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 or an SSA name. 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 if (TREE_CODE (res
) == SSA_NAME
)
1222 return get_or_alloc_expr_for_name (res
);
1227 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1229 if ((folded
= fully_constant_vn_reference_p (ref
)))
1230 return get_or_alloc_expr_for_constant (folded
);
1239 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1240 it has the value it would have in BLOCK. Set *SAME_VALID to true
1241 in case the new vuse doesn't change the value id of the OPERANDS. */
1244 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1245 alias_set_type set
, tree type
, tree vuse
,
1246 basic_block phiblock
,
1247 basic_block block
, bool *same_valid
)
1249 gimple
*phi
= SSA_NAME_DEF_STMT (vuse
);
1256 if (gimple_bb (phi
) != phiblock
)
1259 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1261 /* Use the alias-oracle to find either the PHI node in this block,
1262 the first VUSE used in this block that is equivalent to vuse or
1263 the first VUSE which definition in this block kills the value. */
1264 if (gimple_code (phi
) == GIMPLE_PHI
)
1265 e
= find_edge (block
, phiblock
);
1266 else if (use_oracle
)
1267 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1269 vuse
= gimple_vuse (phi
);
1270 phi
= SSA_NAME_DEF_STMT (vuse
);
1271 if (gimple_bb (phi
) != phiblock
)
1273 if (gimple_code (phi
) == GIMPLE_PHI
)
1275 e
= find_edge (block
, phiblock
);
1286 bitmap visited
= NULL
;
1288 /* Try to find a vuse that dominates this phi node by skipping
1289 non-clobbering statements. */
1290 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false,
1293 BITMAP_FREE (visited
);
1299 /* If we didn't find any, the value ID can't stay the same,
1300 but return the translated vuse. */
1301 *same_valid
= false;
1302 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1304 /* ??? We would like to return vuse here as this is the canonical
1305 upmost vdef that this reference is associated with. But during
1306 insertion of the references into the hash tables we only ever
1307 directly insert with their direct gimple_vuse, hence returning
1308 something else would make us not find the other expression. */
1309 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1315 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1316 SET2. This is used to avoid making a set consisting of the union
1317 of PA_IN and ANTIC_IN during insert. */
1319 static inline pre_expr
1320 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1324 result
= bitmap_find_leader (set1
, val
);
1325 if (!result
&& set2
)
1326 result
= bitmap_find_leader (set2
, val
);
1330 /* Get the tree type for our PRE expression e. */
1333 get_expr_type (const pre_expr e
)
1338 return TREE_TYPE (PRE_EXPR_NAME (e
));
1340 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1342 return PRE_EXPR_REFERENCE (e
)->type
;
1344 return PRE_EXPR_NARY (e
)->type
;
1349 /* Get a representative SSA_NAME for a given expression.
1350 Since all of our sub-expressions are treated as values, we require
1351 them to be SSA_NAME's for simplicity.
1352 Prior versions of GVNPRE used to use "value handles" here, so that
1353 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1354 either case, the operands are really values (IE we do not expect
1355 them to be usable without finding leaders). */
1358 get_representative_for (const pre_expr e
)
1361 unsigned int value_id
= get_expr_value_id (e
);
1366 return VN_INFO (PRE_EXPR_NAME (e
))->valnum
;
1368 return PRE_EXPR_CONSTANT (e
);
1372 /* Go through all of the expressions representing this value
1373 and pick out an SSA_NAME. */
1376 bitmap exprs
= value_expressions
[value_id
];
1377 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1379 pre_expr rep
= expression_for_id (i
);
1380 if (rep
->kind
== NAME
)
1381 return VN_INFO (PRE_EXPR_NAME (rep
))->valnum
;
1382 else if (rep
->kind
== CONSTANT
)
1383 return PRE_EXPR_CONSTANT (rep
);
1389 /* If we reached here we couldn't find an SSA_NAME. This can
1390 happen when we've discovered a value that has never appeared in
1391 the program as set to an SSA_NAME, as the result of phi translation.
1393 ??? We should be able to re-use this when we insert the statement
1395 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1396 VN_INFO_GET (name
)->value_id
= value_id
;
1397 VN_INFO (name
)->valnum
= name
;
1398 /* ??? For now mark this SSA name for release by SCCVN. */
1399 VN_INFO (name
)->needs_insertion
= true;
1400 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1401 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1403 fprintf (dump_file
, "Created SSA_NAME representative ");
1404 print_generic_expr (dump_file
, name
, 0);
1405 fprintf (dump_file
, " for expression:");
1406 print_pre_expr (dump_file
, e
);
1407 fprintf (dump_file
, " (%04d)\n", value_id
);
1416 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1417 basic_block pred
, basic_block phiblock
);
1419 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1420 the phis in PRED. Return NULL if we can't find a leader for each part
1421 of the translated expression. */
1424 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1425 basic_block pred
, basic_block phiblock
)
1432 bool changed
= false;
1433 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1434 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1435 sizeof_vn_nary_op (nary
->length
));
1436 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1438 for (i
= 0; i
< newnary
->length
; i
++)
1440 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1444 pre_expr leader
, result
;
1445 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1446 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1447 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1448 if (result
&& result
!= leader
)
1449 newnary
->op
[i
] = get_representative_for (result
);
1453 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1459 unsigned int new_val_id
;
1461 PRE_EXPR_NARY (expr
) = newnary
;
1462 constant
= fully_constant_expression (expr
);
1463 PRE_EXPR_NARY (expr
) = nary
;
1464 if (constant
!= expr
)
1466 /* For non-CONSTANTs we have to make sure we can eventually
1467 insert the expression. Which means we need to have a
1469 if (constant
->kind
!= CONSTANT
)
1471 unsigned value_id
= get_expr_value_id (constant
);
1472 constant
= find_leader_in_sets (value_id
, set1
, set2
);
1480 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1485 if (result
&& is_gimple_min_invariant (result
))
1486 return get_or_alloc_expr_for_constant (result
);
1488 expr
= pre_expr_pool
.allocate ();
1493 PRE_EXPR_NARY (expr
) = nary
;
1494 new_val_id
= nary
->value_id
;
1495 get_or_alloc_expression_id (expr
);
1499 new_val_id
= get_next_value_id ();
1500 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1501 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1505 result
, new_val_id
);
1506 PRE_EXPR_NARY (expr
) = nary
;
1507 get_or_alloc_expression_id (expr
);
1509 add_to_value (new_val_id
, expr
);
1517 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1518 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1519 tree vuse
= ref
->vuse
;
1520 tree newvuse
= vuse
;
1521 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1522 bool changed
= false, same_valid
= true;
1524 vn_reference_op_t operand
;
1525 vn_reference_t newref
;
1527 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1532 tree type
= operand
->type
;
1533 vn_reference_op_s newop
= *operand
;
1534 op
[0] = operand
->op0
;
1535 op
[1] = operand
->op1
;
1536 op
[2] = operand
->op2
;
1537 for (n
= 0; n
< 3; ++n
)
1539 unsigned int op_val_id
;
1542 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1544 /* We can't possibly insert these. */
1546 && !is_gimple_min_invariant (op
[n
]))
1550 op_val_id
= VN_INFO (op
[n
])->value_id
;
1551 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1552 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1553 if (opresult
&& opresult
!= leader
)
1555 tree name
= get_representative_for (opresult
);
1556 changed
|= name
!= op
[n
];
1564 newoperands
.release ();
1569 if (!newoperands
.exists ())
1570 newoperands
= operands
.copy ();
1571 /* We may have changed from an SSA_NAME to a constant */
1572 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1573 newop
.opcode
= TREE_CODE (op
[0]);
1578 newoperands
[i
] = newop
;
1580 gcc_checking_assert (i
== operands
.length ());
1584 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1585 ? newoperands
: operands
,
1586 ref
->set
, ref
->type
,
1587 vuse
, phiblock
, pred
,
1589 if (newvuse
== NULL_TREE
)
1591 newoperands
.release ();
1596 if (changed
|| newvuse
!= vuse
)
1598 unsigned int new_val_id
;
1601 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1603 newoperands
.exists ()
1604 ? newoperands
: operands
,
1607 newoperands
.release ();
1609 /* We can always insert constants, so if we have a partial
1610 redundant constant load of another type try to translate it
1611 to a constant of appropriate type. */
1612 if (result
&& is_gimple_min_invariant (result
))
1615 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1617 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1618 if (tem
&& !is_gimple_min_invariant (tem
))
1622 return get_or_alloc_expr_for_constant (tem
);
1625 /* If we'd have to convert things we would need to validate
1626 if we can insert the translated expression. So fail
1627 here for now - we cannot insert an alias with a different
1628 type in the VN tables either, as that would assert. */
1630 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1632 else if (!result
&& newref
1633 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1635 newoperands
.release ();
1639 expr
= pre_expr_pool
.allocate ();
1640 expr
->kind
= REFERENCE
;
1645 PRE_EXPR_REFERENCE (expr
) = newref
;
1646 constant
= fully_constant_expression (expr
);
1647 if (constant
!= expr
)
1650 new_val_id
= newref
->value_id
;
1651 get_or_alloc_expression_id (expr
);
1655 if (changed
|| !same_valid
)
1657 new_val_id
= get_next_value_id ();
1658 value_expressions
.safe_grow_cleared
1659 (get_max_value_id () + 1);
1662 new_val_id
= ref
->value_id
;
1663 if (!newoperands
.exists ())
1664 newoperands
= operands
.copy ();
1665 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1668 result
, new_val_id
);
1669 newoperands
= vNULL
;
1670 PRE_EXPR_REFERENCE (expr
) = newref
;
1671 constant
= fully_constant_expression (expr
);
1672 if (constant
!= expr
)
1674 get_or_alloc_expression_id (expr
);
1676 add_to_value (new_val_id
, expr
);
1678 newoperands
.release ();
1685 tree name
= PRE_EXPR_NAME (expr
);
1686 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1687 /* If the SSA name is defined by a PHI node in this block,
1689 if (gimple_code (def_stmt
) == GIMPLE_PHI
1690 && gimple_bb (def_stmt
) == phiblock
)
1692 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1693 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1695 /* Handle constant. */
1696 if (is_gimple_min_invariant (def
))
1697 return get_or_alloc_expr_for_constant (def
);
1699 return get_or_alloc_expr_for_name (def
);
1701 /* Otherwise return it unchanged - it will get removed if its
1702 value is not available in PREDs AVAIL_OUT set of expressions
1703 by the subtraction of TMP_GEN. */
1712 /* Wrapper around phi_translate_1 providing caching functionality. */
1715 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1716 basic_block pred
, basic_block phiblock
)
1718 expr_pred_trans_t slot
= NULL
;
1724 /* Constants contain no values that need translation. */
1725 if (expr
->kind
== CONSTANT
)
1728 if (value_id_constant_p (get_expr_value_id (expr
)))
1731 /* Don't add translations of NAMEs as those are cheap to translate. */
1732 if (expr
->kind
!= NAME
)
1734 if (phi_trans_add (&slot
, expr
, pred
))
1736 /* Store NULL for the value we want to return in the case of
1742 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1749 /* Remove failed translations again, they cause insert
1750 iteration to not pick up new opportunities reliably. */
1751 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1758 /* For each expression in SET, translate the values through phi nodes
1759 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1760 expressions in DEST. */
1763 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1764 basic_block phiblock
)
1766 vec
<pre_expr
> exprs
;
1770 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1772 bitmap_set_copy (dest
, set
);
1776 exprs
= sorted_array_from_bitmap_set (set
);
1777 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1779 pre_expr translated
;
1780 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1784 /* We might end up with multiple expressions from SET being
1785 translated to the same value. In this case we do not want
1786 to retain the NARY or REFERENCE expression but prefer a NAME
1787 which would be the leader. */
1788 if (translated
->kind
== NAME
)
1789 bitmap_value_replace_in_set (dest
, translated
);
1791 bitmap_value_insert_into_set (dest
, translated
);
1796 /* Find the leader for a value (i.e., the name representing that
1797 value) in a given set, and return it. Return NULL if no leader
1801 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1803 if (value_id_constant_p (val
))
1807 bitmap exprset
= value_expressions
[val
];
1809 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1811 pre_expr expr
= expression_for_id (i
);
1812 if (expr
->kind
== CONSTANT
)
1816 if (bitmap_set_contains_value (set
, val
))
1818 /* Rather than walk the entire bitmap of expressions, and see
1819 whether any of them has the value we are looking for, we look
1820 at the reverse mapping, which tells us the set of expressions
1821 that have a given value (IE value->expressions with that
1822 value) and see if any of those expressions are in our set.
1823 The number of expressions per value is usually significantly
1824 less than the number of expressions in the set. In fact, for
1825 large testcases, doing it this way is roughly 5-10x faster
1826 than walking the bitmap.
1827 If this is somehow a significant lose for some cases, we can
1828 choose which set to walk based on which set is smaller. */
1831 bitmap exprset
= value_expressions
[val
];
1833 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1834 return expression_for_id (i
);
1839 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1840 BLOCK by seeing if it is not killed in the block. Note that we are
1841 only determining whether there is a store that kills it. Because
1842 of the order in which clean iterates over values, we are guaranteed
1843 that altered operands will have caused us to be eliminated from the
1844 ANTIC_IN set already. */
1847 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1849 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1850 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1852 gimple_stmt_iterator gsi
;
1853 unsigned id
= get_expression_id (expr
);
1860 /* Lookup a previously calculated result. */
1861 if (EXPR_DIES (block
)
1862 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1863 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1865 /* A memory expression {e, VUSE} dies in the block if there is a
1866 statement that may clobber e. If, starting statement walk from the
1867 top of the basic block, a statement uses VUSE there can be no kill
1868 inbetween that use and the original statement that loaded {e, VUSE},
1869 so we can stop walking. */
1870 ref
.base
= NULL_TREE
;
1871 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1873 tree def_vuse
, def_vdef
;
1874 def
= gsi_stmt (gsi
);
1875 def_vuse
= gimple_vuse (def
);
1876 def_vdef
= gimple_vdef (def
);
1878 /* Not a memory statement. */
1882 /* Not a may-def. */
1885 /* A load with the same VUSE, we're done. */
1886 if (def_vuse
== vuse
)
1892 /* Init ref only if we really need it. */
1893 if (ref
.base
== NULL_TREE
1894 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1900 /* If the statement may clobber expr, it dies. */
1901 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1908 /* Remember the result. */
1909 if (!EXPR_DIES (block
))
1910 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1911 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1913 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1919 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1920 contains its value-id. */
1923 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1925 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1927 unsigned int value_id
= VN_INFO (op
)->value_id
;
1928 if (!(bitmap_set_contains_value (set1
, value_id
)
1929 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1935 /* Determine if the expression EXPR is valid in SET1 U SET2.
1936 ONLY SET2 CAN BE NULL.
1937 This means that we have a leader for each part of the expression
1938 (if it consists of values), or the expression is an SSA_NAME.
1939 For loads/calls, we also see if the vuse is killed in this block. */
1942 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1947 /* By construction all NAMEs are available. Non-available
1948 NAMEs are removed by subtracting TMP_GEN from the sets. */
1953 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1954 for (i
= 0; i
< nary
->length
; i
++)
1955 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1962 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1963 vn_reference_op_t vro
;
1966 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1968 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1969 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1970 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1980 /* Clean the set of expressions that are no longer valid in SET1 or
1981 SET2. This means expressions that are made up of values we have no
1982 leaders for in SET1 or SET2. This version is used for partial
1983 anticipation, which means it is not valid in either ANTIC_IN or
1987 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
)
1989 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
1993 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1995 if (!valid_in_sets (set1
, set2
, expr
))
1996 bitmap_remove_from_set (set1
, expr
);
2001 /* Clean the set of expressions that are no longer valid in SET. This
2002 means expressions that are made up of values we have no leaders for
2006 clean (bitmap_set_t set
)
2008 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2012 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2014 if (!valid_in_sets (set
, NULL
, expr
))
2015 bitmap_remove_from_set (set
, expr
);
2020 /* Clean the set of expressions that are no longer valid in SET because
2021 they are clobbered in BLOCK or because they trap and may not be executed. */
2024 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2029 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2031 pre_expr expr
= expression_for_id (i
);
2032 if (expr
->kind
== REFERENCE
)
2034 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2037 gimple
*def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2038 if (!gimple_nop_p (def_stmt
)
2039 && ((gimple_bb (def_stmt
) != block
2040 && !dominated_by_p (CDI_DOMINATORS
,
2041 block
, gimple_bb (def_stmt
)))
2042 || (gimple_bb (def_stmt
) == block
2043 && value_dies_in_block_x (expr
, block
))))
2044 bitmap_remove_from_set (set
, expr
);
2047 else if (expr
->kind
== NARY
)
2049 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2050 /* If the NARY may trap make sure the block does not contain
2051 a possible exit point.
2052 ??? This is overly conservative if we translate AVAIL_OUT
2053 as the available expression might be after the exit point. */
2054 if (BB_MAY_NOTRETURN (block
)
2055 && vn_nary_may_trap (nary
))
2056 bitmap_remove_from_set (set
, expr
);
2061 static sbitmap has_abnormal_preds
;
2063 /* Compute the ANTIC set for BLOCK.
2065 If succs(BLOCK) > 1 then
2066 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2067 else if succs(BLOCK) == 1 then
2068 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2070 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2074 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2076 bool changed
= false;
2077 bitmap_set_t S
, old
, ANTIC_OUT
;
2082 bool was_visited
= BB_VISITED (block
);
2084 old
= ANTIC_OUT
= S
= NULL
;
2085 BB_VISITED (block
) = 1;
2087 /* If any edges from predecessors are abnormal, antic_in is empty,
2089 if (block_has_abnormal_pred_edge
)
2090 goto maybe_dump_sets
;
2092 old
= ANTIC_IN (block
);
2093 ANTIC_OUT
= bitmap_set_new ();
2095 /* If the block has no successors, ANTIC_OUT is empty. */
2096 if (EDGE_COUNT (block
->succs
) == 0)
2098 /* If we have one successor, we could have some phi nodes to
2099 translate through. */
2100 else if (single_succ_p (block
))
2102 basic_block succ_bb
= single_succ (block
);
2103 gcc_assert (BB_VISITED (succ_bb
));
2104 phi_translate_set (ANTIC_OUT
, ANTIC_IN (succ_bb
), block
, succ_bb
);
2106 /* If we have multiple successors, we take the intersection of all of
2107 them. Note that in the case of loop exit phi nodes, we may have
2108 phis to translate through. */
2112 basic_block bprime
, first
= NULL
;
2114 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2115 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2118 && BB_VISITED (e
->dest
))
2120 else if (BB_VISITED (e
->dest
))
2121 worklist
.quick_push (e
->dest
);
2124 /* Unvisited successors get their ANTIC_IN replaced by the
2125 maximal set to arrive at a maximum ANTIC_IN solution.
2126 We can ignore them in the intersection operation and thus
2127 need not explicitely represent that maximum solution. */
2128 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2129 fprintf (dump_file
, "ANTIC_IN is MAX on %d->%d\n",
2130 e
->src
->index
, e
->dest
->index
);
2134 /* Of multiple successors we have to have visited one already
2135 which is guaranteed by iteration order. */
2136 gcc_assert (first
!= NULL
);
2138 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2140 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2142 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2144 bitmap_set_t tmp
= bitmap_set_new ();
2145 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2146 bitmap_set_and (ANTIC_OUT
, tmp
);
2147 bitmap_set_free (tmp
);
2150 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2154 /* Prune expressions that are clobbered in block and thus become
2155 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2156 prune_clobbered_mems (ANTIC_OUT
, block
);
2158 /* Generate ANTIC_OUT - TMP_GEN. */
2159 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2161 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2162 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2165 /* Then union in the ANTIC_OUT - TMP_GEN values,
2166 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2167 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2168 bitmap_value_insert_into_set (ANTIC_IN (block
),
2169 expression_for_id (bii
));
2171 clean (ANTIC_IN (block
));
2173 if (!was_visited
|| !bitmap_set_equal (old
, ANTIC_IN (block
)))
2177 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2180 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2183 fprintf (dump_file
, "[changed] ");
2184 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2188 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2191 bitmap_set_free (old
);
2193 bitmap_set_free (S
);
2195 bitmap_set_free (ANTIC_OUT
);
2199 /* Compute PARTIAL_ANTIC for BLOCK.
2201 If succs(BLOCK) > 1 then
2202 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2203 in ANTIC_OUT for all succ(BLOCK)
2204 else if succs(BLOCK) == 1 then
2205 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2207 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2212 compute_partial_antic_aux (basic_block block
,
2213 bool block_has_abnormal_pred_edge
)
2215 bitmap_set_t old_PA_IN
;
2216 bitmap_set_t PA_OUT
;
2219 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2221 old_PA_IN
= PA_OUT
= NULL
;
2223 /* If any edges from predecessors are abnormal, antic_in is empty,
2225 if (block_has_abnormal_pred_edge
)
2226 goto maybe_dump_sets
;
2228 /* If there are too many partially anticipatable values in the
2229 block, phi_translate_set can take an exponential time: stop
2230 before the translation starts. */
2232 && single_succ_p (block
)
2233 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2234 goto maybe_dump_sets
;
2236 old_PA_IN
= PA_IN (block
);
2237 PA_OUT
= bitmap_set_new ();
2239 /* If the block has no successors, ANTIC_OUT is empty. */
2240 if (EDGE_COUNT (block
->succs
) == 0)
2242 /* If we have one successor, we could have some phi nodes to
2243 translate through. Note that we can't phi translate across DFS
2244 back edges in partial antic, because it uses a union operation on
2245 the successors. For recurrences like IV's, we will end up
2246 generating a new value in the set on each go around (i + 3 (VH.1)
2247 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2248 else if (single_succ_p (block
))
2250 basic_block succ
= single_succ (block
);
2251 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2252 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2254 /* If we have multiple successors, we take the union of all of
2261 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2262 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2264 if (e
->flags
& EDGE_DFS_BACK
)
2266 worklist
.quick_push (e
->dest
);
2268 if (worklist
.length () > 0)
2270 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2275 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2276 bitmap_value_insert_into_set (PA_OUT
,
2277 expression_for_id (i
));
2278 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2280 bitmap_set_t pa_in
= bitmap_set_new ();
2281 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2282 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2283 bitmap_value_insert_into_set (PA_OUT
,
2284 expression_for_id (i
));
2285 bitmap_set_free (pa_in
);
2288 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2289 bitmap_value_insert_into_set (PA_OUT
,
2290 expression_for_id (i
));
2295 /* Prune expressions that are clobbered in block and thus become
2296 invalid if translated from PA_OUT to PA_IN. */
2297 prune_clobbered_mems (PA_OUT
, block
);
2299 /* PA_IN starts with PA_OUT - TMP_GEN.
2300 Then we subtract things from ANTIC_IN. */
2301 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2303 /* For partial antic, we want to put back in the phi results, since
2304 we will properly avoid making them partially antic over backedges. */
2305 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2306 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2308 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2309 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2311 dependent_clean (PA_IN (block
), ANTIC_IN (block
));
2314 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2317 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2319 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2322 bitmap_set_free (old_PA_IN
);
2324 bitmap_set_free (PA_OUT
);
2327 /* Compute ANTIC and partial ANTIC sets. */
2330 compute_antic (void)
2332 bool changed
= true;
2333 int num_iterations
= 0;
2339 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2340 We pre-build the map of blocks with incoming abnormal edges here. */
2341 has_abnormal_preds
= sbitmap_alloc (last_basic_block_for_fn (cfun
));
2342 bitmap_clear (has_abnormal_preds
);
2344 FOR_ALL_BB_FN (block
, cfun
)
2346 BB_VISITED (block
) = 0;
2348 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2349 if (e
->flags
& EDGE_ABNORMAL
)
2351 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2353 /* We also anticipate nothing. */
2354 BB_VISITED (block
) = 1;
2358 /* While we are here, give empty ANTIC_IN sets to each block. */
2359 ANTIC_IN (block
) = bitmap_set_new ();
2360 if (do_partial_partial
)
2361 PA_IN (block
) = bitmap_set_new ();
2364 /* At the exit block we anticipate nothing. */
2365 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2367 /* For ANTIC computation we need a postorder that also guarantees that
2368 a block with a single successor is visited after its successor.
2369 RPO on the inverted CFG has this property. */
2370 int *postorder
= XNEWVEC (int, n_basic_blocks_for_fn (cfun
));
2371 int postorder_num
= inverted_post_order_compute (postorder
);
2373 auto_sbitmap
worklist (last_basic_block_for_fn (cfun
) + 1);
2374 bitmap_ones (worklist
);
2377 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2378 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2379 /* ??? We need to clear our PHI translation cache here as the
2380 ANTIC sets shrink and we restrict valid translations to
2381 those having operands with leaders in ANTIC. Same below
2382 for PA ANTIC computation. */
2385 for (i
= postorder_num
- 1; i
>= 0; i
--)
2387 if (bitmap_bit_p (worklist
, postorder
[i
]))
2389 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2390 bitmap_clear_bit (worklist
, block
->index
);
2391 if (compute_antic_aux (block
,
2392 bitmap_bit_p (has_abnormal_preds
,
2395 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2396 bitmap_set_bit (worklist
, e
->src
->index
);
2401 /* Theoretically possible, but *highly* unlikely. */
2402 gcc_checking_assert (num_iterations
< 500);
2405 statistics_histogram_event (cfun
, "compute_antic iterations",
2408 if (do_partial_partial
)
2410 /* For partial antic we ignore backedges and thus we do not need
2411 to perform any iteration when we process blocks in postorder. */
2412 postorder_num
= pre_and_rev_post_order_compute (NULL
, postorder
, false);
2413 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2415 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2416 compute_partial_antic_aux (block
,
2417 bitmap_bit_p (has_abnormal_preds
,
2422 sbitmap_free (has_abnormal_preds
);
2427 /* Inserted expressions are placed onto this worklist, which is used
2428 for performing quick dead code elimination of insertions we made
2429 that didn't turn out to be necessary. */
2430 static bitmap inserted_exprs
;
2432 /* The actual worker for create_component_ref_by_pieces. */
2435 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2436 unsigned int *operand
, gimple_seq
*stmts
)
2438 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2441 switch (currop
->opcode
)
2448 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2452 tree offset
= currop
->op0
;
2453 if (TREE_CODE (baseop
) == ADDR_EXPR
2454 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2458 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2461 offset
= int_const_binop (PLUS_EXPR
, offset
,
2462 build_int_cst (TREE_TYPE (offset
),
2464 baseop
= build_fold_addr_expr (base
);
2466 genop
= build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2467 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2468 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2469 REF_REVERSE_STORAGE_ORDER (genop
) = currop
->reverse
;
2473 case TARGET_MEM_REF
:
2475 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2476 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2477 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2483 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2489 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2493 genop
= build5 (TARGET_MEM_REF
, currop
->type
,
2494 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2496 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2497 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2504 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2510 case VIEW_CONVERT_EXPR
:
2512 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2516 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2519 case WITH_SIZE_EXPR
:
2521 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2525 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2528 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2533 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2537 tree op1
= currop
->op0
;
2538 tree op2
= currop
->op1
;
2539 tree t
= build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2540 REF_REVERSE_STORAGE_ORDER (t
) = currop
->reverse
;
2544 /* For array ref vn_reference_op's, operand 1 of the array ref
2545 is op0 of the reference op and operand 3 of the array ref is
2547 case ARRAY_RANGE_REF
:
2551 tree genop1
= currop
->op0
;
2552 tree genop2
= currop
->op1
;
2553 tree genop3
= currop
->op2
;
2554 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2558 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2563 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2564 /* Drop zero minimum index if redundant. */
2565 if (integer_zerop (genop2
)
2567 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2571 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2578 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2579 /* We can't always put a size in units of the element alignment
2580 here as the element alignment may be not visible. See
2581 PR43783. Simply drop the element size for constant
2583 if (TREE_CODE (genop3
) == INTEGER_CST
2584 && TREE_CODE (TYPE_SIZE_UNIT (elmt_type
)) == INTEGER_CST
2585 && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type
)),
2586 (wi::to_offset (genop3
)
2587 * vn_ref_op_align_unit (currop
))))
2591 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2596 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2603 tree genop2
= currop
->op1
;
2604 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2607 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2611 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2615 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2620 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2641 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2642 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2643 trying to rename aggregates into ssa form directly, which is a no no.
2645 Thus, this routine doesn't create temporaries, it just builds a
2646 single access expression for the array, calling
2647 find_or_generate_expression to build the innermost pieces.
2649 This function is a subroutine of create_expression_by_pieces, and
2650 should not be called on it's own unless you really know what you
2654 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2657 unsigned int op
= 0;
2658 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2661 /* Find a simple leader for an expression, or generate one using
2662 create_expression_by_pieces from a NARY expression for the value.
2663 BLOCK is the basic_block we are looking for leaders in.
2664 OP is the tree expression to find a leader for or generate.
2665 Returns the leader or NULL_TREE on failure. */
2668 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2670 pre_expr expr
= get_or_alloc_expr_for (op
);
2671 unsigned int lookfor
= get_expr_value_id (expr
);
2672 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2675 if (leader
->kind
== NAME
)
2676 return PRE_EXPR_NAME (leader
);
2677 else if (leader
->kind
== CONSTANT
)
2678 return PRE_EXPR_CONSTANT (leader
);
2684 /* It must be a complex expression, so generate it recursively. Note
2685 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2686 where the insert algorithm fails to insert a required expression. */
2687 bitmap exprset
= value_expressions
[lookfor
];
2690 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2692 pre_expr temp
= expression_for_id (i
);
2693 /* We cannot insert random REFERENCE expressions at arbitrary
2694 places. We can insert NARYs which eventually re-materializes
2695 its operand values. */
2696 if (temp
->kind
== NARY
)
2697 return create_expression_by_pieces (block
, temp
, stmts
,
2698 get_expr_type (expr
));
2705 #define NECESSARY GF_PLF_1
2707 /* Create an expression in pieces, so that we can handle very complex
2708 expressions that may be ANTIC, but not necessary GIMPLE.
2709 BLOCK is the basic block the expression will be inserted into,
2710 EXPR is the expression to insert (in value form)
2711 STMTS is a statement list to append the necessary insertions into.
2713 This function will die if we hit some value that shouldn't be
2714 ANTIC but is (IE there is no leader for it, or its components).
2715 The function returns NULL_TREE in case a different antic expression
2716 has to be inserted first.
2717 This function may also generate expressions that are themselves
2718 partially or fully redundant. Those that are will be either made
2719 fully redundant during the next iteration of insert (for partially
2720 redundant ones), or eliminated by eliminate (for fully redundant
2724 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2725 gimple_seq
*stmts
, tree type
)
2729 gimple_seq forced_stmts
= NULL
;
2730 unsigned int value_id
;
2731 gimple_stmt_iterator gsi
;
2732 tree exprtype
= type
? type
: get_expr_type (expr
);
2738 /* We may hit the NAME/CONSTANT case if we have to convert types
2739 that value numbering saw through. */
2741 folded
= PRE_EXPR_NAME (expr
);
2742 if (useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2747 folded
= PRE_EXPR_CONSTANT (expr
);
2748 tree tem
= fold_convert (exprtype
, folded
);
2749 if (is_gimple_min_invariant (tem
))
2754 if (PRE_EXPR_REFERENCE (expr
)->operands
[0].opcode
== CALL_EXPR
)
2756 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2757 unsigned int operand
= 1;
2758 vn_reference_op_t currop
= &ref
->operands
[0];
2759 tree sc
= NULL_TREE
;
2761 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2764 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2769 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2773 auto_vec
<tree
> args (ref
->operands
.length () - 1);
2774 while (operand
< ref
->operands
.length ())
2776 tree arg
= create_component_ref_by_pieces_1 (block
, ref
,
2780 args
.quick_push (arg
);
2783 = gimple_build_call_vec ((TREE_CODE (fn
) == FUNCTION_DECL
2784 ? build_fold_addr_expr (fn
) : fn
), args
);
2785 gimple_call_set_with_bounds (call
, currop
->with_bounds
);
2787 gimple_call_set_chain (call
, sc
);
2788 tree forcedname
= make_ssa_name (currop
->type
);
2789 gimple_call_set_lhs (call
, forcedname
);
2790 gimple_set_vuse (call
, BB_LIVE_VOP_ON_EXIT (block
));
2791 gimple_seq_add_stmt_without_update (&forced_stmts
, call
);
2792 folded
= forcedname
;
2796 folded
= create_component_ref_by_pieces (block
,
2797 PRE_EXPR_REFERENCE (expr
),
2801 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2802 newstmt
= gimple_build_assign (name
, folded
);
2803 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2804 gimple_set_vuse (newstmt
, BB_LIVE_VOP_ON_EXIT (block
));
2810 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2811 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2813 for (i
= 0; i
< nary
->length
; ++i
)
2815 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2818 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2819 may have conversions stripped. */
2820 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2823 genop
[i
] = gimple_convert (&forced_stmts
,
2824 nary
->type
, genop
[i
]);
2826 genop
[i
] = gimple_convert (&forced_stmts
,
2827 sizetype
, genop
[i
]);
2830 genop
[i
] = gimple_convert (&forced_stmts
,
2831 TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2833 if (nary
->opcode
== CONSTRUCTOR
)
2835 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2836 for (i
= 0; i
< nary
->length
; ++i
)
2837 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2838 folded
= build_constructor (nary
->type
, elts
);
2839 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2840 newstmt
= gimple_build_assign (name
, folded
);
2841 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2846 switch (nary
->length
)
2849 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2853 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2854 genop
[0], genop
[1]);
2857 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2858 genop
[0], genop
[1], genop
[2]);
2870 folded
= gimple_convert (&forced_stmts
, exprtype
, folded
);
2872 /* If there is nothing to insert, return the simplified result. */
2873 if (gimple_seq_empty_p (forced_stmts
))
2875 /* If we simplified to a constant return it and discard eventually
2877 if (is_gimple_min_invariant (folded
))
2879 gimple_seq_discard (forced_stmts
);
2882 /* Likewise if we simplified to sth not queued for insertion. */
2884 gsi
= gsi_start (forced_stmts
);
2885 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2887 gimple
*stmt
= gsi_stmt (gsi
);
2888 tree forcedname
= gimple_get_lhs (stmt
);
2889 if (forcedname
== folded
)
2894 gimple_seq_discard (forced_stmts
);
2897 gcc_assert (TREE_CODE (folded
) == SSA_NAME
);
2899 /* If we have any intermediate expressions to the value sets, add them
2900 to the value sets and chain them in the instruction stream. */
2903 gsi
= gsi_start (forced_stmts
);
2904 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2906 gimple
*stmt
= gsi_stmt (gsi
);
2907 tree forcedname
= gimple_get_lhs (stmt
);
2910 if (forcedname
!= folded
)
2912 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2913 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2914 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2915 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2916 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2917 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2920 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2921 gimple_set_plf (stmt
, NECESSARY
, false);
2923 gimple_seq_add_seq (stmts
, forced_stmts
);
2928 /* Fold the last statement. */
2929 gsi
= gsi_last (*stmts
);
2930 if (fold_stmt_inplace (&gsi
))
2931 update_stmt (gsi_stmt (gsi
));
2933 /* Add a value number to the temporary.
2934 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2935 we are creating the expression by pieces, and this particular piece of
2936 the expression may have been represented. There is no harm in replacing
2938 value_id
= get_expr_value_id (expr
);
2939 VN_INFO_GET (name
)->value_id
= value_id
;
2940 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2941 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2942 VN_INFO (name
)->valnum
= name
;
2943 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2944 nameexpr
= get_or_alloc_expr_for_name (name
);
2945 add_to_value (value_id
, nameexpr
);
2946 if (NEW_SETS (block
))
2947 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2948 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2950 pre_stats
.insertions
++;
2951 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2953 fprintf (dump_file
, "Inserted ");
2954 print_gimple_stmt (dump_file
, gsi_stmt (gsi_last (*stmts
)), 0, 0);
2955 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2956 block
->index
, value_id
);
2963 /* Insert the to-be-made-available values of expression EXPRNUM for each
2964 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2965 merge the result with a phi node, given the same value number as
2966 NODE. Return true if we have inserted new stuff. */
2969 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2970 vec
<pre_expr
> avail
)
2972 pre_expr expr
= expression_for_id (exprnum
);
2974 unsigned int val
= get_expr_value_id (expr
);
2976 bool insertions
= false;
2981 tree type
= get_expr_type (expr
);
2985 /* Make sure we aren't creating an induction variable. */
2986 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
2988 bool firstinsideloop
= false;
2989 bool secondinsideloop
= false;
2990 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2991 EDGE_PRED (block
, 0)->src
);
2992 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2993 EDGE_PRED (block
, 1)->src
);
2994 /* Induction variables only have one edge inside the loop. */
2995 if ((firstinsideloop
^ secondinsideloop
)
2996 && expr
->kind
!= REFERENCE
)
2998 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2999 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3004 /* Make the necessary insertions. */
3005 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3007 gimple_seq stmts
= NULL
;
3010 eprime
= avail
[pred
->dest_idx
];
3011 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
3013 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3014 if (!gimple_seq_empty_p (stmts
))
3016 gsi_insert_seq_on_edge (pred
, stmts
);
3021 /* We cannot insert a PHI node if we failed to insert
3026 if (is_gimple_min_invariant (builtexpr
))
3027 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_constant (builtexpr
);
3029 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3031 /* If we didn't want a phi node, and we made insertions, we still have
3032 inserted new stuff, and thus return true. If we didn't want a phi node,
3033 and didn't make insertions, we haven't added anything new, so return
3035 if (nophi
&& insertions
)
3037 else if (nophi
&& !insertions
)
3040 /* Now build a phi for the new variable. */
3041 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3042 phi
= create_phi_node (temp
, block
);
3044 gimple_set_plf (phi
, NECESSARY
, false);
3045 VN_INFO_GET (temp
)->value_id
= val
;
3046 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3047 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3048 VN_INFO (temp
)->valnum
= temp
;
3049 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3050 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3052 pre_expr ae
= avail
[pred
->dest_idx
];
3053 gcc_assert (get_expr_type (ae
) == type
3054 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3055 if (ae
->kind
== CONSTANT
)
3056 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3057 pred
, UNKNOWN_LOCATION
);
3059 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3062 newphi
= get_or_alloc_expr_for_name (temp
);
3063 add_to_value (val
, newphi
);
3065 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3066 this insertion, since we test for the existence of this value in PHI_GEN
3067 before proceeding with the partial redundancy checks in insert_aux.
3069 The value may exist in AVAIL_OUT, in particular, it could be represented
3070 by the expression we are trying to eliminate, in which case we want the
3071 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3074 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3075 this block, because if it did, it would have existed in our dominator's
3076 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3079 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3080 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3082 bitmap_insert_into_set (NEW_SETS (block
),
3085 /* If we insert a PHI node for a conversion of another PHI node
3086 in the same basic-block try to preserve range information.
3087 This is important so that followup loop passes receive optimal
3088 number of iteration analysis results. See PR61743. */
3089 if (expr
->kind
== NARY
3090 && CONVERT_EXPR_CODE_P (expr
->u
.nary
->opcode
)
3091 && TREE_CODE (expr
->u
.nary
->op
[0]) == SSA_NAME
3092 && gimple_bb (SSA_NAME_DEF_STMT (expr
->u
.nary
->op
[0])) == block
3093 && INTEGRAL_TYPE_P (type
)
3094 && INTEGRAL_TYPE_P (TREE_TYPE (expr
->u
.nary
->op
[0]))
3095 && (TYPE_PRECISION (type
)
3096 >= TYPE_PRECISION (TREE_TYPE (expr
->u
.nary
->op
[0])))
3097 && SSA_NAME_RANGE_INFO (expr
->u
.nary
->op
[0]))
3100 if (get_range_info (expr
->u
.nary
->op
[0], &min
, &max
) == VR_RANGE
3101 && !wi::neg_p (min
, SIGNED
)
3102 && !wi::neg_p (max
, SIGNED
))
3103 /* Just handle extension and sign-changes of all-positive ranges. */
3104 set_range_info (temp
,
3105 SSA_NAME_RANGE_TYPE (expr
->u
.nary
->op
[0]),
3106 wide_int_storage::from (min
, TYPE_PRECISION (type
),
3108 wide_int_storage::from (max
, TYPE_PRECISION (type
),
3112 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3114 fprintf (dump_file
, "Created phi ");
3115 print_gimple_stmt (dump_file
, phi
, 0, 0);
3116 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3124 /* Perform insertion of partially redundant or hoistable values.
3125 For BLOCK, do the following:
3126 1. Propagate the NEW_SETS of the dominator into the current block.
3127 If the block has multiple predecessors,
3128 2a. Iterate over the ANTIC expressions for the block to see if
3129 any of them are partially redundant.
3130 2b. If so, insert them into the necessary predecessors to make
3131 the expression fully redundant.
3132 2c. Insert a new PHI merging the values of the predecessors.
3133 2d. Insert the new PHI, and the new expressions, into the
3135 If the block has multiple successors,
3136 3a. Iterate over the ANTIC values for the block to see if
3137 any of them are good candidates for hoisting.
3138 3b. If so, insert expressions computing the values in BLOCK,
3139 and add the new expressions into the NEW_SETS set.
3140 4. Recursively call ourselves on the dominator children of BLOCK.
3142 Steps 1, 2a, and 4 are done by insert_aux. 2b, 2c and 2d are done by
3143 do_pre_regular_insertion and do_partial_insertion. 3a and 3b are
3144 done in do_hoist_insertion.
3148 do_pre_regular_insertion (basic_block block
, basic_block dom
)
3150 bool new_stuff
= false;
3151 vec
<pre_expr
> exprs
;
3153 auto_vec
<pre_expr
> avail
;
3156 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3157 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3159 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3161 if (expr
->kind
== NARY
3162 || expr
->kind
== REFERENCE
)
3165 bool by_some
= false;
3166 bool cant_insert
= false;
3167 bool all_same
= true;
3168 pre_expr first_s
= NULL
;
3171 pre_expr eprime
= NULL
;
3173 pre_expr edoubleprime
= NULL
;
3174 bool do_insertion
= false;
3176 val
= get_expr_value_id (expr
);
3177 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3179 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3181 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3183 fprintf (dump_file
, "Found fully redundant value: ");
3184 print_pre_expr (dump_file
, expr
);
3185 fprintf (dump_file
, "\n");
3190 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3192 unsigned int vprime
;
3194 /* We should never run insertion for the exit block
3195 and so not come across fake pred edges. */
3196 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3198 /* We are looking at ANTIC_OUT of bprime. */
3199 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3202 /* eprime will generally only be NULL if the
3203 value of the expression, translated
3204 through the PHI for this predecessor, is
3205 undefined. If that is the case, we can't
3206 make the expression fully redundant,
3207 because its value is undefined along a
3208 predecessor path. We can thus break out
3209 early because it doesn't matter what the
3210 rest of the results are. */
3213 avail
[pred
->dest_idx
] = NULL
;
3218 vprime
= get_expr_value_id (eprime
);
3219 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3221 if (edoubleprime
== NULL
)
3223 avail
[pred
->dest_idx
] = eprime
;
3228 avail
[pred
->dest_idx
] = edoubleprime
;
3230 /* We want to perform insertions to remove a redundancy on
3231 a path in the CFG we want to optimize for speed. */
3232 if (optimize_edge_for_speed_p (pred
))
3233 do_insertion
= true;
3234 if (first_s
== NULL
)
3235 first_s
= edoubleprime
;
3236 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3240 /* If we can insert it, it's not the same value
3241 already existing along every predecessor, and
3242 it's defined by some predecessor, it is
3243 partially redundant. */
3244 if (!cant_insert
&& !all_same
&& by_some
)
3248 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3250 fprintf (dump_file
, "Skipping partial redundancy for "
3252 print_pre_expr (dump_file
, expr
);
3253 fprintf (dump_file
, " (%04d), no redundancy on to be "
3254 "optimized for speed edge\n", val
);
3257 else if (dbg_cnt (treepre_insert
))
3259 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3261 fprintf (dump_file
, "Found partial redundancy for "
3263 print_pre_expr (dump_file
, expr
);
3264 fprintf (dump_file
, " (%04d)\n",
3265 get_expr_value_id (expr
));
3267 if (insert_into_preds_of_block (block
,
3268 get_expression_id (expr
),
3273 /* If all edges produce the same value and that value is
3274 an invariant, then the PHI has the same value on all
3275 edges. Note this. */
3276 else if (!cant_insert
&& all_same
)
3278 gcc_assert (edoubleprime
->kind
== CONSTANT
3279 || edoubleprime
->kind
== NAME
);
3281 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3284 = gimple_build_assign (temp
,
3285 edoubleprime
->kind
== CONSTANT
?
3286 PRE_EXPR_CONSTANT (edoubleprime
) :
3287 PRE_EXPR_NAME (edoubleprime
));
3288 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3289 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3291 gimple_set_plf (assign
, NECESSARY
, false);
3292 VN_INFO_GET (temp
)->value_id
= val
;
3293 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3294 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3295 VN_INFO (temp
)->valnum
= temp
;
3296 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3297 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3298 add_to_value (val
, newe
);
3299 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3300 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3310 /* Perform insertion for partially anticipatable expressions. There
3311 is only one case we will perform insertion for these. This case is
3312 if the expression is partially anticipatable, and fully available.
3313 In this case, we know that putting it earlier will enable us to
3314 remove the later computation. */
3317 do_pre_partial_partial_insertion (basic_block block
, basic_block dom
)
3319 bool new_stuff
= false;
3320 vec
<pre_expr
> exprs
;
3322 auto_vec
<pre_expr
> avail
;
3325 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3326 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3328 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3330 if (expr
->kind
== NARY
3331 || expr
->kind
== REFERENCE
)
3335 bool cant_insert
= false;
3338 pre_expr eprime
= NULL
;
3341 val
= get_expr_value_id (expr
);
3342 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3344 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3347 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3349 unsigned int vprime
;
3350 pre_expr edoubleprime
;
3352 /* We should never run insertion for the exit block
3353 and so not come across fake pred edges. */
3354 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3356 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3360 /* eprime will generally only be NULL if the
3361 value of the expression, translated
3362 through the PHI for this predecessor, is
3363 undefined. If that is the case, we can't
3364 make the expression fully redundant,
3365 because its value is undefined along a
3366 predecessor path. We can thus break out
3367 early because it doesn't matter what the
3368 rest of the results are. */
3371 avail
[pred
->dest_idx
] = NULL
;
3376 vprime
= get_expr_value_id (eprime
);
3377 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3378 avail
[pred
->dest_idx
] = edoubleprime
;
3379 if (edoubleprime
== NULL
)
3386 /* If we can insert it, it's not the same value
3387 already existing along every predecessor, and
3388 it's defined by some predecessor, it is
3389 partially redundant. */
3390 if (!cant_insert
&& by_all
)
3393 bool do_insertion
= false;
3395 /* Insert only if we can remove a later expression on a path
3396 that we want to optimize for speed.
3397 The phi node that we will be inserting in BLOCK is not free,
3398 and inserting it for the sake of !optimize_for_speed successor
3399 may cause regressions on the speed path. */
3400 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3402 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3403 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3405 if (optimize_edge_for_speed_p (succ
))
3406 do_insertion
= true;
3412 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3414 fprintf (dump_file
, "Skipping partial partial redundancy "
3416 print_pre_expr (dump_file
, expr
);
3417 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3418 "on any to be optimized for speed edges\n", val
);
3421 else if (dbg_cnt (treepre_insert
))
3423 pre_stats
.pa_insert
++;
3424 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3426 fprintf (dump_file
, "Found partial partial redundancy "
3428 print_pre_expr (dump_file
, expr
);
3429 fprintf (dump_file
, " (%04d)\n",
3430 get_expr_value_id (expr
));
3432 if (insert_into_preds_of_block (block
,
3433 get_expression_id (expr
),
3445 /* Insert expressions in BLOCK to compute hoistable values up.
3446 Return TRUE if something was inserted, otherwise return FALSE.
3447 The caller has to make sure that BLOCK has at least two successors. */
3450 do_hoist_insertion (basic_block block
)
3454 bool new_stuff
= false;
3456 gimple_stmt_iterator last
;
3458 /* At least two successors, or else... */
3459 gcc_assert (EDGE_COUNT (block
->succs
) >= 2);
3461 /* Check that all successors of BLOCK are dominated by block.
3462 We could use dominated_by_p() for this, but actually there is a much
3463 quicker check: any successor that is dominated by BLOCK can't have
3464 more than one predecessor edge. */
3465 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3466 if (! single_pred_p (e
->dest
))
3469 /* Determine the insertion point. If we cannot safely insert before
3470 the last stmt if we'd have to, bail out. */
3471 last
= gsi_last_bb (block
);
3472 if (!gsi_end_p (last
)
3473 && !is_ctrl_stmt (gsi_stmt (last
))
3474 && stmt_ends_bb_p (gsi_stmt (last
)))
3477 /* Compute the set of hoistable expressions from ANTIC_IN. First compute
3478 hoistable values. */
3479 bitmap_set hoistable_set
;
3481 /* A hoistable value must be in ANTIC_IN(block)
3482 but not in AVAIL_OUT(BLOCK). */
3483 bitmap_initialize (&hoistable_set
.values
, &grand_bitmap_obstack
);
3484 bitmap_and_compl (&hoistable_set
.values
,
3485 &ANTIC_IN (block
)->values
, &AVAIL_OUT (block
)->values
);
3487 /* Short-cut for a common case: hoistable_set is empty. */
3488 if (bitmap_empty_p (&hoistable_set
.values
))
3491 /* Compute which of the hoistable values is in AVAIL_OUT of
3492 at least one of the successors of BLOCK. */
3493 bitmap_head availout_in_some
;
3494 bitmap_initialize (&availout_in_some
, &grand_bitmap_obstack
);
3495 FOR_EACH_EDGE (e
, ei
, block
->succs
)
3496 /* Do not consider expressions solely because their availability
3497 on loop exits. They'd be ANTIC-IN throughout the whole loop
3498 and thus effectively hoisted across loops by combination of
3499 PRE and hoisting. */
3500 if (! loop_exit_edge_p (block
->loop_father
, e
))
3501 bitmap_ior_and_into (&availout_in_some
, &hoistable_set
.values
,
3502 &AVAIL_OUT (e
->dest
)->values
);
3503 bitmap_clear (&hoistable_set
.values
);
3505 /* Short-cut for a common case: availout_in_some is empty. */
3506 if (bitmap_empty_p (&availout_in_some
))
3509 /* Hack hoitable_set in-place so we can use sorted_array_from_bitmap_set. */
3510 hoistable_set
.values
= availout_in_some
;
3511 hoistable_set
.expressions
= ANTIC_IN (block
)->expressions
;
3513 /* Now finally construct the topological-ordered expression set. */
3514 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (&hoistable_set
);
3516 bitmap_clear (&hoistable_set
.values
);
3518 /* If there are candidate values for hoisting, insert expressions
3519 strategically to make the hoistable expressions fully redundant. */
3521 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3523 /* While we try to sort expressions topologically above the
3524 sorting doesn't work out perfectly. Catch expressions we
3525 already inserted. */
3526 unsigned int value_id
= get_expr_value_id (expr
);
3527 if (bitmap_set_contains_value (AVAIL_OUT (block
), value_id
))
3529 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3532 "Already inserted expression for ");
3533 print_pre_expr (dump_file
, expr
);
3534 fprintf (dump_file
, " (%04d)\n", value_id
);
3539 /* OK, we should hoist this value. Perform the transformation. */
3540 pre_stats
.hoist_insert
++;
3541 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3544 "Inserting expression in block %d for code hoisting: ",
3546 print_pre_expr (dump_file
, expr
);
3547 fprintf (dump_file
, " (%04d)\n", value_id
);
3550 gimple_seq stmts
= NULL
;
3551 tree res
= create_expression_by_pieces (block
, expr
, &stmts
,
3552 get_expr_type (expr
));
3554 /* Do not return true if expression creation ultimately
3555 did not insert any statements. */
3556 if (gimple_seq_empty_p (stmts
))
3560 if (gsi_end_p (last
) || is_ctrl_stmt (gsi_stmt (last
)))
3561 gsi_insert_seq_before (&last
, stmts
, GSI_SAME_STMT
);
3563 gsi_insert_seq_after (&last
, stmts
, GSI_NEW_STMT
);
3566 /* Make sure to not return true if expression creation ultimately
3567 failed but also make sure to insert any stmts produced as they
3568 are tracked in inserted_exprs. */
3580 /* Do a dominator walk on the control flow graph, and insert computations
3581 of values as necessary for PRE and hoisting. */
3584 insert_aux (basic_block block
, bool do_pre
, bool do_hoist
)
3587 bool new_stuff
= false;
3592 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3597 bitmap_set_t newset
;
3599 /* First, update the AVAIL_OUT set with anything we may have
3600 inserted higher up in the dominator tree. */
3601 newset
= NEW_SETS (dom
);
3604 /* Note that we need to value_replace both NEW_SETS, and
3605 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3606 represented by some non-simple expression here that we want
3607 to replace it with. */
3608 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3610 pre_expr expr
= expression_for_id (i
);
3611 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3612 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3616 /* Insert expressions for partial redundancies. */
3617 if (do_pre
&& !single_pred_p (block
))
3619 new_stuff
|= do_pre_regular_insertion (block
, dom
);
3620 if (do_partial_partial
)
3621 new_stuff
|= do_pre_partial_partial_insertion (block
, dom
);
3624 /* Insert expressions for hoisting. */
3625 if (do_hoist
&& EDGE_COUNT (block
->succs
) >= 2)
3626 new_stuff
|= do_hoist_insertion (block
);
3629 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3631 son
= next_dom_son (CDI_DOMINATORS
, son
))
3633 new_stuff
|= insert_aux (son
, do_pre
, do_hoist
);
3639 /* Perform insertion of partially redundant and hoistable values. */
3644 bool new_stuff
= true;
3646 int num_iterations
= 0;
3648 FOR_ALL_BB_FN (bb
, cfun
)
3649 NEW_SETS (bb
) = bitmap_set_new ();
3654 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3655 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3656 new_stuff
= insert_aux (ENTRY_BLOCK_PTR_FOR_FN (cfun
), flag_tree_pre
,
3657 flag_code_hoisting
);
3659 /* Clear the NEW sets before the next iteration. We have already
3660 fully propagated its contents. */
3662 FOR_ALL_BB_FN (bb
, cfun
)
3663 bitmap_set_free (NEW_SETS (bb
));
3665 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3669 /* Compute the AVAIL set for all basic blocks.
3671 This function performs value numbering of the statements in each basic
3672 block. The AVAIL sets are built from information we glean while doing
3673 this value numbering, since the AVAIL sets contain only one entry per
3676 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3677 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3680 compute_avail (void)
3683 basic_block block
, son
;
3684 basic_block
*worklist
;
3689 /* We pretend that default definitions are defined in the entry block.
3690 This includes function arguments and the static chain decl. */
3691 FOR_EACH_SSA_NAME (i
, name
, cfun
)
3694 if (!SSA_NAME_IS_DEFAULT_DEF (name
)
3695 || has_zero_uses (name
)
3696 || virtual_operand_p (name
))
3699 e
= get_or_alloc_expr_for_name (name
);
3700 add_to_value (get_expr_value_id (e
), e
);
3701 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3702 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3706 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3708 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3709 "tmp_gen", ENTRY_BLOCK
);
3710 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3711 "avail_out", ENTRY_BLOCK
);
3714 /* Allocate the worklist. */
3715 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3717 /* Seed the algorithm by putting the dominator children of the entry
3718 block on the worklist. */
3719 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3721 son
= next_dom_son (CDI_DOMINATORS
, son
))
3722 worklist
[sp
++] = son
;
3724 BB_LIVE_VOP_ON_EXIT (ENTRY_BLOCK_PTR_FOR_FN (cfun
))
3725 = ssa_default_def (cfun
, gimple_vop (cfun
));
3727 /* Loop until the worklist is empty. */
3733 /* Pick a block from the worklist. */
3734 block
= worklist
[--sp
];
3736 /* Initially, the set of available values in BLOCK is that of
3737 its immediate dominator. */
3738 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3741 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3742 BB_LIVE_VOP_ON_EXIT (block
) = BB_LIVE_VOP_ON_EXIT (dom
);
3745 /* Generate values for PHI nodes. */
3746 for (gphi_iterator gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
);
3749 tree result
= gimple_phi_result (gsi
.phi ());
3751 /* We have no need for virtual phis, as they don't represent
3752 actual computations. */
3753 if (virtual_operand_p (result
))
3755 BB_LIVE_VOP_ON_EXIT (block
) = result
;
3759 pre_expr e
= get_or_alloc_expr_for_name (result
);
3760 add_to_value (get_expr_value_id (e
), e
);
3761 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3762 bitmap_insert_into_set (PHI_GEN (block
), e
);
3765 BB_MAY_NOTRETURN (block
) = 0;
3767 /* Now compute value numbers and populate value sets with all
3768 the expressions computed in BLOCK. */
3769 for (gimple_stmt_iterator gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
);
3775 stmt
= gsi_stmt (gsi
);
3777 /* Cache whether the basic-block has any non-visible side-effect
3779 If this isn't a call or it is the last stmt in the
3780 basic-block then the CFG represents things correctly. */
3781 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3783 /* Non-looping const functions always return normally.
3784 Otherwise the call might not return or have side-effects
3785 that forbids hoisting possibly trapping expressions
3787 int flags
= gimple_call_flags (stmt
);
3788 if (!(flags
& ECF_CONST
)
3789 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3790 BB_MAY_NOTRETURN (block
) = 1;
3793 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3795 pre_expr e
= get_or_alloc_expr_for_name (op
);
3797 add_to_value (get_expr_value_id (e
), e
);
3798 bitmap_insert_into_set (TMP_GEN (block
), e
);
3799 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3802 if (gimple_vdef (stmt
))
3803 BB_LIVE_VOP_ON_EXIT (block
) = gimple_vdef (stmt
);
3805 if (gimple_has_side_effects (stmt
)
3806 || stmt_could_throw_p (stmt
)
3807 || is_gimple_debug (stmt
))
3810 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3812 if (ssa_undefined_value_p (op
))
3814 pre_expr e
= get_or_alloc_expr_for_name (op
);
3815 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3818 switch (gimple_code (stmt
))
3826 vn_reference_s ref1
;
3827 pre_expr result
= NULL
;
3829 /* We can value number only calls to real functions. */
3830 if (gimple_call_internal_p (stmt
))
3833 vn_reference_lookup_call (as_a
<gcall
*> (stmt
), &ref
, &ref1
);
3837 /* If the value of the call is not invalidated in
3838 this block until it is computed, add the expression
3840 if (!gimple_vuse (stmt
)
3842 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3843 || gimple_bb (SSA_NAME_DEF_STMT
3844 (gimple_vuse (stmt
))) != block
)
3846 result
= pre_expr_pool
.allocate ();
3847 result
->kind
= REFERENCE
;
3849 PRE_EXPR_REFERENCE (result
) = ref
;
3851 get_or_alloc_expression_id (result
);
3852 add_to_value (get_expr_value_id (result
), result
);
3853 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3860 pre_expr result
= NULL
;
3861 switch (vn_get_stmt_kind (stmt
))
3865 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3868 /* COND_EXPR and VEC_COND_EXPR are awkward in
3869 that they contain an embedded complex expression.
3870 Don't even try to shove those through PRE. */
3871 if (code
== COND_EXPR
3872 || code
== VEC_COND_EXPR
)
3875 vn_nary_op_lookup_stmt (stmt
, &nary
);
3879 /* If the NARY traps and there was a preceding
3880 point in the block that might not return avoid
3881 adding the nary to EXP_GEN. */
3882 if (BB_MAY_NOTRETURN (block
)
3883 && vn_nary_may_trap (nary
))
3886 result
= pre_expr_pool
.allocate ();
3887 result
->kind
= NARY
;
3889 PRE_EXPR_NARY (result
) = nary
;
3895 tree rhs1
= gimple_assign_rhs1 (stmt
);
3896 alias_set_type set
= get_alias_set (rhs1
);
3897 vec
<vn_reference_op_s
> operands
3898 = vn_reference_operands_for_lookup (rhs1
);
3900 vn_reference_lookup_pieces (gimple_vuse (stmt
), set
,
3902 operands
, &ref
, VN_WALK
);
3905 operands
.release ();
3909 /* If the value of the reference is not invalidated in
3910 this block until it is computed, add the expression
3912 if (gimple_vuse (stmt
))
3916 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3917 while (!gimple_nop_p (def_stmt
)
3918 && gimple_code (def_stmt
) != GIMPLE_PHI
3919 && gimple_bb (def_stmt
) == block
)
3921 if (stmt_may_clobber_ref_p
3922 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3928 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3932 operands
.release ();
3937 /* If the load was value-numbered to another
3938 load make sure we do not use its expression
3939 for insertion if it wouldn't be a valid
3941 /* At the momemt we have a testcase
3942 for hoist insertion of aligned vs. misaligned
3943 variants in gcc.dg/torture/pr65270-1.c thus
3944 with just alignment to be considered we can
3945 simply replace the expression in the hashtable
3946 with the most conservative one. */
3947 vn_reference_op_t ref1
= &ref
->operands
.last ();
3948 while (ref1
->opcode
!= TARGET_MEM_REF
3949 && ref1
->opcode
!= MEM_REF
3950 && ref1
!= &ref
->operands
[0])
3952 vn_reference_op_t ref2
= &operands
.last ();
3953 while (ref2
->opcode
!= TARGET_MEM_REF
3954 && ref2
->opcode
!= MEM_REF
3955 && ref2
!= &operands
[0])
3957 if ((ref1
->opcode
== TARGET_MEM_REF
3958 || ref1
->opcode
== MEM_REF
)
3959 && (TYPE_ALIGN (ref1
->type
)
3960 > TYPE_ALIGN (ref2
->type
)))
3962 = build_aligned_type (ref1
->type
,
3963 TYPE_ALIGN (ref2
->type
));
3964 /* TBAA behavior is an obvious part so make sure
3965 that the hashtable one covers this as well
3966 by adjusting the ref alias set and its base. */
3968 || alias_set_subset_of (set
, ref
->set
))
3970 else if (alias_set_subset_of (ref
->set
, set
))
3973 if (ref1
->opcode
== MEM_REF
)
3974 ref1
->op0
= fold_convert (TREE_TYPE (ref2
->op0
),
3977 ref1
->op2
= fold_convert (TREE_TYPE (ref2
->op2
),
3983 if (ref1
->opcode
== MEM_REF
)
3984 ref1
->op0
= fold_convert (ptr_type_node
,
3987 ref1
->op2
= fold_convert (ptr_type_node
,
3990 operands
.release ();
3992 result
= pre_expr_pool
.allocate ();
3993 result
->kind
= REFERENCE
;
3995 PRE_EXPR_REFERENCE (result
) = ref
;
4003 get_or_alloc_expression_id (result
);
4004 add_to_value (get_expr_value_id (result
), result
);
4005 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4013 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4015 print_bitmap_set (dump_file
, EXP_GEN (block
),
4016 "exp_gen", block
->index
);
4017 print_bitmap_set (dump_file
, PHI_GEN (block
),
4018 "phi_gen", block
->index
);
4019 print_bitmap_set (dump_file
, TMP_GEN (block
),
4020 "tmp_gen", block
->index
);
4021 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
4022 "avail_out", block
->index
);
4025 /* Put the dominator children of BLOCK on the worklist of blocks
4026 to compute available sets for. */
4027 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4029 son
= next_dom_son (CDI_DOMINATORS
, son
))
4030 worklist
[sp
++] = son
;
4037 /* Local state for the eliminate domwalk. */
4038 static vec
<gimple
*> el_to_remove
;
4039 static vec
<gimple
*> el_to_fixup
;
4040 static unsigned int el_todo
;
4041 static vec
<tree
> el_avail
;
4042 static vec
<tree
> el_avail_stack
;
4044 /* Return a leader for OP that is available at the current point of the
4045 eliminate domwalk. */
4048 eliminate_avail (tree op
)
4050 tree valnum
= VN_INFO (op
)->valnum
;
4051 if (TREE_CODE (valnum
) == SSA_NAME
)
4053 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
4055 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
4056 return el_avail
[SSA_NAME_VERSION (valnum
)];
4058 else if (is_gimple_min_invariant (valnum
))
4063 /* At the current point of the eliminate domwalk make OP available. */
4066 eliminate_push_avail (tree op
)
4068 tree valnum
= VN_INFO (op
)->valnum
;
4069 if (TREE_CODE (valnum
) == SSA_NAME
)
4071 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
4072 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
4074 if (el_avail
[SSA_NAME_VERSION (valnum
)])
4075 pushop
= el_avail
[SSA_NAME_VERSION (valnum
)];
4076 el_avail_stack
.safe_push (pushop
);
4077 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
4081 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
4082 the leader for the expression if insertion was successful. */
4085 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
4087 gimple
*stmt
= gimple_seq_first_stmt (VN_INFO (val
)->expr
);
4088 if (!is_gimple_assign (stmt
)
4089 || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt
))
4090 && gimple_assign_rhs_code (stmt
) != VIEW_CONVERT_EXPR
4091 && gimple_assign_rhs_code (stmt
) != BIT_FIELD_REF
))
4094 tree op
= gimple_assign_rhs1 (stmt
);
4095 if (gimple_assign_rhs_code (stmt
) == VIEW_CONVERT_EXPR
4096 || gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4097 op
= TREE_OPERAND (op
, 0);
4098 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
4102 gimple_seq stmts
= NULL
;
4104 if (gimple_assign_rhs_code (stmt
) == BIT_FIELD_REF
)
4105 res
= gimple_build (&stmts
, BIT_FIELD_REF
,
4106 TREE_TYPE (val
), leader
,
4107 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 1),
4108 TREE_OPERAND (gimple_assign_rhs1 (stmt
), 2));
4110 res
= gimple_build (&stmts
, gimple_assign_rhs_code (stmt
),
4111 TREE_TYPE (val
), leader
);
4112 gsi_insert_seq_before (gsi
, stmts
, GSI_SAME_STMT
);
4113 VN_INFO_GET (res
)->valnum
= val
;
4115 if (TREE_CODE (leader
) == SSA_NAME
)
4116 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
4118 pre_stats
.insertions
++;
4119 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4121 fprintf (dump_file
, "Inserted ");
4122 print_gimple_stmt (dump_file
, SSA_NAME_DEF_STMT (res
), 0, 0);
4128 class eliminate_dom_walker
: public dom_walker
4131 eliminate_dom_walker (cdi_direction direction
, bool do_pre_
)
4132 : dom_walker (direction
), do_pre (do_pre_
) {}
4134 virtual edge
before_dom_children (basic_block
);
4135 virtual void after_dom_children (basic_block
);
4140 /* Perform elimination for the basic-block B during the domwalk. */
4143 eliminate_dom_walker::before_dom_children (basic_block b
)
4146 el_avail_stack
.safe_push (NULL_TREE
);
4148 /* ??? If we do nothing for unreachable blocks then this will confuse
4149 tailmerging. Eventually we can reduce its reliance on SCCVN now
4150 that we fully copy/constant-propagate (most) things. */
4152 for (gphi_iterator gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4154 gphi
*phi
= gsi
.phi ();
4155 tree res
= PHI_RESULT (phi
);
4157 if (virtual_operand_p (res
))
4163 tree sprime
= eliminate_avail (res
);
4167 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4169 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4170 print_generic_expr (dump_file
, res
, 0);
4171 fprintf (dump_file
, " with ");
4172 print_generic_expr (dump_file
, sprime
, 0);
4173 fprintf (dump_file
, "\n");
4176 /* If we inserted this PHI node ourself, it's not an elimination. */
4178 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4181 pre_stats
.eliminations
++;
4183 /* If we will propagate into all uses don't bother to do
4185 if (may_propagate_copy (res
, sprime
))
4187 /* Mark the PHI for removal. */
4188 el_to_remove
.safe_push (phi
);
4193 remove_phi_node (&gsi
, false);
4196 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4197 && TREE_CODE (sprime
) == SSA_NAME
)
4198 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4200 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4201 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4202 gimple
*stmt
= gimple_build_assign (res
, sprime
);
4203 /* ??? It cannot yet be necessary (DOM walk). */
4204 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4206 gimple_stmt_iterator gsi2
= gsi_after_labels (b
);
4207 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4211 eliminate_push_avail (res
);
4215 for (gimple_stmt_iterator gsi
= gsi_start_bb (b
);
4219 tree sprime
= NULL_TREE
;
4220 gimple
*stmt
= gsi_stmt (gsi
);
4221 tree lhs
= gimple_get_lhs (stmt
);
4222 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
4223 && !gimple_has_volatile_ops (stmt
)
4224 /* See PR43491. Do not replace a global register variable when
4225 it is a the RHS of an assignment. Do replace local register
4226 variables since gcc does not guarantee a local variable will
4227 be allocated in register.
4228 ??? The fix isn't effective here. This should instead
4229 be ensured by not value-numbering them the same but treating
4230 them like volatiles? */
4231 && !(gimple_assign_single_p (stmt
)
4232 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
4233 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
))
4234 && is_global_var (gimple_assign_rhs1 (stmt
)))))
4236 sprime
= eliminate_avail (lhs
);
4239 /* If there is no existing usable leader but SCCVN thinks
4240 it has an expression it wants to use as replacement,
4242 tree val
= VN_INFO (lhs
)->valnum
;
4244 && TREE_CODE (val
) == SSA_NAME
4245 && VN_INFO (val
)->needs_insertion
4246 && VN_INFO (val
)->expr
!= NULL
4247 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4248 eliminate_push_avail (sprime
);
4251 /* If this now constitutes a copy duplicate points-to
4252 and range info appropriately. This is especially
4253 important for inserted code. See tree-ssa-copy.c
4254 for similar code. */
4256 && TREE_CODE (sprime
) == SSA_NAME
)
4258 basic_block sprime_b
= gimple_bb (SSA_NAME_DEF_STMT (sprime
));
4259 if (POINTER_TYPE_P (TREE_TYPE (lhs
))
4260 && VN_INFO_PTR_INFO (lhs
)
4261 && ! VN_INFO_PTR_INFO (sprime
))
4263 duplicate_ssa_name_ptr_info (sprime
,
4264 VN_INFO_PTR_INFO (lhs
));
4266 mark_ptr_info_alignment_unknown
4267 (SSA_NAME_PTR_INFO (sprime
));
4269 else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
4270 && VN_INFO_RANGE_INFO (lhs
)
4271 && ! VN_INFO_RANGE_INFO (sprime
)
4273 duplicate_ssa_name_range_info (sprime
,
4274 VN_INFO_RANGE_TYPE (lhs
),
4275 VN_INFO_RANGE_INFO (lhs
));
4278 /* Inhibit the use of an inserted PHI on a loop header when
4279 the address of the memory reference is a simple induction
4280 variable. In other cases the vectorizer won't do anything
4281 anyway (either it's loop invariant or a complicated
4284 && TREE_CODE (sprime
) == SSA_NAME
4286 && (flag_tree_loop_vectorize
|| flag_tree_parallelize_loops
> 1)
4287 && loop_outer (b
->loop_father
)
4288 && has_zero_uses (sprime
)
4289 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))
4290 && gimple_assign_load_p (stmt
))
4292 gimple
*def_stmt
= SSA_NAME_DEF_STMT (sprime
);
4293 basic_block def_bb
= gimple_bb (def_stmt
);
4294 if (gimple_code (def_stmt
) == GIMPLE_PHI
4295 && def_bb
->loop_father
->header
== def_bb
)
4297 loop_p loop
= def_bb
->loop_father
;
4301 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4304 def_bb
= gimple_bb (SSA_NAME_DEF_STMT (op
));
4306 && flow_bb_inside_loop_p (loop
, def_bb
)
4307 && simple_iv (loop
, loop
, op
, &iv
, true))
4315 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4317 fprintf (dump_file
, "Not replacing ");
4318 print_gimple_expr (dump_file
, stmt
, 0, 0);
4319 fprintf (dump_file
, " with ");
4320 print_generic_expr (dump_file
, sprime
, 0);
4321 fprintf (dump_file
, " which would add a loop"
4322 " carried dependence to loop %d\n",
4325 /* Don't keep sprime available. */
4333 /* If we can propagate the value computed for LHS into
4334 all uses don't bother doing anything with this stmt. */
4335 if (may_propagate_copy (lhs
, sprime
))
4337 /* Mark it for removal. */
4338 el_to_remove
.safe_push (stmt
);
4340 /* ??? Don't count copy/constant propagations. */
4341 if (gimple_assign_single_p (stmt
)
4342 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4343 || gimple_assign_rhs1 (stmt
) == sprime
))
4346 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4348 fprintf (dump_file
, "Replaced ");
4349 print_gimple_expr (dump_file
, stmt
, 0, 0);
4350 fprintf (dump_file
, " with ");
4351 print_generic_expr (dump_file
, sprime
, 0);
4352 fprintf (dump_file
, " in all uses of ");
4353 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4356 pre_stats
.eliminations
++;
4360 /* If this is an assignment from our leader (which
4361 happens in the case the value-number is a constant)
4362 then there is nothing to do. */
4363 if (gimple_assign_single_p (stmt
)
4364 && sprime
== gimple_assign_rhs1 (stmt
))
4367 /* Else replace its RHS. */
4368 bool can_make_abnormal_goto
4369 = is_gimple_call (stmt
)
4370 && stmt_can_make_abnormal_goto (stmt
);
4372 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4374 fprintf (dump_file
, "Replaced ");
4375 print_gimple_expr (dump_file
, stmt
, 0, 0);
4376 fprintf (dump_file
, " with ");
4377 print_generic_expr (dump_file
, sprime
, 0);
4378 fprintf (dump_file
, " in ");
4379 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4382 if (TREE_CODE (sprime
) == SSA_NAME
)
4383 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4386 pre_stats
.eliminations
++;
4387 gimple
*orig_stmt
= stmt
;
4388 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4389 TREE_TYPE (sprime
)))
4390 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4391 tree vdef
= gimple_vdef (stmt
);
4392 tree vuse
= gimple_vuse (stmt
);
4393 propagate_tree_value_into_stmt (&gsi
, sprime
);
4394 stmt
= gsi_stmt (gsi
);
4396 if (vdef
!= gimple_vdef (stmt
))
4397 VN_INFO (vdef
)->valnum
= vuse
;
4399 /* If we removed EH side-effects from the statement, clean
4400 its EH information. */
4401 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4403 bitmap_set_bit (need_eh_cleanup
,
4404 gimple_bb (stmt
)->index
);
4405 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4406 fprintf (dump_file
, " Removed EH side-effects.\n");
4409 /* Likewise for AB side-effects. */
4410 if (can_make_abnormal_goto
4411 && !stmt_can_make_abnormal_goto (stmt
))
4413 bitmap_set_bit (need_ab_cleanup
,
4414 gimple_bb (stmt
)->index
);
4415 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4416 fprintf (dump_file
, " Removed AB side-effects.\n");
4423 /* If the statement is a scalar store, see if the expression
4424 has the same value number as its rhs. If so, the store is
4426 if (gimple_assign_single_p (stmt
)
4427 && !gimple_has_volatile_ops (stmt
)
4428 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4429 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4430 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4433 tree rhs
= gimple_assign_rhs1 (stmt
);
4434 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4435 gimple_vuse (stmt
), VN_WALK
, NULL
, false);
4436 if (TREE_CODE (rhs
) == SSA_NAME
)
4437 rhs
= VN_INFO (rhs
)->valnum
;
4439 && operand_equal_p (val
, rhs
, 0))
4441 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4443 fprintf (dump_file
, "Deleted redundant store ");
4444 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4447 /* Queue stmt for removal. */
4448 el_to_remove
.safe_push (stmt
);
4453 /* If this is a control statement value numbering left edges
4454 unexecuted on force the condition in a way consistent with
4456 if (gcond
*cond
= dyn_cast
<gcond
*> (stmt
))
4458 if ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
)
4459 ^ (EDGE_SUCC (b
, 1)->flags
& EDGE_EXECUTABLE
))
4461 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4463 fprintf (dump_file
, "Removing unexecutable edge from ");
4464 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4466 if (((EDGE_SUCC (b
, 0)->flags
& EDGE_TRUE_VALUE
) != 0)
4467 == ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
) != 0))
4468 gimple_cond_make_true (cond
);
4470 gimple_cond_make_false (cond
);
4472 el_todo
|= TODO_cleanup_cfg
;
4477 bool can_make_abnormal_goto
= stmt_can_make_abnormal_goto (stmt
);
4478 bool was_noreturn
= (is_gimple_call (stmt
)
4479 && gimple_call_noreturn_p (stmt
));
4480 tree vdef
= gimple_vdef (stmt
);
4481 tree vuse
= gimple_vuse (stmt
);
4483 /* If we didn't replace the whole stmt (or propagate the result
4484 into all uses), replace all uses on this stmt with their
4486 use_operand_p use_p
;
4488 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_USE
)
4490 tree use
= USE_FROM_PTR (use_p
);
4491 /* ??? The call code above leaves stmt operands un-updated. */
4492 if (TREE_CODE (use
) != SSA_NAME
)
4494 tree sprime
= eliminate_avail (use
);
4495 if (sprime
&& sprime
!= use
4496 && may_propagate_copy (use
, sprime
)
4497 /* We substitute into debug stmts to avoid excessive
4498 debug temporaries created by removed stmts, but we need
4499 to avoid doing so for inserted sprimes as we never want
4500 to create debug temporaries for them. */
4502 || TREE_CODE (sprime
) != SSA_NAME
4503 || !is_gimple_debug (stmt
)
4504 || !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))))
4506 propagate_value (use_p
, sprime
);
4507 gimple_set_modified (stmt
, true);
4508 if (TREE_CODE (sprime
) == SSA_NAME
4509 && !is_gimple_debug (stmt
))
4510 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4515 /* Visit indirect calls and turn them into direct calls if
4516 possible using the devirtualization machinery. */
4517 if (gcall
*call_stmt
= dyn_cast
<gcall
*> (stmt
))
4519 tree fn
= gimple_call_fn (call_stmt
);
4521 && flag_devirtualize
4522 && virtual_method_call_p (fn
))
4524 tree otr_type
= obj_type_ref_class (fn
);
4526 ipa_polymorphic_call_context
context (current_function_decl
, fn
, stmt
, &instance
);
4529 context
.get_dynamic_type (instance
, OBJ_TYPE_REF_OBJECT (fn
), otr_type
, stmt
);
4531 vec
<cgraph_node
*>targets
4532 = possible_polymorphic_call_targets (obj_type_ref_class (fn
),
4534 (OBJ_TYPE_REF_TOKEN (fn
)),
4538 dump_possible_polymorphic_call_targets (dump_file
,
4539 obj_type_ref_class (fn
),
4541 (OBJ_TYPE_REF_TOKEN (fn
)),
4543 if (final
&& targets
.length () <= 1 && dbg_cnt (devirt
))
4546 if (targets
.length () == 1)
4547 fn
= targets
[0]->decl
;
4549 fn
= builtin_decl_implicit (BUILT_IN_UNREACHABLE
);
4550 if (dump_enabled_p ())
4552 location_t loc
= gimple_location_safe (stmt
);
4553 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, loc
,
4554 "converting indirect call to "
4556 lang_hooks
.decl_printable_name (fn
, 2));
4558 gimple_call_set_fndecl (call_stmt
, fn
);
4559 /* If changing the call to __builtin_unreachable
4560 or similar noreturn function, adjust gimple_call_fntype
4562 if (gimple_call_noreturn_p (call_stmt
)
4563 && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn
)))
4564 && TYPE_ARG_TYPES (TREE_TYPE (fn
))
4565 && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn
)))
4567 gimple_call_set_fntype (call_stmt
, TREE_TYPE (fn
));
4568 maybe_remove_unused_call_args (cfun
, call_stmt
);
4569 gimple_set_modified (stmt
, true);
4574 if (gimple_modified_p (stmt
))
4576 /* If a formerly non-invariant ADDR_EXPR is turned into an
4577 invariant one it was on a separate stmt. */
4578 if (gimple_assign_single_p (stmt
)
4579 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
4580 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
4581 gimple
*old_stmt
= stmt
;
4582 if (is_gimple_call (stmt
))
4584 /* ??? Only fold calls inplace for now, this may create new
4585 SSA names which in turn will confuse free_scc_vn SSA name
4587 fold_stmt_inplace (&gsi
);
4588 /* When changing a call into a noreturn call, cfg cleanup
4589 is needed to fix up the noreturn call. */
4590 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4591 el_to_fixup
.safe_push (stmt
);
4596 stmt
= gsi_stmt (gsi
);
4597 if ((gimple_code (stmt
) == GIMPLE_COND
4598 && (gimple_cond_true_p (as_a
<gcond
*> (stmt
))
4599 || gimple_cond_false_p (as_a
<gcond
*> (stmt
))))
4600 || (gimple_code (stmt
) == GIMPLE_SWITCH
4601 && TREE_CODE (gimple_switch_index (
4602 as_a
<gswitch
*> (stmt
)))
4604 el_todo
|= TODO_cleanup_cfg
;
4606 /* If we removed EH side-effects from the statement, clean
4607 its EH information. */
4608 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
))
4610 bitmap_set_bit (need_eh_cleanup
,
4611 gimple_bb (stmt
)->index
);
4612 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4613 fprintf (dump_file
, " Removed EH side-effects.\n");
4615 /* Likewise for AB side-effects. */
4616 if (can_make_abnormal_goto
4617 && !stmt_can_make_abnormal_goto (stmt
))
4619 bitmap_set_bit (need_ab_cleanup
,
4620 gimple_bb (stmt
)->index
);
4621 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4622 fprintf (dump_file
, " Removed AB side-effects.\n");
4625 if (vdef
!= gimple_vdef (stmt
))
4626 VN_INFO (vdef
)->valnum
= vuse
;
4629 /* Make new values available - for fully redundant LHS we
4630 continue with the next stmt above and skip this. */
4632 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_DEF
)
4633 eliminate_push_avail (DEF_FROM_PTR (defp
));
4636 /* Replace destination PHI arguments. */
4639 FOR_EACH_EDGE (e
, ei
, b
->succs
)
4641 for (gphi_iterator gsi
= gsi_start_phis (e
->dest
);
4645 gphi
*phi
= gsi
.phi ();
4646 use_operand_p use_p
= PHI_ARG_DEF_PTR_FROM_EDGE (phi
, e
);
4647 tree arg
= USE_FROM_PTR (use_p
);
4648 if (TREE_CODE (arg
) != SSA_NAME
4649 || virtual_operand_p (arg
))
4651 tree sprime
= eliminate_avail (arg
);
4652 if (sprime
&& may_propagate_copy (arg
, sprime
))
4654 propagate_value (use_p
, sprime
);
4655 if (TREE_CODE (sprime
) == SSA_NAME
)
4656 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4663 /* Make no longer available leaders no longer available. */
4666 eliminate_dom_walker::after_dom_children (basic_block
)
4669 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4671 tree valnum
= VN_INFO (entry
)->valnum
;
4672 tree old
= el_avail
[SSA_NAME_VERSION (valnum
)];
4674 el_avail
[SSA_NAME_VERSION (valnum
)] = NULL_TREE
;
4676 el_avail
[SSA_NAME_VERSION (valnum
)] = entry
;
4680 /* Eliminate fully redundant computations. */
4683 eliminate (bool do_pre
)
4685 gimple_stmt_iterator gsi
;
4688 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4689 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4691 el_to_remove
.create (0);
4692 el_to_fixup
.create (0);
4694 el_avail
.create (num_ssa_names
);
4695 el_avail_stack
.create (0);
4697 eliminate_dom_walker (CDI_DOMINATORS
,
4698 do_pre
).walk (cfun
->cfg
->x_entry_block_ptr
);
4700 el_avail
.release ();
4701 el_avail_stack
.release ();
4703 /* We cannot remove stmts during BB walk, especially not release SSA
4704 names there as this confuses the VN machinery. The stmts ending
4705 up in el_to_remove are either stores or simple copies.
4706 Remove stmts in reverse order to make debug stmt creation possible. */
4707 while (!el_to_remove
.is_empty ())
4709 stmt
= el_to_remove
.pop ();
4711 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4713 fprintf (dump_file
, "Removing dead stmt ");
4714 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4718 if (gimple_code (stmt
) == GIMPLE_PHI
)
4719 lhs
= gimple_phi_result (stmt
);
4721 lhs
= gimple_get_lhs (stmt
);
4724 && TREE_CODE (lhs
) == SSA_NAME
)
4725 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4727 gsi
= gsi_for_stmt (stmt
);
4728 if (gimple_code (stmt
) == GIMPLE_PHI
)
4729 remove_phi_node (&gsi
, true);
4732 basic_block bb
= gimple_bb (stmt
);
4733 unlink_stmt_vdef (stmt
);
4734 if (gsi_remove (&gsi
, true))
4735 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4736 if (is_gimple_call (stmt
) && stmt_can_make_abnormal_goto (stmt
))
4737 bitmap_set_bit (need_ab_cleanup
, bb
->index
);
4738 release_defs (stmt
);
4741 /* Removing a stmt may expose a forwarder block. */
4742 el_todo
|= TODO_cleanup_cfg
;
4744 el_to_remove
.release ();
4746 /* Fixup stmts that became noreturn calls. This may require splitting
4747 blocks and thus isn't possible during the dominator walk. Do this
4748 in reverse order so we don't inadvertedly remove a stmt we want to
4749 fixup by visiting a dominating now noreturn call first. */
4750 while (!el_to_fixup
.is_empty ())
4752 stmt
= el_to_fixup
.pop ();
4754 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4756 fprintf (dump_file
, "Fixing up noreturn call ");
4757 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4760 if (fixup_noreturn_call (stmt
))
4761 el_todo
|= TODO_cleanup_cfg
;
4763 el_to_fixup
.release ();
4768 /* Perform CFG cleanups made necessary by elimination. */
4771 fini_eliminate (void)
4773 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4774 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4777 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4780 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4782 BITMAP_FREE (need_eh_cleanup
);
4783 BITMAP_FREE (need_ab_cleanup
);
4785 if (do_eh_cleanup
|| do_ab_cleanup
)
4786 return TODO_cleanup_cfg
;
4790 /* Borrow a bit of tree-ssa-dce.c for the moment.
4791 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4792 this may be a bit faster, and we may want critical edges kept split. */
4794 /* If OP's defining statement has not already been determined to be necessary,
4795 mark that statement necessary. Return the stmt, if it is newly
4798 static inline gimple
*
4799 mark_operand_necessary (tree op
)
4805 if (TREE_CODE (op
) != SSA_NAME
)
4808 stmt
= SSA_NAME_DEF_STMT (op
);
4811 if (gimple_plf (stmt
, NECESSARY
)
4812 || gimple_nop_p (stmt
))
4815 gimple_set_plf (stmt
, NECESSARY
, true);
4819 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4820 to insert PHI nodes sometimes, and because value numbering of casts isn't
4821 perfect, we sometimes end up inserting dead code. This simple DCE-like
4822 pass removes any insertions we made that weren't actually used. */
4825 remove_dead_inserted_code (void)
4832 worklist
= BITMAP_ALLOC (NULL
);
4833 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4835 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4836 if (gimple_plf (t
, NECESSARY
))
4837 bitmap_set_bit (worklist
, i
);
4839 while (!bitmap_empty_p (worklist
))
4841 i
= bitmap_first_set_bit (worklist
);
4842 bitmap_clear_bit (worklist
, i
);
4843 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4845 /* PHI nodes are somewhat special in that each PHI alternative has
4846 data and control dependencies. All the statements feeding the
4847 PHI node's arguments are always necessary. */
4848 if (gimple_code (t
) == GIMPLE_PHI
)
4852 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4854 tree arg
= PHI_ARG_DEF (t
, k
);
4855 if (TREE_CODE (arg
) == SSA_NAME
)
4857 gimple
*n
= mark_operand_necessary (arg
);
4859 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4865 /* Propagate through the operands. Examine all the USE, VUSE and
4866 VDEF operands in this statement. Mark all the statements
4867 which feed this statement's uses as necessary. */
4871 /* The operands of VDEF expressions are also needed as they
4872 represent potential definitions that may reach this
4873 statement (VDEF operands allow us to follow def-def
4876 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4878 gimple
*n
= mark_operand_necessary (use
);
4880 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4885 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4887 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4888 if (!gimple_plf (t
, NECESSARY
))
4890 gimple_stmt_iterator gsi
;
4892 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4894 fprintf (dump_file
, "Removing unnecessary insertion:");
4895 print_gimple_stmt (dump_file
, t
, 0, 0);
4898 gsi
= gsi_for_stmt (t
);
4899 if (gimple_code (t
) == GIMPLE_PHI
)
4900 remove_phi_node (&gsi
, true);
4903 gsi_remove (&gsi
, true);
4908 BITMAP_FREE (worklist
);
4912 /* Initialize data structures used by PRE. */
4919 next_expression_id
= 1;
4920 expressions
.create (0);
4921 expressions
.safe_push (NULL
);
4922 value_expressions
.create (get_max_value_id () + 1);
4923 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4924 name_to_id
.create (0);
4926 inserted_exprs
= BITMAP_ALLOC (NULL
);
4928 connect_infinite_loops_to_exit ();
4929 memset (&pre_stats
, 0, sizeof (pre_stats
));
4931 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4933 calculate_dominance_info (CDI_DOMINATORS
);
4935 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4936 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4937 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4938 FOR_ALL_BB_FN (bb
, cfun
)
4940 EXP_GEN (bb
) = bitmap_set_new ();
4941 PHI_GEN (bb
) = bitmap_set_new ();
4942 TMP_GEN (bb
) = bitmap_set_new ();
4943 AVAIL_OUT (bb
) = bitmap_set_new ();
4948 /* Deallocate data structures used by PRE. */
4953 value_expressions
.release ();
4954 BITMAP_FREE (inserted_exprs
);
4955 bitmap_obstack_release (&grand_bitmap_obstack
);
4956 bitmap_set_pool
.release ();
4957 pre_expr_pool
.release ();
4958 delete phi_translate_table
;
4959 phi_translate_table
= NULL
;
4960 delete expression_to_id
;
4961 expression_to_id
= NULL
;
4962 name_to_id
.release ();
4964 free_aux_for_blocks ();
4969 const pass_data pass_data_pre
=
4971 GIMPLE_PASS
, /* type */
4973 OPTGROUP_NONE
, /* optinfo_flags */
4974 TV_TREE_PRE
, /* tv_id */
4975 /* PROP_no_crit_edges is ensured by placing pass_split_crit_edges before
4977 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4978 0, /* properties_provided */
4979 PROP_no_crit_edges
, /* properties_destroyed */
4980 TODO_rebuild_alias
, /* todo_flags_start */
4981 0, /* todo_flags_finish */
4984 class pass_pre
: public gimple_opt_pass
4987 pass_pre (gcc::context
*ctxt
)
4988 : gimple_opt_pass (pass_data_pre
, ctxt
)
4991 /* opt_pass methods: */
4992 virtual bool gate (function
*)
4993 { return flag_tree_pre
!= 0 || flag_code_hoisting
!= 0; }
4994 virtual unsigned int execute (function
*);
4996 }; // class pass_pre
4999 pass_pre::execute (function
*fun
)
5001 unsigned int todo
= 0;
5003 do_partial_partial
=
5004 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
5006 /* This has to happen before SCCVN runs because
5007 loop_optimizer_init may create new phis, etc. */
5008 loop_optimizer_init (LOOPS_NORMAL
);
5010 if (!run_scc_vn (VN_WALK
))
5012 loop_optimizer_finalize ();
5019 /* Collect and value number expressions computed in each basic block. */
5022 /* Insert can get quite slow on an incredibly large number of basic
5023 blocks due to some quadratic behavior. Until this behavior is
5024 fixed, don't run it when he have an incredibly large number of
5025 bb's. If we aren't going to run insert, there is no point in
5026 computing ANTIC, either, even though it's plenty fast. */
5027 if (n_basic_blocks_for_fn (fun
) < 4000)
5033 /* Make sure to remove fake edges before committing our inserts.
5034 This makes sure we don't end up with extra critical edges that
5035 we would need to split. */
5036 remove_fake_exit_edges ();
5037 gsi_commit_edge_inserts ();
5039 /* Eliminate folds statements which might (should not...) end up
5040 not keeping virtual operands up-to-date. */
5041 gcc_assert (!need_ssa_update_p (fun
));
5043 /* Remove all the redundant expressions. */
5044 todo
|= eliminate (true);
5046 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5047 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
5048 statistics_counter_event (fun
, "HOIST inserted", pre_stats
.hoist_insert
);
5049 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
5050 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5052 clear_expression_ids ();
5053 remove_dead_inserted_code ();
5057 todo
|= fini_eliminate ();
5058 loop_optimizer_finalize ();
5060 /* Restore SSA info before tail-merging as that resets it as well. */
5061 scc_vn_restore_ssa_info ();
5063 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
5064 case we can merge the block with the remaining predecessor of the block.
5066 - call merge_blocks after each tail merge iteration
5067 - call merge_blocks after all tail merge iterations
5068 - mark TODO_cleanup_cfg when necessary
5069 - share the cfg cleanup with fini_pre. */
5070 todo
|= tail_merge_optimize (todo
);
5074 /* Tail merging invalidates the virtual SSA web, together with
5075 cfg-cleanup opportunities exposed by PRE this will wreck the
5076 SSA updating machinery. So make sure to run update-ssa
5077 manually, before eventually scheduling cfg-cleanup as part of
5079 update_ssa (TODO_update_ssa_only_virtuals
);
5087 make_pass_pre (gcc::context
*ctxt
)
5089 return new pass_pre (ctxt
);
5094 const pass_data pass_data_fre
=
5096 GIMPLE_PASS
, /* type */
5098 OPTGROUP_NONE
, /* optinfo_flags */
5099 TV_TREE_FRE
, /* tv_id */
5100 ( PROP_cfg
| PROP_ssa
), /* properties_required */
5101 0, /* properties_provided */
5102 0, /* properties_destroyed */
5103 0, /* todo_flags_start */
5104 0, /* todo_flags_finish */
5107 class pass_fre
: public gimple_opt_pass
5110 pass_fre (gcc::context
*ctxt
)
5111 : gimple_opt_pass (pass_data_fre
, ctxt
)
5114 /* opt_pass methods: */
5115 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
5116 virtual bool gate (function
*) { return flag_tree_fre
!= 0; }
5117 virtual unsigned int execute (function
*);
5119 }; // class pass_fre
5122 pass_fre::execute (function
*fun
)
5124 unsigned int todo
= 0;
5126 if (!run_scc_vn (VN_WALKREWRITE
))
5129 memset (&pre_stats
, 0, sizeof (pre_stats
));
5131 /* Remove all the redundant expressions. */
5132 todo
|= eliminate (false);
5134 todo
|= fini_eliminate ();
5136 scc_vn_restore_ssa_info ();
5139 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
5140 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
5148 make_pass_fre (gcc::context
*ctxt
)
5150 return new pass_fre (ctxt
);