Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / gcc-4.4 / gcc / tree-ssa-pre.c
CommitLineData
c251ad9e
SS
1/* SSA-PRE for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
3 Free Software Foundation, Inc.
4 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
5 <stevenb@suse.de>
6
7This file is part of GCC.
8
9GCC is free software; you can redistribute it and/or modify
10it under the terms of the GNU General Public License as published by
11the Free Software Foundation; either version 3, or (at your option)
12any later version.
13
14GCC is distributed in the hope that it will be useful,
15but WITHOUT ANY WARRANTY; without even the implied warranty of
16MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17GNU General Public License for more details.
18
19You should have received a copy of the GNU General Public License
20along with GCC; see the file COPYING3. If not see
21<http://www.gnu.org/licenses/>. */
22
23#include "config.h"
24#include "system.h"
25#include "coretypes.h"
26#include "tm.h"
27#include "ggc.h"
28#include "tree.h"
29#include "basic-block.h"
30#include "diagnostic.h"
31#include "tree-inline.h"
32#include "tree-flow.h"
33#include "gimple.h"
34#include "tree-dump.h"
35#include "timevar.h"
36#include "fibheap.h"
37#include "hashtab.h"
38#include "tree-iterator.h"
39#include "real.h"
40#include "alloc-pool.h"
41#include "obstack.h"
42#include "tree-pass.h"
43#include "flags.h"
44#include "bitmap.h"
45#include "langhooks.h"
46#include "cfgloop.h"
47#include "tree-ssa-sccvn.h"
48#include "params.h"
49#include "dbgcnt.h"
50
51/* TODO:
52
53 1. Avail sets can be shared by making an avail_find_leader that
54 walks up the dominator tree and looks in those avail sets.
55 This might affect code optimality, it's unclear right now.
56 2. Strength reduction can be performed by anticipating expressions
57 we can repair later on.
58 3. We can do back-substitution or smarter value numbering to catch
59 commutative expressions split up over multiple statements.
60*/
61
62/* For ease of terminology, "expression node" in the below refers to
63 every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
64 represent the actual statement containing the expressions we care about,
65 and we cache the value number by putting it in the expression. */
66
67/* Basic algorithm
68
69 First we walk the statements to generate the AVAIL sets, the
70 EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
71 generation of values/expressions by a given block. We use them
72 when computing the ANTIC sets. The AVAIL sets consist of
73 SSA_NAME's that represent values, so we know what values are
74 available in what blocks. AVAIL is a forward dataflow problem. In
75 SSA, values are never killed, so we don't need a kill set, or a
76 fixpoint iteration, in order to calculate the AVAIL sets. In
77 traditional parlance, AVAIL sets tell us the downsafety of the
78 expressions/values.
79
80 Next, we generate the ANTIC sets. These sets represent the
81 anticipatable expressions. ANTIC is a backwards dataflow
82 problem. An expression is anticipatable in a given block if it could
83 be generated in that block. This means that if we had to perform
84 an insertion in that block, of the value of that expression, we
85 could. Calculating the ANTIC sets requires phi translation of
86 expressions, because the flow goes backwards through phis. We must
87 iterate to a fixpoint of the ANTIC sets, because we have a kill
88 set. Even in SSA form, values are not live over the entire
89 function, only from their definition point onwards. So we have to
90 remove values from the ANTIC set once we go past the definition
91 point of the leaders that make them up.
92 compute_antic/compute_antic_aux performs this computation.
93
94 Third, we perform insertions to make partially redundant
95 expressions fully redundant.
96
97 An expression is partially redundant (excluding partial
98 anticipation) if:
99
100 1. It is AVAIL in some, but not all, of the predecessors of a
101 given block.
102 2. It is ANTIC in all the predecessors.
103
104 In order to make it fully redundant, we insert the expression into
105 the predecessors where it is not available, but is ANTIC.
106
107 For the partial anticipation case, we only perform insertion if it
108 is partially anticipated in some block, and fully available in all
109 of the predecessors.
110
111 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
112 performs these steps.
113
114 Fourth, we eliminate fully redundant expressions.
115 This is a simple statement walk that replaces redundant
116 calculations with the now available values. */
117
118/* Representations of value numbers:
119
120 Value numbers are represented by a representative SSA_NAME. We
121 will create fake SSA_NAME's in situations where we need a
122 representative but do not have one (because it is a complex
123 expression). In order to facilitate storing the value numbers in
124 bitmaps, and keep the number of wasted SSA_NAME's down, we also
125 associate a value_id with each value number, and create full blown
126 ssa_name's only where we actually need them (IE in operands of
127 existing expressions).
128
129 Theoretically you could replace all the value_id's with
130 SSA_NAME_VERSION, but this would allocate a large number of
131 SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
132 It would also require an additional indirection at each point we
133 use the value id. */
134
135/* Representation of expressions on value numbers:
136
137 Expressions consisting of value numbers are represented the same
138 way as our VN internally represents them, with an additional
139 "pre_expr" wrapping around them in order to facilitate storing all
140 of the expressions in the same sets. */
141
142/* Representation of sets:
143
144 The dataflow sets do not need to be sorted in any particular order
145 for the majority of their lifetime, are simply represented as two
146 bitmaps, one that keeps track of values present in the set, and one
147 that keeps track of expressions present in the set.
148
149 When we need them in topological order, we produce it on demand by
150 transforming the bitmap into an array and sorting it into topo
151 order. */
152
153/* Type of expression, used to know which member of the PRE_EXPR union
154 is valid. */
155
156enum pre_expr_kind
157{
158 NAME,
159 NARY,
160 REFERENCE,
161 CONSTANT
162};
163
164typedef union pre_expr_union_d
165{
166 tree name;
167 tree constant;
168 vn_nary_op_t nary;
169 vn_reference_t reference;
170} pre_expr_union;
171
172typedef struct pre_expr_d
173{
174 enum pre_expr_kind kind;
175 unsigned int id;
176 pre_expr_union u;
177} *pre_expr;
178
179#define PRE_EXPR_NAME(e) (e)->u.name
180#define PRE_EXPR_NARY(e) (e)->u.nary
181#define PRE_EXPR_REFERENCE(e) (e)->u.reference
182#define PRE_EXPR_CONSTANT(e) (e)->u.constant
183
184static int
185pre_expr_eq (const void *p1, const void *p2)
186{
187 const struct pre_expr_d *e1 = (const struct pre_expr_d *) p1;
188 const struct pre_expr_d *e2 = (const struct pre_expr_d *) p2;
189
190 if (e1->kind != e2->kind)
191 return false;
192
193 switch (e1->kind)
194 {
195 case CONSTANT:
196 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1),
197 PRE_EXPR_CONSTANT (e2));
198 case NAME:
199 return PRE_EXPR_NAME (e1) == PRE_EXPR_NAME (e2);
200 case NARY:
201 return vn_nary_op_eq (PRE_EXPR_NARY (e1), PRE_EXPR_NARY (e2));
202 case REFERENCE:
203 return vn_reference_eq (PRE_EXPR_REFERENCE (e1),
204 PRE_EXPR_REFERENCE (e2));
205 default:
206 abort();
207 }
208}
209
210static hashval_t
211pre_expr_hash (const void *p1)
212{
213 const struct pre_expr_d *e = (const struct pre_expr_d *) p1;
214 switch (e->kind)
215 {
216 case CONSTANT:
217 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e));
218 case NAME:
219 return iterative_hash_hashval_t (SSA_NAME_VERSION (PRE_EXPR_NAME (e)), 0);
220 case NARY:
221 return PRE_EXPR_NARY (e)->hashcode;
222 case REFERENCE:
223 return PRE_EXPR_REFERENCE (e)->hashcode;
224 default:
225 abort ();
226 }
227}
228
229
230/* Next global expression id number. */
231static unsigned int next_expression_id;
232
233/* Mapping from expression to id number we can use in bitmap sets. */
234DEF_VEC_P (pre_expr);
235DEF_VEC_ALLOC_P (pre_expr, heap);
236static VEC(pre_expr, heap) *expressions;
237static htab_t expression_to_id;
238
239/* Allocate an expression id for EXPR. */
240
241static inline unsigned int
242alloc_expression_id (pre_expr expr)
243{
244 void **slot;
245 /* Make sure we won't overflow. */
246 gcc_assert (next_expression_id + 1 > next_expression_id);
247 expr->id = next_expression_id++;
248 VEC_safe_push (pre_expr, heap, expressions, expr);
249 slot = htab_find_slot (expression_to_id, expr, INSERT);
250 gcc_assert (!*slot);
251 *slot = expr;
252 return next_expression_id - 1;
253}
254
255/* Return the expression id for tree EXPR. */
256
257static inline unsigned int
258get_expression_id (const pre_expr expr)
259{
260 return expr->id;
261}
262
263static inline unsigned int
264lookup_expression_id (const pre_expr expr)
265{
266 void **slot;
267
268 slot = htab_find_slot (expression_to_id, expr, NO_INSERT);
269 if (!slot)
270 return 0;
271 return ((pre_expr)*slot)->id;
272}
273
274/* Return the existing expression id for EXPR, or create one if one
275 does not exist yet. */
276
277static inline unsigned int
278get_or_alloc_expression_id (pre_expr expr)
279{
280 unsigned int id = lookup_expression_id (expr);
281 if (id == 0)
282 return alloc_expression_id (expr);
283 return expr->id = id;
284}
285
286/* Return the expression that has expression id ID */
287
288static inline pre_expr
289expression_for_id (unsigned int id)
290{
291 return VEC_index (pre_expr, expressions, id);
292}
293
294/* Free the expression id field in all of our expressions,
295 and then destroy the expressions array. */
296
297static void
298clear_expression_ids (void)
299{
300 VEC_free (pre_expr, heap, expressions);
301}
302
303static alloc_pool pre_expr_pool;
304
305/* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
306
307static pre_expr
308get_or_alloc_expr_for_name (tree name)
309{
310 pre_expr result = (pre_expr) pool_alloc (pre_expr_pool);
311 unsigned int result_id;
312
313 result->kind = NAME;
314 result->id = 0;
315 PRE_EXPR_NAME (result) = name;
316 result_id = lookup_expression_id (result);
317 if (result_id != 0)
318 {
319 pool_free (pre_expr_pool, result);
320 result = expression_for_id (result_id);
321 return result;
322 }
323 get_or_alloc_expression_id (result);
324 return result;
325}
326
327static bool in_fre = false;
328
329/* An unordered bitmap set. One bitmap tracks values, the other,
330 expressions. */
331typedef struct bitmap_set
332{
333 bitmap expressions;
334 bitmap values;
335} *bitmap_set_t;
336
337#define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
338 EXECUTE_IF_SET_IN_BITMAP((set)->expressions, 0, (id), (bi))
339
340#define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
341 EXECUTE_IF_SET_IN_BITMAP((set)->values, 0, (id), (bi))
342
343/* Mapping from value id to expressions with that value_id. */
344DEF_VEC_P (bitmap_set_t);
345DEF_VEC_ALLOC_P (bitmap_set_t, heap);
346static VEC(bitmap_set_t, heap) *value_expressions;
347
348/* Sets that we need to keep track of. */
349typedef struct bb_bitmap_sets
350{
351 /* The EXP_GEN set, which represents expressions/values generated in
352 a basic block. */
353 bitmap_set_t exp_gen;
354
355 /* The PHI_GEN set, which represents PHI results generated in a
356 basic block. */
357 bitmap_set_t phi_gen;
358
359 /* The TMP_GEN set, which represents results/temporaries generated
360 in a basic block. IE the LHS of an expression. */
361 bitmap_set_t tmp_gen;
362
363 /* The AVAIL_OUT set, which represents which values are available in
364 a given basic block. */
365 bitmap_set_t avail_out;
366
367 /* The ANTIC_IN set, which represents which values are anticipatable
368 in a given basic block. */
369 bitmap_set_t antic_in;
370
371 /* The PA_IN set, which represents which values are
372 partially anticipatable in a given basic block. */
373 bitmap_set_t pa_in;
374
375 /* The NEW_SETS set, which is used during insertion to augment the
376 AVAIL_OUT set of blocks with the new insertions performed during
377 the current iteration. */
378 bitmap_set_t new_sets;
379
380 /* True if we have visited this block during ANTIC calculation. */
381 unsigned int visited:1;
382
383 /* True we have deferred processing this block during ANTIC
384 calculation until its successor is processed. */
385 unsigned int deferred : 1;
386} *bb_value_sets_t;
387
388#define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
389#define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
390#define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
391#define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
392#define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
393#define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
394#define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
395#define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
396#define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
397
398
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399/* Basic block list in postorder. */
400static int *postorder;
401
402/* This structure is used to keep track of statistics on what
403 optimization PRE was able to perform. */
404static struct
405{
406 /* The number of RHS computations eliminated by PRE. */
407 int eliminations;
408
409 /* The number of new expressions/temporaries generated by PRE. */
410 int insertions;
411
412 /* The number of inserts found due to partial anticipation */
413 int pa_insert;
414
415 /* The number of new PHI nodes added by PRE. */
416 int phis;
417
418 /* The number of values found constant. */
419 int constified;
420
421} pre_stats;
422
423static bool do_partial_partial;
424static pre_expr bitmap_find_leader (bitmap_set_t, unsigned int, gimple);
425static void bitmap_value_insert_into_set (bitmap_set_t, pre_expr);
426static void bitmap_value_replace_in_set (bitmap_set_t, pre_expr);
427static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
428static bool bitmap_set_contains_value (bitmap_set_t, unsigned int);
429static void bitmap_insert_into_set (bitmap_set_t, pre_expr);
430static void bitmap_insert_into_set_1 (bitmap_set_t, pre_expr, bool);
431static bitmap_set_t bitmap_set_new (void);
432static tree create_expression_by_pieces (basic_block, pre_expr, gimple_seq *,
433 gimple, tree);
434static tree find_or_generate_expression (basic_block, pre_expr, gimple_seq *,
435 gimple);
436static unsigned int get_expr_value_id (pre_expr);
437
438/* We can add and remove elements and entries to and from sets
439 and hash tables, so we use alloc pools for them. */
440
441static alloc_pool bitmap_set_pool;
442static bitmap_obstack grand_bitmap_obstack;
443
444/* To avoid adding 300 temporary variables when we only need one, we
445 only create one temporary variable, on demand, and build ssa names
446 off that. We do have to change the variable if the types don't
447 match the current variable's type. */
448static tree pretemp;
449static tree storetemp;
450static tree prephitemp;
451
452/* Set of blocks with statements that have had its EH information
453 cleaned up. */
454static bitmap need_eh_cleanup;
455
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456/* The phi_translate_table caches phi translations for a given
457 expression and predecessor. */
458
459static htab_t phi_translate_table;
460
461/* A three tuple {e, pred, v} used to cache phi translations in the
462 phi_translate_table. */
463
464typedef struct expr_pred_trans_d
465{
466 /* The expression. */
467 pre_expr e;
468
469 /* The predecessor block along which we translated the expression. */
470 basic_block pred;
471
472 /* The value that resulted from the translation. */
473 pre_expr v;
474
475 /* The hashcode for the expression, pred pair. This is cached for
476 speed reasons. */
477 hashval_t hashcode;
478} *expr_pred_trans_t;
479typedef const struct expr_pred_trans_d *const_expr_pred_trans_t;
480
481/* Return the hash value for a phi translation table entry. */
482
483static hashval_t
484expr_pred_trans_hash (const void *p)
485{
486 const_expr_pred_trans_t const ve = (const_expr_pred_trans_t) p;
487 return ve->hashcode;
488}
489
490/* Return true if two phi translation table entries are the same.
491 P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
492
493static int
494expr_pred_trans_eq (const void *p1, const void *p2)
495{
496 const_expr_pred_trans_t const ve1 = (const_expr_pred_trans_t) p1;
497 const_expr_pred_trans_t const ve2 = (const_expr_pred_trans_t) p2;
498 basic_block b1 = ve1->pred;
499 basic_block b2 = ve2->pred;
500
501 /* If they are not translations for the same basic block, they can't
502 be equal. */
503 if (b1 != b2)
504 return false;
505 return pre_expr_eq (ve1->e, ve2->e);
506}
507
508/* Search in the phi translation table for the translation of
509 expression E in basic block PRED.
510 Return the translated value, if found, NULL otherwise. */
511
512static inline pre_expr
513phi_trans_lookup (pre_expr e, basic_block pred)
514{
515 void **slot;
516 struct expr_pred_trans_d ept;
517
518 ept.e = e;
519 ept.pred = pred;
520 ept.hashcode = iterative_hash_hashval_t (pre_expr_hash (e), pred->index);
521 slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
522 NO_INSERT);
523 if (!slot)
524 return NULL;
525 else
526 return ((expr_pred_trans_t) *slot)->v;
527}
528
529
530/* Add the tuple mapping from {expression E, basic block PRED} to
531 value V, to the phi translation table. */
532
533static inline void
534phi_trans_add (pre_expr e, pre_expr v, basic_block pred)
535{
536 void **slot;
537 expr_pred_trans_t new_pair = XNEW (struct expr_pred_trans_d);
538 new_pair->e = e;
539 new_pair->pred = pred;
540 new_pair->v = v;
541 new_pair->hashcode = iterative_hash_hashval_t (pre_expr_hash (e),
542 pred->index);
543
544 slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
545 new_pair->hashcode, INSERT);
546 if (*slot)
547 free (*slot);
548 *slot = (void *) new_pair;
549}
550
551
552/* Add expression E to the expression set of value id V. */
553
554void
555add_to_value (unsigned int v, pre_expr e)
556{
557 bitmap_set_t set;
558
559 gcc_assert (get_expr_value_id (e) == v);
560
561 if (v >= VEC_length (bitmap_set_t, value_expressions))
562 {
563 VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
564 v + 1);
565 }
566
567 set = VEC_index (bitmap_set_t, value_expressions, v);
568 if (!set)
569 {
570 set = bitmap_set_new ();
571 VEC_replace (bitmap_set_t, value_expressions, v, set);
572 }
573
574 bitmap_insert_into_set_1 (set, e, true);
575}
576
577/* Create a new bitmap set and return it. */
578
579static bitmap_set_t
580bitmap_set_new (void)
581{
582 bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
583 ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
584 ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
585 return ret;
586}
587
588/* Return the value id for a PRE expression EXPR. */
589
590static unsigned int
591get_expr_value_id (pre_expr expr)
592{
593 switch (expr->kind)
594 {
595 case CONSTANT:
596 {
597 unsigned int id;
598 id = get_constant_value_id (PRE_EXPR_CONSTANT (expr));
599 if (id == 0)
600 {
601 id = get_or_alloc_constant_value_id (PRE_EXPR_CONSTANT (expr));
602 add_to_value (id, expr);
603 }
604 return id;
605 }
606 case NAME:
607 return VN_INFO (PRE_EXPR_NAME (expr))->value_id;
608 case NARY:
609 return PRE_EXPR_NARY (expr)->value_id;
610 case REFERENCE:
611 return PRE_EXPR_REFERENCE (expr)->value_id;
612 default:
613 gcc_unreachable ();
614 }
615}
616
617/* Remove an expression EXPR from a bitmapped set. */
618
619static void
620bitmap_remove_from_set (bitmap_set_t set, pre_expr expr)
621{
622 unsigned int val = get_expr_value_id (expr);
623 if (!value_id_constant_p (val))
624 {
625 bitmap_clear_bit (set->values, val);
626 bitmap_clear_bit (set->expressions, get_expression_id (expr));
627 }
628}
629
630static void
631bitmap_insert_into_set_1 (bitmap_set_t set, pre_expr expr,
632 bool allow_constants)
633{
634 unsigned int val = get_expr_value_id (expr);
635 if (allow_constants || !value_id_constant_p (val))
636 {
637 /* We specifically expect this and only this function to be able to
638 insert constants into a set. */
639 bitmap_set_bit (set->values, val);
640 bitmap_set_bit (set->expressions, get_or_alloc_expression_id (expr));
641 }
642}
643
644/* Insert an expression EXPR into a bitmapped set. */
645
646static void
647bitmap_insert_into_set (bitmap_set_t set, pre_expr expr)
648{
649 bitmap_insert_into_set_1 (set, expr, false);
650}
651
652/* Copy a bitmapped set ORIG, into bitmapped set DEST. */
653
654static void
655bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
656{
657 bitmap_copy (dest->expressions, orig->expressions);
658 bitmap_copy (dest->values, orig->values);
659}
660
661
662/* Free memory used up by SET. */
663static void
664bitmap_set_free (bitmap_set_t set)
665{
666 BITMAP_FREE (set->expressions);
667 BITMAP_FREE (set->values);
668}
669
670
671/* Generate an topological-ordered array of bitmap set SET. */
672
673static VEC(pre_expr, heap) *
674sorted_array_from_bitmap_set (bitmap_set_t set)
675{
676 unsigned int i, j;
677 bitmap_iterator bi, bj;
678 VEC(pre_expr, heap) *result = NULL;
679
680 FOR_EACH_VALUE_ID_IN_SET (set, i, bi)
681 {
682 /* The number of expressions having a given value is usually
683 relatively small. Thus, rather than making a vector of all
684 the expressions and sorting it by value-id, we walk the values
685 and check in the reverse mapping that tells us what expressions
686 have a given value, to filter those in our set. As a result,
687 the expressions are inserted in value-id order, which means
688 topological order.
689
690 If this is somehow a significant lose for some cases, we can
691 choose which set to walk based on the set size. */
692 bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, i);
693 FOR_EACH_EXPR_ID_IN_SET (exprset, j, bj)
694 {
695 if (bitmap_bit_p (set->expressions, j))
696 VEC_safe_push (pre_expr, heap, result, expression_for_id (j));
697 }
698 }
699
700 return result;
701}
702
703/* Perform bitmapped set operation DEST &= ORIG. */
704
705static void
706bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
707{
708 bitmap_iterator bi;
709 unsigned int i;
710
711 if (dest != orig)
712 {
713 bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
714
715 bitmap_and_into (dest->values, orig->values);
716 bitmap_copy (temp, dest->expressions);
717 EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
718 {
719 pre_expr expr = expression_for_id (i);
720 unsigned int value_id = get_expr_value_id (expr);
721 if (!bitmap_bit_p (dest->values, value_id))
722 bitmap_clear_bit (dest->expressions, i);
723 }
724 BITMAP_FREE (temp);
725 }
726}
727
728/* Subtract all values and expressions contained in ORIG from DEST. */
729
730static bitmap_set_t
731bitmap_set_subtract (bitmap_set_t dest, bitmap_set_t orig)
732{
733 bitmap_set_t result = bitmap_set_new ();
734 bitmap_iterator bi;
735 unsigned int i;
736
737 bitmap_and_compl (result->expressions, dest->expressions,
738 orig->expressions);
739
740 FOR_EACH_EXPR_ID_IN_SET (result, i, bi)
741 {
742 pre_expr expr = expression_for_id (i);
743 unsigned int value_id = get_expr_value_id (expr);
744 bitmap_set_bit (result->values, value_id);
745 }
746
747 return result;
748}
749
750/* Subtract all the values in bitmap set B from bitmap set A. */
751
752static void
753bitmap_set_subtract_values (bitmap_set_t a, bitmap_set_t b)
754{
755 unsigned int i;
756 bitmap_iterator bi;
757 bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
758
759 bitmap_copy (temp, a->expressions);
760 EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
761 {
762 pre_expr expr = expression_for_id (i);
763 if (bitmap_set_contains_value (b, get_expr_value_id (expr)))
764 bitmap_remove_from_set (a, expr);
765 }
766 BITMAP_FREE (temp);
767}
768
769
770/* Return true if bitmapped set SET contains the value VALUE_ID. */
771
772static bool
773bitmap_set_contains_value (bitmap_set_t set, unsigned int value_id)
774{
775 if (value_id_constant_p (value_id))
776 return true;
777
778 if (!set || bitmap_empty_p (set->expressions))
779 return false;
780
781 return bitmap_bit_p (set->values, value_id);
782}
783
784static inline bool
785bitmap_set_contains_expr (bitmap_set_t set, const pre_expr expr)
786{
787 return bitmap_bit_p (set->expressions, get_expression_id (expr));
788}
789
790/* Replace an instance of value LOOKFOR with expression EXPR in SET. */
791
792static void
793bitmap_set_replace_value (bitmap_set_t set, unsigned int lookfor,
794 const pre_expr expr)
795{
796 bitmap_set_t exprset;
797 unsigned int i;
798 bitmap_iterator bi;
799
800 if (value_id_constant_p (lookfor))
801 return;
802
803 if (!bitmap_set_contains_value (set, lookfor))
804 return;
805
806 /* The number of expressions having a given value is usually
807 significantly less than the total number of expressions in SET.
808 Thus, rather than check, for each expression in SET, whether it
809 has the value LOOKFOR, we walk the reverse mapping that tells us
810 what expressions have a given value, and see if any of those
811 expressions are in our set. For large testcases, this is about
812 5-10x faster than walking the bitmap. If this is somehow a
813 significant lose for some cases, we can choose which set to walk
814 based on the set size. */
815 exprset = VEC_index (bitmap_set_t, value_expressions, lookfor);
816 FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
817 {
818 if (bitmap_bit_p (set->expressions, i))
819 {
820 bitmap_clear_bit (set->expressions, i);
821 bitmap_set_bit (set->expressions, get_expression_id (expr));
822 return;
823 }
824 }
825}
826
827/* Return true if two bitmap sets are equal. */
828
829static bool
830bitmap_set_equal (bitmap_set_t a, bitmap_set_t b)
831{
832 return bitmap_equal_p (a->values, b->values);
833}
834
835/* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
836 and add it otherwise. */
837
838static void
839bitmap_value_replace_in_set (bitmap_set_t set, pre_expr expr)
840{
841 unsigned int val = get_expr_value_id (expr);
842
843 if (bitmap_set_contains_value (set, val))
844 bitmap_set_replace_value (set, val, expr);
845 else
846 bitmap_insert_into_set (set, expr);
847}
848
849/* Insert EXPR into SET if EXPR's value is not already present in
850 SET. */
851
852static void
853bitmap_value_insert_into_set (bitmap_set_t set, pre_expr expr)
854{
855 unsigned int val = get_expr_value_id (expr);
856
857 if (value_id_constant_p (val))
858 return;
859
860 if (!bitmap_set_contains_value (set, val))
861 bitmap_insert_into_set (set, expr);
862}
863
864/* Print out EXPR to outfile. */
865
866static void
867print_pre_expr (FILE *outfile, const pre_expr expr)
868{
869 switch (expr->kind)
870 {
871 case CONSTANT:
872 print_generic_expr (outfile, PRE_EXPR_CONSTANT (expr), 0);
873 break;
874 case NAME:
875 print_generic_expr (outfile, PRE_EXPR_NAME (expr), 0);
876 break;
877 case NARY:
878 {
879 unsigned int i;
880 vn_nary_op_t nary = PRE_EXPR_NARY (expr);
881 fprintf (outfile, "{%s,", tree_code_name [nary->opcode]);
882 for (i = 0; i < nary->length; i++)
883 {
884 print_generic_expr (outfile, nary->op[i], 0);
885 if (i != (unsigned) nary->length - 1)
886 fprintf (outfile, ",");
887 }
888 fprintf (outfile, "}");
889 }
890 break;
891
892 case REFERENCE:
893 {
894 vn_reference_op_t vro;
895 unsigned int i;
896 vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
897 fprintf (outfile, "{");
898 for (i = 0;
899 VEC_iterate (vn_reference_op_s, ref->operands, i, vro);
900 i++)
901 {
902 if (vro->opcode != SSA_NAME
903 && TREE_CODE_CLASS (vro->opcode) != tcc_declaration)
904 fprintf (outfile, "%s ", tree_code_name [vro->opcode]);
905 if (vro->op0)
906 {
907 if (vro->op1)
908 fprintf (outfile, "<");
909 print_generic_expr (outfile, vro->op0, 0);
910 if (vro->op1)
911 {
912 fprintf (outfile, ",");
913 print_generic_expr (outfile, vro->op1, 0);
914 }
915 if (vro->op1)
916 fprintf (outfile, ">");
917 }
918 if (i != VEC_length (vn_reference_op_s, ref->operands) - 1)
919 fprintf (outfile, ",");
920 }
921 fprintf (outfile, "}");
922 }
923 break;
924 }
925}
926void debug_pre_expr (pre_expr);
927
928/* Like print_pre_expr but always prints to stderr. */
929void
930debug_pre_expr (pre_expr e)
931{
932 print_pre_expr (stderr, e);
933 fprintf (stderr, "\n");
934}
935
936/* Print out SET to OUTFILE. */
937
938static void
939print_bitmap_set (FILE *outfile, bitmap_set_t set,
940 const char *setname, int blockindex)
941{
942 fprintf (outfile, "%s[%d] := { ", setname, blockindex);
943 if (set)
944 {
945 bool first = true;
946 unsigned i;
947 bitmap_iterator bi;
948
949 FOR_EACH_EXPR_ID_IN_SET (set, i, bi)
950 {
951 const pre_expr expr = expression_for_id (i);
952
953 if (!first)
954 fprintf (outfile, ", ");
955 first = false;
956 print_pre_expr (outfile, expr);
957
958 fprintf (outfile, " (%04d)", get_expr_value_id (expr));
959 }
960 }
961 fprintf (outfile, " }\n");
962}
963
964void debug_bitmap_set (bitmap_set_t);
965
966void
967debug_bitmap_set (bitmap_set_t set)
968{
969 print_bitmap_set (stderr, set, "debug", 0);
970}
971
972/* Print out the expressions that have VAL to OUTFILE. */
973
974void
975print_value_expressions (FILE *outfile, unsigned int val)
976{
977 bitmap_set_t set = VEC_index (bitmap_set_t, value_expressions, val);
978 if (set)
979 {
980 char s[10];
981 sprintf (s, "%04d", val);
982 print_bitmap_set (outfile, set, s, 0);
983 }
984}
985
986
987void
988debug_value_expressions (unsigned int val)
989{
990 print_value_expressions (stderr, val);
991}
992
993/* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
994 represent it. */
995
996static pre_expr
997get_or_alloc_expr_for_constant (tree constant)
998{
999 unsigned int result_id;
1000 unsigned int value_id;
1001 pre_expr newexpr = (pre_expr) pool_alloc (pre_expr_pool);
1002 newexpr->kind = CONSTANT;
1003 PRE_EXPR_CONSTANT (newexpr) = constant;
1004 result_id = lookup_expression_id (newexpr);
1005 if (result_id != 0)
1006 {
1007 pool_free (pre_expr_pool, newexpr);
1008 newexpr = expression_for_id (result_id);
1009 return newexpr;
1010 }
1011 value_id = get_or_alloc_constant_value_id (constant);
1012 get_or_alloc_expression_id (newexpr);
1013 add_to_value (value_id, newexpr);
1014 return newexpr;
1015}
1016
1017/* Given a value id V, find the actual tree representing the constant
1018 value if there is one, and return it. Return NULL if we can't find
1019 a constant. */
1020
1021static tree
1022get_constant_for_value_id (unsigned int v)
1023{
1024 if (value_id_constant_p (v))
1025 {
1026 unsigned int i;
1027 bitmap_iterator bi;
1028 bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, v);
1029
1030 FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
1031 {
1032 pre_expr expr = expression_for_id (i);
1033 if (expr->kind == CONSTANT)
1034 return PRE_EXPR_CONSTANT (expr);
1035 }
1036 }
1037 return NULL;
1038}
1039
1040/* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1041 Currently only supports constants and SSA_NAMES. */
1042static pre_expr
1043get_or_alloc_expr_for (tree t)
1044{
1045 if (TREE_CODE (t) == SSA_NAME)
1046 return get_or_alloc_expr_for_name (t);
1047 else if (is_gimple_min_invariant (t))
1048 return get_or_alloc_expr_for_constant (t);
1049 else
1050 {
1051 /* More complex expressions can result from SCCVN expression
1052 simplification that inserts values for them. As they all
1053 do not have VOPs the get handled by the nary ops struct. */
1054 vn_nary_op_t result;
1055 unsigned int result_id;
1056 vn_nary_op_lookup (t, &result);
1057 if (result != NULL)
1058 {
1059 pre_expr e = (pre_expr) pool_alloc (pre_expr_pool);
1060 e->kind = NARY;
1061 PRE_EXPR_NARY (e) = result;
1062 result_id = lookup_expression_id (e);
1063 if (result_id != 0)
1064 {
1065 pool_free (pre_expr_pool, e);
1066 e = expression_for_id (result_id);
1067 return e;
1068 }
1069 alloc_expression_id (e);
1070 return e;
1071 }
1072 }
1073 return NULL;
1074}
1075
1076/* Return the folded version of T if T, when folded, is a gimple
1077 min_invariant. Otherwise, return T. */
1078
1079static pre_expr
1080fully_constant_expression (pre_expr e)
1081{
1082 switch (e->kind)
1083 {
1084 case CONSTANT:
1085 return e;
1086 case NARY:
1087 {
1088 vn_nary_op_t nary = PRE_EXPR_NARY (e);
1089 switch (TREE_CODE_CLASS (nary->opcode))
1090 {
1091 case tcc_expression:
1092 if (nary->opcode == TRUTH_NOT_EXPR)
1093 goto do_unary;
1094 if (nary->opcode != TRUTH_AND_EXPR
1095 && nary->opcode != TRUTH_OR_EXPR
1096 && nary->opcode != TRUTH_XOR_EXPR)
1097 return e;
1098 /* Fallthrough. */
1099 case tcc_binary:
1100 case tcc_comparison:
1101 {
1102 /* We have to go from trees to pre exprs to value ids to
1103 constants. */
1104 tree naryop0 = nary->op[0];
1105 tree naryop1 = nary->op[1];
1106 tree result;
1107 if (!is_gimple_min_invariant (naryop0))
1108 {
1109 pre_expr rep0 = get_or_alloc_expr_for (naryop0);
1110 unsigned int vrep0 = get_expr_value_id (rep0);
1111 tree const0 = get_constant_for_value_id (vrep0);
1112 if (const0)
1113 naryop0 = fold_convert (TREE_TYPE (naryop0), const0);
1114 }
1115 if (!is_gimple_min_invariant (naryop1))
1116 {
1117 pre_expr rep1 = get_or_alloc_expr_for (naryop1);
1118 unsigned int vrep1 = get_expr_value_id (rep1);
1119 tree const1 = get_constant_for_value_id (vrep1);
1120 if (const1)
1121 naryop1 = fold_convert (TREE_TYPE (naryop1), const1);
1122 }
1123 result = fold_binary (nary->opcode, nary->type,
1124 naryop0, naryop1);
1125 if (result && is_gimple_min_invariant (result))
1126 return get_or_alloc_expr_for_constant (result);
1127 /* We might have simplified the expression to a
1128 SSA_NAME for example from x_1 * 1. But we cannot
1129 insert a PHI for x_1 unconditionally as x_1 might
1130 not be available readily. */
1131 return e;
1132 }
1133 case tcc_reference:
1134 if (nary->opcode != REALPART_EXPR
1135 && nary->opcode != IMAGPART_EXPR
1136 && nary->opcode != VIEW_CONVERT_EXPR)
1137 return e;
1138 /* Fallthrough. */
1139 case tcc_unary:
1140do_unary:
1141 {
1142 /* We have to go from trees to pre exprs to value ids to
1143 constants. */
1144 tree naryop0 = nary->op[0];
1145 tree const0, result;
1146 if (is_gimple_min_invariant (naryop0))
1147 const0 = naryop0;
1148 else
1149 {
1150 pre_expr rep0 = get_or_alloc_expr_for (naryop0);
1151 unsigned int vrep0 = get_expr_value_id (rep0);
1152 const0 = get_constant_for_value_id (vrep0);
1153 }
1154 result = NULL;
1155 if (const0)
1156 {
1157 tree type1 = TREE_TYPE (nary->op[0]);
1158 const0 = fold_convert (type1, const0);
1159 result = fold_unary (nary->opcode, nary->type, const0);
1160 }
1161 if (result && is_gimple_min_invariant (result))
1162 return get_or_alloc_expr_for_constant (result);
1163 return e;
1164 }
1165 default:
1166 return e;
1167 }
1168 }
1169 case REFERENCE:
1170 {
1171 vn_reference_t ref = PRE_EXPR_REFERENCE (e);
1172 VEC (vn_reference_op_s, heap) *operands = ref->operands;
1173 vn_reference_op_t op;
1174
1175 /* Try to simplify the translated expression if it is
1176 a call to a builtin function with at most two arguments. */
1177 op = VEC_index (vn_reference_op_s, operands, 0);
1178 if (op->opcode == CALL_EXPR
1179 && TREE_CODE (op->op0) == ADDR_EXPR
1180 && TREE_CODE (TREE_OPERAND (op->op0, 0)) == FUNCTION_DECL
1181 && DECL_BUILT_IN (TREE_OPERAND (op->op0, 0))
1182 && VEC_length (vn_reference_op_s, operands) >= 2
1183 && VEC_length (vn_reference_op_s, operands) <= 3)
1184 {
1185 vn_reference_op_t arg0, arg1 = NULL;
1186 bool anyconst = false;
1187 arg0 = VEC_index (vn_reference_op_s, operands, 1);
1188 if (VEC_length (vn_reference_op_s, operands) > 2)
1189 arg1 = VEC_index (vn_reference_op_s, operands, 2);
1190 if (TREE_CODE_CLASS (arg0->opcode) == tcc_constant
1191 || (arg0->opcode == ADDR_EXPR
1192 && is_gimple_min_invariant (arg0->op0)))
1193 anyconst = true;
1194 if (arg1
1195 && (TREE_CODE_CLASS (arg1->opcode) == tcc_constant
1196 || (arg1->opcode == ADDR_EXPR
1197 && is_gimple_min_invariant (arg1->op0))))
1198 anyconst = true;
1199 if (anyconst)
1200 {
1201 tree folded = build_call_expr (TREE_OPERAND (op->op0, 0),
1202 arg1 ? 2 : 1,
1203 arg0->op0,
1204 arg1 ? arg1->op0 : NULL);
1205 if (folded
1206 && TREE_CODE (folded) == NOP_EXPR)
1207 folded = TREE_OPERAND (folded, 0);
1208 if (folded
1209 && is_gimple_min_invariant (folded))
1210 return get_or_alloc_expr_for_constant (folded);
1211 }
1212 }
1213 return e;
1214 }
1215 default:
1216 return e;
1217 }
1218 return e;
1219}
1220
1221/* Translate the vuses in the VUSES vector backwards through phi nodes
1222 in PHIBLOCK, so that they have the value they would have in
1223 BLOCK. */
1224
1225static VEC(tree, gc) *
1226translate_vuses_through_block (VEC (tree, gc) *vuses,
1227 basic_block phiblock,
1228 basic_block block)
1229{
1230 tree oldvuse;
1231 VEC(tree, gc) *result = NULL;
1232 int i;
1233
1234 for (i = 0; VEC_iterate (tree, vuses, i, oldvuse); i++)
1235 {
1236 gimple phi = SSA_NAME_DEF_STMT (oldvuse);
1237 if (gimple_code (phi) == GIMPLE_PHI
1238 && gimple_bb (phi) == phiblock)
1239 {
1240 edge e = find_edge (block, gimple_bb (phi));
1241 if (e)
1242 {
1243 tree def = PHI_ARG_DEF (phi, e->dest_idx);
1244 if (def != oldvuse)
1245 {
1246 if (!result)
1247 result = VEC_copy (tree, gc, vuses);
1248 VEC_replace (tree, result, i, def);
1249 }
1250 }
1251 }
1252 }
1253
1254 /* We avoid creating a new copy of the vuses unless something
1255 actually changed, so result can be NULL. */
1256 if (result)
1257 {
1258 sort_vuses (result);
1259 return result;
1260 }
1261 return vuses;
1262
1263}
1264
1265/* Like find_leader, but checks for the value existing in SET1 *or*
1266 SET2. This is used to avoid making a set consisting of the union
1267 of PA_IN and ANTIC_IN during insert. */
1268
1269static inline pre_expr
1270find_leader_in_sets (unsigned int val, bitmap_set_t set1, bitmap_set_t set2)
1271{
1272 pre_expr result;
1273
1274 result = bitmap_find_leader (set1, val, NULL);
1275 if (!result && set2)
1276 result = bitmap_find_leader (set2, val, NULL);
1277 return result;
1278}
1279
1280/* Get the tree type for our PRE expression e. */
1281
1282static tree
1283get_expr_type (const pre_expr e)
1284{
1285 switch (e->kind)
1286 {
1287 case NAME:
1288 return TREE_TYPE (PRE_EXPR_NAME (e));
1289 case CONSTANT:
1290 return TREE_TYPE (PRE_EXPR_CONSTANT (e));
1291 case REFERENCE:
1292 {
1293 vn_reference_op_t vro;
1294
1295 gcc_assert (PRE_EXPR_REFERENCE (e)->operands);
1296 vro = VEC_index (vn_reference_op_s,
1297 PRE_EXPR_REFERENCE (e)->operands,
1298 0);
1299 /* We don't store type along with COMPONENT_REF because it is
1300 always the same as FIELD_DECL's type. */
1301 if (!vro->type)
1302 {
1303 gcc_assert (vro->opcode == COMPONENT_REF);
1304 return TREE_TYPE (vro->op0);
1305 }
1306 return vro->type;
1307 }
1308
1309 case NARY:
1310 return PRE_EXPR_NARY (e)->type;
1311 }
1312 gcc_unreachable();
1313}
1314
1315/* Get a representative SSA_NAME for a given expression.
1316 Since all of our sub-expressions are treated as values, we require
1317 them to be SSA_NAME's for simplicity.
1318 Prior versions of GVNPRE used to use "value handles" here, so that
1319 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1320 either case, the operands are really values (IE we do not expect
1321 them to be usable without finding leaders). */
1322
1323static tree
1324get_representative_for (const pre_expr e)
1325{
1326 tree exprtype;
1327 tree name;
1328 unsigned int value_id = get_expr_value_id (e);
1329
1330 switch (e->kind)
1331 {
1332 case NAME:
1333 return PRE_EXPR_NAME (e);
1334 case CONSTANT:
1335 return PRE_EXPR_CONSTANT (e);
1336 case NARY:
1337 case REFERENCE:
1338 {
1339 /* Go through all of the expressions representing this value
1340 and pick out an SSA_NAME. */
1341 unsigned int i;
1342 bitmap_iterator bi;
1343 bitmap_set_t exprs = VEC_index (bitmap_set_t, value_expressions,
1344 value_id);
1345 FOR_EACH_EXPR_ID_IN_SET (exprs, i, bi)
1346 {
1347 pre_expr rep = expression_for_id (i);
1348 if (rep->kind == NAME)
1349 return PRE_EXPR_NAME (rep);
1350 }
1351 }
1352 break;
1353 }
1354 /* If we reached here we couldn't find an SSA_NAME. This can
1355 happen when we've discovered a value that has never appeared in
1356 the program as set to an SSA_NAME, most likely as the result of
1357 phi translation. */
1358 if (dump_file)
1359 {
1360 fprintf (dump_file,
1361 "Could not find SSA_NAME representative for expression:");
1362 print_pre_expr (dump_file, e);
1363 fprintf (dump_file, "\n");
1364 }
1365
1366 exprtype = get_expr_type (e);
1367
1368 /* Build and insert the assignment of the end result to the temporary
1369 that we will return. */
1370 if (!pretemp || exprtype != TREE_TYPE (pretemp))
1371 {
1372 pretemp = create_tmp_var (exprtype, "pretmp");
1373 get_var_ann (pretemp);
1374 }
1375
1376 name = make_ssa_name (pretemp, gimple_build_nop ());
1377 VN_INFO_GET (name)->value_id = value_id;
1378 if (e->kind == CONSTANT)
1379 VN_INFO (name)->valnum = PRE_EXPR_CONSTANT (e);
1380 else
1381 VN_INFO (name)->valnum = name;
1382
1383 add_to_value (value_id, get_or_alloc_expr_for_name (name));
1384 if (dump_file)
1385 {
1386 fprintf (dump_file, "Created SSA_NAME representative ");
1387 print_generic_expr (dump_file, name, 0);
1388 fprintf (dump_file, " for expression:");
1389 print_pre_expr (dump_file, e);
1390 fprintf (dump_file, "\n");
1391 }
1392
1393 return name;
1394}
1395
1396
1397
4b1e227d
SW
1398static pre_expr
1399phi_translate (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
1400 basic_block pred, basic_block phiblock);
c251ad9e
SS
1401
1402/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
4b1e227d
SW
1403 the phis in PRED. Return NULL if we can't find a leader for each part
1404 of the translated expression. */
c251ad9e
SS
1405
1406static pre_expr
1407phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
4b1e227d 1408 basic_block pred, basic_block phiblock)
c251ad9e 1409{
c251ad9e
SS
1410 switch (expr->kind)
1411 {
c251ad9e
SS
1412 case NARY:
1413 {
1414 unsigned int i;
1415 bool changed = false;
1416 vn_nary_op_t nary = PRE_EXPR_NARY (expr);
1417 struct vn_nary_op_s newnary;
1418 /* The NARY structure is only guaranteed to have been
1419 allocated to the nary->length operands. */
1420 memcpy (&newnary, nary, (sizeof (struct vn_nary_op_s)
1421 - sizeof (tree) * (4 - nary->length)));
1422
1423 for (i = 0; i < newnary.length; i++)
1424 {
1425 if (TREE_CODE (newnary.op[i]) != SSA_NAME)
1426 continue;
1427 else
1428 {
4b1e227d 1429 pre_expr leader, result;
c251ad9e 1430 unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id;
4b1e227d
SW
1431 leader = find_leader_in_sets (op_val_id, set1, set2);
1432 result = phi_translate (leader, set1, set2, pred, phiblock);
c251ad9e
SS
1433 if (result && result != leader)
1434 {
1435 tree name = get_representative_for (result);
1436 if (!name)
1437 return NULL;
1438 newnary.op[i] = name;
1439 }
1440 else if (!result)
1441 return NULL;
1442
1443 changed |= newnary.op[i] != nary->op[i];
1444 }
1445 }
1446 if (changed)
1447 {
1448 pre_expr constant;
1449
1450 tree result = vn_nary_op_lookup_pieces (newnary.length,
1451 newnary.opcode,
1452 newnary.type,
1453 newnary.op[0],
1454 newnary.op[1],
1455 newnary.op[2],
1456 newnary.op[3],
1457 &nary);
1458 unsigned int new_val_id;
1459
1460 expr = (pre_expr) pool_alloc (pre_expr_pool);
1461 expr->kind = NARY;
1462 expr->id = 0;
1463 if (result && is_gimple_min_invariant (result))
1464 return get_or_alloc_expr_for_constant (result);
1465
1466
1467 if (nary)
1468 {
1469 PRE_EXPR_NARY (expr) = nary;
1470 constant = fully_constant_expression (expr);
1471 if (constant != expr)
1472 return constant;
1473
1474 new_val_id = nary->value_id;
1475 get_or_alloc_expression_id (expr);
1476 }
1477 else
1478 {
1479 new_val_id = get_next_value_id ();
1480 VEC_safe_grow_cleared (bitmap_set_t, heap,
1481 value_expressions,
1482 get_max_value_id() + 1);
1483 nary = vn_nary_op_insert_pieces (newnary.length,
1484 newnary.opcode,
1485 newnary.type,
1486 newnary.op[0],
1487 newnary.op[1],
1488 newnary.op[2],
1489 newnary.op[3],
1490 result, new_val_id);
1491 PRE_EXPR_NARY (expr) = nary;
1492 constant = fully_constant_expression (expr);
1493 if (constant != expr)
1494 return constant;
1495 get_or_alloc_expression_id (expr);
1496 }
1497 add_to_value (new_val_id, expr);
1498 }
c251ad9e
SS
1499 return expr;
1500 }
1501 break;
1502
1503 case REFERENCE:
1504 {
1505 vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
1506 VEC (vn_reference_op_s, heap) *operands = ref->operands;
1507 VEC (tree, gc) *vuses = ref->vuses;
1508 VEC (tree, gc) *newvuses = vuses;
1509 VEC (vn_reference_op_s, heap) *newoperands = NULL;
1510 bool changed = false;
1511 unsigned int i;
1512 vn_reference_op_t operand;
1513 vn_reference_t newref;
1514
1515 for (i = 0; VEC_iterate (vn_reference_op_s, operands, i, operand); i++)
1516 {
1517 pre_expr opresult;
1518 pre_expr leader;
1519 tree oldop0 = operand->op0;
1520 tree oldop1 = operand->op1;
1521 tree oldop2 = operand->op2;
1522 tree op0 = oldop0;
1523 tree op1 = oldop1;
1524 tree op2 = oldop2;
1525 tree type = operand->type;
1526 vn_reference_op_s newop = *operand;
1527
1528 if (op0 && TREE_CODE (op0) == SSA_NAME)
1529 {
1530 unsigned int op_val_id = VN_INFO (op0)->value_id;
1531 leader = find_leader_in_sets (op_val_id, set1, set2);
4b1e227d 1532 opresult = phi_translate (leader, set1, set2, pred, phiblock);
c251ad9e
SS
1533 if (opresult && opresult != leader)
1534 {
1535 tree name = get_representative_for (opresult);
1536 if (!name)
1537 break;
1538 op0 = name;
1539 }
1540 else if (!opresult)
1541 break;
1542 }
1543 changed |= op0 != oldop0;
1544
1545 if (op1 && TREE_CODE (op1) == SSA_NAME)
1546 {
1547 unsigned int op_val_id = VN_INFO (op1)->value_id;
1548 leader = find_leader_in_sets (op_val_id, set1, set2);
4b1e227d 1549 opresult = phi_translate (leader, set1, set2, pred, phiblock);
c251ad9e
SS
1550 if (opresult && opresult != leader)
1551 {
1552 tree name = get_representative_for (opresult);
1553 if (!name)
1554 break;
1555 op1 = name;
1556 }
1557 else if (!opresult)
1558 break;
1559 }
1560 changed |= op1 != oldop1;
1561 if (op2 && TREE_CODE (op2) == SSA_NAME)
1562 {
1563 unsigned int op_val_id = VN_INFO (op2)->value_id;
1564 leader = find_leader_in_sets (op_val_id, set1, set2);
4b1e227d 1565 opresult = phi_translate (leader, set1, set2, pred, phiblock);
c251ad9e
SS
1566 if (opresult && opresult != leader)
1567 {
1568 tree name = get_representative_for (opresult);
1569 if (!name)
1570 break;
1571 op2 = name;
1572 }
1573 else if (!opresult)
1574 break;
1575 }
1576 changed |= op2 != oldop2;
1577
1578 if (!newoperands)
1579 newoperands = VEC_copy (vn_reference_op_s, heap, operands);
1580 /* We may have changed from an SSA_NAME to a constant */
1581 if (newop.opcode == SSA_NAME && TREE_CODE (op0) != SSA_NAME)
1582 newop.opcode = TREE_CODE (op0);
1583 newop.type = type;
1584 newop.op0 = op0;
1585 newop.op1 = op1;
1586 newop.op2 = op2;
1587 VEC_replace (vn_reference_op_s, newoperands, i, &newop);
1588 }
1589 if (i != VEC_length (vn_reference_op_s, operands))
1590 {
1591 if (newoperands)
1592 VEC_free (vn_reference_op_s, heap, newoperands);
1593 return NULL;
1594 }
1595
1596 newvuses = translate_vuses_through_block (vuses, phiblock, pred);
1597 changed |= newvuses != vuses;
1598
1599 if (changed)
1600 {
1601 unsigned int new_val_id;
1602 pre_expr constant;
1603
1604 tree result = vn_reference_lookup_pieces (newvuses,
1605 newoperands,
1606 &newref, true);
1607 if (newref)
1608 VEC_free (vn_reference_op_s, heap, newoperands);
1609
1610 if (result && is_gimple_min_invariant (result))
1611 {
1612 gcc_assert (!newoperands);
1613 return get_or_alloc_expr_for_constant (result);
1614 }
1615
1616 expr = (pre_expr) pool_alloc (pre_expr_pool);
1617 expr->kind = REFERENCE;
1618 expr->id = 0;
1619
1620 if (newref)
1621 {
1622 PRE_EXPR_REFERENCE (expr) = newref;
1623 constant = fully_constant_expression (expr);
1624 if (constant != expr)
1625 return constant;
1626
1627 new_val_id = newref->value_id;
1628 get_or_alloc_expression_id (expr);
1629 }
1630 else
1631 {
1632 new_val_id = get_next_value_id ();
1633 VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
1634 get_max_value_id() + 1);
1635 newref = vn_reference_insert_pieces (newvuses,
1636 newoperands,
1637 result, new_val_id);
1638 newoperands = NULL;
1639 PRE_EXPR_REFERENCE (expr) = newref;
1640 constant = fully_constant_expression (expr);
1641 if (constant != expr)
1642 return constant;
1643 get_or_alloc_expression_id (expr);
1644 }
1645 add_to_value (new_val_id, expr);
1646 }
1647 VEC_free (vn_reference_op_s, heap, newoperands);
c251ad9e
SS
1648 return expr;
1649 }
1650 break;
1651
1652 case NAME:
1653 {
1654 gimple phi = NULL;
1655 edge e;
1656 gimple def_stmt;
1657 tree name = PRE_EXPR_NAME (expr);
1658
1659 def_stmt = SSA_NAME_DEF_STMT (name);
1660 if (gimple_code (def_stmt) == GIMPLE_PHI
1661 && gimple_bb (def_stmt) == phiblock)
1662 phi = def_stmt;
1663 else
1664 return expr;
1665
1666 e = find_edge (pred, gimple_bb (phi));
1667 if (e)
1668 {
1669 tree def = PHI_ARG_DEF (phi, e->dest_idx);
1670 pre_expr newexpr;
1671
1672 if (TREE_CODE (def) == SSA_NAME)
1673 def = VN_INFO (def)->valnum;
1674
1675 /* Handle constant. */
1676 if (is_gimple_min_invariant (def))
1677 return get_or_alloc_expr_for_constant (def);
1678
1679 if (TREE_CODE (def) == SSA_NAME && ssa_undefined_value_p (def))
1680 return NULL;
1681
1682 newexpr = get_or_alloc_expr_for_name (def);
1683 return newexpr;
1684 }
1685 }
1686 return expr;
1687
1688 default:
1689 gcc_unreachable ();
1690 }
1691}
1692
4b1e227d 1693/* Wrapper around phi_translate_1 providing caching functionality. */
c251ad9e
SS
1694
1695static pre_expr
1696phi_translate (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
1697 basic_block pred, basic_block phiblock)
1698{
4b1e227d
SW
1699 pre_expr phitrans;
1700
1701 if (!expr)
1702 return NULL;
1703
1704 /* Constants contain no values that need translation. */
1705 if (expr->kind == CONSTANT)
1706 return expr;
1707
1708 if (value_id_constant_p (get_expr_value_id (expr)))
1709 return expr;
1710
1711 if (expr->kind != NAME)
1712 {
1713 phitrans = phi_trans_lookup (expr, pred);
1714 if (phitrans)
1715 return phitrans;
1716 }
1717
1718 /* Translate. */
1719 phitrans = phi_translate_1 (expr, set1, set2, pred, phiblock);
1720
1721 /* Don't add empty translations to the cache. Neither add
1722 translations of NAMEs as those are cheap to translate. */
1723 if (phitrans
1724 && expr->kind != NAME)
1725 phi_trans_add (expr, phitrans, pred);
1726
1727 return phitrans;
c251ad9e
SS
1728}
1729
4b1e227d 1730
c251ad9e
SS
1731/* For each expression in SET, translate the values through phi nodes
1732 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1733 expressions in DEST. */
1734
1735static void
1736phi_translate_set (bitmap_set_t dest, bitmap_set_t set, basic_block pred,
1737 basic_block phiblock)
1738{
1739 VEC (pre_expr, heap) *exprs;
1740 pre_expr expr;
1741 int i;
1742
4b1e227d 1743 if (gimple_seq_empty_p (phi_nodes (phiblock)))
c251ad9e
SS
1744 {
1745 bitmap_set_copy (dest, set);
1746 return;
1747 }
1748
1749 exprs = sorted_array_from_bitmap_set (set);
1750 for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
1751 {
1752 pre_expr translated;
1753 translated = phi_translate (expr, set, NULL, pred, phiblock);
4b1e227d
SW
1754 if (!translated)
1755 continue;
c251ad9e 1756
4b1e227d
SW
1757 /* We might end up with multiple expressions from SET being
1758 translated to the same value. In this case we do not want
1759 to retain the NARY or REFERENCE expression but prefer a NAME
1760 which would be the leader. */
1761 if (translated->kind == NAME)
1762 bitmap_value_replace_in_set (dest, translated);
1763 else
c251ad9e
SS
1764 bitmap_value_insert_into_set (dest, translated);
1765 }
1766 VEC_free (pre_expr, heap, exprs);
1767}
1768
1769/* Find the leader for a value (i.e., the name representing that
1770 value) in a given set, and return it. If STMT is non-NULL it
1771 makes sure the defining statement for the leader dominates it.
1772 Return NULL if no leader is found. */
1773
1774static pre_expr
1775bitmap_find_leader (bitmap_set_t set, unsigned int val, gimple stmt)
1776{
1777 if (value_id_constant_p (val))
1778 {
1779 unsigned int i;
1780 bitmap_iterator bi;
1781 bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, val);
1782
1783 FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
1784 {
1785 pre_expr expr = expression_for_id (i);
1786 if (expr->kind == CONSTANT)
1787 return expr;
1788 }
1789 }
1790 if (bitmap_set_contains_value (set, val))
1791 {
1792 /* Rather than walk the entire bitmap of expressions, and see
1793 whether any of them has the value we are looking for, we look
1794 at the reverse mapping, which tells us the set of expressions
1795 that have a given value (IE value->expressions with that
1796 value) and see if any of those expressions are in our set.
1797 The number of expressions per value is usually significantly
1798 less than the number of expressions in the set. In fact, for
1799 large testcases, doing it this way is roughly 5-10x faster
1800 than walking the bitmap.
1801 If this is somehow a significant lose for some cases, we can
1802 choose which set to walk based on which set is smaller. */
1803 unsigned int i;
1804 bitmap_iterator bi;
1805 bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, val);
1806
1807 EXECUTE_IF_AND_IN_BITMAP (exprset->expressions,
1808 set->expressions, 0, i, bi)
1809 {
1810 pre_expr val = expression_for_id (i);
1811 /* At the point where stmt is not null, there should always
1812 be an SSA_NAME first in the list of expressions. */
1813 if (stmt)
1814 {
1815 gimple def_stmt = SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val));
1816 if (gimple_code (def_stmt) != GIMPLE_PHI
1817 && gimple_bb (def_stmt) == gimple_bb (stmt)
1818 && gimple_uid (def_stmt) >= gimple_uid (stmt))
1819 continue;
1820 }
1821 return val;
1822 }
1823 }
1824 return NULL;
1825}
1826
1827/* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1828 BLOCK by seeing if it is not killed in the block. Note that we are
1829 only determining whether there is a store that kills it. Because
1830 of the order in which clean iterates over values, we are guaranteed
1831 that altered operands will have caused us to be eliminated from the
1832 ANTIC_IN set already. */
1833
1834static bool
1835value_dies_in_block_x (pre_expr expr, basic_block block)
1836{
1837 int i;
1838 tree vuse;
1839 VEC (tree, gc) *vuses = PRE_EXPR_REFERENCE (expr)->vuses;
1840
1841 /* Conservatively, a value dies if it's vuses are defined in this
1842 block, unless they come from phi nodes (which are merge operations,
1843 rather than stores. */
1844 for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
1845 {
1846 gimple def = SSA_NAME_DEF_STMT (vuse);
1847
1848 if (gimple_bb (def) != block)
1849 continue;
1850 if (gimple_code (def) == GIMPLE_PHI)
1851 continue;
1852 return true;
1853 }
1854 return false;
1855}
1856
1857
1858#define union_contains_value(SET1, SET2, VAL) \
1859 (bitmap_set_contains_value ((SET1), (VAL)) \
1860 || ((SET2) && bitmap_set_contains_value ((SET2), (VAL))))
1861
1862/* Determine if vn_reference_op_t VRO is legal in SET1 U SET2.
1863 */
1864static bool
1865vro_valid_in_sets (bitmap_set_t set1, bitmap_set_t set2,
1866 vn_reference_op_t vro)
1867{
1868 if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
1869 {
1870 struct pre_expr_d temp;
1871 temp.kind = NAME;
1872 temp.id = 0;
1873 PRE_EXPR_NAME (&temp) = vro->op0;
1874 temp.id = lookup_expression_id (&temp);
1875 if (temp.id == 0)
1876 return false;
1877 if (!union_contains_value (set1, set2,
1878 get_expr_value_id (&temp)))
1879 return false;
1880 }
1881 if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
1882 {
1883 struct pre_expr_d temp;
1884 temp.kind = NAME;
1885 temp.id = 0;
1886 PRE_EXPR_NAME (&temp) = vro->op1;
1887 temp.id = lookup_expression_id (&temp);
1888 if (temp.id == 0)
1889 return false;
1890 if (!union_contains_value (set1, set2,
1891 get_expr_value_id (&temp)))
1892 return false;
1893 }
1894
1895 if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
1896 {
1897 struct pre_expr_d temp;
1898 temp.kind = NAME;
1899 temp.id = 0;
1900 PRE_EXPR_NAME (&temp) = vro->op2;
1901 temp.id = lookup_expression_id (&temp);
1902 if (temp.id == 0)
1903 return false;
1904 if (!union_contains_value (set1, set2,
1905 get_expr_value_id (&temp)))
1906 return false;
1907 }
1908
1909 return true;
1910}
1911
1912/* Determine if the expression EXPR is valid in SET1 U SET2.
1913 ONLY SET2 CAN BE NULL.
1914 This means that we have a leader for each part of the expression
1915 (if it consists of values), or the expression is an SSA_NAME.
1916 For loads/calls, we also see if the vuses are killed in this block.
1917*/
1918
1919static bool
1920valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr,
1921 basic_block block)
1922{
1923 switch (expr->kind)
1924 {
1925 case NAME:
1926 return bitmap_set_contains_expr (AVAIL_OUT (block), expr);
1927 case NARY:
1928 {
1929 unsigned int i;
1930 vn_nary_op_t nary = PRE_EXPR_NARY (expr);
1931 for (i = 0; i < nary->length; i++)
1932 {
1933 if (TREE_CODE (nary->op[i]) == SSA_NAME)
1934 {
1935 struct pre_expr_d temp;
1936 temp.kind = NAME;
1937 temp.id = 0;
1938 PRE_EXPR_NAME (&temp) = nary->op[i];
1939 temp.id = lookup_expression_id (&temp);
1940 if (temp.id == 0)
1941 return false;
1942 if (!union_contains_value (set1, set2,
1943 get_expr_value_id (&temp)))
1944 return false;
1945 }
1946 }
1947 return true;
1948 }
1949 break;
1950 case REFERENCE:
1951 {
1952 vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
1953 vn_reference_op_t vro;
1954 unsigned int i;
1955
1956 for (i = 0; VEC_iterate (vn_reference_op_s, ref->operands, i, vro); i++)
1957 {
1958 if (!vro_valid_in_sets (set1, set2, vro))
1959 return false;
1960 }
1961 return !value_dies_in_block_x (expr, block);
1962 }
1963 default:
1964 gcc_unreachable ();
1965 }
1966}
1967
1968/* Clean the set of expressions that are no longer valid in SET1 or
1969 SET2. This means expressions that are made up of values we have no
1970 leaders for in SET1 or SET2. This version is used for partial
1971 anticipation, which means it is not valid in either ANTIC_IN or
1972 PA_IN. */
1973
1974static void
1975dependent_clean (bitmap_set_t set1, bitmap_set_t set2, basic_block block)
1976{
1977 VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (set1);
1978 pre_expr expr;
1979 int i;
1980
1981 for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
1982 {
1983 if (!valid_in_sets (set1, set2, expr, block))
1984 bitmap_remove_from_set (set1, expr);
1985 }
1986 VEC_free (pre_expr, heap, exprs);
1987}
1988
1989/* Clean the set of expressions that are no longer valid in SET. This
1990 means expressions that are made up of values we have no leaders for
1991 in SET. */
1992
1993static void
1994clean (bitmap_set_t set, basic_block block)
1995{
1996 VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (set);
1997 pre_expr expr;
1998 int i;
1999
2000 for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
2001 {
2002 if (!valid_in_sets (set, NULL, expr, block))
2003 bitmap_remove_from_set (set, expr);
2004 }
2005 VEC_free (pre_expr, heap, exprs);
2006}
2007
2008static sbitmap has_abnormal_preds;
2009
2010/* List of blocks that may have changed during ANTIC computation and
2011 thus need to be iterated over. */
2012
2013static sbitmap changed_blocks;
2014
2015/* Decide whether to defer a block for a later iteration, or PHI
2016 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2017 should defer the block, and true if we processed it. */
2018
2019static bool
2020defer_or_phi_translate_block (bitmap_set_t dest, bitmap_set_t source,
2021 basic_block block, basic_block phiblock)
2022{
2023 if (!BB_VISITED (phiblock))
2024 {
2025 SET_BIT (changed_blocks, block->index);
2026 BB_VISITED (block) = 0;
2027 BB_DEFERRED (block) = 1;
2028 return false;
2029 }
2030 else
2031 phi_translate_set (dest, source, block, phiblock);
2032 return true;
2033}
2034
2035/* Compute the ANTIC set for BLOCK.
2036
2037 If succs(BLOCK) > 1 then
2038 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2039 else if succs(BLOCK) == 1 then
2040 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2041
2042 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2043*/
2044
2045static bool
2046compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
2047{
2048 bool changed = false;
2049 bitmap_set_t S, old, ANTIC_OUT;
2050 bitmap_iterator bi;
2051 unsigned int bii;
2052 edge e;
2053 edge_iterator ei;
2054
2055 old = ANTIC_OUT = S = NULL;
2056 BB_VISITED (block) = 1;
2057
2058 /* If any edges from predecessors are abnormal, antic_in is empty,
2059 so do nothing. */
2060 if (block_has_abnormal_pred_edge)
2061 goto maybe_dump_sets;
2062
2063 old = ANTIC_IN (block);
2064 ANTIC_OUT = bitmap_set_new ();
2065
2066 /* If the block has no successors, ANTIC_OUT is empty. */
2067 if (EDGE_COUNT (block->succs) == 0)
2068 ;
2069 /* If we have one successor, we could have some phi nodes to
2070 translate through. */
2071 else if (single_succ_p (block))
2072 {
2073 basic_block succ_bb = single_succ (block);
2074
2075 /* We trade iterations of the dataflow equations for having to
2076 phi translate the maximal set, which is incredibly slow
2077 (since the maximal set often has 300+ members, even when you
2078 have a small number of blocks).
2079 Basically, we defer the computation of ANTIC for this block
2080 until we have processed it's successor, which will inevitably
2081 have a *much* smaller set of values to phi translate once
2082 clean has been run on it.
2083 The cost of doing this is that we technically perform more
2084 iterations, however, they are lower cost iterations.
2085
2086 Timings for PRE on tramp3d-v4:
2087 without maximal set fix: 11 seconds
2088 with maximal set fix/without deferring: 26 seconds
2089 with maximal set fix/with deferring: 11 seconds
2090 */
2091
2092 if (!defer_or_phi_translate_block (ANTIC_OUT, ANTIC_IN (succ_bb),
2093 block, succ_bb))
2094 {
2095 changed = true;
2096 goto maybe_dump_sets;
2097 }
2098 }
2099 /* If we have multiple successors, we take the intersection of all of
2100 them. Note that in the case of loop exit phi nodes, we may have
2101 phis to translate through. */
2102 else
2103 {
2104 VEC(basic_block, heap) * worklist;
2105 size_t i;
dff90b41 2106 basic_block bprime, first = NULL;
c251ad9e
SS
2107
2108 worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
2109 FOR_EACH_EDGE (e, ei, block->succs)
c251ad9e 2110 {
dff90b41
SS
2111 if (!first
2112 && BB_VISITED (e->dest))
2113 first = e->dest;
2114 else if (BB_VISITED (e->dest))
2115 VEC_quick_push (basic_block, worklist, e->dest);
c251ad9e 2116 }
dff90b41
SS
2117
2118 /* Of multiple successors we have to have visited one already. */
2119 if (!first)
c251ad9e 2120 {
dff90b41
SS
2121 SET_BIT (changed_blocks, block->index);
2122 BB_VISITED (block) = 0;
2123 BB_DEFERRED (block) = 1;
2124 changed = true;
2125 VEC_free (basic_block, heap, worklist);
2126 goto maybe_dump_sets;
c251ad9e
SS
2127 }
2128
4b1e227d 2129 if (!gimple_seq_empty_p (phi_nodes (first)))
dff90b41
SS
2130 phi_translate_set (ANTIC_OUT, ANTIC_IN (first), block, first);
2131 else
2132 bitmap_set_copy (ANTIC_OUT, ANTIC_IN (first));
2133
2134 for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
c251ad9e 2135 {
4b1e227d 2136 if (!gimple_seq_empty_p (phi_nodes (bprime)))
c251ad9e
SS
2137 {
2138 bitmap_set_t tmp = bitmap_set_new ();
dff90b41 2139 phi_translate_set (tmp, ANTIC_IN (bprime), block, bprime);
c251ad9e
SS
2140 bitmap_set_and (ANTIC_OUT, tmp);
2141 bitmap_set_free (tmp);
2142 }
2143 else
dff90b41 2144 bitmap_set_and (ANTIC_OUT, ANTIC_IN (bprime));
c251ad9e
SS
2145 }
2146 VEC_free (basic_block, heap, worklist);
2147 }
2148
2149 /* Generate ANTIC_OUT - TMP_GEN. */
2150 S = bitmap_set_subtract (ANTIC_OUT, TMP_GEN (block));
2151
2152 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2153 ANTIC_IN (block) = bitmap_set_subtract (EXP_GEN (block),
2154 TMP_GEN (block));
2155
2156 /* Then union in the ANTIC_OUT - TMP_GEN values,
2157 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2158 FOR_EACH_EXPR_ID_IN_SET (S, bii, bi)
2159 bitmap_value_insert_into_set (ANTIC_IN (block),
2160 expression_for_id (bii));
2161
2162 clean (ANTIC_IN (block), block);
2163
2164 /* !old->expressions can happen when we deferred a block. */
2165 if (!old->expressions || !bitmap_set_equal (old, ANTIC_IN (block)))
2166 {
2167 changed = true;
2168 SET_BIT (changed_blocks, block->index);
2169 FOR_EACH_EDGE (e, ei, block->preds)
2170 SET_BIT (changed_blocks, e->src->index);
2171 }
2172 else
2173 RESET_BIT (changed_blocks, block->index);
2174
2175 maybe_dump_sets:
2176 if (dump_file && (dump_flags & TDF_DETAILS))
2177 {
2178 if (!BB_DEFERRED (block) || BB_VISITED (block))
2179 {
2180 if (ANTIC_OUT)
2181 print_bitmap_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
2182
2183 print_bitmap_set (dump_file, ANTIC_IN (block), "ANTIC_IN",
2184 block->index);
2185
2186 if (S)
2187 print_bitmap_set (dump_file, S, "S", block->index);
2188 }
2189 else
2190 {
2191 fprintf (dump_file,
2192 "Block %d was deferred for a future iteration.\n",
2193 block->index);
2194 }
2195 }
2196 if (old)
2197 bitmap_set_free (old);
2198 if (S)
2199 bitmap_set_free (S);
2200 if (ANTIC_OUT)
2201 bitmap_set_free (ANTIC_OUT);
2202 return changed;
2203}
2204
2205/* Compute PARTIAL_ANTIC for BLOCK.
2206
2207 If succs(BLOCK) > 1 then
2208 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2209 in ANTIC_OUT for all succ(BLOCK)
2210 else if succs(BLOCK) == 1 then
2211 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2212
2213 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2214 - ANTIC_IN[BLOCK])
2215
2216*/
2217static bool
2218compute_partial_antic_aux (basic_block block,
2219 bool block_has_abnormal_pred_edge)
2220{
2221 bool changed = false;
2222 bitmap_set_t old_PA_IN;
2223 bitmap_set_t PA_OUT;
2224 edge e;
2225 edge_iterator ei;
2226 unsigned long max_pa = PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH);
2227
2228 old_PA_IN = PA_OUT = NULL;
2229
2230 /* If any edges from predecessors are abnormal, antic_in is empty,
2231 so do nothing. */
2232 if (block_has_abnormal_pred_edge)
2233 goto maybe_dump_sets;
2234
2235 /* If there are too many partially anticipatable values in the
2236 block, phi_translate_set can take an exponential time: stop
2237 before the translation starts. */
2238 if (max_pa
2239 && single_succ_p (block)
2240 && bitmap_count_bits (PA_IN (single_succ (block))->values) > max_pa)
2241 goto maybe_dump_sets;
2242
2243 old_PA_IN = PA_IN (block);
2244 PA_OUT = bitmap_set_new ();
2245
2246 /* If the block has no successors, ANTIC_OUT is empty. */
2247 if (EDGE_COUNT (block->succs) == 0)
2248 ;
2249 /* If we have one successor, we could have some phi nodes to
2250 translate through. Note that we can't phi translate across DFS
2251 back edges in partial antic, because it uses a union operation on
2252 the successors. For recurrences like IV's, we will end up
2253 generating a new value in the set on each go around (i + 3 (VH.1)
2254 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2255 else if (single_succ_p (block))
2256 {
2257 basic_block succ = single_succ (block);
2258 if (!(single_succ_edge (block)->flags & EDGE_DFS_BACK))
2259 phi_translate_set (PA_OUT, PA_IN (succ), block, succ);
2260 }
2261 /* If we have multiple successors, we take the union of all of
2262 them. */
2263 else
2264 {
2265 VEC(basic_block, heap) * worklist;
2266 size_t i;
2267 basic_block bprime;
2268
2269 worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
2270 FOR_EACH_EDGE (e, ei, block->succs)
2271 {
2272 if (e->flags & EDGE_DFS_BACK)
2273 continue;
2274 VEC_quick_push (basic_block, worklist, e->dest);
2275 }
2276 if (VEC_length (basic_block, worklist) > 0)
2277 {
2278 for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
2279 {
2280 unsigned int i;
2281 bitmap_iterator bi;
2282
2283 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime), i, bi)
2284 bitmap_value_insert_into_set (PA_OUT,
2285 expression_for_id (i));
4b1e227d 2286 if (!gimple_seq_empty_p (phi_nodes (bprime)))
c251ad9e
SS
2287 {
2288 bitmap_set_t pa_in = bitmap_set_new ();
2289 phi_translate_set (pa_in, PA_IN (bprime), block, bprime);
2290 FOR_EACH_EXPR_ID_IN_SET (pa_in, i, bi)
2291 bitmap_value_insert_into_set (PA_OUT,
2292 expression_for_id (i));
2293 bitmap_set_free (pa_in);
2294 }
2295 else
2296 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime), i, bi)
2297 bitmap_value_insert_into_set (PA_OUT,
2298 expression_for_id (i));
2299 }
2300 }
2301 VEC_free (basic_block, heap, worklist);
2302 }
2303
2304 /* PA_IN starts with PA_OUT - TMP_GEN.
2305 Then we subtract things from ANTIC_IN. */
2306 PA_IN (block) = bitmap_set_subtract (PA_OUT, TMP_GEN (block));
2307
2308 /* For partial antic, we want to put back in the phi results, since
2309 we will properly avoid making them partially antic over backedges. */
2310 bitmap_ior_into (PA_IN (block)->values, PHI_GEN (block)->values);
2311 bitmap_ior_into (PA_IN (block)->expressions, PHI_GEN (block)->expressions);
2312
2313 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2314 bitmap_set_subtract_values (PA_IN (block), ANTIC_IN (block));
2315
2316 dependent_clean (PA_IN (block), ANTIC_IN (block), block);
2317
2318 if (!bitmap_set_equal (old_PA_IN, PA_IN (block)))
2319 {
2320 changed = true;
2321 SET_BIT (changed_blocks, block->index);
2322 FOR_EACH_EDGE (e, ei, block->preds)
2323 SET_BIT (changed_blocks, e->src->index);
2324 }
2325 else
2326 RESET_BIT (changed_blocks, block->index);
2327
2328 maybe_dump_sets:
2329 if (dump_file && (dump_flags & TDF_DETAILS))
2330 {
2331 if (PA_OUT)
2332 print_bitmap_set (dump_file, PA_OUT, "PA_OUT", block->index);
2333
2334 print_bitmap_set (dump_file, PA_IN (block), "PA_IN", block->index);
2335 }
2336 if (old_PA_IN)
2337 bitmap_set_free (old_PA_IN);
2338 if (PA_OUT)
2339 bitmap_set_free (PA_OUT);
2340 return changed;
2341}
2342
2343/* Compute ANTIC and partial ANTIC sets. */
2344
2345static void
2346compute_antic (void)
2347{
2348 bool changed = true;
2349 int num_iterations = 0;
2350 basic_block block;
2351 int i;
2352
2353 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2354 We pre-build the map of blocks with incoming abnormal edges here. */
2355 has_abnormal_preds = sbitmap_alloc (last_basic_block);
2356 sbitmap_zero (has_abnormal_preds);
2357
2358 FOR_EACH_BB (block)
2359 {
2360 edge_iterator ei;
2361 edge e;
2362
2363 FOR_EACH_EDGE (e, ei, block->preds)
2364 {
2365 e->flags &= ~EDGE_DFS_BACK;
2366 if (e->flags & EDGE_ABNORMAL)
2367 {
2368 SET_BIT (has_abnormal_preds, block->index);
2369 break;
2370 }
2371 }
2372
2373 BB_VISITED (block) = 0;
2374 BB_DEFERRED (block) = 0;
2375 /* While we are here, give empty ANTIC_IN sets to each block. */
2376 ANTIC_IN (block) = bitmap_set_new ();
2377 PA_IN (block) = bitmap_set_new ();
2378 }
2379
2380 /* At the exit block we anticipate nothing. */
2381 ANTIC_IN (EXIT_BLOCK_PTR) = bitmap_set_new ();
2382 BB_VISITED (EXIT_BLOCK_PTR) = 1;
2383 PA_IN (EXIT_BLOCK_PTR) = bitmap_set_new ();
2384
2385 changed_blocks = sbitmap_alloc (last_basic_block + 1);
2386 sbitmap_ones (changed_blocks);
2387 while (changed)
2388 {
2389 if (dump_file && (dump_flags & TDF_DETAILS))
2390 fprintf (dump_file, "Starting iteration %d\n", num_iterations);
2391 num_iterations++;
2392 changed = false;
2393 for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
2394 {
2395 if (TEST_BIT (changed_blocks, postorder[i]))
2396 {
2397 basic_block block = BASIC_BLOCK (postorder[i]);
2398 changed |= compute_antic_aux (block,
2399 TEST_BIT (has_abnormal_preds,
2400 block->index));
2401 }
2402 }
2403#ifdef ENABLE_CHECKING
2404 /* Theoretically possible, but *highly* unlikely. */
2405 gcc_assert (num_iterations < 500);
2406#endif
2407 }
2408
2409 statistics_histogram_event (cfun, "compute_antic iterations",
2410 num_iterations);
2411
2412 if (do_partial_partial)
2413 {
2414 sbitmap_ones (changed_blocks);
2415 mark_dfs_back_edges ();
2416 num_iterations = 0;
2417 changed = true;
2418 while (changed)
2419 {
2420 if (dump_file && (dump_flags & TDF_DETAILS))
2421 fprintf (dump_file, "Starting iteration %d\n", num_iterations);
2422 num_iterations++;
2423 changed = false;
2424 for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
2425 {
2426 if (TEST_BIT (changed_blocks, postorder[i]))
2427 {
2428 basic_block block = BASIC_BLOCK (postorder[i]);
2429 changed
2430 |= compute_partial_antic_aux (block,
2431 TEST_BIT (has_abnormal_preds,
2432 block->index));
2433 }
2434 }
2435#ifdef ENABLE_CHECKING
2436 /* Theoretically possible, but *highly* unlikely. */
2437 gcc_assert (num_iterations < 500);
2438#endif
2439 }
2440 statistics_histogram_event (cfun, "compute_partial_antic iterations",
2441 num_iterations);
2442 }
2443 sbitmap_free (has_abnormal_preds);
2444 sbitmap_free (changed_blocks);
2445}
2446
2447/* Return true if we can value number the call in STMT. This is true
2448 if we have a pure or constant call. */
2449
2450static bool
2451can_value_number_call (gimple stmt)
2452{
2453 if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
2454 return true;
2455 return false;
2456}
2457
2458/* Return true if OP is an exception handler related operation, such as
2459 FILTER_EXPR or EXC_PTR_EXPR. */
2460
2461static bool
2462is_exception_related (gimple stmt)
2463{
2464 return (is_gimple_assign (stmt)
2465 && (gimple_assign_rhs_code (stmt) == FILTER_EXPR
2466 || gimple_assign_rhs_code (stmt) == EXC_PTR_EXPR));
2467}
2468
2469/* Return true if OP is a tree which we can perform PRE on
2470 on. This may not match the operations we can value number, but in
2471 a perfect world would. */
2472
2473static bool
2474can_PRE_operation (tree op)
2475{
2476 return UNARY_CLASS_P (op)
2477 || BINARY_CLASS_P (op)
2478 || COMPARISON_CLASS_P (op)
2479 || TREE_CODE (op) == INDIRECT_REF
2480 || TREE_CODE (op) == COMPONENT_REF
2481 || TREE_CODE (op) == VIEW_CONVERT_EXPR
2482 || TREE_CODE (op) == CALL_EXPR
2483 || TREE_CODE (op) == ARRAY_REF;
2484}
2485
2486
2487/* Inserted expressions are placed onto this worklist, which is used
2488 for performing quick dead code elimination of insertions we made
2489 that didn't turn out to be necessary. */
2490static VEC(gimple,heap) *inserted_exprs;
2491
2492/* Pool allocated fake store expressions are placed onto this
2493 worklist, which, after performing dead code elimination, is walked
2494 to see which expressions need to be put into GC'able memory */
2495static VEC(gimple, heap) *need_creation;
2496
2497/* The actual worker for create_component_ref_by_pieces. */
2498
2499static tree
2500create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
2501 unsigned int *operand, gimple_seq *stmts,
2502 gimple domstmt)
2503{
2504 vn_reference_op_t currop = VEC_index (vn_reference_op_s, ref->operands,
2505 *operand);
2506 tree genop;
2507 ++*operand;
2508 switch (currop->opcode)
2509 {
2510 case CALL_EXPR:
2511 {
4b1e227d 2512 tree folded, sc = NULL_TREE;
c251ad9e 2513 unsigned int nargs = 0;
4b1e227d
SW
2514 tree fn, *args;
2515 if (TREE_CODE (currop->op0) == FUNCTION_DECL)
2516 fn = currop->op0;
2517 else
2518 {
2519 pre_expr op0 = get_or_alloc_expr_for (currop->op0);
2520 fn = find_or_generate_expression (block, op0, stmts, domstmt);
2521 if (!fn)
2522 return NULL_TREE;
2523 }
2524 if (currop->op1)
2525 {
2526 pre_expr scexpr = get_or_alloc_expr_for (currop->op1);
2527 sc = find_or_generate_expression (block, scexpr, stmts, domstmt);
2528 if (!sc)
2529 return NULL_TREE;
2530 }
2531 args = XNEWVEC (tree, VEC_length (vn_reference_op_s,
2532 ref->operands) - 1);
c251ad9e
SS
2533 while (*operand < VEC_length (vn_reference_op_s, ref->operands))
2534 {
2535 args[nargs] = create_component_ref_by_pieces_1 (block, ref,
2536 operand, stmts,
2537 domstmt);
4b1e227d
SW
2538 if (!args[nargs])
2539 {
2540 free (args);
2541 return NULL_TREE;
2542 }
c251ad9e
SS
2543 nargs++;
2544 }
2545 folded = build_call_array (currop->type,
4b1e227d
SW
2546 (TREE_CODE (fn) == FUNCTION_DECL
2547 ? build_fold_addr_expr (fn) : fn),
c251ad9e
SS
2548 nargs, args);
2549 free (args);
2550 if (sc)
4b1e227d 2551 CALL_EXPR_STATIC_CHAIN (folded) = sc;
c251ad9e
SS
2552 return folded;
2553 }
2554 break;
2555 case ADDR_EXPR:
2556 if (currop->op0)
2557 {
2558 gcc_assert (is_gimple_min_invariant (currop->op0));
2559 return currop->op0;
2560 }
2561 /* Fallthrough. */
2562 case REALPART_EXPR:
2563 case IMAGPART_EXPR:
2564 case VIEW_CONVERT_EXPR:
2565 {
2566 tree folded;
2567 tree genop0 = create_component_ref_by_pieces_1 (block, ref,
2568 operand,
2569 stmts, domstmt);
2570 if (!genop0)
2571 return NULL_TREE;
2572 folded = fold_build1 (currop->opcode, currop->type,
2573 genop0);
2574 return folded;
2575 }
2576 break;
2577 case ALIGN_INDIRECT_REF:
2578 case MISALIGNED_INDIRECT_REF:
2579 case INDIRECT_REF:
2580 {
2581 tree folded;
2582 tree genop1 = create_component_ref_by_pieces_1 (block, ref,
2583 operand,
2584 stmts, domstmt);
2585 if (!genop1)
2586 return NULL_TREE;
2587 genop1 = fold_convert (build_pointer_type (currop->type),
2588 genop1);
2589
2590 if (currop->opcode == MISALIGNED_INDIRECT_REF)
2591 folded = fold_build2 (currop->opcode, currop->type,
2592 genop1, currop->op1);
2593 else
2594 folded = fold_build1 (currop->opcode, currop->type,
2595 genop1);
2596 return folded;
2597 }
2598 break;
2599 case BIT_FIELD_REF:
2600 {
2601 tree folded;
2602 tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand,
2603 stmts, domstmt);
2604 pre_expr op1expr = get_or_alloc_expr_for (currop->op0);
2605 pre_expr op2expr = get_or_alloc_expr_for (currop->op1);
2606 tree genop1;
2607 tree genop2;
2608
2609 if (!genop0)
2610 return NULL_TREE;
2611 genop1 = find_or_generate_expression (block, op1expr, stmts, domstmt);
2612 if (!genop1)
2613 return NULL_TREE;
2614 genop2 = find_or_generate_expression (block, op2expr, stmts, domstmt);
2615 if (!genop2)
2616 return NULL_TREE;
2617 folded = fold_build3 (BIT_FIELD_REF, currop->type, genop0, genop1,
2618 genop2);
2619 return folded;
2620 }
2621
2622 /* For array ref vn_reference_op's, operand 1 of the array ref
2623 is op0 of the reference op and operand 3 of the array ref is
2624 op1. */
2625 case ARRAY_RANGE_REF:
2626 case ARRAY_REF:
2627 {
2628 tree genop0;
2629 tree genop1 = currop->op0;
2630 pre_expr op1expr;
2631 tree genop2 = currop->op1;
2632 pre_expr op2expr;
2633 tree genop3;
2634 genop0 = create_component_ref_by_pieces_1 (block, ref, operand,
2635 stmts, domstmt);
2636 if (!genop0)
2637 return NULL_TREE;
2638 op1expr = get_or_alloc_expr_for (genop1);
2639 genop1 = find_or_generate_expression (block, op1expr, stmts, domstmt);
2640 if (!genop1)
2641 return NULL_TREE;
2642 if (genop2)
2643 {
2644 op2expr = get_or_alloc_expr_for (genop2);
2645 genop2 = find_or_generate_expression (block, op2expr, stmts,
2646 domstmt);
2647 if (!genop2)
2648 return NULL_TREE;
2649 }
2650
2651 genop3 = currop->op2;
2652 return build4 (currop->opcode, currop->type, genop0, genop1,
2653 genop2, genop3);
2654 }
2655 case COMPONENT_REF:
2656 {
2657 tree op0;
2658 tree op1;
2659 tree genop2 = currop->op1;
2660 pre_expr op2expr;
2661 op0 = create_component_ref_by_pieces_1 (block, ref, operand,
2662 stmts, domstmt);
2663 if (!op0)
2664 return NULL_TREE;
2665 /* op1 should be a FIELD_DECL, which are represented by
2666 themselves. */
2667 op1 = currop->op0;
2668 if (genop2)
2669 {
2670 op2expr = get_or_alloc_expr_for (genop2);
2671 genop2 = find_or_generate_expression (block, op2expr, stmts,
2672 domstmt);
2673 if (!genop2)
2674 return NULL_TREE;
2675 }
2676
2677 return fold_build3 (COMPONENT_REF, TREE_TYPE (op1), op0, op1,
2678 genop2);
2679 }
2680 break;
2681 case SSA_NAME:
2682 {
2683 pre_expr op0expr = get_or_alloc_expr_for (currop->op0);
2684 genop = find_or_generate_expression (block, op0expr, stmts, domstmt);
2685 return genop;
2686 }
2687 case STRING_CST:
2688 case INTEGER_CST:
2689 case COMPLEX_CST:
2690 case VECTOR_CST:
2691 case REAL_CST:
2692 case CONSTRUCTOR:
2693 case VAR_DECL:
2694 case PARM_DECL:
2695 case CONST_DECL:
2696 case RESULT_DECL:
2697 case FUNCTION_DECL:
2698 return currop->op0;
2699
2700 default:
2701 gcc_unreachable ();
2702 }
2703}
2704
2705/* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2706 COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
2707 trying to rename aggregates into ssa form directly, which is a no no.
2708
2709 Thus, this routine doesn't create temporaries, it just builds a
2710 single access expression for the array, calling
2711 find_or_generate_expression to build the innermost pieces.
2712
2713 This function is a subroutine of create_expression_by_pieces, and
2714 should not be called on it's own unless you really know what you
2715 are doing. */
2716
2717static tree
2718create_component_ref_by_pieces (basic_block block, vn_reference_t ref,
2719 gimple_seq *stmts, gimple domstmt)
2720{
2721 unsigned int op = 0;
2722 return create_component_ref_by_pieces_1 (block, ref, &op, stmts, domstmt);
2723}
2724
2725/* Find a leader for an expression, or generate one using
2726 create_expression_by_pieces if it's ANTIC but
2727 complex.
2728 BLOCK is the basic_block we are looking for leaders in.
2729 EXPR is the expression to find a leader or generate for.
2730 STMTS is the statement list to put the inserted expressions on.
2731 Returns the SSA_NAME of the LHS of the generated expression or the
2732 leader.
2733 DOMSTMT if non-NULL is a statement that should be dominated by
2734 all uses in the generated expression. If DOMSTMT is non-NULL this
2735 routine can fail and return NULL_TREE. Otherwise it will assert
2736 on failure. */
2737
2738static tree
2739find_or_generate_expression (basic_block block, pre_expr expr,
2740 gimple_seq *stmts, gimple domstmt)
2741{
2742 pre_expr leader = bitmap_find_leader (AVAIL_OUT (block),
2743 get_expr_value_id (expr), domstmt);
2744 tree genop = NULL;
2745 if (leader)
2746 {
2747 if (leader->kind == NAME)
2748 genop = PRE_EXPR_NAME (leader);
2749 else if (leader->kind == CONSTANT)
2750 genop = PRE_EXPR_CONSTANT (leader);
2751 }
2752
2753 /* If it's still NULL, it must be a complex expression, so generate
2754 it recursively. Not so for FRE though. */
2755 if (genop == NULL
2756 && !in_fre)
2757 {
2758 bitmap_set_t exprset;
2759 unsigned int lookfor = get_expr_value_id (expr);
2760 bool handled = false;
2761 bitmap_iterator bi;
2762 unsigned int i;
2763
2764 exprset = VEC_index (bitmap_set_t, value_expressions, lookfor);
2765 FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
2766 {
2767 pre_expr temp = expression_for_id (i);
2768 if (temp->kind != NAME)
2769 {
2770 handled = true;
2771 genop = create_expression_by_pieces (block, temp, stmts,
2772 domstmt,
2773 get_expr_type (expr));
2774 break;
2775 }
2776 }
2777 if (!handled && domstmt)
2778 return NULL_TREE;
2779
2780 gcc_assert (handled);
2781 }
2782 return genop;
2783}
2784
2785#define NECESSARY GF_PLF_1
2786
2787/* Create an expression in pieces, so that we can handle very complex
2788 expressions that may be ANTIC, but not necessary GIMPLE.
2789 BLOCK is the basic block the expression will be inserted into,
2790 EXPR is the expression to insert (in value form)
2791 STMTS is a statement list to append the necessary insertions into.
2792
2793 This function will die if we hit some value that shouldn't be
2794 ANTIC but is (IE there is no leader for it, or its components).
2795 This function may also generate expressions that are themselves
2796 partially or fully redundant. Those that are will be either made
2797 fully redundant during the next iteration of insert (for partially
2798 redundant ones), or eliminated by eliminate (for fully redundant
2799 ones).
2800
2801 If DOMSTMT is non-NULL then we make sure that all uses in the
2802 expressions dominate that statement. In this case the function
2803 can return NULL_TREE to signal failure. */
2804
2805static tree
2806create_expression_by_pieces (basic_block block, pre_expr expr,
2807 gimple_seq *stmts, gimple domstmt, tree type)
2808{
2809 tree temp, name;
2810 tree folded, newexpr;
2811 gimple_seq forced_stmts;
2812 unsigned int value_id;
2813 gimple_stmt_iterator gsi;
2814 tree exprtype = type ? type : get_expr_type (expr);
2815 pre_expr nameexpr;
2816 gimple newstmt;
2817
2818 switch (expr->kind)
2819 {
2820 /* We may hit the NAME/CONSTANT case if we have to convert types
2821 that value numbering saw through. */
2822 case NAME:
2823 folded = PRE_EXPR_NAME (expr);
2824 break;
2825 case CONSTANT:
2826 folded = PRE_EXPR_CONSTANT (expr);
2827 break;
2828 case REFERENCE:
2829 {
2830 vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
2831 folded = create_component_ref_by_pieces (block, ref, stmts, domstmt);
2832 }
2833 break;
2834 case NARY:
2835 {
2836 vn_nary_op_t nary = PRE_EXPR_NARY (expr);
2837 switch (nary->length)
2838 {
2839 case 2:
2840 {
2841 pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
2842 pre_expr op2 = get_or_alloc_expr_for (nary->op[1]);
2843 tree genop1 = find_or_generate_expression (block, op1,
2844 stmts, domstmt);
2845 tree genop2 = find_or_generate_expression (block, op2,
2846 stmts, domstmt);
2847 if (!genop1 || !genop2)
2848 return NULL_TREE;
2849 genop1 = fold_convert (TREE_TYPE (nary->op[0]),
2850 genop1);
2851 /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR. It
2852 may be a constant with the wrong type. */
2853 if (nary->opcode == POINTER_PLUS_EXPR)
2854 genop2 = fold_convert (sizetype, genop2);
2855 else
2856 genop2 = fold_convert (TREE_TYPE (nary->op[1]), genop2);
2857
2858 folded = fold_build2 (nary->opcode, nary->type,
2859 genop1, genop2);
2860 }
2861 break;
2862 case 1:
2863 {
2864 pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
2865 tree genop1 = find_or_generate_expression (block, op1,
2866 stmts, domstmt);
2867 if (!genop1)
2868 return NULL_TREE;
2869 genop1 = fold_convert (TREE_TYPE (nary->op[0]), genop1);
2870
2871 folded = fold_build1 (nary->opcode, nary->type,
2872 genop1);
2873 }
2874 break;
2875 default:
2876 return NULL_TREE;
2877 }
2878 }
2879 break;
2880 default:
2881 return NULL_TREE;
2882 }
2883 folded = fold_convert (exprtype, folded);
2884 /* Force the generated expression to be a sequence of GIMPLE
2885 statements.
2886 We have to call unshare_expr because force_gimple_operand may
2887 modify the tree we pass to it. */
2888 newexpr = force_gimple_operand (unshare_expr (folded), &forced_stmts,
2889 false, NULL);
2890
2891 /* If we have any intermediate expressions to the value sets, add them
2892 to the value sets and chain them in the instruction stream. */
2893 if (forced_stmts)
2894 {
2895 gsi = gsi_start (forced_stmts);
2896 for (; !gsi_end_p (gsi); gsi_next (&gsi))
2897 {
2898 gimple stmt = gsi_stmt (gsi);
2899 tree forcedname = gimple_get_lhs (stmt);
2900 pre_expr nameexpr;
2901
2902 VEC_safe_push (gimple, heap, inserted_exprs, stmt);
2903 if (TREE_CODE (forcedname) == SSA_NAME)
2904 {
2905 VN_INFO_GET (forcedname)->valnum = forcedname;
2906 VN_INFO (forcedname)->value_id = get_next_value_id ();
2907 nameexpr = get_or_alloc_expr_for_name (forcedname);
2908 add_to_value (VN_INFO (forcedname)->value_id, nameexpr);
2909 if (!in_fre)
2910 bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
2911 bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
2912 }
2913 mark_symbols_for_renaming (stmt);
2914 }
2915 gimple_seq_add_seq (stmts, forced_stmts);
2916 }
2917
2918 /* Build and insert the assignment of the end result to the temporary
2919 that we will return. */
2920 if (!pretemp || exprtype != TREE_TYPE (pretemp))
2921 {
2922 pretemp = create_tmp_var (exprtype, "pretmp");
2923 get_var_ann (pretemp);
2924 }
2925
2926 temp = pretemp;
2927 add_referenced_var (temp);
2928
2929 if (TREE_CODE (exprtype) == COMPLEX_TYPE
2930 || TREE_CODE (exprtype) == VECTOR_TYPE)
2931 DECL_GIMPLE_REG_P (temp) = 1;
2932
2933 newstmt = gimple_build_assign (temp, newexpr);
2934 name = make_ssa_name (temp, newstmt);
2935 gimple_assign_set_lhs (newstmt, name);
2936 gimple_set_plf (newstmt, NECESSARY, false);
2937
2938 gimple_seq_add_stmt (stmts, newstmt);
2939 VEC_safe_push (gimple, heap, inserted_exprs, newstmt);
2940
2941 /* All the symbols in NEWEXPR should be put into SSA form. */
2942 mark_symbols_for_renaming (newstmt);
2943
2944 /* Add a value number to the temporary.
2945 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2946 we are creating the expression by pieces, and this particular piece of
2947 the expression may have been represented. There is no harm in replacing
2948 here. */
2949 VN_INFO_GET (name)->valnum = name;
2950 value_id = get_expr_value_id (expr);
2951 VN_INFO (name)->value_id = value_id;
2952 nameexpr = get_or_alloc_expr_for_name (name);
2953 add_to_value (value_id, nameexpr);
2954 if (!in_fre)
2955 bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
2956 bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
2957
2958 pre_stats.insertions++;
2959 if (dump_file && (dump_flags & TDF_DETAILS))
2960 {
2961 fprintf (dump_file, "Inserted ");
2962 print_gimple_stmt (dump_file, newstmt, 0, 0);
2963 fprintf (dump_file, " in predecessor %d\n", block->index);
2964 }
2965
2966 return name;
2967}
2968
2969
2970/* Insert the to-be-made-available values of expression EXPRNUM for each
2971 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2972 merge the result with a phi node, given the same value number as
2973 NODE. Return true if we have inserted new stuff. */
2974
2975static bool
2976insert_into_preds_of_block (basic_block block, unsigned int exprnum,
2977 pre_expr *avail)
2978{
2979 pre_expr expr = expression_for_id (exprnum);
2980 pre_expr newphi;
2981 unsigned int val = get_expr_value_id (expr);
2982 edge pred;
2983 bool insertions = false;
2984 bool nophi = false;
2985 basic_block bprime;
2986 pre_expr eprime;
2987 edge_iterator ei;
2988 tree type = get_expr_type (expr);
2989 tree temp;
2990 gimple phi;
2991
2992 if (dump_file && (dump_flags & TDF_DETAILS))
2993 {
2994 fprintf (dump_file, "Found partial redundancy for expression ");
2995 print_pre_expr (dump_file, expr);
2996 fprintf (dump_file, " (%04d)\n", val);
2997 }
2998
2999 /* Make sure we aren't creating an induction variable. */
3000 if (block->loop_depth > 0 && EDGE_COUNT (block->preds) == 2
3001 && expr->kind != REFERENCE)
3002 {
3003 bool firstinsideloop = false;
3004 bool secondinsideloop = false;
3005 firstinsideloop = flow_bb_inside_loop_p (block->loop_father,
3006 EDGE_PRED (block, 0)->src);
3007 secondinsideloop = flow_bb_inside_loop_p (block->loop_father,
3008 EDGE_PRED (block, 1)->src);
3009 /* Induction variables only have one edge inside the loop. */
3010 if (firstinsideloop ^ secondinsideloop)
3011 {
3012 if (dump_file && (dump_flags & TDF_DETAILS))
3013 fprintf (dump_file, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3014 nophi = true;
3015 }
3016 }
3017
3018 /* Make sure we are not inserting trapping expressions. */
3019 FOR_EACH_EDGE (pred, ei, block->preds)
3020 {
3021 bprime = pred->src;
3022 eprime = avail[bprime->index];
3023 if (eprime->kind == NARY
3024 && vn_nary_may_trap (PRE_EXPR_NARY (eprime)))
3025 return false;
3026 }
3027
3028 /* Make the necessary insertions. */
3029 FOR_EACH_EDGE (pred, ei, block->preds)
3030 {
3031 gimple_seq stmts = NULL;
3032 tree builtexpr;
3033 bprime = pred->src;
3034 eprime = avail[bprime->index];
3035
3036 if (eprime->kind != NAME && eprime->kind != CONSTANT)
3037 {
3038 builtexpr = create_expression_by_pieces (bprime,
3039 eprime,
3040 &stmts, NULL,
3041 type);
3042 gcc_assert (!(pred->flags & EDGE_ABNORMAL));
3043 gsi_insert_seq_on_edge (pred, stmts);
3044 avail[bprime->index] = get_or_alloc_expr_for_name (builtexpr);
3045 insertions = true;
3046 }
3047 else if (eprime->kind == CONSTANT)
3048 {
3049 /* Constants may not have the right type, fold_convert
3050 should give us back a constant with the right type.
3051 */
3052 tree constant = PRE_EXPR_CONSTANT (eprime);
3053 if (!useless_type_conversion_p (type, TREE_TYPE (constant)))
3054 {
3055 tree builtexpr = fold_convert (type, constant);
3056 if (!is_gimple_min_invariant (builtexpr))
3057 {
3058 tree forcedexpr = force_gimple_operand (builtexpr,
3059 &stmts, true,
3060 NULL);
3061 if (!is_gimple_min_invariant (forcedexpr))
3062 {
3063 if (forcedexpr != builtexpr)
3064 {
3065 VN_INFO_GET (forcedexpr)->valnum = PRE_EXPR_CONSTANT (eprime);
3066 VN_INFO (forcedexpr)->value_id = get_expr_value_id (eprime);
3067 }
3068 if (stmts)
3069 {
3070 gimple_stmt_iterator gsi;
3071 gsi = gsi_start (stmts);
3072 for (; !gsi_end_p (gsi); gsi_next (&gsi))
3073 {
3074 gimple stmt = gsi_stmt (gsi);
3075 VEC_safe_push (gimple, heap, inserted_exprs, stmt);
3076 gimple_set_plf (stmt, NECESSARY, false);
3077 }
3078 gsi_insert_seq_on_edge (pred, stmts);
3079 }
3080 avail[bprime->index] = get_or_alloc_expr_for_name (forcedexpr);
3081 }
3082 }
3083 }
3084 }
3085 else if (eprime->kind == NAME)
3086 {
3087 /* We may have to do a conversion because our value
3088 numbering can look through types in certain cases, but
3089 our IL requires all operands of a phi node have the same
3090 type. */
3091 tree name = PRE_EXPR_NAME (eprime);
3092 if (!useless_type_conversion_p (type, TREE_TYPE (name)))
3093 {
3094 tree builtexpr;
3095 tree forcedexpr;
3096 builtexpr = fold_convert (type, name);
3097 forcedexpr = force_gimple_operand (builtexpr,
3098 &stmts, true,
3099 NULL);
3100
3101 if (forcedexpr != name)
3102 {
3103 VN_INFO_GET (forcedexpr)->valnum = VN_INFO (name)->valnum;
3104 VN_INFO (forcedexpr)->value_id = VN_INFO (name)->value_id;
3105 }
3106
3107 if (stmts)
3108 {
3109 gimple_stmt_iterator gsi;
3110 gsi = gsi_start (stmts);
3111 for (; !gsi_end_p (gsi); gsi_next (&gsi))
3112 {
3113 gimple stmt = gsi_stmt (gsi);
3114 VEC_safe_push (gimple, heap, inserted_exprs, stmt);
3115 gimple_set_plf (stmt, NECESSARY, false);
3116 }
3117 gsi_insert_seq_on_edge (pred, stmts);
3118 }
3119 avail[bprime->index] = get_or_alloc_expr_for_name (forcedexpr);
3120 }
3121 }
3122 }
3123 /* If we didn't want a phi node, and we made insertions, we still have
3124 inserted new stuff, and thus return true. If we didn't want a phi node,
3125 and didn't make insertions, we haven't added anything new, so return
3126 false. */
3127 if (nophi && insertions)
3128 return true;
3129 else if (nophi && !insertions)
3130 return false;
3131
3132 /* Now build a phi for the new variable. */
3133 if (!prephitemp || TREE_TYPE (prephitemp) != type)
3134 {
3135 prephitemp = create_tmp_var (type, "prephitmp");
3136 get_var_ann (prephitemp);
3137 }
3138
3139 temp = prephitemp;
3140 add_referenced_var (temp);
3141
3142 if (TREE_CODE (type) == COMPLEX_TYPE
3143 || TREE_CODE (type) == VECTOR_TYPE)
3144 DECL_GIMPLE_REG_P (temp) = 1;
3145 phi = create_phi_node (temp, block);
3146
3147 gimple_set_plf (phi, NECESSARY, false);
3148 VN_INFO_GET (gimple_phi_result (phi))->valnum = gimple_phi_result (phi);
3149 VN_INFO (gimple_phi_result (phi))->value_id = val;
3150 VEC_safe_push (gimple, heap, inserted_exprs, phi);
3151 FOR_EACH_EDGE (pred, ei, block->preds)
3152 {
3153 pre_expr ae = avail[pred->src->index];
3154 gcc_assert (get_expr_type (ae) == type
3155 || useless_type_conversion_p (type, get_expr_type (ae)));
3156 if (ae->kind == CONSTANT)
3157 add_phi_arg (phi, PRE_EXPR_CONSTANT (ae), pred);
3158 else
3159 add_phi_arg (phi, PRE_EXPR_NAME (avail[pred->src->index]), pred);
3160 }
3161
3162 newphi = get_or_alloc_expr_for_name (gimple_phi_result (phi));
3163 add_to_value (val, newphi);
3164
3165 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3166 this insertion, since we test for the existence of this value in PHI_GEN
3167 before proceeding with the partial redundancy checks in insert_aux.
3168
3169 The value may exist in AVAIL_OUT, in particular, it could be represented
3170 by the expression we are trying to eliminate, in which case we want the
3171 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3172 inserted there.
3173
3174 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3175 this block, because if it did, it would have existed in our dominator's
3176 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3177 */
3178
3179 bitmap_insert_into_set (PHI_GEN (block), newphi);
3180 bitmap_value_replace_in_set (AVAIL_OUT (block),
3181 newphi);
3182 bitmap_insert_into_set (NEW_SETS (block),
3183 newphi);
3184
3185 if (dump_file && (dump_flags & TDF_DETAILS))
3186 {
3187 fprintf (dump_file, "Created phi ");
3188 print_gimple_stmt (dump_file, phi, 0, 0);
3189 fprintf (dump_file, " in block %d\n", block->index);
3190 }
3191 pre_stats.phis++;
3192 return true;
3193}
3194
3195
3196
3197/* Perform insertion of partially redundant values.
3198 For BLOCK, do the following:
3199 1. Propagate the NEW_SETS of the dominator into the current block.
3200 If the block has multiple predecessors,
3201 2a. Iterate over the ANTIC expressions for the block to see if
3202 any of them are partially redundant.
3203 2b. If so, insert them into the necessary predecessors to make
3204 the expression fully redundant.
3205 2c. Insert a new PHI merging the values of the predecessors.
3206 2d. Insert the new PHI, and the new expressions, into the
3207 NEW_SETS set.
3208 3. Recursively call ourselves on the dominator children of BLOCK.
3209
3210 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3211 do_regular_insertion and do_partial_insertion.
3212
3213*/
3214
3215static bool
3216do_regular_insertion (basic_block block, basic_block dom)
3217{
3218 bool new_stuff = false;
3219 VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (ANTIC_IN (block));
3220 pre_expr expr;
3221 int i;
3222
3223 for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
3224 {
3225 if (expr->kind != NAME)
3226 {
3227 pre_expr *avail;
3228 unsigned int val;
3229 bool by_some = false;
3230 bool cant_insert = false;
3231 bool all_same = true;
3232 pre_expr first_s = NULL;
3233 edge pred;
3234 basic_block bprime;
3235 pre_expr eprime = NULL;
3236 edge_iterator ei;
3237 pre_expr edoubleprime = NULL;
3238
3239 val = get_expr_value_id (expr);
3240 if (bitmap_set_contains_value (PHI_GEN (block), val))
3241 continue;
3242 if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
3243 {
3244 if (dump_file && (dump_flags & TDF_DETAILS))
3245 fprintf (dump_file, "Found fully redundant value\n");
3246 continue;
3247 }
3248
3249 avail = XCNEWVEC (pre_expr, last_basic_block);
3250 FOR_EACH_EDGE (pred, ei, block->preds)
3251 {
3252 unsigned int vprime;
3253
3254 /* We should never run insertion for the exit block
3255 and so not come across fake pred edges. */
3256 gcc_assert (!(pred->flags & EDGE_FAKE));
3257 bprime = pred->src;
3258 eprime = phi_translate (expr, ANTIC_IN (block), NULL,
3259 bprime, block);
3260
3261 /* eprime will generally only be NULL if the
3262 value of the expression, translated
3263 through the PHI for this predecessor, is
3264 undefined. If that is the case, we can't
3265 make the expression fully redundant,
3266 because its value is undefined along a
3267 predecessor path. We can thus break out
3268 early because it doesn't matter what the
3269 rest of the results are. */
3270 if (eprime == NULL)
3271 {
3272 cant_insert = true;
3273 break;
3274 }
3275
3276 eprime = fully_constant_expression (eprime);
3277 vprime = get_expr_value_id (eprime);
3278 edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
3279 vprime, NULL);
3280 if (edoubleprime == NULL)
3281 {
3282 avail[bprime->index] = eprime;
3283 all_same = false;
3284 }
3285 else
3286 {
3287 avail[bprime->index] = edoubleprime;
3288 by_some = true;
3289 if (first_s == NULL)
3290 first_s = edoubleprime;
3291 else if (!pre_expr_eq (first_s, edoubleprime))
3292 all_same = false;
3293 }
3294 }
3295 /* If we can insert it, it's not the same value
3296 already existing along every predecessor, and
3297 it's defined by some predecessor, it is
3298 partially redundant. */
3299 if (!cant_insert && !all_same && by_some && dbg_cnt (treepre_insert))
3300 {
3301 if (insert_into_preds_of_block (block, get_expression_id (expr),
3302 avail))
3303 new_stuff = true;
3304 }
3305 /* If all edges produce the same value and that value is
3306 an invariant, then the PHI has the same value on all
3307 edges. Note this. */
3308 else if (!cant_insert && all_same && eprime
3309 && (edoubleprime->kind == CONSTANT
3310 || edoubleprime->kind == NAME)
3311 && !value_id_constant_p (val))
3312 {
3313 unsigned int j;
3314 bitmap_iterator bi;
3315 bitmap_set_t exprset = VEC_index (bitmap_set_t,
3316 value_expressions, val);
3317
3318 unsigned int new_val = get_expr_value_id (edoubleprime);
3319 FOR_EACH_EXPR_ID_IN_SET (exprset, j, bi)
3320 {
3321 pre_expr expr = expression_for_id (j);
3322
3323 if (expr->kind == NAME)
3324 {
3325 vn_ssa_aux_t info = VN_INFO (PRE_EXPR_NAME (expr));
3326 /* Just reset the value id and valnum so it is
3327 the same as the constant we have discovered. */
3328 if (edoubleprime->kind == CONSTANT)
3329 {
3330 info->valnum = PRE_EXPR_CONSTANT (edoubleprime);
3331 pre_stats.constified++;
3332 }
3333 else
3334 info->valnum = VN_INFO (PRE_EXPR_NAME (edoubleprime))->valnum;
3335 info->value_id = new_val;
3336 }
3337 }
3338 }
3339 free (avail);
3340 }
3341 }
3342
3343 VEC_free (pre_expr, heap, exprs);
3344 return new_stuff;
3345}
3346
3347
3348/* Perform insertion for partially anticipatable expressions. There
3349 is only one case we will perform insertion for these. This case is
3350 if the expression is partially anticipatable, and fully available.
3351 In this case, we know that putting it earlier will enable us to
3352 remove the later computation. */
3353
3354
3355static bool
3356do_partial_partial_insertion (basic_block block, basic_block dom)
3357{
3358 bool new_stuff = false;
3359 VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (PA_IN (block));
3360 pre_expr expr;
3361 int i;
3362
3363 for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
3364 {
3365 if (expr->kind != NAME)
3366 {
3367 pre_expr *avail;
3368 unsigned int val;
3369 bool by_all = true;
3370 bool cant_insert = false;
3371 edge pred;
3372 basic_block bprime;
3373 pre_expr eprime = NULL;
3374 edge_iterator ei;
3375
3376 val = get_expr_value_id (expr);
3377 if (bitmap_set_contains_value (PHI_GEN (block), val))
3378 continue;
3379 if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
3380 continue;
3381
3382 avail = XCNEWVEC (pre_expr, last_basic_block);
3383 FOR_EACH_EDGE (pred, ei, block->preds)
3384 {
3385 unsigned int vprime;
3386 pre_expr edoubleprime;
3387
3388 /* We should never run insertion for the exit block
3389 and so not come across fake pred edges. */
3390 gcc_assert (!(pred->flags & EDGE_FAKE));
3391 bprime = pred->src;
3392 eprime = phi_translate (expr, ANTIC_IN (block),
3393 PA_IN (block),
3394 bprime, block);
3395
3396 /* eprime will generally only be NULL if the
3397 value of the expression, translated
3398 through the PHI for this predecessor, is
3399 undefined. If that is the case, we can't
3400 make the expression fully redundant,
3401 because its value is undefined along a
3402 predecessor path. We can thus break out
3403 early because it doesn't matter what the
3404 rest of the results are. */
3405 if (eprime == NULL)
3406 {
3407 cant_insert = true;
3408 break;
3409 }
3410
3411 eprime = fully_constant_expression (eprime);
3412 vprime = get_expr_value_id (eprime);
3413 edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
3414 vprime, NULL);
3415 if (edoubleprime == NULL)
3416 {
3417 by_all = false;
3418 break;
3419 }
3420 else
3421 avail[bprime->index] = edoubleprime;
3422
3423 }
3424
3425 /* If we can insert it, it's not the same value
3426 already existing along every predecessor, and
3427 it's defined by some predecessor, it is
3428 partially redundant. */
3429 if (!cant_insert && by_all && dbg_cnt (treepre_insert))
3430 {
3431 pre_stats.pa_insert++;
3432 if (insert_into_preds_of_block (block, get_expression_id (expr),
3433 avail))
3434 new_stuff = true;
3435 }
3436 free (avail);
3437 }
3438 }
3439
3440 VEC_free (pre_expr, heap, exprs);
3441 return new_stuff;
3442}
3443
3444static bool
3445insert_aux (basic_block block)
3446{
3447 basic_block son;
3448 bool new_stuff = false;
3449
3450 if (block)
3451 {
3452 basic_block dom;
3453 dom = get_immediate_dominator (CDI_DOMINATORS, block);
3454 if (dom)
3455 {
3456 unsigned i;
3457 bitmap_iterator bi;
3458 bitmap_set_t newset = NEW_SETS (dom);
3459 if (newset)
3460 {
3461 /* Note that we need to value_replace both NEW_SETS, and
3462 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3463 represented by some non-simple expression here that we want
3464 to replace it with. */
3465 FOR_EACH_EXPR_ID_IN_SET (newset, i, bi)
3466 {
3467 pre_expr expr = expression_for_id (i);
3468 bitmap_value_replace_in_set (NEW_SETS (block), expr);
3469 bitmap_value_replace_in_set (AVAIL_OUT (block), expr);
3470 }
3471 }
3472 if (!single_pred_p (block))
3473 {
3474 new_stuff |= do_regular_insertion (block, dom);
3475 if (do_partial_partial)
3476 new_stuff |= do_partial_partial_insertion (block, dom);
3477 }
3478 }
3479 }
3480 for (son = first_dom_son (CDI_DOMINATORS, block);
3481 son;
3482 son = next_dom_son (CDI_DOMINATORS, son))
3483 {
3484 new_stuff |= insert_aux (son);
3485 }
3486
3487 return new_stuff;
3488}
3489
3490/* Perform insertion of partially redundant values. */
3491
3492static void
3493insert (void)
3494{
3495 bool new_stuff = true;
3496 basic_block bb;
3497 int num_iterations = 0;
3498
3499 FOR_ALL_BB (bb)
3500 NEW_SETS (bb) = bitmap_set_new ();
3501
3502 while (new_stuff)
3503 {
3504 num_iterations++;
3505 new_stuff = insert_aux (ENTRY_BLOCK_PTR);
3506 }
3507 statistics_histogram_event (cfun, "insert iterations", num_iterations);
3508}
3509
3510
dff90b41 3511/* Add OP to EXP_GEN (block), and possibly to the maximal set. */
c251ad9e
SS
3512
3513static void
3514add_to_exp_gen (basic_block block, tree op)
3515{
3516 if (!in_fre)
3517 {
3518 pre_expr result;
3519 if (TREE_CODE (op) == SSA_NAME && ssa_undefined_value_p (op))
3520 return;
3521 result = get_or_alloc_expr_for_name (op);
3522 bitmap_value_insert_into_set (EXP_GEN (block), result);
c251ad9e
SS
3523 }
3524}
3525
3526/* Create value ids for PHI in BLOCK. */
3527
3528static void
3529make_values_for_phi (gimple phi, basic_block block)
3530{
3531 tree result = gimple_phi_result (phi);
3532
3533 /* We have no need for virtual phis, as they don't represent
3534 actual computations. */
3535 if (is_gimple_reg (result))
3536 {
3537 pre_expr e = get_or_alloc_expr_for_name (result);
3538 add_to_value (get_expr_value_id (e), e);
3539 bitmap_insert_into_set (PHI_GEN (block), e);
3540 bitmap_value_insert_into_set (AVAIL_OUT (block), e);
dff90b41
SS
3541 if (!in_fre)
3542 {
3543 unsigned i;
3544 for (i = 0; i < gimple_phi_num_args (phi); ++i)
3545 {
3546 tree arg = gimple_phi_arg_def (phi, i);
3547 if (TREE_CODE (arg) == SSA_NAME)
3548 {
3549 e = get_or_alloc_expr_for_name (arg);
3550 add_to_value (get_expr_value_id (e), e);
3551 }
3552 }
3553 }
c251ad9e
SS
3554 }
3555}
3556
3557/* Compute the AVAIL set for all basic blocks.
3558
3559 This function performs value numbering of the statements in each basic
3560 block. The AVAIL sets are built from information we glean while doing
3561 this value numbering, since the AVAIL sets contain only one entry per
3562 value.
3563
3564 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3565 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3566
3567static void
3568compute_avail (void)
3569{
3570
3571 basic_block block, son;
3572 basic_block *worklist;
3573 size_t sp = 0;
3574 tree param;
3575
3576 /* For arguments with default definitions, we pretend they are
3577 defined in the entry block. */
3578 for (param = DECL_ARGUMENTS (current_function_decl);
3579 param;
3580 param = TREE_CHAIN (param))
3581 {
3582 if (gimple_default_def (cfun, param) != NULL)
3583 {
3584 tree def = gimple_default_def (cfun, param);
3585 pre_expr e = get_or_alloc_expr_for_name (def);
3586
3587 add_to_value (get_expr_value_id (e), e);
3588 if (!in_fre)
dff90b41 3589 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
c251ad9e
SS
3590 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), e);
3591 }
3592 }
3593
3594 /* Likewise for the static chain decl. */
3595 if (cfun->static_chain_decl)
3596 {
3597 param = cfun->static_chain_decl;
3598 if (gimple_default_def (cfun, param) != NULL)
3599 {
3600 tree def = gimple_default_def (cfun, param);
3601 pre_expr e = get_or_alloc_expr_for_name (def);
3602
3603 add_to_value (get_expr_value_id (e), e);
3604 if (!in_fre)
dff90b41 3605 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
c251ad9e
SS
3606 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), e);
3607 }
3608 }
3609
3610 /* Allocate the worklist. */
3611 worklist = XNEWVEC (basic_block, n_basic_blocks);
3612
3613 /* Seed the algorithm by putting the dominator children of the entry
3614 block on the worklist. */
3615 for (son = first_dom_son (CDI_DOMINATORS, ENTRY_BLOCK_PTR);
3616 son;
3617 son = next_dom_son (CDI_DOMINATORS, son))
3618 worklist[sp++] = son;
3619
3620 /* Loop until the worklist is empty. */
3621 while (sp)
3622 {
3623 gimple_stmt_iterator gsi;
3624 gimple stmt;
3625 basic_block dom;
3626 unsigned int stmt_uid = 1;
3627
3628 /* Pick a block from the worklist. */
3629 block = worklist[--sp];
3630
3631 /* Initially, the set of available values in BLOCK is that of
3632 its immediate dominator. */
3633 dom = get_immediate_dominator (CDI_DOMINATORS, block);
3634 if (dom)
3635 bitmap_set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
3636
3637 /* Generate values for PHI nodes. */
3638 for (gsi = gsi_start_phis (block); !gsi_end_p (gsi); gsi_next (&gsi))
3639 make_values_for_phi (gsi_stmt (gsi), block);
3640
3641 /* Now compute value numbers and populate value sets with all
3642 the expressions computed in BLOCK. */
3643 for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi))
3644 {
3645 ssa_op_iter iter;
3646 tree op;
3647
3648 stmt = gsi_stmt (gsi);
3649 gimple_set_uid (stmt, stmt_uid++);
3650
3651 FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
3652 {
3653 pre_expr e = get_or_alloc_expr_for_name (op);
3654
3655 add_to_value (get_expr_value_id (e), e);
3656 if (!in_fre)
3657 bitmap_insert_into_set (TMP_GEN (block), e);
3658 bitmap_value_insert_into_set (AVAIL_OUT (block), e);
3659 }
3660
3661 if (gimple_has_volatile_ops (stmt)
3662 || stmt_could_throw_p (stmt))
3663 continue;
3664
3665 switch (gimple_code (stmt))
3666 {
3667 case GIMPLE_RETURN:
3668 FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
3669 add_to_exp_gen (block, op);
3670 continue;
3671
3672 case GIMPLE_CALL:
3673 {
3674 vn_reference_t ref;
3675 unsigned int i;
3676 vn_reference_op_t vro;
3677 pre_expr result = NULL;
3678 VEC(vn_reference_op_s, heap) *ops = NULL;
3679
3680 if (!can_value_number_call (stmt))
3681 continue;
3682
3683 copy_reference_ops_from_call (stmt, &ops);
3684 vn_reference_lookup_pieces (shared_vuses_from_stmt (stmt),
3685 ops, &ref, false);
3686 VEC_free (vn_reference_op_s, heap, ops);
3687 if (!ref)
3688 continue;
3689
3690 for (i = 0; VEC_iterate (vn_reference_op_s,
3691 ref->operands, i,
3692 vro); i++)
3693 {
3694 if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
3695 add_to_exp_gen (block, vro->op0);
3696 if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
3697 add_to_exp_gen (block, vro->op1);
3698 if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
3699 add_to_exp_gen (block, vro->op2);
3700 }
3701 result = (pre_expr) pool_alloc (pre_expr_pool);
3702 result->kind = REFERENCE;
3703 result->id = 0;
3704 PRE_EXPR_REFERENCE (result) = ref;
3705
3706 get_or_alloc_expression_id (result);
3707 add_to_value (get_expr_value_id (result), result);
3708 if (!in_fre)
dff90b41 3709 bitmap_value_insert_into_set (EXP_GEN (block), result);
c251ad9e
SS
3710 continue;
3711 }
3712
3713 case GIMPLE_ASSIGN:
3714 {
3715 pre_expr result = NULL;
3716 switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
3717 {
3718 case tcc_unary:
3719 if (is_exception_related (stmt))
3720 continue;
3721 case tcc_binary:
3722 case tcc_comparison:
3723 {
3724 vn_nary_op_t nary;
3725 unsigned int i;
3726
3727 vn_nary_op_lookup_pieces (gimple_num_ops (stmt) - 1,
3728 gimple_assign_rhs_code (stmt),
3729 gimple_expr_type (stmt),
3730 gimple_assign_rhs1 (stmt),
3731 gimple_assign_rhs2 (stmt),
3732 NULL_TREE, NULL_TREE, &nary);
3733
3734 if (!nary)
3735 continue;
3736
3737 for (i = 0; i < nary->length; i++)
3738 if (TREE_CODE (nary->op[i]) == SSA_NAME)
3739 add_to_exp_gen (block, nary->op[i]);
3740
3741 result = (pre_expr) pool_alloc (pre_expr_pool);
3742 result->kind = NARY;
3743 result->id = 0;
3744 PRE_EXPR_NARY (result) = nary;
3745 break;
3746 }
3747
3748 case tcc_declaration:
3749 case tcc_reference:
3750 {
3751 vn_reference_t ref;
3752 unsigned int i;
3753 vn_reference_op_t vro;
3754
3755 vn_reference_lookup (gimple_assign_rhs1 (stmt),
3756 shared_vuses_from_stmt (stmt),
3757 false, &ref);
3758 if (!ref)
3759 continue;
3760
3761 for (i = 0; VEC_iterate (vn_reference_op_s,
3762 ref->operands, i,
3763 vro); i++)
3764 {
3765 if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
3766 add_to_exp_gen (block, vro->op0);
3767 if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
3768 add_to_exp_gen (block, vro->op1);
3769 if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
3770 add_to_exp_gen (block, vro->op2);
3771 }
3772 result = (pre_expr) pool_alloc (pre_expr_pool);
3773 result->kind = REFERENCE;
3774 result->id = 0;
3775 PRE_EXPR_REFERENCE (result) = ref;
3776 break;
3777 }
3778
3779 default: