2 Copyright (C) 2001-2016 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
30 #include "alloc-pool.h"
31 #include "tree-pass.h"
34 #include "gimple-pretty-print.h"
35 #include "fold-const.h"
37 #include "gimple-fold.h"
40 #include "gimple-iterator.h"
42 #include "tree-ssa-loop.h"
43 #include "tree-into-ssa.h"
47 #include "tree-ssa-sccvn.h"
48 #include "tree-scalar-evolution.h"
52 #include "tree-ssa-propagate.h"
53 #include "ipa-utils.h"
54 #include "tree-cfgcleanup.h"
55 #include "langhooks.h"
59 1. Avail sets can be shared by making an avail_find_leader that
60 walks up the dominator tree and looks in those avail sets.
61 This might affect code optimality, it's unclear right now.
62 2. Strength reduction can be performed by anticipating expressions
63 we can repair later on.
64 3. We can do back-substitution or smarter value numbering to catch
65 commutative expressions split up over multiple statements.
68 /* For ease of terminology, "expression node" in the below refers to
69 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
70 represent the actual statement containing the expressions we care about,
71 and we cache the value number by putting it in the expression. */
75 First we walk the statements to generate the AVAIL sets, the
76 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
77 generation of values/expressions by a given block. We use them
78 when computing the ANTIC sets. The AVAIL sets consist of
79 SSA_NAME's that represent values, so we know what values are
80 available in what blocks. AVAIL is a forward dataflow problem. In
81 SSA, values are never killed, so we don't need a kill set, or a
82 fixpoint iteration, in order to calculate the AVAIL sets. In
83 traditional parlance, AVAIL sets tell us the downsafety of the
86 Next, we generate the ANTIC sets. These sets represent the
87 anticipatable expressions. ANTIC is a backwards dataflow
88 problem. An expression is anticipatable in a given block if it could
89 be generated in that block. This means that if we had to perform
90 an insertion in that block, of the value of that expression, we
91 could. Calculating the ANTIC sets requires phi translation of
92 expressions, because the flow goes backwards through phis. We must
93 iterate to a fixpoint of the ANTIC sets, because we have a kill
94 set. Even in SSA form, values are not live over the entire
95 function, only from their definition point onwards. So we have to
96 remove values from the ANTIC set once we go past the definition
97 point of the leaders that make them up.
98 compute_antic/compute_antic_aux performs this computation.
100 Third, we perform insertions to make partially redundant
101 expressions fully redundant.
103 An expression is partially redundant (excluding partial
106 1. It is AVAIL in some, but not all, of the predecessors of a
108 2. It is ANTIC in all the predecessors.
110 In order to make it fully redundant, we insert the expression into
111 the predecessors where it is not available, but is ANTIC.
113 For the partial anticipation case, we only perform insertion if it
114 is partially anticipated in some block, and fully available in all
117 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
118 performs these steps.
120 Fourth, we eliminate fully redundant expressions.
121 This is a simple statement walk that replaces redundant
122 calculations with the now available values. */
124 /* Representations of value numbers:
126 Value numbers are represented by a representative SSA_NAME. We
127 will create fake SSA_NAME's in situations where we need a
128 representative but do not have one (because it is a complex
129 expression). In order to facilitate storing the value numbers in
130 bitmaps, and keep the number of wasted SSA_NAME's down, we also
131 associate a value_id with each value number, and create full blown
132 ssa_name's only where we actually need them (IE in operands of
133 existing expressions).
135 Theoretically you could replace all the value_id's with
136 SSA_NAME_VERSION, but this would allocate a large number of
137 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
138 It would also require an additional indirection at each point we
141 /* Representation of expressions on value numbers:
143 Expressions consisting of value numbers are represented the same
144 way as our VN internally represents them, with an additional
145 "pre_expr" wrapping around them in order to facilitate storing all
146 of the expressions in the same sets. */
148 /* Representation of sets:
150 The dataflow sets do not need to be sorted in any particular order
151 for the majority of their lifetime, are simply represented as two
152 bitmaps, one that keeps track of values present in the set, and one
153 that keeps track of expressions present in the set.
155 When we need them in topological order, we produce it on demand by
156 transforming the bitmap into an array and sorting it into topo
159 /* Type of expression, used to know which member of the PRE_EXPR union
175 vn_reference_t reference
;
178 typedef struct pre_expr_d
: nofree_ptr_hash
<pre_expr_d
>
180 enum pre_expr_kind kind
;
184 /* hash_table support. */
185 static inline hashval_t
hash (const pre_expr_d
*);
186 static inline int equal (const pre_expr_d
*, const pre_expr_d
*);
189 #define PRE_EXPR_NAME(e) (e)->u.name
190 #define PRE_EXPR_NARY(e) (e)->u.nary
191 #define PRE_EXPR_REFERENCE(e) (e)->u.reference
192 #define PRE_EXPR_CONSTANT(e) (e)->u.constant
194 /* Compare E1 and E1 for equality. */
197 pre_expr_d::equal (const pre_expr_d
*e1
, const pre_expr_d
*e2
)
199 if (e1
->kind
!= e2
->kind
)
205 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
206 PRE_EXPR_CONSTANT (e2
));
208 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
210 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
212 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
213 PRE_EXPR_REFERENCE (e2
));
222 pre_expr_d::hash (const pre_expr_d
*e
)
227 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
229 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
231 return PRE_EXPR_NARY (e
)->hashcode
;
233 return PRE_EXPR_REFERENCE (e
)->hashcode
;
239 /* Next global expression id number. */
240 static unsigned int next_expression_id
;
242 /* Mapping from expression to id number we can use in bitmap sets. */
243 static vec
<pre_expr
> expressions
;
244 static hash_table
<pre_expr_d
> *expression_to_id
;
245 static vec
<unsigned> name_to_id
;
247 /* Allocate an expression id for EXPR. */
249 static inline unsigned int
250 alloc_expression_id (pre_expr expr
)
252 struct pre_expr_d
**slot
;
253 /* Make sure we won't overflow. */
254 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
255 expr
->id
= next_expression_id
++;
256 expressions
.safe_push (expr
);
257 if (expr
->kind
== NAME
)
259 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
260 /* vec::safe_grow_cleared allocates no headroom. Avoid frequent
261 re-allocations by using vec::reserve upfront. */
262 unsigned old_len
= name_to_id
.length ();
263 name_to_id
.reserve (num_ssa_names
- old_len
);
264 name_to_id
.quick_grow_cleared (num_ssa_names
);
265 gcc_assert (name_to_id
[version
] == 0);
266 name_to_id
[version
] = expr
->id
;
270 slot
= expression_to_id
->find_slot (expr
, INSERT
);
274 return next_expression_id
- 1;
277 /* Return the expression id for tree EXPR. */
279 static inline unsigned int
280 get_expression_id (const pre_expr expr
)
285 static inline unsigned int
286 lookup_expression_id (const pre_expr expr
)
288 struct pre_expr_d
**slot
;
290 if (expr
->kind
== NAME
)
292 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
293 if (name_to_id
.length () <= version
)
295 return name_to_id
[version
];
299 slot
= expression_to_id
->find_slot (expr
, NO_INSERT
);
302 return ((pre_expr
)*slot
)->id
;
306 /* Return the existing expression id for EXPR, or create one if one
307 does not exist yet. */
309 static inline unsigned int
310 get_or_alloc_expression_id (pre_expr expr
)
312 unsigned int id
= lookup_expression_id (expr
);
314 return alloc_expression_id (expr
);
315 return expr
->id
= id
;
318 /* Return the expression that has expression id ID */
320 static inline pre_expr
321 expression_for_id (unsigned int id
)
323 return expressions
[id
];
326 /* Free the expression id field in all of our expressions,
327 and then destroy the expressions array. */
330 clear_expression_ids (void)
332 expressions
.release ();
335 static object_allocator
<pre_expr_d
> pre_expr_pool ("pre_expr nodes");
337 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
340 get_or_alloc_expr_for_name (tree name
)
342 struct pre_expr_d expr
;
344 unsigned int result_id
;
348 PRE_EXPR_NAME (&expr
) = name
;
349 result_id
= lookup_expression_id (&expr
);
351 return expression_for_id (result_id
);
353 result
= pre_expr_pool
.allocate ();
355 PRE_EXPR_NAME (result
) = name
;
356 alloc_expression_id (result
);
360 /* An unordered bitmap set. One bitmap tracks values, the other,
362 typedef struct bitmap_set
364 bitmap_head expressions
;
368 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
369 EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi))
371 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
372 EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi))
374 /* Mapping from value id to expressions with that value_id. */
375 static vec
<bitmap
> value_expressions
;
377 /* Sets that we need to keep track of. */
378 typedef struct bb_bitmap_sets
380 /* The EXP_GEN set, which represents expressions/values generated in
382 bitmap_set_t exp_gen
;
384 /* The PHI_GEN set, which represents PHI results generated in a
386 bitmap_set_t phi_gen
;
388 /* The TMP_GEN set, which represents results/temporaries generated
389 in a basic block. IE the LHS of an expression. */
390 bitmap_set_t tmp_gen
;
392 /* The AVAIL_OUT set, which represents which values are available in
393 a given basic block. */
394 bitmap_set_t avail_out
;
396 /* The ANTIC_IN set, which represents which values are anticipatable
397 in a given basic block. */
398 bitmap_set_t antic_in
;
400 /* The PA_IN set, which represents which values are
401 partially anticipatable in a given basic block. */
404 /* The NEW_SETS set, which is used during insertion to augment the
405 AVAIL_OUT set of blocks with the new insertions performed during
406 the current iteration. */
407 bitmap_set_t new_sets
;
409 /* A cache for value_dies_in_block_x. */
412 /* The live virtual operand on successor edges. */
415 /* True if we have visited this block during ANTIC calculation. */
416 unsigned int visited
: 1;
418 /* True when the block contains a call that might not return. */
419 unsigned int contains_may_not_return_call
: 1;
422 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
423 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
424 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
425 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
426 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
427 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
428 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
429 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
430 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
431 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
432 #define BB_LIVE_VOP_ON_EXIT(BB) ((bb_value_sets_t) ((BB)->aux))->vop_on_exit
435 /* This structure is used to keep track of statistics on what
436 optimization PRE was able to perform. */
439 /* The number of RHS computations eliminated by PRE. */
442 /* The number of new expressions/temporaries generated by PRE. */
445 /* The number of inserts found due to partial anticipation */
448 /* The number of new PHI nodes added by PRE. */
452 static bool do_partial_partial
;
453 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int);
454 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
455 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
456 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
457 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
458 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
459 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
461 static bitmap_set_t
bitmap_set_new (void);
462 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
464 static tree
find_or_generate_expression (basic_block
, tree
, gimple_seq
*);
465 static unsigned int get_expr_value_id (pre_expr
);
467 /* We can add and remove elements and entries to and from sets
468 and hash tables, so we use alloc pools for them. */
470 static object_allocator
<bitmap_set
> bitmap_set_pool ("Bitmap sets");
471 static bitmap_obstack grand_bitmap_obstack
;
473 /* Set of blocks with statements that have had their EH properties changed. */
474 static bitmap need_eh_cleanup
;
476 /* Set of blocks with statements that have had their AB properties changed. */
477 static bitmap need_ab_cleanup
;
479 /* A three tuple {e, pred, v} used to cache phi translations in the
480 phi_translate_table. */
482 typedef struct expr_pred_trans_d
: free_ptr_hash
<expr_pred_trans_d
>
484 /* The expression. */
487 /* The predecessor block along which we translated the expression. */
490 /* The value that resulted from the translation. */
493 /* The hashcode for the expression, pred pair. This is cached for
497 /* hash_table support. */
498 static inline hashval_t
hash (const expr_pred_trans_d
*);
499 static inline int equal (const expr_pred_trans_d
*, const expr_pred_trans_d
*);
500 } *expr_pred_trans_t
;
501 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
504 expr_pred_trans_d::hash (const expr_pred_trans_d
*e
)
510 expr_pred_trans_d::equal (const expr_pred_trans_d
*ve1
,
511 const expr_pred_trans_d
*ve2
)
513 basic_block b1
= ve1
->pred
;
514 basic_block b2
= ve2
->pred
;
516 /* If they are not translations for the same basic block, they can't
520 return pre_expr_d::equal (ve1
->e
, ve2
->e
);
523 /* The phi_translate_table caches phi translations for a given
524 expression and predecessor. */
525 static hash_table
<expr_pred_trans_d
> *phi_translate_table
;
527 /* Add the tuple mapping from {expression E, basic block PRED} to
528 the phi translation table and return whether it pre-existed. */
531 phi_trans_add (expr_pred_trans_t
*entry
, pre_expr e
, basic_block pred
)
533 expr_pred_trans_t
*slot
;
534 expr_pred_trans_d tem
;
535 hashval_t hash
= iterative_hash_hashval_t (pre_expr_d::hash (e
),
540 slot
= phi_translate_table
->find_slot_with_hash (&tem
, hash
, INSERT
);
547 *entry
= *slot
= XNEW (struct expr_pred_trans_d
);
549 (*entry
)->pred
= pred
;
550 (*entry
)->hashcode
= hash
;
555 /* Add expression E to the expression set of value id V. */
558 add_to_value (unsigned int v
, pre_expr e
)
562 gcc_checking_assert (get_expr_value_id (e
) == v
);
564 if (v
>= value_expressions
.length ())
566 value_expressions
.safe_grow_cleared (v
+ 1);
569 set
= value_expressions
[v
];
572 set
= BITMAP_ALLOC (&grand_bitmap_obstack
);
573 value_expressions
[v
] = set
;
576 bitmap_set_bit (set
, get_or_alloc_expression_id (e
));
579 /* Create a new bitmap set and return it. */
582 bitmap_set_new (void)
584 bitmap_set_t ret
= bitmap_set_pool
.allocate ();
585 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
586 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
590 /* Return the value id for a PRE expression EXPR. */
593 get_expr_value_id (pre_expr expr
)
599 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
602 id
= VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
605 id
= PRE_EXPR_NARY (expr
)->value_id
;
608 id
= PRE_EXPR_REFERENCE (expr
)->value_id
;
613 /* ??? We cannot assert that expr has a value-id (it can be 0), because
614 we assign value-ids only to expressions that have a result
615 in set_hashtable_value_ids. */
619 /* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
622 sccvn_valnum_from_value_id (unsigned int val
)
626 bitmap exprset
= value_expressions
[val
];
627 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
629 pre_expr vexpr
= expression_for_id (i
);
630 if (vexpr
->kind
== NAME
)
631 return VN_INFO (PRE_EXPR_NAME (vexpr
))->valnum
;
632 else if (vexpr
->kind
== CONSTANT
)
633 return PRE_EXPR_CONSTANT (vexpr
);
638 /* Remove an expression EXPR from a bitmapped set. */
641 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
643 unsigned int val
= get_expr_value_id (expr
);
644 if (!value_id_constant_p (val
))
646 bitmap_clear_bit (&set
->values
, val
);
647 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
652 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
653 unsigned int val
, bool allow_constants
)
655 if (allow_constants
|| !value_id_constant_p (val
))
657 /* We specifically expect this and only this function to be able to
658 insert constants into a set. */
659 bitmap_set_bit (&set
->values
, val
);
660 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
664 /* Insert an expression EXPR into a bitmapped set. */
667 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
669 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
672 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
675 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
677 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
678 bitmap_copy (&dest
->values
, &orig
->values
);
682 /* Free memory used up by SET. */
684 bitmap_set_free (bitmap_set_t set
)
686 bitmap_clear (&set
->expressions
);
687 bitmap_clear (&set
->values
);
691 /* Generate an topological-ordered array of bitmap set SET. */
694 sorted_array_from_bitmap_set (bitmap_set_t set
)
697 bitmap_iterator bi
, bj
;
698 vec
<pre_expr
> result
;
700 /* Pre-allocate enough space for the array. */
701 result
.create (bitmap_count_bits (&set
->expressions
));
703 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
705 /* The number of expressions having a given value is usually
706 relatively small. Thus, rather than making a vector of all
707 the expressions and sorting it by value-id, we walk the values
708 and check in the reverse mapping that tells us what expressions
709 have a given value, to filter those in our set. As a result,
710 the expressions are inserted in value-id order, which means
713 If this is somehow a significant lose for some cases, we can
714 choose which set to walk based on the set size. */
715 bitmap exprset
= value_expressions
[i
];
716 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, j
, bj
)
718 if (bitmap_bit_p (&set
->expressions
, j
))
719 result
.quick_push (expression_for_id (j
));
726 /* Perform bitmapped set operation DEST &= ORIG. */
729 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
737 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
739 bitmap_and_into (&dest
->values
, &orig
->values
);
740 bitmap_copy (&temp
, &dest
->expressions
);
741 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
743 pre_expr expr
= expression_for_id (i
);
744 unsigned int value_id
= get_expr_value_id (expr
);
745 if (!bitmap_bit_p (&dest
->values
, value_id
))
746 bitmap_clear_bit (&dest
->expressions
, i
);
748 bitmap_clear (&temp
);
752 /* Subtract all values and expressions contained in ORIG from DEST. */
755 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
757 bitmap_set_t result
= bitmap_set_new ();
761 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
764 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
766 pre_expr expr
= expression_for_id (i
);
767 unsigned int value_id
= get_expr_value_id (expr
);
768 bitmap_set_bit (&result
->values
, value_id
);
774 /* Subtract all the values in bitmap set B from bitmap set A. */
777 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
783 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
785 bitmap_copy (&temp
, &a
->expressions
);
786 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
788 pre_expr expr
= expression_for_id (i
);
789 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
790 bitmap_remove_from_set (a
, expr
);
792 bitmap_clear (&temp
);
796 /* Return true if bitmapped set SET contains the value VALUE_ID. */
799 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
801 if (value_id_constant_p (value_id
))
804 if (!set
|| bitmap_empty_p (&set
->expressions
))
807 return bitmap_bit_p (&set
->values
, value_id
);
811 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
813 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
816 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
819 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
826 if (value_id_constant_p (lookfor
))
829 if (!bitmap_set_contains_value (set
, lookfor
))
832 /* The number of expressions having a given value is usually
833 significantly less than the total number of expressions in SET.
834 Thus, rather than check, for each expression in SET, whether it
835 has the value LOOKFOR, we walk the reverse mapping that tells us
836 what expressions have a given value, and see if any of those
837 expressions are in our set. For large testcases, this is about
838 5-10x faster than walking the bitmap. If this is somehow a
839 significant lose for some cases, we can choose which set to walk
840 based on the set size. */
841 exprset
= value_expressions
[lookfor
];
842 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
844 if (bitmap_clear_bit (&set
->expressions
, i
))
846 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
854 /* Return true if two bitmap sets are equal. */
857 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
859 return bitmap_equal_p (&a
->values
, &b
->values
);
862 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
863 and add it otherwise. */
866 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
868 unsigned int val
= get_expr_value_id (expr
);
870 if (bitmap_set_contains_value (set
, val
))
871 bitmap_set_replace_value (set
, val
, expr
);
873 bitmap_insert_into_set (set
, expr
);
876 /* Insert EXPR into SET if EXPR's value is not already present in
880 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
882 unsigned int val
= get_expr_value_id (expr
);
884 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
886 /* Constant values are always considered to be part of the set. */
887 if (value_id_constant_p (val
))
890 /* If the value membership changed, add the expression. */
891 if (bitmap_set_bit (&set
->values
, val
))
892 bitmap_set_bit (&set
->expressions
, expr
->id
);
895 /* Print out EXPR to outfile. */
898 print_pre_expr (FILE *outfile
, const pre_expr expr
)
903 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
906 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
911 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
912 fprintf (outfile
, "{%s,", get_tree_code_name (nary
->opcode
));
913 for (i
= 0; i
< nary
->length
; i
++)
915 print_generic_expr (outfile
, nary
->op
[i
], 0);
916 if (i
!= (unsigned) nary
->length
- 1)
917 fprintf (outfile
, ",");
919 fprintf (outfile
, "}");
925 vn_reference_op_t vro
;
927 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
928 fprintf (outfile
, "{");
930 ref
->operands
.iterate (i
, &vro
);
933 bool closebrace
= false;
934 if (vro
->opcode
!= SSA_NAME
935 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
937 fprintf (outfile
, "%s", get_tree_code_name (vro
->opcode
));
940 fprintf (outfile
, "<");
946 print_generic_expr (outfile
, vro
->op0
, 0);
949 fprintf (outfile
, ",");
950 print_generic_expr (outfile
, vro
->op1
, 0);
954 fprintf (outfile
, ",");
955 print_generic_expr (outfile
, vro
->op2
, 0);
959 fprintf (outfile
, ">");
960 if (i
!= ref
->operands
.length () - 1)
961 fprintf (outfile
, ",");
963 fprintf (outfile
, "}");
966 fprintf (outfile
, "@");
967 print_generic_expr (outfile
, ref
->vuse
, 0);
973 void debug_pre_expr (pre_expr
);
975 /* Like print_pre_expr but always prints to stderr. */
977 debug_pre_expr (pre_expr e
)
979 print_pre_expr (stderr
, e
);
980 fprintf (stderr
, "\n");
983 /* Print out SET to OUTFILE. */
986 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
987 const char *setname
, int blockindex
)
989 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
996 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
998 const pre_expr expr
= expression_for_id (i
);
1001 fprintf (outfile
, ", ");
1003 print_pre_expr (outfile
, expr
);
1005 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1008 fprintf (outfile
, " }\n");
1011 void debug_bitmap_set (bitmap_set_t
);
1014 debug_bitmap_set (bitmap_set_t set
)
1016 print_bitmap_set (stderr
, set
, "debug", 0);
1019 void debug_bitmap_sets_for (basic_block
);
1022 debug_bitmap_sets_for (basic_block bb
)
1024 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1025 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1026 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1027 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1028 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1029 if (do_partial_partial
)
1030 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1031 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1034 /* Print out the expressions that have VAL to OUTFILE. */
1037 print_value_expressions (FILE *outfile
, unsigned int val
)
1039 bitmap set
= value_expressions
[val
];
1044 sprintf (s
, "%04d", val
);
1045 x
.expressions
= *set
;
1046 print_bitmap_set (outfile
, &x
, s
, 0);
1052 debug_value_expressions (unsigned int val
)
1054 print_value_expressions (stderr
, val
);
1057 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1061 get_or_alloc_expr_for_constant (tree constant
)
1063 unsigned int result_id
;
1064 unsigned int value_id
;
1065 struct pre_expr_d expr
;
1068 expr
.kind
= CONSTANT
;
1069 PRE_EXPR_CONSTANT (&expr
) = constant
;
1070 result_id
= lookup_expression_id (&expr
);
1072 return expression_for_id (result_id
);
1074 newexpr
= pre_expr_pool
.allocate ();
1075 newexpr
->kind
= CONSTANT
;
1076 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1077 alloc_expression_id (newexpr
);
1078 value_id
= get_or_alloc_constant_value_id (constant
);
1079 add_to_value (value_id
, newexpr
);
1083 /* Given a value id V, find the actual tree representing the constant
1084 value if there is one, and return it. Return NULL if we can't find
1088 get_constant_for_value_id (unsigned int v
)
1090 if (value_id_constant_p (v
))
1094 bitmap exprset
= value_expressions
[v
];
1096 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1098 pre_expr expr
= expression_for_id (i
);
1099 if (expr
->kind
== CONSTANT
)
1100 return PRE_EXPR_CONSTANT (expr
);
1106 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1107 Currently only supports constants and SSA_NAMES. */
1109 get_or_alloc_expr_for (tree t
)
1111 if (TREE_CODE (t
) == SSA_NAME
)
1112 return get_or_alloc_expr_for_name (t
);
1113 else if (is_gimple_min_invariant (t
))
1114 return get_or_alloc_expr_for_constant (t
);
1117 /* More complex expressions can result from SCCVN expression
1118 simplification that inserts values for them. As they all
1119 do not have VOPs the get handled by the nary ops struct. */
1120 vn_nary_op_t result
;
1121 unsigned int result_id
;
1122 vn_nary_op_lookup (t
, &result
);
1125 pre_expr e
= pre_expr_pool
.allocate ();
1127 PRE_EXPR_NARY (e
) = result
;
1128 result_id
= lookup_expression_id (e
);
1131 pre_expr_pool
.remove (e
);
1132 e
= expression_for_id (result_id
);
1135 alloc_expression_id (e
);
1142 /* Return the folded version of T if T, when folded, is a gimple
1143 min_invariant. Otherwise, return T. */
1146 fully_constant_expression (pre_expr e
)
1154 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1155 switch (TREE_CODE_CLASS (nary
->opcode
))
1158 case tcc_comparison
:
1160 /* We have to go from trees to pre exprs to value ids to
1162 tree naryop0
= nary
->op
[0];
1163 tree naryop1
= nary
->op
[1];
1165 if (!is_gimple_min_invariant (naryop0
))
1167 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1168 unsigned int vrep0
= get_expr_value_id (rep0
);
1169 tree const0
= get_constant_for_value_id (vrep0
);
1171 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1173 if (!is_gimple_min_invariant (naryop1
))
1175 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1176 unsigned int vrep1
= get_expr_value_id (rep1
);
1177 tree const1
= get_constant_for_value_id (vrep1
);
1179 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1181 result
= fold_binary (nary
->opcode
, nary
->type
,
1183 if (result
&& is_gimple_min_invariant (result
))
1184 return get_or_alloc_expr_for_constant (result
);
1185 /* We might have simplified the expression to a
1186 SSA_NAME for example from x_1 * 1. But we cannot
1187 insert a PHI for x_1 unconditionally as x_1 might
1188 not be available readily. */
1192 if (nary
->opcode
!= REALPART_EXPR
1193 && nary
->opcode
!= IMAGPART_EXPR
1194 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1199 /* We have to go from trees to pre exprs to value ids to
1201 tree naryop0
= nary
->op
[0];
1202 tree const0
, result
;
1203 if (is_gimple_min_invariant (naryop0
))
1207 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1208 unsigned int vrep0
= get_expr_value_id (rep0
);
1209 const0
= get_constant_for_value_id (vrep0
);
1214 tree type1
= TREE_TYPE (nary
->op
[0]);
1215 const0
= fold_convert (type1
, const0
);
1216 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1218 if (result
&& is_gimple_min_invariant (result
))
1219 return get_or_alloc_expr_for_constant (result
);
1228 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1230 if ((folded
= fully_constant_vn_reference_p (ref
)))
1231 return get_or_alloc_expr_for_constant (folded
);
1240 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1241 it has the value it would have in BLOCK. Set *SAME_VALID to true
1242 in case the new vuse doesn't change the value id of the OPERANDS. */
1245 translate_vuse_through_block (vec
<vn_reference_op_s
> operands
,
1246 alias_set_type set
, tree type
, tree vuse
,
1247 basic_block phiblock
,
1248 basic_block block
, bool *same_valid
)
1250 gimple
*phi
= SSA_NAME_DEF_STMT (vuse
);
1257 if (gimple_bb (phi
) != phiblock
)
1260 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1262 /* Use the alias-oracle to find either the PHI node in this block,
1263 the first VUSE used in this block that is equivalent to vuse or
1264 the first VUSE which definition in this block kills the value. */
1265 if (gimple_code (phi
) == GIMPLE_PHI
)
1266 e
= find_edge (block
, phiblock
);
1267 else if (use_oracle
)
1268 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1270 vuse
= gimple_vuse (phi
);
1271 phi
= SSA_NAME_DEF_STMT (vuse
);
1272 if (gimple_bb (phi
) != phiblock
)
1274 if (gimple_code (phi
) == GIMPLE_PHI
)
1276 e
= find_edge (block
, phiblock
);
1287 bitmap visited
= NULL
;
1289 /* Try to find a vuse that dominates this phi node by skipping
1290 non-clobbering statements. */
1291 vuse
= get_continuation_for_phi (phi
, &ref
, &cnt
, &visited
, false,
1294 BITMAP_FREE (visited
);
1300 /* If we didn't find any, the value ID can't stay the same,
1301 but return the translated vuse. */
1302 *same_valid
= false;
1303 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1305 /* ??? We would like to return vuse here as this is the canonical
1306 upmost vdef that this reference is associated with. But during
1307 insertion of the references into the hash tables we only ever
1308 directly insert with their direct gimple_vuse, hence returning
1309 something else would make us not find the other expression. */
1310 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1316 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1317 SET2. This is used to avoid making a set consisting of the union
1318 of PA_IN and ANTIC_IN during insert. */
1320 static inline pre_expr
1321 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1325 result
= bitmap_find_leader (set1
, val
);
1326 if (!result
&& set2
)
1327 result
= bitmap_find_leader (set2
, val
);
1331 /* Get the tree type for our PRE expression e. */
1334 get_expr_type (const pre_expr e
)
1339 return TREE_TYPE (PRE_EXPR_NAME (e
));
1341 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1343 return PRE_EXPR_REFERENCE (e
)->type
;
1345 return PRE_EXPR_NARY (e
)->type
;
1350 /* Get a representative SSA_NAME for a given expression.
1351 Since all of our sub-expressions are treated as values, we require
1352 them to be SSA_NAME's for simplicity.
1353 Prior versions of GVNPRE used to use "value handles" here, so that
1354 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1355 either case, the operands are really values (IE we do not expect
1356 them to be usable without finding leaders). */
1359 get_representative_for (const pre_expr e
)
1362 unsigned int value_id
= get_expr_value_id (e
);
1367 return PRE_EXPR_NAME (e
);
1369 return PRE_EXPR_CONSTANT (e
);
1373 /* Go through all of the expressions representing this value
1374 and pick out an SSA_NAME. */
1377 bitmap exprs
= value_expressions
[value_id
];
1378 EXECUTE_IF_SET_IN_BITMAP (exprs
, 0, i
, bi
)
1380 pre_expr rep
= expression_for_id (i
);
1381 if (rep
->kind
== NAME
)
1382 return PRE_EXPR_NAME (rep
);
1383 else if (rep
->kind
== CONSTANT
)
1384 return PRE_EXPR_CONSTANT (rep
);
1390 /* If we reached here we couldn't find an SSA_NAME. This can
1391 happen when we've discovered a value that has never appeared in
1392 the program as set to an SSA_NAME, as the result of phi translation.
1394 ??? We should be able to re-use this when we insert the statement
1396 name
= make_temp_ssa_name (get_expr_type (e
), gimple_build_nop (), "pretmp");
1397 VN_INFO_GET (name
)->value_id
= value_id
;
1398 VN_INFO (name
)->valnum
= name
;
1399 /* ??? For now mark this SSA name for release by SCCVN. */
1400 VN_INFO (name
)->needs_insertion
= true;
1401 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1402 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1404 fprintf (dump_file
, "Created SSA_NAME representative ");
1405 print_generic_expr (dump_file
, name
, 0);
1406 fprintf (dump_file
, " for expression:");
1407 print_pre_expr (dump_file
, e
);
1408 fprintf (dump_file
, " (%04d)\n", value_id
);
1417 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1418 basic_block pred
, basic_block phiblock
);
1420 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1421 the phis in PRED. Return NULL if we can't find a leader for each part
1422 of the translated expression. */
1425 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1426 basic_block pred
, basic_block phiblock
)
1433 bool changed
= false;
1434 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1435 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1436 sizeof_vn_nary_op (nary
->length
));
1437 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1439 for (i
= 0; i
< newnary
->length
; i
++)
1441 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1445 pre_expr leader
, result
;
1446 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1447 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1448 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1449 if (result
&& result
!= leader
)
1451 tree name
= get_representative_for (result
);
1454 newnary
->op
[i
] = name
;
1459 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1465 unsigned int new_val_id
;
1467 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1472 if (result
&& is_gimple_min_invariant (result
))
1473 return get_or_alloc_expr_for_constant (result
);
1475 expr
= pre_expr_pool
.allocate ();
1480 PRE_EXPR_NARY (expr
) = nary
;
1481 constant
= fully_constant_expression (expr
);
1482 if (constant
!= expr
)
1485 new_val_id
= nary
->value_id
;
1486 get_or_alloc_expression_id (expr
);
1490 new_val_id
= get_next_value_id ();
1491 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
1492 nary
= vn_nary_op_insert_pieces (newnary
->length
,
1496 result
, new_val_id
);
1497 PRE_EXPR_NARY (expr
) = nary
;
1498 constant
= fully_constant_expression (expr
);
1499 if (constant
!= expr
)
1501 get_or_alloc_expression_id (expr
);
1503 add_to_value (new_val_id
, expr
);
1511 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1512 vec
<vn_reference_op_s
> operands
= ref
->operands
;
1513 tree vuse
= ref
->vuse
;
1514 tree newvuse
= vuse
;
1515 vec
<vn_reference_op_s
> newoperands
= vNULL
;
1516 bool changed
= false, same_valid
= true;
1518 vn_reference_op_t operand
;
1519 vn_reference_t newref
;
1521 for (i
= 0; operands
.iterate (i
, &operand
); i
++)
1526 tree type
= operand
->type
;
1527 vn_reference_op_s newop
= *operand
;
1528 op
[0] = operand
->op0
;
1529 op
[1] = operand
->op1
;
1530 op
[2] = operand
->op2
;
1531 for (n
= 0; n
< 3; ++n
)
1533 unsigned int op_val_id
;
1536 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1538 /* We can't possibly insert these. */
1540 && !is_gimple_min_invariant (op
[n
]))
1544 op_val_id
= VN_INFO (op
[n
])->value_id
;
1545 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1548 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1551 if (opresult
!= leader
)
1553 tree name
= get_representative_for (opresult
);
1556 changed
|= name
!= op
[n
];
1562 newoperands
.release ();
1567 if (!newoperands
.exists ())
1568 newoperands
= operands
.copy ();
1569 /* We may have changed from an SSA_NAME to a constant */
1570 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1571 newop
.opcode
= TREE_CODE (op
[0]);
1576 newoperands
[i
] = newop
;
1578 gcc_checking_assert (i
== operands
.length ());
1582 newvuse
= translate_vuse_through_block (newoperands
.exists ()
1583 ? newoperands
: operands
,
1584 ref
->set
, ref
->type
,
1585 vuse
, phiblock
, pred
,
1587 if (newvuse
== NULL_TREE
)
1589 newoperands
.release ();
1594 if (changed
|| newvuse
!= vuse
)
1596 unsigned int new_val_id
;
1599 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1601 newoperands
.exists ()
1602 ? newoperands
: operands
,
1605 newoperands
.release ();
1607 /* We can always insert constants, so if we have a partial
1608 redundant constant load of another type try to translate it
1609 to a constant of appropriate type. */
1610 if (result
&& is_gimple_min_invariant (result
))
1613 if (!useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1615 tem
= fold_unary (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1616 if (tem
&& !is_gimple_min_invariant (tem
))
1620 return get_or_alloc_expr_for_constant (tem
);
1623 /* If we'd have to convert things we would need to validate
1624 if we can insert the translated expression. So fail
1625 here for now - we cannot insert an alias with a different
1626 type in the VN tables either, as that would assert. */
1628 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1630 else if (!result
&& newref
1631 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1633 newoperands
.release ();
1637 expr
= pre_expr_pool
.allocate ();
1638 expr
->kind
= REFERENCE
;
1643 PRE_EXPR_REFERENCE (expr
) = newref
;
1644 constant
= fully_constant_expression (expr
);
1645 if (constant
!= expr
)
1648 new_val_id
= newref
->value_id
;
1649 get_or_alloc_expression_id (expr
);
1653 if (changed
|| !same_valid
)
1655 new_val_id
= get_next_value_id ();
1656 value_expressions
.safe_grow_cleared
1657 (get_max_value_id () + 1);
1660 new_val_id
= ref
->value_id
;
1661 if (!newoperands
.exists ())
1662 newoperands
= operands
.copy ();
1663 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1666 result
, new_val_id
);
1667 newoperands
= vNULL
;
1668 PRE_EXPR_REFERENCE (expr
) = newref
;
1669 constant
= fully_constant_expression (expr
);
1670 if (constant
!= expr
)
1672 get_or_alloc_expression_id (expr
);
1674 add_to_value (new_val_id
, expr
);
1676 newoperands
.release ();
1683 tree name
= PRE_EXPR_NAME (expr
);
1684 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1685 /* If the SSA name is defined by a PHI node in this block,
1687 if (gimple_code (def_stmt
) == GIMPLE_PHI
1688 && gimple_bb (def_stmt
) == phiblock
)
1690 edge e
= find_edge (pred
, gimple_bb (def_stmt
));
1691 tree def
= PHI_ARG_DEF (def_stmt
, e
->dest_idx
);
1693 /* Handle constant. */
1694 if (is_gimple_min_invariant (def
))
1695 return get_or_alloc_expr_for_constant (def
);
1697 return get_or_alloc_expr_for_name (def
);
1699 /* Otherwise return it unchanged - it will get removed if its
1700 value is not available in PREDs AVAIL_OUT set of expressions
1701 by the subtraction of TMP_GEN. */
1710 /* Wrapper around phi_translate_1 providing caching functionality. */
1713 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1714 basic_block pred
, basic_block phiblock
)
1716 expr_pred_trans_t slot
= NULL
;
1722 /* Constants contain no values that need translation. */
1723 if (expr
->kind
== CONSTANT
)
1726 if (value_id_constant_p (get_expr_value_id (expr
)))
1729 /* Don't add translations of NAMEs as those are cheap to translate. */
1730 if (expr
->kind
!= NAME
)
1732 if (phi_trans_add (&slot
, expr
, pred
))
1734 /* Store NULL for the value we want to return in the case of
1740 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1747 /* Remove failed translations again, they cause insert
1748 iteration to not pick up new opportunities reliably. */
1749 phi_translate_table
->remove_elt_with_hash (slot
, slot
->hashcode
);
1756 /* For each expression in SET, translate the values through phi nodes
1757 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1758 expressions in DEST. */
1761 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1762 basic_block phiblock
)
1764 vec
<pre_expr
> exprs
;
1768 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1770 bitmap_set_copy (dest
, set
);
1774 exprs
= sorted_array_from_bitmap_set (set
);
1775 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1777 pre_expr translated
;
1778 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1782 /* We might end up with multiple expressions from SET being
1783 translated to the same value. In this case we do not want
1784 to retain the NARY or REFERENCE expression but prefer a NAME
1785 which would be the leader. */
1786 if (translated
->kind
== NAME
)
1787 bitmap_value_replace_in_set (dest
, translated
);
1789 bitmap_value_insert_into_set (dest
, translated
);
1794 /* Find the leader for a value (i.e., the name representing that
1795 value) in a given set, and return it. Return NULL if no leader
1799 bitmap_find_leader (bitmap_set_t set
, unsigned int val
)
1801 if (value_id_constant_p (val
))
1805 bitmap exprset
= value_expressions
[val
];
1807 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
1809 pre_expr expr
= expression_for_id (i
);
1810 if (expr
->kind
== CONSTANT
)
1814 if (bitmap_set_contains_value (set
, val
))
1816 /* Rather than walk the entire bitmap of expressions, and see
1817 whether any of them has the value we are looking for, we look
1818 at the reverse mapping, which tells us the set of expressions
1819 that have a given value (IE value->expressions with that
1820 value) and see if any of those expressions are in our set.
1821 The number of expressions per value is usually significantly
1822 less than the number of expressions in the set. In fact, for
1823 large testcases, doing it this way is roughly 5-10x faster
1824 than walking the bitmap.
1825 If this is somehow a significant lose for some cases, we can
1826 choose which set to walk based on which set is smaller. */
1829 bitmap exprset
= value_expressions
[val
];
1831 EXECUTE_IF_AND_IN_BITMAP (exprset
, &set
->expressions
, 0, i
, bi
)
1832 return expression_for_id (i
);
1837 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1838 BLOCK by seeing if it is not killed in the block. Note that we are
1839 only determining whether there is a store that kills it. Because
1840 of the order in which clean iterates over values, we are guaranteed
1841 that altered operands will have caused us to be eliminated from the
1842 ANTIC_IN set already. */
1845 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1847 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1848 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1850 gimple_stmt_iterator gsi
;
1851 unsigned id
= get_expression_id (expr
);
1858 /* Lookup a previously calculated result. */
1859 if (EXPR_DIES (block
)
1860 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1861 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1863 /* A memory expression {e, VUSE} dies in the block if there is a
1864 statement that may clobber e. If, starting statement walk from the
1865 top of the basic block, a statement uses VUSE there can be no kill
1866 inbetween that use and the original statement that loaded {e, VUSE},
1867 so we can stop walking. */
1868 ref
.base
= NULL_TREE
;
1869 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1871 tree def_vuse
, def_vdef
;
1872 def
= gsi_stmt (gsi
);
1873 def_vuse
= gimple_vuse (def
);
1874 def_vdef
= gimple_vdef (def
);
1876 /* Not a memory statement. */
1880 /* Not a may-def. */
1883 /* A load with the same VUSE, we're done. */
1884 if (def_vuse
== vuse
)
1890 /* Init ref only if we really need it. */
1891 if (ref
.base
== NULL_TREE
1892 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
1898 /* If the statement may clobber expr, it dies. */
1899 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
1906 /* Remember the result. */
1907 if (!EXPR_DIES (block
))
1908 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
1909 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
1911 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
1917 /* Determine if OP is valid in SET1 U SET2, which it is when the union
1918 contains its value-id. */
1921 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
1923 if (op
&& TREE_CODE (op
) == SSA_NAME
)
1925 unsigned int value_id
= VN_INFO (op
)->value_id
;
1926 if (!(bitmap_set_contains_value (set1
, value_id
)
1927 || (set2
&& bitmap_set_contains_value (set2
, value_id
))))
1933 /* Determine if the expression EXPR is valid in SET1 U SET2.
1934 ONLY SET2 CAN BE NULL.
1935 This means that we have a leader for each part of the expression
1936 (if it consists of values), or the expression is an SSA_NAME.
1937 For loads/calls, we also see if the vuse is killed in this block. */
1940 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
)
1945 /* By construction all NAMEs are available. Non-available
1946 NAMEs are removed by subtracting TMP_GEN from the sets. */
1951 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1952 for (i
= 0; i
< nary
->length
; i
++)
1953 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
1960 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1961 vn_reference_op_t vro
;
1964 FOR_EACH_VEC_ELT (ref
->operands
, i
, vro
)
1966 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
1967 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
1968 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
1978 /* Clean the set of expressions that are no longer valid in SET1 or
1979 SET2. This means expressions that are made up of values we have no
1980 leaders for in SET1 or SET2. This version is used for partial
1981 anticipation, which means it is not valid in either ANTIC_IN or
1985 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
)
1987 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set1
);
1991 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
1993 if (!valid_in_sets (set1
, set2
, expr
))
1994 bitmap_remove_from_set (set1
, expr
);
1999 /* Clean the set of expressions that are no longer valid in SET. This
2000 means expressions that are made up of values we have no leaders for
2004 clean (bitmap_set_t set
)
2006 vec
<pre_expr
> exprs
= sorted_array_from_bitmap_set (set
);
2010 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
2012 if (!valid_in_sets (set
, NULL
, expr
))
2013 bitmap_remove_from_set (set
, expr
);
2018 /* Clean the set of expressions that are no longer valid in SET because
2019 they are clobbered in BLOCK or because they trap and may not be executed. */
2022 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2027 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
2029 pre_expr expr
= expression_for_id (i
);
2030 if (expr
->kind
== REFERENCE
)
2032 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2035 gimple
*def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2036 if (!gimple_nop_p (def_stmt
)
2037 && ((gimple_bb (def_stmt
) != block
2038 && !dominated_by_p (CDI_DOMINATORS
,
2039 block
, gimple_bb (def_stmt
)))
2040 || (gimple_bb (def_stmt
) == block
2041 && value_dies_in_block_x (expr
, block
))))
2042 bitmap_remove_from_set (set
, expr
);
2045 else if (expr
->kind
== NARY
)
2047 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2048 /* If the NARY may trap make sure the block does not contain
2049 a possible exit point.
2050 ??? This is overly conservative if we translate AVAIL_OUT
2051 as the available expression might be after the exit point. */
2052 if (BB_MAY_NOTRETURN (block
)
2053 && vn_nary_may_trap (nary
))
2054 bitmap_remove_from_set (set
, expr
);
2059 static sbitmap has_abnormal_preds
;
2061 /* Compute the ANTIC set for BLOCK.
2063 If succs(BLOCK) > 1 then
2064 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2065 else if succs(BLOCK) == 1 then
2066 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2068 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2072 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2074 bool changed
= false;
2075 bitmap_set_t S
, old
, ANTIC_OUT
;
2081 old
= ANTIC_OUT
= S
= NULL
;
2082 BB_VISITED (block
) = 1;
2084 /* If any edges from predecessors are abnormal, antic_in is empty,
2086 if (block_has_abnormal_pred_edge
)
2087 goto maybe_dump_sets
;
2089 old
= ANTIC_IN (block
);
2090 ANTIC_OUT
= bitmap_set_new ();
2092 /* If the block has no successors, ANTIC_OUT is empty. */
2093 if (EDGE_COUNT (block
->succs
) == 0)
2095 /* If we have one successor, we could have some phi nodes to
2096 translate through. */
2097 else if (single_succ_p (block
))
2099 basic_block succ_bb
= single_succ (block
);
2100 gcc_assert (BB_VISITED (succ_bb
));
2101 phi_translate_set (ANTIC_OUT
, ANTIC_IN (succ_bb
), block
, succ_bb
);
2103 /* If we have multiple successors, we take the intersection of all of
2104 them. Note that in the case of loop exit phi nodes, we may have
2105 phis to translate through. */
2109 basic_block bprime
, first
= NULL
;
2111 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2112 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2115 && BB_VISITED (e
->dest
))
2117 else if (BB_VISITED (e
->dest
))
2118 worklist
.quick_push (e
->dest
);
2121 /* Unvisited successors get their ANTIC_IN replaced by the
2122 maximal set to arrive at a maximum ANTIC_IN solution.
2123 We can ignore them in the intersection operation and thus
2124 need not explicitely represent that maximum solution. */
2125 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2126 fprintf (dump_file
, "ANTIC_IN is MAX on %d->%d\n",
2127 e
->src
->index
, e
->dest
->index
);
2131 /* Of multiple successors we have to have visited one already
2132 which is guaranteed by iteration order. */
2133 gcc_assert (first
!= NULL
);
2135 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2137 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2139 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2141 bitmap_set_t tmp
= bitmap_set_new ();
2142 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2143 bitmap_set_and (ANTIC_OUT
, tmp
);
2144 bitmap_set_free (tmp
);
2147 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2151 /* Prune expressions that are clobbered in block and thus become
2152 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2153 prune_clobbered_mems (ANTIC_OUT
, block
);
2155 /* Generate ANTIC_OUT - TMP_GEN. */
2156 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2158 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2159 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2162 /* Then union in the ANTIC_OUT - TMP_GEN values,
2163 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2164 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2165 bitmap_value_insert_into_set (ANTIC_IN (block
),
2166 expression_for_id (bii
));
2168 clean (ANTIC_IN (block
));
2170 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2174 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2177 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2180 fprintf (dump_file
, "[changed] ");
2181 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2185 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2188 bitmap_set_free (old
);
2190 bitmap_set_free (S
);
2192 bitmap_set_free (ANTIC_OUT
);
2196 /* Compute PARTIAL_ANTIC for BLOCK.
2198 If succs(BLOCK) > 1 then
2199 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2200 in ANTIC_OUT for all succ(BLOCK)
2201 else if succs(BLOCK) == 1 then
2202 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2204 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2209 compute_partial_antic_aux (basic_block block
,
2210 bool block_has_abnormal_pred_edge
)
2212 bitmap_set_t old_PA_IN
;
2213 bitmap_set_t PA_OUT
;
2216 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2218 old_PA_IN
= PA_OUT
= NULL
;
2220 /* If any edges from predecessors are abnormal, antic_in is empty,
2222 if (block_has_abnormal_pred_edge
)
2223 goto maybe_dump_sets
;
2225 /* If there are too many partially anticipatable values in the
2226 block, phi_translate_set can take an exponential time: stop
2227 before the translation starts. */
2229 && single_succ_p (block
)
2230 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2231 goto maybe_dump_sets
;
2233 old_PA_IN
= PA_IN (block
);
2234 PA_OUT
= bitmap_set_new ();
2236 /* If the block has no successors, ANTIC_OUT is empty. */
2237 if (EDGE_COUNT (block
->succs
) == 0)
2239 /* If we have one successor, we could have some phi nodes to
2240 translate through. Note that we can't phi translate across DFS
2241 back edges in partial antic, because it uses a union operation on
2242 the successors. For recurrences like IV's, we will end up
2243 generating a new value in the set on each go around (i + 3 (VH.1)
2244 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2245 else if (single_succ_p (block
))
2247 basic_block succ
= single_succ (block
);
2248 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2249 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2251 /* If we have multiple successors, we take the union of all of
2258 auto_vec
<basic_block
> worklist (EDGE_COUNT (block
->succs
));
2259 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2261 if (e
->flags
& EDGE_DFS_BACK
)
2263 worklist
.quick_push (e
->dest
);
2265 if (worklist
.length () > 0)
2267 FOR_EACH_VEC_ELT (worklist
, i
, bprime
)
2272 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2273 bitmap_value_insert_into_set (PA_OUT
,
2274 expression_for_id (i
));
2275 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2277 bitmap_set_t pa_in
= bitmap_set_new ();
2278 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2279 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2280 bitmap_value_insert_into_set (PA_OUT
,
2281 expression_for_id (i
));
2282 bitmap_set_free (pa_in
);
2285 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2286 bitmap_value_insert_into_set (PA_OUT
,
2287 expression_for_id (i
));
2292 /* Prune expressions that are clobbered in block and thus become
2293 invalid if translated from PA_OUT to PA_IN. */
2294 prune_clobbered_mems (PA_OUT
, block
);
2296 /* PA_IN starts with PA_OUT - TMP_GEN.
2297 Then we subtract things from ANTIC_IN. */
2298 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2300 /* For partial antic, we want to put back in the phi results, since
2301 we will properly avoid making them partially antic over backedges. */
2302 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2303 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2305 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2306 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2308 dependent_clean (PA_IN (block
), ANTIC_IN (block
));
2311 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2314 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2316 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2319 bitmap_set_free (old_PA_IN
);
2321 bitmap_set_free (PA_OUT
);
2324 /* Compute ANTIC and partial ANTIC sets. */
2327 compute_antic (void)
2329 bool changed
= true;
2330 int num_iterations
= 0;
2336 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2337 We pre-build the map of blocks with incoming abnormal edges here. */
2338 has_abnormal_preds
= sbitmap_alloc (last_basic_block_for_fn (cfun
));
2339 bitmap_clear (has_abnormal_preds
);
2341 FOR_ALL_BB_FN (block
, cfun
)
2343 BB_VISITED (block
) = 0;
2345 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2346 if (e
->flags
& EDGE_ABNORMAL
)
2348 bitmap_set_bit (has_abnormal_preds
, block
->index
);
2350 /* We also anticipate nothing. */
2351 BB_VISITED (block
) = 1;
2355 /* While we are here, give empty ANTIC_IN sets to each block. */
2356 ANTIC_IN (block
) = bitmap_set_new ();
2357 if (do_partial_partial
)
2358 PA_IN (block
) = bitmap_set_new ();
2361 /* At the exit block we anticipate nothing. */
2362 BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun
)) = 1;
2364 /* For ANTIC computation we need a postorder that also guarantees that
2365 a block with a single successor is visited after its successor.
2366 RPO on the inverted CFG has this property. */
2367 int *postorder
= XNEWVEC (int, n_basic_blocks_for_fn (cfun
));
2368 int postorder_num
= inverted_post_order_compute (postorder
);
2370 sbitmap worklist
= sbitmap_alloc (last_basic_block_for_fn (cfun
) + 1);
2371 bitmap_ones (worklist
);
2374 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2375 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2376 /* ??? We need to clear our PHI translation cache here as the
2377 ANTIC sets shrink and we restrict valid translations to
2378 those having operands with leaders in ANTIC. Same below
2379 for PA ANTIC computation. */
2382 for (i
= postorder_num
- 1; i
>= 0; i
--)
2384 if (bitmap_bit_p (worklist
, postorder
[i
]))
2386 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2387 bitmap_clear_bit (worklist
, block
->index
);
2388 if (compute_antic_aux (block
,
2389 bitmap_bit_p (has_abnormal_preds
,
2392 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2393 bitmap_set_bit (worklist
, e
->src
->index
);
2398 /* Theoretically possible, but *highly* unlikely. */
2399 gcc_checking_assert (num_iterations
< 500);
2402 statistics_histogram_event (cfun
, "compute_antic iterations",
2405 if (do_partial_partial
)
2407 /* For partial antic we ignore backedges and thus we do not need
2408 to perform any iteration when we process blocks in postorder. */
2409 postorder_num
= pre_and_rev_post_order_compute (NULL
, postorder
, false);
2410 for (i
= postorder_num
- 1 ; i
>= 0; i
--)
2412 basic_block block
= BASIC_BLOCK_FOR_FN (cfun
, postorder
[i
]);
2413 compute_partial_antic_aux (block
,
2414 bitmap_bit_p (has_abnormal_preds
,
2419 sbitmap_free (has_abnormal_preds
);
2420 sbitmap_free (worklist
);
2425 /* Inserted expressions are placed onto this worklist, which is used
2426 for performing quick dead code elimination of insertions we made
2427 that didn't turn out to be necessary. */
2428 static bitmap inserted_exprs
;
2430 /* The actual worker for create_component_ref_by_pieces. */
2433 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2434 unsigned int *operand
, gimple_seq
*stmts
)
2436 vn_reference_op_t currop
= &ref
->operands
[*operand
];
2439 switch (currop
->opcode
)
2446 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2450 tree offset
= currop
->op0
;
2451 if (TREE_CODE (baseop
) == ADDR_EXPR
2452 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2456 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2459 offset
= int_const_binop (PLUS_EXPR
, offset
,
2460 build_int_cst (TREE_TYPE (offset
),
2462 baseop
= build_fold_addr_expr (base
);
2464 genop
= build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2465 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2466 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2467 REF_REVERSE_STORAGE_ORDER (genop
) = currop
->reverse
;
2471 case TARGET_MEM_REF
:
2473 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2474 vn_reference_op_t nextop
= &ref
->operands
[++*operand
];
2475 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2481 genop0
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2487 genop1
= find_or_generate_expression (block
, nextop
->op0
, stmts
);
2491 genop
= build5 (TARGET_MEM_REF
, currop
->type
,
2492 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2494 MR_DEPENDENCE_CLIQUE (genop
) = currop
->clique
;
2495 MR_DEPENDENCE_BASE (genop
) = currop
->base
;
2502 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2508 case VIEW_CONVERT_EXPR
:
2510 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2514 return fold_build1 (currop
->opcode
, currop
->type
, genop0
);
2517 case WITH_SIZE_EXPR
:
2519 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2523 tree genop1
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2526 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2531 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2535 tree op1
= currop
->op0
;
2536 tree op2
= currop
->op1
;
2537 tree t
= build3 (BIT_FIELD_REF
, currop
->type
, genop0
, op1
, op2
);
2538 REF_REVERSE_STORAGE_ORDER (t
) = currop
->reverse
;
2542 /* For array ref vn_reference_op's, operand 1 of the array ref
2543 is op0 of the reference op and operand 3 of the array ref is
2545 case ARRAY_RANGE_REF
:
2549 tree genop1
= currop
->op0
;
2550 tree genop2
= currop
->op1
;
2551 tree genop3
= currop
->op2
;
2552 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2556 genop1
= find_or_generate_expression (block
, genop1
, stmts
);
2561 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2562 /* Drop zero minimum index if redundant. */
2563 if (integer_zerop (genop2
)
2565 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2569 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2576 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2577 /* We can't always put a size in units of the element alignment
2578 here as the element alignment may be not visible. See
2579 PR43783. Simply drop the element size for constant
2581 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2585 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2586 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2587 genop3
= find_or_generate_expression (block
, genop3
, stmts
);
2592 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2599 tree genop2
= currop
->op1
;
2600 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
, stmts
);
2603 /* op1 should be a FIELD_DECL, which are represented by themselves. */
2607 genop2
= find_or_generate_expression (block
, genop2
, stmts
);
2611 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
, genop2
);
2616 genop
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2637 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2638 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2639 trying to rename aggregates into ssa form directly, which is a no no.
2641 Thus, this routine doesn't create temporaries, it just builds a
2642 single access expression for the array, calling
2643 find_or_generate_expression to build the innermost pieces.
2645 This function is a subroutine of create_expression_by_pieces, and
2646 should not be called on it's own unless you really know what you
2650 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2653 unsigned int op
= 0;
2654 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
);
2657 /* Find a simple leader for an expression, or generate one using
2658 create_expression_by_pieces from a NARY expression for the value.
2659 BLOCK is the basic_block we are looking for leaders in.
2660 OP is the tree expression to find a leader for or generate.
2661 Returns the leader or NULL_TREE on failure. */
2664 find_or_generate_expression (basic_block block
, tree op
, gimple_seq
*stmts
)
2666 pre_expr expr
= get_or_alloc_expr_for (op
);
2667 unsigned int lookfor
= get_expr_value_id (expr
);
2668 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
), lookfor
);
2671 if (leader
->kind
== NAME
)
2672 return PRE_EXPR_NAME (leader
);
2673 else if (leader
->kind
== CONSTANT
)
2674 return PRE_EXPR_CONSTANT (leader
);
2680 /* It must be a complex expression, so generate it recursively. Note
2681 that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c
2682 where the insert algorithm fails to insert a required expression. */
2683 bitmap exprset
= value_expressions
[lookfor
];
2686 EXECUTE_IF_SET_IN_BITMAP (exprset
, 0, i
, bi
)
2688 pre_expr temp
= expression_for_id (i
);
2689 /* We cannot insert random REFERENCE expressions at arbitrary
2690 places. We can insert NARYs which eventually re-materializes
2691 its operand values. */
2692 if (temp
->kind
== NARY
)
2693 return create_expression_by_pieces (block
, temp
, stmts
,
2694 get_expr_type (expr
));
2701 #define NECESSARY GF_PLF_1
2703 /* Create an expression in pieces, so that we can handle very complex
2704 expressions that may be ANTIC, but not necessary GIMPLE.
2705 BLOCK is the basic block the expression will be inserted into,
2706 EXPR is the expression to insert (in value form)
2707 STMTS is a statement list to append the necessary insertions into.
2709 This function will die if we hit some value that shouldn't be
2710 ANTIC but is (IE there is no leader for it, or its components).
2711 The function returns NULL_TREE in case a different antic expression
2712 has to be inserted first.
2713 This function may also generate expressions that are themselves
2714 partially or fully redundant. Those that are will be either made
2715 fully redundant during the next iteration of insert (for partially
2716 redundant ones), or eliminated by eliminate (for fully redundant
2720 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2721 gimple_seq
*stmts
, tree type
)
2725 gimple_seq forced_stmts
= NULL
;
2726 unsigned int value_id
;
2727 gimple_stmt_iterator gsi
;
2728 tree exprtype
= type
? type
: get_expr_type (expr
);
2734 /* We may hit the NAME/CONSTANT case if we have to convert types
2735 that value numbering saw through. */
2737 folded
= PRE_EXPR_NAME (expr
);
2738 if (useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
2743 folded
= PRE_EXPR_CONSTANT (expr
);
2744 tree tem
= fold_convert (exprtype
, folded
);
2745 if (is_gimple_min_invariant (tem
))
2750 if (PRE_EXPR_REFERENCE (expr
)->operands
[0].opcode
== CALL_EXPR
)
2752 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2753 unsigned int operand
= 1;
2754 vn_reference_op_t currop
= &ref
->operands
[0];
2755 tree sc
= NULL_TREE
;
2757 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2760 fn
= find_or_generate_expression (block
, currop
->op0
, stmts
);
2765 sc
= find_or_generate_expression (block
, currop
->op1
, stmts
);
2769 auto_vec
<tree
> args (ref
->operands
.length () - 1);
2770 while (operand
< ref
->operands
.length ())
2772 tree arg
= create_component_ref_by_pieces_1 (block
, ref
,
2776 args
.quick_push (arg
);
2779 = gimple_build_call_vec ((TREE_CODE (fn
) == FUNCTION_DECL
2780 ? build_fold_addr_expr (fn
) : fn
), args
);
2781 gimple_call_set_with_bounds (call
, currop
->with_bounds
);
2783 gimple_call_set_chain (call
, sc
);
2784 tree forcedname
= make_ssa_name (currop
->type
);
2785 gimple_call_set_lhs (call
, forcedname
);
2786 gimple_set_vuse (call
, BB_LIVE_VOP_ON_EXIT (block
));
2787 gimple_seq_add_stmt_without_update (&forced_stmts
, call
);
2788 folded
= forcedname
;
2792 folded
= create_component_ref_by_pieces (block
,
2793 PRE_EXPR_REFERENCE (expr
),
2797 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2798 newstmt
= gimple_build_assign (name
, folded
);
2799 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2800 gimple_set_vuse (newstmt
, BB_LIVE_VOP_ON_EXIT (block
));
2806 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2807 tree
*genop
= XALLOCAVEC (tree
, nary
->length
);
2809 for (i
= 0; i
< nary
->length
; ++i
)
2811 genop
[i
] = find_or_generate_expression (block
, nary
->op
[i
], stmts
);
2814 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
2815 may have conversions stripped. */
2816 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2819 genop
[i
] = gimple_convert (&forced_stmts
,
2820 nary
->type
, genop
[i
]);
2822 genop
[i
] = gimple_convert (&forced_stmts
,
2823 sizetype
, genop
[i
]);
2826 genop
[i
] = gimple_convert (&forced_stmts
,
2827 TREE_TYPE (nary
->op
[i
]), genop
[i
]);
2829 if (nary
->opcode
== CONSTRUCTOR
)
2831 vec
<constructor_elt
, va_gc
> *elts
= NULL
;
2832 for (i
= 0; i
< nary
->length
; ++i
)
2833 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
2834 folded
= build_constructor (nary
->type
, elts
);
2835 name
= make_temp_ssa_name (exprtype
, NULL
, "pretmp");
2836 newstmt
= gimple_build_assign (name
, folded
);
2837 gimple_seq_add_stmt_without_update (&forced_stmts
, newstmt
);
2842 switch (nary
->length
)
2845 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2849 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2850 genop
[0], genop
[1]);
2853 folded
= gimple_build (&forced_stmts
, nary
->opcode
, nary
->type
,
2854 genop
[0], genop
[1], genop
[2]);
2866 folded
= gimple_convert (&forced_stmts
, exprtype
, folded
);
2868 /* If there is nothing to insert, return the simplified result. */
2869 if (gimple_seq_empty_p (forced_stmts
))
2871 /* If we simplified to a constant return it and discard eventually
2873 if (is_gimple_min_invariant (folded
))
2875 gimple_seq_discard (forced_stmts
);
2879 gcc_assert (TREE_CODE (folded
) == SSA_NAME
);
2881 /* If we have any intermediate expressions to the value sets, add them
2882 to the value sets and chain them in the instruction stream. */
2885 gsi
= gsi_start (forced_stmts
);
2886 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2888 gimple
*stmt
= gsi_stmt (gsi
);
2889 tree forcedname
= gimple_get_lhs (stmt
);
2892 if (forcedname
!= folded
)
2894 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2895 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2896 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2897 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2898 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2899 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2902 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
2903 gimple_set_plf (stmt
, NECESSARY
, false);
2905 gimple_seq_add_seq (stmts
, forced_stmts
);
2910 /* Fold the last statement. */
2911 gsi
= gsi_last (*stmts
);
2912 if (fold_stmt_inplace (&gsi
))
2913 update_stmt (gsi_stmt (gsi
));
2915 /* Add a value number to the temporary.
2916 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2917 we are creating the expression by pieces, and this particular piece of
2918 the expression may have been represented. There is no harm in replacing
2920 value_id
= get_expr_value_id (expr
);
2921 VN_INFO_GET (name
)->value_id
= value_id
;
2922 VN_INFO (name
)->valnum
= sccvn_valnum_from_value_id (value_id
);
2923 if (VN_INFO (name
)->valnum
== NULL_TREE
)
2924 VN_INFO (name
)->valnum
= name
;
2925 gcc_assert (VN_INFO (name
)->valnum
!= NULL_TREE
);
2926 nameexpr
= get_or_alloc_expr_for_name (name
);
2927 add_to_value (value_id
, nameexpr
);
2928 if (NEW_SETS (block
))
2929 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2930 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2932 pre_stats
.insertions
++;
2933 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2935 fprintf (dump_file
, "Inserted ");
2936 print_gimple_stmt (dump_file
, gsi_stmt (gsi_last (*stmts
)), 0, 0);
2937 fprintf (dump_file
, " in predecessor %d (%04d)\n",
2938 block
->index
, value_id
);
2945 /* Insert the to-be-made-available values of expression EXPRNUM for each
2946 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2947 merge the result with a phi node, given the same value number as
2948 NODE. Return true if we have inserted new stuff. */
2951 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2952 vec
<pre_expr
> avail
)
2954 pre_expr expr
= expression_for_id (exprnum
);
2956 unsigned int val
= get_expr_value_id (expr
);
2958 bool insertions
= false;
2963 tree type
= get_expr_type (expr
);
2967 /* Make sure we aren't creating an induction variable. */
2968 if (bb_loop_depth (block
) > 0 && EDGE_COUNT (block
->preds
) == 2)
2970 bool firstinsideloop
= false;
2971 bool secondinsideloop
= false;
2972 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2973 EDGE_PRED (block
, 0)->src
);
2974 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2975 EDGE_PRED (block
, 1)->src
);
2976 /* Induction variables only have one edge inside the loop. */
2977 if ((firstinsideloop
^ secondinsideloop
)
2978 && expr
->kind
!= REFERENCE
)
2980 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2981 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
2986 /* Make the necessary insertions. */
2987 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
2989 gimple_seq stmts
= NULL
;
2992 eprime
= avail
[pred
->dest_idx
];
2993 builtexpr
= create_expression_by_pieces (bprime
, eprime
,
2995 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
2996 if (!gimple_seq_empty_p (stmts
))
2998 gsi_insert_seq_on_edge (pred
, stmts
);
3003 /* We cannot insert a PHI node if we failed to insert
3008 if (is_gimple_min_invariant (builtexpr
))
3009 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_constant (builtexpr
);
3011 avail
[pred
->dest_idx
] = get_or_alloc_expr_for_name (builtexpr
);
3013 /* If we didn't want a phi node, and we made insertions, we still have
3014 inserted new stuff, and thus return true. If we didn't want a phi node,
3015 and didn't make insertions, we haven't added anything new, so return
3017 if (nophi
&& insertions
)
3019 else if (nophi
&& !insertions
)
3022 /* Now build a phi for the new variable. */
3023 temp
= make_temp_ssa_name (type
, NULL
, "prephitmp");
3024 phi
= create_phi_node (temp
, block
);
3026 gimple_set_plf (phi
, NECESSARY
, false);
3027 VN_INFO_GET (temp
)->value_id
= val
;
3028 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3029 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3030 VN_INFO (temp
)->valnum
= temp
;
3031 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3032 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3034 pre_expr ae
= avail
[pred
->dest_idx
];
3035 gcc_assert (get_expr_type (ae
) == type
3036 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3037 if (ae
->kind
== CONSTANT
)
3038 add_phi_arg (phi
, unshare_expr (PRE_EXPR_CONSTANT (ae
)),
3039 pred
, UNKNOWN_LOCATION
);
3041 add_phi_arg (phi
, PRE_EXPR_NAME (ae
), pred
, UNKNOWN_LOCATION
);
3044 newphi
= get_or_alloc_expr_for_name (temp
);
3045 add_to_value (val
, newphi
);
3047 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3048 this insertion, since we test for the existence of this value in PHI_GEN
3049 before proceeding with the partial redundancy checks in insert_aux.
3051 The value may exist in AVAIL_OUT, in particular, it could be represented
3052 by the expression we are trying to eliminate, in which case we want the
3053 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3056 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3057 this block, because if it did, it would have existed in our dominator's
3058 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3061 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3062 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3064 bitmap_insert_into_set (NEW_SETS (block
),
3067 /* If we insert a PHI node for a conversion of another PHI node
3068 in the same basic-block try to preserve range information.
3069 This is important so that followup loop passes receive optimal
3070 number of iteration analysis results. See PR61743. */
3071 if (expr
->kind
== NARY
3072 && CONVERT_EXPR_CODE_P (expr
->u
.nary
->opcode
)
3073 && TREE_CODE (expr
->u
.nary
->op
[0]) == SSA_NAME
3074 && gimple_bb (SSA_NAME_DEF_STMT (expr
->u
.nary
->op
[0])) == block
3075 && INTEGRAL_TYPE_P (type
)
3076 && INTEGRAL_TYPE_P (TREE_TYPE (expr
->u
.nary
->op
[0]))
3077 && (TYPE_PRECISION (type
)
3078 >= TYPE_PRECISION (TREE_TYPE (expr
->u
.nary
->op
[0])))
3079 && SSA_NAME_RANGE_INFO (expr
->u
.nary
->op
[0]))
3082 if (get_range_info (expr
->u
.nary
->op
[0], &min
, &max
) == VR_RANGE
3083 && !wi::neg_p (min
, SIGNED
)
3084 && !wi::neg_p (max
, SIGNED
))
3085 /* Just handle extension and sign-changes of all-positive ranges. */
3086 set_range_info (temp
,
3087 SSA_NAME_RANGE_TYPE (expr
->u
.nary
->op
[0]),
3088 wide_int_storage::from (min
, TYPE_PRECISION (type
),
3090 wide_int_storage::from (max
, TYPE_PRECISION (type
),
3094 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3096 fprintf (dump_file
, "Created phi ");
3097 print_gimple_stmt (dump_file
, phi
, 0, 0);
3098 fprintf (dump_file
, " in block %d (%04d)\n", block
->index
, val
);
3106 /* Perform insertion of partially redundant values.
3107 For BLOCK, do the following:
3108 1. Propagate the NEW_SETS of the dominator into the current block.
3109 If the block has multiple predecessors,
3110 2a. Iterate over the ANTIC expressions for the block to see if
3111 any of them are partially redundant.
3112 2b. If so, insert them into the necessary predecessors to make
3113 the expression fully redundant.
3114 2c. Insert a new PHI merging the values of the predecessors.
3115 2d. Insert the new PHI, and the new expressions, into the
3117 3. Recursively call ourselves on the dominator children of BLOCK.
3119 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3120 do_regular_insertion and do_partial_insertion.
3125 do_regular_insertion (basic_block block
, basic_block dom
)
3127 bool new_stuff
= false;
3128 vec
<pre_expr
> exprs
;
3130 auto_vec
<pre_expr
> avail
;
3133 exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3134 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3136 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3138 if (expr
->kind
== NARY
3139 || expr
->kind
== REFERENCE
)
3142 bool by_some
= false;
3143 bool cant_insert
= false;
3144 bool all_same
= true;
3145 pre_expr first_s
= NULL
;
3148 pre_expr eprime
= NULL
;
3150 pre_expr edoubleprime
= NULL
;
3151 bool do_insertion
= false;
3153 val
= get_expr_value_id (expr
);
3154 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3156 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3158 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3160 fprintf (dump_file
, "Found fully redundant value: ");
3161 print_pre_expr (dump_file
, expr
);
3162 fprintf (dump_file
, "\n");
3167 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3169 unsigned int vprime
;
3171 /* We should never run insertion for the exit block
3172 and so not come across fake pred edges. */
3173 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3175 /* We are looking at ANTIC_OUT of bprime. */
3176 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3179 /* eprime will generally only be NULL if the
3180 value of the expression, translated
3181 through the PHI for this predecessor, is
3182 undefined. If that is the case, we can't
3183 make the expression fully redundant,
3184 because its value is undefined along a
3185 predecessor path. We can thus break out
3186 early because it doesn't matter what the
3187 rest of the results are. */
3190 avail
[pred
->dest_idx
] = NULL
;
3195 eprime
= fully_constant_expression (eprime
);
3196 vprime
= get_expr_value_id (eprime
);
3197 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3199 if (edoubleprime
== NULL
)
3201 avail
[pred
->dest_idx
] = eprime
;
3206 avail
[pred
->dest_idx
] = edoubleprime
;
3208 /* We want to perform insertions to remove a redundancy on
3209 a path in the CFG we want to optimize for speed. */
3210 if (optimize_edge_for_speed_p (pred
))
3211 do_insertion
= true;
3212 if (first_s
== NULL
)
3213 first_s
= edoubleprime
;
3214 else if (!pre_expr_d::equal (first_s
, edoubleprime
))
3218 /* If we can insert it, it's not the same value
3219 already existing along every predecessor, and
3220 it's defined by some predecessor, it is
3221 partially redundant. */
3222 if (!cant_insert
&& !all_same
&& by_some
)
3226 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3228 fprintf (dump_file
, "Skipping partial redundancy for "
3230 print_pre_expr (dump_file
, expr
);
3231 fprintf (dump_file
, " (%04d), no redundancy on to be "
3232 "optimized for speed edge\n", val
);
3235 else if (dbg_cnt (treepre_insert
))
3237 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3239 fprintf (dump_file
, "Found partial redundancy for "
3241 print_pre_expr (dump_file
, expr
);
3242 fprintf (dump_file
, " (%04d)\n",
3243 get_expr_value_id (expr
));
3245 if (insert_into_preds_of_block (block
,
3246 get_expression_id (expr
),
3251 /* If all edges produce the same value and that value is
3252 an invariant, then the PHI has the same value on all
3253 edges. Note this. */
3254 else if (!cant_insert
&& all_same
)
3256 gcc_assert (edoubleprime
->kind
== CONSTANT
3257 || edoubleprime
->kind
== NAME
);
3259 tree temp
= make_temp_ssa_name (get_expr_type (expr
),
3262 = gimple_build_assign (temp
,
3263 edoubleprime
->kind
== CONSTANT
?
3264 PRE_EXPR_CONSTANT (edoubleprime
) :
3265 PRE_EXPR_NAME (edoubleprime
));
3266 gimple_stmt_iterator gsi
= gsi_after_labels (block
);
3267 gsi_insert_before (&gsi
, assign
, GSI_NEW_STMT
);
3269 gimple_set_plf (assign
, NECESSARY
, false);
3270 VN_INFO_GET (temp
)->value_id
= val
;
3271 VN_INFO (temp
)->valnum
= sccvn_valnum_from_value_id (val
);
3272 if (VN_INFO (temp
)->valnum
== NULL_TREE
)
3273 VN_INFO (temp
)->valnum
= temp
;
3274 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (temp
));
3275 pre_expr newe
= get_or_alloc_expr_for_name (temp
);
3276 add_to_value (val
, newe
);
3277 bitmap_value_replace_in_set (AVAIL_OUT (block
), newe
);
3278 bitmap_insert_into_set (NEW_SETS (block
), newe
);
3288 /* Perform insertion for partially anticipatable expressions. There
3289 is only one case we will perform insertion for these. This case is
3290 if the expression is partially anticipatable, and fully available.
3291 In this case, we know that putting it earlier will enable us to
3292 remove the later computation. */
3296 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3298 bool new_stuff
= false;
3299 vec
<pre_expr
> exprs
;
3301 auto_vec
<pre_expr
> avail
;
3304 exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3305 avail
.safe_grow (EDGE_COUNT (block
->preds
));
3307 FOR_EACH_VEC_ELT (exprs
, i
, expr
)
3309 if (expr
->kind
== NARY
3310 || expr
->kind
== REFERENCE
)
3314 bool cant_insert
= false;
3317 pre_expr eprime
= NULL
;
3320 val
= get_expr_value_id (expr
);
3321 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3323 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3326 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3328 unsigned int vprime
;
3329 pre_expr edoubleprime
;
3331 /* We should never run insertion for the exit block
3332 and so not come across fake pred edges. */
3333 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3335 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3339 /* eprime will generally only be NULL if the
3340 value of the expression, translated
3341 through the PHI for this predecessor, is
3342 undefined. If that is the case, we can't
3343 make the expression fully redundant,
3344 because its value is undefined along a
3345 predecessor path. We can thus break out
3346 early because it doesn't matter what the
3347 rest of the results are. */
3350 avail
[pred
->dest_idx
] = NULL
;
3355 eprime
= fully_constant_expression (eprime
);
3356 vprime
= get_expr_value_id (eprime
);
3357 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
), vprime
);
3358 avail
[pred
->dest_idx
] = edoubleprime
;
3359 if (edoubleprime
== NULL
)
3366 /* If we can insert it, it's not the same value
3367 already existing along every predecessor, and
3368 it's defined by some predecessor, it is
3369 partially redundant. */
3370 if (!cant_insert
&& by_all
)
3373 bool do_insertion
= false;
3375 /* Insert only if we can remove a later expression on a path
3376 that we want to optimize for speed.
3377 The phi node that we will be inserting in BLOCK is not free,
3378 and inserting it for the sake of !optimize_for_speed successor
3379 may cause regressions on the speed path. */
3380 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3382 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
)
3383 || bitmap_set_contains_value (ANTIC_IN (succ
->dest
), val
))
3385 if (optimize_edge_for_speed_p (succ
))
3386 do_insertion
= true;
3392 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3394 fprintf (dump_file
, "Skipping partial partial redundancy "
3396 print_pre_expr (dump_file
, expr
);
3397 fprintf (dump_file
, " (%04d), not (partially) anticipated "
3398 "on any to be optimized for speed edges\n", val
);
3401 else if (dbg_cnt (treepre_insert
))
3403 pre_stats
.pa_insert
++;
3404 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3406 fprintf (dump_file
, "Found partial partial redundancy "
3408 print_pre_expr (dump_file
, expr
);
3409 fprintf (dump_file
, " (%04d)\n",
3410 get_expr_value_id (expr
));
3412 if (insert_into_preds_of_block (block
,
3413 get_expression_id (expr
),
3426 insert_aux (basic_block block
)
3429 bool new_stuff
= false;
3434 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3439 bitmap_set_t newset
= NEW_SETS (dom
);
3442 /* Note that we need to value_replace both NEW_SETS, and
3443 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3444 represented by some non-simple expression here that we want
3445 to replace it with. */
3446 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3448 pre_expr expr
= expression_for_id (i
);
3449 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3450 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3453 if (!single_pred_p (block
))
3455 new_stuff
|= do_regular_insertion (block
, dom
);
3456 if (do_partial_partial
)
3457 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3461 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3463 son
= next_dom_son (CDI_DOMINATORS
, son
))
3465 new_stuff
|= insert_aux (son
);
3471 /* Perform insertion of partially redundant values. */
3476 bool new_stuff
= true;
3478 int num_iterations
= 0;
3480 FOR_ALL_BB_FN (bb
, cfun
)
3481 NEW_SETS (bb
) = bitmap_set_new ();
3486 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3487 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3488 new_stuff
= insert_aux (ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3490 /* Clear the NEW sets before the next iteration. We have already
3491 fully propagated its contents. */
3493 FOR_ALL_BB_FN (bb
, cfun
)
3494 bitmap_set_free (NEW_SETS (bb
));
3496 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3500 /* Compute the AVAIL set for all basic blocks.
3502 This function performs value numbering of the statements in each basic
3503 block. The AVAIL sets are built from information we glean while doing
3504 this value numbering, since the AVAIL sets contain only one entry per
3507 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3508 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3511 compute_avail (void)
3514 basic_block block
, son
;
3515 basic_block
*worklist
;
3519 /* We pretend that default definitions are defined in the entry block.
3520 This includes function arguments and the static chain decl. */
3521 for (i
= 1; i
< num_ssa_names
; ++i
)
3523 tree name
= ssa_name (i
);
3526 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3527 || has_zero_uses (name
)
3528 || virtual_operand_p (name
))
3531 e
= get_or_alloc_expr_for_name (name
);
3532 add_to_value (get_expr_value_id (e
), e
);
3533 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)), e
);
3534 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3538 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3540 print_bitmap_set (dump_file
, TMP_GEN (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3541 "tmp_gen", ENTRY_BLOCK
);
3542 print_bitmap_set (dump_file
, AVAIL_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun
)),
3543 "avail_out", ENTRY_BLOCK
);
3546 /* Allocate the worklist. */
3547 worklist
= XNEWVEC (basic_block
, n_basic_blocks_for_fn (cfun
));
3549 /* Seed the algorithm by putting the dominator children of the entry
3550 block on the worklist. */
3551 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR_FOR_FN (cfun
));
3553 son
= next_dom_son (CDI_DOMINATORS
, son
))
3554 worklist
[sp
++] = son
;
3556 BB_LIVE_VOP_ON_EXIT (ENTRY_BLOCK_PTR_FOR_FN (cfun
))
3557 = ssa_default_def (cfun
, gimple_vop (cfun
));
3559 /* Loop until the worklist is empty. */
3565 /* Pick a block from the worklist. */
3566 block
= worklist
[--sp
];
3568 /* Initially, the set of available values in BLOCK is that of
3569 its immediate dominator. */
3570 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3573 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3574 BB_LIVE_VOP_ON_EXIT (block
) = BB_LIVE_VOP_ON_EXIT (dom
);
3577 /* Generate values for PHI nodes. */
3578 for (gphi_iterator gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
);
3581 tree result
= gimple_phi_result (gsi
.phi ());
3583 /* We have no need for virtual phis, as they don't represent
3584 actual computations. */
3585 if (virtual_operand_p (result
))
3587 BB_LIVE_VOP_ON_EXIT (block
) = result
;
3591 pre_expr e
= get_or_alloc_expr_for_name (result
);
3592 add_to_value (get_expr_value_id (e
), e
);
3593 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3594 bitmap_insert_into_set (PHI_GEN (block
), e
);
3597 BB_MAY_NOTRETURN (block
) = 0;
3599 /* Now compute value numbers and populate value sets with all
3600 the expressions computed in BLOCK. */
3601 for (gimple_stmt_iterator gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
);
3607 stmt
= gsi_stmt (gsi
);
3609 /* Cache whether the basic-block has any non-visible side-effect
3611 If this isn't a call or it is the last stmt in the
3612 basic-block then the CFG represents things correctly. */
3613 if (is_gimple_call (stmt
) && !stmt_ends_bb_p (stmt
))
3615 /* Non-looping const functions always return normally.
3616 Otherwise the call might not return or have side-effects
3617 that forbids hoisting possibly trapping expressions
3619 int flags
= gimple_call_flags (stmt
);
3620 if (!(flags
& ECF_CONST
)
3621 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3622 BB_MAY_NOTRETURN (block
) = 1;
3625 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3627 pre_expr e
= get_or_alloc_expr_for_name (op
);
3629 add_to_value (get_expr_value_id (e
), e
);
3630 bitmap_insert_into_set (TMP_GEN (block
), e
);
3631 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3634 if (gimple_vdef (stmt
))
3635 BB_LIVE_VOP_ON_EXIT (block
) = gimple_vdef (stmt
);
3637 if (gimple_has_side_effects (stmt
)
3638 || stmt_could_throw_p (stmt
)
3639 || is_gimple_debug (stmt
))
3642 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3644 if (ssa_undefined_value_p (op
))
3646 pre_expr e
= get_or_alloc_expr_for_name (op
);
3647 bitmap_value_insert_into_set (EXP_GEN (block
), e
);
3650 switch (gimple_code (stmt
))
3658 vn_reference_s ref1
;
3659 pre_expr result
= NULL
;
3661 /* We can value number only calls to real functions. */
3662 if (gimple_call_internal_p (stmt
))
3665 vn_reference_lookup_call (as_a
<gcall
*> (stmt
), &ref
, &ref1
);
3669 /* If the value of the call is not invalidated in
3670 this block until it is computed, add the expression
3672 if (!gimple_vuse (stmt
)
3674 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
3675 || gimple_bb (SSA_NAME_DEF_STMT
3676 (gimple_vuse (stmt
))) != block
)
3678 result
= pre_expr_pool
.allocate ();
3679 result
->kind
= REFERENCE
;
3681 PRE_EXPR_REFERENCE (result
) = ref
;
3683 get_or_alloc_expression_id (result
);
3684 add_to_value (get_expr_value_id (result
), result
);
3685 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3692 pre_expr result
= NULL
;
3693 switch (vn_get_stmt_kind (stmt
))
3697 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3700 /* COND_EXPR and VEC_COND_EXPR are awkward in
3701 that they contain an embedded complex expression.
3702 Don't even try to shove those through PRE. */
3703 if (code
== COND_EXPR
3704 || code
== VEC_COND_EXPR
)
3707 vn_nary_op_lookup_stmt (stmt
, &nary
);
3711 /* If the NARY traps and there was a preceding
3712 point in the block that might not return avoid
3713 adding the nary to EXP_GEN. */
3714 if (BB_MAY_NOTRETURN (block
)
3715 && vn_nary_may_trap (nary
))
3718 result
= pre_expr_pool
.allocate ();
3719 result
->kind
= NARY
;
3721 PRE_EXPR_NARY (result
) = nary
;
3728 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
3730 VN_WALK
, &ref
, true);
3734 /* If the value of the reference is not invalidated in
3735 this block until it is computed, add the expression
3737 if (gimple_vuse (stmt
))
3741 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
3742 while (!gimple_nop_p (def_stmt
)
3743 && gimple_code (def_stmt
) != GIMPLE_PHI
3744 && gimple_bb (def_stmt
) == block
)
3746 if (stmt_may_clobber_ref_p
3747 (def_stmt
, gimple_assign_rhs1 (stmt
)))
3753 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
3759 result
= pre_expr_pool
.allocate ();
3760 result
->kind
= REFERENCE
;
3762 PRE_EXPR_REFERENCE (result
) = ref
;
3770 get_or_alloc_expression_id (result
);
3771 add_to_value (get_expr_value_id (result
), result
);
3772 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3780 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3782 print_bitmap_set (dump_file
, EXP_GEN (block
),
3783 "exp_gen", block
->index
);
3784 print_bitmap_set (dump_file
, PHI_GEN (block
),
3785 "phi_gen", block
->index
);
3786 print_bitmap_set (dump_file
, TMP_GEN (block
),
3787 "tmp_gen", block
->index
);
3788 print_bitmap_set (dump_file
, AVAIL_OUT (block
),
3789 "avail_out", block
->index
);
3792 /* Put the dominator children of BLOCK on the worklist of blocks
3793 to compute available sets for. */
3794 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3796 son
= next_dom_son (CDI_DOMINATORS
, son
))
3797 worklist
[sp
++] = son
;
3804 /* Local state for the eliminate domwalk. */
3805 static vec
<gimple
*> el_to_remove
;
3806 static vec
<gimple
*> el_to_fixup
;
3807 static unsigned int el_todo
;
3808 static vec
<tree
> el_avail
;
3809 static vec
<tree
> el_avail_stack
;
3811 /* Return a leader for OP that is available at the current point of the
3812 eliminate domwalk. */
3815 eliminate_avail (tree op
)
3817 tree valnum
= VN_INFO (op
)->valnum
;
3818 if (TREE_CODE (valnum
) == SSA_NAME
)
3820 if (SSA_NAME_IS_DEFAULT_DEF (valnum
))
3822 if (el_avail
.length () > SSA_NAME_VERSION (valnum
))
3823 return el_avail
[SSA_NAME_VERSION (valnum
)];
3825 else if (is_gimple_min_invariant (valnum
))
3830 /* At the current point of the eliminate domwalk make OP available. */
3833 eliminate_push_avail (tree op
)
3835 tree valnum
= VN_INFO (op
)->valnum
;
3836 if (TREE_CODE (valnum
) == SSA_NAME
)
3838 if (el_avail
.length () <= SSA_NAME_VERSION (valnum
))
3839 el_avail
.safe_grow_cleared (SSA_NAME_VERSION (valnum
) + 1);
3841 if (el_avail
[SSA_NAME_VERSION (valnum
)])
3842 pushop
= el_avail
[SSA_NAME_VERSION (valnum
)];
3843 el_avail_stack
.safe_push (pushop
);
3844 el_avail
[SSA_NAME_VERSION (valnum
)] = op
;
3848 /* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
3849 the leader for the expression if insertion was successful. */
3852 eliminate_insert (gimple_stmt_iterator
*gsi
, tree val
)
3854 gimple
*stmt
= gimple_seq_first_stmt (VN_INFO (val
)->expr
);
3855 if (!is_gimple_assign (stmt
)
3856 || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt
))
3857 && gimple_assign_rhs_code (stmt
) != VIEW_CONVERT_EXPR
))
3860 tree op
= gimple_assign_rhs1 (stmt
);
3861 if (gimple_assign_rhs_code (stmt
) == VIEW_CONVERT_EXPR
)
3862 op
= TREE_OPERAND (op
, 0);
3863 tree leader
= TREE_CODE (op
) == SSA_NAME
? eliminate_avail (op
) : op
;
3867 gimple_seq stmts
= NULL
;
3868 tree res
= gimple_build (&stmts
, gimple_assign_rhs_code (stmt
),
3869 TREE_TYPE (val
), leader
);
3870 gsi_insert_seq_before (gsi
, stmts
, GSI_SAME_STMT
);
3871 VN_INFO_GET (res
)->valnum
= val
;
3873 if (TREE_CODE (leader
) == SSA_NAME
)
3874 gimple_set_plf (SSA_NAME_DEF_STMT (leader
), NECESSARY
, true);
3876 pre_stats
.insertions
++;
3877 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3879 fprintf (dump_file
, "Inserted ");
3880 print_gimple_stmt (dump_file
, SSA_NAME_DEF_STMT (res
), 0, 0);
3886 class eliminate_dom_walker
: public dom_walker
3889 eliminate_dom_walker (cdi_direction direction
, bool do_pre_
)
3890 : dom_walker (direction
), do_pre (do_pre_
) {}
3892 virtual edge
before_dom_children (basic_block
);
3893 virtual void after_dom_children (basic_block
);
3898 /* Perform elimination for the basic-block B during the domwalk. */
3901 eliminate_dom_walker::before_dom_children (basic_block b
)
3904 el_avail_stack
.safe_push (NULL_TREE
);
3906 /* ??? If we do nothing for unreachable blocks then this will confuse
3907 tailmerging. Eventually we can reduce its reliance on SCCVN now
3908 that we fully copy/constant-propagate (most) things. */
3910 for (gphi_iterator gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
3912 gphi
*phi
= gsi
.phi ();
3913 tree res
= PHI_RESULT (phi
);
3915 if (virtual_operand_p (res
))
3921 tree sprime
= eliminate_avail (res
);
3925 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3927 fprintf (dump_file
, "Replaced redundant PHI node defining ");
3928 print_generic_expr (dump_file
, res
, 0);
3929 fprintf (dump_file
, " with ");
3930 print_generic_expr (dump_file
, sprime
, 0);
3931 fprintf (dump_file
, "\n");
3934 /* If we inserted this PHI node ourself, it's not an elimination. */
3936 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
3939 pre_stats
.eliminations
++;
3941 /* If we will propagate into all uses don't bother to do
3943 if (may_propagate_copy (res
, sprime
))
3945 /* Mark the PHI for removal. */
3946 el_to_remove
.safe_push (phi
);
3951 remove_phi_node (&gsi
, false);
3954 && !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
3955 && TREE_CODE (sprime
) == SSA_NAME
)
3956 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
3958 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
3959 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
3960 gimple
*stmt
= gimple_build_assign (res
, sprime
);
3961 /* ??? It cannot yet be necessary (DOM walk). */
3962 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
3964 gimple_stmt_iterator gsi2
= gsi_after_labels (b
);
3965 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
3969 eliminate_push_avail (res
);
3973 for (gimple_stmt_iterator gsi
= gsi_start_bb (b
);
3977 tree sprime
= NULL_TREE
;
3978 gimple
*stmt
= gsi_stmt (gsi
);
3979 tree lhs
= gimple_get_lhs (stmt
);
3980 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
3981 && !gimple_has_volatile_ops (stmt
)
3982 /* See PR43491. Do not replace a global register variable when
3983 it is a the RHS of an assignment. Do replace local register
3984 variables since gcc does not guarantee a local variable will
3985 be allocated in register.
3986 ??? The fix isn't effective here. This should instead
3987 be ensured by not value-numbering them the same but treating
3988 them like volatiles? */
3989 && !(gimple_assign_single_p (stmt
)
3990 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == VAR_DECL
3991 && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt
))
3992 && is_global_var (gimple_assign_rhs1 (stmt
)))))
3994 sprime
= eliminate_avail (lhs
);
3997 /* If there is no existing usable leader but SCCVN thinks
3998 it has an expression it wants to use as replacement,
4000 tree val
= VN_INFO (lhs
)->valnum
;
4002 && TREE_CODE (val
) == SSA_NAME
4003 && VN_INFO (val
)->needs_insertion
4004 && VN_INFO (val
)->expr
!= NULL
4005 && (sprime
= eliminate_insert (&gsi
, val
)) != NULL_TREE
)
4006 eliminate_push_avail (sprime
);
4009 /* If this now constitutes a copy duplicate points-to
4010 and range info appropriately. This is especially
4011 important for inserted code. See tree-ssa-copy.c
4012 for similar code. */
4014 && TREE_CODE (sprime
) == SSA_NAME
)
4016 basic_block sprime_b
= gimple_bb (SSA_NAME_DEF_STMT (sprime
));
4017 if (POINTER_TYPE_P (TREE_TYPE (lhs
))
4018 && VN_INFO_PTR_INFO (lhs
)
4019 && ! VN_INFO_PTR_INFO (sprime
))
4021 duplicate_ssa_name_ptr_info (sprime
,
4022 VN_INFO_PTR_INFO (lhs
));
4024 mark_ptr_info_alignment_unknown
4025 (SSA_NAME_PTR_INFO (sprime
));
4027 else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
4028 && VN_INFO_RANGE_INFO (lhs
)
4029 && ! VN_INFO_RANGE_INFO (sprime
)
4031 duplicate_ssa_name_range_info (sprime
,
4032 VN_INFO_RANGE_TYPE (lhs
),
4033 VN_INFO_RANGE_INFO (lhs
));
4036 /* Inhibit the use of an inserted PHI on a loop header when
4037 the address of the memory reference is a simple induction
4038 variable. In other cases the vectorizer won't do anything
4039 anyway (either it's loop invariant or a complicated
4042 && TREE_CODE (sprime
) == SSA_NAME
4044 && flag_tree_loop_vectorize
4045 && loop_outer (b
->loop_father
)
4046 && has_zero_uses (sprime
)
4047 && bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))
4048 && gimple_assign_load_p (stmt
))
4050 gimple
*def_stmt
= SSA_NAME_DEF_STMT (sprime
);
4051 basic_block def_bb
= gimple_bb (def_stmt
);
4052 if (gimple_code (def_stmt
) == GIMPLE_PHI
4053 && def_bb
->loop_father
->header
== def_bb
)
4055 loop_p loop
= def_bb
->loop_father
;
4059 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4062 def_bb
= gimple_bb (SSA_NAME_DEF_STMT (op
));
4064 && flow_bb_inside_loop_p (loop
, def_bb
)
4065 && simple_iv (loop
, loop
, op
, &iv
, true))
4073 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4075 fprintf (dump_file
, "Not replacing ");
4076 print_gimple_expr (dump_file
, stmt
, 0, 0);
4077 fprintf (dump_file
, " with ");
4078 print_generic_expr (dump_file
, sprime
, 0);
4079 fprintf (dump_file
, " which would add a loop"
4080 " carried dependence to loop %d\n",
4083 /* Don't keep sprime available. */
4091 /* If we can propagate the value computed for LHS into
4092 all uses don't bother doing anything with this stmt. */
4093 if (may_propagate_copy (lhs
, sprime
))
4095 /* Mark it for removal. */
4096 el_to_remove
.safe_push (stmt
);
4098 /* ??? Don't count copy/constant propagations. */
4099 if (gimple_assign_single_p (stmt
)
4100 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4101 || gimple_assign_rhs1 (stmt
) == sprime
))
4104 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4106 fprintf (dump_file
, "Replaced ");
4107 print_gimple_expr (dump_file
, stmt
, 0, 0);
4108 fprintf (dump_file
, " with ");
4109 print_generic_expr (dump_file
, sprime
, 0);
4110 fprintf (dump_file
, " in all uses of ");
4111 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4114 pre_stats
.eliminations
++;
4118 /* If this is an assignment from our leader (which
4119 happens in the case the value-number is a constant)
4120 then there is nothing to do. */
4121 if (gimple_assign_single_p (stmt
)
4122 && sprime
== gimple_assign_rhs1 (stmt
))
4125 /* Else replace its RHS. */
4126 bool can_make_abnormal_goto
4127 = is_gimple_call (stmt
)
4128 && stmt_can_make_abnormal_goto (stmt
);
4130 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4132 fprintf (dump_file
, "Replaced ");
4133 print_gimple_expr (dump_file
, stmt
, 0, 0);
4134 fprintf (dump_file
, " with ");
4135 print_generic_expr (dump_file
, sprime
, 0);
4136 fprintf (dump_file
, " in ");
4137 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4140 if (TREE_CODE (sprime
) == SSA_NAME
)
4141 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4144 pre_stats
.eliminations
++;
4145 gimple
*orig_stmt
= stmt
;
4146 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4147 TREE_TYPE (sprime
)))
4148 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4149 tree vdef
= gimple_vdef (stmt
);
4150 tree vuse
= gimple_vuse (stmt
);
4151 propagate_tree_value_into_stmt (&gsi
, sprime
);
4152 stmt
= gsi_stmt (gsi
);
4154 if (vdef
!= gimple_vdef (stmt
))
4155 VN_INFO (vdef
)->valnum
= vuse
;
4157 /* If we removed EH side-effects from the statement, clean
4158 its EH information. */
4159 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4161 bitmap_set_bit (need_eh_cleanup
,
4162 gimple_bb (stmt
)->index
);
4163 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4164 fprintf (dump_file
, " Removed EH side-effects.\n");
4167 /* Likewise for AB side-effects. */
4168 if (can_make_abnormal_goto
4169 && !stmt_can_make_abnormal_goto (stmt
))
4171 bitmap_set_bit (need_ab_cleanup
,
4172 gimple_bb (stmt
)->index
);
4173 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4174 fprintf (dump_file
, " Removed AB side-effects.\n");
4181 /* If the statement is a scalar store, see if the expression
4182 has the same value number as its rhs. If so, the store is
4184 if (gimple_assign_single_p (stmt
)
4185 && !gimple_has_volatile_ops (stmt
)
4186 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4187 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4188 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4191 tree rhs
= gimple_assign_rhs1 (stmt
);
4192 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4193 gimple_vuse (stmt
), VN_WALK
, NULL
, false);
4194 if (TREE_CODE (rhs
) == SSA_NAME
)
4195 rhs
= VN_INFO (rhs
)->valnum
;
4197 && operand_equal_p (val
, rhs
, 0))
4199 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4201 fprintf (dump_file
, "Deleted redundant store ");
4202 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4205 /* Queue stmt for removal. */
4206 el_to_remove
.safe_push (stmt
);
4211 /* If this is a control statement value numbering left edges
4212 unexecuted on force the condition in a way consistent with
4214 if (gcond
*cond
= dyn_cast
<gcond
*> (stmt
))
4216 if ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
)
4217 ^ (EDGE_SUCC (b
, 1)->flags
& EDGE_EXECUTABLE
))
4219 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4221 fprintf (dump_file
, "Removing unexecutable edge from ");
4222 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4224 if (((EDGE_SUCC (b
, 0)->flags
& EDGE_TRUE_VALUE
) != 0)
4225 == ((EDGE_SUCC (b
, 0)->flags
& EDGE_EXECUTABLE
) != 0))
4226 gimple_cond_make_true (cond
);
4228 gimple_cond_make_false (cond
);
4230 el_todo
|= TODO_cleanup_cfg
;
4235 bool can_make_abnormal_goto
= stmt_can_make_abnormal_goto (stmt
);
4236 bool was_noreturn
= (is_gimple_call (stmt
)
4237 && gimple_call_noreturn_p (stmt
));
4238 tree vdef
= gimple_vdef (stmt
);
4239 tree vuse
= gimple_vuse (stmt
);
4241 /* If we didn't replace the whole stmt (or propagate the result
4242 into all uses), replace all uses on this stmt with their
4244 use_operand_p use_p
;
4246 FOR_EACH_SSA_USE_OPERAND (use_p
, stmt
, iter
, SSA_OP_USE
)
4248 tree use
= USE_FROM_PTR (use_p
);
4249 /* ??? The call code above leaves stmt operands un-updated. */
4250 if (TREE_CODE (use
) != SSA_NAME
)
4252 tree sprime
= eliminate_avail (use
);
4253 if (sprime
&& sprime
!= use
4254 && may_propagate_copy (use
, sprime
)
4255 /* We substitute into debug stmts to avoid excessive
4256 debug temporaries created by removed stmts, but we need
4257 to avoid doing so for inserted sprimes as we never want
4258 to create debug temporaries for them. */
4260 || TREE_CODE (sprime
) != SSA_NAME
4261 || !is_gimple_debug (stmt
)
4262 || !bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (sprime
))))
4264 propagate_value (use_p
, sprime
);
4265 gimple_set_modified (stmt
, true);
4266 if (TREE_CODE (sprime
) == SSA_NAME
4267 && !is_gimple_debug (stmt
))
4268 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4273 /* Visit indirect calls and turn them into direct calls if
4274 possible using the devirtualization machinery. */
4275 if (gcall
*call_stmt
= dyn_cast
<gcall
*> (stmt
))
4277 tree fn
= gimple_call_fn (call_stmt
);
4279 && flag_devirtualize
4280 && virtual_method_call_p (fn
))
4282 tree otr_type
= obj_type_ref_class (fn
);
4284 ipa_polymorphic_call_context
context (current_function_decl
, fn
, stmt
, &instance
);
4287 context
.get_dynamic_type (instance
, OBJ_TYPE_REF_OBJECT (fn
), otr_type
, stmt
);
4289 vec
<cgraph_node
*>targets
4290 = possible_polymorphic_call_targets (obj_type_ref_class (fn
),
4292 (OBJ_TYPE_REF_TOKEN (fn
)),
4296 dump_possible_polymorphic_call_targets (dump_file
,
4297 obj_type_ref_class (fn
),
4299 (OBJ_TYPE_REF_TOKEN (fn
)),
4301 if (final
&& targets
.length () <= 1 && dbg_cnt (devirt
))
4304 if (targets
.length () == 1)
4305 fn
= targets
[0]->decl
;
4307 fn
= builtin_decl_implicit (BUILT_IN_UNREACHABLE
);
4308 if (dump_enabled_p ())
4310 location_t loc
= gimple_location_safe (stmt
);
4311 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, loc
,
4312 "converting indirect call to "
4314 lang_hooks
.decl_printable_name (fn
, 2));
4316 gimple_call_set_fndecl (call_stmt
, fn
);
4317 maybe_remove_unused_call_args (cfun
, call_stmt
);
4318 gimple_set_modified (stmt
, true);
4323 if (gimple_modified_p (stmt
))
4325 /* If a formerly non-invariant ADDR_EXPR is turned into an
4326 invariant one it was on a separate stmt. */
4327 if (gimple_assign_single_p (stmt
)
4328 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
4329 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
4330 gimple
*old_stmt
= stmt
;
4331 if (is_gimple_call (stmt
))
4333 /* ??? Only fold calls inplace for now, this may create new
4334 SSA names which in turn will confuse free_scc_vn SSA name
4336 fold_stmt_inplace (&gsi
);
4337 /* When changing a call into a noreturn call, cfg cleanup
4338 is needed to fix up the noreturn call. */
4339 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4340 el_to_fixup
.safe_push (stmt
);
4345 stmt
= gsi_stmt (gsi
);
4346 if ((gimple_code (stmt
) == GIMPLE_COND
4347 && (gimple_cond_true_p (as_a
<gcond
*> (stmt
))
4348 || gimple_cond_false_p (as_a
<gcond
*> (stmt
))))
4349 || (gimple_code (stmt
) == GIMPLE_SWITCH
4350 && TREE_CODE (gimple_switch_index (
4351 as_a
<gswitch
*> (stmt
)))
4353 el_todo
|= TODO_cleanup_cfg
;
4355 /* If we removed EH side-effects from the statement, clean
4356 its EH information. */
4357 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
))
4359 bitmap_set_bit (need_eh_cleanup
,
4360 gimple_bb (stmt
)->index
);
4361 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4362 fprintf (dump_file
, " Removed EH side-effects.\n");
4364 /* Likewise for AB side-effects. */
4365 if (can_make_abnormal_goto
4366 && !stmt_can_make_abnormal_goto (stmt
))
4368 bitmap_set_bit (need_ab_cleanup
,
4369 gimple_bb (stmt
)->index
);
4370 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4371 fprintf (dump_file
, " Removed AB side-effects.\n");
4374 if (vdef
!= gimple_vdef (stmt
))
4375 VN_INFO (vdef
)->valnum
= vuse
;
4378 /* Make new values available - for fully redundant LHS we
4379 continue with the next stmt above and skip this. */
4381 FOR_EACH_SSA_DEF_OPERAND (defp
, stmt
, iter
, SSA_OP_DEF
)
4382 eliminate_push_avail (DEF_FROM_PTR (defp
));
4385 /* Replace destination PHI arguments. */
4388 FOR_EACH_EDGE (e
, ei
, b
->succs
)
4390 for (gphi_iterator gsi
= gsi_start_phis (e
->dest
);
4394 gphi
*phi
= gsi
.phi ();
4395 use_operand_p use_p
= PHI_ARG_DEF_PTR_FROM_EDGE (phi
, e
);
4396 tree arg
= USE_FROM_PTR (use_p
);
4397 if (TREE_CODE (arg
) != SSA_NAME
4398 || virtual_operand_p (arg
))
4400 tree sprime
= eliminate_avail (arg
);
4401 if (sprime
&& may_propagate_copy (arg
, sprime
))
4403 propagate_value (use_p
, sprime
);
4404 if (TREE_CODE (sprime
) == SSA_NAME
)
4405 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4412 /* Make no longer available leaders no longer available. */
4415 eliminate_dom_walker::after_dom_children (basic_block
)
4418 while ((entry
= el_avail_stack
.pop ()) != NULL_TREE
)
4420 tree valnum
= VN_INFO (entry
)->valnum
;
4421 tree old
= el_avail
[SSA_NAME_VERSION (valnum
)];
4423 el_avail
[SSA_NAME_VERSION (valnum
)] = NULL_TREE
;
4425 el_avail
[SSA_NAME_VERSION (valnum
)] = entry
;
4429 /* Eliminate fully redundant computations. */
4432 eliminate (bool do_pre
)
4434 gimple_stmt_iterator gsi
;
4437 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4438 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4440 el_to_remove
.create (0);
4441 el_to_fixup
.create (0);
4443 el_avail
.create (num_ssa_names
);
4444 el_avail_stack
.create (0);
4446 eliminate_dom_walker (CDI_DOMINATORS
,
4447 do_pre
).walk (cfun
->cfg
->x_entry_block_ptr
);
4449 el_avail
.release ();
4450 el_avail_stack
.release ();
4452 /* We cannot remove stmts during BB walk, especially not release SSA
4453 names there as this confuses the VN machinery. The stmts ending
4454 up in el_to_remove are either stores or simple copies.
4455 Remove stmts in reverse order to make debug stmt creation possible. */
4456 while (!el_to_remove
.is_empty ())
4458 stmt
= el_to_remove
.pop ();
4460 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4462 fprintf (dump_file
, "Removing dead stmt ");
4463 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4467 if (gimple_code (stmt
) == GIMPLE_PHI
)
4468 lhs
= gimple_phi_result (stmt
);
4470 lhs
= gimple_get_lhs (stmt
);
4473 && TREE_CODE (lhs
) == SSA_NAME
)
4474 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4476 gsi
= gsi_for_stmt (stmt
);
4477 if (gimple_code (stmt
) == GIMPLE_PHI
)
4478 remove_phi_node (&gsi
, true);
4481 basic_block bb
= gimple_bb (stmt
);
4482 unlink_stmt_vdef (stmt
);
4483 if (gsi_remove (&gsi
, true))
4484 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4485 if (is_gimple_call (stmt
) && stmt_can_make_abnormal_goto (stmt
))
4486 bitmap_set_bit (need_ab_cleanup
, bb
->index
);
4487 release_defs (stmt
);
4490 /* Removing a stmt may expose a forwarder block. */
4491 el_todo
|= TODO_cleanup_cfg
;
4493 el_to_remove
.release ();
4495 /* Fixup stmts that became noreturn calls. This may require splitting
4496 blocks and thus isn't possible during the dominator walk. Do this
4497 in reverse order so we don't inadvertedly remove a stmt we want to
4498 fixup by visiting a dominating now noreturn call first. */
4499 while (!el_to_fixup
.is_empty ())
4501 stmt
= el_to_fixup
.pop ();
4503 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4505 fprintf (dump_file
, "Fixing up noreturn call ");
4506 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4509 if (fixup_noreturn_call (stmt
))
4510 el_todo
|= TODO_cleanup_cfg
;
4512 el_to_fixup
.release ();
4517 /* Perform CFG cleanups made necessary by elimination. */
4520 fini_eliminate (void)
4522 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4523 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4526 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4529 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4531 BITMAP_FREE (need_eh_cleanup
);
4532 BITMAP_FREE (need_ab_cleanup
);
4534 if (do_eh_cleanup
|| do_ab_cleanup
)
4535 return TODO_cleanup_cfg
;
4539 /* Borrow a bit of tree-ssa-dce.c for the moment.
4540 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4541 this may be a bit faster, and we may want critical edges kept split. */
4543 /* If OP's defining statement has not already been determined to be necessary,
4544 mark that statement necessary. Return the stmt, if it is newly
4547 static inline gimple
*
4548 mark_operand_necessary (tree op
)
4554 if (TREE_CODE (op
) != SSA_NAME
)
4557 stmt
= SSA_NAME_DEF_STMT (op
);
4560 if (gimple_plf (stmt
, NECESSARY
)
4561 || gimple_nop_p (stmt
))
4564 gimple_set_plf (stmt
, NECESSARY
, true);
4568 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4569 to insert PHI nodes sometimes, and because value numbering of casts isn't
4570 perfect, we sometimes end up inserting dead code. This simple DCE-like
4571 pass removes any insertions we made that weren't actually used. */
4574 remove_dead_inserted_code (void)
4581 worklist
= BITMAP_ALLOC (NULL
);
4582 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4584 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4585 if (gimple_plf (t
, NECESSARY
))
4586 bitmap_set_bit (worklist
, i
);
4588 while (!bitmap_empty_p (worklist
))
4590 i
= bitmap_first_set_bit (worklist
);
4591 bitmap_clear_bit (worklist
, i
);
4592 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4594 /* PHI nodes are somewhat special in that each PHI alternative has
4595 data and control dependencies. All the statements feeding the
4596 PHI node's arguments are always necessary. */
4597 if (gimple_code (t
) == GIMPLE_PHI
)
4601 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4603 tree arg
= PHI_ARG_DEF (t
, k
);
4604 if (TREE_CODE (arg
) == SSA_NAME
)
4606 gimple
*n
= mark_operand_necessary (arg
);
4608 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4614 /* Propagate through the operands. Examine all the USE, VUSE and
4615 VDEF operands in this statement. Mark all the statements
4616 which feed this statement's uses as necessary. */
4620 /* The operands of VDEF expressions are also needed as they
4621 represent potential definitions that may reach this
4622 statement (VDEF operands allow us to follow def-def
4625 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4627 gimple
*n
= mark_operand_necessary (use
);
4629 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4634 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4636 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4637 if (!gimple_plf (t
, NECESSARY
))
4639 gimple_stmt_iterator gsi
;
4641 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4643 fprintf (dump_file
, "Removing unnecessary insertion:");
4644 print_gimple_stmt (dump_file
, t
, 0, 0);
4647 gsi
= gsi_for_stmt (t
);
4648 if (gimple_code (t
) == GIMPLE_PHI
)
4649 remove_phi_node (&gsi
, true);
4652 gsi_remove (&gsi
, true);
4657 BITMAP_FREE (worklist
);
4661 /* Initialize data structures used by PRE. */
4668 next_expression_id
= 1;
4669 expressions
.create (0);
4670 expressions
.safe_push (NULL
);
4671 value_expressions
.create (get_max_value_id () + 1);
4672 value_expressions
.safe_grow_cleared (get_max_value_id () + 1);
4673 name_to_id
.create (0);
4675 inserted_exprs
= BITMAP_ALLOC (NULL
);
4677 connect_infinite_loops_to_exit ();
4678 memset (&pre_stats
, 0, sizeof (pre_stats
));
4680 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4682 calculate_dominance_info (CDI_DOMINATORS
);
4684 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4685 phi_translate_table
= new hash_table
<expr_pred_trans_d
> (5110);
4686 expression_to_id
= new hash_table
<pre_expr_d
> (num_ssa_names
* 3);
4687 FOR_ALL_BB_FN (bb
, cfun
)
4689 EXP_GEN (bb
) = bitmap_set_new ();
4690 PHI_GEN (bb
) = bitmap_set_new ();
4691 TMP_GEN (bb
) = bitmap_set_new ();
4692 AVAIL_OUT (bb
) = bitmap_set_new ();
4697 /* Deallocate data structures used by PRE. */
4702 value_expressions
.release ();
4703 BITMAP_FREE (inserted_exprs
);
4704 bitmap_obstack_release (&grand_bitmap_obstack
);
4705 bitmap_set_pool
.release ();
4706 pre_expr_pool
.release ();
4707 delete phi_translate_table
;
4708 phi_translate_table
= NULL
;
4709 delete expression_to_id
;
4710 expression_to_id
= NULL
;
4711 name_to_id
.release ();
4713 free_aux_for_blocks ();
4718 const pass_data pass_data_pre
=
4720 GIMPLE_PASS
, /* type */
4722 OPTGROUP_NONE
, /* optinfo_flags */
4723 TV_TREE_PRE
, /* tv_id */
4724 /* PROP_no_crit_edges is ensured by placing pass_split_crit_edges before
4726 ( PROP_no_crit_edges
| PROP_cfg
| PROP_ssa
), /* properties_required */
4727 0, /* properties_provided */
4728 PROP_no_crit_edges
, /* properties_destroyed */
4729 TODO_rebuild_alias
, /* todo_flags_start */
4730 0, /* todo_flags_finish */
4733 class pass_pre
: public gimple_opt_pass
4736 pass_pre (gcc::context
*ctxt
)
4737 : gimple_opt_pass (pass_data_pre
, ctxt
)
4740 /* opt_pass methods: */
4741 virtual bool gate (function
*) { return flag_tree_pre
!= 0; }
4742 virtual unsigned int execute (function
*);
4744 }; // class pass_pre
4747 pass_pre::execute (function
*fun
)
4749 unsigned int todo
= 0;
4751 do_partial_partial
=
4752 flag_tree_partial_pre
&& optimize_function_for_speed_p (fun
);
4754 /* This has to happen before SCCVN runs because
4755 loop_optimizer_init may create new phis, etc. */
4756 loop_optimizer_init (LOOPS_NORMAL
);
4758 if (!run_scc_vn (VN_WALK
))
4760 loop_optimizer_finalize ();
4767 /* Collect and value number expressions computed in each basic block. */
4770 /* Insert can get quite slow on an incredibly large number of basic
4771 blocks due to some quadratic behavior. Until this behavior is
4772 fixed, don't run it when he have an incredibly large number of
4773 bb's. If we aren't going to run insert, there is no point in
4774 computing ANTIC, either, even though it's plenty fast. */
4775 if (n_basic_blocks_for_fn (fun
) < 4000)
4781 /* Make sure to remove fake edges before committing our inserts.
4782 This makes sure we don't end up with extra critical edges that
4783 we would need to split. */
4784 remove_fake_exit_edges ();
4785 gsi_commit_edge_inserts ();
4787 /* Eliminate folds statements which might (should not...) end up
4788 not keeping virtual operands up-to-date. */
4789 gcc_assert (!need_ssa_update_p (fun
));
4791 /* Remove all the redundant expressions. */
4792 todo
|= eliminate (true);
4794 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
4795 statistics_counter_event (fun
, "PA inserted", pre_stats
.pa_insert
);
4796 statistics_counter_event (fun
, "New PHIs", pre_stats
.phis
);
4797 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
4799 clear_expression_ids ();
4800 remove_dead_inserted_code ();
4804 todo
|= fini_eliminate ();
4805 loop_optimizer_finalize ();
4807 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
4808 case we can merge the block with the remaining predecessor of the block.
4810 - call merge_blocks after each tail merge iteration
4811 - call merge_blocks after all tail merge iterations
4812 - mark TODO_cleanup_cfg when necessary
4813 - share the cfg cleanup with fini_pre. */
4814 todo
|= tail_merge_optimize (todo
);
4818 /* Tail merging invalidates the virtual SSA web, together with
4819 cfg-cleanup opportunities exposed by PRE this will wreck the
4820 SSA updating machinery. So make sure to run update-ssa
4821 manually, before eventually scheduling cfg-cleanup as part of
4823 update_ssa (TODO_update_ssa_only_virtuals
);
4831 make_pass_pre (gcc::context
*ctxt
)
4833 return new pass_pre (ctxt
);
4838 const pass_data pass_data_fre
=
4840 GIMPLE_PASS
, /* type */
4842 OPTGROUP_NONE
, /* optinfo_flags */
4843 TV_TREE_FRE
, /* tv_id */
4844 ( PROP_cfg
| PROP_ssa
), /* properties_required */
4845 0, /* properties_provided */
4846 0, /* properties_destroyed */
4847 0, /* todo_flags_start */
4848 0, /* todo_flags_finish */
4851 class pass_fre
: public gimple_opt_pass
4854 pass_fre (gcc::context
*ctxt
)
4855 : gimple_opt_pass (pass_data_fre
, ctxt
)
4858 /* opt_pass methods: */
4859 opt_pass
* clone () { return new pass_fre (m_ctxt
); }
4860 virtual bool gate (function
*) { return flag_tree_fre
!= 0; }
4861 virtual unsigned int execute (function
*);
4863 }; // class pass_fre
4866 pass_fre::execute (function
*fun
)
4868 unsigned int todo
= 0;
4870 if (!run_scc_vn (VN_WALKREWRITE
))
4873 memset (&pre_stats
, 0, sizeof (pre_stats
));
4875 /* Remove all the redundant expressions. */
4876 todo
|= eliminate (false);
4878 todo
|= fini_eliminate ();
4882 statistics_counter_event (fun
, "Insertions", pre_stats
.insertions
);
4883 statistics_counter_event (fun
, "Eliminated", pre_stats
.eliminations
);
4891 make_pass_fre (gcc::context
*ctxt
)
4893 return new pass_fre (ctxt
);