2 Copyright (C) 2001-2013 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"
27 #include "basic-block.h"
28 #include "gimple-pretty-print.h"
29 #include "tree-inline.h"
31 #include "gimple-ssa.h"
33 #include "tree-phinodes.h"
34 #include "ssa-iterators.h"
35 #include "tree-ssanames.h"
36 #include "tree-ssa-loop.h"
37 #include "tree-into-ssa.h"
40 #include "hash-table.h"
41 #include "tree-iterator.h"
42 #include "alloc-pool.h"
44 #include "tree-pass.h"
46 #include "langhooks.h"
48 #include "tree-ssa-sccvn.h"
49 #include "tree-scalar-evolution.h"
54 #include "tree-ssa-propagate.h"
58 1. Avail sets can be shared by making an avail_find_leader that
59 walks up the dominator tree and looks in those avail sets.
60 This might affect code optimality, it's unclear right now.
61 2. Strength reduction can be performed by anticipating expressions
62 we can repair later on.
63 3. We can do back-substitution or smarter value numbering to catch
64 commutative expressions split up over multiple statements.
67 /* For ease of terminology, "expression node" in the below refers to
68 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
69 represent the actual statement containing the expressions we care about,
70 and we cache the value number by putting it in the expression. */
74 First we walk the statements to generate the AVAIL sets, the
75 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
76 generation of values/expressions by a given block. We use them
77 when computing the ANTIC sets. The AVAIL sets consist of
78 SSA_NAME's that represent values, so we know what values are
79 available in what blocks. AVAIL is a forward dataflow problem. In
80 SSA, values are never killed, so we don't need a kill set, or a
81 fixpoint iteration, in order to calculate the AVAIL sets. In
82 traditional parlance, AVAIL sets tell us the downsafety of the
85 Next, we generate the ANTIC sets. These sets represent the
86 anticipatable expressions. ANTIC is a backwards dataflow
87 problem. An expression is anticipatable in a given block if it could
88 be generated in that block. This means that if we had to perform
89 an insertion in that block, of the value of that expression, we
90 could. Calculating the ANTIC sets requires phi translation of
91 expressions, because the flow goes backwards through phis. We must
92 iterate to a fixpoint of the ANTIC sets, because we have a kill
93 set. Even in SSA form, values are not live over the entire
94 function, only from their definition point onwards. So we have to
95 remove values from the ANTIC set once we go past the definition
96 point of the leaders that make them up.
97 compute_antic/compute_antic_aux performs this computation.
99 Third, we perform insertions to make partially redundant
100 expressions fully redundant.
102 An expression is partially redundant (excluding partial
105 1. It is AVAIL in some, but not all, of the predecessors of a
107 2. It is ANTIC in all the predecessors.
109 In order to make it fully redundant, we insert the expression into
110 the predecessors where it is not available, but is ANTIC.
112 For the partial anticipation case, we only perform insertion if it
113 is partially anticipated in some block, and fully available in all
116 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
117 performs these steps.
119 Fourth, we eliminate fully redundant expressions.
120 This is a simple statement walk that replaces redundant
121 calculations with the now available values. */
123 /* Representations of value numbers:
125 Value numbers are represented by a representative SSA_NAME. We
126 will create fake SSA_NAME's in situations where we need a
127 representative but do not have one (because it is a complex
128 expression). In order to facilitate storing the value numbers in
129 bitmaps, and keep the number of wasted SSA_NAME's down, we also
130 associate a value_id with each value number, and create full blown
131 ssa_name's only where we actually need them (IE in operands of
132 existing expressions).
134 Theoretically you could replace all the value_id's with
135 SSA_NAME_VERSION, but this would allocate a large number of
136 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
137 It would also require an additional indirection at each point we
140 /* Representation of expressions on value numbers:
142 Expressions consisting of value numbers are represented the same
143 way as our VN internally represents them, with an additional
144 "pre_expr" wrapping around them in order to facilitate storing all
145 of the expressions in the same sets. */
147 /* Representation of sets:
149 The dataflow sets do not need to be sorted in any particular order
150 for the majority of their lifetime, are simply represented as two
151 bitmaps, one that keeps track of values present in the set, and one
152 that keeps track of expressions present in the set.
154 When we need them in topological order, we produce it on demand by
155 transforming the bitmap into an array and sorting it into topo
158 /* Type of expression, used to know which member of the PRE_EXPR union
169 typedef union pre_expr_union_d
174 vn_reference_t reference
;
177 typedef struct pre_expr_d
: typed_noop_remove
<pre_expr_d
>
179 enum pre_expr_kind kind
;
183 /* hash_table support. */
184 typedef pre_expr_d value_type
;
185 typedef pre_expr_d compare_type
;
186 static inline hashval_t
hash (const pre_expr_d
*);
187 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
190 #define PRE_EXPR_NAME(e) (e)->u.name
191 #define PRE_EXPR_NARY(e) (e)->u.nary
192 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
193 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
195 /* Compare E1 and E1 for equality. */
198 pre_expr_d::equal (const value_type
*e1
, const compare_type
*e2
)
200 if (e1
->kind
!= e2
->kind
)
206 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
207 PRE_EXPR_CONSTANT (e2
));
209 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
211 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
213 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
214 PRE_EXPR_REFERENCE (e2
));
223 pre_expr_d::hash (const value_type
*e
)
228 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
230 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
232 return PRE_EXPR_NARY (e
)->hashcode
;
234 return PRE_EXPR_REFERENCE (e
)->hashcode
;
240 /* Next global expression id number. */
241 static unsigned int next_expression_id
;
243 /* Mapping from expression to id number we can use in bitmap sets. */
244 static vec
<pre_expr
> expressions
;
245 static hash_table
<pre_expr_d
> expression_to_id
;
246 static vec
<unsigned> name_to_id
;
248 /* Allocate an expression id for EXPR. */
250 static inline unsigned int
251 alloc_expression_id (pre_expr expr
)
253 struct pre_expr_d
**slot
;
254 /* Make sure we won't overflow. */
255 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
256 expr
->id
= next_expression_id
++;
257 expressions
.safe_push (expr
);
258 if (expr
->kind
== NAME
)
260 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
261 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
262 re-allocations by using vec::reserve upfront. There is no
263 vec::quick_grow_cleared unfortunately. */
264 unsigned old_len
= name_to_id
.length ();
265 name_to_id
.reserve (num_ssa_names
- old_len
);
266 name_to_id
.safe_grow_cleared (num_ssa_names
);
267 gcc_assert (name_to_id
[version
] == 0);
268 name_to_id
[version
] = expr
->id
;
272 slot
= expression_to_id
.find_slot (expr
, INSERT
);
276 return next_expression_id
- 1;
279 /* Return the expression id for tree EXPR. */
281 static inline unsigned int
282 get_expression_id (const pre_expr expr
)
287 static inline unsigned int
288 lookup_expression_id (const pre_expr expr
)
290 struct pre_expr_d
**slot
;
292 if (expr
->kind
== NAME
)
294 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
295 if (name_to_id
.length () <= version
)
297 return name_to_id
[version
];
301 slot
= expression_to_id
.find_slot (expr
, NO_INSERT
);
304 return ((pre_expr
)*slot
)->id
;
308 /* Return the existing expression id for EXPR, or create one if one
309 does not exist yet. */
311 static inline unsigned int
312 get_or_alloc_expression_id (pre_expr expr
)
314 unsigned int id
= lookup_expression_id (expr
);
316 return alloc_expression_id (expr
);
317 return expr
->id
= id
;
320 /* Return the expression that has expression id ID */
322 static inline pre_expr
323 expression_for_id (unsigned int id
)
325 return expressions
[id
];
328 /* Free the expression id field in all of our expressions,
329 and then destroy the expressions array. */
332 clear_expression_ids (void)
334 expressions
.release ();
337 static alloc_pool pre_expr_pool
;
339 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
342 get_or_alloc_expr_for_name (tree name
)
344 struct pre_expr_d expr
;
346 unsigned int result_id
;
350 PRE_EXPR_NAME (&expr
) = name
;
351 result_id
= lookup_expression_id (&expr
);
353 return expression_for_id (result_id
);
355 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
357 PRE_EXPR_NAME (result
) = name
;
358 alloc_expression_id (result
);
362 /* An unordered bitmap set. One bitmap tracks values, the other,
364 typedef struct bitmap_set
366 bitmap_head expressions
;
370 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
371 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
373 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
374 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
376 /* Mapping from value id to expressions with that value_id. */
377 static vec
<bitmap
> value_expressions
;
379 /* Sets that we need to keep track of. */
380 typedef struct bb_bitmap_sets
382 /* The EXP_GEN set, which represents expressions/values generated in
384 bitmap_set_t exp_gen
;
386 /* The PHI_GEN set, which represents PHI results generated in a
388 bitmap_set_t phi_gen
;
390 /* The TMP_GEN set, which represents results/temporaries generated
391 in a basic block. IE the LHS of an expression. */
392 bitmap_set_t tmp_gen
;
394 /* The AVAIL_OUT set, which represents which values are available in
395 a given basic block. */
396 bitmap_set_t avail_out
;
398 /* The ANTIC_IN set, which represents which values are anticipatable
399 in a given basic block. */
400 bitmap_set_t antic_in
;
402 /* The PA_IN set, which represents which values are
403 partially anticipatable in a given basic block. */
406 /* The NEW_SETS set, which is used during insertion to augment the
407 AVAIL_OUT set of blocks with the new insertions performed during
408 the current iteration. */
409 bitmap_set_t new_sets
;
411 /* A cache for value_dies_in_block_x. */
414 /* True if we have visited this block during ANTIC calculation. */
415 unsigned int visited
: 1;
417 /* True we have deferred processing this block during ANTIC
418 calculation until its successor is processed. */
419 unsigned int deferred
: 1;
421 /* True when the block contains a call that might not return. */
422 unsigned int contains_may_not_return_call
: 1;
425 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
426 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
427 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
428 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
429 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
430 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
431 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
432 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
433 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
434 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
435 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
438 /* Basic block list in postorder. */
439 static int *postorder
;
440 static int postorder_num
;
442 /* This structure is used to keep track of statistics on what
443 optimization PRE was able to perform. */
446 /* The number of RHS computations eliminated by PRE. */
449 /* The number of new expressions/temporaries generated by PRE. */
452 /* The number of inserts found due to partial anticipation */
455 /* The number of new PHI nodes added by PRE. */
459 static bool do_partial_partial
;
460 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
461 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
462 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
463 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
464 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
465 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
466 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
468 static bitmap_set_t
bitmap_set_new (void);
469 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
471 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
472 static unsigned int get_expr_value_id (pre_expr
);
474 /* We can add and remove elements and entries to and from sets
475 and hash tables, so we use alloc pools for them. */
477 static alloc_pool bitmap_set_pool
;
478 static bitmap_obstack grand_bitmap_obstack
;
480 /* Set of blocks with statements that have had their EH properties changed. */
481 static bitmap need_eh_cleanup
;
483 /* Set of blocks with statements that have had their AB properties changed. */
484 static bitmap need_ab_cleanup
;
486 /* A three tuple {e, pred, v} used to cache phi translations in the
487 phi_translate_table. */
489 typedef struct expr_pred_trans_d
: typed_free_remove
<expr_pred_trans_d
>
491 /* The expression. */
494 /* The predecessor block along which we translated the expression. */
497 /* The value that resulted from the translation. */
500 /* The hashcode for the expression, pred pair. This is cached for
504 /* hash_table support. */
505 typedef expr_pred_trans_d value_type
;
506 typedef expr_pred_trans_d compare_type
;
507 static inline hashval_t
hash (const value_type
*);
508 static inline int equal (const value_type
*, const compare_type
*);
509 } *expr_pred_trans_t
;
510 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
513 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
519 expr_pred_trans_d::equal (const value_type
*ve1
,
520 const compare_type
*ve2
)
522 basic_block b1
= ve1
->pred
;
523 basic_block b2
= ve2
->pred
;
525 /* If they are not translations for the same basic block, they can't
529 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
532 /* The phi_translate_table caches phi translations for a given
533 expression and predecessor. */
534 static hash_table
<expr_pred_trans_d
> phi_translate_table
;
536 /* Add the tuple mapping from {expression E, basic block PRED} to
537 the phi translation table and return whether it pre-existed. */
540 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
542 expr_pred_trans_t
*slot
;
543 expr_pred_trans_d tem
;
544 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
549 slot
= phi_translate_table
.find_slot_with_hash (&tem
, hash
, INSERT
);
556 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
558 (*entry
)->pred
= pred
;
559 (*entry
)->hashcode
= hash
;
564 /* Add expression E to the expression set of value id V. */
567 add_to_value (unsigned int v
, pre_expr e
)
571 gcc_checking_assert (get_expr_value_id (e
) == v
);
573 if (v
>= value_expressions
.length ())
575 value_expressions
.safe_grow_cleared (v
+ 1);
578 set
= value_expressions
[v
];
581 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
582 value_expressions
[v
] = set
;
585 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
588 /* Create a new bitmap set and return it. */
591 bitmap_set_new (void)
593 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
594 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
595 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
599 /* Return the value id for a PRE expression EXPR. */
602 get_expr_value_id (pre_expr expr
)
608 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
611 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
614 id
= PRE_EXPR_NARY (expr
)->value_id
;
617 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
622 /* ??? We cannot assert that expr has a value-id (it can be 0), because
623 we assign value-ids only to expressions that have a result
624 in set_hashtable_value_ids. */
628 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
631 sccvn_valnum_from_value_id (unsigned int val
)
635 bitmap exprset
= value_expressions
[val
];
636 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
638 pre_expr vexpr
= expression_for_id (i
);
639 if (vexpr
->kind
== NAME
)
640 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
641 else if (vexpr
->kind
== CONSTANT
)
642 return PRE_EXPR_CONSTANT (vexpr
);
647 /* Remove an expression EXPR from a bitmapped set. */
650 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
652 unsigned int val
= get_expr_value_id (expr
);
653 if (!value_id_constant_p (val
))
655 bitmap_clear_bit (&set
->values
, val
);
656 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
661 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
662 unsigned int val
, bool allow_constants
)
664 if (allow_constants
|| !value_id_constant_p (val
))
666 /* We specifically expect this and only this function to be able to
667 insert constants into a set. */
668 bitmap_set_bit (&set
->values
, val
);
669 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
673 /* Insert an expression EXPR into a bitmapped set. */
676 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
678 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
681 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
684 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
686 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
687 bitmap_copy (&dest
->values
, &orig
->values
);
691 /* Free memory used up by SET. */
693 bitmap_set_free (bitmap_set_t set
)
695 bitmap_clear (&set
->expressions
);
696 bitmap_clear (&set
->values
);
700 /* Generate an topological-ordered array of bitmap set SET. */
703 sorted_array_from_bitmap_set (bitmap_set_t set
)
706 bitmap_iterator bi
, bj
;
707 vec
<pre_expr
> result
;
709 /* Pre-allocate roughly enough space for the array. */
710 result
.create (bitmap_count_bits (&set
->values
));
712 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
714 /* The number of expressions having a given value is usually
715 relatively small. Thus, rather than making a vector of all
716 the expressions and sorting it by value-id, we walk the values
717 and check in the reverse mapping that tells us what expressions
718 have a given value, to filter those in our set. As a result,
719 the expressions are inserted in value-id order, which means
722 If this is somehow a significant lose for some cases, we can
723 choose which set to walk based on the set size. */
724 bitmap exprset
= value_expressions
[i
];
725 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
727 if (bitmap_bit_p (&set
->expressions
, j
))
728 result
.safe_push (expression_for_id (j
));
735 /* Perform bitmapped set operation DEST &= ORIG. */
738 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
746 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
748 bitmap_and_into (&dest
->values
, &orig
->values
);
749 bitmap_copy (&temp
, &dest
->expressions
);
750 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
752 pre_expr expr
= expression_for_id (i
);
753 unsigned int value_id
= get_expr_value_id (expr
);
754 if (!bitmap_bit_p (&dest
->values
, value_id
))
755 bitmap_clear_bit (&dest
->expressions
, i
);
757 bitmap_clear (&temp
);
761 /* Subtract all values and expressions contained in ORIG from DEST. */
764 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
766 bitmap_set_t result
= bitmap_set_new ();
770 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
773 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
775 pre_expr expr
= expression_for_id (i
);
776 unsigned int value_id
= get_expr_value_id (expr
);
777 bitmap_set_bit (&result
->values
, value_id
);
783 /* Subtract all the values in bitmap set B from bitmap set A. */
786 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
792 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
794 bitmap_copy (&temp
, &a
->expressions
);
795 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
797 pre_expr expr
= expression_for_id (i
);
798 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
799 bitmap_remove_from_set (a
, expr
);
801 bitmap_clear (&temp
);
805 /* Return true if bitmapped set SET contains the value VALUE_ID. */
808 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
810 if (value_id_constant_p (value_id
))
813 if (!set
|| bitmap_empty_p (&set
->expressions
))
816 return bitmap_bit_p (&set
->values
, value_id
);
820 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
822 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
825 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
828 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
835 if (value_id_constant_p (lookfor
))
838 if (!bitmap_set_contains_value (set
, lookfor
))
841 /* The number of expressions having a given value is usually
842 significantly less than the total number of expressions in SET.
843 Thus, rather than check, for each expression in SET, whether it
844 has the value LOOKFOR, we walk the reverse mapping that tells us
845 what expressions have a given value, and see if any of those
846 expressions are in our set. For large testcases, this is about
847 5-10x faster than walking the bitmap. If this is somehow a
848 significant lose for some cases, we can choose which set to walk
849 based on the set size. */
850 exprset
= value_expressions
[lookfor
];
851 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
853 if (bitmap_clear_bit (&set
->expressions
, i
))
855 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
863 /* Return true if two bitmap sets are equal. */
866 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
868 return bitmap_equal_p (&a
->values
, &b
->values
);
871 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
872 and add it otherwise. */
875 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
877 unsigned int val
= get_expr_value_id (expr
);
879 if (bitmap_set_contains_value (set
, val
))
880 bitmap_set_replace_value (set
, val
, expr
);
882 bitmap_insert_into_set (set
, expr
);
885 /* Insert EXPR into SET if EXPR's value is not already present in
889 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
891 unsigned int val
= get_expr_value_id (expr
);
893 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
895 /* Constant values are always considered to be part of the set. */
896 if (value_id_constant_p (val
))
899 /* If the value membership changed, add the expression. */
900 if (bitmap_set_bit (&set
->values
, val
))
901 bitmap_set_bit (&set
->expressions
, expr
->id
);
904 /* Print out EXPR to outfile. */
907 print_pre_expr (FILE *outfile
, const pre_expr expr
)
912 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
915 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
920 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
921 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
922 for (i
= 0; i
< nary
->length
; i
++)
924 print_generic_expr (outfile
, nary
->op
[i
], 0);
925 if (i
!= (unsigned) nary
->length
- 1)
926 fprintf (outfile
, ",");
928 fprintf (outfile
, "}");
934 vn_reference_op_t vro
;
936 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
937 fprintf (outfile
, "{");
939 ref
->operands
.iterate (i
, &vro
);
942 bool closebrace
= false;
943 if (vro
->opcode
!= SSA_NAME
944 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
946 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
949 fprintf (outfile
, "<");
955 print_generic_expr (outfile
, vro
->op0
, 0);
958 fprintf (outfile
, ",");
959 print_generic_expr (outfile
, vro
->op1
, 0);
963 fprintf (outfile
, ",");
964 print_generic_expr (outfile
, vro
->op2
, 0);
968 fprintf (outfile
, ">");
969 if (i
!= ref
->operands
.length () - 1)
970 fprintf (outfile
, ",");
972 fprintf (outfile
, "}");
975 fprintf (outfile
, "@");
976 print_generic_expr (outfile
, ref
->vuse
, 0);
982 void debug_pre_expr (pre_expr
);
984 /* Like print_pre_expr but always prints to stderr. */
986 debug_pre_expr (pre_expr e
)
988 print_pre_expr (stderr
, e
);
989 fprintf (stderr
, "\n");
992 /* Print out SET to OUTFILE. */
995 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
996 const char *setname
, int blockindex
)
998 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1005 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1007 const pre_expr expr
= expression_for_id (i
);
1010 fprintf (outfile
, ", ");
1012 print_pre_expr (outfile
, expr
);
1014 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1017 fprintf (outfile
, " }\n");
1020 void debug_bitmap_set (bitmap_set_t
);
1023 debug_bitmap_set (bitmap_set_t set
)
1025 print_bitmap_set (stderr
, set
, "debug", 0);
1028 void debug_bitmap_sets_for (basic_block
);
1031 debug_bitmap_sets_for (basic_block bb
)
1033 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1034 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1035 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1036 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1037 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1038 if (do_partial_partial
)
1039 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1040 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1043 /* Print out the expressions that have VAL to OUTFILE. */
1046 print_value_expressions (FILE *outfile
, unsigned int val
)
1048 bitmap set
= value_expressions
[val
];
1053 sprintf (s
, "%04d", val
);
1054 x
.expressions
= *set
;
1055 print_bitmap_set (outfile
, &x
, s
, 0);
1061 debug_value_expressions (unsigned int val
)
1063 print_value_expressions (stderr
, val
);
1066 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1070 get_or_alloc_expr_for_constant (tree constant
)
1072 unsigned int result_id
;
1073 unsigned int value_id
;
1074 struct pre_expr_d expr
;
1077 expr
.kind
= CONSTANT
;
1078 PRE_EXPR_CONSTANT (&expr
) = constant
;
1079 result_id
= lookup_expression_id (&expr
);
1081 return expression_for_id (result_id
);
1083 newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1084 newexpr
->kind
= CONSTANT
;
1085 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1086 alloc_expression_id (newexpr
);
1087 value_id
= get_or_alloc_constant_value_id (constant
);
1088 add_to_value (value_id
, newexpr
);
1092 /* Given a value id V, find the actual tree representing the constant
1093 value if there is one, and return it. Return NULL if we can't find
1097 get_constant_for_value_id (unsigned int v
)
1099 if (value_id_constant_p (v
))
1103 bitmap exprset
= value_expressions
[v
];
1105 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1107 pre_expr expr
= expression_for_id (i
);
1108 if (expr
->kind
== CONSTANT
)
1109 return PRE_EXPR_CONSTANT (expr
);
1115 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1116 Currently only supports constants and SSA_NAMES. */
1118 get_or_alloc_expr_for (tree t
)
1120 if (TREE_CODE (t
) == SSA_NAME
)
1121 return get_or_alloc_expr_for_name (t
);
1122 else if (is_gimple_min_invariant (t
))
1123 return get_or_alloc_expr_for_constant (t
);
1126 /* More complex expressions can result from SCCVN expression
1127 simplification that inserts values for them. As they all
1128 do not have VOPs the get handled by the nary ops struct. */
1129 vn_nary_op_t result
;
1130 unsigned int result_id
;
1131 vn_nary_op_lookup (t
, &result
);
1134 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1136 PRE_EXPR_NARY (e
) = result
;
1137 result_id
= lookup_expression_id (e
);
1140 pool_free (pre_expr_pool
, e
);
1141 e
= expression_for_id (result_id
);
1144 alloc_expression_id (e
);
1151 /* Return the folded version of T if T, when folded, is a gimple
1152 min_invariant. Otherwise, return T. */
1155 fully_constant_expression (pre_expr e
)
1163 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1164 switch (TREE_CODE_CLASS (nary
->opcode
))
1167 case tcc_comparison
:
1169 /* We have to go from trees to pre exprs to value ids to
1171 tree naryop0
= nary
->op
[0];
1172 tree naryop1
= nary
->op
[1];
1174 if (!is_gimple_min_invariant (naryop0
))
1176 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1177 unsigned int vrep0
= get_expr_value_id (rep0
);
1178 tree const0
= get_constant_for_value_id (vrep0
);
1180 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1182 if (!is_gimple_min_invariant (naryop1
))
1184 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1185 unsigned int vrep1
= get_expr_value_id (rep1
);
1186 tree const1
= get_constant_for_value_id (vrep1
);
1188 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1190 result
= fold_binary (nary
->opcode
, nary
->type
,
1192 if (result
&& is_gimple_min_invariant (result
))
1193 return get_or_alloc_expr_for_constant (result
);
1194 /* We might have simplified the expression to a
1195 SSA_NAME for example from x_1 * 1. But we cannot
1196 insert a PHI for x_1 unconditionally as x_1 might
1197 not be available readily. */
1201 if (nary
->opcode
!= REALPART_EXPR
1202 && nary
->opcode
!= IMAGPART_EXPR
1203 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1208 /* We have to go from trees to pre exprs to value ids to
1210 tree naryop0
= nary
->op
[0];
1211 tree const0
, result
;
1212 if (is_gimple_min_invariant (naryop0
))
1216 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1217 unsigned int vrep0
= get_expr_value_id (rep0
);
1218 const0
= get_constant_for_value_id (vrep0
);
1223 tree type1
= TREE_TYPE (nary
->op
[0]);
1224 const0
= fold_convert (type1
, const0
);
1225 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1227 if (result
&& is_gimple_min_invariant (result
))
1228 return get_or_alloc_expr_for_constant (result
);
1237 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1239 if ((folded
= fully_constant_vn_reference_p (ref
)))
1240 return get_or_alloc_expr_for_constant (folded
);
1249 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1250 it has the value it would have in BLOCK. Set *SAME_VALID to true
1251 in case the new vuse doesn't change the value id of the OPERANDS. */
1254 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1255 alias_set_type set
, tree type
, tree vuse
,
1256 basic_block phiblock
,
1257 basic_block block
, bool *same_valid
)
1259 gimple phi
= SSA_NAME_DEF_STMT (vuse
);
1266 if (gimple_bb (phi
) != phiblock
)
1269 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1271 /* Use the alias-oracle to find either the PHI node in this block,
1272 the first VUSE used in this block that is equivalent to vuse or
1273 the first VUSE which definition in this block kills the value. */
1274 if (gimple_code (phi
) == GIMPLE_PHI
)
1275 e
= find_edge (block
, phiblock
);
1276 else if (use_oracle
)
1277 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1279 vuse
= gimple_vuse (phi
);
1280 phi
= SSA_NAME_DEF_STMT (vuse
);
1281 if (gimple_bb (phi
) != phiblock
)
1283 if (gimple_code (phi
) == GIMPLE_PHI
)
1285 e
= find_edge (block
, phiblock
);
1296 bitmap visited
= NULL
;
1298 /* Try to find a vuse that dominates this phi node by skipping
1299 non-clobbering statements. */
1300 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false);
1302 BITMAP_FREE (visited
);
1308 /* If we didn't find any, the value ID can't stay the same,
1309 but return the translated vuse. */
1310 *same_valid
= false;
1311 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1313 /* ??? We would like to return vuse here as this is the canonical
1314 upmost vdef that this reference is associated with. But during
1315 insertion of the references into the hash tables we only ever
1316 directly insert with their direct gimple_vuse, hence returning
1317 something else would make us not find the other expression. */
1318 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1324 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1325 SET2. This is used to avoid making a set consisting of the union
1326 of PA_IN and ANTIC_IN during insert. */
1328 static inline pre_expr
1329 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1333 result
= bitmap_find_leader (set1
, val
);
1334 if (!result
&& set2
)
1335 result
= bitmap_find_leader (set2
, val
);
1339 /* Get the tree type for our PRE expression e. */
1342 get_expr_type (const pre_expr e
)
1347 return TREE_TYPE (PRE_EXPR_NAME (e
));
1349 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1351 return PRE_EXPR_REFERENCE (e
)->type
;
1353 return PRE_EXPR_NARY (e
)->type
;
1358 /* Get a representative SSA_NAME for a given expression.
1359 Since all of our sub-expressions are treated as values, we require
1360 them to be SSA_NAME's for simplicity.
1361 Prior versions of GVNPRE used to use "value handles" here, so that
1362 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1363 either case, the operands are really values (IE we do not expect
1364 them to be usable without finding leaders). */
1367 get_representative_for (const pre_expr e
)
1370 unsigned int value_id
= get_expr_value_id (e
);
1375 return PRE_EXPR_NAME (e
);
1377 return PRE_EXPR_CONSTANT (e
);
1381 /* Go through all of the expressions representing this value
1382 and pick out an SSA_NAME. */
1385 bitmap exprs
= value_expressions
[value_id
];
1386 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1388 pre_expr rep
= expression_for_id (i
);
1389 if (rep
->kind
== NAME
)
1390 return PRE_EXPR_NAME (rep
);
1391 else if (rep
->kind
== CONSTANT
)
1392 return PRE_EXPR_CONSTANT (rep
);
1398 /* If we reached here we couldn't find an SSA_NAME. This can
1399 happen when we've discovered a value that has never appeared in
1400 the program as set to an SSA_NAME, as the result of phi translation.
1402 ??? We should be able to re-use this when we insert the statement
1404 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1405 VN_INFO_GET (name
)->value_id
= value_id
;
1406 VN_INFO (name
)->valnum
= name
;
1407 /* ??? For now mark this SSA name for release by SCCVN. */
1408 VN_INFO (name
)->needs_insertion
= true;
1409 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1410 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1412 fprintf (dump_file
, "Created SSA_NAME representative ");
1413 print_generic_expr (dump_file
, name
, 0);
1414 fprintf (dump_file
, " for expression:");
1415 print_pre_expr (dump_file
, e
);
1416 fprintf (dump_file
, " (%04d)\n", value_id
);
1425 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1426 basic_block pred
, basic_block phiblock
);
1428 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1429 the phis in PRED. Return NULL if we can't find a leader for each part
1430 of the translated expression. */
1433 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1434 basic_block pred
, basic_block phiblock
)
1441 bool changed
= false;
1442 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1443 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1444 sizeof_vn_nary_op (nary
->length
));
1445 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1447 for (i
= 0; i
< newnary
->length
; i
++)
1449 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1453 pre_expr leader
, result
;
1454 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1455 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1456 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1457 if (result
&& result
!= leader
)
1459 tree name
= get_representative_for (result
);
1462 newnary
->op
[i
] = name
;
1467 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1473 unsigned int new_val_id
;
1475 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1480 if (result
&& is_gimple_min_invariant (result
))
1481 return get_or_alloc_expr_for_constant (result
);
1483 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1488 PRE_EXPR_NARY (expr
) = nary
;
1489 constant
= fully_constant_expression (expr
);
1490 if (constant
!= expr
)
1493 new_val_id
= nary
->value_id
;
1494 get_or_alloc_expression_id (expr
);
1498 new_val_id
= get_next_value_id ();
1499 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1500 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1504 result
, new_val_id
);
1505 PRE_EXPR_NARY (expr
) = nary
;
1506 constant
= fully_constant_expression (expr
);
1507 if (constant
!= expr
)
1509 get_or_alloc_expression_id (expr
);
1511 add_to_value (new_val_id
, expr
);
1519 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1520 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1521 tree vuse
= ref
->vuse
;
1522 tree newvuse
= vuse
;
1523 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1524 bool changed
= false, same_valid
= true;
1525 unsigned int i
, j
, n
;
1526 vn_reference_op_t operand
;
1527 vn_reference_t newref
;
1530 operands
.iterate (i
, &operand
); i
++, j
++)
1535 tree type
= operand
->type
;
1536 vn_reference_op_s newop
= *operand
;
1537 op
[0] = operand
->op0
;
1538 op
[1] = operand
->op1
;
1539 op
[2] = operand
->op2
;
1540 for (n
= 0; n
< 3; ++n
)
1542 unsigned int op_val_id
;
1545 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1547 /* We can't possibly insert these. */
1549 && !is_gimple_min_invariant (op
[n
]))
1553 op_val_id
= VN_INFO (op
[n
])->value_id
;
1554 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1557 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1560 if (opresult
!= leader
)
1562 tree name
= get_representative_for (opresult
);
1565 changed
|= name
!= op
[n
];
1571 newoperands
.release ();
1574 if (!newoperands
.exists ())
1575 newoperands
= operands
.copy ();
1576 /* We may have changed from an SSA_NAME to a constant */
1577 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1578 newop
.opcode
= TREE_CODE (op
[0]);
1583 /* If it transforms a non-constant ARRAY_REF into a constant
1584 one, adjust the constant offset. */
1585 if (newop
.opcode
== ARRAY_REF
1587 && TREE_CODE (op
[0]) == INTEGER_CST
1588 && TREE_CODE (op
[1]) == INTEGER_CST
1589 && TREE_CODE (op
[2]) == INTEGER_CST
)
1591 double_int off
= tree_to_double_int (op
[0]);
1592 off
+= -tree_to_double_int (op
[1]);
1593 off
*= tree_to_double_int (op
[2]);
1594 if (off
.fits_shwi ())
1595 newop
.off
= off
.low
;
1597 newoperands
[j
] = newop
;
1598 /* If it transforms from an SSA_NAME to an address, fold with
1599 a preceding indirect reference. */
1600 if (j
> 0 && op
[0] && TREE_CODE (op
[0]) == ADDR_EXPR
1601 && newoperands
[j
- 1].opcode
== MEM_REF
)
1602 vn_reference_fold_indirect (&newoperands
, &j
);
1604 if (i
!= operands
.length ())
1606 newoperands
.release ();
1612 newvuse
= translate_vuse_through_block (newoperands
,
1613 ref
->set
, ref
->type
,
1614 vuse
, phiblock
, pred
,
1616 if (newvuse
== NULL_TREE
)
1618 newoperands
.release ();
1623 if (changed
|| newvuse
!= vuse
)
1625 unsigned int new_val_id
;
1628 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1633 newoperands
.release ();
1635 /* We can always insert constants, so if we have a partial
1636 redundant constant load of another type try to translate it
1637 to a constant of appropriate type. */
1638 if (result
&& is_gimple_min_invariant (result
))
1641 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1643 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1644 if (tem
&& !is_gimple_min_invariant (tem
))
1648 return get_or_alloc_expr_for_constant (tem
);
1651 /* If we'd have to convert things we would need to validate
1652 if we can insert the translated expression. So fail
1653 here for now - we cannot insert an alias with a different
1654 type in the VN tables either, as that would assert. */
1656 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1658 else if (!result
&& newref
1659 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1661 newoperands
.release ();
1665 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1666 expr
->kind
= REFERENCE
;
1671 PRE_EXPR_REFERENCE (expr
) = newref
;
1672 constant
= fully_constant_expression (expr
);
1673 if (constant
!= expr
)
1676 new_val_id
= newref
->value_id
;
1677 get_or_alloc_expression_id (expr
);
1681 if (changed
|| !same_valid
)
1683 new_val_id
= get_next_value_id ();
1684 value_expressions
.safe_grow_cleared
1685 (get_max_value_id () + 1);
1688 new_val_id
= ref
->value_id
;
1689 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1692 result
, new_val_id
);
1693 newoperands
.create (0);
1694 PRE_EXPR_REFERENCE (expr
) = newref
;
1695 constant
= fully_constant_expression (expr
);
1696 if (constant
!= expr
)
1698 get_or_alloc_expression_id (expr
);
1700 add_to_value (new_val_id
, expr
);
1702 newoperands
.release ();
1709 tree name
= PRE_EXPR_NAME (expr
);
1710 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
1711 /* If the SSA name is defined by a PHI node in this block,
1713 if (gimple_code (def_stmt
) == GIMPLE_PHI
1714 && gimple_bb (def_stmt
) == phiblock
)
1716 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1717 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1719 /* Handle constant. */
1720 if (is_gimple_min_invariant (def
))
1721 return get_or_alloc_expr_for_constant (def
);
1723 return get_or_alloc_expr_for_name (def
);
1725 /* Otherwise return it unchanged - it will get cleaned if its
1726 value is not available in PREDs AVAIL_OUT set of expressions. */
1735 /* Wrapper around phi_translate_1 providing caching functionality. */
1738 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1739 basic_block pred
, basic_block phiblock
)
1741 expr_pred_trans_t slot
= NULL
;
1747 /* Constants contain no values that need translation. */
1748 if (expr
->kind
== CONSTANT
)
1751 if (value_id_constant_p (get_expr_value_id (expr
)))
1754 /* Don't add translations of NAMEs as those are cheap to translate. */
1755 if (expr
->kind
!= NAME
)
1757 if (phi_trans_add (&slot
, expr
, pred
))
1759 /* Store NULL for the value we want to return in the case of
1765 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1772 /* Remove failed translations again, they cause insert
1773 iteration to not pick up new opportunities reliably. */
1774 phi_translate_table
.remove_elt_with_hash (slot
, slot
->hashcode
);
1781 /* For each expression in SET, translate the values through phi nodes
1782 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1783 expressions in DEST. */
1786 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1787 basic_block phiblock
)
1789 vec
<pre_expr
> exprs
;
1793 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1795 bitmap_set_copy (dest
, set
);
1799 exprs
= sorted_array_from_bitmap_set (set
);
1800 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1802 pre_expr translated
;
1803 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1807 /* We might end up with multiple expressions from SET being
1808 translated to the same value. In this case we do not want
1809 to retain the NARY or REFERENCE expression but prefer a NAME
1810 which would be the leader. */
1811 if (translated
->kind
== NAME
)
1812 bitmap_value_replace_in_set (dest
, translated
);
1814 bitmap_value_insert_into_set (dest
, translated
);
1819 /* Find the leader for a value (i.e., the name representing that
1820 value) in a given set, and return it. Return NULL if no leader
1824 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1826 if (value_id_constant_p (val
))
1830 bitmap exprset
= value_expressions
[val
];
1832 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1834 pre_expr expr
= expression_for_id (i
);
1835 if (expr
->kind
== CONSTANT
)
1839 if (bitmap_set_contains_value (set
, val
))
1841 /* Rather than walk the entire bitmap of expressions, and see
1842 whether any of them has the value we are looking for, we look
1843 at the reverse mapping, which tells us the set of expressions
1844 that have a given value (IE value->expressions with that
1845 value) and see if any of those expressions are in our set.
1846 The number of expressions per value is usually significantly
1847 less than the number of expressions in the set. In fact, for
1848 large testcases, doing it this way is roughly 5-10x faster
1849 than walking the bitmap.
1850 If this is somehow a significant lose for some cases, we can
1851 choose which set to walk based on which set is smaller. */
1854 bitmap exprset
= value_expressions
[val
];
1856 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1857 return expression_for_id (i
);
1862 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1863 BLOCK by seeing if it is not killed in the block. Note that we are
1864 only determining whether there is a store that kills it. Because
1865 of the order in which clean iterates over values, we are guaranteed
1866 that altered operands will have caused us to be eliminated from the
1867 ANTIC_IN set already. */
1870 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1872 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1873 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1875 gimple_stmt_iterator gsi
;
1876 unsigned id
= get_expression_id (expr
);
1883 /* Lookup a previously calculated result. */
1884 if (EXPR_DIES (block
)
1885 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1886 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1888 /* A memory expression {e, VUSE} dies in the block if there is a
1889 statement that may clobber e. If, starting statement walk from the
1890 top of the basic block, a statement uses VUSE there can be no kill
1891 inbetween that use and the original statement that loaded {e, VUSE},
1892 so we can stop walking. */
1893 ref
.base
= NULL_TREE
;
1894 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1896 tree def_vuse
, def_vdef
;
1897 def
= gsi_stmt (gsi
);
1898 def_vuse
= gimple_vuse (def
);
1899 def_vdef
= gimple_vdef (def
);
1901 /* Not a memory statement. */
1905 /* Not a may-def. */
1908 /* A load with the same VUSE, we're done. */
1909 if (def_vuse
== vuse
)
1915 /* Init ref only if we really need it. */
1916 if (ref
.base
== NULL_TREE
1917 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1923 /* If the statement may clobber expr, it dies. */
1924 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1931 /* Remember the result. */
1932 if (!EXPR_DIES (block
))
1933 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1934 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1936 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1942 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1943 contains its value-id. */
1946 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1948 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1950 unsigned int value_id
= VN_INFO (op
)->value_id
;
1951 if (!(bitmap_set_contains_value (set1
, value_id
)
1952 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1958 /* Determine if the expression EXPR is valid in SET1 U SET2.
1959 ONLY SET2 CAN BE NULL.
1960 This means that we have a leader for each part of the expression
1961 (if it consists of values), or the expression is an SSA_NAME.
1962 For loads/calls, we also see if the vuse is killed in this block. */
1965 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
1971 return bitmap_find_leader (AVAIL_OUT (block
),
1972 get_expr_value_id (expr
)) != NULL
;
1976 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1977 for (i
= 0; i
< nary
->length
; i
++)
1978 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1985 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1986 vn_reference_op_t vro
;
1989 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1991 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1992 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1993 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
2003 /* Clean the set of expressions that are no longer valid in SET1 or
2004 SET2. This means expressions that are made up of values we have no
2005 leaders for in SET1 or SET2. This version is used for partial
2006 anticipation, which means it is not valid in either ANTIC_IN or
2010 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
2012 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
2016 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2018 if (!valid_in_sets (set1
, set2
, expr
, block
))
2019 bitmap_remove_from_set (set1
, expr
);
2024 /* Clean the set of expressions that are no longer valid in SET. This
2025 means expressions that are made up of values we have no leaders for
2029 clean (bitmap_set_t set
, basic_block block
)
2031 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2035 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2037 if (!valid_in_sets (set
, NULL
, expr
, block
))
2038 bitmap_remove_from_set (set
, expr
);
2043 /* Clean the set of expressions that are no longer valid in SET because
2044 they are clobbered in BLOCK or because they trap and may not be executed. */
2047 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2052 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2054 pre_expr expr
= expression_for_id (i
);
2055 if (expr
->kind
== REFERENCE
)
2057 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2060 gimple def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2061 if (!gimple_nop_p (def_stmt
)
2062 && ((gimple_bb (def_stmt
) != block
2063 && !dominated_by_p (CDI_DOMINATORS
,
2064 block
, gimple_bb (def_stmt
)))
2065 || (gimple_bb (def_stmt
) == block
2066 && value_dies_in_block_x (expr
, block
))))
2067 bitmap_remove_from_set (set
, expr
);
2070 else if (expr
->kind
== NARY
)
2072 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2073 /* If the NARY may trap make sure the block does not contain
2074 a possible exit point.
2075 ??? This is overly conservative if we translate AVAIL_OUT
2076 as the available expression might be after the exit point. */
2077 if (BB_MAY_NOTRETURN (block
)
2078 && vn_nary_may_trap (nary
))
2079 bitmap_remove_from_set (set
, expr
);
2084 static sbitmap has_abnormal_preds
;
2086 /* List of blocks that may have changed during ANTIC computation and
2087 thus need to be iterated over. */
2089 static sbitmap changed_blocks
;
2091 /* Decide whether to defer a block for a later iteration, or PHI
2092 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2093 should defer the block, and true if we processed it. */
2096 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2097 basic_block block
, basic_block phiblock
)
2099 if (!BB_VISITED (phiblock
))
2101 bitmap_set_bit (changed_blocks
, block
->index
);
2102 BB_VISITED (block
) = 0;
2103 BB_DEFERRED (block
) = 1;
2107 phi_translate_set (dest
, source
, block
, phiblock
);
2111 /* Compute the ANTIC set for BLOCK.
2113 If succs(BLOCK) > 1 then
2114 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2115 else if succs(BLOCK) == 1 then
2116 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2118 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2122 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2124 bool changed
= false;
2125 bitmap_set_t S
, old
, ANTIC_OUT
;
2131 old
= ANTIC_OUT
= S
= NULL
;
2132 BB_VISITED (block
) = 1;
2134 /* If any edges from predecessors are abnormal, antic_in is empty,
2136 if (block_has_abnormal_pred_edge
)
2137 goto maybe_dump_sets
;
2139 old
= ANTIC_IN (block
);
2140 ANTIC_OUT
= bitmap_set_new ();
2142 /* If the block has no successors, ANTIC_OUT is empty. */
2143 if (EDGE_COUNT (block
->succs
) == 0)
2145 /* If we have one successor, we could have some phi nodes to
2146 translate through. */
2147 else if (single_succ_p (block
))
2149 basic_block succ_bb
= single_succ (block
);
2151 /* We trade iterations of the dataflow equations for having to
2152 phi translate the maximal set, which is incredibly slow
2153 (since the maximal set often has 300+ members, even when you
2154 have a small number of blocks).
2155 Basically, we defer the computation of ANTIC for this block
2156 until we have processed it's successor, which will inevitably
2157 have a *much* smaller set of values to phi translate once
2158 clean has been run on it.
2159 The cost of doing this is that we technically perform more
2160 iterations, however, they are lower cost iterations.
2162 Timings for PRE on tramp3d-v4:
2163 without maximal set fix: 11 seconds
2164 with maximal set fix/without deferring: 26 seconds
2165 with maximal set fix/with deferring: 11 seconds
2168 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2172 goto maybe_dump_sets
;
2175 /* If we have multiple successors, we take the intersection of all of
2176 them. Note that in the case of loop exit phi nodes, we may have
2177 phis to translate through. */
2180 vec
<basic_block
> worklist
;
2182 basic_block bprime
, first
= NULL
;
2184 worklist
.create (EDGE_COUNT (block
->succs
));
2185 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2188 && BB_VISITED (e
->dest
))
2190 else if (BB_VISITED (e
->dest
))
2191 worklist
.quick_push (e
->dest
);
2194 /* Of multiple successors we have to have visited one already. */
2197 bitmap_set_bit (changed_blocks
, block
->index
);
2198 BB_VISITED (block
) = 0;
2199 BB_DEFERRED (block
) = 1;
2201 worklist
.release ();
2202 goto maybe_dump_sets
;
2205 if (!gimple_seq_empty_p (phi_nodes (first
)))
2206 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2208 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2210 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2212 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2214 bitmap_set_t tmp
= bitmap_set_new ();
2215 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2216 bitmap_set_and (ANTIC_OUT
, tmp
);
2217 bitmap_set_free (tmp
);
2220 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2222 worklist
.release ();
2225 /* Prune expressions that are clobbered in block and thus become
2226 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2227 prune_clobbered_mems (ANTIC_OUT
, block
);
2229 /* Generate ANTIC_OUT - TMP_GEN. */
2230 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2232 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2233 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2236 /* Then union in the ANTIC_OUT - TMP_GEN values,
2237 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2238 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2239 bitmap_value_insert_into_set (ANTIC_IN (block
),
2240 expression_for_id (bii
));
2242 clean (ANTIC_IN (block
), block
);
2244 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2247 bitmap_set_bit (changed_blocks
, block
->index
);
2248 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2249 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2252 bitmap_clear_bit (changed_blocks
, block
->index
);
2255 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2257 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2260 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2262 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2266 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2271 "Block %d was deferred for a future iteration.\n",
2276 bitmap_set_free (old
);
2278 bitmap_set_free (S
);
2280 bitmap_set_free (ANTIC_OUT
);
2284 /* Compute PARTIAL_ANTIC for BLOCK.
2286 If succs(BLOCK) > 1 then
2287 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2288 in ANTIC_OUT for all succ(BLOCK)
2289 else if succs(BLOCK) == 1 then
2290 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2292 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2297 compute_partial_antic_aux (basic_block block
,
2298 bool block_has_abnormal_pred_edge
)
2300 bool changed
= false;
2301 bitmap_set_t old_PA_IN
;
2302 bitmap_set_t PA_OUT
;
2305 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2307 old_PA_IN
= PA_OUT
= NULL
;
2309 /* If any edges from predecessors are abnormal, antic_in is empty,
2311 if (block_has_abnormal_pred_edge
)
2312 goto maybe_dump_sets
;
2314 /* If there are too many partially anticipatable values in the
2315 block, phi_translate_set can take an exponential time: stop
2316 before the translation starts. */
2318 && single_succ_p (block
)
2319 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2320 goto maybe_dump_sets
;
2322 old_PA_IN
= PA_IN (block
);
2323 PA_OUT
= bitmap_set_new ();
2325 /* If the block has no successors, ANTIC_OUT is empty. */
2326 if (EDGE_COUNT (block
->succs
) == 0)
2328 /* If we have one successor, we could have some phi nodes to
2329 translate through. Note that we can't phi translate across DFS
2330 back edges in partial antic, because it uses a union operation on
2331 the successors. For recurrences like IV's, we will end up
2332 generating a new value in the set on each go around (i + 3 (VH.1)
2333 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2334 else if (single_succ_p (block
))
2336 basic_block succ
= single_succ (block
);
2337 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2338 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2340 /* If we have multiple successors, we take the union of all of
2344 vec
<basic_block
> worklist
;
2348 worklist
.create (EDGE_COUNT (block
->succs
));
2349 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2351 if (e
->flags
& EDGE_DFS_BACK
)
2353 worklist
.quick_push (e
->dest
);
2355 if (worklist
.length () > 0)
2357 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2362 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2363 bitmap_value_insert_into_set (PA_OUT
,
2364 expression_for_id (i
));
2365 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2367 bitmap_set_t pa_in
= bitmap_set_new ();
2368 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2369 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2370 bitmap_value_insert_into_set (PA_OUT
,
2371 expression_for_id (i
));
2372 bitmap_set_free (pa_in
);
2375 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2376 bitmap_value_insert_into_set (PA_OUT
,
2377 expression_for_id (i
));
2380 worklist
.release ();
2383 /* Prune expressions that are clobbered in block and thus become
2384 invalid if translated from PA_OUT to PA_IN. */
2385 prune_clobbered_mems (PA_OUT
, block
);
2387 /* PA_IN starts with PA_OUT - TMP_GEN.
2388 Then we subtract things from ANTIC_IN. */
2389 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2391 /* For partial antic, we want to put back in the phi results, since
2392 we will properly avoid making them partially antic over backedges. */
2393 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2394 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2396 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2397 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2399 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2401 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2404 bitmap_set_bit (changed_blocks
, block
->index
);
2405 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2406 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2409 bitmap_clear_bit (changed_blocks
, block
->index
);
2412 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2415 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2417 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2420 bitmap_set_free (old_PA_IN
);
2422 bitmap_set_free (PA_OUT
);
2426 /* Compute ANTIC and partial ANTIC sets. */
2429 compute_antic (void)
2431 bool changed
= true;
2432 int num_iterations
= 0;
2436 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2437 We pre-build the map of blocks with incoming abnormal edges here. */
2438 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2439 bitmap_clear (has_abnormal_preds
);
2446 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2448 e
->flags
&= ~EDGE_DFS_BACK
;
2449 if (e
->flags
& EDGE_ABNORMAL
)
2451 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2456 BB_VISITED (block
) = 0;
2457 BB_DEFERRED (block
) = 0;
2459 /* While we are here, give empty ANTIC_IN sets to each block. */
2460 ANTIC_IN (block
) = bitmap_set_new ();
2461 PA_IN (block
) = bitmap_set_new ();
2464 /* At the exit block we anticipate nothing. */
2465 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2467 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2468 bitmap_ones (changed_blocks
);
2471 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2472 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2473 /* ??? We need to clear our PHI translation cache here as the
2474 ANTIC sets shrink and we restrict valid translations to
2475 those having operands with leaders in ANTIC. Same below
2476 for PA ANTIC computation. */
2479 for (i
= postorder_num
- 1; i
>= 0; i
--)
2481 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2483 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2484 changed
|= compute_antic_aux (block
,
2485 bitmap_bit_p (has_abnormal_preds
,
2489 /* Theoretically possible, but *highly* unlikely. */
2490 gcc_checking_assert (num_iterations
< 500);
2493 statistics_histogram_event (cfun
, "compute_antic iterations",
2496 if (do_partial_partial
)
2498 bitmap_ones (changed_blocks
);
2499 mark_dfs_back_edges ();
2504 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2505 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2508 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2510 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2512 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2514 |= compute_partial_antic_aux (block
,
2515 bitmap_bit_p (has_abnormal_preds
,
2519 /* Theoretically possible, but *highly* unlikely. */
2520 gcc_checking_assert (num_iterations
< 500);
2522 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2525 sbitmap_free (has_abnormal_preds
);
2526 sbitmap_free (changed_blocks
);
2530 /* Inserted expressions are placed onto this worklist, which is used
2531 for performing quick dead code elimination of insertions we made
2532 that didn't turn out to be necessary. */
2533 static bitmap inserted_exprs
;
2535 /* The actual worker for create_component_ref_by_pieces. */
2538 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2539 unsigned int *operand
, gimple_seq
*stmts
)
2541 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2544 switch (currop
->opcode
)
2548 tree folded
, sc
= NULL_TREE
;
2549 unsigned int nargs
= 0;
2551 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2554 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2559 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2563 args
= XNEWVEC (tree
, ref
->operands
.length () - 1);
2564 while (*operand
< ref
->operands
.length ())
2566 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2572 folded
= build_call_array (currop
->type
,
2573 (TREE_CODE (fn
) == FUNCTION_DECL
2574 ? build_fold_addr_expr (fn
) : fn
),
2578 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2584 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2588 tree offset
= currop
->op0
;
2589 if (TREE_CODE (baseop
) == ADDR_EXPR
2590 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2594 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2597 offset
= int_const_binop (PLUS_EXPR
, offset
,
2598 build_int_cst (TREE_TYPE (offset
),
2600 baseop
= build_fold_addr_expr (base
);
2602 return fold_build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2605 case TARGET_MEM_REF
:
2607 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2608 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2609 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2615 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2621 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2625 return build5 (TARGET_MEM_REF
, currop
->type
,
2626 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2632 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2638 case VIEW_CONVERT_EXPR
:
2640 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2644 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2647 case WITH_SIZE_EXPR
:
2649 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2653 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2656 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2661 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2665 tree op1
= currop
->op0
;
2666 tree op2
= currop
->op1
;
2667 return fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2670 /* For array ref vn_reference_op's, operand 1 of the array ref
2671 is op0 of the reference op and operand 3 of the array ref is
2673 case ARRAY_RANGE_REF
:
2677 tree genop1
= currop
->op0
;
2678 tree genop2
= currop
->op1
;
2679 tree genop3
= currop
->op2
;
2680 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2684 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2689 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2690 /* Drop zero minimum index if redundant. */
2691 if (integer_zerop (genop2
)
2693 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2697 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2704 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2705 /* We can't always put a size in units of the element alignment
2706 here as the element alignment may be not visible. See
2707 PR43783. Simply drop the element size for constant
2709 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2713 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2714 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2715 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2720 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2727 tree genop2
= currop
->op1
;
2728 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2731 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2735 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2739 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2744 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2765 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2766 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2767 trying to rename aggregates into ssa form directly, which is a no no.
2769 Thus, this routine doesn't create temporaries, it just builds a
2770 single access expression for the array, calling
2771 find_or_generate_expression to build the innermost pieces.
2773 This function is a subroutine of create_expression_by_pieces, and
2774 should not be called on it's own unless you really know what you
2778 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2781 unsigned int op
= 0;
2782 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2785 /* Find a simple leader for an expression, or generate one using
2786 create_expression_by_pieces from a NARY expression for the value.
2787 BLOCK is the basic_block we are looking for leaders in.
2788 OP is the tree expression to find a leader for or generate.
2789 Returns the leader or NULL_TREE on failure. */
2792 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2794 pre_expr expr
= get_or_alloc_expr_for (op
);
2795 unsigned int lookfor
= get_expr_value_id (expr
);
2796 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2799 if (leader
->kind
== NAME
)
2800 return PRE_EXPR_NAME (leader
);
2801 else if (leader
->kind
== CONSTANT
)
2802 return PRE_EXPR_CONSTANT (leader
);
2808 /* It must be a complex expression, so generate it recursively. Note
2809 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2810 where the insert algorithm fails to insert a required expression. */
2811 bitmap exprset
= value_expressions
[lookfor
];
2814 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2816 pre_expr temp
= expression_for_id (i
);
2817 /* We cannot insert random REFERENCE expressions at arbitrary
2818 places. We can insert NARYs which eventually re-materializes
2819 its operand values. */
2820 if (temp
->kind
== NARY
)
2821 return create_expression_by_pieces (block
, temp
, stmts
,
2822 get_expr_type (expr
));
2829 #define NECESSARY GF_PLF_1
2831 /* Create an expression in pieces, so that we can handle very complex
2832 expressions that may be ANTIC, but not necessary GIMPLE.
2833 BLOCK is the basic block the expression will be inserted into,
2834 EXPR is the expression to insert (in value form)
2835 STMTS is a statement list to append the necessary insertions into.
2837 This function will die if we hit some value that shouldn't be
2838 ANTIC but is (IE there is no leader for it, or its components).
2839 The function returns NULL_TREE in case a different antic expression
2840 has to be inserted first.
2841 This function may also generate expressions that are themselves
2842 partially or fully redundant. Those that are will be either made
2843 fully redundant during the next iteration of insert (for partially
2844 redundant ones), or eliminated by eliminate (for fully redundant
2848 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2849 gimple_seq
*stmts
, tree type
)
2853 gimple_seq forced_stmts
= NULL
;
2854 unsigned int value_id
;
2855 gimple_stmt_iterator gsi
;
2856 tree exprtype
= type
? type
: get_expr_type (expr
);
2862 /* We may hit the NAME/CONSTANT case if we have to convert types
2863 that value numbering saw through. */
2865 folded
= PRE_EXPR_NAME (expr
);
2868 folded
= PRE_EXPR_CONSTANT (expr
);
2872 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2873 folded
= create_component_ref_by_pieces (block
, ref
, stmts
);
2880 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2881 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2883 for (i
= 0; i
< nary
->length
; ++i
)
2885 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2888 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2889 may have conversions stripped. */
2890 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2893 genop
[i
] = fold_convert (nary
->type
, genop
[i
]);
2895 genop
[i
] = convert_to_ptrofftype (genop
[i
]);
2898 genop
[i
] = fold_convert (TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2900 if (nary
->opcode
== CONSTRUCTOR
)
2902 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2903 for (i
= 0; i
< nary
->length
; ++i
)
2904 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2905 folded
= build_constructor (nary
->type
, elts
);
2909 switch (nary
->length
)
2912 folded
= fold_build1 (nary
->opcode
, nary
->type
,
2916 folded
= fold_build2 (nary
->opcode
, nary
->type
,
2917 genop
[0], genop
[1]);
2920 folded
= fold_build3 (nary
->opcode
, nary
->type
,
2921 genop
[0], genop
[1], genop
[2]);
2933 if (!useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2934 folded
= fold_convert (exprtype
, folded
);
2936 /* Force the generated expression to be a sequence of GIMPLE
2938 We have to call unshare_expr because force_gimple_operand may
2939 modify the tree we pass to it. */
2940 folded
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
2943 /* If we have any intermediate expressions to the value sets, add them
2944 to the value sets and chain them in the instruction stream. */
2947 gsi
= gsi_start (forced_stmts
);
2948 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2950 gimple stmt
= gsi_stmt (gsi
);
2951 tree forcedname
= gimple_get_lhs (stmt
);
2954 if (TREE_CODE (forcedname
) == SSA_NAME
)
2956 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2957 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2958 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2959 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2960 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2961 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2962 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2965 gimple_seq_add_seq (stmts
, forced_stmts
);
2968 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2969 newstmt
= gimple_build_assign (name
, folded
);
2970 gimple_set_plf (newstmt
, NECESSARY
, false);
2972 gimple_seq_add_stmt (stmts
, newstmt
);
2973 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (name
));
2975 /* Fold the last statement. */
2976 gsi
= gsi_last (*stmts
);
2977 if (fold_stmt_inplace (&gsi
))
2978 update_stmt (gsi_stmt (gsi
));
2980 /* Add a value number to the temporary.
2981 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2982 we are creating the expression by pieces, and this particular piece of
2983 the expression may have been represented. There is no harm in replacing
2985 value_id
= get_expr_value_id (expr
);
2986 VN_INFO_GET (name
)->value_id
= value_id
;
2987 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2988 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2989 VN_INFO (name
)->valnum
= name
;
2990 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2991 nameexpr
= get_or_alloc_expr_for_name (name
);
2992 add_to_value (value_id
, nameexpr
);
2993 if (NEW_SETS (block
))
2994 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2995 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2997 pre_stats
.insertions
++;
2998 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3000 fprintf (dump_file
, "Inserted ");
3001 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
3002 fprintf (dump_file
, " in predecessor %d (%04d)\n",
3003 block
->index
, value_id
);
3010 /* Returns true if we want to inhibit the insertions of PHI nodes
3011 for the given EXPR for basic block BB (a member of a loop).
3012 We want to do this, when we fear that the induction variable we
3013 create might inhibit vectorization. */
3016 inhibit_phi_insertion (basic_block bb
, pre_expr expr
)
3018 vn_reference_t vr
= PRE_EXPR_REFERENCE (expr
);
3019 vec
<vn_reference_op_s
> ops
= vr
->operands
;
3020 vn_reference_op_t op
;
3023 /* If we aren't going to vectorize we don't inhibit anything. */
3024 if (!flag_tree_loop_vectorize
)
3027 /* Otherwise we inhibit the insertion when the address of the
3028 memory reference is a simple induction variable. In other
3029 cases the vectorizer won't do anything anyway (either it's
3030 loop invariant or a complicated expression). */
3031 FOR_EACH_VEC_ELT (ops
, i
, op
)
3036 /* Calls are not a problem. */
3040 case ARRAY_RANGE_REF
:
3041 if (TREE_CODE (op
->op0
) != SSA_NAME
)
3046 basic_block defbb
= gimple_bb (SSA_NAME_DEF_STMT (op
->op0
));
3048 /* Default defs are loop invariant. */
3051 /* Defined outside this loop, also loop invariant. */
3052 if (!flow_bb_inside_loop_p (bb
->loop_father
, defbb
))
3054 /* If it's a simple induction variable inhibit insertion,
3055 the vectorizer might be interested in this one. */
3056 if (simple_iv (bb
->loop_father
, bb
->loop_father
,
3057 op
->op0
, &iv
, true))
3059 /* No simple IV, vectorizer can't do anything, hence no
3060 reason to inhibit the transformation for this operand. */
3070 /* Insert the to-be-made-available values of expression EXPRNUM for each
3071 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3072 merge the result with a phi node, given the same value number as
3073 NODE. Return true if we have inserted new stuff. */
3076 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3077 vec
<pre_expr
> avail
)
3079 pre_expr expr
= expression_for_id (exprnum
);
3081 unsigned int val
= get_expr_value_id (expr
);
3083 bool insertions
= false;
3088 tree type
= get_expr_type (expr
);
3092 /* Make sure we aren't creating an induction variable. */
3093 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
3095 bool firstinsideloop
= false;
3096 bool secondinsideloop
= false;
3097 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3098 EDGE_PRED (block
, 0)->src
);
3099 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3100 EDGE_PRED (block
, 1)->src
);
3101 /* Induction variables only have one edge inside the loop. */
3102 if ((firstinsideloop
^ secondinsideloop
)
3103 && (expr
->kind
!= REFERENCE
3104 || inhibit_phi_insertion (block
, expr
)))
3106 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3107 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3112 /* Make the necessary insertions. */
3113 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3115 gimple_seq stmts
= NULL
;
3118 eprime
= avail
[pred
->dest_idx
];
3120 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3122 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
3124 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3125 gsi_insert_seq_on_edge (pred
, stmts
);
3128 /* We cannot insert a PHI node if we failed to insert
3133 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3136 else if (eprime
->kind
== CONSTANT
)
3138 /* Constants may not have the right type, fold_convert
3139 should give us back a constant with the right type. */
3140 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3141 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3143 tree builtexpr
= fold_convert (type
, constant
);
3144 if (!is_gimple_min_invariant (builtexpr
))
3146 tree forcedexpr
= force_gimple_operand (builtexpr
,
3149 if (!is_gimple_min_invariant (forcedexpr
))
3151 if (forcedexpr
!= builtexpr
)
3153 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3154 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3158 gimple_stmt_iterator gsi
;
3159 gsi
= gsi_start (stmts
);
3160 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3162 gimple stmt
= gsi_stmt (gsi
);
3163 tree lhs
= gimple_get_lhs (stmt
);
3164 if (TREE_CODE (lhs
) == SSA_NAME
)
3165 bitmap_set_bit (inserted_exprs
,
3166 SSA_NAME_VERSION (lhs
));
3167 gimple_set_plf (stmt
, NECESSARY
, false);
3169 gsi_insert_seq_on_edge (pred
, stmts
);
3171 avail
[pred
->dest_idx
]
3172 = get_or_alloc_expr_for_name (forcedexpr
);
3176 avail
[pred
->dest_idx
]
3177 = get_or_alloc_expr_for_constant (builtexpr
);
3180 else if (eprime
->kind
== NAME
)
3182 /* We may have to do a conversion because our value
3183 numbering can look through types in certain cases, but
3184 our IL requires all operands of a phi node have the same
3186 tree name
= PRE_EXPR_NAME (eprime
);
3187 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3191 builtexpr
= fold_convert (type
, name
);
3192 forcedexpr
= force_gimple_operand (builtexpr
,
3196 if (forcedexpr
!= name
)
3198 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3199 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3204 gimple_stmt_iterator gsi
;
3205 gsi
= gsi_start (stmts
);
3206 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3208 gimple stmt
= gsi_stmt (gsi
);
3209 tree lhs
= gimple_get_lhs (stmt
);
3210 if (TREE_CODE (lhs
) == SSA_NAME
)
3211 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
3212 gimple_set_plf (stmt
, NECESSARY
, false);
3214 gsi_insert_seq_on_edge (pred
, stmts
);
3216 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (forcedexpr
);
3220 /* If we didn't want a phi node, and we made insertions, we still have
3221 inserted new stuff, and thus return true. If we didn't want a phi node,
3222 and didn't make insertions, we haven't added anything new, so return
3224 if (nophi
&& insertions
)
3226 else if (nophi
&& !insertions
)
3229 /* Now build a phi for the new variable. */
3230 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3231 phi
= create_phi_node (temp
, block
);
3233 gimple_set_plf (phi
, NECESSARY
, false);
3234 VN_INFO_GET (temp
)->value_id
= val
;
3235 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3236 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3237 VN_INFO (temp
)->valnum
= temp
;
3238 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3239 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3241 pre_expr ae
= avail
[pred
->dest_idx
];
3242 gcc_assert (get_expr_type (ae
) == type
3243 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3244 if (ae
->kind
== CONSTANT
)
3245 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3246 pred
, UNKNOWN_LOCATION
);
3248 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3251 newphi
= get_or_alloc_expr_for_name (temp
);
3252 add_to_value (val
, newphi
);
3254 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3255 this insertion, since we test for the existence of this value in PHI_GEN
3256 before proceeding with the partial redundancy checks in insert_aux.
3258 The value may exist in AVAIL_OUT, in particular, it could be represented
3259 by the expression we are trying to eliminate, in which case we want the
3260 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3263 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3264 this block, because if it did, it would have existed in our dominator's
3265 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3268 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3269 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3271 bitmap_insert_into_set (NEW_SETS (block
),
3274 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3276 fprintf (dump_file
, "Created phi ");
3277 print_gimple_stmt (dump_file
, phi
, 0, 0);
3278 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3286 /* Perform insertion of partially redundant values.
3287 For BLOCK, do the following:
3288 1. Propagate the NEW_SETS of the dominator into the current block.
3289 If the block has multiple predecessors,
3290 2a. Iterate over the ANTIC expressions for the block to see if
3291 any of them are partially redundant.
3292 2b. If so, insert them into the necessary predecessors to make
3293 the expression fully redundant.
3294 2c. Insert a new PHI merging the values of the predecessors.
3295 2d. Insert the new PHI, and the new expressions, into the
3297 3. Recursively call ourselves on the dominator children of BLOCK.
3299 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3300 do_regular_insertion and do_partial_insertion.
3305 do_regular_insertion (basic_block block
, basic_block dom
)
3307 bool new_stuff
= false;
3308 vec
<pre_expr
> exprs
;
3310 vec
<pre_expr
> avail
= vNULL
;
3313 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3314 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3316 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3318 if (expr
->kind
== NARY
3319 || expr
->kind
== REFERENCE
)
3322 bool by_some
= false;
3323 bool cant_insert
= false;
3324 bool all_same
= true;
3325 pre_expr first_s
= NULL
;
3328 pre_expr eprime
= NULL
;
3330 pre_expr edoubleprime
= NULL
;
3331 bool do_insertion
= false;
3333 val
= get_expr_value_id (expr
);
3334 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3336 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3338 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3340 fprintf (dump_file
, "Found fully redundant value: ");
3341 print_pre_expr (dump_file
, expr
);
3342 fprintf (dump_file
, "\n");
3347 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3349 unsigned int vprime
;
3351 /* We should never run insertion for the exit block
3352 and so not come across fake pred edges. */
3353 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3355 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3358 /* eprime will generally only be NULL if the
3359 value of the expression, translated
3360 through the PHI for this predecessor, is
3361 undefined. If that is the case, we can't
3362 make the expression fully redundant,
3363 because its value is undefined along a
3364 predecessor path. We can thus break out
3365 early because it doesn't matter what the
3366 rest of the results are. */
3369 avail
[pred
->dest_idx
] = NULL
;
3374 eprime
= fully_constant_expression (eprime
);
3375 vprime
= get_expr_value_id (eprime
);
3376 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3378 if (edoubleprime
== NULL
)
3380 avail
[pred
->dest_idx
] = eprime
;
3385 avail
[pred
->dest_idx
] = edoubleprime
;
3387 /* We want to perform insertions to remove a redundancy on
3388 a path in the CFG we want to optimize for speed. */
3389 if (optimize_edge_for_speed_p (pred
))
3390 do_insertion
= true;
3391 if (first_s
== NULL
)
3392 first_s
= edoubleprime
;
3393 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3397 /* If we can insert it, it's not the same value
3398 already existing along every predecessor, and
3399 it's defined by some predecessor, it is
3400 partially redundant. */
3401 if (!cant_insert
&& !all_same
&& by_some
)
3405 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3407 fprintf (dump_file
, "Skipping partial redundancy for "
3409 print_pre_expr (dump_file
, expr
);
3410 fprintf (dump_file
, " (%04d), no redundancy on to be "
3411 "optimized for speed edge\n", val
);
3414 else if (dbg_cnt (treepre_insert
))
3416 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3418 fprintf (dump_file
, "Found partial redundancy for "
3420 print_pre_expr (dump_file
, expr
);
3421 fprintf (dump_file
, " (%04d)\n",
3422 get_expr_value_id (expr
));
3424 if (insert_into_preds_of_block (block
,
3425 get_expression_id (expr
),
3430 /* If all edges produce the same value and that value is
3431 an invariant, then the PHI has the same value on all
3432 edges. Note this. */
3433 else if (!cant_insert
&& all_same
)
3435 gcc_assert (edoubleprime
->kind
== CONSTANT
3436 || edoubleprime
->kind
== NAME
);
3438 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3440 gimple assign
= gimple_build_assign (temp
,
3441 edoubleprime
->kind
== CONSTANT
? PRE_EXPR_CONSTANT (edoubleprime
) : PRE_EXPR_NAME (edoubleprime
));
3442 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3443 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3445 gimple_set_plf (assign
, NECESSARY
, false);
3446 VN_INFO_GET (temp
)->value_id
= val
;
3447 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3448 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3449 VN_INFO (temp
)->valnum
= temp
;
3450 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3451 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3452 add_to_value (val
, newe
);
3453 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3454 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3465 /* Perform insertion for partially anticipatable expressions. There
3466 is only one case we will perform insertion for these. This case is
3467 if the expression is partially anticipatable, and fully available.
3468 In this case, we know that putting it earlier will enable us to
3469 remove the later computation. */
3473 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3475 bool new_stuff
= false;
3476 vec
<pre_expr
> exprs
;
3478 vec
<pre_expr
> avail
= vNULL
;
3481 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3482 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3484 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3486 if (expr
->kind
== NARY
3487 || expr
->kind
== REFERENCE
)
3491 bool cant_insert
= false;
3494 pre_expr eprime
= NULL
;
3497 val
= get_expr_value_id (expr
);
3498 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3500 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3503 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3505 unsigned int vprime
;
3506 pre_expr edoubleprime
;
3508 /* We should never run insertion for the exit block
3509 and so not come across fake pred edges. */
3510 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3512 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3516 /* eprime will generally only be NULL if the
3517 value of the expression, translated
3518 through the PHI for this predecessor, is
3519 undefined. If that is the case, we can't
3520 make the expression fully redundant,
3521 because its value is undefined along a
3522 predecessor path. We can thus break out
3523 early because it doesn't matter what the
3524 rest of the results are. */
3527 avail
[pred
->dest_idx
] = NULL
;
3532 eprime
= fully_constant_expression (eprime
);
3533 vprime
= get_expr_value_id (eprime
);
3534 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3535 avail
[pred
->dest_idx
] = edoubleprime
;
3536 if (edoubleprime
== NULL
)
3543 /* If we can insert it, it's not the same value
3544 already existing along every predecessor, and
3545 it's defined by some predecessor, it is
3546 partially redundant. */
3547 if (!cant_insert
&& by_all
)
3550 bool do_insertion
= false;
3552 /* Insert only if we can remove a later expression on a path
3553 that we want to optimize for speed.
3554 The phi node that we will be inserting in BLOCK is not free,
3555 and inserting it for the sake of !optimize_for_speed successor
3556 may cause regressions on the speed path. */
3557 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3559 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3560 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3562 if (optimize_edge_for_speed_p (succ
))
3563 do_insertion
= true;
3569 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3571 fprintf (dump_file
, "Skipping partial partial redundancy "
3573 print_pre_expr (dump_file
, expr
);
3574 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3575 "on any to be optimized for speed edges\n", val
);
3578 else if (dbg_cnt (treepre_insert
))
3580 pre_stats
.pa_insert
++;
3581 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3583 fprintf (dump_file
, "Found partial partial redundancy "
3585 print_pre_expr (dump_file
, expr
);
3586 fprintf (dump_file
, " (%04d)\n",
3587 get_expr_value_id (expr
));
3589 if (insert_into_preds_of_block (block
,
3590 get_expression_id (expr
),
3604 insert_aux (basic_block block
)
3607 bool new_stuff
= false;
3612 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3617 bitmap_set_t newset
= NEW_SETS (dom
);
3620 /* Note that we need to value_replace both NEW_SETS, and
3621 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3622 represented by some non-simple expression here that we want
3623 to replace it with. */
3624 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3626 pre_expr expr
= expression_for_id (i
);
3627 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3628 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3631 if (!single_pred_p (block
))
3633 new_stuff
|= do_regular_insertion (block
, dom
);
3634 if (do_partial_partial
)
3635 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3639 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3641 son
= next_dom_son (CDI_DOMINATORS
, son
))
3643 new_stuff
|= insert_aux (son
);
3649 /* Perform insertion of partially redundant values. */
3654 bool new_stuff
= true;
3656 int num_iterations
= 0;
3659 NEW_SETS (bb
) = bitmap_set_new ();
3664 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3665 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3666 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3668 /* Clear the NEW sets before the next iteration. We have already
3669 fully propagated its contents. */
3672 bitmap_set_free (NEW_SETS (bb
));
3674 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3678 /* Compute the AVAIL set for all basic blocks.
3680 This function performs value numbering of the statements in each basic
3681 block. The AVAIL sets are built from information we glean while doing
3682 this value numbering, since the AVAIL sets contain only one entry per
3685 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3686 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3689 compute_avail (void)
3692 basic_block block
, son
;
3693 basic_block
*worklist
;
3697 /* We pretend that default definitions are defined in the entry block.
3698 This includes function arguments and the static chain decl. */
3699 for (i
= 1; i
< num_ssa_names
; ++i
)
3701 tree name
= ssa_name (i
);
3704 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3705 || has_zero_uses (name
)
3706 || virtual_operand_p (name
))
3709 e
= get_or_alloc_expr_for_name (name
);
3710 add_to_value (get_expr_value_id (e
), e
);
3711 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3712 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3715 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3717 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR
),
3718 "tmp_gen", ENTRY_BLOCK
);
3719 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR
),
3720 "avail_out", ENTRY_BLOCK
);
3723 /* Allocate the worklist. */
3724 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3726 /* Seed the algorithm by putting the dominator children of the entry
3727 block on the worklist. */
3728 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3730 son
= next_dom_son (CDI_DOMINATORS
, son
))
3731 worklist
[sp
++] = son
;
3733 /* Loop until the worklist is empty. */
3736 gimple_stmt_iterator gsi
;
3740 /* Pick a block from the worklist. */
3741 block
= worklist
[--sp
];
3743 /* Initially, the set of available values in BLOCK is that of
3744 its immediate dominator. */
3745 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3747 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3749 /* Generate values for PHI nodes. */
3750 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3752 tree result
= gimple_phi_result (gsi_stmt (gsi
));
3754 /* We have no need for virtual phis, as they don't represent
3755 actual computations. */
3756 if (virtual_operand_p (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 (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3774 stmt
= gsi_stmt (gsi
);
3776 /* Cache whether the basic-block has any non-visible side-effect
3778 If this isn't a call or it is the last stmt in the
3779 basic-block then the CFG represents things correctly. */
3780 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3782 /* Non-looping const functions always return normally.
3783 Otherwise the call might not return or have side-effects
3784 that forbids hoisting possibly trapping expressions
3786 int flags
= gimple_call_flags (stmt
);
3787 if (!(flags
& ECF_CONST
)
3788 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3789 BB_MAY_NOTRETURN (block
) = 1;
3792 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3794 pre_expr e
= get_or_alloc_expr_for_name (op
);
3796 add_to_value (get_expr_value_id (e
), e
);
3797 bitmap_insert_into_set (TMP_GEN (block
), e
);
3798 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3801 if (gimple_has_side_effects (stmt
)
3802 || stmt_could_throw_p (stmt
)
3803 || is_gimple_debug (stmt
))
3806 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3808 if (ssa_undefined_value_p (op
))
3810 pre_expr e
= get_or_alloc_expr_for_name (op
);
3811 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3814 switch (gimple_code (stmt
))
3822 pre_expr result
= NULL
;
3823 vec
<vn_reference_op_s
> ops
= vNULL
;
3825 /* We can value number only calls to real functions. */
3826 if (gimple_call_internal_p (stmt
))
3829 copy_reference_ops_from_call (stmt
, &ops
);
3830 vn_reference_lookup_pieces (gimple_vuse (stmt
), 0,
3831 gimple_expr_type (stmt
),
3832 ops
, &ref
, VN_NOWALK
);
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_alloc (pre_expr_pool
);
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_alloc (pre_expr_pool
);
3887 result
->kind
= NARY
;
3889 PRE_EXPR_NARY (result
) = nary
;
3896 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
3902 /* If the value of the reference is not invalidated in
3903 this block until it is computed, add the expression
3905 if (gimple_vuse (stmt
))
3909 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3910 while (!gimple_nop_p (def_stmt
)
3911 && gimple_code (def_stmt
) != GIMPLE_PHI
3912 && gimple_bb (def_stmt
) == block
)
3914 if (stmt_may_clobber_ref_p
3915 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3921 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3927 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3928 result
->kind
= REFERENCE
;
3930 PRE_EXPR_REFERENCE (result
) = ref
;
3938 get_or_alloc_expression_id (result
);
3939 add_to_value (get_expr_value_id (result
), result
);
3940 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3948 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3950 print_bitmap_set (dump_file
, EXP_GEN (block
),
3951 "exp_gen", block
->index
);
3952 print_bitmap_set (dump_file
, PHI_GEN (block
),
3953 "phi_gen", block
->index
);
3954 print_bitmap_set (dump_file
, TMP_GEN (block
),
3955 "tmp_gen", block
->index
);
3956 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
3957 "avail_out", block
->index
);
3960 /* Put the dominator children of BLOCK on the worklist of blocks
3961 to compute available sets for. */
3962 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3964 son
= next_dom_son (CDI_DOMINATORS
, son
))
3965 worklist
[sp
++] = son
;
3972 /* Local state for the eliminate domwalk. */
3973 static vec
<gimple
> el_to_remove
;
3974 static vec
<gimple
> el_to_update
;
3975 static unsigned int el_todo
;
3976 static vec
<tree
> el_avail
;
3977 static vec
<tree
> el_avail_stack
;
3979 /* Return a leader for OP that is available at the current point of the
3980 eliminate domwalk. */
3983 eliminate_avail (tree op
)
3985 tree valnum
= VN_INFO (op
)->valnum
;
3986 if (TREE_CODE (valnum
) == SSA_NAME
)
3988 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
3990 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
3991 return el_avail
[SSA_NAME_VERSION (valnum
)];
3993 else if (is_gimple_min_invariant (valnum
))
3998 /* At the current point of the eliminate domwalk make OP available. */
4001 eliminate_push_avail (tree op
)
4003 tree valnum
= VN_INFO (op
)->valnum
;
4004 if (TREE_CODE (valnum
) == SSA_NAME
)
4006 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
4007 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
4008 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
4009 el_avail_stack
.safe_push (op
);
4013 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
4014 the leader for the expression if insertion was successful. */
4017 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
4019 tree expr
= vn_get_expr_for (val
);
4020 if (!CONVERT_EXPR_P (expr
)
4021 && TREE_CODE (expr
) != VIEW_CONVERT_EXPR
)
4024 tree op
= TREE_OPERAND (expr
, 0);
4025 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
4029 tree res
= make_temp_ssa_name (TREE_TYPE (val
), NULL
, "pretmp");
4030 gimple tem
= gimple_build_assign (res
,
4031 fold_build1 (TREE_CODE (expr
),
4032 TREE_TYPE (expr
), leader
));
4033 gsi_insert_before (gsi
, tem
, GSI_SAME_STMT
);
4034 VN_INFO_GET (res
)->valnum
= val
;
4036 if (TREE_CODE (leader
) == SSA_NAME
)
4037 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
4039 pre_stats
.insertions
++;
4040 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4042 fprintf (dump_file
, "Inserted ");
4043 print_gimple_stmt (dump_file
, tem
, 0, 0);
4049 class eliminate_dom_walker
: public dom_walker
4052 eliminate_dom_walker (cdi_direction direction
) : dom_walker (direction
) {}
4054 virtual void before_dom_children (basic_block
);
4055 virtual void after_dom_children (basic_block
);
4058 /* Perform elimination for the basic-block B during the domwalk. */
4061 eliminate_dom_walker::before_dom_children (basic_block b
)
4063 gimple_stmt_iterator gsi
;
4067 el_avail_stack
.safe_push (NULL_TREE
);
4069 for (gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4071 gimple stmt
, phi
= gsi_stmt (gsi
);
4072 tree sprime
= NULL_TREE
, res
= PHI_RESULT (phi
);
4073 gimple_stmt_iterator gsi2
;
4075 /* We want to perform redundant PHI elimination. Do so by
4076 replacing the PHI with a single copy if possible.
4077 Do not touch inserted, single-argument or virtual PHIs. */
4078 if (gimple_phi_num_args (phi
) == 1
4079 || virtual_operand_p (res
))
4085 sprime
= eliminate_avail (res
);
4089 eliminate_push_avail (res
);
4093 else if (is_gimple_min_invariant (sprime
))
4095 if (!useless_type_conversion_p (TREE_TYPE (res
),
4096 TREE_TYPE (sprime
)))
4097 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4100 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4102 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4103 print_generic_expr (dump_file
, res
, 0);
4104 fprintf (dump_file
, " with ");
4105 print_generic_expr (dump_file
, sprime
, 0);
4106 fprintf (dump_file
, "\n");
4109 remove_phi_node (&gsi
, false);
4112 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4113 && TREE_CODE (sprime
) == SSA_NAME
)
4114 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4116 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4117 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4118 stmt
= gimple_build_assign (res
, sprime
);
4119 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4121 gsi2
= gsi_after_labels (b
);
4122 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4123 /* Queue the copy for eventual removal. */
4124 el_to_remove
.safe_push (stmt
);
4125 /* If we inserted this PHI node ourself, it's not an elimination. */
4127 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4130 pre_stats
.eliminations
++;
4133 for (gsi
= gsi_start_bb (b
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4135 tree lhs
= NULL_TREE
;
4136 tree rhs
= NULL_TREE
;
4138 stmt
= gsi_stmt (gsi
);
4140 if (gimple_has_lhs (stmt
))
4141 lhs
= gimple_get_lhs (stmt
);
4143 if (gimple_assign_single_p (stmt
))
4144 rhs
= gimple_assign_rhs1 (stmt
);
4146 /* Lookup the RHS of the expression, see if we have an
4147 available computation for it. If so, replace the RHS with
4148 the available computation. */
4149 if (gimple_has_lhs (stmt
)
4150 && TREE_CODE (lhs
) == SSA_NAME
4151 && !gimple_has_volatile_ops (stmt
))
4154 gimple orig_stmt
= stmt
;
4156 sprime
= eliminate_avail (lhs
);
4157 /* If there is no usable leader mark lhs as leader for its value. */
4159 eliminate_push_avail (lhs
);
4161 /* See PR43491. Do not replace a global register variable when
4162 it is a the RHS of an assignment. Do replace local register
4163 variables since gcc does not guarantee a local variable will
4164 be allocated in register.
4165 Do not perform copy propagation or undo constant propagation. */
4166 if (gimple_assign_single_p (stmt
)
4167 && (TREE_CODE (rhs
) == SSA_NAME
4168 || is_gimple_min_invariant (rhs
)
4169 || (TREE_CODE (rhs
) == VAR_DECL
4170 && is_global_var (rhs
)
4171 && DECL_HARD_REGISTER (rhs
))))
4176 /* If there is no existing usable leader but SCCVN thinks
4177 it has an expression it wants to use as replacement,
4179 tree val
= VN_INFO (lhs
)->valnum
;
4181 && TREE_CODE (val
) == SSA_NAME
4182 && VN_INFO (val
)->needs_insertion
4183 && VN_INFO (val
)->expr
!= NULL_TREE
4184 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4185 eliminate_push_avail (sprime
);
4187 else if (is_gimple_min_invariant (sprime
))
4189 /* If there is no existing leader but SCCVN knows this
4190 value is constant, use that constant. */
4191 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4192 TREE_TYPE (sprime
)))
4193 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4195 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4197 fprintf (dump_file
, "Replaced ");
4198 print_gimple_expr (dump_file
, stmt
, 0, 0);
4199 fprintf (dump_file
, " with ");
4200 print_generic_expr (dump_file
, sprime
, 0);
4201 fprintf (dump_file
, " in ");
4202 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4204 pre_stats
.eliminations
++;
4205 propagate_tree_value_into_stmt (&gsi
, sprime
);
4206 stmt
= gsi_stmt (gsi
);
4209 /* If we removed EH side-effects from the statement, clean
4210 its EH information. */
4211 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4213 bitmap_set_bit (need_eh_cleanup
,
4214 gimple_bb (stmt
)->index
);
4215 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4216 fprintf (dump_file
, " Removed EH side-effects.\n");
4223 && (rhs
== NULL_TREE
4224 || TREE_CODE (rhs
) != SSA_NAME
4225 || may_propagate_copy (rhs
, sprime
)))
4227 bool can_make_abnormal_goto
4228 = is_gimple_call (stmt
)
4229 && stmt_can_make_abnormal_goto (stmt
);
4231 gcc_assert (sprime
!= rhs
);
4233 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4235 fprintf (dump_file
, "Replaced ");
4236 print_gimple_expr (dump_file
, stmt
, 0, 0);
4237 fprintf (dump_file
, " with ");
4238 print_generic_expr (dump_file
, sprime
, 0);
4239 fprintf (dump_file
, " in ");
4240 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4243 if (TREE_CODE (sprime
) == SSA_NAME
)
4244 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4246 /* We need to make sure the new and old types actually match,
4247 which may require adding a simple cast, which fold_convert
4249 if ((!rhs
|| TREE_CODE (rhs
) != SSA_NAME
)
4250 && !useless_type_conversion_p (gimple_expr_type (stmt
),
4251 TREE_TYPE (sprime
)))
4252 sprime
= fold_convert (gimple_expr_type (stmt
), sprime
);
4254 pre_stats
.eliminations
++;
4255 propagate_tree_value_into_stmt (&gsi
, sprime
);
4256 stmt
= gsi_stmt (gsi
);
4259 /* If we removed EH side-effects from the statement, clean
4260 its EH information. */
4261 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4263 bitmap_set_bit (need_eh_cleanup
,
4264 gimple_bb (stmt
)->index
);
4265 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4266 fprintf (dump_file
, " Removed EH side-effects.\n");
4269 /* Likewise for AB side-effects. */
4270 if (can_make_abnormal_goto
4271 && !stmt_can_make_abnormal_goto (stmt
))
4273 bitmap_set_bit (need_ab_cleanup
,
4274 gimple_bb (stmt
)->index
);
4275 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4276 fprintf (dump_file
, " Removed AB side-effects.\n");
4280 /* If the statement is a scalar store, see if the expression
4281 has the same value number as its rhs. If so, the store is
4283 else if (gimple_assign_single_p (stmt
)
4284 && !gimple_has_volatile_ops (stmt
)
4285 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4286 && (TREE_CODE (rhs
) == SSA_NAME
4287 || is_gimple_min_invariant (rhs
)))
4290 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4291 gimple_vuse (stmt
), VN_WALK
, NULL
);
4292 if (TREE_CODE (rhs
) == SSA_NAME
)
4293 rhs
= VN_INFO (rhs
)->valnum
;
4295 && operand_equal_p (val
, rhs
, 0))
4297 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4299 fprintf (dump_file
, "Deleted redundant store ");
4300 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4303 /* Queue stmt for removal. */
4304 el_to_remove
.safe_push (stmt
);
4307 /* Visit COND_EXPRs and fold the comparison with the
4308 available value-numbers. */
4309 else if (gimple_code (stmt
) == GIMPLE_COND
)
4311 tree op0
= gimple_cond_lhs (stmt
);
4312 tree op1
= gimple_cond_rhs (stmt
);
4315 if (TREE_CODE (op0
) == SSA_NAME
)
4316 op0
= VN_INFO (op0
)->valnum
;
4317 if (TREE_CODE (op1
) == SSA_NAME
)
4318 op1
= VN_INFO (op1
)->valnum
;
4319 result
= fold_binary (gimple_cond_code (stmt
), boolean_type_node
,
4321 if (result
&& TREE_CODE (result
) == INTEGER_CST
)
4323 if (integer_zerop (result
))
4324 gimple_cond_make_false (stmt
);
4326 gimple_cond_make_true (stmt
);
4328 el_todo
= TODO_cleanup_cfg
;
4331 /* Visit indirect calls and turn them into direct calls if
4333 if (is_gimple_call (stmt
))
4335 tree orig_fn
= gimple_call_fn (stmt
);
4339 if (TREE_CODE (orig_fn
) == SSA_NAME
)
4340 fn
= VN_INFO (orig_fn
)->valnum
;
4341 else if (TREE_CODE (orig_fn
) == OBJ_TYPE_REF
4342 && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn
)) == SSA_NAME
)
4344 fn
= VN_INFO (OBJ_TYPE_REF_EXPR (orig_fn
))->valnum
;
4345 if (!gimple_call_addr_fndecl (fn
))
4347 fn
= ipa_intraprocedural_devirtualization (stmt
);
4349 fn
= build_fold_addr_expr (fn
);
4354 if (gimple_call_addr_fndecl (fn
) != NULL_TREE
4355 && useless_type_conversion_p (TREE_TYPE (orig_fn
),
4358 bool can_make_abnormal_goto
4359 = stmt_can_make_abnormal_goto (stmt
);
4360 bool was_noreturn
= gimple_call_noreturn_p (stmt
);
4362 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4364 fprintf (dump_file
, "Replacing call target with ");
4365 print_generic_expr (dump_file
, fn
, 0);
4366 fprintf (dump_file
, " in ");
4367 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4370 gimple_call_set_fn (stmt
, fn
);
4371 el_to_update
.safe_push (stmt
);
4373 /* When changing a call into a noreturn call, cfg cleanup
4374 is needed to fix up the noreturn call. */
4375 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4376 el_todo
|= TODO_cleanup_cfg
;
4378 /* If we removed EH side-effects from the statement, clean
4379 its EH information. */
4380 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
4382 bitmap_set_bit (need_eh_cleanup
,
4383 gimple_bb (stmt
)->index
);
4384 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4385 fprintf (dump_file
, " Removed EH side-effects.\n");
4388 /* Likewise for AB side-effects. */
4389 if (can_make_abnormal_goto
4390 && !stmt_can_make_abnormal_goto (stmt
))
4392 bitmap_set_bit (need_ab_cleanup
,
4393 gimple_bb (stmt
)->index
);
4394 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4395 fprintf (dump_file
, " Removed AB side-effects.\n");
4398 /* Changing an indirect call to a direct call may
4399 have exposed different semantics. This may
4400 require an SSA update. */
4401 el_todo
|= TODO_update_ssa_only_virtuals
;
4407 /* Make no longer available leaders no longer available. */
4410 eliminate_dom_walker::after_dom_children (basic_block
)
4413 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4414 el_avail
[SSA_NAME_VERSION (VN_INFO (entry
)->valnum
)] = NULL_TREE
;
4417 /* Eliminate fully redundant computations. */
4422 gimple_stmt_iterator gsi
;
4426 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4427 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4429 el_to_remove
.create (0);
4430 el_to_update
.create (0);
4432 el_avail
.create (0);
4433 el_avail_stack
.create (0);
4435 eliminate_dom_walker (CDI_DOMINATORS
).walk (cfun
->cfg
->x_entry_block_ptr
);
4437 el_avail
.release ();
4438 el_avail_stack
.release ();
4440 /* We cannot remove stmts during BB walk, especially not release SSA
4441 names there as this confuses the VN machinery. The stmts ending
4442 up in el_to_remove are either stores or simple copies. */
4443 FOR_EACH_VEC_ELT (el_to_remove
, i
, stmt
)
4445 tree lhs
= gimple_assign_lhs (stmt
);
4446 tree rhs
= gimple_assign_rhs1 (stmt
);
4447 use_operand_p use_p
;
4450 /* If there is a single use only, propagate the equivalency
4451 instead of keeping the copy. */
4452 if (TREE_CODE (lhs
) == SSA_NAME
4453 && TREE_CODE (rhs
) == SSA_NAME
4454 && single_imm_use (lhs
, &use_p
, &use_stmt
)
4455 && may_propagate_copy (USE_FROM_PTR (use_p
), rhs
))
4457 SET_USE (use_p
, rhs
);
4458 update_stmt (use_stmt
);
4460 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (lhs
))
4461 && TREE_CODE (rhs
) == SSA_NAME
)
4462 gimple_set_plf (SSA_NAME_DEF_STMT (rhs
), NECESSARY
, true);
4465 /* If this is a store or a now unused copy, remove it. */
4466 if (TREE_CODE (lhs
) != SSA_NAME
4467 || has_zero_uses (lhs
))
4469 basic_block bb
= gimple_bb (stmt
);
4470 gsi
= gsi_for_stmt (stmt
);
4471 unlink_stmt_vdef (stmt
);
4472 if (gsi_remove (&gsi
, true))
4473 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4475 && TREE_CODE (lhs
) == SSA_NAME
)
4476 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4477 release_defs (stmt
);
4480 el_to_remove
.release ();
4482 /* We cannot update call statements with virtual operands during
4483 SSA walk. This might remove them which in turn makes our
4484 VN lattice invalid. */
4485 FOR_EACH_VEC_ELT (el_to_update
, i
, stmt
)
4487 el_to_update
.release ();
4492 /* Perform CFG cleanups made necessary by elimination. */
4495 fini_eliminate (void)
4497 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4498 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4501 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4504 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4506 BITMAP_FREE (need_eh_cleanup
);
4507 BITMAP_FREE (need_ab_cleanup
);
4509 if (do_eh_cleanup
|| do_ab_cleanup
)
4510 return TODO_cleanup_cfg
;
4514 /* Borrow a bit of tree-ssa-dce.c for the moment.
4515 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4516 this may be a bit faster, and we may want critical edges kept split. */
4518 /* If OP's defining statement has not already been determined to be necessary,
4519 mark that statement necessary. Return the stmt, if it is newly
4522 static inline gimple
4523 mark_operand_necessary (tree op
)
4529 if (TREE_CODE (op
) != SSA_NAME
)
4532 stmt
= SSA_NAME_DEF_STMT (op
);
4535 if (gimple_plf (stmt
, NECESSARY
)
4536 || gimple_nop_p (stmt
))
4539 gimple_set_plf (stmt
, NECESSARY
, true);
4543 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4544 to insert PHI nodes sometimes, and because value numbering of casts isn't
4545 perfect, we sometimes end up inserting dead code. This simple DCE-like
4546 pass removes any insertions we made that weren't actually used. */
4549 remove_dead_inserted_code (void)
4556 worklist
= BITMAP_ALLOC (NULL
);
4557 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4559 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4560 if (gimple_plf (t
, NECESSARY
))
4561 bitmap_set_bit (worklist
, i
);
4563 while (!bitmap_empty_p (worklist
))
4565 i
= bitmap_first_set_bit (worklist
);
4566 bitmap_clear_bit (worklist
, i
);
4567 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4569 /* PHI nodes are somewhat special in that each PHI alternative has
4570 data and control dependencies. All the statements feeding the
4571 PHI node's arguments are always necessary. */
4572 if (gimple_code (t
) == GIMPLE_PHI
)
4576 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4578 tree arg
= PHI_ARG_DEF (t
, k
);
4579 if (TREE_CODE (arg
) == SSA_NAME
)
4581 gimple n
= mark_operand_necessary (arg
);
4583 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4589 /* Propagate through the operands. Examine all the USE, VUSE and
4590 VDEF operands in this statement. Mark all the statements
4591 which feed this statement's uses as necessary. */
4595 /* The operands of VDEF expressions are also needed as they
4596 represent potential definitions that may reach this
4597 statement (VDEF operands allow us to follow def-def
4600 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4602 gimple n
= mark_operand_necessary (use
);
4604 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4609 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4611 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4612 if (!gimple_plf (t
, NECESSARY
))
4614 gimple_stmt_iterator gsi
;
4616 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4618 fprintf (dump_file
, "Removing unnecessary insertion:");
4619 print_gimple_stmt (dump_file
, t
, 0, 0);
4622 gsi
= gsi_for_stmt (t
);
4623 if (gimple_code (t
) == GIMPLE_PHI
)
4624 remove_phi_node (&gsi
, true);
4627 gsi_remove (&gsi
, true);
4632 BITMAP_FREE (worklist
);
4636 /* Initialize data structures used by PRE. */
4643 next_expression_id
= 1;
4644 expressions
.create (0);
4645 expressions
.safe_push (NULL
);
4646 value_expressions
.create (get_max_value_id () + 1);
4647 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4648 name_to_id
.create (0);
4650 inserted_exprs
= BITMAP_ALLOC (NULL
);
4652 connect_infinite_loops_to_exit ();
4653 memset (&pre_stats
, 0, sizeof (pre_stats
));
4655 postorder
= XNEWVEC (int, n_basic_blocks
);
4656 postorder_num
= inverted_post_order_compute (postorder
);
4658 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4660 calculate_dominance_info (CDI_POST_DOMINATORS
);
4661 calculate_dominance_info (CDI_DOMINATORS
);
4663 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4664 phi_translate_table
.create (5110);
4665 expression_to_id
.create (num_ssa_names
* 3);
4666 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4667 sizeof (struct bitmap_set
), 30);
4668 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4669 sizeof (struct pre_expr_d
), 30);
4672 EXP_GEN (bb
) = bitmap_set_new ();
4673 PHI_GEN (bb
) = bitmap_set_new ();
4674 TMP_GEN (bb
) = bitmap_set_new ();
4675 AVAIL_OUT (bb
) = bitmap_set_new ();
4680 /* Deallocate data structures used by PRE. */
4686 value_expressions
.release ();
4687 BITMAP_FREE (inserted_exprs
);
4688 bitmap_obstack_release (&grand_bitmap_obstack
);
4689 free_alloc_pool (bitmap_set_pool
);
4690 free_alloc_pool (pre_expr_pool
);
4691 phi_translate_table
.dispose ();
4692 expression_to_id
.dispose ();
4693 name_to_id
.release ();
4695 free_aux_for_blocks ();
4697 free_dominance_info (CDI_POST_DOMINATORS
);
4700 /* Gate and execute functions for PRE. */
4705 unsigned int todo
= 0;
4707 do_partial_partial
=
4708 flag_tree_partial_pre
&& optimize_function_for_speed_p (cfun
);
4710 /* This has to happen before SCCVN runs because
4711 loop_optimizer_init may create new phis, etc. */
4712 loop_optimizer_init (LOOPS_NORMAL
);
4714 if (!run_scc_vn (VN_WALK
))
4716 loop_optimizer_finalize ();
4723 /* Collect and value number expressions computed in each basic block. */
4726 /* Insert can get quite slow on an incredibly large number of basic
4727 blocks due to some quadratic behavior. Until this behavior is
4728 fixed, don't run it when he have an incredibly large number of
4729 bb's. If we aren't going to run insert, there is no point in
4730 computing ANTIC, either, even though it's plenty fast. */
4731 if (n_basic_blocks
< 4000)
4737 /* Make sure to remove fake edges before committing our inserts.
4738 This makes sure we don't end up with extra critical edges that
4739 we would need to split. */
4740 remove_fake_exit_edges ();
4741 gsi_commit_edge_inserts ();
4743 /* Remove all the redundant expressions. */
4744 todo
|= eliminate ();
4746 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4747 statistics_counter_event (cfun
, "PA inserted", pre_stats
.pa_insert
);
4748 statistics_counter_event (cfun
, "New PHIs", pre_stats
.phis
);
4749 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4751 clear_expression_ids ();
4752 remove_dead_inserted_code ();
4753 todo
|= TODO_verify_flow
;
4757 todo
|= fini_eliminate ();
4758 loop_optimizer_finalize ();
4760 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
4761 case we can merge the block with the remaining predecessor of the block.
4763 - call merge_blocks after each tail merge iteration
4764 - call merge_blocks after all tail merge iterations
4765 - mark TODO_cleanup_cfg when necessary
4766 - share the cfg cleanup with fini_pre. */
4767 todo
|= tail_merge_optimize (todo
);
4771 /* Tail merging invalidates the virtual SSA web, together with
4772 cfg-cleanup opportunities exposed by PRE this will wreck the
4773 SSA updating machinery. So make sure to run update-ssa
4774 manually, before eventually scheduling cfg-cleanup as part of
4776 update_ssa (TODO_update_ssa_only_virtuals
);
4784 return flag_tree_pre
!= 0;
4789 const pass_data pass_data_pre
=
4791 GIMPLE_PASS
, /* type */
4793 OPTGROUP_NONE
, /* optinfo_flags */
4794 true, /* has_gate */
4795 true, /* has_execute */
4796 TV_TREE_PRE
, /* tv_id */
4797 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4798 0, /* properties_provided */
4799 0, /* properties_destroyed */
4800 TODO_rebuild_alias
, /* todo_flags_start */
4801 TODO_verify_ssa
, /* todo_flags_finish */
4804 class pass_pre
: public gimple_opt_pass
4807 pass_pre (gcc::context
*ctxt
)
4808 : gimple_opt_pass (pass_data_pre
, ctxt
)
4811 /* opt_pass methods: */
4812 bool gate () { return gate_pre (); }
4813 unsigned int execute () { return do_pre (); }
4815 }; // class pass_pre
4820 make_pass_pre (gcc::context
*ctxt
)
4822 return new pass_pre (ctxt
);
4826 /* Gate and execute functions for FRE. */
4831 unsigned int todo
= 0;
4833 if (!run_scc_vn (VN_WALKREWRITE
))
4836 memset (&pre_stats
, 0, sizeof (pre_stats
));
4838 /* Remove all the redundant expressions. */
4839 todo
|= eliminate ();
4841 todo
|= fini_eliminate ();
4845 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4846 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4854 return flag_tree_fre
!= 0;
4859 const pass_data pass_data_fre
=
4861 GIMPLE_PASS
, /* type */
4863 OPTGROUP_NONE
, /* optinfo_flags */
4864 true, /* has_gate */
4865 true, /* has_execute */
4866 TV_TREE_FRE
, /* tv_id */
4867 ( PROP_cfg
| PROP_ssa
), /* properties_required */
4868 0, /* properties_provided */
4869 0, /* properties_destroyed */
4870 0, /* todo_flags_start */
4871 TODO_verify_ssa
, /* todo_flags_finish */
4874 class pass_fre
: public gimple_opt_pass
4877 pass_fre (gcc::context
*ctxt
)
4878 : gimple_opt_pass (pass_data_fre
, ctxt
)
4881 /* opt_pass methods: */
4882 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
4883 bool gate () { return gate_fre (); }
4884 unsigned int execute () { return execute_fre (); }
4886 }; // class pass_fre
4891 make_pass_fre (gcc::context
*ctxt
)
4893 return new pass_fre (ctxt
);