_REF
)
697 align
= BITS_PER_UNIT
;
698 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
699 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
701 else if (GET_CODE (x
) == LABEL_REF
)
702 align
= BITS_PER_UNIT
;
703 else if (GET_CODE (x
) == CONST
704 && GET_CODE (XEXP (x
, 0)) == PLUS
705 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
706 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
708 rtx s
= XEXP (XEXP (x
, 0), 0);
709 rtx c
= XEXP (XEXP (x
, 0), 1);
713 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
714 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
720 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
721 align
= MIN (sa
, ca
);
725 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
726 mark_reg_pointer (temp
, align
);
732 /* If X is a memory ref, copy its contents to a new temp reg and return
733 that reg. Otherwise, return X. */
736 force_not_mem (rtx x
)
740 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
743 temp
= gen_reg_rtx (GET_MODE (x
));
746 REG_POINTER (temp
) = 1;
748 emit_move_insn (temp
, x
);
752 /* Copy X to TARGET (if it's nonzero and a reg)
753 or to a new temp reg and return that reg.
754 MODE is the mode to use for X in case it is a constant. */
757 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
761 if (target
&& REG_P (target
))
764 temp
= gen_reg_rtx (mode
);
766 emit_move_insn (temp
, x
);
770 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
771 PUNSIGNEDP points to the signedness of the type and may be adjusted
772 to show what signedness to use on extension operations.
774 FOR_RETURN is nonzero if the caller is promoting the return value
775 of FNDECL, else it is for promoting args. */
778 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
779 const_tree funtype
, int for_return
)
781 /* Called without a type node for a libcall. */
782 if (type
== NULL_TREE
)
784 if (INTEGRAL_MODE_P (mode
))
785 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
792 switch (TREE_CODE (type
))
794 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
795 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
796 case POINTER_TYPE
: case REFERENCE_TYPE
:
797 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
804 /* Return the mode to use to store a scalar of TYPE and MODE.
805 PUNSIGNEDP points to the signedness of the type and may be adjusted
806 to show what signedness to use on extension operations. */
809 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
810 int *punsignedp ATTRIBUTE_UNUSED
)
817 /* For libcalls this is invoked without TYPE from the backends
818 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
820 if (type
== NULL_TREE
)
823 /* FIXME: this is the same logic that was there until GCC 4.4, but we
824 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
825 is not defined. The affected targets are M32C, S390, SPARC. */
827 code
= TREE_CODE (type
);
828 unsignedp
= *punsignedp
;
832 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
833 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
834 PROMOTE_MODE (mode
, unsignedp
, type
);
835 *punsignedp
= unsignedp
;
839 #ifdef POINTERS_EXTEND_UNSIGNED
842 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
843 if (upc_shared_type_p (TREE_TYPE (type
)))
844 return TYPE_MODE (upc_pts_type_node
);
845 return targetm
.addr_space
.address_mode
846 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
859 /* Use one of promote_mode or promote_function_mode to find the promoted
860 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
861 of DECL after promotion. */
864 promote_decl_mode (const_tree decl
, int *punsignedp
)
866 tree type
= TREE_TYPE (decl
);
867 int unsignedp
= TYPE_UNSIGNED (type
);
868 enum machine_mode mode
= DECL_MODE (decl
);
869 enum machine_mode pmode
;
871 if (TREE_CODE (decl
) == RESULT_DECL
872 || TREE_CODE (decl
) == PARM_DECL
)
873 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
874 TREE_TYPE (current_function_decl
), 2);
876 pmode
= promote_mode (type
, mode
, &unsignedp
);
879 *punsignedp
= unsignedp
;
884 /* Controls the behaviour of {anti_,}adjust_stack. */
885 static bool suppress_reg_args_size
;
887 /* A helper for adjust_stack and anti_adjust_stack. */
890 adjust_stack_1 (rtx adjust
, bool anti_p
)
894 #ifndef STACK_GROWS_DOWNWARD
895 /* Hereafter anti_p means subtract_p. */
899 temp
= expand_binop (Pmode
,
900 anti_p
? sub_optab
: add_optab
,
901 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
904 if (temp
!= stack_pointer_rtx
)
905 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
908 insn
= get_last_insn ();
909 temp
= single_set (insn
);
910 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
913 if (!suppress_reg_args_size
)
914 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
917 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
918 This pops when ADJUST is positive. ADJUST need not be constant. */
921 adjust_stack (rtx adjust
)
923 if (adjust
== const0_rtx
)
926 /* We expect all variable sized adjustments to be multiple of
927 PREFERRED_STACK_BOUNDARY. */
928 if (CONST_INT_P (adjust
))
929 stack_pointer_delta
-= INTVAL (adjust
);
931 adjust_stack_1 (adjust
, false);
934 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
935 This pushes when ADJUST is positive. ADJUST need not be constant. */
938 anti_adjust_stack (rtx adjust
)
940 if (adjust
== const0_rtx
)
943 /* We expect all variable sized adjustments to be multiple of
944 PREFERRED_STACK_BOUNDARY. */
945 if (CONST_INT_P (adjust
))
946 stack_pointer_delta
+= INTVAL (adjust
);
948 adjust_stack_1 (adjust
, true);
951 /* Round the size of a block to be pushed up to the boundary required
952 by this machine. SIZE is the desired size, which need not be constant. */
955 round_push (rtx size
)
957 rtx align_rtx
, alignm1_rtx
;
959 if (!SUPPORTS_STACK_ALIGNMENT
960 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
962 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
967 if (CONST_INT_P (size
))
969 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
971 if (INTVAL (size
) != new_size
)
972 size
= GEN_INT (new_size
);
976 align_rtx
= GEN_INT (align
);
977 alignm1_rtx
= GEN_INT (align
- 1);
981 /* If crtl->preferred_stack_boundary might still grow, use
982 virtual_preferred_stack_boundary_rtx instead. This will be
983 substituted by the right value in vregs pass and optimized
985 align_rtx
= virtual_preferred_stack_boundary_rtx
;
986 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
990 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
991 but we know it can't. So add ourselves and then do
993 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
994 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
995 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
997 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1002 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1003 to a previously-created save area. If no save area has been allocated,
1004 this function will allocate one. If a save area is specified, it
1005 must be of the proper mode. */
1008 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1011 /* The default is that we use a move insn and save in a Pmode object. */
1012 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1013 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1015 /* See if this machine has anything special to do for this kind of save. */
1018 #ifdef HAVE_save_stack_block
1020 if (HAVE_save_stack_block
)
1021 fcn
= gen_save_stack_block
;
1024 #ifdef HAVE_save_stack_function
1026 if (HAVE_save_stack_function
)
1027 fcn
= gen_save_stack_function
;
1030 #ifdef HAVE_save_stack_nonlocal
1032 if (HAVE_save_stack_nonlocal
)
1033 fcn
= gen_save_stack_nonlocal
;
1040 /* If there is no save area and we have to allocate one, do so. Otherwise
1041 verify the save area is the proper mode. */
1045 if (mode
!= VOIDmode
)
1047 if (save_level
== SAVE_NONLOCAL
)
1048 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1050 *psave
= sa
= gen_reg_rtx (mode
);
1054 do_pending_stack_adjust ();
1056 sa
= validize_mem (sa
);
1057 emit_insn (fcn (sa
, stack_pointer_rtx
));
1060 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1061 area made by emit_stack_save. If it is zero, we have nothing to do. */
1064 emit_stack_restore (enum save_level save_level
, rtx sa
)
1066 /* The default is that we use a move insn. */
1067 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1069 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1070 STACK_POINTER and HARD_FRAME_POINTER.
1071 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1072 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1073 aligned variables, which is reflected in ix86_can_eliminate.
1074 We normally still have the realigned STACK_POINTER that we can use.
1075 But if there is a stack restore still present at reload, it can trigger
1076 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1077 FRAME_POINTER into a hard reg.
1078 To prevent this situation, we force need_drap if we emit a stack
1080 if (SUPPORTS_STACK_ALIGNMENT
)
1081 crtl
->need_drap
= true;
1083 /* See if this machine has anything special to do for this kind of save. */
1086 #ifdef HAVE_restore_stack_block
1088 if (HAVE_restore_stack_block
)
1089 fcn
= gen_restore_stack_block
;
1092 #ifdef HAVE_restore_stack_function
1094 if (HAVE_restore_stack_function
)
1095 fcn
= gen_restore_stack_function
;
1098 #ifdef HAVE_restore_stack_nonlocal
1100 if (HAVE_restore_stack_nonlocal
)
1101 fcn
= gen_restore_stack_nonlocal
;
1110 sa
= validize_mem (sa
);
1111 /* These clobbers prevent the scheduler from moving
1112 references to variable arrays below the code
1113 that deletes (pops) the arrays. */
1114 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1115 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1118 discard_pending_stack_adjust ();
1120 emit_insn (fcn (stack_pointer_rtx
, sa
));
1123 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1124 function. This function should be called whenever we allocate or
1125 deallocate dynamic stack space. */
1128 update_nonlocal_goto_save_area (void)
1133 /* The nonlocal_goto_save_area object is an array of N pointers. The
1134 first one is used for the frame pointer save; the rest are sized by
1135 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1136 of the stack save area slots. */
1137 t_save
= build4 (ARRAY_REF
,
1138 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1139 cfun
->nonlocal_goto_save_area
,
1140 integer_one_node
, NULL_TREE
, NULL_TREE
);
1141 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1143 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1146 /* Return an rtx representing the address of an area of memory dynamically
1147 pushed on the stack.
1149 Any required stack pointer alignment is preserved.
1151 SIZE is an rtx representing the size of the area.
1153 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1154 parameter may be zero. If so, a proper value will be extracted
1155 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1157 REQUIRED_ALIGN is the alignment (in bits) required for the region
1160 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1161 stack space allocated by the generated code cannot be added with itself
1162 in the course of the execution of the function. It is always safe to
1163 pass FALSE here and the following criterion is sufficient in order to
1164 pass TRUE: every path in the CFG that starts at the allocation point and
1165 loops to it executes the associated deallocation code. */
1168 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1169 unsigned required_align
, bool cannot_accumulate
)
1171 HOST_WIDE_INT stack_usage_size
= -1;
1172 rtx final_label
, final_target
, target
;
1173 unsigned extra_align
= 0;
1176 /* If we're asking for zero bytes, it doesn't matter what we point
1177 to since we can't dereference it. But return a reasonable
1179 if (size
== const0_rtx
)
1180 return virtual_stack_dynamic_rtx
;
1182 /* Otherwise, show we're calling alloca or equivalent. */
1183 cfun
->calls_alloca
= 1;
1185 /* If stack usage info is requested, look into the size we are passed.
1186 We need to do so this early to avoid the obfuscation that may be
1187 introduced later by the various alignment operations. */
1188 if (flag_stack_usage_info
)
1190 if (CONST_INT_P (size
))
1191 stack_usage_size
= INTVAL (size
);
1192 else if (REG_P (size
))
1194 /* Look into the last emitted insn and see if we can deduce
1195 something for the register. */
1196 rtx insn
, set
, note
;
1197 insn
= get_last_insn ();
1198 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1200 if (CONST_INT_P (SET_SRC (set
)))
1201 stack_usage_size
= INTVAL (SET_SRC (set
));
1202 else if ((note
= find_reg_equal_equiv_note (insn
))
1203 && CONST_INT_P (XEXP (note
, 0)))
1204 stack_usage_size
= INTVAL (XEXP (note
, 0));
1208 /* If the size is not constant, we can't say anything. */
1209 if (stack_usage_size
== -1)
1211 current_function_has_unbounded_dynamic_stack_size
= 1;
1212 stack_usage_size
= 0;
1216 /* Ensure the size is in the proper mode. */
1217 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1218 size
= convert_to_mode (Pmode
, size
, 1);
1220 /* Adjust SIZE_ALIGN, if needed. */
1221 if (CONST_INT_P (size
))
1223 unsigned HOST_WIDE_INT lsb
;
1225 lsb
= INTVAL (size
);
1228 /* Watch out for overflow truncating to "unsigned". */
1229 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1230 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1232 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1234 else if (size_align
< BITS_PER_UNIT
)
1235 size_align
= BITS_PER_UNIT
;
1237 /* We can't attempt to minimize alignment necessary, because we don't
1238 know the final value of preferred_stack_boundary yet while executing
1240 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1241 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1243 /* We will need to ensure that the address we return is aligned to
1244 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1245 always know its final value at this point in the compilation (it
1246 might depend on the size of the outgoing parameter lists, for
1247 example), so we must align the value to be returned in that case.
1248 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1249 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1250 We must also do an alignment operation on the returned value if
1251 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1253 If we have to align, we must leave space in SIZE for the hole
1254 that might result from the alignment operation. */
1256 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1259 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1260 extra_align
= PREFERRED_STACK_BOUNDARY
;
1261 else if (required_align
> STACK_BOUNDARY
)
1262 extra_align
= STACK_BOUNDARY
;
1264 extra_align
= BITS_PER_UNIT
;
1267 /* ??? STACK_POINTER_OFFSET is always defined now. */
1268 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1270 extra_align
= BITS_PER_UNIT
;
1275 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1277 size
= plus_constant (Pmode
, size
, extra
);
1278 size
= force_operand (size
, NULL_RTX
);
1280 if (flag_stack_usage_info
)
1281 stack_usage_size
+= extra
;
1283 if (extra
&& size_align
> extra_align
)
1284 size_align
= extra_align
;
1287 /* Round the size to a multiple of the required stack alignment.
1288 Since the stack if presumed to be rounded before this allocation,
1289 this will maintain the required alignment.
1291 If the stack grows downward, we could save an insn by subtracting
1292 SIZE from the stack pointer and then aligning the stack pointer.
1293 The problem with this is that the stack pointer may be unaligned
1294 between the execution of the subtraction and alignment insns and
1295 some machines do not allow this. Even on those that do, some
1296 signal handlers malfunction if a signal should occur between those
1297 insns. Since this is an extremely rare event, we have no reliable
1298 way of knowing which systems have this problem. So we avoid even
1299 momentarily mis-aligning the stack. */
1300 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1302 size
= round_push (size
);
1304 if (flag_stack_usage_info
)
1306 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1307 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1311 target
= gen_reg_rtx (Pmode
);
1313 /* The size is supposed to be fully adjusted at this point so record it
1314 if stack usage info is requested. */
1315 if (flag_stack_usage_info
)
1317 current_function_dynamic_stack_size
+= stack_usage_size
;
1319 /* ??? This is gross but the only safe stance in the absence
1320 of stack usage oriented flow analysis. */
1321 if (!cannot_accumulate
)
1322 current_function_has_unbounded_dynamic_stack_size
= 1;
1325 final_label
= NULL_RTX
;
1326 final_target
= NULL_RTX
;
1328 /* If we are splitting the stack, we need to ask the backend whether
1329 there is enough room on the current stack. If there isn't, or if
1330 the backend doesn't know how to tell is, then we need to call a
1331 function to allocate memory in some other way. This memory will
1332 be released when we release the current stack segment. The
1333 effect is that stack allocation becomes less efficient, but at
1334 least it doesn't cause a stack overflow. */
1335 if (flag_split_stack
)
1337 rtx available_label
, ask
, space
, func
;
1339 available_label
= NULL_RTX
;
1341 #ifdef HAVE_split_stack_space_check
1342 if (HAVE_split_stack_space_check
)
1344 available_label
= gen_label_rtx ();
1346 /* This instruction will branch to AVAILABLE_LABEL if there
1347 are SIZE bytes available on the stack. */
1348 emit_insn (gen_split_stack_space_check (size
, available_label
));
1352 /* The __morestack_allocate_stack_space function will allocate
1353 memory using malloc. If the alignment of the memory returned
1354 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1355 make sure we allocate enough space. */
1356 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1360 ask
= expand_binop (Pmode
, add_optab
, size
,
1361 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1363 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1367 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1369 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1372 if (available_label
== NULL_RTX
)
1375 final_target
= gen_reg_rtx (Pmode
);
1377 emit_move_insn (final_target
, space
);
1379 final_label
= gen_label_rtx ();
1380 emit_jump (final_label
);
1382 emit_label (available_label
);
1385 do_pending_stack_adjust ();
1387 /* We ought to be called always on the toplevel and stack ought to be aligned
1389 gcc_assert (!(stack_pointer_delta
1390 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1392 /* If needed, check that we have the required amount of stack. Take into
1393 account what has already been checked. */
1394 if (STACK_CHECK_MOVING_SP
)
1396 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1397 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1399 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1400 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1402 /* Don't let anti_adjust_stack emit notes. */
1403 suppress_reg_args_size
= true;
1405 /* Perform the required allocation from the stack. Some systems do
1406 this differently than simply incrementing/decrementing from the
1407 stack pointer, such as acquiring the space by calling malloc(). */
1408 #ifdef HAVE_allocate_stack
1409 if (HAVE_allocate_stack
)
1411 struct expand_operand ops
[2];
1412 /* We don't have to check against the predicate for operand 0 since
1413 TARGET is known to be a pseudo of the proper mode, which must
1414 be valid for the operand. */
1415 create_fixed_operand (&ops
[0], target
);
1416 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1417 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1422 int saved_stack_pointer_delta
;
1424 #ifndef STACK_GROWS_DOWNWARD
1425 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1428 /* Check stack bounds if necessary. */
1429 if (crtl
->limit_stack
)
1432 rtx space_available
= gen_label_rtx ();
1433 #ifdef STACK_GROWS_DOWNWARD
1434 available
= expand_binop (Pmode
, sub_optab
,
1435 stack_pointer_rtx
, stack_limit_rtx
,
1436 NULL_RTX
, 1, OPTAB_WIDEN
);
1438 available
= expand_binop (Pmode
, sub_optab
,
1439 stack_limit_rtx
, stack_pointer_rtx
,
1440 NULL_RTX
, 1, OPTAB_WIDEN
);
1442 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1446 emit_insn (gen_trap ());
1449 error ("stack limits not supported on this target");
1451 emit_label (space_available
);
1454 saved_stack_pointer_delta
= stack_pointer_delta
;
1456 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1457 anti_adjust_stack_and_probe (size
, false);
1459 anti_adjust_stack (size
);
1461 /* Even if size is constant, don't modify stack_pointer_delta.
1462 The constant size alloca should preserve
1463 crtl->preferred_stack_boundary alignment. */
1464 stack_pointer_delta
= saved_stack_pointer_delta
;
1466 #ifdef STACK_GROWS_DOWNWARD
1467 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1471 suppress_reg_args_size
= false;
1473 /* Finish up the split stack handling. */
1474 if (final_label
!= NULL_RTX
)
1476 gcc_assert (flag_split_stack
);
1477 emit_move_insn (final_target
, target
);
1478 emit_label (final_label
);
1479 target
= final_target
;
1484 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1485 but we know it can't. So add ourselves and then do
1487 target
= expand_binop (Pmode
, add_optab
, target
,
1488 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1490 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1491 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1492 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1495 target
= expand_mult (Pmode
, target
,
1496 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1501 /* Now that we've committed to a return value, mark its alignment. */
1502 mark_reg_pointer (target
, required_align
);
1504 /* Record the new stack level for nonlocal gotos. */
1505 if (cfun
->nonlocal_goto_save_area
!= 0)
1506 update_nonlocal_goto_save_area ();
1511 /* A front end may want to override GCC's stack checking by providing a
1512 run-time routine to call to check the stack, so provide a mechanism for
1513 calling that routine. */
1515 static GTY(()) rtx stack_check_libfunc
;
1518 set_stack_check_libfunc (const char *libfunc_name
)
1520 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1521 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1524 /* Emit one stack probe at ADDRESS, an address within the stack. */
1527 emit_stack_probe (rtx address
)
1529 #ifdef HAVE_probe_stack_address
1530 if (HAVE_probe_stack_address
)
1531 emit_insn (gen_probe_stack_address (address
));
1535 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1537 MEM_VOLATILE_P (memref
) = 1;
1539 /* See if we have an insn to probe the stack. */
1540 #ifdef HAVE_probe_stack
1541 if (HAVE_probe_stack
)
1542 emit_insn (gen_probe_stack (memref
));
1545 emit_move_insn (memref
, const0_rtx
);
1549 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1550 FIRST is a constant and size is a Pmode RTX. These are offsets from
1551 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1552 or subtract them from the stack pointer. */
1554 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1556 #ifdef STACK_GROWS_DOWNWARD
1557 #define STACK_GROW_OP MINUS
1558 #define STACK_GROW_OPTAB sub_optab
1559 #define STACK_GROW_OFF(off) -(off)
1561 #define STACK_GROW_OP PLUS
1562 #define STACK_GROW_OPTAB add_optab
1563 #define STACK_GROW_OFF(off) (off)
1567 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1569 /* First ensure SIZE is Pmode. */
1570 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1571 size
= convert_to_mode (Pmode
, size
, 1);
1573 /* Next see if we have a function to check the stack. */
1574 if (stack_check_libfunc
)
1576 rtx addr
= memory_address (Pmode
,
1577 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1579 plus_constant (Pmode
,
1581 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1585 /* Next see if we have an insn to check the stack. */
1586 #ifdef HAVE_check_stack
1587 else if (HAVE_check_stack
)
1589 struct expand_operand ops
[1];
1590 rtx addr
= memory_address (Pmode
,
1591 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1593 plus_constant (Pmode
,
1596 create_input_operand (&ops
[0], addr
, Pmode
);
1597 success
= maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
);
1598 gcc_assert (success
);
1602 /* Otherwise we have to generate explicit probes. If we have a constant
1603 small number of them to generate, that's the easy case. */
1604 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1606 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1609 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1610 it exceeds SIZE. If only one probe is needed, this will not
1611 generate any code. Then probe at FIRST + SIZE. */
1612 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1614 addr
= memory_address (Pmode
,
1615 plus_constant (Pmode
, stack_pointer_rtx
,
1616 STACK_GROW_OFF (first
+ i
)));
1617 emit_stack_probe (addr
);
1620 addr
= memory_address (Pmode
,
1621 plus_constant (Pmode
, stack_pointer_rtx
,
1622 STACK_GROW_OFF (first
+ isize
)));
1623 emit_stack_probe (addr
);
1626 /* In the variable case, do the same as above, but in a loop. Note that we
1627 must be extra careful with variables wrapping around because we might be
1628 at the very top (or the very bottom) of the address space and we have to
1629 be able to handle this case properly; in particular, we use an equality
1630 test for the loop condition. */
1633 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1634 rtx loop_lab
= gen_label_rtx ();
1635 rtx end_lab
= gen_label_rtx ();
1638 /* Step 1: round SIZE to the previous multiple of the interval. */
1640 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1642 = simplify_gen_binary (AND
, Pmode
, size
,
1643 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1644 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1647 /* Step 2: compute initial and final value of the loop counter. */
1649 /* TEST_ADDR = SP + FIRST. */
1650 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1652 gen_int_mode (first
, Pmode
)),
1655 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1656 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1658 rounded_size_op
), NULL_RTX
);
1663 while (TEST_ADDR != LAST_ADDR)
1665 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1669 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1670 until it is equal to ROUNDED_SIZE. */
1672 emit_label (loop_lab
);
1674 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1675 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1678 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1679 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1680 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1683 gcc_assert (temp
== test_addr
);
1685 /* Probe at TEST_ADDR. */
1686 emit_stack_probe (test_addr
);
1688 emit_jump (loop_lab
);
1690 emit_label (end_lab
);
1693 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1694 that SIZE is equal to ROUNDED_SIZE. */
1696 /* TEMP = SIZE - ROUNDED_SIZE. */
1697 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1698 if (temp
!= const0_rtx
)
1702 if (CONST_INT_P (temp
))
1704 /* Use [base + disp} addressing mode if supported. */
1705 HOST_WIDE_INT offset
= INTVAL (temp
);
1706 addr
= memory_address (Pmode
,
1707 plus_constant (Pmode
, last_addr
,
1708 STACK_GROW_OFF (offset
)));
1712 /* Manual CSE if the difference is not known at compile-time. */
1713 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1714 addr
= memory_address (Pmode
,
1715 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1719 emit_stack_probe (addr
);
1724 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1725 while probing it. This pushes when SIZE is positive. SIZE need not
1726 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1727 by plus SIZE at the end. */
1730 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1732 /* We skip the probe for the first interval + a small dope of 4 words and
1733 probe that many bytes past the specified size to maintain a protection
1734 area at the botton of the stack. */
1735 const int dope
= 4 * UNITS_PER_WORD
;
1737 /* First ensure SIZE is Pmode. */
1738 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1739 size
= convert_to_mode (Pmode
, size
, 1);
1741 /* If we have a constant small number of probes to generate, that's the
1743 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1745 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1746 bool first_probe
= true;
1748 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1749 values of N from 1 until it exceeds SIZE. If only one probe is
1750 needed, this will not generate any code. Then adjust and probe
1751 to PROBE_INTERVAL + SIZE. */
1752 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1756 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1757 first_probe
= false;
1760 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1761 emit_stack_probe (stack_pointer_rtx
);
1765 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1767 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1768 emit_stack_probe (stack_pointer_rtx
);
1771 /* In the variable case, do the same as above, but in a loop. Note that we
1772 must be extra careful with variables wrapping around because we might be
1773 at the very top (or the very bottom) of the address space and we have to
1774 be able to handle this case properly; in particular, we use an equality
1775 test for the loop condition. */
1778 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1779 rtx loop_lab
= gen_label_rtx ();
1780 rtx end_lab
= gen_label_rtx ();
1783 /* Step 1: round SIZE to the previous multiple of the interval. */
1785 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1787 = simplify_gen_binary (AND
, Pmode
, size
,
1788 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1789 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1792 /* Step 2: compute initial and final value of the loop counter. */
1794 /* SP = SP_0 + PROBE_INTERVAL. */
1795 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1797 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1798 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1800 rounded_size_op
), NULL_RTX
);
1805 while (SP != LAST_ADDR)
1807 SP = SP + PROBE_INTERVAL
1811 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1812 values of N from 1 until it is equal to ROUNDED_SIZE. */
1814 emit_label (loop_lab
);
1816 /* Jump to END_LAB if SP == LAST_ADDR. */
1817 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1820 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1821 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1822 emit_stack_probe (stack_pointer_rtx
);
1824 emit_jump (loop_lab
);
1826 emit_label (end_lab
);
1829 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1830 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1832 /* TEMP = SIZE - ROUNDED_SIZE. */
1833 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1834 if (temp
!= const0_rtx
)
1836 /* Manual CSE if the difference is not known at compile-time. */
1837 if (GET_CODE (temp
) != CONST_INT
)
1838 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1839 anti_adjust_stack (temp
);
1840 emit_stack_probe (stack_pointer_rtx
);
1844 /* Adjust back and account for the additional first interval. */
1846 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1848 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1851 /* Return an rtx representing the register or memory location
1852 in which a scalar value of data type VALTYPE
1853 was returned by a function call to function FUNC.
1854 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1855 function is known, otherwise 0.
1856 OUTGOING is 1 if on a machine with register windows this function
1857 should return the register in which the function will put its result
1861 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1862 int outgoing ATTRIBUTE_UNUSED
)
1866 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1869 && GET_MODE (val
) == BLKmode
)
1871 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1872 enum machine_mode tmpmode
;
1874 /* int_size_in_bytes can return -1. We don't need a check here
1875 since the value of bytes will then be large enough that no
1876 mode will match anyway. */
1878 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1879 tmpmode
!= VOIDmode
;
1880 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1882 /* Have we found a large enough mode? */
1883 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1887 /* No suitable mode found. */
1888 gcc_assert (tmpmode
!= VOIDmode
);
1890 PUT_MODE (val
, tmpmode
);
1895 /* Return an rtx representing the register or memory location
1896 in which a scalar value of mode MODE was returned by a library call. */
1899 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1901 return targetm
.calls
.libcall_value (mode
, fun
);
1904 /* Look up the tree code for a given rtx code
1905 to provide the arithmetic operation for REAL_ARITHMETIC.
1906 The function returns an int because the caller may not know
1907 what `enum tree_code' means. */
1910 rtx_to_tree_code (enum rtx_code code
)
1912 enum tree_code tcode
;
1935 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1938 return ((int) tcode
);
1941 #include "gt-explow.h"