1 /* Full and partial redundancy elimination and code hoisting on SSA GIMPLE.
2 Copyright (C) 2001-2020 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-into-ssa.h"
46 #include "tree-ssa-sccvn.h"
47 #include "tree-scalar-evolution.h"
50 #include "tree-ssa-propagate.h"
51 #include "tree-ssa-dce.h"
52 #include "tree-cfgcleanup.h"
55 /* Even though this file is called tree-ssa-pre.c, we actually
56 implement a bit more than just PRE here. All of them piggy-back
57 on GVN which is implemented in tree-ssa-sccvn.c.
59 1. Full Redundancy Elimination (FRE)
60 This is the elimination phase of GVN.
62 2. Partial Redundancy Elimination (PRE)
63 This is adds computation of AVAIL_OUT and ANTIC_IN and
64 doing expression insertion to form GVN-PRE.
67 This optimization uses the ANTIC_IN sets computed for PRE
68 to move expressions further up than PRE would do, to make
69 multiple computations of the same value fully redundant.
70 This pass is explained below (after the explanation of the
71 basic algorithm for PRE).
76 1. Avail sets can be shared by making an avail_find_leader that
77 walks up the dominator tree and looks in those avail sets.
78 This might affect code optimality, it's unclear right now.
79 Currently the AVAIL_OUT sets are the remaining quadraticness in
81 2. Strength reduction can be performed by anticipating expressions
82 we can repair later on.
83 3. We can do back-substitution or smarter value numbering to catch
84 commutative expressions split up over multiple statements.
87 /* For ease of terminology, "expression node" in the below refers to
88 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
89 represent the actual statement containing the expressions we care about,
90 and we cache the value number by putting it in the expression. */
92 /* Basic algorithm for Partial Redundancy Elimination:
94 First we walk the statements to generate the AVAIL sets, the
95 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
96 generation of values/expressions by a given block. We use them
97 when computing the ANTIC sets. The AVAIL sets consist of
98 SSA_NAME's that represent values, so we know what values are
99 available in what blocks. AVAIL is a forward dataflow problem. In
100 SSA, values are never killed, so we don't need a kill set, or a
101 fixpoint iteration, in order to calculate the AVAIL sets. In
102 traditional parlance, AVAIL sets tell us the downsafety of the
105 Next, we generate the ANTIC sets. These sets represent the
106 anticipatable expressions. ANTIC is a backwards dataflow
107 problem. An expression is anticipatable in a given block if it could
108 be generated in that block. This means that if we had to perform
109 an insertion in that block, of the value of that expression, we
110 could. Calculating the ANTIC sets requires phi translation of
111 expressions, because the flow goes backwards through phis. We must
112 iterate to a fixpoint of the ANTIC sets, because we have a kill
113 set. Even in SSA form, values are not live over the entire
114 function, only from their definition point onwards. So we have to
115 remove values from the ANTIC set once we go past the definition
116 point of the leaders that make them up.
117 compute_antic/compute_antic_aux performs this computation.
119 Third, we perform insertions to make partially redundant
120 expressions fully redundant.
122 An expression is partially redundant (excluding partial
125 1. It is AVAIL in some, but not all, of the predecessors of a
127 2. It is ANTIC in all the predecessors.
129 In order to make it fully redundant, we insert the expression into
130 the predecessors where it is not available, but is ANTIC.
132 When optimizing for size, we only eliminate the partial redundancy
133 if we need to insert in only one predecessor. This avoids almost
134 completely the code size increase that PRE usually causes.
136 For the partial anticipation case, we only perform insertion if it
137 is partially anticipated in some block, and fully available in all
140 do_pre_regular_insertion/do_pre_partial_partial_insertion
141 performs these steps, driven by insert/insert_aux.
143 Fourth, we eliminate fully redundant expressions.
144 This is a simple statement walk that replaces redundant
145 calculations with the now available values. */
147 /* Basic algorithm for Code Hoisting:
149 Code hoisting is: Moving value computations up in the control flow
150 graph to make multiple copies redundant. Typically this is a size
151 optimization, but there are cases where it also is helpful for speed.
153 A simple code hoisting algorithm is implemented that piggy-backs on
154 the PRE infrastructure. For code hoisting, we have to know ANTIC_OUT
155 which is effectively ANTIC_IN - AVAIL_OUT. The latter two have to be
156 computed for PRE, and we can use them to perform a limited version of
159 For the purpose of this implementation, a value is hoistable to a basic
160 block B if the following properties are met:
162 1. The value is in ANTIC_IN(B) -- the value will be computed on all
163 paths from B to function exit and it can be computed in B);
165 2. The value is not in AVAIL_OUT(B) -- there would be no need to
166 compute the value again and make it available twice;
168 3. All successors of B are dominated by B -- makes sure that inserting
169 a computation of the value in B will make the remaining
170 computations fully redundant;
172 4. At least one successor has the value in AVAIL_OUT -- to avoid
173 hoisting values up too far;
175 5. There are at least two successors of B -- hoisting in straight
176 line code is pointless.
178 The third condition is not strictly necessary, but it would complicate
179 the hoisting pass a lot. In fact, I don't know of any code hoisting
180 algorithm that does not have this requirement. Fortunately, experiments
181 have show that most candidate hoistable values are in regions that meet
182 this condition (e.g. diamond-shape regions).
184 The forth condition is necessary to avoid hoisting things up too far
185 away from the uses of the value. Nothing else limits the algorithm
186 from hoisting everything up as far as ANTIC_IN allows. Experiments
187 with SPEC and CSiBE have shown that hoisting up too far results in more
188 spilling, less benefits for code size, and worse benchmark scores.
189 Fortunately, in practice most of the interesting hoisting opportunities
190 are caught despite this limitation.
192 For hoistable values that meet all conditions, expressions are inserted
193 to make the calculation of the hoistable value fully redundant. We
194 perform code hoisting insertions after each round of PRE insertions,
195 because code hoisting never exposes new PRE opportunities, but PRE can
196 create new code hoisting opportunities.
198 The code hoisting algorithm is implemented in do_hoist_insert, driven
199 by insert/insert_aux. */
201 /* Representations of value numbers:
203 Value numbers are represented by a representative SSA_NAME. We
204 will create fake SSA_NAME's in situations where we need a
205 representative but do not have one (because it is a complex
206 expression). In order to facilitate storing the value numbers in
207 bitmaps, and keep the number of wasted SSA_NAME's down, we also
208 associate a value_id with each value number, and create full blown
209 ssa_name's only where we actually need them (IE in operands of
210 existing expressions).
212 Theoretically you could replace all the value_id's with
213 SSA_NAME_VERSION, but this would allocate a large number of
214 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
215 It would also require an additional indirection at each point we
218 /* Representation of expressions on value numbers:
220 Expressions consisting of value numbers are represented the same
221 way as our VN internally represents them, with an additional
222 "pre_expr" wrapping around them in order to facilitate storing all
223 of the expressions in the same sets. */
225 /* Representation of sets:
227 The dataflow sets do not need to be sorted in any particular order
228 for the majority of their lifetime, are simply represented as two
229 bitmaps, one that keeps track of values present in the set, and one
230 that keeps track of expressions present in the set.
232 When we need them in topological order, we produce it on demand by
233 transforming the bitmap into an array and sorting it into topo
236 /* Type of expression, used to know which member of the PRE_EXPR union
252 vn_reference_t reference
;
255 typedef struct pre_expr_d
: nofree_ptr_hash
<pre_expr_d
>
257 enum pre_expr_kind kind
;
262 /* hash_table support. */
263 static inline hashval_t
hash (const pre_expr_d
*);
264 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
267 #define PRE_EXPR_NAME(e) (e)->u.name
268 #define PRE_EXPR_NARY(e) (e)->u.nary
269 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
270 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
272 /* Compare E1 and E1 for equality. */
275 pre_expr_d::equal (const pre_expr_d
*e1
, const pre_expr_d
*e2
)
277 if (e1
->kind
!= e2
->kind
)
283 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
284 PRE_EXPR_CONSTANT (e2
));
286 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
288 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
290 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
291 PRE_EXPR_REFERENCE (e2
));
300 pre_expr_d::hash (const pre_expr_d
*e
)
305 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
307 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
309 return PRE_EXPR_NARY (e
)->hashcode
;
311 return PRE_EXPR_REFERENCE (e
)->hashcode
;
317 /* Next global expression id number. */
318 static unsigned int next_expression_id
;
320 /* Mapping from expression to id number we can use in bitmap sets. */
321 static vec
<pre_expr
> expressions
;
322 static hash_table
<pre_expr_d
> *expression_to_id
;
323 static vec
<unsigned> name_to_id
;
325 /* Allocate an expression id for EXPR. */
327 static inline unsigned int
328 alloc_expression_id (pre_expr expr
)
330 struct pre_expr_d
**slot
;
331 /* Make sure we won't overflow. */
332 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
333 expr
->id
= next_expression_id
++;
334 expressions
.safe_push (expr
);
335 if (expr
->kind
== NAME
)
337 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
338 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
339 re-allocations by using vec::reserve upfront. */
340 unsigned old_len
= name_to_id
.length ();
341 name_to_id
.reserve (num_ssa_names
- old_len
);
342 name_to_id
.quick_grow_cleared (num_ssa_names
);
343 gcc_assert (name_to_id
[version
] == 0);
344 name_to_id
[version
] = expr
->id
;
348 slot
= expression_to_id
->find_slot (expr
, INSERT
);
352 return next_expression_id
- 1;
355 /* Return the expression id for tree EXPR. */
357 static inline unsigned int
358 get_expression_id (const pre_expr expr
)
363 static inline unsigned int
364 lookup_expression_id (const pre_expr expr
)
366 struct pre_expr_d
**slot
;
368 if (expr
->kind
== NAME
)
370 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
371 if (name_to_id
.length () <= version
)
373 return name_to_id
[version
];
377 slot
= expression_to_id
->find_slot (expr
, NO_INSERT
);
380 return ((pre_expr
)*slot
)->id
;
384 /* Return the existing expression id for EXPR, or create one if one
385 does not exist yet. */
387 static inline unsigned int
388 get_or_alloc_expression_id (pre_expr expr
)
390 unsigned int id
= lookup_expression_id (expr
);
392 return alloc_expression_id (expr
);
393 return expr
->id
= id
;
396 /* Return the expression that has expression id ID */
398 static inline pre_expr
399 expression_for_id (unsigned int id
)
401 return expressions
[id
];
404 static object_allocator
<pre_expr_d
> pre_expr_pool ("pre_expr nodes");
406 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
409 get_or_alloc_expr_for_name (tree name
)
411 struct pre_expr_d expr
;
413 unsigned int result_id
;
417 PRE_EXPR_NAME (&expr
) = name
;
418 result_id
= lookup_expression_id (&expr
);
420 return expression_for_id (result_id
);
422 result
= pre_expr_pool
.allocate ();
424 result
->loc
= UNKNOWN_LOCATION
;
425 PRE_EXPR_NAME (result
) = name
;
426 alloc_expression_id (result
);
430 /* An unordered bitmap set. One bitmap tracks values, the other,
432 typedef class bitmap_set
435 bitmap_head expressions
;
439 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
440 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
442 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
443 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
445 /* Mapping from value id to expressions with that value_id. */
446 static vec
<bitmap
> value_expressions
;
448 /* Sets that we need to keep track of. */
449 typedef struct bb_bitmap_sets
451 /* The EXP_GEN set, which represents expressions/values generated in
453 bitmap_set_t exp_gen
;
455 /* The PHI_GEN set, which represents PHI results generated in a
457 bitmap_set_t phi_gen
;
459 /* The TMP_GEN set, which represents results/temporaries generated
460 in a basic block. IE the LHS of an expression. */
461 bitmap_set_t tmp_gen
;
463 /* The AVAIL_OUT set, which represents which values are available in
464 a given basic block. */
465 bitmap_set_t avail_out
;
467 /* The ANTIC_IN set, which represents which values are anticipatable
468 in a given basic block. */
469 bitmap_set_t antic_in
;
471 /* The PA_IN set, which represents which values are
472 partially anticipatable in a given basic block. */
475 /* The NEW_SETS set, which is used during insertion to augment the
476 AVAIL_OUT set of blocks with the new insertions performed during
477 the current iteration. */
478 bitmap_set_t new_sets
;
480 /* A cache for value_dies_in_block_x. */
483 /* The live virtual operand on successor edges. */
486 /* True if we have visited this block during ANTIC calculation. */
487 unsigned int visited
: 1;
489 /* True when the block contains a call that might not return. */
490 unsigned int contains_may_not_return_call
: 1;
493 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
494 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
495 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
496 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
497 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
498 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
499 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
500 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
501 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
502 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
503 #define BB_LIVE_VOP_ON_EXIT(BB) ((bb_value_sets_t) ((BB)->aux))->vop_on_exit
506 /* This structure is used to keep track of statistics on what
507 optimization PRE was able to perform. */
510 /* The number of new expressions/temporaries generated by PRE. */
513 /* The number of inserts found due to partial anticipation */
516 /* The number of inserts made for code hoisting. */
519 /* The number of new PHI nodes added by PRE. */
523 static bool do_partial_partial
;
524 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
525 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
526 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
527 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
528 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
529 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
530 static bitmap_set_t
bitmap_set_new (void);
531 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
533 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
534 static unsigned int get_expr_value_id (pre_expr
);
536 /* We can add and remove elements and entries to and from sets
537 and hash tables, so we use alloc pools for them. */
539 static object_allocator
<bitmap_set
> bitmap_set_pool ("Bitmap sets");
540 static bitmap_obstack grand_bitmap_obstack
;
542 /* A three tuple {e, pred, v} used to cache phi translations in the
543 phi_translate_table. */
545 typedef struct expr_pred_trans_d
: free_ptr_hash
<expr_pred_trans_d
>
547 /* The expression. */
550 /* The predecessor block along which we translated the expression. */
553 /* The value that resulted from the translation. */
556 /* The hashcode for the expression, pred pair. This is cached for
560 /* hash_table support. */
561 static inline hashval_t
hash (const expr_pred_trans_d
*);
562 static inline int equal (const expr_pred_trans_d
*, const expr_pred_trans_d
*);
563 } *expr_pred_trans_t
;
564 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
567 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
573 expr_pred_trans_d::equal (const expr_pred_trans_d
*ve1
,
574 const expr_pred_trans_d
*ve2
)
576 basic_block b1
= ve1
->pred
;
577 basic_block b2
= ve2
->pred
;
579 /* If they are not translations for the same basic block, they can't
583 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
586 /* The phi_translate_table caches phi translations for a given
587 expression and predecessor. */
588 static hash_table
<expr_pred_trans_d
> *phi_translate_table
;
590 /* Add the tuple mapping from {expression E, basic block PRED} to
591 the phi translation table and return whether it pre-existed. */
594 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
596 expr_pred_trans_t
*slot
;
597 expr_pred_trans_d tem
;
598 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
603 slot
= phi_translate_table
->find_slot_with_hash (&tem
, hash
, INSERT
);
610 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
612 (*entry
)->pred
= pred
;
613 (*entry
)->hashcode
= hash
;
618 /* Add expression E to the expression set of value id V. */
621 add_to_value (unsigned int v
, pre_expr e
)
625 gcc_checking_assert (get_expr_value_id (e
) == v
);
627 if (v
>= value_expressions
.length ())
629 value_expressions
.safe_grow_cleared (v
+ 1);
632 set
= value_expressions
[v
];
635 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
636 value_expressions
[v
] = set
;
639 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
642 /* Create a new bitmap set and return it. */
645 bitmap_set_new (void)
647 bitmap_set_t ret
= bitmap_set_pool
.allocate ();
648 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
649 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
653 /* Return the value id for a PRE expression EXPR. */
656 get_expr_value_id (pre_expr expr
)
662 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
665 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
668 gcc_assert (!PRE_EXPR_NARY (expr
)->predicated_values
);
669 id
= PRE_EXPR_NARY (expr
)->value_id
;
672 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
677 /* ??? We cannot assert that expr has a value-id (it can be 0), because
678 we assign value-ids only to expressions that have a result
679 in set_hashtable_value_ids. */
683 /* Return a VN valnum (SSA name or constant) for the PRE value-id VAL. */
686 vn_valnum_from_value_id (unsigned int val
)
690 bitmap exprset
= value_expressions
[val
];
691 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
693 pre_expr vexpr
= expression_for_id (i
);
694 if (vexpr
->kind
== NAME
)
695 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
696 else if (vexpr
->kind
== CONSTANT
)
697 return PRE_EXPR_CONSTANT (vexpr
);
702 /* Insert an expression EXPR into a bitmapped set. */
705 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
707 unsigned int val
= get_expr_value_id (expr
);
708 if (! value_id_constant_p (val
))
710 /* Note this is the only function causing multiple expressions
711 for the same value to appear in a set. This is needed for
712 TMP_GEN, PHI_GEN and NEW_SETs. */
713 bitmap_set_bit (&set
->values
, val
);
714 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
718 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
721 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
723 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
724 bitmap_copy (&dest
->values
, &orig
->values
);
728 /* Free memory used up by SET. */
730 bitmap_set_free (bitmap_set_t set
)
732 bitmap_clear (&set
->expressions
);
733 bitmap_clear (&set
->values
);
737 /* Generate an topological-ordered array of bitmap set SET. */
740 sorted_array_from_bitmap_set (bitmap_set_t set
)
743 bitmap_iterator bi
, bj
;
744 vec
<pre_expr
> result
;
746 /* Pre-allocate enough space for the array. */
747 result
.create (bitmap_count_bits (&set
->expressions
));
749 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
751 /* The number of expressions having a given value is usually
752 relatively small. Thus, rather than making a vector of all
753 the expressions and sorting it by value-id, we walk the values
754 and check in the reverse mapping that tells us what expressions
755 have a given value, to filter those in our set. As a result,
756 the expressions are inserted in value-id order, which means
759 If this is somehow a significant lose for some cases, we can
760 choose which set to walk based on the set size. */
761 bitmap exprset
= value_expressions
[i
];
762 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
764 if (bitmap_bit_p (&set
->expressions
, j
))
765 result
.quick_push (expression_for_id (j
));
772 /* Subtract all expressions contained in ORIG from DEST. */
775 bitmap_set_subtract_expressions (bitmap_set_t dest
, bitmap_set_t orig
)
777 bitmap_set_t result
= bitmap_set_new ();
781 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
784 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
786 pre_expr expr
= expression_for_id (i
);
787 unsigned int value_id
= get_expr_value_id (expr
);
788 bitmap_set_bit (&result
->values
, value_id
);
794 /* Subtract all values in bitmap set B from bitmap set A. */
797 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
801 unsigned to_remove
= -1U;
802 bitmap_and_compl_into (&a
->values
, &b
->values
);
803 FOR_EACH_EXPR_ID_IN_SET (a
, i
, bi
)
805 if (to_remove
!= -1U)
807 bitmap_clear_bit (&a
->expressions
, to_remove
);
810 pre_expr expr
= expression_for_id (i
);
811 if (! bitmap_bit_p (&a
->values
, get_expr_value_id (expr
)))
814 if (to_remove
!= -1U)
815 bitmap_clear_bit (&a
->expressions
, to_remove
);
819 /* Return true if bitmapped set SET contains the value VALUE_ID. */
822 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
824 if (value_id_constant_p (value_id
))
827 return bitmap_bit_p (&set
->values
, value_id
);
830 /* Return true if two bitmap sets are equal. */
833 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
835 return bitmap_equal_p (&a
->values
, &b
->values
);
838 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
839 and add it otherwise. */
842 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
844 unsigned int val
= get_expr_value_id (expr
);
845 if (value_id_constant_p (val
))
848 if (bitmap_set_contains_value (set
, val
))
850 /* The number of expressions having a given value is usually
851 significantly less than the total number of expressions in SET.
852 Thus, rather than check, for each expression in SET, whether it
853 has the value LOOKFOR, we walk the reverse mapping that tells us
854 what expressions have a given value, and see if any of those
855 expressions are in our set. For large testcases, this is about
856 5-10x faster than walking the bitmap. If this is somehow a
857 significant lose for some cases, we can choose which set to walk
858 based on the set size. */
861 bitmap exprset
= value_expressions
[val
];
862 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
864 if (bitmap_clear_bit (&set
->expressions
, i
))
866 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
873 bitmap_insert_into_set (set
, expr
);
876 /* Insert EXPR into SET if EXPR's value is not already present in
880 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
882 unsigned int val
= get_expr_value_id (expr
);
884 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
886 /* Constant values are always considered to be part of the set. */
887 if (value_id_constant_p (val
))
890 /* If the value membership changed, add the expression. */
891 if (bitmap_set_bit (&set
->values
, val
))
892 bitmap_set_bit (&set
->expressions
, expr
->id
);
895 /* Print out EXPR to outfile. */
898 print_pre_expr (FILE *outfile
, const pre_expr expr
)
902 fprintf (outfile
, "NULL");
908 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
));
911 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
));
916 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
917 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
918 for (i
= 0; i
< nary
->length
; i
++)
920 print_generic_expr (outfile
, nary
->op
[i
]);
921 if (i
!= (unsigned) nary
->length
- 1)
922 fprintf (outfile
, ",");
924 fprintf (outfile
, "}");
930 vn_reference_op_t vro
;
932 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
933 fprintf (outfile
, "{");
935 ref
->operands
.iterate (i
, &vro
);
938 bool closebrace
= false;
939 if (vro
->opcode
!= SSA_NAME
940 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
942 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
945 fprintf (outfile
, "<");
951 print_generic_expr (outfile
, vro
->op0
);
954 fprintf (outfile
, ",");
955 print_generic_expr (outfile
, vro
->op1
);
959 fprintf (outfile
, ",");
960 print_generic_expr (outfile
, vro
->op2
);
964 fprintf (outfile
, ">");
965 if (i
!= ref
->operands
.length () - 1)
966 fprintf (outfile
, ",");
968 fprintf (outfile
, "}");
971 fprintf (outfile
, "@");
972 print_generic_expr (outfile
, ref
->vuse
);
978 void debug_pre_expr (pre_expr
);
980 /* Like print_pre_expr but always prints to stderr. */
982 debug_pre_expr (pre_expr e
)
984 print_pre_expr (stderr
, e
);
985 fprintf (stderr
, "\n");
988 /* Print out SET to OUTFILE. */
991 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
992 const char *setname
, int blockindex
)
994 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1001 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1003 const pre_expr expr
= expression_for_id (i
);
1006 fprintf (outfile
, ", ");
1008 print_pre_expr (outfile
, expr
);
1010 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1013 fprintf (outfile
, " }\n");
1016 void debug_bitmap_set (bitmap_set_t
);
1019 debug_bitmap_set (bitmap_set_t set
)
1021 print_bitmap_set (stderr
, set
, "debug", 0);
1024 void debug_bitmap_sets_for (basic_block
);
1027 debug_bitmap_sets_for (basic_block bb
)
1029 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1030 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1031 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1032 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1033 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1034 if (do_partial_partial
)
1035 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1036 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1039 /* Print out the expressions that have VAL to OUTFILE. */
1042 print_value_expressions (FILE *outfile
, unsigned int val
)
1044 bitmap set
= value_expressions
[val
];
1049 sprintf (s
, "%04d", val
);
1050 x
.expressions
= *set
;
1051 print_bitmap_set (outfile
, &x
, s
, 0);
1057 debug_value_expressions (unsigned int val
)
1059 print_value_expressions (stderr
, val
);
1062 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1066 get_or_alloc_expr_for_constant (tree constant
)
1068 unsigned int result_id
;
1069 unsigned int value_id
;
1070 struct pre_expr_d expr
;
1073 expr
.kind
= CONSTANT
;
1074 PRE_EXPR_CONSTANT (&expr
) = constant
;
1075 result_id
= lookup_expression_id (&expr
);
1077 return expression_for_id (result_id
);
1079 newexpr
= pre_expr_pool
.allocate ();
1080 newexpr
->kind
= CONSTANT
;
1081 newexpr
->loc
= UNKNOWN_LOCATION
;
1082 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1083 alloc_expression_id (newexpr
);
1084 value_id
= get_or_alloc_constant_value_id (constant
);
1085 add_to_value (value_id
, newexpr
);
1089 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1090 Currently only supports constants and SSA_NAMES. */
1092 get_or_alloc_expr_for (tree t
)
1094 if (TREE_CODE (t
) == SSA_NAME
)
1095 return get_or_alloc_expr_for_name (t
);
1096 else if (is_gimple_min_invariant (t
))
1097 return get_or_alloc_expr_for_constant (t
);
1101 /* Return the folded version of T if T, when folded, is a gimple
1102 min_invariant or an SSA name. Otherwise, return T. */
1105 fully_constant_expression (pre_expr e
)
1113 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1114 tree res
= vn_nary_simplify (nary
);
1117 if (is_gimple_min_invariant (res
))
1118 return get_or_alloc_expr_for_constant (res
);
1119 if (TREE_CODE (res
) == SSA_NAME
)
1120 return get_or_alloc_expr_for_name (res
);
1125 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1127 if ((folded
= fully_constant_vn_reference_p (ref
)))
1128 return get_or_alloc_expr_for_constant (folded
);
1137 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1138 it has the value it would have in BLOCK. Set *SAME_VALID to true
1139 in case the new vuse doesn't change the value id of the OPERANDS. */
1142 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1143 alias_set_type set
, alias_set_type base_set
,
1144 tree type
, tree vuse
,
1145 basic_block phiblock
,
1146 basic_block block
, bool *same_valid
)
1148 gimple
*phi
= SSA_NAME_DEF_STMT (vuse
);
1156 if (gimple_bb (phi
) != phiblock
)
1159 unsigned int cnt
= param_sccvn_max_alias_queries_per_access
;
1160 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, base_set
,
1163 /* Use the alias-oracle to find either the PHI node in this block,
1164 the first VUSE used in this block that is equivalent to vuse or
1165 the first VUSE which definition in this block kills the value. */
1166 if (gimple_code (phi
) == GIMPLE_PHI
)
1167 e
= find_edge (block
, phiblock
);
1168 else if (use_oracle
)
1170 && !stmt_may_clobber_ref_p_1 (phi
, &ref
))
1173 vuse
= gimple_vuse (phi
);
1174 phi
= SSA_NAME_DEF_STMT (vuse
);
1175 if (gimple_bb (phi
) != phiblock
)
1177 if (gimple_code (phi
) == GIMPLE_PHI
)
1179 e
= find_edge (block
, phiblock
);
1188 if (use_oracle
&& same_valid
)
1190 bitmap visited
= NULL
;
1191 /* Try to find a vuse that dominates this phi node by skipping
1192 non-clobbering statements. */
1193 vuse
= get_continuation_for_phi (phi
, &ref
, true,
1194 cnt
, &visited
, false, NULL
, NULL
);
1196 BITMAP_FREE (visited
);
1200 /* If we didn't find any, the value ID can't stay the same. */
1201 if (!vuse
&& same_valid
)
1202 *same_valid
= false;
1203 /* ??? We would like to return vuse here as this is the canonical
1204 upmost vdef that this reference is associated with. But during
1205 insertion of the references into the hash tables we only ever
1206 directly insert with their direct gimple_vuse, hence returning
1207 something else would make us not find the other expression. */
1208 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1214 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1215 SET2 *or* SET3. This is used to avoid making a set consisting of the union
1216 of PA_IN and ANTIC_IN during insert and phi-translation. */
1218 static inline pre_expr
1219 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
,
1220 bitmap_set_t set3
= NULL
)
1222 pre_expr result
= NULL
;
1225 result
= bitmap_find_leader (set1
, val
);
1226 if (!result
&& set2
)
1227 result
= bitmap_find_leader (set2
, val
);
1228 if (!result
&& set3
)
1229 result
= bitmap_find_leader (set3
, val
);
1233 /* Get the tree type for our PRE expression e. */
1236 get_expr_type (const pre_expr e
)
1241 return TREE_TYPE (PRE_EXPR_NAME (e
));
1243 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1245 return PRE_EXPR_REFERENCE (e
)->type
;
1247 return PRE_EXPR_NARY (e
)->type
;
1252 /* Get a representative SSA_NAME for a given expression that is available in B.
1253 Since all of our sub-expressions are treated as values, we require
1254 them to be SSA_NAME's for simplicity.
1255 Prior versions of GVNPRE used to use "value handles" here, so that
1256 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1257 either case, the operands are really values (IE we do not expect
1258 them to be usable without finding leaders). */
1261 get_representative_for (const pre_expr e
, basic_block b
= NULL
)
1263 tree name
, valnum
= NULL_TREE
;
1264 unsigned int value_id
= get_expr_value_id (e
);
1269 return PRE_EXPR_NAME (e
);
1271 return PRE_EXPR_CONSTANT (e
);
1275 /* Go through all of the expressions representing this value
1276 and pick out an SSA_NAME. */
1279 bitmap exprs
= value_expressions
[value_id
];
1280 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1282 pre_expr rep
= expression_for_id (i
);
1283 if (rep
->kind
== NAME
)
1285 tree name
= PRE_EXPR_NAME (rep
);
1286 valnum
= VN_INFO (name
)->valnum
;
1287 gimple
*def
= SSA_NAME_DEF_STMT (name
);
1288 /* We have to return either a new representative or one
1289 that can be used for expression simplification and thus
1290 is available in B. */
1292 || gimple_nop_p (def
)
1293 || dominated_by_p (CDI_DOMINATORS
, b
, gimple_bb (def
)))
1296 else if (rep
->kind
== CONSTANT
)
1297 return PRE_EXPR_CONSTANT (rep
);
1303 /* If we reached here we couldn't find an SSA_NAME. This can
1304 happen when we've discovered a value that has never appeared in
1305 the program as set to an SSA_NAME, as the result of phi translation.
1307 ??? We should be able to re-use this when we insert the statement
1309 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1310 VN_INFO (name
)->value_id
= value_id
;
1311 VN_INFO (name
)->valnum
= valnum
? valnum
: name
;
1312 /* ??? For now mark this SSA name for release by VN. */
1313 VN_INFO (name
)->needs_insertion
= true;
1314 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1315 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1317 fprintf (dump_file
, "Created SSA_NAME representative ");
1318 print_generic_expr (dump_file
, name
);
1319 fprintf (dump_file
, " for expression:");
1320 print_pre_expr (dump_file
, e
);
1321 fprintf (dump_file
, " (%04d)\n", value_id
);
1329 phi_translate (bitmap_set_t
, pre_expr
, bitmap_set_t
, bitmap_set_t
, edge
);
1331 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1332 the phis in PRED. Return NULL if we can't find a leader for each part
1333 of the translated expression. */
1336 phi_translate_1 (bitmap_set_t dest
,
1337 pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
, edge e
)
1339 basic_block pred
= e
->src
;
1340 basic_block phiblock
= e
->dest
;
1341 location_t expr_loc
= expr
->loc
;
1347 bool changed
= false;
1348 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1349 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1350 sizeof_vn_nary_op (nary
->length
));
1351 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1353 for (i
= 0; i
< newnary
->length
; i
++)
1355 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1359 pre_expr leader
, result
;
1360 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1361 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1362 result
= phi_translate (dest
, leader
, set1
, set2
, e
);
1363 if (result
&& result
!= leader
)
1364 /* If op has a leader in the sets we translate make
1365 sure to use the value of the translated expression.
1366 We might need a new representative for that. */
1367 newnary
->op
[i
] = get_representative_for (result
, pred
);
1371 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1377 unsigned int new_val_id
;
1379 PRE_EXPR_NARY (expr
) = newnary
;
1380 constant
= fully_constant_expression (expr
);
1381 PRE_EXPR_NARY (expr
) = nary
;
1382 if (constant
!= expr
)
1384 /* For non-CONSTANTs we have to make sure we can eventually
1385 insert the expression. Which means we need to have a
1387 if (constant
->kind
!= CONSTANT
)
1389 /* Do not allow simplifications to non-constants over
1390 backedges as this will likely result in a loop PHI node
1391 to be inserted and increased register pressure.
1392 See PR77498 - this avoids doing predcoms work in
1393 a less efficient way. */
1394 if (e
->flags
& EDGE_DFS_BACK
)
1398 unsigned value_id
= get_expr_value_id (constant
);
1399 /* We want a leader in ANTIC_OUT or AVAIL_OUT here.
1400 dest has what we computed into ANTIC_OUT sofar
1401 so pick from that - since topological sorting
1402 by sorted_array_from_bitmap_set isn't perfect
1403 we may lose some cases here. */
1404 constant
= find_leader_in_sets (value_id
, dest
,
1408 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1410 fprintf (dump_file
, "simplifying ");
1411 print_pre_expr (dump_file
, expr
);
1412 fprintf (dump_file
, " translated %d -> %d to ",
1413 phiblock
->index
, pred
->index
);
1414 PRE_EXPR_NARY (expr
) = newnary
;
1415 print_pre_expr (dump_file
, expr
);
1416 PRE_EXPR_NARY (expr
) = nary
;
1417 fprintf (dump_file
, " to ");
1418 print_pre_expr (dump_file
, constant
);
1419 fprintf (dump_file
, "\n");
1429 /* vn_nary_* do not valueize operands. */
1430 for (i
= 0; i
< newnary
->length
; ++i
)
1431 if (TREE_CODE (newnary
->op
[i
]) == SSA_NAME
)
1432 newnary
->op
[i
] = VN_INFO (newnary
->op
[i
])->valnum
;
1433 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1438 if (result
&& is_gimple_min_invariant (result
))
1439 return get_or_alloc_expr_for_constant (result
);
1441 expr
= pre_expr_pool
.allocate ();
1444 expr
->loc
= expr_loc
;
1445 if (nary
&& !nary
->predicated_values
)
1447 PRE_EXPR_NARY (expr
) = nary
;
1448 new_val_id
= nary
->value_id
;
1449 get_or_alloc_expression_id (expr
);
1453 new_val_id
= get_next_value_id ();
1454 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1455 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1459 result
, new_val_id
);
1460 PRE_EXPR_NARY (expr
) = nary
;
1461 get_or_alloc_expression_id (expr
);
1463 add_to_value (new_val_id
, expr
);
1471 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1472 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1473 tree vuse
= ref
->vuse
;
1474 tree newvuse
= vuse
;
1475 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1476 bool changed
= false, same_valid
= true;
1478 vn_reference_op_t operand
;
1479 vn_reference_t newref
;
1481 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1486 tree type
= operand
->type
;
1487 vn_reference_op_s newop
= *operand
;
1488 op
[0] = operand
->op0
;
1489 op
[1] = operand
->op1
;
1490 op
[2] = operand
->op2
;
1491 for (n
= 0; n
< 3; ++n
)
1493 unsigned int op_val_id
;
1496 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1498 /* We can't possibly insert these. */
1500 && !is_gimple_min_invariant (op
[n
]))
1504 op_val_id
= VN_INFO (op
[n
])->value_id
;
1505 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1506 opresult
= phi_translate (dest
, leader
, set1
, set2
, e
);
1507 if (opresult
&& opresult
!= leader
)
1509 tree name
= get_representative_for (opresult
);
1510 changed
|= name
!= op
[n
];
1518 newoperands
.release ();
1523 if (!newoperands
.exists ())
1524 newoperands
= operands
.copy ();
1525 /* We may have changed from an SSA_NAME to a constant */
1526 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1527 newop
.opcode
= TREE_CODE (op
[0]);
1532 newoperands
[i
] = newop
;
1534 gcc_checking_assert (i
== operands
.length ());
1538 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1539 ? newoperands
: operands
,
1540 ref
->set
, ref
->base_set
,
1542 vuse
, phiblock
, pred
,
1544 ? NULL
: &same_valid
);
1545 if (newvuse
== NULL_TREE
)
1547 newoperands
.release ();
1552 if (changed
|| newvuse
!= vuse
)
1554 unsigned int new_val_id
;
1556 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1559 newoperands
.exists ()
1560 ? newoperands
: operands
,
1563 newoperands
.release ();
1565 /* We can always insert constants, so if we have a partial
1566 redundant constant load of another type try to translate it
1567 to a constant of appropriate type. */
1568 if (result
&& is_gimple_min_invariant (result
))
1571 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1573 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1574 if (tem
&& !is_gimple_min_invariant (tem
))
1578 return get_or_alloc_expr_for_constant (tem
);
1581 /* If we'd have to convert things we would need to validate
1582 if we can insert the translated expression. So fail
1583 here for now - we cannot insert an alias with a different
1584 type in the VN tables either, as that would assert. */
1586 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1588 else if (!result
&& newref
1589 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1591 newoperands
.release ();
1595 expr
= pre_expr_pool
.allocate ();
1596 expr
->kind
= REFERENCE
;
1598 expr
->loc
= expr_loc
;
1601 new_val_id
= newref
->value_id
;
1604 if (changed
|| !same_valid
)
1606 new_val_id
= get_next_value_id ();
1607 value_expressions
.safe_grow_cleared
1608 (get_max_value_id () + 1);
1611 new_val_id
= ref
->value_id
;
1612 if (!newoperands
.exists ())
1613 newoperands
= operands
.copy ();
1614 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1615 ref
->base_set
, ref
->type
,
1617 result
, new_val_id
);
1618 newoperands
= vNULL
;
1620 PRE_EXPR_REFERENCE (expr
) = newref
;
1621 get_or_alloc_expression_id (expr
);
1622 add_to_value (new_val_id
, expr
);
1624 newoperands
.release ();
1631 tree name
= PRE_EXPR_NAME (expr
);
1632 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1633 /* If the SSA name is defined by a PHI node in this block,
1635 if (gimple_code (def_stmt
) == GIMPLE_PHI
1636 && gimple_bb (def_stmt
) == phiblock
)
1638 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1640 /* Handle constant. */
1641 if (is_gimple_min_invariant (def
))
1642 return get_or_alloc_expr_for_constant (def
);
1644 return get_or_alloc_expr_for_name (def
);
1646 /* Otherwise return it unchanged - it will get removed if its
1647 value is not available in PREDs AVAIL_OUT set of expressions
1648 by the subtraction of TMP_GEN. */
1657 /* Wrapper around phi_translate_1 providing caching functionality. */
1660 phi_translate (bitmap_set_t dest
, pre_expr expr
,
1661 bitmap_set_t set1
, bitmap_set_t set2
, edge e
)
1663 expr_pred_trans_t slot
= NULL
;
1669 /* Constants contain no values that need translation. */
1670 if (expr
->kind
== CONSTANT
)
1673 if (value_id_constant_p (get_expr_value_id (expr
)))
1676 /* Don't add translations of NAMEs as those are cheap to translate. */
1677 if (expr
->kind
!= NAME
)
1679 if (phi_trans_add (&slot
, expr
, e
->src
))
1681 /* Store NULL for the value we want to return in the case of
1687 basic_block saved_valueize_bb
= vn_context_bb
;
1688 vn_context_bb
= e
->src
;
1689 phitrans
= phi_translate_1 (dest
, expr
, set1
, set2
, e
);
1690 vn_context_bb
= saved_valueize_bb
;
1697 /* Remove failed translations again, they cause insert
1698 iteration to not pick up new opportunities reliably. */
1699 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1706 /* For each expression in SET, translate the values through phi nodes
1707 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1708 expressions in DEST. */
1711 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, edge e
)
1713 vec
<pre_expr
> exprs
;
1717 if (gimple_seq_empty_p (phi_nodes (e
->dest
)))
1719 bitmap_set_copy (dest
, set
);
1723 exprs
= sorted_array_from_bitmap_set (set
);
1724 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1726 pre_expr translated
;
1727 translated
= phi_translate (dest
, expr
, set
, NULL
, e
);
1731 bitmap_insert_into_set (dest
, translated
);
1736 /* Find the leader for a value (i.e., the name representing that
1737 value) in a given set, and return it. Return NULL if no leader
1741 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1743 if (value_id_constant_p (val
))
1747 bitmap exprset
= value_expressions
[val
];
1749 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1751 pre_expr expr
= expression_for_id (i
);
1752 if (expr
->kind
== CONSTANT
)
1756 if (bitmap_set_contains_value (set
, val
))
1758 /* Rather than walk the entire bitmap of expressions, and see
1759 whether any of them has the value we are looking for, we look
1760 at the reverse mapping, which tells us the set of expressions
1761 that have a given value (IE value->expressions with that
1762 value) and see if any of those expressions are in our set.
1763 The number of expressions per value is usually significantly
1764 less than the number of expressions in the set. In fact, for
1765 large testcases, doing it this way is roughly 5-10x faster
1766 than walking the bitmap.
1767 If this is somehow a significant lose for some cases, we can
1768 choose which set to walk based on which set is smaller. */
1771 bitmap exprset
= value_expressions
[val
];
1773 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1774 return expression_for_id (i
);
1779 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1780 BLOCK by seeing if it is not killed in the block. Note that we are
1781 only determining whether there is a store that kills it. Because
1782 of the order in which clean iterates over values, we are guaranteed
1783 that altered operands will have caused us to be eliminated from the
1784 ANTIC_IN set already. */
1787 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1789 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1790 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1792 gimple_stmt_iterator gsi
;
1793 unsigned id
= get_expression_id (expr
);
1800 /* Lookup a previously calculated result. */
1801 if (EXPR_DIES (block
)
1802 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1803 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1805 /* A memory expression {e, VUSE} dies in the block if there is a
1806 statement that may clobber e. If, starting statement walk from the
1807 top of the basic block, a statement uses VUSE there can be no kill
1808 inbetween that use and the original statement that loaded {e, VUSE},
1809 so we can stop walking. */
1810 ref
.base
= NULL_TREE
;
1811 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1813 tree def_vuse
, def_vdef
;
1814 def
= gsi_stmt (gsi
);
1815 def_vuse
= gimple_vuse (def
);
1816 def_vdef
= gimple_vdef (def
);
1818 /* Not a memory statement. */
1822 /* Not a may-def. */
1825 /* A load with the same VUSE, we're done. */
1826 if (def_vuse
== vuse
)
1832 /* Init ref only if we really need it. */
1833 if (ref
.base
== NULL_TREE
1834 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->base_set
,
1835 refx
->type
, refx
->operands
))
1840 /* If the statement may clobber expr, it dies. */
1841 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1848 /* Remember the result. */
1849 if (!EXPR_DIES (block
))
1850 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1851 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1853 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1859 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1860 contains its value-id. */
1863 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1865 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1867 unsigned int value_id
= VN_INFO (op
)->value_id
;
1868 if (!(bitmap_set_contains_value (set1
, value_id
)
1869 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1875 /* Determine if the expression EXPR is valid in SET1 U SET2.
1876 ONLY SET2 CAN BE NULL.
1877 This means that we have a leader for each part of the expression
1878 (if it consists of values), or the expression is an SSA_NAME.
1879 For loads/calls, we also see if the vuse is killed in this block. */
1882 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1887 /* By construction all NAMEs are available. Non-available
1888 NAMEs are removed by subtracting TMP_GEN from the sets. */
1893 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1894 for (i
= 0; i
< nary
->length
; i
++)
1895 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1902 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1903 vn_reference_op_t vro
;
1906 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1908 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1909 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1910 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1920 /* Clean the set of expressions SET1 that are no longer valid in SET1 or SET2.
1921 This means expressions that are made up of values we have no leaders for
1925 clean (bitmap_set_t set1
, bitmap_set_t set2
= NULL
)
1927 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
1931 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1933 if (!valid_in_sets (set1
, set2
, expr
))
1935 unsigned int val
= get_expr_value_id (expr
);
1936 bitmap_clear_bit (&set1
->expressions
, get_expression_id (expr
));
1937 /* We are entered with possibly multiple expressions for a value
1938 so before removing a value from the set see if there's an
1939 expression for it left. */
1940 if (! bitmap_find_leader (set1
, val
))
1941 bitmap_clear_bit (&set1
->values
, val
);
1947 /* Clean the set of expressions that are no longer valid in SET because
1948 they are clobbered in BLOCK or because they trap and may not be executed. */
1951 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
1955 unsigned to_remove
= -1U;
1956 bool any_removed
= false;
1958 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1960 /* Remove queued expr. */
1961 if (to_remove
!= -1U)
1963 bitmap_clear_bit (&set
->expressions
, to_remove
);
1968 pre_expr expr
= expression_for_id (i
);
1969 if (expr
->kind
== REFERENCE
)
1971 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1974 gimple
*def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
1975 if (!gimple_nop_p (def_stmt
)
1976 && ((gimple_bb (def_stmt
) != block
1977 && !dominated_by_p (CDI_DOMINATORS
,
1978 block
, gimple_bb (def_stmt
)))
1979 || (gimple_bb (def_stmt
) == block
1980 && value_dies_in_block_x (expr
, block
))))
1984 else if (expr
->kind
== NARY
)
1986 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1987 /* If the NARY may trap make sure the block does not contain
1988 a possible exit point.
1989 ??? This is overly conservative if we translate AVAIL_OUT
1990 as the available expression might be after the exit point. */
1991 if (BB_MAY_NOTRETURN (block
)
1992 && vn_nary_may_trap (nary
))
1997 /* Remove queued expr. */
1998 if (to_remove
!= -1U)
2000 bitmap_clear_bit (&set
->expressions
, to_remove
);
2004 /* Above we only removed expressions, now clean the set of values
2005 which no longer have any corresponding expression. We cannot
2006 clear the value at the time we remove an expression since there
2007 may be multiple expressions per value.
2008 If we'd queue possibly to be removed values we could use
2009 the bitmap_find_leader way to see if there's still an expression
2010 for it. For some ratio of to be removed values and number of
2011 values/expressions in the set this might be faster than rebuilding
2015 bitmap_clear (&set
->values
);
2016 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2018 pre_expr expr
= expression_for_id (i
);
2019 unsigned int value_id
= get_expr_value_id (expr
);
2020 bitmap_set_bit (&set
->values
, value_id
);
2025 /* Compute the ANTIC set for BLOCK.
2027 If succs(BLOCK) > 1 then
2028 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2029 else if succs(BLOCK) == 1 then
2030 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2032 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2034 Note that clean() is deferred until after the iteration. */
2037 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2039 bitmap_set_t S
, old
, ANTIC_OUT
;
2043 bool was_visited
= BB_VISITED (block
);
2044 bool changed
= ! BB_VISITED (block
);
2045 BB_VISITED (block
) = 1;
2046 old
= ANTIC_OUT
= S
= NULL
;
2048 /* If any edges from predecessors are abnormal, antic_in is empty,
2050 if (block_has_abnormal_pred_edge
)
2051 goto maybe_dump_sets
;
2053 old
= ANTIC_IN (block
);
2054 ANTIC_OUT
= bitmap_set_new ();
2056 /* If the block has no successors, ANTIC_OUT is empty. */
2057 if (EDGE_COUNT (block
->succs
) == 0)
2059 /* If we have one successor, we could have some phi nodes to
2060 translate through. */
2061 else if (single_succ_p (block
))
2063 e
= single_succ_edge (block
);
2064 gcc_assert (BB_VISITED (e
->dest
));
2065 phi_translate_set (ANTIC_OUT
, ANTIC_IN (e
->dest
), e
);
2067 /* If we have multiple successors, we take the intersection of all of
2068 them. Note that in the case of loop exit phi nodes, we may have
2069 phis to translate through. */
2075 auto_vec
<edge
> worklist (EDGE_COUNT (block
->succs
));
2076 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2079 && BB_VISITED (e
->dest
))
2081 else if (BB_VISITED (e
->dest
))
2082 worklist
.quick_push (e
);
2085 /* Unvisited successors get their ANTIC_IN replaced by the
2086 maximal set to arrive at a maximum ANTIC_IN solution.
2087 We can ignore them in the intersection operation and thus
2088 need not explicitely represent that maximum solution. */
2089 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2090 fprintf (dump_file
, "ANTIC_IN is MAX on %d->%d\n",
2091 e
->src
->index
, e
->dest
->index
);
2095 /* Of multiple successors we have to have visited one already
2096 which is guaranteed by iteration order. */
2097 gcc_assert (first
!= NULL
);
2099 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
->dest
), first
);
2101 /* If we have multiple successors we need to intersect the ANTIC_OUT
2102 sets. For values that's a simple intersection but for
2103 expressions it is a union. Given we want to have a single
2104 expression per value in our sets we have to canonicalize.
2105 Avoid randomness and running into cycles like for PR82129 and
2106 canonicalize the expression we choose to the one with the
2107 lowest id. This requires we actually compute the union first. */
2108 FOR_EACH_VEC_ELT (worklist
, i
, e
)
2110 if (!gimple_seq_empty_p (phi_nodes (e
->dest
)))
2112 bitmap_set_t tmp
= bitmap_set_new ();
2113 phi_translate_set (tmp
, ANTIC_IN (e
->dest
), e
);
2114 bitmap_and_into (&ANTIC_OUT
->values
, &tmp
->values
);
2115 bitmap_ior_into (&ANTIC_OUT
->expressions
, &tmp
->expressions
);
2116 bitmap_set_free (tmp
);
2120 bitmap_and_into (&ANTIC_OUT
->values
, &ANTIC_IN (e
->dest
)->values
);
2121 bitmap_ior_into (&ANTIC_OUT
->expressions
,
2122 &ANTIC_IN (e
->dest
)->expressions
);
2125 if (! worklist
.is_empty ())
2127 /* Prune expressions not in the value set. */
2130 unsigned int to_clear
= -1U;
2131 FOR_EACH_EXPR_ID_IN_SET (ANTIC_OUT
, i
, bi
)
2133 if (to_clear
!= -1U)
2135 bitmap_clear_bit (&ANTIC_OUT
->expressions
, to_clear
);
2138 pre_expr expr
= expression_for_id (i
);
2139 unsigned int value_id
= get_expr_value_id (expr
);
2140 if (!bitmap_bit_p (&ANTIC_OUT
->values
, value_id
))
2143 if (to_clear
!= -1U)
2144 bitmap_clear_bit (&ANTIC_OUT
->expressions
, to_clear
);
2148 /* Prune expressions that are clobbered in block and thus become
2149 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2150 prune_clobbered_mems (ANTIC_OUT
, block
);
2152 /* Generate ANTIC_OUT - TMP_GEN. */
2153 S
= bitmap_set_subtract_expressions (ANTIC_OUT
, TMP_GEN (block
));
2155 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2156 ANTIC_IN (block
) = bitmap_set_subtract_expressions (EXP_GEN (block
),
2159 /* Then union in the ANTIC_OUT - TMP_GEN values,
2160 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2161 bitmap_ior_into (&ANTIC_IN (block
)->values
, &S
->values
);
2162 bitmap_ior_into (&ANTIC_IN (block
)->expressions
, &S
->expressions
);
2164 /* clean (ANTIC_IN (block)) is defered to after the iteration converged
2165 because it can cause non-convergence, see for example PR81181. */
2167 /* Intersect ANTIC_IN with the old ANTIC_IN. This is required until
2168 we properly represent the maximum expression set, thus not prune
2169 values without expressions during the iteration. */
2171 && bitmap_and_into (&ANTIC_IN (block
)->values
, &old
->values
))
2173 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2174 fprintf (dump_file
, "warning: intersecting with old ANTIC_IN "
2175 "shrinks the set\n");
2176 /* Prune expressions not in the value set. */
2179 unsigned int to_clear
= -1U;
2180 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (block
), i
, bi
)
2182 if (to_clear
!= -1U)
2184 bitmap_clear_bit (&ANTIC_IN (block
)->expressions
, to_clear
);
2187 pre_expr expr
= expression_for_id (i
);
2188 unsigned int value_id
= get_expr_value_id (expr
);
2189 if (!bitmap_bit_p (&ANTIC_IN (block
)->values
, value_id
))
2192 if (to_clear
!= -1U)
2193 bitmap_clear_bit (&ANTIC_IN (block
)->expressions
, to_clear
);
2196 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2200 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2203 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2206 fprintf (dump_file
, "[changed] ");
2207 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2211 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2214 bitmap_set_free (old
);
2216 bitmap_set_free (S
);
2218 bitmap_set_free (ANTIC_OUT
);
2222 /* Compute PARTIAL_ANTIC for BLOCK.
2224 If succs(BLOCK) > 1 then
2225 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2226 in ANTIC_OUT for all succ(BLOCK)
2227 else if succs(BLOCK) == 1 then
2228 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2230 PA_IN[BLOCK] = clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK] - ANTIC_IN[BLOCK])
2234 compute_partial_antic_aux (basic_block block
,
2235 bool block_has_abnormal_pred_edge
)
2237 bitmap_set_t old_PA_IN
;
2238 bitmap_set_t PA_OUT
;
2241 unsigned long max_pa
= param_max_partial_antic_length
;
2243 old_PA_IN
= PA_OUT
= NULL
;
2245 /* If any edges from predecessors are abnormal, antic_in is empty,
2247 if (block_has_abnormal_pred_edge
)
2248 goto maybe_dump_sets
;
2250 /* If there are too many partially anticipatable values in the
2251 block, phi_translate_set can take an exponential time: stop
2252 before the translation starts. */
2254 && single_succ_p (block
)
2255 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2256 goto maybe_dump_sets
;
2258 old_PA_IN
= PA_IN (block
);
2259 PA_OUT
= bitmap_set_new ();
2261 /* If the block has no successors, ANTIC_OUT is empty. */
2262 if (EDGE_COUNT (block
->succs
) == 0)
2264 /* If we have one successor, we could have some phi nodes to
2265 translate through. Note that we can't phi translate across DFS
2266 back edges in partial antic, because it uses a union operation on
2267 the successors. For recurrences like IV's, we will end up
2268 generating a new value in the set on each go around (i + 3 (VH.1)
2269 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2270 else if (single_succ_p (block
))
2272 e
= single_succ_edge (block
);
2273 if (!(e
->flags
& EDGE_DFS_BACK
))
2274 phi_translate_set (PA_OUT
, PA_IN (e
->dest
), e
);
2276 /* If we have multiple successors, we take the union of all of
2282 auto_vec
<edge
> worklist (EDGE_COUNT (block
->succs
));
2283 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2285 if (e
->flags
& EDGE_DFS_BACK
)
2287 worklist
.quick_push (e
);
2289 if (worklist
.length () > 0)
2291 FOR_EACH_VEC_ELT (worklist
, i
, e
)
2296 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (e
->dest
), i
, bi
)
2297 bitmap_value_insert_into_set (PA_OUT
,
2298 expression_for_id (i
));
2299 if (!gimple_seq_empty_p (phi_nodes (e
->dest
)))
2301 bitmap_set_t pa_in
= bitmap_set_new ();
2302 phi_translate_set (pa_in
, PA_IN (e
->dest
), e
);
2303 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2304 bitmap_value_insert_into_set (PA_OUT
,
2305 expression_for_id (i
));
2306 bitmap_set_free (pa_in
);
2309 FOR_EACH_EXPR_ID_IN_SET (PA_IN (e
->dest
), i
, bi
)
2310 bitmap_value_insert_into_set (PA_OUT
,
2311 expression_for_id (i
));
2316 /* Prune expressions that are clobbered in block and thus become
2317 invalid if translated from PA_OUT to PA_IN. */
2318 prune_clobbered_mems (PA_OUT
, block
);
2320 /* PA_IN starts with PA_OUT - TMP_GEN.
2321 Then we subtract things from ANTIC_IN. */
2322 PA_IN (block
) = bitmap_set_subtract_expressions (PA_OUT
, TMP_GEN (block
));
2324 /* For partial antic, we want to put back in the phi results, since
2325 we will properly avoid making them partially antic over backedges. */
2326 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2327 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2329 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2330 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2332 clean (PA_IN (block
), ANTIC_IN (block
));
2335 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2338 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2340 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2343 bitmap_set_free (old_PA_IN
);
2345 bitmap_set_free (PA_OUT
);
2348 /* Compute ANTIC and partial ANTIC sets. */
2351 compute_antic (void)
2353 bool changed
= true;
2354 int num_iterations
= 0;
2360 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2361 We pre-build the map of blocks with incoming abnormal edges here. */
2362 auto_sbitmap
has_abnormal_preds (last_basic_block_for_fn (cfun
));
2363 bitmap_clear (has_abnormal_preds
);
2365 FOR_ALL_BB_FN (block
, cfun
)
2367 BB_VISITED (block
) = 0;
2369 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2370 if (e
->flags
& EDGE_ABNORMAL
)
2372 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2376 /* While we are here, give empty ANTIC_IN sets to each block. */
2377 ANTIC_IN (block
) = bitmap_set_new ();
2378 if (do_partial_partial
)
2379 PA_IN (block
) = bitmap_set_new ();
2382 /* At the exit block we anticipate nothing. */
2383 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2385 /* For ANTIC computation we need a postorder that also guarantees that
2386 a block with a single successor is visited after its successor.
2387 RPO on the inverted CFG has this property. */
2388 auto_vec
<int, 20> postorder
;
2389 inverted_post_order_compute (&postorder
);
2391 auto_sbitmap
worklist (last_basic_block_for_fn (cfun
) + 1);
2392 bitmap_clear (worklist
);
2393 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR_FOR_FN (cfun
)->preds
)
2394 bitmap_set_bit (worklist
, e
->src
->index
);
2397 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2398 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2399 /* ??? We need to clear our PHI translation cache here as the
2400 ANTIC sets shrink and we restrict valid translations to
2401 those having operands with leaders in ANTIC. Same below
2402 for PA ANTIC computation. */
2405 for (i
= postorder
.length () - 1; i
>= 0; i
--)
2407 if (bitmap_bit_p (worklist
, postorder
[i
]))
2409 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2410 bitmap_clear_bit (worklist
, block
->index
);
2411 if (compute_antic_aux (block
,
2412 bitmap_bit_p (has_abnormal_preds
,
2415 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2416 bitmap_set_bit (worklist
, e
->src
->index
);
2421 /* Theoretically possible, but *highly* unlikely. */
2422 gcc_checking_assert (num_iterations
< 500);
2425 /* We have to clean after the dataflow problem converged as cleaning
2426 can cause non-convergence because it is based on expressions
2427 rather than values. */
2428 FOR_EACH_BB_FN (block
, cfun
)
2429 clean (ANTIC_IN (block
));
2431 statistics_histogram_event (cfun
, "compute_antic iterations",
2434 if (do_partial_partial
)
2436 /* For partial antic we ignore backedges and thus we do not need
2437 to perform any iteration when we process blocks in postorder. */
2438 for (i
= postorder
.length () - 1; i
>= 0; i
--)
2440 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2441 compute_partial_antic_aux (block
,
2442 bitmap_bit_p (has_abnormal_preds
,
2449 /* Inserted expressions are placed onto this worklist, which is used
2450 for performing quick dead code elimination of insertions we made
2451 that didn't turn out to be necessary. */
2452 static bitmap inserted_exprs
;
2454 /* The actual worker for create_component_ref_by_pieces. */
2457 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2458 unsigned int *operand
, gimple_seq
*stmts
)
2460 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2463 switch (currop
->opcode
)
2470 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2474 tree offset
= currop
->op0
;
2475 if (TREE_CODE (baseop
) == ADDR_EXPR
2476 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2480 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2483 offset
= int_const_binop (PLUS_EXPR
, offset
,
2484 build_int_cst (TREE_TYPE (offset
),
2486 baseop
= build_fold_addr_expr (base
);
2488 genop
= build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2489 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2490 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2491 REF_REVERSE_STORAGE_ORDER (genop
) = currop
->reverse
;
2495 case TARGET_MEM_REF
:
2497 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2498 vn_reference_op_t nextop
= &ref
->operands
[(*operand
)++];
2499 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2505 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2511 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2515 genop
= build5 (TARGET_MEM_REF
, currop
->type
,
2516 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2518 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2519 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2526 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2532 case VIEW_CONVERT_EXPR
:
2534 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2538 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2541 case WITH_SIZE_EXPR
:
2543 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2547 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2550 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2555 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2559 tree op1
= currop
->op0
;
2560 tree op2
= currop
->op1
;
2561 tree t
= build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2562 REF_REVERSE_STORAGE_ORDER (t
) = currop
->reverse
;
2566 /* For array ref vn_reference_op's, operand 1 of the array ref
2567 is op0 of the reference op and operand 3 of the array ref is
2569 case ARRAY_RANGE_REF
:
2573 tree genop1
= currop
->op0
;
2574 tree genop2
= currop
->op1
;
2575 tree genop3
= currop
->op2
;
2576 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2580 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2585 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2586 /* Drop zero minimum index if redundant. */
2587 if (integer_zerop (genop2
)
2589 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2593 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2600 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2601 /* We can't always put a size in units of the element alignment
2602 here as the element alignment may be not visible. See
2603 PR43783. Simply drop the element size for constant
2605 if (TREE_CODE (genop3
) == INTEGER_CST
2606 && TREE_CODE (TYPE_SIZE_UNIT (elmt_type
)) == INTEGER_CST
2607 && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type
)),
2608 (wi::to_offset (genop3
)
2609 * vn_ref_op_align_unit (currop
))))
2613 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2618 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2625 tree genop2
= currop
->op1
;
2626 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2629 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2633 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2637 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2642 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2664 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2665 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2666 trying to rename aggregates into ssa form directly, which is a no no.
2668 Thus, this routine doesn't create temporaries, it just builds a
2669 single access expression for the array, calling
2670 find_or_generate_expression to build the innermost pieces.
2672 This function is a subroutine of create_expression_by_pieces, and
2673 should not be called on it's own unless you really know what you
2677 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2680 unsigned int op
= 0;
2681 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2684 /* Find a simple leader for an expression, or generate one using
2685 create_expression_by_pieces from a NARY expression for the value.
2686 BLOCK is the basic_block we are looking for leaders in.
2687 OP is the tree expression to find a leader for or generate.
2688 Returns the leader or NULL_TREE on failure. */
2691 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2693 pre_expr expr
= get_or_alloc_expr_for (op
);
2694 unsigned int lookfor
= get_expr_value_id (expr
);
2695 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2698 if (leader
->kind
== NAME
)
2699 return PRE_EXPR_NAME (leader
);
2700 else if (leader
->kind
== CONSTANT
)
2701 return PRE_EXPR_CONSTANT (leader
);
2707 /* It must be a complex expression, so generate it recursively. Note
2708 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2709 where the insert algorithm fails to insert a required expression. */
2710 bitmap exprset
= value_expressions
[lookfor
];
2713 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2715 pre_expr temp
= expression_for_id (i
);
2716 /* We cannot insert random REFERENCE expressions at arbitrary
2717 places. We can insert NARYs which eventually re-materializes
2718 its operand values. */
2719 if (temp
->kind
== NARY
)
2720 return create_expression_by_pieces (block
, temp
, stmts
,
2721 get_expr_type (expr
));
2728 /* Create an expression in pieces, so that we can handle very complex
2729 expressions that may be ANTIC, but not necessary GIMPLE.
2730 BLOCK is the basic block the expression will be inserted into,
2731 EXPR is the expression to insert (in value form)
2732 STMTS is a statement list to append the necessary insertions into.
2734 This function will die if we hit some value that shouldn't be
2735 ANTIC but is (IE there is no leader for it, or its components).
2736 The function returns NULL_TREE in case a different antic expression
2737 has to be inserted first.
2738 This function may also generate expressions that are themselves
2739 partially or fully redundant. Those that are will be either made
2740 fully redundant during the next iteration of insert (for partially
2741 redundant ones), or eliminated by eliminate (for fully redundant
2745 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2746 gimple_seq
*stmts
, tree type
)
2750 gimple_seq forced_stmts
= NULL
;
2751 unsigned int value_id
;
2752 gimple_stmt_iterator gsi
;
2753 tree exprtype
= type
? type
: get_expr_type (expr
);
2759 /* We may hit the NAME/CONSTANT case if we have to convert types
2760 that value numbering saw through. */
2762 folded
= PRE_EXPR_NAME (expr
);
2763 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (folded
))
2765 if (useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2770 folded
= PRE_EXPR_CONSTANT (expr
);
2771 tree tem
= fold_convert (exprtype
, folded
);
2772 if (is_gimple_min_invariant (tem
))
2777 if (PRE_EXPR_REFERENCE (expr
)->operands
[0].opcode
== CALL_EXPR
)
2779 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2780 unsigned int operand
= 1;
2781 vn_reference_op_t currop
= &ref
->operands
[0];
2782 tree sc
= NULL_TREE
;
2783 tree fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2788 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2792 auto_vec
<tree
> args (ref
->operands
.length () - 1);
2793 while (operand
< ref
->operands
.length ())
2795 tree arg
= create_component_ref_by_pieces_1 (block
, ref
,
2799 args
.quick_push (arg
);
2801 gcall
*call
= gimple_build_call_vec (fn
, args
);
2802 gimple_set_location (call
, expr
->loc
);
2803 gimple_call_set_fntype (call
, currop
->type
);
2805 gimple_call_set_chain (call
, sc
);
2806 tree forcedname
= make_ssa_name (TREE_TYPE (currop
->type
));
2807 gimple_call_set_lhs (call
, forcedname
);
2808 /* There's no CCP pass after PRE which would re-compute alignment
2809 information so make sure we re-materialize this here. */
2810 if (gimple_call_builtin_p (call
, BUILT_IN_ASSUME_ALIGNED
)
2811 && args
.length () - 2 <= 1
2812 && tree_fits_uhwi_p (args
[1])
2813 && (args
.length () != 3 || tree_fits_uhwi_p (args
[2])))
2815 unsigned HOST_WIDE_INT halign
= tree_to_uhwi (args
[1]);
2816 unsigned HOST_WIDE_INT hmisalign
2817 = args
.length () == 3 ? tree_to_uhwi (args
[2]) : 0;
2818 if ((halign
& (halign
- 1)) == 0
2819 && (hmisalign
& ~(halign
- 1)) == 0
2820 && (unsigned int)halign
!= 0)
2821 set_ptr_info_alignment (get_ptr_info (forcedname
),
2824 gimple_set_vuse (call
, BB_LIVE_VOP_ON_EXIT (block
));
2825 gimple_seq_add_stmt_without_update (&forced_stmts
, call
);
2826 folded
= forcedname
;
2830 folded
= create_component_ref_by_pieces (block
,
2831 PRE_EXPR_REFERENCE (expr
),
2835 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2836 newstmt
= gimple_build_assign (name
, folded
);
2837 gimple_set_location (newstmt
, expr
->loc
);
2838 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2839 gimple_set_vuse (newstmt
, BB_LIVE_VOP_ON_EXIT (block
));
2845 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2846 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2848 for (i
= 0; i
< nary
->length
; ++i
)
2850 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2853 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2854 may have conversions stripped. */
2855 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2858 genop
[i
] = gimple_convert (&forced_stmts
,
2859 nary
->type
, genop
[i
]);
2861 genop
[i
] = gimple_convert (&forced_stmts
,
2862 sizetype
, genop
[i
]);
2865 genop
[i
] = gimple_convert (&forced_stmts
,
2866 TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2868 if (nary
->opcode
== CONSTRUCTOR
)
2870 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2871 for (i
= 0; i
< nary
->length
; ++i
)
2872 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2873 folded
= build_constructor (nary
->type
, elts
);
2874 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2875 newstmt
= gimple_build_assign (name
, folded
);
2876 gimple_set_location (newstmt
, expr
->loc
);
2877 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2882 switch (nary
->length
)
2885 folded
= gimple_build (&forced_stmts
, expr
->loc
,
2886 nary
->opcode
, nary
->type
, genop
[0]);
2889 folded
= gimple_build (&forced_stmts
, expr
->loc
, nary
->opcode
,
2890 nary
->type
, genop
[0], genop
[1]);
2893 folded
= gimple_build (&forced_stmts
, expr
->loc
, nary
->opcode
,
2894 nary
->type
, genop
[0], genop
[1],
2907 folded
= gimple_convert (&forced_stmts
, exprtype
, folded
);
2909 /* If there is nothing to insert, return the simplified result. */
2910 if (gimple_seq_empty_p (forced_stmts
))
2912 /* If we simplified to a constant return it and discard eventually
2914 if (is_gimple_min_invariant (folded
))
2916 gimple_seq_discard (forced_stmts
);
2919 /* Likewise if we simplified to sth not queued for insertion. */
2921 gsi
= gsi_last (forced_stmts
);
2922 for (; !gsi_end_p (gsi
); gsi_prev (&gsi
))
2924 gimple
*stmt
= gsi_stmt (gsi
);
2925 tree forcedname
= gimple_get_lhs (stmt
);
2926 if (forcedname
== folded
)
2934 gimple_seq_discard (forced_stmts
);
2937 gcc_assert (TREE_CODE (folded
) == SSA_NAME
);
2939 /* If we have any intermediate expressions to the value sets, add them
2940 to the value sets and chain them in the instruction stream. */
2943 gsi
= gsi_start (forced_stmts
);
2944 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2946 gimple
*stmt
= gsi_stmt (gsi
);
2947 tree forcedname
= gimple_get_lhs (stmt
);
2950 if (forcedname
!= folded
)
2952 VN_INFO (forcedname
)->valnum
= forcedname
;
2953 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2954 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2955 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2956 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2957 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2960 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2962 gimple_seq_add_seq (stmts
, forced_stmts
);
2967 /* Fold the last statement. */
2968 gsi
= gsi_last (*stmts
);
2969 if (fold_stmt_inplace (&gsi
))
2970 update_stmt (gsi_stmt (gsi
));
2972 /* Add a value number to the temporary.
2973 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2974 we are creating the expression by pieces, and this particular piece of
2975 the expression may have been represented. There is no harm in replacing
2977 value_id
= get_expr_value_id (expr
);
2978 VN_INFO (name
)->value_id
= value_id
;
2979 VN_INFO (name
)->valnum
= vn_valnum_from_value_id (value_id
);
2980 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2981 VN_INFO (name
)->valnum
= name
;
2982 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2983 nameexpr
= get_or_alloc_expr_for_name (name
);
2984 add_to_value (value_id
, nameexpr
);
2985 if (NEW_SETS (block
))
2986 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2987 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2989 pre_stats
.insertions
++;
2990 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2992 fprintf (dump_file
, "Inserted ");
2993 print_gimple_stmt (dump_file
, gsi_stmt (gsi_last (*stmts
)), 0);
2994 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2995 block
->index
, value_id
);
3002 /* Insert the to-be-made-available values of expression EXPRNUM for each
3003 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3004 merge the result with a phi node, given the same value number as
3005 NODE. Return true if we have inserted new stuff. */
3008 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3009 vec
<pre_expr
> avail
)
3011 pre_expr expr
= expression_for_id (exprnum
);
3013 unsigned int val
= get_expr_value_id (expr
);
3015 bool insertions
= false;
3020 tree type
= get_expr_type (expr
);
3024 /* Make sure we aren't creating an induction variable. */
3025 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
3027 bool firstinsideloop
= false;
3028 bool secondinsideloop
= false;
3029 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3030 EDGE_PRED (block
, 0)->src
);
3031 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3032 EDGE_PRED (block
, 1)->src
);
3033 /* Induction variables only have one edge inside the loop. */
3034 if ((firstinsideloop
^ secondinsideloop
)
3035 && expr
->kind
!= REFERENCE
)
3037 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3038 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3043 /* Make the necessary insertions. */
3044 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3046 gimple_seq stmts
= NULL
;
3049 eprime
= avail
[pred
->dest_idx
];
3050 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
3052 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3053 if (!gimple_seq_empty_p (stmts
))
3055 basic_block new_bb
= gsi_insert_seq_on_edge_immediate (pred
, stmts
);
3056 gcc_assert (! new_bb
);
3061 /* We cannot insert a PHI node if we failed to insert
3066 if (is_gimple_min_invariant (builtexpr
))
3067 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_constant (builtexpr
);
3069 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3071 /* If we didn't want a phi node, and we made insertions, we still have
3072 inserted new stuff, and thus return true. If we didn't want a phi node,
3073 and didn't make insertions, we haven't added anything new, so return
3075 if (nophi
&& insertions
)
3077 else if (nophi
&& !insertions
)
3080 /* Now build a phi for the new variable. */
3081 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3082 phi
= create_phi_node (temp
, block
);
3084 VN_INFO (temp
)->value_id
= val
;
3085 VN_INFO (temp
)->valnum
= vn_valnum_from_value_id (val
);
3086 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3087 VN_INFO (temp
)->valnum
= temp
;
3088 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3089 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3091 pre_expr ae
= avail
[pred
->dest_idx
];
3092 gcc_assert (get_expr_type (ae
) == type
3093 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3094 if (ae
->kind
== CONSTANT
)
3095 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3096 pred
, UNKNOWN_LOCATION
);
3098 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3101 newphi
= get_or_alloc_expr_for_name (temp
);
3102 add_to_value (val
, newphi
);
3104 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3105 this insertion, since we test for the existence of this value in PHI_GEN
3106 before proceeding with the partial redundancy checks in insert_aux.
3108 The value may exist in AVAIL_OUT, in particular, it could be represented
3109 by the expression we are trying to eliminate, in which case we want the
3110 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3113 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3114 this block, because if it did, it would have existed in our dominator's
3115 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3118 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3119 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3121 bitmap_insert_into_set (NEW_SETS (block
),
3124 /* If we insert a PHI node for a conversion of another PHI node
3125 in the same basic-block try to preserve range information.
3126 This is important so that followup loop passes receive optimal
3127 number of iteration analysis results. See PR61743. */
3128 if (expr
->kind
== NARY
3129 && CONVERT_EXPR_CODE_P (expr
->u
.nary
->opcode
)
3130 && TREE_CODE (expr
->u
.nary
->op
[0]) == SSA_NAME
3131 && gimple_bb (SSA_NAME_DEF_STMT (expr
->u
.nary
->op
[0])) == block
3132 && INTEGRAL_TYPE_P (type
)
3133 && INTEGRAL_TYPE_P (TREE_TYPE (expr
->u
.nary
->op
[0]))
3134 && (TYPE_PRECISION (type
)
3135 >= TYPE_PRECISION (TREE_TYPE (expr
->u
.nary
->op
[0])))
3136 && SSA_NAME_RANGE_INFO (expr
->u
.nary
->op
[0]))
3139 if (get_range_info (expr
->u
.nary
->op
[0], &min
, &max
) == VR_RANGE
3140 && !wi::neg_p (min
, SIGNED
)
3141 && !wi::neg_p (max
, SIGNED
))
3142 /* Just handle extension and sign-changes of all-positive ranges. */
3143 set_range_info (temp
,
3144 SSA_NAME_RANGE_TYPE (expr
->u
.nary
->op
[0]),
3145 wide_int_storage::from (min
, TYPE_PRECISION (type
),
3147 wide_int_storage::from (max
, TYPE_PRECISION (type
),
3151 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3153 fprintf (dump_file
, "Created phi ");
3154 print_gimple_stmt (dump_file
, phi
, 0);
3155 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3163 /* Perform insertion of partially redundant or hoistable values.
3164 For BLOCK, do the following:
3165 1. Propagate the NEW_SETS of the dominator into the current block.
3166 If the block has multiple predecessors,
3167 2a. Iterate over the ANTIC expressions for the block to see if
3168 any of them are partially redundant.
3169 2b. If so, insert them into the necessary predecessors to make
3170 the expression fully redundant.
3171 2c. Insert a new PHI merging the values of the predecessors.
3172 2d. Insert the new PHI, and the new expressions, into the
3174 If the block has multiple successors,
3175 3a. Iterate over the ANTIC values for the block to see if
3176 any of them are good candidates for hoisting.
3177 3b. If so, insert expressions computing the values in BLOCK,
3178 and add the new expressions into the NEW_SETS set.
3179 4. Recursively call ourselves on the dominator children of BLOCK.
3181 Steps 1, 2a, and 4 are done by insert_aux. 2b, 2c and 2d are done by
3182 do_pre_regular_insertion and do_partial_insertion. 3a and 3b are
3183 done in do_hoist_insertion.
3187 do_pre_regular_insertion (basic_block block
, basic_block dom
)
3189 bool new_stuff
= false;
3190 vec
<pre_expr
> exprs
;
3192 auto_vec
<pre_expr
> avail
;
3195 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3196 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3198 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3200 if (expr
->kind
== NARY
3201 || expr
->kind
== REFERENCE
)
3204 bool by_some
= false;
3205 bool cant_insert
= false;
3206 bool all_same
= true;
3207 pre_expr first_s
= NULL
;
3210 pre_expr eprime
= NULL
;
3212 pre_expr edoubleprime
= NULL
;
3213 bool do_insertion
= false;
3215 val
= get_expr_value_id (expr
);
3216 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3218 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3220 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3222 fprintf (dump_file
, "Found fully redundant value: ");
3223 print_pre_expr (dump_file
, expr
);
3224 fprintf (dump_file
, "\n");
3229 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3231 unsigned int vprime
;
3233 /* We should never run insertion for the exit block
3234 and so not come across fake pred edges. */
3235 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3237 /* We are looking at ANTIC_OUT of bprime. */
3238 eprime
= phi_translate (NULL
, expr
, ANTIC_IN (block
), NULL
, pred
);
3240 /* eprime will generally only be NULL if the
3241 value of the expression, translated
3242 through the PHI for this predecessor, is
3243 undefined. If that is the case, we can't
3244 make the expression fully redundant,
3245 because its value is undefined along a
3246 predecessor path. We can thus break out
3247 early because it doesn't matter what the
3248 rest of the results are. */
3251 avail
[pred
->dest_idx
] = NULL
;
3256 vprime
= get_expr_value_id (eprime
);
3257 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3259 if (edoubleprime
== NULL
)
3261 avail
[pred
->dest_idx
] = eprime
;
3266 avail
[pred
->dest_idx
] = edoubleprime
;
3268 /* We want to perform insertions to remove a redundancy on
3269 a path in the CFG we want to optimize for speed. */
3270 if (optimize_edge_for_speed_p (pred
))
3271 do_insertion
= true;
3272 if (first_s
== NULL
)
3273 first_s
= edoubleprime
;
3274 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3278 /* If we can insert it, it's not the same value
3279 already existing along every predecessor, and
3280 it's defined by some predecessor, it is
3281 partially redundant. */
3282 if (!cant_insert
&& !all_same
&& by_some
)
3286 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3288 fprintf (dump_file
, "Skipping partial redundancy for "
3290 print_pre_expr (dump_file
, expr
);
3291 fprintf (dump_file
, " (%04d), no redundancy on to be "
3292 "optimized for speed edge\n", val
);
3295 else if (dbg_cnt (treepre_insert
))
3297 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3299 fprintf (dump_file
, "Found partial redundancy for "
3301 print_pre_expr (dump_file
, expr
);
3302 fprintf (dump_file
, " (%04d)\n",
3303 get_expr_value_id (expr
));
3305 if (insert_into_preds_of_block (block
,
3306 get_expression_id (expr
),
3311 /* If all edges produce the same value and that value is
3312 an invariant, then the PHI has the same value on all
3313 edges. Note this. */
3314 else if (!cant_insert
&& all_same
)
3316 gcc_assert (edoubleprime
->kind
== CONSTANT
3317 || edoubleprime
->kind
== NAME
);
3319 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3322 = gimple_build_assign (temp
,
3323 edoubleprime
->kind
== CONSTANT
?
3324 PRE_EXPR_CONSTANT (edoubleprime
) :
3325 PRE_EXPR_NAME (edoubleprime
));
3326 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3327 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3329 VN_INFO (temp
)->value_id
= val
;
3330 VN_INFO (temp
)->valnum
= vn_valnum_from_value_id (val
);
3331 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3332 VN_INFO (temp
)->valnum
= temp
;
3333 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3334 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3335 add_to_value (val
, newe
);
3336 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3337 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3347 /* Perform insertion for partially anticipatable expressions. There
3348 is only one case we will perform insertion for these. This case is
3349 if the expression is partially anticipatable, and fully available.
3350 In this case, we know that putting it earlier will enable us to
3351 remove the later computation. */
3354 do_pre_partial_partial_insertion (basic_block block
, basic_block dom
)
3356 bool new_stuff
= false;
3357 vec
<pre_expr
> exprs
;
3359 auto_vec
<pre_expr
> avail
;
3362 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3363 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3365 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3367 if (expr
->kind
== NARY
3368 || expr
->kind
== REFERENCE
)
3372 bool cant_insert
= false;
3375 pre_expr eprime
= NULL
;
3378 val
= get_expr_value_id (expr
);
3379 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3381 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3384 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3386 unsigned int vprime
;
3387 pre_expr edoubleprime
;
3389 /* We should never run insertion for the exit block
3390 and so not come across fake pred edges. */
3391 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3393 eprime
= phi_translate (NULL
, expr
, ANTIC_IN (block
),
3394 PA_IN (block
), pred
);
3396 /* eprime will generally only be NULL if the
3397 value of the expression, translated
3398 through the PHI for this predecessor, is
3399 undefined. If that is the case, we can't
3400 make the expression fully redundant,
3401 because its value is undefined along a
3402 predecessor path. We can thus break out
3403 early because it doesn't matter what the
3404 rest of the results are. */
3407 avail
[pred
->dest_idx
] = NULL
;
3412 vprime
= get_expr_value_id (eprime
);
3413 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3414 avail
[pred
->dest_idx
] = edoubleprime
;
3415 if (edoubleprime
== NULL
)
3422 /* If we can insert it, it's not the same value
3423 already existing along every predecessor, and
3424 it's defined by some predecessor, it is
3425 partially redundant. */
3426 if (!cant_insert
&& by_all
)
3429 bool do_insertion
= false;
3431 /* Insert only if we can remove a later expression on a path
3432 that we want to optimize for speed.
3433 The phi node that we will be inserting in BLOCK is not free,
3434 and inserting it for the sake of !optimize_for_speed successor
3435 may cause regressions on the speed path. */
3436 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3438 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3439 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3441 if (optimize_edge_for_speed_p (succ
))
3442 do_insertion
= true;
3448 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3450 fprintf (dump_file
, "Skipping partial partial redundancy "
3452 print_pre_expr (dump_file
, expr
);
3453 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3454 "on any to be optimized for speed edges\n", val
);
3457 else if (dbg_cnt (treepre_insert
))
3459 pre_stats
.pa_insert
++;
3460 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3462 fprintf (dump_file
, "Found partial partial redundancy "
3464 print_pre_expr (dump_file
, expr
);
3465 fprintf (dump_file
, " (%04d)\n",
3466 get_expr_value_id (expr
));
3468 if (insert_into_preds_of_block (block
,
3469 get_expression_id (expr
),
3481 /* Insert expressions in BLOCK to compute hoistable values up.
3482 Return TRUE if something was inserted, otherwise return FALSE.
3483 The caller has to make sure that BLOCK has at least two successors. */
3486 do_hoist_insertion (basic_block block
)
3490 bool new_stuff
= false;
3492 gimple_stmt_iterator last
;
3494 /* At least two successors, or else... */
3495 gcc_assert (EDGE_COUNT (block
->succs
) >= 2);
3497 /* Check that all successors of BLOCK are dominated by block.
3498 We could use dominated_by_p() for this, but actually there is a much
3499 quicker check: any successor that is dominated by BLOCK can't have
3500 more than one predecessor edge. */
3501 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3502 if (! single_pred_p (e
->dest
))
3505 /* Determine the insertion point. If we cannot safely insert before
3506 the last stmt if we'd have to, bail out. */
3507 last
= gsi_last_bb (block
);
3508 if (!gsi_end_p (last
)
3509 && !is_ctrl_stmt (gsi_stmt (last
))
3510 && stmt_ends_bb_p (gsi_stmt (last
)))
3513 /* Compute the set of hoistable expressions from ANTIC_IN. First compute
3514 hoistable values. */
3515 bitmap_set hoistable_set
;
3517 /* A hoistable value must be in ANTIC_IN(block)
3518 but not in AVAIL_OUT(BLOCK). */
3519 bitmap_initialize (&hoistable_set
.values
, &grand_bitmap_obstack
);
3520 bitmap_and_compl (&hoistable_set
.values
,
3521 &ANTIC_IN (block
)->values
, &AVAIL_OUT (block
)->values
);
3523 /* Short-cut for a common case: hoistable_set is empty. */
3524 if (bitmap_empty_p (&hoistable_set
.values
))
3527 /* Compute which of the hoistable values is in AVAIL_OUT of
3528 at least one of the successors of BLOCK. */
3529 bitmap_head availout_in_some
;
3530 bitmap_initialize (&availout_in_some
, &grand_bitmap_obstack
);
3531 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3532 /* Do not consider expressions solely because their availability
3533 on loop exits. They'd be ANTIC-IN throughout the whole loop
3534 and thus effectively hoisted across loops by combination of
3535 PRE and hoisting. */
3536 if (! loop_exit_edge_p (block
->loop_father
, e
))
3537 bitmap_ior_and_into (&availout_in_some
, &hoistable_set
.values
,
3538 &AVAIL_OUT (e
->dest
)->values
);
3539 bitmap_clear (&hoistable_set
.values
);
3541 /* Short-cut for a common case: availout_in_some is empty. */
3542 if (bitmap_empty_p (&availout_in_some
))
3545 /* Hack hoitable_set in-place so we can use sorted_array_from_bitmap_set. */
3546 bitmap_move (&hoistable_set
.values
, &availout_in_some
);
3547 hoistable_set
.expressions
= ANTIC_IN (block
)->expressions
;
3549 /* Now finally construct the topological-ordered expression set. */
3550 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (&hoistable_set
);
3552 bitmap_clear (&hoistable_set
.values
);
3554 /* If there are candidate values for hoisting, insert expressions
3555 strategically to make the hoistable expressions fully redundant. */
3557 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3559 /* While we try to sort expressions topologically above the
3560 sorting doesn't work out perfectly. Catch expressions we
3561 already inserted. */
3562 unsigned int value_id
= get_expr_value_id (expr
);
3563 if (bitmap_set_contains_value (AVAIL_OUT (block
), value_id
))
3565 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3568 "Already inserted expression for ");
3569 print_pre_expr (dump_file
, expr
);
3570 fprintf (dump_file
, " (%04d)\n", value_id
);
3575 /* If we end up with a punned expression representation and this
3576 happens to be a float typed one give up - we can't know for
3577 sure whether all paths perform the floating-point load we are
3578 about to insert and on some targets this can cause correctness
3579 issues. See PR88240. */
3580 if (expr
->kind
== REFERENCE
3581 && PRE_EXPR_REFERENCE (expr
)->punned
3582 && FLOAT_TYPE_P (get_expr_type (expr
)))
3585 /* OK, we should hoist this value. Perform the transformation. */
3586 pre_stats
.hoist_insert
++;
3587 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3590 "Inserting expression in block %d for code hoisting: ",
3592 print_pre_expr (dump_file
, expr
);
3593 fprintf (dump_file
, " (%04d)\n", value_id
);
3596 gimple_seq stmts
= NULL
;
3597 tree res
= create_expression_by_pieces (block
, expr
, &stmts
,
3598 get_expr_type (expr
));
3600 /* Do not return true if expression creation ultimately
3601 did not insert any statements. */
3602 if (gimple_seq_empty_p (stmts
))
3606 if (gsi_end_p (last
) || is_ctrl_stmt (gsi_stmt (last
)))
3607 gsi_insert_seq_before (&last
, stmts
, GSI_SAME_STMT
);
3609 gsi_insert_seq_after (&last
, stmts
, GSI_NEW_STMT
);
3612 /* Make sure to not return true if expression creation ultimately
3613 failed but also make sure to insert any stmts produced as they
3614 are tracked in inserted_exprs. */
3626 /* Perform insertion of partially redundant and hoistable values. */
3633 FOR_ALL_BB_FN (bb
, cfun
)
3634 NEW_SETS (bb
) = bitmap_set_new ();
3636 int *rpo
= XNEWVEC (int, n_basic_blocks_for_fn (cfun
));
3637 int rpo_num
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
3639 int num_iterations
= 0;
3644 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3645 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3648 for (int idx
= 0; idx
< rpo_num
; ++idx
)
3650 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, rpo
[idx
]);
3651 basic_block dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3656 bitmap_set_t newset
;
3658 /* First, update the AVAIL_OUT set with anything we may have
3659 inserted higher up in the dominator tree. */
3660 newset
= NEW_SETS (dom
);
3663 /* Note that we need to value_replace both NEW_SETS, and
3664 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3665 represented by some non-simple expression here that we want
3666 to replace it with. */
3667 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3669 pre_expr expr
= expression_for_id (i
);
3670 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3671 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3675 /* Insert expressions for partial redundancies. */
3676 if (flag_tree_pre
&& !single_pred_p (block
))
3678 changed
|= do_pre_regular_insertion (block
, dom
);
3679 if (do_partial_partial
)
3680 changed
|= do_pre_partial_partial_insertion (block
, dom
);
3683 /* Insert expressions for hoisting. */
3684 if (flag_code_hoisting
&& EDGE_COUNT (block
->succs
) >= 2)
3685 changed
|= do_hoist_insertion (block
);
3689 /* Clear the NEW sets before the next iteration. We have already
3690 fully propagated its contents. */
3692 FOR_ALL_BB_FN (bb
, cfun
)
3693 bitmap_set_free (NEW_SETS (bb
));
3697 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3703 /* Compute the AVAIL set for all basic blocks.
3705 This function performs value numbering of the statements in each basic
3706 block. The AVAIL sets are built from information we glean while doing
3707 this value numbering, since the AVAIL sets contain only one entry per
3710 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3711 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3714 compute_avail (void)
3717 basic_block block
, son
;
3718 basic_block
*worklist
;
3723 /* We pretend that default definitions are defined in the entry block.
3724 This includes function arguments and the static chain decl. */
3725 FOR_EACH_SSA_NAME (i
, name
, cfun
)
3728 if (!SSA_NAME_IS_DEFAULT_DEF (name
)
3729 || has_zero_uses (name
)
3730 || virtual_operand_p (name
))
3733 e
= get_or_alloc_expr_for_name (name
);
3734 add_to_value (get_expr_value_id (e
), e
);
3735 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3736 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3740 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3742 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3743 "tmp_gen", ENTRY_BLOCK
);
3744 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3745 "avail_out", ENTRY_BLOCK
);
3748 /* Allocate the worklist. */
3749 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3751 /* Seed the algorithm by putting the dominator children of the entry
3752 block on the worklist. */
3753 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3755 son
= next_dom_son (CDI_DOMINATORS
, son
))
3756 worklist
[sp
++] = son
;
3758 BB_LIVE_VOP_ON_EXIT (ENTRY_BLOCK_PTR_FOR_FN (cfun
))
3759 = ssa_default_def (cfun
, gimple_vop (cfun
));
3761 /* Loop until the worklist is empty. */
3767 /* Pick a block from the worklist. */
3768 block
= worklist
[--sp
];
3769 vn_context_bb
= block
;
3771 /* Initially, the set of available values in BLOCK is that of
3772 its immediate dominator. */
3773 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3776 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3777 BB_LIVE_VOP_ON_EXIT (block
) = BB_LIVE_VOP_ON_EXIT (dom
);
3780 /* Generate values for PHI nodes. */
3781 for (gphi_iterator gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
);
3784 tree result
= gimple_phi_result (gsi
.phi ());
3786 /* We have no need for virtual phis, as they don't represent
3787 actual computations. */
3788 if (virtual_operand_p (result
))
3790 BB_LIVE_VOP_ON_EXIT (block
) = result
;
3794 pre_expr e
= get_or_alloc_expr_for_name (result
);
3795 add_to_value (get_expr_value_id (e
), e
);
3796 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3797 bitmap_insert_into_set (PHI_GEN (block
), e
);
3800 BB_MAY_NOTRETURN (block
) = 0;
3802 /* Now compute value numbers and populate value sets with all
3803 the expressions computed in BLOCK. */
3804 for (gimple_stmt_iterator gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
);
3810 stmt
= gsi_stmt (gsi
);
3812 /* Cache whether the basic-block has any non-visible side-effect
3814 If this isn't a call or it is the last stmt in the
3815 basic-block then the CFG represents things correctly. */
3816 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3818 /* Non-looping const functions always return normally.
3819 Otherwise the call might not return or have side-effects
3820 that forbids hoisting possibly trapping expressions
3822 int flags
= gimple_call_flags (stmt
);
3823 if (!(flags
& ECF_CONST
)
3824 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3825 BB_MAY_NOTRETURN (block
) = 1;
3828 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3830 pre_expr e
= get_or_alloc_expr_for_name (op
);
3832 add_to_value (get_expr_value_id (e
), e
);
3833 bitmap_insert_into_set (TMP_GEN (block
), e
);
3834 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3837 if (gimple_vdef (stmt
))
3838 BB_LIVE_VOP_ON_EXIT (block
) = gimple_vdef (stmt
);
3840 if (gimple_has_side_effects (stmt
)
3841 || stmt_could_throw_p (cfun
, stmt
)
3842 || is_gimple_debug (stmt
))
3845 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3847 if (ssa_undefined_value_p (op
))
3849 pre_expr e
= get_or_alloc_expr_for_name (op
);
3850 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3853 switch (gimple_code (stmt
))
3861 vn_reference_s ref1
;
3862 pre_expr result
= NULL
;
3864 /* We can value number only calls to real functions. */
3865 if (gimple_call_internal_p (stmt
))
3868 vn_reference_lookup_call (as_a
<gcall
*> (stmt
), &ref
, &ref1
);
3872 /* If the value of the call is not invalidated in
3873 this block until it is computed, add the expression
3875 if (!gimple_vuse (stmt
)
3877 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3878 || gimple_bb (SSA_NAME_DEF_STMT
3879 (gimple_vuse (stmt
))) != block
)
3881 result
= pre_expr_pool
.allocate ();
3882 result
->kind
= REFERENCE
;
3884 result
->loc
= gimple_location (stmt
);
3885 PRE_EXPR_REFERENCE (result
) = ref
;
3887 get_or_alloc_expression_id (result
);
3888 add_to_value (get_expr_value_id (result
), result
);
3889 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3896 pre_expr result
= NULL
;
3897 switch (vn_get_stmt_kind (stmt
))
3901 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3904 /* COND_EXPR and VEC_COND_EXPR are awkward in
3905 that they contain an embedded complex expression.
3906 Don't even try to shove those through PRE. */
3907 if (code
== COND_EXPR
3908 || code
== VEC_COND_EXPR
)
3911 vn_nary_op_lookup_stmt (stmt
, &nary
);
3912 if (!nary
|| nary
->predicated_values
)
3915 /* If the NARY traps and there was a preceding
3916 point in the block that might not return avoid
3917 adding the nary to EXP_GEN. */
3918 if (BB_MAY_NOTRETURN (block
)
3919 && vn_nary_may_trap (nary
))
3922 result
= pre_expr_pool
.allocate ();
3923 result
->kind
= NARY
;
3925 result
->loc
= gimple_location (stmt
);
3926 PRE_EXPR_NARY (result
) = nary
;
3932 tree rhs1
= gimple_assign_rhs1 (stmt
);
3934 ao_ref_init (&rhs1_ref
, rhs1
);
3935 alias_set_type set
= ao_ref_alias_set (&rhs1_ref
);
3936 alias_set_type base_set
3937 = ao_ref_base_alias_set (&rhs1_ref
);
3938 vec
<vn_reference_op_s
> operands
3939 = vn_reference_operands_for_lookup (rhs1
);
3941 vn_reference_lookup_pieces (gimple_vuse (stmt
), set
,
3942 base_set
, TREE_TYPE (rhs1
),
3943 operands
, &ref
, VN_WALK
);
3946 operands
.release ();
3950 /* If the REFERENCE traps and there was a preceding
3951 point in the block that might not return avoid
3952 adding the reference to EXP_GEN. */
3953 if (BB_MAY_NOTRETURN (block
)
3954 && vn_reference_may_trap (ref
))
3957 /* If the value of the reference is not invalidated in
3958 this block until it is computed, add the expression
3960 if (gimple_vuse (stmt
))
3964 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3965 while (!gimple_nop_p (def_stmt
)
3966 && gimple_code (def_stmt
) != GIMPLE_PHI
3967 && gimple_bb (def_stmt
) == block
)
3969 if (stmt_may_clobber_ref_p
3970 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3976 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3980 operands
.release ();
3985 /* If the load was value-numbered to another
3986 load make sure we do not use its expression
3987 for insertion if it wouldn't be a valid
3989 /* At the momemt we have a testcase
3990 for hoist insertion of aligned vs. misaligned
3991 variants in gcc.dg/torture/pr65270-1.c thus
3992 with just alignment to be considered we can
3993 simply replace the expression in the hashtable
3994 with the most conservative one. */
3995 vn_reference_op_t ref1
= &ref
->operands
.last ();
3996 while (ref1
->opcode
!= TARGET_MEM_REF
3997 && ref1
->opcode
!= MEM_REF
3998 && ref1
!= &ref
->operands
[0])
4000 vn_reference_op_t ref2
= &operands
.last ();
4001 while (ref2
->opcode
!= TARGET_MEM_REF
4002 && ref2
->opcode
!= MEM_REF
4003 && ref2
!= &operands
[0])
4005 if ((ref1
->opcode
== TARGET_MEM_REF
4006 || ref1
->opcode
== MEM_REF
)
4007 && (TYPE_ALIGN (ref1
->type
)
4008 > TYPE_ALIGN (ref2
->type
)))
4010 = build_aligned_type (ref1
->type
,
4011 TYPE_ALIGN (ref2
->type
));
4012 /* TBAA behavior is an obvious part so make sure
4013 that the hashtable one covers this as well
4014 by adjusting the ref alias set and its base. */
4016 || alias_set_subset_of (set
, ref
->set
))
4018 else if (alias_set_subset_of (ref
->set
, set
))
4021 if (ref1
->opcode
== MEM_REF
)
4023 = wide_int_to_tree (TREE_TYPE (ref2
->op0
),
4024 wi::to_wide (ref1
->op0
));
4027 = wide_int_to_tree (TREE_TYPE (ref2
->op2
),
4028 wi::to_wide (ref1
->op2
));
4033 if (ref1
->opcode
== MEM_REF
)
4035 = wide_int_to_tree (ptr_type_node
,
4036 wi::to_wide (ref1
->op0
));
4039 = wide_int_to_tree (ptr_type_node
,
4040 wi::to_wide (ref1
->op2
));
4042 operands
.release ();
4044 result
= pre_expr_pool
.allocate ();
4045 result
->kind
= REFERENCE
;
4047 result
->loc
= gimple_location (stmt
);
4048 PRE_EXPR_REFERENCE (result
) = ref
;
4056 get_or_alloc_expression_id (result
);
4057 add_to_value (get_expr_value_id (result
), result
);
4058 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4066 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4068 print_bitmap_set (dump_file
, EXP_GEN (block
),
4069 "exp_gen", block
->index
);
4070 print_bitmap_set (dump_file
, PHI_GEN (block
),
4071 "phi_gen", block
->index
);
4072 print_bitmap_set (dump_file
, TMP_GEN (block
),
4073 "tmp_gen", block
->index
);
4074 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
4075 "avail_out", block
->index
);
4078 /* Put the dominator children of BLOCK on the worklist of blocks
4079 to compute available sets for. */
4080 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4082 son
= next_dom_son (CDI_DOMINATORS
, son
))
4083 worklist
[sp
++] = son
;
4085 vn_context_bb
= NULL
;
4091 /* Initialize data structures used by PRE. */
4098 next_expression_id
= 1;
4099 expressions
.create (0);
4100 expressions
.safe_push (NULL
);
4101 value_expressions
.create (get_max_value_id () + 1);
4102 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4103 name_to_id
.create (0);
4105 inserted_exprs
= BITMAP_ALLOC (NULL
);
4107 connect_infinite_loops_to_exit ();
4108 memset (&pre_stats
, 0, sizeof (pre_stats
));
4110 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4112 calculate_dominance_info (CDI_DOMINATORS
);
4114 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4115 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4116 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4117 FOR_ALL_BB_FN (bb
, cfun
)
4119 EXP_GEN (bb
) = bitmap_set_new ();
4120 PHI_GEN (bb
) = bitmap_set_new ();
4121 TMP_GEN (bb
) = bitmap_set_new ();
4122 AVAIL_OUT (bb
) = bitmap_set_new ();
4127 /* Deallocate data structures used by PRE. */
4132 value_expressions
.release ();
4133 expressions
.release ();
4134 BITMAP_FREE (inserted_exprs
);
4135 bitmap_obstack_release (&grand_bitmap_obstack
);
4136 bitmap_set_pool
.release ();
4137 pre_expr_pool
.release ();
4138 delete phi_translate_table
;
4139 phi_translate_table
= NULL
;
4140 delete expression_to_id
;
4141 expression_to_id
= NULL
;
4142 name_to_id
.release ();
4144 free_aux_for_blocks ();
4149 const pass_data pass_data_pre
=
4151 GIMPLE_PASS
, /* type */
4153 OPTGROUP_NONE
, /* optinfo_flags */
4154 TV_TREE_PRE
, /* tv_id */
4155 ( PROP_cfg
| PROP_ssa
), /* properties_required */
4156 0, /* properties_provided */
4157 0, /* properties_destroyed */
4158 TODO_rebuild_alias
, /* todo_flags_start */
4159 0, /* todo_flags_finish */
4162 class pass_pre
: public gimple_opt_pass
4165 pass_pre (gcc::context
*ctxt
)
4166 : gimple_opt_pass (pass_data_pre
, ctxt
)
4169 /* opt_pass methods: */
4170 virtual bool gate (function
*)
4171 { return flag_tree_pre
!= 0 || flag_code_hoisting
!= 0; }
4172 virtual unsigned int execute (function
*);
4174 }; // class pass_pre
4176 /* Valueization hook for RPO VN when we are calling back to it
4177 at ANTIC compute time. */
4180 pre_valueize (tree name
)
4182 if (TREE_CODE (name
) == SSA_NAME
)
4184 tree tem
= VN_INFO (name
)->valnum
;
4185 if (tem
!= VN_TOP
&& tem
!= name
)
4187 if (TREE_CODE (tem
) != SSA_NAME
4188 || SSA_NAME_IS_DEFAULT_DEF (tem
))
4190 /* We create temporary SSA names for representatives that
4191 do not have a definition (yet) but are not default defs either
4192 assume they are fine to use. */
4193 basic_block def_bb
= gimple_bb (SSA_NAME_DEF_STMT (tem
));
4195 || dominated_by_p (CDI_DOMINATORS
, vn_context_bb
, def_bb
))
4197 /* ??? Now we could look for a leader. Ideally we'd somehow
4198 expose RPO VN leaders and get rid of AVAIL_OUT as well... */
4205 pass_pre::execute (function
*fun
)
4207 unsigned int todo
= 0;
4209 do_partial_partial
=
4210 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
4212 /* This has to happen before VN runs because
4213 loop_optimizer_init may create new phis, etc. */
4214 loop_optimizer_init (LOOPS_NORMAL
);
4215 split_edges_for_insertion ();
4217 calculate_dominance_info (CDI_DOMINATORS
);
4219 run_rpo_vn (VN_WALK
);
4223 vn_valueize
= pre_valueize
;
4225 /* Insert can get quite slow on an incredibly large number of basic
4226 blocks due to some quadratic behavior. Until this behavior is
4227 fixed, don't run it when he have an incredibly large number of
4228 bb's. If we aren't going to run insert, there is no point in
4229 computing ANTIC, either, even though it's plenty fast nor do
4230 we require AVAIL. */
4231 if (n_basic_blocks_for_fn (fun
) < 4000)
4238 /* Make sure to remove fake edges before committing our inserts.
4239 This makes sure we don't end up with extra critical edges that
4240 we would need to split. */
4241 remove_fake_exit_edges ();
4242 gsi_commit_edge_inserts ();
4244 /* Eliminate folds statements which might (should not...) end up
4245 not keeping virtual operands up-to-date. */
4246 gcc_assert (!need_ssa_update_p (fun
));
4248 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
4249 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
4250 statistics_counter_event (fun
, "HOIST inserted", pre_stats
.hoist_insert
);
4251 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
4253 todo
|= eliminate_with_rpo_vn (inserted_exprs
);
4257 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4258 to insert PHI nodes sometimes, and because value numbering of casts isn't
4259 perfect, we sometimes end up inserting dead code. This simple DCE-like
4260 pass removes any insertions we made that weren't actually used. */
4261 simple_dce_from_worklist (inserted_exprs
);
4266 loop_optimizer_finalize ();
4268 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
4269 case we can merge the block with the remaining predecessor of the block.
4271 - call merge_blocks after each tail merge iteration
4272 - call merge_blocks after all tail merge iterations
4273 - mark TODO_cleanup_cfg when necessary
4274 - share the cfg cleanup with fini_pre. */
4275 todo
|= tail_merge_optimize (todo
);
4279 /* Tail merging invalidates the virtual SSA web, together with
4280 cfg-cleanup opportunities exposed by PRE this will wreck the
4281 SSA updating machinery. So make sure to run update-ssa
4282 manually, before eventually scheduling cfg-cleanup as part of
4284 update_ssa (TODO_update_ssa_only_virtuals
);
4292 make_pass_pre (gcc::context
*ctxt
)
4294 return new pass_pre (ctxt
);