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"
40 #include "insn-codes.h"
43 #include "insn-config.h"
46 #include "langhooks.h"
48 #include "common/common-target.h"
51 static rtx
break_out_memory_refs (rtx
);
54 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
57 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
59 int width
= GET_MODE_PRECISION (mode
);
61 /* You want to truncate to a _what_? */
62 gcc_assert (SCALAR_INT_MODE_P (mode
));
64 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
66 return c
& 1 ? STORE_FLAG_VALUE
: 0;
68 /* Sign-extend for the requested mode. */
70 if (width
< HOST_BITS_PER_WIDE_INT
)
72 HOST_WIDE_INT sign
= 1;
82 /* Return an rtx for the sum of X and the integer C, given that X has
83 mode MODE. INPLACE is true if X can be modified inplace or false
84 if it must be treated as immutable. */
87 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
95 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
107 CASE_CONST_SCALAR_INT
:
108 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
111 /* If this is a reference to the constant pool, try replacing it with
112 a reference to a new constant. If the resulting address isn't
113 valid, don't return it because we have no way to validize it. */
114 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
115 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
117 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
118 tem
= force_const_mem (GET_MODE (x
), tem
);
119 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
125 /* If adding to something entirely constant, set a flag
126 so that we can add a CONST around the result. */
127 if (inplace
&& shared_const_p (x
))
139 /* The interesting case is adding the integer to a sum. Look
140 for constant term in the sum and combine with C. For an
141 integer constant term or a constant term that is not an
142 explicit integer, we combine or group them together anyway.
144 We may not immediately return from the recursive call here, lest
145 all_constant gets lost. */
147 if (CONSTANT_P (XEXP (x
, 1)))
149 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
150 if (term
== const0_rtx
)
155 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
158 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
162 /* We need to be careful since X may be shared and we can't
163 modify it in place. */
165 const_loc
= find_constant_term_loc (&x
);
167 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
177 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
179 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
181 else if (all_constant
)
182 return gen_rtx_CONST (mode
, x
);
187 /* If X is a sum, return a new sum like X but lacking any constant terms.
188 Add all the removed constant terms into *CONSTPTR.
189 X itself is not altered. The result != X if and only if
190 it is not isomorphic to X. */
193 eliminate_constant_term (rtx x
, rtx
*constptr
)
198 if (GET_CODE (x
) != PLUS
)
201 /* First handle constants appearing at this level explicitly. */
202 if (CONST_INT_P (XEXP (x
, 1))
203 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
205 && CONST_INT_P (tem
))
208 return eliminate_constant_term (XEXP (x
, 0), constptr
);
212 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
213 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
214 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
215 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
217 && CONST_INT_P (tem
))
220 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
226 /* Returns a tree for the size of EXP in bytes. */
229 tree_expr_size (const_tree exp
)
232 && DECL_SIZE_UNIT (exp
) != 0)
233 return DECL_SIZE_UNIT (exp
);
235 return size_in_bytes (TREE_TYPE (exp
));
238 /* Return an rtx for the size in bytes of the value of EXP. */
245 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
246 size
= TREE_OPERAND (exp
, 1);
249 size
= tree_expr_size (exp
);
251 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
254 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
257 /* Return a wide integer for the size in bytes of the value of EXP, or -1
258 if the size can vary or is larger than an integer. */
261 int_expr_size (tree exp
)
265 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
266 size
= TREE_OPERAND (exp
, 1);
269 size
= tree_expr_size (exp
);
273 if (size
== 0 || !tree_fits_shwi_p (size
))
276 return tree_to_shwi (size
);
279 /* Return a copy of X in which all memory references
280 and all constants that involve symbol refs
281 have been replaced with new temporary registers.
282 Also emit code to load the memory locations and constants
283 into those registers.
285 If X contains no such constants or memory references,
286 X itself (not a copy) is returned.
288 If a constant is found in the address that is not a legitimate constant
289 in an insn, it is left alone in the hope that it might be valid in the
292 X may contain no arithmetic except addition, subtraction and multiplication.
293 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
296 break_out_memory_refs (rtx x
)
299 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
300 && GET_MODE (x
) != VOIDmode
))
301 x
= force_reg (GET_MODE (x
), x
);
302 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
303 || GET_CODE (x
) == MULT
)
305 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
306 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
308 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
309 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
315 /* Given X, a memory address in address space AS' pointer mode, convert it to
316 an address in the address space's address mode, or vice versa (TO_MODE says
317 which way). We take advantage of the fact that pointers are not allowed to
318 overflow by commuting arithmetic operations over conversions so that address
319 arithmetic insns can be used. IN_CONST is true if this conversion is inside
323 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
324 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
325 bool in_const ATTRIBUTE_UNUSED
)
327 #ifndef POINTERS_EXTEND_UNSIGNED
328 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
330 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
331 machine_mode pointer_mode
, address_mode
, from_mode
;
335 /* If X already has the right mode, just return it. */
336 if (GET_MODE (x
) == to_mode
)
339 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
340 address_mode
= targetm
.addr_space
.address_mode (as
);
341 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
343 /* Here we handle some special cases. If none of them apply, fall through
344 to the default case. */
345 switch (GET_CODE (x
))
347 CASE_CONST_SCALAR_INT
:
348 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
350 else if (POINTERS_EXTEND_UNSIGNED
< 0)
352 else if (POINTERS_EXTEND_UNSIGNED
> 0)
356 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
362 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
363 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
364 return SUBREG_REG (x
);
368 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
369 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
374 temp
= shallow_copy_rtx (x
);
375 PUT_MODE (temp
, to_mode
);
380 return gen_rtx_CONST (to_mode
,
381 convert_memory_address_addr_space_1
382 (to_mode
, XEXP (x
, 0), as
, true));
387 /* For addition we can safely permute the conversion and addition
388 operation if one operand is a constant and converting the constant
389 does not change it or if one operand is a constant and we are
390 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
391 We can always safely permute them if we are making the address
392 narrower. Inside a CONST RTL, this is safe for both pointers
393 zero or sign extended as pointers cannot wrap. */
394 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
395 || (GET_CODE (x
) == PLUS
396 && CONST_INT_P (XEXP (x
, 1))
397 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
398 || XEXP (x
, 1) == convert_memory_address_addr_space_1
399 (to_mode
, XEXP (x
, 1), as
, in_const
)
400 || POINTERS_EXTEND_UNSIGNED
< 0)))
401 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
402 convert_memory_address_addr_space_1
403 (to_mode
, XEXP (x
, 0), as
, in_const
),
411 return convert_modes (to_mode
, from_mode
,
412 x
, POINTERS_EXTEND_UNSIGNED
);
413 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
416 /* Given X, a memory address in address space AS' pointer mode, convert it to
417 an address in the address space's address mode, or vice versa (TO_MODE says
418 which way). We take advantage of the fact that pointers are not allowed to
419 overflow by commuting arithmetic operations over conversions so that address
420 arithmetic insns can be used. */
423 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
425 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false);
428 /* Return something equivalent to X but valid as a memory address for something
429 of mode MODE in the named address space AS. When X is not itself valid,
430 this works by copying X or subexpressions of it into registers. */
433 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
436 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
438 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
440 /* By passing constant addresses through registers
441 we get a chance to cse them. */
442 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
443 x
= force_reg (address_mode
, x
);
445 /* We get better cse by rejecting indirect addressing at this stage.
446 Let the combiner create indirect addresses where appropriate.
447 For now, generate the code so that the subexpressions useful to share
448 are visible. But not if cse won't be done! */
451 if (! cse_not_expected
&& !REG_P (x
))
452 x
= break_out_memory_refs (x
);
454 /* At this point, any valid address is accepted. */
455 if (memory_address_addr_space_p (mode
, x
, as
))
458 /* If it was valid before but breaking out memory refs invalidated it,
459 use it the old way. */
460 if (memory_address_addr_space_p (mode
, oldx
, as
))
466 /* Perform machine-dependent transformations on X
467 in certain cases. This is not necessary since the code
468 below can handle all possible cases, but machine-dependent
469 transformations can make better code. */
472 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
473 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
477 /* PLUS and MULT can appear in special ways
478 as the result of attempts to make an address usable for indexing.
479 Usually they are dealt with by calling force_operand, below.
480 But a sum containing constant terms is special
481 if removing them makes the sum a valid address:
482 then we generate that address in a register
483 and index off of it. We do this because it often makes
484 shorter code, and because the addresses thus generated
485 in registers often become common subexpressions. */
486 if (GET_CODE (x
) == PLUS
)
488 rtx constant_term
= const0_rtx
;
489 rtx y
= eliminate_constant_term (x
, &constant_term
);
490 if (constant_term
== const0_rtx
491 || ! memory_address_addr_space_p (mode
, y
, as
))
492 x
= force_operand (x
, NULL_RTX
);
495 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
496 if (! memory_address_addr_space_p (mode
, y
, as
))
497 x
= force_operand (x
, NULL_RTX
);
503 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
504 x
= force_operand (x
, NULL_RTX
);
506 /* If we have a register that's an invalid address,
507 it must be a hard reg of the wrong class. Copy it to a pseudo. */
511 /* Last resort: copy the value to a register, since
512 the register is a valid address. */
514 x
= force_reg (address_mode
, x
);
519 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
520 /* If we didn't change the address, we are done. Otherwise, mark
521 a reg as a pointer if we have REG or REG + CONST_INT. */
525 mark_reg_pointer (x
, BITS_PER_UNIT
);
526 else if (GET_CODE (x
) == PLUS
527 && REG_P (XEXP (x
, 0))
528 && CONST_INT_P (XEXP (x
, 1)))
529 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
531 /* OLDX may have been the address on a temporary. Update the address
532 to indicate that X is now used. */
533 update_temp_slot_address (oldx
, x
);
538 /* If REF is a MEM with an invalid address, change it into a valid address.
539 Pass through anything else unchanged. REF must be an unshared rtx and
540 the function may modify it in-place. */
543 validize_mem (rtx ref
)
547 ref
= use_anchored_address (ref
);
548 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
549 MEM_ADDR_SPACE (ref
)))
552 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
555 /* If X is a memory reference to a member of an object block, try rewriting
556 it to use an anchor instead. Return the new memory reference on success
557 and the old one on failure. */
560 use_anchored_address (rtx x
)
563 HOST_WIDE_INT offset
;
566 if (!flag_section_anchors
)
572 /* Split the address into a base and offset. */
575 if (GET_CODE (base
) == CONST
576 && GET_CODE (XEXP (base
, 0)) == PLUS
577 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
579 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
580 base
= XEXP (XEXP (base
, 0), 0);
583 /* Check whether BASE is suitable for anchors. */
584 if (GET_CODE (base
) != SYMBOL_REF
585 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
586 || SYMBOL_REF_ANCHOR_P (base
)
587 || SYMBOL_REF_BLOCK (base
) == NULL
588 || !targetm
.use_anchors_for_symbol_p (base
))
591 /* Decide where BASE is going to be. */
592 place_block_symbol (base
);
594 /* Get the anchor we need to use. */
595 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
596 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
597 SYMBOL_REF_TLS_MODEL (base
));
599 /* Work out the offset from the anchor. */
600 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
602 /* If we're going to run a CSE pass, force the anchor into a register.
603 We will then be able to reuse registers for several accesses, if the
604 target costs say that that's worthwhile. */
605 mode
= GET_MODE (base
);
606 if (!cse_not_expected
)
607 base
= force_reg (mode
, base
);
609 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
612 /* Copy the value or contents of X to a new temp reg and return that reg. */
617 rtx temp
= gen_reg_rtx (GET_MODE (x
));
619 /* If not an operand, must be an address with PLUS and MULT so
620 do the computation. */
621 if (! general_operand (x
, VOIDmode
))
622 x
= force_operand (x
, temp
);
625 emit_move_insn (temp
, x
);
630 /* Like copy_to_reg but always give the new register mode Pmode
631 in case X is a constant. */
634 copy_addr_to_reg (rtx x
)
636 return copy_to_mode_reg (Pmode
, x
);
639 /* Like copy_to_reg but always give the new register mode MODE
640 in case X is a constant. */
643 copy_to_mode_reg (machine_mode mode
, rtx x
)
645 rtx temp
= gen_reg_rtx (mode
);
647 /* If not an operand, must be an address with PLUS and MULT so
648 do the computation. */
649 if (! general_operand (x
, VOIDmode
))
650 x
= force_operand (x
, temp
);
652 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
654 emit_move_insn (temp
, x
);
658 /* Load X into a register if it is not already one.
659 Use mode MODE for the register.
660 X should be valid for mode MODE, but it may be a constant which
661 is valid for all integer modes; that's why caller must specify MODE.
663 The caller must not alter the value in the register we return,
664 since we mark it as a "constant" register. */
667 force_reg (machine_mode mode
, rtx x
)
675 if (general_operand (x
, mode
))
677 temp
= gen_reg_rtx (mode
);
678 insn
= emit_move_insn (temp
, x
);
682 temp
= force_operand (x
, NULL_RTX
);
684 insn
= get_last_insn ();
687 rtx temp2
= gen_reg_rtx (mode
);
688 insn
= emit_move_insn (temp2
, temp
);
693 /* Let optimizers know that TEMP's value never changes
694 and that X can be substituted for it. Don't get confused
695 if INSN set something else (such as a SUBREG of TEMP). */
697 && (set
= single_set (insn
)) != 0
698 && SET_DEST (set
) == temp
699 && ! rtx_equal_p (x
, SET_SRC (set
)))
700 set_unique_reg_note (insn
, REG_EQUAL
, x
);
702 /* Let optimizers know that TEMP is a pointer, and if so, the
703 known alignment of that pointer. */
706 if (GET_CODE (x
) == SYMBOL_REF
)
708 align
= BITS_PER_UNIT
;
709 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
710 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
712 else if (GET_CODE (x
) == LABEL_REF
)
713 align
= BITS_PER_UNIT
;
714 else if (GET_CODE (x
) == CONST
715 && GET_CODE (XEXP (x
, 0)) == PLUS
716 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
717 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
719 rtx s
= XEXP (XEXP (x
, 0), 0);
720 rtx c
= XEXP (XEXP (x
, 0), 1);
724 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
725 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
731 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
732 align
= MIN (sa
, ca
);
736 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
737 mark_reg_pointer (temp
, align
);
743 /* If X is a memory ref, copy its contents to a new temp reg and return
744 that reg. Otherwise, return X. */
747 force_not_mem (rtx x
)
751 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
754 temp
= gen_reg_rtx (GET_MODE (x
));
757 REG_POINTER (temp
) = 1;
759 emit_move_insn (temp
, x
);
763 /* Copy X to TARGET (if it's nonzero and a reg)
764 or to a new temp reg and return that reg.
765 MODE is the mode to use for X in case it is a constant. */
768 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
772 if (target
&& REG_P (target
))
775 temp
= gen_reg_rtx (mode
);
777 emit_move_insn (temp
, x
);
781 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
782 PUNSIGNEDP points to the signedness of the type and may be adjusted
783 to show what signedness to use on extension operations.
785 FOR_RETURN is nonzero if the caller is promoting the return value
786 of FNDECL, else it is for promoting args. */
789 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
790 const_tree funtype
, int for_return
)
792 /* Called without a type node for a libcall. */
793 if (type
== NULL_TREE
)
795 if (INTEGRAL_MODE_P (mode
))
796 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
803 switch (TREE_CODE (type
))
805 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
806 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
807 case POINTER_TYPE
: case REFERENCE_TYPE
:
808 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
815 /* Return the mode to use to store a scalar of TYPE and MODE.
816 PUNSIGNEDP points to the signedness of the type and may be adjusted
817 to show what signedness to use on extension operations. */
820 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
821 int *punsignedp ATTRIBUTE_UNUSED
)
828 /* For libcalls this is invoked without TYPE from the backends
829 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
831 if (type
== NULL_TREE
)
834 /* FIXME: this is the same logic that was there until GCC 4.4, but we
835 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
836 is not defined. The affected targets are M32C, S390, SPARC. */
838 code
= TREE_CODE (type
);
839 unsignedp
= *punsignedp
;
843 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
844 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
845 PROMOTE_MODE (mode
, unsignedp
, type
);
846 *punsignedp
= unsignedp
;
850 #ifdef POINTERS_EXTEND_UNSIGNED
853 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
854 return targetm
.addr_space
.address_mode
855 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
868 /* Use one of promote_mode or promote_function_mode to find the promoted
869 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
870 of DECL after promotion. */
873 promote_decl_mode (const_tree decl
, int *punsignedp
)
875 tree type
= TREE_TYPE (decl
);
876 int unsignedp
= TYPE_UNSIGNED (type
);
877 machine_mode mode
= DECL_MODE (decl
);
880 if (TREE_CODE (decl
) == RESULT_DECL
881 || TREE_CODE (decl
) == PARM_DECL
)
882 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
883 TREE_TYPE (current_function_decl
), 2);
885 pmode
= promote_mode (type
, mode
, &unsignedp
);
888 *punsignedp
= unsignedp
;
893 /* Controls the behaviour of {anti_,}adjust_stack. */
894 static bool suppress_reg_args_size
;
896 /* A helper for adjust_stack and anti_adjust_stack. */
899 adjust_stack_1 (rtx adjust
, bool anti_p
)
904 #ifndef STACK_GROWS_DOWNWARD
905 /* Hereafter anti_p means subtract_p. */
909 temp
= expand_binop (Pmode
,
910 anti_p
? sub_optab
: add_optab
,
911 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
914 if (temp
!= stack_pointer_rtx
)
915 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
918 insn
= get_last_insn ();
919 temp
= single_set (insn
);
920 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
923 if (!suppress_reg_args_size
)
924 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
927 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
928 This pops when ADJUST is positive. ADJUST need not be constant. */
931 adjust_stack (rtx adjust
)
933 if (adjust
== const0_rtx
)
936 /* We expect all variable sized adjustments to be multiple of
937 PREFERRED_STACK_BOUNDARY. */
938 if (CONST_INT_P (adjust
))
939 stack_pointer_delta
-= INTVAL (adjust
);
941 adjust_stack_1 (adjust
, false);
944 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
945 This pushes when ADJUST is positive. ADJUST need not be constant. */
948 anti_adjust_stack (rtx adjust
)
950 if (adjust
== const0_rtx
)
953 /* We expect all variable sized adjustments to be multiple of
954 PREFERRED_STACK_BOUNDARY. */
955 if (CONST_INT_P (adjust
))
956 stack_pointer_delta
+= INTVAL (adjust
);
958 adjust_stack_1 (adjust
, true);
961 /* Round the size of a block to be pushed up to the boundary required
962 by this machine. SIZE is the desired size, which need not be constant. */
965 round_push (rtx size
)
967 rtx align_rtx
, alignm1_rtx
;
969 if (!SUPPORTS_STACK_ALIGNMENT
970 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
972 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
977 if (CONST_INT_P (size
))
979 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
981 if (INTVAL (size
) != new_size
)
982 size
= GEN_INT (new_size
);
986 align_rtx
= GEN_INT (align
);
987 alignm1_rtx
= GEN_INT (align
- 1);
991 /* If crtl->preferred_stack_boundary might still grow, use
992 virtual_preferred_stack_boundary_rtx instead. This will be
993 substituted by the right value in vregs pass and optimized
995 align_rtx
= virtual_preferred_stack_boundary_rtx
;
996 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
1000 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1001 but we know it can't. So add ourselves and then do
1003 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1004 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1005 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1007 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1012 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1013 to a previously-created save area. If no save area has been allocated,
1014 this function will allocate one. If a save area is specified, it
1015 must be of the proper mode. */
1018 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1021 /* The default is that we use a move insn and save in a Pmode object. */
1022 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1023 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1025 /* See if this machine has anything special to do for this kind of save. */
1028 #ifdef HAVE_save_stack_block
1030 if (HAVE_save_stack_block
)
1031 fcn
= gen_save_stack_block
;
1034 #ifdef HAVE_save_stack_function
1036 if (HAVE_save_stack_function
)
1037 fcn
= gen_save_stack_function
;
1040 #ifdef HAVE_save_stack_nonlocal
1042 if (HAVE_save_stack_nonlocal
)
1043 fcn
= gen_save_stack_nonlocal
;
1050 /* If there is no save area and we have to allocate one, do so. Otherwise
1051 verify the save area is the proper mode. */
1055 if (mode
!= VOIDmode
)
1057 if (save_level
== SAVE_NONLOCAL
)
1058 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1060 *psave
= sa
= gen_reg_rtx (mode
);
1064 do_pending_stack_adjust ();
1066 sa
= validize_mem (sa
);
1067 emit_insn (fcn (sa
, stack_pointer_rtx
));
1070 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1071 area made by emit_stack_save. If it is zero, we have nothing to do. */
1074 emit_stack_restore (enum save_level save_level
, rtx sa
)
1076 /* The default is that we use a move insn. */
1077 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1079 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1080 STACK_POINTER and HARD_FRAME_POINTER.
1081 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1082 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1083 aligned variables, which is reflected in ix86_can_eliminate.
1084 We normally still have the realigned STACK_POINTER that we can use.
1085 But if there is a stack restore still present at reload, it can trigger
1086 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1087 FRAME_POINTER into a hard reg.
1088 To prevent this situation, we force need_drap if we emit a stack
1090 if (SUPPORTS_STACK_ALIGNMENT
)
1091 crtl
->need_drap
= true;
1093 /* See if this machine has anything special to do for this kind of save. */
1096 #ifdef HAVE_restore_stack_block
1098 if (HAVE_restore_stack_block
)
1099 fcn
= gen_restore_stack_block
;
1102 #ifdef HAVE_restore_stack_function
1104 if (HAVE_restore_stack_function
)
1105 fcn
= gen_restore_stack_function
;
1108 #ifdef HAVE_restore_stack_nonlocal
1110 if (HAVE_restore_stack_nonlocal
)
1111 fcn
= gen_restore_stack_nonlocal
;
1120 sa
= validize_mem (sa
);
1121 /* These clobbers prevent the scheduler from moving
1122 references to variable arrays below the code
1123 that deletes (pops) the arrays. */
1124 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1125 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1128 discard_pending_stack_adjust ();
1130 emit_insn (fcn (stack_pointer_rtx
, sa
));
1133 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1134 function. This function should be called whenever we allocate or
1135 deallocate dynamic stack space. */
1138 update_nonlocal_goto_save_area (void)
1143 /* The nonlocal_goto_save_area object is an array of N pointers. The
1144 first one is used for the frame pointer save; the rest are sized by
1145 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1146 of the stack save area slots. */
1147 t_save
= build4 (ARRAY_REF
,
1148 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1149 cfun
->nonlocal_goto_save_area
,
1150 integer_one_node
, NULL_TREE
, NULL_TREE
);
1151 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1153 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1156 /* Return an rtx representing the address of an area of memory dynamically
1157 pushed on the stack.
1159 Any required stack pointer alignment is preserved.
1161 SIZE is an rtx representing the size of the area.
1163 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1164 parameter may be zero. If so, a proper value will be extracted
1165 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1167 REQUIRED_ALIGN is the alignment (in bits) required for the region
1170 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1171 stack space allocated by the generated code cannot be added with itself
1172 in the course of the execution of the function. It is always safe to
1173 pass FALSE here and the following criterion is sufficient in order to
1174 pass TRUE: every path in the CFG that starts at the allocation point and
1175 loops to it executes the associated deallocation code. */
1178 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1179 unsigned required_align
, bool cannot_accumulate
)
1181 HOST_WIDE_INT stack_usage_size
= -1;
1182 rtx_code_label
*final_label
;
1183 rtx final_target
, target
;
1184 unsigned extra_align
= 0;
1187 /* If we're asking for zero bytes, it doesn't matter what we point
1188 to since we can't dereference it. But return a reasonable
1190 if (size
== const0_rtx
)
1191 return virtual_stack_dynamic_rtx
;
1193 /* Otherwise, show we're calling alloca or equivalent. */
1194 cfun
->calls_alloca
= 1;
1196 /* If stack usage info is requested, look into the size we are passed.
1197 We need to do so this early to avoid the obfuscation that may be
1198 introduced later by the various alignment operations. */
1199 if (flag_stack_usage_info
)
1201 if (CONST_INT_P (size
))
1202 stack_usage_size
= INTVAL (size
);
1203 else if (REG_P (size
))
1205 /* Look into the last emitted insn and see if we can deduce
1206 something for the register. */
1209 insn
= get_last_insn ();
1210 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1212 if (CONST_INT_P (SET_SRC (set
)))
1213 stack_usage_size
= INTVAL (SET_SRC (set
));
1214 else if ((note
= find_reg_equal_equiv_note (insn
))
1215 && CONST_INT_P (XEXP (note
, 0)))
1216 stack_usage_size
= INTVAL (XEXP (note
, 0));
1220 /* If the size is not constant, we can't say anything. */
1221 if (stack_usage_size
== -1)
1223 current_function_has_unbounded_dynamic_stack_size
= 1;
1224 stack_usage_size
= 0;
1228 /* Ensure the size is in the proper mode. */
1229 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1230 size
= convert_to_mode (Pmode
, size
, 1);
1232 /* Adjust SIZE_ALIGN, if needed. */
1233 if (CONST_INT_P (size
))
1235 unsigned HOST_WIDE_INT lsb
;
1237 lsb
= INTVAL (size
);
1240 /* Watch out for overflow truncating to "unsigned". */
1241 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1242 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1244 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1246 else if (size_align
< BITS_PER_UNIT
)
1247 size_align
= BITS_PER_UNIT
;
1249 /* We can't attempt to minimize alignment necessary, because we don't
1250 know the final value of preferred_stack_boundary yet while executing
1252 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1253 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1255 /* We will need to ensure that the address we return is aligned to
1256 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1257 always know its final value at this point in the compilation (it
1258 might depend on the size of the outgoing parameter lists, for
1259 example), so we must align the value to be returned in that case.
1260 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1261 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1262 We must also do an alignment operation on the returned value if
1263 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1265 If we have to align, we must leave space in SIZE for the hole
1266 that might result from the alignment operation. */
1268 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1271 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1272 extra_align
= PREFERRED_STACK_BOUNDARY
;
1273 else if (required_align
> STACK_BOUNDARY
)
1274 extra_align
= STACK_BOUNDARY
;
1276 extra_align
= BITS_PER_UNIT
;
1279 /* ??? STACK_POINTER_OFFSET is always defined now. */
1280 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1282 extra_align
= BITS_PER_UNIT
;
1287 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1289 size
= plus_constant (Pmode
, size
, extra
);
1290 size
= force_operand (size
, NULL_RTX
);
1292 if (flag_stack_usage_info
)
1293 stack_usage_size
+= extra
;
1295 if (extra
&& size_align
> extra_align
)
1296 size_align
= extra_align
;
1299 /* Round the size to a multiple of the required stack alignment.
1300 Since the stack if presumed to be rounded before this allocation,
1301 this will maintain the required alignment.
1303 If the stack grows downward, we could save an insn by subtracting
1304 SIZE from the stack pointer and then aligning the stack pointer.
1305 The problem with this is that the stack pointer may be unaligned
1306 between the execution of the subtraction and alignment insns and
1307 some machines do not allow this. Even on those that do, some
1308 signal handlers malfunction if a signal should occur between those
1309 insns. Since this is an extremely rare event, we have no reliable
1310 way of knowing which systems have this problem. So we avoid even
1311 momentarily mis-aligning the stack. */
1312 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1314 size
= round_push (size
);
1316 if (flag_stack_usage_info
)
1318 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1319 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1323 target
= gen_reg_rtx (Pmode
);
1325 /* The size is supposed to be fully adjusted at this point so record it
1326 if stack usage info is requested. */
1327 if (flag_stack_usage_info
)
1329 current_function_dynamic_stack_size
+= stack_usage_size
;
1331 /* ??? This is gross but the only safe stance in the absence
1332 of stack usage oriented flow analysis. */
1333 if (!cannot_accumulate
)
1334 current_function_has_unbounded_dynamic_stack_size
= 1;
1338 final_target
= NULL_RTX
;
1340 /* If we are splitting the stack, we need to ask the backend whether
1341 there is enough room on the current stack. If there isn't, or if
1342 the backend doesn't know how to tell is, then we need to call a
1343 function to allocate memory in some other way. This memory will
1344 be released when we release the current stack segment. The
1345 effect is that stack allocation becomes less efficient, but at
1346 least it doesn't cause a stack overflow. */
1347 if (flag_split_stack
)
1349 rtx_code_label
*available_label
;
1350 rtx ask
, space
, func
;
1352 available_label
= NULL
;
1354 #ifdef HAVE_split_stack_space_check
1355 if (HAVE_split_stack_space_check
)
1357 available_label
= gen_label_rtx ();
1359 /* This instruction will branch to AVAILABLE_LABEL if there
1360 are SIZE bytes available on the stack. */
1361 emit_insn (gen_split_stack_space_check (size
, available_label
));
1365 /* The __morestack_allocate_stack_space function will allocate
1366 memory using malloc. If the alignment of the memory returned
1367 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1368 make sure we allocate enough space. */
1369 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1373 ask
= expand_binop (Pmode
, add_optab
, size
,
1374 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1376 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1380 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1382 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1385 if (available_label
== NULL_RTX
)
1388 final_target
= gen_reg_rtx (Pmode
);
1390 emit_move_insn (final_target
, space
);
1392 final_label
= gen_label_rtx ();
1393 emit_jump (final_label
);
1395 emit_label (available_label
);
1398 do_pending_stack_adjust ();
1400 /* We ought to be called always on the toplevel and stack ought to be aligned
1402 gcc_assert (!(stack_pointer_delta
1403 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1405 /* If needed, check that we have the required amount of stack. Take into
1406 account what has already been checked. */
1407 if (STACK_CHECK_MOVING_SP
)
1409 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1410 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1412 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1413 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1415 /* Don't let anti_adjust_stack emit notes. */
1416 suppress_reg_args_size
= true;
1418 /* Perform the required allocation from the stack. Some systems do
1419 this differently than simply incrementing/decrementing from the
1420 stack pointer, such as acquiring the space by calling malloc(). */
1421 #ifdef HAVE_allocate_stack
1422 if (HAVE_allocate_stack
)
1424 struct expand_operand ops
[2];
1425 /* We don't have to check against the predicate for operand 0 since
1426 TARGET is known to be a pseudo of the proper mode, which must
1427 be valid for the operand. */
1428 create_fixed_operand (&ops
[0], target
);
1429 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1430 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1435 int saved_stack_pointer_delta
;
1437 #ifndef STACK_GROWS_DOWNWARD
1438 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1441 /* Check stack bounds if necessary. */
1442 if (crtl
->limit_stack
)
1445 rtx_code_label
*space_available
= gen_label_rtx ();
1446 #ifdef STACK_GROWS_DOWNWARD
1447 available
= expand_binop (Pmode
, sub_optab
,
1448 stack_pointer_rtx
, stack_limit_rtx
,
1449 NULL_RTX
, 1, OPTAB_WIDEN
);
1451 available
= expand_binop (Pmode
, sub_optab
,
1452 stack_limit_rtx
, stack_pointer_rtx
,
1453 NULL_RTX
, 1, OPTAB_WIDEN
);
1455 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1459 emit_insn (gen_trap ());
1462 error ("stack limits not supported on this target");
1464 emit_label (space_available
);
1467 saved_stack_pointer_delta
= stack_pointer_delta
;
1469 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1470 anti_adjust_stack_and_probe (size
, false);
1472 anti_adjust_stack (size
);
1474 /* Even if size is constant, don't modify stack_pointer_delta.
1475 The constant size alloca should preserve
1476 crtl->preferred_stack_boundary alignment. */
1477 stack_pointer_delta
= saved_stack_pointer_delta
;
1479 #ifdef STACK_GROWS_DOWNWARD
1480 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1484 suppress_reg_args_size
= false;
1486 /* Finish up the split stack handling. */
1487 if (final_label
!= NULL_RTX
)
1489 gcc_assert (flag_split_stack
);
1490 emit_move_insn (final_target
, target
);
1491 emit_label (final_label
);
1492 target
= final_target
;
1497 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1498 but we know it can't. So add ourselves and then do
1500 target
= expand_binop (Pmode
, add_optab
, target
,
1501 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1503 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1504 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1505 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1508 target
= expand_mult (Pmode
, target
,
1509 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1514 /* Now that we've committed to a return value, mark its alignment. */
1515 mark_reg_pointer (target
, required_align
);
1517 /* Record the new stack level for nonlocal gotos. */
1518 if (cfun
->nonlocal_goto_save_area
!= 0)
1519 update_nonlocal_goto_save_area ();
1524 /* A front end may want to override GCC's stack checking by providing a
1525 run-time routine to call to check the stack, so provide a mechanism for
1526 calling that routine. */
1528 static GTY(()) rtx stack_check_libfunc
;
1531 set_stack_check_libfunc (const char *libfunc_name
)
1533 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1534 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1537 /* Emit one stack probe at ADDRESS, an address within the stack. */
1540 emit_stack_probe (rtx address
)
1542 #ifdef HAVE_probe_stack_address
1543 if (HAVE_probe_stack_address
)
1544 emit_insn (gen_probe_stack_address (address
));
1548 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1550 MEM_VOLATILE_P (memref
) = 1;
1552 /* See if we have an insn to probe the stack. */
1553 #ifdef HAVE_probe_stack
1554 if (HAVE_probe_stack
)
1555 emit_insn (gen_probe_stack (memref
));
1558 emit_move_insn (memref
, const0_rtx
);
1562 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1563 FIRST is a constant and size is a Pmode RTX. These are offsets from
1564 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1565 or subtract them from the stack pointer. */
1567 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1569 #ifdef STACK_GROWS_DOWNWARD
1570 #define STACK_GROW_OP MINUS
1571 #define STACK_GROW_OPTAB sub_optab
1572 #define STACK_GROW_OFF(off) -(off)
1574 #define STACK_GROW_OP PLUS
1575 #define STACK_GROW_OPTAB add_optab
1576 #define STACK_GROW_OFF(off) (off)
1580 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1582 /* First ensure SIZE is Pmode. */
1583 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1584 size
= convert_to_mode (Pmode
, size
, 1);
1586 /* Next see if we have a function to check the stack. */
1587 if (stack_check_libfunc
)
1589 rtx addr
= memory_address (Pmode
,
1590 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1592 plus_constant (Pmode
,
1594 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1598 /* Next see if we have an insn to check the stack. */
1599 #ifdef HAVE_check_stack
1600 else if (HAVE_check_stack
)
1602 struct expand_operand ops
[1];
1603 rtx addr
= memory_address (Pmode
,
1604 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1606 plus_constant (Pmode
,
1609 create_input_operand (&ops
[0], addr
, Pmode
);
1610 success
= maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
);
1611 gcc_assert (success
);
1615 /* Otherwise we have to generate explicit probes. If we have a constant
1616 small number of them to generate, that's the easy case. */
1617 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1619 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1622 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1623 it exceeds SIZE. If only one probe is needed, this will not
1624 generate any code. Then probe at FIRST + SIZE. */
1625 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1627 addr
= memory_address (Pmode
,
1628 plus_constant (Pmode
, stack_pointer_rtx
,
1629 STACK_GROW_OFF (first
+ i
)));
1630 emit_stack_probe (addr
);
1633 addr
= memory_address (Pmode
,
1634 plus_constant (Pmode
, stack_pointer_rtx
,
1635 STACK_GROW_OFF (first
+ isize
)));
1636 emit_stack_probe (addr
);
1639 /* In the variable case, do the same as above, but in a loop. Note that we
1640 must be extra careful with variables wrapping around because we might be
1641 at the very top (or the very bottom) of the address space and we have to
1642 be able to handle this case properly; in particular, we use an equality
1643 test for the loop condition. */
1646 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1647 rtx_code_label
*loop_lab
= gen_label_rtx ();
1648 rtx_code_label
*end_lab
= gen_label_rtx ();
1650 /* Step 1: round SIZE to the previous multiple of the interval. */
1652 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1654 = simplify_gen_binary (AND
, Pmode
, size
,
1655 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1656 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1659 /* Step 2: compute initial and final value of the loop counter. */
1661 /* TEST_ADDR = SP + FIRST. */
1662 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1664 gen_int_mode (first
, Pmode
)),
1667 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1668 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1670 rounded_size_op
), NULL_RTX
);
1675 while (TEST_ADDR != LAST_ADDR)
1677 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1681 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1682 until it is equal to ROUNDED_SIZE. */
1684 emit_label (loop_lab
);
1686 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1687 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1690 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1691 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1692 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1695 gcc_assert (temp
== test_addr
);
1697 /* Probe at TEST_ADDR. */
1698 emit_stack_probe (test_addr
);
1700 emit_jump (loop_lab
);
1702 emit_label (end_lab
);
1705 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1706 that SIZE is equal to ROUNDED_SIZE. */
1708 /* TEMP = SIZE - ROUNDED_SIZE. */
1709 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1710 if (temp
!= const0_rtx
)
1714 if (CONST_INT_P (temp
))
1716 /* Use [base + disp} addressing mode if supported. */
1717 HOST_WIDE_INT offset
= INTVAL (temp
);
1718 addr
= memory_address (Pmode
,
1719 plus_constant (Pmode
, last_addr
,
1720 STACK_GROW_OFF (offset
)));
1724 /* Manual CSE if the difference is not known at compile-time. */
1725 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1726 addr
= memory_address (Pmode
,
1727 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1731 emit_stack_probe (addr
);
1735 /* Make sure nothing is scheduled before we are done. */
1736 emit_insn (gen_blockage ());
1739 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1740 while probing it. This pushes when SIZE is positive. SIZE need not
1741 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1742 by plus SIZE at the end. */
1745 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1747 /* We skip the probe for the first interval + a small dope of 4 words and
1748 probe that many bytes past the specified size to maintain a protection
1749 area at the botton of the stack. */
1750 const int dope
= 4 * UNITS_PER_WORD
;
1752 /* First ensure SIZE is Pmode. */
1753 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1754 size
= convert_to_mode (Pmode
, size
, 1);
1756 /* If we have a constant small number of probes to generate, that's the
1758 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1760 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1761 bool first_probe
= true;
1763 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1764 values of N from 1 until it exceeds SIZE. If only one probe is
1765 needed, this will not generate any code. Then adjust and probe
1766 to PROBE_INTERVAL + SIZE. */
1767 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1771 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1772 first_probe
= false;
1775 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1776 emit_stack_probe (stack_pointer_rtx
);
1780 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1782 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1783 emit_stack_probe (stack_pointer_rtx
);
1786 /* In the variable case, do the same as above, but in a loop. Note that we
1787 must be extra careful with variables wrapping around because we might be
1788 at the very top (or the very bottom) of the address space and we have to
1789 be able to handle this case properly; in particular, we use an equality
1790 test for the loop condition. */
1793 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1794 rtx_code_label
*loop_lab
= gen_label_rtx ();
1795 rtx_code_label
*end_lab
= gen_label_rtx ();
1798 /* Step 1: round SIZE to the previous multiple of the interval. */
1800 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1802 = simplify_gen_binary (AND
, Pmode
, size
,
1803 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1804 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1807 /* Step 2: compute initial and final value of the loop counter. */
1809 /* SP = SP_0 + PROBE_INTERVAL. */
1810 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1812 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1813 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1815 rounded_size_op
), NULL_RTX
);
1820 while (SP != LAST_ADDR)
1822 SP = SP + PROBE_INTERVAL
1826 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1827 values of N from 1 until it is equal to ROUNDED_SIZE. */
1829 emit_label (loop_lab
);
1831 /* Jump to END_LAB if SP == LAST_ADDR. */
1832 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1835 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1836 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1837 emit_stack_probe (stack_pointer_rtx
);
1839 emit_jump (loop_lab
);
1841 emit_label (end_lab
);
1844 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1845 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1847 /* TEMP = SIZE - ROUNDED_SIZE. */
1848 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1849 if (temp
!= const0_rtx
)
1851 /* Manual CSE if the difference is not known at compile-time. */
1852 if (GET_CODE (temp
) != CONST_INT
)
1853 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1854 anti_adjust_stack (temp
);
1855 emit_stack_probe (stack_pointer_rtx
);
1859 /* Adjust back and account for the additional first interval. */
1861 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1863 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1866 /* Return an rtx representing the register or memory location
1867 in which a scalar value of data type VALTYPE
1868 was returned by a function call to function FUNC.
1869 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1870 function is known, otherwise 0.
1871 OUTGOING is 1 if on a machine with register windows this function
1872 should return the register in which the function will put its result
1876 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1877 int outgoing ATTRIBUTE_UNUSED
)
1881 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1884 && GET_MODE (val
) == BLKmode
)
1886 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1887 machine_mode tmpmode
;
1889 /* int_size_in_bytes can return -1. We don't need a check here
1890 since the value of bytes will then be large enough that no
1891 mode will match anyway. */
1893 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1894 tmpmode
!= VOIDmode
;
1895 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1897 /* Have we found a large enough mode? */
1898 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1902 /* No suitable mode found. */
1903 gcc_assert (tmpmode
!= VOIDmode
);
1905 PUT_MODE (val
, tmpmode
);
1910 /* Return an rtx representing the register or memory location
1911 in which a scalar value of mode MODE was returned by a library call. */
1914 hard_libcall_value (machine_mode mode
, rtx fun
)
1916 return targetm
.calls
.libcall_value (mode
, fun
);
1919 /* Look up the tree code for a given rtx code
1920 to provide the arithmetic operation for REAL_ARITHMETIC.
1921 The function returns an int because the caller may not know
1922 what `enum tree_code' means. */
1925 rtx_to_tree_code (enum rtx_code code
)
1927 enum tree_code tcode
;
1950 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1953 return ((int) tcode
);
1956 #include "gt-explow.h"