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"
31 #include "stor-layout.h"
35 #include "hard-reg-set.h"
37 #include "insn-config.h"
46 #include "insn-codes.h"
50 #include "langhooks.h"
52 #include "common/common-target.h"
55 static rtx
break_out_memory_refs (rtx
);
58 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
61 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
63 int width
= GET_MODE_PRECISION (mode
);
65 /* You want to truncate to a _what_? */
66 gcc_assert (SCALAR_INT_MODE_P (mode
)
67 || POINTER_BOUNDS_MODE_P (mode
));
69 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
71 return c
& 1 ? STORE_FLAG_VALUE
: 0;
73 /* Sign-extend for the requested mode. */
75 if (width
< HOST_BITS_PER_WIDE_INT
)
77 HOST_WIDE_INT sign
= 1;
87 /* Return an rtx for the sum of X and the integer C, given that X has
88 mode MODE. INPLACE is true if X can be modified inplace or false
89 if it must be treated as immutable. */
92 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
100 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
112 CASE_CONST_SCALAR_INT
:
113 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
116 /* If this is a reference to the constant pool, try replacing it with
117 a reference to a new constant. If the resulting address isn't
118 valid, don't return it because we have no way to validize it. */
119 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
120 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
122 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
123 tem
= force_const_mem (GET_MODE (x
), tem
);
124 /* Targets may disallow some constants in the constant pool, thus
125 force_const_mem may return NULL_RTX. */
126 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
132 /* If adding to something entirely constant, set a flag
133 so that we can add a CONST around the result. */
134 if (inplace
&& shared_const_p (x
))
146 /* The interesting case is adding the integer to a sum. Look
147 for constant term in the sum and combine with C. For an
148 integer constant term or a constant term that is not an
149 explicit integer, we combine or group them together anyway.
151 We may not immediately return from the recursive call here, lest
152 all_constant gets lost. */
154 if (CONSTANT_P (XEXP (x
, 1)))
156 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
157 if (term
== const0_rtx
)
162 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
165 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
169 /* We need to be careful since X may be shared and we can't
170 modify it in place. */
172 const_loc
= find_constant_term_loc (&x
);
174 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
184 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
186 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
188 else if (all_constant
)
189 return gen_rtx_CONST (mode
, x
);
194 /* If X is a sum, return a new sum like X but lacking any constant terms.
195 Add all the removed constant terms into *CONSTPTR.
196 X itself is not altered. The result != X if and only if
197 it is not isomorphic to X. */
200 eliminate_constant_term (rtx x
, rtx
*constptr
)
205 if (GET_CODE (x
) != PLUS
)
208 /* First handle constants appearing at this level explicitly. */
209 if (CONST_INT_P (XEXP (x
, 1))
210 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
212 && CONST_INT_P (tem
))
215 return eliminate_constant_term (XEXP (x
, 0), constptr
);
219 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
220 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
221 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
222 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
224 && CONST_INT_P (tem
))
227 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
234 /* Return a copy of X in which all memory references
235 and all constants that involve symbol refs
236 have been replaced with new temporary registers.
237 Also emit code to load the memory locations and constants
238 into those registers.
240 If X contains no such constants or memory references,
241 X itself (not a copy) is returned.
243 If a constant is found in the address that is not a legitimate constant
244 in an insn, it is left alone in the hope that it might be valid in the
247 X may contain no arithmetic except addition, subtraction and multiplication.
248 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
251 break_out_memory_refs (rtx x
)
254 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
255 && GET_MODE (x
) != VOIDmode
))
256 x
= force_reg (GET_MODE (x
), x
);
257 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
258 || GET_CODE (x
) == MULT
)
260 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
261 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
263 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
264 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
270 /* Given X, a memory address in address space AS' pointer mode, convert it to
271 an address in the address space's address mode, or vice versa (TO_MODE says
272 which way). We take advantage of the fact that pointers are not allowed to
273 overflow by commuting arithmetic operations over conversions so that address
274 arithmetic insns can be used. IN_CONST is true if this conversion is inside
278 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
279 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
280 bool in_const ATTRIBUTE_UNUSED
)
282 #ifndef POINTERS_EXTEND_UNSIGNED
283 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
285 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
286 machine_mode pointer_mode
, address_mode
, from_mode
;
290 /* If X already has the right mode, just return it. */
291 if (GET_MODE (x
) == to_mode
)
294 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
295 address_mode
= targetm
.addr_space
.address_mode (as
);
296 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
298 /* Here we handle some special cases. If none of them apply, fall through
299 to the default case. */
300 switch (GET_CODE (x
))
302 CASE_CONST_SCALAR_INT
:
303 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
305 else if (POINTERS_EXTEND_UNSIGNED
< 0)
307 else if (POINTERS_EXTEND_UNSIGNED
> 0)
311 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
317 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
318 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
319 return SUBREG_REG (x
);
323 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
324 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
329 temp
= shallow_copy_rtx (x
);
330 PUT_MODE (temp
, to_mode
);
335 return gen_rtx_CONST (to_mode
,
336 convert_memory_address_addr_space_1
337 (to_mode
, XEXP (x
, 0), as
, true));
342 /* For addition we can safely permute the conversion and addition
343 operation if one operand is a constant and converting the constant
344 does not change it or if one operand is a constant and we are
345 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
346 We can always safely permute them if we are making the address
347 narrower. Inside a CONST RTL, this is safe for both pointers
348 zero or sign extended as pointers cannot wrap. */
349 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
350 || (GET_CODE (x
) == PLUS
351 && CONST_INT_P (XEXP (x
, 1))
352 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
353 || XEXP (x
, 1) == convert_memory_address_addr_space_1
354 (to_mode
, XEXP (x
, 1), as
, in_const
)
355 || POINTERS_EXTEND_UNSIGNED
< 0)))
356 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
357 convert_memory_address_addr_space_1
358 (to_mode
, XEXP (x
, 0), as
, in_const
),
366 return convert_modes (to_mode
, from_mode
,
367 x
, POINTERS_EXTEND_UNSIGNED
);
368 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
371 /* Given X, a memory address in address space AS' pointer mode, convert it to
372 an address in the address space's address mode, or vice versa (TO_MODE says
373 which way). We take advantage of the fact that pointers are not allowed to
374 overflow by commuting arithmetic operations over conversions so that address
375 arithmetic insns can be used. */
378 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
380 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false);
384 /* Return something equivalent to X but valid as a memory address for something
385 of mode MODE in the named address space AS. When X is not itself valid,
386 this works by copying X or subexpressions of it into registers. */
389 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
392 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
394 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
396 /* By passing constant addresses through registers
397 we get a chance to cse them. */
398 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
399 x
= force_reg (address_mode
, x
);
401 /* We get better cse by rejecting indirect addressing at this stage.
402 Let the combiner create indirect addresses where appropriate.
403 For now, generate the code so that the subexpressions useful to share
404 are visible. But not if cse won't be done! */
407 if (! cse_not_expected
&& !REG_P (x
))
408 x
= break_out_memory_refs (x
);
410 /* At this point, any valid address is accepted. */
411 if (memory_address_addr_space_p (mode
, x
, as
))
414 /* If it was valid before but breaking out memory refs invalidated it,
415 use it the old way. */
416 if (memory_address_addr_space_p (mode
, oldx
, as
))
422 /* Perform machine-dependent transformations on X
423 in certain cases. This is not necessary since the code
424 below can handle all possible cases, but machine-dependent
425 transformations can make better code. */
428 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
429 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
433 /* PLUS and MULT can appear in special ways
434 as the result of attempts to make an address usable for indexing.
435 Usually they are dealt with by calling force_operand, below.
436 But a sum containing constant terms is special
437 if removing them makes the sum a valid address:
438 then we generate that address in a register
439 and index off of it. We do this because it often makes
440 shorter code, and because the addresses thus generated
441 in registers often become common subexpressions. */
442 if (GET_CODE (x
) == PLUS
)
444 rtx constant_term
= const0_rtx
;
445 rtx y
= eliminate_constant_term (x
, &constant_term
);
446 if (constant_term
== const0_rtx
447 || ! memory_address_addr_space_p (mode
, y
, as
))
448 x
= force_operand (x
, NULL_RTX
);
451 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
452 if (! memory_address_addr_space_p (mode
, y
, as
))
453 x
= force_operand (x
, NULL_RTX
);
459 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
460 x
= force_operand (x
, NULL_RTX
);
462 /* If we have a register that's an invalid address,
463 it must be a hard reg of the wrong class. Copy it to a pseudo. */
467 /* Last resort: copy the value to a register, since
468 the register is a valid address. */
470 x
= force_reg (address_mode
, x
);
475 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
476 /* If we didn't change the address, we are done. Otherwise, mark
477 a reg as a pointer if we have REG or REG + CONST_INT. */
481 mark_reg_pointer (x
, BITS_PER_UNIT
);
482 else if (GET_CODE (x
) == PLUS
483 && REG_P (XEXP (x
, 0))
484 && CONST_INT_P (XEXP (x
, 1)))
485 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
487 /* OLDX may have been the address on a temporary. Update the address
488 to indicate that X is now used. */
489 update_temp_slot_address (oldx
, x
);
494 /* If REF is a MEM with an invalid address, change it into a valid address.
495 Pass through anything else unchanged. REF must be an unshared rtx and
496 the function may modify it in-place. */
499 validize_mem (rtx ref
)
503 ref
= use_anchored_address (ref
);
504 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
505 MEM_ADDR_SPACE (ref
)))
508 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
511 /* If X is a memory reference to a member of an object block, try rewriting
512 it to use an anchor instead. Return the new memory reference on success
513 and the old one on failure. */
516 use_anchored_address (rtx x
)
519 HOST_WIDE_INT offset
;
522 if (!flag_section_anchors
)
528 /* Split the address into a base and offset. */
531 if (GET_CODE (base
) == CONST
532 && GET_CODE (XEXP (base
, 0)) == PLUS
533 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
535 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
536 base
= XEXP (XEXP (base
, 0), 0);
539 /* Check whether BASE is suitable for anchors. */
540 if (GET_CODE (base
) != SYMBOL_REF
541 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
542 || SYMBOL_REF_ANCHOR_P (base
)
543 || SYMBOL_REF_BLOCK (base
) == NULL
544 || !targetm
.use_anchors_for_symbol_p (base
))
547 /* Decide where BASE is going to be. */
548 place_block_symbol (base
);
550 /* Get the anchor we need to use. */
551 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
552 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
553 SYMBOL_REF_TLS_MODEL (base
));
555 /* Work out the offset from the anchor. */
556 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
558 /* If we're going to run a CSE pass, force the anchor into a register.
559 We will then be able to reuse registers for several accesses, if the
560 target costs say that that's worthwhile. */
561 mode
= GET_MODE (base
);
562 if (!cse_not_expected
)
563 base
= force_reg (mode
, base
);
565 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
568 /* Copy the value or contents of X to a new temp reg and return that reg. */
573 rtx temp
= gen_reg_rtx (GET_MODE (x
));
575 /* If not an operand, must be an address with PLUS and MULT so
576 do the computation. */
577 if (! general_operand (x
, VOIDmode
))
578 x
= force_operand (x
, temp
);
581 emit_move_insn (temp
, x
);
586 /* Like copy_to_reg but always give the new register mode Pmode
587 in case X is a constant. */
590 copy_addr_to_reg (rtx x
)
592 return copy_to_mode_reg (Pmode
, x
);
595 /* Like copy_to_reg but always give the new register mode MODE
596 in case X is a constant. */
599 copy_to_mode_reg (machine_mode mode
, rtx x
)
601 rtx temp
= gen_reg_rtx (mode
);
603 /* If not an operand, must be an address with PLUS and MULT so
604 do the computation. */
605 if (! general_operand (x
, VOIDmode
))
606 x
= force_operand (x
, temp
);
608 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
610 emit_move_insn (temp
, x
);
614 /* Load X into a register if it is not already one.
615 Use mode MODE for the register.
616 X should be valid for mode MODE, but it may be a constant which
617 is valid for all integer modes; that's why caller must specify MODE.
619 The caller must not alter the value in the register we return,
620 since we mark it as a "constant" register. */
623 force_reg (machine_mode mode
, rtx x
)
631 if (general_operand (x
, mode
))
633 temp
= gen_reg_rtx (mode
);
634 insn
= emit_move_insn (temp
, x
);
638 temp
= force_operand (x
, NULL_RTX
);
640 insn
= get_last_insn ();
643 rtx temp2
= gen_reg_rtx (mode
);
644 insn
= emit_move_insn (temp2
, temp
);
649 /* Let optimizers know that TEMP's value never changes
650 and that X can be substituted for it. Don't get confused
651 if INSN set something else (such as a SUBREG of TEMP). */
653 && (set
= single_set (insn
)) != 0
654 && SET_DEST (set
) == temp
655 && ! rtx_equal_p (x
, SET_SRC (set
)))
656 set_unique_reg_note (insn
, REG_EQUAL
, x
);
658 /* Let optimizers know that TEMP is a pointer, and if so, the
659 known alignment of that pointer. */
662 if (GET_CODE (x
) == SYMBOL_REF
)
664 align
= BITS_PER_UNIT
;
665 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
666 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
668 else if (GET_CODE (x
) == LABEL_REF
)
669 align
= BITS_PER_UNIT
;
670 else if (GET_CODE (x
) == CONST
671 && GET_CODE (XEXP (x
, 0)) == PLUS
672 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
673 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
675 rtx s
= XEXP (XEXP (x
, 0), 0);
676 rtx c
= XEXP (XEXP (x
, 0), 1);
680 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
681 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
687 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
688 align
= MIN (sa
, ca
);
692 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
693 mark_reg_pointer (temp
, align
);
699 /* If X is a memory ref, copy its contents to a new temp reg and return
700 that reg. Otherwise, return X. */
703 force_not_mem (rtx x
)
707 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
710 temp
= gen_reg_rtx (GET_MODE (x
));
713 REG_POINTER (temp
) = 1;
715 emit_move_insn (temp
, x
);
719 /* Copy X to TARGET (if it's nonzero and a reg)
720 or to a new temp reg and return that reg.
721 MODE is the mode to use for X in case it is a constant. */
724 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
728 if (target
&& REG_P (target
))
731 temp
= gen_reg_rtx (mode
);
733 emit_move_insn (temp
, x
);
737 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
738 PUNSIGNEDP points to the signedness of the type and may be adjusted
739 to show what signedness to use on extension operations.
741 FOR_RETURN is nonzero if the caller is promoting the return value
742 of FNDECL, else it is for promoting args. */
745 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
746 const_tree funtype
, int for_return
)
748 /* Called without a type node for a libcall. */
749 if (type
== NULL_TREE
)
751 if (INTEGRAL_MODE_P (mode
))
752 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
759 switch (TREE_CODE (type
))
761 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
762 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
763 case POINTER_TYPE
: case REFERENCE_TYPE
:
764 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
771 /* Return the mode to use to store a scalar of TYPE and MODE.
772 PUNSIGNEDP points to the signedness of the type and may be adjusted
773 to show what signedness to use on extension operations. */
776 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
777 int *punsignedp ATTRIBUTE_UNUSED
)
784 /* For libcalls this is invoked without TYPE from the backends
785 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
787 if (type
== NULL_TREE
)
790 /* FIXME: this is the same logic that was there until GCC 4.4, but we
791 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
792 is not defined. The affected targets are M32C, S390, SPARC. */
794 code
= TREE_CODE (type
);
795 unsignedp
= *punsignedp
;
799 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
800 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
801 PROMOTE_MODE (mode
, unsignedp
, type
);
802 *punsignedp
= unsignedp
;
806 #ifdef POINTERS_EXTEND_UNSIGNED
809 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
810 return targetm
.addr_space
.address_mode
811 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
824 /* Use one of promote_mode or promote_function_mode to find the promoted
825 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
826 of DECL after promotion. */
829 promote_decl_mode (const_tree decl
, int *punsignedp
)
831 tree type
= TREE_TYPE (decl
);
832 int unsignedp
= TYPE_UNSIGNED (type
);
833 machine_mode mode
= DECL_MODE (decl
);
836 if (TREE_CODE (decl
) == RESULT_DECL
837 || TREE_CODE (decl
) == PARM_DECL
)
838 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
839 TREE_TYPE (current_function_decl
), 2);
841 pmode
= promote_mode (type
, mode
, &unsignedp
);
844 *punsignedp
= unsignedp
;
849 /* Controls the behaviour of {anti_,}adjust_stack. */
850 static bool suppress_reg_args_size
;
852 /* A helper for adjust_stack and anti_adjust_stack. */
855 adjust_stack_1 (rtx adjust
, bool anti_p
)
860 /* Hereafter anti_p means subtract_p. */
861 if (!STACK_GROWS_DOWNWARD
)
864 temp
= expand_binop (Pmode
,
865 anti_p
? sub_optab
: add_optab
,
866 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
869 if (temp
!= stack_pointer_rtx
)
870 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
873 insn
= get_last_insn ();
874 temp
= single_set (insn
);
875 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
878 if (!suppress_reg_args_size
)
879 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
882 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
883 This pops when ADJUST is positive. ADJUST need not be constant. */
886 adjust_stack (rtx adjust
)
888 if (adjust
== const0_rtx
)
891 /* We expect all variable sized adjustments to be multiple of
892 PREFERRED_STACK_BOUNDARY. */
893 if (CONST_INT_P (adjust
))
894 stack_pointer_delta
-= INTVAL (adjust
);
896 adjust_stack_1 (adjust
, false);
899 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
900 This pushes when ADJUST is positive. ADJUST need not be constant. */
903 anti_adjust_stack (rtx adjust
)
905 if (adjust
== const0_rtx
)
908 /* We expect all variable sized adjustments to be multiple of
909 PREFERRED_STACK_BOUNDARY. */
910 if (CONST_INT_P (adjust
))
911 stack_pointer_delta
+= INTVAL (adjust
);
913 adjust_stack_1 (adjust
, true);
916 /* Round the size of a block to be pushed up to the boundary required
917 by this machine. SIZE is the desired size, which need not be constant. */
920 round_push (rtx size
)
922 rtx align_rtx
, alignm1_rtx
;
924 if (!SUPPORTS_STACK_ALIGNMENT
925 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
927 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
932 if (CONST_INT_P (size
))
934 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
936 if (INTVAL (size
) != new_size
)
937 size
= GEN_INT (new_size
);
941 align_rtx
= GEN_INT (align
);
942 alignm1_rtx
= GEN_INT (align
- 1);
946 /* If crtl->preferred_stack_boundary might still grow, use
947 virtual_preferred_stack_boundary_rtx instead. This will be
948 substituted by the right value in vregs pass and optimized
950 align_rtx
= virtual_preferred_stack_boundary_rtx
;
951 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
955 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
956 but we know it can't. So add ourselves and then do
958 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
959 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
960 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
962 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
967 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
968 to a previously-created save area. If no save area has been allocated,
969 this function will allocate one. If a save area is specified, it
970 must be of the proper mode. */
973 emit_stack_save (enum save_level save_level
, rtx
*psave
)
976 /* The default is that we use a move insn and save in a Pmode object. */
977 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn_uncast
;
978 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
980 /* See if this machine has anything special to do for this kind of save. */
983 #ifdef HAVE_save_stack_block
985 if (HAVE_save_stack_block
)
986 fcn
= gen_save_stack_block
;
989 #ifdef HAVE_save_stack_function
991 if (HAVE_save_stack_function
)
992 fcn
= gen_save_stack_function
;
995 #ifdef HAVE_save_stack_nonlocal
997 if (HAVE_save_stack_nonlocal
)
998 fcn
= gen_save_stack_nonlocal
;
1005 /* If there is no save area and we have to allocate one, do so. Otherwise
1006 verify the save area is the proper mode. */
1010 if (mode
!= VOIDmode
)
1012 if (save_level
== SAVE_NONLOCAL
)
1013 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1015 *psave
= sa
= gen_reg_rtx (mode
);
1019 do_pending_stack_adjust ();
1021 sa
= validize_mem (sa
);
1022 emit_insn (fcn (sa
, stack_pointer_rtx
));
1025 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1026 area made by emit_stack_save. If it is zero, we have nothing to do. */
1029 emit_stack_restore (enum save_level save_level
, rtx sa
)
1031 /* The default is that we use a move insn. */
1032 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn_uncast
;
1034 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1035 STACK_POINTER and HARD_FRAME_POINTER.
1036 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1037 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1038 aligned variables, which is reflected in ix86_can_eliminate.
1039 We normally still have the realigned STACK_POINTER that we can use.
1040 But if there is a stack restore still present at reload, it can trigger
1041 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1042 FRAME_POINTER into a hard reg.
1043 To prevent this situation, we force need_drap if we emit a stack
1045 if (SUPPORTS_STACK_ALIGNMENT
)
1046 crtl
->need_drap
= true;
1048 /* See if this machine has anything special to do for this kind of save. */
1051 #ifdef HAVE_restore_stack_block
1053 if (HAVE_restore_stack_block
)
1054 fcn
= gen_restore_stack_block
;
1057 #ifdef HAVE_restore_stack_function
1059 if (HAVE_restore_stack_function
)
1060 fcn
= gen_restore_stack_function
;
1063 #ifdef HAVE_restore_stack_nonlocal
1065 if (HAVE_restore_stack_nonlocal
)
1066 fcn
= gen_restore_stack_nonlocal
;
1075 sa
= validize_mem (sa
);
1076 /* These clobbers prevent the scheduler from moving
1077 references to variable arrays below the code
1078 that deletes (pops) the arrays. */
1079 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1080 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1083 discard_pending_stack_adjust ();
1085 emit_insn (fcn (stack_pointer_rtx
, sa
));
1088 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1089 function. This should be called whenever we allocate or deallocate
1090 dynamic stack space. */
1093 update_nonlocal_goto_save_area (void)
1098 /* The nonlocal_goto_save_area object is an array of N pointers. The
1099 first one is used for the frame pointer save; the rest are sized by
1100 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1101 of the stack save area slots. */
1102 t_save
= build4 (ARRAY_REF
,
1103 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1104 cfun
->nonlocal_goto_save_area
,
1105 integer_one_node
, NULL_TREE
, NULL_TREE
);
1106 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1108 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1111 /* Record a new stack level for the current function. This should be called
1112 whenever we allocate or deallocate dynamic stack space. */
1115 record_new_stack_level (void)
1117 /* Record the new stack level for nonlocal gotos. */
1118 if (cfun
->nonlocal_goto_save_area
)
1119 update_nonlocal_goto_save_area ();
1121 /* Record the new stack level for SJLJ exceptions. */
1122 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1123 update_sjlj_context ();
1126 /* Return an rtx representing the address of an area of memory dynamically
1127 pushed on the stack.
1129 Any required stack pointer alignment is preserved.
1131 SIZE is an rtx representing the size of the area.
1133 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1134 parameter may be zero. If so, a proper value will be extracted
1135 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1137 REQUIRED_ALIGN is the alignment (in bits) required for the region
1140 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1141 stack space allocated by the generated code cannot be added with itself
1142 in the course of the execution of the function. It is always safe to
1143 pass FALSE here and the following criterion is sufficient in order to
1144 pass TRUE: every path in the CFG that starts at the allocation point and
1145 loops to it executes the associated deallocation code. */
1148 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1149 unsigned required_align
, bool cannot_accumulate
)
1151 HOST_WIDE_INT stack_usage_size
= -1;
1152 rtx_code_label
*final_label
;
1153 rtx final_target
, target
;
1154 unsigned extra_align
= 0;
1157 /* If we're asking for zero bytes, it doesn't matter what we point
1158 to since we can't dereference it. But return a reasonable
1160 if (size
== const0_rtx
)
1161 return virtual_stack_dynamic_rtx
;
1163 /* Otherwise, show we're calling alloca or equivalent. */
1164 cfun
->calls_alloca
= 1;
1166 /* If stack usage info is requested, look into the size we are passed.
1167 We need to do so this early to avoid the obfuscation that may be
1168 introduced later by the various alignment operations. */
1169 if (flag_stack_usage_info
)
1171 if (CONST_INT_P (size
))
1172 stack_usage_size
= INTVAL (size
);
1173 else if (REG_P (size
))
1175 /* Look into the last emitted insn and see if we can deduce
1176 something for the register. */
1179 insn
= get_last_insn ();
1180 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1182 if (CONST_INT_P (SET_SRC (set
)))
1183 stack_usage_size
= INTVAL (SET_SRC (set
));
1184 else if ((note
= find_reg_equal_equiv_note (insn
))
1185 && CONST_INT_P (XEXP (note
, 0)))
1186 stack_usage_size
= INTVAL (XEXP (note
, 0));
1190 /* If the size is not constant, we can't say anything. */
1191 if (stack_usage_size
== -1)
1193 current_function_has_unbounded_dynamic_stack_size
= 1;
1194 stack_usage_size
= 0;
1198 /* Ensure the size is in the proper mode. */
1199 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1200 size
= convert_to_mode (Pmode
, size
, 1);
1202 /* Adjust SIZE_ALIGN, if needed. */
1203 if (CONST_INT_P (size
))
1205 unsigned HOST_WIDE_INT lsb
;
1207 lsb
= INTVAL (size
);
1210 /* Watch out for overflow truncating to "unsigned". */
1211 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1212 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1214 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1216 else if (size_align
< BITS_PER_UNIT
)
1217 size_align
= BITS_PER_UNIT
;
1219 /* We can't attempt to minimize alignment necessary, because we don't
1220 know the final value of preferred_stack_boundary yet while executing
1222 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1223 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1225 /* We will need to ensure that the address we return is aligned to
1226 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1227 always know its final value at this point in the compilation (it
1228 might depend on the size of the outgoing parameter lists, for
1229 example), so we must align the value to be returned in that case.
1230 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1231 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1232 We must also do an alignment operation on the returned value if
1233 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1235 If we have to align, we must leave space in SIZE for the hole
1236 that might result from the alignment operation. */
1238 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1241 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1242 extra_align
= PREFERRED_STACK_BOUNDARY
;
1243 else if (required_align
> STACK_BOUNDARY
)
1244 extra_align
= STACK_BOUNDARY
;
1246 extra_align
= BITS_PER_UNIT
;
1249 /* ??? STACK_POINTER_OFFSET is always defined now. */
1250 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1252 extra_align
= BITS_PER_UNIT
;
1257 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1259 size
= plus_constant (Pmode
, size
, extra
);
1260 size
= force_operand (size
, NULL_RTX
);
1262 if (flag_stack_usage_info
)
1263 stack_usage_size
+= extra
;
1265 if (extra
&& size_align
> extra_align
)
1266 size_align
= extra_align
;
1269 /* Round the size to a multiple of the required stack alignment.
1270 Since the stack if presumed to be rounded before this allocation,
1271 this will maintain the required alignment.
1273 If the stack grows downward, we could save an insn by subtracting
1274 SIZE from the stack pointer and then aligning the stack pointer.
1275 The problem with this is that the stack pointer may be unaligned
1276 between the execution of the subtraction and alignment insns and
1277 some machines do not allow this. Even on those that do, some
1278 signal handlers malfunction if a signal should occur between those
1279 insns. Since this is an extremely rare event, we have no reliable
1280 way of knowing which systems have this problem. So we avoid even
1281 momentarily mis-aligning the stack. */
1282 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1284 size
= round_push (size
);
1286 if (flag_stack_usage_info
)
1288 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1289 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1293 target
= gen_reg_rtx (Pmode
);
1295 /* The size is supposed to be fully adjusted at this point so record it
1296 if stack usage info is requested. */
1297 if (flag_stack_usage_info
)
1299 current_function_dynamic_stack_size
+= stack_usage_size
;
1301 /* ??? This is gross but the only safe stance in the absence
1302 of stack usage oriented flow analysis. */
1303 if (!cannot_accumulate
)
1304 current_function_has_unbounded_dynamic_stack_size
= 1;
1308 final_target
= NULL_RTX
;
1310 /* If we are splitting the stack, we need to ask the backend whether
1311 there is enough room on the current stack. If there isn't, or if
1312 the backend doesn't know how to tell is, then we need to call a
1313 function to allocate memory in some other way. This memory will
1314 be released when we release the current stack segment. The
1315 effect is that stack allocation becomes less efficient, but at
1316 least it doesn't cause a stack overflow. */
1317 if (flag_split_stack
)
1319 rtx_code_label
*available_label
;
1320 rtx ask
, space
, func
;
1322 available_label
= NULL
;
1324 #ifdef HAVE_split_stack_space_check
1325 if (HAVE_split_stack_space_check
)
1327 available_label
= gen_label_rtx ();
1329 /* This instruction will branch to AVAILABLE_LABEL if there
1330 are SIZE bytes available on the stack. */
1331 emit_insn (gen_split_stack_space_check (size
, available_label
));
1335 /* The __morestack_allocate_stack_space function will allocate
1336 memory using malloc. If the alignment of the memory returned
1337 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1338 make sure we allocate enough space. */
1339 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1343 ask
= expand_binop (Pmode
, add_optab
, size
,
1344 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1346 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1350 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1352 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1355 if (available_label
== NULL_RTX
)
1358 final_target
= gen_reg_rtx (Pmode
);
1360 emit_move_insn (final_target
, space
);
1362 final_label
= gen_label_rtx ();
1363 emit_jump (final_label
);
1365 emit_label (available_label
);
1368 do_pending_stack_adjust ();
1370 /* We ought to be called always on the toplevel and stack ought to be aligned
1372 gcc_assert (!(stack_pointer_delta
1373 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1375 /* If needed, check that we have the required amount of stack. Take into
1376 account what has already been checked. */
1377 if (STACK_CHECK_MOVING_SP
)
1379 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1380 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1382 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1383 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1385 /* Don't let anti_adjust_stack emit notes. */
1386 suppress_reg_args_size
= true;
1388 /* Perform the required allocation from the stack. Some systems do
1389 this differently than simply incrementing/decrementing from the
1390 stack pointer, such as acquiring the space by calling malloc(). */
1391 #ifdef HAVE_allocate_stack
1392 if (HAVE_allocate_stack
)
1394 struct expand_operand ops
[2];
1395 /* We don't have to check against the predicate for operand 0 since
1396 TARGET is known to be a pseudo of the proper mode, which must
1397 be valid for the operand. */
1398 create_fixed_operand (&ops
[0], target
);
1399 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1400 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1405 int saved_stack_pointer_delta
;
1407 if (!STACK_GROWS_DOWNWARD
)
1408 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1410 /* Check stack bounds if necessary. */
1411 if (crtl
->limit_stack
)
1414 rtx_code_label
*space_available
= gen_label_rtx ();
1415 if (STACK_GROWS_DOWNWARD
)
1416 available
= expand_binop (Pmode
, sub_optab
,
1417 stack_pointer_rtx
, stack_limit_rtx
,
1418 NULL_RTX
, 1, OPTAB_WIDEN
);
1420 available
= expand_binop (Pmode
, sub_optab
,
1421 stack_limit_rtx
, stack_pointer_rtx
,
1422 NULL_RTX
, 1, OPTAB_WIDEN
);
1424 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1428 emit_insn (gen_trap ());
1431 error ("stack limits not supported on this target");
1433 emit_label (space_available
);
1436 saved_stack_pointer_delta
= stack_pointer_delta
;
1438 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1439 anti_adjust_stack_and_probe (size
, false);
1441 anti_adjust_stack (size
);
1443 /* Even if size is constant, don't modify stack_pointer_delta.
1444 The constant size alloca should preserve
1445 crtl->preferred_stack_boundary alignment. */
1446 stack_pointer_delta
= saved_stack_pointer_delta
;
1448 if (STACK_GROWS_DOWNWARD
)
1449 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1452 suppress_reg_args_size
= false;
1454 /* Finish up the split stack handling. */
1455 if (final_label
!= NULL_RTX
)
1457 gcc_assert (flag_split_stack
);
1458 emit_move_insn (final_target
, target
);
1459 emit_label (final_label
);
1460 target
= final_target
;
1465 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1466 but we know it can't. So add ourselves and then do
1468 target
= expand_binop (Pmode
, add_optab
, target
,
1469 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1471 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1472 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1473 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1476 target
= expand_mult (Pmode
, target
,
1477 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1482 /* Now that we've committed to a return value, mark its alignment. */
1483 mark_reg_pointer (target
, required_align
);
1485 /* Record the new stack level. */
1486 record_new_stack_level ();
1491 /* A front end may want to override GCC's stack checking by providing a
1492 run-time routine to call to check the stack, so provide a mechanism for
1493 calling that routine. */
1495 static GTY(()) rtx stack_check_libfunc
;
1498 set_stack_check_libfunc (const char *libfunc_name
)
1500 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1501 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1504 /* Emit one stack probe at ADDRESS, an address within the stack. */
1507 emit_stack_probe (rtx address
)
1509 #ifdef HAVE_probe_stack_address
1510 if (HAVE_probe_stack_address
)
1511 emit_insn (gen_probe_stack_address (address
));
1515 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1517 MEM_VOLATILE_P (memref
) = 1;
1519 /* See if we have an insn to probe the stack. */
1520 #ifdef HAVE_probe_stack
1521 if (HAVE_probe_stack
)
1522 emit_insn (gen_probe_stack (memref
));
1525 emit_move_insn (memref
, const0_rtx
);
1529 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1530 FIRST is a constant and size is a Pmode RTX. These are offsets from
1531 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1532 or subtract them from the stack pointer. */
1534 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1536 #if STACK_GROWS_DOWNWARD
1537 #define STACK_GROW_OP MINUS
1538 #define STACK_GROW_OPTAB sub_optab
1539 #define STACK_GROW_OFF(off) -(off)
1541 #define STACK_GROW_OP PLUS
1542 #define STACK_GROW_OPTAB add_optab
1543 #define STACK_GROW_OFF(off) (off)
1547 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1549 /* First ensure SIZE is Pmode. */
1550 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1551 size
= convert_to_mode (Pmode
, size
, 1);
1553 /* Next see if we have a function to check the stack. */
1554 if (stack_check_libfunc
)
1556 rtx addr
= memory_address (Pmode
,
1557 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1559 plus_constant (Pmode
,
1561 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1565 /* Next see if we have an insn to check the stack. */
1566 #ifdef HAVE_check_stack
1567 else if (HAVE_check_stack
)
1569 struct expand_operand ops
[1];
1570 rtx addr
= memory_address (Pmode
,
1571 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1573 plus_constant (Pmode
,
1576 create_input_operand (&ops
[0], addr
, Pmode
);
1577 success
= maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
);
1578 gcc_assert (success
);
1582 /* Otherwise we have to generate explicit probes. If we have a constant
1583 small number of them to generate, that's the easy case. */
1584 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1586 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1589 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1590 it exceeds SIZE. If only one probe is needed, this will not
1591 generate any code. Then probe at FIRST + SIZE. */
1592 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1594 addr
= memory_address (Pmode
,
1595 plus_constant (Pmode
, stack_pointer_rtx
,
1596 STACK_GROW_OFF (first
+ i
)));
1597 emit_stack_probe (addr
);
1600 addr
= memory_address (Pmode
,
1601 plus_constant (Pmode
, stack_pointer_rtx
,
1602 STACK_GROW_OFF (first
+ isize
)));
1603 emit_stack_probe (addr
);
1606 /* In the variable case, do the same as above, but in a loop. Note that we
1607 must be extra careful with variables wrapping around because we might be
1608 at the very top (or the very bottom) of the address space and we have to
1609 be able to handle this case properly; in particular, we use an equality
1610 test for the loop condition. */
1613 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1614 rtx_code_label
*loop_lab
= gen_label_rtx ();
1615 rtx_code_label
*end_lab
= gen_label_rtx ();
1617 /* Step 1: round SIZE to the previous multiple of the interval. */
1619 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1621 = simplify_gen_binary (AND
, Pmode
, size
,
1622 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1623 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1626 /* Step 2: compute initial and final value of the loop counter. */
1628 /* TEST_ADDR = SP + FIRST. */
1629 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1631 gen_int_mode (first
, Pmode
)),
1634 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1635 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1637 rounded_size_op
), NULL_RTX
);
1642 while (TEST_ADDR != LAST_ADDR)
1644 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1648 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1649 until it is equal to ROUNDED_SIZE. */
1651 emit_label (loop_lab
);
1653 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1654 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1657 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1658 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1659 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1662 gcc_assert (temp
== test_addr
);
1664 /* Probe at TEST_ADDR. */
1665 emit_stack_probe (test_addr
);
1667 emit_jump (loop_lab
);
1669 emit_label (end_lab
);
1672 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1673 that SIZE is equal to ROUNDED_SIZE. */
1675 /* TEMP = SIZE - ROUNDED_SIZE. */
1676 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1677 if (temp
!= const0_rtx
)
1681 if (CONST_INT_P (temp
))
1683 /* Use [base + disp} addressing mode if supported. */
1684 HOST_WIDE_INT offset
= INTVAL (temp
);
1685 addr
= memory_address (Pmode
,
1686 plus_constant (Pmode
, last_addr
,
1687 STACK_GROW_OFF (offset
)));
1691 /* Manual CSE if the difference is not known at compile-time. */
1692 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1693 addr
= memory_address (Pmode
,
1694 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1698 emit_stack_probe (addr
);
1702 /* Make sure nothing is scheduled before we are done. */
1703 emit_insn (gen_blockage ());
1706 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1707 while probing it. This pushes when SIZE is positive. SIZE need not
1708 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1709 by plus SIZE at the end. */
1712 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1714 /* We skip the probe for the first interval + a small dope of 4 words and
1715 probe that many bytes past the specified size to maintain a protection
1716 area at the botton of the stack. */
1717 const int dope
= 4 * UNITS_PER_WORD
;
1719 /* First ensure SIZE is Pmode. */
1720 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1721 size
= convert_to_mode (Pmode
, size
, 1);
1723 /* If we have a constant small number of probes to generate, that's the
1725 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1727 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1728 bool first_probe
= true;
1730 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1731 values of N from 1 until it exceeds SIZE. If only one probe is
1732 needed, this will not generate any code. Then adjust and probe
1733 to PROBE_INTERVAL + SIZE. */
1734 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1738 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1739 first_probe
= false;
1742 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1743 emit_stack_probe (stack_pointer_rtx
);
1747 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1749 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1750 emit_stack_probe (stack_pointer_rtx
);
1753 /* In the variable case, do the same as above, but in a loop. Note that we
1754 must be extra careful with variables wrapping around because we might be
1755 at the very top (or the very bottom) of the address space and we have to
1756 be able to handle this case properly; in particular, we use an equality
1757 test for the loop condition. */
1760 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1761 rtx_code_label
*loop_lab
= gen_label_rtx ();
1762 rtx_code_label
*end_lab
= gen_label_rtx ();
1765 /* Step 1: round SIZE to the previous multiple of the interval. */
1767 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1769 = simplify_gen_binary (AND
, Pmode
, size
,
1770 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1771 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1774 /* Step 2: compute initial and final value of the loop counter. */
1776 /* SP = SP_0 + PROBE_INTERVAL. */
1777 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1779 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1780 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1782 rounded_size_op
), NULL_RTX
);
1787 while (SP != LAST_ADDR)
1789 SP = SP + PROBE_INTERVAL
1793 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1794 values of N from 1 until it is equal to ROUNDED_SIZE. */
1796 emit_label (loop_lab
);
1798 /* Jump to END_LAB if SP == LAST_ADDR. */
1799 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1802 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1803 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1804 emit_stack_probe (stack_pointer_rtx
);
1806 emit_jump (loop_lab
);
1808 emit_label (end_lab
);
1811 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1812 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1814 /* TEMP = SIZE - ROUNDED_SIZE. */
1815 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1816 if (temp
!= const0_rtx
)
1818 /* Manual CSE if the difference is not known at compile-time. */
1819 if (GET_CODE (temp
) != CONST_INT
)
1820 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1821 anti_adjust_stack (temp
);
1822 emit_stack_probe (stack_pointer_rtx
);
1826 /* Adjust back and account for the additional first interval. */
1828 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1830 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1833 /* Return an rtx representing the register or memory location
1834 in which a scalar value of data type VALTYPE
1835 was returned by a function call to function FUNC.
1836 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1837 function is known, otherwise 0.
1838 OUTGOING is 1 if on a machine with register windows this function
1839 should return the register in which the function will put its result
1843 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1844 int outgoing ATTRIBUTE_UNUSED
)
1848 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1851 && GET_MODE (val
) == BLKmode
)
1853 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1854 machine_mode tmpmode
;
1856 /* int_size_in_bytes can return -1. We don't need a check here
1857 since the value of bytes will then be large enough that no
1858 mode will match anyway. */
1860 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1861 tmpmode
!= VOIDmode
;
1862 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1864 /* Have we found a large enough mode? */
1865 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1869 /* No suitable mode found. */
1870 gcc_assert (tmpmode
!= VOIDmode
);
1872 PUT_MODE (val
, tmpmode
);
1877 /* Return an rtx representing the register or memory location
1878 in which a scalar value of mode MODE was returned by a library call. */
1881 hard_libcall_value (machine_mode mode
, rtx fun
)
1883 return targetm
.calls
.libcall_value (mode
, fun
);
1886 /* Look up the tree code for a given rtx code
1887 to provide the arithmetic operation for REAL_ARITHMETIC.
1888 The function returns an int because the caller may not know
1889 what `enum tree_code' means. */
1892 rtx_to_tree_code (enum rtx_code code
)
1894 enum tree_code tcode
;
1917 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1920 return ((int) tcode
);
1923 #include "gt-explow.h"