1 /* Full and partial redundancy elimination and code hoisting on SSA GIMPLE.
2 Copyright (C) 2001-2017 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
30 #include "alloc-pool.h"
31 #include "tree-pass.h"
34 #include "gimple-pretty-print.h"
35 #include "fold-const.h"
37 #include "gimple-fold.h"
40 #include "gimple-iterator.h"
42 #include "tree-ssa-loop.h"
43 #include "tree-into-ssa.h"
47 #include "tree-ssa-sccvn.h"
48 #include "tree-scalar-evolution.h"
52 #include "tree-ssa-propagate.h"
53 #include "ipa-utils.h"
54 #include "tree-cfgcleanup.h"
55 #include "langhooks.h"
58 /* Even though this file is called tree-ssa-pre.c, we actually
59 implement a bit more than just PRE here. All of them piggy-back
60 on GVN which is implemented in tree-ssa-sccvn.c.
62 1. Full Redundancy Elimination (FRE)
63 This is the elimination phase of GVN.
65 2. Partial Redundancy Elimination (PRE)
66 This is adds computation of AVAIL_OUT and ANTIC_IN and
67 doing expression insertion to form GVN-PRE.
70 This optimization uses the ANTIC_IN sets computed for PRE
71 to move expressions further up than PRE would do, to make
72 multiple computations of the same value fully redundant.
73 This pass is explained below (after the explanation of the
74 basic algorithm for PRE).
79 1. Avail sets can be shared by making an avail_find_leader that
80 walks up the dominator tree and looks in those avail sets.
81 This might affect code optimality, it's unclear right now.
82 Currently the AVAIL_OUT sets are the remaining quadraticness in
84 2. Strength reduction can be performed by anticipating expressions
85 we can repair later on.
86 3. We can do back-substitution or smarter value numbering to catch
87 commutative expressions split up over multiple statements.
90 /* For ease of terminology, "expression node" in the below refers to
91 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
92 represent the actual statement containing the expressions we care about,
93 and we cache the value number by putting it in the expression. */
95 /* Basic algorithm for Partial Redundancy Elimination:
97 First we walk the statements to generate the AVAIL sets, the
98 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
99 generation of values/expressions by a given block. We use them
100 when computing the ANTIC sets. The AVAIL sets consist of
101 SSA_NAME's that represent values, so we know what values are
102 available in what blocks. AVAIL is a forward dataflow problem. In
103 SSA, values are never killed, so we don't need a kill set, or a
104 fixpoint iteration, in order to calculate the AVAIL sets. In
105 traditional parlance, AVAIL sets tell us the downsafety of the
108 Next, we generate the ANTIC sets. These sets represent the
109 anticipatable expressions. ANTIC is a backwards dataflow
110 problem. An expression is anticipatable in a given block if it could
111 be generated in that block. This means that if we had to perform
112 an insertion in that block, of the value of that expression, we
113 could. Calculating the ANTIC sets requires phi translation of
114 expressions, because the flow goes backwards through phis. We must
115 iterate to a fixpoint of the ANTIC sets, because we have a kill
116 set. Even in SSA form, values are not live over the entire
117 function, only from their definition point onwards. So we have to
118 remove values from the ANTIC set once we go past the definition
119 point of the leaders that make them up.
120 compute_antic/compute_antic_aux performs this computation.
122 Third, we perform insertions to make partially redundant
123 expressions fully redundant.
125 An expression is partially redundant (excluding partial
128 1. It is AVAIL in some, but not all, of the predecessors of a
130 2. It is ANTIC in all the predecessors.
132 In order to make it fully redundant, we insert the expression into
133 the predecessors where it is not available, but is ANTIC.
135 When optimizing for size, we only eliminate the partial redundancy
136 if we need to insert in only one predecessor. This avoids almost
137 completely the code size increase that PRE usually causes.
139 For the partial anticipation case, we only perform insertion if it
140 is partially anticipated in some block, and fully available in all
143 do_pre_regular_insertion/do_pre_partial_partial_insertion
144 performs these steps, driven by insert/insert_aux.
146 Fourth, we eliminate fully redundant expressions.
147 This is a simple statement walk that replaces redundant
148 calculations with the now available values. */
150 /* Basic algorithm for Code Hoisting:
152 Code hoisting is: Moving value computations up in the control flow
153 graph to make multiple copies redundant. Typically this is a size
154 optimization, but there are cases where it also is helpful for speed.
156 A simple code hoisting algorithm is implemented that piggy-backs on
157 the PRE infrastructure. For code hoisting, we have to know ANTIC_OUT
158 which is effectively ANTIC_IN - AVAIL_OUT. The latter two have to be
159 computed for PRE, and we can use them to perform a limited version of
162 For the purpose of this implementation, a value is hoistable to a basic
163 block B if the following properties are met:
165 1. The value is in ANTIC_IN(B) -- the value will be computed on all
166 paths from B to function exit and it can be computed in B);
168 2. The value is not in AVAIL_OUT(B) -- there would be no need to
169 compute the value again and make it available twice;
171 3. All successors of B are dominated by B -- makes sure that inserting
172 a computation of the value in B will make the remaining
173 computations fully redundant;
175 4. At least one successor has the value in AVAIL_OUT -- to avoid
176 hoisting values up too far;
178 5. There are at least two successors of B -- hoisting in straight
179 line code is pointless.
181 The third condition is not strictly necessary, but it would complicate
182 the hoisting pass a lot. In fact, I don't know of any code hoisting
183 algorithm that does not have this requirement. Fortunately, experiments
184 have show that most candidate hoistable values are in regions that meet
185 this condition (e.g. diamond-shape regions).
187 The forth condition is necessary to avoid hoisting things up too far
188 away from the uses of the value. Nothing else limits the algorithm
189 from hoisting everything up as far as ANTIC_IN allows. Experiments
190 with SPEC and CSiBE have shown that hoisting up too far results in more
191 spilling, less benefits for code size, and worse benchmark scores.
192 Fortunately, in practice most of the interesting hoisting opportunities
193 are caught despite this limitation.
195 For hoistable values that meet all conditions, expressions are inserted
196 to make the calculation of the hoistable value fully redundant. We
197 perform code hoisting insertions after each round of PRE insertions,
198 because code hoisting never exposes new PRE opportunities, but PRE can
199 create new code hoisting opportunities.
201 The code hoisting algorithm is implemented in do_hoist_insert, driven
202 by insert/insert_aux. */
204 /* Representations of value numbers:
206 Value numbers are represented by a representative SSA_NAME. We
207 will create fake SSA_NAME's in situations where we need a
208 representative but do not have one (because it is a complex
209 expression). In order to facilitate storing the value numbers in
210 bitmaps, and keep the number of wasted SSA_NAME's down, we also
211 associate a value_id with each value number, and create full blown
212 ssa_name's only where we actually need them (IE in operands of
213 existing expressions).
215 Theoretically you could replace all the value_id's with
216 SSA_NAME_VERSION, but this would allocate a large number of
217 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
218 It would also require an additional indirection at each point we
221 /* Representation of expressions on value numbers:
223 Expressions consisting of value numbers are represented the same
224 way as our VN internally represents them, with an additional
225 "pre_expr" wrapping around them in order to facilitate storing all
226 of the expressions in the same sets. */
228 /* Representation of sets:
230 The dataflow sets do not need to be sorted in any particular order
231 for the majority of their lifetime, are simply represented as two
232 bitmaps, one that keeps track of values present in the set, and one
233 that keeps track of expressions present in the set.
235 When we need them in topological order, we produce it on demand by
236 transforming the bitmap into an array and sorting it into topo
239 /* Type of expression, used to know which member of the PRE_EXPR union
255 vn_reference_t reference
;
258 typedef struct pre_expr_d
: nofree_ptr_hash
<pre_expr_d
>
260 enum pre_expr_kind kind
;
264 /* hash_table support. */
265 static inline hashval_t
hash (const pre_expr_d
*);
266 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
269 #define PRE_EXPR_NAME(e) (e)->u.name
270 #define PRE_EXPR_NARY(e) (e)->u.nary
271 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
272 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
274 /* Compare E1 and E1 for equality. */
277 pre_expr_d::equal (const pre_expr_d
*e1
, const pre_expr_d
*e2
)
279 if (e1
->kind
!= e2
->kind
)
285 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
286 PRE_EXPR_CONSTANT (e2
));
288 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
290 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
292 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
293 PRE_EXPR_REFERENCE (e2
));
302 pre_expr_d::hash (const pre_expr_d
*e
)
307 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
309 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
311 return PRE_EXPR_NARY (e
)->hashcode
;
313 return PRE_EXPR_REFERENCE (e
)->hashcode
;
319 /* Next global expression id number. */
320 static unsigned int next_expression_id
;
322 /* Mapping from expression to id number we can use in bitmap sets. */
323 static vec
<pre_expr
> expressions
;
324 static hash_table
<pre_expr_d
> *expression_to_id
;
325 static vec
<unsigned> name_to_id
;
327 /* Allocate an expression id for EXPR. */
329 static inline unsigned int
330 alloc_expression_id (pre_expr expr
)
332 struct pre_expr_d
**slot
;
333 /* Make sure we won't overflow. */
334 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
335 expr
->id
= next_expression_id
++;
336 expressions
.safe_push (expr
);
337 if (expr
->kind
== NAME
)
339 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
340 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
341 re-allocations by using vec::reserve upfront. */
342 unsigned old_len
= name_to_id
.length ();
343 name_to_id
.reserve (num_ssa_names
- old_len
);
344 name_to_id
.quick_grow_cleared (num_ssa_names
);
345 gcc_assert (name_to_id
[version
] == 0);
346 name_to_id
[version
] = expr
->id
;
350 slot
= expression_to_id
->find_slot (expr
, INSERT
);
354 return next_expression_id
- 1;
357 /* Return the expression id for tree EXPR. */
359 static inline unsigned int
360 get_expression_id (const pre_expr expr
)
365 static inline unsigned int
366 lookup_expression_id (const pre_expr expr
)
368 struct pre_expr_d
**slot
;
370 if (expr
->kind
== NAME
)
372 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
373 if (name_to_id
.length () <= version
)
375 return name_to_id
[version
];
379 slot
= expression_to_id
->find_slot (expr
, NO_INSERT
);
382 return ((pre_expr
)*slot
)->id
;
386 /* Return the existing expression id for EXPR, or create one if one
387 does not exist yet. */
389 static inline unsigned int
390 get_or_alloc_expression_id (pre_expr expr
)
392 unsigned int id
= lookup_expression_id (expr
);
394 return alloc_expression_id (expr
);
395 return expr
->id
= id
;
398 /* Return the expression that has expression id ID */
400 static inline pre_expr
401 expression_for_id (unsigned int id
)
403 return expressions
[id
];
406 /* Free the expression id field in all of our expressions,
407 and then destroy the expressions array. */
410 clear_expression_ids (void)
412 expressions
.release ();
415 static object_allocator
<pre_expr_d
> pre_expr_pool ("pre_expr nodes");
417 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
420 get_or_alloc_expr_for_name (tree name
)
422 struct pre_expr_d expr
;
424 unsigned int result_id
;
428 PRE_EXPR_NAME (&expr
) = name
;
429 result_id
= lookup_expression_id (&expr
);
431 return expression_for_id (result_id
);
433 result
= pre_expr_pool
.allocate ();
435 PRE_EXPR_NAME (result
) = name
;
436 alloc_expression_id (result
);
440 /* An unordered bitmap set. One bitmap tracks values, the other,
442 typedef struct bitmap_set
444 bitmap_head expressions
;
448 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
449 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
451 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
452 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
454 /* Mapping from value id to expressions with that value_id. */
455 static vec
<bitmap
> value_expressions
;
457 /* Sets that we need to keep track of. */
458 typedef struct bb_bitmap_sets
460 /* The EXP_GEN set, which represents expressions/values generated in
462 bitmap_set_t exp_gen
;
464 /* The PHI_GEN set, which represents PHI results generated in a
466 bitmap_set_t phi_gen
;
468 /* The TMP_GEN set, which represents results/temporaries generated
469 in a basic block. IE the LHS of an expression. */
470 bitmap_set_t tmp_gen
;
472 /* The AVAIL_OUT set, which represents which values are available in
473 a given basic block. */
474 bitmap_set_t avail_out
;
476 /* The ANTIC_IN set, which represents which values are anticipatable
477 in a given basic block. */
478 bitmap_set_t antic_in
;
480 /* The PA_IN set, which represents which values are
481 partially anticipatable in a given basic block. */
484 /* The NEW_SETS set, which is used during insertion to augment the
485 AVAIL_OUT set of blocks with the new insertions performed during
486 the current iteration. */
487 bitmap_set_t new_sets
;
489 /* A cache for value_dies_in_block_x. */
492 /* The live virtual operand on successor edges. */
495 /* True if we have visited this block during ANTIC calculation. */
496 unsigned int visited
: 1;
498 /* True when the block contains a call that might not return. */
499 unsigned int contains_may_not_return_call
: 1;
502 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
503 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
504 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
505 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
506 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
507 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
508 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
509 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
510 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
511 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
512 #define BB_LIVE_VOP_ON_EXIT(BB) ((bb_value_sets_t) ((BB)->aux))->vop_on_exit
515 /* This structure is used to keep track of statistics on what
516 optimization PRE was able to perform. */
519 /* The number of RHS computations eliminated by PRE. */
522 /* The number of new expressions/temporaries generated by PRE. */
525 /* The number of inserts found due to partial anticipation */
528 /* The number of inserts made for code hoisting. */
531 /* The number of new PHI nodes added by PRE. */
535 static bool do_partial_partial
;
536 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
537 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
538 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
539 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
540 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
541 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
542 static bitmap_set_t
bitmap_set_new (void);
543 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
545 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
546 static unsigned int get_expr_value_id (pre_expr
);
548 /* We can add and remove elements and entries to and from sets
549 and hash tables, so we use alloc pools for them. */
551 static object_allocator
<bitmap_set
> bitmap_set_pool ("Bitmap sets");
552 static bitmap_obstack grand_bitmap_obstack
;
554 /* Set of blocks with statements that have had their EH properties changed. */
555 static bitmap need_eh_cleanup
;
557 /* Set of blocks with statements that have had their AB properties changed. */
558 static bitmap need_ab_cleanup
;
560 /* A three tuple {e, pred, v} used to cache phi translations in the
561 phi_translate_table. */
563 typedef struct expr_pred_trans_d
: free_ptr_hash
<expr_pred_trans_d
>
565 /* The expression. */
568 /* The predecessor block along which we translated the expression. */
571 /* The value that resulted from the translation. */
574 /* The hashcode for the expression, pred pair. This is cached for
578 /* hash_table support. */
579 static inline hashval_t
hash (const expr_pred_trans_d
*);
580 static inline int equal (const expr_pred_trans_d
*, const expr_pred_trans_d
*);
581 } *expr_pred_trans_t
;
582 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
585 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
591 expr_pred_trans_d::equal (const expr_pred_trans_d
*ve1
,
592 const expr_pred_trans_d
*ve2
)
594 basic_block b1
= ve1
->pred
;
595 basic_block b2
= ve2
->pred
;
597 /* If they are not translations for the same basic block, they can't
601 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
604 /* The phi_translate_table caches phi translations for a given
605 expression and predecessor. */
606 static hash_table
<expr_pred_trans_d
> *phi_translate_table
;
608 /* Add the tuple mapping from {expression E, basic block PRED} to
609 the phi translation table and return whether it pre-existed. */
612 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
614 expr_pred_trans_t
*slot
;
615 expr_pred_trans_d tem
;
616 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
621 slot
= phi_translate_table
->find_slot_with_hash (&tem
, hash
, INSERT
);
628 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
630 (*entry
)->pred
= pred
;
631 (*entry
)->hashcode
= hash
;
636 /* Add expression E to the expression set of value id V. */
639 add_to_value (unsigned int v
, pre_expr e
)
643 gcc_checking_assert (get_expr_value_id (e
) == v
);
645 if (v
>= value_expressions
.length ())
647 value_expressions
.safe_grow_cleared (v
+ 1);
650 set
= value_expressions
[v
];
653 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
654 value_expressions
[v
] = set
;
657 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
660 /* Create a new bitmap set and return it. */
663 bitmap_set_new (void)
665 bitmap_set_t ret
= bitmap_set_pool
.allocate ();
666 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
667 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
671 /* Return the value id for a PRE expression EXPR. */
674 get_expr_value_id (pre_expr expr
)
680 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
683 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
686 id
= PRE_EXPR_NARY (expr
)->value_id
;
689 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
694 /* ??? We cannot assert that expr has a value-id (it can be 0), because
695 we assign value-ids only to expressions that have a result
696 in set_hashtable_value_ids. */
700 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
703 sccvn_valnum_from_value_id (unsigned int val
)
707 bitmap exprset
= value_expressions
[val
];
708 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
710 pre_expr vexpr
= expression_for_id (i
);
711 if (vexpr
->kind
== NAME
)
712 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
713 else if (vexpr
->kind
== CONSTANT
)
714 return PRE_EXPR_CONSTANT (vexpr
);
719 /* Remove an expression EXPR from a bitmapped set. */
722 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
724 unsigned int val
= get_expr_value_id (expr
);
725 if (!value_id_constant_p (val
))
727 bitmap_clear_bit (&set
->values
, val
);
728 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
732 /* Insert an expression EXPR into a bitmapped set. */
735 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
737 unsigned int val
= get_expr_value_id (expr
);
738 if (! value_id_constant_p (val
))
740 /* Note this is the only function causing multiple expressions
741 for the same value to appear in a set. This is needed for
742 TMP_GEN, PHI_GEN and NEW_SETs. */
743 bitmap_set_bit (&set
->values
, val
);
744 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
748 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
751 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
753 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
754 bitmap_copy (&dest
->values
, &orig
->values
);
758 /* Free memory used up by SET. */
760 bitmap_set_free (bitmap_set_t set
)
762 bitmap_clear (&set
->expressions
);
763 bitmap_clear (&set
->values
);
767 /* Generate an topological-ordered array of bitmap set SET. */
770 sorted_array_from_bitmap_set (bitmap_set_t set
)
773 bitmap_iterator bi
, bj
;
774 vec
<pre_expr
> result
;
776 /* Pre-allocate enough space for the array. */
777 result
.create (bitmap_count_bits (&set
->expressions
));
779 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
781 /* The number of expressions having a given value is usually
782 relatively small. Thus, rather than making a vector of all
783 the expressions and sorting it by value-id, we walk the values
784 and check in the reverse mapping that tells us what expressions
785 have a given value, to filter those in our set. As a result,
786 the expressions are inserted in value-id order, which means
789 If this is somehow a significant lose for some cases, we can
790 choose which set to walk based on the set size. */
791 bitmap exprset
= value_expressions
[i
];
792 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
794 if (bitmap_bit_p (&set
->expressions
, j
))
795 result
.quick_push (expression_for_id (j
));
802 /* Subtract all expressions contained in ORIG from DEST. */
805 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
807 bitmap_set_t result
= bitmap_set_new ();
811 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
814 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
816 pre_expr expr
= expression_for_id (i
);
817 unsigned int value_id
= get_expr_value_id (expr
);
818 bitmap_set_bit (&result
->values
, value_id
);
824 /* Subtract all values in bitmap set B from bitmap set A. */
827 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
831 pre_expr to_remove
= NULL
;
832 FOR_EACH_EXPR_ID_IN_SET (a
, i
, bi
)
836 bitmap_remove_from_set (a
, to_remove
);
839 pre_expr expr
= expression_for_id (i
);
840 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
844 bitmap_remove_from_set (a
, to_remove
);
848 /* Return true if bitmapped set SET contains the value VALUE_ID. */
851 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
853 if (value_id_constant_p (value_id
))
856 if (!set
|| bitmap_empty_p (&set
->expressions
))
859 return bitmap_bit_p (&set
->values
, value_id
);
863 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
865 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
868 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
871 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
878 if (value_id_constant_p (lookfor
))
881 if (!bitmap_set_contains_value (set
, lookfor
))
884 /* The number of expressions having a given value is usually
885 significantly less than the total number of expressions in SET.
886 Thus, rather than check, for each expression in SET, whether it
887 has the value LOOKFOR, we walk the reverse mapping that tells us
888 what expressions have a given value, and see if any of those
889 expressions are in our set. For large testcases, this is about
890 5-10x faster than walking the bitmap. If this is somehow a
891 significant lose for some cases, we can choose which set to walk
892 based on the set size. */
893 exprset
= value_expressions
[lookfor
];
894 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
896 if (bitmap_clear_bit (&set
->expressions
, i
))
898 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
906 /* Return true if two bitmap sets are equal. */
909 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
911 return bitmap_equal_p (&a
->values
, &b
->values
);
914 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
915 and add it otherwise. */
918 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
920 unsigned int val
= get_expr_value_id (expr
);
922 if (bitmap_set_contains_value (set
, val
))
923 bitmap_set_replace_value (set
, val
, expr
);
925 bitmap_insert_into_set (set
, expr
);
928 /* Insert EXPR into SET if EXPR's value is not already present in
932 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
934 unsigned int val
= get_expr_value_id (expr
);
936 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
938 /* Constant values are always considered to be part of the set. */
939 if (value_id_constant_p (val
))
942 /* If the value membership changed, add the expression. */
943 if (bitmap_set_bit (&set
->values
, val
))
944 bitmap_set_bit (&set
->expressions
, expr
->id
);
947 /* Print out EXPR to outfile. */
950 print_pre_expr (FILE *outfile
, const pre_expr expr
)
954 fprintf (outfile
, "NULL");
960 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
));
963 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
));
968 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
969 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
970 for (i
= 0; i
< nary
->length
; i
++)
972 print_generic_expr (outfile
, nary
->op
[i
]);
973 if (i
!= (unsigned) nary
->length
- 1)
974 fprintf (outfile
, ",");
976 fprintf (outfile
, "}");
982 vn_reference_op_t vro
;
984 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
985 fprintf (outfile
, "{");
987 ref
->operands
.iterate (i
, &vro
);
990 bool closebrace
= false;
991 if (vro
->opcode
!= SSA_NAME
992 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
994 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
997 fprintf (outfile
, "<");
1003 print_generic_expr (outfile
, vro
->op0
);
1006 fprintf (outfile
, ",");
1007 print_generic_expr (outfile
, vro
->op1
);
1011 fprintf (outfile
, ",");
1012 print_generic_expr (outfile
, vro
->op2
);
1016 fprintf (outfile
, ">");
1017 if (i
!= ref
->operands
.length () - 1)
1018 fprintf (outfile
, ",");
1020 fprintf (outfile
, "}");
1023 fprintf (outfile
, "@");
1024 print_generic_expr (outfile
, ref
->vuse
);
1030 void debug_pre_expr (pre_expr
);
1032 /* Like print_pre_expr but always prints to stderr. */
1034 debug_pre_expr (pre_expr e
)
1036 print_pre_expr (stderr
, e
);
1037 fprintf (stderr
, "\n");
1040 /* Print out SET to OUTFILE. */
1043 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
1044 const char *setname
, int blockindex
)
1046 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1053 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1055 const pre_expr expr
= expression_for_id (i
);
1058 fprintf (outfile
, ", ");
1060 print_pre_expr (outfile
, expr
);
1062 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1065 fprintf (outfile
, " }\n");
1068 void debug_bitmap_set (bitmap_set_t
);
1071 debug_bitmap_set (bitmap_set_t set
)
1073 print_bitmap_set (stderr
, set
, "debug", 0);
1076 void debug_bitmap_sets_for (basic_block
);
1079 debug_bitmap_sets_for (basic_block bb
)
1081 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1082 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1083 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1084 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1085 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1086 if (do_partial_partial
)
1087 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1088 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1091 /* Print out the expressions that have VAL to OUTFILE. */
1094 print_value_expressions (FILE *outfile
, unsigned int val
)
1096 bitmap set
= value_expressions
[val
];
1101 sprintf (s
, "%04d", val
);
1102 x
.expressions
= *set
;
1103 print_bitmap_set (outfile
, &x
, s
, 0);
1109 debug_value_expressions (unsigned int val
)
1111 print_value_expressions (stderr
, val
);
1114 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1118 get_or_alloc_expr_for_constant (tree constant
)
1120 unsigned int result_id
;
1121 unsigned int value_id
;
1122 struct pre_expr_d expr
;
1125 expr
.kind
= CONSTANT
;
1126 PRE_EXPR_CONSTANT (&expr
) = constant
;
1127 result_id
= lookup_expression_id (&expr
);
1129 return expression_for_id (result_id
);
1131 newexpr
= pre_expr_pool
.allocate ();
1132 newexpr
->kind
= CONSTANT
;
1133 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1134 alloc_expression_id (newexpr
);
1135 value_id
= get_or_alloc_constant_value_id (constant
);
1136 add_to_value (value_id
, newexpr
);
1140 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1141 Currently only supports constants and SSA_NAMES. */
1143 get_or_alloc_expr_for (tree t
)
1145 if (TREE_CODE (t
) == SSA_NAME
)
1146 return get_or_alloc_expr_for_name (t
);
1147 else if (is_gimple_min_invariant (t
))
1148 return get_or_alloc_expr_for_constant (t
);
1152 /* Return the folded version of T if T, when folded, is a gimple
1153 min_invariant or an SSA name. Otherwise, return T. */
1156 fully_constant_expression (pre_expr e
)
1164 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1165 tree res
= vn_nary_simplify (nary
);
1168 if (is_gimple_min_invariant (res
))
1169 return get_or_alloc_expr_for_constant (res
);
1170 if (TREE_CODE (res
) == SSA_NAME
)
1171 return get_or_alloc_expr_for_name (res
);
1176 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1178 if ((folded
= fully_constant_vn_reference_p (ref
)))
1179 return get_or_alloc_expr_for_constant (folded
);
1188 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1189 it has the value it would have in BLOCK. Set *SAME_VALID to true
1190 in case the new vuse doesn't change the value id of the OPERANDS. */
1193 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1194 alias_set_type set
, tree type
, tree vuse
,
1195 basic_block phiblock
,
1196 basic_block block
, bool *same_valid
)
1198 gimple
*phi
= SSA_NAME_DEF_STMT (vuse
);
1205 if (gimple_bb (phi
) != phiblock
)
1208 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1210 /* Use the alias-oracle to find either the PHI node in this block,
1211 the first VUSE used in this block that is equivalent to vuse or
1212 the first VUSE which definition in this block kills the value. */
1213 if (gimple_code (phi
) == GIMPLE_PHI
)
1214 e
= find_edge (block
, phiblock
);
1215 else if (use_oracle
)
1216 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1218 vuse
= gimple_vuse (phi
);
1219 phi
= SSA_NAME_DEF_STMT (vuse
);
1220 if (gimple_bb (phi
) != phiblock
)
1222 if (gimple_code (phi
) == GIMPLE_PHI
)
1224 e
= find_edge (block
, phiblock
);
1235 bitmap visited
= NULL
;
1237 /* Try to find a vuse that dominates this phi node by skipping
1238 non-clobbering statements. */
1239 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false,
1242 BITMAP_FREE (visited
);
1248 /* If we didn't find any, the value ID can't stay the same,
1249 but return the translated vuse. */
1250 *same_valid
= false;
1251 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1253 /* ??? We would like to return vuse here as this is the canonical
1254 upmost vdef that this reference is associated with. But during
1255 insertion of the references into the hash tables we only ever
1256 directly insert with their direct gimple_vuse, hence returning
1257 something else would make us not find the other expression. */
1258 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1264 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1265 SET2 *or* SET3. This is used to avoid making a set consisting of the union
1266 of PA_IN and ANTIC_IN during insert and phi-translation. */
1268 static inline pre_expr
1269 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
,
1270 bitmap_set_t set3
= NULL
)
1274 result
= bitmap_find_leader (set1
, val
);
1275 if (!result
&& set2
)
1276 result
= bitmap_find_leader (set2
, val
);
1277 if (!result
&& set3
)
1278 result
= bitmap_find_leader (set3
, val
);
1282 /* Get the tree type for our PRE expression e. */
1285 get_expr_type (const pre_expr e
)
1290 return TREE_TYPE (PRE_EXPR_NAME (e
));
1292 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1294 return PRE_EXPR_REFERENCE (e
)->type
;
1296 return PRE_EXPR_NARY (e
)->type
;
1301 /* Get a representative SSA_NAME for a given expression.
1302 Since all of our sub-expressions are treated as values, we require
1303 them to be SSA_NAME's for simplicity.
1304 Prior versions of GVNPRE used to use "value handles" here, so that
1305 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1306 either case, the operands are really values (IE we do not expect
1307 them to be usable without finding leaders). */
1310 get_representative_for (const pre_expr e
)
1313 unsigned int value_id
= get_expr_value_id (e
);
1318 return VN_INFO (PRE_EXPR_NAME (e
))->valnum
;
1320 return PRE_EXPR_CONSTANT (e
);
1324 /* Go through all of the expressions representing this value
1325 and pick out an SSA_NAME. */
1328 bitmap exprs
= value_expressions
[value_id
];
1329 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1331 pre_expr rep
= expression_for_id (i
);
1332 if (rep
->kind
== NAME
)
1333 return VN_INFO (PRE_EXPR_NAME (rep
))->valnum
;
1334 else if (rep
->kind
== CONSTANT
)
1335 return PRE_EXPR_CONSTANT (rep
);
1341 /* If we reached here we couldn't find an SSA_NAME. This can
1342 happen when we've discovered a value that has never appeared in
1343 the program as set to an SSA_NAME, as the result of phi translation.
1345 ??? We should be able to re-use this when we insert the statement
1347 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1348 VN_INFO_GET (name
)->value_id
= value_id
;
1349 VN_INFO (name
)->valnum
= name
;
1350 /* ??? For now mark this SSA name for release by SCCVN. */
1351 VN_INFO (name
)->needs_insertion
= true;
1352 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1353 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1355 fprintf (dump_file
, "Created SSA_NAME representative ");
1356 print_generic_expr (dump_file
, name
);
1357 fprintf (dump_file
, " for expression:");
1358 print_pre_expr (dump_file
, e
);
1359 fprintf (dump_file
, " (%04d)\n", value_id
);
1368 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1369 basic_block pred
, basic_block phiblock
);
1371 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1372 the phis in PRED. Return NULL if we can't find a leader for each part
1373 of the translated expression. */
1376 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1377 basic_block pred
, basic_block phiblock
)
1384 bool changed
= false;
1385 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1386 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1387 sizeof_vn_nary_op (nary
->length
));
1388 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1390 for (i
= 0; i
< newnary
->length
; i
++)
1392 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1396 pre_expr leader
, result
;
1397 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1398 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1399 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1400 if (result
&& result
!= leader
)
1401 newnary
->op
[i
] = get_representative_for (result
);
1405 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1411 unsigned int new_val_id
;
1413 PRE_EXPR_NARY (expr
) = newnary
;
1414 constant
= fully_constant_expression (expr
);
1415 PRE_EXPR_NARY (expr
) = nary
;
1416 if (constant
!= expr
)
1418 /* For non-CONSTANTs we have to make sure we can eventually
1419 insert the expression. Which means we need to have a
1421 if (constant
->kind
!= CONSTANT
)
1423 /* Do not allow simplifications to non-constants over
1424 backedges as this will likely result in a loop PHI node
1425 to be inserted and increased register pressure.
1426 See PR77498 - this avoids doing predcoms work in
1427 a less efficient way. */
1428 if (find_edge (pred
, phiblock
)->flags
& EDGE_DFS_BACK
)
1432 unsigned value_id
= get_expr_value_id (constant
);
1433 constant
= find_leader_in_sets (value_id
, set1
, set2
,
1443 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1448 if (result
&& is_gimple_min_invariant (result
))
1449 return get_or_alloc_expr_for_constant (result
);
1451 expr
= pre_expr_pool
.allocate ();
1456 PRE_EXPR_NARY (expr
) = nary
;
1457 new_val_id
= nary
->value_id
;
1458 get_or_alloc_expression_id (expr
);
1459 /* When we end up re-using a value number make sure that
1460 doesn't have unrelated (which we can't check here)
1461 range or points-to info on it. */
1463 && INTEGRAL_TYPE_P (TREE_TYPE (result
))
1464 && SSA_NAME_RANGE_INFO (result
)
1465 && ! SSA_NAME_IS_DEFAULT_DEF (result
))
1467 if (! VN_INFO (result
)->info
.range_info
)
1469 VN_INFO (result
)->info
.range_info
1470 = SSA_NAME_RANGE_INFO (result
);
1471 VN_INFO (result
)->range_info_anti_range_p
1472 = SSA_NAME_ANTI_RANGE_P (result
);
1474 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1476 fprintf (dump_file
, "clearing range info of ");
1477 print_generic_expr (dump_file
, result
);
1478 fprintf (dump_file
, "\n");
1480 SSA_NAME_RANGE_INFO (result
) = NULL
;
1483 && POINTER_TYPE_P (TREE_TYPE (result
))
1484 && SSA_NAME_PTR_INFO (result
)
1485 && ! SSA_NAME_IS_DEFAULT_DEF (result
))
1487 if (! VN_INFO (result
)->info
.ptr_info
)
1488 VN_INFO (result
)->info
.ptr_info
1489 = SSA_NAME_PTR_INFO (result
);
1490 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1492 fprintf (dump_file
, "clearing points-to info of ");
1493 print_generic_expr (dump_file
, result
);
1494 fprintf (dump_file
, "\n");
1496 SSA_NAME_PTR_INFO (result
) = NULL
;
1501 new_val_id
= get_next_value_id ();
1502 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1503 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1507 result
, new_val_id
);
1508 PRE_EXPR_NARY (expr
) = nary
;
1509 get_or_alloc_expression_id (expr
);
1511 add_to_value (new_val_id
, expr
);
1519 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1520 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1521 tree vuse
= ref
->vuse
;
1522 tree newvuse
= vuse
;
1523 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1524 bool changed
= false, same_valid
= true;
1526 vn_reference_op_t operand
;
1527 vn_reference_t newref
;
1529 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1534 tree type
= operand
->type
;
1535 vn_reference_op_s newop
= *operand
;
1536 op
[0] = operand
->op0
;
1537 op
[1] = operand
->op1
;
1538 op
[2] = operand
->op2
;
1539 for (n
= 0; n
< 3; ++n
)
1541 unsigned int op_val_id
;
1544 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1546 /* We can't possibly insert these. */
1548 && !is_gimple_min_invariant (op
[n
]))
1552 op_val_id
= VN_INFO (op
[n
])->value_id
;
1553 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1554 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1555 if (opresult
&& opresult
!= leader
)
1557 tree name
= get_representative_for (opresult
);
1558 changed
|= name
!= op
[n
];
1566 newoperands
.release ();
1571 if (!newoperands
.exists ())
1572 newoperands
= operands
.copy ();
1573 /* We may have changed from an SSA_NAME to a constant */
1574 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1575 newop
.opcode
= TREE_CODE (op
[0]);
1580 newoperands
[i
] = newop
;
1582 gcc_checking_assert (i
== operands
.length ());
1586 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1587 ? newoperands
: operands
,
1588 ref
->set
, ref
->type
,
1589 vuse
, phiblock
, pred
,
1591 if (newvuse
== NULL_TREE
)
1593 newoperands
.release ();
1598 if (changed
|| newvuse
!= vuse
)
1600 unsigned int new_val_id
;
1603 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1605 newoperands
.exists ()
1606 ? newoperands
: operands
,
1609 newoperands
.release ();
1611 /* We can always insert constants, so if we have a partial
1612 redundant constant load of another type try to translate it
1613 to a constant of appropriate type. */
1614 if (result
&& is_gimple_min_invariant (result
))
1617 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1619 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1620 if (tem
&& !is_gimple_min_invariant (tem
))
1624 return get_or_alloc_expr_for_constant (tem
);
1627 /* If we'd have to convert things we would need to validate
1628 if we can insert the translated expression. So fail
1629 here for now - we cannot insert an alias with a different
1630 type in the VN tables either, as that would assert. */
1632 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1634 else if (!result
&& newref
1635 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1637 newoperands
.release ();
1641 expr
= pre_expr_pool
.allocate ();
1642 expr
->kind
= REFERENCE
;
1647 PRE_EXPR_REFERENCE (expr
) = newref
;
1648 constant
= fully_constant_expression (expr
);
1649 if (constant
!= expr
)
1652 new_val_id
= newref
->value_id
;
1653 get_or_alloc_expression_id (expr
);
1657 if (changed
|| !same_valid
)
1659 new_val_id
= get_next_value_id ();
1660 value_expressions
.safe_grow_cleared
1661 (get_max_value_id () + 1);
1664 new_val_id
= ref
->value_id
;
1665 if (!newoperands
.exists ())
1666 newoperands
= operands
.copy ();
1667 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1670 result
, new_val_id
);
1671 newoperands
= vNULL
;
1672 PRE_EXPR_REFERENCE (expr
) = newref
;
1673 constant
= fully_constant_expression (expr
);
1674 if (constant
!= expr
)
1676 get_or_alloc_expression_id (expr
);
1678 add_to_value (new_val_id
, expr
);
1680 newoperands
.release ();
1687 tree name
= PRE_EXPR_NAME (expr
);
1688 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1689 /* If the SSA name is defined by a PHI node in this block,
1691 if (gimple_code (def_stmt
) == GIMPLE_PHI
1692 && gimple_bb (def_stmt
) == phiblock
)
1694 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1695 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1697 /* Handle constant. */
1698 if (is_gimple_min_invariant (def
))
1699 return get_or_alloc_expr_for_constant (def
);
1701 return get_or_alloc_expr_for_name (def
);
1703 /* Otherwise return it unchanged - it will get removed if its
1704 value is not available in PREDs AVAIL_OUT set of expressions
1705 by the subtraction of TMP_GEN. */
1714 /* Wrapper around phi_translate_1 providing caching functionality. */
1717 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1718 basic_block pred
, basic_block phiblock
)
1720 expr_pred_trans_t slot
= NULL
;
1726 /* Constants contain no values that need translation. */
1727 if (expr
->kind
== CONSTANT
)
1730 if (value_id_constant_p (get_expr_value_id (expr
)))
1733 /* Don't add translations of NAMEs as those are cheap to translate. */
1734 if (expr
->kind
!= NAME
)
1736 if (phi_trans_add (&slot
, expr
, pred
))
1738 /* Store NULL for the value we want to return in the case of
1744 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1751 /* Remove failed translations again, they cause insert
1752 iteration to not pick up new opportunities reliably. */
1753 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1760 /* For each expression in SET, translate the values through phi nodes
1761 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1762 expressions in DEST. */
1765 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1766 basic_block phiblock
)
1768 vec
<pre_expr
> exprs
;
1772 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1774 bitmap_set_copy (dest
, set
);
1778 exprs
= sorted_array_from_bitmap_set (set
);
1779 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1781 pre_expr translated
;
1782 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1786 /* We might end up with multiple expressions from SET being
1787 translated to the same value. In this case we do not want
1788 to retain the NARY or REFERENCE expression but prefer a NAME
1789 which would be the leader. */
1790 if (translated
->kind
== NAME
)
1791 bitmap_value_replace_in_set (dest
, translated
);
1793 bitmap_value_insert_into_set (dest
, translated
);
1798 /* Find the leader for a value (i.e., the name representing that
1799 value) in a given set, and return it. Return NULL if no leader
1803 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1805 if (value_id_constant_p (val
))
1809 bitmap exprset
= value_expressions
[val
];
1811 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1813 pre_expr expr
= expression_for_id (i
);
1814 if (expr
->kind
== CONSTANT
)
1818 if (bitmap_set_contains_value (set
, val
))
1820 /* Rather than walk the entire bitmap of expressions, and see
1821 whether any of them has the value we are looking for, we look
1822 at the reverse mapping, which tells us the set of expressions
1823 that have a given value (IE value->expressions with that
1824 value) and see if any of those expressions are in our set.
1825 The number of expressions per value is usually significantly
1826 less than the number of expressions in the set. In fact, for
1827 large testcases, doing it this way is roughly 5-10x faster
1828 than walking the bitmap.
1829 If this is somehow a significant lose for some cases, we can
1830 choose which set to walk based on which set is smaller. */
1833 bitmap exprset
= value_expressions
[val
];
1835 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1836 return expression_for_id (i
);
1841 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1842 BLOCK by seeing if it is not killed in the block. Note that we are
1843 only determining whether there is a store that kills it. Because
1844 of the order in which clean iterates over values, we are guaranteed
1845 that altered operands will have caused us to be eliminated from the
1846 ANTIC_IN set already. */
1849 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1851 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1852 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1854 gimple_stmt_iterator gsi
;
1855 unsigned id
= get_expression_id (expr
);
1862 /* Lookup a previously calculated result. */
1863 if (EXPR_DIES (block
)
1864 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1865 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1867 /* A memory expression {e, VUSE} dies in the block if there is a
1868 statement that may clobber e. If, starting statement walk from the
1869 top of the basic block, a statement uses VUSE there can be no kill
1870 inbetween that use and the original statement that loaded {e, VUSE},
1871 so we can stop walking. */
1872 ref
.base
= NULL_TREE
;
1873 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1875 tree def_vuse
, def_vdef
;
1876 def
= gsi_stmt (gsi
);
1877 def_vuse
= gimple_vuse (def
);
1878 def_vdef
= gimple_vdef (def
);
1880 /* Not a memory statement. */
1884 /* Not a may-def. */
1887 /* A load with the same VUSE, we're done. */
1888 if (def_vuse
== vuse
)
1894 /* Init ref only if we really need it. */
1895 if (ref
.base
== NULL_TREE
1896 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1902 /* If the statement may clobber expr, it dies. */
1903 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1910 /* Remember the result. */
1911 if (!EXPR_DIES (block
))
1912 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1913 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1915 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1921 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1922 contains its value-id. */
1925 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1927 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1929 unsigned int value_id
= VN_INFO (op
)->value_id
;
1930 if (!(bitmap_set_contains_value (set1
, value_id
)
1931 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1937 /* Determine if the expression EXPR is valid in SET1 U SET2.
1938 ONLY SET2 CAN BE NULL.
1939 This means that we have a leader for each part of the expression
1940 (if it consists of values), or the expression is an SSA_NAME.
1941 For loads/calls, we also see if the vuse is killed in this block. */
1944 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1949 /* By construction all NAMEs are available. Non-available
1950 NAMEs are removed by subtracting TMP_GEN from the sets. */
1955 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1956 for (i
= 0; i
< nary
->length
; i
++)
1957 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1964 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1965 vn_reference_op_t vro
;
1968 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1970 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1971 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1972 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1982 /* Clean the set of expressions that are no longer valid in SET1 or
1983 SET2. This means expressions that are made up of values we have no
1984 leaders for in SET1 or SET2. This version is used for partial
1985 anticipation, which means it is not valid in either ANTIC_IN or
1989 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
)
1991 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
1995 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1997 if (!valid_in_sets (set1
, set2
, expr
))
1998 bitmap_remove_from_set (set1
, expr
);
2003 /* Clean the set of expressions that are no longer valid in SET. This
2004 means expressions that are made up of values we have no leaders for
2008 clean (bitmap_set_t set
)
2010 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2014 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2016 if (!valid_in_sets (set
, NULL
, expr
))
2017 bitmap_remove_from_set (set
, expr
);
2022 /* Clean the set of expressions that are no longer valid in SET because
2023 they are clobbered in BLOCK or because they trap and may not be executed. */
2026 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2030 pre_expr to_remove
= NULL
;
2032 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2034 /* Remove queued expr. */
2037 bitmap_remove_from_set (set
, to_remove
);
2041 pre_expr expr
= expression_for_id (i
);
2042 if (expr
->kind
== REFERENCE
)
2044 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2047 gimple
*def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2048 if (!gimple_nop_p (def_stmt
)
2049 && ((gimple_bb (def_stmt
) != block
2050 && !dominated_by_p (CDI_DOMINATORS
,
2051 block
, gimple_bb (def_stmt
)))
2052 || (gimple_bb (def_stmt
) == block
2053 && value_dies_in_block_x (expr
, block
))))
2057 else if (expr
->kind
== NARY
)
2059 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2060 /* If the NARY may trap make sure the block does not contain
2061 a possible exit point.
2062 ??? This is overly conservative if we translate AVAIL_OUT
2063 as the available expression might be after the exit point. */
2064 if (BB_MAY_NOTRETURN (block
)
2065 && vn_nary_may_trap (nary
))
2070 /* Remove queued expr. */
2072 bitmap_remove_from_set (set
, to_remove
);
2075 static sbitmap has_abnormal_preds
;
2077 /* Compute the ANTIC set for BLOCK.
2079 If succs(BLOCK) > 1 then
2080 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2081 else if succs(BLOCK) == 1 then
2082 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2084 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2086 Note that clean() is deferred until after the iteration. */
2089 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2091 bitmap_set_t S
, old
, ANTIC_OUT
;
2097 bool changed
= ! BB_VISITED (block
);
2098 BB_VISITED (block
) = 1;
2099 old
= ANTIC_OUT
= S
= NULL
;
2101 /* If any edges from predecessors are abnormal, antic_in is empty,
2103 if (block_has_abnormal_pred_edge
)
2104 goto maybe_dump_sets
;
2106 old
= ANTIC_IN (block
);
2107 ANTIC_OUT
= bitmap_set_new ();
2109 /* If the block has no successors, ANTIC_OUT is empty. */
2110 if (EDGE_COUNT (block
->succs
) == 0)
2112 /* If we have one successor, we could have some phi nodes to
2113 translate through. */
2114 else if (single_succ_p (block
))
2116 basic_block succ_bb
= single_succ (block
);
2117 gcc_assert (BB_VISITED (succ_bb
));
2118 phi_translate_set (ANTIC_OUT
, ANTIC_IN (succ_bb
), block
, succ_bb
);
2120 /* If we have multiple successors, we take the intersection of all of
2121 them. Note that in the case of loop exit phi nodes, we may have
2122 phis to translate through. */
2126 basic_block bprime
, first
= NULL
;
2128 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2129 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2132 && BB_VISITED (e
->dest
))
2134 else if (BB_VISITED (e
->dest
))
2135 worklist
.quick_push (e
->dest
);
2138 /* Unvisited successors get their ANTIC_IN replaced by the
2139 maximal set to arrive at a maximum ANTIC_IN solution.
2140 We can ignore them in the intersection operation and thus
2141 need not explicitely represent that maximum solution. */
2142 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2143 fprintf (dump_file
, "ANTIC_IN is MAX on %d->%d\n",
2144 e
->src
->index
, e
->dest
->index
);
2148 /* Of multiple successors we have to have visited one already
2149 which is guaranteed by iteration order. */
2150 gcc_assert (first
!= NULL
);
2152 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2154 /* If we have multiple successors we need to intersect the ANTIC_OUT
2155 sets. For values that's a simple intersection but for
2156 expressions it is a union. Given we want to have a single
2157 expression per value in our sets we have to canonicalize.
2158 Avoid randomness and running into cycles like for PR82129 and
2159 canonicalize the expression we choose to the one with the
2160 lowest id. This requires we actually compute the union first. */
2161 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2163 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2165 bitmap_set_t tmp
= bitmap_set_new ();
2166 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2167 bitmap_and_into (&ANTIC_OUT
->values
, &tmp
->values
);
2168 bitmap_ior_into (&ANTIC_OUT
->expressions
, &tmp
->expressions
);
2169 bitmap_set_free (tmp
);
2173 bitmap_and_into (&ANTIC_OUT
->values
, &ANTIC_IN (bprime
)->values
);
2174 bitmap_ior_into (&ANTIC_OUT
->expressions
,
2175 &ANTIC_IN (bprime
)->expressions
);
2178 if (! worklist
.is_empty ())
2180 /* Prune expressions not in the value set, canonicalizing to
2181 expression with lowest ID. */
2184 unsigned int to_clear
= -1U;
2185 bitmap seen_value
= BITMAP_ALLOC (NULL
);
2186 FOR_EACH_EXPR_ID_IN_SET (ANTIC_OUT
, i
, bi
)
2188 if (to_clear
!= -1U)
2190 bitmap_clear_bit (&ANTIC_OUT
->expressions
, to_clear
);
2193 pre_expr expr
= expression_for_id (i
);
2194 unsigned int value_id
= get_expr_value_id (expr
);
2195 if (!bitmap_bit_p (&ANTIC_OUT
->values
, value_id
)
2196 || !bitmap_set_bit (seen_value
, value_id
))
2199 if (to_clear
!= -1U)
2200 bitmap_clear_bit (&ANTIC_OUT
->expressions
, to_clear
);
2201 BITMAP_FREE (seen_value
);
2205 /* Prune expressions that are clobbered in block and thus become
2206 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2207 prune_clobbered_mems (ANTIC_OUT
, block
);
2209 /* Generate ANTIC_OUT - TMP_GEN. */
2210 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2212 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2213 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2216 /* Then union in the ANTIC_OUT - TMP_GEN values,
2217 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2218 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2219 bitmap_value_insert_into_set (ANTIC_IN (block
),
2220 expression_for_id (bii
));
2222 /* clean (ANTIC_IN (block)) is defered to after the iteration converged
2223 because it can cause non-convergence, see for example PR81181. */
2225 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2229 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2232 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2235 fprintf (dump_file
, "[changed] ");
2236 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2240 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2243 bitmap_set_free (old
);
2245 bitmap_set_free (S
);
2247 bitmap_set_free (ANTIC_OUT
);
2251 /* Compute PARTIAL_ANTIC for BLOCK.
2253 If succs(BLOCK) > 1 then
2254 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2255 in ANTIC_OUT for all succ(BLOCK)
2256 else if succs(BLOCK) == 1 then
2257 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2259 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2264 compute_partial_antic_aux (basic_block block
,
2265 bool block_has_abnormal_pred_edge
)
2267 bitmap_set_t old_PA_IN
;
2268 bitmap_set_t PA_OUT
;
2271 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2273 old_PA_IN
= PA_OUT
= NULL
;
2275 /* If any edges from predecessors are abnormal, antic_in is empty,
2277 if (block_has_abnormal_pred_edge
)
2278 goto maybe_dump_sets
;
2280 /* If there are too many partially anticipatable values in the
2281 block, phi_translate_set can take an exponential time: stop
2282 before the translation starts. */
2284 && single_succ_p (block
)
2285 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2286 goto maybe_dump_sets
;
2288 old_PA_IN
= PA_IN (block
);
2289 PA_OUT
= bitmap_set_new ();
2291 /* If the block has no successors, ANTIC_OUT is empty. */
2292 if (EDGE_COUNT (block
->succs
) == 0)
2294 /* If we have one successor, we could have some phi nodes to
2295 translate through. Note that we can't phi translate across DFS
2296 back edges in partial antic, because it uses a union operation on
2297 the successors. For recurrences like IV's, we will end up
2298 generating a new value in the set on each go around (i + 3 (VH.1)
2299 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2300 else if (single_succ_p (block
))
2302 basic_block succ
= single_succ (block
);
2303 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2304 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2306 /* If we have multiple successors, we take the union of all of
2313 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2314 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2316 if (e
->flags
& EDGE_DFS_BACK
)
2318 worklist
.quick_push (e
->dest
);
2320 if (worklist
.length () > 0)
2322 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2327 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2328 bitmap_value_insert_into_set (PA_OUT
,
2329 expression_for_id (i
));
2330 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2332 bitmap_set_t pa_in
= bitmap_set_new ();
2333 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2334 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2335 bitmap_value_insert_into_set (PA_OUT
,
2336 expression_for_id (i
));
2337 bitmap_set_free (pa_in
);
2340 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2341 bitmap_value_insert_into_set (PA_OUT
,
2342 expression_for_id (i
));
2347 /* Prune expressions that are clobbered in block and thus become
2348 invalid if translated from PA_OUT to PA_IN. */
2349 prune_clobbered_mems (PA_OUT
, block
);
2351 /* PA_IN starts with PA_OUT - TMP_GEN.
2352 Then we subtract things from ANTIC_IN. */
2353 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2355 /* For partial antic, we want to put back in the phi results, since
2356 we will properly avoid making them partially antic over backedges. */
2357 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2358 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2360 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2361 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2363 dependent_clean (PA_IN (block
), ANTIC_IN (block
));
2366 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2369 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2371 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2374 bitmap_set_free (old_PA_IN
);
2376 bitmap_set_free (PA_OUT
);
2379 /* Compute ANTIC and partial ANTIC sets. */
2382 compute_antic (void)
2384 bool changed
= true;
2385 int num_iterations
= 0;
2391 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2392 We pre-build the map of blocks with incoming abnormal edges here. */
2393 has_abnormal_preds
= sbitmap_alloc (last_basic_block_for_fn (cfun
));
2394 bitmap_clear (has_abnormal_preds
);
2396 FOR_ALL_BB_FN (block
, cfun
)
2398 BB_VISITED (block
) = 0;
2400 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2401 if (e
->flags
& EDGE_ABNORMAL
)
2403 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2407 /* While we are here, give empty ANTIC_IN sets to each block. */
2408 ANTIC_IN (block
) = bitmap_set_new ();
2409 if (do_partial_partial
)
2410 PA_IN (block
) = bitmap_set_new ();
2413 /* At the exit block we anticipate nothing. */
2414 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2416 /* For ANTIC computation we need a postorder that also guarantees that
2417 a block with a single successor is visited after its successor.
2418 RPO on the inverted CFG has this property. */
2419 auto_vec
<int, 20> postorder
;
2420 inverted_post_order_compute (&postorder
);
2422 auto_sbitmap
worklist (last_basic_block_for_fn (cfun
) + 1);
2423 bitmap_clear (worklist
);
2424 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR_FOR_FN (cfun
)->preds
)
2425 bitmap_set_bit (worklist
, e
->src
->index
);
2428 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2429 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2430 /* ??? We need to clear our PHI translation cache here as the
2431 ANTIC sets shrink and we restrict valid translations to
2432 those having operands with leaders in ANTIC. Same below
2433 for PA ANTIC computation. */
2436 for (i
= postorder
.length () - 1; i
>= 0; i
--)
2438 if (bitmap_bit_p (worklist
, postorder
[i
]))
2440 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2441 bitmap_clear_bit (worklist
, block
->index
);
2442 if (compute_antic_aux (block
,
2443 bitmap_bit_p (has_abnormal_preds
,
2446 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2447 bitmap_set_bit (worklist
, e
->src
->index
);
2452 /* Theoretically possible, but *highly* unlikely. */
2453 gcc_checking_assert (num_iterations
< 500);
2456 /* We have to clean after the dataflow problem converged as cleaning
2457 can cause non-convergence because it is based on expressions
2458 rather than values. */
2459 FOR_EACH_BB_FN (block
, cfun
)
2460 clean (ANTIC_IN (block
));
2462 statistics_histogram_event (cfun
, "compute_antic iterations",
2465 if (do_partial_partial
)
2467 /* For partial antic we ignore backedges and thus we do not need
2468 to perform any iteration when we process blocks in postorder. */
2470 = pre_and_rev_post_order_compute (NULL
, postorder
.address (), false);
2471 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2473 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2474 compute_partial_antic_aux (block
,
2475 bitmap_bit_p (has_abnormal_preds
,
2480 sbitmap_free (has_abnormal_preds
);
2484 /* Inserted expressions are placed onto this worklist, which is used
2485 for performing quick dead code elimination of insertions we made
2486 that didn't turn out to be necessary. */
2487 static bitmap inserted_exprs
;
2489 /* The actual worker for create_component_ref_by_pieces. */
2492 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2493 unsigned int *operand
, gimple_seq
*stmts
)
2495 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2498 switch (currop
->opcode
)
2505 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2509 tree offset
= currop
->op0
;
2510 if (TREE_CODE (baseop
) == ADDR_EXPR
2511 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2515 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2518 offset
= int_const_binop (PLUS_EXPR
, offset
,
2519 build_int_cst (TREE_TYPE (offset
),
2521 baseop
= build_fold_addr_expr (base
);
2523 genop
= build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2524 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2525 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2526 REF_REVERSE_STORAGE_ORDER (genop
) = currop
->reverse
;
2530 case TARGET_MEM_REF
:
2532 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2533 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2534 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2540 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2546 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2550 genop
= build5 (TARGET_MEM_REF
, currop
->type
,
2551 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2553 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2554 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2561 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2567 case VIEW_CONVERT_EXPR
:
2569 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2573 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2576 case WITH_SIZE_EXPR
:
2578 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2582 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2585 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2590 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2594 tree op1
= currop
->op0
;
2595 tree op2
= currop
->op1
;
2596 tree t
= build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2597 REF_REVERSE_STORAGE_ORDER (t
) = currop
->reverse
;
2601 /* For array ref vn_reference_op's, operand 1 of the array ref
2602 is op0 of the reference op and operand 3 of the array ref is
2604 case ARRAY_RANGE_REF
:
2608 tree genop1
= currop
->op0
;
2609 tree genop2
= currop
->op1
;
2610 tree genop3
= currop
->op2
;
2611 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2615 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2620 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2621 /* Drop zero minimum index if redundant. */
2622 if (integer_zerop (genop2
)
2624 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2628 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2635 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2636 /* We can't always put a size in units of the element alignment
2637 here as the element alignment may be not visible. See
2638 PR43783. Simply drop the element size for constant
2640 if (TREE_CODE (genop3
) == INTEGER_CST
2641 && TREE_CODE (TYPE_SIZE_UNIT (elmt_type
)) == INTEGER_CST
2642 && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type
)),
2643 (wi::to_offset (genop3
)
2644 * vn_ref_op_align_unit (currop
))))
2648 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2653 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2660 tree genop2
= currop
->op1
;
2661 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2664 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2668 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2672 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2677 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2698 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2699 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2700 trying to rename aggregates into ssa form directly, which is a no no.
2702 Thus, this routine doesn't create temporaries, it just builds a
2703 single access expression for the array, calling
2704 find_or_generate_expression to build the innermost pieces.
2706 This function is a subroutine of create_expression_by_pieces, and
2707 should not be called on it's own unless you really know what you
2711 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2714 unsigned int op
= 0;
2715 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2718 /* Find a simple leader for an expression, or generate one using
2719 create_expression_by_pieces from a NARY expression for the value.
2720 BLOCK is the basic_block we are looking for leaders in.
2721 OP is the tree expression to find a leader for or generate.
2722 Returns the leader or NULL_TREE on failure. */
2725 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2727 pre_expr expr
= get_or_alloc_expr_for (op
);
2728 unsigned int lookfor
= get_expr_value_id (expr
);
2729 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2732 if (leader
->kind
== NAME
)
2733 return PRE_EXPR_NAME (leader
);
2734 else if (leader
->kind
== CONSTANT
)
2735 return PRE_EXPR_CONSTANT (leader
);
2741 /* It must be a complex expression, so generate it recursively. Note
2742 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2743 where the insert algorithm fails to insert a required expression. */
2744 bitmap exprset
= value_expressions
[lookfor
];
2747 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2749 pre_expr temp
= expression_for_id (i
);
2750 /* We cannot insert random REFERENCE expressions at arbitrary
2751 places. We can insert NARYs which eventually re-materializes
2752 its operand values. */
2753 if (temp
->kind
== NARY
)
2754 return create_expression_by_pieces (block
, temp
, stmts
,
2755 get_expr_type (expr
));
2762 /* Create an expression in pieces, so that we can handle very complex
2763 expressions that may be ANTIC, but not necessary GIMPLE.
2764 BLOCK is the basic block the expression will be inserted into,
2765 EXPR is the expression to insert (in value form)
2766 STMTS is a statement list to append the necessary insertions into.
2768 This function will die if we hit some value that shouldn't be
2769 ANTIC but is (IE there is no leader for it, or its components).
2770 The function returns NULL_TREE in case a different antic expression
2771 has to be inserted first.
2772 This function may also generate expressions that are themselves
2773 partially or fully redundant. Those that are will be either made
2774 fully redundant during the next iteration of insert (for partially
2775 redundant ones), or eliminated by eliminate (for fully redundant
2779 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2780 gimple_seq
*stmts
, tree type
)
2784 gimple_seq forced_stmts
= NULL
;
2785 unsigned int value_id
;
2786 gimple_stmt_iterator gsi
;
2787 tree exprtype
= type
? type
: get_expr_type (expr
);
2793 /* We may hit the NAME/CONSTANT case if we have to convert types
2794 that value numbering saw through. */
2796 folded
= PRE_EXPR_NAME (expr
);
2797 if (useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2802 folded
= PRE_EXPR_CONSTANT (expr
);
2803 tree tem
= fold_convert (exprtype
, folded
);
2804 if (is_gimple_min_invariant (tem
))
2809 if (PRE_EXPR_REFERENCE (expr
)->operands
[0].opcode
== CALL_EXPR
)
2811 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2812 unsigned int operand
= 1;
2813 vn_reference_op_t currop
= &ref
->operands
[0];
2814 tree sc
= NULL_TREE
;
2816 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2819 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2824 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2828 auto_vec
<tree
> args (ref
->operands
.length () - 1);
2829 while (operand
< ref
->operands
.length ())
2831 tree arg
= create_component_ref_by_pieces_1 (block
, ref
,
2835 args
.quick_push (arg
);
2838 = gimple_build_call_vec ((TREE_CODE (fn
) == FUNCTION_DECL
2839 ? build_fold_addr_expr (fn
) : fn
), args
);
2840 gimple_call_set_with_bounds (call
, currop
->with_bounds
);
2842 gimple_call_set_chain (call
, sc
);
2843 tree forcedname
= make_ssa_name (currop
->type
);
2844 gimple_call_set_lhs (call
, forcedname
);
2845 gimple_set_vuse (call
, BB_LIVE_VOP_ON_EXIT (block
));
2846 gimple_seq_add_stmt_without_update (&forced_stmts
, call
);
2847 folded
= forcedname
;
2851 folded
= create_component_ref_by_pieces (block
,
2852 PRE_EXPR_REFERENCE (expr
),
2856 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2857 newstmt
= gimple_build_assign (name
, folded
);
2858 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2859 gimple_set_vuse (newstmt
, BB_LIVE_VOP_ON_EXIT (block
));
2865 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2866 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2868 for (i
= 0; i
< nary
->length
; ++i
)
2870 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2873 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2874 may have conversions stripped. */
2875 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2878 genop
[i
] = gimple_convert (&forced_stmts
,
2879 nary
->type
, genop
[i
]);
2881 genop
[i
] = gimple_convert (&forced_stmts
,
2882 sizetype
, genop
[i
]);
2885 genop
[i
] = gimple_convert (&forced_stmts
,
2886 TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2888 if (nary
->opcode
== CONSTRUCTOR
)
2890 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2891 for (i
= 0; i
< nary
->length
; ++i
)
2892 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2893 folded
= build_constructor (nary
->type
, elts
);
2894 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2895 newstmt
= gimple_build_assign (name
, folded
);
2896 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2901 switch (nary
->length
)
2904 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2908 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2909 genop
[0], genop
[1]);
2912 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2913 genop
[0], genop
[1], genop
[2]);
2925 folded
= gimple_convert (&forced_stmts
, exprtype
, folded
);
2927 /* If there is nothing to insert, return the simplified result. */
2928 if (gimple_seq_empty_p (forced_stmts
))
2930 /* If we simplified to a constant return it and discard eventually
2932 if (is_gimple_min_invariant (folded
))
2934 gimple_seq_discard (forced_stmts
);
2937 /* Likewise if we simplified to sth not queued for insertion. */
2939 gsi
= gsi_last (forced_stmts
);
2940 for (; !gsi_end_p (gsi
); gsi_prev (&gsi
))
2942 gimple
*stmt
= gsi_stmt (gsi
);
2943 tree forcedname
= gimple_get_lhs (stmt
);
2944 if (forcedname
== folded
)
2952 gimple_seq_discard (forced_stmts
);
2955 gcc_assert (TREE_CODE (folded
) == SSA_NAME
);
2957 /* If we have any intermediate expressions to the value sets, add them
2958 to the value sets and chain them in the instruction stream. */
2961 gsi
= gsi_start (forced_stmts
);
2962 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2964 gimple
*stmt
= gsi_stmt (gsi
);
2965 tree forcedname
= gimple_get_lhs (stmt
);
2968 if (forcedname
!= folded
)
2970 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2971 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2972 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2973 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2974 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2975 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2978 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2980 gimple_seq_add_seq (stmts
, forced_stmts
);
2985 /* Fold the last statement. */
2986 gsi
= gsi_last (*stmts
);
2987 if (fold_stmt_inplace (&gsi
))
2988 update_stmt (gsi_stmt (gsi
));
2990 /* Add a value number to the temporary.
2991 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2992 we are creating the expression by pieces, and this particular piece of
2993 the expression may have been represented. There is no harm in replacing
2995 value_id
= get_expr_value_id (expr
);
2996 VN_INFO_GET (name
)->value_id
= value_id
;
2997 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2998 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2999 VN_INFO (name
)->valnum
= name
;
3000 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
3001 nameexpr
= get_or_alloc_expr_for_name (name
);
3002 add_to_value (value_id
, nameexpr
);
3003 if (NEW_SETS (block
))
3004 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
3005 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
3007 pre_stats
.insertions
++;
3008 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3010 fprintf (dump_file
, "Inserted ");
3011 print_gimple_stmt (dump_file
, gsi_stmt (gsi_last (*stmts
)), 0);
3012 fprintf (dump_file
, " in predecessor %d (%04d)\n",
3013 block
->index
, value_id
);
3020 /* Insert the to-be-made-available values of expression EXPRNUM for each
3021 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3022 merge the result with a phi node, given the same value number as
3023 NODE. Return true if we have inserted new stuff. */
3026 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3027 vec
<pre_expr
> avail
)
3029 pre_expr expr
= expression_for_id (exprnum
);
3031 unsigned int val
= get_expr_value_id (expr
);
3033 bool insertions
= false;
3038 tree type
= get_expr_type (expr
);
3042 /* Make sure we aren't creating an induction variable. */
3043 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
3045 bool firstinsideloop
= false;
3046 bool secondinsideloop
= false;
3047 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3048 EDGE_PRED (block
, 0)->src
);
3049 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3050 EDGE_PRED (block
, 1)->src
);
3051 /* Induction variables only have one edge inside the loop. */
3052 if ((firstinsideloop
^ secondinsideloop
)
3053 && expr
->kind
!= REFERENCE
)
3055 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3056 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3061 /* Make the necessary insertions. */
3062 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3064 gimple_seq stmts
= NULL
;
3067 eprime
= avail
[pred
->dest_idx
];
3068 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
3070 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3071 if (!gimple_seq_empty_p (stmts
))
3073 gsi_insert_seq_on_edge (pred
, stmts
);
3078 /* We cannot insert a PHI node if we failed to insert
3083 if (is_gimple_min_invariant (builtexpr
))
3084 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_constant (builtexpr
);
3086 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3088 /* If we didn't want a phi node, and we made insertions, we still have
3089 inserted new stuff, and thus return true. If we didn't want a phi node,
3090 and didn't make insertions, we haven't added anything new, so return
3092 if (nophi
&& insertions
)
3094 else if (nophi
&& !insertions
)
3097 /* Now build a phi for the new variable. */
3098 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3099 phi
= create_phi_node (temp
, block
);
3101 VN_INFO_GET (temp
)->value_id
= val
;
3102 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3103 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3104 VN_INFO (temp
)->valnum
= temp
;
3105 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3106 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3108 pre_expr ae
= avail
[pred
->dest_idx
];
3109 gcc_assert (get_expr_type (ae
) == type
3110 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3111 if (ae
->kind
== CONSTANT
)
3112 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3113 pred
, UNKNOWN_LOCATION
);
3115 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3118 newphi
= get_or_alloc_expr_for_name (temp
);
3119 add_to_value (val
, newphi
);
3121 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3122 this insertion, since we test for the existence of this value in PHI_GEN
3123 before proceeding with the partial redundancy checks in insert_aux.
3125 The value may exist in AVAIL_OUT, in particular, it could be represented
3126 by the expression we are trying to eliminate, in which case we want the
3127 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3130 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3131 this block, because if it did, it would have existed in our dominator's
3132 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3135 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3136 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3138 bitmap_insert_into_set (NEW_SETS (block
),
3141 /* If we insert a PHI node for a conversion of another PHI node
3142 in the same basic-block try to preserve range information.
3143 This is important so that followup loop passes receive optimal
3144 number of iteration analysis results. See PR61743. */
3145 if (expr
->kind
== NARY
3146 && CONVERT_EXPR_CODE_P (expr
->u
.nary
->opcode
)
3147 && TREE_CODE (expr
->u
.nary
->op
[0]) == SSA_NAME
3148 && gimple_bb (SSA_NAME_DEF_STMT (expr
->u
.nary
->op
[0])) == block
3149 && INTEGRAL_TYPE_P (type
)
3150 && INTEGRAL_TYPE_P (TREE_TYPE (expr
->u
.nary
->op
[0]))
3151 && (TYPE_PRECISION (type
)
3152 >= TYPE_PRECISION (TREE_TYPE (expr
->u
.nary
->op
[0])))
3153 && SSA_NAME_RANGE_INFO (expr
->u
.nary
->op
[0]))
3156 if (get_range_info (expr
->u
.nary
->op
[0], &min
, &max
) == VR_RANGE
3157 && !wi::neg_p (min
, SIGNED
)
3158 && !wi::neg_p (max
, SIGNED
))
3159 /* Just handle extension and sign-changes of all-positive ranges. */
3160 set_range_info (temp
,
3161 SSA_NAME_RANGE_TYPE (expr
->u
.nary
->op
[0]),
3162 wide_int_storage::from (min
, TYPE_PRECISION (type
),
3164 wide_int_storage::from (max
, TYPE_PRECISION (type
),
3168 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3170 fprintf (dump_file
, "Created phi ");
3171 print_gimple_stmt (dump_file
, phi
, 0);
3172 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3180 /* Perform insertion of partially redundant or hoistable values.
3181 For BLOCK, do the following:
3182 1. Propagate the NEW_SETS of the dominator into the current block.
3183 If the block has multiple predecessors,
3184 2a. Iterate over the ANTIC expressions for the block to see if
3185 any of them are partially redundant.
3186 2b. If so, insert them into the necessary predecessors to make
3187 the expression fully redundant.
3188 2c. Insert a new PHI merging the values of the predecessors.
3189 2d. Insert the new PHI, and the new expressions, into the
3191 If the block has multiple successors,
3192 3a. Iterate over the ANTIC values for the block to see if
3193 any of them are good candidates for hoisting.
3194 3b. If so, insert expressions computing the values in BLOCK,
3195 and add the new expressions into the NEW_SETS set.
3196 4. Recursively call ourselves on the dominator children of BLOCK.
3198 Steps 1, 2a, and 4 are done by insert_aux. 2b, 2c and 2d are done by
3199 do_pre_regular_insertion and do_partial_insertion. 3a and 3b are
3200 done in do_hoist_insertion.
3204 do_pre_regular_insertion (basic_block block
, basic_block dom
)
3206 bool new_stuff
= false;
3207 vec
<pre_expr
> exprs
;
3209 auto_vec
<pre_expr
> avail
;
3212 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3213 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3215 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3217 if (expr
->kind
== NARY
3218 || expr
->kind
== REFERENCE
)
3221 bool by_some
= false;
3222 bool cant_insert
= false;
3223 bool all_same
= true;
3224 pre_expr first_s
= NULL
;
3227 pre_expr eprime
= NULL
;
3229 pre_expr edoubleprime
= NULL
;
3230 bool do_insertion
= false;
3232 val
= get_expr_value_id (expr
);
3233 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3235 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3237 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3239 fprintf (dump_file
, "Found fully redundant value: ");
3240 print_pre_expr (dump_file
, expr
);
3241 fprintf (dump_file
, "\n");
3246 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3248 unsigned int vprime
;
3250 /* We should never run insertion for the exit block
3251 and so not come across fake pred edges. */
3252 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3254 /* We are looking at ANTIC_OUT of bprime. */
3255 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3258 /* eprime will generally only be NULL if the
3259 value of the expression, translated
3260 through the PHI for this predecessor, is
3261 undefined. If that is the case, we can't
3262 make the expression fully redundant,
3263 because its value is undefined along a
3264 predecessor path. We can thus break out
3265 early because it doesn't matter what the
3266 rest of the results are. */
3269 avail
[pred
->dest_idx
] = NULL
;
3274 vprime
= get_expr_value_id (eprime
);
3275 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3277 if (edoubleprime
== NULL
)
3279 avail
[pred
->dest_idx
] = eprime
;
3284 avail
[pred
->dest_idx
] = edoubleprime
;
3286 /* We want to perform insertions to remove a redundancy on
3287 a path in the CFG we want to optimize for speed. */
3288 if (optimize_edge_for_speed_p (pred
))
3289 do_insertion
= true;
3290 if (first_s
== NULL
)
3291 first_s
= edoubleprime
;
3292 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3296 /* If we can insert it, it's not the same value
3297 already existing along every predecessor, and
3298 it's defined by some predecessor, it is
3299 partially redundant. */
3300 if (!cant_insert
&& !all_same
&& by_some
)
3304 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3306 fprintf (dump_file
, "Skipping partial redundancy for "
3308 print_pre_expr (dump_file
, expr
);
3309 fprintf (dump_file
, " (%04d), no redundancy on to be "
3310 "optimized for speed edge\n", val
);
3313 else if (dbg_cnt (treepre_insert
))
3315 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3317 fprintf (dump_file
, "Found partial redundancy for "
3319 print_pre_expr (dump_file
, expr
);
3320 fprintf (dump_file
, " (%04d)\n",
3321 get_expr_value_id (expr
));
3323 if (insert_into_preds_of_block (block
,
3324 get_expression_id (expr
),
3329 /* If all edges produce the same value and that value is
3330 an invariant, then the PHI has the same value on all
3331 edges. Note this. */
3332 else if (!cant_insert
&& all_same
)
3334 gcc_assert (edoubleprime
->kind
== CONSTANT
3335 || edoubleprime
->kind
== NAME
);
3337 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3340 = gimple_build_assign (temp
,
3341 edoubleprime
->kind
== CONSTANT
?
3342 PRE_EXPR_CONSTANT (edoubleprime
) :
3343 PRE_EXPR_NAME (edoubleprime
));
3344 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3345 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3347 VN_INFO_GET (temp
)->value_id
= val
;
3348 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3349 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3350 VN_INFO (temp
)->valnum
= temp
;
3351 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3352 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3353 add_to_value (val
, newe
);
3354 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3355 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3365 /* Perform insertion for partially anticipatable expressions. There
3366 is only one case we will perform insertion for these. This case is
3367 if the expression is partially anticipatable, and fully available.
3368 In this case, we know that putting it earlier will enable us to
3369 remove the later computation. */
3372 do_pre_partial_partial_insertion (basic_block block
, basic_block dom
)
3374 bool new_stuff
= false;
3375 vec
<pre_expr
> exprs
;
3377 auto_vec
<pre_expr
> avail
;
3380 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3381 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3383 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3385 if (expr
->kind
== NARY
3386 || expr
->kind
== REFERENCE
)
3390 bool cant_insert
= false;
3393 pre_expr eprime
= NULL
;
3396 val
= get_expr_value_id (expr
);
3397 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3399 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3402 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3404 unsigned int vprime
;
3405 pre_expr edoubleprime
;
3407 /* We should never run insertion for the exit block
3408 and so not come across fake pred edges. */
3409 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3411 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3415 /* eprime will generally only be NULL if the
3416 value of the expression, translated
3417 through the PHI for this predecessor, is
3418 undefined. If that is the case, we can't
3419 make the expression fully redundant,
3420 because its value is undefined along a
3421 predecessor path. We can thus break out
3422 early because it doesn't matter what the
3423 rest of the results are. */
3426 avail
[pred
->dest_idx
] = NULL
;
3431 vprime
= get_expr_value_id (eprime
);
3432 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3433 avail
[pred
->dest_idx
] = edoubleprime
;
3434 if (edoubleprime
== NULL
)
3441 /* If we can insert it, it's not the same value
3442 already existing along every predecessor, and
3443 it's defined by some predecessor, it is
3444 partially redundant. */
3445 if (!cant_insert
&& by_all
)
3448 bool do_insertion
= false;
3450 /* Insert only if we can remove a later expression on a path
3451 that we want to optimize for speed.
3452 The phi node that we will be inserting in BLOCK is not free,
3453 and inserting it for the sake of !optimize_for_speed successor
3454 may cause regressions on the speed path. */
3455 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3457 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3458 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3460 if (optimize_edge_for_speed_p (succ
))
3461 do_insertion
= true;
3467 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3469 fprintf (dump_file
, "Skipping partial partial redundancy "
3471 print_pre_expr (dump_file
, expr
);
3472 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3473 "on any to be optimized for speed edges\n", val
);
3476 else if (dbg_cnt (treepre_insert
))
3478 pre_stats
.pa_insert
++;
3479 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3481 fprintf (dump_file
, "Found partial partial redundancy "
3483 print_pre_expr (dump_file
, expr
);
3484 fprintf (dump_file
, " (%04d)\n",
3485 get_expr_value_id (expr
));
3487 if (insert_into_preds_of_block (block
,
3488 get_expression_id (expr
),
3500 /* Insert expressions in BLOCK to compute hoistable values up.
3501 Return TRUE if something was inserted, otherwise return FALSE.
3502 The caller has to make sure that BLOCK has at least two successors. */
3505 do_hoist_insertion (basic_block block
)
3509 bool new_stuff
= false;
3511 gimple_stmt_iterator last
;
3513 /* At least two successors, or else... */
3514 gcc_assert (EDGE_COUNT (block
->succs
) >= 2);
3516 /* Check that all successors of BLOCK are dominated by block.
3517 We could use dominated_by_p() for this, but actually there is a much
3518 quicker check: any successor that is dominated by BLOCK can't have
3519 more than one predecessor edge. */
3520 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3521 if (! single_pred_p (e
->dest
))
3524 /* Determine the insertion point. If we cannot safely insert before
3525 the last stmt if we'd have to, bail out. */
3526 last
= gsi_last_bb (block
);
3527 if (!gsi_end_p (last
)
3528 && !is_ctrl_stmt (gsi_stmt (last
))
3529 && stmt_ends_bb_p (gsi_stmt (last
)))
3532 /* Compute the set of hoistable expressions from ANTIC_IN. First compute
3533 hoistable values. */
3534 bitmap_set hoistable_set
;
3536 /* A hoistable value must be in ANTIC_IN(block)
3537 but not in AVAIL_OUT(BLOCK). */
3538 bitmap_initialize (&hoistable_set
.values
, &grand_bitmap_obstack
);
3539 bitmap_and_compl (&hoistable_set
.values
,
3540 &ANTIC_IN (block
)->values
, &AVAIL_OUT (block
)->values
);
3542 /* Short-cut for a common case: hoistable_set is empty. */
3543 if (bitmap_empty_p (&hoistable_set
.values
))
3546 /* Compute which of the hoistable values is in AVAIL_OUT of
3547 at least one of the successors of BLOCK. */
3548 bitmap_head availout_in_some
;
3549 bitmap_initialize (&availout_in_some
, &grand_bitmap_obstack
);
3550 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3551 /* Do not consider expressions solely because their availability
3552 on loop exits. They'd be ANTIC-IN throughout the whole loop
3553 and thus effectively hoisted across loops by combination of
3554 PRE and hoisting. */
3555 if (! loop_exit_edge_p (block
->loop_father
, e
))
3556 bitmap_ior_and_into (&availout_in_some
, &hoistable_set
.values
,
3557 &AVAIL_OUT (e
->dest
)->values
);
3558 bitmap_clear (&hoistable_set
.values
);
3560 /* Short-cut for a common case: availout_in_some is empty. */
3561 if (bitmap_empty_p (&availout_in_some
))
3564 /* Hack hoitable_set in-place so we can use sorted_array_from_bitmap_set. */
3565 hoistable_set
.values
= availout_in_some
;
3566 hoistable_set
.expressions
= ANTIC_IN (block
)->expressions
;
3568 /* Now finally construct the topological-ordered expression set. */
3569 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (&hoistable_set
);
3571 bitmap_clear (&hoistable_set
.values
);
3573 /* If there are candidate values for hoisting, insert expressions
3574 strategically to make the hoistable expressions fully redundant. */
3576 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3578 /* While we try to sort expressions topologically above the
3579 sorting doesn't work out perfectly. Catch expressions we
3580 already inserted. */
3581 unsigned int value_id
= get_expr_value_id (expr
);
3582 if (bitmap_set_contains_value (AVAIL_OUT (block
), value_id
))
3584 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3587 "Already inserted expression for ");
3588 print_pre_expr (dump_file
, expr
);
3589 fprintf (dump_file
, " (%04d)\n", value_id
);
3594 /* OK, we should hoist this value. Perform the transformation. */
3595 pre_stats
.hoist_insert
++;
3596 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3599 "Inserting expression in block %d for code hoisting: ",
3601 print_pre_expr (dump_file
, expr
);
3602 fprintf (dump_file
, " (%04d)\n", value_id
);
3605 gimple_seq stmts
= NULL
;
3606 tree res
= create_expression_by_pieces (block
, expr
, &stmts
,
3607 get_expr_type (expr
));
3609 /* Do not return true if expression creation ultimately
3610 did not insert any statements. */
3611 if (gimple_seq_empty_p (stmts
))
3615 if (gsi_end_p (last
) || is_ctrl_stmt (gsi_stmt (last
)))
3616 gsi_insert_seq_before (&last
, stmts
, GSI_SAME_STMT
);
3618 gsi_insert_seq_after (&last
, stmts
, GSI_NEW_STMT
);
3621 /* Make sure to not return true if expression creation ultimately
3622 failed but also make sure to insert any stmts produced as they
3623 are tracked in inserted_exprs. */
3635 /* Do a dominator walk on the control flow graph, and insert computations
3636 of values as necessary for PRE and hoisting. */
3639 insert_aux (basic_block block
, bool do_pre
, bool do_hoist
)
3642 bool new_stuff
= false;
3647 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3652 bitmap_set_t newset
;
3654 /* First, update the AVAIL_OUT set with anything we may have
3655 inserted higher up in the dominator tree. */
3656 newset
= NEW_SETS (dom
);
3659 /* Note that we need to value_replace both NEW_SETS, and
3660 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3661 represented by some non-simple expression here that we want
3662 to replace it with. */
3663 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3665 pre_expr expr
= expression_for_id (i
);
3666 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3667 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3671 /* Insert expressions for partial redundancies. */
3672 if (do_pre
&& !single_pred_p (block
))
3674 new_stuff
|= do_pre_regular_insertion (block
, dom
);
3675 if (do_partial_partial
)
3676 new_stuff
|= do_pre_partial_partial_insertion (block
, dom
);
3679 /* Insert expressions for hoisting. */
3680 if (do_hoist
&& EDGE_COUNT (block
->succs
) >= 2)
3681 new_stuff
|= do_hoist_insertion (block
);
3684 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3686 son
= next_dom_son (CDI_DOMINATORS
, son
))
3688 new_stuff
|= insert_aux (son
, do_pre
, do_hoist
);
3694 /* Perform insertion of partially redundant and hoistable values. */
3699 bool new_stuff
= true;
3701 int num_iterations
= 0;
3703 FOR_ALL_BB_FN (bb
, cfun
)
3704 NEW_SETS (bb
) = bitmap_set_new ();
3709 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3710 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3711 new_stuff
= insert_aux (ENTRY_BLOCK_PTR_FOR_FN (cfun
), flag_tree_pre
,
3712 flag_code_hoisting
);
3714 /* Clear the NEW sets before the next iteration. We have already
3715 fully propagated its contents. */
3717 FOR_ALL_BB_FN (bb
, cfun
)
3718 bitmap_set_free (NEW_SETS (bb
));
3720 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3724 /* Compute the AVAIL set for all basic blocks.
3726 This function performs value numbering of the statements in each basic
3727 block. The AVAIL sets are built from information we glean while doing
3728 this value numbering, since the AVAIL sets contain only one entry per
3731 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3732 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3735 compute_avail (void)
3738 basic_block block
, son
;
3739 basic_block
*worklist
;
3744 /* We pretend that default definitions are defined in the entry block.
3745 This includes function arguments and the static chain decl. */
3746 FOR_EACH_SSA_NAME (i
, name
, cfun
)
3749 if (!SSA_NAME_IS_DEFAULT_DEF (name
)
3750 || has_zero_uses (name
)
3751 || virtual_operand_p (name
))
3754 e
= get_or_alloc_expr_for_name (name
);
3755 add_to_value (get_expr_value_id (e
), e
);
3756 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3757 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3761 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3763 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3764 "tmp_gen", ENTRY_BLOCK
);
3765 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3766 "avail_out", ENTRY_BLOCK
);
3769 /* Allocate the worklist. */
3770 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3772 /* Seed the algorithm by putting the dominator children of the entry
3773 block on the worklist. */
3774 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3776 son
= next_dom_son (CDI_DOMINATORS
, son
))
3777 worklist
[sp
++] = son
;
3779 BB_LIVE_VOP_ON_EXIT (ENTRY_BLOCK_PTR_FOR_FN (cfun
))
3780 = ssa_default_def (cfun
, gimple_vop (cfun
));
3782 /* Loop until the worklist is empty. */
3788 /* Pick a block from the worklist. */
3789 block
= worklist
[--sp
];
3791 /* Initially, the set of available values in BLOCK is that of
3792 its immediate dominator. */
3793 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3796 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3797 BB_LIVE_VOP_ON_EXIT (block
) = BB_LIVE_VOP_ON_EXIT (dom
);
3800 /* Generate values for PHI nodes. */
3801 for (gphi_iterator gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
);
3804 tree result
= gimple_phi_result (gsi
.phi ());
3806 /* We have no need for virtual phis, as they don't represent
3807 actual computations. */
3808 if (virtual_operand_p (result
))
3810 BB_LIVE_VOP_ON_EXIT (block
) = result
;
3814 pre_expr e
= get_or_alloc_expr_for_name (result
);
3815 add_to_value (get_expr_value_id (e
), e
);
3816 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3817 bitmap_insert_into_set (PHI_GEN (block
), e
);
3820 BB_MAY_NOTRETURN (block
) = 0;
3822 /* Now compute value numbers and populate value sets with all
3823 the expressions computed in BLOCK. */
3824 for (gimple_stmt_iterator gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
);
3830 stmt
= gsi_stmt (gsi
);
3832 /* Cache whether the basic-block has any non-visible side-effect
3834 If this isn't a call or it is the last stmt in the
3835 basic-block then the CFG represents things correctly. */
3836 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3838 /* Non-looping const functions always return normally.
3839 Otherwise the call might not return or have side-effects
3840 that forbids hoisting possibly trapping expressions
3842 int flags
= gimple_call_flags (stmt
);
3843 if (!(flags
& ECF_CONST
)
3844 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3845 BB_MAY_NOTRETURN (block
) = 1;
3848 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3850 pre_expr e
= get_or_alloc_expr_for_name (op
);
3852 add_to_value (get_expr_value_id (e
), e
);
3853 bitmap_insert_into_set (TMP_GEN (block
), e
);
3854 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3857 if (gimple_vdef (stmt
))
3858 BB_LIVE_VOP_ON_EXIT (block
) = gimple_vdef (stmt
);
3860 if (gimple_has_side_effects (stmt
)
3861 || stmt_could_throw_p (stmt
)
3862 || is_gimple_debug (stmt
))
3865 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3867 if (ssa_undefined_value_p (op
))
3869 pre_expr e
= get_or_alloc_expr_for_name (op
);
3870 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3873 switch (gimple_code (stmt
))
3881 vn_reference_s ref1
;
3882 pre_expr result
= NULL
;
3884 /* We can value number only calls to real functions. */
3885 if (gimple_call_internal_p (stmt
))
3888 vn_reference_lookup_call (as_a
<gcall
*> (stmt
), &ref
, &ref1
);
3892 /* If the value of the call is not invalidated in
3893 this block until it is computed, add the expression
3895 if (!gimple_vuse (stmt
)
3897 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3898 || gimple_bb (SSA_NAME_DEF_STMT
3899 (gimple_vuse (stmt
))) != block
)
3901 result
= pre_expr_pool
.allocate ();
3902 result
->kind
= REFERENCE
;
3904 PRE_EXPR_REFERENCE (result
) = ref
;
3906 get_or_alloc_expression_id (result
);
3907 add_to_value (get_expr_value_id (result
), result
);
3908 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3915 pre_expr result
= NULL
;
3916 switch (vn_get_stmt_kind (stmt
))
3920 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3923 /* COND_EXPR and VEC_COND_EXPR are awkward in
3924 that they contain an embedded complex expression.
3925 Don't even try to shove those through PRE. */
3926 if (code
== COND_EXPR
3927 || code
== VEC_COND_EXPR
)
3930 vn_nary_op_lookup_stmt (stmt
, &nary
);
3934 /* If the NARY traps and there was a preceding
3935 point in the block that might not return avoid
3936 adding the nary to EXP_GEN. */
3937 if (BB_MAY_NOTRETURN (block
)
3938 && vn_nary_may_trap (nary
))
3941 result
= pre_expr_pool
.allocate ();
3942 result
->kind
= NARY
;
3944 PRE_EXPR_NARY (result
) = nary
;
3950 tree rhs1
= gimple_assign_rhs1 (stmt
);
3951 alias_set_type set
= get_alias_set (rhs1
);
3952 vec
<vn_reference_op_s
> operands
3953 = vn_reference_operands_for_lookup (rhs1
);
3955 vn_reference_lookup_pieces (gimple_vuse (stmt
), set
,
3957 operands
, &ref
, VN_WALK
);
3960 operands
.release ();
3964 /* If the value of the reference is not invalidated in
3965 this block until it is computed, add the expression
3967 if (gimple_vuse (stmt
))
3971 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3972 while (!gimple_nop_p (def_stmt
)
3973 && gimple_code (def_stmt
) != GIMPLE_PHI
3974 && gimple_bb (def_stmt
) == block
)
3976 if (stmt_may_clobber_ref_p
3977 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3983 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3987 operands
.release ();
3992 /* If the load was value-numbered to another
3993 load make sure we do not use its expression
3994 for insertion if it wouldn't be a valid
3996 /* At the momemt we have a testcase
3997 for hoist insertion of aligned vs. misaligned
3998 variants in gcc.dg/torture/pr65270-1.c thus
3999 with just alignment to be considered we can
4000 simply replace the expression in the hashtable
4001 with the most conservative one. */
4002 vn_reference_op_t ref1
= &ref
->operands
.last ();
4003 while (ref1
->opcode
!= TARGET_MEM_REF
4004 && ref1
->opcode
!= MEM_REF
4005 && ref1
!= &ref
->operands
[0])
4007 vn_reference_op_t ref2
= &operands
.last ();
4008 while (ref2
->opcode
!= TARGET_MEM_REF
4009 && ref2
->opcode
!= MEM_REF
4010 && ref2
!= &operands
[0])
4012 if ((ref1
->opcode
== TARGET_MEM_REF
4013 || ref1
->opcode
== MEM_REF
)
4014 && (TYPE_ALIGN (ref1
->type
)
4015 > TYPE_ALIGN (ref2
->type
)))
4017 = build_aligned_type (ref1
->type
,
4018 TYPE_ALIGN (ref2
->type
));
4019 /* TBAA behavior is an obvious part so make sure
4020 that the hashtable one covers this as well
4021 by adjusting the ref alias set and its base. */
4023 || alias_set_subset_of (set
, ref
->set
))
4025 else if (alias_set_subset_of (ref
->set
, set
))
4028 if (ref1
->opcode
== MEM_REF
)
4030 = wide_int_to_tree (TREE_TYPE (ref2
->op0
),
4031 wi::to_wide (ref1
->op0
));
4034 = wide_int_to_tree (TREE_TYPE (ref2
->op2
),
4035 wi::to_wide (ref1
->op2
));
4040 if (ref1
->opcode
== MEM_REF
)
4042 = wide_int_to_tree (ptr_type_node
,
4043 wi::to_wide (ref1
->op0
));
4046 = wide_int_to_tree (ptr_type_node
,
4047 wi::to_wide (ref1
->op2
));
4049 operands
.release ();
4051 result
= pre_expr_pool
.allocate ();
4052 result
->kind
= REFERENCE
;
4054 PRE_EXPR_REFERENCE (result
) = ref
;
4062 get_or_alloc_expression_id (result
);
4063 add_to_value (get_expr_value_id (result
), result
);
4064 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4072 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4074 print_bitmap_set (dump_file
, EXP_GEN (block
),
4075 "exp_gen", block
->index
);
4076 print_bitmap_set (dump_file
, PHI_GEN (block
),
4077 "phi_gen", block
->index
);
4078 print_bitmap_set (dump_file
, TMP_GEN (block
),
4079 "tmp_gen", block
->index
);
4080 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
4081 "avail_out", block
->index
);
4084 /* Put the dominator children of BLOCK on the worklist of blocks
4085 to compute available sets for. */
4086 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4088 son
= next_dom_son (CDI_DOMINATORS
, son
))
4089 worklist
[sp
++] = son
;
4096 /* Local state for the eliminate domwalk. */
4097 static vec
<gimple
*> el_to_remove
;
4098 static vec
<gimple
*> el_to_fixup
;
4099 static unsigned int el_todo
;
4100 static vec
<tree
> el_avail
;
4101 static vec
<tree
> el_avail_stack
;
4103 /* Return a leader for OP that is available at the current point of the
4104 eliminate domwalk. */
4107 eliminate_avail (tree op
)
4109 tree valnum
= VN_INFO (op
)->valnum
;
4110 if (TREE_CODE (valnum
) == SSA_NAME
)
4112 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
4114 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
4115 return el_avail
[SSA_NAME_VERSION (valnum
)];
4117 else if (is_gimple_min_invariant (valnum
))
4122 /* At the current point of the eliminate domwalk make OP available. */
4125 eliminate_push_avail (tree op
)
4127 tree valnum
= VN_INFO (op
)->valnum
;
4128 if (TREE_CODE (valnum
) == SSA_NAME
)
4130 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
4131 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
4133 if (el_avail
[SSA_NAME_VERSION (valnum
)])
4134 pushop
= el_avail
[SSA_NAME_VERSION (valnum
)];
4135 el_avail_stack
.safe_push (pushop
);
4136 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
4140 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
4141 the leader for the expression if insertion was successful. */
4144 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
4146 /* We can insert a sequence with a single assignment only. */
4147 gimple_seq stmts
= VN_INFO (val
)->expr
;
4148 if (!gimple_seq_singleton_p (stmts
))
4150 gassign
*stmt
= dyn_cast
<gassign
*> (gimple_seq_first_stmt (stmts
));
4152 || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt
))
4153 && gimple_assign_rhs_code (stmt
) != VIEW_CONVERT_EXPR
4154 && gimple_assign_rhs_code (stmt
) != BIT_FIELD_REF
4155 && (gimple_assign_rhs_code (stmt
) != BIT_AND_EXPR
4156 || TREE_CODE (gimple_assign_rhs2 (stmt
)) != INTEGER_CST
)))
4159 tree op
= gimple_assign_rhs1 (stmt
);
4160 if (gimple_assign_rhs_code (stmt
) == VIEW_CONVERT_EXPR
4161 || gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4162 op
= TREE_OPERAND (op
, 0);
4163 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
4169 if (gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4170 res
= gimple_build (&stmts
, BIT_FIELD_REF
,
4171 TREE_TYPE (val
), leader
,
4172 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 1),
4173 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 2));
4174 else if (gimple_assign_rhs_code (stmt
) == BIT_AND_EXPR
)
4175 res
= gimple_build (&stmts
, BIT_AND_EXPR
,
4176 TREE_TYPE (val
), leader
, gimple_assign_rhs2 (stmt
));
4178 res
= gimple_build (&stmts
, gimple_assign_rhs_code (stmt
),
4179 TREE_TYPE (val
), leader
);
4180 if (TREE_CODE (res
) != SSA_NAME
4181 || SSA_NAME_IS_DEFAULT_DEF (res
)
4182 || gimple_bb (SSA_NAME_DEF_STMT (res
)))
4184 gimple_seq_discard (stmts
);
4186 /* During propagation we have to treat SSA info conservatively
4187 and thus we can end up simplifying the inserted expression
4188 at elimination time to sth not defined in stmts. */
4189 /* But then this is a redundancy we failed to detect. Which means
4190 res now has two values. That doesn't play well with how
4191 we track availability here, so give up. */
4192 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4194 if (TREE_CODE (res
) == SSA_NAME
)
4195 res
= eliminate_avail (res
);
4198 fprintf (dump_file
, "Failed to insert expression for value ");
4199 print_generic_expr (dump_file
, val
);
4200 fprintf (dump_file
, " which is really fully redundant to ");
4201 print_generic_expr (dump_file
, res
);
4202 fprintf (dump_file
, "\n");
4210 gsi_insert_seq_before (gsi
, stmts
, GSI_SAME_STMT
);
4211 VN_INFO_GET (res
)->valnum
= val
;
4214 pre_stats
.insertions
++;
4215 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4217 fprintf (dump_file
, "Inserted ");
4218 print_gimple_stmt (dump_file
, SSA_NAME_DEF_STMT (res
), 0);
4224 class eliminate_dom_walker
: public dom_walker
4227 eliminate_dom_walker (cdi_direction direction
, bool do_pre_
)
4228 : dom_walker (direction
), do_pre (do_pre_
) {}
4230 virtual edge
before_dom_children (basic_block
);
4231 virtual void after_dom_children (basic_block
);
4236 /* Perform elimination for the basic-block B during the domwalk. */
4239 eliminate_dom_walker::before_dom_children (basic_block b
)
4242 el_avail_stack
.safe_push (NULL_TREE
);
4244 /* Skip unreachable blocks marked unreachable during the SCCVN domwalk. */
4247 FOR_EACH_EDGE (e
, ei
, b
->preds
)
4248 if (e
->flags
& EDGE_EXECUTABLE
)
4253 for (gphi_iterator gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4255 gphi
*phi
= gsi
.phi ();
4256 tree res
= PHI_RESULT (phi
);
4258 if (virtual_operand_p (res
))
4264 tree sprime
= eliminate_avail (res
);
4268 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4270 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4271 print_generic_expr (dump_file
, res
);
4272 fprintf (dump_file
, " with ");
4273 print_generic_expr (dump_file
, sprime
);
4274 fprintf (dump_file
, "\n");
4277 /* If we inserted this PHI node ourself, it's not an elimination. */
4279 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4282 pre_stats
.eliminations
++;
4284 /* If we will propagate into all uses don't bother to do
4286 if (may_propagate_copy (res
, sprime
))
4288 /* Mark the PHI for removal. */
4289 el_to_remove
.safe_push (phi
);
4294 remove_phi_node (&gsi
, false);
4296 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4297 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4298 gimple
*stmt
= gimple_build_assign (res
, sprime
);
4299 gimple_stmt_iterator gsi2
= gsi_after_labels (b
);
4300 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4304 eliminate_push_avail (res
);
4308 for (gimple_stmt_iterator gsi
= gsi_start_bb (b
);
4312 tree sprime
= NULL_TREE
;
4313 gimple
*stmt
= gsi_stmt (gsi
);
4314 tree lhs
= gimple_get_lhs (stmt
);
4315 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
4316 && !gimple_has_volatile_ops (stmt
)
4317 /* See PR43491. Do not replace a global register variable when
4318 it is a the RHS of an assignment. Do replace local register
4319 variables since gcc does not guarantee a local variable will
4320 be allocated in register.
4321 ??? The fix isn't effective here. This should instead
4322 be ensured by not value-numbering them the same but treating
4323 them like volatiles? */
4324 && !(gimple_assign_single_p (stmt
)
4325 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
4326 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
))
4327 && is_global_var (gimple_assign_rhs1 (stmt
)))))
4329 sprime
= eliminate_avail (lhs
);
4332 /* If there is no existing usable leader but SCCVN thinks
4333 it has an expression it wants to use as replacement,
4335 tree val
= VN_INFO (lhs
)->valnum
;
4337 && TREE_CODE (val
) == SSA_NAME
4338 && VN_INFO (val
)->needs_insertion
4339 && VN_INFO (val
)->expr
!= NULL
4340 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4341 eliminate_push_avail (sprime
);
4344 /* If this now constitutes a copy duplicate points-to
4345 and range info appropriately. This is especially
4346 important for inserted code. See tree-ssa-copy.c
4347 for similar code. */
4349 && TREE_CODE (sprime
) == SSA_NAME
)
4351 basic_block sprime_b
= gimple_bb (SSA_NAME_DEF_STMT (sprime
));
4352 if (POINTER_TYPE_P (TREE_TYPE (lhs
))
4353 && VN_INFO_PTR_INFO (lhs
)
4354 && ! VN_INFO_PTR_INFO (sprime
))
4356 duplicate_ssa_name_ptr_info (sprime
,
4357 VN_INFO_PTR_INFO (lhs
));
4359 mark_ptr_info_alignment_unknown
4360 (SSA_NAME_PTR_INFO (sprime
));
4362 else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
4363 && VN_INFO_RANGE_INFO (lhs
)
4364 && ! VN_INFO_RANGE_INFO (sprime
)
4366 duplicate_ssa_name_range_info (sprime
,
4367 VN_INFO_RANGE_TYPE (lhs
),
4368 VN_INFO_RANGE_INFO (lhs
));
4371 /* Inhibit the use of an inserted PHI on a loop header when
4372 the address of the memory reference is a simple induction
4373 variable. In other cases the vectorizer won't do anything
4374 anyway (either it's loop invariant or a complicated
4377 && TREE_CODE (sprime
) == SSA_NAME
4379 && (flag_tree_loop_vectorize
|| flag_tree_parallelize_loops
> 1)
4380 && loop_outer (b
->loop_father
)
4381 && has_zero_uses (sprime
)
4382 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))
4383 && gimple_assign_load_p (stmt
))
4385 gimple
*def_stmt
= SSA_NAME_DEF_STMT (sprime
);
4386 basic_block def_bb
= gimple_bb (def_stmt
);
4387 if (gimple_code (def_stmt
) == GIMPLE_PHI
4388 && def_bb
->loop_father
->header
== def_bb
)
4390 loop_p loop
= def_bb
->loop_father
;
4394 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4397 def_bb
= gimple_bb (SSA_NAME_DEF_STMT (op
));
4399 && flow_bb_inside_loop_p (loop
, def_bb
)
4400 && simple_iv (loop
, loop
, op
, &iv
, true))
4408 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4410 fprintf (dump_file
, "Not replacing ");
4411 print_gimple_expr (dump_file
, stmt
, 0);
4412 fprintf (dump_file
, " with ");
4413 print_generic_expr (dump_file
, sprime
);
4414 fprintf (dump_file
, " which would add a loop"
4415 " carried dependence to loop %d\n",
4418 /* Don't keep sprime available. */
4426 /* If we can propagate the value computed for LHS into
4427 all uses don't bother doing anything with this stmt. */
4428 if (may_propagate_copy (lhs
, sprime
))
4430 /* Mark it for removal. */
4431 el_to_remove
.safe_push (stmt
);
4433 /* ??? Don't count copy/constant propagations. */
4434 if (gimple_assign_single_p (stmt
)
4435 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4436 || gimple_assign_rhs1 (stmt
) == sprime
))
4439 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4441 fprintf (dump_file
, "Replaced ");
4442 print_gimple_expr (dump_file
, stmt
, 0);
4443 fprintf (dump_file
, " with ");
4444 print_generic_expr (dump_file
, sprime
);
4445 fprintf (dump_file
, " in all uses of ");
4446 print_gimple_stmt (dump_file
, stmt
, 0);
4449 pre_stats
.eliminations
++;
4453 /* If this is an assignment from our leader (which
4454 happens in the case the value-number is a constant)
4455 then there is nothing to do. */
4456 if (gimple_assign_single_p (stmt
)
4457 && sprime
== gimple_assign_rhs1 (stmt
))
4460 /* Else replace its RHS. */
4461 bool can_make_abnormal_goto
4462 = is_gimple_call (stmt
)
4463 && stmt_can_make_abnormal_goto (stmt
);
4465 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4467 fprintf (dump_file
, "Replaced ");
4468 print_gimple_expr (dump_file
, stmt
, 0);
4469 fprintf (dump_file
, " with ");
4470 print_generic_expr (dump_file
, sprime
);
4471 fprintf (dump_file
, " in ");
4472 print_gimple_stmt (dump_file
, stmt
, 0);
4475 pre_stats
.eliminations
++;
4476 gimple
*orig_stmt
= stmt
;
4477 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4478 TREE_TYPE (sprime
)))
4479 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4480 tree vdef
= gimple_vdef (stmt
);
4481 tree vuse
= gimple_vuse (stmt
);
4482 propagate_tree_value_into_stmt (&gsi
, sprime
);
4483 stmt
= gsi_stmt (gsi
);
4485 if (vdef
!= gimple_vdef (stmt
))
4486 VN_INFO (vdef
)->valnum
= vuse
;
4488 /* If we removed EH side-effects from the statement, clean
4489 its EH information. */
4490 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4492 bitmap_set_bit (need_eh_cleanup
,
4493 gimple_bb (stmt
)->index
);
4494 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4495 fprintf (dump_file
, " Removed EH side-effects.\n");
4498 /* Likewise for AB side-effects. */
4499 if (can_make_abnormal_goto
4500 && !stmt_can_make_abnormal_goto (stmt
))
4502 bitmap_set_bit (need_ab_cleanup
,
4503 gimple_bb (stmt
)->index
);
4504 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4505 fprintf (dump_file
, " Removed AB side-effects.\n");
4512 /* If the statement is a scalar store, see if the expression
4513 has the same value number as its rhs. If so, the store is
4515 if (gimple_assign_single_p (stmt
)
4516 && !gimple_has_volatile_ops (stmt
)
4517 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4518 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4519 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4522 tree rhs
= gimple_assign_rhs1 (stmt
);
4523 vn_reference_t vnresult
;
4524 val
= vn_reference_lookup (lhs
, gimple_vuse (stmt
), VN_WALKREWRITE
,
4526 if (TREE_CODE (rhs
) == SSA_NAME
)
4527 rhs
= VN_INFO (rhs
)->valnum
;
4529 && operand_equal_p (val
, rhs
, 0))
4531 /* We can only remove the later store if the former aliases
4532 at least all accesses the later one does or if the store
4533 was to readonly memory storing the same value. */
4534 alias_set_type set
= get_alias_set (lhs
);
4536 || vnresult
->set
== set
4537 || alias_set_subset_of (set
, vnresult
->set
))
4539 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4541 fprintf (dump_file
, "Deleted redundant store ");
4542 print_gimple_stmt (dump_file
, stmt
, 0);
4545 /* Queue stmt for removal. */
4546 el_to_remove
.safe_push (stmt
);
4552 /* If this is a control statement value numbering left edges
4553 unexecuted on force the condition in a way consistent with
4555 if (gcond
*cond
= dyn_cast
<gcond
*> (stmt
))
4557 if ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
)
4558 ^ (EDGE_SUCC (b
, 1)->flags
& EDGE_EXECUTABLE
))
4560 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4562 fprintf (dump_file
, "Removing unexecutable edge from ");
4563 print_gimple_stmt (dump_file
, stmt
, 0);
4565 if (((EDGE_SUCC (b
, 0)->flags
& EDGE_TRUE_VALUE
) != 0)
4566 == ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
) != 0))
4567 gimple_cond_make_true (cond
);
4569 gimple_cond_make_false (cond
);
4571 el_todo
|= TODO_cleanup_cfg
;
4576 bool can_make_abnormal_goto
= stmt_can_make_abnormal_goto (stmt
);
4577 bool was_noreturn
= (is_gimple_call (stmt
)
4578 && gimple_call_noreturn_p (stmt
));
4579 tree vdef
= gimple_vdef (stmt
);
4580 tree vuse
= gimple_vuse (stmt
);
4582 /* If we didn't replace the whole stmt (or propagate the result
4583 into all uses), replace all uses on this stmt with their
4585 bool modified
= false;
4586 use_operand_p use_p
;
4588 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_USE
)
4590 tree use
= USE_FROM_PTR (use_p
);
4591 /* ??? The call code above leaves stmt operands un-updated. */
4592 if (TREE_CODE (use
) != SSA_NAME
)
4594 tree sprime
= eliminate_avail (use
);
4595 if (sprime
&& sprime
!= use
4596 && may_propagate_copy (use
, sprime
)
4597 /* We substitute into debug stmts to avoid excessive
4598 debug temporaries created by removed stmts, but we need
4599 to avoid doing so for inserted sprimes as we never want
4600 to create debug temporaries for them. */
4602 || TREE_CODE (sprime
) != SSA_NAME
4603 || !is_gimple_debug (stmt
)
4604 || !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))))
4606 propagate_value (use_p
, sprime
);
4611 /* Fold the stmt if modified, this canonicalizes MEM_REFs we propagated
4612 into which is a requirement for the IPA devirt machinery. */
4613 gimple
*old_stmt
= stmt
;
4616 /* If a formerly non-invariant ADDR_EXPR is turned into an
4617 invariant one it was on a separate stmt. */
4618 if (gimple_assign_single_p (stmt
)
4619 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
4620 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
4621 gimple_stmt_iterator prev
= gsi
;
4623 if (fold_stmt (&gsi
))
4625 /* fold_stmt may have created new stmts inbetween
4626 the previous stmt and the folded stmt. Mark
4627 all defs created there as varying to not confuse
4628 the SCCVN machinery as we're using that even during
4630 if (gsi_end_p (prev
))
4631 prev
= gsi_start_bb (b
);
4634 if (gsi_stmt (prev
) != gsi_stmt (gsi
))
4639 FOR_EACH_SSA_TREE_OPERAND (def
, gsi_stmt (prev
),
4640 dit
, SSA_OP_ALL_DEFS
)
4641 /* As existing DEFs may move between stmts
4642 we have to guard VN_INFO_GET. */
4643 if (! has_VN_INFO (def
))
4644 VN_INFO_GET (def
)->valnum
= def
;
4645 if (gsi_stmt (prev
) == gsi_stmt (gsi
))
4651 stmt
= gsi_stmt (gsi
);
4652 /* In case we folded the stmt away schedule the NOP for removal. */
4653 if (gimple_nop_p (stmt
))
4654 el_to_remove
.safe_push (stmt
);
4657 /* Visit indirect calls and turn them into direct calls if
4658 possible using the devirtualization machinery. Do this before
4659 checking for required EH/abnormal/noreturn cleanup as devird
4660 may expose more of those. */
4661 if (gcall
*call_stmt
= dyn_cast
<gcall
*> (stmt
))
4663 tree fn
= gimple_call_fn (call_stmt
);
4665 && flag_devirtualize
4666 && virtual_method_call_p (fn
))
4668 tree otr_type
= obj_type_ref_class (fn
);
4669 unsigned HOST_WIDE_INT otr_tok
4670 = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (fn
));
4672 ipa_polymorphic_call_context
context (current_function_decl
,
4673 fn
, stmt
, &instance
);
4674 context
.get_dynamic_type (instance
, OBJ_TYPE_REF_OBJECT (fn
),
4677 vec
<cgraph_node
*> targets
4678 = possible_polymorphic_call_targets (obj_type_ref_class (fn
),
4679 otr_tok
, context
, &final
);
4681 dump_possible_polymorphic_call_targets (dump_file
,
4682 obj_type_ref_class (fn
),
4684 if (final
&& targets
.length () <= 1 && dbg_cnt (devirt
))
4687 if (targets
.length () == 1)
4688 fn
= targets
[0]->decl
;
4690 fn
= builtin_decl_implicit (BUILT_IN_UNREACHABLE
);
4691 if (dump_enabled_p ())
4693 location_t loc
= gimple_location (stmt
);
4694 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, loc
,
4695 "converting indirect call to "
4697 lang_hooks
.decl_printable_name (fn
, 2));
4699 gimple_call_set_fndecl (call_stmt
, fn
);
4700 /* If changing the call to __builtin_unreachable
4701 or similar noreturn function, adjust gimple_call_fntype
4703 if (gimple_call_noreturn_p (call_stmt
)
4704 && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn
)))
4705 && TYPE_ARG_TYPES (TREE_TYPE (fn
))
4706 && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn
)))
4708 gimple_call_set_fntype (call_stmt
, TREE_TYPE (fn
));
4709 maybe_remove_unused_call_args (cfun
, call_stmt
);
4717 /* When changing a call into a noreturn call, cfg cleanup
4718 is needed to fix up the noreturn call. */
4720 && is_gimple_call (stmt
) && gimple_call_noreturn_p (stmt
))
4721 el_to_fixup
.safe_push (stmt
);
4722 /* When changing a condition or switch into one we know what
4723 edge will be executed, schedule a cfg cleanup. */
4724 if ((gimple_code (stmt
) == GIMPLE_COND
4725 && (gimple_cond_true_p (as_a
<gcond
*> (stmt
))
4726 || gimple_cond_false_p (as_a
<gcond
*> (stmt
))))
4727 || (gimple_code (stmt
) == GIMPLE_SWITCH
4728 && TREE_CODE (gimple_switch_index
4729 (as_a
<gswitch
*> (stmt
))) == INTEGER_CST
))
4730 el_todo
|= TODO_cleanup_cfg
;
4731 /* If we removed EH side-effects from the statement, clean
4732 its EH information. */
4733 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
))
4735 bitmap_set_bit (need_eh_cleanup
,
4736 gimple_bb (stmt
)->index
);
4737 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4738 fprintf (dump_file
, " Removed EH side-effects.\n");
4740 /* Likewise for AB side-effects. */
4741 if (can_make_abnormal_goto
4742 && !stmt_can_make_abnormal_goto (stmt
))
4744 bitmap_set_bit (need_ab_cleanup
,
4745 gimple_bb (stmt
)->index
);
4746 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4747 fprintf (dump_file
, " Removed AB side-effects.\n");
4750 if (vdef
!= gimple_vdef (stmt
))
4751 VN_INFO (vdef
)->valnum
= vuse
;
4754 /* Make new values available - for fully redundant LHS we
4755 continue with the next stmt above and skip this. */
4757 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_DEF
)
4758 eliminate_push_avail (DEF_FROM_PTR (defp
));
4761 /* Replace destination PHI arguments. */
4762 FOR_EACH_EDGE (e
, ei
, b
->succs
)
4763 if (e
->flags
& EDGE_EXECUTABLE
)
4764 for (gphi_iterator gsi
= gsi_start_phis (e
->dest
);
4768 gphi
*phi
= gsi
.phi ();
4769 use_operand_p use_p
= PHI_ARG_DEF_PTR_FROM_EDGE (phi
, e
);
4770 tree arg
= USE_FROM_PTR (use_p
);
4771 if (TREE_CODE (arg
) != SSA_NAME
4772 || virtual_operand_p (arg
))
4774 tree sprime
= eliminate_avail (arg
);
4775 if (sprime
&& may_propagate_copy (arg
, sprime
))
4776 propagate_value (use_p
, sprime
);
4781 /* Make no longer available leaders no longer available. */
4784 eliminate_dom_walker::after_dom_children (basic_block
)
4787 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4789 tree valnum
= VN_INFO (entry
)->valnum
;
4790 tree old
= el_avail
[SSA_NAME_VERSION (valnum
)];
4792 el_avail
[SSA_NAME_VERSION (valnum
)] = NULL_TREE
;
4794 el_avail
[SSA_NAME_VERSION (valnum
)] = entry
;
4798 /* Eliminate fully redundant computations. */
4801 eliminate (bool do_pre
)
4803 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4804 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4806 el_to_remove
.create (0);
4807 el_to_fixup
.create (0);
4809 el_avail
.create (num_ssa_names
);
4810 el_avail_stack
.create (0);
4812 eliminate_dom_walker (CDI_DOMINATORS
,
4813 do_pre
).walk (cfun
->cfg
->x_entry_block_ptr
);
4815 el_avail
.release ();
4816 el_avail_stack
.release ();
4821 /* Perform CFG cleanups made necessary by elimination. */
4824 fini_eliminate (void)
4826 gimple_stmt_iterator gsi
;
4830 /* We cannot remove stmts during BB walk, especially not release SSA
4831 names there as this confuses the VN machinery. The stmts ending
4832 up in el_to_remove are either stores or simple copies.
4833 Remove stmts in reverse order to make debug stmt creation possible. */
4834 while (!el_to_remove
.is_empty ())
4836 stmt
= el_to_remove
.pop ();
4838 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4840 fprintf (dump_file
, "Removing dead stmt ");
4841 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4844 gsi
= gsi_for_stmt (stmt
);
4845 if (gimple_code (stmt
) == GIMPLE_PHI
)
4846 remove_phi_node (&gsi
, true);
4849 basic_block bb
= gimple_bb (stmt
);
4850 unlink_stmt_vdef (stmt
);
4851 if (gsi_remove (&gsi
, true))
4852 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4853 if (is_gimple_call (stmt
) && stmt_can_make_abnormal_goto (stmt
))
4854 bitmap_set_bit (need_ab_cleanup
, bb
->index
);
4855 release_defs (stmt
);
4858 /* Removing a stmt may expose a forwarder block. */
4859 todo
|= TODO_cleanup_cfg
;
4861 el_to_remove
.release ();
4863 /* Fixup stmts that became noreturn calls. This may require splitting
4864 blocks and thus isn't possible during the dominator walk. Do this
4865 in reverse order so we don't inadvertedly remove a stmt we want to
4866 fixup by visiting a dominating now noreturn call first. */
4867 while (!el_to_fixup
.is_empty ())
4869 stmt
= el_to_fixup
.pop ();
4871 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4873 fprintf (dump_file
, "Fixing up noreturn call ");
4874 print_gimple_stmt (dump_file
, stmt
, 0);
4877 if (fixup_noreturn_call (stmt
))
4878 todo
|= TODO_cleanup_cfg
;
4880 el_to_fixup
.release ();
4882 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4883 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4886 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4889 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4891 BITMAP_FREE (need_eh_cleanup
);
4892 BITMAP_FREE (need_ab_cleanup
);
4894 if (do_eh_cleanup
|| do_ab_cleanup
)
4895 todo
|= TODO_cleanup_cfg
;
4899 /* Cheap DCE of a known set of possibly dead stmts.
4901 Because we don't follow exactly the standard PRE algorithm, and decide not
4902 to insert PHI nodes sometimes, and because value numbering of casts isn't
4903 perfect, we sometimes end up inserting dead code. This simple DCE-like
4904 pass removes any insertions we made that weren't actually used. */
4907 remove_dead_inserted_code (void)
4909 /* ??? Re-use inserted_exprs as worklist not only as initial set.
4910 This may end up removing non-inserted code as well. If we
4911 keep inserted_exprs unchanged we could restrict new worklist
4912 elements to members of inserted_exprs. */
4913 bitmap worklist
= inserted_exprs
;
4914 while (! bitmap_empty_p (worklist
))
4917 unsigned i
= bitmap_first_set_bit (worklist
);
4918 bitmap_clear_bit (worklist
, i
);
4920 tree def
= ssa_name (i
);
4921 /* Removed by somebody else or still in use. */
4922 if (! def
|| ! has_zero_uses (def
))
4925 gimple
*t
= SSA_NAME_DEF_STMT (def
);
4926 if (gimple_has_side_effects (t
))
4929 /* Add uses to the worklist. */
4931 use_operand_p use_p
;
4932 FOR_EACH_PHI_OR_STMT_USE (use_p
, t
, iter
, SSA_OP_USE
)
4934 tree use
= USE_FROM_PTR (use_p
);
4935 if (TREE_CODE (use
) == SSA_NAME
4936 && ! SSA_NAME_IS_DEFAULT_DEF (use
))
4937 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4941 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4943 fprintf (dump_file
, "Removing unnecessary insertion:");
4944 print_gimple_stmt (dump_file
, t
, 0);
4946 gimple_stmt_iterator gsi
= gsi_for_stmt (t
);
4947 if (gimple_code (t
) == GIMPLE_PHI
)
4948 remove_phi_node (&gsi
, true);
4951 gsi_remove (&gsi
, true);
4958 /* Initialize data structures used by PRE. */
4965 next_expression_id
= 1;
4966 expressions
.create (0);
4967 expressions
.safe_push (NULL
);
4968 value_expressions
.create (get_max_value_id () + 1);
4969 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4970 name_to_id
.create (0);
4972 inserted_exprs
= BITMAP_ALLOC (NULL
);
4974 connect_infinite_loops_to_exit ();
4975 memset (&pre_stats
, 0, sizeof (pre_stats
));
4977 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4979 calculate_dominance_info (CDI_DOMINATORS
);
4981 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4982 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4983 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4984 FOR_ALL_BB_FN (bb
, cfun
)
4986 EXP_GEN (bb
) = bitmap_set_new ();
4987 PHI_GEN (bb
) = bitmap_set_new ();
4988 TMP_GEN (bb
) = bitmap_set_new ();
4989 AVAIL_OUT (bb
) = bitmap_set_new ();
4994 /* Deallocate data structures used by PRE. */
4999 value_expressions
.release ();
5000 BITMAP_FREE (inserted_exprs
);
5001 bitmap_obstack_release (&grand_bitmap_obstack
);
5002 bitmap_set_pool
.release ();
5003 pre_expr_pool
.release ();
5004 delete phi_translate_table
;
5005 phi_translate_table
= NULL
;
5006 delete expression_to_id
;
5007 expression_to_id
= NULL
;
5008 name_to_id
.release ();
5010 free_aux_for_blocks ();
5015 const pass_data pass_data_pre
=
5017 GIMPLE_PASS
, /* type */
5019 OPTGROUP_NONE
, /* optinfo_flags */
5020 TV_TREE_PRE
, /* tv_id */
5021 ( PROP_cfg
| PROP_ssa
), /* properties_required */
5022 0, /* properties_provided */
5023 0, /* properties_destroyed */
5024 TODO_rebuild_alias
, /* todo_flags_start */
5025 0, /* todo_flags_finish */
5028 class pass_pre
: public gimple_opt_pass
5031 pass_pre (gcc::context
*ctxt
)
5032 : gimple_opt_pass (pass_data_pre
, ctxt
)
5035 /* opt_pass methods: */
5036 virtual bool gate (function
*)
5037 { return flag_tree_pre
!= 0 || flag_code_hoisting
!= 0; }
5038 virtual unsigned int execute (function
*);
5040 }; // class pass_pre
5043 pass_pre::execute (function
*fun
)
5045 unsigned int todo
= 0;
5047 do_partial_partial
=
5048 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
5050 /* This has to happen before SCCVN runs because
5051 loop_optimizer_init may create new phis, etc. */
5052 loop_optimizer_init (LOOPS_NORMAL
);
5053 split_critical_edges ();
5055 run_scc_vn (VN_WALK
);
5060 /* Collect and value number expressions computed in each basic block. */
5063 /* Insert can get quite slow on an incredibly large number of basic
5064 blocks due to some quadratic behavior. Until this behavior is
5065 fixed, don't run it when he have an incredibly large number of
5066 bb's. If we aren't going to run insert, there is no point in
5067 computing ANTIC, either, even though it's plenty fast. */
5068 if (n_basic_blocks_for_fn (fun
) < 4000)
5074 /* Make sure to remove fake edges before committing our inserts.
5075 This makes sure we don't end up with extra critical edges that
5076 we would need to split. */
5077 remove_fake_exit_edges ();
5078 gsi_commit_edge_inserts ();
5080 /* Eliminate folds statements which might (should not...) end up
5081 not keeping virtual operands up-to-date. */
5082 gcc_assert (!need_ssa_update_p (fun
));
5084 /* Remove all the redundant expressions. */
5085 todo
|= eliminate (true);
5087 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5088 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
5089 statistics_counter_event (fun
, "HOIST inserted", pre_stats
.hoist_insert
);
5090 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
5091 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5093 clear_expression_ids ();
5096 todo
|= fini_eliminate ();
5097 remove_dead_inserted_code ();
5099 loop_optimizer_finalize ();
5101 /* Restore SSA info before tail-merging as that resets it as well. */
5102 scc_vn_restore_ssa_info ();
5104 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
5105 case we can merge the block with the remaining predecessor of the block.
5107 - call merge_blocks after each tail merge iteration
5108 - call merge_blocks after all tail merge iterations
5109 - mark TODO_cleanup_cfg when necessary
5110 - share the cfg cleanup with fini_pre. */
5111 todo
|= tail_merge_optimize (todo
);
5115 /* Tail merging invalidates the virtual SSA web, together with
5116 cfg-cleanup opportunities exposed by PRE this will wreck the
5117 SSA updating machinery. So make sure to run update-ssa
5118 manually, before eventually scheduling cfg-cleanup as part of
5120 update_ssa (TODO_update_ssa_only_virtuals
);
5128 make_pass_pre (gcc::context
*ctxt
)
5130 return new pass_pre (ctxt
);
5135 const pass_data pass_data_fre
=
5137 GIMPLE_PASS
, /* type */
5139 OPTGROUP_NONE
, /* optinfo_flags */
5140 TV_TREE_FRE
, /* tv_id */
5141 ( PROP_cfg
| PROP_ssa
), /* properties_required */
5142 0, /* properties_provided */
5143 0, /* properties_destroyed */
5144 0, /* todo_flags_start */
5145 0, /* todo_flags_finish */
5148 class pass_fre
: public gimple_opt_pass
5151 pass_fre (gcc::context
*ctxt
)
5152 : gimple_opt_pass (pass_data_fre
, ctxt
)
5155 /* opt_pass methods: */
5156 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
5157 virtual bool gate (function
*) { return flag_tree_fre
!= 0; }
5158 virtual unsigned int execute (function
*);
5160 }; // class pass_fre
5163 pass_fre::execute (function
*fun
)
5165 unsigned int todo
= 0;
5167 run_scc_vn (VN_WALKREWRITE
);
5169 memset (&pre_stats
, 0, sizeof (pre_stats
));
5171 /* Remove all the redundant expressions. */
5172 todo
|= eliminate (false);
5174 todo
|= fini_eliminate ();
5176 scc_vn_restore_ssa_info ();
5179 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5180 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5188 make_pass_fre (gcc::context
*ctxt
)
5190 return new pass_fre (ctxt
);