1 /* SCC value numbering for trees
2 Copyright (C) 2006-2016 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
28 #include "alloc-pool.h"
31 #include "insn-config.h"
34 #include "gimple-pretty-print.h"
36 #include "fold-const.h"
37 #include "stor-layout.h"
39 #include "tree-inline.h"
40 #include "internal-fn.h"
41 #include "gimple-fold.h"
56 #include "tree-ssa-propagate.h"
57 #include "tree-ssa-sccvn.h"
60 #include "gimple-iterator.h"
61 #include "gimple-match.h"
63 /* This algorithm is based on the SCC algorithm presented by Keith
64 Cooper and L. Taylor Simpson in "SCC-Based Value numbering"
65 (http://citeseer.ist.psu.edu/41805.html). In
66 straight line code, it is equivalent to a regular hash based value
67 numbering that is performed in reverse postorder.
69 For code with cycles, there are two alternatives, both of which
70 require keeping the hashtables separate from the actual list of
71 value numbers for SSA names.
73 1. Iterate value numbering in an RPO walk of the blocks, removing
74 all the entries from the hashtable after each iteration (but
75 keeping the SSA name->value number mapping between iterations).
76 Iterate until it does not change.
78 2. Perform value numbering as part of an SCC walk on the SSA graph,
79 iterating only the cycles in the SSA graph until they do not change
80 (using a separate, optimistic hashtable for value numbering the SCC
83 The second is not just faster in practice (because most SSA graph
84 cycles do not involve all the variables in the graph), it also has
87 One of these nice properties is that when we pop an SCC off the
88 stack, we are guaranteed to have processed all the operands coming from
89 *outside of that SCC*, so we do not need to do anything special to
90 ensure they have value numbers.
92 Another nice property is that the SCC walk is done as part of a DFS
93 of the SSA graph, which makes it easy to perform combining and
94 simplifying operations at the same time.
96 The code below is deliberately written in a way that makes it easy
97 to separate the SCC walk from the other work it does.
99 In order to propagate constants through the code, we track which
100 expressions contain constants, and use those while folding. In
101 theory, we could also track expressions whose value numbers are
102 replaced, in case we end up folding based on expression
105 In order to value number memory, we assign value numbers to vuses.
106 This enables us to note that, for example, stores to the same
107 address of the same value from the same starting memory states are
111 1. We can iterate only the changing portions of the SCC's, but
112 I have not seen an SCC big enough for this to be a win.
113 2. If you differentiate between phi nodes for loops and phi nodes
114 for if-then-else, you can properly consider phi nodes in different
115 blocks for equivalence.
116 3. We could value number vuses in more cases, particularly, whole
121 static tree
*last_vuse_ptr
;
122 static vn_lookup_kind vn_walk_kind
;
123 static vn_lookup_kind default_vn_walk_kind
;
126 /* vn_nary_op hashtable helpers. */
128 struct vn_nary_op_hasher
: nofree_ptr_hash
<vn_nary_op_s
>
130 typedef vn_nary_op_s
*compare_type
;
131 static inline hashval_t
hash (const vn_nary_op_s
*);
132 static inline bool equal (const vn_nary_op_s
*, const vn_nary_op_s
*);
135 /* Return the computed hashcode for nary operation P1. */
138 vn_nary_op_hasher::hash (const vn_nary_op_s
*vno1
)
140 return vno1
->hashcode
;
143 /* Compare nary operations P1 and P2 and return true if they are
147 vn_nary_op_hasher::equal (const vn_nary_op_s
*vno1
, const vn_nary_op_s
*vno2
)
149 return vn_nary_op_eq (vno1
, vno2
);
152 typedef hash_table
<vn_nary_op_hasher
> vn_nary_op_table_type
;
153 typedef vn_nary_op_table_type::iterator vn_nary_op_iterator_type
;
156 /* vn_phi hashtable helpers. */
159 vn_phi_eq (const_vn_phi_t
const vp1
, const_vn_phi_t
const vp2
);
161 struct vn_phi_hasher
: pointer_hash
<vn_phi_s
>
163 static inline hashval_t
hash (const vn_phi_s
*);
164 static inline bool equal (const vn_phi_s
*, const vn_phi_s
*);
165 static inline void remove (vn_phi_s
*);
168 /* Return the computed hashcode for phi operation P1. */
171 vn_phi_hasher::hash (const vn_phi_s
*vp1
)
173 return vp1
->hashcode
;
176 /* Compare two phi entries for equality, ignoring VN_TOP arguments. */
179 vn_phi_hasher::equal (const vn_phi_s
*vp1
, const vn_phi_s
*vp2
)
181 return vn_phi_eq (vp1
, vp2
);
184 /* Free a phi operation structure VP. */
187 vn_phi_hasher::remove (vn_phi_s
*phi
)
189 phi
->phiargs
.release ();
192 typedef hash_table
<vn_phi_hasher
> vn_phi_table_type
;
193 typedef vn_phi_table_type::iterator vn_phi_iterator_type
;
196 /* Compare two reference operands P1 and P2 for equality. Return true if
197 they are equal, and false otherwise. */
200 vn_reference_op_eq (const void *p1
, const void *p2
)
202 const_vn_reference_op_t
const vro1
= (const_vn_reference_op_t
) p1
;
203 const_vn_reference_op_t
const vro2
= (const_vn_reference_op_t
) p2
;
205 return (vro1
->opcode
== vro2
->opcode
206 /* We do not care for differences in type qualification. */
207 && (vro1
->type
== vro2
->type
208 || (vro1
->type
&& vro2
->type
209 && types_compatible_p (TYPE_MAIN_VARIANT (vro1
->type
),
210 TYPE_MAIN_VARIANT (vro2
->type
))))
211 && expressions_equal_p (vro1
->op0
, vro2
->op0
)
212 && expressions_equal_p (vro1
->op1
, vro2
->op1
)
213 && expressions_equal_p (vro1
->op2
, vro2
->op2
));
216 /* Free a reference operation structure VP. */
219 free_reference (vn_reference_s
*vr
)
221 vr
->operands
.release ();
225 /* vn_reference hashtable helpers. */
227 struct vn_reference_hasher
: pointer_hash
<vn_reference_s
>
229 static inline hashval_t
hash (const vn_reference_s
*);
230 static inline bool equal (const vn_reference_s
*, const vn_reference_s
*);
231 static inline void remove (vn_reference_s
*);
234 /* Return the hashcode for a given reference operation P1. */
237 vn_reference_hasher::hash (const vn_reference_s
*vr1
)
239 return vr1
->hashcode
;
243 vn_reference_hasher::equal (const vn_reference_s
*v
, const vn_reference_s
*c
)
245 return vn_reference_eq (v
, c
);
249 vn_reference_hasher::remove (vn_reference_s
*v
)
254 typedef hash_table
<vn_reference_hasher
> vn_reference_table_type
;
255 typedef vn_reference_table_type::iterator vn_reference_iterator_type
;
258 /* The set of hashtables and alloc_pool's for their items. */
260 typedef struct vn_tables_s
262 vn_nary_op_table_type
*nary
;
263 vn_phi_table_type
*phis
;
264 vn_reference_table_type
*references
;
265 struct obstack nary_obstack
;
266 object_allocator
<vn_phi_s
> *phis_pool
;
267 object_allocator
<vn_reference_s
> *references_pool
;
271 /* vn_constant hashtable helpers. */
273 struct vn_constant_hasher
: free_ptr_hash
<vn_constant_s
>
275 static inline hashval_t
hash (const vn_constant_s
*);
276 static inline bool equal (const vn_constant_s
*, const vn_constant_s
*);
279 /* Hash table hash function for vn_constant_t. */
282 vn_constant_hasher::hash (const vn_constant_s
*vc1
)
284 return vc1
->hashcode
;
287 /* Hash table equality function for vn_constant_t. */
290 vn_constant_hasher::equal (const vn_constant_s
*vc1
, const vn_constant_s
*vc2
)
292 if (vc1
->hashcode
!= vc2
->hashcode
)
295 return vn_constant_eq_with_type (vc1
->constant
, vc2
->constant
);
298 static hash_table
<vn_constant_hasher
> *constant_to_value_id
;
299 static bitmap constant_value_ids
;
302 /* Valid hashtables storing information we have proven to be
305 static vn_tables_t valid_info
;
307 /* Optimistic hashtables storing information we are making assumptions about
308 during iterations. */
310 static vn_tables_t optimistic_info
;
312 /* Pointer to the set of hashtables that is currently being used.
313 Should always point to either the optimistic_info, or the
316 static vn_tables_t current_info
;
319 /* Reverse post order index for each basic block. */
321 static int *rpo_numbers
;
323 #define SSA_VAL(x) (VN_INFO ((x))->valnum)
325 /* Return the SSA value of the VUSE x, supporting released VDEFs
326 during elimination which will value-number the VDEF to the
327 associated VUSE (but not substitute in the whole lattice). */
330 vuse_ssa_val (tree x
)
339 while (SSA_NAME_IN_FREE_LIST (x
));
344 /* This represents the top of the VN lattice, which is the universal
349 /* Unique counter for our value ids. */
351 static unsigned int next_value_id
;
353 /* Next DFS number and the stack for strongly connected component
356 static unsigned int next_dfs_num
;
357 static vec
<tree
> sccstack
;
361 /* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
362 are allocated on an obstack for locality reasons, and to free them
363 without looping over the vec. */
365 static vec
<vn_ssa_aux_t
> vn_ssa_aux_table
;
366 static struct obstack vn_ssa_aux_obstack
;
368 /* Return whether there is value numbering information for a given SSA name. */
371 has_VN_INFO (tree name
)
373 if (SSA_NAME_VERSION (name
) < vn_ssa_aux_table
.length ())
374 return vn_ssa_aux_table
[SSA_NAME_VERSION (name
)] != NULL
;
378 /* Return the value numbering information for a given SSA name. */
383 vn_ssa_aux_t res
= vn_ssa_aux_table
[SSA_NAME_VERSION (name
)];
384 gcc_checking_assert (res
);
388 /* Set the value numbering info for a given SSA name to a given
392 VN_INFO_SET (tree name
, vn_ssa_aux_t value
)
394 vn_ssa_aux_table
[SSA_NAME_VERSION (name
)] = value
;
397 /* Initialize the value numbering info for a given SSA name.
398 This should be called just once for every SSA name. */
401 VN_INFO_GET (tree name
)
403 vn_ssa_aux_t newinfo
;
405 gcc_assert (SSA_NAME_VERSION (name
) >= vn_ssa_aux_table
.length ()
406 || vn_ssa_aux_table
[SSA_NAME_VERSION (name
)] == NULL
);
407 newinfo
= XOBNEW (&vn_ssa_aux_obstack
, struct vn_ssa_aux
);
408 memset (newinfo
, 0, sizeof (struct vn_ssa_aux
));
409 if (SSA_NAME_VERSION (name
) >= vn_ssa_aux_table
.length ())
410 vn_ssa_aux_table
.safe_grow (SSA_NAME_VERSION (name
) + 1);
411 vn_ssa_aux_table
[SSA_NAME_VERSION (name
)] = newinfo
;
416 /* Return the vn_kind the expression computed by the stmt should be
420 vn_get_stmt_kind (gimple
*stmt
)
422 switch (gimple_code (stmt
))
430 enum tree_code code
= gimple_assign_rhs_code (stmt
);
431 tree rhs1
= gimple_assign_rhs1 (stmt
);
432 switch (get_gimple_rhs_class (code
))
434 case GIMPLE_UNARY_RHS
:
435 case GIMPLE_BINARY_RHS
:
436 case GIMPLE_TERNARY_RHS
:
438 case GIMPLE_SINGLE_RHS
:
439 switch (TREE_CODE_CLASS (code
))
442 /* VOP-less references can go through unary case. */
443 if ((code
== REALPART_EXPR
444 || code
== IMAGPART_EXPR
445 || code
== VIEW_CONVERT_EXPR
446 || code
== BIT_FIELD_REF
)
447 && TREE_CODE (TREE_OPERAND (rhs1
, 0)) == SSA_NAME
)
451 case tcc_declaration
:
458 if (code
== ADDR_EXPR
)
459 return (is_gimple_min_invariant (rhs1
)
460 ? VN_CONSTANT
: VN_REFERENCE
);
461 else if (code
== CONSTRUCTOR
)
474 /* Lookup a value id for CONSTANT and return it. If it does not
478 get_constant_value_id (tree constant
)
480 vn_constant_s
**slot
;
481 struct vn_constant_s vc
;
483 vc
.hashcode
= vn_hash_constant_with_type (constant
);
484 vc
.constant
= constant
;
485 slot
= constant_to_value_id
->find_slot (&vc
, NO_INSERT
);
487 return (*slot
)->value_id
;
491 /* Lookup a value id for CONSTANT, and if it does not exist, create a
492 new one and return it. If it does exist, return it. */
495 get_or_alloc_constant_value_id (tree constant
)
497 vn_constant_s
**slot
;
498 struct vn_constant_s vc
;
501 vc
.hashcode
= vn_hash_constant_with_type (constant
);
502 vc
.constant
= constant
;
503 slot
= constant_to_value_id
->find_slot (&vc
, INSERT
);
505 return (*slot
)->value_id
;
507 vcp
= XNEW (struct vn_constant_s
);
508 vcp
->hashcode
= vc
.hashcode
;
509 vcp
->constant
= constant
;
510 vcp
->value_id
= get_next_value_id ();
512 bitmap_set_bit (constant_value_ids
, vcp
->value_id
);
513 return vcp
->value_id
;
516 /* Return true if V is a value id for a constant. */
519 value_id_constant_p (unsigned int v
)
521 return bitmap_bit_p (constant_value_ids
, v
);
524 /* Compute the hash for a reference operand VRO1. */
527 vn_reference_op_compute_hash (const vn_reference_op_t vro1
, inchash::hash
&hstate
)
529 hstate
.add_int (vro1
->opcode
);
531 inchash::add_expr (vro1
->op0
, hstate
);
533 inchash::add_expr (vro1
->op1
, hstate
);
535 inchash::add_expr (vro1
->op2
, hstate
);
538 /* Compute a hash for the reference operation VR1 and return it. */
541 vn_reference_compute_hash (const vn_reference_t vr1
)
543 inchash::hash hstate
;
546 vn_reference_op_t vro
;
547 HOST_WIDE_INT off
= -1;
550 FOR_EACH_VEC_ELT (vr1
->operands
, i
, vro
)
552 if (vro
->opcode
== MEM_REF
)
554 else if (vro
->opcode
!= ADDR_EXPR
)
566 hstate
.add_int (off
);
569 && vro
->opcode
== ADDR_EXPR
)
573 tree op
= TREE_OPERAND (vro
->op0
, 0);
574 hstate
.add_int (TREE_CODE (op
));
575 inchash::add_expr (op
, hstate
);
579 vn_reference_op_compute_hash (vro
, hstate
);
582 result
= hstate
.end ();
583 /* ??? We would ICE later if we hash instead of adding that in. */
585 result
+= SSA_NAME_VERSION (vr1
->vuse
);
590 /* Return true if reference operations VR1 and VR2 are equivalent. This
591 means they have the same set of operands and vuses. */
594 vn_reference_eq (const_vn_reference_t
const vr1
, const_vn_reference_t
const vr2
)
598 /* Early out if this is not a hash collision. */
599 if (vr1
->hashcode
!= vr2
->hashcode
)
602 /* The VOP needs to be the same. */
603 if (vr1
->vuse
!= vr2
->vuse
)
606 /* If the operands are the same we are done. */
607 if (vr1
->operands
== vr2
->operands
)
610 if (!expressions_equal_p (TYPE_SIZE (vr1
->type
), TYPE_SIZE (vr2
->type
)))
613 if (INTEGRAL_TYPE_P (vr1
->type
)
614 && INTEGRAL_TYPE_P (vr2
->type
))
616 if (TYPE_PRECISION (vr1
->type
) != TYPE_PRECISION (vr2
->type
))
619 else if (INTEGRAL_TYPE_P (vr1
->type
)
620 && (TYPE_PRECISION (vr1
->type
)
621 != TREE_INT_CST_LOW (TYPE_SIZE (vr1
->type
))))
623 else if (INTEGRAL_TYPE_P (vr2
->type
)
624 && (TYPE_PRECISION (vr2
->type
)
625 != TREE_INT_CST_LOW (TYPE_SIZE (vr2
->type
))))
632 HOST_WIDE_INT off1
= 0, off2
= 0;
633 vn_reference_op_t vro1
, vro2
;
634 vn_reference_op_s tem1
, tem2
;
635 bool deref1
= false, deref2
= false;
636 for (; vr1
->operands
.iterate (i
, &vro1
); i
++)
638 if (vro1
->opcode
== MEM_REF
)
640 /* Do not look through a storage order barrier. */
641 else if (vro1
->opcode
== VIEW_CONVERT_EXPR
&& vro1
->reverse
)
647 for (; vr2
->operands
.iterate (j
, &vro2
); j
++)
649 if (vro2
->opcode
== MEM_REF
)
651 /* Do not look through a storage order barrier. */
652 else if (vro2
->opcode
== VIEW_CONVERT_EXPR
&& vro2
->reverse
)
660 if (deref1
&& vro1
->opcode
== ADDR_EXPR
)
662 memset (&tem1
, 0, sizeof (tem1
));
663 tem1
.op0
= TREE_OPERAND (vro1
->op0
, 0);
664 tem1
.type
= TREE_TYPE (tem1
.op0
);
665 tem1
.opcode
= TREE_CODE (tem1
.op0
);
669 if (deref2
&& vro2
->opcode
== ADDR_EXPR
)
671 memset (&tem2
, 0, sizeof (tem2
));
672 tem2
.op0
= TREE_OPERAND (vro2
->op0
, 0);
673 tem2
.type
= TREE_TYPE (tem2
.op0
);
674 tem2
.opcode
= TREE_CODE (tem2
.op0
);
678 if (deref1
!= deref2
)
680 if (!vn_reference_op_eq (vro1
, vro2
))
685 while (vr1
->operands
.length () != i
686 || vr2
->operands
.length () != j
);
691 /* Copy the operations present in load/store REF into RESULT, a vector of
692 vn_reference_op_s's. */
695 copy_reference_ops_from_ref (tree ref
, vec
<vn_reference_op_s
> *result
)
697 if (TREE_CODE (ref
) == TARGET_MEM_REF
)
699 vn_reference_op_s temp
;
703 memset (&temp
, 0, sizeof (temp
));
704 temp
.type
= TREE_TYPE (ref
);
705 temp
.opcode
= TREE_CODE (ref
);
706 temp
.op0
= TMR_INDEX (ref
);
707 temp
.op1
= TMR_STEP (ref
);
708 temp
.op2
= TMR_OFFSET (ref
);
710 temp
.clique
= MR_DEPENDENCE_CLIQUE (ref
);
711 temp
.base
= MR_DEPENDENCE_BASE (ref
);
712 result
->quick_push (temp
);
714 memset (&temp
, 0, sizeof (temp
));
715 temp
.type
= NULL_TREE
;
716 temp
.opcode
= ERROR_MARK
;
717 temp
.op0
= TMR_INDEX2 (ref
);
719 result
->quick_push (temp
);
721 memset (&temp
, 0, sizeof (temp
));
722 temp
.type
= NULL_TREE
;
723 temp
.opcode
= TREE_CODE (TMR_BASE (ref
));
724 temp
.op0
= TMR_BASE (ref
);
726 result
->quick_push (temp
);
730 /* For non-calls, store the information that makes up the address. */
734 vn_reference_op_s temp
;
736 memset (&temp
, 0, sizeof (temp
));
737 temp
.type
= TREE_TYPE (ref
);
738 temp
.opcode
= TREE_CODE (ref
);
744 temp
.op0
= TREE_OPERAND (ref
, 1);
747 temp
.op0
= TREE_OPERAND (ref
, 1);
751 /* The base address gets its own vn_reference_op_s structure. */
752 temp
.op0
= TREE_OPERAND (ref
, 1);
754 offset_int off
= mem_ref_offset (ref
);
755 if (wi::fits_shwi_p (off
))
756 temp
.off
= off
.to_shwi ();
758 temp
.clique
= MR_DEPENDENCE_CLIQUE (ref
);
759 temp
.base
= MR_DEPENDENCE_BASE (ref
);
760 temp
.reverse
= REF_REVERSE_STORAGE_ORDER (ref
);
763 /* Record bits, position and storage order. */
764 temp
.op0
= TREE_OPERAND (ref
, 1);
765 temp
.op1
= TREE_OPERAND (ref
, 2);
766 if (tree_fits_shwi_p (TREE_OPERAND (ref
, 2)))
768 HOST_WIDE_INT off
= tree_to_shwi (TREE_OPERAND (ref
, 2));
769 if (off
% BITS_PER_UNIT
== 0)
770 temp
.off
= off
/ BITS_PER_UNIT
;
772 temp
.reverse
= REF_REVERSE_STORAGE_ORDER (ref
);
775 /* The field decl is enough to unambiguously specify the field,
776 a matching type is not necessary and a mismatching type
777 is always a spurious difference. */
778 temp
.type
= NULL_TREE
;
779 temp
.op0
= TREE_OPERAND (ref
, 1);
780 temp
.op1
= TREE_OPERAND (ref
, 2);
782 tree this_offset
= component_ref_field_offset (ref
);
784 && TREE_CODE (this_offset
) == INTEGER_CST
)
786 tree bit_offset
= DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref
, 1));
787 if (TREE_INT_CST_LOW (bit_offset
) % BITS_PER_UNIT
== 0)
790 = (wi::to_offset (this_offset
)
791 + wi::lrshift (wi::to_offset (bit_offset
),
792 LOG2_BITS_PER_UNIT
));
793 if (wi::fits_shwi_p (off
)
794 /* Probibit value-numbering zero offset components
795 of addresses the same before the pass folding
796 __builtin_object_size had a chance to run
797 (checking cfun->after_inlining does the
799 && (TREE_CODE (orig
) != ADDR_EXPR
801 || cfun
->after_inlining
))
802 temp
.off
= off
.to_shwi ();
807 case ARRAY_RANGE_REF
:
809 /* Record index as operand. */
810 temp
.op0
= TREE_OPERAND (ref
, 1);
811 /* Always record lower bounds and element size. */
812 temp
.op1
= array_ref_low_bound (ref
);
813 temp
.op2
= array_ref_element_size (ref
);
814 if (TREE_CODE (temp
.op0
) == INTEGER_CST
815 && TREE_CODE (temp
.op1
) == INTEGER_CST
816 && TREE_CODE (temp
.op2
) == INTEGER_CST
)
818 offset_int off
= ((wi::to_offset (temp
.op0
)
819 - wi::to_offset (temp
.op1
))
820 * wi::to_offset (temp
.op2
));
821 if (wi::fits_shwi_p (off
))
822 temp
.off
= off
.to_shwi();
826 if (DECL_HARD_REGISTER (ref
))
835 /* Canonicalize decls to MEM[&decl] which is what we end up with
836 when valueizing MEM[ptr] with ptr = &decl. */
837 temp
.opcode
= MEM_REF
;
838 temp
.op0
= build_int_cst (build_pointer_type (TREE_TYPE (ref
)), 0);
840 result
->safe_push (temp
);
841 temp
.opcode
= ADDR_EXPR
;
842 temp
.op0
= build1 (ADDR_EXPR
, TREE_TYPE (temp
.op0
), ref
);
843 temp
.type
= TREE_TYPE (temp
.op0
);
857 if (is_gimple_min_invariant (ref
))
863 /* These are only interesting for their operands, their
864 existence, and their type. They will never be the last
865 ref in the chain of references (IE they require an
866 operand), so we don't have to put anything
867 for op* as it will be handled by the iteration */
871 case VIEW_CONVERT_EXPR
:
873 temp
.reverse
= storage_order_barrier_p (ref
);
876 /* This is only interesting for its constant offset. */
877 temp
.off
= TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (ref
)));
882 result
->safe_push (temp
);
884 if (REFERENCE_CLASS_P (ref
)
885 || TREE_CODE (ref
) == MODIFY_EXPR
886 || TREE_CODE (ref
) == WITH_SIZE_EXPR
887 || (TREE_CODE (ref
) == ADDR_EXPR
888 && !is_gimple_min_invariant (ref
)))
889 ref
= TREE_OPERAND (ref
, 0);
895 /* Build a alias-oracle reference abstraction in *REF from the vn_reference
896 operands in *OPS, the reference alias set SET and the reference type TYPE.
897 Return true if something useful was produced. */
900 ao_ref_init_from_vn_reference (ao_ref
*ref
,
901 alias_set_type set
, tree type
,
902 vec
<vn_reference_op_s
> ops
)
904 vn_reference_op_t op
;
906 tree base
= NULL_TREE
;
908 offset_int offset
= 0;
910 offset_int size
= -1;
911 tree size_tree
= NULL_TREE
;
912 alias_set_type base_alias_set
= -1;
914 /* First get the final access size from just the outermost expression. */
916 if (op
->opcode
== COMPONENT_REF
)
917 size_tree
= DECL_SIZE (op
->op0
);
918 else if (op
->opcode
== BIT_FIELD_REF
)
922 machine_mode mode
= TYPE_MODE (type
);
924 size_tree
= TYPE_SIZE (type
);
926 size
= int (GET_MODE_BITSIZE (mode
));
928 if (size_tree
!= NULL_TREE
929 && TREE_CODE (size_tree
) == INTEGER_CST
)
930 size
= wi::to_offset (size_tree
);
932 /* Initially, maxsize is the same as the accessed element size.
933 In the following it will only grow (or become -1). */
936 /* Compute cumulative bit-offset for nested component-refs and array-refs,
937 and find the ultimate containing object. */
938 FOR_EACH_VEC_ELT (ops
, i
, op
)
942 /* These may be in the reference ops, but we cannot do anything
943 sensible with them here. */
945 /* Apart from ADDR_EXPR arguments to MEM_REF. */
946 if (base
!= NULL_TREE
947 && TREE_CODE (base
) == MEM_REF
949 && DECL_P (TREE_OPERAND (op
->op0
, 0)))
951 vn_reference_op_t pop
= &ops
[i
-1];
952 base
= TREE_OPERAND (op
->op0
, 0);
959 offset
+= pop
->off
* BITS_PER_UNIT
;
967 /* Record the base objects. */
969 base_alias_set
= get_deref_alias_set (op
->op0
);
970 *op0_p
= build2 (MEM_REF
, op
->type
,
972 MR_DEPENDENCE_CLIQUE (*op0_p
) = op
->clique
;
973 MR_DEPENDENCE_BASE (*op0_p
) = op
->base
;
974 op0_p
= &TREE_OPERAND (*op0_p
, 0);
985 /* And now the usual component-reference style ops. */
987 offset
+= wi::to_offset (op
->op1
);
992 tree field
= op
->op0
;
993 /* We do not have a complete COMPONENT_REF tree here so we
994 cannot use component_ref_field_offset. Do the interesting
996 tree this_offset
= DECL_FIELD_OFFSET (field
);
998 if (op
->op1
|| TREE_CODE (this_offset
) != INTEGER_CST
)
1002 offset_int woffset
= wi::lshift (wi::to_offset (this_offset
),
1003 LOG2_BITS_PER_UNIT
);
1004 woffset
+= wi::to_offset (DECL_FIELD_BIT_OFFSET (field
));
1010 case ARRAY_RANGE_REF
:
1012 /* We recorded the lower bound and the element size. */
1013 if (TREE_CODE (op
->op0
) != INTEGER_CST
1014 || TREE_CODE (op
->op1
) != INTEGER_CST
1015 || TREE_CODE (op
->op2
) != INTEGER_CST
)
1020 = wi::sext (wi::to_offset (op
->op0
) - wi::to_offset (op
->op1
),
1021 TYPE_PRECISION (TREE_TYPE (op
->op0
)));
1022 woffset
*= wi::to_offset (op
->op2
);
1023 woffset
= wi::lshift (woffset
, LOG2_BITS_PER_UNIT
);
1035 case VIEW_CONVERT_EXPR
:
1052 if (base
== NULL_TREE
)
1055 ref
->ref
= NULL_TREE
;
1057 ref
->ref_alias_set
= set
;
1058 if (base_alias_set
!= -1)
1059 ref
->base_alias_set
= base_alias_set
;
1061 ref
->base_alias_set
= get_alias_set (base
);
1062 /* We discount volatiles from value-numbering elsewhere. */
1063 ref
->volatile_p
= false;
1065 if (!wi::fits_shwi_p (size
) || wi::neg_p (size
))
1073 ref
->size
= size
.to_shwi ();
1075 if (!wi::fits_shwi_p (offset
))
1082 ref
->offset
= offset
.to_shwi ();
1084 if (!wi::fits_shwi_p (max_size
) || wi::neg_p (max_size
))
1087 ref
->max_size
= max_size
.to_shwi ();
1092 /* Copy the operations present in load/store/call REF into RESULT, a vector of
1093 vn_reference_op_s's. */
1096 copy_reference_ops_from_call (gcall
*call
,
1097 vec
<vn_reference_op_s
> *result
)
1099 vn_reference_op_s temp
;
1101 tree lhs
= gimple_call_lhs (call
);
1104 /* If 2 calls have a different non-ssa lhs, vdef value numbers should be
1105 different. By adding the lhs here in the vector, we ensure that the
1106 hashcode is different, guaranteeing a different value number. */
1107 if (lhs
&& TREE_CODE (lhs
) != SSA_NAME
)
1109 memset (&temp
, 0, sizeof (temp
));
1110 temp
.opcode
= MODIFY_EXPR
;
1111 temp
.type
= TREE_TYPE (lhs
);
1114 result
->safe_push (temp
);
1117 /* Copy the type, opcode, function, static chain and EH region, if any. */
1118 memset (&temp
, 0, sizeof (temp
));
1119 temp
.type
= gimple_call_return_type (call
);
1120 temp
.opcode
= CALL_EXPR
;
1121 temp
.op0
= gimple_call_fn (call
);
1122 temp
.op1
= gimple_call_chain (call
);
1123 if (stmt_could_throw_p (call
) && (lr
= lookup_stmt_eh_lp (call
)) > 0)
1124 temp
.op2
= size_int (lr
);
1126 if (gimple_call_with_bounds_p (call
))
1127 temp
.with_bounds
= 1;
1128 result
->safe_push (temp
);
1130 /* Copy the call arguments. As they can be references as well,
1131 just chain them together. */
1132 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1134 tree callarg
= gimple_call_arg (call
, i
);
1135 copy_reference_ops_from_ref (callarg
, result
);
1139 /* Fold *& at position *I_P in a vn_reference_op_s vector *OPS. Updates
1140 *I_P to point to the last element of the replacement. */
1142 vn_reference_fold_indirect (vec
<vn_reference_op_s
> *ops
,
1145 unsigned int i
= *i_p
;
1146 vn_reference_op_t op
= &(*ops
)[i
];
1147 vn_reference_op_t mem_op
= &(*ops
)[i
- 1];
1149 HOST_WIDE_INT addr_offset
= 0;
1151 /* The only thing we have to do is from &OBJ.foo.bar add the offset
1152 from .foo.bar to the preceding MEM_REF offset and replace the
1153 address with &OBJ. */
1154 addr_base
= get_addr_base_and_unit_offset (TREE_OPERAND (op
->op0
, 0),
1156 gcc_checking_assert (addr_base
&& TREE_CODE (addr_base
) != MEM_REF
);
1157 if (addr_base
!= TREE_OPERAND (op
->op0
, 0))
1159 offset_int off
= offset_int::from (mem_op
->op0
, SIGNED
);
1161 mem_op
->op0
= wide_int_to_tree (TREE_TYPE (mem_op
->op0
), off
);
1162 op
->op0
= build_fold_addr_expr (addr_base
);
1163 if (tree_fits_shwi_p (mem_op
->op0
))
1164 mem_op
->off
= tree_to_shwi (mem_op
->op0
);
1172 /* Fold *& at position *I_P in a vn_reference_op_s vector *OPS. Updates
1173 *I_P to point to the last element of the replacement. */
1175 vn_reference_maybe_forwprop_address (vec
<vn_reference_op_s
> *ops
,
1178 unsigned int i
= *i_p
;
1179 vn_reference_op_t op
= &(*ops
)[i
];
1180 vn_reference_op_t mem_op
= &(*ops
)[i
- 1];
1182 enum tree_code code
;
1185 def_stmt
= SSA_NAME_DEF_STMT (op
->op0
);
1186 if (!is_gimple_assign (def_stmt
))
1189 code
= gimple_assign_rhs_code (def_stmt
);
1190 if (code
!= ADDR_EXPR
1191 && code
!= POINTER_PLUS_EXPR
)
1194 off
= offset_int::from (mem_op
->op0
, SIGNED
);
1196 /* The only thing we have to do is from &OBJ.foo.bar add the offset
1197 from .foo.bar to the preceding MEM_REF offset and replace the
1198 address with &OBJ. */
1199 if (code
== ADDR_EXPR
)
1201 tree addr
, addr_base
;
1202 HOST_WIDE_INT addr_offset
;
1204 addr
= gimple_assign_rhs1 (def_stmt
);
1205 addr_base
= get_addr_base_and_unit_offset (TREE_OPERAND (addr
, 0),
1207 /* If that didn't work because the address isn't invariant propagate
1208 the reference tree from the address operation in case the current
1209 dereference isn't offsetted. */
1211 && *i_p
== ops
->length () - 1
1213 /* This makes us disable this transform for PRE where the
1214 reference ops might be also used for code insertion which
1216 && default_vn_walk_kind
== VN_WALKREWRITE
)
1218 auto_vec
<vn_reference_op_s
, 32> tem
;
1219 copy_reference_ops_from_ref (TREE_OPERAND (addr
, 0), &tem
);
1222 ops
->safe_splice (tem
);
1227 || TREE_CODE (addr_base
) != MEM_REF
)
1231 off
+= mem_ref_offset (addr_base
);
1232 op
->op0
= TREE_OPERAND (addr_base
, 0);
1237 ptr
= gimple_assign_rhs1 (def_stmt
);
1238 ptroff
= gimple_assign_rhs2 (def_stmt
);
1239 if (TREE_CODE (ptr
) != SSA_NAME
1240 || TREE_CODE (ptroff
) != INTEGER_CST
)
1243 off
+= wi::to_offset (ptroff
);
1247 mem_op
->op0
= wide_int_to_tree (TREE_TYPE (mem_op
->op0
), off
);
1248 if (tree_fits_shwi_p (mem_op
->op0
))
1249 mem_op
->off
= tree_to_shwi (mem_op
->op0
);
1252 if (TREE_CODE (op
->op0
) == SSA_NAME
)
1253 op
->op0
= SSA_VAL (op
->op0
);
1254 if (TREE_CODE (op
->op0
) != SSA_NAME
)
1255 op
->opcode
= TREE_CODE (op
->op0
);
1258 if (TREE_CODE (op
->op0
) == SSA_NAME
)
1259 vn_reference_maybe_forwprop_address (ops
, i_p
);
1260 else if (TREE_CODE (op
->op0
) == ADDR_EXPR
)
1261 vn_reference_fold_indirect (ops
, i_p
);
1265 /* Optimize the reference REF to a constant if possible or return
1266 NULL_TREE if not. */
1269 fully_constant_vn_reference_p (vn_reference_t ref
)
1271 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1272 vn_reference_op_t op
;
1274 /* Try to simplify the translated expression if it is
1275 a call to a builtin function with at most two arguments. */
1277 if (op
->opcode
== CALL_EXPR
1278 && TREE_CODE (op
->op0
) == ADDR_EXPR
1279 && TREE_CODE (TREE_OPERAND (op
->op0
, 0)) == FUNCTION_DECL
1280 && DECL_BUILT_IN (TREE_OPERAND (op
->op0
, 0))
1281 && operands
.length () >= 2
1282 && operands
.length () <= 3)
1284 vn_reference_op_t arg0
, arg1
= NULL
;
1285 bool anyconst
= false;
1286 arg0
= &operands
[1];
1287 if (operands
.length () > 2)
1288 arg1
= &operands
[2];
1289 if (TREE_CODE_CLASS (arg0
->opcode
) == tcc_constant
1290 || (arg0
->opcode
== ADDR_EXPR
1291 && is_gimple_min_invariant (arg0
->op0
)))
1294 && (TREE_CODE_CLASS (arg1
->opcode
) == tcc_constant
1295 || (arg1
->opcode
== ADDR_EXPR
1296 && is_gimple_min_invariant (arg1
->op0
))))
1300 tree folded
= build_call_expr (TREE_OPERAND (op
->op0
, 0),
1303 arg1
? arg1
->op0
: NULL
);
1305 && TREE_CODE (folded
) == NOP_EXPR
)
1306 folded
= TREE_OPERAND (folded
, 0);
1308 && is_gimple_min_invariant (folded
))
1313 /* Simplify reads from constants or constant initializers. */
1314 else if (BITS_PER_UNIT
== 8
1315 && is_gimple_reg_type (ref
->type
)
1316 && (!INTEGRAL_TYPE_P (ref
->type
)
1317 || TYPE_PRECISION (ref
->type
) % BITS_PER_UNIT
== 0))
1319 HOST_WIDE_INT off
= 0;
1321 if (INTEGRAL_TYPE_P (ref
->type
))
1322 size
= TYPE_PRECISION (ref
->type
);
1324 size
= tree_to_shwi (TYPE_SIZE (ref
->type
));
1325 if (size
% BITS_PER_UNIT
!= 0
1326 || size
> MAX_BITSIZE_MODE_ANY_MODE
)
1328 size
/= BITS_PER_UNIT
;
1330 for (i
= 0; i
< operands
.length (); ++i
)
1332 if (operands
[i
].off
== -1)
1334 off
+= operands
[i
].off
;
1335 if (operands
[i
].opcode
== MEM_REF
)
1341 vn_reference_op_t base
= &operands
[--i
];
1342 tree ctor
= error_mark_node
;
1343 tree decl
= NULL_TREE
;
1344 if (TREE_CODE_CLASS (base
->opcode
) == tcc_constant
)
1346 else if (base
->opcode
== MEM_REF
1347 && base
[1].opcode
== ADDR_EXPR
1348 && (TREE_CODE (TREE_OPERAND (base
[1].op0
, 0)) == VAR_DECL
1349 || TREE_CODE (TREE_OPERAND (base
[1].op0
, 0)) == CONST_DECL
))
1351 decl
= TREE_OPERAND (base
[1].op0
, 0);
1352 ctor
= ctor_for_folding (decl
);
1354 if (ctor
== NULL_TREE
)
1355 return build_zero_cst (ref
->type
);
1356 else if (ctor
!= error_mark_node
)
1360 tree res
= fold_ctor_reference (ref
->type
, ctor
,
1361 off
* BITS_PER_UNIT
,
1362 size
* BITS_PER_UNIT
, decl
);
1365 STRIP_USELESS_TYPE_CONVERSION (res
);
1366 if (is_gimple_min_invariant (res
))
1372 unsigned char buf
[MAX_BITSIZE_MODE_ANY_MODE
/ BITS_PER_UNIT
];
1373 int len
= native_encode_expr (ctor
, buf
, size
, off
);
1375 return native_interpret_expr (ref
->type
, buf
, len
);
1383 /* Return true if OPS contain a storage order barrier. */
1386 contains_storage_order_barrier_p (vec
<vn_reference_op_s
> ops
)
1388 vn_reference_op_t op
;
1391 FOR_EACH_VEC_ELT (ops
, i
, op
)
1392 if (op
->opcode
== VIEW_CONVERT_EXPR
&& op
->reverse
)
1398 /* Transform any SSA_NAME's in a vector of vn_reference_op_s
1399 structures into their value numbers. This is done in-place, and
1400 the vector passed in is returned. *VALUEIZED_ANYTHING will specify
1401 whether any operands were valueized. */
1403 static vec
<vn_reference_op_s
>
1404 valueize_refs_1 (vec
<vn_reference_op_s
> orig
, bool *valueized_anything
)
1406 vn_reference_op_t vro
;
1409 *valueized_anything
= false;
1411 FOR_EACH_VEC_ELT (orig
, i
, vro
)
1413 if (vro
->opcode
== SSA_NAME
1414 || (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
))
1416 tree tem
= SSA_VAL (vro
->op0
);
1417 if (tem
!= vro
->op0
)
1419 *valueized_anything
= true;
1422 /* If it transforms from an SSA_NAME to a constant, update
1424 if (TREE_CODE (vro
->op0
) != SSA_NAME
&& vro
->opcode
== SSA_NAME
)
1425 vro
->opcode
= TREE_CODE (vro
->op0
);
1427 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
1429 tree tem
= SSA_VAL (vro
->op1
);
1430 if (tem
!= vro
->op1
)
1432 *valueized_anything
= true;
1436 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
1438 tree tem
= SSA_VAL (vro
->op2
);
1439 if (tem
!= vro
->op2
)
1441 *valueized_anything
= true;
1445 /* If it transforms from an SSA_NAME to an address, fold with
1446 a preceding indirect reference. */
1449 && TREE_CODE (vro
->op0
) == ADDR_EXPR
1450 && orig
[i
- 1].opcode
== MEM_REF
)
1452 if (vn_reference_fold_indirect (&orig
, &i
))
1453 *valueized_anything
= true;
1456 && vro
->opcode
== SSA_NAME
1457 && orig
[i
- 1].opcode
== MEM_REF
)
1459 if (vn_reference_maybe_forwprop_address (&orig
, &i
))
1460 *valueized_anything
= true;
1462 /* If it transforms a non-constant ARRAY_REF into a constant
1463 one, adjust the constant offset. */
1464 else if (vro
->opcode
== ARRAY_REF
1466 && TREE_CODE (vro
->op0
) == INTEGER_CST
1467 && TREE_CODE (vro
->op1
) == INTEGER_CST
1468 && TREE_CODE (vro
->op2
) == INTEGER_CST
)
1470 offset_int off
= ((wi::to_offset (vro
->op0
)
1471 - wi::to_offset (vro
->op1
))
1472 * wi::to_offset (vro
->op2
));
1473 if (wi::fits_shwi_p (off
))
1474 vro
->off
= off
.to_shwi ();
1481 static vec
<vn_reference_op_s
>
1482 valueize_refs (vec
<vn_reference_op_s
> orig
)
1485 return valueize_refs_1 (orig
, &tem
);
1488 static vec
<vn_reference_op_s
> shared_lookup_references
;
1490 /* Create a vector of vn_reference_op_s structures from REF, a
1491 REFERENCE_CLASS_P tree. The vector is shared among all callers of
1492 this function. *VALUEIZED_ANYTHING will specify whether any
1493 operands were valueized. */
1495 static vec
<vn_reference_op_s
>
1496 valueize_shared_reference_ops_from_ref (tree ref
, bool *valueized_anything
)
1500 shared_lookup_references
.truncate (0);
1501 copy_reference_ops_from_ref (ref
, &shared_lookup_references
);
1502 shared_lookup_references
= valueize_refs_1 (shared_lookup_references
,
1503 valueized_anything
);
1504 return shared_lookup_references
;
1507 /* Create a vector of vn_reference_op_s structures from CALL, a
1508 call statement. The vector is shared among all callers of
1511 static vec
<vn_reference_op_s
>
1512 valueize_shared_reference_ops_from_call (gcall
*call
)
1516 shared_lookup_references
.truncate (0);
1517 copy_reference_ops_from_call (call
, &shared_lookup_references
);
1518 shared_lookup_references
= valueize_refs (shared_lookup_references
);
1519 return shared_lookup_references
;
1522 /* Lookup a SCCVN reference operation VR in the current hash table.
1523 Returns the resulting value number if it exists in the hash table,
1524 NULL_TREE otherwise. VNRESULT will be filled in with the actual
1525 vn_reference_t stored in the hashtable if something is found. */
1528 vn_reference_lookup_1 (vn_reference_t vr
, vn_reference_t
*vnresult
)
1530 vn_reference_s
**slot
;
1533 hash
= vr
->hashcode
;
1534 slot
= current_info
->references
->find_slot_with_hash (vr
, hash
, NO_INSERT
);
1535 if (!slot
&& current_info
== optimistic_info
)
1536 slot
= valid_info
->references
->find_slot_with_hash (vr
, hash
, NO_INSERT
);
1540 *vnresult
= (vn_reference_t
)*slot
;
1541 return ((vn_reference_t
)*slot
)->result
;
1547 /* Callback for walk_non_aliased_vuses. Adjusts the vn_reference_t VR_
1548 with the current VUSE and performs the expression lookup. */
1551 vn_reference_lookup_2 (ao_ref
*op ATTRIBUTE_UNUSED
, tree vuse
,
1552 unsigned int cnt
, void *vr_
)
1554 vn_reference_t vr
= (vn_reference_t
)vr_
;
1555 vn_reference_s
**slot
;
1558 /* This bounds the stmt walks we perform on reference lookups
1559 to O(1) instead of O(N) where N is the number of dominating
1561 if (cnt
> (unsigned) PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS
))
1565 *last_vuse_ptr
= vuse
;
1567 /* Fixup vuse and hash. */
1569 vr
->hashcode
= vr
->hashcode
- SSA_NAME_VERSION (vr
->vuse
);
1570 vr
->vuse
= vuse_ssa_val (vuse
);
1572 vr
->hashcode
= vr
->hashcode
+ SSA_NAME_VERSION (vr
->vuse
);
1574 hash
= vr
->hashcode
;
1575 slot
= current_info
->references
->find_slot_with_hash (vr
, hash
, NO_INSERT
);
1576 if (!slot
&& current_info
== optimistic_info
)
1577 slot
= valid_info
->references
->find_slot_with_hash (vr
, hash
, NO_INSERT
);
1584 /* Lookup an existing or insert a new vn_reference entry into the
1585 value table for the VUSE, SET, TYPE, OPERANDS reference which
1586 has the value VALUE which is either a constant or an SSA name. */
1588 static vn_reference_t
1589 vn_reference_lookup_or_insert_for_pieces (tree vuse
,
1592 vec
<vn_reference_op_s
,
1597 vn_reference_t result
;
1600 vr1
.operands
= operands
;
1603 vr1
.hashcode
= vn_reference_compute_hash (&vr1
);
1604 if (vn_reference_lookup_1 (&vr1
, &result
))
1606 if (TREE_CODE (value
) == SSA_NAME
)
1607 value_id
= VN_INFO (value
)->value_id
;
1609 value_id
= get_or_alloc_constant_value_id (value
);
1610 return vn_reference_insert_pieces (vuse
, set
, type
,
1611 operands
.copy (), value
, value_id
);
1614 /* Callback for walk_non_aliased_vuses. Tries to perform a lookup
1615 from the statement defining VUSE and if not successful tries to
1616 translate *REFP and VR_ through an aggregate copy at the definition
1617 of VUSE. If *DISAMBIGUATE_ONLY is true then do not perform translation
1618 of *REF and *VR. If only disambiguation was performed then
1619 *DISAMBIGUATE_ONLY is set to true. */
1622 vn_reference_lookup_3 (ao_ref
*ref
, tree vuse
, void *vr_
,
1623 bool *disambiguate_only
)
1625 vn_reference_t vr
= (vn_reference_t
)vr_
;
1626 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
1627 tree base
= ao_ref_base (ref
);
1628 HOST_WIDE_INT offset
, maxsize
;
1629 static vec
<vn_reference_op_s
>
1632 bool lhs_ref_ok
= false;
1634 /* If the reference is based on a parameter that was determined as
1635 pointing to readonly memory it doesn't change. */
1636 if (TREE_CODE (base
) == MEM_REF
1637 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
1638 && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base
, 0))
1639 && bitmap_bit_p (const_parms
,
1640 SSA_NAME_VERSION (TREE_OPERAND (base
, 0))))
1642 *disambiguate_only
= true;
1646 /* First try to disambiguate after value-replacing in the definitions LHS. */
1647 if (is_gimple_assign (def_stmt
))
1649 tree lhs
= gimple_assign_lhs (def_stmt
);
1650 bool valueized_anything
= false;
1651 /* Avoid re-allocation overhead. */
1652 lhs_ops
.truncate (0);
1653 copy_reference_ops_from_ref (lhs
, &lhs_ops
);
1654 lhs_ops
= valueize_refs_1 (lhs_ops
, &valueized_anything
);
1655 if (valueized_anything
)
1657 lhs_ref_ok
= ao_ref_init_from_vn_reference (&lhs_ref
,
1658 get_alias_set (lhs
),
1659 TREE_TYPE (lhs
), lhs_ops
);
1661 && !refs_may_alias_p_1 (ref
, &lhs_ref
, true))
1663 *disambiguate_only
= true;
1669 ao_ref_init (&lhs_ref
, lhs
);
1673 else if (gimple_call_builtin_p (def_stmt
, BUILT_IN_NORMAL
)
1674 && gimple_call_num_args (def_stmt
) <= 4)
1676 /* For builtin calls valueize its arguments and call the
1677 alias oracle again. Valueization may improve points-to
1678 info of pointers and constify size and position arguments.
1679 Originally this was motivated by PR61034 which has
1680 conditional calls to free falsely clobbering ref because
1681 of imprecise points-to info of the argument. */
1683 bool valueized_anything
= false;
1684 for (unsigned i
= 0; i
< gimple_call_num_args (def_stmt
); ++i
)
1686 oldargs
[i
] = gimple_call_arg (def_stmt
, i
);
1687 if (TREE_CODE (oldargs
[i
]) == SSA_NAME
1688 && VN_INFO (oldargs
[i
])->valnum
!= oldargs
[i
])
1690 gimple_call_set_arg (def_stmt
, i
, VN_INFO (oldargs
[i
])->valnum
);
1691 valueized_anything
= true;
1694 if (valueized_anything
)
1696 bool res
= call_may_clobber_ref_p_1 (as_a
<gcall
*> (def_stmt
),
1698 for (unsigned i
= 0; i
< gimple_call_num_args (def_stmt
); ++i
)
1699 gimple_call_set_arg (def_stmt
, i
, oldargs
[i
]);
1702 *disambiguate_only
= true;
1708 if (*disambiguate_only
)
1711 offset
= ref
->offset
;
1712 maxsize
= ref
->max_size
;
1714 /* If we cannot constrain the size of the reference we cannot
1715 test if anything kills it. */
1719 /* We can't deduce anything useful from clobbers. */
1720 if (gimple_clobber_p (def_stmt
))
1723 /* def_stmt may-defs *ref. See if we can derive a value for *ref
1724 from that definition.
1726 if (is_gimple_reg_type (vr
->type
)
1727 && gimple_call_builtin_p (def_stmt
, BUILT_IN_MEMSET
)
1728 && integer_zerop (gimple_call_arg (def_stmt
, 1))
1729 && tree_fits_uhwi_p (gimple_call_arg (def_stmt
, 2))
1730 && TREE_CODE (gimple_call_arg (def_stmt
, 0)) == ADDR_EXPR
)
1732 tree ref2
= TREE_OPERAND (gimple_call_arg (def_stmt
, 0), 0);
1734 HOST_WIDE_INT offset2
, size2
, maxsize2
;
1736 base2
= get_ref_base_and_extent (ref2
, &offset2
, &size2
, &maxsize2
,
1738 size2
= tree_to_uhwi (gimple_call_arg (def_stmt
, 2)) * 8;
1739 if ((unsigned HOST_WIDE_INT
)size2
/ 8
1740 == tree_to_uhwi (gimple_call_arg (def_stmt
, 2))
1742 && operand_equal_p (base
, base2
, 0)
1743 && offset2
<= offset
1744 && offset2
+ size2
>= offset
+ maxsize
)
1746 tree val
= build_zero_cst (vr
->type
);
1747 return vn_reference_lookup_or_insert_for_pieces
1748 (vuse
, vr
->set
, vr
->type
, vr
->operands
, val
);
1752 /* 2) Assignment from an empty CONSTRUCTOR. */
1753 else if (is_gimple_reg_type (vr
->type
)
1754 && gimple_assign_single_p (def_stmt
)
1755 && gimple_assign_rhs_code (def_stmt
) == CONSTRUCTOR
1756 && CONSTRUCTOR_NELTS (gimple_assign_rhs1 (def_stmt
)) == 0)
1759 HOST_WIDE_INT offset2
, size2
, maxsize2
;
1761 base2
= get_ref_base_and_extent (gimple_assign_lhs (def_stmt
),
1762 &offset2
, &size2
, &maxsize2
, &reverse
);
1764 && operand_equal_p (base
, base2
, 0)
1765 && offset2
<= offset
1766 && offset2
+ size2
>= offset
+ maxsize
)
1768 tree val
= build_zero_cst (vr
->type
);
1769 return vn_reference_lookup_or_insert_for_pieces
1770 (vuse
, vr
->set
, vr
->type
, vr
->operands
, val
);
1774 /* 3) Assignment from a constant. We can use folds native encode/interpret
1775 routines to extract the assigned bits. */
1776 else if (vn_walk_kind
== VN_WALKREWRITE
1777 && CHAR_BIT
== 8 && BITS_PER_UNIT
== 8
1778 && ref
->size
== maxsize
1779 && maxsize
% BITS_PER_UNIT
== 0
1780 && offset
% BITS_PER_UNIT
== 0
1781 && is_gimple_reg_type (vr
->type
)
1782 && !contains_storage_order_barrier_p (vr
->operands
)
1783 && gimple_assign_single_p (def_stmt
)
1784 && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt
)))
1787 HOST_WIDE_INT offset2
, size2
, maxsize2
;
1789 base2
= get_ref_base_and_extent (gimple_assign_lhs (def_stmt
),
1790 &offset2
, &size2
, &maxsize2
, &reverse
);
1793 && maxsize2
== size2
1794 && size2
% BITS_PER_UNIT
== 0
1795 && offset2
% BITS_PER_UNIT
== 0
1796 && operand_equal_p (base
, base2
, 0)
1797 && offset2
<= offset
1798 && offset2
+ size2
>= offset
+ maxsize
)
1800 /* We support up to 512-bit values (for V8DFmode). */
1801 unsigned char buffer
[64];
1804 len
= native_encode_expr (gimple_assign_rhs1 (def_stmt
),
1805 buffer
, sizeof (buffer
));
1808 tree val
= native_interpret_expr (vr
->type
,
1810 + ((offset
- offset2
)
1812 ref
->size
/ BITS_PER_UNIT
);
1814 return vn_reference_lookup_or_insert_for_pieces
1815 (vuse
, vr
->set
, vr
->type
, vr
->operands
, val
);
1820 /* 4) Assignment from an SSA name which definition we may be able
1821 to access pieces from. */
1822 else if (ref
->size
== maxsize
1823 && is_gimple_reg_type (vr
->type
)
1824 && !contains_storage_order_barrier_p (vr
->operands
)
1825 && gimple_assign_single_p (def_stmt
)
1826 && TREE_CODE (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
)
1828 tree rhs1
= gimple_assign_rhs1 (def_stmt
);
1829 gimple
*def_stmt2
= SSA_NAME_DEF_STMT (rhs1
);
1830 if (is_gimple_assign (def_stmt2
)
1831 && (gimple_assign_rhs_code (def_stmt2
) == COMPLEX_EXPR
1832 || gimple_assign_rhs_code (def_stmt2
) == CONSTRUCTOR
)
1833 && types_compatible_p (vr
->type
, TREE_TYPE (TREE_TYPE (rhs1
))))
1836 HOST_WIDE_INT offset2
, size2
, maxsize2
, off
;
1838 base2
= get_ref_base_and_extent (gimple_assign_lhs (def_stmt
),
1839 &offset2
, &size2
, &maxsize2
,
1841 off
= offset
- offset2
;
1844 && maxsize2
== size2
1845 && operand_equal_p (base
, base2
, 0)
1846 && offset2
<= offset
1847 && offset2
+ size2
>= offset
+ maxsize
)
1849 tree val
= NULL_TREE
;
1851 = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (TREE_TYPE (rhs1
))));
1852 if (gimple_assign_rhs_code (def_stmt2
) == COMPLEX_EXPR
)
1855 val
= gimple_assign_rhs1 (def_stmt2
);
1856 else if (off
== elsz
)
1857 val
= gimple_assign_rhs2 (def_stmt2
);
1859 else if (gimple_assign_rhs_code (def_stmt2
) == CONSTRUCTOR
1862 tree ctor
= gimple_assign_rhs1 (def_stmt2
);
1863 unsigned i
= off
/ elsz
;
1864 if (i
< CONSTRUCTOR_NELTS (ctor
))
1866 constructor_elt
*elt
= CONSTRUCTOR_ELT (ctor
, i
);
1867 if (TREE_CODE (TREE_TYPE (rhs1
)) == VECTOR_TYPE
)
1869 if (TREE_CODE (TREE_TYPE (elt
->value
))
1876 return vn_reference_lookup_or_insert_for_pieces
1877 (vuse
, vr
->set
, vr
->type
, vr
->operands
, val
);
1882 /* 5) For aggregate copies translate the reference through them if
1883 the copy kills ref. */
1884 else if (vn_walk_kind
== VN_WALKREWRITE
1885 && gimple_assign_single_p (def_stmt
)
1886 && (DECL_P (gimple_assign_rhs1 (def_stmt
))
1887 || TREE_CODE (gimple_assign_rhs1 (def_stmt
)) == MEM_REF
1888 || handled_component_p (gimple_assign_rhs1 (def_stmt
))))
1891 HOST_WIDE_INT maxsize2
;
1893 auto_vec
<vn_reference_op_s
> rhs
;
1894 vn_reference_op_t vro
;
1900 /* See if the assignment kills REF. */
1901 base2
= ao_ref_base (&lhs_ref
);
1902 maxsize2
= lhs_ref
.max_size
;
1905 && (TREE_CODE (base
) != MEM_REF
1906 || TREE_CODE (base2
) != MEM_REF
1907 || TREE_OPERAND (base
, 0) != TREE_OPERAND (base2
, 0)
1908 || !tree_int_cst_equal (TREE_OPERAND (base
, 1),
1909 TREE_OPERAND (base2
, 1))))
1910 || !stmt_kills_ref_p (def_stmt
, ref
))
1913 /* Find the common base of ref and the lhs. lhs_ops already
1914 contains valueized operands for the lhs. */
1915 i
= vr
->operands
.length () - 1;
1916 j
= lhs_ops
.length () - 1;
1917 while (j
>= 0 && i
>= 0
1918 && vn_reference_op_eq (&vr
->operands
[i
], &lhs_ops
[j
]))
1924 /* ??? The innermost op should always be a MEM_REF and we already
1925 checked that the assignment to the lhs kills vr. Thus for
1926 aggregate copies using char[] types the vn_reference_op_eq
1927 may fail when comparing types for compatibility. But we really
1928 don't care here - further lookups with the rewritten operands
1929 will simply fail if we messed up types too badly. */
1930 HOST_WIDE_INT extra_off
= 0;
1931 if (j
== 0 && i
>= 0
1932 && lhs_ops
[0].opcode
== MEM_REF
1933 && lhs_ops
[0].off
!= -1)
1935 if (lhs_ops
[0].off
== vr
->operands
[i
].off
)
1937 else if (vr
->operands
[i
].opcode
== MEM_REF
1938 && vr
->operands
[i
].off
!= -1)
1940 extra_off
= vr
->operands
[i
].off
- lhs_ops
[0].off
;
1945 /* i now points to the first additional op.
1946 ??? LHS may not be completely contained in VR, one or more
1947 VIEW_CONVERT_EXPRs could be in its way. We could at least
1948 try handling outermost VIEW_CONVERT_EXPRs. */
1952 /* Punt if the additional ops contain a storage order barrier. */
1953 for (k
= i
; k
>= 0; k
--)
1955 vro
= &vr
->operands
[k
];
1956 if (vro
->opcode
== VIEW_CONVERT_EXPR
&& vro
->reverse
)
1960 /* Now re-write REF to be based on the rhs of the assignment. */
1961 copy_reference_ops_from_ref (gimple_assign_rhs1 (def_stmt
), &rhs
);
1963 /* Apply an extra offset to the inner MEM_REF of the RHS. */
1966 if (rhs
.length () < 2
1967 || rhs
[0].opcode
!= MEM_REF
1968 || rhs
[0].off
== -1)
1970 rhs
[0].off
+= extra_off
;
1971 rhs
[0].op0
= int_const_binop (PLUS_EXPR
, rhs
[0].op0
,
1972 build_int_cst (TREE_TYPE (rhs
[0].op0
),
1976 /* We need to pre-pend vr->operands[0..i] to rhs. */
1977 vec
<vn_reference_op_s
> old
= vr
->operands
;
1978 if (i
+ 1 + rhs
.length () > vr
->operands
.length ())
1980 vr
->operands
.safe_grow (i
+ 1 + rhs
.length ());
1981 if (old
== shared_lookup_references
)
1982 shared_lookup_references
= vr
->operands
;
1985 vr
->operands
.truncate (i
+ 1 + rhs
.length ());
1986 FOR_EACH_VEC_ELT (rhs
, j
, vro
)
1987 vr
->operands
[i
+ 1 + j
] = *vro
;
1988 vr
->operands
= valueize_refs (vr
->operands
);
1989 if (old
== shared_lookup_references
)
1990 shared_lookup_references
= vr
->operands
;
1991 vr
->hashcode
= vn_reference_compute_hash (vr
);
1993 /* Try folding the new reference to a constant. */
1994 tree val
= fully_constant_vn_reference_p (vr
);
1996 return vn_reference_lookup_or_insert_for_pieces
1997 (vuse
, vr
->set
, vr
->type
, vr
->operands
, val
);
1999 /* Adjust *ref from the new operands. */
2000 if (!ao_ref_init_from_vn_reference (&r
, vr
->set
, vr
->type
, vr
->operands
))
2002 /* This can happen with bitfields. */
2003 if (ref
->size
!= r
.size
)
2007 /* Do not update last seen VUSE after translating. */
2008 last_vuse_ptr
= NULL
;
2010 /* Keep looking for the adjusted *REF / VR pair. */
2014 /* 6) For memcpy copies translate the reference through them if
2015 the copy kills ref. */
2016 else if (vn_walk_kind
== VN_WALKREWRITE
2017 && is_gimple_reg_type (vr
->type
)
2018 /* ??? Handle BCOPY as well. */
2019 && (gimple_call_builtin_p (def_stmt
, BUILT_IN_MEMCPY
)
2020 || gimple_call_builtin_p (def_stmt
, BUILT_IN_MEMPCPY
)
2021 || gimple_call_builtin_p (def_stmt
, BUILT_IN_MEMMOVE
))
2022 && (TREE_CODE (gimple_call_arg (def_stmt
, 0)) == ADDR_EXPR
2023 || TREE_CODE (gimple_call_arg (def_stmt
, 0)) == SSA_NAME
)
2024 && (TREE_CODE (gimple_call_arg (def_stmt
, 1)) == ADDR_EXPR
2025 || TREE_CODE (gimple_call_arg (def_stmt
, 1)) == SSA_NAME
)
2026 && tree_fits_uhwi_p (gimple_call_arg (def_stmt
, 2)))
2030 HOST_WIDE_INT rhs_offset
, copy_size
, lhs_offset
;
2031 vn_reference_op_s op
;
2034 /* Only handle non-variable, addressable refs. */
2035 if (ref
->size
!= maxsize
2036 || offset
% BITS_PER_UNIT
!= 0
2037 || ref
->size
% BITS_PER_UNIT
!= 0)
2040 /* Extract a pointer base and an offset for the destination. */
2041 lhs
= gimple_call_arg (def_stmt
, 0);
2043 if (TREE_CODE (lhs
) == SSA_NAME
)
2045 lhs
= SSA_VAL (lhs
);
2046 if (TREE_CODE (lhs
) == SSA_NAME
)
2048 gimple
*def_stmt
= SSA_NAME_DEF_STMT (lhs
);
2049 if (gimple_assign_single_p (def_stmt
)
2050 && gimple_assign_rhs_code (def_stmt
) == ADDR_EXPR
)
2051 lhs
= gimple_assign_rhs1 (def_stmt
);
2054 if (TREE_CODE (lhs
) == ADDR_EXPR
)
2056 tree tem
= get_addr_base_and_unit_offset (TREE_OPERAND (lhs
, 0),
2060 if (TREE_CODE (tem
) == MEM_REF
2061 && tree_fits_uhwi_p (TREE_OPERAND (tem
, 1)))
2063 lhs
= TREE_OPERAND (tem
, 0);
2064 if (TREE_CODE (lhs
) == SSA_NAME
)
2065 lhs
= SSA_VAL (lhs
);
2066 lhs_offset
+= tree_to_uhwi (TREE_OPERAND (tem
, 1));
2068 else if (DECL_P (tem
))
2069 lhs
= build_fold_addr_expr (tem
);
2073 if (TREE_CODE (lhs
) != SSA_NAME
2074 && TREE_CODE (lhs
) != ADDR_EXPR
)
2077 /* Extract a pointer base and an offset for the source. */
2078 rhs
= gimple_call_arg (def_stmt
, 1);
2080 if (TREE_CODE (rhs
) == SSA_NAME
)
2081 rhs
= SSA_VAL (rhs
);
2082 if (TREE_CODE (rhs
) == ADDR_EXPR
)
2084 tree tem
= get_addr_base_and_unit_offset (TREE_OPERAND (rhs
, 0),
2088 if (TREE_CODE (tem
) == MEM_REF
2089 && tree_fits_uhwi_p (TREE_OPERAND (tem
, 1)))
2091 rhs
= TREE_OPERAND (tem
, 0);
2092 rhs_offset
+= tree_to_uhwi (TREE_OPERAND (tem
, 1));
2094 else if (DECL_P (tem
))
2095 rhs
= build_fold_addr_expr (tem
);
2099 if (TREE_CODE (rhs
) != SSA_NAME
2100 && TREE_CODE (rhs
) != ADDR_EXPR
)
2103 copy_size
= tree_to_uhwi (gimple_call_arg (def_stmt
, 2));
2105 /* The bases of the destination and the references have to agree. */
2106 if ((TREE_CODE (base
) != MEM_REF
2108 || (TREE_CODE (base
) == MEM_REF
2109 && (TREE_OPERAND (base
, 0) != lhs
2110 || !tree_fits_uhwi_p (TREE_OPERAND (base
, 1))))
2112 && (TREE_CODE (lhs
) != ADDR_EXPR
2113 || TREE_OPERAND (lhs
, 0) != base
)))
2116 at
= offset
/ BITS_PER_UNIT
;
2117 if (TREE_CODE (base
) == MEM_REF
)
2118 at
+= tree_to_uhwi (TREE_OPERAND (base
, 1));
2119 /* If the access is completely outside of the memcpy destination
2120 area there is no aliasing. */
2121 if (lhs_offset
>= at
+ maxsize
/ BITS_PER_UNIT
2122 || lhs_offset
+ copy_size
<= at
)
2124 /* And the access has to be contained within the memcpy destination. */
2126 || lhs_offset
+ copy_size
< at
+ maxsize
/ BITS_PER_UNIT
)
2129 /* Make room for 2 operands in the new reference. */
2130 if (vr
->operands
.length () < 2)
2132 vec
<vn_reference_op_s
> old
= vr
->operands
;
2133 vr
->operands
.safe_grow_cleared (2);
2134 if (old
== shared_lookup_references
2135 && vr
->operands
!= old
)
2136 shared_lookup_references
= vr
->operands
;
2139 vr
->operands
.truncate (2);
2141 /* The looked-through reference is a simple MEM_REF. */
2142 memset (&op
, 0, sizeof (op
));
2144 op
.opcode
= MEM_REF
;
2145 op
.op0
= build_int_cst (ptr_type_node
, at
- rhs_offset
);
2146 op
.off
= at
- lhs_offset
+ rhs_offset
;
2147 vr
->operands
[0] = op
;
2148 op
.type
= TREE_TYPE (rhs
);
2149 op
.opcode
= TREE_CODE (rhs
);
2152 vr
->operands
[1] = op
;
2153 vr
->hashcode
= vn_reference_compute_hash (vr
);
2155 /* Adjust *ref from the new operands. */
2156 if (!ao_ref_init_from_vn_reference (&r
, vr
->set
, vr
->type
, vr
->operands
))
2158 /* This can happen with bitfields. */
2159 if (ref
->size
!= r
.size
)
2163 /* Do not update last seen VUSE after translating. */
2164 last_vuse_ptr
= NULL
;
2166 /* Keep looking for the adjusted *REF / VR pair. */
2170 /* Bail out and stop walking. */
2174 /* Lookup a reference operation by it's parts, in the current hash table.
2175 Returns the resulting value number if it exists in the hash table,
2176 NULL_TREE otherwise. VNRESULT will be filled in with the actual
2177 vn_reference_t stored in the hashtable if something is found. */
2180 vn_reference_lookup_pieces (tree vuse
, alias_set_type set
, tree type
,
2181 vec
<vn_reference_op_s
> operands
,
2182 vn_reference_t
*vnresult
, vn_lookup_kind kind
)
2184 struct vn_reference_s vr1
;
2192 vr1
.vuse
= vuse_ssa_val (vuse
);
2193 shared_lookup_references
.truncate (0);
2194 shared_lookup_references
.safe_grow (operands
.length ());
2195 memcpy (shared_lookup_references
.address (),
2196 operands
.address (),
2197 sizeof (vn_reference_op_s
)
2198 * operands
.length ());
2199 vr1
.operands
= operands
= shared_lookup_references
2200 = valueize_refs (shared_lookup_references
);
2203 vr1
.hashcode
= vn_reference_compute_hash (&vr1
);
2204 if ((cst
= fully_constant_vn_reference_p (&vr1
)))
2207 vn_reference_lookup_1 (&vr1
, vnresult
);
2209 && kind
!= VN_NOWALK
2213 vn_walk_kind
= kind
;
2214 if (ao_ref_init_from_vn_reference (&r
, set
, type
, vr1
.operands
))
2216 (vn_reference_t
)walk_non_aliased_vuses (&r
, vr1
.vuse
,
2217 vn_reference_lookup_2
,
2218 vn_reference_lookup_3
,
2219 vuse_ssa_val
, &vr1
);
2220 gcc_checking_assert (vr1
.operands
== shared_lookup_references
);
2224 return (*vnresult
)->result
;
2229 /* Lookup OP in the current hash table, and return the resulting value
2230 number if it exists in the hash table. Return NULL_TREE if it does
2231 not exist in the hash table or if the result field of the structure
2232 was NULL.. VNRESULT will be filled in with the vn_reference_t
2233 stored in the hashtable if one exists. */
2236 vn_reference_lookup (tree op
, tree vuse
, vn_lookup_kind kind
,
2237 vn_reference_t
*vnresult
)
2239 vec
<vn_reference_op_s
> operands
;
2240 struct vn_reference_s vr1
;
2242 bool valuezied_anything
;
2247 vr1
.vuse
= vuse_ssa_val (vuse
);
2248 vr1
.operands
= operands
2249 = valueize_shared_reference_ops_from_ref (op
, &valuezied_anything
);
2250 vr1
.type
= TREE_TYPE (op
);
2251 vr1
.set
= get_alias_set (op
);
2252 vr1
.hashcode
= vn_reference_compute_hash (&vr1
);
2253 if ((cst
= fully_constant_vn_reference_p (&vr1
)))
2256 if (kind
!= VN_NOWALK
2259 vn_reference_t wvnresult
;
2261 /* Make sure to use a valueized reference if we valueized anything.
2262 Otherwise preserve the full reference for advanced TBAA. */
2263 if (!valuezied_anything
2264 || !ao_ref_init_from_vn_reference (&r
, vr1
.set
, vr1
.type
,
2266 ao_ref_init (&r
, op
);
2267 vn_walk_kind
= kind
;
2269 (vn_reference_t
)walk_non_aliased_vuses (&r
, vr1
.vuse
,
2270 vn_reference_lookup_2
,
2271 vn_reference_lookup_3
,
2272 vuse_ssa_val
, &vr1
);
2273 gcc_checking_assert (vr1
.operands
== shared_lookup_references
);
2277 *vnresult
= wvnresult
;
2278 return wvnresult
->result
;
2284 return vn_reference_lookup_1 (&vr1
, vnresult
);
2287 /* Lookup CALL in the current hash table and return the entry in
2288 *VNRESULT if found. Populates *VR for the hashtable lookup. */
2291 vn_reference_lookup_call (gcall
*call
, vn_reference_t
*vnresult
,
2297 tree vuse
= gimple_vuse (call
);
2299 vr
->vuse
= vuse
? SSA_VAL (vuse
) : NULL_TREE
;
2300 vr
->operands
= valueize_shared_reference_ops_from_call (call
);
2301 vr
->type
= gimple_expr_type (call
);
2303 vr
->hashcode
= vn_reference_compute_hash (vr
);
2304 vn_reference_lookup_1 (vr
, vnresult
);
2307 /* Insert OP into the current hash table with a value number of
2308 RESULT, and return the resulting reference structure we created. */
2310 static vn_reference_t
2311 vn_reference_insert (tree op
, tree result
, tree vuse
, tree vdef
)
2313 vn_reference_s
**slot
;
2317 vr1
= current_info
->references_pool
->allocate ();
2318 if (TREE_CODE (result
) == SSA_NAME
)
2319 vr1
->value_id
= VN_INFO (result
)->value_id
;
2321 vr1
->value_id
= get_or_alloc_constant_value_id (result
);
2322 vr1
->vuse
= vuse
? SSA_VAL (vuse
) : NULL_TREE
;
2323 vr1
->operands
= valueize_shared_reference_ops_from_ref (op
, &tem
).copy ();
2324 vr1
->type
= TREE_TYPE (op
);
2325 vr1
->set
= get_alias_set (op
);
2326 vr1
->hashcode
= vn_reference_compute_hash (vr1
);
2327 vr1
->result
= TREE_CODE (result
) == SSA_NAME
? SSA_VAL (result
) : result
;
2328 vr1
->result_vdef
= vdef
;
2330 slot
= current_info
->references
->find_slot_with_hash (vr1
, vr1
->hashcode
,
2333 /* Because we lookup stores using vuses, and value number failures
2334 using the vdefs (see visit_reference_op_store for how and why),
2335 it's possible that on failure we may try to insert an already
2336 inserted store. This is not wrong, there is no ssa name for a
2337 store that we could use as a differentiator anyway. Thus, unlike
2338 the other lookup functions, you cannot gcc_assert (!*slot)
2341 /* But free the old slot in case of a collision. */
2343 free_reference (*slot
);
2349 /* Insert a reference by it's pieces into the current hash table with
2350 a value number of RESULT. Return the resulting reference
2351 structure we created. */
2354 vn_reference_insert_pieces (tree vuse
, alias_set_type set
, tree type
,
2355 vec
<vn_reference_op_s
> operands
,
2356 tree result
, unsigned int value_id
)
2359 vn_reference_s
**slot
;
2362 vr1
= current_info
->references_pool
->allocate ();
2363 vr1
->value_id
= value_id
;
2364 vr1
->vuse
= vuse
? SSA_VAL (vuse
) : NULL_TREE
;
2365 vr1
->operands
= valueize_refs (operands
);
2368 vr1
->hashcode
= vn_reference_compute_hash (vr1
);
2369 if (result
&& TREE_CODE (result
) == SSA_NAME
)
2370 result
= SSA_VAL (result
);
2371 vr1
->result
= result
;
2373 slot
= current_info
->references
->find_slot_with_hash (vr1
, vr1
->hashcode
,
2376 /* At this point we should have all the things inserted that we have
2377 seen before, and we should never try inserting something that
2379 gcc_assert (!*slot
);
2381 free_reference (*slot
);
2387 /* Compute and return the hash value for nary operation VBO1. */
2390 vn_nary_op_compute_hash (const vn_nary_op_t vno1
)
2392 inchash::hash hstate
;
2395 for (i
= 0; i
< vno1
->length
; ++i
)
2396 if (TREE_CODE (vno1
->op
[i
]) == SSA_NAME
)
2397 vno1
->op
[i
] = SSA_VAL (vno1
->op
[i
]);
2399 if (((vno1
->length
== 2
2400 && commutative_tree_code (vno1
->opcode
))
2401 || (vno1
->length
== 3
2402 && commutative_ternary_tree_code (vno1
->opcode
)))
2403 && tree_swap_operands_p (vno1
->op
[0], vno1
->op
[1], false))
2404 std::swap (vno1
->op
[0], vno1
->op
[1]);
2405 else if (TREE_CODE_CLASS (vno1
->opcode
) == tcc_comparison
2406 && tree_swap_operands_p (vno1
->op
[0], vno1
->op
[1], false))
2408 std::swap (vno1
->op
[0], vno1
->op
[1]);
2409 vno1
->opcode
= swap_tree_comparison (vno1
->opcode
);
2412 hstate
.add_int (vno1
->opcode
);
2413 for (i
= 0; i
< vno1
->length
; ++i
)
2414 inchash::add_expr (vno1
->op
[i
], hstate
);
2416 return hstate
.end ();
2419 /* Compare nary operations VNO1 and VNO2 and return true if they are
2423 vn_nary_op_eq (const_vn_nary_op_t
const vno1
, const_vn_nary_op_t
const vno2
)
2427 if (vno1
->hashcode
!= vno2
->hashcode
)
2430 if (vno1
->length
!= vno2
->length
)
2433 if (vno1
->opcode
!= vno2
->opcode
2434 || !types_compatible_p (vno1
->type
, vno2
->type
))
2437 for (i
= 0; i
< vno1
->length
; ++i
)
2438 if (!expressions_equal_p (vno1
->op
[i
], vno2
->op
[i
]))
2444 /* Initialize VNO from the pieces provided. */
2447 init_vn_nary_op_from_pieces (vn_nary_op_t vno
, unsigned int length
,
2448 enum tree_code code
, tree type
, tree
*ops
)
2451 vno
->length
= length
;
2453 memcpy (&vno
->op
[0], ops
, sizeof (tree
) * length
);
2456 /* Initialize VNO from OP. */
2459 init_vn_nary_op_from_op (vn_nary_op_t vno
, tree op
)
2463 vno
->opcode
= TREE_CODE (op
);
2464 vno
->length
= TREE_CODE_LENGTH (TREE_CODE (op
));
2465 vno
->type
= TREE_TYPE (op
);
2466 for (i
= 0; i
< vno
->length
; ++i
)
2467 vno
->op
[i
] = TREE_OPERAND (op
, i
);
2470 /* Return the number of operands for a vn_nary ops structure from STMT. */
2473 vn_nary_length_from_stmt (gimple
*stmt
)
2475 switch (gimple_assign_rhs_code (stmt
))
2479 case VIEW_CONVERT_EXPR
:
2486 return CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt
));
2489 return gimple_num_ops (stmt
) - 1;
2493 /* Initialize VNO from STMT. */
2496 init_vn_nary_op_from_stmt (vn_nary_op_t vno
, gimple
*stmt
)
2500 vno
->opcode
= gimple_assign_rhs_code (stmt
);
2501 vno
->type
= gimple_expr_type (stmt
);
2502 switch (vno
->opcode
)
2506 case VIEW_CONVERT_EXPR
:
2508 vno
->op
[0] = TREE_OPERAND (gimple_assign_rhs1 (stmt
), 0);
2513 vno
->op
[0] = TREE_OPERAND (gimple_assign_rhs1 (stmt
), 0);
2514 vno
->op
[1] = TREE_OPERAND (gimple_assign_rhs1 (stmt
), 1);
2515 vno
->op
[2] = TREE_OPERAND (gimple_assign_rhs1 (stmt
), 2);
2519 vno
->length
= CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt
));
2520 for (i
= 0; i
< vno
->length
; ++i
)
2521 vno
->op
[i
] = CONSTRUCTOR_ELT (gimple_assign_rhs1 (stmt
), i
)->value
;
2525 gcc_checking_assert (!gimple_assign_single_p (stmt
));
2526 vno
->length
= gimple_num_ops (stmt
) - 1;
2527 for (i
= 0; i
< vno
->length
; ++i
)
2528 vno
->op
[i
] = gimple_op (stmt
, i
+ 1);
2532 /* Compute the hashcode for VNO and look for it in the hash table;
2533 return the resulting value number if it exists in the hash table.
2534 Return NULL_TREE if it does not exist in the hash table or if the
2535 result field of the operation is NULL. VNRESULT will contain the
2536 vn_nary_op_t from the hashtable if it exists. */
2539 vn_nary_op_lookup_1 (vn_nary_op_t vno
, vn_nary_op_t
*vnresult
)
2541 vn_nary_op_s
**slot
;
2546 vno
->hashcode
= vn_nary_op_compute_hash (vno
);
2547 slot
= current_info
->nary
->find_slot_with_hash (vno
, vno
->hashcode
,
2549 if (!slot
&& current_info
== optimistic_info
)
2550 slot
= valid_info
->nary
->find_slot_with_hash (vno
, vno
->hashcode
,
2556 return (*slot
)->result
;
2559 /* Lookup a n-ary operation by its pieces and return the resulting value
2560 number if it exists in the hash table. Return NULL_TREE if it does
2561 not exist in the hash table or if the result field of the operation
2562 is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
2566 vn_nary_op_lookup_pieces (unsigned int length
, enum tree_code code
,
2567 tree type
, tree
*ops
, vn_nary_op_t
*vnresult
)
2569 vn_nary_op_t vno1
= XALLOCAVAR (struct vn_nary_op_s
,
2570 sizeof_vn_nary_op (length
));
2571 init_vn_nary_op_from_pieces (vno1
, length
, code
, type
, ops
);
2572 return vn_nary_op_lookup_1 (vno1
, vnresult
);
2575 /* Lookup OP in the current hash table, and return the resulting value
2576 number if it exists in the hash table. Return NULL_TREE if it does
2577 not exist in the hash table or if the result field of the operation
2578 is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
2582 vn_nary_op_lookup (tree op
, vn_nary_op_t
*vnresult
)
2585 = XALLOCAVAR (struct vn_nary_op_s
,
2586 sizeof_vn_nary_op (TREE_CODE_LENGTH (TREE_CODE (op
))));
2587 init_vn_nary_op_from_op (vno1
, op
);
2588 return vn_nary_op_lookup_1 (vno1
, vnresult
);
2591 /* Lookup the rhs of STMT in the current hash table, and return the resulting
2592 value number if it exists in the hash table. Return NULL_TREE if
2593 it does not exist in the hash table. VNRESULT will contain the
2594 vn_nary_op_t from the hashtable if it exists. */
2597 vn_nary_op_lookup_stmt (gimple
*stmt
, vn_nary_op_t
*vnresult
)
2600 = XALLOCAVAR (struct vn_nary_op_s
,
2601 sizeof_vn_nary_op (vn_nary_length_from_stmt (stmt
)));
2602 init_vn_nary_op_from_stmt (vno1
, stmt
);
2603 return vn_nary_op_lookup_1 (vno1
, vnresult
);
2606 /* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
2609 vn_lookup_simplify_result (code_helper rcode
, tree type
, tree
*ops
)
2611 if (!rcode
.is_tree_code ())
2613 vn_nary_op_t vnresult
= NULL
;
2614 return vn_nary_op_lookup_pieces (TREE_CODE_LENGTH ((tree_code
) rcode
),
2615 (tree_code
) rcode
, type
, ops
, &vnresult
);
2618 /* Allocate a vn_nary_op_t with LENGTH operands on STACK. */
2621 alloc_vn_nary_op_noinit (unsigned int length
, struct obstack
*stack
)
2623 return (vn_nary_op_t
) obstack_alloc (stack
, sizeof_vn_nary_op (length
));
2626 /* Allocate and initialize a vn_nary_op_t on CURRENT_INFO's
2630 alloc_vn_nary_op (unsigned int length
, tree result
, unsigned int value_id
)
2632 vn_nary_op_t vno1
= alloc_vn_nary_op_noinit (length
,
2633 ¤t_info
->nary_obstack
);
2635 vno1
->value_id
= value_id
;
2636 vno1
->length
= length
;
2637 vno1
->result
= result
;
2642 /* Insert VNO into TABLE. If COMPUTE_HASH is true, then compute
2643 VNO->HASHCODE first. */
2646 vn_nary_op_insert_into (vn_nary_op_t vno
, vn_nary_op_table_type
*table
,
2649 vn_nary_op_s
**slot
;
2652 vno
->hashcode
= vn_nary_op_compute_hash (vno
);
2654 slot
= table
->find_slot_with_hash (vno
, vno
->hashcode
, INSERT
);
2655 gcc_assert (!*slot
);
2661 /* Insert a n-ary operation into the current hash table using it's
2662 pieces. Return the vn_nary_op_t structure we created and put in
2666 vn_nary_op_insert_pieces (unsigned int length
, enum tree_code code
,
2667 tree type
, tree
*ops
,
2668 tree result
, unsigned int value_id
)
2670 vn_nary_op_t vno1
= alloc_vn_nary_op (length
, result
, value_id
);
2671 init_vn_nary_op_from_pieces (vno1
, length
, code
, type
, ops
);
2672 return vn_nary_op_insert_into (vno1
, current_info
->nary
, true);
2675 /* Insert OP into the current hash table with a value number of
2676 RESULT. Return the vn_nary_op_t structure we created and put in
2680 vn_nary_op_insert (tree op
, tree result
)
2682 unsigned length
= TREE_CODE_LENGTH (TREE_CODE (op
));
2685 vno1
= alloc_vn_nary_op (length
, result
, VN_INFO (result
)->value_id
);
2686 init_vn_nary_op_from_op (vno1
, op
);
2687 return vn_nary_op_insert_into (vno1
, current_info
->nary
, true);
2690 /* Insert the rhs of STMT into the current hash table with a value number of
2694 vn_nary_op_insert_stmt (gimple
*stmt
, tree result
)
2697 = alloc_vn_nary_op (vn_nary_length_from_stmt (stmt
),
2698 result
, VN_INFO (result
)->value_id
);
2699 init_vn_nary_op_from_stmt (vno1
, stmt
);
2700 return vn_nary_op_insert_into (vno1
, current_info
->nary
, true);
2703 /* Compute a hashcode for PHI operation VP1 and return it. */
2705 static inline hashval_t
2706 vn_phi_compute_hash (vn_phi_t vp1
)
2708 inchash::hash
hstate (vp1
->phiargs
.length () > 2
2709 ? vp1
->block
->index
: vp1
->phiargs
.length ());
2715 /* If all PHI arguments are constants we need to distinguish
2716 the PHI node via its type. */
2718 hstate
.merge_hash (vn_hash_type (type
));
2720 FOR_EACH_EDGE (e
, ei
, vp1
->block
->preds
)
2722 /* Don't hash backedge values they need to be handled as VN_TOP
2723 for optimistic value-numbering. */
2724 if (e
->flags
& EDGE_DFS_BACK
)
2727 phi1op
= vp1
->phiargs
[e
->dest_idx
];
2728 if (phi1op
== VN_TOP
)
2730 inchash::add_expr (phi1op
, hstate
);
2733 return hstate
.end ();
2737 /* Return true if COND1 and COND2 represent the same condition, set
2738 *INVERTED_P if one needs to be inverted to make it the same as
2742 cond_stmts_equal_p (gcond
*cond1
, gcond
*cond2
, bool *inverted_p
)
2744 enum tree_code code1
= gimple_cond_code (cond1
);
2745 enum tree_code code2
= gimple_cond_code (cond2
);
2746 tree lhs1
= gimple_cond_lhs (cond1
);
2747 tree lhs2
= gimple_cond_lhs (cond2
);
2748 tree rhs1
= gimple_cond_rhs (cond1
);
2749 tree rhs2
= gimple_cond_rhs (cond2
);
2751 *inverted_p
= false;
2754 else if (code1
== swap_tree_comparison (code2
))
2755 std::swap (lhs2
, rhs2
);
2756 else if (code1
== invert_tree_comparison (code2
, HONOR_NANS (lhs2
)))
2758 else if (code1
== invert_tree_comparison
2759 (swap_tree_comparison (code2
), HONOR_NANS (lhs2
)))
2761 std::swap (lhs2
, rhs2
);
2767 lhs1
= vn_valueize (lhs1
);
2768 rhs1
= vn_valueize (rhs1
);
2769 lhs2
= vn_valueize (lhs2
);
2770 rhs2
= vn_valueize (rhs2
);
2771 return ((expressions_equal_p (lhs1
, lhs2
)
2772 && expressions_equal_p (rhs1
, rhs2
))
2773 || (commutative_tree_code (code1
)
2774 && expressions_equal_p (lhs1
, rhs2
)
2775 && expressions_equal_p (rhs1
, lhs2
)));
2778 /* Compare two phi entries for equality, ignoring VN_TOP arguments. */
2781 vn_phi_eq (const_vn_phi_t
const vp1
, const_vn_phi_t
const vp2
)
2783 if (vp1
->hashcode
!= vp2
->hashcode
)
2786 if (vp1
->block
!= vp2
->block
)
2788 if (vp1
->phiargs
.length () != vp2
->phiargs
.length ())
2791 switch (vp1
->phiargs
.length ())
2794 /* Single-arg PHIs are just copies. */
2799 /* Rule out backedges into the PHI. */
2800 if (vp1
->block
->loop_father
->header
== vp1
->block
2801 || vp2
->block
->loop_father
->header
== vp2
->block
)
2804 /* If the PHI nodes do not have compatible types
2805 they are not the same. */
2806 if (!types_compatible_p (vp1
->type
, vp2
->type
))
2810 = get_immediate_dominator (CDI_DOMINATORS
, vp1
->block
);
2812 = get_immediate_dominator (CDI_DOMINATORS
, vp2
->block
);
2813 /* If the immediate dominator end in switch stmts multiple
2814 values may end up in the same PHI arg via intermediate
2816 if (EDGE_COUNT (idom1
->succs
) != 2
2817 || EDGE_COUNT (idom2
->succs
) != 2)
2820 /* Verify the controlling stmt is the same. */
2821 gimple
*last1
= last_stmt (idom1
);
2822 gimple
*last2
= last_stmt (idom2
);
2823 if (gimple_code (last1
) != GIMPLE_COND
2824 || gimple_code (last2
) != GIMPLE_COND
)
2827 if (! cond_stmts_equal_p (as_a
<gcond
*> (last1
),
2828 as_a
<gcond
*> (last2
), &inverted_p
))
2831 /* Get at true/false controlled edges into the PHI. */
2832 edge te1
, te2
, fe1
, fe2
;
2833 if (! extract_true_false_controlled_edges (idom1
, vp1
->block
,
2835 || ! extract_true_false_controlled_edges (idom2
, vp2
->block
,
2839 /* Swap edges if the second condition is the inverted of the
2842 std::swap (te2
, fe2
);
2844 /* ??? Handle VN_TOP specially. */
2845 if (! expressions_equal_p (vp1
->phiargs
[te1
->dest_idx
],
2846 vp2
->phiargs
[te2
->dest_idx
])
2847 || ! expressions_equal_p (vp1
->phiargs
[fe1
->dest_idx
],
2848 vp2
->phiargs
[fe2
->dest_idx
]))
2859 /* If the PHI nodes do not have compatible types
2860 they are not the same. */
2861 if (!types_compatible_p (vp1
->type
, vp2
->type
))
2864 /* Any phi in the same block will have it's arguments in the
2865 same edge order, because of how we store phi nodes. */
2868 FOR_EACH_VEC_ELT (vp1
->phiargs
, i
, phi1op
)
2870 tree phi2op
= vp2
->phiargs
[i
];
2871 if (phi1op
== VN_TOP
|| phi2op
== VN_TOP
)
2873 if (!expressions_equal_p (phi1op
, phi2op
))
2880 static vec
<tree
> shared_lookup_phiargs
;
2882 /* Lookup PHI in the current hash table, and return the resulting
2883 value number if it exists in the hash table. Return NULL_TREE if
2884 it does not exist in the hash table. */
2887 vn_phi_lookup (gimple
*phi
)
2890 struct vn_phi_s vp1
;
2894 shared_lookup_phiargs
.truncate (0);
2895 shared_lookup_phiargs
.safe_grow (gimple_phi_num_args (phi
));
2897 /* Canonicalize the SSA_NAME's to their value number. */
2898 FOR_EACH_EDGE (e
, ei
, gimple_bb (phi
)->preds
)
2900 tree def
= PHI_ARG_DEF_FROM_EDGE (phi
, e
);
2901 def
= TREE_CODE (def
) == SSA_NAME
? SSA_VAL (def
) : def
;
2902 shared_lookup_phiargs
[e
->dest_idx
] = def
;
2904 vp1
.type
= TREE_TYPE (gimple_phi_result (phi
));
2905 vp1
.phiargs
= shared_lookup_phiargs
;
2906 vp1
.block
= gimple_bb (phi
);
2907 vp1
.hashcode
= vn_phi_compute_hash (&vp1
);
2908 slot
= current_info
->phis
->find_slot_with_hash (&vp1
, vp1
.hashcode
,
2910 if (!slot
&& current_info
== optimistic_info
)
2911 slot
= valid_info
->phis
->find_slot_with_hash (&vp1
, vp1
.hashcode
,
2915 return (*slot
)->result
;
2918 /* Insert PHI into the current hash table with a value number of
2922 vn_phi_insert (gimple
*phi
, tree result
)
2925 vn_phi_t vp1
= current_info
->phis_pool
->allocate ();
2926 vec
<tree
> args
= vNULL
;
2930 args
.safe_grow (gimple_phi_num_args (phi
));
2932 /* Canonicalize the SSA_NAME's to their value number. */
2933 FOR_EACH_EDGE (e
, ei
, gimple_bb (phi
)->preds
)
2935 tree def
= PHI_ARG_DEF_FROM_EDGE (phi
, e
);
2936 def
= TREE_CODE (def
) == SSA_NAME
? SSA_VAL (def
) : def
;
2937 args
[e
->dest_idx
] = def
;
2939 vp1
->value_id
= VN_INFO (result
)->value_id
;
2940 vp1
->type
= TREE_TYPE (gimple_phi_result (phi
));
2941 vp1
->phiargs
= args
;
2942 vp1
->block
= gimple_bb (phi
);
2943 vp1
->result
= result
;
2944 vp1
->hashcode
= vn_phi_compute_hash (vp1
);
2946 slot
= current_info
->phis
->find_slot_with_hash (vp1
, vp1
->hashcode
, INSERT
);
2948 /* Because we iterate over phi operations more than once, it's
2949 possible the slot might already exist here, hence no assert.*/
2955 /* Print set of components in strongly connected component SCC to OUT. */
2958 print_scc (FILE *out
, vec
<tree
> scc
)
2963 fprintf (out
, "SCC consists of:");
2964 FOR_EACH_VEC_ELT (scc
, i
, var
)
2967 print_generic_expr (out
, var
, 0);
2969 fprintf (out
, "\n");
2972 /* Return true if BB1 is dominated by BB2 taking into account edges
2973 that are not executable. */
2976 dominated_by_p_w_unex (basic_block bb1
, basic_block bb2
)
2981 if (dominated_by_p (CDI_DOMINATORS
, bb1
, bb2
))
2984 /* Before iterating we'd like to know if there exists a
2985 (executable) path from bb2 to bb1 at all, if not we can
2986 directly return false. For now simply iterate once. */
2988 /* Iterate to the single executable bb1 predecessor. */
2989 if (EDGE_COUNT (bb1
->preds
) > 1)
2992 FOR_EACH_EDGE (e
, ei
, bb1
->preds
)
2993 if (e
->flags
& EDGE_EXECUTABLE
)
3006 /* Re-do the dominance check with changed bb1. */
3007 if (dominated_by_p (CDI_DOMINATORS
, bb1
, bb2
))
3012 /* Iterate to the single executable bb2 successor. */
3014 FOR_EACH_EDGE (e
, ei
, bb2
->succs
)
3015 if (e
->flags
& EDGE_EXECUTABLE
)
3026 /* Verify the reached block is only reached through succe.
3027 If there is only one edge we can spare us the dominator
3028 check and iterate directly. */
3029 if (EDGE_COUNT (succe
->dest
->preds
) > 1)
3031 FOR_EACH_EDGE (e
, ei
, succe
->dest
->preds
)
3033 && (e
->flags
& EDGE_EXECUTABLE
))
3043 /* Re-do the dominance check with changed bb2. */
3044 if (dominated_by_p (CDI_DOMINATORS
, bb1
, bb2
))
3049 /* We could now iterate updating bb1 / bb2. */
3053 /* Set the value number of FROM to TO, return true if it has changed
3057 set_ssa_val_to (tree from
, tree to
)
3059 tree currval
= SSA_VAL (from
);
3060 HOST_WIDE_INT toff
, coff
;
3062 /* The only thing we allow as value numbers are ssa_names
3063 and invariants. So assert that here. We don't allow VN_TOP
3064 as visiting a stmt should produce a value-number other than
3066 ??? Still VN_TOP can happen for unreachable code, so force
3067 it to varying in that case. Not all code is prepared to
3068 get VN_TOP on valueization. */
3071 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3072 fprintf (dump_file
, "Forcing value number to varying on "
3073 "receiving VN_TOP\n");
3077 gcc_assert (to
!= NULL_TREE
3078 && ((TREE_CODE (to
) == SSA_NAME
3079 && (to
== from
|| SSA_VAL (to
) == to
))
3080 || is_gimple_min_invariant (to
)));
3084 if (currval
== from
)
3086 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3088 fprintf (dump_file
, "Not changing value number of ");
3089 print_generic_expr (dump_file
, from
, 0);
3090 fprintf (dump_file
, " from VARYING to ");
3091 print_generic_expr (dump_file
, to
, 0);
3092 fprintf (dump_file
, "\n");
3096 else if (TREE_CODE (to
) == SSA_NAME
3097 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to
))
3101 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3103 fprintf (dump_file
, "Setting value number of ");
3104 print_generic_expr (dump_file
, from
, 0);
3105 fprintf (dump_file
, " to ");
3106 print_generic_expr (dump_file
, to
, 0);
3110 && !operand_equal_p (currval
, to
, 0)
3111 /* ??? For addresses involving volatile objects or types operand_equal_p
3112 does not reliably detect ADDR_EXPRs as equal. We know we are only
3113 getting invariant gimple addresses here, so can use
3114 get_addr_base_and_unit_offset to do this comparison. */
3115 && !(TREE_CODE (currval
) == ADDR_EXPR
3116 && TREE_CODE (to
) == ADDR_EXPR
3117 && (get_addr_base_and_unit_offset (TREE_OPERAND (currval
, 0), &coff
)
3118 == get_addr_base_and_unit_offset (TREE_OPERAND (to
, 0), &toff
))
3121 /* If we equate two SSA names we have to make the side-band info
3122 of the leader conservative (and remember whatever original value
3124 if (TREE_CODE (to
) == SSA_NAME
)
3126 if (INTEGRAL_TYPE_P (TREE_TYPE (to
))
3127 && SSA_NAME_RANGE_INFO (to
))
3129 if (SSA_NAME_IS_DEFAULT_DEF (to
)
3130 || dominated_by_p_w_unex
3131 (gimple_bb (SSA_NAME_DEF_STMT (from
)),
3132 gimple_bb (SSA_NAME_DEF_STMT (to
))))
3133 /* Keep the info from the dominator. */
3135 else if (SSA_NAME_IS_DEFAULT_DEF (from
)
3136 || dominated_by_p_w_unex
3137 (gimple_bb (SSA_NAME_DEF_STMT (to
)),
3138 gimple_bb (SSA_NAME_DEF_STMT (from
))))
3140 /* Save old info. */
3141 if (! VN_INFO (to
)->info
.range_info
)
3142 VN_INFO (to
)->info
.range_info
= SSA_NAME_RANGE_INFO (to
);
3143 /* Use that from the dominator. */
3144 SSA_NAME_RANGE_INFO (to
) = SSA_NAME_RANGE_INFO (from
);
3148 /* Save old info. */
3149 if (! VN_INFO (to
)->info
.range_info
)
3150 VN_INFO (to
)->info
.range_info
= SSA_NAME_RANGE_INFO (to
);
3151 /* Rather than allocating memory and unioning the info
3153 SSA_NAME_RANGE_INFO (to
) = NULL
;
3156 else if (POINTER_TYPE_P (TREE_TYPE (to
))
3157 && SSA_NAME_PTR_INFO (to
))
3159 if (SSA_NAME_IS_DEFAULT_DEF (to
)
3160 || dominated_by_p_w_unex
3161 (gimple_bb (SSA_NAME_DEF_STMT (from
)),
3162 gimple_bb (SSA_NAME_DEF_STMT (to
))))
3163 /* Keep the info from the dominator. */
3165 else if (SSA_NAME_IS_DEFAULT_DEF (from
)
3166 || dominated_by_p_w_unex
3167 (gimple_bb (SSA_NAME_DEF_STMT (to
)),
3168 gimple_bb (SSA_NAME_DEF_STMT (from
))))
3170 /* Save old info. */
3171 if (! VN_INFO (to
)->info
.ptr_info
)
3172 VN_INFO (to
)->info
.ptr_info
= SSA_NAME_PTR_INFO (to
);
3173 /* Use that from the dominator. */
3174 SSA_NAME_PTR_INFO (to
) = SSA_NAME_PTR_INFO (from
);
3176 else if (! SSA_NAME_PTR_INFO (from
)
3177 /* Handle the case of trivially equivalent info. */
3178 || memcmp (SSA_NAME_PTR_INFO (to
),
3179 SSA_NAME_PTR_INFO (from
),
3180 sizeof (ptr_info_def
)) != 0)
3182 /* Save old info. */
3183 if (! VN_INFO (to
)->info
.ptr_info
)
3184 VN_INFO (to
)->info
.ptr_info
= SSA_NAME_PTR_INFO (to
);
3185 /* Rather than allocating memory and unioning the info
3187 SSA_NAME_PTR_INFO (to
) = NULL
;
3192 VN_INFO (from
)->valnum
= to
;
3193 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3194 fprintf (dump_file
, " (changed)\n");
3197 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3198 fprintf (dump_file
, "\n");
3202 /* Mark as processed all the definitions in the defining stmt of USE, or
3206 mark_use_processed (tree use
)
3210 gimple
*stmt
= SSA_NAME_DEF_STMT (use
);
3212 if (SSA_NAME_IS_DEFAULT_DEF (use
) || gimple_code (stmt
) == GIMPLE_PHI
)
3214 VN_INFO (use
)->use_processed
= true;
3218 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_ALL_DEFS
)
3220 tree def
= DEF_FROM_PTR (defp
);
3222 VN_INFO (def
)->use_processed
= true;
3226 /* Set all definitions in STMT to value number to themselves.
3227 Return true if a value number changed. */
3230 defs_to_varying (gimple
*stmt
)
3232 bool changed
= false;
3236 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_ALL_DEFS
)
3238 tree def
= DEF_FROM_PTR (defp
);
3239 changed
|= set_ssa_val_to (def
, def
);
3244 /* Visit a copy between LHS and RHS, return true if the value number
3248 visit_copy (tree lhs
, tree rhs
)
3251 rhs
= SSA_VAL (rhs
);
3253 return set_ssa_val_to (lhs
, rhs
);
3256 /* Visit a nary operator RHS, value number it, and return true if the
3257 value number of LHS has changed as a result. */
3260 visit_nary_op (tree lhs
, gimple
*stmt
)
3262 bool changed
= false;
3263 tree result
= vn_nary_op_lookup_stmt (stmt
, NULL
);
3266 changed
= set_ssa_val_to (lhs
, result
);
3269 changed
= set_ssa_val_to (lhs
, lhs
);
3270 vn_nary_op_insert_stmt (stmt
, lhs
);
3276 /* Visit a call STMT storing into LHS. Return true if the value number
3277 of the LHS has changed as a result. */
3280 visit_reference_op_call (tree lhs
, gcall
*stmt
)
3282 bool changed
= false;
3283 struct vn_reference_s vr1
;
3284 vn_reference_t vnresult
= NULL
;
3285 tree vdef
= gimple_vdef (stmt
);
3287 /* Non-ssa lhs is handled in copy_reference_ops_from_call. */
3288 if (lhs
&& TREE_CODE (lhs
) != SSA_NAME
)
3291 vn_reference_lookup_call (stmt
, &vnresult
, &vr1
);
3294 if (vnresult
->result_vdef
&& vdef
)
3295 changed
|= set_ssa_val_to (vdef
, vnresult
->result_vdef
);
3297 if (!vnresult
->result
&& lhs
)
3298 vnresult
->result
= lhs
;
3300 if (vnresult
->result
&& lhs
)
3301 changed
|= set_ssa_val_to (lhs
, vnresult
->result
);
3306 vn_reference_s
**slot
;
3308 changed
|= set_ssa_val_to (vdef
, vdef
);
3310 changed
|= set_ssa_val_to (lhs
, lhs
);
3311 vr2
= current_info
->references_pool
->allocate ();
3312 vr2
->vuse
= vr1
.vuse
;
3313 /* As we are not walking the virtual operand chain we know the
3314 shared_lookup_references are still original so we can re-use
3316 vr2
->operands
= vr1
.operands
.copy ();
3317 vr2
->type
= vr1
.type
;
3319 vr2
->hashcode
= vr1
.hashcode
;
3321 vr2
->result_vdef
= vdef
;
3322 slot
= current_info
->references
->find_slot_with_hash (vr2
, vr2
->hashcode
,
3324 gcc_assert (!*slot
);
3331 /* Visit a load from a reference operator RHS, part of STMT, value number it,
3332 and return true if the value number of the LHS has changed as a result. */
3335 visit_reference_op_load (tree lhs
, tree op
, gimple
*stmt
)
3337 bool changed
= false;
3341 last_vuse
= gimple_vuse (stmt
);
3342 last_vuse_ptr
= &last_vuse
;
3343 result
= vn_reference_lookup (op
, gimple_vuse (stmt
),
3344 default_vn_walk_kind
, NULL
);
3345 last_vuse_ptr
= NULL
;
3347 /* We handle type-punning through unions by value-numbering based
3348 on offset and size of the access. Be prepared to handle a
3349 type-mismatch here via creating a VIEW_CONVERT_EXPR. */
3351 && !useless_type_conversion_p (TREE_TYPE (result
), TREE_TYPE (op
)))
3353 /* We will be setting the value number of lhs to the value number
3354 of VIEW_CONVERT_EXPR <TREE_TYPE (result)> (result).
3355 So first simplify and lookup this expression to see if it
3356 is already available. */
3357 mprts_hook
= vn_lookup_simplify_result
;
3358 code_helper rcode
= VIEW_CONVERT_EXPR
;
3359 tree ops
[3] = { result
};
3360 bool res
= gimple_resimplify1 (NULL
, &rcode
, TREE_TYPE (op
), ops
,
3363 gimple
*new_stmt
= NULL
;
3365 && gimple_simplified_result_is_gimple_val (rcode
, ops
))
3366 /* The expression is already available. */
3370 tree val
= vn_lookup_simplify_result (rcode
, TREE_TYPE (op
), ops
);
3373 gimple_seq stmts
= NULL
;
3374 result
= maybe_push_res_to_seq (rcode
, TREE_TYPE (op
), ops
,
3378 gcc_assert (gimple_seq_singleton_p (stmts
));
3379 new_stmt
= gimple_seq_first_stmt (stmts
);
3383 /* The expression is already available. */
3388 /* The expression is not yet available, value-number lhs to
3389 the new SSA_NAME we created. */
3390 /* Initialize value-number information properly. */
3391 VN_INFO_GET (result
)->valnum
= result
;
3392 VN_INFO (result
)->value_id
= get_next_value_id ();
3393 gimple_seq_add_stmt_without_update (&VN_INFO (result
)->expr
,
3395 VN_INFO (result
)->needs_insertion
= true;
3396 /* As all "inserted" statements are singleton SCCs, insert
3397 to the valid table. This is strictly needed to
3398 avoid re-generating new value SSA_NAMEs for the same
3399 expression during SCC iteration over and over (the
3400 optimistic table gets cleared after each iteration).
3401 We do not need to insert into the optimistic table, as
3402 lookups there will fall back to the valid table. */
3403 if (current_info
== optimistic_info
)
3405 current_info
= valid_info
;
3406 vn_nary_op_insert_stmt (new_stmt
, result
);
3407 current_info
= optimistic_info
;
3410 vn_nary_op_insert_stmt (new_stmt
, result
);
3411 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3413 fprintf (dump_file
, "Inserting name ");
3414 print_generic_expr (dump_file
, result
, 0);
3415 fprintf (dump_file
, " for expression ");
3416 print_gimple_expr (dump_file
, new_stmt
, 0, TDF_SLIM
);
3417 fprintf (dump_file
, "\n");
3423 changed
= set_ssa_val_to (lhs
, result
);
3426 changed
= set_ssa_val_to (lhs
, lhs
);
3427 vn_reference_insert (op
, lhs
, last_vuse
, NULL_TREE
);
3434 /* Visit a store to a reference operator LHS, part of STMT, value number it,
3435 and return true if the value number of the LHS has changed as a result. */
3438 visit_reference_op_store (tree lhs
, tree op
, gimple
*stmt
)
3440 bool changed
= false;
3441 vn_reference_t vnresult
= NULL
;
3442 tree result
, assign
;
3443 bool resultsame
= false;
3444 tree vuse
= gimple_vuse (stmt
);
3445 tree vdef
= gimple_vdef (stmt
);
3447 if (TREE_CODE (op
) == SSA_NAME
)
3450 /* First we want to lookup using the *vuses* from the store and see
3451 if there the last store to this location with the same address
3454 The vuses represent the memory state before the store. If the
3455 memory state, address, and value of the store is the same as the
3456 last store to this location, then this store will produce the
3457 same memory state as that store.
3459 In this case the vdef versions for this store are value numbered to those
3460 vuse versions, since they represent the same memory state after
3463 Otherwise, the vdefs for the store are used when inserting into
3464 the table, since the store generates a new memory state. */
3466 result
= vn_reference_lookup (lhs
, vuse
, VN_NOWALK
, NULL
);
3470 if (TREE_CODE (result
) == SSA_NAME
)
3471 result
= SSA_VAL (result
);
3472 resultsame
= expressions_equal_p (result
, op
);
3475 if ((!result
|| !resultsame
)
3476 /* Only perform the following when being called from PRE
3477 which embeds tail merging. */
3478 && default_vn_walk_kind
== VN_WALK
)
3480 assign
= build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, op
);
3481 vn_reference_lookup (assign
, vuse
, VN_NOWALK
, &vnresult
);
3484 VN_INFO (vdef
)->use_processed
= true;
3485 return set_ssa_val_to (vdef
, vnresult
->result_vdef
);
3489 if (!result
|| !resultsame
)
3491 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3493 fprintf (dump_file
, "No store match\n");
3494 fprintf (dump_file
, "Value numbering store ");
3495 print_generic_expr (dump_file
, lhs
, 0);
3496 fprintf (dump_file
, " to ");
3497 print_generic_expr (dump_file
, op
, 0);
3498 fprintf (dump_file
, "\n");
3500 /* Have to set value numbers before insert, since insert is
3501 going to valueize the references in-place. */
3504 changed
|= set_ssa_val_to (vdef
, vdef
);
3507 /* Do not insert structure copies into the tables. */
3508 if (is_gimple_min_invariant (op
)
3509 || is_gimple_reg (op
))
3510 vn_reference_insert (lhs
, op
, vdef
, NULL
);
3512 /* Only perform the following when being called from PRE
3513 which embeds tail merging. */
3514 if (default_vn_walk_kind
== VN_WALK
)
3516 assign
= build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, op
);
3517 vn_reference_insert (assign
, lhs
, vuse
, vdef
);
3522 /* We had a match, so value number the vdef to have the value
3523 number of the vuse it came from. */
3525 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3526 fprintf (dump_file
, "Store matched earlier value,"
3527 "value numbering store vdefs to matching vuses.\n");
3529 changed
|= set_ssa_val_to (vdef
, SSA_VAL (vuse
));
3535 /* Visit and value number PHI, return true if the value number
3539 visit_phi (gimple
*phi
)
3541 bool changed
= false;
3543 tree sameval
= VN_TOP
;
3544 bool allsame
= true;
3545 unsigned n_executable
= 0;
3547 /* TODO: We could check for this in init_sccvn, and replace this
3548 with a gcc_assert. */
3549 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi
)))
3550 return set_ssa_val_to (PHI_RESULT (phi
), PHI_RESULT (phi
));
3552 /* See if all non-TOP arguments have the same value. TOP is
3553 equivalent to everything, so we can ignore it. */
3556 FOR_EACH_EDGE (e
, ei
, gimple_bb (phi
)->preds
)
3557 if (e
->flags
& EDGE_EXECUTABLE
)
3559 tree def
= PHI_ARG_DEF_FROM_EDGE (phi
, e
);
3562 if (TREE_CODE (def
) == SSA_NAME
)
3563 def
= SSA_VAL (def
);
3566 if (sameval
== VN_TOP
)
3568 else if (!expressions_equal_p (def
, sameval
))
3575 /* If none of the edges was executable or all incoming values are
3576 undefined keep the value-number at VN_TOP. If only a single edge
3577 is exectuable use its value. */
3578 if (sameval
== VN_TOP
3579 || n_executable
== 1)
3580 return set_ssa_val_to (PHI_RESULT (phi
), sameval
);
3582 /* First see if it is equivalent to a phi node in this block. We prefer
3583 this as it allows IV elimination - see PRs 66502 and 67167. */
3584 result
= vn_phi_lookup (phi
);
3586 changed
= set_ssa_val_to (PHI_RESULT (phi
), result
);
3587 /* Otherwise all value numbered to the same value, the phi node has that
3590 changed
= set_ssa_val_to (PHI_RESULT (phi
), sameval
);
3593 vn_phi_insert (phi
, PHI_RESULT (phi
));
3594 changed
= set_ssa_val_to (PHI_RESULT (phi
), PHI_RESULT (phi
));
3600 /* Try to simplify RHS using equivalences and constant folding. */
3603 try_to_simplify (gassign
*stmt
)
3605 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3608 /* For stores we can end up simplifying a SSA_NAME rhs. Just return
3609 in this case, there is no point in doing extra work. */
3610 if (code
== SSA_NAME
)
3613 /* First try constant folding based on our current lattice. */
3614 mprts_hook
= vn_lookup_simplify_result
;
3615 tem
= gimple_fold_stmt_to_constant_1 (stmt
, vn_valueize
, vn_valueize
);
3618 && (TREE_CODE (tem
) == SSA_NAME
3619 || is_gimple_min_invariant (tem
)))
3625 /* Visit and value number USE, return true if the value number
3629 visit_use (tree use
)
3631 bool changed
= false;
3632 gimple
*stmt
= SSA_NAME_DEF_STMT (use
);
3634 mark_use_processed (use
);
3636 gcc_assert (!SSA_NAME_IN_FREE_LIST (use
));
3637 if (dump_file
&& (dump_flags
& TDF_DETAILS
)
3638 && !SSA_NAME_IS_DEFAULT_DEF (use
))
3640 fprintf (dump_file
, "Value numbering ");
3641 print_generic_expr (dump_file
, use
, 0);
3642 fprintf (dump_file
, " stmt = ");
3643 print_gimple_stmt (dump_file
, stmt
, 0, 0);
3646 /* Handle uninitialized uses. */
3647 if (SSA_NAME_IS_DEFAULT_DEF (use
))
3648 changed
= set_ssa_val_to (use
, use
);
3649 else if (gimple_code (stmt
) == GIMPLE_PHI
)
3650 changed
= visit_phi (stmt
);
3651 else if (gimple_has_volatile_ops (stmt
))
3652 changed
= defs_to_varying (stmt
);
3653 else if (gassign
*ass
= dyn_cast
<gassign
*> (stmt
))
3655 enum tree_code code
= gimple_assign_rhs_code (ass
);
3656 tree lhs
= gimple_assign_lhs (ass
);
3657 tree rhs1
= gimple_assign_rhs1 (ass
);
3660 /* Shortcut for copies. Simplifying copies is pointless,
3661 since we copy the expression and value they represent. */
3662 if (code
== SSA_NAME
3663 && TREE_CODE (lhs
) == SSA_NAME
)
3665 changed
= visit_copy (lhs
, rhs1
);
3668 simplified
= try_to_simplify (ass
);
3671 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3673 fprintf (dump_file
, "RHS ");
3674 print_gimple_expr (dump_file
, ass
, 0, 0);
3675 fprintf (dump_file
, " simplified to ");
3676 print_generic_expr (dump_file
, simplified
, 0);
3677 fprintf (dump_file
, "\n");
3680 /* Setting value numbers to constants will occasionally
3681 screw up phi congruence because constants are not
3682 uniquely associated with a single ssa name that can be
3685 && is_gimple_min_invariant (simplified
)
3686 && TREE_CODE (lhs
) == SSA_NAME
)
3688 changed
= set_ssa_val_to (lhs
, simplified
);
3692 && TREE_CODE (simplified
) == SSA_NAME
3693 && TREE_CODE (lhs
) == SSA_NAME
)
3695 changed
= visit_copy (lhs
, simplified
);
3699 if ((TREE_CODE (lhs
) == SSA_NAME
3700 /* We can substitute SSA_NAMEs that are live over
3701 abnormal edges with their constant value. */
3702 && !(gimple_assign_copy_p (ass
)
3703 && is_gimple_min_invariant (rhs1
))
3705 && is_gimple_min_invariant (simplified
))
3706 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
3707 /* Stores or copies from SSA_NAMEs that are live over
3708 abnormal edges are a problem. */
3709 || (code
== SSA_NAME
3710 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs1
)))
3711 changed
= defs_to_varying (ass
);
3712 else if (REFERENCE_CLASS_P (lhs
)
3714 changed
= visit_reference_op_store (lhs
, rhs1
, ass
);
3715 else if (TREE_CODE (lhs
) == SSA_NAME
)
3717 if ((gimple_assign_copy_p (ass
)
3718 && is_gimple_min_invariant (rhs1
))
3720 && is_gimple_min_invariant (simplified
)))
3723 changed
= set_ssa_val_to (lhs
, simplified
);
3725 changed
= set_ssa_val_to (lhs
, rhs1
);
3729 /* Visit the original statement. */
3730 switch (vn_get_stmt_kind (ass
))
3733 changed
= visit_nary_op (lhs
, ass
);
3736 changed
= visit_reference_op_load (lhs
, rhs1
, ass
);
3739 changed
= defs_to_varying (ass
);
3745 changed
= defs_to_varying (ass
);
3747 else if (gcall
*call_stmt
= dyn_cast
<gcall
*> (stmt
))
3749 tree lhs
= gimple_call_lhs (call_stmt
);
3750 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
)
3752 /* Try constant folding based on our current lattice. */
3753 tree simplified
= gimple_fold_stmt_to_constant_1 (call_stmt
,
3757 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3759 fprintf (dump_file
, "call ");
3760 print_gimple_expr (dump_file
, call_stmt
, 0, 0);
3761 fprintf (dump_file
, " simplified to ");
3762 print_generic_expr (dump_file
, simplified
, 0);
3763 fprintf (dump_file
, "\n");
3766 /* Setting value numbers to constants will occasionally
3767 screw up phi congruence because constants are not
3768 uniquely associated with a single ssa name that can be
3771 && is_gimple_min_invariant (simplified
))
3773 changed
= set_ssa_val_to (lhs
, simplified
);
3774 if (gimple_vdef (call_stmt
))
3775 changed
|= set_ssa_val_to (gimple_vdef (call_stmt
),
3776 SSA_VAL (gimple_vuse (call_stmt
)));
3780 && TREE_CODE (simplified
) == SSA_NAME
)
3782 changed
= visit_copy (lhs
, simplified
);
3783 if (gimple_vdef (call_stmt
))
3784 changed
|= set_ssa_val_to (gimple_vdef (call_stmt
),
3785 SSA_VAL (gimple_vuse (call_stmt
)));
3788 else if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
3790 changed
= defs_to_varying (call_stmt
);
3795 if (!gimple_call_internal_p (call_stmt
)
3796 && (/* Calls to the same function with the same vuse
3797 and the same operands do not necessarily return the same
3798 value, unless they're pure or const. */
3799 gimple_call_flags (call_stmt
) & (ECF_PURE
| ECF_CONST
)
3800 /* If calls have a vdef, subsequent calls won't have
3801 the same incoming vuse. So, if 2 calls with vdef have the
3802 same vuse, we know they're not subsequent.
3803 We can value number 2 calls to the same function with the
3804 same vuse and the same operands which are not subsequent
3805 the same, because there is no code in the program that can
3806 compare the 2 values... */
3807 || (gimple_vdef (call_stmt
)
3808 /* ... unless the call returns a pointer which does
3809 not alias with anything else. In which case the
3810 information that the values are distinct are encoded
3812 && !(gimple_call_return_flags (call_stmt
) & ERF_NOALIAS
)
3813 /* Only perform the following when being called from PRE
3814 which embeds tail merging. */
3815 && default_vn_walk_kind
== VN_WALK
)))
3816 changed
= visit_reference_op_call (lhs
, call_stmt
);
3818 changed
= defs_to_varying (call_stmt
);
3821 changed
= defs_to_varying (stmt
);
3826 /* Compare two operands by reverse postorder index */
3829 compare_ops (const void *pa
, const void *pb
)
3831 const tree opa
= *((const tree
*)pa
);
3832 const tree opb
= *((const tree
*)pb
);
3833 gimple
*opstmta
= SSA_NAME_DEF_STMT (opa
);
3834 gimple
*opstmtb
= SSA_NAME_DEF_STMT (opb
);
3838 if (gimple_nop_p (opstmta
) && gimple_nop_p (opstmtb
))
3839 return SSA_NAME_VERSION (opa
) - SSA_NAME_VERSION (opb
);
3840 else if (gimple_nop_p (opstmta
))
3842 else if (gimple_nop_p (opstmtb
))
3845 bba
= gimple_bb (opstmta
);
3846 bbb
= gimple_bb (opstmtb
);
3849 return SSA_NAME_VERSION (opa
) - SSA_NAME_VERSION (opb
);
3857 if (gimple_code (opstmta
) == GIMPLE_PHI
3858 && gimple_code (opstmtb
) == GIMPLE_PHI
)
3859 return SSA_NAME_VERSION (opa
) - SSA_NAME_VERSION (opb
);
3860 else if (gimple_code (opstmta
) == GIMPLE_PHI
)
3862 else if (gimple_code (opstmtb
) == GIMPLE_PHI
)
3864 else if (gimple_uid (opstmta
) != gimple_uid (opstmtb
))
3865 return gimple_uid (opstmta
) - gimple_uid (opstmtb
);
3867 return SSA_NAME_VERSION (opa
) - SSA_NAME_VERSION (opb
);
3869 return rpo_numbers
[bba
->index
] - rpo_numbers
[bbb
->index
];
3872 /* Sort an array containing members of a strongly connected component
3873 SCC so that the members are ordered by RPO number.
3874 This means that when the sort is complete, iterating through the
3875 array will give you the members in RPO order. */
3878 sort_scc (vec
<tree
> scc
)
3880 scc
.qsort (compare_ops
);
3883 /* Insert the no longer used nary ONARY to the hash INFO. */
3886 copy_nary (vn_nary_op_t onary
, vn_tables_t info
)
3888 size_t size
= sizeof_vn_nary_op (onary
->length
);
3889 vn_nary_op_t nary
= alloc_vn_nary_op_noinit (onary
->length
,
3890 &info
->nary_obstack
);
3891 memcpy (nary
, onary
, size
);
3892 vn_nary_op_insert_into (nary
, info
->nary
, false);
3895 /* Insert the no longer used phi OPHI to the hash INFO. */
3898 copy_phi (vn_phi_t ophi
, vn_tables_t info
)
3900 vn_phi_t phi
= info
->phis_pool
->allocate ();
3902 memcpy (phi
, ophi
, sizeof (*phi
));
3903 ophi
->phiargs
.create (0);
3904 slot
= info
->phis
->find_slot_with_hash (phi
, phi
->hashcode
, INSERT
);
3905 gcc_assert (!*slot
);
3909 /* Insert the no longer used reference OREF to the hash INFO. */
3912 copy_reference (vn_reference_t oref
, vn_tables_t info
)
3915 vn_reference_s
**slot
;
3916 ref
= info
->references_pool
->allocate ();
3917 memcpy (ref
, oref
, sizeof (*ref
));
3918 oref
->operands
.create (0);
3919 slot
= info
->references
->find_slot_with_hash (ref
, ref
->hashcode
, INSERT
);
3921 free_reference (*slot
);
3925 /* Process a strongly connected component in the SSA graph. */
3928 process_scc (vec
<tree
> scc
)
3932 unsigned int iterations
= 0;
3933 bool changed
= true;
3934 vn_nary_op_iterator_type hin
;
3935 vn_phi_iterator_type hip
;
3936 vn_reference_iterator_type hir
;
3941 /* If the SCC has a single member, just visit it. */
3942 if (scc
.length () == 1)
3945 if (VN_INFO (use
)->use_processed
)
3947 /* We need to make sure it doesn't form a cycle itself, which can
3948 happen for self-referential PHI nodes. In that case we would
3949 end up inserting an expression with VN_TOP operands into the
3950 valid table which makes us derive bogus equivalences later.
3951 The cheapest way to check this is to assume it for all PHI nodes. */
3952 if (gimple_code (SSA_NAME_DEF_STMT (use
)) == GIMPLE_PHI
)
3953 /* Fallthru to iteration. */ ;
3961 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3962 print_scc (dump_file
, scc
);
3964 /* Iterate over the SCC with the optimistic table until it stops
3966 current_info
= optimistic_info
;
3971 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3972 fprintf (dump_file
, "Starting iteration %d\n", iterations
);
3973 /* As we are value-numbering optimistically we have to
3974 clear the expression tables and the simplified expressions
3975 in each iteration until we converge. */
3976 optimistic_info
->nary
->empty ();
3977 optimistic_info
->phis
->empty ();
3978 optimistic_info
->references
->empty ();
3979 obstack_free (&optimistic_info
->nary_obstack
, NULL
);
3980 gcc_obstack_init (&optimistic_info
->nary_obstack
);
3981 optimistic_info
->phis_pool
->release ();
3982 optimistic_info
->references_pool
->release ();
3983 FOR_EACH_VEC_ELT (scc
, i
, var
)
3984 gcc_assert (!VN_INFO (var
)->needs_insertion
3985 && VN_INFO (var
)->expr
== NULL
);
3986 FOR_EACH_VEC_ELT (scc
, i
, var
)
3987 changed
|= visit_use (var
);
3990 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3991 fprintf (dump_file
, "Processing SCC needed %d iterations\n", iterations
);
3992 statistics_histogram_event (cfun
, "SCC iterations", iterations
);
3994 /* Finally, copy the contents of the no longer used optimistic
3995 table to the valid table. */
3996 FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info
->nary
, nary
, vn_nary_op_t
, hin
)
3997 copy_nary (nary
, valid_info
);
3998 FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info
->phis
, phi
, vn_phi_t
, hip
)
3999 copy_phi (phi
, valid_info
);
4000 FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info
->references
,
4001 ref
, vn_reference_t
, hir
)
4002 copy_reference (ref
, valid_info
);
4004 current_info
= valid_info
;
4008 /* Pop the components of the found SCC for NAME off the SCC stack
4009 and process them. Returns true if all went well, false if
4010 we run into resource limits. */
4013 extract_and_process_scc_for_name (tree name
)
4018 /* Found an SCC, pop the components off the SCC stack and
4022 x
= sccstack
.pop ();
4024 VN_INFO (x
)->on_sccstack
= false;
4026 } while (x
!= name
);
4028 /* Bail out of SCCVN in case a SCC turns out to be incredibly large. */
4030 > (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE
))
4033 fprintf (dump_file
, "WARNING: Giving up with SCCVN due to "
4034 "SCC size %u exceeding %u\n", scc
.length (),
4035 (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE
));
4040 if (scc
.length () > 1)
4048 /* Depth first search on NAME to discover and process SCC's in the SSA
4050 Execution of this algorithm relies on the fact that the SCC's are
4051 popped off the stack in topological order.
4052 Returns true if successful, false if we stopped processing SCC's due
4053 to resource constraints. */
4058 vec
<ssa_op_iter
> itervec
= vNULL
;
4059 vec
<tree
> namevec
= vNULL
;
4060 use_operand_p usep
= NULL
;
4067 VN_INFO (name
)->dfsnum
= next_dfs_num
++;
4068 VN_INFO (name
)->visited
= true;
4069 VN_INFO (name
)->low
= VN_INFO (name
)->dfsnum
;
4071 sccstack
.safe_push (name
);
4072 VN_INFO (name
)->on_sccstack
= true;
4073 defstmt
= SSA_NAME_DEF_STMT (name
);
4075 /* Recursively DFS on our operands, looking for SCC's. */
4076 if (!gimple_nop_p (defstmt
))
4078 /* Push a new iterator. */
4079 if (gphi
*phi
= dyn_cast
<gphi
*> (defstmt
))
4080 usep
= op_iter_init_phiuse (&iter
, phi
, SSA_OP_ALL_USES
);
4082 usep
= op_iter_init_use (&iter
, defstmt
, SSA_OP_ALL_USES
);
4085 clear_and_done_ssa_iter (&iter
);
4089 /* If we are done processing uses of a name, go up the stack
4090 of iterators and process SCCs as we found them. */
4091 if (op_iter_done (&iter
))
4093 /* See if we found an SCC. */
4094 if (VN_INFO (name
)->low
== VN_INFO (name
)->dfsnum
)
4095 if (!extract_and_process_scc_for_name (name
))
4102 /* Check if we are done. */
4103 if (namevec
.is_empty ())
4110 /* Restore the last use walker and continue walking there. */
4112 name
= namevec
.pop ();
4113 memcpy (&iter
, &itervec
.last (),
4114 sizeof (ssa_op_iter
));
4116 goto continue_walking
;
4119 use
= USE_FROM_PTR (usep
);
4121 /* Since we handle phi nodes, we will sometimes get
4122 invariants in the use expression. */
4123 if (TREE_CODE (use
) == SSA_NAME
)
4125 if (! (VN_INFO (use
)->visited
))
4127 /* Recurse by pushing the current use walking state on
4128 the stack and starting over. */
4129 itervec
.safe_push (iter
);
4130 namevec
.safe_push (name
);
4135 VN_INFO (name
)->low
= MIN (VN_INFO (name
)->low
,
4136 VN_INFO (use
)->low
);
4138 if (VN_INFO (use
)->dfsnum
< VN_INFO (name
)->dfsnum
4139 && VN_INFO (use
)->on_sccstack
)
4141 VN_INFO (name
)->low
= MIN (VN_INFO (use
)->dfsnum
,
4142 VN_INFO (name
)->low
);
4146 usep
= op_iter_next_use (&iter
);
4150 /* Allocate a value number table. */
4153 allocate_vn_table (vn_tables_t table
)
4155 table
->phis
= new vn_phi_table_type (23);
4156 table
->nary
= new vn_nary_op_table_type (23);
4157 table
->references
= new vn_reference_table_type (23);
4159 gcc_obstack_init (&table
->nary_obstack
);
4160 table
->phis_pool
= new object_allocator
<vn_phi_s
> ("VN phis");
4161 table
->references_pool
= new object_allocator
<vn_reference_s
>
4165 /* Free a value number table. */
4168 free_vn_table (vn_tables_t table
)
4174 delete table
->references
;
4175 table
->references
= NULL
;
4176 obstack_free (&table
->nary_obstack
, NULL
);
4177 delete table
->phis_pool
;
4178 delete table
->references_pool
;
4186 int *rpo_numbers_temp
;
4188 calculate_dominance_info (CDI_DOMINATORS
);
4189 mark_dfs_back_edges ();
4191 sccstack
.create (0);
4192 constant_to_value_id
= new hash_table
<vn_constant_hasher
> (23);
4194 constant_value_ids
= BITMAP_ALLOC (NULL
);
4199 vn_ssa_aux_table
.create (num_ssa_names
+ 1);
4200 /* VEC_alloc doesn't actually grow it to the right size, it just
4201 preallocates the space to do so. */
4202 vn_ssa_aux_table
.safe_grow_cleared (num_ssa_names
+ 1);
4203 gcc_obstack_init (&vn_ssa_aux_obstack
);
4205 shared_lookup_phiargs
.create (0);
4206 shared_lookup_references
.create (0);
4207 rpo_numbers
= XNEWVEC (int, last_basic_block_for_fn (cfun
));
4209 XNEWVEC (int, n_basic_blocks_for_fn (cfun
) - NUM_FIXED_BLOCKS
);
4210 pre_and_rev_post_order_compute (NULL
, rpo_numbers_temp
, false);
4212 /* RPO numbers is an array of rpo ordering, rpo[i] = bb means that
4213 the i'th block in RPO order is bb. We want to map bb's to RPO
4214 numbers, so we need to rearrange this array. */
4215 for (j
= 0; j
< n_basic_blocks_for_fn (cfun
) - NUM_FIXED_BLOCKS
; j
++)
4216 rpo_numbers
[rpo_numbers_temp
[j
]] = j
;
4218 XDELETE (rpo_numbers_temp
);
4220 VN_TOP
= create_tmp_var_raw (void_type_node
, "vn_top");
4222 renumber_gimple_stmt_uids ();
4224 /* Create the valid and optimistic value numbering tables. */
4225 valid_info
= XCNEW (struct vn_tables_s
);
4226 allocate_vn_table (valid_info
);
4227 optimistic_info
= XCNEW (struct vn_tables_s
);
4228 allocate_vn_table (optimistic_info
);
4229 current_info
= valid_info
;
4231 /* Create the VN_INFO structures, and initialize value numbers to
4232 TOP or VARYING for parameters. */
4233 for (i
= 1; i
< num_ssa_names
; i
++)
4235 tree name
= ssa_name (i
);
4239 VN_INFO_GET (name
)->valnum
= VN_TOP
;
4240 VN_INFO (name
)->needs_insertion
= false;
4241 VN_INFO (name
)->expr
= NULL
;
4242 VN_INFO (name
)->value_id
= 0;
4244 if (!SSA_NAME_IS_DEFAULT_DEF (name
))
4247 switch (TREE_CODE (SSA_NAME_VAR (name
)))
4250 /* Undefined vars keep TOP. */
4254 /* Parameters are VARYING but we can record a condition
4255 if we know it is a non-NULL pointer. */
4256 VN_INFO (name
)->visited
= true;
4257 VN_INFO (name
)->valnum
= name
;
4258 if (POINTER_TYPE_P (TREE_TYPE (name
))
4259 && nonnull_arg_p (SSA_NAME_VAR (name
)))
4263 ops
[1] = build_int_cst (TREE_TYPE (name
), 0);
4264 vn_nary_op_insert_pieces (2, NE_EXPR
, boolean_type_node
, ops
,
4265 boolean_true_node
, 0);
4266 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4268 fprintf (dump_file
, "Recording ");
4269 print_generic_expr (dump_file
, name
, TDF_SLIM
);
4270 fprintf (dump_file
, " != 0\n");
4276 /* If the result is passed by invisible reference the default
4277 def is initialized, otherwise it's uninitialized. */
4278 if (DECL_BY_REFERENCE (SSA_NAME_VAR (name
)))
4280 VN_INFO (name
)->visited
= true;
4281 VN_INFO (name
)->valnum
= name
;
4296 delete constant_to_value_id
;
4297 constant_to_value_id
= NULL
;
4298 BITMAP_FREE (constant_value_ids
);
4299 shared_lookup_phiargs
.release ();
4300 shared_lookup_references
.release ();
4301 XDELETEVEC (rpo_numbers
);
4303 for (i
= 0; i
< num_ssa_names
; i
++)
4305 tree name
= ssa_name (i
);
4307 && has_VN_INFO (name
))
4309 if (VN_INFO (name
)->needs_insertion
)
4310 release_ssa_name (name
);
4311 else if (POINTER_TYPE_P (TREE_TYPE (name
))
4312 && VN_INFO (name
)->info
.ptr_info
)
4313 SSA_NAME_PTR_INFO (name
) = VN_INFO (name
)->info
.ptr_info
;
4314 else if (INTEGRAL_TYPE_P (TREE_TYPE (name
))
4315 && VN_INFO (name
)->info
.range_info
)
4316 SSA_NAME_RANGE_INFO (name
) = VN_INFO (name
)->info
.range_info
;
4319 obstack_free (&vn_ssa_aux_obstack
, NULL
);
4320 vn_ssa_aux_table
.release ();
4322 sccstack
.release ();
4323 free_vn_table (valid_info
);
4324 XDELETE (valid_info
);
4325 free_vn_table (optimistic_info
);
4326 XDELETE (optimistic_info
);
4328 BITMAP_FREE (const_parms
);
4331 /* Set *ID according to RESULT. */
4334 set_value_id_for_result (tree result
, unsigned int *id
)
4336 if (result
&& TREE_CODE (result
) == SSA_NAME
)
4337 *id
= VN_INFO (result
)->value_id
;
4338 else if (result
&& is_gimple_min_invariant (result
))
4339 *id
= get_or_alloc_constant_value_id (result
);
4341 *id
= get_next_value_id ();
4344 /* Set the value ids in the valid hash tables. */
4347 set_hashtable_value_ids (void)
4349 vn_nary_op_iterator_type hin
;
4350 vn_phi_iterator_type hip
;
4351 vn_reference_iterator_type hir
;
4356 /* Now set the value ids of the things we had put in the hash
4359 FOR_EACH_HASH_TABLE_ELEMENT (*valid_info
->nary
, vno
, vn_nary_op_t
, hin
)
4360 set_value_id_for_result (vno
->result
, &vno
->value_id
);
4362 FOR_EACH_HASH_TABLE_ELEMENT (*valid_info
->phis
, vp
, vn_phi_t
, hip
)
4363 set_value_id_for_result (vp
->result
, &vp
->value_id
);
4365 FOR_EACH_HASH_TABLE_ELEMENT (*valid_info
->references
, vr
, vn_reference_t
,
4367 set_value_id_for_result (vr
->result
, &vr
->value_id
);
4370 class sccvn_dom_walker
: public dom_walker
4374 : dom_walker (CDI_DOMINATORS
, true), fail (false), cond_stack (vNULL
) {}
4375 ~sccvn_dom_walker ();
4377 virtual edge
before_dom_children (basic_block
);
4378 virtual void after_dom_children (basic_block
);
4380 void record_cond (basic_block
,
4381 enum tree_code code
, tree lhs
, tree rhs
, bool value
);
4382 void record_conds (basic_block
,
4383 enum tree_code code
, tree lhs
, tree rhs
, bool value
);
4386 vec
<std::pair
<basic_block
, std::pair
<vn_nary_op_t
, vn_nary_op_t
> > >
4390 sccvn_dom_walker::~sccvn_dom_walker ()
4392 cond_stack
.release ();
4395 /* Record a temporary condition for the BB and its dominated blocks. */
4398 sccvn_dom_walker::record_cond (basic_block bb
,
4399 enum tree_code code
, tree lhs
, tree rhs
,
4402 tree ops
[2] = { lhs
, rhs
};
4403 vn_nary_op_t old
= NULL
;
4404 if (vn_nary_op_lookup_pieces (2, code
, boolean_type_node
, ops
, &old
))
4405 current_info
->nary
->remove_elt_with_hash (old
, old
->hashcode
);
4407 = vn_nary_op_insert_pieces (2, code
, boolean_type_node
, ops
,
4410 : boolean_false_node
, 0);
4411 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4413 fprintf (dump_file
, "Recording temporarily ");
4414 print_generic_expr (dump_file
, ops
[0], TDF_SLIM
);
4415 fprintf (dump_file
, " %s ", get_tree_code_name (code
));
4416 print_generic_expr (dump_file
, ops
[1], TDF_SLIM
);
4417 fprintf (dump_file
, " == %s%s\n",
4418 value
? "true" : "false",
4419 old
? " (old entry saved)" : "");
4421 cond_stack
.safe_push (std::make_pair (bb
, std::make_pair (cond
, old
)));
4424 /* Record temporary conditions for the BB and its dominated blocks
4425 according to LHS CODE RHS == VALUE and its dominated conditions. */
4428 sccvn_dom_walker::record_conds (basic_block bb
,
4429 enum tree_code code
, tree lhs
, tree rhs
,
4432 /* Record the original condition. */
4433 record_cond (bb
, code
, lhs
, rhs
, value
);
4438 /* Record dominated conditions if the condition is true. Note that
4439 the inversion is already recorded. */
4444 record_cond (bb
, code
== LT_EXPR
? LE_EXPR
: GE_EXPR
, lhs
, rhs
, true);
4445 record_cond (bb
, NE_EXPR
, lhs
, rhs
, true);
4446 record_cond (bb
, EQ_EXPR
, lhs
, rhs
, false);
4450 record_cond (bb
, LE_EXPR
, lhs
, rhs
, true);
4451 record_cond (bb
, GE_EXPR
, lhs
, rhs
, true);
4452 record_cond (bb
, LT_EXPR
, lhs
, rhs
, false);
4453 record_cond (bb
, GT_EXPR
, lhs
, rhs
, false);
4461 /* Restore expressions and values derived from conditionals. */
4464 sccvn_dom_walker::after_dom_children (basic_block bb
)
4466 while (!cond_stack
.is_empty ()
4467 && cond_stack
.last ().first
== bb
)
4469 vn_nary_op_t cond
= cond_stack
.last ().second
.first
;
4470 vn_nary_op_t old
= cond_stack
.last ().second
.second
;
4471 current_info
->nary
->remove_elt_with_hash (cond
, cond
->hashcode
);
4473 vn_nary_op_insert_into (old
, current_info
->nary
, false);
4478 /* Value number all statements in BB. */
4481 sccvn_dom_walker::before_dom_children (basic_block bb
)
4489 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4490 fprintf (dump_file
, "Visiting BB %d\n", bb
->index
);
4492 /* If we have a single predecessor record the equivalence from a
4493 possible condition on the predecessor edge. */
4495 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4497 /* Ignore simple backedges from this to allow recording conditions
4499 if (dominated_by_p (CDI_DOMINATORS
, e
->src
, e
->dest
))
4511 /* Check if there are multiple executable successor edges in
4512 the source block. Otherwise there is no additional info
4515 FOR_EACH_EDGE (e2
, ei
, pred_e
->src
->succs
)
4517 && e2
->flags
& EDGE_EXECUTABLE
)
4519 if (e2
&& (e2
->flags
& EDGE_EXECUTABLE
))
4521 gimple
*stmt
= last_stmt (pred_e
->src
);
4523 && gimple_code (stmt
) == GIMPLE_COND
)
4525 enum tree_code code
= gimple_cond_code (stmt
);
4526 tree lhs
= gimple_cond_lhs (stmt
);
4527 tree rhs
= gimple_cond_rhs (stmt
);
4528 record_conds (bb
, code
, lhs
, rhs
,
4529 (pred_e
->flags
& EDGE_TRUE_VALUE
) != 0);
4530 code
= invert_tree_comparison (code
, HONOR_NANS (lhs
));
4531 if (code
!= ERROR_MARK
)
4532 record_conds (bb
, code
, lhs
, rhs
,
4533 (pred_e
->flags
& EDGE_TRUE_VALUE
) == 0);
4538 /* Value-number all defs in the basic-block. */
4539 for (gphi_iterator gsi
= gsi_start_phis (bb
);
4540 !gsi_end_p (gsi
); gsi_next (&gsi
))
4542 gphi
*phi
= gsi
.phi ();
4543 tree res
= PHI_RESULT (phi
);
4544 if (!VN_INFO (res
)->visited
4551 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
4552 !gsi_end_p (gsi
); gsi_next (&gsi
))
4556 FOR_EACH_SSA_TREE_OPERAND (op
, gsi_stmt (gsi
), i
, SSA_OP_ALL_DEFS
)
4557 if (!VN_INFO (op
)->visited
4565 /* Finally look at the last stmt. */
4566 gimple
*stmt
= last_stmt (bb
);
4570 enum gimple_code code
= gimple_code (stmt
);
4571 if (code
!= GIMPLE_COND
4572 && code
!= GIMPLE_SWITCH
4573 && code
!= GIMPLE_GOTO
)
4576 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4578 fprintf (dump_file
, "Visiting control stmt ending BB %d: ", bb
->index
);
4579 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4582 /* ??? We can even handle stmts with outgoing EH or ABNORMAL edges
4583 if value-numbering can prove they are not reachable. Handling
4584 computed gotos is also possible. */
4590 tree lhs
= vn_valueize (gimple_cond_lhs (stmt
));
4591 tree rhs
= vn_valueize (gimple_cond_rhs (stmt
));
4592 val
= gimple_simplify (gimple_cond_code (stmt
),
4593 boolean_type_node
, lhs
, rhs
,
4595 /* If that didn't simplify to a constant see if we have recorded
4596 temporary expressions from taken edges. */
4597 if (!val
|| TREE_CODE (val
) != INTEGER_CST
)
4602 val
= vn_nary_op_lookup_pieces (2, gimple_cond_code (stmt
),
4603 boolean_type_node
, ops
, NULL
);
4608 val
= gimple_switch_index (as_a
<gswitch
*> (stmt
));
4611 val
= gimple_goto_dest (stmt
);
4619 edge taken
= find_taken_edge (bb
, vn_valueize (val
));
4623 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4624 fprintf (dump_file
, "Marking all edges out of BB %d but (%d -> %d) as "
4625 "not executable\n", bb
->index
, bb
->index
, taken
->dest
->index
);
4630 /* Do SCCVN. Returns true if it finished, false if we bailed out
4631 due to resource constraints. DEFAULT_VN_WALK_KIND_ specifies
4632 how we use the alias oracle walking during the VN process. */
4635 run_scc_vn (vn_lookup_kind default_vn_walk_kind_
)
4639 default_vn_walk_kind
= default_vn_walk_kind_
;
4643 /* Collect pointers we know point to readonly memory. */
4644 const_parms
= BITMAP_ALLOC (NULL
);
4645 tree fnspec
= lookup_attribute ("fn spec",
4646 TYPE_ATTRIBUTES (TREE_TYPE (cfun
->decl
)));
4649 fnspec
= TREE_VALUE (TREE_VALUE (fnspec
));
4651 for (tree arg
= DECL_ARGUMENTS (cfun
->decl
);
4652 arg
; arg
= DECL_CHAIN (arg
), ++i
)
4654 if (i
>= (unsigned) TREE_STRING_LENGTH (fnspec
))
4656 if (TREE_STRING_POINTER (fnspec
)[i
] == 'R'
4657 || TREE_STRING_POINTER (fnspec
)[i
] == 'r')
4659 tree name
= ssa_default_def (cfun
, arg
);
4661 bitmap_set_bit (const_parms
, SSA_NAME_VERSION (name
));
4666 /* Walk all blocks in dominator order, value-numbering stmts
4667 SSA defs and decide whether outgoing edges are not executable. */
4668 sccvn_dom_walker walker
;
4669 walker
.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun
));
4676 /* Initialize the value ids and prune out remaining VN_TOPs
4678 for (i
= 1; i
< num_ssa_names
; ++i
)
4680 tree name
= ssa_name (i
);
4684 info
= VN_INFO (name
);
4686 info
->valnum
= name
;
4687 if (info
->valnum
== name
4688 || info
->valnum
== VN_TOP
)
4689 info
->value_id
= get_next_value_id ();
4690 else if (is_gimple_min_invariant (info
->valnum
))
4691 info
->value_id
= get_or_alloc_constant_value_id (info
->valnum
);
4695 for (i
= 1; i
< num_ssa_names
; ++i
)
4697 tree name
= ssa_name (i
);
4701 info
= VN_INFO (name
);
4702 if (TREE_CODE (info
->valnum
) == SSA_NAME
4703 && info
->valnum
!= name
4704 && info
->value_id
!= VN_INFO (info
->valnum
)->value_id
)
4705 info
->value_id
= VN_INFO (info
->valnum
)->value_id
;
4708 set_hashtable_value_ids ();
4710 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4712 fprintf (dump_file
, "Value numbers:\n");
4713 for (i
= 0; i
< num_ssa_names
; i
++)
4715 tree name
= ssa_name (i
);
4717 && VN_INFO (name
)->visited
4718 && SSA_VAL (name
) != name
)
4720 print_generic_expr (dump_file
, name
, 0);
4721 fprintf (dump_file
, " = ");
4722 print_generic_expr (dump_file
, SSA_VAL (name
), 0);
4723 fprintf (dump_file
, "\n");
4731 /* Return the maximum value id we have ever seen. */
4734 get_max_value_id (void)
4736 return next_value_id
;
4739 /* Return the next unique value id. */
4742 get_next_value_id (void)
4744 return next_value_id
++;
4748 /* Compare two expressions E1 and E2 and return true if they are equal. */
4751 expressions_equal_p (tree e1
, tree e2
)
4753 /* The obvious case. */
4757 /* If either one is VN_TOP consider them equal. */
4758 if (e1
== VN_TOP
|| e2
== VN_TOP
)
4761 /* If only one of them is null, they cannot be equal. */
4765 /* Now perform the actual comparison. */
4766 if (TREE_CODE (e1
) == TREE_CODE (e2
)
4767 && operand_equal_p (e1
, e2
, OEP_PURE_SAME
))
4774 /* Return true if the nary operation NARY may trap. This is a copy
4775 of stmt_could_throw_1_p adjusted to the SCCVN IL. */
4778 vn_nary_may_trap (vn_nary_op_t nary
)
4781 tree rhs2
= NULL_TREE
;
4782 bool honor_nans
= false;
4783 bool honor_snans
= false;
4784 bool fp_operation
= false;
4785 bool honor_trapv
= false;
4789 if (TREE_CODE_CLASS (nary
->opcode
) == tcc_comparison
4790 || TREE_CODE_CLASS (nary
->opcode
) == tcc_unary
4791 || TREE_CODE_CLASS (nary
->opcode
) == tcc_binary
)
4794 fp_operation
= FLOAT_TYPE_P (type
);
4797 honor_nans
= flag_trapping_math
&& !flag_finite_math_only
;
4798 honor_snans
= flag_signaling_nans
!= 0;
4800 else if (INTEGRAL_TYPE_P (type
)
4801 && TYPE_OVERFLOW_TRAPS (type
))
4804 if (nary
->length
>= 2)
4806 ret
= operation_could_trap_helper_p (nary
->opcode
, fp_operation
,
4808 honor_nans
, honor_snans
, rhs2
,
4814 for (i
= 0; i
< nary
->length
; ++i
)
4815 if (tree_could_trap_p (nary
->op
[i
]))