1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987-2014 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"
28 #include "stor-layout.h"
36 #include "hard-reg-set.h"
37 #include "insn-config.h"
40 #include "langhooks.h"
42 #include "common/common-target.h"
45 static rtx
break_out_memory_refs (rtx
);
48 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
51 trunc_int_for_mode (HOST_WIDE_INT c
, enum machine_mode mode
)
53 int width
= GET_MODE_PRECISION (mode
);
55 /* You want to truncate to a _what_? */
56 gcc_assert (SCALAR_INT_MODE_P (mode
));
58 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
60 return c
& 1 ? STORE_FLAG_VALUE
: 0;
62 /* Sign-extend for the requested mode. */
64 if (width
< HOST_BITS_PER_WIDE_INT
)
66 HOST_WIDE_INT sign
= 1;
76 /* Return an rtx for the sum of X and the integer C, given that X has
80 plus_constant (enum machine_mode mode
, rtx x
, HOST_WIDE_INT c
)
87 gcc_assert (GET_MODE (x
) == VOIDmode
|| GET_MODE (x
) == mode
);
100 if (GET_MODE_BITSIZE (mode
) > HOST_BITS_PER_WIDE_INT
)
102 double_int di_x
= double_int::from_shwi (INTVAL (x
));
103 double_int di_c
= double_int::from_shwi (c
);
106 double_int v
= di_x
.add_with_sign (di_c
, false, &overflow
);
110 return immed_double_int_const (v
, mode
);
113 return gen_int_mode (UINTVAL (x
) + c
, mode
);
117 double_int di_x
= double_int::from_pair (CONST_DOUBLE_HIGH (x
),
118 CONST_DOUBLE_LOW (x
));
119 double_int di_c
= double_int::from_shwi (c
);
122 double_int v
= di_x
.add_with_sign (di_c
, false, &overflow
);
124 /* Sorry, we have no way to represent overflows this wide.
125 To fix, add constant support wider than CONST_DOUBLE. */
126 gcc_assert (GET_MODE_BITSIZE (mode
) <= HOST_BITS_PER_DOUBLE_INT
);
128 return immed_double_int_const (v
, mode
);
132 /* If this is a reference to the constant pool, try replacing it with
133 a reference to a new constant. If the resulting address isn't
134 valid, don't return it because we have no way to validize it. */
135 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
136 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
138 tem
= plus_constant (mode
, get_pool_constant (XEXP (x
, 0)), c
);
139 tem
= force_const_mem (GET_MODE (x
), tem
);
140 /* Targets may disallow some constants in the constant pool, thus
141 force_const_mem may return NULL_RTX. */
142 if (tem
&& memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
148 /* If adding to something entirely constant, set a flag
149 so that we can add a CONST around the result. */
160 /* The interesting case is adding the integer to a sum. Look
161 for constant term in the sum and combine with C. For an
162 integer constant term or a constant term that is not an
163 explicit integer, we combine or group them together anyway.
165 We may not immediately return from the recursive call here, lest
166 all_constant gets lost. */
168 if (CONSTANT_P (XEXP (x
, 1)))
170 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0),
171 plus_constant (mode
, XEXP (x
, 1), c
));
174 else if (find_constant_term_loc (&y
))
176 /* We need to be careful since X may be shared and we can't
177 modify it in place. */
178 rtx copy
= copy_rtx (x
);
179 rtx
*const_loc
= find_constant_term_loc (©
);
181 *const_loc
= plus_constant (mode
, *const_loc
, c
);
192 x
= gen_rtx_PLUS (mode
, x
, gen_int_mode (c
, mode
));
194 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
196 else if (all_constant
)
197 return gen_rtx_CONST (mode
, x
);
202 /* If X is a sum, return a new sum like X but lacking any constant terms.
203 Add all the removed constant terms into *CONSTPTR.
204 X itself is not altered. The result != X if and only if
205 it is not isomorphic to X. */
208 eliminate_constant_term (rtx x
, rtx
*constptr
)
213 if (GET_CODE (x
) != PLUS
)
216 /* First handle constants appearing at this level explicitly. */
217 if (CONST_INT_P (XEXP (x
, 1))
218 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
220 && CONST_INT_P (tem
))
223 return eliminate_constant_term (XEXP (x
, 0), constptr
);
227 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
228 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
229 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
230 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
232 && CONST_INT_P (tem
))
235 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
241 /* Returns a tree for the size of EXP in bytes. */
244 tree_expr_size (const_tree exp
)
247 && DECL_SIZE_UNIT (exp
) != 0)
248 return DECL_SIZE_UNIT (exp
);
250 return size_in_bytes (TREE_TYPE (exp
));
253 /* Return an rtx for the size in bytes of the value of EXP. */
260 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
261 size
= TREE_OPERAND (exp
, 1);
264 size
= tree_expr_size (exp
);
266 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
269 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
272 /* Return a wide integer for the size in bytes of the value of EXP, or -1
273 if the size can vary or is larger than an integer. */
276 int_expr_size (tree exp
)
280 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
281 size
= TREE_OPERAND (exp
, 1);
284 size
= tree_expr_size (exp
);
288 if (size
== 0 || !tree_fits_shwi_p (size
))
291 return tree_to_shwi (size
);
294 /* Return a copy of X in which all memory references
295 and all constants that involve symbol refs
296 have been replaced with new temporary registers.
297 Also emit code to load the memory locations and constants
298 into those registers.
300 If X contains no such constants or memory references,
301 X itself (not a copy) is returned.
303 If a constant is found in the address that is not a legitimate constant
304 in an insn, it is left alone in the hope that it might be valid in the
307 X may contain no arithmetic except addition, subtraction and multiplication.
308 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
311 break_out_memory_refs (rtx x
)
314 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
315 && GET_MODE (x
) != VOIDmode
))
316 x
= force_reg (GET_MODE (x
), x
);
317 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
318 || GET_CODE (x
) == MULT
)
320 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
321 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
323 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
324 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
330 /* Given X, a memory address in address space AS' pointer mode, convert it to
331 an address in the address space's address mode, or vice versa (TO_MODE says
332 which way). We take advantage of the fact that pointers are not allowed to
333 overflow by commuting arithmetic operations over conversions so that address
334 arithmetic insns can be used. */
337 convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED
,
338 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
)
340 #ifndef POINTERS_EXTEND_UNSIGNED
341 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
343 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
344 enum machine_mode pointer_mode
, address_mode
, from_mode
;
348 /* If X already has the right mode, just return it. */
349 if (GET_MODE (x
) == to_mode
)
352 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
353 address_mode
= targetm
.addr_space
.address_mode (as
);
354 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
356 /* Here we handle some special cases. If none of them apply, fall through
357 to the default case. */
358 switch (GET_CODE (x
))
360 CASE_CONST_SCALAR_INT
:
361 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
363 else if (POINTERS_EXTEND_UNSIGNED
< 0)
365 else if (POINTERS_EXTEND_UNSIGNED
> 0)
369 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
375 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
376 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
377 return SUBREG_REG (x
);
381 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
382 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
387 temp
= shallow_copy_rtx (x
);
388 PUT_MODE (temp
, to_mode
);
393 return gen_rtx_CONST (to_mode
,
394 convert_memory_address_addr_space
395 (to_mode
, XEXP (x
, 0), as
));
400 /* FIXME: For addition, we used to permute the conversion and
401 addition operation only if one operand is a constant and
402 converting the constant does not change it or if one operand
403 is a constant and we are using a ptr_extend instruction
404 (POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
405 may overflow/underflow. We relax the condition to include
406 zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
407 parts of the compiler depend on it. See PR 49721.
409 We can always safely permute them if we are making the address
411 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
412 || (GET_CODE (x
) == PLUS
413 && CONST_INT_P (XEXP (x
, 1))
414 && (POINTERS_EXTEND_UNSIGNED
!= 0
415 || XEXP (x
, 1) == convert_memory_address_addr_space
416 (to_mode
, XEXP (x
, 1), as
))))
417 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
418 convert_memory_address_addr_space
419 (to_mode
, XEXP (x
, 0), as
),
427 return convert_modes (to_mode
, from_mode
,
428 x
, POINTERS_EXTEND_UNSIGNED
);
429 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
432 /* Return something equivalent to X but valid as a memory address for something
433 of mode MODE in the named address space AS. When X is not itself valid,
434 this works by copying X or subexpressions of it into registers. */
437 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
440 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
442 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
444 /* By passing constant addresses through registers
445 we get a chance to cse them. */
446 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
447 x
= force_reg (address_mode
, x
);
449 /* We get better cse by rejecting indirect addressing at this stage.
450 Let the combiner create indirect addresses where appropriate.
451 For now, generate the code so that the subexpressions useful to share
452 are visible. But not if cse won't be done! */
455 if (! cse_not_expected
&& !REG_P (x
))
456 x
= break_out_memory_refs (x
);
458 /* At this point, any valid address is accepted. */
459 if (memory_address_addr_space_p (mode
, x
, as
))
462 /* If it was valid before but breaking out memory refs invalidated it,
463 use it the old way. */
464 if (memory_address_addr_space_p (mode
, oldx
, as
))
470 /* Perform machine-dependent transformations on X
471 in certain cases. This is not necessary since the code
472 below can handle all possible cases, but machine-dependent
473 transformations can make better code. */
476 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
477 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
481 /* PLUS and MULT can appear in special ways
482 as the result of attempts to make an address usable for indexing.
483 Usually they are dealt with by calling force_operand, below.
484 But a sum containing constant terms is special
485 if removing them makes the sum a valid address:
486 then we generate that address in a register
487 and index off of it. We do this because it often makes
488 shorter code, and because the addresses thus generated
489 in registers often become common subexpressions. */
490 if (GET_CODE (x
) == PLUS
)
492 rtx constant_term
= const0_rtx
;
493 rtx y
= eliminate_constant_term (x
, &constant_term
);
494 if (constant_term
== const0_rtx
495 || ! memory_address_addr_space_p (mode
, y
, as
))
496 x
= force_operand (x
, NULL_RTX
);
499 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
500 if (! memory_address_addr_space_p (mode
, y
, as
))
501 x
= force_operand (x
, NULL_RTX
);
507 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
508 x
= force_operand (x
, NULL_RTX
);
510 /* If we have a register that's an invalid address,
511 it must be a hard reg of the wrong class. Copy it to a pseudo. */
515 /* Last resort: copy the value to a register, since
516 the register is a valid address. */
518 x
= force_reg (address_mode
, x
);
523 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
524 /* If we didn't change the address, we are done. Otherwise, mark
525 a reg as a pointer if we have REG or REG + CONST_INT. */
529 mark_reg_pointer (x
, BITS_PER_UNIT
);
530 else if (GET_CODE (x
) == PLUS
531 && REG_P (XEXP (x
, 0))
532 && CONST_INT_P (XEXP (x
, 1)))
533 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
535 /* OLDX may have been the address on a temporary. Update the address
536 to indicate that X is now used. */
537 update_temp_slot_address (oldx
, x
);
542 /* Convert a mem ref into one with a valid memory address.
543 Pass through anything else unchanged. */
546 validize_mem (rtx ref
)
550 ref
= use_anchored_address (ref
);
551 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
552 MEM_ADDR_SPACE (ref
)))
555 /* Don't alter REF itself, since that is probably a stack slot. */
556 return replace_equiv_address (ref
, XEXP (ref
, 0));
559 /* If X is a memory reference to a member of an object block, try rewriting
560 it to use an anchor instead. Return the new memory reference on success
561 and the old one on failure. */
564 use_anchored_address (rtx x
)
567 HOST_WIDE_INT offset
;
568 enum machine_mode mode
;
570 if (!flag_section_anchors
)
576 /* Split the address into a base and offset. */
579 if (GET_CODE (base
) == CONST
580 && GET_CODE (XEXP (base
, 0)) == PLUS
581 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
583 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
584 base
= XEXP (XEXP (base
, 0), 0);
587 /* Check whether BASE is suitable for anchors. */
588 if (GET_CODE (base
) != SYMBOL_REF
589 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
590 || SYMBOL_REF_ANCHOR_P (base
)
591 || SYMBOL_REF_BLOCK (base
) == NULL
592 || !targetm
.use_anchors_for_symbol_p (base
))
595 /* Decide where BASE is going to be. */
596 place_block_symbol (base
);
598 /* Get the anchor we need to use. */
599 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
600 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
601 SYMBOL_REF_TLS_MODEL (base
));
603 /* Work out the offset from the anchor. */
604 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
606 /* If we're going to run a CSE pass, force the anchor into a register.
607 We will then be able to reuse registers for several accesses, if the
608 target costs say that that's worthwhile. */
609 mode
= GET_MODE (base
);
610 if (!cse_not_expected
)
611 base
= force_reg (mode
, base
);
613 return replace_equiv_address (x
, plus_constant (mode
, base
, offset
));
616 /* Copy the value or contents of X to a new temp reg and return that reg. */
621 rtx temp
= gen_reg_rtx (GET_MODE (x
));
623 /* If not an operand, must be an address with PLUS and MULT so
624 do the computation. */
625 if (! general_operand (x
, VOIDmode
))
626 x
= force_operand (x
, temp
);
629 emit_move_insn (temp
, x
);
634 /* Like copy_to_reg but always give the new register mode Pmode
635 in case X is a constant. */
638 copy_addr_to_reg (rtx x
)
640 return copy_to_mode_reg (Pmode
, x
);
643 /* Like copy_to_reg but always give the new register mode MODE
644 in case X is a constant. */
647 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
649 rtx temp
= gen_reg_rtx (mode
);
651 /* If not an operand, must be an address with PLUS and MULT so
652 do the computation. */
653 if (! general_operand (x
, VOIDmode
))
654 x
= force_operand (x
, temp
);
656 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
658 emit_move_insn (temp
, x
);
662 /* Load X into a register if it is not already one.
663 Use mode MODE for the register.
664 X should be valid for mode MODE, but it may be a constant which
665 is valid for all integer modes; that's why caller must specify MODE.
667 The caller must not alter the value in the register we return,
668 since we mark it as a "constant" register. */
671 force_reg (enum machine_mode mode
, rtx x
)
678 if (general_operand (x
, mode
))
680 temp
= gen_reg_rtx (mode
);
681 insn
= emit_move_insn (temp
, x
);
685 temp
= force_operand (x
, NULL_RTX
);
687 insn
= get_last_insn ();
690 rtx temp2
= gen_reg_rtx (mode
);
691 insn
= emit_move_insn (temp2
, temp
);
696 /* Let optimizers know that TEMP's value never changes
697 and that X can be substituted for it. Don't get confused
698 if INSN set something else (such as a SUBREG of TEMP). */
700 && (set
= single_set (insn
)) != 0
701 && SET_DEST (set
) == temp
702 && ! rtx_equal_p (x
, SET_SRC (set
)))
703 set_unique_reg_note (insn
, REG_EQUAL
, x
);
705 /* Let optimizers know that TEMP is a pointer, and if so, the
706 known alignment of that pointer. */
709 if (GET_CODE (x
) == SYMBOL_REF
)
711 align
= BITS_PER_UNIT
;
712 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
713 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
715 else if (GET_CODE (x
) == LABEL_REF
)
716 align
= BITS_PER_UNIT
;
717 else if (GET_CODE (x
) == CONST
718 && GET_CODE (XEXP (x
, 0)) == PLUS
719 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
720 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
722 rtx s
= XEXP (XEXP (x
, 0), 0);
723 rtx c
= XEXP (XEXP (x
, 0), 1);
727 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
728 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
734 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
735 align
= MIN (sa
, ca
);
739 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
740 mark_reg_pointer (temp
, align
);
746 /* If X is a memory ref, copy its contents to a new temp reg and return
747 that reg. Otherwise, return X. */
750 force_not_mem (rtx x
)
754 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
757 temp
= gen_reg_rtx (GET_MODE (x
));
760 REG_POINTER (temp
) = 1;
762 emit_move_insn (temp
, x
);
766 /* Copy X to TARGET (if it's nonzero and a reg)
767 or to a new temp reg and return that reg.
768 MODE is the mode to use for X in case it is a constant. */
771 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
775 if (target
&& REG_P (target
))
778 temp
= gen_reg_rtx (mode
);
780 emit_move_insn (temp
, x
);
784 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
785 PUNSIGNEDP points to the signedness of the type and may be adjusted
786 to show what signedness to use on extension operations.
788 FOR_RETURN is nonzero if the caller is promoting the return value
789 of FNDECL, else it is for promoting args. */
792 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
793 const_tree funtype
, int for_return
)
795 /* Called without a type node for a libcall. */
796 if (type
== NULL_TREE
)
798 if (INTEGRAL_MODE_P (mode
))
799 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
806 switch (TREE_CODE (type
))
808 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
809 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
810 case POINTER_TYPE
: case REFERENCE_TYPE
:
811 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
818 /* Return the mode to use to store a scalar of TYPE and MODE.
819 PUNSIGNEDP points to the signedness of the type and may be adjusted
820 to show what signedness to use on extension operations. */
823 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
824 int *punsignedp ATTRIBUTE_UNUSED
)
831 /* For libcalls this is invoked without TYPE from the backends
832 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
834 if (type
== NULL_TREE
)
837 /* FIXME: this is the same logic that was there until GCC 4.4, but we
838 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
839 is not defined. The affected targets are M32C, S390, SPARC. */
841 code
= TREE_CODE (type
);
842 unsignedp
= *punsignedp
;
846 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
847 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
848 PROMOTE_MODE (mode
, unsignedp
, type
);
849 *punsignedp
= unsignedp
;
853 #ifdef POINTERS_EXTEND_UNSIGNED
856 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
857 return targetm
.addr_space
.address_mode
858 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
871 /* Use one of promote_mode or promote_function_mode to find the promoted
872 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
873 of DECL after promotion. */
876 promote_decl_mode (const_tree decl
, int *punsignedp
)
878 tree type
= TREE_TYPE (decl
);
879 int unsignedp
= TYPE_UNSIGNED (type
);
880 enum machine_mode mode
= DECL_MODE (decl
);
881 enum machine_mode pmode
;
883 if (TREE_CODE (decl
) == RESULT_DECL
884 || TREE_CODE (decl
) == PARM_DECL
)
885 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
886 TREE_TYPE (current_function_decl
), 2);
888 pmode
= promote_mode (type
, mode
, &unsignedp
);
891 *punsignedp
= unsignedp
;
896 /* Controls the behaviour of {anti_,}adjust_stack. */
897 static bool suppress_reg_args_size
;
899 /* A helper for adjust_stack and anti_adjust_stack. */
902 adjust_stack_1 (rtx adjust
, bool anti_p
)
906 #ifndef STACK_GROWS_DOWNWARD
907 /* Hereafter anti_p means subtract_p. */
911 temp
= expand_binop (Pmode
,
912 anti_p
? sub_optab
: add_optab
,
913 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
916 if (temp
!= stack_pointer_rtx
)
917 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
920 insn
= get_last_insn ();
921 temp
= single_set (insn
);
922 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
925 if (!suppress_reg_args_size
)
926 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
929 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
930 This pops when ADJUST is positive. ADJUST need not be constant. */
933 adjust_stack (rtx adjust
)
935 if (adjust
== const0_rtx
)
938 /* We expect all variable sized adjustments to be multiple of
939 PREFERRED_STACK_BOUNDARY. */
940 if (CONST_INT_P (adjust
))
941 stack_pointer_delta
-= INTVAL (adjust
);
943 adjust_stack_1 (adjust
, false);
946 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
947 This pushes when ADJUST is positive. ADJUST need not be constant. */
950 anti_adjust_stack (rtx adjust
)
952 if (adjust
== const0_rtx
)
955 /* We expect all variable sized adjustments to be multiple of
956 PREFERRED_STACK_BOUNDARY. */
957 if (CONST_INT_P (adjust
))
958 stack_pointer_delta
+= INTVAL (adjust
);
960 adjust_stack_1 (adjust
, true);
963 /* Round the size of a block to be pushed up to the boundary required
964 by this machine. SIZE is the desired size, which need not be constant. */
967 round_push (rtx size
)
969 rtx align_rtx
, alignm1_rtx
;
971 if (!SUPPORTS_STACK_ALIGNMENT
972 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
974 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
979 if (CONST_INT_P (size
))
981 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
983 if (INTVAL (size
) != new_size
)
984 size
= GEN_INT (new_size
);
988 align_rtx
= GEN_INT (align
);
989 alignm1_rtx
= GEN_INT (align
- 1);
993 /* If crtl->preferred_stack_boundary might still grow, use
994 virtual_preferred_stack_boundary_rtx instead. This will be
995 substituted by the right value in vregs pass and optimized
997 align_rtx
= virtual_preferred_stack_boundary_rtx
;
998 alignm1_rtx
= force_operand (plus_constant (Pmode
, align_rtx
, -1),
1002 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1003 but we know it can't. So add ourselves and then do
1005 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
1006 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1007 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
1009 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
1014 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1015 to a previously-created save area. If no save area has been allocated,
1016 this function will allocate one. If a save area is specified, it
1017 must be of the proper mode. */
1020 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1023 /* The default is that we use a move insn and save in a Pmode object. */
1024 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1025 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1027 /* See if this machine has anything special to do for this kind of save. */
1030 #ifdef HAVE_save_stack_block
1032 if (HAVE_save_stack_block
)
1033 fcn
= gen_save_stack_block
;
1036 #ifdef HAVE_save_stack_function
1038 if (HAVE_save_stack_function
)
1039 fcn
= gen_save_stack_function
;
1042 #ifdef HAVE_save_stack_nonlocal
1044 if (HAVE_save_stack_nonlocal
)
1045 fcn
= gen_save_stack_nonlocal
;
1052 /* If there is no save area and we have to allocate one, do so. Otherwise
1053 verify the save area is the proper mode. */
1057 if (mode
!= VOIDmode
)
1059 if (save_level
== SAVE_NONLOCAL
)
1060 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1062 *psave
= sa
= gen_reg_rtx (mode
);
1066 do_pending_stack_adjust ();
1068 sa
= validize_mem (sa
);
1069 emit_insn (fcn (sa
, stack_pointer_rtx
));
1072 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1073 area made by emit_stack_save. If it is zero, we have nothing to do. */
1076 emit_stack_restore (enum save_level save_level
, rtx sa
)
1078 /* The default is that we use a move insn. */
1079 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1081 /* If stack_realign_drap, the x86 backend emits a prologue that aligns both
1082 STACK_POINTER and HARD_FRAME_POINTER.
1083 If stack_realign_fp, the x86 backend emits a prologue that aligns only
1084 STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing
1085 aligned variables, which is reflected in ix86_can_eliminate.
1086 We normally still have the realigned STACK_POINTER that we can use.
1087 But if there is a stack restore still present at reload, it can trigger
1088 mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate
1089 FRAME_POINTER into a hard reg.
1090 To prevent this situation, we force need_drap if we emit a stack
1092 if (SUPPORTS_STACK_ALIGNMENT
)
1093 crtl
->need_drap
= true;
1095 /* See if this machine has anything special to do for this kind of save. */
1098 #ifdef HAVE_restore_stack_block
1100 if (HAVE_restore_stack_block
)
1101 fcn
= gen_restore_stack_block
;
1104 #ifdef HAVE_restore_stack_function
1106 if (HAVE_restore_stack_function
)
1107 fcn
= gen_restore_stack_function
;
1110 #ifdef HAVE_restore_stack_nonlocal
1112 if (HAVE_restore_stack_nonlocal
)
1113 fcn
= gen_restore_stack_nonlocal
;
1122 sa
= validize_mem (sa
);
1123 /* These clobbers prevent the scheduler from moving
1124 references to variable arrays below the code
1125 that deletes (pops) the arrays. */
1126 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1127 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1130 discard_pending_stack_adjust ();
1132 emit_insn (fcn (stack_pointer_rtx
, sa
));
1135 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1136 function. This function should be called whenever we allocate or
1137 deallocate dynamic stack space. */
1140 update_nonlocal_goto_save_area (void)
1145 /* The nonlocal_goto_save_area object is an array of N pointers. The
1146 first one is used for the frame pointer save; the rest are sized by
1147 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1148 of the stack save area slots. */
1149 t_save
= build4 (ARRAY_REF
,
1150 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1151 cfun
->nonlocal_goto_save_area
,
1152 integer_one_node
, NULL_TREE
, NULL_TREE
);
1153 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1155 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1158 /* Return an rtx representing the address of an area of memory dynamically
1159 pushed on the stack.
1161 Any required stack pointer alignment is preserved.
1163 SIZE is an rtx representing the size of the area.
1165 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1166 parameter may be zero. If so, a proper value will be extracted
1167 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1169 REQUIRED_ALIGN is the alignment (in bits) required for the region
1172 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1173 stack space allocated by the generated code cannot be added with itself
1174 in the course of the execution of the function. It is always safe to
1175 pass FALSE here and the following criterion is sufficient in order to
1176 pass TRUE: every path in the CFG that starts at the allocation point and
1177 loops to it executes the associated deallocation code. */
1180 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1181 unsigned required_align
, bool cannot_accumulate
)
1183 HOST_WIDE_INT stack_usage_size
= -1;
1184 rtx final_label
, final_target
, target
;
1185 unsigned extra_align
= 0;
1188 /* If we're asking for zero bytes, it doesn't matter what we point
1189 to since we can't dereference it. But return a reasonable
1191 if (size
== const0_rtx
)
1192 return virtual_stack_dynamic_rtx
;
1194 /* Otherwise, show we're calling alloca or equivalent. */
1195 cfun
->calls_alloca
= 1;
1197 /* If stack usage info is requested, look into the size we are passed.
1198 We need to do so this early to avoid the obfuscation that may be
1199 introduced later by the various alignment operations. */
1200 if (flag_stack_usage_info
)
1202 if (CONST_INT_P (size
))
1203 stack_usage_size
= INTVAL (size
);
1204 else if (REG_P (size
))
1206 /* Look into the last emitted insn and see if we can deduce
1207 something for the register. */
1208 rtx insn
, set
, note
;
1209 insn
= get_last_insn ();
1210 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1212 if (CONST_INT_P (SET_SRC (set
)))
1213 stack_usage_size
= INTVAL (SET_SRC (set
));
1214 else if ((note
= find_reg_equal_equiv_note (insn
))
1215 && CONST_INT_P (XEXP (note
, 0)))
1216 stack_usage_size
= INTVAL (XEXP (note
, 0));
1220 /* If the size is not constant, we can't say anything. */
1221 if (stack_usage_size
== -1)
1223 current_function_has_unbounded_dynamic_stack_size
= 1;
1224 stack_usage_size
= 0;
1228 /* Ensure the size is in the proper mode. */
1229 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1230 size
= convert_to_mode (Pmode
, size
, 1);
1232 /* Adjust SIZE_ALIGN, if needed. */
1233 if (CONST_INT_P (size
))
1235 unsigned HOST_WIDE_INT lsb
;
1237 lsb
= INTVAL (size
);
1240 /* Watch out for overflow truncating to "unsigned". */
1241 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1242 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1244 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1246 else if (size_align
< BITS_PER_UNIT
)
1247 size_align
= BITS_PER_UNIT
;
1249 /* We can't attempt to minimize alignment necessary, because we don't
1250 know the final value of preferred_stack_boundary yet while executing
1252 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1253 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1255 /* We will need to ensure that the address we return is aligned to
1256 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1257 always know its final value at this point in the compilation (it
1258 might depend on the size of the outgoing parameter lists, for
1259 example), so we must align the value to be returned in that case.
1260 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1261 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1262 We must also do an alignment operation on the returned value if
1263 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1265 If we have to align, we must leave space in SIZE for the hole
1266 that might result from the alignment operation. */
1268 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1271 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1272 extra_align
= PREFERRED_STACK_BOUNDARY
;
1273 else if (required_align
> STACK_BOUNDARY
)
1274 extra_align
= STACK_BOUNDARY
;
1276 extra_align
= BITS_PER_UNIT
;
1279 /* ??? STACK_POINTER_OFFSET is always defined now. */
1280 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1282 extra_align
= BITS_PER_UNIT
;
1287 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1289 size
= plus_constant (Pmode
, size
, extra
);
1290 size
= force_operand (size
, NULL_RTX
);
1292 if (flag_stack_usage_info
)
1293 stack_usage_size
+= extra
;
1295 if (extra
&& size_align
> extra_align
)
1296 size_align
= extra_align
;
1299 /* Round the size to a multiple of the required stack alignment.
1300 Since the stack if presumed to be rounded before this allocation,
1301 this will maintain the required alignment.
1303 If the stack grows downward, we could save an insn by subtracting
1304 SIZE from the stack pointer and then aligning the stack pointer.
1305 The problem with this is that the stack pointer may be unaligned
1306 between the execution of the subtraction and alignment insns and
1307 some machines do not allow this. Even on those that do, some
1308 signal handlers malfunction if a signal should occur between those
1309 insns. Since this is an extremely rare event, we have no reliable
1310 way of knowing which systems have this problem. So we avoid even
1311 momentarily mis-aligning the stack. */
1312 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1314 size
= round_push (size
);
1316 if (flag_stack_usage_info
)
1318 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1319 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1323 target
= gen_reg_rtx (Pmode
);
1325 /* The size is supposed to be fully adjusted at this point so record it
1326 if stack usage info is requested. */
1327 if (flag_stack_usage_info
)
1329 current_function_dynamic_stack_size
+= stack_usage_size
;
1331 /* ??? This is gross but the only safe stance in the absence
1332 of stack usage oriented flow analysis. */
1333 if (!cannot_accumulate
)
1334 current_function_has_unbounded_dynamic_stack_size
= 1;
1337 final_label
= NULL_RTX
;
1338 final_target
= NULL_RTX
;
1340 /* If we are splitting the stack, we need to ask the backend whether
1341 there is enough room on the current stack. If there isn't, or if
1342 the backend doesn't know how to tell is, then we need to call a
1343 function to allocate memory in some other way. This memory will
1344 be released when we release the current stack segment. The
1345 effect is that stack allocation becomes less efficient, but at
1346 least it doesn't cause a stack overflow. */
1347 if (flag_split_stack
)
1349 rtx available_label
, ask
, space
, func
;
1351 available_label
= NULL_RTX
;
1353 #ifdef HAVE_split_stack_space_check
1354 if (HAVE_split_stack_space_check
)
1356 available_label
= gen_label_rtx ();
1358 /* This instruction will branch to AVAILABLE_LABEL if there
1359 are SIZE bytes available on the stack. */
1360 emit_insn (gen_split_stack_space_check (size
, available_label
));
1364 /* The __morestack_allocate_stack_space function will allocate
1365 memory using malloc. If the alignment of the memory returned
1366 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1367 make sure we allocate enough space. */
1368 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1372 ask
= expand_binop (Pmode
, add_optab
, size
,
1373 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1375 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1379 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1381 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1384 if (available_label
== NULL_RTX
)
1387 final_target
= gen_reg_rtx (Pmode
);
1389 emit_move_insn (final_target
, space
);
1391 final_label
= gen_label_rtx ();
1392 emit_jump (final_label
);
1394 emit_label (available_label
);
1397 do_pending_stack_adjust ();
1399 /* We ought to be called always on the toplevel and stack ought to be aligned
1401 gcc_assert (!(stack_pointer_delta
1402 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1404 /* If needed, check that we have the required amount of stack. Take into
1405 account what has already been checked. */
1406 if (STACK_CHECK_MOVING_SP
)
1408 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1409 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1411 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1412 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1414 /* Don't let anti_adjust_stack emit notes. */
1415 suppress_reg_args_size
= true;
1417 /* Perform the required allocation from the stack. Some systems do
1418 this differently than simply incrementing/decrementing from the
1419 stack pointer, such as acquiring the space by calling malloc(). */
1420 #ifdef HAVE_allocate_stack
1421 if (HAVE_allocate_stack
)
1423 struct expand_operand ops
[2];
1424 /* We don't have to check against the predicate for operand 0 since
1425 TARGET is known to be a pseudo of the proper mode, which must
1426 be valid for the operand. */
1427 create_fixed_operand (&ops
[0], target
);
1428 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1429 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1434 int saved_stack_pointer_delta
;
1436 #ifndef STACK_GROWS_DOWNWARD
1437 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1440 /* Check stack bounds if necessary. */
1441 if (crtl
->limit_stack
)
1444 rtx space_available
= gen_label_rtx ();
1445 #ifdef STACK_GROWS_DOWNWARD
1446 available
= expand_binop (Pmode
, sub_optab
,
1447 stack_pointer_rtx
, stack_limit_rtx
,
1448 NULL_RTX
, 1, OPTAB_WIDEN
);
1450 available
= expand_binop (Pmode
, sub_optab
,
1451 stack_limit_rtx
, stack_pointer_rtx
,
1452 NULL_RTX
, 1, OPTAB_WIDEN
);
1454 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1458 emit_insn (gen_trap ());
1461 error ("stack limits not supported on this target");
1463 emit_label (space_available
);
1466 saved_stack_pointer_delta
= stack_pointer_delta
;
1468 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1469 anti_adjust_stack_and_probe (size
, false);
1471 anti_adjust_stack (size
);
1473 /* Even if size is constant, don't modify stack_pointer_delta.
1474 The constant size alloca should preserve
1475 crtl->preferred_stack_boundary alignment. */
1476 stack_pointer_delta
= saved_stack_pointer_delta
;
1478 #ifdef STACK_GROWS_DOWNWARD
1479 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1483 suppress_reg_args_size
= false;
1485 /* Finish up the split stack handling. */
1486 if (final_label
!= NULL_RTX
)
1488 gcc_assert (flag_split_stack
);
1489 emit_move_insn (final_target
, target
);
1490 emit_label (final_label
);
1491 target
= final_target
;
1496 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1497 but we know it can't. So add ourselves and then do
1499 target
= expand_binop (Pmode
, add_optab
, target
,
1500 gen_int_mode (required_align
/ BITS_PER_UNIT
- 1,
1502 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1503 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1504 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1507 target
= expand_mult (Pmode
, target
,
1508 gen_int_mode (required_align
/ BITS_PER_UNIT
,
1513 /* Now that we've committed to a return value, mark its alignment. */
1514 mark_reg_pointer (target
, required_align
);
1516 /* Record the new stack level for nonlocal gotos. */
1517 if (cfun
->nonlocal_goto_save_area
!= 0)
1518 update_nonlocal_goto_save_area ();
1523 /* A front end may want to override GCC's stack checking by providing a
1524 run-time routine to call to check the stack, so provide a mechanism for
1525 calling that routine. */
1527 static GTY(()) rtx stack_check_libfunc
;
1530 set_stack_check_libfunc (const char *libfunc_name
)
1532 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1533 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1536 /* Emit one stack probe at ADDRESS, an address within the stack. */
1539 emit_stack_probe (rtx address
)
1541 #ifdef HAVE_probe_stack_address
1542 if (HAVE_probe_stack_address
)
1543 emit_insn (gen_probe_stack_address (address
));
1547 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1549 MEM_VOLATILE_P (memref
) = 1;
1551 /* See if we have an insn to probe the stack. */
1552 #ifdef HAVE_probe_stack
1553 if (HAVE_probe_stack
)
1554 emit_insn (gen_probe_stack (memref
));
1557 emit_move_insn (memref
, const0_rtx
);
1561 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1562 FIRST is a constant and size is a Pmode RTX. These are offsets from
1563 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1564 or subtract them from the stack pointer. */
1566 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1568 #ifdef STACK_GROWS_DOWNWARD
1569 #define STACK_GROW_OP MINUS
1570 #define STACK_GROW_OPTAB sub_optab
1571 #define STACK_GROW_OFF(off) -(off)
1573 #define STACK_GROW_OP PLUS
1574 #define STACK_GROW_OPTAB add_optab
1575 #define STACK_GROW_OFF(off) (off)
1579 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1581 /* First ensure SIZE is Pmode. */
1582 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1583 size
= convert_to_mode (Pmode
, size
, 1);
1585 /* Next see if we have a function to check the stack. */
1586 if (stack_check_libfunc
)
1588 rtx addr
= memory_address (Pmode
,
1589 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1591 plus_constant (Pmode
,
1593 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1597 /* Next see if we have an insn to check the stack. */
1598 #ifdef HAVE_check_stack
1599 else if (HAVE_check_stack
)
1601 struct expand_operand ops
[1];
1602 rtx addr
= memory_address (Pmode
,
1603 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1605 plus_constant (Pmode
,
1608 create_input_operand (&ops
[0], addr
, Pmode
);
1609 success
= maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
);
1610 gcc_assert (success
);
1614 /* Otherwise we have to generate explicit probes. If we have a constant
1615 small number of them to generate, that's the easy case. */
1616 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1618 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1621 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1622 it exceeds SIZE. If only one probe is needed, this will not
1623 generate any code. Then probe at FIRST + SIZE. */
1624 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1626 addr
= memory_address (Pmode
,
1627 plus_constant (Pmode
, stack_pointer_rtx
,
1628 STACK_GROW_OFF (first
+ i
)));
1629 emit_stack_probe (addr
);
1632 addr
= memory_address (Pmode
,
1633 plus_constant (Pmode
, stack_pointer_rtx
,
1634 STACK_GROW_OFF (first
+ isize
)));
1635 emit_stack_probe (addr
);
1638 /* In the variable case, do the same as above, but in a loop. Note that we
1639 must be extra careful with variables wrapping around because we might be
1640 at the very top (or the very bottom) of the address space and we have to
1641 be able to handle this case properly; in particular, we use an equality
1642 test for the loop condition. */
1645 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1646 rtx loop_lab
= gen_label_rtx ();
1647 rtx end_lab
= gen_label_rtx ();
1650 /* Step 1: round SIZE to the previous multiple of the interval. */
1652 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1654 = simplify_gen_binary (AND
, Pmode
, size
,
1655 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1656 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1659 /* Step 2: compute initial and final value of the loop counter. */
1661 /* TEST_ADDR = SP + FIRST. */
1662 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1664 gen_int_mode (first
, Pmode
)),
1667 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1668 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1670 rounded_size_op
), NULL_RTX
);
1675 while (TEST_ADDR != LAST_ADDR)
1677 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1681 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1682 until it is equal to ROUNDED_SIZE. */
1684 emit_label (loop_lab
);
1686 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1687 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1690 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1691 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1692 gen_int_mode (PROBE_INTERVAL
, Pmode
), test_addr
,
1695 gcc_assert (temp
== test_addr
);
1697 /* Probe at TEST_ADDR. */
1698 emit_stack_probe (test_addr
);
1700 emit_jump (loop_lab
);
1702 emit_label (end_lab
);
1705 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1706 that SIZE is equal to ROUNDED_SIZE. */
1708 /* TEMP = SIZE - ROUNDED_SIZE. */
1709 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1710 if (temp
!= const0_rtx
)
1714 if (CONST_INT_P (temp
))
1716 /* Use [base + disp} addressing mode if supported. */
1717 HOST_WIDE_INT offset
= INTVAL (temp
);
1718 addr
= memory_address (Pmode
,
1719 plus_constant (Pmode
, last_addr
,
1720 STACK_GROW_OFF (offset
)));
1724 /* Manual CSE if the difference is not known at compile-time. */
1725 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1726 addr
= memory_address (Pmode
,
1727 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1731 emit_stack_probe (addr
);
1735 /* Make sure nothing is scheduled before we are done. */
1736 emit_insn (gen_blockage ());
1739 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1740 while probing it. This pushes when SIZE is positive. SIZE need not
1741 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1742 by plus SIZE at the end. */
1745 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1747 /* We skip the probe for the first interval + a small dope of 4 words and
1748 probe that many bytes past the specified size to maintain a protection
1749 area at the botton of the stack. */
1750 const int dope
= 4 * UNITS_PER_WORD
;
1752 /* First ensure SIZE is Pmode. */
1753 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1754 size
= convert_to_mode (Pmode
, size
, 1);
1756 /* If we have a constant small number of probes to generate, that's the
1758 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1760 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1761 bool first_probe
= true;
1763 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1764 values of N from 1 until it exceeds SIZE. If only one probe is
1765 needed, this will not generate any code. Then adjust and probe
1766 to PROBE_INTERVAL + SIZE. */
1767 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1771 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1772 first_probe
= false;
1775 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1776 emit_stack_probe (stack_pointer_rtx
);
1780 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1782 anti_adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
- i
));
1783 emit_stack_probe (stack_pointer_rtx
);
1786 /* In the variable case, do the same as above, but in a loop. Note that we
1787 must be extra careful with variables wrapping around because we might be
1788 at the very top (or the very bottom) of the address space and we have to
1789 be able to handle this case properly; in particular, we use an equality
1790 test for the loop condition. */
1793 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1794 rtx loop_lab
= gen_label_rtx ();
1795 rtx end_lab
= gen_label_rtx ();
1798 /* Step 1: round SIZE to the previous multiple of the interval. */
1800 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1802 = simplify_gen_binary (AND
, Pmode
, size
,
1803 gen_int_mode (-PROBE_INTERVAL
, Pmode
));
1804 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1807 /* Step 2: compute initial and final value of the loop counter. */
1809 /* SP = SP_0 + PROBE_INTERVAL. */
1810 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1812 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1813 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1815 rounded_size_op
), NULL_RTX
);
1820 while (SP != LAST_ADDR)
1822 SP = SP + PROBE_INTERVAL
1826 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1827 values of N from 1 until it is equal to ROUNDED_SIZE. */
1829 emit_label (loop_lab
);
1831 /* Jump to END_LAB if SP == LAST_ADDR. */
1832 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1835 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1836 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1837 emit_stack_probe (stack_pointer_rtx
);
1839 emit_jump (loop_lab
);
1841 emit_label (end_lab
);
1844 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1845 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1847 /* TEMP = SIZE - ROUNDED_SIZE. */
1848 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1849 if (temp
!= const0_rtx
)
1851 /* Manual CSE if the difference is not known at compile-time. */
1852 if (GET_CODE (temp
) != CONST_INT
)
1853 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1854 anti_adjust_stack (temp
);
1855 emit_stack_probe (stack_pointer_rtx
);
1859 /* Adjust back and account for the additional first interval. */
1861 adjust_stack (plus_constant (Pmode
, size
, PROBE_INTERVAL
+ dope
));
1863 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1866 /* Return an rtx representing the register or memory location
1867 in which a scalar value of data type VALTYPE
1868 was returned by a function call to function FUNC.
1869 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1870 function is known, otherwise 0.
1871 OUTGOING is 1 if on a machine with register windows this function
1872 should return the register in which the function will put its result
1876 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1877 int outgoing ATTRIBUTE_UNUSED
)
1881 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1884 && GET_MODE (val
) == BLKmode
)
1886 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1887 enum machine_mode tmpmode
;
1889 /* int_size_in_bytes can return -1. We don't need a check here
1890 since the value of bytes will then be large enough that no
1891 mode will match anyway. */
1893 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1894 tmpmode
!= VOIDmode
;
1895 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1897 /* Have we found a large enough mode? */
1898 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1902 /* No suitable mode found. */
1903 gcc_assert (tmpmode
!= VOIDmode
);
1905 PUT_MODE (val
, tmpmode
);
1910 /* Return an rtx representing the register or memory location
1911 in which a scalar value of mode MODE was returned by a library call. */
1914 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1916 return targetm
.calls
.libcall_value (mode
, fun
);
1919 /* Look up the tree code for a given rtx code
1920 to provide the arithmetic operation for REAL_ARITHMETIC.
1921 The function returns an int because the caller may not know
1922 what `enum tree_code' means. */
1925 rtx_to_tree_code (enum rtx_code code
)
1927 enum tree_code tcode
;
1950 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1953 return ((int) tcode
);
1956 #include "gt-explow.h"