1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2016 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"
33 #include "diagnostic-core.h"
34 #include "stor-layout.h"
39 #include "common/common-target.h"
42 static rtx
break_out_memory_refs (rtx
);
45 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
48 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
50 int width
= GET_MODE_PRECISION (mode
);
52 /* You want to truncate to a _what_? */
53 gcc_assert (SCALAR_INT_MODE_P (mode
)
54 || POINTER_BOUNDS_MODE_P (mode
));
56 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
58 return c
& 1 ? STORE_FLAG_VALUE
: 0;
60 /* Sign-extend for the requested mode. */
62 if (width
< HOST_BITS_PER_WIDE_INT
)
64 HOST_WIDE_INT sign
= 1;
74 /* Return an rtx for the sum of X and the integer C, given that X has
75 mode MODE. INPLACE is true if X can be modified inplace or false
76 if it must be treated as immutable. */
79 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
87 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
99 CASE_CONST_SCALAR_INT
:
100 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
103 /* If this is a reference to the constant pool, try replacing it with
104 a reference to a new constant. If the resulting address isn't
105 valid, don't return it because we have no way to validize it. */
106 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
107 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
109 rtx cst
= get_pool_constant (XEXP (x
, 0));
111 if (GET_CODE (cst
) == CONST_VECTOR
112 && GET_MODE_INNER (GET_MODE (cst
)) == mode
)
114 cst
= gen_lowpart (mode
, cst
);
117 tem
= plus_constant (mode
, cst
, c
);
118 tem
= force_const_mem (GET_MODE (x
), tem
);
119 /* Targets may disallow some constants in the constant pool, thus
120 force_const_mem may return NULL_RTX. */
121 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
127 /* If adding to something entirely constant, set a flag
128 so that we can add a CONST around the result. */
129 if (inplace
&& shared_const_p (x
))
141 /* The interesting case is adding the integer to a sum. Look
142 for constant term in the sum and combine with C. For an
143 integer constant term or a constant term that is not an
144 explicit integer, we combine or group them together anyway.
146 We may not immediately return from the recursive call here, lest
147 all_constant gets lost. */
149 if (CONSTANT_P (XEXP (x
, 1)))
151 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
152 if (term
== const0_rtx
)
157 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
160 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
164 /* We need to be careful since X may be shared and we can't
165 modify it in place. */
167 const_loc
= find_constant_term_loc (&x
);
169 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
179 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
181 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
183 else if (all_constant
)
184 return gen_rtx_CONST (mode
, x
);
189 /* If X is a sum, return a new sum like X but lacking any constant terms.
190 Add all the removed constant terms into *CONSTPTR.
191 X itself is not altered. The result != X if and only if
192 it is not isomorphic to X. */
195 eliminate_constant_term (rtx x
, rtx
*constptr
)
200 if (GET_CODE (x
) != PLUS
)
203 /* First handle constants appearing at this level explicitly. */
204 if (CONST_INT_P (XEXP (x
, 1))
205 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
207 && CONST_INT_P (tem
))
210 return eliminate_constant_term (XEXP (x
, 0), constptr
);
214 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
215 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
216 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
217 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
219 && CONST_INT_P (tem
))
222 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
229 /* Return a copy of X in which all memory references
230 and all constants that involve symbol refs
231 have been replaced with new temporary registers.
232 Also emit code to load the memory locations and constants
233 into those registers.
235 If X contains no such constants or memory references,
236 X itself (not a copy) is returned.
238 If a constant is found in the address that is not a legitimate constant
239 in an insn, it is left alone in the hope that it might be valid in the
242 X may contain no arithmetic except addition, subtraction and multiplication.
243 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
246 break_out_memory_refs (rtx x
)
249 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
250 && GET_MODE (x
) != VOIDmode
))
251 x
= force_reg (GET_MODE (x
), x
);
252 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
253 || GET_CODE (x
) == MULT
)
255 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
256 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
258 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
259 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
265 /* Given X, a memory address in address space AS' pointer mode, convert it to
266 an address in the address space's address mode, or vice versa (TO_MODE says
267 which way). We take advantage of the fact that pointers are not allowed to
268 overflow by commuting arithmetic operations over conversions so that address
269 arithmetic insns can be used. IN_CONST is true if this conversion is inside
270 a CONST. NO_EMIT is true if no insns should be emitted, and instead
271 it should return NULL if it can't be simplified without emitting insns. */
274 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
275 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
276 bool in_const ATTRIBUTE_UNUSED
,
277 bool no_emit ATTRIBUTE_UNUSED
)
279 #ifndef POINTERS_EXTEND_UNSIGNED
280 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
282 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
283 machine_mode pointer_mode
, address_mode
, from_mode
;
287 /* If X already has the right mode, just return it. */
288 if (GET_MODE (x
) == to_mode
)
291 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
292 address_mode
= targetm
.addr_space
.address_mode (as
);
293 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
295 /* Here we handle some special cases. If none of them apply, fall through
296 to the default case. */
297 switch (GET_CODE (x
))
299 CASE_CONST_SCALAR_INT
:
300 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
302 else if (POINTERS_EXTEND_UNSIGNED
< 0)
304 else if (POINTERS_EXTEND_UNSIGNED
> 0)
308 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
314 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
315 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
316 return SUBREG_REG (x
);
320 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
321 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
325 temp
= shallow_copy_rtx (x
);
326 PUT_MODE (temp
, to_mode
);
330 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0), as
,
332 return temp
? gen_rtx_CONST (to_mode
, temp
) : temp
;
336 /* For addition we can safely permute the conversion and addition
337 operation if one operand is a constant and converting the constant
338 does not change it or if one operand is a constant and we are
339 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
340 We can always safely permute them if we are making the address
341 narrower. Inside a CONST RTL, this is safe for both pointers
342 zero or sign extended as pointers cannot wrap. */
343 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
344 || (GET_CODE (x
) == PLUS
345 && CONST_INT_P (XEXP (x
, 1))
346 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
347 || XEXP (x
, 1) == convert_memory_address_addr_space_1
348 (to_mode
, XEXP (x
, 1), as
, in_const
,
350 || POINTERS_EXTEND_UNSIGNED
< 0)))
352 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0),
353 as
, in_const
, no_emit
);
354 return (temp
? gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
367 return convert_modes (to_mode
, from_mode
,
368 x
, POINTERS_EXTEND_UNSIGNED
);
369 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
372 /* Given X, a memory address in address space AS' pointer mode, convert it to
373 an address in the address space's address mode, or vice versa (TO_MODE says
374 which way). We take advantage of the fact that pointers are not allowed to
375 overflow by commuting arithmetic operations over conversions so that address
376 arithmetic insns can be used. */
379 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
381 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false, false);
385 /* Return something equivalent to X but valid as a memory address for something
386 of mode MODE in the named address space AS. When X is not itself valid,
387 this works by copying X or subexpressions of it into registers. */
390 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
393 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
395 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
397 /* By passing constant addresses through registers
398 we get a chance to cse them. */
399 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
400 x
= force_reg (address_mode
, x
);
402 /* We get better cse by rejecting indirect addressing at this stage.
403 Let the combiner create indirect addresses where appropriate.
404 For now, generate the code so that the subexpressions useful to share
405 are visible. But not if cse won't be done! */
408 if (! cse_not_expected
&& !REG_P (x
))
409 x
= break_out_memory_refs (x
);
411 /* At this point, any valid address is accepted. */
412 if (memory_address_addr_space_p (mode
, x
, as
))
415 /* If it was valid before but breaking out memory refs invalidated it,
416 use it the old way. */
417 if (memory_address_addr_space_p (mode
, oldx
, as
))
423 /* Perform machine-dependent transformations on X
424 in certain cases. This is not necessary since the code
425 below can handle all possible cases, but machine-dependent
426 transformations can make better code. */
429 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
430 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
434 /* PLUS and MULT can appear in special ways
435 as the result of attempts to make an address usable for indexing.
436 Usually they are dealt with by calling force_operand, below.
437 But a sum containing constant terms is special
438 if removing them makes the sum a valid address:
439 then we generate that address in a register
440 and index off of it. We do this because it often makes
441 shorter code, and because the addresses thus generated
442 in registers often become common subexpressions. */
443 if (GET_CODE (x
) == PLUS
)
445 rtx constant_term
= const0_rtx
;
446 rtx y
= eliminate_constant_term (x
, &constant_term
);
447 if (constant_term
== const0_rtx
448 || ! memory_address_addr_space_p (mode
, y
, as
))
449 x
= force_operand (x
, NULL_RTX
);
452 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
453 if (! memory_address_addr_space_p (mode
, y
, as
))
454 x
= force_operand (x
, NULL_RTX
);
460 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
461 x
= force_operand (x
, NULL_RTX
);
463 /* If we have a register that's an invalid address,
464 it must be a hard reg of the wrong class. Copy it to a pseudo. */
468 /* Last resort: copy the value to a register, since
469 the register is a valid address. */
471 x
= force_reg (address_mode
, x
);
476 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
477 /* If we didn't change the address, we are done. Otherwise, mark
478 a reg as a pointer if we have REG or REG + CONST_INT. */
482 mark_reg_pointer (x
, BITS_PER_UNIT
);
483 else if (GET_CODE (x
) == PLUS
484 && REG_P (XEXP (x
, 0))
485 && CONST_INT_P (XEXP (x
, 1)))
486 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
488 /* OLDX may have been the address on a temporary. Update the address
489 to indicate that X is now used. */
490 update_temp_slot_address (oldx
, x
);
495 /* If REF is a MEM with an invalid address, change it into a valid address.
496 Pass through anything else unchanged. REF must be an unshared rtx and
497 the function may modify it in-place. */
500 validize_mem (rtx ref
)
504 ref
= use_anchored_address (ref
);
505 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
506 MEM_ADDR_SPACE (ref
)))
509 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
512 /* If X is a memory reference to a member of an object block, try rewriting
513 it to use an anchor instead. Return the new memory reference on success
514 and the old one on failure. */
517 use_anchored_address (rtx x
)
520 HOST_WIDE_INT offset
;
523 if (!flag_section_anchors
)
529 /* Split the address into a base and offset. */
532 if (GET_CODE (base
) == CONST
533 && GET_CODE (XEXP (base
, 0)) == PLUS
534 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
536 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
537 base
= XEXP (XEXP (base
, 0), 0);
540 /* Check whether BASE is suitable for anchors. */
541 if (GET_CODE (base
) != SYMBOL_REF
542 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
543 || SYMBOL_REF_ANCHOR_P (base
)
544 || SYMBOL_REF_BLOCK (base
) == NULL
545 || !targetm
.use_anchors_for_symbol_p (base
))
548 /* Decide where BASE is going to be. */
549 place_block_symbol (base
);
551 /* Get the anchor we need to use. */
552 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
553 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
554 SYMBOL_REF_TLS_MODEL (base
));
556 /* Work out the offset from the anchor. */
557 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
559 /* If we're going to run a CSE pass, force the anchor into a register.
560 We will then be able to reuse registers for several accesses, if the
561 target costs say that that's worthwhile. */
562 mode
= GET_MODE (base
);
563 if (!cse_not_expected
)
564 base
= force_reg (mode
, base
);
566 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
569 /* Copy the value or contents of X to a new temp reg and return that reg. */
574 rtx temp
= gen_reg_rtx (GET_MODE (x
));
576 /* If not an operand, must be an address with PLUS and MULT so
577 do the computation. */
578 if (! general_operand (x
, VOIDmode
))
579 x
= force_operand (x
, temp
);
582 emit_move_insn (temp
, x
);
587 /* Like copy_to_reg but always give the new register mode Pmode
588 in case X is a constant. */
591 copy_addr_to_reg (rtx x
)
593 return copy_to_mode_reg (Pmode
, x
);
596 /* Like copy_to_reg but always give the new register mode MODE
597 in case X is a constant. */
600 copy_to_mode_reg (machine_mode mode
, rtx x
)
602 rtx temp
= gen_reg_rtx (mode
);
604 /* If not an operand, must be an address with PLUS and MULT so
605 do the computation. */
606 if (! general_operand (x
, VOIDmode
))
607 x
= force_operand (x
, temp
);
609 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
611 emit_move_insn (temp
, x
);
615 /* Load X into a register if it is not already one.
616 Use mode MODE for the register.
617 X should be valid for mode MODE, but it may be a constant which
618 is valid for all integer modes; that's why caller must specify MODE.
620 The caller must not alter the value in the register we return,
621 since we mark it as a "constant" register. */
624 force_reg (machine_mode mode
, rtx x
)
632 if (general_operand (x
, mode
))
634 temp
= gen_reg_rtx (mode
);
635 insn
= emit_move_insn (temp
, x
);
639 temp
= force_operand (x
, NULL_RTX
);
641 insn
= get_last_insn ();
644 rtx temp2
= gen_reg_rtx (mode
);
645 insn
= emit_move_insn (temp2
, temp
);
650 /* Let optimizers know that TEMP's value never changes
651 and that X can be substituted for it. Don't get confused
652 if INSN set something else (such as a SUBREG of TEMP). */
654 && (set
= single_set (insn
)) != 0
655 && SET_DEST (set
) == temp
656 && ! rtx_equal_p (x
, SET_SRC (set
)))
657 set_unique_reg_note (insn
, REG_EQUAL
, x
);
659 /* Let optimizers know that TEMP is a pointer, and if so, the
660 known alignment of that pointer. */
663 if (GET_CODE (x
) == SYMBOL_REF
)
665 align
= BITS_PER_UNIT
;
666 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
667 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
669 else if (GET_CODE (x
) == LABEL_REF
)
670 align
= BITS_PER_UNIT
;
671 else if (GET_CODE (x
) == CONST
672 && GET_CODE (XEXP (x
, 0)) == PLUS
673 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
674 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
676 rtx s
= XEXP (XEXP (x
, 0), 0);
677 rtx c
= XEXP (XEXP (x
, 0), 1);
681 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
682 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
688 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
689 align
= MIN (sa
, ca
);
693 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
694 mark_reg_pointer (temp
, align
);
700 /* If X is a memory ref, copy its contents to a new temp reg and return
701 that reg. Otherwise, return X. */
704 force_not_mem (rtx x
)
708 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
711 temp
= gen_reg_rtx (GET_MODE (x
));
714 REG_POINTER (temp
) = 1;
716 emit_move_insn (temp
, x
);
720 /* Copy X to TARGET (if it's nonzero and a reg)
721 or to a new temp reg and return that reg.
722 MODE is the mode to use for X in case it is a constant. */
725 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
729 if (target
&& REG_P (target
))
732 temp
= gen_reg_rtx (mode
);
734 emit_move_insn (temp
, x
);
738 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
739 PUNSIGNEDP points to the signedness of the type and may be adjusted
740 to show what signedness to use on extension operations.
742 FOR_RETURN is nonzero if the caller is promoting the return value
743 of FNDECL, else it is for promoting args. */
746 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
747 const_tree funtype
, int for_return
)
749 /* Called without a type node for a libcall. */
750 if (type
== NULL_TREE
)
752 if (INTEGRAL_MODE_P (mode
))
753 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
760 switch (TREE_CODE (type
))
762 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
763 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
764 case POINTER_TYPE
: case REFERENCE_TYPE
:
765 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
772 /* Return the mode to use to store a scalar of TYPE and MODE.
773 PUNSIGNEDP points to the signedness of the type and may be adjusted
774 to show what signedness to use on extension operations. */
777 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
778 int *punsignedp ATTRIBUTE_UNUSED
)
785 /* For libcalls this is invoked without TYPE from the backends
786 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
788 if (type
== NULL_TREE
)
791 /* FIXME: this is the same logic that was there until GCC 4.4, but we
792 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
793 is not defined. The affected targets are M32C, S390, SPARC. */
795 code
= TREE_CODE (type
);
796 unsignedp
= *punsignedp
;
800 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
801 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
802 PROMOTE_MODE (mode
, unsignedp
, type
);
803 *punsignedp
= unsignedp
;
806 #ifdef POINTERS_EXTEND_UNSIGNED
809 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
810 return targetm
.addr_space
.address_mode
811 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
823 /* Use one of promote_mode or promote_function_mode to find the promoted
824 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
825 of DECL after promotion. */
828 promote_decl_mode (const_tree decl
, int *punsignedp
)
830 tree type
= TREE_TYPE (decl
);
831 int unsignedp
= TYPE_UNSIGNED (type
);
832 machine_mode mode
= DECL_MODE (decl
);
835 if (TREE_CODE (decl
) == RESULT_DECL
&& !DECL_BY_REFERENCE (decl
))
836 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
837 TREE_TYPE (current_function_decl
), 1);
838 else if (TREE_CODE (decl
) == RESULT_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
839 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
840 TREE_TYPE (current_function_decl
), 2);
842 pmode
= promote_mode (type
, mode
, &unsignedp
);
845 *punsignedp
= unsignedp
;
849 /* Return the promoted mode for name. If it is a named SSA_NAME, it
850 is the same as promote_decl_mode. Otherwise, it is the promoted
851 mode of a temp decl of same type as the SSA_NAME, if we had created
855 promote_ssa_mode (const_tree name
, int *punsignedp
)
857 gcc_assert (TREE_CODE (name
) == SSA_NAME
);
859 /* Partitions holding parms and results must be promoted as expected
861 if (SSA_NAME_VAR (name
)
862 && (TREE_CODE (SSA_NAME_VAR (name
)) == PARM_DECL
863 || TREE_CODE (SSA_NAME_VAR (name
)) == RESULT_DECL
))
865 machine_mode mode
= promote_decl_mode (SSA_NAME_VAR (name
), punsignedp
);
870 tree type
= TREE_TYPE (name
);
871 int unsignedp
= TYPE_UNSIGNED (type
);
872 machine_mode mode
= TYPE_MODE (type
);
874 /* Bypass TYPE_MODE when it maps vector modes to BLKmode. */
877 gcc_assert (VECTOR_TYPE_P (type
));
878 mode
= type
->type_common
.mode
;
881 machine_mode pmode
= promote_mode (type
, mode
, &unsignedp
);
883 *punsignedp
= unsignedp
;
890 /* Controls the behavior of {anti_,}adjust_stack. */
891 static bool suppress_reg_args_size
;
893 /* A helper for adjust_stack and anti_adjust_stack. */
896 adjust_stack_1 (rtx adjust
, bool anti_p
)
901 /* Hereafter anti_p means subtract_p. */
902 if (!STACK_GROWS_DOWNWARD
)
905 temp
= expand_binop (Pmode
,
906 anti_p
? sub_optab
: add_optab
,
907 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
910 if (temp
!= stack_pointer_rtx
)
911 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
914 insn
= get_last_insn ();
915 temp
= single_set (insn
);
916 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
919 if (!suppress_reg_args_size
)
920 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
923 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
924 This pops when ADJUST is positive. ADJUST need not be constant. */
927 adjust_stack (rtx adjust
)
929 if (adjust
== const0_rtx
)
932 /* We expect all variable sized adjustments to be multiple of
933 PREFERRED_STACK_BOUNDARY. */
934 if (CONST_INT_P (adjust
))
935 stack_pointer_delta
-= INTVAL (adjust
);
937 adjust_stack_1 (adjust
, false);
940 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
941 This pushes when ADJUST is positive. ADJUST need not be constant. */
944 anti_adjust_stack (rtx adjust
)
946 if (adjust
== const0_rtx
)
949 /* We expect all variable sized adjustments to be multiple of
950 PREFERRED_STACK_BOUNDARY. */
951 if (CONST_INT_P (adjust
))
952 stack_pointer_delta
+= INTVAL (adjust
);
954 adjust_stack_1 (adjust
, true);
957 /* Round the size of a block to be pushed up to the boundary required
958 by this machine. SIZE is the desired size, which need not be constant. */
961 round_push (rtx size
)
963 rtx align_rtx
, alignm1_rtx
;
965 if (!SUPPORTS_STACK_ALIGNMENT
966 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
968 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
973 if (CONST_INT_P (size
))
975 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
977 if (INTVAL (size
) != new_size
)
978 size
= GEN_INT (new_size
);
982 align_rtx
= GEN_INT (align
);
983 alignm1_rtx
= GEN_INT (align
- 1);
987 /* If crtl->preferred_stack_boundary might still grow, use
988 virtual_preferred_stack_boundary_rtx instead. This will be
989 substituted by the right value in vregs pass and optimized
991 align_rtx
= virtual_preferred_stack_boundary_rtx
;
992 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
996 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
997 but we know it can't. So add ourselves and then do
999 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1000 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1001 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1003 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1008 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1009 to a previously-created save area. If no save area has been allocated,
1010 this function will allocate one. If a save area is specified, it
1011 must be of the proper mode. */
1014 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1017 /* The default is that we use a move insn and save in a Pmode object. */
1018 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1019 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1021 /* See if this machine has anything special to do for this kind of save. */
1025 if (targetm
.have_save_stack_block ())
1026 fcn
= targetm
.gen_save_stack_block
;
1029 if (targetm
.have_save_stack_function ())
1030 fcn
= targetm
.gen_save_stack_function
;
1033 if (targetm
.have_save_stack_nonlocal ())
1034 fcn
= targetm
.gen_save_stack_nonlocal
;
1040 /* If there is no save area and we have to allocate one, do so. Otherwise
1041 verify the save area is the proper mode. */
1045 if (mode
!= VOIDmode
)
1047 if (save_level
== SAVE_NONLOCAL
)
1048 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1050 *psave
= sa
= gen_reg_rtx (mode
);
1054 do_pending_stack_adjust ();
1056 sa
= validize_mem (sa
);
1057 emit_insn (fcn (sa
, stack_pointer_rtx
));
1060 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1061 area made by emit_stack_save. If it is zero, we have nothing to do. */
1064 emit_stack_restore (enum save_level save_level
, rtx sa
)
1066 /* The default is that we use a move insn. */
1067 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1069 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1070 STACK_POINTER and HARD_FRAME_POINTER.
1071 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1072 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1073 aligned variables, which is reflected in ix86_can_eliminate.
1074 We normally still have the realigned STACK_POINTER that we can use.
1075 But if there is a stack restore still present at reload, it can trigger
1076 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1077 FRAME_POINTER into a hard reg.
1078 To prevent this situation, we force need_drap if we emit a stack
1080 if (SUPPORTS_STACK_ALIGNMENT
)
1081 crtl
->need_drap
= true;
1083 /* See if this machine has anything special to do for this kind of save. */
1087 if (targetm
.have_restore_stack_block ())
1088 fcn
= targetm
.gen_restore_stack_block
;
1091 if (targetm
.have_restore_stack_function ())
1092 fcn
= targetm
.gen_restore_stack_function
;
1095 if (targetm
.have_restore_stack_nonlocal ())
1096 fcn
= targetm
.gen_restore_stack_nonlocal
;
1104 sa
= validize_mem (sa
);
1105 /* These clobbers prevent the scheduler from moving
1106 references to variable arrays below the code
1107 that deletes (pops) the arrays. */
1108 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1109 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1112 discard_pending_stack_adjust ();
1114 emit_insn (fcn (stack_pointer_rtx
, sa
));
1117 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1118 function. This should be called whenever we allocate or deallocate
1119 dynamic stack space. */
1122 update_nonlocal_goto_save_area (void)
1127 /* The nonlocal_goto_save_area object is an array of N pointers. The
1128 first one is used for the frame pointer save; the rest are sized by
1129 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1130 of the stack save area slots. */
1131 t_save
= build4 (ARRAY_REF
,
1132 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1133 cfun
->nonlocal_goto_save_area
,
1134 integer_one_node
, NULL_TREE
, NULL_TREE
);
1135 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1137 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1140 /* Record a new stack level for the current function. This should be called
1141 whenever we allocate or deallocate dynamic stack space. */
1144 record_new_stack_level (void)
1146 /* Record the new stack level for nonlocal gotos. */
1147 if (cfun
->nonlocal_goto_save_area
)
1148 update_nonlocal_goto_save_area ();
1150 /* Record the new stack level for SJLJ exceptions. */
1151 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1152 update_sjlj_context ();
1155 /* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */
1157 align_dynamic_address (rtx target
, unsigned required_align
)
1159 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1160 but we know it can't. So add ourselves and then do
1162 target
= expand_binop (Pmode
, add_optab
, target
,
1163 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1165 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1166 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1167 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1170 target
= expand_mult (Pmode
, target
,
1171 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1178 /* Return an rtx through *PSIZE, representing the size of an area of memory to
1179 be dynamically pushed on the stack.
1181 *PSIZE is an rtx representing the size of the area.
1183 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1184 parameter may be zero. If so, a proper value will be extracted
1185 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1187 REQUIRED_ALIGN is the alignment (in bits) required for the region
1190 If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for
1191 the additional size returned. */
1193 get_dynamic_stack_size (rtx
*psize
, unsigned size_align
,
1194 unsigned required_align
,
1195 HOST_WIDE_INT
*pstack_usage_size
)
1200 /* Ensure the size is in the proper mode. */
1201 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1202 size
= convert_to_mode (Pmode
, size
, 1);
1204 if (CONST_INT_P (size
))
1206 unsigned HOST_WIDE_INT lsb
;
1208 lsb
= INTVAL (size
);
1211 /* Watch out for overflow truncating to "unsigned". */
1212 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1213 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1215 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1217 else if (size_align
< BITS_PER_UNIT
)
1218 size_align
= BITS_PER_UNIT
;
1220 /* We can't attempt to minimize alignment necessary, because we don't
1221 know the final value of preferred_stack_boundary yet while executing
1223 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1224 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1226 /* We will need to ensure that the address we return is aligned to
1227 REQUIRED_ALIGN. At this point in the compilation, we don't always
1228 know the final value of the STACK_DYNAMIC_OFFSET used in function.c
1229 (it might depend on the size of the outgoing parameter lists, for
1230 example), so we must preventively align the value. We leave space
1231 in SIZE for the hole that might result from the alignment operation. */
1233 extra
= (required_align
- BITS_PER_UNIT
) / BITS_PER_UNIT
;
1234 size
= plus_constant (Pmode
, size
, extra
);
1235 size
= force_operand (size
, NULL_RTX
);
1237 if (flag_stack_usage_info
&& pstack_usage_size
)
1238 *pstack_usage_size
+= extra
;
1240 if (extra
&& size_align
> BITS_PER_UNIT
)
1241 size_align
= BITS_PER_UNIT
;
1243 /* Round the size to a multiple of the required stack alignment.
1244 Since the stack is presumed to be rounded before this allocation,
1245 this will maintain the required alignment.
1247 If the stack grows downward, we could save an insn by subtracting
1248 SIZE from the stack pointer and then aligning the stack pointer.
1249 The problem with this is that the stack pointer may be unaligned
1250 between the execution of the subtraction and alignment insns and
1251 some machines do not allow this. Even on those that do, some
1252 signal handlers malfunction if a signal should occur between those
1253 insns. Since this is an extremely rare event, we have no reliable
1254 way of knowing which systems have this problem. So we avoid even
1255 momentarily mis-aligning the stack. */
1256 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1258 size
= round_push (size
);
1260 if (flag_stack_usage_info
&& pstack_usage_size
)
1262 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1263 *pstack_usage_size
=
1264 (*pstack_usage_size
+ align
- 1) / align
* align
;
1271 /* Return an rtx representing the address of an area of memory dynamically
1272 pushed on the stack.
1274 Any required stack pointer alignment is preserved.
1276 SIZE is an rtx representing the size of the area.
1278 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1279 parameter may be zero. If so, a proper value will be extracted
1280 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1282 REQUIRED_ALIGN is the alignment (in bits) required for the region
1285 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1286 stack space allocated by the generated code cannot be added with itself
1287 in the course of the execution of the function. It is always safe to
1288 pass FALSE here and the following criterion is sufficient in order to
1289 pass TRUE: every path in the CFG that starts at the allocation point and
1290 loops to it executes the associated deallocation code. */
1293 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1294 unsigned required_align
, bool cannot_accumulate
)
1296 HOST_WIDE_INT stack_usage_size
= -1;
1297 rtx_code_label
*final_label
;
1298 rtx final_target
, target
;
1300 /* If we're asking for zero bytes, it doesn't matter what we point
1301 to since we can't dereference it. But return a reasonable
1303 if (size
== const0_rtx
)
1304 return virtual_stack_dynamic_rtx
;
1306 /* Otherwise, show we're calling alloca or equivalent. */
1307 cfun
->calls_alloca
= 1;
1309 /* If stack usage info is requested, look into the size we are passed.
1310 We need to do so this early to avoid the obfuscation that may be
1311 introduced later by the various alignment operations. */
1312 if (flag_stack_usage_info
)
1314 if (CONST_INT_P (size
))
1315 stack_usage_size
= INTVAL (size
);
1316 else if (REG_P (size
))
1318 /* Look into the last emitted insn and see if we can deduce
1319 something for the register. */
1322 insn
= get_last_insn ();
1323 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1325 if (CONST_INT_P (SET_SRC (set
)))
1326 stack_usage_size
= INTVAL (SET_SRC (set
));
1327 else if ((note
= find_reg_equal_equiv_note (insn
))
1328 && CONST_INT_P (XEXP (note
, 0)))
1329 stack_usage_size
= INTVAL (XEXP (note
, 0));
1333 /* If the size is not constant, we can't say anything. */
1334 if (stack_usage_size
== -1)
1336 current_function_has_unbounded_dynamic_stack_size
= 1;
1337 stack_usage_size
= 0;
1341 get_dynamic_stack_size (&size
, size_align
, required_align
, &stack_usage_size
);
1343 target
= gen_reg_rtx (Pmode
);
1345 /* The size is supposed to be fully adjusted at this point so record it
1346 if stack usage info is requested. */
1347 if (flag_stack_usage_info
)
1349 current_function_dynamic_stack_size
+= stack_usage_size
;
1351 /* ??? This is gross but the only safe stance in the absence
1352 of stack usage oriented flow analysis. */
1353 if (!cannot_accumulate
)
1354 current_function_has_unbounded_dynamic_stack_size
= 1;
1358 final_target
= NULL_RTX
;
1360 /* If we are splitting the stack, we need to ask the backend whether
1361 there is enough room on the current stack. If there isn't, or if
1362 the backend doesn't know how to tell is, then we need to call a
1363 function to allocate memory in some other way. This memory will
1364 be released when we release the current stack segment. The
1365 effect is that stack allocation becomes less efficient, but at
1366 least it doesn't cause a stack overflow. */
1367 if (flag_split_stack
)
1369 rtx_code_label
*available_label
;
1370 rtx ask
, space
, func
;
1372 available_label
= NULL
;
1374 if (targetm
.have_split_stack_space_check ())
1376 available_label
= gen_label_rtx ();
1378 /* This instruction will branch to AVAILABLE_LABEL if there
1379 are SIZE bytes available on the stack. */
1380 emit_insn (targetm
.gen_split_stack_space_check
1381 (size
, available_label
));
1384 /* The __morestack_allocate_stack_space function will allocate
1385 memory using malloc. If the alignment of the memory returned
1386 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1387 make sure we allocate enough space. */
1388 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1391 ask
= expand_binop (Pmode
, add_optab
, size
,
1392 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1394 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1396 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1398 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1401 if (available_label
== NULL_RTX
)
1404 final_target
= gen_reg_rtx (Pmode
);
1406 emit_move_insn (final_target
, space
);
1408 final_label
= gen_label_rtx ();
1409 emit_jump (final_label
);
1411 emit_label (available_label
);
1414 do_pending_stack_adjust ();
1416 /* We ought to be called always on the toplevel and stack ought to be aligned
1418 gcc_assert (!(stack_pointer_delta
1419 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1421 /* If needed, check that we have the required amount of stack. Take into
1422 account what has already been checked. */
1423 if (STACK_CHECK_MOVING_SP
)
1425 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1426 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1428 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1429 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1431 /* Don't let anti_adjust_stack emit notes. */
1432 suppress_reg_args_size
= true;
1434 /* Perform the required allocation from the stack. Some systems do
1435 this differently than simply incrementing/decrementing from the
1436 stack pointer, such as acquiring the space by calling malloc(). */
1437 if (targetm
.have_allocate_stack ())
1439 struct expand_operand ops
[2];
1440 /* We don't have to check against the predicate for operand 0 since
1441 TARGET is known to be a pseudo of the proper mode, which must
1442 be valid for the operand. */
1443 create_fixed_operand (&ops
[0], target
);
1444 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1445 expand_insn (targetm
.code_for_allocate_stack
, 2, ops
);
1449 int saved_stack_pointer_delta
;
1451 if (!STACK_GROWS_DOWNWARD
)
1452 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1454 /* Check stack bounds if necessary. */
1455 if (crtl
->limit_stack
)
1458 rtx_code_label
*space_available
= gen_label_rtx ();
1459 if (STACK_GROWS_DOWNWARD
)
1460 available
= expand_binop (Pmode
, sub_optab
,
1461 stack_pointer_rtx
, stack_limit_rtx
,
1462 NULL_RTX
, 1, OPTAB_WIDEN
);
1464 available
= expand_binop (Pmode
, sub_optab
,
1465 stack_limit_rtx
, stack_pointer_rtx
,
1466 NULL_RTX
, 1, OPTAB_WIDEN
);
1468 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1470 if (targetm
.have_trap ())
1471 emit_insn (targetm
.gen_trap ());
1473 error ("stack limits not supported on this target");
1475 emit_label (space_available
);
1478 saved_stack_pointer_delta
= stack_pointer_delta
;
1480 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1481 anti_adjust_stack_and_probe (size
, false);
1483 anti_adjust_stack (size
);
1485 /* Even if size is constant, don't modify stack_pointer_delta.
1486 The constant size alloca should preserve
1487 crtl->preferred_stack_boundary alignment. */
1488 stack_pointer_delta
= saved_stack_pointer_delta
;
1490 if (STACK_GROWS_DOWNWARD
)
1491 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1494 suppress_reg_args_size
= false;
1496 /* Finish up the split stack handling. */
1497 if (final_label
!= NULL_RTX
)
1499 gcc_assert (flag_split_stack
);
1500 emit_move_insn (final_target
, target
);
1501 emit_label (final_label
);
1502 target
= final_target
;
1505 target
= align_dynamic_address (target
, required_align
);
1507 /* Now that we've committed to a return value, mark its alignment. */
1508 mark_reg_pointer (target
, required_align
);
1510 /* Record the new stack level. */
1511 record_new_stack_level ();
1516 /* Return an rtx representing the address of an area of memory already
1517 statically pushed onto the stack in the virtual stack vars area. (It is
1518 assumed that the area is allocated in the function prologue.)
1520 Any required stack pointer alignment is preserved.
1522 OFFSET is the offset of the area into the virtual stack vars area.
1524 REQUIRED_ALIGN is the alignment (in bits) required for the region
1528 get_dynamic_stack_base (HOST_WIDE_INT offset
, unsigned required_align
)
1532 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1533 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1535 target
= gen_reg_rtx (Pmode
);
1536 emit_move_insn (target
, virtual_stack_vars_rtx
);
1537 target
= expand_binop (Pmode
, add_optab
, target
,
1538 gen_int_mode (offset
, Pmode
),
1539 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1540 target
= align_dynamic_address (target
, required_align
);
1542 /* Now that we've committed to a return value, mark its alignment. */
1543 mark_reg_pointer (target
, required_align
);
1548 /* A front end may want to override GCC's stack checking by providing a
1549 run-time routine to call to check the stack, so provide a mechanism for
1550 calling that routine. */
1552 static GTY(()) rtx stack_check_libfunc
;
1555 set_stack_check_libfunc (const char *libfunc_name
)
1557 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1558 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1561 /* Emit one stack probe at ADDRESS, an address within the stack. */
1564 emit_stack_probe (rtx address
)
1566 if (targetm
.have_probe_stack_address ())
1567 emit_insn (targetm
.gen_probe_stack_address (address
));
1570 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1572 MEM_VOLATILE_P (memref
) = 1;
1574 /* See if we have an insn to probe the stack. */
1575 if (targetm
.have_probe_stack ())
1576 emit_insn (targetm
.gen_probe_stack (memref
));
1578 emit_move_insn (memref
, const0_rtx
);
1582 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1583 FIRST is a constant and size is a Pmode RTX. These are offsets from
1584 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1585 or subtract them from the stack pointer. */
1587 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1589 #if STACK_GROWS_DOWNWARD
1590 #define STACK_GROW_OP MINUS
1591 #define STACK_GROW_OPTAB sub_optab
1592 #define STACK_GROW_OFF(off) -(off)
1594 #define STACK_GROW_OP PLUS
1595 #define STACK_GROW_OPTAB add_optab
1596 #define STACK_GROW_OFF(off) (off)
1600 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1602 /* First ensure SIZE is Pmode. */
1603 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1604 size
= convert_to_mode (Pmode
, size
, 1);
1606 /* Next see if we have a function to check the stack. */
1607 if (stack_check_libfunc
)
1609 rtx addr
= memory_address (Pmode
,
1610 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1612 plus_constant (Pmode
,
1614 emit_library_call (stack_check_libfunc
, LCT_THROW
, VOIDmode
, 1, addr
,
1618 /* Next see if we have an insn to check the stack. */
1619 else if (targetm
.have_check_stack ())
1621 struct expand_operand ops
[1];
1622 rtx addr
= memory_address (Pmode
,
1623 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1625 plus_constant (Pmode
,
1628 create_input_operand (&ops
[0], addr
, Pmode
);
1629 success
= maybe_expand_insn (targetm
.code_for_check_stack
, 1, ops
);
1630 gcc_assert (success
);
1633 /* Otherwise we have to generate explicit probes. If we have a constant
1634 small number of them to generate, that's the easy case. */
1635 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1637 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1640 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1641 it exceeds SIZE. If only one probe is needed, this will not
1642 generate any code. Then probe at FIRST + SIZE. */
1643 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1645 addr
= memory_address (Pmode
,
1646 plus_constant (Pmode
, stack_pointer_rtx
,
1647 STACK_GROW_OFF (first
+ i
)));
1648 emit_stack_probe (addr
);
1651 addr
= memory_address (Pmode
,
1652 plus_constant (Pmode
, stack_pointer_rtx
,
1653 STACK_GROW_OFF (first
+ isize
)));
1654 emit_stack_probe (addr
);
1657 /* In the variable case, do the same as above, but in a loop. Note that we
1658 must be extra careful with variables wrapping around because we might be
1659 at the very top (or the very bottom) of the address space and we have to
1660 be able to handle this case properly; in particular, we use an equality
1661 test for the loop condition. */
1664 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1665 rtx_code_label
*loop_lab
= gen_label_rtx ();
1666 rtx_code_label
*end_lab
= gen_label_rtx ();
1668 /* Step 1: round SIZE to the previous multiple of the interval. */
1670 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1672 = simplify_gen_binary (AND
, Pmode
, size
,
1673 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1674 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1677 /* Step 2: compute initial and final value of the loop counter. */
1679 /* TEST_ADDR = SP + FIRST. */
1680 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1682 gen_int_mode (first
, Pmode
)),
1685 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1686 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1688 rounded_size_op
), NULL_RTX
);
1693 while (TEST_ADDR != LAST_ADDR)
1695 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1699 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1700 until it is equal to ROUNDED_SIZE. */
1702 emit_label (loop_lab
);
1704 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1705 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1708 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1709 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1710 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1713 gcc_assert (temp
== test_addr
);
1715 /* Probe at TEST_ADDR. */
1716 emit_stack_probe (test_addr
);
1718 emit_jump (loop_lab
);
1720 emit_label (end_lab
);
1723 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1724 that SIZE is equal to ROUNDED_SIZE. */
1726 /* TEMP = SIZE - ROUNDED_SIZE. */
1727 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1728 if (temp
!= const0_rtx
)
1732 if (CONST_INT_P (temp
))
1734 /* Use [base + disp} addressing mode if supported. */
1735 HOST_WIDE_INT offset
= INTVAL (temp
);
1736 addr
= memory_address (Pmode
,
1737 plus_constant (Pmode
, last_addr
,
1738 STACK_GROW_OFF (offset
)));
1742 /* Manual CSE if the difference is not known at compile-time. */
1743 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1744 addr
= memory_address (Pmode
,
1745 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1749 emit_stack_probe (addr
);
1753 /* Make sure nothing is scheduled before we are done. */
1754 emit_insn (gen_blockage ());
1757 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1758 while probing it. This pushes when SIZE is positive. SIZE need not
1759 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1760 by plus SIZE at the end. */
1763 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1765 /* We skip the probe for the first interval + a small dope of 4 words and
1766 probe that many bytes past the specified size to maintain a protection
1767 area at the botton of the stack. */
1768 const int dope
= 4 * UNITS_PER_WORD
;
1770 /* First ensure SIZE is Pmode. */
1771 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1772 size
= convert_to_mode (Pmode
, size
, 1);
1774 /* If we have a constant small number of probes to generate, that's the
1776 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1778 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1779 bool first_probe
= true;
1781 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1782 values of N from 1 until it exceeds SIZE. If only one probe is
1783 needed, this will not generate any code. Then adjust and probe
1784 to PROBE_INTERVAL + SIZE. */
1785 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1789 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1790 first_probe
= false;
1793 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1794 emit_stack_probe (stack_pointer_rtx
);
1798 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1800 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1801 emit_stack_probe (stack_pointer_rtx
);
1804 /* In the variable case, do the same as above, but in a loop. Note that we
1805 must be extra careful with variables wrapping around because we might be
1806 at the very top (or the very bottom) of the address space and we have to
1807 be able to handle this case properly; in particular, we use an equality
1808 test for the loop condition. */
1811 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1812 rtx_code_label
*loop_lab
= gen_label_rtx ();
1813 rtx_code_label
*end_lab
= gen_label_rtx ();
1816 /* Step 1: round SIZE to the previous multiple of the interval. */
1818 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1820 = simplify_gen_binary (AND
, Pmode
, size
,
1821 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1822 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1825 /* Step 2: compute initial and final value of the loop counter. */
1827 /* SP = SP_0 + PROBE_INTERVAL. */
1828 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1830 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1831 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1833 rounded_size_op
), NULL_RTX
);
1838 while (SP != LAST_ADDR)
1840 SP = SP + PROBE_INTERVAL
1844 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1845 values of N from 1 until it is equal to ROUNDED_SIZE. */
1847 emit_label (loop_lab
);
1849 /* Jump to END_LAB if SP == LAST_ADDR. */
1850 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1853 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1854 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1855 emit_stack_probe (stack_pointer_rtx
);
1857 emit_jump (loop_lab
);
1859 emit_label (end_lab
);
1862 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1863 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1865 /* TEMP = SIZE - ROUNDED_SIZE. */
1866 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1867 if (temp
!= const0_rtx
)
1869 /* Manual CSE if the difference is not known at compile-time. */
1870 if (GET_CODE (temp
) != CONST_INT
)
1871 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1872 anti_adjust_stack (temp
);
1873 emit_stack_probe (stack_pointer_rtx
);
1877 /* Adjust back and account for the additional first interval. */
1879 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1881 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1884 /* Return an rtx representing the register or memory location
1885 in which a scalar value of data type VALTYPE
1886 was returned by a function call to function FUNC.
1887 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1888 function is known, otherwise 0.
1889 OUTGOING is 1 if on a machine with register windows this function
1890 should return the register in which the function will put its result
1894 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1895 int outgoing ATTRIBUTE_UNUSED
)
1899 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1902 && GET_MODE (val
) == BLKmode
)
1904 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1905 machine_mode tmpmode
;
1907 /* int_size_in_bytes can return -1. We don't need a check here
1908 since the value of bytes will then be large enough that no
1909 mode will match anyway. */
1911 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1912 tmpmode
!= VOIDmode
;
1913 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1915 /* Have we found a large enough mode? */
1916 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1920 /* No suitable mode found. */
1921 gcc_assert (tmpmode
!= VOIDmode
);
1923 PUT_MODE (val
, tmpmode
);
1928 /* Return an rtx representing the register or memory location
1929 in which a scalar value of mode MODE was returned by a library call. */
1932 hard_libcall_value (machine_mode mode
, rtx fun
)
1934 return targetm
.calls
.libcall_value (mode
, fun
);
1937 /* Look up the tree code for a given rtx code
1938 to provide the arithmetic operation for real_arithmetic.
1939 The function returns an int because the caller may not know
1940 what `enum tree_code' means. */
1943 rtx_to_tree_code (enum rtx_code code
)
1945 enum tree_code tcode
;
1968 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1971 return ((int) tcode
);
1974 #include "gt-explow.h"