1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
31 #include "profile-count.h"
35 #include "diagnostic-core.h"
36 #include "stor-layout.h"
41 #include "common/common-target.h"
44 static rtx
break_out_memory_refs (rtx
);
47 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
50 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
52 /* Not scalar_int_mode because we also allow pointer bound modes. */
53 scalar_mode smode
= as_a
<scalar_mode
> (mode
);
54 int width
= GET_MODE_PRECISION (smode
);
56 /* You want to truncate to a _what_? */
57 gcc_assert (SCALAR_INT_MODE_P (mode
)
58 || POINTER_BOUNDS_MODE_P (mode
));
60 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
62 return c
& 1 ? STORE_FLAG_VALUE
: 0;
64 /* Sign-extend for the requested mode. */
66 if (width
< HOST_BITS_PER_WIDE_INT
)
68 HOST_WIDE_INT sign
= 1;
78 /* Return an rtx for the sum of X and the integer C, given that X has
79 mode MODE. INPLACE is true if X can be modified inplace or false
80 if it must be treated as immutable. */
83 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
91 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
103 CASE_CONST_SCALAR_INT
:
104 return immed_wide_int_const (wi::add (rtx_mode_t (x
, mode
), c
), mode
);
106 /* If this is a reference to the constant pool, try replacing it with
107 a reference to a new constant. If the resulting address isn't
108 valid, don't return it because we have no way to validize it. */
109 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
110 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
112 rtx cst
= get_pool_constant (XEXP (x
, 0));
114 if (GET_CODE (cst
) == CONST_VECTOR
115 && GET_MODE_INNER (GET_MODE (cst
)) == mode
)
117 cst
= gen_lowpart (mode
, cst
);
120 if (GET_MODE (cst
) == VOIDmode
|| GET_MODE (cst
) == mode
)
122 tem
= plus_constant (mode
, cst
, c
);
123 tem
= force_const_mem (GET_MODE (x
), tem
);
124 /* Targets may disallow some constants in the constant pool, thus
125 force_const_mem may return NULL_RTX. */
126 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
133 /* If adding to something entirely constant, set a flag
134 so that we can add a CONST around the result. */
135 if (inplace
&& shared_const_p (x
))
147 /* The interesting case is adding the integer to a sum. Look
148 for constant term in the sum and combine with C. For an
149 integer constant term or a constant term that is not an
150 explicit integer, we combine or group them together anyway.
152 We may not immediately return from the recursive call here, lest
153 all_constant gets lost. */
155 if (CONSTANT_P (XEXP (x
, 1)))
157 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
158 if (term
== const0_rtx
)
163 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
166 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
170 /* We need to be careful since X may be shared and we can't
171 modify it in place. */
173 const_loc
= find_constant_term_loc (&x
);
175 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
185 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
187 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
189 else if (all_constant
)
190 return gen_rtx_CONST (mode
, x
);
195 /* If X is a sum, return a new sum like X but lacking any constant terms.
196 Add all the removed constant terms into *CONSTPTR.
197 X itself is not altered. The result != X if and only if
198 it is not isomorphic to X. */
201 eliminate_constant_term (rtx x
, rtx
*constptr
)
206 if (GET_CODE (x
) != PLUS
)
209 /* First handle constants appearing at this level explicitly. */
210 if (CONST_INT_P (XEXP (x
, 1))
211 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
213 && CONST_INT_P (tem
))
216 return eliminate_constant_term (XEXP (x
, 0), constptr
);
220 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
221 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
222 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
223 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
225 && CONST_INT_P (tem
))
228 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
235 /* Return a copy of X in which all memory references
236 and all constants that involve symbol refs
237 have been replaced with new temporary registers.
238 Also emit code to load the memory locations and constants
239 into those registers.
241 If X contains no such constants or memory references,
242 X itself (not a copy) is returned.
244 If a constant is found in the address that is not a legitimate constant
245 in an insn, it is left alone in the hope that it might be valid in the
248 X may contain no arithmetic except addition, subtraction and multiplication.
249 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
252 break_out_memory_refs (rtx x
)
255 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
256 && GET_MODE (x
) != VOIDmode
))
257 x
= force_reg (GET_MODE (x
), x
);
258 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
259 || GET_CODE (x
) == MULT
)
261 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
262 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
264 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
265 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
271 /* Given X, a memory address in address space AS' pointer mode, convert it to
272 an address in the address space's address mode, or vice versa (TO_MODE says
273 which way). We take advantage of the fact that pointers are not allowed to
274 overflow by commuting arithmetic operations over conversions so that address
275 arithmetic insns can be used. IN_CONST is true if this conversion is inside
276 a CONST. NO_EMIT is true if no insns should be emitted, and instead
277 it should return NULL if it can't be simplified without emitting insns. */
280 convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED
,
281 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
282 bool in_const ATTRIBUTE_UNUSED
,
283 bool no_emit ATTRIBUTE_UNUSED
)
285 #ifndef POINTERS_EXTEND_UNSIGNED
286 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
288 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
289 scalar_int_mode pointer_mode
, address_mode
, from_mode
;
293 /* If X already has the right mode, just return it. */
294 if (GET_MODE (x
) == to_mode
)
297 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
298 address_mode
= targetm
.addr_space
.address_mode (as
);
299 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
301 /* Here we handle some special cases. If none of them apply, fall through
302 to the default case. */
303 switch (GET_CODE (x
))
305 CASE_CONST_SCALAR_INT
:
306 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
308 else if (POINTERS_EXTEND_UNSIGNED
< 0)
310 else if (POINTERS_EXTEND_UNSIGNED
> 0)
314 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
320 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
321 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
322 return SUBREG_REG (x
);
326 temp
= gen_rtx_LABEL_REF (to_mode
, label_ref_label (x
));
327 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
331 temp
= shallow_copy_rtx (x
);
332 PUT_MODE (temp
, to_mode
);
336 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0), as
,
338 return temp
? gen_rtx_CONST (to_mode
, temp
) : temp
;
342 /* For addition we can safely permute the conversion and addition
343 operation if one operand is a constant and converting the constant
344 does not change it or if one operand is a constant and we are
345 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
346 We can always safely permute them if we are making the address
347 narrower. Inside a CONST RTL, this is safe for both pointers
348 zero or sign extended as pointers cannot wrap. */
349 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
350 || (GET_CODE (x
) == PLUS
351 && CONST_INT_P (XEXP (x
, 1))
352 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
353 || XEXP (x
, 1) == convert_memory_address_addr_space_1
354 (to_mode
, XEXP (x
, 1), as
, in_const
,
356 || POINTERS_EXTEND_UNSIGNED
< 0)))
358 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0),
359 as
, in_const
, no_emit
);
360 return (temp
? gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
373 return convert_modes (to_mode
, from_mode
,
374 x
, POINTERS_EXTEND_UNSIGNED
);
375 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
378 /* Given X, a memory address in address space AS' pointer mode, convert it to
379 an address in the address space's address mode, or vice versa (TO_MODE says
380 which way). We take advantage of the fact that pointers are not allowed to
381 overflow by commuting arithmetic operations over conversions so that address
382 arithmetic insns can be used. */
385 convert_memory_address_addr_space (scalar_int_mode to_mode
, rtx x
,
388 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false, false);
392 /* Return something equivalent to X but valid as a memory address for something
393 of mode MODE in the named address space AS. When X is not itself valid,
394 this works by copying X or subexpressions of it into registers. */
397 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
400 scalar_int_mode address_mode
= targetm
.addr_space
.address_mode (as
);
402 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
404 /* By passing constant addresses through registers
405 we get a chance to cse them. */
406 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
407 x
= force_reg (address_mode
, x
);
409 /* We get better cse by rejecting indirect addressing at this stage.
410 Let the combiner create indirect addresses where appropriate.
411 For now, generate the code so that the subexpressions useful to share
412 are visible. But not if cse won't be done! */
415 if (! cse_not_expected
&& !REG_P (x
))
416 x
= break_out_memory_refs (x
);
418 /* At this point, any valid address is accepted. */
419 if (memory_address_addr_space_p (mode
, x
, as
))
422 /* If it was valid before but breaking out memory refs invalidated it,
423 use it the old way. */
424 if (memory_address_addr_space_p (mode
, oldx
, as
))
430 /* Perform machine-dependent transformations on X
431 in certain cases. This is not necessary since the code
432 below can handle all possible cases, but machine-dependent
433 transformations can make better code. */
436 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
437 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
441 /* PLUS and MULT can appear in special ways
442 as the result of attempts to make an address usable for indexing.
443 Usually they are dealt with by calling force_operand, below.
444 But a sum containing constant terms is special
445 if removing them makes the sum a valid address:
446 then we generate that address in a register
447 and index off of it. We do this because it often makes
448 shorter code, and because the addresses thus generated
449 in registers often become common subexpressions. */
450 if (GET_CODE (x
) == PLUS
)
452 rtx constant_term
= const0_rtx
;
453 rtx y
= eliminate_constant_term (x
, &constant_term
);
454 if (constant_term
== const0_rtx
455 || ! memory_address_addr_space_p (mode
, y
, as
))
456 x
= force_operand (x
, NULL_RTX
);
459 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
460 if (! memory_address_addr_space_p (mode
, y
, as
))
461 x
= force_operand (x
, NULL_RTX
);
467 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
468 x
= force_operand (x
, NULL_RTX
);
470 /* If we have a register that's an invalid address,
471 it must be a hard reg of the wrong class. Copy it to a pseudo. */
475 /* Last resort: copy the value to a register, since
476 the register is a valid address. */
478 x
= force_reg (address_mode
, x
);
483 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
484 /* If we didn't change the address, we are done. Otherwise, mark
485 a reg as a pointer if we have REG or REG + CONST_INT. */
489 mark_reg_pointer (x
, BITS_PER_UNIT
);
490 else if (GET_CODE (x
) == PLUS
491 && REG_P (XEXP (x
, 0))
492 && CONST_INT_P (XEXP (x
, 1)))
493 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
495 /* OLDX may have been the address on a temporary. Update the address
496 to indicate that X is now used. */
497 update_temp_slot_address (oldx
, x
);
502 /* Convert a mem ref into one with a valid memory address.
503 Pass through anything else unchanged. */
506 validize_mem (rtx ref
)
510 ref
= use_anchored_address (ref
);
511 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
512 MEM_ADDR_SPACE (ref
)))
515 /* Don't alter REF itself, since that is probably a stack slot. */
516 return replace_equiv_address (ref
, XEXP (ref
, 0));
519 /* If X is a memory reference to a member of an object block, try rewriting
520 it to use an anchor instead. Return the new memory reference on success
521 and the old one on failure. */
524 use_anchored_address (rtx x
)
527 HOST_WIDE_INT offset
;
530 if (!flag_section_anchors
)
536 /* Split the address into a base and offset. */
539 if (GET_CODE (base
) == CONST
540 && GET_CODE (XEXP (base
, 0)) == PLUS
541 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
543 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
544 base
= XEXP (XEXP (base
, 0), 0);
547 /* Check whether BASE is suitable for anchors. */
548 if (GET_CODE (base
) != SYMBOL_REF
549 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
550 || SYMBOL_REF_ANCHOR_P (base
)
551 || SYMBOL_REF_BLOCK (base
) == NULL
552 || !targetm
.use_anchors_for_symbol_p (base
))
555 /* Decide where BASE is going to be. */
556 place_block_symbol (base
);
558 /* Get the anchor we need to use. */
559 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
560 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
561 SYMBOL_REF_TLS_MODEL (base
));
563 /* Work out the offset from the anchor. */
564 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
566 /* If we're going to run a CSE pass, force the anchor into a register.
567 We will then be able to reuse registers for several accesses, if the
568 target costs say that that's worthwhile. */
569 mode
= GET_MODE (base
);
570 if (!cse_not_expected
)
571 base
= force_reg (mode
, base
);
573 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
576 /* Copy the value or contents of X to a new temp reg and return that reg. */
581 rtx temp
= gen_reg_rtx (GET_MODE (x
));
583 /* If not an operand, must be an address with PLUS and MULT so
584 do the computation. */
585 if (! general_operand (x
, VOIDmode
))
586 x
= force_operand (x
, temp
);
589 emit_move_insn (temp
, x
);
594 /* Like copy_to_reg but always give the new register mode Pmode
595 in case X is a constant. */
598 copy_addr_to_reg (rtx x
)
600 return copy_to_mode_reg (Pmode
, x
);
603 /* Like copy_to_reg but always give the new register mode MODE
604 in case X is a constant. */
607 copy_to_mode_reg (machine_mode mode
, rtx x
)
609 rtx temp
= gen_reg_rtx (mode
);
611 /* If not an operand, must be an address with PLUS and MULT so
612 do the computation. */
613 if (! general_operand (x
, VOIDmode
))
614 x
= force_operand (x
, temp
);
616 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
618 emit_move_insn (temp
, x
);
622 /* Load X into a register if it is not already one.
623 Use mode MODE for the register.
624 X should be valid for mode MODE, but it may be a constant which
625 is valid for all integer modes; that's why caller must specify MODE.
627 The caller must not alter the value in the register we return,
628 since we mark it as a "constant" register. */
631 force_reg (machine_mode mode
, rtx x
)
639 if (general_operand (x
, mode
))
641 temp
= gen_reg_rtx (mode
);
642 insn
= emit_move_insn (temp
, x
);
646 temp
= force_operand (x
, NULL_RTX
);
648 insn
= get_last_insn ();
651 rtx temp2
= gen_reg_rtx (mode
);
652 insn
= emit_move_insn (temp2
, temp
);
657 /* Let optimizers know that TEMP's value never changes
658 and that X can be substituted for it. Don't get confused
659 if INSN set something else (such as a SUBREG of TEMP). */
661 && (set
= single_set (insn
)) != 0
662 && SET_DEST (set
) == temp
663 && ! rtx_equal_p (x
, SET_SRC (set
)))
664 set_unique_reg_note (insn
, REG_EQUAL
, x
);
666 /* Let optimizers know that TEMP is a pointer, and if so, the
667 known alignment of that pointer. */
670 if (GET_CODE (x
) == SYMBOL_REF
)
672 align
= BITS_PER_UNIT
;
673 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
674 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
676 else if (GET_CODE (x
) == LABEL_REF
)
677 align
= BITS_PER_UNIT
;
678 else if (GET_CODE (x
) == CONST
679 && GET_CODE (XEXP (x
, 0)) == PLUS
680 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
681 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
683 rtx s
= XEXP (XEXP (x
, 0), 0);
684 rtx c
= XEXP (XEXP (x
, 0), 1);
688 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
689 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
695 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
696 align
= MIN (sa
, ca
);
700 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
701 mark_reg_pointer (temp
, align
);
707 /* If X is a memory ref, copy its contents to a new temp reg and return
708 that reg. Otherwise, return X. */
711 force_not_mem (rtx x
)
715 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
718 temp
= gen_reg_rtx (GET_MODE (x
));
721 REG_POINTER (temp
) = 1;
723 emit_move_insn (temp
, x
);
727 /* Copy X to TARGET (if it's nonzero and a reg)
728 or to a new temp reg and return that reg.
729 MODE is the mode to use for X in case it is a constant. */
732 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
736 if (target
&& REG_P (target
))
739 temp
= gen_reg_rtx (mode
);
741 emit_move_insn (temp
, x
);
745 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
746 PUNSIGNEDP points to the signedness of the type and may be adjusted
747 to show what signedness to use on extension operations.
749 FOR_RETURN is nonzero if the caller is promoting the return value
750 of FNDECL, else it is for promoting args. */
753 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
754 const_tree funtype
, int for_return
)
756 /* Called without a type node for a libcall. */
757 if (type
== NULL_TREE
)
759 if (INTEGRAL_MODE_P (mode
))
760 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
767 switch (TREE_CODE (type
))
769 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
770 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
771 case POINTER_TYPE
: case REFERENCE_TYPE
:
772 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
779 /* Return the mode to use to store a scalar of TYPE and MODE.
780 PUNSIGNEDP points to the signedness of the type and may be adjusted
781 to show what signedness to use on extension operations. */
784 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
785 int *punsignedp ATTRIBUTE_UNUSED
)
793 /* For libcalls this is invoked without TYPE from the backends
794 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
796 if (type
== NULL_TREE
)
799 /* FIXME: this is the same logic that was there until GCC 4.4, but we
800 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
801 is not defined. The affected targets are M32C, S390, SPARC. */
803 code
= TREE_CODE (type
);
804 unsignedp
= *punsignedp
;
808 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
809 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
810 /* Values of these types always have scalar mode. */
811 smode
= as_a
<scalar_mode
> (mode
);
812 PROMOTE_MODE (smode
, unsignedp
, type
);
813 *punsignedp
= unsignedp
;
816 #ifdef POINTERS_EXTEND_UNSIGNED
819 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
820 return targetm
.addr_space
.address_mode
821 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
833 /* Use one of promote_mode or promote_function_mode to find the promoted
834 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
835 of DECL after promotion. */
838 promote_decl_mode (const_tree decl
, int *punsignedp
)
840 tree type
= TREE_TYPE (decl
);
841 int unsignedp
= TYPE_UNSIGNED (type
);
842 machine_mode mode
= DECL_MODE (decl
);
845 if (TREE_CODE (decl
) == RESULT_DECL
&& !DECL_BY_REFERENCE (decl
))
846 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
847 TREE_TYPE (current_function_decl
), 1);
848 else if (TREE_CODE (decl
) == RESULT_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
849 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
850 TREE_TYPE (current_function_decl
), 2);
852 pmode
= promote_mode (type
, mode
, &unsignedp
);
855 *punsignedp
= unsignedp
;
859 /* Return the promoted mode for name. If it is a named SSA_NAME, it
860 is the same as promote_decl_mode. Otherwise, it is the promoted
861 mode of a temp decl of same type as the SSA_NAME, if we had created
865 promote_ssa_mode (const_tree name
, int *punsignedp
)
867 gcc_assert (TREE_CODE (name
) == SSA_NAME
);
869 /* Partitions holding parms and results must be promoted as expected
871 if (SSA_NAME_VAR (name
)
872 && (TREE_CODE (SSA_NAME_VAR (name
)) == PARM_DECL
873 || TREE_CODE (SSA_NAME_VAR (name
)) == RESULT_DECL
))
875 machine_mode mode
= promote_decl_mode (SSA_NAME_VAR (name
), punsignedp
);
880 tree type
= TREE_TYPE (name
);
881 int unsignedp
= TYPE_UNSIGNED (type
);
882 machine_mode mode
= TYPE_MODE (type
);
884 /* Bypass TYPE_MODE when it maps vector modes to BLKmode. */
887 gcc_assert (VECTOR_TYPE_P (type
));
888 mode
= type
->type_common
.mode
;
891 machine_mode pmode
= promote_mode (type
, mode
, &unsignedp
);
893 *punsignedp
= unsignedp
;
900 /* Controls the behavior of {anti_,}adjust_stack. */
901 static bool suppress_reg_args_size
;
903 /* A helper for adjust_stack and anti_adjust_stack. */
906 adjust_stack_1 (rtx adjust
, bool anti_p
)
911 /* Hereafter anti_p means subtract_p. */
912 if (!STACK_GROWS_DOWNWARD
)
915 temp
= expand_binop (Pmode
,
916 anti_p
? sub_optab
: add_optab
,
917 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
920 if (temp
!= stack_pointer_rtx
)
921 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
924 insn
= get_last_insn ();
925 temp
= single_set (insn
);
926 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
929 if (!suppress_reg_args_size
)
930 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
933 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
934 This pops when ADJUST is positive. ADJUST need not be constant. */
937 adjust_stack (rtx adjust
)
939 if (adjust
== const0_rtx
)
942 /* We expect all variable sized adjustments to be multiple of
943 PREFERRED_STACK_BOUNDARY. */
944 if (CONST_INT_P (adjust
))
945 stack_pointer_delta
-= INTVAL (adjust
);
947 adjust_stack_1 (adjust
, false);
950 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
951 This pushes when ADJUST is positive. ADJUST need not be constant. */
954 anti_adjust_stack (rtx adjust
)
956 if (adjust
== const0_rtx
)
959 /* We expect all variable sized adjustments to be multiple of
960 PREFERRED_STACK_BOUNDARY. */
961 if (CONST_INT_P (adjust
))
962 stack_pointer_delta
+= INTVAL (adjust
);
964 adjust_stack_1 (adjust
, true);
967 /* Round the size of a block to be pushed up to the boundary required
968 by this machine. SIZE is the desired size, which need not be constant. */
971 round_push (rtx size
)
973 rtx align_rtx
, alignm1_rtx
;
975 if (!SUPPORTS_STACK_ALIGNMENT
976 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
978 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
983 if (CONST_INT_P (size
))
985 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
987 if (INTVAL (size
) != new_size
)
988 size
= GEN_INT (new_size
);
992 align_rtx
= GEN_INT (align
);
993 alignm1_rtx
= GEN_INT (align
- 1);
997 /* If crtl->preferred_stack_boundary might still grow, use
998 virtual_preferred_stack_boundary_rtx instead. This will be
999 substituted by the right value in vregs pass and optimized
1001 align_rtx
= virtual_preferred_stack_boundary_rtx
;
1002 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
1006 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1007 but we know it can't. So add ourselves and then do
1009 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1010 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1011 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1013 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1018 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1019 to a previously-created save area. If no save area has been allocated,
1020 this function will allocate one. If a save area is specified, it
1021 must be of the proper mode. */
1024 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1027 /* The default is that we use a move insn and save in a Pmode object. */
1028 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1029 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1031 /* See if this machine has anything special to do for this kind of save. */
1035 if (targetm
.have_save_stack_block ())
1036 fcn
= targetm
.gen_save_stack_block
;
1039 if (targetm
.have_save_stack_function ())
1040 fcn
= targetm
.gen_save_stack_function
;
1043 if (targetm
.have_save_stack_nonlocal ())
1044 fcn
= targetm
.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_insn
*(*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. */
1097 if (targetm
.have_restore_stack_block ())
1098 fcn
= targetm
.gen_restore_stack_block
;
1101 if (targetm
.have_restore_stack_function ())
1102 fcn
= targetm
.gen_restore_stack_function
;
1105 if (targetm
.have_restore_stack_nonlocal ())
1106 fcn
= targetm
.gen_restore_stack_nonlocal
;
1114 sa
= validize_mem (sa
);
1115 /* These clobbers prevent the scheduler from moving
1116 references to variable arrays below the code
1117 that deletes (pops) the arrays. */
1118 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1119 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1122 discard_pending_stack_adjust ();
1124 emit_insn (fcn (stack_pointer_rtx
, sa
));
1127 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1128 function. This should be called whenever we allocate or deallocate
1129 dynamic stack space. */
1132 update_nonlocal_goto_save_area (void)
1137 /* The nonlocal_goto_save_area object is an array of N pointers. The
1138 first one is used for the frame pointer save; the rest are sized by
1139 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1140 of the stack save area slots. */
1141 t_save
= build4 (ARRAY_REF
,
1142 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1143 cfun
->nonlocal_goto_save_area
,
1144 integer_one_node
, NULL_TREE
, NULL_TREE
);
1145 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1147 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1150 /* Record a new stack level for the current function. This should be called
1151 whenever we allocate or deallocate dynamic stack space. */
1154 record_new_stack_level (void)
1156 /* Record the new stack level for nonlocal gotos. */
1157 if (cfun
->nonlocal_goto_save_area
)
1158 update_nonlocal_goto_save_area ();
1160 /* Record the new stack level for SJLJ exceptions. */
1161 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1162 update_sjlj_context ();
1165 /* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */
1167 align_dynamic_address (rtx target
, unsigned required_align
)
1169 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1170 but we know it can't. So add ourselves and then do
1172 target
= expand_binop (Pmode
, add_optab
, target
,
1173 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1175 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1176 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1177 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1180 target
= expand_mult (Pmode
, target
,
1181 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1188 /* Return an rtx through *PSIZE, representing the size of an area of memory to
1189 be dynamically pushed on the stack.
1191 *PSIZE is an rtx representing the size of the area.
1193 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1194 parameter may be zero. If so, a proper value will be extracted
1195 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1197 REQUIRED_ALIGN is the alignment (in bits) required for the region
1200 If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for
1201 the additional size returned. */
1203 get_dynamic_stack_size (rtx
*psize
, unsigned size_align
,
1204 unsigned required_align
,
1205 HOST_WIDE_INT
*pstack_usage_size
)
1210 /* Ensure the size is in the proper mode. */
1211 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1212 size
= convert_to_mode (Pmode
, size
, 1);
1214 if (CONST_INT_P (size
))
1216 unsigned HOST_WIDE_INT lsb
;
1218 lsb
= INTVAL (size
);
1221 /* Watch out for overflow truncating to "unsigned". */
1222 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1223 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1225 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1227 else if (size_align
< BITS_PER_UNIT
)
1228 size_align
= BITS_PER_UNIT
;
1230 /* We can't attempt to minimize alignment necessary, because we don't
1231 know the final value of preferred_stack_boundary yet while executing
1233 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1234 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1236 /* We will need to ensure that the address we return is aligned to
1237 REQUIRED_ALIGN. At this point in the compilation, we don't always
1238 know the final value of the STACK_DYNAMIC_OFFSET used in function.c
1239 (it might depend on the size of the outgoing parameter lists, for
1240 example), so we must preventively align the value. We leave space
1241 in SIZE for the hole that might result from the alignment operation. */
1243 /* Since the stack is presumed to be aligned before this allocation,
1244 we only need to increase the size of the allocation if the required
1245 alignment is more than the stack alignment. */
1246 if (required_align
> STACK_BOUNDARY
)
1248 extra
= (required_align
- STACK_BOUNDARY
) / BITS_PER_UNIT
;
1249 size
= plus_constant (Pmode
, size
, extra
);
1250 size
= force_operand (size
, NULL_RTX
);
1251 if (size_align
> STACK_BOUNDARY
)
1252 size_align
= STACK_BOUNDARY
;
1254 if (flag_stack_usage_info
&& pstack_usage_size
)
1255 *pstack_usage_size
+= extra
;
1258 /* Round the size to a multiple of the required stack alignment.
1259 Since the stack is presumed to be rounded before this allocation,
1260 this will maintain the required alignment.
1262 If the stack grows downward, we could save an insn by subtracting
1263 SIZE from the stack pointer and then aligning the stack pointer.
1264 The problem with this is that the stack pointer may be unaligned
1265 between the execution of the subtraction and alignment insns and
1266 some machines do not allow this. Even on those that do, some
1267 signal handlers malfunction if a signal should occur between those
1268 insns. Since this is an extremely rare event, we have no reliable
1269 way of knowing which systems have this problem. So we avoid even
1270 momentarily mis-aligning the stack. */
1271 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1273 size
= round_push (size
);
1275 if (flag_stack_usage_info
&& pstack_usage_size
)
1277 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1278 *pstack_usage_size
=
1279 (*pstack_usage_size
+ align
- 1) / align
* align
;
1286 /* Return an rtx representing the address of an area of memory dynamically
1287 pushed on the stack.
1289 Any required stack pointer alignment is preserved.
1291 SIZE is an rtx representing the size of the area.
1293 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1294 parameter may be zero. If so, a proper value will be extracted
1295 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1297 REQUIRED_ALIGN is the alignment (in bits) required for the region
1300 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1301 stack space allocated by the generated code cannot be added with itself
1302 in the course of the execution of the function. It is always safe to
1303 pass FALSE here and the following criterion is sufficient in order to
1304 pass TRUE: every path in the CFG that starts at the allocation point and
1305 loops to it executes the associated deallocation code. */
1308 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1309 unsigned required_align
, bool cannot_accumulate
)
1311 HOST_WIDE_INT stack_usage_size
= -1;
1312 rtx_code_label
*final_label
;
1313 rtx final_target
, target
;
1315 /* If we're asking for zero bytes, it doesn't matter what we point
1316 to since we can't dereference it. But return a reasonable
1318 if (size
== const0_rtx
)
1319 return virtual_stack_dynamic_rtx
;
1321 /* Otherwise, show we're calling alloca or equivalent. */
1322 cfun
->calls_alloca
= 1;
1324 /* If stack usage info is requested, look into the size we are passed.
1325 We need to do so this early to avoid the obfuscation that may be
1326 introduced later by the various alignment operations. */
1327 if (flag_stack_usage_info
)
1329 if (CONST_INT_P (size
))
1330 stack_usage_size
= INTVAL (size
);
1331 else if (REG_P (size
))
1333 /* Look into the last emitted insn and see if we can deduce
1334 something for the register. */
1337 insn
= get_last_insn ();
1338 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1340 if (CONST_INT_P (SET_SRC (set
)))
1341 stack_usage_size
= INTVAL (SET_SRC (set
));
1342 else if ((note
= find_reg_equal_equiv_note (insn
))
1343 && CONST_INT_P (XEXP (note
, 0)))
1344 stack_usage_size
= INTVAL (XEXP (note
, 0));
1348 /* If the size is not constant, we can't say anything. */
1349 if (stack_usage_size
== -1)
1351 current_function_has_unbounded_dynamic_stack_size
= 1;
1352 stack_usage_size
= 0;
1356 get_dynamic_stack_size (&size
, size_align
, required_align
, &stack_usage_size
);
1358 target
= gen_reg_rtx (Pmode
);
1360 /* The size is supposed to be fully adjusted at this point so record it
1361 if stack usage info is requested. */
1362 if (flag_stack_usage_info
)
1364 current_function_dynamic_stack_size
+= stack_usage_size
;
1366 /* ??? This is gross but the only safe stance in the absence
1367 of stack usage oriented flow analysis. */
1368 if (!cannot_accumulate
)
1369 current_function_has_unbounded_dynamic_stack_size
= 1;
1372 do_pending_stack_adjust ();
1375 final_target
= NULL_RTX
;
1377 /* If we are splitting the stack, we need to ask the backend whether
1378 there is enough room on the current stack. If there isn't, or if
1379 the backend doesn't know how to tell is, then we need to call a
1380 function to allocate memory in some other way. This memory will
1381 be released when we release the current stack segment. The
1382 effect is that stack allocation becomes less efficient, but at
1383 least it doesn't cause a stack overflow. */
1384 if (flag_split_stack
)
1386 rtx_code_label
*available_label
;
1387 rtx ask
, space
, func
;
1389 available_label
= NULL
;
1391 if (targetm
.have_split_stack_space_check ())
1393 available_label
= gen_label_rtx ();
1395 /* This instruction will branch to AVAILABLE_LABEL if there
1396 are SIZE bytes available on the stack. */
1397 emit_insn (targetm
.gen_split_stack_space_check
1398 (size
, available_label
));
1401 /* The __morestack_allocate_stack_space function will allocate
1402 memory using malloc. If the alignment of the memory returned
1403 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1404 make sure we allocate enough space. */
1405 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1408 ask
= expand_binop (Pmode
, add_optab
, size
,
1409 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1411 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1413 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1415 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1418 if (available_label
== NULL_RTX
)
1421 final_target
= gen_reg_rtx (Pmode
);
1423 emit_move_insn (final_target
, space
);
1425 final_label
= gen_label_rtx ();
1426 emit_jump (final_label
);
1428 emit_label (available_label
);
1431 /* We ought to be called always on the toplevel and stack ought to be aligned
1433 gcc_assert (!(stack_pointer_delta
1434 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1436 /* If needed, check that we have the required amount of stack. Take into
1437 account what has already been checked. */
1438 if (STACK_CHECK_MOVING_SP
)
1440 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1441 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1443 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1444 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1446 /* Don't let anti_adjust_stack emit notes. */
1447 suppress_reg_args_size
= true;
1449 /* Perform the required allocation from the stack. Some systems do
1450 this differently than simply incrementing/decrementing from the
1451 stack pointer, such as acquiring the space by calling malloc(). */
1452 if (targetm
.have_allocate_stack ())
1454 struct expand_operand ops
[2];
1455 /* We don't have to check against the predicate for operand 0 since
1456 TARGET is known to be a pseudo of the proper mode, which must
1457 be valid for the operand. */
1458 create_fixed_operand (&ops
[0], target
);
1459 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1460 expand_insn (targetm
.code_for_allocate_stack
, 2, ops
);
1464 int saved_stack_pointer_delta
;
1466 if (!STACK_GROWS_DOWNWARD
)
1467 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1469 /* Check stack bounds if necessary. */
1470 if (crtl
->limit_stack
)
1473 rtx_code_label
*space_available
= gen_label_rtx ();
1474 if (STACK_GROWS_DOWNWARD
)
1475 available
= expand_binop (Pmode
, sub_optab
,
1476 stack_pointer_rtx
, stack_limit_rtx
,
1477 NULL_RTX
, 1, OPTAB_WIDEN
);
1479 available
= expand_binop (Pmode
, sub_optab
,
1480 stack_limit_rtx
, stack_pointer_rtx
,
1481 NULL_RTX
, 1, OPTAB_WIDEN
);
1483 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1485 if (targetm
.have_trap ())
1486 emit_insn (targetm
.gen_trap ());
1488 error ("stack limits not supported on this target");
1490 emit_label (space_available
);
1493 saved_stack_pointer_delta
= stack_pointer_delta
;
1495 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1496 anti_adjust_stack_and_probe (size
, false);
1498 anti_adjust_stack (size
);
1500 /* Even if size is constant, don't modify stack_pointer_delta.
1501 The constant size alloca should preserve
1502 crtl->preferred_stack_boundary alignment. */
1503 stack_pointer_delta
= saved_stack_pointer_delta
;
1505 if (STACK_GROWS_DOWNWARD
)
1506 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1509 suppress_reg_args_size
= false;
1511 /* Finish up the split stack handling. */
1512 if (final_label
!= NULL_RTX
)
1514 gcc_assert (flag_split_stack
);
1515 emit_move_insn (final_target
, target
);
1516 emit_label (final_label
);
1517 target
= final_target
;
1520 target
= align_dynamic_address (target
, required_align
);
1522 /* Now that we've committed to a return value, mark its alignment. */
1523 mark_reg_pointer (target
, required_align
);
1525 /* Record the new stack level. */
1526 record_new_stack_level ();
1531 /* Return an rtx representing the address of an area of memory already
1532 statically pushed onto the stack in the virtual stack vars area. (It is
1533 assumed that the area is allocated in the function prologue.)
1535 Any required stack pointer alignment is preserved.
1537 OFFSET is the offset of the area into the virtual stack vars area.
1539 REQUIRED_ALIGN is the alignment (in bits) required for the region
1543 get_dynamic_stack_base (HOST_WIDE_INT offset
, unsigned required_align
)
1547 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1548 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1550 target
= gen_reg_rtx (Pmode
);
1551 emit_move_insn (target
, virtual_stack_vars_rtx
);
1552 target
= expand_binop (Pmode
, add_optab
, target
,
1553 gen_int_mode (offset
, Pmode
),
1554 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1555 target
= align_dynamic_address (target
, required_align
);
1557 /* Now that we've committed to a return value, mark its alignment. */
1558 mark_reg_pointer (target
, required_align
);
1563 /* A front end may want to override GCC's stack checking by providing a
1564 run-time routine to call to check the stack, so provide a mechanism for
1565 calling that routine. */
1567 static GTY(()) rtx stack_check_libfunc
;
1570 set_stack_check_libfunc (const char *libfunc_name
)
1572 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1573 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1576 /* Emit one stack probe at ADDRESS, an address within the stack. */
1579 emit_stack_probe (rtx address
)
1581 if (targetm
.have_probe_stack_address ())
1582 emit_insn (targetm
.gen_probe_stack_address (address
));
1585 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1587 MEM_VOLATILE_P (memref
) = 1;
1589 /* See if we have an insn to probe the stack. */
1590 if (targetm
.have_probe_stack ())
1591 emit_insn (targetm
.gen_probe_stack (memref
));
1593 emit_move_insn (memref
, const0_rtx
);
1597 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1598 FIRST is a constant and size is a Pmode RTX. These are offsets from
1599 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1600 or subtract them from the stack pointer. */
1602 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1604 #if STACK_GROWS_DOWNWARD
1605 #define STACK_GROW_OP MINUS
1606 #define STACK_GROW_OPTAB sub_optab
1607 #define STACK_GROW_OFF(off) -(off)
1609 #define STACK_GROW_OP PLUS
1610 #define STACK_GROW_OPTAB add_optab
1611 #define STACK_GROW_OFF(off) (off)
1615 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1617 /* First ensure SIZE is Pmode. */
1618 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1619 size
= convert_to_mode (Pmode
, size
, 1);
1621 /* Next see if we have a function to check the stack. */
1622 if (stack_check_libfunc
)
1624 rtx addr
= memory_address (Pmode
,
1625 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1627 plus_constant (Pmode
,
1629 emit_library_call (stack_check_libfunc
, LCT_THROW
, VOIDmode
,
1633 /* Next see if we have an insn to check the stack. */
1634 else if (targetm
.have_check_stack ())
1636 struct expand_operand ops
[1];
1637 rtx addr
= memory_address (Pmode
,
1638 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1640 plus_constant (Pmode
,
1643 create_input_operand (&ops
[0], addr
, Pmode
);
1644 success
= maybe_expand_insn (targetm
.code_for_check_stack
, 1, ops
);
1645 gcc_assert (success
);
1648 /* Otherwise we have to generate explicit probes. If we have a constant
1649 small number of them to generate, that's the easy case. */
1650 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1652 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1655 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1656 it exceeds SIZE. If only one probe is needed, this will not
1657 generate any code. Then probe at FIRST + SIZE. */
1658 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1660 addr
= memory_address (Pmode
,
1661 plus_constant (Pmode
, stack_pointer_rtx
,
1662 STACK_GROW_OFF (first
+ i
)));
1663 emit_stack_probe (addr
);
1666 addr
= memory_address (Pmode
,
1667 plus_constant (Pmode
, stack_pointer_rtx
,
1668 STACK_GROW_OFF (first
+ isize
)));
1669 emit_stack_probe (addr
);
1672 /* In the variable case, do the same as above, but in a loop. Note that we
1673 must be extra careful with variables wrapping around because we might be
1674 at the very top (or the very bottom) of the address space and we have to
1675 be able to handle this case properly; in particular, we use an equality
1676 test for the loop condition. */
1679 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1680 rtx_code_label
*loop_lab
= gen_label_rtx ();
1681 rtx_code_label
*end_lab
= gen_label_rtx ();
1683 /* Step 1: round SIZE to the previous multiple of the interval. */
1685 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1687 = simplify_gen_binary (AND
, Pmode
, size
,
1688 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1689 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1692 /* Step 2: compute initial and final value of the loop counter. */
1694 /* TEST_ADDR = SP + FIRST. */
1695 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1697 gen_int_mode (first
, Pmode
)),
1700 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1701 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1703 rounded_size_op
), NULL_RTX
);
1708 while (TEST_ADDR != LAST_ADDR)
1710 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1714 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1715 until it is equal to ROUNDED_SIZE. */
1717 emit_label (loop_lab
);
1719 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1720 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1723 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1724 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1725 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1728 gcc_assert (temp
== test_addr
);
1730 /* Probe at TEST_ADDR. */
1731 emit_stack_probe (test_addr
);
1733 emit_jump (loop_lab
);
1735 emit_label (end_lab
);
1738 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1739 that SIZE is equal to ROUNDED_SIZE. */
1741 /* TEMP = SIZE - ROUNDED_SIZE. */
1742 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1743 if (temp
!= const0_rtx
)
1747 if (CONST_INT_P (temp
))
1749 /* Use [base + disp} addressing mode if supported. */
1750 HOST_WIDE_INT offset
= INTVAL (temp
);
1751 addr
= memory_address (Pmode
,
1752 plus_constant (Pmode
, last_addr
,
1753 STACK_GROW_OFF (offset
)));
1757 /* Manual CSE if the difference is not known at compile-time. */
1758 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1759 addr
= memory_address (Pmode
,
1760 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1764 emit_stack_probe (addr
);
1768 /* Make sure nothing is scheduled before we are done. */
1769 emit_insn (gen_blockage ());
1772 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1773 while probing it. This pushes when SIZE is positive. SIZE need not
1774 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1775 by plus SIZE at the end. */
1778 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1780 /* We skip the probe for the first interval + a small dope of 4 words and
1781 probe that many bytes past the specified size to maintain a protection
1782 area at the botton of the stack. */
1783 const int dope
= 4 * UNITS_PER_WORD
;
1785 /* First ensure SIZE is Pmode. */
1786 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1787 size
= convert_to_mode (Pmode
, size
, 1);
1789 /* If we have a constant small number of probes to generate, that's the
1791 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1793 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1794 bool first_probe
= true;
1796 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1797 values of N from 1 until it exceeds SIZE. If only one probe is
1798 needed, this will not generate any code. Then adjust and probe
1799 to PROBE_INTERVAL + SIZE. */
1800 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1804 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1805 first_probe
= false;
1808 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1809 emit_stack_probe (stack_pointer_rtx
);
1813 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1815 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1816 emit_stack_probe (stack_pointer_rtx
);
1819 /* In the variable case, do the same as above, but in a loop. Note that we
1820 must be extra careful with variables wrapping around because we might be
1821 at the very top (or the very bottom) of the address space and we have to
1822 be able to handle this case properly; in particular, we use an equality
1823 test for the loop condition. */
1826 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1827 rtx_code_label
*loop_lab
= gen_label_rtx ();
1828 rtx_code_label
*end_lab
= gen_label_rtx ();
1831 /* Step 1: round SIZE to the previous multiple of the interval. */
1833 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1835 = simplify_gen_binary (AND
, Pmode
, size
,
1836 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1837 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1840 /* Step 2: compute initial and final value of the loop counter. */
1842 /* SP = SP_0 + PROBE_INTERVAL. */
1843 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1845 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1846 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1848 rounded_size_op
), NULL_RTX
);
1853 while (SP != LAST_ADDR)
1855 SP = SP + PROBE_INTERVAL
1859 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1860 values of N from 1 until it is equal to ROUNDED_SIZE. */
1862 emit_label (loop_lab
);
1864 /* Jump to END_LAB if SP == LAST_ADDR. */
1865 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1868 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1869 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1870 emit_stack_probe (stack_pointer_rtx
);
1872 emit_jump (loop_lab
);
1874 emit_label (end_lab
);
1877 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1878 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1880 /* TEMP = SIZE - ROUNDED_SIZE. */
1881 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1882 if (temp
!= const0_rtx
)
1884 /* Manual CSE if the difference is not known at compile-time. */
1885 if (GET_CODE (temp
) != CONST_INT
)
1886 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1887 anti_adjust_stack (temp
);
1888 emit_stack_probe (stack_pointer_rtx
);
1892 /* Adjust back and account for the additional first interval. */
1894 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1896 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1899 /* Return an rtx representing the register or memory location
1900 in which a scalar value of data type VALTYPE
1901 was returned by a function call to function FUNC.
1902 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1903 function is known, otherwise 0.
1904 OUTGOING is 1 if on a machine with register windows this function
1905 should return the register in which the function will put its result
1909 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1910 int outgoing ATTRIBUTE_UNUSED
)
1914 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1917 && GET_MODE (val
) == BLKmode
)
1919 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1920 opt_scalar_int_mode tmpmode
;
1922 /* int_size_in_bytes can return -1. We don't need a check here
1923 since the value of bytes will then be large enough that no
1924 mode will match anyway. */
1926 FOR_EACH_MODE_IN_CLASS (tmpmode
, MODE_INT
)
1928 /* Have we found a large enough mode? */
1929 if (GET_MODE_SIZE (tmpmode
.require ()) >= bytes
)
1933 PUT_MODE (val
, tmpmode
.require ());
1938 /* Return an rtx representing the register or memory location
1939 in which a scalar value of mode MODE was returned by a library call. */
1942 hard_libcall_value (machine_mode mode
, rtx fun
)
1944 return targetm
.calls
.libcall_value (mode
, fun
);
1947 /* Look up the tree code for a given rtx code
1948 to provide the arithmetic operation for real_arithmetic.
1949 The function returns an int because the caller may not know
1950 what `enum tree_code' means. */
1953 rtx_to_tree_code (enum rtx_code code
)
1955 enum tree_code tcode
;
1978 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1981 return ((int) tcode
);
1984 #include "gt-explow.h"