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"
30 #include "double-int.h"
38 #include "stor-layout.h"
42 #include "hard-reg-set.h"
45 #include "statistics.h"
46 #include "fixed-value.h"
47 #include "insn-config.h"
56 #include "insn-codes.h"
61 #include "langhooks.h"
63 #include "common/common-target.h"
66 static rtx
break_out_memory_refs (rtx
);
69 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
72 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
74 int width
= GET_MODE_PRECISION (mode
);
76 /* You want to truncate to a _what_? */
77 gcc_assert (SCALAR_INT_MODE_P (mode
)
78 || POINTER_BOUNDS_MODE_P (mode
));
80 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
82 return c
& 1 ? STORE_FLAG_VALUE
: 0;
84 /* Sign-extend for the requested mode. */
86 if (width
< HOST_BITS_PER_WIDE_INT
)
88 HOST_WIDE_INT sign
= 1;
98 /* Return an rtx for the sum of X and the integer C, given that X has
99 mode MODE. INPLACE is true if X can be modified inplace or false
100 if it must be treated as immutable. */
103 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
109 int all_constant
= 0;
111 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
123 CASE_CONST_SCALAR_INT
:
124 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
127 /* If this is a reference to the constant pool, try replacing it with
128 a reference to a new constant. If the resulting address isn't
129 valid, don't return it because we have no way to validize it. */
130 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
131 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
133 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
134 tem
= force_const_mem (GET_MODE (x
), tem
);
135 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
141 /* If adding to something entirely constant, set a flag
142 so that we can add a CONST around the result. */
143 if (inplace
&& shared_const_p (x
))
155 /* The interesting case is adding the integer to a sum. Look
156 for constant term in the sum and combine with C. For an
157 integer constant term or a constant term that is not an
158 explicit integer, we combine or group them together anyway.
160 We may not immediately return from the recursive call here, lest
161 all_constant gets lost. */
163 if (CONSTANT_P (XEXP (x
, 1)))
165 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
166 if (term
== const0_rtx
)
171 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
174 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
178 /* We need to be careful since X may be shared and we can't
179 modify it in place. */
181 const_loc
= find_constant_term_loc (&x
);
183 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
193 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
195 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
197 else if (all_constant
)
198 return gen_rtx_CONST (mode
, x
);
203 /* If X is a sum, return a new sum like X but lacking any constant terms.
204 Add all the removed constant terms into *CONSTPTR.
205 X itself is not altered. The result != X if and only if
206 it is not isomorphic to X. */
209 eliminate_constant_term (rtx x
, rtx
*constptr
)
214 if (GET_CODE (x
) != PLUS
)
217 /* First handle constants appearing at this level explicitly. */
218 if (CONST_INT_P (XEXP (x
, 1))
219 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
221 && CONST_INT_P (tem
))
224 return eliminate_constant_term (XEXP (x
, 0), constptr
);
228 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
229 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
230 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
231 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
233 && CONST_INT_P (tem
))
236 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
243 /* Return a copy of X in which all memory references
244 and all constants that involve symbol refs
245 have been replaced with new temporary registers.
246 Also emit code to load the memory locations and constants
247 into those registers.
249 If X contains no such constants or memory references,
250 X itself (not a copy) is returned.
252 If a constant is found in the address that is not a legitimate constant
253 in an insn, it is left alone in the hope that it might be valid in the
256 X may contain no arithmetic except addition, subtraction and multiplication.
257 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
260 break_out_memory_refs (rtx x
)
263 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
264 && GET_MODE (x
) != VOIDmode
))
265 x
= force_reg (GET_MODE (x
), x
);
266 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
267 || GET_CODE (x
) == MULT
)
269 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
270 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
272 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
273 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
279 /* Given X, a memory address in address space AS' pointer mode, convert it to
280 an address in the address space's address mode, or vice versa (TO_MODE says
281 which way). We take advantage of the fact that pointers are not allowed to
282 overflow by commuting arithmetic operations over conversions so that address
283 arithmetic insns can be used. IN_CONST is true if this conversion is inside
284 a CONST. NO_EMIT is true if no insns should be emitted, and instead
285 it should return NULL if it can't be simplified without emitting insns. */
288 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
289 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
290 bool in_const ATTRIBUTE_UNUSED
,
291 bool no_emit ATTRIBUTE_UNUSED
)
293 #ifndef POINTERS_EXTEND_UNSIGNED
294 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
296 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
297 machine_mode pointer_mode
, address_mode
, from_mode
;
301 /* If X already has the right mode, just return it. */
302 if (GET_MODE (x
) == to_mode
)
305 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
306 address_mode
= targetm
.addr_space
.address_mode (as
);
307 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
309 /* Here we handle some special cases. If none of them apply, fall through
310 to the default case. */
311 switch (GET_CODE (x
))
313 CASE_CONST_SCALAR_INT
:
314 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
316 else if (POINTERS_EXTEND_UNSIGNED
< 0)
318 else if (POINTERS_EXTEND_UNSIGNED
> 0)
322 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
328 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
329 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
330 return SUBREG_REG (x
);
334 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
335 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
339 temp
= shallow_copy_rtx (x
);
340 PUT_MODE (temp
, to_mode
);
344 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0), as
,
346 return temp
? gen_rtx_CONST (to_mode
, temp
) : temp
;
350 /* For addition we can safely permute the conversion and addition
351 operation if one operand is a constant and converting the constant
352 does not change it or if one operand is a constant and we are
353 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
354 We can always safely permute them if we are making the address
355 narrower. Inside a CONST RTL, this is safe for both pointers
356 zero or sign extended as pointers cannot wrap. */
357 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
358 || (GET_CODE (x
) == PLUS
359 && CONST_INT_P (XEXP (x
, 1))
360 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
361 || XEXP (x
, 1) == convert_memory_address_addr_space_1
362 (to_mode
, XEXP (x
, 1), as
, in_const
,
364 || POINTERS_EXTEND_UNSIGNED
< 0)))
366 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0),
367 as
, in_const
, no_emit
);
368 return (temp
? gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
381 return convert_modes (to_mode
, from_mode
,
382 x
, POINTERS_EXTEND_UNSIGNED
);
383 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
386 /* Given X, a memory address in address space AS' pointer mode, convert it to
387 an address in the address space's address mode, or vice versa (TO_MODE says
388 which way). We take advantage of the fact that pointers are not allowed to
389 overflow by commuting arithmetic operations over conversions so that address
390 arithmetic insns can be used. */
393 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
395 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false, false);
399 /* Return something equivalent to X but valid as a memory address for something
400 of mode MODE in the named address space AS. When X is not itself valid,
401 this works by copying X or subexpressions of it into registers. */
404 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
407 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
409 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
411 /* By passing constant addresses through registers
412 we get a chance to cse them. */
413 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
414 x
= force_reg (address_mode
, x
);
416 /* We get better cse by rejecting indirect addressing at this stage.
417 Let the combiner create indirect addresses where appropriate.
418 For now, generate the code so that the subexpressions useful to share
419 are visible. But not if cse won't be done! */
422 if (! cse_not_expected
&& !REG_P (x
))
423 x
= break_out_memory_refs (x
);
425 /* At this point, any valid address is accepted. */
426 if (memory_address_addr_space_p (mode
, x
, as
))
429 /* If it was valid before but breaking out memory refs invalidated it,
430 use it the old way. */
431 if (memory_address_addr_space_p (mode
, oldx
, as
))
437 /* Perform machine-dependent transformations on X
438 in certain cases. This is not necessary since the code
439 below can handle all possible cases, but machine-dependent
440 transformations can make better code. */
443 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
444 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
448 /* PLUS and MULT can appear in special ways
449 as the result of attempts to make an address usable for indexing.
450 Usually they are dealt with by calling force_operand, below.
451 But a sum containing constant terms is special
452 if removing them makes the sum a valid address:
453 then we generate that address in a register
454 and index off of it. We do this because it often makes
455 shorter code, and because the addresses thus generated
456 in registers often become common subexpressions. */
457 if (GET_CODE (x
) == PLUS
)
459 rtx constant_term
= const0_rtx
;
460 rtx y
= eliminate_constant_term (x
, &constant_term
);
461 if (constant_term
== const0_rtx
462 || ! memory_address_addr_space_p (mode
, y
, as
))
463 x
= force_operand (x
, NULL_RTX
);
466 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
467 if (! memory_address_addr_space_p (mode
, y
, as
))
468 x
= force_operand (x
, NULL_RTX
);
474 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
475 x
= force_operand (x
, NULL_RTX
);
477 /* If we have a register that's an invalid address,
478 it must be a hard reg of the wrong class. Copy it to a pseudo. */
482 /* Last resort: copy the value to a register, since
483 the register is a valid address. */
485 x
= force_reg (address_mode
, x
);
490 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
491 /* If we didn't change the address, we are done. Otherwise, mark
492 a reg as a pointer if we have REG or REG + CONST_INT. */
496 mark_reg_pointer (x
, BITS_PER_UNIT
);
497 else if (GET_CODE (x
) == PLUS
498 && REG_P (XEXP (x
, 0))
499 && CONST_INT_P (XEXP (x
, 1)))
500 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
502 /* OLDX may have been the address on a temporary. Update the address
503 to indicate that X is now used. */
504 update_temp_slot_address (oldx
, x
);
509 /* If REF is a MEM with an invalid address, change it into a valid address.
510 Pass through anything else unchanged. REF must be an unshared rtx and
511 the function may modify it in-place. */
514 validize_mem (rtx ref
)
518 ref
= use_anchored_address (ref
);
519 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
520 MEM_ADDR_SPACE (ref
)))
523 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
526 /* If X is a memory reference to a member of an object block, try rewriting
527 it to use an anchor instead. Return the new memory reference on success
528 and the old one on failure. */
531 use_anchored_address (rtx x
)
534 HOST_WIDE_INT offset
;
537 if (!flag_section_anchors
)
543 /* Split the address into a base and offset. */
546 if (GET_CODE (base
) == CONST
547 && GET_CODE (XEXP (base
, 0)) == PLUS
548 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
550 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
551 base
= XEXP (XEXP (base
, 0), 0);
554 /* Check whether BASE is suitable for anchors. */
555 if (GET_CODE (base
) != SYMBOL_REF
556 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
557 || SYMBOL_REF_ANCHOR_P (base
)
558 || SYMBOL_REF_BLOCK (base
) == NULL
559 || !targetm
.use_anchors_for_symbol_p (base
))
562 /* Decide where BASE is going to be. */
563 place_block_symbol (base
);
565 /* Get the anchor we need to use. */
566 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
567 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
568 SYMBOL_REF_TLS_MODEL (base
));
570 /* Work out the offset from the anchor. */
571 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
573 /* If we're going to run a CSE pass, force the anchor into a register.
574 We will then be able to reuse registers for several accesses, if the
575 target costs say that that's worthwhile. */
576 mode
= GET_MODE (base
);
577 if (!cse_not_expected
)
578 base
= force_reg (mode
, base
);
580 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
583 /* Copy the value or contents of X to a new temp reg and return that reg. */
588 rtx temp
= gen_reg_rtx (GET_MODE (x
));
590 /* If not an operand, must be an address with PLUS and MULT so
591 do the computation. */
592 if (! general_operand (x
, VOIDmode
))
593 x
= force_operand (x
, temp
);
596 emit_move_insn (temp
, x
);
601 /* Like copy_to_reg but always give the new register mode Pmode
602 in case X is a constant. */
605 copy_addr_to_reg (rtx x
)
607 return copy_to_mode_reg (Pmode
, x
);
610 /* Like copy_to_reg but always give the new register mode MODE
611 in case X is a constant. */
614 copy_to_mode_reg (machine_mode mode
, rtx x
)
616 rtx temp
= gen_reg_rtx (mode
);
618 /* If not an operand, must be an address with PLUS and MULT so
619 do the computation. */
620 if (! general_operand (x
, VOIDmode
))
621 x
= force_operand (x
, temp
);
623 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
625 emit_move_insn (temp
, x
);
629 /* Load X into a register if it is not already one.
630 Use mode MODE for the register.
631 X should be valid for mode MODE, but it may be a constant which
632 is valid for all integer modes; that's why caller must specify MODE.
634 The caller must not alter the value in the register we return,
635 since we mark it as a "constant" register. */
638 force_reg (machine_mode mode
, rtx x
)
646 if (general_operand (x
, mode
))
648 temp
= gen_reg_rtx (mode
);
649 insn
= emit_move_insn (temp
, x
);
653 temp
= force_operand (x
, NULL_RTX
);
655 insn
= get_last_insn ();
658 rtx temp2
= gen_reg_rtx (mode
);
659 insn
= emit_move_insn (temp2
, temp
);
664 /* Let optimizers know that TEMP's value never changes
665 and that X can be substituted for it. Don't get confused
666 if INSN set something else (such as a SUBREG of TEMP). */
668 && (set
= single_set (insn
)) != 0
669 && SET_DEST (set
) == temp
670 && ! rtx_equal_p (x
, SET_SRC (set
)))
671 set_unique_reg_note (insn
, REG_EQUAL
, x
);
673 /* Let optimizers know that TEMP is a pointer, and if so, the
674 known alignment of that pointer. */
677 if (GET_CODE (x
) == SYMBOL_REF
)
679 align
= BITS_PER_UNIT
;
680 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
681 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
683 else if (GET_CODE (x
) == LABEL_REF
)
684 align
= BITS_PER_UNIT
;
685 else if (GET_CODE (x
) == CONST
686 && GET_CODE (XEXP (x
, 0)) == PLUS
687 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
688 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
690 rtx s
= XEXP (XEXP (x
, 0), 0);
691 rtx c
= XEXP (XEXP (x
, 0), 1);
695 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
696 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
702 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
703 align
= MIN (sa
, ca
);
707 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
708 mark_reg_pointer (temp
, align
);
714 /* If X is a memory ref, copy its contents to a new temp reg and return
715 that reg. Otherwise, return X. */
718 force_not_mem (rtx x
)
722 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
725 temp
= gen_reg_rtx (GET_MODE (x
));
728 REG_POINTER (temp
) = 1;
730 emit_move_insn (temp
, x
);
734 /* Copy X to TARGET (if it's nonzero and a reg)
735 or to a new temp reg and return that reg.
736 MODE is the mode to use for X in case it is a constant. */
739 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
743 if (target
&& REG_P (target
))
746 temp
= gen_reg_rtx (mode
);
748 emit_move_insn (temp
, x
);
752 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
753 PUNSIGNEDP points to the signedness of the type and may be adjusted
754 to show what signedness to use on extension operations.
756 FOR_RETURN is nonzero if the caller is promoting the return value
757 of FNDECL, else it is for promoting args. */
760 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
761 const_tree funtype
, int for_return
)
763 /* Called without a type node for a libcall. */
764 if (type
== NULL_TREE
)
766 if (INTEGRAL_MODE_P (mode
))
767 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
774 switch (TREE_CODE (type
))
776 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
777 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
778 case POINTER_TYPE
: case REFERENCE_TYPE
:
779 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
786 /* Return the mode to use to store a scalar of TYPE and MODE.
787 PUNSIGNEDP points to the signedness of the type and may be adjusted
788 to show what signedness to use on extension operations. */
791 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
792 int *punsignedp ATTRIBUTE_UNUSED
)
799 /* For libcalls this is invoked without TYPE from the backends
800 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
802 if (type
== NULL_TREE
)
805 /* FIXME: this is the same logic that was there until GCC 4.4, but we
806 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
807 is not defined. The affected targets are M32C, S390, SPARC. */
809 code
= TREE_CODE (type
);
810 unsignedp
= *punsignedp
;
814 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
815 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
816 PROMOTE_MODE (mode
, unsignedp
, type
);
817 *punsignedp
= unsignedp
;
821 #ifdef POINTERS_EXTEND_UNSIGNED
824 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
825 return targetm
.addr_space
.address_mode
826 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
839 /* Use one of promote_mode or promote_function_mode to find the promoted
840 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
841 of DECL after promotion. */
844 promote_decl_mode (const_tree decl
, int *punsignedp
)
846 tree type
= TREE_TYPE (decl
);
847 int unsignedp
= TYPE_UNSIGNED (type
);
848 machine_mode mode
= DECL_MODE (decl
);
851 if (TREE_CODE (decl
) == RESULT_DECL
852 || TREE_CODE (decl
) == PARM_DECL
)
853 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
854 TREE_TYPE (current_function_decl
), 2);
856 pmode
= promote_mode (type
, mode
, &unsignedp
);
859 *punsignedp
= unsignedp
;
864 /* Controls the behaviour of {anti_,}adjust_stack. */
865 static bool suppress_reg_args_size
;
867 /* A helper for adjust_stack and anti_adjust_stack. */
870 adjust_stack_1 (rtx adjust
, bool anti_p
)
875 #ifndef STACK_GROWS_DOWNWARD
876 /* Hereafter anti_p means subtract_p. */
880 temp
= expand_binop (Pmode
,
881 anti_p
? sub_optab
: add_optab
,
882 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
885 if (temp
!= stack_pointer_rtx
)
886 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
889 insn
= get_last_insn ();
890 temp
= single_set (insn
);
891 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
894 if (!suppress_reg_args_size
)
895 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
898 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
899 This pops when ADJUST is positive. ADJUST need not be constant. */
902 adjust_stack (rtx adjust
)
904 if (adjust
== const0_rtx
)
907 /* We expect all variable sized adjustments to be multiple of
908 PREFERRED_STACK_BOUNDARY. */
909 if (CONST_INT_P (adjust
))
910 stack_pointer_delta
-= INTVAL (adjust
);
912 adjust_stack_1 (adjust
, false);
915 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
916 This pushes when ADJUST is positive. ADJUST need not be constant. */
919 anti_adjust_stack (rtx adjust
)
921 if (adjust
== const0_rtx
)
924 /* We expect all variable sized adjustments to be multiple of
925 PREFERRED_STACK_BOUNDARY. */
926 if (CONST_INT_P (adjust
))
927 stack_pointer_delta
+= INTVAL (adjust
);
929 adjust_stack_1 (adjust
, true);
932 /* Round the size of a block to be pushed up to the boundary required
933 by this machine. SIZE is the desired size, which need not be constant. */
936 round_push (rtx size
)
938 rtx align_rtx
, alignm1_rtx
;
940 if (!SUPPORTS_STACK_ALIGNMENT
941 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
943 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
948 if (CONST_INT_P (size
))
950 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
952 if (INTVAL (size
) != new_size
)
953 size
= GEN_INT (new_size
);
957 align_rtx
= GEN_INT (align
);
958 alignm1_rtx
= GEN_INT (align
- 1);
962 /* If crtl->preferred_stack_boundary might still grow, use
963 virtual_preferred_stack_boundary_rtx instead. This will be
964 substituted by the right value in vregs pass and optimized
966 align_rtx
= virtual_preferred_stack_boundary_rtx
;
967 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
971 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
972 but we know it can't. So add ourselves and then do
974 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
975 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
976 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
978 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
983 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
984 to a previously-created save area. If no save area has been allocated,
985 this function will allocate one. If a save area is specified, it
986 must be of the proper mode. */
989 emit_stack_save (enum save_level save_level
, rtx
*psave
)
992 /* The default is that we use a move insn and save in a Pmode object. */
993 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
994 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
996 /* See if this machine has anything special to do for this kind of save. */
999 #ifdef HAVE_save_stack_block
1001 if (HAVE_save_stack_block
)
1002 fcn
= gen_save_stack_block
;
1005 #ifdef HAVE_save_stack_function
1007 if (HAVE_save_stack_function
)
1008 fcn
= gen_save_stack_function
;
1011 #ifdef HAVE_save_stack_nonlocal
1013 if (HAVE_save_stack_nonlocal
)
1014 fcn
= gen_save_stack_nonlocal
;
1021 /* If there is no save area and we have to allocate one, do so. Otherwise
1022 verify the save area is the proper mode. */
1026 if (mode
!= VOIDmode
)
1028 if (save_level
== SAVE_NONLOCAL
)
1029 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1031 *psave
= sa
= gen_reg_rtx (mode
);
1035 do_pending_stack_adjust ();
1037 sa
= validize_mem (sa
);
1038 emit_insn (fcn (sa
, stack_pointer_rtx
));
1041 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1042 area made by emit_stack_save. If it is zero, we have nothing to do. */
1045 emit_stack_restore (enum save_level save_level
, rtx sa
)
1047 /* The default is that we use a move insn. */
1048 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1050 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1051 STACK_POINTER and HARD_FRAME_POINTER.
1052 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1053 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1054 aligned variables, which is reflected in ix86_can_eliminate.
1055 We normally still have the realigned STACK_POINTER that we can use.
1056 But if there is a stack restore still present at reload, it can trigger
1057 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1058 FRAME_POINTER into a hard reg.
1059 To prevent this situation, we force need_drap if we emit a stack
1061 if (SUPPORTS_STACK_ALIGNMENT
)
1062 crtl
->need_drap
= true;
1064 /* See if this machine has anything special to do for this kind of save. */
1067 #ifdef HAVE_restore_stack_block
1069 if (HAVE_restore_stack_block
)
1070 fcn
= gen_restore_stack_block
;
1073 #ifdef HAVE_restore_stack_function
1075 if (HAVE_restore_stack_function
)
1076 fcn
= gen_restore_stack_function
;
1079 #ifdef HAVE_restore_stack_nonlocal
1081 if (HAVE_restore_stack_nonlocal
)
1082 fcn
= gen_restore_stack_nonlocal
;
1091 sa
= validize_mem (sa
);
1092 /* These clobbers prevent the scheduler from moving
1093 references to variable arrays below the code
1094 that deletes (pops) the arrays. */
1095 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1096 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1099 discard_pending_stack_adjust ();
1101 emit_insn (fcn (stack_pointer_rtx
, sa
));
1104 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1105 function. This function should be called whenever we allocate or
1106 deallocate dynamic stack space. */
1109 update_nonlocal_goto_save_area (void)
1114 /* The nonlocal_goto_save_area object is an array of N pointers. The
1115 first one is used for the frame pointer save; the rest are sized by
1116 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1117 of the stack save area slots. */
1118 t_save
= build4 (ARRAY_REF
,
1119 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1120 cfun
->nonlocal_goto_save_area
,
1121 integer_one_node
, NULL_TREE
, NULL_TREE
);
1122 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1124 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1127 /* Return an rtx representing the address of an area of memory dynamically
1128 pushed on the stack.
1130 Any required stack pointer alignment is preserved.
1132 SIZE is an rtx representing the size of the area.
1134 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1135 parameter may be zero. If so, a proper value will be extracted
1136 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1138 REQUIRED_ALIGN is the alignment (in bits) required for the region
1141 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1142 stack space allocated by the generated code cannot be added with itself
1143 in the course of the execution of the function. It is always safe to
1144 pass FALSE here and the following criterion is sufficient in order to
1145 pass TRUE: every path in the CFG that starts at the allocation point and
1146 loops to it executes the associated deallocation code. */
1149 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1150 unsigned required_align
, bool cannot_accumulate
)
1152 HOST_WIDE_INT stack_usage_size
= -1;
1153 rtx_code_label
*final_label
;
1154 rtx final_target
, target
;
1155 unsigned extra_align
= 0;
1158 /* If we're asking for zero bytes, it doesn't matter what we point
1159 to since we can't dereference it. But return a reasonable
1161 if (size
== const0_rtx
)
1162 return virtual_stack_dynamic_rtx
;
1164 /* Otherwise, show we're calling alloca or equivalent. */
1165 cfun
->calls_alloca
= 1;
1167 /* If stack usage info is requested, look into the size we are passed.
1168 We need to do so this early to avoid the obfuscation that may be
1169 introduced later by the various alignment operations. */
1170 if (flag_stack_usage_info
)
1172 if (CONST_INT_P (size
))
1173 stack_usage_size
= INTVAL (size
);
1174 else if (REG_P (size
))
1176 /* Look into the last emitted insn and see if we can deduce
1177 something for the register. */
1180 insn
= get_last_insn ();
1181 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1183 if (CONST_INT_P (SET_SRC (set
)))
1184 stack_usage_size
= INTVAL (SET_SRC (set
));
1185 else if ((note
= find_reg_equal_equiv_note (insn
))
1186 && CONST_INT_P (XEXP (note
, 0)))
1187 stack_usage_size
= INTVAL (XEXP (note
, 0));
1191 /* If the size is not constant, we can't say anything. */
1192 if (stack_usage_size
== -1)
1194 current_function_has_unbounded_dynamic_stack_size
= 1;
1195 stack_usage_size
= 0;
1199 /* Ensure the size is in the proper mode. */
1200 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1201 size
= convert_to_mode (Pmode
, size
, 1);
1203 /* Adjust SIZE_ALIGN, if needed. */
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. If STACK_DYNAMIC_OFFSET is defined, we don't
1228 always know its final value at this point in the compilation (it
1229 might depend on the size of the outgoing parameter lists, for
1230 example), so we must align the value to be returned in that case.
1231 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1232 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1233 We must also do an alignment operation on the returned value if
1234 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1236 If we have to align, we must leave space in SIZE for the hole
1237 that might result from the alignment operation. */
1239 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1242 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1243 extra_align
= PREFERRED_STACK_BOUNDARY
;
1244 else if (required_align
> STACK_BOUNDARY
)
1245 extra_align
= STACK_BOUNDARY
;
1247 extra_align
= BITS_PER_UNIT
;
1250 /* ??? STACK_POINTER_OFFSET is always defined now. */
1251 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1253 extra_align
= BITS_PER_UNIT
;
1258 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1260 size
= plus_constant (Pmode
, size
, extra
);
1261 size
= force_operand (size
, NULL_RTX
);
1263 if (flag_stack_usage_info
)
1264 stack_usage_size
+= extra
;
1266 if (extra
&& size_align
> extra_align
)
1267 size_align
= extra_align
;
1270 /* Round the size to a multiple of the required stack alignment.
1271 Since the stack if presumed to be rounded before this allocation,
1272 this will maintain the required alignment.
1274 If the stack grows downward, we could save an insn by subtracting
1275 SIZE from the stack pointer and then aligning the stack pointer.
1276 The problem with this is that the stack pointer may be unaligned
1277 between the execution of the subtraction and alignment insns and
1278 some machines do not allow this. Even on those that do, some
1279 signal handlers malfunction if a signal should occur between those
1280 insns. Since this is an extremely rare event, we have no reliable
1281 way of knowing which systems have this problem. So we avoid even
1282 momentarily mis-aligning the stack. */
1283 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1285 size
= round_push (size
);
1287 if (flag_stack_usage_info
)
1289 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1290 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1294 target
= gen_reg_rtx (Pmode
);
1296 /* The size is supposed to be fully adjusted at this point so record it
1297 if stack usage info is requested. */
1298 if (flag_stack_usage_info
)
1300 current_function_dynamic_stack_size
+= stack_usage_size
;
1302 /* ??? This is gross but the only safe stance in the absence
1303 of stack usage oriented flow analysis. */
1304 if (!cannot_accumulate
)
1305 current_function_has_unbounded_dynamic_stack_size
= 1;
1309 final_target
= NULL_RTX
;
1311 /* If we are splitting the stack, we need to ask the backend whether
1312 there is enough room on the current stack. If there isn't, or if
1313 the backend doesn't know how to tell is, then we need to call a
1314 function to allocate memory in some other way. This memory will
1315 be released when we release the current stack segment. The
1316 effect is that stack allocation becomes less efficient, but at
1317 least it doesn't cause a stack overflow. */
1318 if (flag_split_stack
)
1320 rtx_code_label
*available_label
;
1321 rtx ask
, space
, func
;
1323 available_label
= NULL
;
1325 #ifdef HAVE_split_stack_space_check
1326 if (HAVE_split_stack_space_check
)
1328 available_label
= gen_label_rtx ();
1330 /* This instruction will branch to AVAILABLE_LABEL if there
1331 are SIZE bytes available on the stack. */
1332 emit_insn (gen_split_stack_space_check (size
, available_label
));
1336 /* The __morestack_allocate_stack_space function will allocate
1337 memory using malloc. If the alignment of the memory returned
1338 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1339 make sure we allocate enough space. */
1340 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1344 ask
= expand_binop (Pmode
, add_optab
, size
,
1345 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1347 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1351 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1353 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1356 if (available_label
== NULL_RTX
)
1359 final_target
= gen_reg_rtx (Pmode
);
1361 emit_move_insn (final_target
, space
);
1363 final_label
= gen_label_rtx ();
1364 emit_jump (final_label
);
1366 emit_label (available_label
);
1369 do_pending_stack_adjust ();
1371 /* We ought to be called always on the toplevel and stack ought to be aligned
1373 gcc_assert (!(stack_pointer_delta
1374 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1376 /* If needed, check that we have the required amount of stack. Take into
1377 account what has already been checked. */
1378 if (STACK_CHECK_MOVING_SP
)
1380 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1381 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1383 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1384 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1386 /* Don't let anti_adjust_stack emit notes. */
1387 suppress_reg_args_size
= true;
1389 /* Perform the required allocation from the stack. Some systems do
1390 this differently than simply incrementing/decrementing from the
1391 stack pointer, such as acquiring the space by calling malloc(). */
1392 #ifdef HAVE_allocate_stack
1393 if (HAVE_allocate_stack
)
1395 struct expand_operand ops
[2];
1396 /* We don't have to check against the predicate for operand 0 since
1397 TARGET is known to be a pseudo of the proper mode, which must
1398 be valid for the operand. */
1399 create_fixed_operand (&ops
[0], target
);
1400 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1401 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1406 int saved_stack_pointer_delta
;
1408 #ifndef STACK_GROWS_DOWNWARD
1409 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1412 /* Check stack bounds if necessary. */
1413 if (crtl
->limit_stack
)
1416 rtx_code_label
*space_available
= gen_label_rtx ();
1417 #ifdef STACK_GROWS_DOWNWARD
1418 available
= expand_binop (Pmode
, sub_optab
,
1419 stack_pointer_rtx
, stack_limit_rtx
,
1420 NULL_RTX
, 1, OPTAB_WIDEN
);
1422 available
= expand_binop (Pmode
, sub_optab
,
1423 stack_limit_rtx
, stack_pointer_rtx
,
1424 NULL_RTX
, 1, OPTAB_WIDEN
);
1426 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1430 emit_insn (gen_trap ());
1433 error ("stack limits not supported on this target");
1435 emit_label (space_available
);
1438 saved_stack_pointer_delta
= stack_pointer_delta
;
1440 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1441 anti_adjust_stack_and_probe (size
, false);
1443 anti_adjust_stack (size
);
1445 /* Even if size is constant, don't modify stack_pointer_delta.
1446 The constant size alloca should preserve
1447 crtl->preferred_stack_boundary alignment. */
1448 stack_pointer_delta
= saved_stack_pointer_delta
;
1450 #ifdef STACK_GROWS_DOWNWARD
1451 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1455 suppress_reg_args_size
= false;
1457 /* Finish up the split stack handling. */
1458 if (final_label
!= NULL_RTX
)
1460 gcc_assert (flag_split_stack
);
1461 emit_move_insn (final_target
, target
);
1462 emit_label (final_label
);
1463 target
= final_target
;
1468 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1469 but we know it can't. So add ourselves and then do
1471 target
= expand_binop (Pmode
, add_optab
, target
,
1472 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1474 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1475 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1476 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1479 target
= expand_mult (Pmode
, target
,
1480 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1485 /* Now that we've committed to a return value, mark its alignment. */
1486 mark_reg_pointer (target
, required_align
);
1488 /* Record the new stack level for nonlocal gotos. */
1489 if (cfun
->nonlocal_goto_save_area
!= 0)
1490 update_nonlocal_goto_save_area ();
1495 /* A front end may want to override GCC's stack checking by providing a
1496 run-time routine to call to check the stack, so provide a mechanism for
1497 calling that routine. */
1499 static GTY(()) rtx stack_check_libfunc
;
1502 set_stack_check_libfunc (const char *libfunc_name
)
1504 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1505 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1508 /* Emit one stack probe at ADDRESS, an address within the stack. */
1511 emit_stack_probe (rtx address
)
1513 #ifdef HAVE_probe_stack_address
1514 if (HAVE_probe_stack_address
)
1515 emit_insn (gen_probe_stack_address (address
));
1519 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1521 MEM_VOLATILE_P (memref
) = 1;
1523 /* See if we have an insn to probe the stack. */
1524 #ifdef HAVE_probe_stack
1525 if (HAVE_probe_stack
)
1526 emit_insn (gen_probe_stack (memref
));
1529 emit_move_insn (memref
, const0_rtx
);
1533 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1534 FIRST is a constant and size is a Pmode RTX. These are offsets from
1535 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1536 or subtract them from the stack pointer. */
1538 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1540 #ifdef STACK_GROWS_DOWNWARD
1541 #define STACK_GROW_OP MINUS
1542 #define STACK_GROW_OPTAB sub_optab
1543 #define STACK_GROW_OFF(off) -(off)
1545 #define STACK_GROW_OP PLUS
1546 #define STACK_GROW_OPTAB add_optab
1547 #define STACK_GROW_OFF(off) (off)
1551 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1553 /* First ensure SIZE is Pmode. */
1554 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1555 size
= convert_to_mode (Pmode
, size
, 1);
1557 /* Next see if we have a function to check the stack. */
1558 if (stack_check_libfunc
)
1560 rtx addr
= memory_address (Pmode
,
1561 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1563 plus_constant (Pmode
,
1565 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1569 /* Next see if we have an insn to check the stack. */
1570 #ifdef HAVE_check_stack
1571 else if (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 (CODE_FOR_check_stack
, 1, ops
);
1582 gcc_assert (success
);
1586 /* Otherwise we have to generate explicit probes. If we have a constant
1587 small number of them to generate, that's the easy case. */
1588 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1590 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1593 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1594 it exceeds SIZE. If only one probe is needed, this will not
1595 generate any code. Then probe at FIRST + SIZE. */
1596 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1598 addr
= memory_address (Pmode
,
1599 plus_constant (Pmode
, stack_pointer_rtx
,
1600 STACK_GROW_OFF (first
+ i
)));
1601 emit_stack_probe (addr
);
1604 addr
= memory_address (Pmode
,
1605 plus_constant (Pmode
, stack_pointer_rtx
,
1606 STACK_GROW_OFF (first
+ isize
)));
1607 emit_stack_probe (addr
);
1610 /* In the variable case, do the same as above, but in a loop. Note that we
1611 must be extra careful with variables wrapping around because we might be
1612 at the very top (or the very bottom) of the address space and we have to
1613 be able to handle this case properly; in particular, we use an equality
1614 test for the loop condition. */
1617 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1618 rtx_code_label
*loop_lab
= gen_label_rtx ();
1619 rtx_code_label
*end_lab
= gen_label_rtx ();
1621 /* Step 1: round SIZE to the previous multiple of the interval. */
1623 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1625 = simplify_gen_binary (AND
, Pmode
, size
,
1626 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1627 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1630 /* Step 2: compute initial and final value of the loop counter. */
1632 /* TEST_ADDR = SP + FIRST. */
1633 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1635 gen_int_mode (first
, Pmode
)),
1638 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1639 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1641 rounded_size_op
), NULL_RTX
);
1646 while (TEST_ADDR != LAST_ADDR)
1648 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1652 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1653 until it is equal to ROUNDED_SIZE. */
1655 emit_label (loop_lab
);
1657 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1658 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1661 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1662 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1663 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1666 gcc_assert (temp
== test_addr
);
1668 /* Probe at TEST_ADDR. */
1669 emit_stack_probe (test_addr
);
1671 emit_jump (loop_lab
);
1673 emit_label (end_lab
);
1676 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1677 that SIZE is equal to ROUNDED_SIZE. */
1679 /* TEMP = SIZE - ROUNDED_SIZE. */
1680 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1681 if (temp
!= const0_rtx
)
1685 if (CONST_INT_P (temp
))
1687 /* Use [base + disp} addressing mode if supported. */
1688 HOST_WIDE_INT offset
= INTVAL (temp
);
1689 addr
= memory_address (Pmode
,
1690 plus_constant (Pmode
, last_addr
,
1691 STACK_GROW_OFF (offset
)));
1695 /* Manual CSE if the difference is not known at compile-time. */
1696 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1697 addr
= memory_address (Pmode
,
1698 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1702 emit_stack_probe (addr
);
1706 /* Make sure nothing is scheduled before we are done. */
1707 emit_insn (gen_blockage ());
1710 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1711 while probing it. This pushes when SIZE is positive. SIZE need not
1712 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1713 by plus SIZE at the end. */
1716 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1718 /* We skip the probe for the first interval + a small dope of 4 words and
1719 probe that many bytes past the specified size to maintain a protection
1720 area at the botton of the stack. */
1721 const int dope
= 4 * UNITS_PER_WORD
;
1723 /* First ensure SIZE is Pmode. */
1724 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1725 size
= convert_to_mode (Pmode
, size
, 1);
1727 /* If we have a constant small number of probes to generate, that's the
1729 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1731 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1732 bool first_probe
= true;
1734 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1735 values of N from 1 until it exceeds SIZE. If only one probe is
1736 needed, this will not generate any code. Then adjust and probe
1737 to PROBE_INTERVAL + SIZE. */
1738 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1742 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1743 first_probe
= false;
1746 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1747 emit_stack_probe (stack_pointer_rtx
);
1751 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1753 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1754 emit_stack_probe (stack_pointer_rtx
);
1757 /* In the variable case, do the same as above, but in a loop. Note that we
1758 must be extra careful with variables wrapping around because we might be
1759 at the very top (or the very bottom) of the address space and we have to
1760 be able to handle this case properly; in particular, we use an equality
1761 test for the loop condition. */
1764 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1765 rtx_code_label
*loop_lab
= gen_label_rtx ();
1766 rtx_code_label
*end_lab
= gen_label_rtx ();
1769 /* Step 1: round SIZE to the previous multiple of the interval. */
1771 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1773 = simplify_gen_binary (AND
, Pmode
, size
,
1774 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1775 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1778 /* Step 2: compute initial and final value of the loop counter. */
1780 /* SP = SP_0 + PROBE_INTERVAL. */
1781 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1783 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1784 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1786 rounded_size_op
), NULL_RTX
);
1791 while (SP != LAST_ADDR)
1793 SP = SP + PROBE_INTERVAL
1797 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1798 values of N from 1 until it is equal to ROUNDED_SIZE. */
1800 emit_label (loop_lab
);
1802 /* Jump to END_LAB if SP == LAST_ADDR. */
1803 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1806 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1807 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1808 emit_stack_probe (stack_pointer_rtx
);
1810 emit_jump (loop_lab
);
1812 emit_label (end_lab
);
1815 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1816 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1818 /* TEMP = SIZE - ROUNDED_SIZE. */
1819 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1820 if (temp
!= const0_rtx
)
1822 /* Manual CSE if the difference is not known at compile-time. */
1823 if (GET_CODE (temp
) != CONST_INT
)
1824 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1825 anti_adjust_stack (temp
);
1826 emit_stack_probe (stack_pointer_rtx
);
1830 /* Adjust back and account for the additional first interval. */
1832 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1834 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1837 /* Return an rtx representing the register or memory location
1838 in which a scalar value of data type VALTYPE
1839 was returned by a function call to function FUNC.
1840 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1841 function is known, otherwise 0.
1842 OUTGOING is 1 if on a machine with register windows this function
1843 should return the register in which the function will put its result
1847 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1848 int outgoing ATTRIBUTE_UNUSED
)
1852 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1855 && GET_MODE (val
) == BLKmode
)
1857 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1858 machine_mode tmpmode
;
1860 /* int_size_in_bytes can return -1. We don't need a check here
1861 since the value of bytes will then be large enough that no
1862 mode will match anyway. */
1864 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1865 tmpmode
!= VOIDmode
;
1866 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1868 /* Have we found a large enough mode? */
1869 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1873 /* No suitable mode found. */
1874 gcc_assert (tmpmode
!= VOIDmode
);
1876 PUT_MODE (val
, tmpmode
);
1881 /* Return an rtx representing the register or memory location
1882 in which a scalar value of mode MODE was returned by a library call. */
1885 hard_libcall_value (machine_mode mode
, rtx fun
)
1887 return targetm
.calls
.libcall_value (mode
, fun
);
1890 /* Look up the tree code for a given rtx code
1891 to provide the arithmetic operation for REAL_ARITHMETIC.
1892 The function returns an int because the caller may not know
1893 what `enum tree_code' means. */
1896 rtx_to_tree_code (enum rtx_code code
)
1898 enum tree_code tcode
;
1921 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1924 return ((int) tcode
);
1927 #include "gt-explow.h"