2 Copyright (C) 2001-2014 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
27 #include "basic-block.h"
28 #include "gimple-pretty-print.h"
29 #include "tree-inline.h"
31 #include "hash-table.h"
32 #include "tree-ssa-alias.h"
33 #include "internal-fn.h"
34 #include "gimple-fold.h"
36 #include "gimple-expr.h"
40 #include "gimple-iterator.h"
41 #include "gimplify-me.h"
42 #include "gimple-ssa.h"
44 #include "tree-phinodes.h"
45 #include "ssa-iterators.h"
46 #include "stringpool.h"
47 #include "tree-ssanames.h"
48 #include "tree-ssa-loop.h"
49 #include "tree-into-ssa.h"
53 #include "tree-iterator.h"
54 #include "alloc-pool.h"
56 #include "tree-pass.h"
58 #include "langhooks.h"
60 #include "tree-ssa-sccvn.h"
61 #include "tree-scalar-evolution.h"
66 #include "tree-ssa-propagate.h"
67 #include "ipa-utils.h"
71 1. Avail sets can be shared by making an avail_find_leader that
72 walks up the dominator tree and looks in those avail sets.
73 This might affect code optimality, it's unclear right now.
74 2. Strength reduction can be performed by anticipating expressions
75 we can repair later on.
76 3. We can do back-substitution or smarter value numbering to catch
77 commutative expressions split up over multiple statements.
80 /* For ease of terminology, "expression node" in the below refers to
81 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
82 represent the actual statement containing the expressions we care about,
83 and we cache the value number by putting it in the expression. */
87 First we walk the statements to generate the AVAIL sets, the
88 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
89 generation of values/expressions by a given block. We use them
90 when computing the ANTIC sets. The AVAIL sets consist of
91 SSA_NAME's that represent values, so we know what values are
92 available in what blocks. AVAIL is a forward dataflow problem. In
93 SSA, values are never killed, so we don't need a kill set, or a
94 fixpoint iteration, in order to calculate the AVAIL sets. In
95 traditional parlance, AVAIL sets tell us the downsafety of the
98 Next, we generate the ANTIC sets. These sets represent the
99 anticipatable expressions. ANTIC is a backwards dataflow
100 problem. An expression is anticipatable in a given block if it could
101 be generated in that block. This means that if we had to perform
102 an insertion in that block, of the value of that expression, we
103 could. Calculating the ANTIC sets requires phi translation of
104 expressions, because the flow goes backwards through phis. We must
105 iterate to a fixpoint of the ANTIC sets, because we have a kill
106 set. Even in SSA form, values are not live over the entire
107 function, only from their definition point onwards. So we have to
108 remove values from the ANTIC set once we go past the definition
109 point of the leaders that make them up.
110 compute_antic/compute_antic_aux performs this computation.
112 Third, we perform insertions to make partially redundant
113 expressions fully redundant.
115 An expression is partially redundant (excluding partial
118 1. It is AVAIL in some, but not all, of the predecessors of a
120 2. It is ANTIC in all the predecessors.
122 In order to make it fully redundant, we insert the expression into
123 the predecessors where it is not available, but is ANTIC.
125 For the partial anticipation case, we only perform insertion if it
126 is partially anticipated in some block, and fully available in all
129 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
130 performs these steps.
132 Fourth, we eliminate fully redundant expressions.
133 This is a simple statement walk that replaces redundant
134 calculations with the now available values. */
136 /* Representations of value numbers:
138 Value numbers are represented by a representative SSA_NAME. We
139 will create fake SSA_NAME's in situations where we need a
140 representative but do not have one (because it is a complex
141 expression). In order to facilitate storing the value numbers in
142 bitmaps, and keep the number of wasted SSA_NAME's down, we also
143 associate a value_id with each value number, and create full blown
144 ssa_name's only where we actually need them (IE in operands of
145 existing expressions).
147 Theoretically you could replace all the value_id's with
148 SSA_NAME_VERSION, but this would allocate a large number of
149 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
150 It would also require an additional indirection at each point we
153 /* Representation of expressions on value numbers:
155 Expressions consisting of value numbers are represented the same
156 way as our VN internally represents them, with an additional
157 "pre_expr" wrapping around them in order to facilitate storing all
158 of the expressions in the same sets. */
160 /* Representation of sets:
162 The dataflow sets do not need to be sorted in any particular order
163 for the majority of their lifetime, are simply represented as two
164 bitmaps, one that keeps track of values present in the set, and one
165 that keeps track of expressions present in the set.
167 When we need them in topological order, we produce it on demand by
168 transforming the bitmap into an array and sorting it into topo
171 /* Type of expression, used to know which member of the PRE_EXPR union
182 typedef union pre_expr_union_d
187 vn_reference_t reference
;
190 typedef struct pre_expr_d
: typed_noop_remove
<pre_expr_d
>
192 enum pre_expr_kind kind
;
196 /* hash_table support. */
197 typedef pre_expr_d value_type
;
198 typedef pre_expr_d compare_type
;
199 static inline hashval_t
hash (const pre_expr_d
*);
200 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
203 #define PRE_EXPR_NAME(e) (e)->u.name
204 #define PRE_EXPR_NARY(e) (e)->u.nary
205 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
206 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
208 /* Compare E1 and E1 for equality. */
211 pre_expr_d::equal (const value_type
*e1
, const compare_type
*e2
)
213 if (e1
->kind
!= e2
->kind
)
219 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
220 PRE_EXPR_CONSTANT (e2
));
222 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
224 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
226 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
227 PRE_EXPR_REFERENCE (e2
));
236 pre_expr_d::hash (const value_type
*e
)
241 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
243 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
245 return PRE_EXPR_NARY (e
)->hashcode
;
247 return PRE_EXPR_REFERENCE (e
)->hashcode
;
253 /* Next global expression id number. */
254 static unsigned int next_expression_id
;
256 /* Mapping from expression to id number we can use in bitmap sets. */
257 static vec
<pre_expr
> expressions
;
258 static hash_table
<pre_expr_d
> *expression_to_id
;
259 static vec
<unsigned> name_to_id
;
261 /* Allocate an expression id for EXPR. */
263 static inline unsigned int
264 alloc_expression_id (pre_expr expr
)
266 struct pre_expr_d
**slot
;
267 /* Make sure we won't overflow. */
268 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
269 expr
->id
= next_expression_id
++;
270 expressions
.safe_push (expr
);
271 if (expr
->kind
== NAME
)
273 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
274 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
275 re-allocations by using vec::reserve upfront. */
276 unsigned old_len
= name_to_id
.length ();
277 name_to_id
.reserve (num_ssa_names
- old_len
);
278 name_to_id
.quick_grow_cleared (num_ssa_names
);
279 gcc_assert (name_to_id
[version
] == 0);
280 name_to_id
[version
] = expr
->id
;
284 slot
= expression_to_id
->find_slot (expr
, INSERT
);
288 return next_expression_id
- 1;
291 /* Return the expression id for tree EXPR. */
293 static inline unsigned int
294 get_expression_id (const pre_expr expr
)
299 static inline unsigned int
300 lookup_expression_id (const pre_expr expr
)
302 struct pre_expr_d
**slot
;
304 if (expr
->kind
== NAME
)
306 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
307 if (name_to_id
.length () <= version
)
309 return name_to_id
[version
];
313 slot
= expression_to_id
->find_slot (expr
, NO_INSERT
);
316 return ((pre_expr
)*slot
)->id
;
320 /* Return the existing expression id for EXPR, or create one if one
321 does not exist yet. */
323 static inline unsigned int
324 get_or_alloc_expression_id (pre_expr expr
)
326 unsigned int id
= lookup_expression_id (expr
);
328 return alloc_expression_id (expr
);
329 return expr
->id
= id
;
332 /* Return the expression that has expression id ID */
334 static inline pre_expr
335 expression_for_id (unsigned int id
)
337 return expressions
[id
];
340 /* Free the expression id field in all of our expressions,
341 and then destroy the expressions array. */
344 clear_expression_ids (void)
346 expressions
.release ();
349 static alloc_pool pre_expr_pool
;
351 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
354 get_or_alloc_expr_for_name (tree name
)
356 struct pre_expr_d expr
;
358 unsigned int result_id
;
362 PRE_EXPR_NAME (&expr
) = name
;
363 result_id
= lookup_expression_id (&expr
);
365 return expression_for_id (result_id
);
367 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
369 PRE_EXPR_NAME (result
) = name
;
370 alloc_expression_id (result
);
374 /* An unordered bitmap set. One bitmap tracks values, the other,
376 typedef struct bitmap_set
378 bitmap_head expressions
;
382 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
383 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
385 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
386 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
388 /* Mapping from value id to expressions with that value_id. */
389 static vec
<bitmap
> value_expressions
;
391 /* Sets that we need to keep track of. */
392 typedef struct bb_bitmap_sets
394 /* The EXP_GEN set, which represents expressions/values generated in
396 bitmap_set_t exp_gen
;
398 /* The PHI_GEN set, which represents PHI results generated in a
400 bitmap_set_t phi_gen
;
402 /* The TMP_GEN set, which represents results/temporaries generated
403 in a basic block. IE the LHS of an expression. */
404 bitmap_set_t tmp_gen
;
406 /* The AVAIL_OUT set, which represents which values are available in
407 a given basic block. */
408 bitmap_set_t avail_out
;
410 /* The ANTIC_IN set, which represents which values are anticipatable
411 in a given basic block. */
412 bitmap_set_t antic_in
;
414 /* The PA_IN set, which represents which values are
415 partially anticipatable in a given basic block. */
418 /* The NEW_SETS set, which is used during insertion to augment the
419 AVAIL_OUT set of blocks with the new insertions performed during
420 the current iteration. */
421 bitmap_set_t new_sets
;
423 /* A cache for value_dies_in_block_x. */
426 /* True if we have visited this block during ANTIC calculation. */
427 unsigned int visited
: 1;
429 /* True when the block contains a call that might not return. */
430 unsigned int contains_may_not_return_call
: 1;
433 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
434 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
435 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
436 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
437 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
438 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
439 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
440 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
441 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
442 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
445 /* Basic block list in postorder. */
446 static int *postorder
;
447 static int postorder_num
;
449 /* This structure is used to keep track of statistics on what
450 optimization PRE was able to perform. */
453 /* The number of RHS computations eliminated by PRE. */
456 /* The number of new expressions/temporaries generated by PRE. */
459 /* The number of inserts found due to partial anticipation */
462 /* The number of new PHI nodes added by PRE. */
466 static bool do_partial_partial
;
467 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
468 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
469 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
470 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
471 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
472 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
473 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
475 static bitmap_set_t
bitmap_set_new (void);
476 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
478 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
479 static unsigned int get_expr_value_id (pre_expr
);
481 /* We can add and remove elements and entries to and from sets
482 and hash tables, so we use alloc pools for them. */
484 static alloc_pool bitmap_set_pool
;
485 static bitmap_obstack grand_bitmap_obstack
;
487 /* Set of blocks with statements that have had their EH properties changed. */
488 static bitmap need_eh_cleanup
;
490 /* Set of blocks with statements that have had their AB properties changed. */
491 static bitmap need_ab_cleanup
;
493 /* A three tuple {e, pred, v} used to cache phi translations in the
494 phi_translate_table. */
496 typedef struct expr_pred_trans_d
: typed_free_remove
<expr_pred_trans_d
>
498 /* The expression. */
501 /* The predecessor block along which we translated the expression. */
504 /* The value that resulted from the translation. */
507 /* The hashcode for the expression, pred pair. This is cached for
511 /* hash_table support. */
512 typedef expr_pred_trans_d value_type
;
513 typedef expr_pred_trans_d compare_type
;
514 static inline hashval_t
hash (const value_type
*);
515 static inline int equal (const value_type
*, const compare_type
*);
516 } *expr_pred_trans_t
;
517 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
520 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
526 expr_pred_trans_d::equal (const value_type
*ve1
,
527 const compare_type
*ve2
)
529 basic_block b1
= ve1
->pred
;
530 basic_block b2
= ve2
->pred
;
532 /* If they are not translations for the same basic block, they can't
536 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
539 /* The phi_translate_table caches phi translations for a given
540 expression and predecessor. */
541 static hash_table
<expr_pred_trans_d
> *phi_translate_table
;
543 /* Add the tuple mapping from {expression E, basic block PRED} to
544 the phi translation table and return whether it pre-existed. */
547 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
549 expr_pred_trans_t
*slot
;
550 expr_pred_trans_d tem
;
551 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
556 slot
= phi_translate_table
->find_slot_with_hash (&tem
, hash
, INSERT
);
563 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
565 (*entry
)->pred
= pred
;
566 (*entry
)->hashcode
= hash
;
571 /* Add expression E to the expression set of value id V. */
574 add_to_value (unsigned int v
, pre_expr e
)
578 gcc_checking_assert (get_expr_value_id (e
) == v
);
580 if (v
>= value_expressions
.length ())
582 value_expressions
.safe_grow_cleared (v
+ 1);
585 set
= value_expressions
[v
];
588 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
589 value_expressions
[v
] = set
;
592 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
595 /* Create a new bitmap set and return it. */
598 bitmap_set_new (void)
600 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
601 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
602 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
606 /* Return the value id for a PRE expression EXPR. */
609 get_expr_value_id (pre_expr expr
)
615 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
618 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
621 id
= PRE_EXPR_NARY (expr
)->value_id
;
624 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
629 /* ??? We cannot assert that expr has a value-id (it can be 0), because
630 we assign value-ids only to expressions that have a result
631 in set_hashtable_value_ids. */
635 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
638 sccvn_valnum_from_value_id (unsigned int val
)
642 bitmap exprset
= value_expressions
[val
];
643 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
645 pre_expr vexpr
= expression_for_id (i
);
646 if (vexpr
->kind
== NAME
)
647 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
648 else if (vexpr
->kind
== CONSTANT
)
649 return PRE_EXPR_CONSTANT (vexpr
);
654 /* Remove an expression EXPR from a bitmapped set. */
657 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
659 unsigned int val
= get_expr_value_id (expr
);
660 if (!value_id_constant_p (val
))
662 bitmap_clear_bit (&set
->values
, val
);
663 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
668 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
669 unsigned int val
, bool allow_constants
)
671 if (allow_constants
|| !value_id_constant_p (val
))
673 /* We specifically expect this and only this function to be able to
674 insert constants into a set. */
675 bitmap_set_bit (&set
->values
, val
);
676 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
680 /* Insert an expression EXPR into a bitmapped set. */
683 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
685 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
688 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
691 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
693 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
694 bitmap_copy (&dest
->values
, &orig
->values
);
698 /* Free memory used up by SET. */
700 bitmap_set_free (bitmap_set_t set
)
702 bitmap_clear (&set
->expressions
);
703 bitmap_clear (&set
->values
);
707 /* Generate an topological-ordered array of bitmap set SET. */
710 sorted_array_from_bitmap_set (bitmap_set_t set
)
713 bitmap_iterator bi
, bj
;
714 vec
<pre_expr
> result
;
716 /* Pre-allocate enough space for the array. */
717 result
.create (bitmap_count_bits (&set
->expressions
));
719 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
721 /* The number of expressions having a given value is usually
722 relatively small. Thus, rather than making a vector of all
723 the expressions and sorting it by value-id, we walk the values
724 and check in the reverse mapping that tells us what expressions
725 have a given value, to filter those in our set. As a result,
726 the expressions are inserted in value-id order, which means
729 If this is somehow a significant lose for some cases, we can
730 choose which set to walk based on the set size. */
731 bitmap exprset
= value_expressions
[i
];
732 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
734 if (bitmap_bit_p (&set
->expressions
, j
))
735 result
.quick_push (expression_for_id (j
));
742 /* Perform bitmapped set operation DEST &= ORIG. */
745 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
753 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
755 bitmap_and_into (&dest
->values
, &orig
->values
);
756 bitmap_copy (&temp
, &dest
->expressions
);
757 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
759 pre_expr expr
= expression_for_id (i
);
760 unsigned int value_id
= get_expr_value_id (expr
);
761 if (!bitmap_bit_p (&dest
->values
, value_id
))
762 bitmap_clear_bit (&dest
->expressions
, i
);
764 bitmap_clear (&temp
);
768 /* Subtract all values and expressions contained in ORIG from DEST. */
771 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
773 bitmap_set_t result
= bitmap_set_new ();
777 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
780 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
782 pre_expr expr
= expression_for_id (i
);
783 unsigned int value_id
= get_expr_value_id (expr
);
784 bitmap_set_bit (&result
->values
, value_id
);
790 /* Subtract all the values in bitmap set B from bitmap set A. */
793 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
799 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
801 bitmap_copy (&temp
, &a
->expressions
);
802 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
804 pre_expr expr
= expression_for_id (i
);
805 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
806 bitmap_remove_from_set (a
, expr
);
808 bitmap_clear (&temp
);
812 /* Return true if bitmapped set SET contains the value VALUE_ID. */
815 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
817 if (value_id_constant_p (value_id
))
820 if (!set
|| bitmap_empty_p (&set
->expressions
))
823 return bitmap_bit_p (&set
->values
, value_id
);
827 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
829 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
832 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
835 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
842 if (value_id_constant_p (lookfor
))
845 if (!bitmap_set_contains_value (set
, lookfor
))
848 /* The number of expressions having a given value is usually
849 significantly less than the total number of expressions in SET.
850 Thus, rather than check, for each expression in SET, whether it
851 has the value LOOKFOR, we walk the reverse mapping that tells us
852 what expressions have a given value, and see if any of those
853 expressions are in our set. For large testcases, this is about
854 5-10x faster than walking the bitmap. If this is somehow a
855 significant lose for some cases, we can choose which set to walk
856 based on the set size. */
857 exprset
= value_expressions
[lookfor
];
858 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
860 if (bitmap_clear_bit (&set
->expressions
, i
))
862 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
870 /* Return true if two bitmap sets are equal. */
873 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
875 return bitmap_equal_p (&a
->values
, &b
->values
);
878 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
879 and add it otherwise. */
882 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
884 unsigned int val
= get_expr_value_id (expr
);
886 if (bitmap_set_contains_value (set
, val
))
887 bitmap_set_replace_value (set
, val
, expr
);
889 bitmap_insert_into_set (set
, expr
);
892 /* Insert EXPR into SET if EXPR's value is not already present in
896 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
898 unsigned int val
= get_expr_value_id (expr
);
900 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
902 /* Constant values are always considered to be part of the set. */
903 if (value_id_constant_p (val
))
906 /* If the value membership changed, add the expression. */
907 if (bitmap_set_bit (&set
->values
, val
))
908 bitmap_set_bit (&set
->expressions
, expr
->id
);
911 /* Print out EXPR to outfile. */
914 print_pre_expr (FILE *outfile
, const pre_expr expr
)
919 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
922 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
927 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
928 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
929 for (i
= 0; i
< nary
->length
; i
++)
931 print_generic_expr (outfile
, nary
->op
[i
], 0);
932 if (i
!= (unsigned) nary
->length
- 1)
933 fprintf (outfile
, ",");
935 fprintf (outfile
, "}");
941 vn_reference_op_t vro
;
943 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
944 fprintf (outfile
, "{");
946 ref
->operands
.iterate (i
, &vro
);
949 bool closebrace
= false;
950 if (vro
->opcode
!= SSA_NAME
951 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
953 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
956 fprintf (outfile
, "<");
962 print_generic_expr (outfile
, vro
->op0
, 0);
965 fprintf (outfile
, ",");
966 print_generic_expr (outfile
, vro
->op1
, 0);
970 fprintf (outfile
, ",");
971 print_generic_expr (outfile
, vro
->op2
, 0);
975 fprintf (outfile
, ">");
976 if (i
!= ref
->operands
.length () - 1)
977 fprintf (outfile
, ",");
979 fprintf (outfile
, "}");
982 fprintf (outfile
, "@");
983 print_generic_expr (outfile
, ref
->vuse
, 0);
989 void debug_pre_expr (pre_expr
);
991 /* Like print_pre_expr but always prints to stderr. */
993 debug_pre_expr (pre_expr e
)
995 print_pre_expr (stderr
, e
);
996 fprintf (stderr
, "\n");
999 /* Print out SET to OUTFILE. */
1002 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
1003 const char *setname
, int blockindex
)
1005 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1012 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1014 const pre_expr expr
= expression_for_id (i
);
1017 fprintf (outfile
, ", ");
1019 print_pre_expr (outfile
, expr
);
1021 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1024 fprintf (outfile
, " }\n");
1027 void debug_bitmap_set (bitmap_set_t
);
1030 debug_bitmap_set (bitmap_set_t set
)
1032 print_bitmap_set (stderr
, set
, "debug", 0);
1035 void debug_bitmap_sets_for (basic_block
);
1038 debug_bitmap_sets_for (basic_block bb
)
1040 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1041 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1042 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1043 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1044 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1045 if (do_partial_partial
)
1046 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1047 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1050 /* Print out the expressions that have VAL to OUTFILE. */
1053 print_value_expressions (FILE *outfile
, unsigned int val
)
1055 bitmap set
= value_expressions
[val
];
1060 sprintf (s
, "%04d", val
);
1061 x
.expressions
= *set
;
1062 print_bitmap_set (outfile
, &x
, s
, 0);
1068 debug_value_expressions (unsigned int val
)
1070 print_value_expressions (stderr
, val
);
1073 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1077 get_or_alloc_expr_for_constant (tree constant
)
1079 unsigned int result_id
;
1080 unsigned int value_id
;
1081 struct pre_expr_d expr
;
1084 expr
.kind
= CONSTANT
;
1085 PRE_EXPR_CONSTANT (&expr
) = constant
;
1086 result_id
= lookup_expression_id (&expr
);
1088 return expression_for_id (result_id
);
1090 newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1091 newexpr
->kind
= CONSTANT
;
1092 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1093 alloc_expression_id (newexpr
);
1094 value_id
= get_or_alloc_constant_value_id (constant
);
1095 add_to_value (value_id
, newexpr
);
1099 /* Given a value id V, find the actual tree representing the constant
1100 value if there is one, and return it. Return NULL if we can't find
1104 get_constant_for_value_id (unsigned int v
)
1106 if (value_id_constant_p (v
))
1110 bitmap exprset
= value_expressions
[v
];
1112 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1114 pre_expr expr
= expression_for_id (i
);
1115 if (expr
->kind
== CONSTANT
)
1116 return PRE_EXPR_CONSTANT (expr
);
1122 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1123 Currently only supports constants and SSA_NAMES. */
1125 get_or_alloc_expr_for (tree t
)
1127 if (TREE_CODE (t
) == SSA_NAME
)
1128 return get_or_alloc_expr_for_name (t
);
1129 else if (is_gimple_min_invariant (t
))
1130 return get_or_alloc_expr_for_constant (t
);
1133 /* More complex expressions can result from SCCVN expression
1134 simplification that inserts values for them. As they all
1135 do not have VOPs the get handled by the nary ops struct. */
1136 vn_nary_op_t result
;
1137 unsigned int result_id
;
1138 vn_nary_op_lookup (t
, &result
);
1141 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1143 PRE_EXPR_NARY (e
) = result
;
1144 result_id
= lookup_expression_id (e
);
1147 pool_free (pre_expr_pool
, e
);
1148 e
= expression_for_id (result_id
);
1151 alloc_expression_id (e
);
1158 /* Return the folded version of T if T, when folded, is a gimple
1159 min_invariant. Otherwise, return T. */
1162 fully_constant_expression (pre_expr e
)
1170 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1171 switch (TREE_CODE_CLASS (nary
->opcode
))
1174 case tcc_comparison
:
1176 /* We have to go from trees to pre exprs to value ids to
1178 tree naryop0
= nary
->op
[0];
1179 tree naryop1
= nary
->op
[1];
1181 if (!is_gimple_min_invariant (naryop0
))
1183 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1184 unsigned int vrep0
= get_expr_value_id (rep0
);
1185 tree const0
= get_constant_for_value_id (vrep0
);
1187 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1189 if (!is_gimple_min_invariant (naryop1
))
1191 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1192 unsigned int vrep1
= get_expr_value_id (rep1
);
1193 tree const1
= get_constant_for_value_id (vrep1
);
1195 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1197 result
= fold_binary (nary
->opcode
, nary
->type
,
1199 if (result
&& is_gimple_min_invariant (result
))
1200 return get_or_alloc_expr_for_constant (result
);
1201 /* We might have simplified the expression to a
1202 SSA_NAME for example from x_1 * 1. But we cannot
1203 insert a PHI for x_1 unconditionally as x_1 might
1204 not be available readily. */
1208 if (nary
->opcode
!= REALPART_EXPR
1209 && nary
->opcode
!= IMAGPART_EXPR
1210 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1215 /* We have to go from trees to pre exprs to value ids to
1217 tree naryop0
= nary
->op
[0];
1218 tree const0
, result
;
1219 if (is_gimple_min_invariant (naryop0
))
1223 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1224 unsigned int vrep0
= get_expr_value_id (rep0
);
1225 const0
= get_constant_for_value_id (vrep0
);
1230 tree type1
= TREE_TYPE (nary
->op
[0]);
1231 const0
= fold_convert (type1
, const0
);
1232 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1234 if (result
&& is_gimple_min_invariant (result
))
1235 return get_or_alloc_expr_for_constant (result
);
1244 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1246 if ((folded
= fully_constant_vn_reference_p (ref
)))
1247 return get_or_alloc_expr_for_constant (folded
);
1256 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1257 it has the value it would have in BLOCK. Set *SAME_VALID to true
1258 in case the new vuse doesn't change the value id of the OPERANDS. */
1261 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1262 alias_set_type set
, tree type
, tree vuse
,
1263 basic_block phiblock
,
1264 basic_block block
, bool *same_valid
)
1266 gimple phi
= SSA_NAME_DEF_STMT (vuse
);
1273 if (gimple_bb (phi
) != phiblock
)
1276 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1278 /* Use the alias-oracle to find either the PHI node in this block,
1279 the first VUSE used in this block that is equivalent to vuse or
1280 the first VUSE which definition in this block kills the value. */
1281 if (gimple_code (phi
) == GIMPLE_PHI
)
1282 e
= find_edge (block
, phiblock
);
1283 else if (use_oracle
)
1284 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1286 vuse
= gimple_vuse (phi
);
1287 phi
= SSA_NAME_DEF_STMT (vuse
);
1288 if (gimple_bb (phi
) != phiblock
)
1290 if (gimple_code (phi
) == GIMPLE_PHI
)
1292 e
= find_edge (block
, phiblock
);
1303 bitmap visited
= NULL
;
1305 /* Try to find a vuse that dominates this phi node by skipping
1306 non-clobbering statements. */
1307 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false,
1310 BITMAP_FREE (visited
);
1316 /* If we didn't find any, the value ID can't stay the same,
1317 but return the translated vuse. */
1318 *same_valid
= false;
1319 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1321 /* ??? We would like to return vuse here as this is the canonical
1322 upmost vdef that this reference is associated with. But during
1323 insertion of the references into the hash tables we only ever
1324 directly insert with their direct gimple_vuse, hence returning
1325 something else would make us not find the other expression. */
1326 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1332 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1333 SET2. This is used to avoid making a set consisting of the union
1334 of PA_IN and ANTIC_IN during insert. */
1336 static inline pre_expr
1337 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1341 result
= bitmap_find_leader (set1
, val
);
1342 if (!result
&& set2
)
1343 result
= bitmap_find_leader (set2
, val
);
1347 /* Get the tree type for our PRE expression e. */
1350 get_expr_type (const pre_expr e
)
1355 return TREE_TYPE (PRE_EXPR_NAME (e
));
1357 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1359 return PRE_EXPR_REFERENCE (e
)->type
;
1361 return PRE_EXPR_NARY (e
)->type
;
1366 /* Get a representative SSA_NAME for a given expression.
1367 Since all of our sub-expressions are treated as values, we require
1368 them to be SSA_NAME's for simplicity.
1369 Prior versions of GVNPRE used to use "value handles" here, so that
1370 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1371 either case, the operands are really values (IE we do not expect
1372 them to be usable without finding leaders). */
1375 get_representative_for (const pre_expr e
)
1378 unsigned int value_id
= get_expr_value_id (e
);
1383 return PRE_EXPR_NAME (e
);
1385 return PRE_EXPR_CONSTANT (e
);
1389 /* Go through all of the expressions representing this value
1390 and pick out an SSA_NAME. */
1393 bitmap exprs
= value_expressions
[value_id
];
1394 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1396 pre_expr rep
= expression_for_id (i
);
1397 if (rep
->kind
== NAME
)
1398 return PRE_EXPR_NAME (rep
);
1399 else if (rep
->kind
== CONSTANT
)
1400 return PRE_EXPR_CONSTANT (rep
);
1406 /* If we reached here we couldn't find an SSA_NAME. This can
1407 happen when we've discovered a value that has never appeared in
1408 the program as set to an SSA_NAME, as the result of phi translation.
1410 ??? We should be able to re-use this when we insert the statement
1412 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1413 VN_INFO_GET (name
)->value_id
= value_id
;
1414 VN_INFO (name
)->valnum
= name
;
1415 /* ??? For now mark this SSA name for release by SCCVN. */
1416 VN_INFO (name
)->needs_insertion
= true;
1417 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1418 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1420 fprintf (dump_file
, "Created SSA_NAME representative ");
1421 print_generic_expr (dump_file
, name
, 0);
1422 fprintf (dump_file
, " for expression:");
1423 print_pre_expr (dump_file
, e
);
1424 fprintf (dump_file
, " (%04d)\n", value_id
);
1433 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1434 basic_block pred
, basic_block phiblock
);
1436 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1437 the phis in PRED. Return NULL if we can't find a leader for each part
1438 of the translated expression. */
1441 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1442 basic_block pred
, basic_block phiblock
)
1449 bool changed
= false;
1450 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1451 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1452 sizeof_vn_nary_op (nary
->length
));
1453 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1455 for (i
= 0; i
< newnary
->length
; i
++)
1457 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1461 pre_expr leader
, result
;
1462 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1463 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1464 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1465 if (result
&& result
!= leader
)
1467 tree name
= get_representative_for (result
);
1470 newnary
->op
[i
] = name
;
1475 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1481 unsigned int new_val_id
;
1483 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1488 if (result
&& is_gimple_min_invariant (result
))
1489 return get_or_alloc_expr_for_constant (result
);
1491 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1496 PRE_EXPR_NARY (expr
) = nary
;
1497 constant
= fully_constant_expression (expr
);
1498 if (constant
!= expr
)
1501 new_val_id
= nary
->value_id
;
1502 get_or_alloc_expression_id (expr
);
1506 new_val_id
= get_next_value_id ();
1507 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1508 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1512 result
, new_val_id
);
1513 PRE_EXPR_NARY (expr
) = nary
;
1514 constant
= fully_constant_expression (expr
);
1515 if (constant
!= expr
)
1517 get_or_alloc_expression_id (expr
);
1519 add_to_value (new_val_id
, expr
);
1527 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1528 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1529 tree vuse
= ref
->vuse
;
1530 tree newvuse
= vuse
;
1531 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1532 bool changed
= false, same_valid
= true;
1534 vn_reference_op_t operand
;
1535 vn_reference_t newref
;
1537 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1542 tree type
= operand
->type
;
1543 vn_reference_op_s newop
= *operand
;
1544 op
[0] = operand
->op0
;
1545 op
[1] = operand
->op1
;
1546 op
[2] = operand
->op2
;
1547 for (n
= 0; n
< 3; ++n
)
1549 unsigned int op_val_id
;
1552 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1554 /* We can't possibly insert these. */
1556 && !is_gimple_min_invariant (op
[n
]))
1560 op_val_id
= VN_INFO (op
[n
])->value_id
;
1561 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1564 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1567 if (opresult
!= leader
)
1569 tree name
= get_representative_for (opresult
);
1572 changed
|= name
!= op
[n
];
1578 newoperands
.release ();
1583 if (!newoperands
.exists ())
1584 newoperands
= operands
.copy ();
1585 /* We may have changed from an SSA_NAME to a constant */
1586 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1587 newop
.opcode
= TREE_CODE (op
[0]);
1592 newoperands
[i
] = newop
;
1594 gcc_checking_assert (i
== operands
.length ());
1598 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1599 ? newoperands
: operands
,
1600 ref
->set
, ref
->type
,
1601 vuse
, phiblock
, pred
,
1603 if (newvuse
== NULL_TREE
)
1605 newoperands
.release ();
1610 if (changed
|| newvuse
!= vuse
)
1612 unsigned int new_val_id
;
1615 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1617 newoperands
.exists ()
1618 ? newoperands
: operands
,
1621 newoperands
.release ();
1623 /* We can always insert constants, so if we have a partial
1624 redundant constant load of another type try to translate it
1625 to a constant of appropriate type. */
1626 if (result
&& is_gimple_min_invariant (result
))
1629 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1631 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1632 if (tem
&& !is_gimple_min_invariant (tem
))
1636 return get_or_alloc_expr_for_constant (tem
);
1639 /* If we'd have to convert things we would need to validate
1640 if we can insert the translated expression. So fail
1641 here for now - we cannot insert an alias with a different
1642 type in the VN tables either, as that would assert. */
1644 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1646 else if (!result
&& newref
1647 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1649 newoperands
.release ();
1653 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1654 expr
->kind
= REFERENCE
;
1659 PRE_EXPR_REFERENCE (expr
) = newref
;
1660 constant
= fully_constant_expression (expr
);
1661 if (constant
!= expr
)
1664 new_val_id
= newref
->value_id
;
1665 get_or_alloc_expression_id (expr
);
1669 if (changed
|| !same_valid
)
1671 new_val_id
= get_next_value_id ();
1672 value_expressions
.safe_grow_cleared
1673 (get_max_value_id () + 1);
1676 new_val_id
= ref
->value_id
;
1677 if (!newoperands
.exists ())
1678 newoperands
= operands
.copy ();
1679 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1682 result
, new_val_id
);
1683 newoperands
= vNULL
;
1684 PRE_EXPR_REFERENCE (expr
) = newref
;
1685 constant
= fully_constant_expression (expr
);
1686 if (constant
!= expr
)
1688 get_or_alloc_expression_id (expr
);
1690 add_to_value (new_val_id
, expr
);
1692 newoperands
.release ();
1699 tree name
= PRE_EXPR_NAME (expr
);
1700 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
1701 /* If the SSA name is defined by a PHI node in this block,
1703 if (gimple_code (def_stmt
) == GIMPLE_PHI
1704 && gimple_bb (def_stmt
) == phiblock
)
1706 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1707 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1709 /* Handle constant. */
1710 if (is_gimple_min_invariant (def
))
1711 return get_or_alloc_expr_for_constant (def
);
1713 return get_or_alloc_expr_for_name (def
);
1715 /* Otherwise return it unchanged - it will get removed if its
1716 value is not available in PREDs AVAIL_OUT set of expressions
1717 by the subtraction of TMP_GEN. */
1726 /* Wrapper around phi_translate_1 providing caching functionality. */
1729 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1730 basic_block pred
, basic_block phiblock
)
1732 expr_pred_trans_t slot
= NULL
;
1738 /* Constants contain no values that need translation. */
1739 if (expr
->kind
== CONSTANT
)
1742 if (value_id_constant_p (get_expr_value_id (expr
)))
1745 /* Don't add translations of NAMEs as those are cheap to translate. */
1746 if (expr
->kind
!= NAME
)
1748 if (phi_trans_add (&slot
, expr
, pred
))
1750 /* Store NULL for the value we want to return in the case of
1756 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1763 /* Remove failed translations again, they cause insert
1764 iteration to not pick up new opportunities reliably. */
1765 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1772 /* For each expression in SET, translate the values through phi nodes
1773 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1774 expressions in DEST. */
1777 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1778 basic_block phiblock
)
1780 vec
<pre_expr
> exprs
;
1784 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1786 bitmap_set_copy (dest
, set
);
1790 exprs
= sorted_array_from_bitmap_set (set
);
1791 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1793 pre_expr translated
;
1794 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1798 /* We might end up with multiple expressions from SET being
1799 translated to the same value. In this case we do not want
1800 to retain the NARY or REFERENCE expression but prefer a NAME
1801 which would be the leader. */
1802 if (translated
->kind
== NAME
)
1803 bitmap_value_replace_in_set (dest
, translated
);
1805 bitmap_value_insert_into_set (dest
, translated
);
1810 /* Find the leader for a value (i.e., the name representing that
1811 value) in a given set, and return it. Return NULL if no leader
1815 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1817 if (value_id_constant_p (val
))
1821 bitmap exprset
= value_expressions
[val
];
1823 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1825 pre_expr expr
= expression_for_id (i
);
1826 if (expr
->kind
== CONSTANT
)
1830 if (bitmap_set_contains_value (set
, val
))
1832 /* Rather than walk the entire bitmap of expressions, and see
1833 whether any of them has the value we are looking for, we look
1834 at the reverse mapping, which tells us the set of expressions
1835 that have a given value (IE value->expressions with that
1836 value) and see if any of those expressions are in our set.
1837 The number of expressions per value is usually significantly
1838 less than the number of expressions in the set. In fact, for
1839 large testcases, doing it this way is roughly 5-10x faster
1840 than walking the bitmap.
1841 If this is somehow a significant lose for some cases, we can
1842 choose which set to walk based on which set is smaller. */
1845 bitmap exprset
= value_expressions
[val
];
1847 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1848 return expression_for_id (i
);
1853 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1854 BLOCK by seeing if it is not killed in the block. Note that we are
1855 only determining whether there is a store that kills it. Because
1856 of the order in which clean iterates over values, we are guaranteed
1857 that altered operands will have caused us to be eliminated from the
1858 ANTIC_IN set already. */
1861 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1863 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1864 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1866 gimple_stmt_iterator gsi
;
1867 unsigned id
= get_expression_id (expr
);
1874 /* Lookup a previously calculated result. */
1875 if (EXPR_DIES (block
)
1876 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1877 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1879 /* A memory expression {e, VUSE} dies in the block if there is a
1880 statement that may clobber e. If, starting statement walk from the
1881 top of the basic block, a statement uses VUSE there can be no kill
1882 inbetween that use and the original statement that loaded {e, VUSE},
1883 so we can stop walking. */
1884 ref
.base
= NULL_TREE
;
1885 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1887 tree def_vuse
, def_vdef
;
1888 def
= gsi_stmt (gsi
);
1889 def_vuse
= gimple_vuse (def
);
1890 def_vdef
= gimple_vdef (def
);
1892 /* Not a memory statement. */
1896 /* Not a may-def. */
1899 /* A load with the same VUSE, we're done. */
1900 if (def_vuse
== vuse
)
1906 /* Init ref only if we really need it. */
1907 if (ref
.base
== NULL_TREE
1908 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1914 /* If the statement may clobber expr, it dies. */
1915 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1922 /* Remember the result. */
1923 if (!EXPR_DIES (block
))
1924 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1925 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1927 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1933 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1934 contains its value-id. */
1937 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1939 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1941 unsigned int value_id
= VN_INFO (op
)->value_id
;
1942 if (!(bitmap_set_contains_value (set1
, value_id
)
1943 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1949 /* Determine if the expression EXPR is valid in SET1 U SET2.
1950 ONLY SET2 CAN BE NULL.
1951 This means that we have a leader for each part of the expression
1952 (if it consists of values), or the expression is an SSA_NAME.
1953 For loads/calls, we also see if the vuse is killed in this block. */
1956 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1961 /* By construction all NAMEs are available. Non-available
1962 NAMEs are removed by subtracting TMP_GEN from the sets. */
1967 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1968 for (i
= 0; i
< nary
->length
; i
++)
1969 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1976 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1977 vn_reference_op_t vro
;
1980 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1982 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1983 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1984 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1994 /* Clean the set of expressions that are no longer valid in SET1 or
1995 SET2. This means expressions that are made up of values we have no
1996 leaders for in SET1 or SET2. This version is used for partial
1997 anticipation, which means it is not valid in either ANTIC_IN or
2001 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
)
2003 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
2007 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2009 if (!valid_in_sets (set1
, set2
, expr
))
2010 bitmap_remove_from_set (set1
, expr
);
2015 /* Clean the set of expressions that are no longer valid in SET. This
2016 means expressions that are made up of values we have no leaders for
2020 clean (bitmap_set_t set
)
2022 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2026 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2028 if (!valid_in_sets (set
, NULL
, expr
))
2029 bitmap_remove_from_set (set
, expr
);
2034 /* Clean the set of expressions that are no longer valid in SET because
2035 they are clobbered in BLOCK or because they trap and may not be executed. */
2038 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2043 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2045 pre_expr expr
= expression_for_id (i
);
2046 if (expr
->kind
== REFERENCE
)
2048 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2051 gimple def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2052 if (!gimple_nop_p (def_stmt
)
2053 && ((gimple_bb (def_stmt
) != block
2054 && !dominated_by_p (CDI_DOMINATORS
,
2055 block
, gimple_bb (def_stmt
)))
2056 || (gimple_bb (def_stmt
) == block
2057 && value_dies_in_block_x (expr
, block
))))
2058 bitmap_remove_from_set (set
, expr
);
2061 else if (expr
->kind
== NARY
)
2063 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2064 /* If the NARY may trap make sure the block does not contain
2065 a possible exit point.
2066 ??? This is overly conservative if we translate AVAIL_OUT
2067 as the available expression might be after the exit point. */
2068 if (BB_MAY_NOTRETURN (block
)
2069 && vn_nary_may_trap (nary
))
2070 bitmap_remove_from_set (set
, expr
);
2075 static sbitmap has_abnormal_preds
;
2077 /* List of blocks that may have changed during ANTIC computation and
2078 thus need to be iterated over. */
2080 static sbitmap changed_blocks
;
2082 /* Compute the ANTIC set for BLOCK.
2084 If succs(BLOCK) > 1 then
2085 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2086 else if succs(BLOCK) == 1 then
2087 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2089 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2093 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2095 bool changed
= false;
2096 bitmap_set_t S
, old
, ANTIC_OUT
;
2102 old
= ANTIC_OUT
= S
= NULL
;
2103 BB_VISITED (block
) = 1;
2105 /* If any edges from predecessors are abnormal, antic_in is empty,
2107 if (block_has_abnormal_pred_edge
)
2108 goto maybe_dump_sets
;
2110 old
= ANTIC_IN (block
);
2111 ANTIC_OUT
= bitmap_set_new ();
2113 /* If the block has no successors, ANTIC_OUT is empty. */
2114 if (EDGE_COUNT (block
->succs
) == 0)
2116 /* If we have one successor, we could have some phi nodes to
2117 translate through. */
2118 else if (single_succ_p (block
))
2120 basic_block succ_bb
= single_succ (block
);
2121 gcc_assert (BB_VISITED (succ_bb
));
2122 phi_translate_set (ANTIC_OUT
, ANTIC_IN (succ_bb
), block
, succ_bb
);
2124 /* If we have multiple successors, we take the intersection of all of
2125 them. Note that in the case of loop exit phi nodes, we may have
2126 phis to translate through. */
2130 basic_block bprime
, first
= NULL
;
2132 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2133 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2136 && BB_VISITED (e
->dest
))
2138 else if (BB_VISITED (e
->dest
))
2139 worklist
.quick_push (e
->dest
);
2142 /* Of multiple successors we have to have visited one already
2143 which is guaranteed by iteration order. */
2144 gcc_assert (first
!= NULL
);
2146 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2148 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2150 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2152 bitmap_set_t tmp
= bitmap_set_new ();
2153 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2154 bitmap_set_and (ANTIC_OUT
, tmp
);
2155 bitmap_set_free (tmp
);
2158 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2162 /* Prune expressions that are clobbered in block and thus become
2163 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2164 prune_clobbered_mems (ANTIC_OUT
, block
);
2166 /* Generate ANTIC_OUT - TMP_GEN. */
2167 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2169 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2170 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2173 /* Then union in the ANTIC_OUT - TMP_GEN values,
2174 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2175 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2176 bitmap_value_insert_into_set (ANTIC_IN (block
),
2177 expression_for_id (bii
));
2179 clean (ANTIC_IN (block
));
2181 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2184 bitmap_set_bit (changed_blocks
, block
->index
);
2185 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2186 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2189 bitmap_clear_bit (changed_blocks
, block
->index
);
2192 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2195 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2197 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2201 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2204 bitmap_set_free (old
);
2206 bitmap_set_free (S
);
2208 bitmap_set_free (ANTIC_OUT
);
2212 /* Compute PARTIAL_ANTIC for BLOCK.
2214 If succs(BLOCK) > 1 then
2215 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2216 in ANTIC_OUT for all succ(BLOCK)
2217 else if succs(BLOCK) == 1 then
2218 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2220 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2225 compute_partial_antic_aux (basic_block block
,
2226 bool block_has_abnormal_pred_edge
)
2228 bool changed
= false;
2229 bitmap_set_t old_PA_IN
;
2230 bitmap_set_t PA_OUT
;
2233 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2235 old_PA_IN
= PA_OUT
= NULL
;
2237 /* If any edges from predecessors are abnormal, antic_in is empty,
2239 if (block_has_abnormal_pred_edge
)
2240 goto maybe_dump_sets
;
2242 /* If there are too many partially anticipatable values in the
2243 block, phi_translate_set can take an exponential time: stop
2244 before the translation starts. */
2246 && single_succ_p (block
)
2247 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2248 goto maybe_dump_sets
;
2250 old_PA_IN
= PA_IN (block
);
2251 PA_OUT
= bitmap_set_new ();
2253 /* If the block has no successors, ANTIC_OUT is empty. */
2254 if (EDGE_COUNT (block
->succs
) == 0)
2256 /* If we have one successor, we could have some phi nodes to
2257 translate through. Note that we can't phi translate across DFS
2258 back edges in partial antic, because it uses a union operation on
2259 the successors. For recurrences like IV's, we will end up
2260 generating a new value in the set on each go around (i + 3 (VH.1)
2261 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2262 else if (single_succ_p (block
))
2264 basic_block succ
= single_succ (block
);
2265 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2266 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2268 /* If we have multiple successors, we take the union of all of
2275 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2276 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2278 if (e
->flags
& EDGE_DFS_BACK
)
2280 worklist
.quick_push (e
->dest
);
2282 if (worklist
.length () > 0)
2284 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2289 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2290 bitmap_value_insert_into_set (PA_OUT
,
2291 expression_for_id (i
));
2292 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2294 bitmap_set_t pa_in
= bitmap_set_new ();
2295 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2296 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2297 bitmap_value_insert_into_set (PA_OUT
,
2298 expression_for_id (i
));
2299 bitmap_set_free (pa_in
);
2302 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2303 bitmap_value_insert_into_set (PA_OUT
,
2304 expression_for_id (i
));
2309 /* Prune expressions that are clobbered in block and thus become
2310 invalid if translated from PA_OUT to PA_IN. */
2311 prune_clobbered_mems (PA_OUT
, block
);
2313 /* PA_IN starts with PA_OUT - TMP_GEN.
2314 Then we subtract things from ANTIC_IN. */
2315 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2317 /* For partial antic, we want to put back in the phi results, since
2318 we will properly avoid making them partially antic over backedges. */
2319 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2320 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2322 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2323 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2325 dependent_clean (PA_IN (block
), ANTIC_IN (block
));
2327 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2330 bitmap_set_bit (changed_blocks
, block
->index
);
2331 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2332 bitmap_set_bit (changed_blocks
, e
->src
->index
);
2335 bitmap_clear_bit (changed_blocks
, block
->index
);
2338 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2341 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2343 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2346 bitmap_set_free (old_PA_IN
);
2348 bitmap_set_free (PA_OUT
);
2352 /* Compute ANTIC and partial ANTIC sets. */
2355 compute_antic (void)
2357 bool changed
= true;
2358 int num_iterations
= 0;
2362 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2363 We pre-build the map of blocks with incoming abnormal edges here. */
2364 has_abnormal_preds
= sbitmap_alloc (last_basic_block_for_fn (cfun
));
2365 bitmap_clear (has_abnormal_preds
);
2367 FOR_ALL_BB_FN (block
, cfun
)
2372 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2374 e
->flags
&= ~EDGE_DFS_BACK
;
2375 if (e
->flags
& EDGE_ABNORMAL
)
2377 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2382 BB_VISITED (block
) = 0;
2384 /* While we are here, give empty ANTIC_IN sets to each block. */
2385 ANTIC_IN (block
) = bitmap_set_new ();
2386 PA_IN (block
) = bitmap_set_new ();
2389 /* At the exit block we anticipate nothing. */
2390 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2392 changed_blocks
= sbitmap_alloc (last_basic_block_for_fn (cfun
) + 1);
2393 bitmap_ones (changed_blocks
);
2396 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2397 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2398 /* ??? We need to clear our PHI translation cache here as the
2399 ANTIC sets shrink and we restrict valid translations to
2400 those having operands with leaders in ANTIC. Same below
2401 for PA ANTIC computation. */
2404 for (i
= postorder_num
- 1; i
>= 0; i
--)
2406 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2408 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2409 changed
|= compute_antic_aux (block
,
2410 bitmap_bit_p (has_abnormal_preds
,
2414 /* Theoretically possible, but *highly* unlikely. */
2415 gcc_checking_assert (num_iterations
< 500);
2418 statistics_histogram_event (cfun
, "compute_antic iterations",
2421 if (do_partial_partial
)
2423 bitmap_ones (changed_blocks
);
2424 mark_dfs_back_edges ();
2429 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2430 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2433 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2435 if (bitmap_bit_p (changed_blocks
, postorder
[i
]))
2437 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2439 |= compute_partial_antic_aux (block
,
2440 bitmap_bit_p (has_abnormal_preds
,
2444 /* Theoretically possible, but *highly* unlikely. */
2445 gcc_checking_assert (num_iterations
< 500);
2447 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2450 sbitmap_free (has_abnormal_preds
);
2451 sbitmap_free (changed_blocks
);
2455 /* Inserted expressions are placed onto this worklist, which is used
2456 for performing quick dead code elimination of insertions we made
2457 that didn't turn out to be necessary. */
2458 static bitmap inserted_exprs
;
2460 /* The actual worker for create_component_ref_by_pieces. */
2463 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2464 unsigned int *operand
, gimple_seq
*stmts
)
2466 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2469 switch (currop
->opcode
)
2473 tree folded
, sc
= NULL_TREE
;
2474 unsigned int nargs
= 0;
2476 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2479 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2484 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2488 args
= XNEWVEC (tree
, ref
->operands
.length () - 1);
2489 while (*operand
< ref
->operands
.length ())
2491 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2497 folded
= build_call_array (currop
->type
,
2498 (TREE_CODE (fn
) == FUNCTION_DECL
2499 ? build_fold_addr_expr (fn
) : fn
),
2503 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2509 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2513 tree offset
= currop
->op0
;
2514 if (TREE_CODE (baseop
) == ADDR_EXPR
2515 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2519 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2522 offset
= int_const_binop (PLUS_EXPR
, offset
,
2523 build_int_cst (TREE_TYPE (offset
),
2525 baseop
= build_fold_addr_expr (base
);
2527 return fold_build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2530 case TARGET_MEM_REF
:
2532 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2533 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2534 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2540 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2546 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2550 return build5 (TARGET_MEM_REF
, currop
->type
,
2551 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2557 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2563 case VIEW_CONVERT_EXPR
:
2565 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2569 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2572 case WITH_SIZE_EXPR
:
2574 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2578 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2581 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2586 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2590 tree op1
= currop
->op0
;
2591 tree op2
= currop
->op1
;
2592 return fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2595 /* For array ref vn_reference_op's, operand 1 of the array ref
2596 is op0 of the reference op and operand 3 of the array ref is
2598 case ARRAY_RANGE_REF
:
2602 tree genop1
= currop
->op0
;
2603 tree genop2
= currop
->op1
;
2604 tree genop3
= currop
->op2
;
2605 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2609 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2614 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2615 /* Drop zero minimum index if redundant. */
2616 if (integer_zerop (genop2
)
2618 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2622 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2629 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2630 /* We can't always put a size in units of the element alignment
2631 here as the element alignment may be not visible. See
2632 PR43783. Simply drop the element size for constant
2634 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2638 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2639 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2640 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2645 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2652 tree genop2
= currop
->op1
;
2653 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2656 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2660 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2664 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2669 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2690 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2691 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2692 trying to rename aggregates into ssa form directly, which is a no no.
2694 Thus, this routine doesn't create temporaries, it just builds a
2695 single access expression for the array, calling
2696 find_or_generate_expression to build the innermost pieces.
2698 This function is a subroutine of create_expression_by_pieces, and
2699 should not be called on it's own unless you really know what you
2703 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2706 unsigned int op
= 0;
2707 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2710 /* Find a simple leader for an expression, or generate one using
2711 create_expression_by_pieces from a NARY expression for the value.
2712 BLOCK is the basic_block we are looking for leaders in.
2713 OP is the tree expression to find a leader for or generate.
2714 Returns the leader or NULL_TREE on failure. */
2717 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2719 pre_expr expr
= get_or_alloc_expr_for (op
);
2720 unsigned int lookfor
= get_expr_value_id (expr
);
2721 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2724 if (leader
->kind
== NAME
)
2725 return PRE_EXPR_NAME (leader
);
2726 else if (leader
->kind
== CONSTANT
)
2727 return PRE_EXPR_CONSTANT (leader
);
2733 /* It must be a complex expression, so generate it recursively. Note
2734 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2735 where the insert algorithm fails to insert a required expression. */
2736 bitmap exprset
= value_expressions
[lookfor
];
2739 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2741 pre_expr temp
= expression_for_id (i
);
2742 /* We cannot insert random REFERENCE expressions at arbitrary
2743 places. We can insert NARYs which eventually re-materializes
2744 its operand values. */
2745 if (temp
->kind
== NARY
)
2746 return create_expression_by_pieces (block
, temp
, stmts
,
2747 get_expr_type (expr
));
2754 #define NECESSARY GF_PLF_1
2756 /* Create an expression in pieces, so that we can handle very complex
2757 expressions that may be ANTIC, but not necessary GIMPLE.
2758 BLOCK is the basic block the expression will be inserted into,
2759 EXPR is the expression to insert (in value form)
2760 STMTS is a statement list to append the necessary insertions into.
2762 This function will die if we hit some value that shouldn't be
2763 ANTIC but is (IE there is no leader for it, or its components).
2764 The function returns NULL_TREE in case a different antic expression
2765 has to be inserted first.
2766 This function may also generate expressions that are themselves
2767 partially or fully redundant. Those that are will be either made
2768 fully redundant during the next iteration of insert (for partially
2769 redundant ones), or eliminated by eliminate (for fully redundant
2773 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2774 gimple_seq
*stmts
, tree type
)
2778 gimple_seq forced_stmts
= NULL
;
2779 unsigned int value_id
;
2780 gimple_stmt_iterator gsi
;
2781 tree exprtype
= type
? type
: get_expr_type (expr
);
2787 /* We may hit the NAME/CONSTANT case if we have to convert types
2788 that value numbering saw through. */
2790 folded
= PRE_EXPR_NAME (expr
);
2793 folded
= PRE_EXPR_CONSTANT (expr
);
2797 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2798 folded
= create_component_ref_by_pieces (block
, ref
, stmts
);
2805 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2806 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2808 for (i
= 0; i
< nary
->length
; ++i
)
2810 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2813 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2814 may have conversions stripped. */
2815 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2818 genop
[i
] = fold_convert (nary
->type
, genop
[i
]);
2820 genop
[i
] = convert_to_ptrofftype (genop
[i
]);
2823 genop
[i
] = fold_convert (TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2825 if (nary
->opcode
== CONSTRUCTOR
)
2827 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2828 for (i
= 0; i
< nary
->length
; ++i
)
2829 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2830 folded
= build_constructor (nary
->type
, elts
);
2834 switch (nary
->length
)
2837 folded
= fold_build1 (nary
->opcode
, nary
->type
,
2841 folded
= fold_build2 (nary
->opcode
, nary
->type
,
2842 genop
[0], genop
[1]);
2845 folded
= fold_build3 (nary
->opcode
, nary
->type
,
2846 genop
[0], genop
[1], genop
[2]);
2858 if (!useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2859 folded
= fold_convert (exprtype
, folded
);
2861 /* Force the generated expression to be a sequence of GIMPLE
2863 We have to call unshare_expr because force_gimple_operand may
2864 modify the tree we pass to it. */
2865 folded
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
2868 /* If we have any intermediate expressions to the value sets, add them
2869 to the value sets and chain them in the instruction stream. */
2872 gsi
= gsi_start (forced_stmts
);
2873 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2875 gimple stmt
= gsi_stmt (gsi
);
2876 tree forcedname
= gimple_get_lhs (stmt
);
2879 if (TREE_CODE (forcedname
) == SSA_NAME
)
2881 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2882 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2883 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2884 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2885 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2886 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2887 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2890 gimple_seq_add_seq (stmts
, forced_stmts
);
2893 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2894 newstmt
= gimple_build_assign (name
, folded
);
2895 gimple_set_plf (newstmt
, NECESSARY
, false);
2897 gimple_seq_add_stmt (stmts
, newstmt
);
2898 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (name
));
2900 /* Fold the last statement. */
2901 gsi
= gsi_last (*stmts
);
2902 if (fold_stmt_inplace (&gsi
))
2903 update_stmt (gsi_stmt (gsi
));
2905 /* Add a value number to the temporary.
2906 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2907 we are creating the expression by pieces, and this particular piece of
2908 the expression may have been represented. There is no harm in replacing
2910 value_id
= get_expr_value_id (expr
);
2911 VN_INFO_GET (name
)->value_id
= value_id
;
2912 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2913 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2914 VN_INFO (name
)->valnum
= name
;
2915 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2916 nameexpr
= get_or_alloc_expr_for_name (name
);
2917 add_to_value (value_id
, nameexpr
);
2918 if (NEW_SETS (block
))
2919 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2920 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2922 pre_stats
.insertions
++;
2923 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2925 fprintf (dump_file
, "Inserted ");
2926 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
2927 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2928 block
->index
, value_id
);
2935 /* Insert the to-be-made-available values of expression EXPRNUM for each
2936 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2937 merge the result with a phi node, given the same value number as
2938 NODE. Return true if we have inserted new stuff. */
2941 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2942 vec
<pre_expr
> avail
)
2944 pre_expr expr
= expression_for_id (exprnum
);
2946 unsigned int val
= get_expr_value_id (expr
);
2948 bool insertions
= false;
2953 tree type
= get_expr_type (expr
);
2957 /* Make sure we aren't creating an induction variable. */
2958 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
2960 bool firstinsideloop
= false;
2961 bool secondinsideloop
= false;
2962 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2963 EDGE_PRED (block
, 0)->src
);
2964 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2965 EDGE_PRED (block
, 1)->src
);
2966 /* Induction variables only have one edge inside the loop. */
2967 if ((firstinsideloop
^ secondinsideloop
)
2968 && expr
->kind
!= REFERENCE
)
2970 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2971 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
2976 /* Make the necessary insertions. */
2977 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
2979 gimple_seq stmts
= NULL
;
2982 eprime
= avail
[pred
->dest_idx
];
2984 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
2986 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
2988 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
2989 gsi_insert_seq_on_edge (pred
, stmts
);
2992 /* We cannot insert a PHI node if we failed to insert
2997 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3000 else if (eprime
->kind
== CONSTANT
)
3002 /* Constants may not have the right type, fold_convert
3003 should give us back a constant with the right type. */
3004 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3005 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3007 tree builtexpr
= fold_convert (type
, constant
);
3008 if (!is_gimple_min_invariant (builtexpr
))
3010 tree forcedexpr
= force_gimple_operand (builtexpr
,
3013 if (!is_gimple_min_invariant (forcedexpr
))
3015 if (forcedexpr
!= builtexpr
)
3017 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3018 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3022 gimple_stmt_iterator gsi
;
3023 gsi
= gsi_start (stmts
);
3024 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3026 gimple stmt
= gsi_stmt (gsi
);
3027 tree lhs
= gimple_get_lhs (stmt
);
3028 if (TREE_CODE (lhs
) == SSA_NAME
)
3029 bitmap_set_bit (inserted_exprs
,
3030 SSA_NAME_VERSION (lhs
));
3031 gimple_set_plf (stmt
, NECESSARY
, false);
3033 gsi_insert_seq_on_edge (pred
, stmts
);
3035 avail
[pred
->dest_idx
]
3036 = get_or_alloc_expr_for_name (forcedexpr
);
3040 avail
[pred
->dest_idx
]
3041 = get_or_alloc_expr_for_constant (builtexpr
);
3044 else if (eprime
->kind
== NAME
)
3046 /* We may have to do a conversion because our value
3047 numbering can look through types in certain cases, but
3048 our IL requires all operands of a phi node have the same
3050 tree name
= PRE_EXPR_NAME (eprime
);
3051 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3055 builtexpr
= fold_convert (type
, name
);
3056 forcedexpr
= force_gimple_operand (builtexpr
,
3060 if (forcedexpr
!= name
)
3062 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3063 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3068 gimple_stmt_iterator gsi
;
3069 gsi
= gsi_start (stmts
);
3070 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3072 gimple stmt
= gsi_stmt (gsi
);
3073 tree lhs
= gimple_get_lhs (stmt
);
3074 if (TREE_CODE (lhs
) == SSA_NAME
)
3075 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
3076 gimple_set_plf (stmt
, NECESSARY
, false);
3078 gsi_insert_seq_on_edge (pred
, stmts
);
3080 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (forcedexpr
);
3084 /* If we didn't want a phi node, and we made insertions, we still have
3085 inserted new stuff, and thus return true. If we didn't want a phi node,
3086 and didn't make insertions, we haven't added anything new, so return
3088 if (nophi
&& insertions
)
3090 else if (nophi
&& !insertions
)
3093 /* Now build a phi for the new variable. */
3094 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3095 phi
= create_phi_node (temp
, block
);
3097 gimple_set_plf (phi
, NECESSARY
, false);
3098 VN_INFO_GET (temp
)->value_id
= val
;
3099 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3100 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3101 VN_INFO (temp
)->valnum
= temp
;
3102 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3103 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3105 pre_expr ae
= avail
[pred
->dest_idx
];
3106 gcc_assert (get_expr_type (ae
) == type
3107 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3108 if (ae
->kind
== CONSTANT
)
3109 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3110 pred
, UNKNOWN_LOCATION
);
3112 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3115 newphi
= get_or_alloc_expr_for_name (temp
);
3116 add_to_value (val
, newphi
);
3118 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3119 this insertion, since we test for the existence of this value in PHI_GEN
3120 before proceeding with the partial redundancy checks in insert_aux.
3122 The value may exist in AVAIL_OUT, in particular, it could be represented
3123 by the expression we are trying to eliminate, in which case we want the
3124 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3127 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3128 this block, because if it did, it would have existed in our dominator's
3129 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3132 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3133 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3135 bitmap_insert_into_set (NEW_SETS (block
),
3138 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3140 fprintf (dump_file
, "Created phi ");
3141 print_gimple_stmt (dump_file
, phi
, 0, 0);
3142 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3150 /* Perform insertion of partially redundant values.
3151 For BLOCK, do the following:
3152 1. Propagate the NEW_SETS of the dominator into the current block.
3153 If the block has multiple predecessors,
3154 2a. Iterate over the ANTIC expressions for the block to see if
3155 any of them are partially redundant.
3156 2b. If so, insert them into the necessary predecessors to make
3157 the expression fully redundant.
3158 2c. Insert a new PHI merging the values of the predecessors.
3159 2d. Insert the new PHI, and the new expressions, into the
3161 3. Recursively call ourselves on the dominator children of BLOCK.
3163 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3164 do_regular_insertion and do_partial_insertion.
3169 do_regular_insertion (basic_block block
, basic_block dom
)
3171 bool new_stuff
= false;
3172 vec
<pre_expr
> exprs
;
3174 vec
<pre_expr
> avail
= vNULL
;
3177 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3178 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3180 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3182 if (expr
->kind
== NARY
3183 || expr
->kind
== REFERENCE
)
3186 bool by_some
= false;
3187 bool cant_insert
= false;
3188 bool all_same
= true;
3189 pre_expr first_s
= NULL
;
3192 pre_expr eprime
= NULL
;
3194 pre_expr edoubleprime
= NULL
;
3195 bool do_insertion
= false;
3197 val
= get_expr_value_id (expr
);
3198 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3200 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3202 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3204 fprintf (dump_file
, "Found fully redundant value: ");
3205 print_pre_expr (dump_file
, expr
);
3206 fprintf (dump_file
, "\n");
3211 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3213 unsigned int vprime
;
3215 /* We should never run insertion for the exit block
3216 and so not come across fake pred edges. */
3217 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3219 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3222 /* eprime will generally only be NULL if the
3223 value of the expression, translated
3224 through the PHI for this predecessor, is
3225 undefined. If that is the case, we can't
3226 make the expression fully redundant,
3227 because its value is undefined along a
3228 predecessor path. We can thus break out
3229 early because it doesn't matter what the
3230 rest of the results are. */
3233 avail
[pred
->dest_idx
] = NULL
;
3238 eprime
= fully_constant_expression (eprime
);
3239 vprime
= get_expr_value_id (eprime
);
3240 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3242 if (edoubleprime
== NULL
)
3244 avail
[pred
->dest_idx
] = eprime
;
3249 avail
[pred
->dest_idx
] = edoubleprime
;
3251 /* We want to perform insertions to remove a redundancy on
3252 a path in the CFG we want to optimize for speed. */
3253 if (optimize_edge_for_speed_p (pred
))
3254 do_insertion
= true;
3255 if (first_s
== NULL
)
3256 first_s
= edoubleprime
;
3257 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3261 /* If we can insert it, it's not the same value
3262 already existing along every predecessor, and
3263 it's defined by some predecessor, it is
3264 partially redundant. */
3265 if (!cant_insert
&& !all_same
&& by_some
)
3269 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3271 fprintf (dump_file
, "Skipping partial redundancy for "
3273 print_pre_expr (dump_file
, expr
);
3274 fprintf (dump_file
, " (%04d), no redundancy on to be "
3275 "optimized for speed edge\n", val
);
3278 else if (dbg_cnt (treepre_insert
))
3280 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3282 fprintf (dump_file
, "Found partial redundancy for "
3284 print_pre_expr (dump_file
, expr
);
3285 fprintf (dump_file
, " (%04d)\n",
3286 get_expr_value_id (expr
));
3288 if (insert_into_preds_of_block (block
,
3289 get_expression_id (expr
),
3294 /* If all edges produce the same value and that value is
3295 an invariant, then the PHI has the same value on all
3296 edges. Note this. */
3297 else if (!cant_insert
&& all_same
)
3299 gcc_assert (edoubleprime
->kind
== CONSTANT
3300 || edoubleprime
->kind
== NAME
);
3302 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3304 gimple assign
= gimple_build_assign (temp
,
3305 edoubleprime
->kind
== CONSTANT
? PRE_EXPR_CONSTANT (edoubleprime
) : PRE_EXPR_NAME (edoubleprime
));
3306 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3307 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3309 gimple_set_plf (assign
, NECESSARY
, false);
3310 VN_INFO_GET (temp
)->value_id
= val
;
3311 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3312 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3313 VN_INFO (temp
)->valnum
= temp
;
3314 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3315 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3316 add_to_value (val
, newe
);
3317 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3318 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3328 /* Perform insertion for partially anticipatable expressions. There
3329 is only one case we will perform insertion for these. This case is
3330 if the expression is partially anticipatable, and fully available.
3331 In this case, we know that putting it earlier will enable us to
3332 remove the later computation. */
3336 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3338 bool new_stuff
= false;
3339 vec
<pre_expr
> exprs
;
3341 auto_vec
<pre_expr
> avail
;
3344 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3345 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3347 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3349 if (expr
->kind
== NARY
3350 || expr
->kind
== REFERENCE
)
3354 bool cant_insert
= false;
3357 pre_expr eprime
= NULL
;
3360 val
= get_expr_value_id (expr
);
3361 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3363 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3366 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3368 unsigned int vprime
;
3369 pre_expr edoubleprime
;
3371 /* We should never run insertion for the exit block
3372 and so not come across fake pred edges. */
3373 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3375 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3379 /* eprime will generally only be NULL if the
3380 value of the expression, translated
3381 through the PHI for this predecessor, is
3382 undefined. If that is the case, we can't
3383 make the expression fully redundant,
3384 because its value is undefined along a
3385 predecessor path. We can thus break out
3386 early because it doesn't matter what the
3387 rest of the results are. */
3390 avail
[pred
->dest_idx
] = NULL
;
3395 eprime
= fully_constant_expression (eprime
);
3396 vprime
= get_expr_value_id (eprime
);
3397 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3398 avail
[pred
->dest_idx
] = edoubleprime
;
3399 if (edoubleprime
== NULL
)
3406 /* If we can insert it, it's not the same value
3407 already existing along every predecessor, and
3408 it's defined by some predecessor, it is
3409 partially redundant. */
3410 if (!cant_insert
&& by_all
)
3413 bool do_insertion
= false;
3415 /* Insert only if we can remove a later expression on a path
3416 that we want to optimize for speed.
3417 The phi node that we will be inserting in BLOCK is not free,
3418 and inserting it for the sake of !optimize_for_speed successor
3419 may cause regressions on the speed path. */
3420 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3422 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3423 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3425 if (optimize_edge_for_speed_p (succ
))
3426 do_insertion
= true;
3432 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3434 fprintf (dump_file
, "Skipping partial partial redundancy "
3436 print_pre_expr (dump_file
, expr
);
3437 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3438 "on any to be optimized for speed edges\n", val
);
3441 else if (dbg_cnt (treepre_insert
))
3443 pre_stats
.pa_insert
++;
3444 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3446 fprintf (dump_file
, "Found partial partial redundancy "
3448 print_pre_expr (dump_file
, expr
);
3449 fprintf (dump_file
, " (%04d)\n",
3450 get_expr_value_id (expr
));
3452 if (insert_into_preds_of_block (block
,
3453 get_expression_id (expr
),
3466 insert_aux (basic_block block
)
3469 bool new_stuff
= false;
3474 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3479 bitmap_set_t newset
= NEW_SETS (dom
);
3482 /* Note that we need to value_replace both NEW_SETS, and
3483 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3484 represented by some non-simple expression here that we want
3485 to replace it with. */
3486 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3488 pre_expr expr
= expression_for_id (i
);
3489 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3490 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3493 if (!single_pred_p (block
))
3495 new_stuff
|= do_regular_insertion (block
, dom
);
3496 if (do_partial_partial
)
3497 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3501 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3503 son
= next_dom_son (CDI_DOMINATORS
, son
))
3505 new_stuff
|= insert_aux (son
);
3511 /* Perform insertion of partially redundant values. */
3516 bool new_stuff
= true;
3518 int num_iterations
= 0;
3520 FOR_ALL_BB_FN (bb
, cfun
)
3521 NEW_SETS (bb
) = bitmap_set_new ();
3526 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3527 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3528 new_stuff
= insert_aux (ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3530 /* Clear the NEW sets before the next iteration. We have already
3531 fully propagated its contents. */
3533 FOR_ALL_BB_FN (bb
, cfun
)
3534 bitmap_set_free (NEW_SETS (bb
));
3536 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3540 /* Compute the AVAIL set for all basic blocks.
3542 This function performs value numbering of the statements in each basic
3543 block. The AVAIL sets are built from information we glean while doing
3544 this value numbering, since the AVAIL sets contain only one entry per
3547 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3548 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3551 compute_avail (void)
3554 basic_block block
, son
;
3555 basic_block
*worklist
;
3559 /* We pretend that default definitions are defined in the entry block.
3560 This includes function arguments and the static chain decl. */
3561 for (i
= 1; i
< num_ssa_names
; ++i
)
3563 tree name
= ssa_name (i
);
3566 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3567 || has_zero_uses (name
)
3568 || virtual_operand_p (name
))
3571 e
= get_or_alloc_expr_for_name (name
);
3572 add_to_value (get_expr_value_id (e
), e
);
3573 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3574 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3578 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3580 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3581 "tmp_gen", ENTRY_BLOCK
);
3582 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3583 "avail_out", ENTRY_BLOCK
);
3586 /* Allocate the worklist. */
3587 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3589 /* Seed the algorithm by putting the dominator children of the entry
3590 block on the worklist. */
3591 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3593 son
= next_dom_son (CDI_DOMINATORS
, son
))
3594 worklist
[sp
++] = son
;
3596 /* Loop until the worklist is empty. */
3599 gimple_stmt_iterator gsi
;
3603 /* Pick a block from the worklist. */
3604 block
= worklist
[--sp
];
3606 /* Initially, the set of available values in BLOCK is that of
3607 its immediate dominator. */
3608 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3610 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3612 /* Generate values for PHI nodes. */
3613 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3615 tree result
= gimple_phi_result (gsi_stmt (gsi
));
3617 /* We have no need for virtual phis, as they don't represent
3618 actual computations. */
3619 if (virtual_operand_p (result
))
3622 pre_expr e
= get_or_alloc_expr_for_name (result
);
3623 add_to_value (get_expr_value_id (e
), e
);
3624 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3625 bitmap_insert_into_set (PHI_GEN (block
), e
);
3628 BB_MAY_NOTRETURN (block
) = 0;
3630 /* Now compute value numbers and populate value sets with all
3631 the expressions computed in BLOCK. */
3632 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3637 stmt
= gsi_stmt (gsi
);
3639 /* Cache whether the basic-block has any non-visible side-effect
3641 If this isn't a call or it is the last stmt in the
3642 basic-block then the CFG represents things correctly. */
3643 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3645 /* Non-looping const functions always return normally.
3646 Otherwise the call might not return or have side-effects
3647 that forbids hoisting possibly trapping expressions
3649 int flags
= gimple_call_flags (stmt
);
3650 if (!(flags
& ECF_CONST
)
3651 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3652 BB_MAY_NOTRETURN (block
) = 1;
3655 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3657 pre_expr e
= get_or_alloc_expr_for_name (op
);
3659 add_to_value (get_expr_value_id (e
), e
);
3660 bitmap_insert_into_set (TMP_GEN (block
), e
);
3661 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3664 if (gimple_has_side_effects (stmt
)
3665 || stmt_could_throw_p (stmt
)
3666 || is_gimple_debug (stmt
))
3669 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3671 if (ssa_undefined_value_p (op
))
3673 pre_expr e
= get_or_alloc_expr_for_name (op
);
3674 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3677 switch (gimple_code (stmt
))
3685 vn_reference_s ref1
;
3686 pre_expr result
= NULL
;
3688 /* We can value number only calls to real functions. */
3689 if (gimple_call_internal_p (stmt
))
3692 vn_reference_lookup_call (stmt
, &ref
, &ref1
);
3696 /* If the value of the call is not invalidated in
3697 this block until it is computed, add the expression
3699 if (!gimple_vuse (stmt
)
3701 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3702 || gimple_bb (SSA_NAME_DEF_STMT
3703 (gimple_vuse (stmt
))) != block
)
3705 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3706 result
->kind
= REFERENCE
;
3708 PRE_EXPR_REFERENCE (result
) = ref
;
3710 get_or_alloc_expression_id (result
);
3711 add_to_value (get_expr_value_id (result
), result
);
3712 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3719 pre_expr result
= NULL
;
3720 switch (vn_get_stmt_kind (stmt
))
3724 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3727 /* COND_EXPR and VEC_COND_EXPR are awkward in
3728 that they contain an embedded complex expression.
3729 Don't even try to shove those through PRE. */
3730 if (code
== COND_EXPR
3731 || code
== VEC_COND_EXPR
)
3734 vn_nary_op_lookup_stmt (stmt
, &nary
);
3738 /* If the NARY traps and there was a preceding
3739 point in the block that might not return avoid
3740 adding the nary to EXP_GEN. */
3741 if (BB_MAY_NOTRETURN (block
)
3742 && vn_nary_may_trap (nary
))
3745 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3746 result
->kind
= NARY
;
3748 PRE_EXPR_NARY (result
) = nary
;
3755 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
3761 /* If the value of the reference is not invalidated in
3762 this block until it is computed, add the expression
3764 if (gimple_vuse (stmt
))
3768 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3769 while (!gimple_nop_p (def_stmt
)
3770 && gimple_code (def_stmt
) != GIMPLE_PHI
3771 && gimple_bb (def_stmt
) == block
)
3773 if (stmt_may_clobber_ref_p
3774 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3780 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3786 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3787 result
->kind
= REFERENCE
;
3789 PRE_EXPR_REFERENCE (result
) = ref
;
3797 get_or_alloc_expression_id (result
);
3798 add_to_value (get_expr_value_id (result
), result
);
3799 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3807 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3809 print_bitmap_set (dump_file
, EXP_GEN (block
),
3810 "exp_gen", block
->index
);
3811 print_bitmap_set (dump_file
, PHI_GEN (block
),
3812 "phi_gen", block
->index
);
3813 print_bitmap_set (dump_file
, TMP_GEN (block
),
3814 "tmp_gen", block
->index
);
3815 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
3816 "avail_out", block
->index
);
3819 /* Put the dominator children of BLOCK on the worklist of blocks
3820 to compute available sets for. */
3821 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3823 son
= next_dom_son (CDI_DOMINATORS
, son
))
3824 worklist
[sp
++] = son
;
3831 /* Local state for the eliminate domwalk. */
3832 static vec
<gimple
> el_to_remove
;
3833 static unsigned int el_todo
;
3834 static vec
<tree
> el_avail
;
3835 static vec
<tree
> el_avail_stack
;
3837 /* Return a leader for OP that is available at the current point of the
3838 eliminate domwalk. */
3841 eliminate_avail (tree op
)
3843 tree valnum
= VN_INFO (op
)->valnum
;
3844 if (TREE_CODE (valnum
) == SSA_NAME
)
3846 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
3848 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
3849 return el_avail
[SSA_NAME_VERSION (valnum
)];
3851 else if (is_gimple_min_invariant (valnum
))
3856 /* At the current point of the eliminate domwalk make OP available. */
3859 eliminate_push_avail (tree op
)
3861 tree valnum
= VN_INFO (op
)->valnum
;
3862 if (TREE_CODE (valnum
) == SSA_NAME
)
3864 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
3865 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
3866 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
3867 el_avail_stack
.safe_push (op
);
3871 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
3872 the leader for the expression if insertion was successful. */
3875 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
3877 tree expr
= vn_get_expr_for (val
);
3878 if (!CONVERT_EXPR_P (expr
)
3879 && TREE_CODE (expr
) != VIEW_CONVERT_EXPR
)
3882 tree op
= TREE_OPERAND (expr
, 0);
3883 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
3887 tree res
= make_temp_ssa_name (TREE_TYPE (val
), NULL
, "pretmp");
3888 gimple tem
= gimple_build_assign (res
,
3889 fold_build1 (TREE_CODE (expr
),
3890 TREE_TYPE (expr
), leader
));
3891 gsi_insert_before (gsi
, tem
, GSI_SAME_STMT
);
3892 VN_INFO_GET (res
)->valnum
= val
;
3894 if (TREE_CODE (leader
) == SSA_NAME
)
3895 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
3897 pre_stats
.insertions
++;
3898 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3900 fprintf (dump_file
, "Inserted ");
3901 print_gimple_stmt (dump_file
, tem
, 0, 0);
3907 class eliminate_dom_walker
: public dom_walker
3910 eliminate_dom_walker (cdi_direction direction
, bool do_pre_
)
3911 : dom_walker (direction
), do_pre (do_pre_
) {}
3913 virtual void before_dom_children (basic_block
);
3914 virtual void after_dom_children (basic_block
);
3919 /* Perform elimination for the basic-block B during the domwalk. */
3922 eliminate_dom_walker::before_dom_children (basic_block b
)
3924 gimple_stmt_iterator gsi
;
3928 el_avail_stack
.safe_push (NULL_TREE
);
3930 /* ??? If we do nothing for unreachable blocks then this will confuse
3931 tailmerging. Eventually we can reduce its reliance on SCCVN now
3932 that we fully copy/constant-propagate (most) things. */
3934 for (gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
3936 gimple phi
= gsi_stmt (gsi
);
3937 tree res
= PHI_RESULT (phi
);
3939 if (virtual_operand_p (res
))
3945 tree sprime
= eliminate_avail (res
);
3949 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3951 fprintf (dump_file
, "Replaced redundant PHI node defining ");
3952 print_generic_expr (dump_file
, res
, 0);
3953 fprintf (dump_file
, " with ");
3954 print_generic_expr (dump_file
, sprime
, 0);
3955 fprintf (dump_file
, "\n");
3958 /* If we inserted this PHI node ourself, it's not an elimination. */
3960 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
3963 pre_stats
.eliminations
++;
3965 /* If we will propagate into all uses don't bother to do
3967 if (may_propagate_copy (res
, sprime
))
3969 /* Mark the PHI for removal. */
3970 el_to_remove
.safe_push (phi
);
3975 remove_phi_node (&gsi
, false);
3978 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
3979 && TREE_CODE (sprime
) == SSA_NAME
)
3980 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
3982 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
3983 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
3984 gimple stmt
= gimple_build_assign (res
, sprime
);
3985 /* ??? It cannot yet be necessary (DOM walk). */
3986 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
3988 gimple_stmt_iterator gsi2
= gsi_after_labels (b
);
3989 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
3993 eliminate_push_avail (res
);
3997 for (gsi
= gsi_start_bb (b
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3999 tree sprime
= NULL_TREE
;
4000 stmt
= gsi_stmt (gsi
);
4001 tree lhs
= gimple_get_lhs (stmt
);
4002 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
4003 && !gimple_has_volatile_ops (stmt
)
4004 /* See PR43491. Do not replace a global register variable when
4005 it is a the RHS of an assignment. Do replace local register
4006 variables since gcc does not guarantee a local variable will
4007 be allocated in register.
4008 ??? The fix isn't effective here. This should instead
4009 be ensured by not value-numbering them the same but treating
4010 them like volatiles? */
4011 && !(gimple_assign_single_p (stmt
)
4012 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
4013 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
))
4014 && is_global_var (gimple_assign_rhs1 (stmt
)))))
4016 sprime
= eliminate_avail (lhs
);
4019 /* If there is no existing usable leader but SCCVN thinks
4020 it has an expression it wants to use as replacement,
4022 tree val
= VN_INFO (lhs
)->valnum
;
4024 && TREE_CODE (val
) == SSA_NAME
4025 && VN_INFO (val
)->needs_insertion
4026 && VN_INFO (val
)->expr
!= NULL_TREE
4027 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4028 eliminate_push_avail (sprime
);
4031 /* If this now constitutes a copy duplicate points-to
4032 and range info appropriately. This is especially
4033 important for inserted code. See tree-ssa-copy.c
4034 for similar code. */
4036 && TREE_CODE (sprime
) == SSA_NAME
)
4038 basic_block sprime_b
= gimple_bb (SSA_NAME_DEF_STMT (sprime
));
4039 if (POINTER_TYPE_P (TREE_TYPE (lhs
))
4040 && SSA_NAME_PTR_INFO (lhs
)
4041 && !SSA_NAME_PTR_INFO (sprime
))
4043 duplicate_ssa_name_ptr_info (sprime
,
4044 SSA_NAME_PTR_INFO (lhs
));
4046 mark_ptr_info_alignment_unknown
4047 (SSA_NAME_PTR_INFO (sprime
));
4049 else if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
4050 && SSA_NAME_RANGE_INFO (lhs
)
4051 && !SSA_NAME_RANGE_INFO (sprime
)
4053 duplicate_ssa_name_range_info (sprime
,
4054 SSA_NAME_RANGE_TYPE (lhs
),
4055 SSA_NAME_RANGE_INFO (lhs
));
4058 /* Inhibit the use of an inserted PHI on a loop header when
4059 the address of the memory reference is a simple induction
4060 variable. In other cases the vectorizer won't do anything
4061 anyway (either it's loop invariant or a complicated
4064 && TREE_CODE (sprime
) == SSA_NAME
4066 && flag_tree_loop_vectorize
4067 && loop_outer (b
->loop_father
)
4068 && has_zero_uses (sprime
)
4069 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))
4070 && gimple_assign_load_p (stmt
))
4072 gimple def_stmt
= SSA_NAME_DEF_STMT (sprime
);
4073 basic_block def_bb
= gimple_bb (def_stmt
);
4074 if (gimple_code (def_stmt
) == GIMPLE_PHI
4075 && b
->loop_father
->header
== def_bb
)
4080 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4083 def_bb
= gimple_bb (SSA_NAME_DEF_STMT (op
));
4085 && flow_bb_inside_loop_p (b
->loop_father
, def_bb
)
4086 && simple_iv (b
->loop_father
,
4087 b
->loop_father
, op
, &iv
, true))
4095 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4097 fprintf (dump_file
, "Not replacing ");
4098 print_gimple_expr (dump_file
, stmt
, 0, 0);
4099 fprintf (dump_file
, " with ");
4100 print_generic_expr (dump_file
, sprime
, 0);
4101 fprintf (dump_file
, " which would add a loop"
4102 " carried dependence to loop %d\n",
4103 b
->loop_father
->num
);
4105 /* Don't keep sprime available. */
4113 /* If we can propagate the value computed for LHS into
4114 all uses don't bother doing anything with this stmt. */
4115 if (may_propagate_copy (lhs
, sprime
))
4117 /* Mark it for removal. */
4118 el_to_remove
.safe_push (stmt
);
4120 /* ??? Don't count copy/constant propagations. */
4121 if (gimple_assign_single_p (stmt
)
4122 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4123 || gimple_assign_rhs1 (stmt
) == sprime
))
4126 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4128 fprintf (dump_file
, "Replaced ");
4129 print_gimple_expr (dump_file
, stmt
, 0, 0);
4130 fprintf (dump_file
, " with ");
4131 print_generic_expr (dump_file
, sprime
, 0);
4132 fprintf (dump_file
, " in all uses of ");
4133 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4136 pre_stats
.eliminations
++;
4140 /* If this is an assignment from our leader (which
4141 happens in the case the value-number is a constant)
4142 then there is nothing to do. */
4143 if (gimple_assign_single_p (stmt
)
4144 && sprime
== gimple_assign_rhs1 (stmt
))
4147 /* Else replace its RHS. */
4148 bool can_make_abnormal_goto
4149 = is_gimple_call (stmt
)
4150 && stmt_can_make_abnormal_goto (stmt
);
4152 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4154 fprintf (dump_file
, "Replaced ");
4155 print_gimple_expr (dump_file
, stmt
, 0, 0);
4156 fprintf (dump_file
, " with ");
4157 print_generic_expr (dump_file
, sprime
, 0);
4158 fprintf (dump_file
, " in ");
4159 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4162 if (TREE_CODE (sprime
) == SSA_NAME
)
4163 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4166 pre_stats
.eliminations
++;
4167 gimple orig_stmt
= stmt
;
4168 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4169 TREE_TYPE (sprime
)))
4170 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4171 tree vdef
= gimple_vdef (stmt
);
4172 tree vuse
= gimple_vuse (stmt
);
4173 propagate_tree_value_into_stmt (&gsi
, sprime
);
4174 stmt
= gsi_stmt (gsi
);
4176 if (vdef
!= gimple_vdef (stmt
))
4177 VN_INFO (vdef
)->valnum
= vuse
;
4179 /* If we removed EH side-effects from the statement, clean
4180 its EH information. */
4181 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4183 bitmap_set_bit (need_eh_cleanup
,
4184 gimple_bb (stmt
)->index
);
4185 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4186 fprintf (dump_file
, " Removed EH side-effects.\n");
4189 /* Likewise for AB side-effects. */
4190 if (can_make_abnormal_goto
4191 && !stmt_can_make_abnormal_goto (stmt
))
4193 bitmap_set_bit (need_ab_cleanup
,
4194 gimple_bb (stmt
)->index
);
4195 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4196 fprintf (dump_file
, " Removed AB side-effects.\n");
4203 /* If the statement is a scalar store, see if the expression
4204 has the same value number as its rhs. If so, the store is
4206 if (gimple_assign_single_p (stmt
)
4207 && !gimple_has_volatile_ops (stmt
)
4208 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4209 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4210 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4213 tree rhs
= gimple_assign_rhs1 (stmt
);
4214 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4215 gimple_vuse (stmt
), VN_WALK
, NULL
);
4216 if (TREE_CODE (rhs
) == SSA_NAME
)
4217 rhs
= VN_INFO (rhs
)->valnum
;
4219 && operand_equal_p (val
, rhs
, 0))
4221 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4223 fprintf (dump_file
, "Deleted redundant store ");
4224 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4227 /* Queue stmt for removal. */
4228 el_to_remove
.safe_push (stmt
);
4233 bool can_make_abnormal_goto
= stmt_can_make_abnormal_goto (stmt
);
4234 bool was_noreturn
= (is_gimple_call (stmt
)
4235 && gimple_call_noreturn_p (stmt
));
4236 tree vdef
= gimple_vdef (stmt
);
4237 tree vuse
= gimple_vuse (stmt
);
4239 /* If we didn't replace the whole stmt (or propagate the result
4240 into all uses), replace all uses on this stmt with their
4242 use_operand_p use_p
;
4244 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_USE
)
4246 tree use
= USE_FROM_PTR (use_p
);
4247 /* ??? The call code above leaves stmt operands un-updated. */
4248 if (TREE_CODE (use
) != SSA_NAME
)
4250 tree sprime
= eliminate_avail (use
);
4251 if (sprime
&& sprime
!= use
4252 && may_propagate_copy (use
, sprime
)
4253 /* We substitute into debug stmts to avoid excessive
4254 debug temporaries created by removed stmts, but we need
4255 to avoid doing so for inserted sprimes as we never want
4256 to create debug temporaries for them. */
4258 || TREE_CODE (sprime
) != SSA_NAME
4259 || !is_gimple_debug (stmt
)
4260 || !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))))
4262 propagate_value (use_p
, sprime
);
4263 gimple_set_modified (stmt
, true);
4264 if (TREE_CODE (sprime
) == SSA_NAME
4265 && !is_gimple_debug (stmt
))
4266 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4271 /* Visit indirect calls and turn them into direct calls if
4272 possible using the devirtualization machinery. */
4273 if (is_gimple_call (stmt
))
4275 tree fn
= gimple_call_fn (stmt
);
4277 && flag_devirtualize
4278 && virtual_method_call_p (fn
))
4280 tree otr_type
= obj_type_ref_class (fn
);
4282 ipa_polymorphic_call_context
context (current_function_decl
, fn
, stmt
, &instance
);
4285 context
.get_dynamic_type (instance
, OBJ_TYPE_REF_OBJECT (fn
), otr_type
, stmt
);
4287 vec
<cgraph_node
*>targets
4288 = possible_polymorphic_call_targets (obj_type_ref_class (fn
),
4290 (OBJ_TYPE_REF_TOKEN (fn
)),
4293 if (dump_enabled_p ())
4294 dump_possible_polymorphic_call_targets (dump_file
,
4295 obj_type_ref_class (fn
),
4297 (OBJ_TYPE_REF_TOKEN (fn
)),
4299 if (final
&& targets
.length () <= 1 && dbg_cnt (devirt
))
4302 if (targets
.length () == 1)
4303 fn
= targets
[0]->decl
;
4305 fn
= builtin_decl_implicit (BUILT_IN_UNREACHABLE
);
4306 if (dump_enabled_p ())
4308 location_t loc
= gimple_location_safe (stmt
);
4309 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, loc
,
4310 "converting indirect call to "
4312 cgraph_node::get (fn
)->name ());
4314 gimple_call_set_fndecl (stmt
, fn
);
4315 gimple_set_modified (stmt
, true);
4318 gcc_assert (!ipa_intraprocedural_devirtualization (stmt
));
4322 if (gimple_modified_p (stmt
))
4324 /* If a formerly non-invariant ADDR_EXPR is turned into an
4325 invariant one it was on a separate stmt. */
4326 if (gimple_assign_single_p (stmt
)
4327 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
4328 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
4329 gimple old_stmt
= stmt
;
4330 if (is_gimple_call (stmt
))
4332 /* ??? Only fold calls inplace for now, this may create new
4333 SSA names which in turn will confuse free_scc_vn SSA name
4335 fold_stmt_inplace (&gsi
);
4336 /* When changing a call into a noreturn call, cfg cleanup
4337 is needed to fix up the noreturn call. */
4338 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4339 el_todo
|= TODO_cleanup_cfg
;
4344 stmt
= gsi_stmt (gsi
);
4345 if ((gimple_code (stmt
) == GIMPLE_COND
4346 && (gimple_cond_true_p (stmt
)
4347 || gimple_cond_false_p (stmt
)))
4348 || (gimple_code (stmt
) == GIMPLE_SWITCH
4349 && TREE_CODE (gimple_switch_index (stmt
)) == INTEGER_CST
))
4350 el_todo
|= TODO_cleanup_cfg
;
4352 /* If we removed EH side-effects from the statement, clean
4353 its EH information. */
4354 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
))
4356 bitmap_set_bit (need_eh_cleanup
,
4357 gimple_bb (stmt
)->index
);
4358 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4359 fprintf (dump_file
, " Removed EH side-effects.\n");
4361 /* Likewise for AB side-effects. */
4362 if (can_make_abnormal_goto
4363 && !stmt_can_make_abnormal_goto (stmt
))
4365 bitmap_set_bit (need_ab_cleanup
,
4366 gimple_bb (stmt
)->index
);
4367 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4368 fprintf (dump_file
, " Removed AB side-effects.\n");
4371 if (vdef
!= gimple_vdef (stmt
))
4372 VN_INFO (vdef
)->valnum
= vuse
;
4375 /* Make new values available - for fully redundant LHS we
4376 continue with the next stmt above and skip this. */
4378 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_DEF
)
4379 eliminate_push_avail (DEF_FROM_PTR (defp
));
4382 /* Replace destination PHI arguments. */
4385 FOR_EACH_EDGE (e
, ei
, b
->succs
)
4387 for (gsi
= gsi_start_phis (e
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4389 gimple phi
= gsi_stmt (gsi
);
4390 use_operand_p use_p
= PHI_ARG_DEF_PTR_FROM_EDGE (phi
, e
);
4391 tree arg
= USE_FROM_PTR (use_p
);
4392 if (TREE_CODE (arg
) != SSA_NAME
4393 || virtual_operand_p (arg
))
4395 tree sprime
= eliminate_avail (arg
);
4396 if (sprime
&& may_propagate_copy (arg
, sprime
))
4398 propagate_value (use_p
, sprime
);
4399 if (TREE_CODE (sprime
) == SSA_NAME
)
4400 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4406 /* Make no longer available leaders no longer available. */
4409 eliminate_dom_walker::after_dom_children (basic_block
)
4412 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4413 el_avail
[SSA_NAME_VERSION (VN_INFO (entry
)->valnum
)] = NULL_TREE
;
4416 /* Eliminate fully redundant computations. */
4419 eliminate (bool do_pre
)
4421 gimple_stmt_iterator gsi
;
4424 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4425 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4427 el_to_remove
.create (0);
4429 el_avail
.create (num_ssa_names
);
4430 el_avail_stack
.create (0);
4432 eliminate_dom_walker (CDI_DOMINATORS
,
4433 do_pre
).walk (cfun
->cfg
->x_entry_block_ptr
);
4435 el_avail
.release ();
4436 el_avail_stack
.release ();
4438 /* We cannot remove stmts during BB walk, especially not release SSA
4439 names there as this confuses the VN machinery. The stmts ending
4440 up in el_to_remove are either stores or simple copies.
4441 Remove stmts in reverse order to make debug stmt creation possible. */
4442 while (!el_to_remove
.is_empty ())
4444 stmt
= el_to_remove
.pop ();
4446 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4448 fprintf (dump_file
, "Removing dead stmt ");
4449 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4453 if (gimple_code (stmt
) == GIMPLE_PHI
)
4454 lhs
= gimple_phi_result (stmt
);
4456 lhs
= gimple_get_lhs (stmt
);
4459 && TREE_CODE (lhs
) == SSA_NAME
)
4460 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4462 gsi
= gsi_for_stmt (stmt
);
4463 if (gimple_code (stmt
) == GIMPLE_PHI
)
4464 remove_phi_node (&gsi
, true);
4467 basic_block bb
= gimple_bb (stmt
);
4468 unlink_stmt_vdef (stmt
);
4469 if (gsi_remove (&gsi
, true))
4470 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4471 release_defs (stmt
);
4474 /* Removing a stmt may expose a forwarder block. */
4475 el_todo
|= TODO_cleanup_cfg
;
4477 el_to_remove
.release ();
4482 /* Perform CFG cleanups made necessary by elimination. */
4485 fini_eliminate (void)
4487 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4488 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4491 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4494 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4496 BITMAP_FREE (need_eh_cleanup
);
4497 BITMAP_FREE (need_ab_cleanup
);
4499 if (do_eh_cleanup
|| do_ab_cleanup
)
4500 return TODO_cleanup_cfg
;
4504 /* Borrow a bit of tree-ssa-dce.c for the moment.
4505 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4506 this may be a bit faster, and we may want critical edges kept split. */
4508 /* If OP's defining statement has not already been determined to be necessary,
4509 mark that statement necessary. Return the stmt, if it is newly
4512 static inline gimple
4513 mark_operand_necessary (tree op
)
4519 if (TREE_CODE (op
) != SSA_NAME
)
4522 stmt
= SSA_NAME_DEF_STMT (op
);
4525 if (gimple_plf (stmt
, NECESSARY
)
4526 || gimple_nop_p (stmt
))
4529 gimple_set_plf (stmt
, NECESSARY
, true);
4533 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4534 to insert PHI nodes sometimes, and because value numbering of casts isn't
4535 perfect, we sometimes end up inserting dead code. This simple DCE-like
4536 pass removes any insertions we made that weren't actually used. */
4539 remove_dead_inserted_code (void)
4546 worklist
= BITMAP_ALLOC (NULL
);
4547 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4549 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4550 if (gimple_plf (t
, NECESSARY
))
4551 bitmap_set_bit (worklist
, i
);
4553 while (!bitmap_empty_p (worklist
))
4555 i
= bitmap_first_set_bit (worklist
);
4556 bitmap_clear_bit (worklist
, i
);
4557 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4559 /* PHI nodes are somewhat special in that each PHI alternative has
4560 data and control dependencies. All the statements feeding the
4561 PHI node's arguments are always necessary. */
4562 if (gimple_code (t
) == GIMPLE_PHI
)
4566 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4568 tree arg
= PHI_ARG_DEF (t
, k
);
4569 if (TREE_CODE (arg
) == SSA_NAME
)
4571 gimple n
= mark_operand_necessary (arg
);
4573 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4579 /* Propagate through the operands. Examine all the USE, VUSE and
4580 VDEF operands in this statement. Mark all the statements
4581 which feed this statement's uses as necessary. */
4585 /* The operands of VDEF expressions are also needed as they
4586 represent potential definitions that may reach this
4587 statement (VDEF operands allow us to follow def-def
4590 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4592 gimple n
= mark_operand_necessary (use
);
4594 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4599 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4601 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4602 if (!gimple_plf (t
, NECESSARY
))
4604 gimple_stmt_iterator gsi
;
4606 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4608 fprintf (dump_file
, "Removing unnecessary insertion:");
4609 print_gimple_stmt (dump_file
, t
, 0, 0);
4612 gsi
= gsi_for_stmt (t
);
4613 if (gimple_code (t
) == GIMPLE_PHI
)
4614 remove_phi_node (&gsi
, true);
4617 gsi_remove (&gsi
, true);
4622 BITMAP_FREE (worklist
);
4626 /* Initialize data structures used by PRE. */
4633 next_expression_id
= 1;
4634 expressions
.create (0);
4635 expressions
.safe_push (NULL
);
4636 value_expressions
.create (get_max_value_id () + 1);
4637 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4638 name_to_id
.create (0);
4640 inserted_exprs
= BITMAP_ALLOC (NULL
);
4642 connect_infinite_loops_to_exit ();
4643 memset (&pre_stats
, 0, sizeof (pre_stats
));
4645 postorder
= XNEWVEC (int, n_basic_blocks_for_fn (cfun
));
4646 postorder_num
= inverted_post_order_compute (postorder
);
4648 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4650 calculate_dominance_info (CDI_POST_DOMINATORS
);
4651 calculate_dominance_info (CDI_DOMINATORS
);
4653 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4654 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4655 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4656 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4657 sizeof (struct bitmap_set
), 30);
4658 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4659 sizeof (struct pre_expr_d
), 30);
4660 FOR_ALL_BB_FN (bb
, cfun
)
4662 EXP_GEN (bb
) = bitmap_set_new ();
4663 PHI_GEN (bb
) = bitmap_set_new ();
4664 TMP_GEN (bb
) = bitmap_set_new ();
4665 AVAIL_OUT (bb
) = bitmap_set_new ();
4670 /* Deallocate data structures used by PRE. */
4676 value_expressions
.release ();
4677 BITMAP_FREE (inserted_exprs
);
4678 bitmap_obstack_release (&grand_bitmap_obstack
);
4679 free_alloc_pool (bitmap_set_pool
);
4680 free_alloc_pool (pre_expr_pool
);
4681 delete phi_translate_table
;
4682 phi_translate_table
= NULL
;
4683 delete expression_to_id
;
4684 expression_to_id
= NULL
;
4685 name_to_id
.release ();
4687 free_aux_for_blocks ();
4689 free_dominance_info (CDI_POST_DOMINATORS
);
4694 const pass_data pass_data_pre
=
4696 GIMPLE_PASS
, /* type */
4698 OPTGROUP_NONE
, /* optinfo_flags */
4699 TV_TREE_PRE
, /* tv_id */
4700 /* PROP_no_crit_edges is ensured by placing pass_split_crit_edges before
4702 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4703 0, /* properties_provided */
4704 PROP_no_crit_edges
, /* properties_destroyed */
4705 TODO_rebuild_alias
, /* todo_flags_start */
4706 0, /* todo_flags_finish */
4709 class pass_pre
: public gimple_opt_pass
4712 pass_pre (gcc::context
*ctxt
)
4713 : gimple_opt_pass (pass_data_pre
, ctxt
)
4716 /* opt_pass methods: */
4717 virtual bool gate (function
*) { return flag_tree_pre
!= 0; }
4718 virtual unsigned int execute (function
*);
4720 }; // class pass_pre
4723 pass_pre::execute (function
*fun
)
4725 unsigned int todo
= 0;
4727 do_partial_partial
=
4728 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
4730 /* This has to happen before SCCVN runs because
4731 loop_optimizer_init may create new phis, etc. */
4732 loop_optimizer_init (LOOPS_NORMAL
);
4734 if (!run_scc_vn (VN_WALK
))
4736 loop_optimizer_finalize ();
4743 /* Collect and value number expressions computed in each basic block. */
4746 /* Insert can get quite slow on an incredibly large number of basic
4747 blocks due to some quadratic behavior. Until this behavior is
4748 fixed, don't run it when he have an incredibly large number of
4749 bb's. If we aren't going to run insert, there is no point in
4750 computing ANTIC, either, even though it's plenty fast. */
4751 if (n_basic_blocks_for_fn (fun
) < 4000)
4757 /* Make sure to remove fake edges before committing our inserts.
4758 This makes sure we don't end up with extra critical edges that
4759 we would need to split. */
4760 remove_fake_exit_edges ();
4761 gsi_commit_edge_inserts ();
4763 /* Remove all the redundant expressions. */
4764 todo
|= eliminate (true);
4766 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
4767 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
4768 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
4769 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
4771 clear_expression_ids ();
4772 remove_dead_inserted_code ();
4776 todo
|= fini_eliminate ();
4777 loop_optimizer_finalize ();
4779 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
4780 case we can merge the block with the remaining predecessor of the block.
4782 - call merge_blocks after each tail merge iteration
4783 - call merge_blocks after all tail merge iterations
4784 - mark TODO_cleanup_cfg when necessary
4785 - share the cfg cleanup with fini_pre. */
4786 todo
|= tail_merge_optimize (todo
);
4790 /* Tail merging invalidates the virtual SSA web, together with
4791 cfg-cleanup opportunities exposed by PRE this will wreck the
4792 SSA updating machinery. So make sure to run update-ssa
4793 manually, before eventually scheduling cfg-cleanup as part of
4795 update_ssa (TODO_update_ssa_only_virtuals
);
4803 make_pass_pre (gcc::context
*ctxt
)
4805 return new pass_pre (ctxt
);
4810 const pass_data pass_data_fre
=
4812 GIMPLE_PASS
, /* type */
4814 OPTGROUP_NONE
, /* optinfo_flags */
4815 TV_TREE_FRE
, /* tv_id */
4816 ( PROP_cfg
| PROP_ssa
), /* properties_required */
4817 0, /* properties_provided */
4818 0, /* properties_destroyed */
4819 0, /* todo_flags_start */
4820 0, /* todo_flags_finish */
4823 class pass_fre
: public gimple_opt_pass
4826 pass_fre (gcc::context
*ctxt
)
4827 : gimple_opt_pass (pass_data_fre
, ctxt
)
4830 /* opt_pass methods: */
4831 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
4832 virtual bool gate (function
*) { return flag_tree_fre
!= 0; }
4833 virtual unsigned int execute (function
*);
4835 }; // class pass_fre
4838 pass_fre::execute (function
*fun
)
4840 unsigned int todo
= 0;
4842 if (!run_scc_vn (VN_WALKREWRITE
))
4845 memset (&pre_stats
, 0, sizeof (pre_stats
));
4847 /* Remove all the redundant expressions. */
4848 todo
|= eliminate (false);
4850 todo
|= fini_eliminate ();
4854 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
4855 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
4863 make_pass_fre (gcc::context
*ctxt
)
4865 return new pass_fre (ctxt
);