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"
32 #include "hash-table.h"
33 #include "tree-iterator.h"
34 #include "alloc-pool.h"
36 #include "tree-pass.h"
39 #include "langhooks.h"
41 #include "tree-ssa-sccvn.h"
42 #include "tree-scalar-evolution.h"
47 #include "tree-ssa-propagate.h"
51 1. Avail sets can be shared by making an avail_find_leader that
52 walks up the dominator tree and looks in those avail sets.
53 This might affect code optimality, it's unclear right now.
54 2. Strength reduction can be performed by anticipating expressions
55 we can repair later on.
56 3. We can do back-substitution or smarter value numbering to catch
57 commutative expressions split up over multiple statements.
60 /* For ease of terminology, "expression node" in the below refers to
61 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
62 represent the actual statement containing the expressions we care about,
63 and we cache the value number by putting it in the expression. */
67 First we walk the statements to generate the AVAIL sets, the
68 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
69 generation of values/expressions by a given block. We use them
70 when computing the ANTIC sets. The AVAIL sets consist of
71 SSA_NAME's that represent values, so we know what values are
72 available in what blocks. AVAIL is a forward dataflow problem. In
73 SSA, values are never killed, so we don't need a kill set, or a
74 fixpoint iteration, in order to calculate the AVAIL sets. In
75 traditional parlance, AVAIL sets tell us the downsafety of the
78 Next, we generate the ANTIC sets. These sets represent the
79 anticipatable expressions. ANTIC is a backwards dataflow
80 problem. An expression is anticipatable in a given block if it could
81 be generated in that block. This means that if we had to perform
82 an insertion in that block, of the value of that expression, we
83 could. Calculating the ANTIC sets requires phi translation of
84 expressions, because the flow goes backwards through phis. We must
85 iterate to a fixpoint of the ANTIC sets, because we have a kill
86 set. Even in SSA form, values are not live over the entire
87 function, only from their definition point onwards. So we have to
88 remove values from the ANTIC set once we go past the definition
89 point of the leaders that make them up.
90 compute_antic/compute_antic_aux performs this computation.
92 Third, we perform insertions to make partially redundant
93 expressions fully redundant.
95 An expression is partially redundant (excluding partial
98 1. It is AVAIL in some, but not all, of the predecessors of a
100 2. It is ANTIC in all the predecessors.
102 In order to make it fully redundant, we insert the expression into
103 the predecessors where it is not available, but is ANTIC.
105 For the partial anticipation case, we only perform insertion if it
106 is partially anticipated in some block, and fully available in all
109 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
110 performs these steps.
112 Fourth, we eliminate fully redundant expressions.
113 This is a simple statement walk that replaces redundant
114 calculations with the now available values. */
116 /* Representations of value numbers:
118 Value numbers are represented by a representative SSA_NAME. We
119 will create fake SSA_NAME's in situations where we need a
120 representative but do not have one (because it is a complex
121 expression). In order to facilitate storing the value numbers in
122 bitmaps, and keep the number of wasted SSA_NAME's down, we also
123 associate a value_id with each value number, and create full blown
124 ssa_name's only where we actually need them (IE in operands of
125 existing expressions).
127 Theoretically you could replace all the value_id's with
128 SSA_NAME_VERSION, but this would allocate a large number of
129 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
130 It would also require an additional indirection at each point we
133 /* Representation of expressions on value numbers:
135 Expressions consisting of value numbers are represented the same
136 way as our VN internally represents them, with an additional
137 "pre_expr" wrapping around them in order to facilitate storing all
138 of the expressions in the same sets. */
140 /* Representation of sets:
142 The dataflow sets do not need to be sorted in any particular order
143 for the majority of their lifetime, are simply represented as two
144 bitmaps, one that keeps track of values present in the set, and one
145 that keeps track of expressions present in the set.
147 When we need them in topological order, we produce it on demand by
148 transforming the bitmap into an array and sorting it into topo
151 /* Type of expression, used to know which member of the PRE_EXPR union
162 typedef union pre_expr_union_d
167 vn_reference_t reference
;
170 typedef struct pre_expr_d
: typed_noop_remove
<pre_expr_d
>
172 enum pre_expr_kind kind
;
176 /* hash_table support. */
177 typedef pre_expr_d value_type
;
178 typedef pre_expr_d compare_type
;
179 static inline hashval_t
hash (const pre_expr_d
*);
180 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
183 #define PRE_EXPR_NAME(e) (e)->u.name
184 #define PRE_EXPR_NARY(e) (e)->u.nary
185 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
186 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
188 /* Compare E1 and E1 for equality. */
191 pre_expr_d::equal (const value_type
*e1
, const compare_type
*e2
)
193 if (e1
->kind
!= e2
->kind
)
199 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
200 PRE_EXPR_CONSTANT (e2
));
202 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
204 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
206 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
207 PRE_EXPR_REFERENCE (e2
));
216 pre_expr_d::hash (const value_type
*e
)
221 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
223 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
225 return PRE_EXPR_NARY (e
)->hashcode
;
227 return PRE_EXPR_REFERENCE (e
)->hashcode
;
233 /* Next global expression id number. */
234 static unsigned int next_expression_id
;
236 /* Mapping from expression to id number we can use in bitmap sets. */
237 static vec
<pre_expr
> expressions
;
238 static hash_table
<pre_expr_d
> expression_to_id
;
239 static vec
<unsigned> name_to_id
;
241 /* Allocate an expression id for EXPR. */
243 static inline unsigned int
244 alloc_expression_id (pre_expr expr
)
246 struct pre_expr_d
**slot
;
247 /* Make sure we won't overflow. */
248 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
249 expr
->id
= next_expression_id
++;
250 expressions
.safe_push (expr
);
251 if (expr
->kind
== NAME
)
253 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
254 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
255 re-allocations by using vec::reserve upfront. There is no
256 vec::quick_grow_cleared unfortunately. */
257 unsigned old_len
= name_to_id
.length ();
258 name_to_id
.reserve (num_ssa_names
- old_len
);
259 name_to_id
.safe_grow_cleared (num_ssa_names
);
260 gcc_assert (name_to_id
[version
] == 0);
261 name_to_id
[version
] = expr
->id
;
265 slot
= expression_to_id
.find_slot (expr
, INSERT
);
269 return next_expression_id
- 1;
272 /* Return the expression id for tree EXPR. */
274 static inline unsigned int
275 get_expression_id (const pre_expr expr
)
280 static inline unsigned int
281 lookup_expression_id (const pre_expr expr
)
283 struct pre_expr_d
**slot
;
285 if (expr
->kind
== NAME
)
287 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
288 if (name_to_id
.length () <= version
)
290 return name_to_id
[version
];
294 slot
= expression_to_id
.find_slot (expr
, NO_INSERT
);
297 return ((pre_expr
)*slot
)->id
;
301 /* Return the existing expression id for EXPR, or create one if one
302 does not exist yet. */
304 static inline unsigned int
305 get_or_alloc_expression_id (pre_expr expr
)
307 unsigned int id
= lookup_expression_id (expr
);
309 return alloc_expression_id (expr
);
310 return expr
->id
= id
;
313 /* Return the expression that has expression id ID */
315 static inline pre_expr
316 expression_for_id (unsigned int id
)
318 return expressions
[id
];
321 /* Free the expression id field in all of our expressions,
322 and then destroy the expressions array. */
325 clear_expression_ids (void)
327 expressions
.release ();
330 static alloc_pool pre_expr_pool
;
332 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
335 get_or_alloc_expr_for_name (tree name
)
337 struct pre_expr_d expr
;
339 unsigned int result_id
;
343 PRE_EXPR_NAME (&expr
) = name
;
344 result_id
= lookup_expression_id (&expr
);
346 return expression_for_id (result_id
);
348 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
350 PRE_EXPR_NAME (result
) = name
;
351 alloc_expression_id (result
);
355 /* An unordered bitmap set. One bitmap tracks values, the other,
357 typedef struct bitmap_set
359 bitmap_head expressions
;
363 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
364 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
366 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
367 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
369 /* Mapping from value id to expressions with that value_id. */
370 static vec
<bitmap
> value_expressions
;
372 /* Sets that we need to keep track of. */
373 typedef struct bb_bitmap_sets
375 /* The EXP_GEN set, which represents expressions/values generated in
377 bitmap_set_t exp_gen
;
379 /* The PHI_GEN set, which represents PHI results generated in a
381 bitmap_set_t phi_gen
;
383 /* The TMP_GEN set, which represents results/temporaries generated
384 in a basic block. IE the LHS of an expression. */
385 bitmap_set_t tmp_gen
;
387 /* The AVAIL_OUT set, which represents which values are available in
388 a given basic block. */
389 bitmap_set_t avail_out
;
391 /* The ANTIC_IN set, which represents which values are anticipatable
392 in a given basic block. */
393 bitmap_set_t antic_in
;
395 /* The PA_IN set, which represents which values are
396 partially anticipatable in a given basic block. */
399 /* The NEW_SETS set, which is used during insertion to augment the
400 AVAIL_OUT set of blocks with the new insertions performed during
401 the current iteration. */
402 bitmap_set_t new_sets
;
404 /* A cache for value_dies_in_block_x. */
407 /* True if we have visited this block during ANTIC calculation. */
408 unsigned int visited
: 1;
410 /* True we have deferred processing this block during ANTIC
411 calculation until its successor is processed. */
412 unsigned int deferred
: 1;
414 /* True when the block contains a call that might not return. */
415 unsigned int contains_may_not_return_call
: 1;
418 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
419 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
420 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
421 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
422 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
423 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
424 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
425 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
426 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
427 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
428 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
431 /* Basic block list in postorder. */
432 static int *postorder
;
433 static int postorder_num
;
435 /* This structure is used to keep track of statistics on what
436 optimization PRE was able to perform. */
439 /* The number of RHS computations eliminated by PRE. */
442 /* The number of new expressions/temporaries generated by PRE. */
445 /* The number of inserts found due to partial anticipation */
448 /* The number of new PHI nodes added by PRE. */
452 static bool do_partial_partial
;
453 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
454 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
455 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
456 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
457 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
458 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
459 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
461 static bitmap_set_t
bitmap_set_new (void);
462 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
464 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
465 static unsigned int get_expr_value_id (pre_expr
);
467 /* We can add and remove elements and entries to and from sets
468 and hash tables, so we use alloc pools for them. */
470 static alloc_pool bitmap_set_pool
;
471 static bitmap_obstack grand_bitmap_obstack
;
473 /* Set of blocks with statements that have had their EH properties changed. */
474 static bitmap need_eh_cleanup
;
476 /* Set of blocks with statements that have had their AB properties changed. */
477 static bitmap need_ab_cleanup
;
479 /* A three tuple {e, pred, v} used to cache phi translations in the
480 phi_translate_table. */
482 typedef struct expr_pred_trans_d
: typed_free_remove
<expr_pred_trans_d
>
484 /* The expression. */
487 /* The predecessor block along which we translated the expression. */
490 /* The value that resulted from the translation. */
493 /* The hashcode for the expression, pred pair. This is cached for
497 /* hash_table support. */
498 typedef expr_pred_trans_d value_type
;
499 typedef expr_pred_trans_d compare_type
;
500 static inline hashval_t
hash (const value_type
*);
501 static inline int equal (const value_type
*, const compare_type
*);
502 } *expr_pred_trans_t
;
503 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
506 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
512 expr_pred_trans_d::equal (const value_type
*ve1
,
513 const compare_type
*ve2
)
515 basic_block b1
= ve1
->pred
;
516 basic_block b2
= ve2
->pred
;
518 /* If they are not translations for the same basic block, they can't
522 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
525 /* The phi_translate_table caches phi translations for a given
526 expression and predecessor. */
527 static hash_table
<expr_pred_trans_d
> phi_translate_table
;
529 /* Add the tuple mapping from {expression E, basic block PRED} to
530 the phi translation table and return whether it pre-existed. */
533 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
535 expr_pred_trans_t
*slot
;
536 expr_pred_trans_d tem
;
537 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
542 slot
= phi_translate_table
.find_slot_with_hash (&tem
, hash
, INSERT
);
549 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
551 (*entry
)->pred
= pred
;
552 (*entry
)->hashcode
= hash
;
557 /* Add expression E to the expression set of value id V. */
560 add_to_value (unsigned int v
, pre_expr e
)
564 gcc_checking_assert (get_expr_value_id (e
) == v
);
566 if (v
>= value_expressions
.length ())
568 value_expressions
.safe_grow_cleared (v
+ 1);
571 set
= value_expressions
[v
];
574 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
575 value_expressions
[v
] = set
;
578 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
581 /* Create a new bitmap set and return it. */
584 bitmap_set_new (void)
586 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
587 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
588 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
592 /* Return the value id for a PRE expression EXPR. */
595 get_expr_value_id (pre_expr expr
)
601 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
604 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
607 id
= PRE_EXPR_NARY (expr
)->value_id
;
610 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
615 /* ??? We cannot assert that expr has a value-id (it can be 0), because
616 we assign value-ids only to expressions that have a result
617 in set_hashtable_value_ids. */
621 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
624 sccvn_valnum_from_value_id (unsigned int val
)
628 bitmap exprset
= value_expressions
[val
];
629 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
631 pre_expr vexpr
= expression_for_id (i
);
632 if (vexpr
->kind
== NAME
)
633 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
634 else if (vexpr
->kind
== CONSTANT
)
635 return PRE_EXPR_CONSTANT (vexpr
);
640 /* Remove an expression EXPR from a bitmapped set. */
643 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
645 unsigned int val
= get_expr_value_id (expr
);
646 if (!value_id_constant_p (val
))
648 bitmap_clear_bit (&set
->values
, val
);
649 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
654 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
655 unsigned int val
, bool allow_constants
)
657 if (allow_constants
|| !value_id_constant_p (val
))
659 /* We specifically expect this and only this function to be able to
660 insert constants into a set. */
661 bitmap_set_bit (&set
->values
, val
);
662 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
666 /* Insert an expression EXPR into a bitmapped set. */
669 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
671 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
674 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
677 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
679 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
680 bitmap_copy (&dest
->values
, &orig
->values
);
684 /* Free memory used up by SET. */
686 bitmap_set_free (bitmap_set_t set
)
688 bitmap_clear (&set
->expressions
);
689 bitmap_clear (&set
->values
);
693 /* Generate an topological-ordered array of bitmap set SET. */
696 sorted_array_from_bitmap_set (bitmap_set_t set
)
699 bitmap_iterator bi
, bj
;
700 vec
<pre_expr
> result
;
702 /* Pre-allocate roughly enough space for the array. */
703 result
.create (bitmap_count_bits (&set
->values
));
705 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
707 /* The number of expressions having a given value is usually
708 relatively small. Thus, rather than making a vector of all
709 the expressions and sorting it by value-id, we walk the values
710 and check in the reverse mapping that tells us what expressions
711 have a given value, to filter those in our set. As a result,
712 the expressions are inserted in value-id order, which means
715 If this is somehow a significant lose for some cases, we can
716 choose which set to walk based on the set size. */
717 bitmap exprset
= value_expressions
[i
];
718 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
720 if (bitmap_bit_p (&set
->expressions
, j
))
721 result
.safe_push (expression_for_id (j
));
728 /* Perform bitmapped set operation DEST &= ORIG. */
731 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
739 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
741 bitmap_and_into (&dest
->values
, &orig
->values
);
742 bitmap_copy (&temp
, &dest
->expressions
);
743 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
745 pre_expr expr
= expression_for_id (i
);
746 unsigned int value_id
= get_expr_value_id (expr
);
747 if (!bitmap_bit_p (&dest
->values
, value_id
))
748 bitmap_clear_bit (&dest
->expressions
, i
);
750 bitmap_clear (&temp
);
754 /* Subtract all values and expressions contained in ORIG from DEST. */
757 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
759 bitmap_set_t result
= bitmap_set_new ();
763 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
766 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
768 pre_expr expr
= expression_for_id (i
);
769 unsigned int value_id
= get_expr_value_id (expr
);
770 bitmap_set_bit (&result
->values
, value_id
);
776 /* Subtract all the values in bitmap set B from bitmap set A. */
779 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
785 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
787 bitmap_copy (&temp
, &a
->expressions
);
788 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
790 pre_expr expr
= expression_for_id (i
);
791 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
792 bitmap_remove_from_set (a
, expr
);
794 bitmap_clear (&temp
);
798 /* Return true if bitmapped set SET contains the value VALUE_ID. */
801 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
803 if (value_id_constant_p (value_id
))
806 if (!set
|| bitmap_empty_p (&set
->expressions
))
809 return bitmap_bit_p (&set
->values
, value_id
);
813 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
815 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
818 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
821 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
828 if (value_id_constant_p (lookfor
))
831 if (!bitmap_set_contains_value (set
, lookfor
))
834 /* The number of expressions having a given value is usually
835 significantly less than the total number of expressions in SET.
836 Thus, rather than check, for each expression in SET, whether it
837 has the value LOOKFOR, we walk the reverse mapping that tells us
838 what expressions have a given value, and see if any of those
839 expressions are in our set. For large testcases, this is about
840 5-10x faster than walking the bitmap. If this is somehow a
841 significant lose for some cases, we can choose which set to walk
842 based on the set size. */
843 exprset
= value_expressions
[lookfor
];
844 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
846 if (bitmap_clear_bit (&set
->expressions
, i
))
848 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
856 /* Return true if two bitmap sets are equal. */
859 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
861 return bitmap_equal_p (&a
->values
, &b
->values
);
864 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
865 and add it otherwise. */
868 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
870 unsigned int val
= get_expr_value_id (expr
);
872 if (bitmap_set_contains_value (set
, val
))
873 bitmap_set_replace_value (set
, val
, expr
);
875 bitmap_insert_into_set (set
, expr
);
878 /* Insert EXPR into SET if EXPR's value is not already present in
882 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
884 unsigned int val
= get_expr_value_id (expr
);
886 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
888 /* Constant values are always considered to be part of the set. */
889 if (value_id_constant_p (val
))
892 /* If the value membership changed, add the expression. */
893 if (bitmap_set_bit (&set
->values
, val
))
894 bitmap_set_bit (&set
->expressions
, expr
->id
);
897 /* Print out EXPR to outfile. */
900 print_pre_expr (FILE *outfile
, const pre_expr expr
)
905 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
908 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
913 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
914 fprintf (outfile
, "{%s,", tree_code_name
[nary
->opcode
]);
915 for (i
= 0; i
< nary
->length
; i
++)
917 print_generic_expr (outfile
, nary
->op
[i
], 0);
918 if (i
!= (unsigned) nary
->length
- 1)
919 fprintf (outfile
, ",");
921 fprintf (outfile
, "}");
927 vn_reference_op_t vro
;
929 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
930 fprintf (outfile
, "{");
932 ref
->operands
.iterate (i
, &vro
);
935 bool closebrace
= false;
936 if (vro
->opcode
!= SSA_NAME
937 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
939 fprintf (outfile
, "%s", tree_code_name
[vro
->opcode
]);
942 fprintf (outfile
, "<");
948 print_generic_expr (outfile
, vro
->op0
, 0);
951 fprintf (outfile
, ",");
952 print_generic_expr (outfile
, vro
->op1
, 0);
956 fprintf (outfile
, ",");
957 print_generic_expr (outfile
, vro
->op2
, 0);
961 fprintf (outfile
, ">");
962 if (i
!= ref
->operands
.length () - 1)
963 fprintf (outfile
, ",");
965 fprintf (outfile
, "}");
968 fprintf (outfile
, "@");
969 print_generic_expr (outfile
, ref
->vuse
, 0);
975 void debug_pre_expr (pre_expr
);
977 /* Like print_pre_expr but always prints to stderr. */
979 debug_pre_expr (pre_expr e
)
981 print_pre_expr (stderr
, e
);
982 fprintf (stderr
, "\n");
985 /* Print out SET to OUTFILE. */
988 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
989 const char *setname
, int blockindex
)
991 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
998 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1000 const pre_expr expr
= expression_for_id (i
);
1003 fprintf (outfile
, ", ");
1005 print_pre_expr (outfile
, expr
);
1007 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1010 fprintf (outfile
, " }\n");
1013 void debug_bitmap_set (bitmap_set_t
);
1016 debug_bitmap_set (bitmap_set_t set
)
1018 print_bitmap_set (stderr
, set
, "debug", 0);
1021 void debug_bitmap_sets_for (basic_block
);
1024 debug_bitmap_sets_for (basic_block bb
)
1026 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1027 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1028 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1029 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1030 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1031 if (do_partial_partial
)
1032 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1033 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1036 /* Print out the expressions that have VAL to OUTFILE. */
1039 print_value_expressions (FILE *outfile
, unsigned int val
)
1041 bitmap set
= value_expressions
[val
];
1046 sprintf (s
, "%04d", val
);
1047 x
.expressions
= *set
;
1048 print_bitmap_set (outfile
, &x
, s
, 0);
1054 debug_value_expressions (unsigned int val
)
1056 print_value_expressions (stderr
, val
);
1059 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1063 get_or_alloc_expr_for_constant (tree constant
)
1065 unsigned int result_id
;
1066 unsigned int value_id
;
1067 struct pre_expr_d expr
;
1070 expr
.kind
= CONSTANT
;
1071 PRE_EXPR_CONSTANT (&expr
) = constant
;
1072 result_id
= lookup_expression_id (&expr
);
1074 return expression_for_id (result_id
);
1076 newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1077 newexpr
->kind
= CONSTANT
;
1078 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1079 alloc_expression_id (newexpr
);
1080 value_id
= get_or_alloc_constant_value_id (constant
);
1081 add_to_value (value_id
, newexpr
);
1085 /* Given a value id V, find the actual tree representing the constant
1086 value if there is one, and return it. Return NULL if we can't find
1090 get_constant_for_value_id (unsigned int v
)
1092 if (value_id_constant_p (v
))
1096 bitmap exprset
= value_expressions
[v
];
1098 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1100 pre_expr expr
= expression_for_id (i
);
1101 if (expr
->kind
== CONSTANT
)
1102 return PRE_EXPR_CONSTANT (expr
);
1108 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1109 Currently only supports constants and SSA_NAMES. */
1111 get_or_alloc_expr_for (tree t
)
1113 if (TREE_CODE (t
) == SSA_NAME
)
1114 return get_or_alloc_expr_for_name (t
);
1115 else if (is_gimple_min_invariant (t
))
1116 return get_or_alloc_expr_for_constant (t
);
1119 /* More complex expressions can result from SCCVN expression
1120 simplification that inserts values for them. As they all
1121 do not have VOPs the get handled by the nary ops struct. */
1122 vn_nary_op_t result
;
1123 unsigned int result_id
;
1124 vn_nary_op_lookup (t
, &result
);
1127 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1129 PRE_EXPR_NARY (e
) = result
;
1130 result_id
= lookup_expression_id (e
);
1133 pool_free (pre_expr_pool
, e
);
1134 e
= expression_for_id (result_id
);
1137 alloc_expression_id (e
);
1144 /* Return the folded version of T if T, when folded, is a gimple
1145 min_invariant. Otherwise, return T. */
1148 fully_constant_expression (pre_expr e
)
1156 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1157 switch (TREE_CODE_CLASS (nary
->opcode
))
1160 case tcc_comparison
:
1162 /* We have to go from trees to pre exprs to value ids to
1164 tree naryop0
= nary
->op
[0];
1165 tree naryop1
= nary
->op
[1];
1167 if (!is_gimple_min_invariant (naryop0
))
1169 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1170 unsigned int vrep0
= get_expr_value_id (rep0
);
1171 tree const0
= get_constant_for_value_id (vrep0
);
1173 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1175 if (!is_gimple_min_invariant (naryop1
))
1177 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1178 unsigned int vrep1
= get_expr_value_id (rep1
);
1179 tree const1
= get_constant_for_value_id (vrep1
);
1181 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1183 result
= fold_binary (nary
->opcode
, nary
->type
,
1185 if (result
&& is_gimple_min_invariant (result
))
1186 return get_or_alloc_expr_for_constant (result
);
1187 /* We might have simplified the expression to a
1188 SSA_NAME for example from x_1 * 1. But we cannot
1189 insert a PHI for x_1 unconditionally as x_1 might
1190 not be available readily. */
1194 if (nary
->opcode
!= REALPART_EXPR
1195 && nary
->opcode
!= IMAGPART_EXPR
1196 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1201 /* We have to go from trees to pre exprs to value ids to
1203 tree naryop0
= nary
->op
[0];
1204 tree const0
, result
;
1205 if (is_gimple_min_invariant (naryop0
))
1209 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1210 unsigned int vrep0
= get_expr_value_id (rep0
);
1211 const0
= get_constant_for_value_id (vrep0
);
1216 tree type1
= TREE_TYPE (nary
->op
[0]);
1217 const0
= fold_convert (type1
, const0
);
1218 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1220 if (result
&& is_gimple_min_invariant (result
))
1221 return get_or_alloc_expr_for_constant (result
);
1230 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1232 if ((folded
= fully_constant_vn_reference_p (ref
)))
1233 return get_or_alloc_expr_for_constant (folded
);
1242 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1243 it has the value it would have in BLOCK. Set *SAME_VALID to true
1244 in case the new vuse doesn't change the value id of the OPERANDS. */
1247 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1248 alias_set_type set
, tree type
, tree vuse
,
1249 basic_block phiblock
,
1250 basic_block block
, bool *same_valid
)
1252 gimple phi
= SSA_NAME_DEF_STMT (vuse
);
1259 if (gimple_bb (phi
) != phiblock
)
1262 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1264 /* Use the alias-oracle to find either the PHI node in this block,
1265 the first VUSE used in this block that is equivalent to vuse or
1266 the first VUSE which definition in this block kills the value. */
1267 if (gimple_code (phi
) == GIMPLE_PHI
)
1268 e
= find_edge (block
, phiblock
);
1269 else if (use_oracle
)
1270 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1272 vuse
= gimple_vuse (phi
);
1273 phi
= SSA_NAME_DEF_STMT (vuse
);
1274 if (gimple_bb (phi
) != phiblock
)
1276 if (gimple_code (phi
) == GIMPLE_PHI
)
1278 e
= find_edge (block
, phiblock
);
1289 bitmap visited
= NULL
;
1291 /* Try to find a vuse that dominates this phi node by skipping
1292 non-clobbering statements. */
1293 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false);
1295 BITMAP_FREE (visited
);
1301 /* If we didn't find any, the value ID can't stay the same,
1302 but return the translated vuse. */
1303 *same_valid
= false;
1304 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1306 /* ??? We would like to return vuse here as this is the canonical
1307 upmost vdef that this reference is associated with. But during
1308 insertion of the references into the hash tables we only ever
1309 directly insert with their direct gimple_vuse, hence returning
1310 something else would make us not find the other expression. */
1311 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1317 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1318 SET2. This is used to avoid making a set consisting of the union
1319 of PA_IN and ANTIC_IN during insert. */
1321 static inline pre_expr
1322 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1326 result
= bitmap_find_leader (set1
, val
);
1327 if (!result
&& set2
)
1328 result
= bitmap_find_leader (set2
, val
);
1332 /* Get the tree type for our PRE expression e. */
1335 get_expr_type (const pre_expr e
)
1340 return TREE_TYPE (PRE_EXPR_NAME (e
));
1342 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1344 return PRE_EXPR_REFERENCE (e
)->type
;
1346 return PRE_EXPR_NARY (e
)->type
;
1351 /* Get a representative SSA_NAME for a given expression.
1352 Since all of our sub-expressions are treated as values, we require
1353 them to be SSA_NAME's for simplicity.
1354 Prior versions of GVNPRE used to use "value handles" here, so that
1355 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1356 either case, the operands are really values (IE we do not expect
1357 them to be usable without finding leaders). */
1360 get_representative_for (const pre_expr e
)
1363 unsigned int value_id
= get_expr_value_id (e
);
1368 return PRE_EXPR_NAME (e
);
1370 return PRE_EXPR_CONSTANT (e
);
1374 /* Go through all of the expressions representing this value
1375 and pick out an SSA_NAME. */
1378 bitmap exprs
= value_expressions
[value_id
];
1379 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1381 pre_expr rep
= expression_for_id (i
);
1382 if (rep
->kind
== NAME
)
1383 return PRE_EXPR_NAME (rep
);
1384 else if (rep
->kind
== CONSTANT
)
1385 return PRE_EXPR_CONSTANT (rep
);
1391 /* If we reached here we couldn't find an SSA_NAME. This can
1392 happen when we've discovered a value that has never appeared in
1393 the program as set to an SSA_NAME, as the result of phi translation.
1395 ??? We should be able to re-use this when we insert the statement
1397 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1398 VN_INFO_GET (name
)->value_id
= value_id
;
1399 VN_INFO (name
)->valnum
= name
;
1400 /* ??? For now mark this SSA name for release by SCCVN. */
1401 VN_INFO (name
)->needs_insertion
= true;
1402 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1403 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1405 fprintf (dump_file
, "Created SSA_NAME representative ");
1406 print_generic_expr (dump_file
, name
, 0);
1407 fprintf (dump_file
, " for expression:");
1408 print_pre_expr (dump_file
, e
);
1409 fprintf (dump_file
, " (%04d)\n", value_id
);
1418 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1419 basic_block pred
, basic_block phiblock
);
1421 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1422 the phis in PRED. Return NULL if we can't find a leader for each part
1423 of the translated expression. */
1426 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1427 basic_block pred
, basic_block phiblock
)
1434 bool changed
= false;
1435 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1436 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1437 sizeof_vn_nary_op (nary
->length
));
1438 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1440 for (i
= 0; i
< newnary
->length
; i
++)
1442 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1446 pre_expr leader
, result
;
1447 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1448 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1449 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1450 if (result
&& result
!= leader
)
1452 tree name
= get_representative_for (result
);
1455 newnary
->op
[i
] = name
;
1460 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1466 unsigned int new_val_id
;
1468 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1473 if (result
&& is_gimple_min_invariant (result
))
1474 return get_or_alloc_expr_for_constant (result
);
1476 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1481 PRE_EXPR_NARY (expr
) = nary
;
1482 constant
= fully_constant_expression (expr
);
1483 if (constant
!= expr
)
1486 new_val_id
= nary
->value_id
;
1487 get_or_alloc_expression_id (expr
);
1491 new_val_id
= get_next_value_id ();
1492 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1493 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1497 result
, new_val_id
);
1498 PRE_EXPR_NARY (expr
) = nary
;
1499 constant
= fully_constant_expression (expr
);
1500 if (constant
!= expr
)
1502 get_or_alloc_expression_id (expr
);
1504 add_to_value (new_val_id
, expr
);
1512 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1513 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1514 tree vuse
= ref
->vuse
;
1515 tree newvuse
= vuse
;
1516 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1517 bool changed
= false, same_valid
= true;
1518 unsigned int i
, j
, n
;
1519 vn_reference_op_t operand
;
1520 vn_reference_t newref
;
1523 operands
.iterate (i
, &operand
); i
++, j
++)
1528 tree type
= operand
->type
;
1529 vn_reference_op_s newop
= *operand
;
1530 op
[0] = operand
->op0
;
1531 op
[1] = operand
->op1
;
1532 op
[2] = operand
->op2
;
1533 for (n
= 0; n
< 3; ++n
)
1535 unsigned int op_val_id
;
1538 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1540 /* We can't possibly insert these. */
1542 && !is_gimple_min_invariant (op
[n
]))
1546 op_val_id
= VN_INFO (op
[n
])->value_id
;
1547 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1550 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1553 if (opresult
!= leader
)
1555 tree name
= get_representative_for (opresult
);
1558 changed
|= name
!= op
[n
];
1564 newoperands
.release ();
1567 if (!newoperands
.exists ())
1568 newoperands
= operands
.copy ();
1569 /* We may have changed from an SSA_NAME to a constant */
1570 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1571 newop
.opcode
= TREE_CODE (op
[0]);
1576 /* If it transforms a non-constant ARRAY_REF into a constant
1577 one, adjust the constant offset. */
1578 if (newop
.opcode
== ARRAY_REF
1580 && TREE_CODE (op
[0]) == INTEGER_CST
1581 && TREE_CODE (op
[1]) == INTEGER_CST
1582 && TREE_CODE (op
[2]) == INTEGER_CST
)
1584 double_int off
= tree_to_double_int (op
[0]);
1585 off
+= -tree_to_double_int (op
[1]);
1586 off
*= tree_to_double_int (op
[2]);
1587 if (off
.fits_shwi ())
1588 newop
.off
= off
.low
;
1590 newoperands
[j
] = newop
;
1591 /* If it transforms from an SSA_NAME to an address, fold with
1592 a preceding indirect reference. */
1593 if (j
> 0 && op
[0] && TREE_CODE (op
[0]) == ADDR_EXPR
1594 && newoperands
[j
- 1].opcode
== MEM_REF
)
1595 vn_reference_fold_indirect (&newoperands
, &j
);
1597 if (i
!= operands
.length ())
1599 newoperands
.release ();
1605 newvuse
= translate_vuse_through_block (newoperands
,
1606 ref
->set
, ref
->type
,
1607 vuse
, phiblock
, pred
,
1609 if (newvuse
== NULL_TREE
)
1611 newoperands
.release ();
1616 if (changed
|| newvuse
!= vuse
)
1618 unsigned int new_val_id
;
1621 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1626 newoperands
.release ();
1628 /* We can always insert constants, so if we have a partial
1629 redundant constant load of another type try to translate it
1630 to a constant of appropriate type. */
1631 if (result
&& is_gimple_min_invariant (result
))
1634 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1636 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1637 if (tem
&& !is_gimple_min_invariant (tem
))
1641 return get_or_alloc_expr_for_constant (tem
);
1644 /* If we'd have to convert things we would need to validate
1645 if we can insert the translated expression. So fail
1646 here for now - we cannot insert an alias with a different
1647 type in the VN tables either, as that would assert. */
1649 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1651 else if (!result
&& newref
1652 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1654 newoperands
.release ();
1658 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1659 expr
->kind
= REFERENCE
;
1664 PRE_EXPR_REFERENCE (expr
) = newref
;
1665 constant
= fully_constant_expression (expr
);
1666 if (constant
!= expr
)
1669 new_val_id
= newref
->value_id
;
1670 get_or_alloc_expression_id (expr
);
1674 if (changed
|| !same_valid
)
1676 new_val_id
= get_next_value_id ();
1677 value_expressions
.safe_grow_cleared
1678 (get_max_value_id () + 1);
1681 new_val_id
= ref
->value_id
;
1682 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1685 result
, new_val_id
);
1686 newoperands
.create (0);
1687 PRE_EXPR_REFERENCE (expr
) = newref
;
1688 constant
= fully_constant_expression (expr
);
1689 if (constant
!= expr
)
1691 get_or_alloc_expression_id (expr
);
1693 add_to_value (new_val_id
, expr
);
1695 newoperands
.release ();
1702 tree name
= PRE_EXPR_NAME (expr
);
1703 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
1704 /* If the SSA name is defined by a PHI node in this block,
1706 if (gimple_code (def_stmt
) == GIMPLE_PHI
1707 && gimple_bb (def_stmt
) == phiblock
)
1709 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1710 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1712 /* Handle constant. */
1713 if (is_gimple_min_invariant (def
))
1714 return get_or_alloc_expr_for_constant (def
);
1716 return get_or_alloc_expr_for_name (def
);
1718 /* Otherwise return it unchanged - it will get cleaned if its
1719 value is not available in PREDs AVAIL_OUT set of expressions. */
1728 /* Wrapper around phi_translate_1 providing caching functionality. */
1731 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1732 basic_block pred
, basic_block phiblock
)
1734 expr_pred_trans_t slot
= NULL
;
1740 /* Constants contain no values that need translation. */
1741 if (expr
->kind
== CONSTANT
)
1744 if (value_id_constant_p (get_expr_value_id (expr
)))
1747 /* Don't add translations of NAMEs as those are cheap to translate. */
1748 if (expr
->kind
!= NAME
)
1750 if (phi_trans_add (&slot
, expr
, pred
))
1752 /* Store NULL for the value we want to return in the case of
1758 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1767 /* For each expression in SET, translate the values through phi nodes
1768 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1769 expressions in DEST. */
1772 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1773 basic_block phiblock
)
1775 vec
<pre_expr
> exprs
;
1779 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1781 bitmap_set_copy (dest
, set
);
1785 exprs
= sorted_array_from_bitmap_set (set
);
1786 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1788 pre_expr translated
;
1789 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1793 /* We might end up with multiple expressions from SET being
1794 translated to the same value. In this case we do not want
1795 to retain the NARY or REFERENCE expression but prefer a NAME
1796 which would be the leader. */
1797 if (translated
->kind
== NAME
)
1798 bitmap_value_replace_in_set (dest
, translated
);
1800 bitmap_value_insert_into_set (dest
, translated
);
1805 /* Find the leader for a value (i.e., the name representing that
1806 value) in a given set, and return it. Return NULL if no leader
1810 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1812 if (value_id_constant_p (val
))
1816 bitmap exprset
= value_expressions
[val
];
1818 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1820 pre_expr expr
= expression_for_id (i
);
1821 if (expr
->kind
== CONSTANT
)
1825 if (bitmap_set_contains_value (set
, val
))
1827 /* Rather than walk the entire bitmap of expressions, and see
1828 whether any of them has the value we are looking for, we look
1829 at the reverse mapping, which tells us the set of expressions
1830 that have a given value (IE value->expressions with that
1831 value) and see if any of those expressions are in our set.
1832 The number of expressions per value is usually significantly
1833 less than the number of expressions in the set. In fact, for
1834 large testcases, doing it this way is roughly 5-10x faster
1835 than walking the bitmap.
1836 If this is somehow a significant lose for some cases, we can
1837 choose which set to walk based on which set is smaller. */
1840 bitmap exprset
= value_expressions
[val
];
1842 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1843 return expression_for_id (i
);
1848 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1849 BLOCK by seeing if it is not killed in the block. Note that we are
1850 only determining whether there is a store that kills it. Because
1851 of the order in which clean iterates over values, we are guaranteed
1852 that altered operands will have caused us to be eliminated from the
1853 ANTIC_IN set already. */
1856 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1858 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1859 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1861 gimple_stmt_iterator gsi
;
1862 unsigned id
= get_expression_id (expr
);
1869 /* Lookup a previously calculated result. */
1870 if (EXPR_DIES (block
)
1871 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1872 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1874 /* A memory expression {e, VUSE} dies in the block if there is a
1875 statement that may clobber e. If, starting statement walk from the
1876 top of the basic block, a statement uses VUSE there can be no kill
1877 inbetween that use and the original statement that loaded {e, VUSE},
1878 so we can stop walking. */
1879 ref
.base
= NULL_TREE
;
1880 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1882 tree def_vuse
, def_vdef
;
1883 def
= gsi_stmt (gsi
);
1884 def_vuse
= gimple_vuse (def
);
1885 def_vdef
= gimple_vdef (def
);
1887 /* Not a memory statement. */
1891 /* Not a may-def. */
1894 /* A load with the same VUSE, we're done. */
1895 if (def_vuse
== vuse
)
1901 /* Init ref only if we really need it. */
1902 if (ref
.base
== NULL_TREE
1903 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1909 /* If the statement may clobber expr, it dies. */
1910 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1917 /* Remember the result. */
1918 if (!EXPR_DIES (block
))
1919 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1920 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1922 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1928 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1929 contains its value-id. */
1932 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1934 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1936 unsigned int value_id
= VN_INFO (op
)->value_id
;
1937 if (!(bitmap_set_contains_value (set1
, value_id
)
1938 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1944 /* Determine if the expression EXPR is valid in SET1 U SET2.
1945 ONLY SET2 CAN BE NULL.
1946 This means that we have a leader for each part of the expression
1947 (if it consists of values), or the expression is an SSA_NAME.
1948 For loads/calls, we also see if the vuse is killed in this block. */
1951 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
1957 return bitmap_find_leader (AVAIL_OUT (block
),
1958 get_expr_value_id (expr
)) != NULL
;
1962 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1963 for (i
= 0; i
< nary
->length
; i
++)
1964 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1971 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1972 vn_reference_op_t vro
;
1975 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1977 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1978 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1979 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1989 /* Clean the set of expressions that are no longer valid in SET1 or
1990 SET2. This means expressions that are made up of values we have no
1991 leaders for in SET1 or SET2. This version is used for partial
1992 anticipation, which means it is not valid in either ANTIC_IN or
1996 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
1998 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
2002 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2004 if (!valid_in_sets (set1
, set2
, expr
, block
))
2005 bitmap_remove_from_set (set1
, expr
);
2010 /* Clean the set of expressions that are no longer valid in SET. This
2011 means expressions that are made up of values we have no leaders for
2015 clean (bitmap_set_t set
, basic_block block
)
2017 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2021 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2023 if (!valid_in_sets (set
, NULL
, expr
, block
))
2024 bitmap_remove_from_set (set
, expr
);
2029 /* Clean the set of expressions that are no longer valid in SET because
2030 they are clobbered in BLOCK or because they trap and may not be executed. */
2033 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2038 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2040 pre_expr expr
= expression_for_id (i
);
2041 if (expr
->kind
== REFERENCE
)
2043 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2046 gimple def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2047 if (!gimple_nop_p (def_stmt
)
2048 && ((gimple_bb (def_stmt
) != block
2049 && !dominated_by_p (CDI_DOMINATORS
,
2050 block
, gimple_bb (def_stmt
)))
2051 || (gimple_bb (def_stmt
) == block
2052 && value_dies_in_block_x (expr
, block
))))
2053 bitmap_remove_from_set (set
, expr
);
2056 else if (expr
->kind
== NARY
)
2058 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2059 /* If the NARY may trap make sure the block does not contain
2060 a possible exit point.
2061 ??? This is overly conservative if we translate AVAIL_OUT
2062 as the available expression might be after the exit point. */
2063 if (BB_MAY_NOTRETURN (block
)
2064 && vn_nary_may_trap (nary
))
2065 bitmap_remove_from_set (set
, expr
);
2070 static sbitmap has_abnormal_preds
;
2072 /* List of blocks that may have changed during ANTIC computation and
2073 thus need to be iterated over. */
2075 static sbitmap changed_blocks
;
2077 /* Decide whether to defer a block for a later iteration, or PHI
2078 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2079 should defer the block, and true if we processed it. */
2082 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2083 basic_block block
, basic_block phiblock
)
2085 if (!BB_VISITED (phiblock
))
2087 bitmap_set_bit (changed_blocks
, block
->index
);
2088 BB_VISITED (block
) = 0;
2089 BB_DEFERRED (block
) = 1;
2093 phi_translate_set (dest
, source
, block
, phiblock
);
2097 /* Compute the ANTIC set for BLOCK.
2099 If succs(BLOCK) > 1 then
2100 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2101 else if succs(BLOCK) == 1 then
2102 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2104 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2108 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2110 bool changed
= false;
2111 bitmap_set_t S
, old
, ANTIC_OUT
;
2117 old
= ANTIC_OUT
= S
= NULL
;
2118 BB_VISITED (block
) = 1;
2120 /* If any edges from predecessors are abnormal, antic_in is empty,
2122 if (block_has_abnormal_pred_edge
)
2123 goto maybe_dump_sets
;
2125 old
= ANTIC_IN (block
);
2126 ANTIC_OUT
= bitmap_set_new ();
2128 /* If the block has no successors, ANTIC_OUT is empty. */
2129 if (EDGE_COUNT (block
->succs
) == 0)
2131 /* If we have one successor, we could have some phi nodes to
2132 translate through. */
2133 else if (single_succ_p (block
))
2135 basic_block succ_bb
= single_succ (block
);
2137 /* We trade iterations of the dataflow equations for having to
2138 phi translate the maximal set, which is incredibly slow
2139 (since the maximal set often has 300+ members, even when you
2140 have a small number of blocks).
2141 Basically, we defer the computation of ANTIC for this block
2142 until we have processed it's successor, which will inevitably
2143 have a *much* smaller set of values to phi translate once
2144 clean has been run on it.
2145 The cost of doing this is that we technically perform more
2146 iterations, however, they are lower cost iterations.
2148 Timings for PRE on tramp3d-v4:
2149 without maximal set fix: 11 seconds
2150 with maximal set fix/without deferring: 26 seconds
2151 with maximal set fix/with deferring: 11 seconds
2154 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2158 goto maybe_dump_sets
;
2161 /* If we have multiple successors, we take the intersection of all of
2162 them. Note that in the case of loop exit phi nodes, we may have
2163 phis to translate through. */
2166 vec
<basic_block
> worklist
;
2168 basic_block bprime
, first
= NULL
;
2170 worklist
.create (EDGE_COUNT (block
->succs
));
2171 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2174 && BB_VISITED (e
->dest
))
2176 else if (BB_VISITED (e
->dest
))
2177 worklist
.quick_push (e
->dest
);
2180 /* Of multiple successors we have to have visited one already. */
2183 bitmap_set_bit (changed_blocks
, block
->index
);
2184 BB_VISITED (block
) = 0;
2185 BB_DEFERRED (block
) = 1;
2187 worklist
.release ();
2188 goto maybe_dump_sets
;
2191 if (!gimple_seq_empty_p (phi_nodes (first
)))
2192 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2194 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2196 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2198 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2200 bitmap_set_t tmp
= bitmap_set_new ();
2201 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2202 bitmap_set_and (ANTIC_OUT
, tmp
);
2203 bitmap_set_free (tmp
);
2206 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2208 worklist
.release ();
2211 /* Prune expressions that are clobbered in block and thus become
2212 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2213 prune_clobbered_mems (ANTIC_OUT
, block
);
2215 /* Generate ANTIC_OUT - TMP_GEN. */
2216 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2218 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2219 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2222 /* Then union in the ANTIC_OUT - TMP_GEN values,
2223 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2224 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2225 bitmap_value_insert_into_set (ANTIC_IN (block
),
2226 expression_for_id (bii
));
2228 clean (ANTIC_IN (block
), block
);
2230 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2233 bitmap_set_bit (changed_blocks
, block
->index
);
2234 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2235 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2238 bitmap_clear_bit (changed_blocks
, block
->index
);
2241 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2243 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2246 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2248 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2252 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2257 "Block %d was deferred for a future iteration.\n",
2262 bitmap_set_free (old
);
2264 bitmap_set_free (S
);
2266 bitmap_set_free (ANTIC_OUT
);
2270 /* Compute PARTIAL_ANTIC for BLOCK.
2272 If succs(BLOCK) > 1 then
2273 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2274 in ANTIC_OUT for all succ(BLOCK)
2275 else if succs(BLOCK) == 1 then
2276 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2278 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2283 compute_partial_antic_aux (basic_block block
,
2284 bool block_has_abnormal_pred_edge
)
2286 bool changed
= false;
2287 bitmap_set_t old_PA_IN
;
2288 bitmap_set_t PA_OUT
;
2291 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2293 old_PA_IN
= PA_OUT
= NULL
;
2295 /* If any edges from predecessors are abnormal, antic_in is empty,
2297 if (block_has_abnormal_pred_edge
)
2298 goto maybe_dump_sets
;
2300 /* If there are too many partially anticipatable values in the
2301 block, phi_translate_set can take an exponential time: stop
2302 before the translation starts. */
2304 && single_succ_p (block
)
2305 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2306 goto maybe_dump_sets
;
2308 old_PA_IN
= PA_IN (block
);
2309 PA_OUT
= bitmap_set_new ();
2311 /* If the block has no successors, ANTIC_OUT is empty. */
2312 if (EDGE_COUNT (block
->succs
) == 0)
2314 /* If we have one successor, we could have some phi nodes to
2315 translate through. Note that we can't phi translate across DFS
2316 back edges in partial antic, because it uses a union operation on
2317 the successors. For recurrences like IV's, we will end up
2318 generating a new value in the set on each go around (i + 3 (VH.1)
2319 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2320 else if (single_succ_p (block
))
2322 basic_block succ
= single_succ (block
);
2323 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2324 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2326 /* If we have multiple successors, we take the union of all of
2330 vec
<basic_block
> worklist
;
2334 worklist
.create (EDGE_COUNT (block
->succs
));
2335 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2337 if (e
->flags
& EDGE_DFS_BACK
)
2339 worklist
.quick_push (e
->dest
);
2341 if (worklist
.length () > 0)
2343 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2348 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2349 bitmap_value_insert_into_set (PA_OUT
,
2350 expression_for_id (i
));
2351 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2353 bitmap_set_t pa_in
= bitmap_set_new ();
2354 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2355 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2356 bitmap_value_insert_into_set (PA_OUT
,
2357 expression_for_id (i
));
2358 bitmap_set_free (pa_in
);
2361 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2362 bitmap_value_insert_into_set (PA_OUT
,
2363 expression_for_id (i
));
2366 worklist
.release ();
2369 /* Prune expressions that are clobbered in block and thus become
2370 invalid if translated from PA_OUT to PA_IN. */
2371 prune_clobbered_mems (PA_OUT
, block
);
2373 /* PA_IN starts with PA_OUT - TMP_GEN.
2374 Then we subtract things from ANTIC_IN. */
2375 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2377 /* For partial antic, we want to put back in the phi results, since
2378 we will properly avoid making them partially antic over backedges. */
2379 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2380 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2382 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2383 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2385 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2387 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2390 bitmap_set_bit (changed_blocks
, block
->index
);
2391 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2392 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2395 bitmap_clear_bit (changed_blocks
, block
->index
);
2398 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2401 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2403 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2406 bitmap_set_free (old_PA_IN
);
2408 bitmap_set_free (PA_OUT
);
2412 /* Compute ANTIC and partial ANTIC sets. */
2415 compute_antic (void)
2417 bool changed
= true;
2418 int num_iterations
= 0;
2422 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2423 We pre-build the map of blocks with incoming abnormal edges here. */
2424 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2425 bitmap_clear (has_abnormal_preds
);
2432 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2434 e
->flags
&= ~EDGE_DFS_BACK
;
2435 if (e
->flags
& EDGE_ABNORMAL
)
2437 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2442 BB_VISITED (block
) = 0;
2443 BB_DEFERRED (block
) = 0;
2445 /* While we are here, give empty ANTIC_IN sets to each block. */
2446 ANTIC_IN (block
) = bitmap_set_new ();
2447 PA_IN (block
) = bitmap_set_new ();
2450 /* At the exit block we anticipate nothing. */
2451 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2453 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2454 bitmap_ones (changed_blocks
);
2457 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2458 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2459 /* ??? We need to clear our PHI translation cache here as the
2460 ANTIC sets shrink and we restrict valid translations to
2461 those having operands with leaders in ANTIC. Same below
2462 for PA ANTIC computation. */
2465 for (i
= postorder_num
- 1; i
>= 0; i
--)
2467 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2469 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2470 changed
|= compute_antic_aux (block
,
2471 bitmap_bit_p (has_abnormal_preds
,
2475 /* Theoretically possible, but *highly* unlikely. */
2476 gcc_checking_assert (num_iterations
< 500);
2479 statistics_histogram_event (cfun
, "compute_antic iterations",
2482 if (do_partial_partial
)
2484 bitmap_ones (changed_blocks
);
2485 mark_dfs_back_edges ();
2490 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2491 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2494 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2496 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2498 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2500 |= compute_partial_antic_aux (block
,
2501 bitmap_bit_p (has_abnormal_preds
,
2505 /* Theoretically possible, but *highly* unlikely. */
2506 gcc_checking_assert (num_iterations
< 500);
2508 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2511 sbitmap_free (has_abnormal_preds
);
2512 sbitmap_free (changed_blocks
);
2516 /* Inserted expressions are placed onto this worklist, which is used
2517 for performing quick dead code elimination of insertions we made
2518 that didn't turn out to be necessary. */
2519 static bitmap inserted_exprs
;
2521 /* The actual worker for create_component_ref_by_pieces. */
2524 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2525 unsigned int *operand
, gimple_seq
*stmts
)
2527 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2530 switch (currop
->opcode
)
2534 tree folded
, sc
= NULL_TREE
;
2535 unsigned int nargs
= 0;
2537 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2540 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2545 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2549 args
= XNEWVEC (tree
, ref
->operands
.length () - 1);
2550 while (*operand
< ref
->operands
.length ())
2552 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2558 folded
= build_call_array (currop
->type
,
2559 (TREE_CODE (fn
) == FUNCTION_DECL
2560 ? build_fold_addr_expr (fn
) : fn
),
2564 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2570 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2574 tree offset
= currop
->op0
;
2575 if (TREE_CODE (baseop
) == ADDR_EXPR
2576 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2580 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2583 offset
= int_const_binop (PLUS_EXPR
, offset
,
2584 build_int_cst (TREE_TYPE (offset
),
2586 baseop
= build_fold_addr_expr (base
);
2588 return fold_build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2591 case TARGET_MEM_REF
:
2593 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2594 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2595 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2601 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2607 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2611 return build5 (TARGET_MEM_REF
, currop
->type
,
2612 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2618 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2624 case VIEW_CONVERT_EXPR
:
2626 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2630 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2633 case WITH_SIZE_EXPR
:
2635 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2639 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2642 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2647 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2651 tree op1
= currop
->op0
;
2652 tree op2
= currop
->op1
;
2653 return fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2656 /* For array ref vn_reference_op's, operand 1 of the array ref
2657 is op0 of the reference op and operand 3 of the array ref is
2659 case ARRAY_RANGE_REF
:
2663 tree genop1
= currop
->op0
;
2664 tree genop2
= currop
->op1
;
2665 tree genop3
= currop
->op2
;
2666 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2670 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2675 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2676 /* Drop zero minimum index if redundant. */
2677 if (integer_zerop (genop2
)
2679 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2683 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2690 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2691 /* We can't always put a size in units of the element alignment
2692 here as the element alignment may be not visible. See
2693 PR43783. Simply drop the element size for constant
2695 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2699 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2700 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2701 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2706 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2713 tree genop2
= currop
->op1
;
2714 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2717 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2721 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2725 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2730 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2751 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2752 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2753 trying to rename aggregates into ssa form directly, which is a no no.
2755 Thus, this routine doesn't create temporaries, it just builds a
2756 single access expression for the array, calling
2757 find_or_generate_expression to build the innermost pieces.
2759 This function is a subroutine of create_expression_by_pieces, and
2760 should not be called on it's own unless you really know what you
2764 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2767 unsigned int op
= 0;
2768 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2771 /* Find a simple leader for an expression, or generate one using
2772 create_expression_by_pieces from a NARY expression for the value.
2773 BLOCK is the basic_block we are looking for leaders in.
2774 OP is the tree expression to find a leader for or generate.
2775 Returns the leader or NULL_TREE on failure. */
2778 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2780 pre_expr expr
= get_or_alloc_expr_for (op
);
2781 unsigned int lookfor
= get_expr_value_id (expr
);
2782 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2785 if (leader
->kind
== NAME
)
2786 return PRE_EXPR_NAME (leader
);
2787 else if (leader
->kind
== CONSTANT
)
2788 return PRE_EXPR_CONSTANT (leader
);
2794 /* It must be a complex expression, so generate it recursively. Note
2795 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2796 where the insert algorithm fails to insert a required expression. */
2797 bitmap exprset
= value_expressions
[lookfor
];
2800 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2802 pre_expr temp
= expression_for_id (i
);
2803 /* We cannot insert random REFERENCE expressions at arbitrary
2804 places. We can insert NARYs which eventually re-materializes
2805 its operand values. */
2806 if (temp
->kind
== NARY
)
2807 return create_expression_by_pieces (block
, temp
, stmts
,
2808 get_expr_type (expr
));
2815 #define NECESSARY GF_PLF_1
2817 /* Create an expression in pieces, so that we can handle very complex
2818 expressions that may be ANTIC, but not necessary GIMPLE.
2819 BLOCK is the basic block the expression will be inserted into,
2820 EXPR is the expression to insert (in value form)
2821 STMTS is a statement list to append the necessary insertions into.
2823 This function will die if we hit some value that shouldn't be
2824 ANTIC but is (IE there is no leader for it, or its components).
2825 The function returns NULL_TREE in case a different antic expression
2826 has to be inserted first.
2827 This function may also generate expressions that are themselves
2828 partially or fully redundant. Those that are will be either made
2829 fully redundant during the next iteration of insert (for partially
2830 redundant ones), or eliminated by eliminate (for fully redundant
2834 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2835 gimple_seq
*stmts
, tree type
)
2839 gimple_seq forced_stmts
= NULL
;
2840 unsigned int value_id
;
2841 gimple_stmt_iterator gsi
;
2842 tree exprtype
= type
? type
: get_expr_type (expr
);
2848 /* We may hit the NAME/CONSTANT case if we have to convert types
2849 that value numbering saw through. */
2851 folded
= PRE_EXPR_NAME (expr
);
2854 folded
= PRE_EXPR_CONSTANT (expr
);
2858 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2859 folded
= create_component_ref_by_pieces (block
, ref
, stmts
);
2866 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2867 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2869 for (i
= 0; i
< nary
->length
; ++i
)
2871 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2874 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2875 may have conversions stripped. */
2876 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2879 genop
[i
] = fold_convert (nary
->type
, genop
[i
]);
2881 genop
[i
] = convert_to_ptrofftype (genop
[i
]);
2884 genop
[i
] = fold_convert (TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2886 if (nary
->opcode
== CONSTRUCTOR
)
2888 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2889 for (i
= 0; i
< nary
->length
; ++i
)
2890 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2891 folded
= build_constructor (nary
->type
, elts
);
2895 switch (nary
->length
)
2898 folded
= fold_build1 (nary
->opcode
, nary
->type
,
2902 folded
= fold_build2 (nary
->opcode
, nary
->type
,
2903 genop
[0], genop
[1]);
2906 folded
= fold_build3 (nary
->opcode
, nary
->type
,
2907 genop
[0], genop
[1], genop
[2]);
2919 if (!useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2920 folded
= fold_convert (exprtype
, folded
);
2922 /* Force the generated expression to be a sequence of GIMPLE
2924 We have to call unshare_expr because force_gimple_operand may
2925 modify the tree we pass to it. */
2926 folded
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
2929 /* If we have any intermediate expressions to the value sets, add them
2930 to the value sets and chain them in the instruction stream. */
2933 gsi
= gsi_start (forced_stmts
);
2934 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2936 gimple stmt
= gsi_stmt (gsi
);
2937 tree forcedname
= gimple_get_lhs (stmt
);
2940 if (TREE_CODE (forcedname
) == SSA_NAME
)
2942 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2943 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2944 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2945 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2946 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2947 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2948 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2951 gimple_seq_add_seq (stmts
, forced_stmts
);
2954 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2955 newstmt
= gimple_build_assign (name
, folded
);
2956 gimple_set_plf (newstmt
, NECESSARY
, false);
2958 gimple_seq_add_stmt (stmts
, newstmt
);
2959 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (name
));
2961 /* Fold the last statement. */
2962 gsi
= gsi_last (*stmts
);
2963 if (fold_stmt_inplace (&gsi
))
2964 update_stmt (gsi_stmt (gsi
));
2966 /* Add a value number to the temporary.
2967 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2968 we are creating the expression by pieces, and this particular piece of
2969 the expression may have been represented. There is no harm in replacing
2971 value_id
= get_expr_value_id (expr
);
2972 VN_INFO_GET (name
)->value_id
= value_id
;
2973 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2974 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2975 VN_INFO (name
)->valnum
= name
;
2976 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2977 nameexpr
= get_or_alloc_expr_for_name (name
);
2978 add_to_value (value_id
, nameexpr
);
2979 if (NEW_SETS (block
))
2980 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2981 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2983 pre_stats
.insertions
++;
2984 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2986 fprintf (dump_file
, "Inserted ");
2987 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
2988 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2989 block
->index
, value_id
);
2996 /* Returns true if we want to inhibit the insertions of PHI nodes
2997 for the given EXPR for basic block BB (a member of a loop).
2998 We want to do this, when we fear that the induction variable we
2999 create might inhibit vectorization. */
3002 inhibit_phi_insertion (basic_block bb
, pre_expr expr
)
3004 vn_reference_t vr
= PRE_EXPR_REFERENCE (expr
);
3005 vec
<vn_reference_op_s
> ops
= vr
->operands
;
3006 vn_reference_op_t op
;
3009 /* If we aren't going to vectorize we don't inhibit anything. */
3010 if (!flag_tree_loop_vectorize
)
3013 /* Otherwise we inhibit the insertion when the address of the
3014 memory reference is a simple induction variable. In other
3015 cases the vectorizer won't do anything anyway (either it's
3016 loop invariant or a complicated expression). */
3017 FOR_EACH_VEC_ELT (ops
, i
, op
)
3022 /* Calls are not a problem. */
3026 case ARRAY_RANGE_REF
:
3027 if (TREE_CODE (op
->op0
) != SSA_NAME
)
3032 basic_block defbb
= gimple_bb (SSA_NAME_DEF_STMT (op
->op0
));
3034 /* Default defs are loop invariant. */
3037 /* Defined outside this loop, also loop invariant. */
3038 if (!flow_bb_inside_loop_p (bb
->loop_father
, defbb
))
3040 /* If it's a simple induction variable inhibit insertion,
3041 the vectorizer might be interested in this one. */
3042 if (simple_iv (bb
->loop_father
, bb
->loop_father
,
3043 op
->op0
, &iv
, true))
3045 /* No simple IV, vectorizer can't do anything, hence no
3046 reason to inhibit the transformation for this operand. */
3056 /* Insert the to-be-made-available values of expression EXPRNUM for each
3057 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3058 merge the result with a phi node, given the same value number as
3059 NODE. Return true if we have inserted new stuff. */
3062 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3063 vec
<pre_expr
> avail
)
3065 pre_expr expr
= expression_for_id (exprnum
);
3067 unsigned int val
= get_expr_value_id (expr
);
3069 bool insertions
= false;
3074 tree type
= get_expr_type (expr
);
3078 /* Make sure we aren't creating an induction variable. */
3079 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
3081 bool firstinsideloop
= false;
3082 bool secondinsideloop
= false;
3083 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3084 EDGE_PRED (block
, 0)->src
);
3085 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3086 EDGE_PRED (block
, 1)->src
);
3087 /* Induction variables only have one edge inside the loop. */
3088 if ((firstinsideloop
^ secondinsideloop
)
3089 && (expr
->kind
!= REFERENCE
3090 || inhibit_phi_insertion (block
, expr
)))
3092 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3093 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3098 /* Make the necessary insertions. */
3099 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3101 gimple_seq stmts
= NULL
;
3104 eprime
= avail
[pred
->dest_idx
];
3106 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3108 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
3110 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3111 gsi_insert_seq_on_edge (pred
, stmts
);
3114 /* We cannot insert a PHI node if we failed to insert
3119 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3122 else if (eprime
->kind
== CONSTANT
)
3124 /* Constants may not have the right type, fold_convert
3125 should give us back a constant with the right type. */
3126 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3127 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3129 tree builtexpr
= fold_convert (type
, constant
);
3130 if (!is_gimple_min_invariant (builtexpr
))
3132 tree forcedexpr
= force_gimple_operand (builtexpr
,
3135 if (!is_gimple_min_invariant (forcedexpr
))
3137 if (forcedexpr
!= builtexpr
)
3139 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3140 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3144 gimple_stmt_iterator gsi
;
3145 gsi
= gsi_start (stmts
);
3146 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3148 gimple stmt
= gsi_stmt (gsi
);
3149 tree lhs
= gimple_get_lhs (stmt
);
3150 if (TREE_CODE (lhs
) == SSA_NAME
)
3151 bitmap_set_bit (inserted_exprs
,
3152 SSA_NAME_VERSION (lhs
));
3153 gimple_set_plf (stmt
, NECESSARY
, false);
3155 gsi_insert_seq_on_edge (pred
, stmts
);
3157 avail
[pred
->dest_idx
]
3158 = get_or_alloc_expr_for_name (forcedexpr
);
3162 avail
[pred
->dest_idx
]
3163 = get_or_alloc_expr_for_constant (builtexpr
);
3166 else if (eprime
->kind
== NAME
)
3168 /* We may have to do a conversion because our value
3169 numbering can look through types in certain cases, but
3170 our IL requires all operands of a phi node have the same
3172 tree name
= PRE_EXPR_NAME (eprime
);
3173 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3177 builtexpr
= fold_convert (type
, name
);
3178 forcedexpr
= force_gimple_operand (builtexpr
,
3182 if (forcedexpr
!= name
)
3184 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3185 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3190 gimple_stmt_iterator gsi
;
3191 gsi
= gsi_start (stmts
);
3192 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3194 gimple stmt
= gsi_stmt (gsi
);
3195 tree lhs
= gimple_get_lhs (stmt
);
3196 if (TREE_CODE (lhs
) == SSA_NAME
)
3197 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
3198 gimple_set_plf (stmt
, NECESSARY
, false);
3200 gsi_insert_seq_on_edge (pred
, stmts
);
3202 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (forcedexpr
);
3206 /* If we didn't want a phi node, and we made insertions, we still have
3207 inserted new stuff, and thus return true. If we didn't want a phi node,
3208 and didn't make insertions, we haven't added anything new, so return
3210 if (nophi
&& insertions
)
3212 else if (nophi
&& !insertions
)
3215 /* Now build a phi for the new variable. */
3216 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3217 phi
= create_phi_node (temp
, block
);
3219 gimple_set_plf (phi
, NECESSARY
, false);
3220 VN_INFO_GET (temp
)->value_id
= val
;
3221 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3222 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3223 VN_INFO (temp
)->valnum
= temp
;
3224 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3225 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3227 pre_expr ae
= avail
[pred
->dest_idx
];
3228 gcc_assert (get_expr_type (ae
) == type
3229 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3230 if (ae
->kind
== CONSTANT
)
3231 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3232 pred
, UNKNOWN_LOCATION
);
3234 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3237 newphi
= get_or_alloc_expr_for_name (temp
);
3238 add_to_value (val
, newphi
);
3240 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3241 this insertion, since we test for the existence of this value in PHI_GEN
3242 before proceeding with the partial redundancy checks in insert_aux.
3244 The value may exist in AVAIL_OUT, in particular, it could be represented
3245 by the expression we are trying to eliminate, in which case we want the
3246 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3249 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3250 this block, because if it did, it would have existed in our dominator's
3251 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3254 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3255 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3257 bitmap_insert_into_set (NEW_SETS (block
),
3260 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3262 fprintf (dump_file
, "Created phi ");
3263 print_gimple_stmt (dump_file
, phi
, 0, 0);
3264 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3272 /* Perform insertion of partially redundant values.
3273 For BLOCK, do the following:
3274 1. Propagate the NEW_SETS of the dominator into the current block.
3275 If the block has multiple predecessors,
3276 2a. Iterate over the ANTIC expressions for the block to see if
3277 any of them are partially redundant.
3278 2b. If so, insert them into the necessary predecessors to make
3279 the expression fully redundant.
3280 2c. Insert a new PHI merging the values of the predecessors.
3281 2d. Insert the new PHI, and the new expressions, into the
3283 3. Recursively call ourselves on the dominator children of BLOCK.
3285 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3286 do_regular_insertion and do_partial_insertion.
3291 do_regular_insertion (basic_block block
, basic_block dom
)
3293 bool new_stuff
= false;
3294 vec
<pre_expr
> exprs
;
3296 vec
<pre_expr
> avail
= vNULL
;
3299 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3300 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3302 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3304 if (expr
->kind
== NARY
3305 || expr
->kind
== REFERENCE
)
3308 bool by_some
= false;
3309 bool cant_insert
= false;
3310 bool all_same
= true;
3311 pre_expr first_s
= NULL
;
3314 pre_expr eprime
= NULL
;
3316 pre_expr edoubleprime
= NULL
;
3317 bool do_insertion
= false;
3319 val
= get_expr_value_id (expr
);
3320 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3322 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3324 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3326 fprintf (dump_file
, "Found fully redundant value: ");
3327 print_pre_expr (dump_file
, expr
);
3328 fprintf (dump_file
, "\n");
3333 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3335 unsigned int vprime
;
3337 /* We should never run insertion for the exit block
3338 and so not come across fake pred edges. */
3339 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3341 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3344 /* eprime will generally only be NULL if the
3345 value of the expression, translated
3346 through the PHI for this predecessor, is
3347 undefined. If that is the case, we can't
3348 make the expression fully redundant,
3349 because its value is undefined along a
3350 predecessor path. We can thus break out
3351 early because it doesn't matter what the
3352 rest of the results are. */
3355 avail
[pred
->dest_idx
] = NULL
;
3360 eprime
= fully_constant_expression (eprime
);
3361 vprime
= get_expr_value_id (eprime
);
3362 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3364 if (edoubleprime
== NULL
)
3366 avail
[pred
->dest_idx
] = eprime
;
3371 avail
[pred
->dest_idx
] = edoubleprime
;
3373 /* We want to perform insertions to remove a redundancy on
3374 a path in the CFG we want to optimize for speed. */
3375 if (optimize_edge_for_speed_p (pred
))
3376 do_insertion
= true;
3377 if (first_s
== NULL
)
3378 first_s
= edoubleprime
;
3379 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3383 /* If we can insert it, it's not the same value
3384 already existing along every predecessor, and
3385 it's defined by some predecessor, it is
3386 partially redundant. */
3387 if (!cant_insert
&& !all_same
&& by_some
)
3391 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3393 fprintf (dump_file
, "Skipping partial redundancy for "
3395 print_pre_expr (dump_file
, expr
);
3396 fprintf (dump_file
, " (%04d), no redundancy on to be "
3397 "optimized for speed edge\n", val
);
3400 else if (dbg_cnt (treepre_insert
))
3402 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3404 fprintf (dump_file
, "Found partial redundancy for "
3406 print_pre_expr (dump_file
, expr
);
3407 fprintf (dump_file
, " (%04d)\n",
3408 get_expr_value_id (expr
));
3410 if (insert_into_preds_of_block (block
,
3411 get_expression_id (expr
),
3416 /* If all edges produce the same value and that value is
3417 an invariant, then the PHI has the same value on all
3418 edges. Note this. */
3419 else if (!cant_insert
&& all_same
)
3421 gcc_assert (edoubleprime
->kind
== CONSTANT
3422 || edoubleprime
->kind
== NAME
);
3424 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3426 gimple assign
= gimple_build_assign (temp
,
3427 edoubleprime
->kind
== CONSTANT
? PRE_EXPR_CONSTANT (edoubleprime
) : PRE_EXPR_NAME (edoubleprime
));
3428 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3429 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3431 gimple_set_plf (assign
, NECESSARY
, false);
3432 VN_INFO_GET (temp
)->value_id
= val
;
3433 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3434 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3435 VN_INFO (temp
)->valnum
= temp
;
3436 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3437 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3438 add_to_value (val
, newe
);
3439 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3440 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3451 /* Perform insertion for partially anticipatable expressions. There
3452 is only one case we will perform insertion for these. This case is
3453 if the expression is partially anticipatable, and fully available.
3454 In this case, we know that putting it earlier will enable us to
3455 remove the later computation. */
3459 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3461 bool new_stuff
= false;
3462 vec
<pre_expr
> exprs
;
3464 vec
<pre_expr
> avail
= vNULL
;
3467 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3468 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3470 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3472 if (expr
->kind
== NARY
3473 || expr
->kind
== REFERENCE
)
3477 bool cant_insert
= false;
3480 pre_expr eprime
= NULL
;
3483 val
= get_expr_value_id (expr
);
3484 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3486 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3489 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3491 unsigned int vprime
;
3492 pre_expr edoubleprime
;
3494 /* We should never run insertion for the exit block
3495 and so not come across fake pred edges. */
3496 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3498 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3502 /* eprime will generally only be NULL if the
3503 value of the expression, translated
3504 through the PHI for this predecessor, is
3505 undefined. If that is the case, we can't
3506 make the expression fully redundant,
3507 because its value is undefined along a
3508 predecessor path. We can thus break out
3509 early because it doesn't matter what the
3510 rest of the results are. */
3513 avail
[pred
->dest_idx
] = NULL
;
3518 eprime
= fully_constant_expression (eprime
);
3519 vprime
= get_expr_value_id (eprime
);
3520 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3521 avail
[pred
->dest_idx
] = edoubleprime
;
3522 if (edoubleprime
== NULL
)
3529 /* If we can insert it, it's not the same value
3530 already existing along every predecessor, and
3531 it's defined by some predecessor, it is
3532 partially redundant. */
3533 if (!cant_insert
&& by_all
)
3536 bool do_insertion
= false;
3538 /* Insert only if we can remove a later expression on a path
3539 that we want to optimize for speed.
3540 The phi node that we will be inserting in BLOCK is not free,
3541 and inserting it for the sake of !optimize_for_speed successor
3542 may cause regressions on the speed path. */
3543 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3545 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3546 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3548 if (optimize_edge_for_speed_p (succ
))
3549 do_insertion
= true;
3555 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3557 fprintf (dump_file
, "Skipping partial partial redundancy "
3559 print_pre_expr (dump_file
, expr
);
3560 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3561 "on any to be optimized for speed edges\n", val
);
3564 else if (dbg_cnt (treepre_insert
))
3566 pre_stats
.pa_insert
++;
3567 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3569 fprintf (dump_file
, "Found partial partial redundancy "
3571 print_pre_expr (dump_file
, expr
);
3572 fprintf (dump_file
, " (%04d)\n",
3573 get_expr_value_id (expr
));
3575 if (insert_into_preds_of_block (block
,
3576 get_expression_id (expr
),
3590 insert_aux (basic_block block
)
3593 bool new_stuff
= false;
3598 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3603 bitmap_set_t newset
= NEW_SETS (dom
);
3606 /* Note that we need to value_replace both NEW_SETS, and
3607 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3608 represented by some non-simple expression here that we want
3609 to replace it with. */
3610 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3612 pre_expr expr
= expression_for_id (i
);
3613 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3614 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3617 if (!single_pred_p (block
))
3619 new_stuff
|= do_regular_insertion (block
, dom
);
3620 if (do_partial_partial
)
3621 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3625 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3627 son
= next_dom_son (CDI_DOMINATORS
, son
))
3629 new_stuff
|= insert_aux (son
);
3635 /* Perform insertion of partially redundant values. */
3640 bool new_stuff
= true;
3642 int num_iterations
= 0;
3645 NEW_SETS (bb
) = bitmap_set_new ();
3650 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3651 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3652 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3654 /* Clear the NEW sets before the next iteration. We have already
3655 fully propagated its contents. */
3658 bitmap_set_free (NEW_SETS (bb
));
3660 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3664 /* Compute the AVAIL set for all basic blocks.
3666 This function performs value numbering of the statements in each basic
3667 block. The AVAIL sets are built from information we glean while doing
3668 this value numbering, since the AVAIL sets contain only one entry per
3671 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3672 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3675 compute_avail (void)
3678 basic_block block
, son
;
3679 basic_block
*worklist
;
3683 /* We pretend that default definitions are defined in the entry block.
3684 This includes function arguments and the static chain decl. */
3685 for (i
= 1; i
< num_ssa_names
; ++i
)
3687 tree name
= ssa_name (i
);
3690 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3691 || has_zero_uses (name
)
3692 || virtual_operand_p (name
))
3695 e
= get_or_alloc_expr_for_name (name
);
3696 add_to_value (get_expr_value_id (e
), e
);
3697 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3698 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3701 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3703 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR
),
3704 "tmp_gen", ENTRY_BLOCK
);
3705 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR
),
3706 "avail_out", ENTRY_BLOCK
);
3709 /* Allocate the worklist. */
3710 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3712 /* Seed the algorithm by putting the dominator children of the entry
3713 block on the worklist. */
3714 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3716 son
= next_dom_son (CDI_DOMINATORS
, son
))
3717 worklist
[sp
++] = son
;
3719 /* Loop until the worklist is empty. */
3722 gimple_stmt_iterator gsi
;
3726 /* Pick a block from the worklist. */
3727 block
= worklist
[--sp
];
3729 /* Initially, the set of available values in BLOCK is that of
3730 its immediate dominator. */
3731 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3733 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3735 /* Generate values for PHI nodes. */
3736 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3738 tree result
= gimple_phi_result (gsi_stmt (gsi
));
3740 /* We have no need for virtual phis, as they don't represent
3741 actual computations. */
3742 if (virtual_operand_p (result
))
3745 pre_expr e
= get_or_alloc_expr_for_name (result
);
3746 add_to_value (get_expr_value_id (e
), e
);
3747 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3748 bitmap_insert_into_set (PHI_GEN (block
), e
);
3751 BB_MAY_NOTRETURN (block
) = 0;
3753 /* Now compute value numbers and populate value sets with all
3754 the expressions computed in BLOCK. */
3755 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3760 stmt
= gsi_stmt (gsi
);
3762 /* Cache whether the basic-block has any non-visible side-effect
3764 If this isn't a call or it is the last stmt in the
3765 basic-block then the CFG represents things correctly. */
3766 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3768 /* Non-looping const functions always return normally.
3769 Otherwise the call might not return or have side-effects
3770 that forbids hoisting possibly trapping expressions
3772 int flags
= gimple_call_flags (stmt
);
3773 if (!(flags
& ECF_CONST
)
3774 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3775 BB_MAY_NOTRETURN (block
) = 1;
3778 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3780 pre_expr e
= get_or_alloc_expr_for_name (op
);
3782 add_to_value (get_expr_value_id (e
), e
);
3783 bitmap_insert_into_set (TMP_GEN (block
), e
);
3784 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3787 if (gimple_has_side_effects (stmt
)
3788 || stmt_could_throw_p (stmt
)
3789 || is_gimple_debug (stmt
))
3792 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3794 if (ssa_undefined_value_p (op
))
3796 pre_expr e
= get_or_alloc_expr_for_name (op
);
3797 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3800 switch (gimple_code (stmt
))
3808 pre_expr result
= NULL
;
3809 vec
<vn_reference_op_s
> ops
= vNULL
;
3811 /* We can value number only calls to real functions. */
3812 if (gimple_call_internal_p (stmt
))
3815 copy_reference_ops_from_call (stmt
, &ops
);
3816 vn_reference_lookup_pieces (gimple_vuse (stmt
), 0,
3817 gimple_expr_type (stmt
),
3818 ops
, &ref
, VN_NOWALK
);
3823 /* If the value of the call is not invalidated in
3824 this block until it is computed, add the expression
3826 if (!gimple_vuse (stmt
)
3828 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3829 || gimple_bb (SSA_NAME_DEF_STMT
3830 (gimple_vuse (stmt
))) != block
)
3832 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3833 result
->kind
= REFERENCE
;
3835 PRE_EXPR_REFERENCE (result
) = ref
;
3837 get_or_alloc_expression_id (result
);
3838 add_to_value (get_expr_value_id (result
), result
);
3839 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3846 pre_expr result
= NULL
;
3847 switch (vn_get_stmt_kind (stmt
))
3851 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3854 /* COND_EXPR and VEC_COND_EXPR are awkward in
3855 that they contain an embedded complex expression.
3856 Don't even try to shove those through PRE. */
3857 if (code
== COND_EXPR
3858 || code
== VEC_COND_EXPR
)
3861 vn_nary_op_lookup_stmt (stmt
, &nary
);
3865 /* If the NARY traps and there was a preceding
3866 point in the block that might not return avoid
3867 adding the nary to EXP_GEN. */
3868 if (BB_MAY_NOTRETURN (block
)
3869 && vn_nary_may_trap (nary
))
3872 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3873 result
->kind
= NARY
;
3875 PRE_EXPR_NARY (result
) = nary
;
3882 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
3888 /* If the value of the reference is not invalidated in
3889 this block until it is computed, add the expression
3891 if (gimple_vuse (stmt
))
3895 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3896 while (!gimple_nop_p (def_stmt
)
3897 && gimple_code (def_stmt
) != GIMPLE_PHI
3898 && gimple_bb (def_stmt
) == block
)
3900 if (stmt_may_clobber_ref_p
3901 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3907 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3913 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3914 result
->kind
= REFERENCE
;
3916 PRE_EXPR_REFERENCE (result
) = ref
;
3924 get_or_alloc_expression_id (result
);
3925 add_to_value (get_expr_value_id (result
), result
);
3926 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3934 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3936 print_bitmap_set (dump_file
, EXP_GEN (block
),
3937 "exp_gen", block
->index
);
3938 print_bitmap_set (dump_file
, PHI_GEN (block
),
3939 "phi_gen", block
->index
);
3940 print_bitmap_set (dump_file
, TMP_GEN (block
),
3941 "tmp_gen", block
->index
);
3942 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
3943 "avail_out", block
->index
);
3946 /* Put the dominator children of BLOCK on the worklist of blocks
3947 to compute available sets for. */
3948 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3950 son
= next_dom_son (CDI_DOMINATORS
, son
))
3951 worklist
[sp
++] = son
;
3958 /* Local state for the eliminate domwalk. */
3959 static vec
<gimple
> el_to_remove
;
3960 static vec
<gimple
> el_to_update
;
3961 static unsigned int el_todo
;
3962 static vec
<tree
> el_avail
;
3963 static vec
<tree
> el_avail_stack
;
3965 /* Return a leader for OP that is available at the current point of the
3966 eliminate domwalk. */
3969 eliminate_avail (tree op
)
3971 tree valnum
= VN_INFO (op
)->valnum
;
3972 if (TREE_CODE (valnum
) == SSA_NAME
)
3974 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
3976 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
3977 return el_avail
[SSA_NAME_VERSION (valnum
)];
3979 else if (is_gimple_min_invariant (valnum
))
3984 /* At the current point of the eliminate domwalk make OP available. */
3987 eliminate_push_avail (tree op
)
3989 tree valnum
= VN_INFO (op
)->valnum
;
3990 if (TREE_CODE (valnum
) == SSA_NAME
)
3992 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
3993 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
3994 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
3995 el_avail_stack
.safe_push (op
);
3999 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
4000 the leader for the expression if insertion was successful. */
4003 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
4005 tree expr
= vn_get_expr_for (val
);
4006 if (!CONVERT_EXPR_P (expr
)
4007 && TREE_CODE (expr
) != VIEW_CONVERT_EXPR
)
4010 tree op
= TREE_OPERAND (expr
, 0);
4011 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
4015 tree res
= make_temp_ssa_name (TREE_TYPE (val
), NULL
, "pretmp");
4016 gimple tem
= gimple_build_assign (res
,
4017 fold_build1 (TREE_CODE (expr
),
4018 TREE_TYPE (expr
), leader
));
4019 gsi_insert_before (gsi
, tem
, GSI_SAME_STMT
);
4020 VN_INFO_GET (res
)->valnum
= val
;
4022 if (TREE_CODE (leader
) == SSA_NAME
)
4023 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
4025 pre_stats
.insertions
++;
4026 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4028 fprintf (dump_file
, "Inserted ");
4029 print_gimple_stmt (dump_file
, tem
, 0, 0);
4035 class eliminate_dom_walker
: public dom_walker
4038 eliminate_dom_walker (cdi_direction direction
) : dom_walker (direction
) {}
4040 virtual void before_dom_children (basic_block
);
4041 virtual void after_dom_children (basic_block
);
4044 /* Perform elimination for the basic-block B during the domwalk. */
4047 eliminate_dom_walker::before_dom_children (basic_block b
)
4049 gimple_stmt_iterator gsi
;
4053 el_avail_stack
.safe_push (NULL_TREE
);
4055 for (gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4057 gimple stmt
, phi
= gsi_stmt (gsi
);
4058 tree sprime
= NULL_TREE
, res
= PHI_RESULT (phi
);
4059 gimple_stmt_iterator gsi2
;
4061 /* We want to perform redundant PHI elimination. Do so by
4062 replacing the PHI with a single copy if possible.
4063 Do not touch inserted, single-argument or virtual PHIs. */
4064 if (gimple_phi_num_args (phi
) == 1
4065 || virtual_operand_p (res
))
4071 sprime
= eliminate_avail (res
);
4075 eliminate_push_avail (res
);
4079 else if (is_gimple_min_invariant (sprime
))
4081 if (!useless_type_conversion_p (TREE_TYPE (res
),
4082 TREE_TYPE (sprime
)))
4083 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4086 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4088 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4089 print_generic_expr (dump_file
, res
, 0);
4090 fprintf (dump_file
, " with ");
4091 print_generic_expr (dump_file
, sprime
, 0);
4092 fprintf (dump_file
, "\n");
4095 remove_phi_node (&gsi
, false);
4098 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4099 && TREE_CODE (sprime
) == SSA_NAME
)
4100 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4102 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4103 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4104 stmt
= gimple_build_assign (res
, sprime
);
4105 SSA_NAME_DEF_STMT (res
) = stmt
;
4106 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4108 gsi2
= gsi_after_labels (b
);
4109 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4110 /* Queue the copy for eventual removal. */
4111 el_to_remove
.safe_push (stmt
);
4112 /* If we inserted this PHI node ourself, it's not an elimination. */
4114 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4117 pre_stats
.eliminations
++;
4120 for (gsi
= gsi_start_bb (b
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4122 tree lhs
= NULL_TREE
;
4123 tree rhs
= NULL_TREE
;
4125 stmt
= gsi_stmt (gsi
);
4127 if (gimple_has_lhs (stmt
))
4128 lhs
= gimple_get_lhs (stmt
);
4130 if (gimple_assign_single_p (stmt
))
4131 rhs
= gimple_assign_rhs1 (stmt
);
4133 /* Lookup the RHS of the expression, see if we have an
4134 available computation for it. If so, replace the RHS with
4135 the available computation. */
4136 if (gimple_has_lhs (stmt
)
4137 && TREE_CODE (lhs
) == SSA_NAME
4138 && !gimple_has_volatile_ops (stmt
))
4141 gimple orig_stmt
= stmt
;
4143 sprime
= eliminate_avail (lhs
);
4144 /* If there is no usable leader mark lhs as leader for its value. */
4146 eliminate_push_avail (lhs
);
4148 /* See PR43491. Do not replace a global register variable when
4149 it is a the RHS of an assignment. Do replace local register
4150 variables since gcc does not guarantee a local variable will
4151 be allocated in register.
4152 Do not perform copy propagation or undo constant propagation. */
4153 if (gimple_assign_single_p (stmt
)
4154 && (TREE_CODE (rhs
) == SSA_NAME
4155 || is_gimple_min_invariant (rhs
)
4156 || (TREE_CODE (rhs
) == VAR_DECL
4157 && is_global_var (rhs
)
4158 && DECL_HARD_REGISTER (rhs
))))
4163 /* If there is no existing usable leader but SCCVN thinks
4164 it has an expression it wants to use as replacement,
4166 tree val
= VN_INFO (lhs
)->valnum
;
4168 && TREE_CODE (val
) == SSA_NAME
4169 && VN_INFO (val
)->needs_insertion
4170 && VN_INFO (val
)->expr
!= NULL_TREE
4171 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4172 eliminate_push_avail (sprime
);
4174 else if (is_gimple_min_invariant (sprime
))
4176 /* If there is no existing leader but SCCVN knows this
4177 value is constant, use that constant. */
4178 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4179 TREE_TYPE (sprime
)))
4180 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4182 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4184 fprintf (dump_file
, "Replaced ");
4185 print_gimple_expr (dump_file
, stmt
, 0, 0);
4186 fprintf (dump_file
, " with ");
4187 print_generic_expr (dump_file
, sprime
, 0);
4188 fprintf (dump_file
, " in ");
4189 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4191 pre_stats
.eliminations
++;
4192 propagate_tree_value_into_stmt (&gsi
, sprime
);
4193 stmt
= gsi_stmt (gsi
);
4196 /* If we removed EH side-effects from the statement, clean
4197 its EH information. */
4198 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4200 bitmap_set_bit (need_eh_cleanup
,
4201 gimple_bb (stmt
)->index
);
4202 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4203 fprintf (dump_file
, " Removed EH side-effects.\n");
4210 && (rhs
== NULL_TREE
4211 || TREE_CODE (rhs
) != SSA_NAME
4212 || may_propagate_copy (rhs
, sprime
)))
4214 bool can_make_abnormal_goto
4215 = is_gimple_call (stmt
)
4216 && stmt_can_make_abnormal_goto (stmt
);
4218 gcc_assert (sprime
!= rhs
);
4220 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4222 fprintf (dump_file
, "Replaced ");
4223 print_gimple_expr (dump_file
, stmt
, 0, 0);
4224 fprintf (dump_file
, " with ");
4225 print_generic_expr (dump_file
, sprime
, 0);
4226 fprintf (dump_file
, " in ");
4227 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4230 if (TREE_CODE (sprime
) == SSA_NAME
)
4231 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4233 /* We need to make sure the new and old types actually match,
4234 which may require adding a simple cast, which fold_convert
4236 if ((!rhs
|| TREE_CODE (rhs
) != SSA_NAME
)
4237 && !useless_type_conversion_p (gimple_expr_type (stmt
),
4238 TREE_TYPE (sprime
)))
4239 sprime
= fold_convert (gimple_expr_type (stmt
), sprime
);
4241 pre_stats
.eliminations
++;
4242 propagate_tree_value_into_stmt (&gsi
, sprime
);
4243 stmt
= gsi_stmt (gsi
);
4246 /* If we removed EH side-effects from the statement, clean
4247 its EH information. */
4248 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4250 bitmap_set_bit (need_eh_cleanup
,
4251 gimple_bb (stmt
)->index
);
4252 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4253 fprintf (dump_file
, " Removed EH side-effects.\n");
4256 /* Likewise for AB side-effects. */
4257 if (can_make_abnormal_goto
4258 && !stmt_can_make_abnormal_goto (stmt
))
4260 bitmap_set_bit (need_ab_cleanup
,
4261 gimple_bb (stmt
)->index
);
4262 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4263 fprintf (dump_file
, " Removed AB side-effects.\n");
4267 /* If the statement is a scalar store, see if the expression
4268 has the same value number as its rhs. If so, the store is
4270 else if (gimple_assign_single_p (stmt
)
4271 && !gimple_has_volatile_ops (stmt
)
4272 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4273 && (TREE_CODE (rhs
) == SSA_NAME
4274 || is_gimple_min_invariant (rhs
)))
4277 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4278 gimple_vuse (stmt
), VN_WALK
, NULL
);
4279 if (TREE_CODE (rhs
) == SSA_NAME
)
4280 rhs
= VN_INFO (rhs
)->valnum
;
4282 && operand_equal_p (val
, rhs
, 0))
4284 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4286 fprintf (dump_file
, "Deleted redundant store ");
4287 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4290 /* Queue stmt for removal. */
4291 el_to_remove
.safe_push (stmt
);
4294 /* Visit COND_EXPRs and fold the comparison with the
4295 available value-numbers. */
4296 else if (gimple_code (stmt
) == GIMPLE_COND
)
4298 tree op0
= gimple_cond_lhs (stmt
);
4299 tree op1
= gimple_cond_rhs (stmt
);
4302 if (TREE_CODE (op0
) == SSA_NAME
)
4303 op0
= VN_INFO (op0
)->valnum
;
4304 if (TREE_CODE (op1
) == SSA_NAME
)
4305 op1
= VN_INFO (op1
)->valnum
;
4306 result
= fold_binary (gimple_cond_code (stmt
), boolean_type_node
,
4308 if (result
&& TREE_CODE (result
) == INTEGER_CST
)
4310 if (integer_zerop (result
))
4311 gimple_cond_make_false (stmt
);
4313 gimple_cond_make_true (stmt
);
4315 el_todo
= TODO_cleanup_cfg
;
4318 /* Visit indirect calls and turn them into direct calls if
4320 if (is_gimple_call (stmt
))
4322 tree orig_fn
= gimple_call_fn (stmt
);
4326 if (TREE_CODE (orig_fn
) == SSA_NAME
)
4327 fn
= VN_INFO (orig_fn
)->valnum
;
4328 else if (TREE_CODE (orig_fn
) == OBJ_TYPE_REF
4329 && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn
)) == SSA_NAME
)
4331 fn
= VN_INFO (OBJ_TYPE_REF_EXPR (orig_fn
))->valnum
;
4332 if (!gimple_call_addr_fndecl (fn
))
4334 fn
= ipa_intraprocedural_devirtualization (stmt
);
4336 fn
= build_fold_addr_expr (fn
);
4341 if (gimple_call_addr_fndecl (fn
) != NULL_TREE
4342 && useless_type_conversion_p (TREE_TYPE (orig_fn
),
4345 bool can_make_abnormal_goto
4346 = stmt_can_make_abnormal_goto (stmt
);
4347 bool was_noreturn
= gimple_call_noreturn_p (stmt
);
4349 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4351 fprintf (dump_file
, "Replacing call target with ");
4352 print_generic_expr (dump_file
, fn
, 0);
4353 fprintf (dump_file
, " in ");
4354 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4357 gimple_call_set_fn (stmt
, fn
);
4358 el_to_update
.safe_push (stmt
);
4360 /* When changing a call into a noreturn call, cfg cleanup
4361 is needed to fix up the noreturn call. */
4362 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4363 el_todo
|= TODO_cleanup_cfg
;
4365 /* If we removed EH side-effects from the statement, clean
4366 its EH information. */
4367 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
4369 bitmap_set_bit (need_eh_cleanup
,
4370 gimple_bb (stmt
)->index
);
4371 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4372 fprintf (dump_file
, " Removed EH side-effects.\n");
4375 /* Likewise for AB side-effects. */
4376 if (can_make_abnormal_goto
4377 && !stmt_can_make_abnormal_goto (stmt
))
4379 bitmap_set_bit (need_ab_cleanup
,
4380 gimple_bb (stmt
)->index
);
4381 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4382 fprintf (dump_file
, " Removed AB side-effects.\n");
4385 /* Changing an indirect call to a direct call may
4386 have exposed different semantics. This may
4387 require an SSA update. */
4388 el_todo
|= TODO_update_ssa_only_virtuals
;
4394 /* Make no longer available leaders no longer available. */
4397 eliminate_dom_walker::after_dom_children (basic_block
)
4400 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4401 el_avail
[SSA_NAME_VERSION (VN_INFO (entry
)->valnum
)] = NULL_TREE
;
4404 /* Eliminate fully redundant computations. */
4409 gimple_stmt_iterator gsi
;
4413 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4414 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4416 el_to_remove
.create (0);
4417 el_to_update
.create (0);
4419 el_avail
.create (0);
4420 el_avail_stack
.create (0);
4422 eliminate_dom_walker (CDI_DOMINATORS
).walk (cfun
->cfg
->x_entry_block_ptr
);
4424 el_avail
.release ();
4425 el_avail_stack
.release ();
4427 /* We cannot remove stmts during BB walk, especially not release SSA
4428 names there as this confuses the VN machinery. The stmts ending
4429 up in el_to_remove are either stores or simple copies. */
4430 FOR_EACH_VEC_ELT (el_to_remove
, i
, stmt
)
4432 tree lhs
= gimple_assign_lhs (stmt
);
4433 tree rhs
= gimple_assign_rhs1 (stmt
);
4434 use_operand_p use_p
;
4437 /* If there is a single use only, propagate the equivalency
4438 instead of keeping the copy. */
4439 if (TREE_CODE (lhs
) == SSA_NAME
4440 && TREE_CODE (rhs
) == SSA_NAME
4441 && single_imm_use (lhs
, &use_p
, &use_stmt
)
4442 && may_propagate_copy (USE_FROM_PTR (use_p
), rhs
))
4444 SET_USE (use_p
, rhs
);
4445 update_stmt (use_stmt
);
4447 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (lhs
))
4448 && TREE_CODE (rhs
) == SSA_NAME
)
4449 gimple_set_plf (SSA_NAME_DEF_STMT (rhs
), NECESSARY
, true);
4452 /* If this is a store or a now unused copy, remove it. */
4453 if (TREE_CODE (lhs
) != SSA_NAME
4454 || has_zero_uses (lhs
))
4456 basic_block bb
= gimple_bb (stmt
);
4457 gsi
= gsi_for_stmt (stmt
);
4458 unlink_stmt_vdef (stmt
);
4459 if (gsi_remove (&gsi
, true))
4460 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4462 && TREE_CODE (lhs
) == SSA_NAME
)
4463 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4464 release_defs (stmt
);
4467 el_to_remove
.release ();
4469 /* We cannot update call statements with virtual operands during
4470 SSA walk. This might remove them which in turn makes our
4471 VN lattice invalid. */
4472 FOR_EACH_VEC_ELT (el_to_update
, i
, stmt
)
4474 el_to_update
.release ();
4479 /* Perform CFG cleanups made necessary by elimination. */
4482 fini_eliminate (void)
4484 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4485 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4488 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4491 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4493 BITMAP_FREE (need_eh_cleanup
);
4494 BITMAP_FREE (need_ab_cleanup
);
4496 if (do_eh_cleanup
|| do_ab_cleanup
)
4497 return TODO_cleanup_cfg
;
4501 /* Borrow a bit of tree-ssa-dce.c for the moment.
4502 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4503 this may be a bit faster, and we may want critical edges kept split. */
4505 /* If OP's defining statement has not already been determined to be necessary,
4506 mark that statement necessary. Return the stmt, if it is newly
4509 static inline gimple
4510 mark_operand_necessary (tree op
)
4516 if (TREE_CODE (op
) != SSA_NAME
)
4519 stmt
= SSA_NAME_DEF_STMT (op
);
4522 if (gimple_plf (stmt
, NECESSARY
)
4523 || gimple_nop_p (stmt
))
4526 gimple_set_plf (stmt
, NECESSARY
, true);
4530 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4531 to insert PHI nodes sometimes, and because value numbering of casts isn't
4532 perfect, we sometimes end up inserting dead code. This simple DCE-like
4533 pass removes any insertions we made that weren't actually used. */
4536 remove_dead_inserted_code (void)
4543 worklist
= BITMAP_ALLOC (NULL
);
4544 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4546 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4547 if (gimple_plf (t
, NECESSARY
))
4548 bitmap_set_bit (worklist
, i
);
4550 while (!bitmap_empty_p (worklist
))
4552 i
= bitmap_first_set_bit (worklist
);
4553 bitmap_clear_bit (worklist
, i
);
4554 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4556 /* PHI nodes are somewhat special in that each PHI alternative has
4557 data and control dependencies. All the statements feeding the
4558 PHI node's arguments are always necessary. */
4559 if (gimple_code (t
) == GIMPLE_PHI
)
4563 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4565 tree arg
= PHI_ARG_DEF (t
, k
);
4566 if (TREE_CODE (arg
) == SSA_NAME
)
4568 gimple n
= mark_operand_necessary (arg
);
4570 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4576 /* Propagate through the operands. Examine all the USE, VUSE and
4577 VDEF operands in this statement. Mark all the statements
4578 which feed this statement's uses as necessary. */
4582 /* The operands of VDEF expressions are also needed as they
4583 represent potential definitions that may reach this
4584 statement (VDEF operands allow us to follow def-def
4587 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4589 gimple n
= mark_operand_necessary (use
);
4591 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4596 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4598 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4599 if (!gimple_plf (t
, NECESSARY
))
4601 gimple_stmt_iterator gsi
;
4603 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4605 fprintf (dump_file
, "Removing unnecessary insertion:");
4606 print_gimple_stmt (dump_file
, t
, 0, 0);
4609 gsi
= gsi_for_stmt (t
);
4610 if (gimple_code (t
) == GIMPLE_PHI
)
4611 remove_phi_node (&gsi
, true);
4614 gsi_remove (&gsi
, true);
4619 BITMAP_FREE (worklist
);
4623 /* Initialize data structures used by PRE. */
4630 next_expression_id
= 1;
4631 expressions
.create (0);
4632 expressions
.safe_push (NULL
);
4633 value_expressions
.create (get_max_value_id () + 1);
4634 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4635 name_to_id
.create (0);
4637 inserted_exprs
= BITMAP_ALLOC (NULL
);
4639 connect_infinite_loops_to_exit ();
4640 memset (&pre_stats
, 0, sizeof (pre_stats
));
4642 postorder
= XNEWVEC (int, n_basic_blocks
);
4643 postorder_num
= inverted_post_order_compute (postorder
);
4645 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4647 calculate_dominance_info (CDI_POST_DOMINATORS
);
4648 calculate_dominance_info (CDI_DOMINATORS
);
4650 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4651 phi_translate_table
.create (5110);
4652 expression_to_id
.create (num_ssa_names
* 3);
4653 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4654 sizeof (struct bitmap_set
), 30);
4655 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4656 sizeof (struct pre_expr_d
), 30);
4659 EXP_GEN (bb
) = bitmap_set_new ();
4660 PHI_GEN (bb
) = bitmap_set_new ();
4661 TMP_GEN (bb
) = bitmap_set_new ();
4662 AVAIL_OUT (bb
) = bitmap_set_new ();
4667 /* Deallocate data structures used by PRE. */
4673 value_expressions
.release ();
4674 BITMAP_FREE (inserted_exprs
);
4675 bitmap_obstack_release (&grand_bitmap_obstack
);
4676 free_alloc_pool (bitmap_set_pool
);
4677 free_alloc_pool (pre_expr_pool
);
4678 phi_translate_table
.dispose ();
4679 expression_to_id
.dispose ();
4680 name_to_id
.release ();
4682 free_aux_for_blocks ();
4684 free_dominance_info (CDI_POST_DOMINATORS
);
4687 /* Gate and execute functions for PRE. */
4692 unsigned int todo
= 0;
4694 do_partial_partial
=
4695 flag_tree_partial_pre
&& optimize_function_for_speed_p (cfun
);
4697 /* This has to happen before SCCVN runs because
4698 loop_optimizer_init may create new phis, etc. */
4699 loop_optimizer_init (LOOPS_NORMAL
);
4701 if (!run_scc_vn (VN_WALK
))
4703 loop_optimizer_finalize ();
4710 /* Collect and value number expressions computed in each basic block. */
4713 /* Insert can get quite slow on an incredibly large number of basic
4714 blocks due to some quadratic behavior. Until this behavior is
4715 fixed, don't run it when he have an incredibly large number of
4716 bb's. If we aren't going to run insert, there is no point in
4717 computing ANTIC, either, even though it's plenty fast. */
4718 if (n_basic_blocks
< 4000)
4724 /* Make sure to remove fake edges before committing our inserts.
4725 This makes sure we don't end up with extra critical edges that
4726 we would need to split. */
4727 remove_fake_exit_edges ();
4728 gsi_commit_edge_inserts ();
4730 /* Remove all the redundant expressions. */
4731 todo
|= eliminate ();
4733 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4734 statistics_counter_event (cfun
, "PA inserted", pre_stats
.pa_insert
);
4735 statistics_counter_event (cfun
, "New PHIs", pre_stats
.phis
);
4736 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4738 clear_expression_ids ();
4739 remove_dead_inserted_code ();
4740 todo
|= TODO_verify_flow
;
4744 todo
|= fini_eliminate ();
4745 loop_optimizer_finalize ();
4747 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
4748 case we can merge the block with the remaining predecessor of the block.
4750 - call merge_blocks after each tail merge iteration
4751 - call merge_blocks after all tail merge iterations
4752 - mark TODO_cleanup_cfg when necessary
4753 - share the cfg cleanup with fini_pre. */
4754 todo
|= tail_merge_optimize (todo
);
4758 /* Tail merging invalidates the virtual SSA web, together with
4759 cfg-cleanup opportunities exposed by PRE this will wreck the
4760 SSA updating machinery. So make sure to run update-ssa
4761 manually, before eventually scheduling cfg-cleanup as part of
4763 update_ssa (TODO_update_ssa_only_virtuals
);
4771 return flag_tree_pre
!= 0;
4776 const pass_data pass_data_pre
=
4778 GIMPLE_PASS
, /* type */
4780 OPTGROUP_NONE
, /* optinfo_flags */
4781 true, /* has_gate */
4782 true, /* has_execute */
4783 TV_TREE_PRE
, /* tv_id */
4784 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4785 0, /* properties_provided */
4786 0, /* properties_destroyed */
4787 TODO_rebuild_alias
, /* todo_flags_start */
4788 TODO_verify_ssa
, /* todo_flags_finish */
4791 class pass_pre
: public gimple_opt_pass
4794 pass_pre (gcc::context
*ctxt
)
4795 : gimple_opt_pass (pass_data_pre
, ctxt
)
4798 /* opt_pass methods: */
4799 bool gate () { return gate_pre (); }
4800 unsigned int execute () { return do_pre (); }
4802 }; // class pass_pre
4807 make_pass_pre (gcc::context
*ctxt
)
4809 return new pass_pre (ctxt
);
4813 /* Gate and execute functions for FRE. */
4818 unsigned int todo
= 0;
4820 if (!run_scc_vn (VN_WALKREWRITE
))
4823 memset (&pre_stats
, 0, sizeof (pre_stats
));
4825 /* Remove all the redundant expressions. */
4826 todo
|= eliminate ();
4828 todo
|= fini_eliminate ();
4832 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4833 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4841 return flag_tree_fre
!= 0;
4846 const pass_data pass_data_fre
=
4848 GIMPLE_PASS
, /* type */
4850 OPTGROUP_NONE
, /* optinfo_flags */
4851 true, /* has_gate */
4852 true, /* has_execute */
4853 TV_TREE_FRE
, /* tv_id */
4854 ( PROP_cfg
| PROP_ssa
), /* properties_required */
4855 0, /* properties_provided */
4856 0, /* properties_destroyed */
4857 0, /* todo_flags_start */
4858 TODO_verify_ssa
, /* todo_flags_finish */
4861 class pass_fre
: public gimple_opt_pass
4864 pass_fre (gcc::context
*ctxt
)
4865 : gimple_opt_pass (pass_data_fre
, ctxt
)
4868 /* opt_pass methods: */
4869 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
4870 bool gate () { return gate_fre (); }
4871 unsigned int execute () { return execute_fre (); }
4873 }; // class pass_fre
4878 make_pass_fre (gcc::context
*ctxt
)
4880 return new pass_fre (ctxt
);