1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2016 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
33 #include "diagnostic-core.h"
34 #include "stor-layout.h"
39 #include "common/common-target.h"
42 static rtx
break_out_memory_refs (rtx
);
45 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
48 trunc_int_for_mode (HOST_WIDE_INT c
, machine_mode mode
)
50 int width
= GET_MODE_PRECISION (mode
);
52 /* You want to truncate to a _what_? */
53 gcc_assert (SCALAR_INT_MODE_P (mode
)
54 || POINTER_BOUNDS_MODE_P (mode
));
56 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
58 return c
& 1 ? STORE_FLAG_VALUE
: 0;
60 /* Sign-extend for the requested mode. */
62 if (width
< HOST_BITS_PER_WIDE_INT
)
64 HOST_WIDE_INT sign
= 1;
74 /* Return an rtx for the sum of X and the integer C, given that X has
75 mode MODE. INPLACE is true if X can be modified inplace or false
76 if it must be treated as immutable. */
79 plus_constant (machine_mode mode
, rtx x
, HOST_WIDE_INT c
,
87 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
99 CASE_CONST_SCALAR_INT
:
100 return immed_wide_int_const (wi::add (std::make_pair (x
, mode
), c
),
103 /* If this is a reference to the constant pool, try replacing it with
104 a reference to a new constant. If the resulting address isn't
105 valid, don't return it because we have no way to validize it. */
106 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
107 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
109 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
110 tem
= force_const_mem (GET_MODE (x
), tem
);
111 /* Targets may disallow some constants in the constant pool, thus
112 force_const_mem may return NULL_RTX. */
113 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
119 /* If adding to something entirely constant, set a flag
120 so that we can add a CONST around the result. */
121 if (inplace
&& shared_const_p (x
))
133 /* The interesting case is adding the integer to a sum. Look
134 for constant term in the sum and combine with C. For an
135 integer constant term or a constant term that is not an
136 explicit integer, we combine or group them together anyway.
138 We may not immediately return from the recursive call here, lest
139 all_constant gets lost. */
141 if (CONSTANT_P (XEXP (x
, 1)))
143 rtx term
= plus_constant (mode
, XEXP (x
, 1), c
, inplace
);
144 if (term
== const0_rtx
)
149 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), term
);
152 else if (rtx
*const_loc
= find_constant_term_loc (&y
))
156 /* We need to be careful since X may be shared and we can't
157 modify it in place. */
159 const_loc
= find_constant_term_loc (&x
);
161 *const_loc
= plus_constant (mode
, *const_loc
, c
, true);
171 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
173 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
175 else if (all_constant
)
176 return gen_rtx_CONST (mode
, x
);
181 /* If X is a sum, return a new sum like X but lacking any constant terms.
182 Add all the removed constant terms into *CONSTPTR.
183 X itself is not altered. The result != X if and only if
184 it is not isomorphic to X. */
187 eliminate_constant_term (rtx x
, rtx
*constptr
)
192 if (GET_CODE (x
) != PLUS
)
195 /* First handle constants appearing at this level explicitly. */
196 if (CONST_INT_P (XEXP (x
, 1))
197 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
199 && CONST_INT_P (tem
))
202 return eliminate_constant_term (XEXP (x
, 0), constptr
);
206 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
207 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
208 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
209 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
211 && CONST_INT_P (tem
))
214 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
221 /* Return a copy of X in which all memory references
222 and all constants that involve symbol refs
223 have been replaced with new temporary registers.
224 Also emit code to load the memory locations and constants
225 into those registers.
227 If X contains no such constants or memory references,
228 X itself (not a copy) is returned.
230 If a constant is found in the address that is not a legitimate constant
231 in an insn, it is left alone in the hope that it might be valid in the
234 X may contain no arithmetic except addition, subtraction and multiplication.
235 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
238 break_out_memory_refs (rtx x
)
241 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
242 && GET_MODE (x
) != VOIDmode
))
243 x
= force_reg (GET_MODE (x
), x
);
244 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
245 || GET_CODE (x
) == MULT
)
247 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
248 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
250 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
251 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
257 /* Given X, a memory address in address space AS' pointer mode, convert it to
258 an address in the address space's address mode, or vice versa (TO_MODE says
259 which way). We take advantage of the fact that pointers are not allowed to
260 overflow by commuting arithmetic operations over conversions so that address
261 arithmetic insns can be used. IN_CONST is true if this conversion is inside
262 a CONST. NO_EMIT is true if no insns should be emitted, and instead
263 it should return NULL if it can't be simplified without emitting insns. */
266 convert_memory_address_addr_space_1 (machine_mode to_mode ATTRIBUTE_UNUSED
,
267 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
,
268 bool in_const ATTRIBUTE_UNUSED
,
269 bool no_emit ATTRIBUTE_UNUSED
)
271 #ifndef POINTERS_EXTEND_UNSIGNED
272 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
274 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
275 machine_mode pointer_mode
, address_mode
, from_mode
;
279 /* If X already has the right mode, just return it. */
280 if (GET_MODE (x
) == to_mode
)
283 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
284 address_mode
= targetm
.addr_space
.address_mode (as
);
285 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
287 /* Here we handle some special cases. If none of them apply, fall through
288 to the default case. */
289 switch (GET_CODE (x
))
291 CASE_CONST_SCALAR_INT
:
292 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
294 else if (POINTERS_EXTEND_UNSIGNED
< 0)
296 else if (POINTERS_EXTEND_UNSIGNED
> 0)
300 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
306 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
307 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
308 return SUBREG_REG (x
);
312 temp
= gen_rtx_LABEL_REF (to_mode
, LABEL_REF_LABEL (x
));
313 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
317 temp
= shallow_copy_rtx (x
);
318 PUT_MODE (temp
, to_mode
);
322 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0), as
,
324 return temp
? gen_rtx_CONST (to_mode
, temp
) : temp
;
328 /* For addition we can safely permute the conversion and addition
329 operation if one operand is a constant and converting the constant
330 does not change it or if one operand is a constant and we are
331 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
332 We can always safely permute them if we are making the address
333 narrower. Inside a CONST RTL, this is safe for both pointers
334 zero or sign extended as pointers cannot wrap. */
335 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
336 || (GET_CODE (x
) == PLUS
337 && CONST_INT_P (XEXP (x
, 1))
338 && ((in_const
&& POINTERS_EXTEND_UNSIGNED
!= 0)
339 || XEXP (x
, 1) == convert_memory_address_addr_space_1
340 (to_mode
, XEXP (x
, 1), as
, in_const
,
342 || POINTERS_EXTEND_UNSIGNED
< 0)))
344 temp
= convert_memory_address_addr_space_1 (to_mode
, XEXP (x
, 0),
345 as
, in_const
, no_emit
);
346 return (temp
? gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
359 return convert_modes (to_mode
, from_mode
,
360 x
, POINTERS_EXTEND_UNSIGNED
);
361 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
364 /* Given X, a memory address in address space AS' pointer mode, convert it to
365 an address in the address space's address mode, or vice versa (TO_MODE says
366 which way). We take advantage of the fact that pointers are not allowed to
367 overflow by commuting arithmetic operations over conversions so that address
368 arithmetic insns can be used. */
371 convert_memory_address_addr_space (machine_mode to_mode
, rtx x
, addr_space_t as
)
373 return convert_memory_address_addr_space_1 (to_mode
, x
, as
, false, false);
377 /* Return something equivalent to X but valid as a memory address for something
378 of mode MODE in the named address space AS. When X is not itself valid,
379 this works by copying X or subexpressions of it into registers. */
382 memory_address_addr_space (machine_mode mode
, rtx x
, addr_space_t as
)
385 machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
387 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
389 /* By passing constant addresses through registers
390 we get a chance to cse them. */
391 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
392 x
= force_reg (address_mode
, x
);
394 /* We get better cse by rejecting indirect addressing at this stage.
395 Let the combiner create indirect addresses where appropriate.
396 For now, generate the code so that the subexpressions useful to share
397 are visible. But not if cse won't be done! */
400 if (! cse_not_expected
&& !REG_P (x
))
401 x
= break_out_memory_refs (x
);
403 /* At this point, any valid address is accepted. */
404 if (memory_address_addr_space_p (mode
, x
, as
))
407 /* If it was valid before but breaking out memory refs invalidated it,
408 use it the old way. */
409 if (memory_address_addr_space_p (mode
, oldx
, as
))
415 /* Perform machine-dependent transformations on X
416 in certain cases. This is not necessary since the code
417 below can handle all possible cases, but machine-dependent
418 transformations can make better code. */
421 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
422 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
426 /* PLUS and MULT can appear in special ways
427 as the result of attempts to make an address usable for indexing.
428 Usually they are dealt with by calling force_operand, below.
429 But a sum containing constant terms is special
430 if removing them makes the sum a valid address:
431 then we generate that address in a register
432 and index off of it. We do this because it often makes
433 shorter code, and because the addresses thus generated
434 in registers often become common subexpressions. */
435 if (GET_CODE (x
) == PLUS
)
437 rtx constant_term
= const0_rtx
;
438 rtx y
= eliminate_constant_term (x
, &constant_term
);
439 if (constant_term
== const0_rtx
440 || ! memory_address_addr_space_p (mode
, y
, as
))
441 x
= force_operand (x
, NULL_RTX
);
444 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
445 if (! memory_address_addr_space_p (mode
, y
, as
))
446 x
= force_operand (x
, NULL_RTX
);
452 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
453 x
= force_operand (x
, NULL_RTX
);
455 /* If we have a register that's an invalid address,
456 it must be a hard reg of the wrong class. Copy it to a pseudo. */
460 /* Last resort: copy the value to a register, since
461 the register is a valid address. */
463 x
= force_reg (address_mode
, x
);
468 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
469 /* If we didn't change the address, we are done. Otherwise, mark
470 a reg as a pointer if we have REG or REG + CONST_INT. */
474 mark_reg_pointer (x
, BITS_PER_UNIT
);
475 else if (GET_CODE (x
) == PLUS
476 && REG_P (XEXP (x
, 0))
477 && CONST_INT_P (XEXP (x
, 1)))
478 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
480 /* OLDX may have been the address on a temporary. Update the address
481 to indicate that X is now used. */
482 update_temp_slot_address (oldx
, x
);
487 /* If REF is a MEM with an invalid address, change it into a valid address.
488 Pass through anything else unchanged. REF must be an unshared rtx and
489 the function may modify it in-place. */
492 validize_mem (rtx ref
)
496 ref
= use_anchored_address (ref
);
497 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
498 MEM_ADDR_SPACE (ref
)))
501 return replace_equiv_address (ref
, XEXP (ref
, 0), true);
504 /* If X is a memory reference to a member of an object block, try rewriting
505 it to use an anchor instead. Return the new memory reference on success
506 and the old one on failure. */
509 use_anchored_address (rtx x
)
512 HOST_WIDE_INT offset
;
515 if (!flag_section_anchors
)
521 /* Split the address into a base and offset. */
524 if (GET_CODE (base
) == CONST
525 && GET_CODE (XEXP (base
, 0)) == PLUS
526 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
528 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
529 base
= XEXP (XEXP (base
, 0), 0);
532 /* Check whether BASE is suitable for anchors. */
533 if (GET_CODE (base
) != SYMBOL_REF
534 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
535 || SYMBOL_REF_ANCHOR_P (base
)
536 || SYMBOL_REF_BLOCK (base
) == NULL
537 || !targetm
.use_anchors_for_symbol_p (base
))
540 /* Decide where BASE is going to be. */
541 place_block_symbol (base
);
543 /* Get the anchor we need to use. */
544 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
545 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
546 SYMBOL_REF_TLS_MODEL (base
));
548 /* Work out the offset from the anchor. */
549 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
551 /* If we're going to run a CSE pass, force the anchor into a register.
552 We will then be able to reuse registers for several accesses, if the
553 target costs say that that's worthwhile. */
554 mode
= GET_MODE (base
);
555 if (!cse_not_expected
)
556 base
= force_reg (mode
, base
);
558 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
561 /* Copy the value or contents of X to a new temp reg and return that reg. */
566 rtx temp
= gen_reg_rtx (GET_MODE (x
));
568 /* If not an operand, must be an address with PLUS and MULT so
569 do the computation. */
570 if (! general_operand (x
, VOIDmode
))
571 x
= force_operand (x
, temp
);
574 emit_move_insn (temp
, x
);
579 /* Like copy_to_reg but always give the new register mode Pmode
580 in case X is a constant. */
583 copy_addr_to_reg (rtx x
)
585 return copy_to_mode_reg (Pmode
, x
);
588 /* Like copy_to_reg but always give the new register mode MODE
589 in case X is a constant. */
592 copy_to_mode_reg (machine_mode mode
, rtx x
)
594 rtx temp
= gen_reg_rtx (mode
);
596 /* If not an operand, must be an address with PLUS and MULT so
597 do the computation. */
598 if (! general_operand (x
, VOIDmode
))
599 x
= force_operand (x
, temp
);
601 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
603 emit_move_insn (temp
, x
);
607 /* Load X into a register if it is not already one.
608 Use mode MODE for the register.
609 X should be valid for mode MODE, but it may be a constant which
610 is valid for all integer modes; that's why caller must specify MODE.
612 The caller must not alter the value in the register we return,
613 since we mark it as a "constant" register. */
616 force_reg (machine_mode mode
, rtx x
)
624 if (general_operand (x
, mode
))
626 temp
= gen_reg_rtx (mode
);
627 insn
= emit_move_insn (temp
, x
);
631 temp
= force_operand (x
, NULL_RTX
);
633 insn
= get_last_insn ();
636 rtx temp2
= gen_reg_rtx (mode
);
637 insn
= emit_move_insn (temp2
, temp
);
642 /* Let optimizers know that TEMP's value never changes
643 and that X can be substituted for it. Don't get confused
644 if INSN set something else (such as a SUBREG of TEMP). */
646 && (set
= single_set (insn
)) != 0
647 && SET_DEST (set
) == temp
648 && ! rtx_equal_p (x
, SET_SRC (set
)))
649 set_unique_reg_note (insn
, REG_EQUAL
, x
);
651 /* Let optimizers know that TEMP is a pointer, and if so, the
652 known alignment of that pointer. */
655 if (GET_CODE (x
) == SYMBOL_REF
)
657 align
= BITS_PER_UNIT
;
658 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
659 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
661 else if (GET_CODE (x
) == LABEL_REF
)
662 align
= BITS_PER_UNIT
;
663 else if (GET_CODE (x
) == CONST
664 && GET_CODE (XEXP (x
, 0)) == PLUS
665 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
666 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
668 rtx s
= XEXP (XEXP (x
, 0), 0);
669 rtx c
= XEXP (XEXP (x
, 0), 1);
673 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
674 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
680 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
681 align
= MIN (sa
, ca
);
685 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
686 mark_reg_pointer (temp
, align
);
692 /* If X is a memory ref, copy its contents to a new temp reg and return
693 that reg. Otherwise, return X. */
696 force_not_mem (rtx x
)
700 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
703 temp
= gen_reg_rtx (GET_MODE (x
));
706 REG_POINTER (temp
) = 1;
708 emit_move_insn (temp
, x
);
712 /* Copy X to TARGET (if it's nonzero and a reg)
713 or to a new temp reg and return that reg.
714 MODE is the mode to use for X in case it is a constant. */
717 copy_to_suggested_reg (rtx x
, rtx target
, machine_mode mode
)
721 if (target
&& REG_P (target
))
724 temp
= gen_reg_rtx (mode
);
726 emit_move_insn (temp
, x
);
730 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
731 PUNSIGNEDP points to the signedness of the type and may be adjusted
732 to show what signedness to use on extension operations.
734 FOR_RETURN is nonzero if the caller is promoting the return value
735 of FNDECL, else it is for promoting args. */
738 promote_function_mode (const_tree type
, machine_mode mode
, int *punsignedp
,
739 const_tree funtype
, int for_return
)
741 /* Called without a type node for a libcall. */
742 if (type
== NULL_TREE
)
744 if (INTEGRAL_MODE_P (mode
))
745 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
752 switch (TREE_CODE (type
))
754 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
755 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
756 case POINTER_TYPE
: case REFERENCE_TYPE
:
757 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
764 /* Return the mode to use to store a scalar of TYPE and MODE.
765 PUNSIGNEDP points to the signedness of the type and may be adjusted
766 to show what signedness to use on extension operations. */
769 promote_mode (const_tree type ATTRIBUTE_UNUSED
, machine_mode mode
,
770 int *punsignedp ATTRIBUTE_UNUSED
)
777 /* For libcalls this is invoked without TYPE from the backends
778 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
780 if (type
== NULL_TREE
)
783 /* FIXME: this is the same logic that was there until GCC 4.4, but we
784 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
785 is not defined. The affected targets are M32C, S390, SPARC. */
787 code
= TREE_CODE (type
);
788 unsignedp
= *punsignedp
;
792 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
793 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
794 PROMOTE_MODE (mode
, unsignedp
, type
);
795 *punsignedp
= unsignedp
;
799 #ifdef POINTERS_EXTEND_UNSIGNED
802 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
803 return targetm
.addr_space
.address_mode
804 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
817 /* Use one of promote_mode or promote_function_mode to find the promoted
818 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
819 of DECL after promotion. */
822 promote_decl_mode (const_tree decl
, int *punsignedp
)
824 tree type
= TREE_TYPE (decl
);
825 int unsignedp
= TYPE_UNSIGNED (type
);
826 machine_mode mode
= DECL_MODE (decl
);
829 if (TREE_CODE (decl
) == RESULT_DECL
&& !DECL_BY_REFERENCE (decl
))
830 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
831 TREE_TYPE (current_function_decl
), 1);
832 else if (TREE_CODE (decl
) == RESULT_DECL
|| TREE_CODE (decl
) == PARM_DECL
)
833 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
834 TREE_TYPE (current_function_decl
), 2);
836 pmode
= promote_mode (type
, mode
, &unsignedp
);
839 *punsignedp
= unsignedp
;
843 /* Return the promoted mode for name. If it is a named SSA_NAME, it
844 is the same as promote_decl_mode. Otherwise, it is the promoted
845 mode of a temp decl of same type as the SSA_NAME, if we had created
849 promote_ssa_mode (const_tree name
, int *punsignedp
)
851 gcc_assert (TREE_CODE (name
) == SSA_NAME
);
853 /* Partitions holding parms and results must be promoted as expected
855 if (SSA_NAME_VAR (name
)
856 && (TREE_CODE (SSA_NAME_VAR (name
)) == PARM_DECL
857 || TREE_CODE (SSA_NAME_VAR (name
)) == RESULT_DECL
))
859 machine_mode mode
= promote_decl_mode (SSA_NAME_VAR (name
), punsignedp
);
864 tree type
= TREE_TYPE (name
);
865 int unsignedp
= TYPE_UNSIGNED (type
);
866 machine_mode mode
= TYPE_MODE (type
);
868 /* Bypass TYPE_MODE when it maps vector modes to BLKmode. */
871 gcc_assert (VECTOR_TYPE_P (type
));
872 mode
= type
->type_common
.mode
;
875 machine_mode pmode
= promote_mode (type
, mode
, &unsignedp
);
877 *punsignedp
= unsignedp
;
884 /* Controls the behavior of {anti_,}adjust_stack. */
885 static bool suppress_reg_args_size
;
887 /* A helper for adjust_stack and anti_adjust_stack. */
890 adjust_stack_1 (rtx adjust
, bool anti_p
)
895 /* Hereafter anti_p means subtract_p. */
896 if (!STACK_GROWS_DOWNWARD
)
899 temp
= expand_binop (Pmode
,
900 anti_p
? sub_optab
: add_optab
,
901 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
904 if (temp
!= stack_pointer_rtx
)
905 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
908 insn
= get_last_insn ();
909 temp
= single_set (insn
);
910 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
913 if (!suppress_reg_args_size
)
914 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
917 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
918 This pops when ADJUST is positive. ADJUST need not be constant. */
921 adjust_stack (rtx adjust
)
923 if (adjust
== const0_rtx
)
926 /* We expect all variable sized adjustments to be multiple of
927 PREFERRED_STACK_BOUNDARY. */
928 if (CONST_INT_P (adjust
))
929 stack_pointer_delta
-= INTVAL (adjust
);
931 adjust_stack_1 (adjust
, false);
934 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
935 This pushes when ADJUST is positive. ADJUST need not be constant. */
938 anti_adjust_stack (rtx adjust
)
940 if (adjust
== const0_rtx
)
943 /* We expect all variable sized adjustments to be multiple of
944 PREFERRED_STACK_BOUNDARY. */
945 if (CONST_INT_P (adjust
))
946 stack_pointer_delta
+= INTVAL (adjust
);
948 adjust_stack_1 (adjust
, true);
951 /* Round the size of a block to be pushed up to the boundary required
952 by this machine. SIZE is the desired size, which need not be constant. */
955 round_push (rtx size
)
957 rtx align_rtx
, alignm1_rtx
;
959 if (!SUPPORTS_STACK_ALIGNMENT
960 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
962 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
967 if (CONST_INT_P (size
))
969 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
971 if (INTVAL (size
) != new_size
)
972 size
= GEN_INT (new_size
);
976 align_rtx
= GEN_INT (align
);
977 alignm1_rtx
= GEN_INT (align
- 1);
981 /* If crtl->preferred_stack_boundary might still grow, use
982 virtual_preferred_stack_boundary_rtx instead. This will be
983 substituted by the right value in vregs pass and optimized
985 align_rtx
= virtual_preferred_stack_boundary_rtx
;
986 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
990 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
991 but we know it can't. So add ourselves and then do
993 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
994 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
995 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
997 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1002 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1003 to a previously-created save area. If no save area has been allocated,
1004 this function will allocate one. If a save area is specified, it
1005 must be of the proper mode. */
1008 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1011 /* The default is that we use a move insn and save in a Pmode object. */
1012 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1013 machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1015 /* See if this machine has anything special to do for this kind of save. */
1019 if (targetm
.have_save_stack_block ())
1020 fcn
= targetm
.gen_save_stack_block
;
1023 if (targetm
.have_save_stack_function ())
1024 fcn
= targetm
.gen_save_stack_function
;
1027 if (targetm
.have_save_stack_nonlocal ())
1028 fcn
= targetm
.gen_save_stack_nonlocal
;
1034 /* If there is no save area and we have to allocate one, do so. Otherwise
1035 verify the save area is the proper mode. */
1039 if (mode
!= VOIDmode
)
1041 if (save_level
== SAVE_NONLOCAL
)
1042 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1044 *psave
= sa
= gen_reg_rtx (mode
);
1048 do_pending_stack_adjust ();
1050 sa
= validize_mem (sa
);
1051 emit_insn (fcn (sa
, stack_pointer_rtx
));
1054 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1055 area made by emit_stack_save. If it is zero, we have nothing to do. */
1058 emit_stack_restore (enum save_level save_level
, rtx sa
)
1060 /* The default is that we use a move insn. */
1061 rtx_insn
*(*fcn
) (rtx
, rtx
) = gen_move_insn
;
1063 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1064 STACK_POINTER and HARD_FRAME_POINTER.
1065 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1066 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1067 aligned variables, which is reflected in ix86_can_eliminate.
1068 We normally still have the realigned STACK_POINTER that we can use.
1069 But if there is a stack restore still present at reload, it can trigger
1070 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1071 FRAME_POINTER into a hard reg.
1072 To prevent this situation, we force need_drap if we emit a stack
1074 if (SUPPORTS_STACK_ALIGNMENT
)
1075 crtl
->need_drap
= true;
1077 /* See if this machine has anything special to do for this kind of save. */
1081 if (targetm
.have_restore_stack_block ())
1082 fcn
= targetm
.gen_restore_stack_block
;
1085 if (targetm
.have_restore_stack_function ())
1086 fcn
= targetm
.gen_restore_stack_function
;
1089 if (targetm
.have_restore_stack_nonlocal ())
1090 fcn
= targetm
.gen_restore_stack_nonlocal
;
1098 sa
= validize_mem (sa
);
1099 /* These clobbers prevent the scheduler from moving
1100 references to variable arrays below the code
1101 that deletes (pops) the arrays. */
1102 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1103 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1106 discard_pending_stack_adjust ();
1108 emit_insn (fcn (stack_pointer_rtx
, sa
));
1111 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1112 function. This should be called whenever we allocate or deallocate
1113 dynamic stack space. */
1116 update_nonlocal_goto_save_area (void)
1121 /* The nonlocal_goto_save_area object is an array of N pointers. The
1122 first one is used for the frame pointer save; the rest are sized by
1123 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1124 of the stack save area slots. */
1125 t_save
= build4 (ARRAY_REF
,
1126 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1127 cfun
->nonlocal_goto_save_area
,
1128 integer_one_node
, NULL_TREE
, NULL_TREE
);
1129 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1131 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1134 /* Record a new stack level for the current function. This should be called
1135 whenever we allocate or deallocate dynamic stack space. */
1138 record_new_stack_level (void)
1140 /* Record the new stack level for nonlocal gotos. */
1141 if (cfun
->nonlocal_goto_save_area
)
1142 update_nonlocal_goto_save_area ();
1144 /* Record the new stack level for SJLJ exceptions. */
1145 if (targetm_common
.except_unwind_info (&global_options
) == UI_SJLJ
)
1146 update_sjlj_context ();
1149 /* Return an rtx representing the address of an area of memory dynamically
1150 pushed on the stack.
1152 Any required stack pointer alignment is preserved.
1154 SIZE is an rtx representing the size of the area.
1156 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1157 parameter may be zero. If so, a proper value will be extracted
1158 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1160 REQUIRED_ALIGN is the alignment (in bits) required for the region
1163 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1164 stack space allocated by the generated code cannot be added with itself
1165 in the course of the execution of the function. It is always safe to
1166 pass FALSE here and the following criterion is sufficient in order to
1167 pass TRUE: every path in the CFG that starts at the allocation point and
1168 loops to it executes the associated deallocation code. */
1171 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1172 unsigned required_align
, bool cannot_accumulate
)
1174 HOST_WIDE_INT stack_usage_size
= -1;
1175 rtx_code_label
*final_label
;
1176 rtx final_target
, target
;
1179 /* If we're asking for zero bytes, it doesn't matter what we point
1180 to since we can't dereference it. But return a reasonable
1182 if (size
== const0_rtx
)
1183 return virtual_stack_dynamic_rtx
;
1185 /* Otherwise, show we're calling alloca or equivalent. */
1186 cfun
->calls_alloca
= 1;
1188 /* If stack usage info is requested, look into the size we are passed.
1189 We need to do so this early to avoid the obfuscation that may be
1190 introduced later by the various alignment operations. */
1191 if (flag_stack_usage_info
)
1193 if (CONST_INT_P (size
))
1194 stack_usage_size
= INTVAL (size
);
1195 else if (REG_P (size
))
1197 /* Look into the last emitted insn and see if we can deduce
1198 something for the register. */
1201 insn
= get_last_insn ();
1202 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1204 if (CONST_INT_P (SET_SRC (set
)))
1205 stack_usage_size
= INTVAL (SET_SRC (set
));
1206 else if ((note
= find_reg_equal_equiv_note (insn
))
1207 && CONST_INT_P (XEXP (note
, 0)))
1208 stack_usage_size
= INTVAL (XEXP (note
, 0));
1212 /* If the size is not constant, we can't say anything. */
1213 if (stack_usage_size
== -1)
1215 current_function_has_unbounded_dynamic_stack_size
= 1;
1216 stack_usage_size
= 0;
1220 /* Ensure the size is in the proper mode. */
1221 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1222 size
= convert_to_mode (Pmode
, size
, 1);
1224 /* Adjust SIZE_ALIGN, if needed. */
1225 if (CONST_INT_P (size
))
1227 unsigned HOST_WIDE_INT lsb
;
1229 lsb
= INTVAL (size
);
1232 /* Watch out for overflow truncating to "unsigned". */
1233 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1234 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1236 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1238 else if (size_align
< BITS_PER_UNIT
)
1239 size_align
= BITS_PER_UNIT
;
1241 /* We can't attempt to minimize alignment necessary, because we don't
1242 know the final value of preferred_stack_boundary yet while executing
1244 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1245 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1247 /* We will need to ensure that the address we return is aligned to
1248 REQUIRED_ALIGN. At this point in the compilation, we don't always
1249 know the final value of the STACK_DYNAMIC_OFFSET used in function.c
1250 (it might depend on the size of the outgoing parameter lists, for
1251 example), so we must preventively align the value. We leave space
1252 in SIZE for the hole that might result from the alignment operation. */
1254 extra
= (required_align
- BITS_PER_UNIT
) / BITS_PER_UNIT
;
1255 size
= plus_constant (Pmode
, size
, extra
);
1256 size
= force_operand (size
, NULL_RTX
);
1258 if (flag_stack_usage_info
)
1259 stack_usage_size
+= extra
;
1261 if (extra
&& size_align
> BITS_PER_UNIT
)
1262 size_align
= BITS_PER_UNIT
;
1264 /* Round the size to a multiple of the required stack alignment.
1265 Since the stack if presumed to be rounded before this allocation,
1266 this will maintain the required alignment.
1268 If the stack grows downward, we could save an insn by subtracting
1269 SIZE from the stack pointer and then aligning the stack pointer.
1270 The problem with this is that the stack pointer may be unaligned
1271 between the execution of the subtraction and alignment insns and
1272 some machines do not allow this. Even on those that do, some
1273 signal handlers malfunction if a signal should occur between those
1274 insns. Since this is an extremely rare event, we have no reliable
1275 way of knowing which systems have this problem. So we avoid even
1276 momentarily mis-aligning the stack. */
1277 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1279 size
= round_push (size
);
1281 if (flag_stack_usage_info
)
1283 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1284 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1288 target
= gen_reg_rtx (Pmode
);
1290 /* The size is supposed to be fully adjusted at this point so record it
1291 if stack usage info is requested. */
1292 if (flag_stack_usage_info
)
1294 current_function_dynamic_stack_size
+= stack_usage_size
;
1296 /* ??? This is gross but the only safe stance in the absence
1297 of stack usage oriented flow analysis. */
1298 if (!cannot_accumulate
)
1299 current_function_has_unbounded_dynamic_stack_size
= 1;
1303 final_target
= NULL_RTX
;
1305 /* If we are splitting the stack, we need to ask the backend whether
1306 there is enough room on the current stack. If there isn't, or if
1307 the backend doesn't know how to tell is, then we need to call a
1308 function to allocate memory in some other way. This memory will
1309 be released when we release the current stack segment. The
1310 effect is that stack allocation becomes less efficient, but at
1311 least it doesn't cause a stack overflow. */
1312 if (flag_split_stack
)
1314 rtx_code_label
*available_label
;
1315 rtx ask
, space
, func
;
1317 available_label
= NULL
;
1319 if (targetm
.have_split_stack_space_check ())
1321 available_label
= gen_label_rtx ();
1323 /* This instruction will branch to AVAILABLE_LABEL if there
1324 are SIZE bytes available on the stack. */
1325 emit_insn (targetm
.gen_split_stack_space_check
1326 (size
, available_label
));
1329 /* The __morestack_allocate_stack_space function will allocate
1330 memory using malloc. If the alignment of the memory returned
1331 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1332 make sure we allocate enough space. */
1333 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1336 ask
= expand_binop (Pmode
, add_optab
, size
,
1337 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1339 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1341 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1343 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1346 if (available_label
== NULL_RTX
)
1349 final_target
= gen_reg_rtx (Pmode
);
1351 emit_move_insn (final_target
, space
);
1353 final_label
= gen_label_rtx ();
1354 emit_jump (final_label
);
1356 emit_label (available_label
);
1359 do_pending_stack_adjust ();
1361 /* We ought to be called always on the toplevel and stack ought to be aligned
1363 gcc_assert (!(stack_pointer_delta
1364 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1366 /* If needed, check that we have the required amount of stack. Take into
1367 account what has already been checked. */
1368 if (STACK_CHECK_MOVING_SP
)
1370 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1371 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1373 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1374 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1376 /* Don't let anti_adjust_stack emit notes. */
1377 suppress_reg_args_size
= true;
1379 /* Perform the required allocation from the stack. Some systems do
1380 this differently than simply incrementing/decrementing from the
1381 stack pointer, such as acquiring the space by calling malloc(). */
1382 if (targetm
.have_allocate_stack ())
1384 struct expand_operand ops
[2];
1385 /* We don't have to check against the predicate for operand 0 since
1386 TARGET is known to be a pseudo of the proper mode, which must
1387 be valid for the operand. */
1388 create_fixed_operand (&ops
[0], target
);
1389 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1390 expand_insn (targetm
.code_for_allocate_stack
, 2, ops
);
1394 int saved_stack_pointer_delta
;
1396 if (!STACK_GROWS_DOWNWARD
)
1397 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1399 /* Check stack bounds if necessary. */
1400 if (crtl
->limit_stack
)
1403 rtx_code_label
*space_available
= gen_label_rtx ();
1404 if (STACK_GROWS_DOWNWARD
)
1405 available
= expand_binop (Pmode
, sub_optab
,
1406 stack_pointer_rtx
, stack_limit_rtx
,
1407 NULL_RTX
, 1, OPTAB_WIDEN
);
1409 available
= expand_binop (Pmode
, sub_optab
,
1410 stack_limit_rtx
, stack_pointer_rtx
,
1411 NULL_RTX
, 1, OPTAB_WIDEN
);
1413 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1415 if (targetm
.have_trap ())
1416 emit_insn (targetm
.gen_trap ());
1418 error ("stack limits not supported on this target");
1420 emit_label (space_available
);
1423 saved_stack_pointer_delta
= stack_pointer_delta
;
1425 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1426 anti_adjust_stack_and_probe (size
, false);
1428 anti_adjust_stack (size
);
1430 /* Even if size is constant, don't modify stack_pointer_delta.
1431 The constant size alloca should preserve
1432 crtl->preferred_stack_boundary alignment. */
1433 stack_pointer_delta
= saved_stack_pointer_delta
;
1435 if (STACK_GROWS_DOWNWARD
)
1436 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1439 suppress_reg_args_size
= false;
1441 /* Finish up the split stack handling. */
1442 if (final_label
!= NULL_RTX
)
1444 gcc_assert (flag_split_stack
);
1445 emit_move_insn (final_target
, target
);
1446 emit_label (final_label
);
1447 target
= final_target
;
1450 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1451 but we know it can't. So add ourselves and then do
1453 target
= expand_binop (Pmode
, add_optab
, target
,
1454 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1456 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1457 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1458 gen_int_mode (required_align
/ BITS_PER_UNIT
, Pmode
),
1460 target
= expand_mult (Pmode
, target
,
1461 gen_int_mode (required_align
/ BITS_PER_UNIT
, Pmode
),
1464 /* Now that we've committed to a return value, mark its alignment. */
1465 mark_reg_pointer (target
, required_align
);
1467 /* Record the new stack level. */
1468 record_new_stack_level ();
1473 /* A front end may want to override GCC's stack checking by providing a
1474 run-time routine to call to check the stack, so provide a mechanism for
1475 calling that routine. */
1477 static GTY(()) rtx stack_check_libfunc
;
1480 set_stack_check_libfunc (const char *libfunc_name
)
1482 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1483 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1486 /* Emit one stack probe at ADDRESS, an address within the stack. */
1489 emit_stack_probe (rtx address
)
1491 if (targetm
.have_probe_stack_address ())
1492 emit_insn (targetm
.gen_probe_stack_address (address
));
1495 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1497 MEM_VOLATILE_P (memref
) = 1;
1499 /* See if we have an insn to probe the stack. */
1500 if (targetm
.have_probe_stack ())
1501 emit_insn (targetm
.gen_probe_stack (memref
));
1503 emit_move_insn (memref
, const0_rtx
);
1507 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1508 FIRST is a constant and size is a Pmode RTX. These are offsets from
1509 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1510 or subtract them from the stack pointer. */
1512 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1514 #if STACK_GROWS_DOWNWARD
1515 #define STACK_GROW_OP MINUS
1516 #define STACK_GROW_OPTAB sub_optab
1517 #define STACK_GROW_OFF(off) -(off)
1519 #define STACK_GROW_OP PLUS
1520 #define STACK_GROW_OPTAB add_optab
1521 #define STACK_GROW_OFF(off) (off)
1525 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1527 /* First ensure SIZE is Pmode. */
1528 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1529 size
= convert_to_mode (Pmode
, size
, 1);
1531 /* Next see if we have a function to check the stack. */
1532 if (stack_check_libfunc
)
1534 rtx addr
= memory_address (Pmode
,
1535 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1537 plus_constant (Pmode
,
1539 emit_library_call (stack_check_libfunc
, LCT_THROW
, VOIDmode
, 1, addr
,
1543 /* Next see if we have an insn to check the stack. */
1544 else if (targetm
.have_check_stack ())
1546 struct expand_operand ops
[1];
1547 rtx addr
= memory_address (Pmode
,
1548 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1550 plus_constant (Pmode
,
1553 create_input_operand (&ops
[0], addr
, Pmode
);
1554 success
= maybe_expand_insn (targetm
.code_for_check_stack
, 1, ops
);
1555 gcc_assert (success
);
1558 /* Otherwise we have to generate explicit probes. If we have a constant
1559 small number of them to generate, that's the easy case. */
1560 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1562 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1565 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1566 it exceeds SIZE. If only one probe is needed, this will not
1567 generate any code. Then probe at FIRST + SIZE. */
1568 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1570 addr
= memory_address (Pmode
,
1571 plus_constant (Pmode
, stack_pointer_rtx
,
1572 STACK_GROW_OFF (first
+ i
)));
1573 emit_stack_probe (addr
);
1576 addr
= memory_address (Pmode
,
1577 plus_constant (Pmode
, stack_pointer_rtx
,
1578 STACK_GROW_OFF (first
+ isize
)));
1579 emit_stack_probe (addr
);
1582 /* In the variable case, do the same as above, but in a loop. Note that we
1583 must be extra careful with variables wrapping around because we might be
1584 at the very top (or the very bottom) of the address space and we have to
1585 be able to handle this case properly; in particular, we use an equality
1586 test for the loop condition. */
1589 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1590 rtx_code_label
*loop_lab
= gen_label_rtx ();
1591 rtx_code_label
*end_lab
= gen_label_rtx ();
1593 /* Step 1: round SIZE to the previous multiple of the interval. */
1595 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1597 = simplify_gen_binary (AND
, Pmode
, size
,
1598 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1599 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1602 /* Step 2: compute initial and final value of the loop counter. */
1604 /* TEST_ADDR = SP + FIRST. */
1605 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1607 gen_int_mode (first
, Pmode
)),
1610 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1611 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1613 rounded_size_op
), NULL_RTX
);
1618 while (TEST_ADDR != LAST_ADDR)
1620 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1624 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1625 until it is equal to ROUNDED_SIZE. */
1627 emit_label (loop_lab
);
1629 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1630 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1633 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1634 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1635 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1638 gcc_assert (temp
== test_addr
);
1640 /* Probe at TEST_ADDR. */
1641 emit_stack_probe (test_addr
);
1643 emit_jump (loop_lab
);
1645 emit_label (end_lab
);
1648 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1649 that SIZE is equal to ROUNDED_SIZE. */
1651 /* TEMP = SIZE - ROUNDED_SIZE. */
1652 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1653 if (temp
!= const0_rtx
)
1657 if (CONST_INT_P (temp
))
1659 /* Use [base + disp} addressing mode if supported. */
1660 HOST_WIDE_INT offset
= INTVAL (temp
);
1661 addr
= memory_address (Pmode
,
1662 plus_constant (Pmode
, last_addr
,
1663 STACK_GROW_OFF (offset
)));
1667 /* Manual CSE if the difference is not known at compile-time. */
1668 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1669 addr
= memory_address (Pmode
,
1670 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1674 emit_stack_probe (addr
);
1678 /* Make sure nothing is scheduled before we are done. */
1679 emit_insn (gen_blockage ());
1682 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1683 while probing it. This pushes when SIZE is positive. SIZE need not
1684 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1685 by plus SIZE at the end. */
1688 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1690 /* We skip the probe for the first interval + a small dope of 4 words and
1691 probe that many bytes past the specified size to maintain a protection
1692 area at the botton of the stack. */
1693 const int dope
= 4 * UNITS_PER_WORD
;
1695 /* First ensure SIZE is Pmode. */
1696 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1697 size
= convert_to_mode (Pmode
, size
, 1);
1699 /* If we have a constant small number of probes to generate, that's the
1701 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1703 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1704 bool first_probe
= true;
1706 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1707 values of N from 1 until it exceeds SIZE. If only one probe is
1708 needed, this will not generate any code. Then adjust and probe
1709 to PROBE_INTERVAL + SIZE. */
1710 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1714 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1715 first_probe
= false;
1718 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1719 emit_stack_probe (stack_pointer_rtx
);
1723 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1725 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1726 emit_stack_probe (stack_pointer_rtx
);
1729 /* In the variable case, do the same as above, but in a loop. Note that we
1730 must be extra careful with variables wrapping around because we might be
1731 at the very top (or the very bottom) of the address space and we have to
1732 be able to handle this case properly; in particular, we use an equality
1733 test for the loop condition. */
1736 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1737 rtx_code_label
*loop_lab
= gen_label_rtx ();
1738 rtx_code_label
*end_lab
= gen_label_rtx ();
1741 /* Step 1: round SIZE to the previous multiple of the interval. */
1743 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1745 = simplify_gen_binary (AND
, Pmode
, size
,
1746 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1747 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1750 /* Step 2: compute initial and final value of the loop counter. */
1752 /* SP = SP_0 + PROBE_INTERVAL. */
1753 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1755 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1756 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1758 rounded_size_op
), NULL_RTX
);
1763 while (SP != LAST_ADDR)
1765 SP = SP + PROBE_INTERVAL
1769 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1770 values of N from 1 until it is equal to ROUNDED_SIZE. */
1772 emit_label (loop_lab
);
1774 /* Jump to END_LAB if SP == LAST_ADDR. */
1775 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1778 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1779 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1780 emit_stack_probe (stack_pointer_rtx
);
1782 emit_jump (loop_lab
);
1784 emit_label (end_lab
);
1787 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1788 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1790 /* TEMP = SIZE - ROUNDED_SIZE. */
1791 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1792 if (temp
!= const0_rtx
)
1794 /* Manual CSE if the difference is not known at compile-time. */
1795 if (GET_CODE (temp
) != CONST_INT
)
1796 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1797 anti_adjust_stack (temp
);
1798 emit_stack_probe (stack_pointer_rtx
);
1802 /* Adjust back and account for the additional first interval. */
1804 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1806 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1809 /* Return an rtx representing the register or memory location
1810 in which a scalar value of data type VALTYPE
1811 was returned by a function call to function FUNC.
1812 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1813 function is known, otherwise 0.
1814 OUTGOING is 1 if on a machine with register windows this function
1815 should return the register in which the function will put its result
1819 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1820 int outgoing ATTRIBUTE_UNUSED
)
1824 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1827 && GET_MODE (val
) == BLKmode
)
1829 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1830 machine_mode tmpmode
;
1832 /* int_size_in_bytes can return -1. We don't need a check here
1833 since the value of bytes will then be large enough that no
1834 mode will match anyway. */
1836 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1837 tmpmode
!= VOIDmode
;
1838 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1840 /* Have we found a large enough mode? */
1841 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1845 /* No suitable mode found. */
1846 gcc_assert (tmpmode
!= VOIDmode
);
1848 PUT_MODE (val
, tmpmode
);
1853 /* Return an rtx representing the register or memory location
1854 in which a scalar value of mode MODE was returned by a library call. */
1857 hard_libcall_value (machine_mode mode
, rtx fun
)
1859 return targetm
.calls
.libcall_value (mode
, fun
);
1862 /* Look up the tree code for a given rtx code
1863 to provide the arithmetic operation for real_arithmetic.
1864 The function returns an int because the caller may not know
1865 what `enum tree_code' means. */
1868 rtx_to_tree_code (enum rtx_code code
)
1870 enum tree_code tcode
;
1893 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1896 return ((int) tcode
);
1899 #include "gt-explow.h"