1 /* Full and partial redundancy elimination and code hoisting on SSA GIMPLE.
2 Copyright (C) 2001-2016 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
30 #include "alloc-pool.h"
31 #include "tree-pass.h"
34 #include "gimple-pretty-print.h"
35 #include "fold-const.h"
37 #include "gimple-fold.h"
40 #include "gimple-iterator.h"
42 #include "tree-ssa-loop.h"
43 #include "tree-into-ssa.h"
47 #include "tree-ssa-sccvn.h"
48 #include "tree-scalar-evolution.h"
52 #include "tree-ssa-propagate.h"
53 #include "ipa-utils.h"
54 #include "tree-cfgcleanup.h"
55 #include "langhooks.h"
58 /* Even though this file is called tree-ssa-pre.c, we actually
59 implement a bit more than just PRE here. All of them piggy-back
60 on GVN which is implemented in tree-ssa-sccvn.c.
62 1. Full Redundancy Elimination (FRE)
63 This is the elimination phase of GVN.
65 2. Partial Redundancy Elimination (PRE)
66 This is adds computation of AVAIL_OUT and ANTIC_IN and
67 doing expression insertion to form GVN-PRE.
70 This optimization uses the ANTIC_IN sets computed for PRE
71 to move expressions further up than PRE would do, to make
72 multiple computations of the same value fully redundant.
73 This pass is explained below (after the explanation of the
74 basic algorithm for PRE).
79 1. Avail sets can be shared by making an avail_find_leader that
80 walks up the dominator tree and looks in those avail sets.
81 This might affect code optimality, it's unclear right now.
82 Currently the AVAIL_OUT sets are the remaining quadraticness in
84 2. Strength reduction can be performed by anticipating expressions
85 we can repair later on.
86 3. We can do back-substitution or smarter value numbering to catch
87 commutative expressions split up over multiple statements.
90 /* For ease of terminology, "expression node" in the below refers to
91 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
92 represent the actual statement containing the expressions we care about,
93 and we cache the value number by putting it in the expression. */
95 /* Basic algorithm for Partial Redundancy Elimination:
97 First we walk the statements to generate the AVAIL sets, the
98 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
99 generation of values/expressions by a given block. We use them
100 when computing the ANTIC sets. The AVAIL sets consist of
101 SSA_NAME's that represent values, so we know what values are
102 available in what blocks. AVAIL is a forward dataflow problem. In
103 SSA, values are never killed, so we don't need a kill set, or a
104 fixpoint iteration, in order to calculate the AVAIL sets. In
105 traditional parlance, AVAIL sets tell us the downsafety of the
108 Next, we generate the ANTIC sets. These sets represent the
109 anticipatable expressions. ANTIC is a backwards dataflow
110 problem. An expression is anticipatable in a given block if it could
111 be generated in that block. This means that if we had to perform
112 an insertion in that block, of the value of that expression, we
113 could. Calculating the ANTIC sets requires phi translation of
114 expressions, because the flow goes backwards through phis. We must
115 iterate to a fixpoint of the ANTIC sets, because we have a kill
116 set. Even in SSA form, values are not live over the entire
117 function, only from their definition point onwards. So we have to
118 remove values from the ANTIC set once we go past the definition
119 point of the leaders that make them up.
120 compute_antic/compute_antic_aux performs this computation.
122 Third, we perform insertions to make partially redundant
123 expressions fully redundant.
125 An expression is partially redundant (excluding partial
128 1. It is AVAIL in some, but not all, of the predecessors of a
130 2. It is ANTIC in all the predecessors.
132 In order to make it fully redundant, we insert the expression into
133 the predecessors where it is not available, but is ANTIC.
135 When optimizing for size, we only eliminate the partial redundancy
136 if we need to insert in only one predecessor. This avoids almost
137 completely the code size increase that PRE usually causes.
139 For the partial anticipation case, we only perform insertion if it
140 is partially anticipated in some block, and fully available in all
143 do_pre_regular_insertion/do_pre_partial_partial_insertion
144 performs these steps, driven by insert/insert_aux.
146 Fourth, we eliminate fully redundant expressions.
147 This is a simple statement walk that replaces redundant
148 calculations with the now available values. */
150 /* Basic algorithm for Code Hoisting:
152 Code hoisting is: Moving value computations up in the control flow
153 graph to make multiple copies redundant. Typically this is a size
154 optimization, but there are cases where it also is helpful for speed.
156 A simple code hoisting algorithm is implemented that piggy-backs on
157 the PRE infrastructure. For code hoisting, we have to know ANTIC_OUT
158 which is effectively ANTIC_IN - AVAIL_OUT. The latter two have to be
159 computed for PRE, and we can use them to perform a limited version of
162 For the purpose of this implementation, a value is hoistable to a basic
163 block B if the following properties are met:
165 1. The value is in ANTIC_IN(B) -- the value will be computed on all
166 paths from B to function exit and it can be computed in B);
168 2. The value is not in AVAIL_OUT(B) -- there would be no need to
169 compute the value again and make it available twice;
171 3. All successors of B are dominated by B -- makes sure that inserting
172 a computation of the value in B will make the remaining
173 computations fully redundant;
175 4. At least one successor has the value in AVAIL_OUT -- to avoid
176 hoisting values up too far;
178 5. There are at least two successors of B -- hoisting in straight
179 line code is pointless.
181 The third condition is not strictly necessary, but it would complicate
182 the hoisting pass a lot. In fact, I don't know of any code hoisting
183 algorithm that does not have this requirement. Fortunately, experiments
184 have show that most candidate hoistable values are in regions that meet
185 this condition (e.g. diamond-shape regions).
187 The forth condition is necessary to avoid hoisting things up too far
188 away from the uses of the value. Nothing else limits the algorithm
189 from hoisting everything up as far as ANTIC_IN allows. Experiments
190 with SPEC and CSiBE have shown that hoisting up too far results in more
191 spilling, less benefits for code size, and worse benchmark scores.
192 Fortunately, in practice most of the interesting hoisting opportunities
193 are caught despite this limitation.
195 For hoistable values that meet all conditions, expressions are inserted
196 to make the calculation of the hoistable value fully redundant. We
197 perform code hoisting insertions after each round of PRE insertions,
198 because code hoisting never exposes new PRE opportunities, but PRE can
199 create new code hoisting opportunities.
201 The code hoisting algorithm is implemented in do_hoist_insert, driven
202 by insert/insert_aux. */
204 /* Representations of value numbers:
206 Value numbers are represented by a representative SSA_NAME. We
207 will create fake SSA_NAME's in situations where we need a
208 representative but do not have one (because it is a complex
209 expression). In order to facilitate storing the value numbers in
210 bitmaps, and keep the number of wasted SSA_NAME's down, we also
211 associate a value_id with each value number, and create full blown
212 ssa_name's only where we actually need them (IE in operands of
213 existing expressions).
215 Theoretically you could replace all the value_id's with
216 SSA_NAME_VERSION, but this would allocate a large number of
217 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
218 It would also require an additional indirection at each point we
221 /* Representation of expressions on value numbers:
223 Expressions consisting of value numbers are represented the same
224 way as our VN internally represents them, with an additional
225 "pre_expr" wrapping around them in order to facilitate storing all
226 of the expressions in the same sets. */
228 /* Representation of sets:
230 The dataflow sets do not need to be sorted in any particular order
231 for the majority of their lifetime, are simply represented as two
232 bitmaps, one that keeps track of values present in the set, and one
233 that keeps track of expressions present in the set.
235 When we need them in topological order, we produce it on demand by
236 transforming the bitmap into an array and sorting it into topo
239 /* Type of expression, used to know which member of the PRE_EXPR union
255 vn_reference_t reference
;
258 typedef struct pre_expr_d
: nofree_ptr_hash
<pre_expr_d
>
260 enum pre_expr_kind kind
;
264 /* hash_table support. */
265 static inline hashval_t
hash (const pre_expr_d
*);
266 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
269 #define PRE_EXPR_NAME(e) (e)->u.name
270 #define PRE_EXPR_NARY(e) (e)->u.nary
271 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
272 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
274 /* Compare E1 and E1 for equality. */
277 pre_expr_d::equal (const pre_expr_d
*e1
, const pre_expr_d
*e2
)
279 if (e1
->kind
!= e2
->kind
)
285 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
286 PRE_EXPR_CONSTANT (e2
));
288 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
290 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
292 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
293 PRE_EXPR_REFERENCE (e2
));
302 pre_expr_d::hash (const pre_expr_d
*e
)
307 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
309 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
311 return PRE_EXPR_NARY (e
)->hashcode
;
313 return PRE_EXPR_REFERENCE (e
)->hashcode
;
319 /* Next global expression id number. */
320 static unsigned int next_expression_id
;
322 /* Mapping from expression to id number we can use in bitmap sets. */
323 static vec
<pre_expr
> expressions
;
324 static hash_table
<pre_expr_d
> *expression_to_id
;
325 static vec
<unsigned> name_to_id
;
327 /* Allocate an expression id for EXPR. */
329 static inline unsigned int
330 alloc_expression_id (pre_expr expr
)
332 struct pre_expr_d
**slot
;
333 /* Make sure we won't overflow. */
334 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
335 expr
->id
= next_expression_id
++;
336 expressions
.safe_push (expr
);
337 if (expr
->kind
== NAME
)
339 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
340 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
341 re-allocations by using vec::reserve upfront. */
342 unsigned old_len
= name_to_id
.length ();
343 name_to_id
.reserve (num_ssa_names
- old_len
);
344 name_to_id
.quick_grow_cleared (num_ssa_names
);
345 gcc_assert (name_to_id
[version
] == 0);
346 name_to_id
[version
] = expr
->id
;
350 slot
= expression_to_id
->find_slot (expr
, INSERT
);
354 return next_expression_id
- 1;
357 /* Return the expression id for tree EXPR. */
359 static inline unsigned int
360 get_expression_id (const pre_expr expr
)
365 static inline unsigned int
366 lookup_expression_id (const pre_expr expr
)
368 struct pre_expr_d
**slot
;
370 if (expr
->kind
== NAME
)
372 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
373 if (name_to_id
.length () <= version
)
375 return name_to_id
[version
];
379 slot
= expression_to_id
->find_slot (expr
, NO_INSERT
);
382 return ((pre_expr
)*slot
)->id
;
386 /* Return the existing expression id for EXPR, or create one if one
387 does not exist yet. */
389 static inline unsigned int
390 get_or_alloc_expression_id (pre_expr expr
)
392 unsigned int id
= lookup_expression_id (expr
);
394 return alloc_expression_id (expr
);
395 return expr
->id
= id
;
398 /* Return the expression that has expression id ID */
400 static inline pre_expr
401 expression_for_id (unsigned int id
)
403 return expressions
[id
];
406 /* Free the expression id field in all of our expressions,
407 and then destroy the expressions array. */
410 clear_expression_ids (void)
412 expressions
.release ();
415 static object_allocator
<pre_expr_d
> pre_expr_pool ("pre_expr nodes");
417 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
420 get_or_alloc_expr_for_name (tree name
)
422 struct pre_expr_d expr
;
424 unsigned int result_id
;
428 PRE_EXPR_NAME (&expr
) = name
;
429 result_id
= lookup_expression_id (&expr
);
431 return expression_for_id (result_id
);
433 result
= pre_expr_pool
.allocate ();
435 PRE_EXPR_NAME (result
) = name
;
436 alloc_expression_id (result
);
440 /* An unordered bitmap set. One bitmap tracks values, the other,
442 typedef struct bitmap_set
444 bitmap_head expressions
;
448 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
449 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
451 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
452 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
454 /* Mapping from value id to expressions with that value_id. */
455 static vec
<bitmap
> value_expressions
;
457 /* Sets that we need to keep track of. */
458 typedef struct bb_bitmap_sets
460 /* The EXP_GEN set, which represents expressions/values generated in
462 bitmap_set_t exp_gen
;
464 /* The PHI_GEN set, which represents PHI results generated in a
466 bitmap_set_t phi_gen
;
468 /* The TMP_GEN set, which represents results/temporaries generated
469 in a basic block. IE the LHS of an expression. */
470 bitmap_set_t tmp_gen
;
472 /* The AVAIL_OUT set, which represents which values are available in
473 a given basic block. */
474 bitmap_set_t avail_out
;
476 /* The ANTIC_IN set, which represents which values are anticipatable
477 in a given basic block. */
478 bitmap_set_t antic_in
;
480 /* The PA_IN set, which represents which values are
481 partially anticipatable in a given basic block. */
484 /* The NEW_SETS set, which is used during insertion to augment the
485 AVAIL_OUT set of blocks with the new insertions performed during
486 the current iteration. */
487 bitmap_set_t new_sets
;
489 /* A cache for value_dies_in_block_x. */
492 /* The live virtual operand on successor edges. */
495 /* True if we have visited this block during ANTIC calculation. */
496 unsigned int visited
: 1;
498 /* True when the block contains a call that might not return. */
499 unsigned int contains_may_not_return_call
: 1;
502 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
503 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
504 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
505 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
506 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
507 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
508 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
509 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
510 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
511 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
512 #define BB_LIVE_VOP_ON_EXIT(BB) ((bb_value_sets_t) ((BB)->aux))->vop_on_exit
515 /* This structure is used to keep track of statistics on what
516 optimization PRE was able to perform. */
519 /* The number of RHS computations eliminated by PRE. */
522 /* The number of new expressions/temporaries generated by PRE. */
525 /* The number of inserts found due to partial anticipation */
528 /* The number of inserts made for code hoisting. */
531 /* The number of new PHI nodes added by PRE. */
535 static bool do_partial_partial
;
536 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
537 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
538 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
539 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
540 static void bitmap_set_and (bitmap_set_t
, bitmap_set_t
);
541 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
542 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
543 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
545 static bitmap_set_t
bitmap_set_new (void);
546 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
548 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
549 static unsigned int get_expr_value_id (pre_expr
);
551 /* We can add and remove elements and entries to and from sets
552 and hash tables, so we use alloc pools for them. */
554 static object_allocator
<bitmap_set
> bitmap_set_pool ("Bitmap sets");
555 static bitmap_obstack grand_bitmap_obstack
;
557 /* Set of blocks with statements that have had their EH properties changed. */
558 static bitmap need_eh_cleanup
;
560 /* Set of blocks with statements that have had their AB properties changed. */
561 static bitmap need_ab_cleanup
;
563 /* A three tuple {e, pred, v} used to cache phi translations in the
564 phi_translate_table. */
566 typedef struct expr_pred_trans_d
: free_ptr_hash
<expr_pred_trans_d
>
568 /* The expression. */
571 /* The predecessor block along which we translated the expression. */
574 /* The value that resulted from the translation. */
577 /* The hashcode for the expression, pred pair. This is cached for
581 /* hash_table support. */
582 static inline hashval_t
hash (const expr_pred_trans_d
*);
583 static inline int equal (const expr_pred_trans_d
*, const expr_pred_trans_d
*);
584 } *expr_pred_trans_t
;
585 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
588 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
594 expr_pred_trans_d::equal (const expr_pred_trans_d
*ve1
,
595 const expr_pred_trans_d
*ve2
)
597 basic_block b1
= ve1
->pred
;
598 basic_block b2
= ve2
->pred
;
600 /* If they are not translations for the same basic block, they can't
604 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
607 /* The phi_translate_table caches phi translations for a given
608 expression and predecessor. */
609 static hash_table
<expr_pred_trans_d
> *phi_translate_table
;
611 /* Add the tuple mapping from {expression E, basic block PRED} to
612 the phi translation table and return whether it pre-existed. */
615 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
617 expr_pred_trans_t
*slot
;
618 expr_pred_trans_d tem
;
619 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
624 slot
= phi_translate_table
->find_slot_with_hash (&tem
, hash
, INSERT
);
631 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
633 (*entry
)->pred
= pred
;
634 (*entry
)->hashcode
= hash
;
639 /* Add expression E to the expression set of value id V. */
642 add_to_value (unsigned int v
, pre_expr e
)
646 gcc_checking_assert (get_expr_value_id (e
) == v
);
648 if (v
>= value_expressions
.length ())
650 value_expressions
.safe_grow_cleared (v
+ 1);
653 set
= value_expressions
[v
];
656 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
657 value_expressions
[v
] = set
;
660 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
663 /* Create a new bitmap set and return it. */
666 bitmap_set_new (void)
668 bitmap_set_t ret
= bitmap_set_pool
.allocate ();
669 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
670 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
674 /* Return the value id for a PRE expression EXPR. */
677 get_expr_value_id (pre_expr expr
)
683 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
686 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
689 id
= PRE_EXPR_NARY (expr
)->value_id
;
692 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
697 /* ??? We cannot assert that expr has a value-id (it can be 0), because
698 we assign value-ids only to expressions that have a result
699 in set_hashtable_value_ids. */
703 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
706 sccvn_valnum_from_value_id (unsigned int val
)
710 bitmap exprset
= value_expressions
[val
];
711 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
713 pre_expr vexpr
= expression_for_id (i
);
714 if (vexpr
->kind
== NAME
)
715 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
716 else if (vexpr
->kind
== CONSTANT
)
717 return PRE_EXPR_CONSTANT (vexpr
);
722 /* Remove an expression EXPR from a bitmapped set. */
725 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
727 unsigned int val
= get_expr_value_id (expr
);
728 if (!value_id_constant_p (val
))
730 bitmap_clear_bit (&set
->values
, val
);
731 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
736 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
737 unsigned int val
, bool allow_constants
)
739 if (allow_constants
|| !value_id_constant_p (val
))
741 /* We specifically expect this and only this function to be able to
742 insert constants into a set. */
743 bitmap_set_bit (&set
->values
, val
);
744 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
748 /* Insert an expression EXPR into a bitmapped set. */
751 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
753 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
756 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
759 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
761 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
762 bitmap_copy (&dest
->values
, &orig
->values
);
766 /* Free memory used up by SET. */
768 bitmap_set_free (bitmap_set_t set
)
770 bitmap_clear (&set
->expressions
);
771 bitmap_clear (&set
->values
);
775 /* Generate an topological-ordered array of bitmap set SET. */
778 sorted_array_from_bitmap_set (bitmap_set_t set
)
781 bitmap_iterator bi
, bj
;
782 vec
<pre_expr
> result
;
784 /* Pre-allocate enough space for the array. */
785 result
.create (bitmap_count_bits (&set
->expressions
));
787 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
789 /* The number of expressions having a given value is usually
790 relatively small. Thus, rather than making a vector of all
791 the expressions and sorting it by value-id, we walk the values
792 and check in the reverse mapping that tells us what expressions
793 have a given value, to filter those in our set. As a result,
794 the expressions are inserted in value-id order, which means
797 If this is somehow a significant lose for some cases, we can
798 choose which set to walk based on the set size. */
799 bitmap exprset
= value_expressions
[i
];
800 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
802 if (bitmap_bit_p (&set
->expressions
, j
))
803 result
.quick_push (expression_for_id (j
));
810 /* Perform bitmapped set operation DEST &= ORIG. */
813 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
821 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
823 bitmap_and_into (&dest
->values
, &orig
->values
);
824 bitmap_copy (&temp
, &dest
->expressions
);
825 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
827 pre_expr expr
= expression_for_id (i
);
828 unsigned int value_id
= get_expr_value_id (expr
);
829 if (!bitmap_bit_p (&dest
->values
, value_id
))
830 bitmap_clear_bit (&dest
->expressions
, i
);
832 bitmap_clear (&temp
);
836 /* Subtract all values and expressions contained in ORIG from DEST. */
839 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
841 bitmap_set_t result
= bitmap_set_new ();
845 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
848 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
850 pre_expr expr
= expression_for_id (i
);
851 unsigned int value_id
= get_expr_value_id (expr
);
852 bitmap_set_bit (&result
->values
, value_id
);
858 /* Subtract all the values in bitmap set B from bitmap set A. */
861 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
867 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
869 bitmap_copy (&temp
, &a
->expressions
);
870 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
872 pre_expr expr
= expression_for_id (i
);
873 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
874 bitmap_remove_from_set (a
, expr
);
876 bitmap_clear (&temp
);
880 /* Return true if bitmapped set SET contains the value VALUE_ID. */
883 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
885 if (value_id_constant_p (value_id
))
888 if (!set
|| bitmap_empty_p (&set
->expressions
))
891 return bitmap_bit_p (&set
->values
, value_id
);
895 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
897 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
900 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
903 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
910 if (value_id_constant_p (lookfor
))
913 if (!bitmap_set_contains_value (set
, lookfor
))
916 /* The number of expressions having a given value is usually
917 significantly less than the total number of expressions in SET.
918 Thus, rather than check, for each expression in SET, whether it
919 has the value LOOKFOR, we walk the reverse mapping that tells us
920 what expressions have a given value, and see if any of those
921 expressions are in our set. For large testcases, this is about
922 5-10x faster than walking the bitmap. If this is somehow a
923 significant lose for some cases, we can choose which set to walk
924 based on the set size. */
925 exprset
= value_expressions
[lookfor
];
926 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
928 if (bitmap_clear_bit (&set
->expressions
, i
))
930 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
938 /* Return true if two bitmap sets are equal. */
941 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
943 return bitmap_equal_p (&a
->values
, &b
->values
);
946 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
947 and add it otherwise. */
950 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
952 unsigned int val
= get_expr_value_id (expr
);
954 if (bitmap_set_contains_value (set
, val
))
955 bitmap_set_replace_value (set
, val
, expr
);
957 bitmap_insert_into_set (set
, expr
);
960 /* Insert EXPR into SET if EXPR's value is not already present in
964 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
966 unsigned int val
= get_expr_value_id (expr
);
968 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
970 /* Constant values are always considered to be part of the set. */
971 if (value_id_constant_p (val
))
974 /* If the value membership changed, add the expression. */
975 if (bitmap_set_bit (&set
->values
, val
))
976 bitmap_set_bit (&set
->expressions
, expr
->id
);
979 /* Print out EXPR to outfile. */
982 print_pre_expr (FILE *outfile
, const pre_expr expr
)
987 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
990 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
995 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
996 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
997 for (i
= 0; i
< nary
->length
; i
++)
999 print_generic_expr (outfile
, nary
->op
[i
], 0);
1000 if (i
!= (unsigned) nary
->length
- 1)
1001 fprintf (outfile
, ",");
1003 fprintf (outfile
, "}");
1009 vn_reference_op_t vro
;
1011 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1012 fprintf (outfile
, "{");
1014 ref
->operands
.iterate (i
, &vro
);
1017 bool closebrace
= false;
1018 if (vro
->opcode
!= SSA_NAME
1019 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
1021 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
1024 fprintf (outfile
, "<");
1030 print_generic_expr (outfile
, vro
->op0
, 0);
1033 fprintf (outfile
, ",");
1034 print_generic_expr (outfile
, vro
->op1
, 0);
1038 fprintf (outfile
, ",");
1039 print_generic_expr (outfile
, vro
->op2
, 0);
1043 fprintf (outfile
, ">");
1044 if (i
!= ref
->operands
.length () - 1)
1045 fprintf (outfile
, ",");
1047 fprintf (outfile
, "}");
1050 fprintf (outfile
, "@");
1051 print_generic_expr (outfile
, ref
->vuse
, 0);
1057 void debug_pre_expr (pre_expr
);
1059 /* Like print_pre_expr but always prints to stderr. */
1061 debug_pre_expr (pre_expr e
)
1063 print_pre_expr (stderr
, e
);
1064 fprintf (stderr
, "\n");
1067 /* Print out SET to OUTFILE. */
1070 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
1071 const char *setname
, int blockindex
)
1073 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1080 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1082 const pre_expr expr
= expression_for_id (i
);
1085 fprintf (outfile
, ", ");
1087 print_pre_expr (outfile
, expr
);
1089 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1092 fprintf (outfile
, " }\n");
1095 void debug_bitmap_set (bitmap_set_t
);
1098 debug_bitmap_set (bitmap_set_t set
)
1100 print_bitmap_set (stderr
, set
, "debug", 0);
1103 void debug_bitmap_sets_for (basic_block
);
1106 debug_bitmap_sets_for (basic_block bb
)
1108 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1109 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1110 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1111 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1112 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1113 if (do_partial_partial
)
1114 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1115 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1118 /* Print out the expressions that have VAL to OUTFILE. */
1121 print_value_expressions (FILE *outfile
, unsigned int val
)
1123 bitmap set
= value_expressions
[val
];
1128 sprintf (s
, "%04d", val
);
1129 x
.expressions
= *set
;
1130 print_bitmap_set (outfile
, &x
, s
, 0);
1136 debug_value_expressions (unsigned int val
)
1138 print_value_expressions (stderr
, val
);
1141 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1145 get_or_alloc_expr_for_constant (tree constant
)
1147 unsigned int result_id
;
1148 unsigned int value_id
;
1149 struct pre_expr_d expr
;
1152 expr
.kind
= CONSTANT
;
1153 PRE_EXPR_CONSTANT (&expr
) = constant
;
1154 result_id
= lookup_expression_id (&expr
);
1156 return expression_for_id (result_id
);
1158 newexpr
= pre_expr_pool
.allocate ();
1159 newexpr
->kind
= CONSTANT
;
1160 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1161 alloc_expression_id (newexpr
);
1162 value_id
= get_or_alloc_constant_value_id (constant
);
1163 add_to_value (value_id
, newexpr
);
1167 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1168 Currently only supports constants and SSA_NAMES. */
1170 get_or_alloc_expr_for (tree t
)
1172 if (TREE_CODE (t
) == SSA_NAME
)
1173 return get_or_alloc_expr_for_name (t
);
1174 else if (is_gimple_min_invariant (t
))
1175 return get_or_alloc_expr_for_constant (t
);
1178 /* More complex expressions can result from SCCVN expression
1179 simplification that inserts values for them. As they all
1180 do not have VOPs the get handled by the nary ops struct. */
1181 vn_nary_op_t result
;
1182 unsigned int result_id
;
1183 vn_nary_op_lookup (t
, &result
);
1186 pre_expr e
= pre_expr_pool
.allocate ();
1188 PRE_EXPR_NARY (e
) = result
;
1189 result_id
= lookup_expression_id (e
);
1192 pre_expr_pool
.remove (e
);
1193 e
= expression_for_id (result_id
);
1196 alloc_expression_id (e
);
1203 /* Return the folded version of T if T, when folded, is a gimple
1204 min_invariant. Otherwise, return T. */
1207 fully_constant_expression (pre_expr e
)
1215 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1216 tree res
= vn_nary_simplify (nary
);
1219 if (is_gimple_min_invariant (res
))
1220 return get_or_alloc_expr_for_constant (res
);
1221 /* We might have simplified the expression to a
1222 SSA_NAME for example from x_1 * 1. But we cannot
1223 insert a PHI for x_1 unconditionally as x_1 might
1224 not be available readily. */
1229 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1231 if ((folded
= fully_constant_vn_reference_p (ref
)))
1232 return get_or_alloc_expr_for_constant (folded
);
1241 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1242 it has the value it would have in BLOCK. Set *SAME_VALID to true
1243 in case the new vuse doesn't change the value id of the OPERANDS. */
1246 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1247 alias_set_type set
, tree type
, tree vuse
,
1248 basic_block phiblock
,
1249 basic_block block
, bool *same_valid
)
1251 gimple
*phi
= SSA_NAME_DEF_STMT (vuse
);
1258 if (gimple_bb (phi
) != phiblock
)
1261 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1263 /* Use the alias-oracle to find either the PHI node in this block,
1264 the first VUSE used in this block that is equivalent to vuse or
1265 the first VUSE which definition in this block kills the value. */
1266 if (gimple_code (phi
) == GIMPLE_PHI
)
1267 e
= find_edge (block
, phiblock
);
1268 else if (use_oracle
)
1269 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1271 vuse
= gimple_vuse (phi
);
1272 phi
= SSA_NAME_DEF_STMT (vuse
);
1273 if (gimple_bb (phi
) != phiblock
)
1275 if (gimple_code (phi
) == GIMPLE_PHI
)
1277 e
= find_edge (block
, phiblock
);
1288 bitmap visited
= NULL
;
1290 /* Try to find a vuse that dominates this phi node by skipping
1291 non-clobbering statements. */
1292 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false,
1295 BITMAP_FREE (visited
);
1301 /* If we didn't find any, the value ID can't stay the same,
1302 but return the translated vuse. */
1303 *same_valid
= false;
1304 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1306 /* ??? We would like to return vuse here as this is the canonical
1307 upmost vdef that this reference is associated with. But during
1308 insertion of the references into the hash tables we only ever
1309 directly insert with their direct gimple_vuse, hence returning
1310 something else would make us not find the other expression. */
1311 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1317 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1318 SET2. This is used to avoid making a set consisting of the union
1319 of PA_IN and ANTIC_IN during insert. */
1321 static inline pre_expr
1322 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1326 result
= bitmap_find_leader (set1
, val
);
1327 if (!result
&& set2
)
1328 result
= bitmap_find_leader (set2
, val
);
1332 /* Get the tree type for our PRE expression e. */
1335 get_expr_type (const pre_expr e
)
1340 return TREE_TYPE (PRE_EXPR_NAME (e
));
1342 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1344 return PRE_EXPR_REFERENCE (e
)->type
;
1346 return PRE_EXPR_NARY (e
)->type
;
1351 /* Get a representative SSA_NAME for a given expression.
1352 Since all of our sub-expressions are treated as values, we require
1353 them to be SSA_NAME's for simplicity.
1354 Prior versions of GVNPRE used to use "value handles" here, so that
1355 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1356 either case, the operands are really values (IE we do not expect
1357 them to be usable without finding leaders). */
1360 get_representative_for (const pre_expr e
)
1363 unsigned int value_id
= get_expr_value_id (e
);
1368 return VN_INFO (PRE_EXPR_NAME (e
))->valnum
;
1370 return PRE_EXPR_CONSTANT (e
);
1374 /* Go through all of the expressions representing this value
1375 and pick out an SSA_NAME. */
1378 bitmap exprs
= value_expressions
[value_id
];
1379 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1381 pre_expr rep
= expression_for_id (i
);
1382 if (rep
->kind
== NAME
)
1383 return VN_INFO (PRE_EXPR_NAME (rep
))->valnum
;
1384 else if (rep
->kind
== CONSTANT
)
1385 return PRE_EXPR_CONSTANT (rep
);
1391 /* If we reached here we couldn't find an SSA_NAME. This can
1392 happen when we've discovered a value that has never appeared in
1393 the program as set to an SSA_NAME, as the result of phi translation.
1395 ??? We should be able to re-use this when we insert the statement
1397 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1398 VN_INFO_GET (name
)->value_id
= value_id
;
1399 VN_INFO (name
)->valnum
= name
;
1400 /* ??? For now mark this SSA name for release by SCCVN. */
1401 VN_INFO (name
)->needs_insertion
= true;
1402 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1403 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1405 fprintf (dump_file
, "Created SSA_NAME representative ");
1406 print_generic_expr (dump_file
, name
, 0);
1407 fprintf (dump_file
, " for expression:");
1408 print_pre_expr (dump_file
, e
);
1409 fprintf (dump_file
, " (%04d)\n", value_id
);
1418 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1419 basic_block pred
, basic_block phiblock
);
1421 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1422 the phis in PRED. Return NULL if we can't find a leader for each part
1423 of the translated expression. */
1426 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1427 basic_block pred
, basic_block phiblock
)
1434 bool changed
= false;
1435 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1436 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1437 sizeof_vn_nary_op (nary
->length
));
1438 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1440 for (i
= 0; i
< newnary
->length
; i
++)
1442 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1446 pre_expr leader
, result
;
1447 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1448 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1449 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1450 if (result
&& result
!= leader
)
1451 newnary
->op
[i
] = get_representative_for (result
);
1455 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1461 unsigned int new_val_id
;
1463 PRE_EXPR_NARY (expr
) = newnary
;
1464 constant
= fully_constant_expression (expr
);
1465 PRE_EXPR_NARY (expr
) = nary
;
1466 if (constant
!= expr
)
1469 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1474 if (result
&& is_gimple_min_invariant (result
))
1475 return get_or_alloc_expr_for_constant (result
);
1477 expr
= pre_expr_pool
.allocate ();
1482 PRE_EXPR_NARY (expr
) = nary
;
1483 new_val_id
= nary
->value_id
;
1484 get_or_alloc_expression_id (expr
);
1488 new_val_id
= get_next_value_id ();
1489 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1490 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1494 result
, new_val_id
);
1495 PRE_EXPR_NARY (expr
) = nary
;
1496 get_or_alloc_expression_id (expr
);
1498 add_to_value (new_val_id
, expr
);
1506 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1507 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1508 tree vuse
= ref
->vuse
;
1509 tree newvuse
= vuse
;
1510 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1511 bool changed
= false, same_valid
= true;
1513 vn_reference_op_t operand
;
1514 vn_reference_t newref
;
1516 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1521 tree type
= operand
->type
;
1522 vn_reference_op_s newop
= *operand
;
1523 op
[0] = operand
->op0
;
1524 op
[1] = operand
->op1
;
1525 op
[2] = operand
->op2
;
1526 for (n
= 0; n
< 3; ++n
)
1528 unsigned int op_val_id
;
1531 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1533 /* We can't possibly insert these. */
1535 && !is_gimple_min_invariant (op
[n
]))
1539 op_val_id
= VN_INFO (op
[n
])->value_id
;
1540 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1541 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1542 if (opresult
&& opresult
!= leader
)
1544 tree name
= get_representative_for (opresult
);
1545 changed
|= name
!= op
[n
];
1553 newoperands
.release ();
1558 if (!newoperands
.exists ())
1559 newoperands
= operands
.copy ();
1560 /* We may have changed from an SSA_NAME to a constant */
1561 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1562 newop
.opcode
= TREE_CODE (op
[0]);
1567 newoperands
[i
] = newop
;
1569 gcc_checking_assert (i
== operands
.length ());
1573 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1574 ? newoperands
: operands
,
1575 ref
->set
, ref
->type
,
1576 vuse
, phiblock
, pred
,
1578 if (newvuse
== NULL_TREE
)
1580 newoperands
.release ();
1585 if (changed
|| newvuse
!= vuse
)
1587 unsigned int new_val_id
;
1590 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1592 newoperands
.exists ()
1593 ? newoperands
: operands
,
1596 newoperands
.release ();
1598 /* We can always insert constants, so if we have a partial
1599 redundant constant load of another type try to translate it
1600 to a constant of appropriate type. */
1601 if (result
&& is_gimple_min_invariant (result
))
1604 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1606 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1607 if (tem
&& !is_gimple_min_invariant (tem
))
1611 return get_or_alloc_expr_for_constant (tem
);
1614 /* If we'd have to convert things we would need to validate
1615 if we can insert the translated expression. So fail
1616 here for now - we cannot insert an alias with a different
1617 type in the VN tables either, as that would assert. */
1619 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1621 else if (!result
&& newref
1622 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1624 newoperands
.release ();
1628 expr
= pre_expr_pool
.allocate ();
1629 expr
->kind
= REFERENCE
;
1634 PRE_EXPR_REFERENCE (expr
) = newref
;
1635 constant
= fully_constant_expression (expr
);
1636 if (constant
!= expr
)
1639 new_val_id
= newref
->value_id
;
1640 get_or_alloc_expression_id (expr
);
1644 if (changed
|| !same_valid
)
1646 new_val_id
= get_next_value_id ();
1647 value_expressions
.safe_grow_cleared
1648 (get_max_value_id () + 1);
1651 new_val_id
= ref
->value_id
;
1652 if (!newoperands
.exists ())
1653 newoperands
= operands
.copy ();
1654 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1657 result
, new_val_id
);
1658 newoperands
= vNULL
;
1659 PRE_EXPR_REFERENCE (expr
) = newref
;
1660 constant
= fully_constant_expression (expr
);
1661 if (constant
!= expr
)
1663 get_or_alloc_expression_id (expr
);
1665 add_to_value (new_val_id
, expr
);
1667 newoperands
.release ();
1674 tree name
= PRE_EXPR_NAME (expr
);
1675 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1676 /* If the SSA name is defined by a PHI node in this block,
1678 if (gimple_code (def_stmt
) == GIMPLE_PHI
1679 && gimple_bb (def_stmt
) == phiblock
)
1681 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1682 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1684 /* Handle constant. */
1685 if (is_gimple_min_invariant (def
))
1686 return get_or_alloc_expr_for_constant (def
);
1688 return get_or_alloc_expr_for_name (def
);
1690 /* Otherwise return it unchanged - it will get removed if its
1691 value is not available in PREDs AVAIL_OUT set of expressions
1692 by the subtraction of TMP_GEN. */
1701 /* Wrapper around phi_translate_1 providing caching functionality. */
1704 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1705 basic_block pred
, basic_block phiblock
)
1707 expr_pred_trans_t slot
= NULL
;
1713 /* Constants contain no values that need translation. */
1714 if (expr
->kind
== CONSTANT
)
1717 if (value_id_constant_p (get_expr_value_id (expr
)))
1720 /* Don't add translations of NAMEs as those are cheap to translate. */
1721 if (expr
->kind
!= NAME
)
1723 if (phi_trans_add (&slot
, expr
, pred
))
1725 /* Store NULL for the value we want to return in the case of
1731 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1738 /* Remove failed translations again, they cause insert
1739 iteration to not pick up new opportunities reliably. */
1740 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1747 /* For each expression in SET, translate the values through phi nodes
1748 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1749 expressions in DEST. */
1752 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1753 basic_block phiblock
)
1755 vec
<pre_expr
> exprs
;
1759 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1761 bitmap_set_copy (dest
, set
);
1765 exprs
= sorted_array_from_bitmap_set (set
);
1766 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1768 pre_expr translated
;
1769 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1773 /* We might end up with multiple expressions from SET being
1774 translated to the same value. In this case we do not want
1775 to retain the NARY or REFERENCE expression but prefer a NAME
1776 which would be the leader. */
1777 if (translated
->kind
== NAME
)
1778 bitmap_value_replace_in_set (dest
, translated
);
1780 bitmap_value_insert_into_set (dest
, translated
);
1785 /* Find the leader for a value (i.e., the name representing that
1786 value) in a given set, and return it. Return NULL if no leader
1790 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1792 if (value_id_constant_p (val
))
1796 bitmap exprset
= value_expressions
[val
];
1798 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1800 pre_expr expr
= expression_for_id (i
);
1801 if (expr
->kind
== CONSTANT
)
1805 if (bitmap_set_contains_value (set
, val
))
1807 /* Rather than walk the entire bitmap of expressions, and see
1808 whether any of them has the value we are looking for, we look
1809 at the reverse mapping, which tells us the set of expressions
1810 that have a given value (IE value->expressions with that
1811 value) and see if any of those expressions are in our set.
1812 The number of expressions per value is usually significantly
1813 less than the number of expressions in the set. In fact, for
1814 large testcases, doing it this way is roughly 5-10x faster
1815 than walking the bitmap.
1816 If this is somehow a significant lose for some cases, we can
1817 choose which set to walk based on which set is smaller. */
1820 bitmap exprset
= value_expressions
[val
];
1822 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1823 return expression_for_id (i
);
1828 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1829 BLOCK by seeing if it is not killed in the block. Note that we are
1830 only determining whether there is a store that kills it. Because
1831 of the order in which clean iterates over values, we are guaranteed
1832 that altered operands will have caused us to be eliminated from the
1833 ANTIC_IN set already. */
1836 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1838 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1839 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1841 gimple_stmt_iterator gsi
;
1842 unsigned id
= get_expression_id (expr
);
1849 /* Lookup a previously calculated result. */
1850 if (EXPR_DIES (block
)
1851 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1852 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1854 /* A memory expression {e, VUSE} dies in the block if there is a
1855 statement that may clobber e. If, starting statement walk from the
1856 top of the basic block, a statement uses VUSE there can be no kill
1857 inbetween that use and the original statement that loaded {e, VUSE},
1858 so we can stop walking. */
1859 ref
.base
= NULL_TREE
;
1860 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1862 tree def_vuse
, def_vdef
;
1863 def
= gsi_stmt (gsi
);
1864 def_vuse
= gimple_vuse (def
);
1865 def_vdef
= gimple_vdef (def
);
1867 /* Not a memory statement. */
1871 /* Not a may-def. */
1874 /* A load with the same VUSE, we're done. */
1875 if (def_vuse
== vuse
)
1881 /* Init ref only if we really need it. */
1882 if (ref
.base
== NULL_TREE
1883 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1889 /* If the statement may clobber expr, it dies. */
1890 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1897 /* Remember the result. */
1898 if (!EXPR_DIES (block
))
1899 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1900 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1902 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1908 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1909 contains its value-id. */
1912 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1914 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1916 unsigned int value_id
= VN_INFO (op
)->value_id
;
1917 if (!(bitmap_set_contains_value (set1
, value_id
)
1918 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1924 /* Determine if the expression EXPR is valid in SET1 U SET2.
1925 ONLY SET2 CAN BE NULL.
1926 This means that we have a leader for each part of the expression
1927 (if it consists of values), or the expression is an SSA_NAME.
1928 For loads/calls, we also see if the vuse is killed in this block. */
1931 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1936 /* By construction all NAMEs are available. Non-available
1937 NAMEs are removed by subtracting TMP_GEN from the sets. */
1942 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1943 for (i
= 0; i
< nary
->length
; i
++)
1944 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1951 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1952 vn_reference_op_t vro
;
1955 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1957 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1958 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1959 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1969 /* Clean the set of expressions that are no longer valid in SET1 or
1970 SET2. This means expressions that are made up of values we have no
1971 leaders for in SET1 or SET2. This version is used for partial
1972 anticipation, which means it is not valid in either ANTIC_IN or
1976 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
)
1978 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
1982 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1984 if (!valid_in_sets (set1
, set2
, expr
))
1985 bitmap_remove_from_set (set1
, expr
);
1990 /* Clean the set of expressions that are no longer valid in SET. This
1991 means expressions that are made up of values we have no leaders for
1995 clean (bitmap_set_t set
)
1997 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2001 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2003 if (!valid_in_sets (set
, NULL
, expr
))
2004 bitmap_remove_from_set (set
, expr
);
2009 /* Clean the set of expressions that are no longer valid in SET because
2010 they are clobbered in BLOCK or because they trap and may not be executed. */
2013 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2018 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2020 pre_expr expr
= expression_for_id (i
);
2021 if (expr
->kind
== REFERENCE
)
2023 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2026 gimple
*def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2027 if (!gimple_nop_p (def_stmt
)
2028 && ((gimple_bb (def_stmt
) != block
2029 && !dominated_by_p (CDI_DOMINATORS
,
2030 block
, gimple_bb (def_stmt
)))
2031 || (gimple_bb (def_stmt
) == block
2032 && value_dies_in_block_x (expr
, block
))))
2033 bitmap_remove_from_set (set
, expr
);
2036 else if (expr
->kind
== NARY
)
2038 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2039 /* If the NARY may trap make sure the block does not contain
2040 a possible exit point.
2041 ??? This is overly conservative if we translate AVAIL_OUT
2042 as the available expression might be after the exit point. */
2043 if (BB_MAY_NOTRETURN (block
)
2044 && vn_nary_may_trap (nary
))
2045 bitmap_remove_from_set (set
, expr
);
2050 static sbitmap has_abnormal_preds
;
2052 /* Compute the ANTIC set for BLOCK.
2054 If succs(BLOCK) > 1 then
2055 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2056 else if succs(BLOCK) == 1 then
2057 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2059 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2063 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2065 bool changed
= false;
2066 bitmap_set_t S
, old
, ANTIC_OUT
;
2071 bool was_visited
= BB_VISITED (block
);
2073 old
= ANTIC_OUT
= S
= NULL
;
2074 BB_VISITED (block
) = 1;
2076 /* If any edges from predecessors are abnormal, antic_in is empty,
2078 if (block_has_abnormal_pred_edge
)
2079 goto maybe_dump_sets
;
2081 old
= ANTIC_IN (block
);
2082 ANTIC_OUT
= bitmap_set_new ();
2084 /* If the block has no successors, ANTIC_OUT is empty. */
2085 if (EDGE_COUNT (block
->succs
) == 0)
2087 /* If we have one successor, we could have some phi nodes to
2088 translate through. */
2089 else if (single_succ_p (block
))
2091 basic_block succ_bb
= single_succ (block
);
2092 gcc_assert (BB_VISITED (succ_bb
));
2093 phi_translate_set (ANTIC_OUT
, ANTIC_IN (succ_bb
), block
, succ_bb
);
2095 /* If we have multiple successors, we take the intersection of all of
2096 them. Note that in the case of loop exit phi nodes, we may have
2097 phis to translate through. */
2101 basic_block bprime
, first
= NULL
;
2103 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2104 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2107 && BB_VISITED (e
->dest
))
2109 else if (BB_VISITED (e
->dest
))
2110 worklist
.quick_push (e
->dest
);
2113 /* Unvisited successors get their ANTIC_IN replaced by the
2114 maximal set to arrive at a maximum ANTIC_IN solution.
2115 We can ignore them in the intersection operation and thus
2116 need not explicitely represent that maximum solution. */
2117 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2118 fprintf (dump_file
, "ANTIC_IN is MAX on %d->%d\n",
2119 e
->src
->index
, e
->dest
->index
);
2123 /* Of multiple successors we have to have visited one already
2124 which is guaranteed by iteration order. */
2125 gcc_assert (first
!= NULL
);
2127 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2129 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2131 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2133 bitmap_set_t tmp
= bitmap_set_new ();
2134 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2135 bitmap_set_and (ANTIC_OUT
, tmp
);
2136 bitmap_set_free (tmp
);
2139 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2143 /* Prune expressions that are clobbered in block and thus become
2144 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2145 prune_clobbered_mems (ANTIC_OUT
, block
);
2147 /* Generate ANTIC_OUT - TMP_GEN. */
2148 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2150 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2151 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2154 /* Then union in the ANTIC_OUT - TMP_GEN values,
2155 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2156 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2157 bitmap_value_insert_into_set (ANTIC_IN (block
),
2158 expression_for_id (bii
));
2160 clean (ANTIC_IN (block
));
2162 if (!was_visited
|| !bitmap_set_equal (old
, ANTIC_IN (block
)))
2166 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2169 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2172 fprintf (dump_file
, "[changed] ");
2173 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2177 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2180 bitmap_set_free (old
);
2182 bitmap_set_free (S
);
2184 bitmap_set_free (ANTIC_OUT
);
2188 /* Compute PARTIAL_ANTIC for BLOCK.
2190 If succs(BLOCK) > 1 then
2191 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2192 in ANTIC_OUT for all succ(BLOCK)
2193 else if succs(BLOCK) == 1 then
2194 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2196 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2201 compute_partial_antic_aux (basic_block block
,
2202 bool block_has_abnormal_pred_edge
)
2204 bitmap_set_t old_PA_IN
;
2205 bitmap_set_t PA_OUT
;
2208 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2210 old_PA_IN
= PA_OUT
= NULL
;
2212 /* If any edges from predecessors are abnormal, antic_in is empty,
2214 if (block_has_abnormal_pred_edge
)
2215 goto maybe_dump_sets
;
2217 /* If there are too many partially anticipatable values in the
2218 block, phi_translate_set can take an exponential time: stop
2219 before the translation starts. */
2221 && single_succ_p (block
)
2222 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2223 goto maybe_dump_sets
;
2225 old_PA_IN
= PA_IN (block
);
2226 PA_OUT
= bitmap_set_new ();
2228 /* If the block has no successors, ANTIC_OUT is empty. */
2229 if (EDGE_COUNT (block
->succs
) == 0)
2231 /* If we have one successor, we could have some phi nodes to
2232 translate through. Note that we can't phi translate across DFS
2233 back edges in partial antic, because it uses a union operation on
2234 the successors. For recurrences like IV's, we will end up
2235 generating a new value in the set on each go around (i + 3 (VH.1)
2236 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2237 else if (single_succ_p (block
))
2239 basic_block succ
= single_succ (block
);
2240 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2241 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2243 /* If we have multiple successors, we take the union of all of
2250 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2251 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2253 if (e
->flags
& EDGE_DFS_BACK
)
2255 worklist
.quick_push (e
->dest
);
2257 if (worklist
.length () > 0)
2259 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2264 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2265 bitmap_value_insert_into_set (PA_OUT
,
2266 expression_for_id (i
));
2267 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2269 bitmap_set_t pa_in
= bitmap_set_new ();
2270 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2271 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2272 bitmap_value_insert_into_set (PA_OUT
,
2273 expression_for_id (i
));
2274 bitmap_set_free (pa_in
);
2277 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2278 bitmap_value_insert_into_set (PA_OUT
,
2279 expression_for_id (i
));
2284 /* Prune expressions that are clobbered in block and thus become
2285 invalid if translated from PA_OUT to PA_IN. */
2286 prune_clobbered_mems (PA_OUT
, block
);
2288 /* PA_IN starts with PA_OUT - TMP_GEN.
2289 Then we subtract things from ANTIC_IN. */
2290 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2292 /* For partial antic, we want to put back in the phi results, since
2293 we will properly avoid making them partially antic over backedges. */
2294 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2295 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2297 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2298 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2300 dependent_clean (PA_IN (block
), ANTIC_IN (block
));
2303 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2306 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2308 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2311 bitmap_set_free (old_PA_IN
);
2313 bitmap_set_free (PA_OUT
);
2316 /* Compute ANTIC and partial ANTIC sets. */
2319 compute_antic (void)
2321 bool changed
= true;
2322 int num_iterations
= 0;
2328 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2329 We pre-build the map of blocks with incoming abnormal edges here. */
2330 has_abnormal_preds
= sbitmap_alloc (last_basic_block_for_fn (cfun
));
2331 bitmap_clear (has_abnormal_preds
);
2333 FOR_ALL_BB_FN (block
, cfun
)
2335 BB_VISITED (block
) = 0;
2337 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2338 if (e
->flags
& EDGE_ABNORMAL
)
2340 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2342 /* We also anticipate nothing. */
2343 BB_VISITED (block
) = 1;
2347 /* While we are here, give empty ANTIC_IN sets to each block. */
2348 ANTIC_IN (block
) = bitmap_set_new ();
2349 if (do_partial_partial
)
2350 PA_IN (block
) = bitmap_set_new ();
2353 /* At the exit block we anticipate nothing. */
2354 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2356 /* For ANTIC computation we need a postorder that also guarantees that
2357 a block with a single successor is visited after its successor.
2358 RPO on the inverted CFG has this property. */
2359 int *postorder
= XNEWVEC (int, n_basic_blocks_for_fn (cfun
));
2360 int postorder_num
= inverted_post_order_compute (postorder
);
2362 sbitmap worklist
= sbitmap_alloc (last_basic_block_for_fn (cfun
) + 1);
2363 bitmap_ones (worklist
);
2366 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2367 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2368 /* ??? We need to clear our PHI translation cache here as the
2369 ANTIC sets shrink and we restrict valid translations to
2370 those having operands with leaders in ANTIC. Same below
2371 for PA ANTIC computation. */
2374 for (i
= postorder_num
- 1; i
>= 0; i
--)
2376 if (bitmap_bit_p (worklist
, postorder
[i
]))
2378 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2379 bitmap_clear_bit (worklist
, block
->index
);
2380 if (compute_antic_aux (block
,
2381 bitmap_bit_p (has_abnormal_preds
,
2384 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2385 bitmap_set_bit (worklist
, e
->src
->index
);
2390 /* Theoretically possible, but *highly* unlikely. */
2391 gcc_checking_assert (num_iterations
< 500);
2394 statistics_histogram_event (cfun
, "compute_antic iterations",
2397 if (do_partial_partial
)
2399 /* For partial antic we ignore backedges and thus we do not need
2400 to perform any iteration when we process blocks in postorder. */
2401 postorder_num
= pre_and_rev_post_order_compute (NULL
, postorder
, false);
2402 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2404 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2405 compute_partial_antic_aux (block
,
2406 bitmap_bit_p (has_abnormal_preds
,
2411 sbitmap_free (has_abnormal_preds
);
2412 sbitmap_free (worklist
);
2417 /* Inserted expressions are placed onto this worklist, which is used
2418 for performing quick dead code elimination of insertions we made
2419 that didn't turn out to be necessary. */
2420 static bitmap inserted_exprs
;
2422 /* The actual worker for create_component_ref_by_pieces. */
2425 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2426 unsigned int *operand
, gimple_seq
*stmts
)
2428 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2431 switch (currop
->opcode
)
2438 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2442 tree offset
= currop
->op0
;
2443 if (TREE_CODE (baseop
) == ADDR_EXPR
2444 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2448 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2451 offset
= int_const_binop (PLUS_EXPR
, offset
,
2452 build_int_cst (TREE_TYPE (offset
),
2454 baseop
= build_fold_addr_expr (base
);
2456 genop
= build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2457 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2458 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2459 REF_REVERSE_STORAGE_ORDER (genop
) = currop
->reverse
;
2463 case TARGET_MEM_REF
:
2465 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2466 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2467 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2473 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2479 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2483 genop
= build5 (TARGET_MEM_REF
, currop
->type
,
2484 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2486 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2487 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2494 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2500 case VIEW_CONVERT_EXPR
:
2502 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2506 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2509 case WITH_SIZE_EXPR
:
2511 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2515 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2518 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2523 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2527 tree op1
= currop
->op0
;
2528 tree op2
= currop
->op1
;
2529 tree t
= build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2530 REF_REVERSE_STORAGE_ORDER (t
) = currop
->reverse
;
2534 /* For array ref vn_reference_op's, operand 1 of the array ref
2535 is op0 of the reference op and operand 3 of the array ref is
2537 case ARRAY_RANGE_REF
:
2541 tree genop1
= currop
->op0
;
2542 tree genop2
= currop
->op1
;
2543 tree genop3
= currop
->op2
;
2544 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2548 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2553 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2554 /* Drop zero minimum index if redundant. */
2555 if (integer_zerop (genop2
)
2557 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2561 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2568 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2569 /* We can't always put a size in units of the element alignment
2570 here as the element alignment may be not visible. See
2571 PR43783. Simply drop the element size for constant
2573 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2577 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2578 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2579 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2584 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2591 tree genop2
= currop
->op1
;
2592 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2595 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2599 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2603 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2608 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2629 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2630 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2631 trying to rename aggregates into ssa form directly, which is a no no.
2633 Thus, this routine doesn't create temporaries, it just builds a
2634 single access expression for the array, calling
2635 find_or_generate_expression to build the innermost pieces.
2637 This function is a subroutine of create_expression_by_pieces, and
2638 should not be called on it's own unless you really know what you
2642 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2645 unsigned int op
= 0;
2646 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2649 /* Find a simple leader for an expression, or generate one using
2650 create_expression_by_pieces from a NARY expression for the value.
2651 BLOCK is the basic_block we are looking for leaders in.
2652 OP is the tree expression to find a leader for or generate.
2653 Returns the leader or NULL_TREE on failure. */
2656 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2658 pre_expr expr
= get_or_alloc_expr_for (op
);
2659 unsigned int lookfor
= get_expr_value_id (expr
);
2660 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2663 if (leader
->kind
== NAME
)
2664 return PRE_EXPR_NAME (leader
);
2665 else if (leader
->kind
== CONSTANT
)
2666 return PRE_EXPR_CONSTANT (leader
);
2672 /* It must be a complex expression, so generate it recursively. Note
2673 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2674 where the insert algorithm fails to insert a required expression. */
2675 bitmap exprset
= value_expressions
[lookfor
];
2678 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2680 pre_expr temp
= expression_for_id (i
);
2681 /* We cannot insert random REFERENCE expressions at arbitrary
2682 places. We can insert NARYs which eventually re-materializes
2683 its operand values. */
2684 if (temp
->kind
== NARY
)
2685 return create_expression_by_pieces (block
, temp
, stmts
,
2686 get_expr_type (expr
));
2693 #define NECESSARY GF_PLF_1
2695 /* Create an expression in pieces, so that we can handle very complex
2696 expressions that may be ANTIC, but not necessary GIMPLE.
2697 BLOCK is the basic block the expression will be inserted into,
2698 EXPR is the expression to insert (in value form)
2699 STMTS is a statement list to append the necessary insertions into.
2701 This function will die if we hit some value that shouldn't be
2702 ANTIC but is (IE there is no leader for it, or its components).
2703 The function returns NULL_TREE in case a different antic expression
2704 has to be inserted first.
2705 This function may also generate expressions that are themselves
2706 partially or fully redundant. Those that are will be either made
2707 fully redundant during the next iteration of insert (for partially
2708 redundant ones), or eliminated by eliminate (for fully redundant
2712 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2713 gimple_seq
*stmts
, tree type
)
2717 gimple_seq forced_stmts
= NULL
;
2718 unsigned int value_id
;
2719 gimple_stmt_iterator gsi
;
2720 tree exprtype
= type
? type
: get_expr_type (expr
);
2726 /* We may hit the NAME/CONSTANT case if we have to convert types
2727 that value numbering saw through. */
2729 folded
= PRE_EXPR_NAME (expr
);
2730 if (useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2735 folded
= PRE_EXPR_CONSTANT (expr
);
2736 tree tem
= fold_convert (exprtype
, folded
);
2737 if (is_gimple_min_invariant (tem
))
2742 if (PRE_EXPR_REFERENCE (expr
)->operands
[0].opcode
== CALL_EXPR
)
2744 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2745 unsigned int operand
= 1;
2746 vn_reference_op_t currop
= &ref
->operands
[0];
2747 tree sc
= NULL_TREE
;
2749 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2752 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2757 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2761 auto_vec
<tree
> args (ref
->operands
.length () - 1);
2762 while (operand
< ref
->operands
.length ())
2764 tree arg
= create_component_ref_by_pieces_1 (block
, ref
,
2768 args
.quick_push (arg
);
2771 = gimple_build_call_vec ((TREE_CODE (fn
) == FUNCTION_DECL
2772 ? build_fold_addr_expr (fn
) : fn
), args
);
2773 gimple_call_set_with_bounds (call
, currop
->with_bounds
);
2775 gimple_call_set_chain (call
, sc
);
2776 tree forcedname
= make_ssa_name (currop
->type
);
2777 gimple_call_set_lhs (call
, forcedname
);
2778 gimple_set_vuse (call
, BB_LIVE_VOP_ON_EXIT (block
));
2779 gimple_seq_add_stmt_without_update (&forced_stmts
, call
);
2780 folded
= forcedname
;
2784 folded
= create_component_ref_by_pieces (block
,
2785 PRE_EXPR_REFERENCE (expr
),
2789 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2790 newstmt
= gimple_build_assign (name
, folded
);
2791 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2792 gimple_set_vuse (newstmt
, BB_LIVE_VOP_ON_EXIT (block
));
2798 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2799 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2801 for (i
= 0; i
< nary
->length
; ++i
)
2803 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2806 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2807 may have conversions stripped. */
2808 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2811 genop
[i
] = gimple_convert (&forced_stmts
,
2812 nary
->type
, genop
[i
]);
2814 genop
[i
] = gimple_convert (&forced_stmts
,
2815 sizetype
, genop
[i
]);
2818 genop
[i
] = gimple_convert (&forced_stmts
,
2819 TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2821 if (nary
->opcode
== CONSTRUCTOR
)
2823 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2824 for (i
= 0; i
< nary
->length
; ++i
)
2825 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2826 folded
= build_constructor (nary
->type
, elts
);
2827 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2828 newstmt
= gimple_build_assign (name
, folded
);
2829 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2834 switch (nary
->length
)
2837 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2841 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2842 genop
[0], genop
[1]);
2845 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2846 genop
[0], genop
[1], genop
[2]);
2858 folded
= gimple_convert (&forced_stmts
, exprtype
, folded
);
2860 /* If there is nothing to insert, return the simplified result. */
2861 if (gimple_seq_empty_p (forced_stmts
))
2863 /* If we simplified to a constant return it and discard eventually
2865 if (is_gimple_min_invariant (folded
))
2867 gimple_seq_discard (forced_stmts
);
2871 gcc_assert (TREE_CODE (folded
) == SSA_NAME
);
2873 /* If we have any intermediate expressions to the value sets, add them
2874 to the value sets and chain them in the instruction stream. */
2877 gsi
= gsi_start (forced_stmts
);
2878 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2880 gimple
*stmt
= gsi_stmt (gsi
);
2881 tree forcedname
= gimple_get_lhs (stmt
);
2884 if (forcedname
!= folded
)
2886 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2887 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2888 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2889 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2890 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2891 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2894 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2895 gimple_set_plf (stmt
, NECESSARY
, false);
2897 gimple_seq_add_seq (stmts
, forced_stmts
);
2902 /* Fold the last statement. */
2903 gsi
= gsi_last (*stmts
);
2904 if (fold_stmt_inplace (&gsi
))
2905 update_stmt (gsi_stmt (gsi
));
2907 /* Add a value number to the temporary.
2908 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2909 we are creating the expression by pieces, and this particular piece of
2910 the expression may have been represented. There is no harm in replacing
2912 value_id
= get_expr_value_id (expr
);
2913 VN_INFO_GET (name
)->value_id
= value_id
;
2914 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2915 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2916 VN_INFO (name
)->valnum
= name
;
2917 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2918 nameexpr
= get_or_alloc_expr_for_name (name
);
2919 add_to_value (value_id
, nameexpr
);
2920 if (NEW_SETS (block
))
2921 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2922 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2924 pre_stats
.insertions
++;
2925 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2927 fprintf (dump_file
, "Inserted ");
2928 print_gimple_stmt (dump_file
, gsi_stmt (gsi_last (*stmts
)), 0, 0);
2929 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2930 block
->index
, value_id
);
2937 /* Insert the to-be-made-available values of expression EXPRNUM for each
2938 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2939 merge the result with a phi node, given the same value number as
2940 NODE. Return true if we have inserted new stuff. */
2943 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2944 vec
<pre_expr
> avail
)
2946 pre_expr expr
= expression_for_id (exprnum
);
2948 unsigned int val
= get_expr_value_id (expr
);
2950 bool insertions
= false;
2955 tree type
= get_expr_type (expr
);
2959 /* Make sure we aren't creating an induction variable. */
2960 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
2962 bool firstinsideloop
= false;
2963 bool secondinsideloop
= false;
2964 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2965 EDGE_PRED (block
, 0)->src
);
2966 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2967 EDGE_PRED (block
, 1)->src
);
2968 /* Induction variables only have one edge inside the loop. */
2969 if ((firstinsideloop
^ secondinsideloop
)
2970 && expr
->kind
!= REFERENCE
)
2972 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2973 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
2978 /* Make the necessary insertions. */
2979 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
2981 gimple_seq stmts
= NULL
;
2984 eprime
= avail
[pred
->dest_idx
];
2985 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
2987 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
2988 if (!gimple_seq_empty_p (stmts
))
2990 gsi_insert_seq_on_edge (pred
, stmts
);
2995 /* We cannot insert a PHI node if we failed to insert
3000 if (is_gimple_min_invariant (builtexpr
))
3001 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_constant (builtexpr
);
3003 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3005 /* If we didn't want a phi node, and we made insertions, we still have
3006 inserted new stuff, and thus return true. If we didn't want a phi node,
3007 and didn't make insertions, we haven't added anything new, so return
3009 if (nophi
&& insertions
)
3011 else if (nophi
&& !insertions
)
3014 /* Now build a phi for the new variable. */
3015 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3016 phi
= create_phi_node (temp
, block
);
3018 gimple_set_plf (phi
, NECESSARY
, false);
3019 VN_INFO_GET (temp
)->value_id
= val
;
3020 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3021 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3022 VN_INFO (temp
)->valnum
= temp
;
3023 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3024 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3026 pre_expr ae
= avail
[pred
->dest_idx
];
3027 gcc_assert (get_expr_type (ae
) == type
3028 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3029 if (ae
->kind
== CONSTANT
)
3030 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3031 pred
, UNKNOWN_LOCATION
);
3033 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3036 newphi
= get_or_alloc_expr_for_name (temp
);
3037 add_to_value (val
, newphi
);
3039 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3040 this insertion, since we test for the existence of this value in PHI_GEN
3041 before proceeding with the partial redundancy checks in insert_aux.
3043 The value may exist in AVAIL_OUT, in particular, it could be represented
3044 by the expression we are trying to eliminate, in which case we want the
3045 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3048 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3049 this block, because if it did, it would have existed in our dominator's
3050 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3053 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3054 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3056 bitmap_insert_into_set (NEW_SETS (block
),
3059 /* If we insert a PHI node for a conversion of another PHI node
3060 in the same basic-block try to preserve range information.
3061 This is important so that followup loop passes receive optimal
3062 number of iteration analysis results. See PR61743. */
3063 if (expr
->kind
== NARY
3064 && CONVERT_EXPR_CODE_P (expr
->u
.nary
->opcode
)
3065 && TREE_CODE (expr
->u
.nary
->op
[0]) == SSA_NAME
3066 && gimple_bb (SSA_NAME_DEF_STMT (expr
->u
.nary
->op
[0])) == block
3067 && INTEGRAL_TYPE_P (type
)
3068 && INTEGRAL_TYPE_P (TREE_TYPE (expr
->u
.nary
->op
[0]))
3069 && (TYPE_PRECISION (type
)
3070 >= TYPE_PRECISION (TREE_TYPE (expr
->u
.nary
->op
[0])))
3071 && SSA_NAME_RANGE_INFO (expr
->u
.nary
->op
[0]))
3074 if (get_range_info (expr
->u
.nary
->op
[0], &min
, &max
) == VR_RANGE
3075 && !wi::neg_p (min
, SIGNED
)
3076 && !wi::neg_p (max
, SIGNED
))
3077 /* Just handle extension and sign-changes of all-positive ranges. */
3078 set_range_info (temp
,
3079 SSA_NAME_RANGE_TYPE (expr
->u
.nary
->op
[0]),
3080 wide_int_storage::from (min
, TYPE_PRECISION (type
),
3082 wide_int_storage::from (max
, TYPE_PRECISION (type
),
3086 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3088 fprintf (dump_file
, "Created phi ");
3089 print_gimple_stmt (dump_file
, phi
, 0, 0);
3090 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3098 /* Perform insertion of partially redundant or hoistable values.
3099 For BLOCK, do the following:
3100 1. Propagate the NEW_SETS of the dominator into the current block.
3101 If the block has multiple predecessors,
3102 2a. Iterate over the ANTIC expressions for the block to see if
3103 any of them are partially redundant.
3104 2b. If so, insert them into the necessary predecessors to make
3105 the expression fully redundant.
3106 2c. Insert a new PHI merging the values of the predecessors.
3107 2d. Insert the new PHI, and the new expressions, into the
3109 If the block has multiple successors,
3110 3a. Iterate over the ANTIC values for the block to see if
3111 any of them are good candidates for hoisting.
3112 3b. If so, insert expressions computing the values in BLOCK,
3113 and add the new expressions into the NEW_SETS set.
3114 4. Recursively call ourselves on the dominator children of BLOCK.
3116 Steps 1, 2a, and 4 are done by insert_aux. 2b, 2c and 2d are done by
3117 do_pre_regular_insertion and do_partial_insertion. 3a and 3b are
3118 done in do_hoist_insertion.
3122 do_pre_regular_insertion (basic_block block
, basic_block dom
)
3124 bool new_stuff
= false;
3125 vec
<pre_expr
> exprs
;
3127 auto_vec
<pre_expr
> avail
;
3130 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3131 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3133 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3135 if (expr
->kind
== NARY
3136 || expr
->kind
== REFERENCE
)
3139 bool by_some
= false;
3140 bool cant_insert
= false;
3141 bool all_same
= true;
3142 pre_expr first_s
= NULL
;
3145 pre_expr eprime
= NULL
;
3147 pre_expr edoubleprime
= NULL
;
3148 bool do_insertion
= false;
3150 val
= get_expr_value_id (expr
);
3151 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3153 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3155 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3157 fprintf (dump_file
, "Found fully redundant value: ");
3158 print_pre_expr (dump_file
, expr
);
3159 fprintf (dump_file
, "\n");
3164 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3166 unsigned int vprime
;
3168 /* We should never run insertion for the exit block
3169 and so not come across fake pred edges. */
3170 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3172 /* We are looking at ANTIC_OUT of bprime. */
3173 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3176 /* eprime will generally only be NULL if the
3177 value of the expression, translated
3178 through the PHI for this predecessor, is
3179 undefined. If that is the case, we can't
3180 make the expression fully redundant,
3181 because its value is undefined along a
3182 predecessor path. We can thus break out
3183 early because it doesn't matter what the
3184 rest of the results are. */
3187 avail
[pred
->dest_idx
] = NULL
;
3192 vprime
= get_expr_value_id (eprime
);
3193 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3195 if (edoubleprime
== NULL
)
3197 avail
[pred
->dest_idx
] = eprime
;
3202 avail
[pred
->dest_idx
] = edoubleprime
;
3204 /* We want to perform insertions to remove a redundancy on
3205 a path in the CFG we want to optimize for speed. */
3206 if (optimize_edge_for_speed_p (pred
))
3207 do_insertion
= true;
3208 if (first_s
== NULL
)
3209 first_s
= edoubleprime
;
3210 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3214 /* If we can insert it, it's not the same value
3215 already existing along every predecessor, and
3216 it's defined by some predecessor, it is
3217 partially redundant. */
3218 if (!cant_insert
&& !all_same
&& by_some
)
3222 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3224 fprintf (dump_file
, "Skipping partial redundancy for "
3226 print_pre_expr (dump_file
, expr
);
3227 fprintf (dump_file
, " (%04d), no redundancy on to be "
3228 "optimized for speed edge\n", val
);
3231 else if (dbg_cnt (treepre_insert
))
3233 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3235 fprintf (dump_file
, "Found partial redundancy for "
3237 print_pre_expr (dump_file
, expr
);
3238 fprintf (dump_file
, " (%04d)\n",
3239 get_expr_value_id (expr
));
3241 if (insert_into_preds_of_block (block
,
3242 get_expression_id (expr
),
3247 /* If all edges produce the same value and that value is
3248 an invariant, then the PHI has the same value on all
3249 edges. Note this. */
3250 else if (!cant_insert
&& all_same
)
3252 gcc_assert (edoubleprime
->kind
== CONSTANT
3253 || edoubleprime
->kind
== NAME
);
3255 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3258 = gimple_build_assign (temp
,
3259 edoubleprime
->kind
== CONSTANT
?
3260 PRE_EXPR_CONSTANT (edoubleprime
) :
3261 PRE_EXPR_NAME (edoubleprime
));
3262 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3263 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3265 gimple_set_plf (assign
, NECESSARY
, false);
3266 VN_INFO_GET (temp
)->value_id
= val
;
3267 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3268 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3269 VN_INFO (temp
)->valnum
= temp
;
3270 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3271 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3272 add_to_value (val
, newe
);
3273 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3274 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3284 /* Perform insertion for partially anticipatable expressions. There
3285 is only one case we will perform insertion for these. This case is
3286 if the expression is partially anticipatable, and fully available.
3287 In this case, we know that putting it earlier will enable us to
3288 remove the later computation. */
3291 do_pre_partial_partial_insertion (basic_block block
, basic_block dom
)
3293 bool new_stuff
= false;
3294 vec
<pre_expr
> exprs
;
3296 auto_vec
<pre_expr
> avail
;
3299 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3300 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3302 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3304 if (expr
->kind
== NARY
3305 || expr
->kind
== REFERENCE
)
3309 bool cant_insert
= false;
3312 pre_expr eprime
= NULL
;
3315 val
= get_expr_value_id (expr
);
3316 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3318 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3321 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3323 unsigned int vprime
;
3324 pre_expr edoubleprime
;
3326 /* We should never run insertion for the exit block
3327 and so not come across fake pred edges. */
3328 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3330 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3334 /* eprime will generally only be NULL if the
3335 value of the expression, translated
3336 through the PHI for this predecessor, is
3337 undefined. If that is the case, we can't
3338 make the expression fully redundant,
3339 because its value is undefined along a
3340 predecessor path. We can thus break out
3341 early because it doesn't matter what the
3342 rest of the results are. */
3345 avail
[pred
->dest_idx
] = NULL
;
3350 vprime
= get_expr_value_id (eprime
);
3351 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3352 avail
[pred
->dest_idx
] = edoubleprime
;
3353 if (edoubleprime
== NULL
)
3360 /* If we can insert it, it's not the same value
3361 already existing along every predecessor, and
3362 it's defined by some predecessor, it is
3363 partially redundant. */
3364 if (!cant_insert
&& by_all
)
3367 bool do_insertion
= false;
3369 /* Insert only if we can remove a later expression on a path
3370 that we want to optimize for speed.
3371 The phi node that we will be inserting in BLOCK is not free,
3372 and inserting it for the sake of !optimize_for_speed successor
3373 may cause regressions on the speed path. */
3374 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3376 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3377 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3379 if (optimize_edge_for_speed_p (succ
))
3380 do_insertion
= true;
3386 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3388 fprintf (dump_file
, "Skipping partial partial redundancy "
3390 print_pre_expr (dump_file
, expr
);
3391 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3392 "on any to be optimized for speed edges\n", val
);
3395 else if (dbg_cnt (treepre_insert
))
3397 pre_stats
.pa_insert
++;
3398 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3400 fprintf (dump_file
, "Found partial partial redundancy "
3402 print_pre_expr (dump_file
, expr
);
3403 fprintf (dump_file
, " (%04d)\n",
3404 get_expr_value_id (expr
));
3406 if (insert_into_preds_of_block (block
,
3407 get_expression_id (expr
),
3419 /* Insert expressions in BLOCK to compute hoistable values up.
3420 Return TRUE if something was inserted, otherwise return FALSE.
3421 The caller has to make sure that BLOCK has at least two successors. */
3424 do_hoist_insertion (basic_block block
)
3428 bool new_stuff
= false;
3430 gimple_stmt_iterator last
;
3432 /* At least two successors, or else... */
3433 gcc_assert (EDGE_COUNT (block
->succs
) >= 2);
3435 /* Check that all successors of BLOCK are dominated by block.
3436 We could use dominated_by_p() for this, but actually there is a much
3437 quicker check: any successor that is dominated by BLOCK can't have
3438 more than one predecessor edge. */
3439 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3440 if (! single_pred_p (e
->dest
))
3443 /* Determine the insertion point. If we cannot safely insert before
3444 the last stmt if we'd have to, bail out. */
3445 last
= gsi_last_bb (block
);
3446 if (!gsi_end_p (last
)
3447 && !is_ctrl_stmt (gsi_stmt (last
))
3448 && stmt_ends_bb_p (gsi_stmt (last
)))
3451 /* Compute the set of hoistable expressions from ANTIC_IN. First compute
3452 hoistable values. */
3453 bitmap_set hoistable_set
;
3455 /* A hoistable value must be in ANTIC_IN(block)
3456 but not in AVAIL_OUT(BLOCK). */
3457 bitmap_initialize (&hoistable_set
.values
, &grand_bitmap_obstack
);
3458 bitmap_and_compl (&hoistable_set
.values
,
3459 &ANTIC_IN (block
)->values
, &AVAIL_OUT (block
)->values
);
3461 /* Short-cut for a common case: hoistable_set is empty. */
3462 if (bitmap_empty_p (&hoistable_set
.values
))
3465 /* Compute which of the hoistable values is in AVAIL_OUT of
3466 at least one of the successors of BLOCK. */
3467 bitmap_head availout_in_some
;
3468 bitmap_initialize (&availout_in_some
, &grand_bitmap_obstack
);
3469 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3470 /* Do not consider expressions solely because their availability
3471 on loop exits. They'd be ANTIC-IN throughout the whole loop
3472 and thus effectively hoisted across loops by combination of
3473 PRE and hoisting. */
3474 if (! loop_exit_edge_p (block
->loop_father
, e
))
3475 bitmap_ior_and_into (&availout_in_some
, &hoistable_set
.values
,
3476 &AVAIL_OUT (e
->dest
)->values
);
3477 bitmap_clear (&hoistable_set
.values
);
3479 /* Short-cut for a common case: availout_in_some is empty. */
3480 if (bitmap_empty_p (&availout_in_some
))
3483 /* Hack hoitable_set in-place so we can use sorted_array_from_bitmap_set. */
3484 hoistable_set
.values
= availout_in_some
;
3485 hoistable_set
.expressions
= ANTIC_IN (block
)->expressions
;
3487 /* Now finally construct the topological-ordered expression set. */
3488 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (&hoistable_set
);
3490 bitmap_clear (&hoistable_set
.values
);
3492 /* If there are candidate values for hoisting, insert expressions
3493 strategically to make the hoistable expressions fully redundant. */
3495 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3497 /* While we try to sort expressions topologically above the
3498 sorting doesn't work out perfectly. Catch expressions we
3499 already inserted. */
3500 unsigned int value_id
= get_expr_value_id (expr
);
3501 if (bitmap_set_contains_value (AVAIL_OUT (block
), value_id
))
3503 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3506 "Already inserted expression for ");
3507 print_pre_expr (dump_file
, expr
);
3508 fprintf (dump_file
, " (%04d)\n", value_id
);
3513 /* OK, we should hoist this value. Perform the transformation. */
3514 pre_stats
.hoist_insert
++;
3515 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3518 "Inserting expression in block %d for code hoisting: ",
3520 print_pre_expr (dump_file
, expr
);
3521 fprintf (dump_file
, " (%04d)\n", value_id
);
3524 gimple_seq stmts
= NULL
;
3525 tree res
= create_expression_by_pieces (block
, expr
, &stmts
,
3526 get_expr_type (expr
));
3528 /* Do not return true if expression creation ultimately
3529 did not insert any statements. */
3530 if (gimple_seq_empty_p (stmts
))
3534 if (gsi_end_p (last
) || is_ctrl_stmt (gsi_stmt (last
)))
3535 gsi_insert_seq_before (&last
, stmts
, GSI_SAME_STMT
);
3537 gsi_insert_seq_after (&last
, stmts
, GSI_NEW_STMT
);
3540 /* Make sure to not return true if expression creation ultimately
3541 failed but also make sure to insert any stmts produced as they
3542 are tracked in inserted_exprs. */
3554 /* Do a dominator walk on the control flow graph, and insert computations
3555 of values as necessary for PRE and hoisting. */
3558 insert_aux (basic_block block
, bool do_pre
, bool do_hoist
)
3561 bool new_stuff
= false;
3566 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3571 bitmap_set_t newset
;
3573 /* First, update the AVAIL_OUT set with anything we may have
3574 inserted higher up in the dominator tree. */
3575 newset
= NEW_SETS (dom
);
3578 /* Note that we need to value_replace both NEW_SETS, and
3579 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3580 represented by some non-simple expression here that we want
3581 to replace it with. */
3582 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3584 pre_expr expr
= expression_for_id (i
);
3585 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3586 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3590 /* Insert expressions for partial redundancies. */
3591 if (do_pre
&& !single_pred_p (block
))
3593 new_stuff
|= do_pre_regular_insertion (block
, dom
);
3594 if (do_partial_partial
)
3595 new_stuff
|= do_pre_partial_partial_insertion (block
, dom
);
3598 /* Insert expressions for hoisting. */
3599 if (do_hoist
&& EDGE_COUNT (block
->succs
) >= 2)
3600 new_stuff
|= do_hoist_insertion (block
);
3603 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3605 son
= next_dom_son (CDI_DOMINATORS
, son
))
3607 new_stuff
|= insert_aux (son
, do_pre
, do_hoist
);
3613 /* Perform insertion of partially redundant and hoistable values. */
3618 bool new_stuff
= true;
3620 int num_iterations
= 0;
3622 FOR_ALL_BB_FN (bb
, cfun
)
3623 NEW_SETS (bb
) = bitmap_set_new ();
3628 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3629 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3630 new_stuff
= insert_aux (ENTRY_BLOCK_PTR_FOR_FN (cfun
), flag_tree_pre
,
3631 flag_code_hoisting
);
3633 /* Clear the NEW sets before the next iteration. We have already
3634 fully propagated its contents. */
3636 FOR_ALL_BB_FN (bb
, cfun
)
3637 bitmap_set_free (NEW_SETS (bb
));
3639 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3643 /* Compute the AVAIL set for all basic blocks.
3645 This function performs value numbering of the statements in each basic
3646 block. The AVAIL sets are built from information we glean while doing
3647 this value numbering, since the AVAIL sets contain only one entry per
3650 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3651 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3654 compute_avail (void)
3657 basic_block block
, son
;
3658 basic_block
*worklist
;
3662 /* We pretend that default definitions are defined in the entry block.
3663 This includes function arguments and the static chain decl. */
3664 for (i
= 1; i
< num_ssa_names
; ++i
)
3666 tree name
= ssa_name (i
);
3669 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3670 || has_zero_uses (name
)
3671 || virtual_operand_p (name
))
3674 e
= get_or_alloc_expr_for_name (name
);
3675 add_to_value (get_expr_value_id (e
), e
);
3676 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3677 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3681 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3683 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3684 "tmp_gen", ENTRY_BLOCK
);
3685 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3686 "avail_out", ENTRY_BLOCK
);
3689 /* Allocate the worklist. */
3690 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3692 /* Seed the algorithm by putting the dominator children of the entry
3693 block on the worklist. */
3694 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3696 son
= next_dom_son (CDI_DOMINATORS
, son
))
3697 worklist
[sp
++] = son
;
3699 BB_LIVE_VOP_ON_EXIT (ENTRY_BLOCK_PTR_FOR_FN (cfun
))
3700 = ssa_default_def (cfun
, gimple_vop (cfun
));
3702 /* Loop until the worklist is empty. */
3708 /* Pick a block from the worklist. */
3709 block
= worklist
[--sp
];
3711 /* Initially, the set of available values in BLOCK is that of
3712 its immediate dominator. */
3713 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3716 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3717 BB_LIVE_VOP_ON_EXIT (block
) = BB_LIVE_VOP_ON_EXIT (dom
);
3720 /* Generate values for PHI nodes. */
3721 for (gphi_iterator gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
);
3724 tree result
= gimple_phi_result (gsi
.phi ());
3726 /* We have no need for virtual phis, as they don't represent
3727 actual computations. */
3728 if (virtual_operand_p (result
))
3730 BB_LIVE_VOP_ON_EXIT (block
) = result
;
3734 pre_expr e
= get_or_alloc_expr_for_name (result
);
3735 add_to_value (get_expr_value_id (e
), e
);
3736 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3737 bitmap_insert_into_set (PHI_GEN (block
), e
);
3740 BB_MAY_NOTRETURN (block
) = 0;
3742 /* Now compute value numbers and populate value sets with all
3743 the expressions computed in BLOCK. */
3744 for (gimple_stmt_iterator gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
);
3750 stmt
= gsi_stmt (gsi
);
3752 /* Cache whether the basic-block has any non-visible side-effect
3754 If this isn't a call or it is the last stmt in the
3755 basic-block then the CFG represents things correctly. */
3756 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3758 /* Non-looping const functions always return normally.
3759 Otherwise the call might not return or have side-effects
3760 that forbids hoisting possibly trapping expressions
3762 int flags
= gimple_call_flags (stmt
);
3763 if (!(flags
& ECF_CONST
)
3764 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3765 BB_MAY_NOTRETURN (block
) = 1;
3768 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3770 pre_expr e
= get_or_alloc_expr_for_name (op
);
3772 add_to_value (get_expr_value_id (e
), e
);
3773 bitmap_insert_into_set (TMP_GEN (block
), e
);
3774 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3777 if (gimple_vdef (stmt
))
3778 BB_LIVE_VOP_ON_EXIT (block
) = gimple_vdef (stmt
);
3780 if (gimple_has_side_effects (stmt
)
3781 || stmt_could_throw_p (stmt
)
3782 || is_gimple_debug (stmt
))
3785 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3787 if (ssa_undefined_value_p (op
))
3789 pre_expr e
= get_or_alloc_expr_for_name (op
);
3790 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3793 switch (gimple_code (stmt
))
3801 vn_reference_s ref1
;
3802 pre_expr result
= NULL
;
3804 /* We can value number only calls to real functions. */
3805 if (gimple_call_internal_p (stmt
))
3808 vn_reference_lookup_call (as_a
<gcall
*> (stmt
), &ref
, &ref1
);
3812 /* If the value of the call is not invalidated in
3813 this block until it is computed, add the expression
3815 if (!gimple_vuse (stmt
)
3817 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3818 || gimple_bb (SSA_NAME_DEF_STMT
3819 (gimple_vuse (stmt
))) != block
)
3821 result
= pre_expr_pool
.allocate ();
3822 result
->kind
= REFERENCE
;
3824 PRE_EXPR_REFERENCE (result
) = ref
;
3826 get_or_alloc_expression_id (result
);
3827 add_to_value (get_expr_value_id (result
), result
);
3828 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3835 pre_expr result
= NULL
;
3836 switch (vn_get_stmt_kind (stmt
))
3840 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3843 /* COND_EXPR and VEC_COND_EXPR are awkward in
3844 that they contain an embedded complex expression.
3845 Don't even try to shove those through PRE. */
3846 if (code
== COND_EXPR
3847 || code
== VEC_COND_EXPR
)
3850 vn_nary_op_lookup_stmt (stmt
, &nary
);
3854 /* If the NARY traps and there was a preceding
3855 point in the block that might not return avoid
3856 adding the nary to EXP_GEN. */
3857 if (BB_MAY_NOTRETURN (block
)
3858 && vn_nary_may_trap (nary
))
3861 result
= pre_expr_pool
.allocate ();
3862 result
->kind
= NARY
;
3864 PRE_EXPR_NARY (result
) = nary
;
3870 tree rhs1
= gimple_assign_rhs1 (stmt
);
3871 alias_set_type set
= get_alias_set (rhs1
);
3872 vec
<vn_reference_op_s
> operands
3873 = vn_reference_operands_for_lookup (rhs1
);
3875 vn_reference_lookup_pieces (gimple_vuse (stmt
), set
,
3877 operands
, &ref
, VN_WALK
);
3880 operands
.release ();
3884 /* If the value of the reference is not invalidated in
3885 this block until it is computed, add the expression
3887 if (gimple_vuse (stmt
))
3891 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3892 while (!gimple_nop_p (def_stmt
)
3893 && gimple_code (def_stmt
) != GIMPLE_PHI
3894 && gimple_bb (def_stmt
) == block
)
3896 if (stmt_may_clobber_ref_p
3897 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3903 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3907 operands
.release ();
3912 /* If the load was value-numbered to another
3913 load make sure we do not use its expression
3914 for insertion if it wouldn't be a valid
3916 /* At the momemt we have a testcase
3917 for hoist insertion of aligned vs. misaligned
3918 variants in gcc.dg/torture/pr65270-1.c thus
3919 with just alignment to be considered we can
3920 simply replace the expression in the hashtable
3921 with the most conservative one. */
3922 vn_reference_op_t ref1
= &ref
->operands
.last ();
3923 while (ref1
->opcode
!= TARGET_MEM_REF
3924 && ref1
->opcode
!= MEM_REF
3925 && ref1
!= &ref
->operands
[0])
3927 vn_reference_op_t ref2
= &operands
.last ();
3928 while (ref2
->opcode
!= TARGET_MEM_REF
3929 && ref2
->opcode
!= MEM_REF
3930 && ref2
!= &operands
[0])
3932 if ((ref1
->opcode
== TARGET_MEM_REF
3933 || ref1
->opcode
== MEM_REF
)
3934 && (TYPE_ALIGN (ref1
->type
)
3935 > TYPE_ALIGN (ref2
->type
)))
3937 = build_aligned_type (ref1
->type
,
3938 TYPE_ALIGN (ref2
->type
));
3939 /* TBAA behavior is an obvious part so make sure
3940 that the hashtable one covers this as well
3941 by adjusting the ref alias set and its base. */
3943 || alias_set_subset_of (set
, ref
->set
))
3945 else if (alias_set_subset_of (ref
->set
, set
))
3948 if (ref1
->opcode
== MEM_REF
)
3949 ref1
->op0
= fold_convert (TREE_TYPE (ref2
->op0
),
3952 ref1
->op2
= fold_convert (TREE_TYPE (ref2
->op2
),
3958 if (ref1
->opcode
== MEM_REF
)
3959 ref1
->op0
= fold_convert (ptr_type_node
,
3962 ref1
->op2
= fold_convert (ptr_type_node
,
3965 operands
.release ();
3967 result
= pre_expr_pool
.allocate ();
3968 result
->kind
= REFERENCE
;
3970 PRE_EXPR_REFERENCE (result
) = ref
;
3978 get_or_alloc_expression_id (result
);
3979 add_to_value (get_expr_value_id (result
), result
);
3980 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3988 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3990 print_bitmap_set (dump_file
, EXP_GEN (block
),
3991 "exp_gen", block
->index
);
3992 print_bitmap_set (dump_file
, PHI_GEN (block
),
3993 "phi_gen", block
->index
);
3994 print_bitmap_set (dump_file
, TMP_GEN (block
),
3995 "tmp_gen", block
->index
);
3996 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
3997 "avail_out", block
->index
);
4000 /* Put the dominator children of BLOCK on the worklist of blocks
4001 to compute available sets for. */
4002 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4004 son
= next_dom_son (CDI_DOMINATORS
, son
))
4005 worklist
[sp
++] = son
;
4012 /* Local state for the eliminate domwalk. */
4013 static vec
<gimple
*> el_to_remove
;
4014 static vec
<gimple
*> el_to_fixup
;
4015 static unsigned int el_todo
;
4016 static vec
<tree
> el_avail
;
4017 static vec
<tree
> el_avail_stack
;
4019 /* Return a leader for OP that is available at the current point of the
4020 eliminate domwalk. */
4023 eliminate_avail (tree op
)
4025 tree valnum
= VN_INFO (op
)->valnum
;
4026 if (TREE_CODE (valnum
) == SSA_NAME
)
4028 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
4030 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
4031 return el_avail
[SSA_NAME_VERSION (valnum
)];
4033 else if (is_gimple_min_invariant (valnum
))
4038 /* At the current point of the eliminate domwalk make OP available. */
4041 eliminate_push_avail (tree op
)
4043 tree valnum
= VN_INFO (op
)->valnum
;
4044 if (TREE_CODE (valnum
) == SSA_NAME
)
4046 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
4047 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
4049 if (el_avail
[SSA_NAME_VERSION (valnum
)])
4050 pushop
= el_avail
[SSA_NAME_VERSION (valnum
)];
4051 el_avail_stack
.safe_push (pushop
);
4052 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
4056 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
4057 the leader for the expression if insertion was successful. */
4060 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
4062 gimple
*stmt
= gimple_seq_first_stmt (VN_INFO (val
)->expr
);
4063 if (!is_gimple_assign (stmt
)
4064 || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt
))
4065 && gimple_assign_rhs_code (stmt
) != VIEW_CONVERT_EXPR
4066 && gimple_assign_rhs_code (stmt
) != BIT_FIELD_REF
))
4069 tree op
= gimple_assign_rhs1 (stmt
);
4070 if (gimple_assign_rhs_code (stmt
) == VIEW_CONVERT_EXPR
4071 || gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4072 op
= TREE_OPERAND (op
, 0);
4073 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
4077 gimple_seq stmts
= NULL
;
4079 if (gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4080 res
= gimple_build (&stmts
, BIT_FIELD_REF
,
4081 TREE_TYPE (val
), leader
,
4082 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 1),
4083 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 2));
4085 res
= gimple_build (&stmts
, gimple_assign_rhs_code (stmt
),
4086 TREE_TYPE (val
), leader
);
4087 gsi_insert_seq_before (gsi
, stmts
, GSI_SAME_STMT
);
4088 VN_INFO_GET (res
)->valnum
= val
;
4090 if (TREE_CODE (leader
) == SSA_NAME
)
4091 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
4093 pre_stats
.insertions
++;
4094 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4096 fprintf (dump_file
, "Inserted ");
4097 print_gimple_stmt (dump_file
, SSA_NAME_DEF_STMT (res
), 0, 0);
4103 class eliminate_dom_walker
: public dom_walker
4106 eliminate_dom_walker (cdi_direction direction
, bool do_pre_
)
4107 : dom_walker (direction
), do_pre (do_pre_
) {}
4109 virtual edge
before_dom_children (basic_block
);
4110 virtual void after_dom_children (basic_block
);
4115 /* Perform elimination for the basic-block B during the domwalk. */
4118 eliminate_dom_walker::before_dom_children (basic_block b
)
4121 el_avail_stack
.safe_push (NULL_TREE
);
4123 /* ??? If we do nothing for unreachable blocks then this will confuse
4124 tailmerging. Eventually we can reduce its reliance on SCCVN now
4125 that we fully copy/constant-propagate (most) things. */
4127 for (gphi_iterator gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4129 gphi
*phi
= gsi
.phi ();
4130 tree res
= PHI_RESULT (phi
);
4132 if (virtual_operand_p (res
))
4138 tree sprime
= eliminate_avail (res
);
4142 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4144 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4145 print_generic_expr (dump_file
, res
, 0);
4146 fprintf (dump_file
, " with ");
4147 print_generic_expr (dump_file
, sprime
, 0);
4148 fprintf (dump_file
, "\n");
4151 /* If we inserted this PHI node ourself, it's not an elimination. */
4153 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4156 pre_stats
.eliminations
++;
4158 /* If we will propagate into all uses don't bother to do
4160 if (may_propagate_copy (res
, sprime
))
4162 /* Mark the PHI for removal. */
4163 el_to_remove
.safe_push (phi
);
4168 remove_phi_node (&gsi
, false);
4171 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4172 && TREE_CODE (sprime
) == SSA_NAME
)
4173 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4175 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4176 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4177 gimple
*stmt
= gimple_build_assign (res
, sprime
);
4178 /* ??? It cannot yet be necessary (DOM walk). */
4179 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4181 gimple_stmt_iterator gsi2
= gsi_after_labels (b
);
4182 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4186 eliminate_push_avail (res
);
4190 for (gimple_stmt_iterator gsi
= gsi_start_bb (b
);
4194 tree sprime
= NULL_TREE
;
4195 gimple
*stmt
= gsi_stmt (gsi
);
4196 tree lhs
= gimple_get_lhs (stmt
);
4197 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
4198 && !gimple_has_volatile_ops (stmt
)
4199 /* See PR43491. Do not replace a global register variable when
4200 it is a the RHS of an assignment. Do replace local register
4201 variables since gcc does not guarantee a local variable will
4202 be allocated in register.
4203 ??? The fix isn't effective here. This should instead
4204 be ensured by not value-numbering them the same but treating
4205 them like volatiles? */
4206 && !(gimple_assign_single_p (stmt
)
4207 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
4208 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
))
4209 && is_global_var (gimple_assign_rhs1 (stmt
)))))
4211 sprime
= eliminate_avail (lhs
);
4214 /* If there is no existing usable leader but SCCVN thinks
4215 it has an expression it wants to use as replacement,
4217 tree val
= VN_INFO (lhs
)->valnum
;
4219 && TREE_CODE (val
) == SSA_NAME
4220 && VN_INFO (val
)->needs_insertion
4221 && VN_INFO (val
)->expr
!= NULL
4222 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4223 eliminate_push_avail (sprime
);
4226 /* If this now constitutes a copy duplicate points-to
4227 and range info appropriately. This is especially
4228 important for inserted code. See tree-ssa-copy.c
4229 for similar code. */
4231 && TREE_CODE (sprime
) == SSA_NAME
)
4233 basic_block sprime_b
= gimple_bb (SSA_NAME_DEF_STMT (sprime
));
4234 if (POINTER_TYPE_P (TREE_TYPE (lhs
))
4235 && VN_INFO_PTR_INFO (lhs
)
4236 && ! VN_INFO_PTR_INFO (sprime
))
4238 duplicate_ssa_name_ptr_info (sprime
,
4239 VN_INFO_PTR_INFO (lhs
));
4241 mark_ptr_info_alignment_unknown
4242 (SSA_NAME_PTR_INFO (sprime
));
4244 else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
4245 && VN_INFO_RANGE_INFO (lhs
)
4246 && ! VN_INFO_RANGE_INFO (sprime
)
4248 duplicate_ssa_name_range_info (sprime
,
4249 VN_INFO_RANGE_TYPE (lhs
),
4250 VN_INFO_RANGE_INFO (lhs
));
4253 /* Inhibit the use of an inserted PHI on a loop header when
4254 the address of the memory reference is a simple induction
4255 variable. In other cases the vectorizer won't do anything
4256 anyway (either it's loop invariant or a complicated
4259 && TREE_CODE (sprime
) == SSA_NAME
4261 && flag_tree_loop_vectorize
4262 && loop_outer (b
->loop_father
)
4263 && has_zero_uses (sprime
)
4264 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))
4265 && gimple_assign_load_p (stmt
))
4267 gimple
*def_stmt
= SSA_NAME_DEF_STMT (sprime
);
4268 basic_block def_bb
= gimple_bb (def_stmt
);
4269 if (gimple_code (def_stmt
) == GIMPLE_PHI
4270 && def_bb
->loop_father
->header
== def_bb
)
4272 loop_p loop
= def_bb
->loop_father
;
4276 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4279 def_bb
= gimple_bb (SSA_NAME_DEF_STMT (op
));
4281 && flow_bb_inside_loop_p (loop
, def_bb
)
4282 && simple_iv (loop
, loop
, op
, &iv
, true))
4290 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4292 fprintf (dump_file
, "Not replacing ");
4293 print_gimple_expr (dump_file
, stmt
, 0, 0);
4294 fprintf (dump_file
, " with ");
4295 print_generic_expr (dump_file
, sprime
, 0);
4296 fprintf (dump_file
, " which would add a loop"
4297 " carried dependence to loop %d\n",
4300 /* Don't keep sprime available. */
4308 /* If we can propagate the value computed for LHS into
4309 all uses don't bother doing anything with this stmt. */
4310 if (may_propagate_copy (lhs
, sprime
))
4312 /* Mark it for removal. */
4313 el_to_remove
.safe_push (stmt
);
4315 /* ??? Don't count copy/constant propagations. */
4316 if (gimple_assign_single_p (stmt
)
4317 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4318 || gimple_assign_rhs1 (stmt
) == sprime
))
4321 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4323 fprintf (dump_file
, "Replaced ");
4324 print_gimple_expr (dump_file
, stmt
, 0, 0);
4325 fprintf (dump_file
, " with ");
4326 print_generic_expr (dump_file
, sprime
, 0);
4327 fprintf (dump_file
, " in all uses of ");
4328 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4331 pre_stats
.eliminations
++;
4335 /* If this is an assignment from our leader (which
4336 happens in the case the value-number is a constant)
4337 then there is nothing to do. */
4338 if (gimple_assign_single_p (stmt
)
4339 && sprime
== gimple_assign_rhs1 (stmt
))
4342 /* Else replace its RHS. */
4343 bool can_make_abnormal_goto
4344 = is_gimple_call (stmt
)
4345 && stmt_can_make_abnormal_goto (stmt
);
4347 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4349 fprintf (dump_file
, "Replaced ");
4350 print_gimple_expr (dump_file
, stmt
, 0, 0);
4351 fprintf (dump_file
, " with ");
4352 print_generic_expr (dump_file
, sprime
, 0);
4353 fprintf (dump_file
, " in ");
4354 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4357 if (TREE_CODE (sprime
) == SSA_NAME
)
4358 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4361 pre_stats
.eliminations
++;
4362 gimple
*orig_stmt
= stmt
;
4363 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4364 TREE_TYPE (sprime
)))
4365 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4366 tree vdef
= gimple_vdef (stmt
);
4367 tree vuse
= gimple_vuse (stmt
);
4368 propagate_tree_value_into_stmt (&gsi
, sprime
);
4369 stmt
= gsi_stmt (gsi
);
4371 if (vdef
!= gimple_vdef (stmt
))
4372 VN_INFO (vdef
)->valnum
= vuse
;
4374 /* If we removed EH side-effects from the statement, clean
4375 its EH information. */
4376 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4378 bitmap_set_bit (need_eh_cleanup
,
4379 gimple_bb (stmt
)->index
);
4380 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4381 fprintf (dump_file
, " Removed EH side-effects.\n");
4384 /* Likewise for AB side-effects. */
4385 if (can_make_abnormal_goto
4386 && !stmt_can_make_abnormal_goto (stmt
))
4388 bitmap_set_bit (need_ab_cleanup
,
4389 gimple_bb (stmt
)->index
);
4390 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4391 fprintf (dump_file
, " Removed AB side-effects.\n");
4398 /* If the statement is a scalar store, see if the expression
4399 has the same value number as its rhs. If so, the store is
4401 if (gimple_assign_single_p (stmt
)
4402 && !gimple_has_volatile_ops (stmt
)
4403 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4404 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4405 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4408 tree rhs
= gimple_assign_rhs1 (stmt
);
4409 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4410 gimple_vuse (stmt
), VN_WALK
, NULL
, false);
4411 if (TREE_CODE (rhs
) == SSA_NAME
)
4412 rhs
= VN_INFO (rhs
)->valnum
;
4414 && operand_equal_p (val
, rhs
, 0))
4416 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4418 fprintf (dump_file
, "Deleted redundant store ");
4419 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4422 /* Queue stmt for removal. */
4423 el_to_remove
.safe_push (stmt
);
4428 /* If this is a control statement value numbering left edges
4429 unexecuted on force the condition in a way consistent with
4431 if (gcond
*cond
= dyn_cast
<gcond
*> (stmt
))
4433 if ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
)
4434 ^ (EDGE_SUCC (b
, 1)->flags
& EDGE_EXECUTABLE
))
4436 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4438 fprintf (dump_file
, "Removing unexecutable edge from ");
4439 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4441 if (((EDGE_SUCC (b
, 0)->flags
& EDGE_TRUE_VALUE
) != 0)
4442 == ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
) != 0))
4443 gimple_cond_make_true (cond
);
4445 gimple_cond_make_false (cond
);
4447 el_todo
|= TODO_cleanup_cfg
;
4452 bool can_make_abnormal_goto
= stmt_can_make_abnormal_goto (stmt
);
4453 bool was_noreturn
= (is_gimple_call (stmt
)
4454 && gimple_call_noreturn_p (stmt
));
4455 tree vdef
= gimple_vdef (stmt
);
4456 tree vuse
= gimple_vuse (stmt
);
4458 /* If we didn't replace the whole stmt (or propagate the result
4459 into all uses), replace all uses on this stmt with their
4461 use_operand_p use_p
;
4463 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_USE
)
4465 tree use
= USE_FROM_PTR (use_p
);
4466 /* ??? The call code above leaves stmt operands un-updated. */
4467 if (TREE_CODE (use
) != SSA_NAME
)
4469 tree sprime
= eliminate_avail (use
);
4470 if (sprime
&& sprime
!= use
4471 && may_propagate_copy (use
, sprime
)
4472 /* We substitute into debug stmts to avoid excessive
4473 debug temporaries created by removed stmts, but we need
4474 to avoid doing so for inserted sprimes as we never want
4475 to create debug temporaries for them. */
4477 || TREE_CODE (sprime
) != SSA_NAME
4478 || !is_gimple_debug (stmt
)
4479 || !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))))
4481 propagate_value (use_p
, sprime
);
4482 gimple_set_modified (stmt
, true);
4483 if (TREE_CODE (sprime
) == SSA_NAME
4484 && !is_gimple_debug (stmt
))
4485 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4490 /* Visit indirect calls and turn them into direct calls if
4491 possible using the devirtualization machinery. */
4492 if (gcall
*call_stmt
= dyn_cast
<gcall
*> (stmt
))
4494 tree fn
= gimple_call_fn (call_stmt
);
4496 && flag_devirtualize
4497 && virtual_method_call_p (fn
))
4499 tree otr_type
= obj_type_ref_class (fn
);
4501 ipa_polymorphic_call_context
context (current_function_decl
, fn
, stmt
, &instance
);
4504 context
.get_dynamic_type (instance
, OBJ_TYPE_REF_OBJECT (fn
), otr_type
, stmt
);
4506 vec
<cgraph_node
*>targets
4507 = possible_polymorphic_call_targets (obj_type_ref_class (fn
),
4509 (OBJ_TYPE_REF_TOKEN (fn
)),
4513 dump_possible_polymorphic_call_targets (dump_file
,
4514 obj_type_ref_class (fn
),
4516 (OBJ_TYPE_REF_TOKEN (fn
)),
4518 if (final
&& targets
.length () <= 1 && dbg_cnt (devirt
))
4521 if (targets
.length () == 1)
4522 fn
= targets
[0]->decl
;
4524 fn
= builtin_decl_implicit (BUILT_IN_UNREACHABLE
);
4525 if (dump_enabled_p ())
4527 location_t loc
= gimple_location_safe (stmt
);
4528 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, loc
,
4529 "converting indirect call to "
4531 lang_hooks
.decl_printable_name (fn
, 2));
4533 gimple_call_set_fndecl (call_stmt
, fn
);
4534 maybe_remove_unused_call_args (cfun
, call_stmt
);
4535 gimple_set_modified (stmt
, true);
4540 if (gimple_modified_p (stmt
))
4542 /* If a formerly non-invariant ADDR_EXPR is turned into an
4543 invariant one it was on a separate stmt. */
4544 if (gimple_assign_single_p (stmt
)
4545 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
4546 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
4547 gimple
*old_stmt
= stmt
;
4548 if (is_gimple_call (stmt
))
4550 /* ??? Only fold calls inplace for now, this may create new
4551 SSA names which in turn will confuse free_scc_vn SSA name
4553 fold_stmt_inplace (&gsi
);
4554 /* When changing a call into a noreturn call, cfg cleanup
4555 is needed to fix up the noreturn call. */
4556 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4557 el_to_fixup
.safe_push (stmt
);
4562 stmt
= gsi_stmt (gsi
);
4563 if ((gimple_code (stmt
) == GIMPLE_COND
4564 && (gimple_cond_true_p (as_a
<gcond
*> (stmt
))
4565 || gimple_cond_false_p (as_a
<gcond
*> (stmt
))))
4566 || (gimple_code (stmt
) == GIMPLE_SWITCH
4567 && TREE_CODE (gimple_switch_index (
4568 as_a
<gswitch
*> (stmt
)))
4570 el_todo
|= TODO_cleanup_cfg
;
4572 /* If we removed EH side-effects from the statement, clean
4573 its EH information. */
4574 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
))
4576 bitmap_set_bit (need_eh_cleanup
,
4577 gimple_bb (stmt
)->index
);
4578 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4579 fprintf (dump_file
, " Removed EH side-effects.\n");
4581 /* Likewise for AB side-effects. */
4582 if (can_make_abnormal_goto
4583 && !stmt_can_make_abnormal_goto (stmt
))
4585 bitmap_set_bit (need_ab_cleanup
,
4586 gimple_bb (stmt
)->index
);
4587 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4588 fprintf (dump_file
, " Removed AB side-effects.\n");
4591 if (vdef
!= gimple_vdef (stmt
))
4592 VN_INFO (vdef
)->valnum
= vuse
;
4595 /* Make new values available - for fully redundant LHS we
4596 continue with the next stmt above and skip this. */
4598 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_DEF
)
4599 eliminate_push_avail (DEF_FROM_PTR (defp
));
4602 /* Replace destination PHI arguments. */
4605 FOR_EACH_EDGE (e
, ei
, b
->succs
)
4607 for (gphi_iterator gsi
= gsi_start_phis (e
->dest
);
4611 gphi
*phi
= gsi
.phi ();
4612 use_operand_p use_p
= PHI_ARG_DEF_PTR_FROM_EDGE (phi
, e
);
4613 tree arg
= USE_FROM_PTR (use_p
);
4614 if (TREE_CODE (arg
) != SSA_NAME
4615 || virtual_operand_p (arg
))
4617 tree sprime
= eliminate_avail (arg
);
4618 if (sprime
&& may_propagate_copy (arg
, sprime
))
4620 propagate_value (use_p
, sprime
);
4621 if (TREE_CODE (sprime
) == SSA_NAME
)
4622 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4629 /* Make no longer available leaders no longer available. */
4632 eliminate_dom_walker::after_dom_children (basic_block
)
4635 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4637 tree valnum
= VN_INFO (entry
)->valnum
;
4638 tree old
= el_avail
[SSA_NAME_VERSION (valnum
)];
4640 el_avail
[SSA_NAME_VERSION (valnum
)] = NULL_TREE
;
4642 el_avail
[SSA_NAME_VERSION (valnum
)] = entry
;
4646 /* Eliminate fully redundant computations. */
4649 eliminate (bool do_pre
)
4651 gimple_stmt_iterator gsi
;
4654 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4655 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4657 el_to_remove
.create (0);
4658 el_to_fixup
.create (0);
4660 el_avail
.create (num_ssa_names
);
4661 el_avail_stack
.create (0);
4663 eliminate_dom_walker (CDI_DOMINATORS
,
4664 do_pre
).walk (cfun
->cfg
->x_entry_block_ptr
);
4666 el_avail
.release ();
4667 el_avail_stack
.release ();
4669 /* We cannot remove stmts during BB walk, especially not release SSA
4670 names there as this confuses the VN machinery. The stmts ending
4671 up in el_to_remove are either stores or simple copies.
4672 Remove stmts in reverse order to make debug stmt creation possible. */
4673 while (!el_to_remove
.is_empty ())
4675 stmt
= el_to_remove
.pop ();
4677 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4679 fprintf (dump_file
, "Removing dead stmt ");
4680 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4684 if (gimple_code (stmt
) == GIMPLE_PHI
)
4685 lhs
= gimple_phi_result (stmt
);
4687 lhs
= gimple_get_lhs (stmt
);
4690 && TREE_CODE (lhs
) == SSA_NAME
)
4691 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4693 gsi
= gsi_for_stmt (stmt
);
4694 if (gimple_code (stmt
) == GIMPLE_PHI
)
4695 remove_phi_node (&gsi
, true);
4698 basic_block bb
= gimple_bb (stmt
);
4699 unlink_stmt_vdef (stmt
);
4700 if (gsi_remove (&gsi
, true))
4701 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4702 if (is_gimple_call (stmt
) && stmt_can_make_abnormal_goto (stmt
))
4703 bitmap_set_bit (need_ab_cleanup
, bb
->index
);
4704 release_defs (stmt
);
4707 /* Removing a stmt may expose a forwarder block. */
4708 el_todo
|= TODO_cleanup_cfg
;
4710 el_to_remove
.release ();
4712 /* Fixup stmts that became noreturn calls. This may require splitting
4713 blocks and thus isn't possible during the dominator walk. Do this
4714 in reverse order so we don't inadvertedly remove a stmt we want to
4715 fixup by visiting a dominating now noreturn call first. */
4716 while (!el_to_fixup
.is_empty ())
4718 stmt
= el_to_fixup
.pop ();
4720 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4722 fprintf (dump_file
, "Fixing up noreturn call ");
4723 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4726 if (fixup_noreturn_call (stmt
))
4727 el_todo
|= TODO_cleanup_cfg
;
4729 el_to_fixup
.release ();
4734 /* Perform CFG cleanups made necessary by elimination. */
4737 fini_eliminate (void)
4739 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4740 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4743 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4746 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4748 BITMAP_FREE (need_eh_cleanup
);
4749 BITMAP_FREE (need_ab_cleanup
);
4751 if (do_eh_cleanup
|| do_ab_cleanup
)
4752 return TODO_cleanup_cfg
;
4756 /* Borrow a bit of tree-ssa-dce.c for the moment.
4757 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4758 this may be a bit faster, and we may want critical edges kept split. */
4760 /* If OP's defining statement has not already been determined to be necessary,
4761 mark that statement necessary. Return the stmt, if it is newly
4764 static inline gimple
*
4765 mark_operand_necessary (tree op
)
4771 if (TREE_CODE (op
) != SSA_NAME
)
4774 stmt
= SSA_NAME_DEF_STMT (op
);
4777 if (gimple_plf (stmt
, NECESSARY
)
4778 || gimple_nop_p (stmt
))
4781 gimple_set_plf (stmt
, NECESSARY
, true);
4785 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4786 to insert PHI nodes sometimes, and because value numbering of casts isn't
4787 perfect, we sometimes end up inserting dead code. This simple DCE-like
4788 pass removes any insertions we made that weren't actually used. */
4791 remove_dead_inserted_code (void)
4798 worklist
= BITMAP_ALLOC (NULL
);
4799 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4801 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4802 if (gimple_plf (t
, NECESSARY
))
4803 bitmap_set_bit (worklist
, i
);
4805 while (!bitmap_empty_p (worklist
))
4807 i
= bitmap_first_set_bit (worklist
);
4808 bitmap_clear_bit (worklist
, i
);
4809 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4811 /* PHI nodes are somewhat special in that each PHI alternative has
4812 data and control dependencies. All the statements feeding the
4813 PHI node's arguments are always necessary. */
4814 if (gimple_code (t
) == GIMPLE_PHI
)
4818 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4820 tree arg
= PHI_ARG_DEF (t
, k
);
4821 if (TREE_CODE (arg
) == SSA_NAME
)
4823 gimple
*n
= mark_operand_necessary (arg
);
4825 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4831 /* Propagate through the operands. Examine all the USE, VUSE and
4832 VDEF operands in this statement. Mark all the statements
4833 which feed this statement's uses as necessary. */
4837 /* The operands of VDEF expressions are also needed as they
4838 represent potential definitions that may reach this
4839 statement (VDEF operands allow us to follow def-def
4842 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4844 gimple
*n
= mark_operand_necessary (use
);
4846 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4851 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4853 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4854 if (!gimple_plf (t
, NECESSARY
))
4856 gimple_stmt_iterator gsi
;
4858 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4860 fprintf (dump_file
, "Removing unnecessary insertion:");
4861 print_gimple_stmt (dump_file
, t
, 0, 0);
4864 gsi
= gsi_for_stmt (t
);
4865 if (gimple_code (t
) == GIMPLE_PHI
)
4866 remove_phi_node (&gsi
, true);
4869 gsi_remove (&gsi
, true);
4874 BITMAP_FREE (worklist
);
4878 /* Initialize data structures used by PRE. */
4885 next_expression_id
= 1;
4886 expressions
.create (0);
4887 expressions
.safe_push (NULL
);
4888 value_expressions
.create (get_max_value_id () + 1);
4889 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4890 name_to_id
.create (0);
4892 inserted_exprs
= BITMAP_ALLOC (NULL
);
4894 connect_infinite_loops_to_exit ();
4895 memset (&pre_stats
, 0, sizeof (pre_stats
));
4897 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4899 calculate_dominance_info (CDI_DOMINATORS
);
4901 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4902 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4903 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4904 FOR_ALL_BB_FN (bb
, cfun
)
4906 EXP_GEN (bb
) = bitmap_set_new ();
4907 PHI_GEN (bb
) = bitmap_set_new ();
4908 TMP_GEN (bb
) = bitmap_set_new ();
4909 AVAIL_OUT (bb
) = bitmap_set_new ();
4914 /* Deallocate data structures used by PRE. */
4919 value_expressions
.release ();
4920 BITMAP_FREE (inserted_exprs
);
4921 bitmap_obstack_release (&grand_bitmap_obstack
);
4922 bitmap_set_pool
.release ();
4923 pre_expr_pool
.release ();
4924 delete phi_translate_table
;
4925 phi_translate_table
= NULL
;
4926 delete expression_to_id
;
4927 expression_to_id
= NULL
;
4928 name_to_id
.release ();
4930 free_aux_for_blocks ();
4935 const pass_data pass_data_pre
=
4937 GIMPLE_PASS
, /* type */
4939 OPTGROUP_NONE
, /* optinfo_flags */
4940 TV_TREE_PRE
, /* tv_id */
4941 /* PROP_no_crit_edges is ensured by placing pass_split_crit_edges before
4943 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4944 0, /* properties_provided */
4945 PROP_no_crit_edges
, /* properties_destroyed */
4946 TODO_rebuild_alias
, /* todo_flags_start */
4947 0, /* todo_flags_finish */
4950 class pass_pre
: public gimple_opt_pass
4953 pass_pre (gcc::context
*ctxt
)
4954 : gimple_opt_pass (pass_data_pre
, ctxt
)
4957 /* opt_pass methods: */
4958 virtual bool gate (function
*)
4959 { return flag_tree_pre
!= 0 || flag_code_hoisting
!= 0; }
4960 virtual unsigned int execute (function
*);
4962 }; // class pass_pre
4965 pass_pre::execute (function
*fun
)
4967 unsigned int todo
= 0;
4969 do_partial_partial
=
4970 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
4972 /* This has to happen before SCCVN runs because
4973 loop_optimizer_init may create new phis, etc. */
4974 loop_optimizer_init (LOOPS_NORMAL
);
4976 if (!run_scc_vn (VN_WALK
))
4978 loop_optimizer_finalize ();
4985 /* Collect and value number expressions computed in each basic block. */
4988 /* Insert can get quite slow on an incredibly large number of basic
4989 blocks due to some quadratic behavior. Until this behavior is
4990 fixed, don't run it when he have an incredibly large number of
4991 bb's. If we aren't going to run insert, there is no point in
4992 computing ANTIC, either, even though it's plenty fast. */
4993 if (n_basic_blocks_for_fn (fun
) < 4000)
4999 /* Make sure to remove fake edges before committing our inserts.
5000 This makes sure we don't end up with extra critical edges that
5001 we would need to split. */
5002 remove_fake_exit_edges ();
5003 gsi_commit_edge_inserts ();
5005 /* Eliminate folds statements which might (should not...) end up
5006 not keeping virtual operands up-to-date. */
5007 gcc_assert (!need_ssa_update_p (fun
));
5009 /* Remove all the redundant expressions. */
5010 todo
|= eliminate (true);
5012 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5013 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
5014 statistics_counter_event (fun
, "HOIST inserted", pre_stats
.hoist_insert
);
5015 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
5016 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5018 clear_expression_ids ();
5019 remove_dead_inserted_code ();
5023 todo
|= fini_eliminate ();
5024 loop_optimizer_finalize ();
5026 /* Restore SSA info before tail-merging as that resets it as well. */
5027 scc_vn_restore_ssa_info ();
5029 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
5030 case we can merge the block with the remaining predecessor of the block.
5032 - call merge_blocks after each tail merge iteration
5033 - call merge_blocks after all tail merge iterations
5034 - mark TODO_cleanup_cfg when necessary
5035 - share the cfg cleanup with fini_pre. */
5036 todo
|= tail_merge_optimize (todo
);
5040 /* Tail merging invalidates the virtual SSA web, together with
5041 cfg-cleanup opportunities exposed by PRE this will wreck the
5042 SSA updating machinery. So make sure to run update-ssa
5043 manually, before eventually scheduling cfg-cleanup as part of
5045 update_ssa (TODO_update_ssa_only_virtuals
);
5053 make_pass_pre (gcc::context
*ctxt
)
5055 return new pass_pre (ctxt
);
5060 const pass_data pass_data_fre
=
5062 GIMPLE_PASS
, /* type */
5064 OPTGROUP_NONE
, /* optinfo_flags */
5065 TV_TREE_FRE
, /* tv_id */
5066 ( PROP_cfg
| PROP_ssa
), /* properties_required */
5067 0, /* properties_provided */
5068 0, /* properties_destroyed */
5069 0, /* todo_flags_start */
5070 0, /* todo_flags_finish */
5073 class pass_fre
: public gimple_opt_pass
5076 pass_fre (gcc::context
*ctxt
)
5077 : gimple_opt_pass (pass_data_fre
, ctxt
)
5080 /* opt_pass methods: */
5081 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
5082 virtual bool gate (function
*) { return flag_tree_fre
!= 0; }
5083 virtual unsigned int execute (function
*);
5085 }; // class pass_fre
5088 pass_fre::execute (function
*fun
)
5090 unsigned int todo
= 0;
5092 if (!run_scc_vn (VN_WALKREWRITE
))
5095 memset (&pre_stats
, 0, sizeof (pre_stats
));
5097 /* Remove all the redundant expressions. */
5098 todo
|= eliminate (false);
5100 todo
|= fini_eliminate ();
5102 scc_vn_restore_ssa_info ();
5105 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5106 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5114 make_pass_fre (gcc::context
*ctxt
)
5116 return new pass_fre (ctxt
);