1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2015 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
25 #include "diagnostic-core.h"
29 #include "stor-layout.h"
34 #include "insn-config.h"
43 #include "insn-codes.h"
47 #include "langhooks.h"
49 #include "common/common-target.h"
52 static rtx
break_out_memory_refs (rtx
);
55 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
58 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
60 int width
= GET_MODE_PRECISION (mode
);
62 /* You want to truncate to a _what_? */
63 gcc_assert (SCALAR_INT_MODE_P (mode
)
64 || POINTER_BOUNDS_MODE_P (mode
));
66 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
68 return c
& 1 ? STORE_FLAG_VALUE
: 0;
70 /* Sign-extend for the requested mode. */
72 if (width
< HOST_BITS_PER_WIDE_INT
)
74 HOST_WIDE_INT sign
= 1;
84 /* Return an rtx for the sum of X and the integer C, given that X has
85 mode MODE. INPLACE is true if X can be modified inplace or false
86 if it must be treated as immutable. */
89 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
97 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
109 CASE_CONST_SCALAR_INT
:
110 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
113 /* If this is a reference to the constant pool, try replacing it with
114 a reference to a new constant. If the resulting address isn't
115 valid, don't return it because we have no way to validize it. */
116 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
117 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
119 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
120 tem
= force_const_mem (GET_MODE (x
), tem
);
121 /* Targets may disallow some constants in the constant pool, thus
122 force_const_mem may return NULL_RTX. */
123 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
129 /* If adding to something entirely constant, set a flag
130 so that we can add a CONST around the result. */
131 if (inplace
&& shared_const_p (x
))
143 /* The interesting case is adding the integer to a sum. Look
144 for constant term in the sum and combine with C. For an
145 integer constant term or a constant term that is not an
146 explicit integer, we combine or group them together anyway.
148 We may not immediately return from the recursive call here, lest
149 all_constant gets lost. */
151 if (CONSTANT_P (XEXP (x
, 1)))
153 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
154 if (term
== const0_rtx
)
159 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
162 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
166 /* We need to be careful since X may be shared and we can't
167 modify it in place. */
169 const_loc
= find_constant_term_loc (&x
);
171 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
181 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
183 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
185 else if (all_constant
)
186 return gen_rtx_CONST (mode
, x
);
191 /* If X is a sum, return a new sum like X but lacking any constant terms.
192 Add all the removed constant terms into *CONSTPTR.
193 X itself is not altered. The result != X if and only if
194 it is not isomorphic to X. */
197 eliminate_constant_term (rtx x
, rtx
*constptr
)
202 if (GET_CODE (x
) != PLUS
)
205 /* First handle constants appearing at this level explicitly. */
206 if (CONST_INT_P (XEXP (x
, 1))
207 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
209 && CONST_INT_P (tem
))
212 return eliminate_constant_term (XEXP (x
, 0), constptr
);
216 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
217 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
218 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
219 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
221 && CONST_INT_P (tem
))
224 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
231 /* Return a copy of X in which all memory references
232 and all constants that involve symbol refs
233 have been replaced with new temporary registers.
234 Also emit code to load the memory locations and constants
235 into those registers.
237 If X contains no such constants or memory references,
238 X itself (not a copy) is returned.
240 If a constant is found in the address that is not a legitimate constant
241 in an insn, it is left alone in the hope that it might be valid in the
244 X may contain no arithmetic except addition, subtraction and multiplication.
245 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
248 break_out_memory_refs (rtx x
)
251 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
252 && GET_MODE (x
) != VOIDmode
))
253 x
= force_reg (GET_MODE (x
), x
);
254 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
255 || GET_CODE (x
) == MULT
)
257 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
258 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
260 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
261 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
267 /* Given X, a memory address in address space AS' pointer mode, convert it to
268 an address in the address space's address mode, or vice versa (TO_MODE says
269 which way). We take advantage of the fact that pointers are not allowed to
270 overflow by commuting arithmetic operations over conversions so that address
271 arithmetic insns can be used. IN_CONST is true if this conversion is inside
275 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
276 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
277 bool in_const 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
);
326 temp
= shallow_copy_rtx (x
);
327 PUT_MODE (temp
, to_mode
);
332 return gen_rtx_CONST (to_mode
,
333 convert_memory_address_addr_space_1
334 (to_mode
, XEXP (x
, 0), as
, true));
339 /* For addition we can safely permute the conversion and addition
340 operation if one operand is a constant and converting the constant
341 does not change it or if one operand is a constant and we are
342 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
343 We can always safely permute them if we are making the address
344 narrower. Inside a CONST RTL, this is safe for both pointers
345 zero or sign extended as pointers cannot wrap. */
346 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
347 || (GET_CODE (x
) == PLUS
348 && CONST_INT_P (XEXP (x
, 1))
349 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
350 || XEXP (x
, 1) == convert_memory_address_addr_space_1
351 (to_mode
, XEXP (x
, 1), as
, in_const
)
352 || POINTERS_EXTEND_UNSIGNED
< 0)))
353 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
354 convert_memory_address_addr_space_1
355 (to_mode
, XEXP (x
, 0), as
, in_const
),
363 return convert_modes (to_mode
, from_mode
,
364 x
, POINTERS_EXTEND_UNSIGNED
);
365 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
368 /* Given X, a memory address in address space AS' pointer mode, convert it to
369 an address in the address space's address mode, or vice versa (TO_MODE says
370 which way). We take advantage of the fact that pointers are not allowed to
371 overflow by commuting arithmetic operations over conversions so that address
372 arithmetic insns can be used. */
375 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
377 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false);
381 /* Return something equivalent to X but valid as a memory address for something
382 of mode MODE in the named address space AS. When X is not itself valid,
383 this works by copying X or subexpressions of it into registers. */
386 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
389 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
391 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
393 /* By passing constant addresses through registers
394 we get a chance to cse them. */
395 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
396 x
= force_reg (address_mode
, x
);
398 /* We get better cse by rejecting indirect addressing at this stage.
399 Let the combiner create indirect addresses where appropriate.
400 For now, generate the code so that the subexpressions useful to share
401 are visible. But not if cse won't be done! */
404 if (! cse_not_expected
&& !REG_P (x
))
405 x
= break_out_memory_refs (x
);
407 /* At this point, any valid address is accepted. */
408 if (memory_address_addr_space_p (mode
, x
, as
))
411 /* If it was valid before but breaking out memory refs invalidated it,
412 use it the old way. */
413 if (memory_address_addr_space_p (mode
, oldx
, as
))
419 /* Perform machine-dependent transformations on X
420 in certain cases. This is not necessary since the code
421 below can handle all possible cases, but machine-dependent
422 transformations can make better code. */
425 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
426 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
430 /* PLUS and MULT can appear in special ways
431 as the result of attempts to make an address usable for indexing.
432 Usually they are dealt with by calling force_operand, below.
433 But a sum containing constant terms is special
434 if removing them makes the sum a valid address:
435 then we generate that address in a register
436 and index off of it. We do this because it often makes
437 shorter code, and because the addresses thus generated
438 in registers often become common subexpressions. */
439 if (GET_CODE (x
) == PLUS
)
441 rtx constant_term
= const0_rtx
;
442 rtx y
= eliminate_constant_term (x
, &constant_term
);
443 if (constant_term
== const0_rtx
444 || ! memory_address_addr_space_p (mode
, y
, as
))
445 x
= force_operand (x
, NULL_RTX
);
448 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
449 if (! memory_address_addr_space_p (mode
, y
, as
))
450 x
= force_operand (x
, NULL_RTX
);
456 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
457 x
= force_operand (x
, NULL_RTX
);
459 /* If we have a register that's an invalid address,
460 it must be a hard reg of the wrong class. Copy it to a pseudo. */
464 /* Last resort: copy the value to a register, since
465 the register is a valid address. */
467 x
= force_reg (address_mode
, x
);
472 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
473 /* If we didn't change the address, we are done. Otherwise, mark
474 a reg as a pointer if we have REG or REG + CONST_INT. */
478 mark_reg_pointer (x
, BITS_PER_UNIT
);
479 else if (GET_CODE (x
) == PLUS
480 && REG_P (XEXP (x
, 0))
481 && CONST_INT_P (XEXP (x
, 1)))
482 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
484 /* OLDX may have been the address on a temporary. Update the address
485 to indicate that X is now used. */
486 update_temp_slot_address (oldx
, x
);
491 /* If REF is a MEM with an invalid address, change it into a valid address.
492 Pass through anything else unchanged. REF must be an unshared rtx and
493 the function may modify it in-place. */
496 validize_mem (rtx ref
)
500 ref
= use_anchored_address (ref
);
501 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
502 MEM_ADDR_SPACE (ref
)))
505 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
508 /* If X is a memory reference to a member of an object block, try rewriting
509 it to use an anchor instead. Return the new memory reference on success
510 and the old one on failure. */
513 use_anchored_address (rtx x
)
516 HOST_WIDE_INT offset
;
519 if (!flag_section_anchors
)
525 /* Split the address into a base and offset. */
528 if (GET_CODE (base
) == CONST
529 && GET_CODE (XEXP (base
, 0)) == PLUS
530 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
532 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
533 base
= XEXP (XEXP (base
, 0), 0);
536 /* Check whether BASE is suitable for anchors. */
537 if (GET_CODE (base
) != SYMBOL_REF
538 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
539 || SYMBOL_REF_ANCHOR_P (base
)
540 || SYMBOL_REF_BLOCK (base
) == NULL
541 || !targetm
.use_anchors_for_symbol_p (base
))
544 /* Decide where BASE is going to be. */
545 place_block_symbol (base
);
547 /* Get the anchor we need to use. */
548 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
549 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
550 SYMBOL_REF_TLS_MODEL (base
));
552 /* Work out the offset from the anchor. */
553 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
555 /* If we're going to run a CSE pass, force the anchor into a register.
556 We will then be able to reuse registers for several accesses, if the
557 target costs say that that's worthwhile. */
558 mode
= GET_MODE (base
);
559 if (!cse_not_expected
)
560 base
= force_reg (mode
, base
);
562 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
565 /* Copy the value or contents of X to a new temp reg and return that reg. */
570 rtx temp
= gen_reg_rtx (GET_MODE (x
));
572 /* If not an operand, must be an address with PLUS and MULT so
573 do the computation. */
574 if (! general_operand (x
, VOIDmode
))
575 x
= force_operand (x
, temp
);
578 emit_move_insn (temp
, x
);
583 /* Like copy_to_reg but always give the new register mode Pmode
584 in case X is a constant. */
587 copy_addr_to_reg (rtx x
)
589 return copy_to_mode_reg (Pmode
, x
);
592 /* Like copy_to_reg but always give the new register mode MODE
593 in case X is a constant. */
596 copy_to_mode_reg (machine_mode mode
, rtx x
)
598 rtx temp
= gen_reg_rtx (mode
);
600 /* If not an operand, must be an address with PLUS and MULT so
601 do the computation. */
602 if (! general_operand (x
, VOIDmode
))
603 x
= force_operand (x
, temp
);
605 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
607 emit_move_insn (temp
, x
);
611 /* Load X into a register if it is not already one.
612 Use mode MODE for the register.
613 X should be valid for mode MODE, but it may be a constant which
614 is valid for all integer modes; that's why caller must specify MODE.
616 The caller must not alter the value in the register we return,
617 since we mark it as a "constant" register. */
620 force_reg (machine_mode mode
, rtx x
)
628 if (general_operand (x
, mode
))
630 temp
= gen_reg_rtx (mode
);
631 insn
= emit_move_insn (temp
, x
);
635 temp
= force_operand (x
, NULL_RTX
);
637 insn
= get_last_insn ();
640 rtx temp2
= gen_reg_rtx (mode
);
641 insn
= emit_move_insn (temp2
, temp
);
646 /* Let optimizers know that TEMP's value never changes
647 and that X can be substituted for it. Don't get confused
648 if INSN set something else (such as a SUBREG of TEMP). */
650 && (set
= single_set (insn
)) != 0
651 && SET_DEST (set
) == temp
652 && ! rtx_equal_p (x
, SET_SRC (set
)))
653 set_unique_reg_note (insn
, REG_EQUAL
, x
);
655 /* Let optimizers know that TEMP is a pointer, and if so, the
656 known alignment of that pointer. */
659 if (GET_CODE (x
) == SYMBOL_REF
)
661 align
= BITS_PER_UNIT
;
662 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
663 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
665 else if (GET_CODE (x
) == LABEL_REF
)
666 align
= BITS_PER_UNIT
;
667 else if (GET_CODE (x
) == CONST
668 && GET_CODE (XEXP (x
, 0)) == PLUS
669 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
670 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
672 rtx s
= XEXP (XEXP (x
, 0), 0);
673 rtx c
= XEXP (XEXP (x
, 0), 1);
677 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
678 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
684 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
685 align
= MIN (sa
, ca
);
689 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
690 mark_reg_pointer (temp
, align
);
696 /* If X is a memory ref, copy its contents to a new temp reg and return
697 that reg. Otherwise, return X. */
700 force_not_mem (rtx x
)
704 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
707 temp
= gen_reg_rtx (GET_MODE (x
));
710 REG_POINTER (temp
) = 1;
712 emit_move_insn (temp
, x
);
716 /* Copy X to TARGET (if it's nonzero and a reg)
717 or to a new temp reg and return that reg.
718 MODE is the mode to use for X in case it is a constant. */
721 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
725 if (target
&& REG_P (target
))
728 temp
= gen_reg_rtx (mode
);
730 emit_move_insn (temp
, x
);
734 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
735 PUNSIGNEDP points to the signedness of the type and may be adjusted
736 to show what signedness to use on extension operations.
738 FOR_RETURN is nonzero if the caller is promoting the return value
739 of FNDECL, else it is for promoting args. */
742 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
743 const_tree funtype
, int for_return
)
745 /* Called without a type node for a libcall. */
746 if (type
== NULL_TREE
)
748 if (INTEGRAL_MODE_P (mode
))
749 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
756 switch (TREE_CODE (type
))
758 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
759 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
760 case POINTER_TYPE
: case REFERENCE_TYPE
:
761 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
768 /* Return the mode to use to store a scalar of TYPE and MODE.
769 PUNSIGNEDP points to the signedness of the type and may be adjusted
770 to show what signedness to use on extension operations. */
773 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
774 int *punsignedp ATTRIBUTE_UNUSED
)
781 /* For libcalls this is invoked without TYPE from the backends
782 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
784 if (type
== NULL_TREE
)
787 /* FIXME: this is the same logic that was there until GCC 4.4, but we
788 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
789 is not defined. The affected targets are M32C, S390, SPARC. */
791 code
= TREE_CODE (type
);
792 unsignedp
= *punsignedp
;
796 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
797 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
798 PROMOTE_MODE (mode
, unsignedp
, type
);
799 *punsignedp
= unsignedp
;
803 #ifdef POINTERS_EXTEND_UNSIGNED
806 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
807 return targetm
.addr_space
.address_mode
808 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
821 /* Use one of promote_mode or promote_function_mode to find the promoted
822 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
823 of DECL after promotion. */
826 promote_decl_mode (const_tree decl
, int *punsignedp
)
828 tree type
= TREE_TYPE (decl
);
829 int unsignedp
= TYPE_UNSIGNED (type
);
830 machine_mode mode
= DECL_MODE (decl
);
833 if (TREE_CODE (decl
) == RESULT_DECL
834 || TREE_CODE (decl
) == PARM_DECL
)
835 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
836 TREE_TYPE (current_function_decl
), 2);
838 pmode
= promote_mode (type
, mode
, &unsignedp
);
841 *punsignedp
= unsignedp
;
845 /* Return the promoted mode for name. If it is a named SSA_NAME, it
846 is the same as promote_decl_mode. Otherwise, it is the promoted
847 mode of a temp decl of same type as the SSA_NAME, if we had created
851 promote_ssa_mode (const_tree name
, int *punsignedp
)
853 gcc_assert (TREE_CODE (name
) == SSA_NAME
);
855 /* Partitions holding parms and results must be promoted as expected
857 if (SSA_NAME_VAR (name
)
858 && (TREE_CODE (SSA_NAME_VAR (name
)) == PARM_DECL
859 || TREE_CODE (SSA_NAME_VAR (name
)) == RESULT_DECL
))
860 return promote_decl_mode (SSA_NAME_VAR (name
), punsignedp
);
862 tree type
= TREE_TYPE (name
);
863 int unsignedp
= TYPE_UNSIGNED (type
);
864 machine_mode mode
= TYPE_MODE (type
);
866 machine_mode pmode
= promote_mode (type
, mode
, &unsignedp
);
868 *punsignedp
= unsignedp
;
875 /* Controls the behaviour of {anti_,}adjust_stack. */
876 static bool suppress_reg_args_size
;
878 /* A helper for adjust_stack and anti_adjust_stack. */
881 adjust_stack_1 (rtx adjust
, bool anti_p
)
886 /* Hereafter anti_p means subtract_p. */
887 if (!STACK_GROWS_DOWNWARD
)
890 temp
= expand_binop (Pmode
,
891 anti_p
? sub_optab
: add_optab
,
892 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
895 if (temp
!= stack_pointer_rtx
)
896 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
899 insn
= get_last_insn ();
900 temp
= single_set (insn
);
901 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
904 if (!suppress_reg_args_size
)
905 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
908 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
909 This pops when ADJUST is positive. ADJUST need not be constant. */
912 adjust_stack (rtx adjust
)
914 if (adjust
== const0_rtx
)
917 /* We expect all variable sized adjustments to be multiple of
918 PREFERRED_STACK_BOUNDARY. */
919 if (CONST_INT_P (adjust
))
920 stack_pointer_delta
-= INTVAL (adjust
);
922 adjust_stack_1 (adjust
, false);
925 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
926 This pushes when ADJUST is positive. ADJUST need not be constant. */
929 anti_adjust_stack (rtx adjust
)
931 if (adjust
== const0_rtx
)
934 /* We expect all variable sized adjustments to be multiple of
935 PREFERRED_STACK_BOUNDARY. */
936 if (CONST_INT_P (adjust
))
937 stack_pointer_delta
+= INTVAL (adjust
);
939 adjust_stack_1 (adjust
, true);
942 /* Round the size of a block to be pushed up to the boundary required
943 by this machine. SIZE is the desired size, which need not be constant. */
946 round_push (rtx size
)
948 rtx align_rtx
, alignm1_rtx
;
950 if (!SUPPORTS_STACK_ALIGNMENT
951 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
953 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
958 if (CONST_INT_P (size
))
960 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
962 if (INTVAL (size
) != new_size
)
963 size
= GEN_INT (new_size
);
967 align_rtx
= GEN_INT (align
);
968 alignm1_rtx
= GEN_INT (align
- 1);
972 /* If crtl->preferred_stack_boundary might still grow, use
973 virtual_preferred_stack_boundary_rtx instead. This will be
974 substituted by the right value in vregs pass and optimized
976 align_rtx
= virtual_preferred_stack_boundary_rtx
;
977 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
981 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
982 but we know it can't. So add ourselves and then do
984 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
985 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
986 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
988 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
993 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
994 to a previously-created save area. If no save area has been allocated,
995 this function will allocate one. If a save area is specified, it
996 must be of the proper mode. */
999 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1002 /* The default is that we use a move insn and save in a Pmode object. */
1003 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1004 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1006 /* See if this machine has anything special to do for this kind of save. */
1010 if (targetm
.have_save_stack_block ())
1011 fcn
= targetm
.gen_save_stack_block
;
1014 if (targetm
.have_save_stack_function ())
1015 fcn
= targetm
.gen_save_stack_function
;
1018 if (targetm
.have_save_stack_nonlocal ())
1019 fcn
= targetm
.gen_save_stack_nonlocal
;
1025 /* If there is no save area and we have to allocate one, do so. Otherwise
1026 verify the save area is the proper mode. */
1030 if (mode
!= VOIDmode
)
1032 if (save_level
== SAVE_NONLOCAL
)
1033 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1035 *psave
= sa
= gen_reg_rtx (mode
);
1039 do_pending_stack_adjust ();
1041 sa
= validize_mem (sa
);
1042 emit_insn (fcn (sa
, stack_pointer_rtx
));
1045 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1046 area made by emit_stack_save. If it is zero, we have nothing to do. */
1049 emit_stack_restore (enum save_level save_level
, rtx sa
)
1051 /* The default is that we use a move insn. */
1052 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1054 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1055 STACK_POINTER and HARD_FRAME_POINTER.
1056 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1057 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1058 aligned variables, which is reflected in ix86_can_eliminate.
1059 We normally still have the realigned STACK_POINTER that we can use.
1060 But if there is a stack restore still present at reload, it can trigger
1061 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1062 FRAME_POINTER into a hard reg.
1063 To prevent this situation, we force need_drap if we emit a stack
1065 if (SUPPORTS_STACK_ALIGNMENT
)
1066 crtl
->need_drap
= true;
1068 /* See if this machine has anything special to do for this kind of save. */
1072 if (targetm
.have_restore_stack_block ())
1073 fcn
= targetm
.gen_restore_stack_block
;
1076 if (targetm
.have_restore_stack_function ())
1077 fcn
= targetm
.gen_restore_stack_function
;
1080 if (targetm
.have_restore_stack_nonlocal ())
1081 fcn
= targetm
.gen_restore_stack_nonlocal
;
1089 sa
= validize_mem (sa
);
1090 /* These clobbers prevent the scheduler from moving
1091 references to variable arrays below the code
1092 that deletes (pops) the arrays. */
1093 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1094 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1097 discard_pending_stack_adjust ();
1099 emit_insn (fcn (stack_pointer_rtx
, sa
));
1102 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1103 function. This should be called whenever we allocate or deallocate
1104 dynamic stack space. */
1107 update_nonlocal_goto_save_area (void)
1112 /* The nonlocal_goto_save_area object is an array of N pointers. The
1113 first one is used for the frame pointer save; the rest are sized by
1114 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1115 of the stack save area slots. */
1116 t_save
= build4 (ARRAY_REF
,
1117 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1118 cfun
->nonlocal_goto_save_area
,
1119 integer_one_node
, NULL_TREE
, NULL_TREE
);
1120 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1122 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1125 /* Record a new stack level for the current function. This should be called
1126 whenever we allocate or deallocate dynamic stack space. */
1129 record_new_stack_level (void)
1131 /* Record the new stack level for nonlocal gotos. */
1132 if (cfun
->nonlocal_goto_save_area
)
1133 update_nonlocal_goto_save_area ();
1135 /* Record the new stack level for SJLJ exceptions. */
1136 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1137 update_sjlj_context ();
1140 /* Return an rtx representing the address of an area of memory dynamically
1141 pushed on the stack.
1143 Any required stack pointer alignment is preserved.
1145 SIZE is an rtx representing the size of the area.
1147 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1148 parameter may be zero. If so, a proper value will be extracted
1149 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1151 REQUIRED_ALIGN is the alignment (in bits) required for the region
1154 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1155 stack space allocated by the generated code cannot be added with itself
1156 in the course of the execution of the function. It is always safe to
1157 pass FALSE here and the following criterion is sufficient in order to
1158 pass TRUE: every path in the CFG that starts at the allocation point and
1159 loops to it executes the associated deallocation code. */
1162 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1163 unsigned required_align
, bool cannot_accumulate
)
1165 HOST_WIDE_INT stack_usage_size
= -1;
1166 rtx_code_label
*final_label
;
1167 rtx final_target
, target
;
1168 unsigned extra_align
= 0;
1171 /* If we're asking for zero bytes, it doesn't matter what we point
1172 to since we can't dereference it. But return a reasonable
1174 if (size
== const0_rtx
)
1175 return virtual_stack_dynamic_rtx
;
1177 /* Otherwise, show we're calling alloca or equivalent. */
1178 cfun
->calls_alloca
= 1;
1180 /* If stack usage info is requested, look into the size we are passed.
1181 We need to do so this early to avoid the obfuscation that may be
1182 introduced later by the various alignment operations. */
1183 if (flag_stack_usage_info
)
1185 if (CONST_INT_P (size
))
1186 stack_usage_size
= INTVAL (size
);
1187 else if (REG_P (size
))
1189 /* Look into the last emitted insn and see if we can deduce
1190 something for the register. */
1193 insn
= get_last_insn ();
1194 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1196 if (CONST_INT_P (SET_SRC (set
)))
1197 stack_usage_size
= INTVAL (SET_SRC (set
));
1198 else if ((note
= find_reg_equal_equiv_note (insn
))
1199 && CONST_INT_P (XEXP (note
, 0)))
1200 stack_usage_size
= INTVAL (XEXP (note
, 0));
1204 /* If the size is not constant, we can't say anything. */
1205 if (stack_usage_size
== -1)
1207 current_function_has_unbounded_dynamic_stack_size
= 1;
1208 stack_usage_size
= 0;
1212 /* Ensure the size is in the proper mode. */
1213 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1214 size
= convert_to_mode (Pmode
, size
, 1);
1216 /* Adjust SIZE_ALIGN, if needed. */
1217 if (CONST_INT_P (size
))
1219 unsigned HOST_WIDE_INT lsb
;
1221 lsb
= INTVAL (size
);
1224 /* Watch out for overflow truncating to "unsigned". */
1225 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1226 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1228 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1230 else if (size_align
< BITS_PER_UNIT
)
1231 size_align
= BITS_PER_UNIT
;
1233 /* We can't attempt to minimize alignment necessary, because we don't
1234 know the final value of preferred_stack_boundary yet while executing
1236 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1237 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1239 /* We will need to ensure that the address we return is aligned to
1240 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1241 always know its final value at this point in the compilation (it
1242 might depend on the size of the outgoing parameter lists, for
1243 example), so we must align the value to be returned in that case.
1244 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1245 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1246 We must also do an alignment operation on the returned value if
1247 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1249 If we have to align, we must leave space in SIZE for the hole
1250 that might result from the alignment operation. */
1252 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1255 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1256 extra_align
= PREFERRED_STACK_BOUNDARY
;
1257 else if (required_align
> STACK_BOUNDARY
)
1258 extra_align
= STACK_BOUNDARY
;
1260 extra_align
= BITS_PER_UNIT
;
1263 /* ??? STACK_POINTER_OFFSET is always defined now. */
1264 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1266 extra_align
= BITS_PER_UNIT
;
1271 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1273 size
= plus_constant (Pmode
, size
, extra
);
1274 size
= force_operand (size
, NULL_RTX
);
1276 if (flag_stack_usage_info
)
1277 stack_usage_size
+= extra
;
1279 if (extra
&& size_align
> extra_align
)
1280 size_align
= extra_align
;
1283 /* Round the size to a multiple of the required stack alignment.
1284 Since the stack if presumed to be rounded before this allocation,
1285 this will maintain the required alignment.
1287 If the stack grows downward, we could save an insn by subtracting
1288 SIZE from the stack pointer and then aligning the stack pointer.
1289 The problem with this is that the stack pointer may be unaligned
1290 between the execution of the subtraction and alignment insns and
1291 some machines do not allow this. Even on those that do, some
1292 signal handlers malfunction if a signal should occur between those
1293 insns. Since this is an extremely rare event, we have no reliable
1294 way of knowing which systems have this problem. So we avoid even
1295 momentarily mis-aligning the stack. */
1296 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1298 size
= round_push (size
);
1300 if (flag_stack_usage_info
)
1302 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1303 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1307 target
= gen_reg_rtx (Pmode
);
1309 /* The size is supposed to be fully adjusted at this point so record it
1310 if stack usage info is requested. */
1311 if (flag_stack_usage_info
)
1313 current_function_dynamic_stack_size
+= stack_usage_size
;
1315 /* ??? This is gross but the only safe stance in the absence
1316 of stack usage oriented flow analysis. */
1317 if (!cannot_accumulate
)
1318 current_function_has_unbounded_dynamic_stack_size
= 1;
1322 final_target
= NULL_RTX
;
1324 /* If we are splitting the stack, we need to ask the backend whether
1325 there is enough room on the current stack. If there isn't, or if
1326 the backend doesn't know how to tell is, then we need to call a
1327 function to allocate memory in some other way. This memory will
1328 be released when we release the current stack segment. The
1329 effect is that stack allocation becomes less efficient, but at
1330 least it doesn't cause a stack overflow. */
1331 if (flag_split_stack
)
1333 rtx_code_label
*available_label
;
1334 rtx ask
, space
, func
;
1336 available_label
= NULL
;
1338 if (targetm
.have_split_stack_space_check ())
1340 available_label
= gen_label_rtx ();
1342 /* This instruction will branch to AVAILABLE_LABEL if there
1343 are SIZE bytes available on the stack. */
1344 emit_insn (targetm
.gen_split_stack_space_check
1345 (size
, available_label
));
1348 /* The __morestack_allocate_stack_space function will allocate
1349 memory using malloc. If the alignment of the memory returned
1350 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1351 make sure we allocate enough space. */
1352 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1356 ask
= expand_binop (Pmode
, add_optab
, size
,
1357 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1359 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1363 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1365 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1368 if (available_label
== NULL_RTX
)
1371 final_target
= gen_reg_rtx (Pmode
);
1373 emit_move_insn (final_target
, space
);
1375 final_label
= gen_label_rtx ();
1376 emit_jump (final_label
);
1378 emit_label (available_label
);
1381 do_pending_stack_adjust ();
1383 /* We ought to be called always on the toplevel and stack ought to be aligned
1385 gcc_assert (!(stack_pointer_delta
1386 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1388 /* If needed, check that we have the required amount of stack. Take into
1389 account what has already been checked. */
1390 if (STACK_CHECK_MOVING_SP
)
1392 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1393 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1395 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1396 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1398 /* Don't let anti_adjust_stack emit notes. */
1399 suppress_reg_args_size
= true;
1401 /* Perform the required allocation from the stack. Some systems do
1402 this differently than simply incrementing/decrementing from the
1403 stack pointer, such as acquiring the space by calling malloc(). */
1404 if (targetm
.have_allocate_stack ())
1406 struct expand_operand ops
[2];
1407 /* We don't have to check against the predicate for operand 0 since
1408 TARGET is known to be a pseudo of the proper mode, which must
1409 be valid for the operand. */
1410 create_fixed_operand (&ops
[0], target
);
1411 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1412 expand_insn (targetm
.code_for_allocate_stack
, 2, ops
);
1416 int saved_stack_pointer_delta
;
1418 if (!STACK_GROWS_DOWNWARD
)
1419 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1421 /* Check stack bounds if necessary. */
1422 if (crtl
->limit_stack
)
1425 rtx_code_label
*space_available
= gen_label_rtx ();
1426 if (STACK_GROWS_DOWNWARD
)
1427 available
= expand_binop (Pmode
, sub_optab
,
1428 stack_pointer_rtx
, stack_limit_rtx
,
1429 NULL_RTX
, 1, OPTAB_WIDEN
);
1431 available
= expand_binop (Pmode
, sub_optab
,
1432 stack_limit_rtx
, stack_pointer_rtx
,
1433 NULL_RTX
, 1, OPTAB_WIDEN
);
1435 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1437 if (targetm
.have_trap ())
1438 emit_insn (targetm
.gen_trap ());
1440 error ("stack limits not supported on this target");
1442 emit_label (space_available
);
1445 saved_stack_pointer_delta
= stack_pointer_delta
;
1447 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1448 anti_adjust_stack_and_probe (size
, false);
1450 anti_adjust_stack (size
);
1452 /* Even if size is constant, don't modify stack_pointer_delta.
1453 The constant size alloca should preserve
1454 crtl->preferred_stack_boundary alignment. */
1455 stack_pointer_delta
= saved_stack_pointer_delta
;
1457 if (STACK_GROWS_DOWNWARD
)
1458 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1461 suppress_reg_args_size
= false;
1463 /* Finish up the split stack handling. */
1464 if (final_label
!= NULL_RTX
)
1466 gcc_assert (flag_split_stack
);
1467 emit_move_insn (final_target
, target
);
1468 emit_label (final_label
);
1469 target
= final_target
;
1474 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1475 but we know it can't. So add ourselves and then do
1477 target
= expand_binop (Pmode
, add_optab
, target
,
1478 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1480 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1481 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1482 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1485 target
= expand_mult (Pmode
, target
,
1486 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1491 /* Now that we've committed to a return value, mark its alignment. */
1492 mark_reg_pointer (target
, required_align
);
1494 /* Record the new stack level. */
1495 record_new_stack_level ();
1500 /* A front end may want to override GCC's stack checking by providing a
1501 run-time routine to call to check the stack, so provide a mechanism for
1502 calling that routine. */
1504 static GTY(()) rtx stack_check_libfunc
;
1507 set_stack_check_libfunc (const char *libfunc_name
)
1509 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1510 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1513 /* Emit one stack probe at ADDRESS, an address within the stack. */
1516 emit_stack_probe (rtx address
)
1518 if (targetm
.have_probe_stack_address ())
1519 emit_insn (targetm
.gen_probe_stack_address (address
));
1522 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1524 MEM_VOLATILE_P (memref
) = 1;
1526 /* See if we have an insn to probe the stack. */
1527 if (targetm
.have_probe_stack ())
1528 emit_insn (targetm
.gen_probe_stack (memref
));
1530 emit_move_insn (memref
, const0_rtx
);
1534 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1535 FIRST is a constant and size is a Pmode RTX. These are offsets from
1536 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1537 or subtract them from the stack pointer. */
1539 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1541 #if STACK_GROWS_DOWNWARD
1542 #define STACK_GROW_OP MINUS
1543 #define STACK_GROW_OPTAB sub_optab
1544 #define STACK_GROW_OFF(off) -(off)
1546 #define STACK_GROW_OP PLUS
1547 #define STACK_GROW_OPTAB add_optab
1548 #define STACK_GROW_OFF(off) (off)
1552 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1554 /* First ensure SIZE is Pmode. */
1555 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1556 size
= convert_to_mode (Pmode
, size
, 1);
1558 /* Next see if we have a function to check the stack. */
1559 if (stack_check_libfunc
)
1561 rtx addr
= memory_address (Pmode
,
1562 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1564 plus_constant (Pmode
,
1566 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1570 /* Next see if we have an insn to check the stack. */
1571 else if (targetm
.have_check_stack ())
1573 struct expand_operand ops
[1];
1574 rtx addr
= memory_address (Pmode
,
1575 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1577 plus_constant (Pmode
,
1580 create_input_operand (&ops
[0], addr
, Pmode
);
1581 success
= maybe_expand_insn (targetm
.code_for_check_stack
, 1, ops
);
1582 gcc_assert (success
);
1585 /* Otherwise we have to generate explicit probes. If we have a constant
1586 small number of them to generate, that's the easy case. */
1587 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1589 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1592 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1593 it exceeds SIZE. If only one probe is needed, this will not
1594 generate any code. Then probe at FIRST + SIZE. */
1595 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1597 addr
= memory_address (Pmode
,
1598 plus_constant (Pmode
, stack_pointer_rtx
,
1599 STACK_GROW_OFF (first
+ i
)));
1600 emit_stack_probe (addr
);
1603 addr
= memory_address (Pmode
,
1604 plus_constant (Pmode
, stack_pointer_rtx
,
1605 STACK_GROW_OFF (first
+ isize
)));
1606 emit_stack_probe (addr
);
1609 /* In the variable case, do the same as above, but in a loop. Note that we
1610 must be extra careful with variables wrapping around because we might be
1611 at the very top (or the very bottom) of the address space and we have to
1612 be able to handle this case properly; in particular, we use an equality
1613 test for the loop condition. */
1616 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1617 rtx_code_label
*loop_lab
= gen_label_rtx ();
1618 rtx_code_label
*end_lab
= gen_label_rtx ();
1620 /* Step 1: round SIZE to the previous multiple of the interval. */
1622 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1624 = simplify_gen_binary (AND
, Pmode
, size
,
1625 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1626 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1629 /* Step 2: compute initial and final value of the loop counter. */
1631 /* TEST_ADDR = SP + FIRST. */
1632 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1634 gen_int_mode (first
, Pmode
)),
1637 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1638 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1640 rounded_size_op
), NULL_RTX
);
1645 while (TEST_ADDR != LAST_ADDR)
1647 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1651 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1652 until it is equal to ROUNDED_SIZE. */
1654 emit_label (loop_lab
);
1656 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1657 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1660 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1661 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1662 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1665 gcc_assert (temp
== test_addr
);
1667 /* Probe at TEST_ADDR. */
1668 emit_stack_probe (test_addr
);
1670 emit_jump (loop_lab
);
1672 emit_label (end_lab
);
1675 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1676 that SIZE is equal to ROUNDED_SIZE. */
1678 /* TEMP = SIZE - ROUNDED_SIZE. */
1679 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1680 if (temp
!= const0_rtx
)
1684 if (CONST_INT_P (temp
))
1686 /* Use [base + disp} addressing mode if supported. */
1687 HOST_WIDE_INT offset
= INTVAL (temp
);
1688 addr
= memory_address (Pmode
,
1689 plus_constant (Pmode
, last_addr
,
1690 STACK_GROW_OFF (offset
)));
1694 /* Manual CSE if the difference is not known at compile-time. */
1695 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1696 addr
= memory_address (Pmode
,
1697 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1701 emit_stack_probe (addr
);
1705 /* Make sure nothing is scheduled before we are done. */
1706 emit_insn (gen_blockage ());
1709 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1710 while probing it. This pushes when SIZE is positive. SIZE need not
1711 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1712 by plus SIZE at the end. */
1715 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1717 /* We skip the probe for the first interval + a small dope of 4 words and
1718 probe that many bytes past the specified size to maintain a protection
1719 area at the botton of the stack. */
1720 const int dope
= 4 * UNITS_PER_WORD
;
1722 /* First ensure SIZE is Pmode. */
1723 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1724 size
= convert_to_mode (Pmode
, size
, 1);
1726 /* If we have a constant small number of probes to generate, that's the
1728 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1730 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1731 bool first_probe
= true;
1733 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1734 values of N from 1 until it exceeds SIZE. If only one probe is
1735 needed, this will not generate any code. Then adjust and probe
1736 to PROBE_INTERVAL + SIZE. */
1737 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1741 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1742 first_probe
= false;
1745 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1746 emit_stack_probe (stack_pointer_rtx
);
1750 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1752 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1753 emit_stack_probe (stack_pointer_rtx
);
1756 /* In the variable case, do the same as above, but in a loop. Note that we
1757 must be extra careful with variables wrapping around because we might be
1758 at the very top (or the very bottom) of the address space and we have to
1759 be able to handle this case properly; in particular, we use an equality
1760 test for the loop condition. */
1763 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1764 rtx_code_label
*loop_lab
= gen_label_rtx ();
1765 rtx_code_label
*end_lab
= gen_label_rtx ();
1768 /* Step 1: round SIZE to the previous multiple of the interval. */
1770 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1772 = simplify_gen_binary (AND
, Pmode
, size
,
1773 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1774 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1777 /* Step 2: compute initial and final value of the loop counter. */
1779 /* SP = SP_0 + PROBE_INTERVAL. */
1780 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1782 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1783 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1785 rounded_size_op
), NULL_RTX
);
1790 while (SP != LAST_ADDR)
1792 SP = SP + PROBE_INTERVAL
1796 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1797 values of N from 1 until it is equal to ROUNDED_SIZE. */
1799 emit_label (loop_lab
);
1801 /* Jump to END_LAB if SP == LAST_ADDR. */
1802 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1805 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1806 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1807 emit_stack_probe (stack_pointer_rtx
);
1809 emit_jump (loop_lab
);
1811 emit_label (end_lab
);
1814 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1815 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1817 /* TEMP = SIZE - ROUNDED_SIZE. */
1818 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1819 if (temp
!= const0_rtx
)
1821 /* Manual CSE if the difference is not known at compile-time. */
1822 if (GET_CODE (temp
) != CONST_INT
)
1823 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1824 anti_adjust_stack (temp
);
1825 emit_stack_probe (stack_pointer_rtx
);
1829 /* Adjust back and account for the additional first interval. */
1831 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1833 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1836 /* Return an rtx representing the register or memory location
1837 in which a scalar value of data type VALTYPE
1838 was returned by a function call to function FUNC.
1839 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1840 function is known, otherwise 0.
1841 OUTGOING is 1 if on a machine with register windows this function
1842 should return the register in which the function will put its result
1846 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1847 int outgoing ATTRIBUTE_UNUSED
)
1851 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1854 && GET_MODE (val
) == BLKmode
)
1856 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1857 machine_mode tmpmode
;
1859 /* int_size_in_bytes can return -1. We don't need a check here
1860 since the value of bytes will then be large enough that no
1861 mode will match anyway. */
1863 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1864 tmpmode
!= VOIDmode
;
1865 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1867 /* Have we found a large enough mode? */
1868 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1872 /* No suitable mode found. */
1873 gcc_assert (tmpmode
!= VOIDmode
);
1875 PUT_MODE (val
, tmpmode
);
1880 /* Return an rtx representing the register or memory location
1881 in which a scalar value of mode MODE was returned by a library call. */
1884 hard_libcall_value (machine_mode mode
, rtx fun
)
1886 return targetm
.calls
.libcall_value (mode
, fun
);
1889 /* Look up the tree code for a given rtx code
1890 to provide the arithmetic operation for REAL_ARITHMETIC.
1891 The function returns an int because the caller may not know
1892 what `enum tree_code' means. */
1895 rtx_to_tree_code (enum rtx_code code
)
1897 enum tree_code tcode
;
1920 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1923 return ((int) tcode
);
1926 #include "gt-explow.h"