2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
28 #include "basic-block.h"
29 #include "tree-pretty-print.h"
30 #include "gimple-pretty-print.h"
31 #include "tree-inline.h"
32 #include "tree-flow.h"
34 #include "tree-dump.h"
38 #include "tree-iterator.h"
39 #include "alloc-pool.h"
41 #include "tree-pass.h"
44 #include "langhooks.h"
46 #include "tree-ssa-sccvn.h"
47 #include "tree-scalar-evolution.h"
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.
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. */
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
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.
94 Third, we perform insertions to make partially redundant
95 expressions fully redundant.
97 An expression is partially redundant (excluding partial
100 1. It is AVAIL in some, but not all, of the predecessors of a
102 2. It is ANTIC in all the predecessors.
104 In order to make it fully redundant, we insert the expression into
105 the predecessors where it is not available, but is ANTIC.
107 For the partial anticipation case, we only perform insertion if it
108 is partially anticipated in some block, and fully available in all
111 insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
112 performs these steps.
114 Fourth, we eliminate fully redundant expressions.
115 This is a simple statement walk that replaces redundant
116 calculations with the now available values. */
118 /* Representations of value numbers:
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).
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
135 /* Representation of expressions on value numbers:
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. */
142 /* Representation of sets:
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.
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
153 /* Type of expression, used to know which member of the PRE_EXPR union
164 typedef union pre_expr_union_d
169 vn_reference_t reference
;
172 typedef struct pre_expr_d
174 enum pre_expr_kind kind
;
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
185 pre_expr_eq (const void *p1
, const void *p2
)
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
;
190 if (e1
->kind
!= e2
->kind
)
196 return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1
),
197 PRE_EXPR_CONSTANT (e2
));
199 return PRE_EXPR_NAME (e1
) == PRE_EXPR_NAME (e2
);
201 return vn_nary_op_eq (PRE_EXPR_NARY (e1
), PRE_EXPR_NARY (e2
));
203 return vn_reference_eq (PRE_EXPR_REFERENCE (e1
),
204 PRE_EXPR_REFERENCE (e2
));
211 pre_expr_hash (const void *p1
)
213 const struct pre_expr_d
*e
= (const struct pre_expr_d
*) p1
;
217 return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e
));
219 return SSA_NAME_VERSION (PRE_EXPR_NAME (e
));
221 return PRE_EXPR_NARY (e
)->hashcode
;
223 return PRE_EXPR_REFERENCE (e
)->hashcode
;
230 /* Next global expression id number. */
231 static unsigned int next_expression_id
;
233 /* Mapping from expression to id number we can use in bitmap sets. */
234 DEF_VEC_P (pre_expr
);
235 DEF_VEC_ALLOC_P (pre_expr
, heap
);
236 static VEC(pre_expr
, heap
) *expressions
;
237 static htab_t expression_to_id
;
238 static VEC(unsigned, heap
) *name_to_id
;
240 /* Allocate an expression id for EXPR. */
242 static inline unsigned int
243 alloc_expression_id (pre_expr expr
)
246 /* Make sure we won't overflow. */
247 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
248 expr
->id
= next_expression_id
++;
249 VEC_safe_push (pre_expr
, heap
, expressions
, expr
);
250 if (expr
->kind
== NAME
)
252 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
253 /* VEC_safe_grow_cleared allocates no headroom. Avoid frequent
254 re-allocations by using VEC_reserve upfront. There is no
255 VEC_quick_grow_cleared unfortunately. */
256 VEC_reserve (unsigned, heap
, name_to_id
, num_ssa_names
);
257 VEC_safe_grow_cleared (unsigned, heap
, name_to_id
, num_ssa_names
);
258 gcc_assert (VEC_index (unsigned, name_to_id
, version
) == 0);
259 VEC_replace (unsigned, name_to_id
, version
, expr
->id
);
263 slot
= htab_find_slot (expression_to_id
, expr
, INSERT
);
267 return next_expression_id
- 1;
270 /* Return the expression id for tree EXPR. */
272 static inline unsigned int
273 get_expression_id (const pre_expr expr
)
278 static inline unsigned int
279 lookup_expression_id (const pre_expr expr
)
283 if (expr
->kind
== NAME
)
285 unsigned version
= SSA_NAME_VERSION (PRE_EXPR_NAME (expr
));
286 if (VEC_length (unsigned, name_to_id
) <= version
)
288 return VEC_index (unsigned, name_to_id
, version
);
292 slot
= htab_find_slot (expression_to_id
, expr
, NO_INSERT
);
295 return ((pre_expr
)*slot
)->id
;
299 /* Return the existing expression id for EXPR, or create one if one
300 does not exist yet. */
302 static inline unsigned int
303 get_or_alloc_expression_id (pre_expr expr
)
305 unsigned int id
= lookup_expression_id (expr
);
307 return alloc_expression_id (expr
);
308 return expr
->id
= id
;
311 /* Return the expression that has expression id ID */
313 static inline pre_expr
314 expression_for_id (unsigned int id
)
316 return VEC_index (pre_expr
, expressions
, id
);
319 /* Free the expression id field in all of our expressions,
320 and then destroy the expressions array. */
323 clear_expression_ids (void)
325 VEC_free (pre_expr
, heap
, expressions
);
328 static alloc_pool pre_expr_pool
;
330 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
333 get_or_alloc_expr_for_name (tree name
)
335 struct pre_expr_d expr
;
337 unsigned int result_id
;
341 PRE_EXPR_NAME (&expr
) = name
;
342 result_id
= lookup_expression_id (&expr
);
344 return expression_for_id (result_id
);
346 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
348 PRE_EXPR_NAME (result
) = name
;
349 alloc_expression_id (result
);
353 static bool in_fre
= false;
355 /* An unordered bitmap set. One bitmap tracks values, the other,
357 typedef struct bitmap_set
359 bitmap_head expressions
;
363 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
364 EXECUTE_IF_SET_IN_BITMAP(&(set)->expressions, 0, (id), (bi))
366 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
367 EXECUTE_IF_SET_IN_BITMAP(&(set)->values, 0, (id), (bi))
369 /* Mapping from value id to expressions with that value_id. */
370 DEF_VEC_P (bitmap_set_t
);
371 DEF_VEC_ALLOC_P (bitmap_set_t
, heap
);
372 static VEC(bitmap_set_t
, heap
) *value_expressions
;
374 /* Sets that we need to keep track of. */
375 typedef struct bb_bitmap_sets
377 /* The EXP_GEN set, which represents expressions/values generated in
379 bitmap_set_t exp_gen
;
381 /* The PHI_GEN set, which represents PHI results generated in a
383 bitmap_set_t phi_gen
;
385 /* The TMP_GEN set, which represents results/temporaries generated
386 in a basic block. IE the LHS of an expression. */
387 bitmap_set_t tmp_gen
;
389 /* The AVAIL_OUT set, which represents which values are available in
390 a given basic block. */
391 bitmap_set_t avail_out
;
393 /* The ANTIC_IN set, which represents which values are anticipatable
394 in a given basic block. */
395 bitmap_set_t antic_in
;
397 /* The PA_IN set, which represents which values are
398 partially anticipatable in a given basic block. */
401 /* The NEW_SETS set, which is used during insertion to augment the
402 AVAIL_OUT set of blocks with the new insertions performed during
403 the current iteration. */
404 bitmap_set_t new_sets
;
406 /* A cache for value_dies_in_block_x. */
409 /* True if we have visited this block during ANTIC calculation. */
410 unsigned int visited
: 1;
412 /* True we have deferred processing this block during ANTIC
413 calculation until its successor is processed. */
414 unsigned int deferred
: 1;
416 /* True when the block contains a call that might not return. */
417 unsigned int contains_may_not_return_call
: 1;
420 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
421 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
422 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
423 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
424 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
425 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
426 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
427 #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies
428 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
429 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
430 #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
433 /* Basic block list in postorder. */
434 static int *postorder
;
436 /* This structure is used to keep track of statistics on what
437 optimization PRE was able to perform. */
440 /* The number of RHS computations eliminated by PRE. */
443 /* The number of new expressions/temporaries generated by PRE. */
446 /* The number of inserts found due to partial anticipation */
449 /* The number of new PHI nodes added by PRE. */
452 /* The number of values found constant. */
457 static bool do_partial_partial
;
458 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int, gimple
);
459 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
460 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
461 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
462 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
463 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
464 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
,
466 static bitmap_set_t
bitmap_set_new (void);
467 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
469 static tree
find_or_generate_expression (basic_block
, pre_expr
, gimple_seq
*,
471 static unsigned int get_expr_value_id (pre_expr
);
473 /* We can add and remove elements and entries to and from sets
474 and hash tables, so we use alloc pools for them. */
476 static alloc_pool bitmap_set_pool
;
477 static bitmap_obstack grand_bitmap_obstack
;
479 /* To avoid adding 300 temporary variables when we only need one, we
480 only create one temporary variable, on demand, and build ssa names
481 off that. We do have to change the variable if the types don't
482 match the current variable's type. */
484 static tree storetemp
;
485 static tree prephitemp
;
487 /* Set of blocks with statements that have had their EH properties changed. */
488 static bitmap need_eh_cleanup
;
490 /* Set of blocks with statements that have had their AB properties changed. */
491 static bitmap need_ab_cleanup
;
493 /* The phi_translate_table caches phi translations for a given
494 expression and predecessor. */
496 static htab_t phi_translate_table
;
498 /* A three tuple {e, pred, v} used to cache phi translations in the
499 phi_translate_table. */
501 typedef struct expr_pred_trans_d
503 /* The expression. */
506 /* The predecessor block along which we translated the expression. */
509 /* The value that resulted from the translation. */
512 /* The hashcode for the expression, pred pair. This is cached for
515 } *expr_pred_trans_t
;
516 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
518 /* Return the hash value for a phi translation table entry. */
521 expr_pred_trans_hash (const void *p
)
523 const_expr_pred_trans_t
const ve
= (const_expr_pred_trans_t
) p
;
527 /* Return true if two phi translation table entries are the same.
528 P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
531 expr_pred_trans_eq (const void *p1
, const void *p2
)
533 const_expr_pred_trans_t
const ve1
= (const_expr_pred_trans_t
) p1
;
534 const_expr_pred_trans_t
const ve2
= (const_expr_pred_trans_t
) p2
;
535 basic_block b1
= ve1
->pred
;
536 basic_block b2
= ve2
->pred
;
538 /* If they are not translations for the same basic block, they can't
542 return pre_expr_eq (ve1
->e
, ve2
->e
);
545 /* Search in the phi translation table for the translation of
546 expression E in basic block PRED.
547 Return the translated value, if found, NULL otherwise. */
549 static inline pre_expr
550 phi_trans_lookup (pre_expr e
, basic_block pred
)
553 struct expr_pred_trans_d ept
;
557 ept
.hashcode
= iterative_hash_hashval_t (pre_expr_hash (e
), pred
->index
);
558 slot
= htab_find_slot_with_hash (phi_translate_table
, &ept
, ept
.hashcode
,
563 return ((expr_pred_trans_t
) *slot
)->v
;
567 /* Add the tuple mapping from {expression E, basic block PRED} to
568 value V, to the phi translation table. */
571 phi_trans_add (pre_expr e
, pre_expr v
, basic_block pred
)
574 expr_pred_trans_t new_pair
= XNEW (struct expr_pred_trans_d
);
576 new_pair
->pred
= pred
;
578 new_pair
->hashcode
= iterative_hash_hashval_t (pre_expr_hash (e
),
581 slot
= htab_find_slot_with_hash (phi_translate_table
, new_pair
,
582 new_pair
->hashcode
, INSERT
);
585 *slot
= (void *) new_pair
;
589 /* Add expression E to the expression set of value id V. */
592 add_to_value (unsigned int v
, pre_expr e
)
596 gcc_assert (get_expr_value_id (e
) == v
);
598 if (v
>= VEC_length (bitmap_set_t
, value_expressions
))
600 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
604 set
= VEC_index (bitmap_set_t
, value_expressions
, v
);
607 set
= bitmap_set_new ();
608 VEC_replace (bitmap_set_t
, value_expressions
, v
, set
);
611 bitmap_insert_into_set_1 (set
, e
, v
, true);
614 /* Create a new bitmap set and return it. */
617 bitmap_set_new (void)
619 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
620 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
621 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
625 /* Return the value id for a PRE expression EXPR. */
628 get_expr_value_id (pre_expr expr
)
635 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
638 id
= get_or_alloc_constant_value_id (PRE_EXPR_CONSTANT (expr
));
639 add_to_value (id
, expr
);
644 return VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
646 return PRE_EXPR_NARY (expr
)->value_id
;
648 return PRE_EXPR_REFERENCE (expr
)->value_id
;
654 /* Remove an expression EXPR from a bitmapped set. */
657 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
659 unsigned int val
= get_expr_value_id (expr
);
660 if (!value_id_constant_p (val
))
662 bitmap_clear_bit (&set
->values
, val
);
663 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
668 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
669 unsigned int val
, bool allow_constants
)
671 if (allow_constants
|| !value_id_constant_p (val
))
673 /* We specifically expect this and only this function to be able to
674 insert constants into a set. */
675 bitmap_set_bit (&set
->values
, val
);
676 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
680 /* Insert an expression EXPR into a bitmapped set. */
683 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
685 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
688 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
691 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
693 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
694 bitmap_copy (&dest
->values
, &orig
->values
);
698 /* Free memory used up by SET. */
700 bitmap_set_free (bitmap_set_t set
)
702 bitmap_clear (&set
->expressions
);
703 bitmap_clear (&set
->values
);
707 /* Generate an topological-ordered array of bitmap set SET. */
709 static VEC(pre_expr
, heap
) *
710 sorted_array_from_bitmap_set (bitmap_set_t set
)
713 bitmap_iterator bi
, bj
;
714 VEC(pre_expr
, heap
) *result
;
716 /* Pre-allocate roughly enough space for the array. */
717 result
= VEC_alloc (pre_expr
, heap
, bitmap_count_bits (&set
->values
));
719 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
721 /* The number of expressions having a given value is usually
722 relatively small. Thus, rather than making a vector of all
723 the expressions and sorting it by value-id, we walk the values
724 and check in the reverse mapping that tells us what expressions
725 have a given value, to filter those in our set. As a result,
726 the expressions are inserted in value-id order, which means
729 If this is somehow a significant lose for some cases, we can
730 choose which set to walk based on the set size. */
731 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, i
);
732 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bj
)
734 if (bitmap_bit_p (&set
->expressions
, j
))
735 VEC_safe_push (pre_expr
, heap
, result
, expression_for_id (j
));
742 /* Perform bitmapped set operation DEST &= ORIG. */
745 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
753 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
755 bitmap_and_into (&dest
->values
, &orig
->values
);
756 bitmap_copy (&temp
, &dest
->expressions
);
757 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
759 pre_expr expr
= expression_for_id (i
);
760 unsigned int value_id
= get_expr_value_id (expr
);
761 if (!bitmap_bit_p (&dest
->values
, value_id
))
762 bitmap_clear_bit (&dest
->expressions
, i
);
764 bitmap_clear (&temp
);
768 /* Subtract all values and expressions contained in ORIG from DEST. */
771 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
773 bitmap_set_t result
= bitmap_set_new ();
777 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
780 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
782 pre_expr expr
= expression_for_id (i
);
783 unsigned int value_id
= get_expr_value_id (expr
);
784 bitmap_set_bit (&result
->values
, value_id
);
790 /* Subtract all the values in bitmap set B from bitmap set A. */
793 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
799 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
801 bitmap_copy (&temp
, &a
->expressions
);
802 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
804 pre_expr expr
= expression_for_id (i
);
805 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
806 bitmap_remove_from_set (a
, expr
);
808 bitmap_clear (&temp
);
812 /* Return true if bitmapped set SET contains the value VALUE_ID. */
815 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
817 if (value_id_constant_p (value_id
))
820 if (!set
|| bitmap_empty_p (&set
->expressions
))
823 return bitmap_bit_p (&set
->values
, value_id
);
827 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
829 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
832 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
835 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
838 bitmap_set_t exprset
;
842 if (value_id_constant_p (lookfor
))
845 if (!bitmap_set_contains_value (set
, lookfor
))
848 /* The number of expressions having a given value is usually
849 significantly less than the total number of expressions in SET.
850 Thus, rather than check, for each expression in SET, whether it
851 has the value LOOKFOR, we walk the reverse mapping that tells us
852 what expressions have a given value, and see if any of those
853 expressions are in our set. For large testcases, this is about
854 5-10x faster than walking the bitmap. If this is somehow a
855 significant lose for some cases, we can choose which set to walk
856 based on the set size. */
857 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
858 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
860 if (bitmap_clear_bit (&set
->expressions
, i
))
862 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
868 /* Return true if two bitmap sets are equal. */
871 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
873 return bitmap_equal_p (&a
->values
, &b
->values
);
876 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
877 and add it otherwise. */
880 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
882 unsigned int val
= get_expr_value_id (expr
);
884 if (bitmap_set_contains_value (set
, val
))
885 bitmap_set_replace_value (set
, val
, expr
);
887 bitmap_insert_into_set (set
, expr
);
890 /* Insert EXPR into SET if EXPR's value is not already present in
894 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
896 unsigned int val
= get_expr_value_id (expr
);
898 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
900 /* Constant values are always considered to be part of the set. */
901 if (value_id_constant_p (val
))
904 /* If the value membership changed, add the expression. */
905 if (bitmap_set_bit (&set
->values
, val
))
906 bitmap_set_bit (&set
->expressions
, expr
->id
);
909 /* Print out EXPR to outfile. */
912 print_pre_expr (FILE *outfile
, const pre_expr expr
)
917 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
920 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
925 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
926 fprintf (outfile
, "{%s,", tree_code_name
[nary
->opcode
]);
927 for (i
= 0; i
< nary
->length
; i
++)
929 print_generic_expr (outfile
, nary
->op
[i
], 0);
930 if (i
!= (unsigned) nary
->length
- 1)
931 fprintf (outfile
, ",");
933 fprintf (outfile
, "}");
939 vn_reference_op_t vro
;
941 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
942 fprintf (outfile
, "{");
944 VEC_iterate (vn_reference_op_s
, ref
->operands
, i
, vro
);
947 bool closebrace
= false;
948 if (vro
->opcode
!= SSA_NAME
949 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
951 fprintf (outfile
, "%s", tree_code_name
[vro
->opcode
]);
954 fprintf (outfile
, "<");
960 print_generic_expr (outfile
, vro
->op0
, 0);
963 fprintf (outfile
, ",");
964 print_generic_expr (outfile
, vro
->op1
, 0);
968 fprintf (outfile
, ",");
969 print_generic_expr (outfile
, vro
->op2
, 0);
973 fprintf (outfile
, ">");
974 if (i
!= VEC_length (vn_reference_op_s
, ref
->operands
) - 1)
975 fprintf (outfile
, ",");
977 fprintf (outfile
, "}");
980 fprintf (outfile
, "@");
981 print_generic_expr (outfile
, ref
->vuse
, 0);
987 void debug_pre_expr (pre_expr
);
989 /* Like print_pre_expr but always prints to stderr. */
991 debug_pre_expr (pre_expr e
)
993 print_pre_expr (stderr
, e
);
994 fprintf (stderr
, "\n");
997 /* Print out SET to OUTFILE. */
1000 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
1001 const char *setname
, int blockindex
)
1003 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1010 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1012 const pre_expr expr
= expression_for_id (i
);
1015 fprintf (outfile
, ", ");
1017 print_pre_expr (outfile
, expr
);
1019 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1022 fprintf (outfile
, " }\n");
1025 void debug_bitmap_set (bitmap_set_t
);
1028 debug_bitmap_set (bitmap_set_t set
)
1030 print_bitmap_set (stderr
, set
, "debug", 0);
1033 /* Print out the expressions that have VAL to OUTFILE. */
1036 print_value_expressions (FILE *outfile
, unsigned int val
)
1038 bitmap_set_t set
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1042 sprintf (s
, "%04d", val
);
1043 print_bitmap_set (outfile
, set
, s
, 0);
1049 debug_value_expressions (unsigned int val
)
1051 print_value_expressions (stderr
, val
);
1054 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1058 get_or_alloc_expr_for_constant (tree constant
)
1060 unsigned int result_id
;
1061 unsigned int value_id
;
1062 struct pre_expr_d expr
;
1065 expr
.kind
= CONSTANT
;
1066 PRE_EXPR_CONSTANT (&expr
) = constant
;
1067 result_id
= lookup_expression_id (&expr
);
1069 return expression_for_id (result_id
);
1071 newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1072 newexpr
->kind
= CONSTANT
;
1073 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1074 alloc_expression_id (newexpr
);
1075 value_id
= get_or_alloc_constant_value_id (constant
);
1076 add_to_value (value_id
, newexpr
);
1080 /* Given a value id V, find the actual tree representing the constant
1081 value if there is one, and return it. Return NULL if we can't find
1085 get_constant_for_value_id (unsigned int v
)
1087 if (value_id_constant_p (v
))
1091 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, v
);
1093 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1095 pre_expr expr
= expression_for_id (i
);
1096 if (expr
->kind
== CONSTANT
)
1097 return PRE_EXPR_CONSTANT (expr
);
1103 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1104 Currently only supports constants and SSA_NAMES. */
1106 get_or_alloc_expr_for (tree t
)
1108 if (TREE_CODE (t
) == SSA_NAME
)
1109 return get_or_alloc_expr_for_name (t
);
1110 else if (is_gimple_min_invariant (t
))
1111 return get_or_alloc_expr_for_constant (t
);
1114 /* More complex expressions can result from SCCVN expression
1115 simplification that inserts values for them. As they all
1116 do not have VOPs the get handled by the nary ops struct. */
1117 vn_nary_op_t result
;
1118 unsigned int result_id
;
1119 vn_nary_op_lookup (t
, &result
);
1122 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1124 PRE_EXPR_NARY (e
) = result
;
1125 result_id
= lookup_expression_id (e
);
1128 pool_free (pre_expr_pool
, e
);
1129 e
= expression_for_id (result_id
);
1132 alloc_expression_id (e
);
1139 /* Return the folded version of T if T, when folded, is a gimple
1140 min_invariant. Otherwise, return T. */
1143 fully_constant_expression (pre_expr e
)
1151 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1152 switch (TREE_CODE_CLASS (nary
->opcode
))
1154 case tcc_expression
:
1155 if (nary
->opcode
== TRUTH_NOT_EXPR
)
1157 if (nary
->opcode
!= TRUTH_AND_EXPR
1158 && nary
->opcode
!= TRUTH_OR_EXPR
1159 && nary
->opcode
!= TRUTH_XOR_EXPR
)
1163 case tcc_comparison
:
1165 /* We have to go from trees to pre exprs to value ids to
1167 tree naryop0
= nary
->op
[0];
1168 tree naryop1
= nary
->op
[1];
1170 if (!is_gimple_min_invariant (naryop0
))
1172 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1173 unsigned int vrep0
= get_expr_value_id (rep0
);
1174 tree const0
= get_constant_for_value_id (vrep0
);
1176 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1178 if (!is_gimple_min_invariant (naryop1
))
1180 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1181 unsigned int vrep1
= get_expr_value_id (rep1
);
1182 tree const1
= get_constant_for_value_id (vrep1
);
1184 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1186 result
= fold_binary (nary
->opcode
, nary
->type
,
1188 if (result
&& is_gimple_min_invariant (result
))
1189 return get_or_alloc_expr_for_constant (result
);
1190 /* We might have simplified the expression to a
1191 SSA_NAME for example from x_1 * 1. But we cannot
1192 insert a PHI for x_1 unconditionally as x_1 might
1193 not be available readily. */
1197 if (nary
->opcode
!= REALPART_EXPR
1198 && nary
->opcode
!= IMAGPART_EXPR
1199 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1205 /* We have to go from trees to pre exprs to value ids to
1207 tree naryop0
= nary
->op
[0];
1208 tree const0
, result
;
1209 if (is_gimple_min_invariant (naryop0
))
1213 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1214 unsigned int vrep0
= get_expr_value_id (rep0
);
1215 const0
= get_constant_for_value_id (vrep0
);
1220 tree type1
= TREE_TYPE (nary
->op
[0]);
1221 const0
= fold_convert (type1
, const0
);
1222 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1224 if (result
&& is_gimple_min_invariant (result
))
1225 return get_or_alloc_expr_for_constant (result
);
1234 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1236 if ((folded
= fully_constant_vn_reference_p (ref
)))
1237 return get_or_alloc_expr_for_constant (folded
);
1246 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1247 it has the value it would have in BLOCK. Set *SAME_VALID to true
1248 in case the new vuse doesn't change the value id of the OPERANDS. */
1251 translate_vuse_through_block (VEC (vn_reference_op_s
, heap
) *operands
,
1252 alias_set_type set
, tree type
, tree vuse
,
1253 basic_block phiblock
,
1254 basic_block block
, bool *same_valid
)
1256 gimple phi
= SSA_NAME_DEF_STMT (vuse
);
1263 if (gimple_bb (phi
) != phiblock
)
1266 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1268 /* Use the alias-oracle to find either the PHI node in this block,
1269 the first VUSE used in this block that is equivalent to vuse or
1270 the first VUSE which definition in this block kills the value. */
1271 if (gimple_code (phi
) == GIMPLE_PHI
)
1272 e
= find_edge (block
, phiblock
);
1273 else if (use_oracle
)
1274 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1276 vuse
= gimple_vuse (phi
);
1277 phi
= SSA_NAME_DEF_STMT (vuse
);
1278 if (gimple_bb (phi
) != phiblock
)
1280 if (gimple_code (phi
) == GIMPLE_PHI
)
1282 e
= find_edge (block
, phiblock
);
1293 bitmap visited
= NULL
;
1294 /* Try to find a vuse that dominates this phi node by skipping
1295 non-clobbering statements. */
1296 vuse
= get_continuation_for_phi (phi
, &ref
, &visited
);
1298 BITMAP_FREE (visited
);
1304 /* If we didn't find any, the value ID can't stay the same,
1305 but return the translated vuse. */
1306 *same_valid
= false;
1307 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1309 /* ??? We would like to return vuse here as this is the canonical
1310 upmost vdef that this reference is associated with. But during
1311 insertion of the references into the hash tables we only ever
1312 directly insert with their direct gimple_vuse, hence returning
1313 something else would make us not find the other expression. */
1314 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1320 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1321 SET2. This is used to avoid making a set consisting of the union
1322 of PA_IN and ANTIC_IN during insert. */
1324 static inline pre_expr
1325 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1329 result
= bitmap_find_leader (set1
, val
, NULL
);
1330 if (!result
&& set2
)
1331 result
= bitmap_find_leader (set2
, val
, NULL
);
1335 /* Get the tree type for our PRE expression e. */
1338 get_expr_type (const pre_expr e
)
1343 return TREE_TYPE (PRE_EXPR_NAME (e
));
1345 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1347 return PRE_EXPR_REFERENCE (e
)->type
;
1349 return PRE_EXPR_NARY (e
)->type
;
1354 /* Get a representative SSA_NAME for a given expression.
1355 Since all of our sub-expressions are treated as values, we require
1356 them to be SSA_NAME's for simplicity.
1357 Prior versions of GVNPRE used to use "value handles" here, so that
1358 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1359 either case, the operands are really values (IE we do not expect
1360 them to be usable without finding leaders). */
1363 get_representative_for (const pre_expr e
)
1367 unsigned int value_id
= get_expr_value_id (e
);
1372 return PRE_EXPR_NAME (e
);
1374 return PRE_EXPR_CONSTANT (e
);
1378 /* Go through all of the expressions representing this value
1379 and pick out an SSA_NAME. */
1382 bitmap_set_t exprs
= VEC_index (bitmap_set_t
, value_expressions
,
1384 FOR_EACH_EXPR_ID_IN_SET (exprs
, i
, bi
)
1386 pre_expr rep
= expression_for_id (i
);
1387 if (rep
->kind
== NAME
)
1388 return PRE_EXPR_NAME (rep
);
1393 /* If we reached here we couldn't find an SSA_NAME. This can
1394 happen when we've discovered a value that has never appeared in
1395 the program as set to an SSA_NAME, most likely as the result of
1400 "Could not find SSA_NAME representative for expression:");
1401 print_pre_expr (dump_file
, e
);
1402 fprintf (dump_file
, "\n");
1405 exprtype
= get_expr_type (e
);
1407 /* Build and insert the assignment of the end result to the temporary
1408 that we will return. */
1409 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
1411 pretemp
= create_tmp_reg (exprtype
, "pretmp");
1412 get_var_ann (pretemp
);
1415 name
= make_ssa_name (pretemp
, gimple_build_nop ());
1416 VN_INFO_GET (name
)->value_id
= value_id
;
1417 if (e
->kind
== CONSTANT
)
1418 VN_INFO (name
)->valnum
= PRE_EXPR_CONSTANT (e
);
1420 VN_INFO (name
)->valnum
= name
;
1422 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1425 fprintf (dump_file
, "Created SSA_NAME representative ");
1426 print_generic_expr (dump_file
, name
, 0);
1427 fprintf (dump_file
, " for expression:");
1428 print_pre_expr (dump_file
, e
);
1429 fprintf (dump_file
, "\n");
1438 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1439 basic_block pred
, basic_block phiblock
);
1441 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1442 the phis in PRED. Return NULL if we can't find a leader for each part
1443 of the translated expression. */
1446 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1447 basic_block pred
, basic_block phiblock
)
1454 bool changed
= false;
1455 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1456 struct vn_nary_op_s newnary
;
1457 /* The NARY structure is only guaranteed to have been
1458 allocated to the nary->length operands. */
1459 memcpy (&newnary
, nary
, (sizeof (struct vn_nary_op_s
)
1460 - sizeof (tree
) * (4 - nary
->length
)));
1462 for (i
= 0; i
< newnary
.length
; i
++)
1464 if (TREE_CODE (newnary
.op
[i
]) != SSA_NAME
)
1468 pre_expr leader
, result
;
1469 unsigned int op_val_id
= VN_INFO (newnary
.op
[i
])->value_id
;
1470 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1471 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1472 if (result
&& result
!= leader
)
1474 tree name
= get_representative_for (result
);
1477 newnary
.op
[i
] = name
;
1482 changed
|= newnary
.op
[i
] != nary
->op
[i
];
1488 unsigned int new_val_id
;
1490 tree result
= vn_nary_op_lookup_pieces (newnary
.length
,
1498 if (result
&& is_gimple_min_invariant (result
))
1499 return get_or_alloc_expr_for_constant (result
);
1501 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1506 PRE_EXPR_NARY (expr
) = nary
;
1507 constant
= fully_constant_expression (expr
);
1508 if (constant
!= expr
)
1511 new_val_id
= nary
->value_id
;
1512 get_or_alloc_expression_id (expr
);
1516 new_val_id
= get_next_value_id ();
1517 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1519 get_max_value_id() + 1);
1520 nary
= vn_nary_op_insert_pieces (newnary
.length
,
1527 result
, new_val_id
);
1528 PRE_EXPR_NARY (expr
) = nary
;
1529 constant
= fully_constant_expression (expr
);
1530 if (constant
!= expr
)
1532 get_or_alloc_expression_id (expr
);
1534 add_to_value (new_val_id
, expr
);
1542 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1543 VEC (vn_reference_op_s
, heap
) *operands
= ref
->operands
;
1544 tree vuse
= ref
->vuse
;
1545 tree newvuse
= vuse
;
1546 VEC (vn_reference_op_s
, heap
) *newoperands
= NULL
;
1547 bool changed
= false, same_valid
= true;
1549 vn_reference_op_t operand
;
1550 vn_reference_t newref
;
1553 VEC_iterate (vn_reference_op_s
, operands
, i
, operand
); i
++, j
++)
1557 tree oldop0
= operand
->op0
;
1558 tree oldop1
= operand
->op1
;
1559 tree oldop2
= operand
->op2
;
1563 tree type
= operand
->type
;
1564 vn_reference_op_s newop
= *operand
;
1566 if (op0
&& TREE_CODE (op0
) == SSA_NAME
)
1568 unsigned int op_val_id
= VN_INFO (op0
)->value_id
;
1569 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1570 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1571 if (opresult
&& opresult
!= leader
)
1573 tree name
= get_representative_for (opresult
);
1581 changed
|= op0
!= oldop0
;
1583 if (op1
&& TREE_CODE (op1
) == SSA_NAME
)
1585 unsigned int op_val_id
= VN_INFO (op1
)->value_id
;
1586 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1587 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1588 if (opresult
&& opresult
!= leader
)
1590 tree name
= get_representative_for (opresult
);
1598 /* We can't possibly insert these. */
1599 else if (op1
&& !is_gimple_min_invariant (op1
))
1601 changed
|= op1
!= oldop1
;
1602 if (op2
&& TREE_CODE (op2
) == SSA_NAME
)
1604 unsigned int op_val_id
= VN_INFO (op2
)->value_id
;
1605 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1606 opresult
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1607 if (opresult
&& opresult
!= leader
)
1609 tree name
= get_representative_for (opresult
);
1617 /* We can't possibly insert these. */
1618 else if (op2
&& !is_gimple_min_invariant (op2
))
1620 changed
|= op2
!= oldop2
;
1623 newoperands
= VEC_copy (vn_reference_op_s
, heap
, operands
);
1624 /* We may have changed from an SSA_NAME to a constant */
1625 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op0
) != SSA_NAME
)
1626 newop
.opcode
= TREE_CODE (op0
);
1631 /* If it transforms a non-constant ARRAY_REF into a constant
1632 one, adjust the constant offset. */
1633 if (newop
.opcode
== ARRAY_REF
1635 && TREE_CODE (op0
) == INTEGER_CST
1636 && TREE_CODE (op1
) == INTEGER_CST
1637 && TREE_CODE (op2
) == INTEGER_CST
)
1639 double_int off
= tree_to_double_int (op0
);
1640 off
= double_int_add (off
,
1642 (tree_to_double_int (op1
)));
1643 off
= double_int_mul (off
, tree_to_double_int (op2
));
1644 if (double_int_fits_in_shwi_p (off
))
1645 newop
.off
= off
.low
;
1647 VEC_replace (vn_reference_op_s
, newoperands
, j
, &newop
);
1648 /* If it transforms from an SSA_NAME to an address, fold with
1649 a preceding indirect reference. */
1650 if (j
> 0 && op0
&& TREE_CODE (op0
) == ADDR_EXPR
1651 && VEC_index (vn_reference_op_s
,
1652 newoperands
, j
- 1)->opcode
== MEM_REF
)
1653 vn_reference_fold_indirect (&newoperands
, &j
);
1655 if (i
!= VEC_length (vn_reference_op_s
, operands
))
1658 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1664 newvuse
= translate_vuse_through_block (newoperands
,
1665 ref
->set
, ref
->type
,
1666 vuse
, phiblock
, pred
,
1668 if (newvuse
== NULL_TREE
)
1670 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1675 if (changed
|| newvuse
!= vuse
)
1677 unsigned int new_val_id
;
1679 bool converted
= false;
1681 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1686 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1689 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1691 result
= fold_build1 (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1694 else if (!result
&& newref
1695 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1697 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1701 if (result
&& is_gimple_min_invariant (result
))
1703 gcc_assert (!newoperands
);
1704 return get_or_alloc_expr_for_constant (result
);
1707 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1708 expr
->kind
= REFERENCE
;
1716 gcc_assert (CONVERT_EXPR_P (result
)
1717 || TREE_CODE (result
) == VIEW_CONVERT_EXPR
);
1719 nresult
= vn_nary_op_lookup_pieces (1, TREE_CODE (result
),
1721 TREE_OPERAND (result
, 0),
1722 NULL_TREE
, NULL_TREE
,
1725 if (nresult
&& is_gimple_min_invariant (nresult
))
1726 return get_or_alloc_expr_for_constant (nresult
);
1731 PRE_EXPR_NARY (expr
) = nary
;
1732 constant
= fully_constant_expression (expr
);
1733 if (constant
!= expr
)
1736 new_val_id
= nary
->value_id
;
1737 get_or_alloc_expression_id (expr
);
1741 new_val_id
= get_next_value_id ();
1742 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1744 get_max_value_id() + 1);
1745 nary
= vn_nary_op_insert_pieces (1, TREE_CODE (result
),
1747 TREE_OPERAND (result
, 0),
1748 NULL_TREE
, NULL_TREE
,
1749 NULL_TREE
, NULL_TREE
,
1751 PRE_EXPR_NARY (expr
) = nary
;
1752 constant
= fully_constant_expression (expr
);
1753 if (constant
!= expr
)
1755 get_or_alloc_expression_id (expr
);
1760 PRE_EXPR_REFERENCE (expr
) = newref
;
1761 constant
= fully_constant_expression (expr
);
1762 if (constant
!= expr
)
1765 new_val_id
= newref
->value_id
;
1766 get_or_alloc_expression_id (expr
);
1770 if (changed
|| !same_valid
)
1772 new_val_id
= get_next_value_id ();
1773 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1775 get_max_value_id() + 1);
1778 new_val_id
= ref
->value_id
;
1779 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1782 result
, new_val_id
);
1784 PRE_EXPR_REFERENCE (expr
) = newref
;
1785 constant
= fully_constant_expression (expr
);
1786 if (constant
!= expr
)
1788 get_or_alloc_expression_id (expr
);
1790 add_to_value (new_val_id
, expr
);
1792 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1802 tree name
= PRE_EXPR_NAME (expr
);
1804 def_stmt
= SSA_NAME_DEF_STMT (name
);
1805 if (gimple_code (def_stmt
) == GIMPLE_PHI
1806 && gimple_bb (def_stmt
) == phiblock
)
1811 e
= find_edge (pred
, gimple_bb (phi
));
1814 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1817 if (TREE_CODE (def
) == SSA_NAME
)
1818 def
= VN_INFO (def
)->valnum
;
1820 /* Handle constant. */
1821 if (is_gimple_min_invariant (def
))
1822 return get_or_alloc_expr_for_constant (def
);
1824 if (TREE_CODE (def
) == SSA_NAME
&& ssa_undefined_value_p (def
))
1827 newexpr
= get_or_alloc_expr_for_name (def
);
1838 /* Wrapper around phi_translate_1 providing caching functionality. */
1841 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1842 basic_block pred
, basic_block phiblock
)
1849 /* Constants contain no values that need translation. */
1850 if (expr
->kind
== CONSTANT
)
1853 if (value_id_constant_p (get_expr_value_id (expr
)))
1856 if (expr
->kind
!= NAME
)
1858 phitrans
= phi_trans_lookup (expr
, pred
);
1864 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1866 /* Don't add empty translations to the cache. Neither add
1867 translations of NAMEs as those are cheap to translate. */
1869 && expr
->kind
!= NAME
)
1870 phi_trans_add (expr
, phitrans
, pred
);
1876 /* For each expression in SET, translate the values through phi nodes
1877 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1878 expressions in DEST. */
1881 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1882 basic_block phiblock
)
1884 VEC (pre_expr
, heap
) *exprs
;
1888 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1890 bitmap_set_copy (dest
, set
);
1894 exprs
= sorted_array_from_bitmap_set (set
);
1895 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
1897 pre_expr translated
;
1898 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1902 /* We might end up with multiple expressions from SET being
1903 translated to the same value. In this case we do not want
1904 to retain the NARY or REFERENCE expression but prefer a NAME
1905 which would be the leader. */
1906 if (translated
->kind
== NAME
)
1907 bitmap_value_replace_in_set (dest
, translated
);
1909 bitmap_value_insert_into_set (dest
, translated
);
1911 VEC_free (pre_expr
, heap
, exprs
);
1914 /* Find the leader for a value (i.e., the name representing that
1915 value) in a given set, and return it. If STMT is non-NULL it
1916 makes sure the defining statement for the leader dominates it.
1917 Return NULL if no leader is found. */
1920 bitmap_find_leader (bitmap_set_t set
, unsigned int val
, gimple stmt
)
1922 if (value_id_constant_p (val
))
1926 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1928 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1930 pre_expr expr
= expression_for_id (i
);
1931 if (expr
->kind
== CONSTANT
)
1935 if (bitmap_set_contains_value (set
, val
))
1937 /* Rather than walk the entire bitmap of expressions, and see
1938 whether any of them has the value we are looking for, we look
1939 at the reverse mapping, which tells us the set of expressions
1940 that have a given value (IE value->expressions with that
1941 value) and see if any of those expressions are in our set.
1942 The number of expressions per value is usually significantly
1943 less than the number of expressions in the set. In fact, for
1944 large testcases, doing it this way is roughly 5-10x faster
1945 than walking the bitmap.
1946 If this is somehow a significant lose for some cases, we can
1947 choose which set to walk based on which set is smaller. */
1950 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1952 EXECUTE_IF_AND_IN_BITMAP (&exprset
->expressions
,
1953 &set
->expressions
, 0, i
, bi
)
1955 pre_expr val
= expression_for_id (i
);
1956 /* At the point where stmt is not null, there should always
1957 be an SSA_NAME first in the list of expressions. */
1960 gimple def_stmt
= SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val
));
1961 if (gimple_code (def_stmt
) != GIMPLE_PHI
1962 && gimple_bb (def_stmt
) == gimple_bb (stmt
)
1963 /* PRE insertions are at the end of the basic-block
1965 && (gimple_uid (def_stmt
) == 0
1966 || gimple_uid (def_stmt
) >= gimple_uid (stmt
)))
1975 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1976 BLOCK by seeing if it is not killed in the block. Note that we are
1977 only determining whether there is a store that kills it. Because
1978 of the order in which clean iterates over values, we are guaranteed
1979 that altered operands will have caused us to be eliminated from the
1980 ANTIC_IN set already. */
1983 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1985 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1986 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1988 gimple_stmt_iterator gsi
;
1989 unsigned id
= get_expression_id (expr
);
1996 /* Lookup a previously calculated result. */
1997 if (EXPR_DIES (block
)
1998 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1999 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
2001 /* A memory expression {e, VUSE} dies in the block if there is a
2002 statement that may clobber e. If, starting statement walk from the
2003 top of the basic block, a statement uses VUSE there can be no kill
2004 inbetween that use and the original statement that loaded {e, VUSE},
2005 so we can stop walking. */
2006 ref
.base
= NULL_TREE
;
2007 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2009 tree def_vuse
, def_vdef
;
2010 def
= gsi_stmt (gsi
);
2011 def_vuse
= gimple_vuse (def
);
2012 def_vdef
= gimple_vdef (def
);
2014 /* Not a memory statement. */
2018 /* Not a may-def. */
2021 /* A load with the same VUSE, we're done. */
2022 if (def_vuse
== vuse
)
2028 /* Init ref only if we really need it. */
2029 if (ref
.base
== NULL_TREE
2030 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
2036 /* If the statement may clobber expr, it dies. */
2037 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
2044 /* Remember the result. */
2045 if (!EXPR_DIES (block
))
2046 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
2047 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
2049 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
2055 #define union_contains_value(SET1, SET2, VAL) \
2056 (bitmap_set_contains_value ((SET1), (VAL)) \
2057 || ((SET2) && bitmap_set_contains_value ((SET2), (VAL))))
2059 /* Determine if vn_reference_op_t VRO is legal in SET1 U SET2.
2062 vro_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
,
2063 vn_reference_op_t vro
)
2065 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
2067 struct pre_expr_d temp
;
2070 PRE_EXPR_NAME (&temp
) = vro
->op0
;
2071 temp
.id
= lookup_expression_id (&temp
);
2074 if (!union_contains_value (set1
, set2
,
2075 get_expr_value_id (&temp
)))
2078 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
2080 struct pre_expr_d temp
;
2083 PRE_EXPR_NAME (&temp
) = vro
->op1
;
2084 temp
.id
= lookup_expression_id (&temp
);
2087 if (!union_contains_value (set1
, set2
,
2088 get_expr_value_id (&temp
)))
2092 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
2094 struct pre_expr_d temp
;
2097 PRE_EXPR_NAME (&temp
) = vro
->op2
;
2098 temp
.id
= lookup_expression_id (&temp
);
2101 if (!union_contains_value (set1
, set2
,
2102 get_expr_value_id (&temp
)))
2109 /* Determine if the expression EXPR is valid in SET1 U SET2.
2110 ONLY SET2 CAN BE NULL.
2111 This means that we have a leader for each part of the expression
2112 (if it consists of values), or the expression is an SSA_NAME.
2113 For loads/calls, we also see if the vuse is killed in this block. */
2116 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
2122 return bitmap_set_contains_expr (AVAIL_OUT (block
), expr
);
2126 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2127 for (i
= 0; i
< nary
->length
; i
++)
2129 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
2131 struct pre_expr_d temp
;
2134 PRE_EXPR_NAME (&temp
) = nary
->op
[i
];
2135 temp
.id
= lookup_expression_id (&temp
);
2138 if (!union_contains_value (set1
, set2
,
2139 get_expr_value_id (&temp
)))
2143 /* If the NARY may trap make sure the block does not contain
2144 a possible exit point.
2145 ??? This is overly conservative if we translate AVAIL_OUT
2146 as the available expression might be after the exit point. */
2147 if (BB_MAY_NOTRETURN (block
)
2148 && vn_nary_may_trap (nary
))
2155 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2156 vn_reference_op_t vro
;
2159 FOR_EACH_VEC_ELT (vn_reference_op_s
, ref
->operands
, i
, vro
)
2161 if (!vro_valid_in_sets (set1
, set2
, vro
))
2166 gimple def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2167 if (!gimple_nop_p (def_stmt
)
2168 && gimple_bb (def_stmt
) != block
2169 && !dominated_by_p (CDI_DOMINATORS
,
2170 block
, gimple_bb (def_stmt
)))
2173 return !value_dies_in_block_x (expr
, block
);
2180 /* Clean the set of expressions that are no longer valid in SET1 or
2181 SET2. This means expressions that are made up of values we have no
2182 leaders for in SET1 or SET2. This version is used for partial
2183 anticipation, which means it is not valid in either ANTIC_IN or
2187 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
2189 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set1
);
2193 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
2195 if (!valid_in_sets (set1
, set2
, expr
, block
))
2196 bitmap_remove_from_set (set1
, expr
);
2198 VEC_free (pre_expr
, heap
, exprs
);
2201 /* Clean the set of expressions that are no longer valid in SET. This
2202 means expressions that are made up of values we have no leaders for
2206 clean (bitmap_set_t set
, basic_block block
)
2208 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set
);
2212 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
2214 if (!valid_in_sets (set
, NULL
, expr
, block
))
2215 bitmap_remove_from_set (set
, expr
);
2217 VEC_free (pre_expr
, heap
, exprs
);
2220 static sbitmap has_abnormal_preds
;
2222 /* List of blocks that may have changed during ANTIC computation and
2223 thus need to be iterated over. */
2225 static sbitmap changed_blocks
;
2227 /* Decide whether to defer a block for a later iteration, or PHI
2228 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2229 should defer the block, and true if we processed it. */
2232 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2233 basic_block block
, basic_block phiblock
)
2235 if (!BB_VISITED (phiblock
))
2237 SET_BIT (changed_blocks
, block
->index
);
2238 BB_VISITED (block
) = 0;
2239 BB_DEFERRED (block
) = 1;
2243 phi_translate_set (dest
, source
, block
, phiblock
);
2247 /* Compute the ANTIC set for BLOCK.
2249 If succs(BLOCK) > 1 then
2250 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2251 else if succs(BLOCK) == 1 then
2252 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2254 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2258 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2260 bool changed
= false;
2261 bitmap_set_t S
, old
, ANTIC_OUT
;
2267 old
= ANTIC_OUT
= S
= NULL
;
2268 BB_VISITED (block
) = 1;
2270 /* If any edges from predecessors are abnormal, antic_in is empty,
2272 if (block_has_abnormal_pred_edge
)
2273 goto maybe_dump_sets
;
2275 old
= ANTIC_IN (block
);
2276 ANTIC_OUT
= bitmap_set_new ();
2278 /* If the block has no successors, ANTIC_OUT is empty. */
2279 if (EDGE_COUNT (block
->succs
) == 0)
2281 /* If we have one successor, we could have some phi nodes to
2282 translate through. */
2283 else if (single_succ_p (block
))
2285 basic_block succ_bb
= single_succ (block
);
2287 /* We trade iterations of the dataflow equations for having to
2288 phi translate the maximal set, which is incredibly slow
2289 (since the maximal set often has 300+ members, even when you
2290 have a small number of blocks).
2291 Basically, we defer the computation of ANTIC for this block
2292 until we have processed it's successor, which will inevitably
2293 have a *much* smaller set of values to phi translate once
2294 clean has been run on it.
2295 The cost of doing this is that we technically perform more
2296 iterations, however, they are lower cost iterations.
2298 Timings for PRE on tramp3d-v4:
2299 without maximal set fix: 11 seconds
2300 with maximal set fix/without deferring: 26 seconds
2301 with maximal set fix/with deferring: 11 seconds
2304 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2308 goto maybe_dump_sets
;
2311 /* If we have multiple successors, we take the intersection of all of
2312 them. Note that in the case of loop exit phi nodes, we may have
2313 phis to translate through. */
2316 VEC(basic_block
, heap
) * worklist
;
2318 basic_block bprime
, first
= NULL
;
2320 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2321 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2324 && BB_VISITED (e
->dest
))
2326 else if (BB_VISITED (e
->dest
))
2327 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2330 /* Of multiple successors we have to have visited one already. */
2333 SET_BIT (changed_blocks
, block
->index
);
2334 BB_VISITED (block
) = 0;
2335 BB_DEFERRED (block
) = 1;
2337 VEC_free (basic_block
, heap
, worklist
);
2338 goto maybe_dump_sets
;
2341 if (!gimple_seq_empty_p (phi_nodes (first
)))
2342 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2344 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2346 FOR_EACH_VEC_ELT (basic_block
, worklist
, i
, bprime
)
2348 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2350 bitmap_set_t tmp
= bitmap_set_new ();
2351 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2352 bitmap_set_and (ANTIC_OUT
, tmp
);
2353 bitmap_set_free (tmp
);
2356 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2358 VEC_free (basic_block
, heap
, worklist
);
2361 /* Generate ANTIC_OUT - TMP_GEN. */
2362 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2364 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2365 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2368 /* Then union in the ANTIC_OUT - TMP_GEN values,
2369 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2370 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2371 bitmap_value_insert_into_set (ANTIC_IN (block
),
2372 expression_for_id (bii
));
2374 clean (ANTIC_IN (block
), block
);
2376 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2379 SET_BIT (changed_blocks
, block
->index
);
2380 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2381 SET_BIT (changed_blocks
, e
->src
->index
);
2384 RESET_BIT (changed_blocks
, block
->index
);
2387 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2389 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2392 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2394 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2398 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2403 "Block %d was deferred for a future iteration.\n",
2408 bitmap_set_free (old
);
2410 bitmap_set_free (S
);
2412 bitmap_set_free (ANTIC_OUT
);
2416 /* Compute PARTIAL_ANTIC for BLOCK.
2418 If succs(BLOCK) > 1 then
2419 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2420 in ANTIC_OUT for all succ(BLOCK)
2421 else if succs(BLOCK) == 1 then
2422 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2424 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2429 compute_partial_antic_aux (basic_block block
,
2430 bool block_has_abnormal_pred_edge
)
2432 bool changed
= false;
2433 bitmap_set_t old_PA_IN
;
2434 bitmap_set_t PA_OUT
;
2437 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2439 old_PA_IN
= PA_OUT
= NULL
;
2441 /* If any edges from predecessors are abnormal, antic_in is empty,
2443 if (block_has_abnormal_pred_edge
)
2444 goto maybe_dump_sets
;
2446 /* If there are too many partially anticipatable values in the
2447 block, phi_translate_set can take an exponential time: stop
2448 before the translation starts. */
2450 && single_succ_p (block
)
2451 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2452 goto maybe_dump_sets
;
2454 old_PA_IN
= PA_IN (block
);
2455 PA_OUT
= bitmap_set_new ();
2457 /* If the block has no successors, ANTIC_OUT is empty. */
2458 if (EDGE_COUNT (block
->succs
) == 0)
2460 /* If we have one successor, we could have some phi nodes to
2461 translate through. Note that we can't phi translate across DFS
2462 back edges in partial antic, because it uses a union operation on
2463 the successors. For recurrences like IV's, we will end up
2464 generating a new value in the set on each go around (i + 3 (VH.1)
2465 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2466 else if (single_succ_p (block
))
2468 basic_block succ
= single_succ (block
);
2469 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2470 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2472 /* If we have multiple successors, we take the union of all of
2476 VEC(basic_block
, heap
) * worklist
;
2480 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2481 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2483 if (e
->flags
& EDGE_DFS_BACK
)
2485 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2487 if (VEC_length (basic_block
, worklist
) > 0)
2489 FOR_EACH_VEC_ELT (basic_block
, worklist
, i
, bprime
)
2494 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2495 bitmap_value_insert_into_set (PA_OUT
,
2496 expression_for_id (i
));
2497 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2499 bitmap_set_t pa_in
= bitmap_set_new ();
2500 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2501 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2502 bitmap_value_insert_into_set (PA_OUT
,
2503 expression_for_id (i
));
2504 bitmap_set_free (pa_in
);
2507 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2508 bitmap_value_insert_into_set (PA_OUT
,
2509 expression_for_id (i
));
2512 VEC_free (basic_block
, heap
, worklist
);
2515 /* PA_IN starts with PA_OUT - TMP_GEN.
2516 Then we subtract things from ANTIC_IN. */
2517 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2519 /* For partial antic, we want to put back in the phi results, since
2520 we will properly avoid making them partially antic over backedges. */
2521 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2522 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2524 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2525 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2527 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2529 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2532 SET_BIT (changed_blocks
, block
->index
);
2533 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2534 SET_BIT (changed_blocks
, e
->src
->index
);
2537 RESET_BIT (changed_blocks
, block
->index
);
2540 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2543 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2545 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2548 bitmap_set_free (old_PA_IN
);
2550 bitmap_set_free (PA_OUT
);
2554 /* Compute ANTIC and partial ANTIC sets. */
2557 compute_antic (void)
2559 bool changed
= true;
2560 int num_iterations
= 0;
2564 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2565 We pre-build the map of blocks with incoming abnormal edges here. */
2566 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2567 sbitmap_zero (has_abnormal_preds
);
2574 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2576 e
->flags
&= ~EDGE_DFS_BACK
;
2577 if (e
->flags
& EDGE_ABNORMAL
)
2579 SET_BIT (has_abnormal_preds
, block
->index
);
2584 BB_VISITED (block
) = 0;
2585 BB_DEFERRED (block
) = 0;
2587 /* While we are here, give empty ANTIC_IN sets to each block. */
2588 ANTIC_IN (block
) = bitmap_set_new ();
2589 PA_IN (block
) = bitmap_set_new ();
2592 /* At the exit block we anticipate nothing. */
2593 ANTIC_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2594 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2595 PA_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2597 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2598 sbitmap_ones (changed_blocks
);
2601 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2602 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2603 /* ??? We need to clear our PHI translation cache here as the
2604 ANTIC sets shrink and we restrict valid translations to
2605 those having operands with leaders in ANTIC. Same below
2606 for PA ANTIC computation. */
2609 for (i
= n_basic_blocks
- NUM_FIXED_BLOCKS
- 1; i
>= 0; i
--)
2611 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2613 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2614 changed
|= compute_antic_aux (block
,
2615 TEST_BIT (has_abnormal_preds
,
2619 /* Theoretically possible, but *highly* unlikely. */
2620 gcc_checking_assert (num_iterations
< 500);
2623 statistics_histogram_event (cfun
, "compute_antic iterations",
2626 if (do_partial_partial
)
2628 sbitmap_ones (changed_blocks
);
2629 mark_dfs_back_edges ();
2634 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2635 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2638 for (i
= n_basic_blocks
- NUM_FIXED_BLOCKS
- 1 ; i
>= 0; i
--)
2640 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2642 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2644 |= compute_partial_antic_aux (block
,
2645 TEST_BIT (has_abnormal_preds
,
2649 /* Theoretically possible, but *highly* unlikely. */
2650 gcc_checking_assert (num_iterations
< 500);
2652 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2655 sbitmap_free (has_abnormal_preds
);
2656 sbitmap_free (changed_blocks
);
2659 /* Return true if we can value number the call in STMT. This is true
2660 if we have a pure or constant call to a real function. */
2663 can_value_number_call (gimple stmt
)
2665 if (gimple_call_internal_p (stmt
))
2667 if (gimple_call_flags (stmt
) & (ECF_PURE
| ECF_CONST
))
2672 /* Return true if OP is a tree which we can perform PRE on.
2673 This may not match the operations we can value number, but in
2674 a perfect world would. */
2677 can_PRE_operation (tree op
)
2679 return UNARY_CLASS_P (op
)
2680 || BINARY_CLASS_P (op
)
2681 || COMPARISON_CLASS_P (op
)
2682 || TREE_CODE (op
) == MEM_REF
2683 || TREE_CODE (op
) == COMPONENT_REF
2684 || TREE_CODE (op
) == VIEW_CONVERT_EXPR
2685 || TREE_CODE (op
) == CALL_EXPR
2686 || TREE_CODE (op
) == ARRAY_REF
;
2690 /* Inserted expressions are placed onto this worklist, which is used
2691 for performing quick dead code elimination of insertions we made
2692 that didn't turn out to be necessary. */
2693 static bitmap inserted_exprs
;
2695 /* Pool allocated fake store expressions are placed onto this
2696 worklist, which, after performing dead code elimination, is walked
2697 to see which expressions need to be put into GC'able memory */
2698 static VEC(gimple
, heap
) *need_creation
;
2700 /* The actual worker for create_component_ref_by_pieces. */
2703 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2704 unsigned int *operand
, gimple_seq
*stmts
,
2707 vn_reference_op_t currop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2711 switch (currop
->opcode
)
2715 tree folded
, sc
= NULL_TREE
;
2716 unsigned int nargs
= 0;
2718 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2722 pre_expr op0
= get_or_alloc_expr_for (currop
->op0
);
2723 fn
= find_or_generate_expression (block
, op0
, stmts
, domstmt
);
2729 pre_expr scexpr
= get_or_alloc_expr_for (currop
->op1
);
2730 sc
= find_or_generate_expression (block
, scexpr
, stmts
, domstmt
);
2734 args
= XNEWVEC (tree
, VEC_length (vn_reference_op_s
,
2735 ref
->operands
) - 1);
2736 while (*operand
< VEC_length (vn_reference_op_s
, ref
->operands
))
2738 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2748 folded
= build_call_array (currop
->type
,
2749 (TREE_CODE (fn
) == FUNCTION_DECL
2750 ? build_fold_addr_expr (fn
) : fn
),
2754 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2760 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2762 tree offset
= currop
->op0
;
2765 if (TREE_CODE (baseop
) == ADDR_EXPR
2766 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2770 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2773 offset
= int_const_binop (PLUS_EXPR
, offset
,
2774 build_int_cst (TREE_TYPE (offset
),
2776 baseop
= build_fold_addr_expr (base
);
2778 return fold_build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2781 case TARGET_MEM_REF
:
2783 pre_expr op0expr
, op1expr
;
2784 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2785 vn_reference_op_t nextop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2787 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2793 op0expr
= get_or_alloc_expr_for (currop
->op0
);
2794 genop0
= find_or_generate_expression (block
, op0expr
,
2801 op1expr
= get_or_alloc_expr_for (nextop
->op0
);
2802 genop1
= find_or_generate_expression (block
, op1expr
,
2807 return build5 (TARGET_MEM_REF
, currop
->type
,
2808 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2814 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2820 case VIEW_CONVERT_EXPR
:
2823 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
,
2828 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2836 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2838 pre_expr op1expr
= get_or_alloc_expr_for (currop
->op0
);
2839 pre_expr op2expr
= get_or_alloc_expr_for (currop
->op1
);
2845 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2848 genop2
= find_or_generate_expression (block
, op2expr
, stmts
, domstmt
);
2851 folded
= fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, genop1
,
2856 /* For array ref vn_reference_op's, operand 1 of the array ref
2857 is op0 of the reference op and operand 3 of the array ref is
2859 case ARRAY_RANGE_REF
:
2863 tree genop1
= currop
->op0
;
2865 tree genop2
= currop
->op1
;
2867 tree genop3
= currop
->op2
;
2869 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2873 op1expr
= get_or_alloc_expr_for (genop1
);
2874 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2879 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2880 /* Drop zero minimum index if redundant. */
2881 if (integer_zerop (genop2
)
2883 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2887 op2expr
= get_or_alloc_expr_for (genop2
);
2888 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2896 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2897 /* We can't always put a size in units of the element alignment
2898 here as the element alignment may be not visible. See
2899 PR43783. Simply drop the element size for constant
2901 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2905 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2906 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2907 op3expr
= get_or_alloc_expr_for (genop3
);
2908 genop3
= find_or_generate_expression (block
, op3expr
, stmts
,
2914 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2921 tree genop2
= currop
->op1
;
2923 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2927 /* op1 should be a FIELD_DECL, which are represented by
2932 op2expr
= get_or_alloc_expr_for (genop2
);
2933 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2939 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
,
2945 pre_expr op0expr
= get_or_alloc_expr_for (currop
->op0
);
2946 genop
= find_or_generate_expression (block
, op0expr
, stmts
, domstmt
);
2967 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2968 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2969 trying to rename aggregates into ssa form directly, which is a no no.
2971 Thus, this routine doesn't create temporaries, it just builds a
2972 single access expression for the array, calling
2973 find_or_generate_expression to build the innermost pieces.
2975 This function is a subroutine of create_expression_by_pieces, and
2976 should not be called on it's own unless you really know what you
2980 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2981 gimple_seq
*stmts
, gimple domstmt
)
2983 unsigned int op
= 0;
2984 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
, domstmt
);
2987 /* Find a leader for an expression, or generate one using
2988 create_expression_by_pieces if it's ANTIC but
2990 BLOCK is the basic_block we are looking for leaders in.
2991 EXPR is the expression to find a leader or generate for.
2992 STMTS is the statement list to put the inserted expressions on.
2993 Returns the SSA_NAME of the LHS of the generated expression or the
2995 DOMSTMT if non-NULL is a statement that should be dominated by
2996 all uses in the generated expression. If DOMSTMT is non-NULL this
2997 routine can fail and return NULL_TREE. Otherwise it will assert
3001 find_or_generate_expression (basic_block block
, pre_expr expr
,
3002 gimple_seq
*stmts
, gimple domstmt
)
3004 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
),
3005 get_expr_value_id (expr
), domstmt
);
3009 if (leader
->kind
== NAME
)
3010 genop
= PRE_EXPR_NAME (leader
);
3011 else if (leader
->kind
== CONSTANT
)
3012 genop
= PRE_EXPR_CONSTANT (leader
);
3015 /* If it's still NULL, it must be a complex expression, so generate
3016 it recursively. Not so if inserting expressions for values generated
3021 bitmap_set_t exprset
;
3022 unsigned int lookfor
= get_expr_value_id (expr
);
3023 bool handled
= false;
3027 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
3028 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
3030 pre_expr temp
= expression_for_id (i
);
3031 if (temp
->kind
!= NAME
)
3034 genop
= create_expression_by_pieces (block
, temp
, stmts
,
3036 get_expr_type (expr
));
3040 if (!handled
&& domstmt
)
3043 gcc_assert (handled
);
3048 #define NECESSARY GF_PLF_1
3050 /* Create an expression in pieces, so that we can handle very complex
3051 expressions that may be ANTIC, but not necessary GIMPLE.
3052 BLOCK is the basic block the expression will be inserted into,
3053 EXPR is the expression to insert (in value form)
3054 STMTS is a statement list to append the necessary insertions into.
3056 This function will die if we hit some value that shouldn't be
3057 ANTIC but is (IE there is no leader for it, or its components).
3058 This function may also generate expressions that are themselves
3059 partially or fully redundant. Those that are will be either made
3060 fully redundant during the next iteration of insert (for partially
3061 redundant ones), or eliminated by eliminate (for fully redundant
3064 If DOMSTMT is non-NULL then we make sure that all uses in the
3065 expressions dominate that statement. In this case the function
3066 can return NULL_TREE to signal failure. */
3069 create_expression_by_pieces (basic_block block
, pre_expr expr
,
3070 gimple_seq
*stmts
, gimple domstmt
, tree type
)
3074 gimple_seq forced_stmts
= NULL
;
3075 unsigned int value_id
;
3076 gimple_stmt_iterator gsi
;
3077 tree exprtype
= type
? type
: get_expr_type (expr
);
3083 /* We may hit the NAME/CONSTANT case if we have to convert types
3084 that value numbering saw through. */
3086 folded
= PRE_EXPR_NAME (expr
);
3089 folded
= PRE_EXPR_CONSTANT (expr
);
3093 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
3094 folded
= create_component_ref_by_pieces (block
, ref
, stmts
, domstmt
);
3099 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
3100 switch (nary
->length
)
3104 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
3105 pre_expr op2
= get_or_alloc_expr_for (nary
->op
[1]);
3106 tree genop1
= find_or_generate_expression (block
, op1
,
3108 tree genop2
= find_or_generate_expression (block
, op2
,
3110 if (!genop1
|| !genop2
)
3112 /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR. It
3113 may be a constant with the wrong type. */
3114 if (nary
->opcode
== POINTER_PLUS_EXPR
)
3116 genop1
= fold_convert (nary
->type
, genop1
);
3117 genop2
= fold_convert (sizetype
, genop2
);
3121 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]), genop1
);
3122 genop2
= fold_convert (TREE_TYPE (nary
->op
[1]), genop2
);
3125 folded
= fold_build2 (nary
->opcode
, nary
->type
,
3131 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
3132 tree genop1
= find_or_generate_expression (block
, op1
,
3136 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]), genop1
);
3138 folded
= fold_build1 (nary
->opcode
, nary
->type
,
3151 if (!useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
3152 folded
= fold_convert (exprtype
, folded
);
3154 /* Force the generated expression to be a sequence of GIMPLE
3156 We have to call unshare_expr because force_gimple_operand may
3157 modify the tree we pass to it. */
3158 folded
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
3161 /* If we have any intermediate expressions to the value sets, add them
3162 to the value sets and chain them in the instruction stream. */
3165 gsi
= gsi_start (forced_stmts
);
3166 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3168 gimple stmt
= gsi_stmt (gsi
);
3169 tree forcedname
= gimple_get_lhs (stmt
);
3172 if (TREE_CODE (forcedname
) == SSA_NAME
)
3174 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
3175 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
3176 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
3177 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
3178 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
3180 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
3181 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
3183 mark_symbols_for_renaming (stmt
);
3185 gimple_seq_add_seq (stmts
, forced_stmts
);
3188 /* Build and insert the assignment of the end result to the temporary
3189 that we will return. */
3190 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
3192 pretemp
= create_tmp_reg (exprtype
, "pretmp");
3193 get_var_ann (pretemp
);
3197 add_referenced_var (temp
);
3199 newstmt
= gimple_build_assign (temp
, folded
);
3200 name
= make_ssa_name (temp
, newstmt
);
3201 gimple_assign_set_lhs (newstmt
, name
);
3202 gimple_set_plf (newstmt
, NECESSARY
, false);
3204 gimple_seq_add_stmt (stmts
, newstmt
);
3205 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (name
));
3207 /* All the symbols in NEWEXPR should be put into SSA form. */
3208 mark_symbols_for_renaming (newstmt
);
3210 /* Add a value number to the temporary.
3211 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
3212 we are creating the expression by pieces, and this particular piece of
3213 the expression may have been represented. There is no harm in replacing
3215 VN_INFO_GET (name
)->valnum
= name
;
3216 value_id
= get_expr_value_id (expr
);
3217 VN_INFO (name
)->value_id
= value_id
;
3218 nameexpr
= get_or_alloc_expr_for_name (name
);
3219 add_to_value (value_id
, nameexpr
);
3220 if (NEW_SETS (block
))
3221 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
3222 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
3224 pre_stats
.insertions
++;
3225 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3227 fprintf (dump_file
, "Inserted ");
3228 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
3229 fprintf (dump_file
, " in predecessor %d\n", block
->index
);
3236 /* Returns true if we want to inhibit the insertions of PHI nodes
3237 for the given EXPR for basic block BB (a member of a loop).
3238 We want to do this, when we fear that the induction variable we
3239 create might inhibit vectorization. */
3242 inhibit_phi_insertion (basic_block bb
, pre_expr expr
)
3244 vn_reference_t vr
= PRE_EXPR_REFERENCE (expr
);
3245 VEC (vn_reference_op_s
, heap
) *ops
= vr
->operands
;
3246 vn_reference_op_t op
;
3249 /* If we aren't going to vectorize we don't inhibit anything. */
3250 if (!flag_tree_vectorize
)
3253 /* Otherwise we inhibit the insertion when the address of the
3254 memory reference is a simple induction variable. In other
3255 cases the vectorizer won't do anything anyway (either it's
3256 loop invariant or a complicated expression). */
3257 FOR_EACH_VEC_ELT (vn_reference_op_s
, ops
, i
, op
)
3262 case ARRAY_RANGE_REF
:
3263 if (TREE_CODE (op
->op0
) != SSA_NAME
)
3268 basic_block defbb
= gimple_bb (SSA_NAME_DEF_STMT (op
->op0
));
3270 /* Default defs are loop invariant. */
3273 /* Defined outside this loop, also loop invariant. */
3274 if (!flow_bb_inside_loop_p (bb
->loop_father
, defbb
))
3276 /* If it's a simple induction variable inhibit insertion,
3277 the vectorizer might be interested in this one. */
3278 if (simple_iv (bb
->loop_father
, bb
->loop_father
,
3279 op
->op0
, &iv
, true))
3281 /* No simple IV, vectorizer can't do anything, hence no
3282 reason to inhibit the transformation for this operand. */
3292 /* Insert the to-be-made-available values of expression EXPRNUM for each
3293 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3294 merge the result with a phi node, given the same value number as
3295 NODE. Return true if we have inserted new stuff. */
3298 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3301 pre_expr expr
= expression_for_id (exprnum
);
3303 unsigned int val
= get_expr_value_id (expr
);
3305 bool insertions
= false;
3310 tree type
= get_expr_type (expr
);
3314 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3316 fprintf (dump_file
, "Found partial redundancy for expression ");
3317 print_pre_expr (dump_file
, expr
);
3318 fprintf (dump_file
, " (%04d)\n", val
);
3321 /* Make sure we aren't creating an induction variable. */
3322 if (block
->loop_depth
> 0 && EDGE_COUNT (block
->preds
) == 2)
3324 bool firstinsideloop
= false;
3325 bool secondinsideloop
= false;
3326 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3327 EDGE_PRED (block
, 0)->src
);
3328 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3329 EDGE_PRED (block
, 1)->src
);
3330 /* Induction variables only have one edge inside the loop. */
3331 if ((firstinsideloop
^ secondinsideloop
)
3332 && (expr
->kind
!= REFERENCE
3333 || inhibit_phi_insertion (block
, expr
)))
3335 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3336 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3341 /* Make the necessary insertions. */
3342 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3344 gimple_seq stmts
= NULL
;
3347 eprime
= avail
[bprime
->index
];
3349 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3351 builtexpr
= create_expression_by_pieces (bprime
,
3355 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3356 gsi_insert_seq_on_edge (pred
, stmts
);
3357 avail
[bprime
->index
] = get_or_alloc_expr_for_name (builtexpr
);
3360 else if (eprime
->kind
== CONSTANT
)
3362 /* Constants may not have the right type, fold_convert
3363 should give us back a constant with the right type.
3365 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3366 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3368 tree builtexpr
= fold_convert (type
, constant
);
3369 if (!is_gimple_min_invariant (builtexpr
))
3371 tree forcedexpr
= force_gimple_operand (builtexpr
,
3374 if (!is_gimple_min_invariant (forcedexpr
))
3376 if (forcedexpr
!= builtexpr
)
3378 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3379 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3383 gimple_stmt_iterator gsi
;
3384 gsi
= gsi_start (stmts
);
3385 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3387 gimple stmt
= gsi_stmt (gsi
);
3388 tree lhs
= gimple_get_lhs (stmt
);
3389 if (TREE_CODE (lhs
) == SSA_NAME
)
3390 bitmap_set_bit (inserted_exprs
,
3391 SSA_NAME_VERSION (lhs
));
3392 gimple_set_plf (stmt
, NECESSARY
, false);
3394 gsi_insert_seq_on_edge (pred
, stmts
);
3396 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3400 avail
[bprime
->index
] = get_or_alloc_expr_for_constant (builtexpr
);
3403 else if (eprime
->kind
== NAME
)
3405 /* We may have to do a conversion because our value
3406 numbering can look through types in certain cases, but
3407 our IL requires all operands of a phi node have the same
3409 tree name
= PRE_EXPR_NAME (eprime
);
3410 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3414 builtexpr
= fold_convert (type
, name
);
3415 forcedexpr
= force_gimple_operand (builtexpr
,
3419 if (forcedexpr
!= name
)
3421 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3422 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3427 gimple_stmt_iterator gsi
;
3428 gsi
= gsi_start (stmts
);
3429 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3431 gimple stmt
= gsi_stmt (gsi
);
3432 tree lhs
= gimple_get_lhs (stmt
);
3433 if (TREE_CODE (lhs
) == SSA_NAME
)
3434 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
3435 gimple_set_plf (stmt
, NECESSARY
, false);
3437 gsi_insert_seq_on_edge (pred
, stmts
);
3439 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3443 /* If we didn't want a phi node, and we made insertions, we still have
3444 inserted new stuff, and thus return true. If we didn't want a phi node,
3445 and didn't make insertions, we haven't added anything new, so return
3447 if (nophi
&& insertions
)
3449 else if (nophi
&& !insertions
)
3452 /* Now build a phi for the new variable. */
3453 if (!prephitemp
|| TREE_TYPE (prephitemp
) != type
)
3455 prephitemp
= create_tmp_var (type
, "prephitmp");
3456 get_var_ann (prephitemp
);
3460 add_referenced_var (temp
);
3462 if (TREE_CODE (type
) == COMPLEX_TYPE
3463 || TREE_CODE (type
) == VECTOR_TYPE
)
3464 DECL_GIMPLE_REG_P (temp
) = 1;
3465 phi
= create_phi_node (temp
, block
);
3467 gimple_set_plf (phi
, NECESSARY
, false);
3468 VN_INFO_GET (gimple_phi_result (phi
))->valnum
= gimple_phi_result (phi
);
3469 VN_INFO (gimple_phi_result (phi
))->value_id
= val
;
3470 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (gimple_phi_result (phi
)));
3471 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3473 pre_expr ae
= avail
[pred
->src
->index
];
3474 gcc_assert (get_expr_type (ae
) == type
3475 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3476 if (ae
->kind
== CONSTANT
)
3477 add_phi_arg (phi
, PRE_EXPR_CONSTANT (ae
), pred
, UNKNOWN_LOCATION
);
3479 add_phi_arg (phi
, PRE_EXPR_NAME (avail
[pred
->src
->index
]), pred
,
3483 newphi
= get_or_alloc_expr_for_name (gimple_phi_result (phi
));
3484 add_to_value (val
, newphi
);
3486 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3487 this insertion, since we test for the existence of this value in PHI_GEN
3488 before proceeding with the partial redundancy checks in insert_aux.
3490 The value may exist in AVAIL_OUT, in particular, it could be represented
3491 by the expression we are trying to eliminate, in which case we want the
3492 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3495 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3496 this block, because if it did, it would have existed in our dominator's
3497 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3500 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3501 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3503 bitmap_insert_into_set (NEW_SETS (block
),
3506 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3508 fprintf (dump_file
, "Created phi ");
3509 print_gimple_stmt (dump_file
, phi
, 0, 0);
3510 fprintf (dump_file
, " in block %d\n", block
->index
);
3518 /* Perform insertion of partially redundant values.
3519 For BLOCK, do the following:
3520 1. Propagate the NEW_SETS of the dominator into the current block.
3521 If the block has multiple predecessors,
3522 2a. Iterate over the ANTIC expressions for the block to see if
3523 any of them are partially redundant.
3524 2b. If so, insert them into the necessary predecessors to make
3525 the expression fully redundant.
3526 2c. Insert a new PHI merging the values of the predecessors.
3527 2d. Insert the new PHI, and the new expressions, into the
3529 3. Recursively call ourselves on the dominator children of BLOCK.
3531 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3532 do_regular_insertion and do_partial_insertion.
3537 do_regular_insertion (basic_block block
, basic_block dom
)
3539 bool new_stuff
= false;
3540 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3544 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
3546 if (expr
->kind
!= NAME
)
3550 bool by_some
= false;
3551 bool cant_insert
= false;
3552 bool all_same
= true;
3553 pre_expr first_s
= NULL
;
3556 pre_expr eprime
= NULL
;
3558 pre_expr edoubleprime
= NULL
;
3559 bool do_insertion
= false;
3561 val
= get_expr_value_id (expr
);
3562 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3564 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3566 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3567 fprintf (dump_file
, "Found fully redundant value\n");
3571 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3572 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3574 unsigned int vprime
;
3576 /* We should never run insertion for the exit block
3577 and so not come across fake pred edges. */
3578 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3580 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3583 /* eprime will generally only be NULL if the
3584 value of the expression, translated
3585 through the PHI for this predecessor, is
3586 undefined. If that is the case, we can't
3587 make the expression fully redundant,
3588 because its value is undefined along a
3589 predecessor path. We can thus break out
3590 early because it doesn't matter what the
3591 rest of the results are. */
3598 eprime
= fully_constant_expression (eprime
);
3599 vprime
= get_expr_value_id (eprime
);
3600 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3602 if (edoubleprime
== NULL
)
3604 avail
[bprime
->index
] = eprime
;
3609 avail
[bprime
->index
] = edoubleprime
;
3611 /* We want to perform insertions to remove a redundancy on
3612 a path in the CFG we want to optimize for speed. */
3613 if (optimize_edge_for_speed_p (pred
))
3614 do_insertion
= true;
3615 if (first_s
== NULL
)
3616 first_s
= edoubleprime
;
3617 else if (!pre_expr_eq (first_s
, edoubleprime
))
3621 /* If we can insert it, it's not the same value
3622 already existing along every predecessor, and
3623 it's defined by some predecessor, it is
3624 partially redundant. */
3625 if (!cant_insert
&& !all_same
&& by_some
)
3629 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3631 fprintf (dump_file
, "Skipping partial redundancy for "
3633 print_pre_expr (dump_file
, expr
);
3634 fprintf (dump_file
, " (%04d), no redundancy on to be "
3635 "optimized for speed edge\n", val
);
3638 else if (dbg_cnt (treepre_insert
)
3639 && insert_into_preds_of_block (block
,
3640 get_expression_id (expr
),
3644 /* If all edges produce the same value and that value is
3645 an invariant, then the PHI has the same value on all
3646 edges. Note this. */
3647 else if (!cant_insert
&& all_same
&& eprime
3648 && (edoubleprime
->kind
== CONSTANT
3649 || edoubleprime
->kind
== NAME
)
3650 && !value_id_constant_p (val
))
3654 bitmap_set_t exprset
= VEC_index (bitmap_set_t
,
3655 value_expressions
, val
);
3657 unsigned int new_val
= get_expr_value_id (edoubleprime
);
3658 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bi
)
3660 pre_expr expr
= expression_for_id (j
);
3662 if (expr
->kind
== NAME
)
3664 vn_ssa_aux_t info
= VN_INFO (PRE_EXPR_NAME (expr
));
3665 /* Just reset the value id and valnum so it is
3666 the same as the constant we have discovered. */
3667 if (edoubleprime
->kind
== CONSTANT
)
3669 info
->valnum
= PRE_EXPR_CONSTANT (edoubleprime
);
3670 pre_stats
.constified
++;
3673 info
->valnum
= VN_INFO (PRE_EXPR_NAME (edoubleprime
))->valnum
;
3674 info
->value_id
= new_val
;
3682 VEC_free (pre_expr
, heap
, exprs
);
3687 /* Perform insertion for partially anticipatable expressions. There
3688 is only one case we will perform insertion for these. This case is
3689 if the expression is partially anticipatable, and fully available.
3690 In this case, we know that putting it earlier will enable us to
3691 remove the later computation. */
3695 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3697 bool new_stuff
= false;
3698 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3702 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
3704 if (expr
->kind
!= NAME
)
3709 bool cant_insert
= false;
3712 pre_expr eprime
= NULL
;
3715 val
= get_expr_value_id (expr
);
3716 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3718 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3721 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3722 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3724 unsigned int vprime
;
3725 pre_expr edoubleprime
;
3727 /* We should never run insertion for the exit block
3728 and so not come across fake pred edges. */
3729 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3731 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3735 /* eprime will generally only be NULL if the
3736 value of the expression, translated
3737 through the PHI for this predecessor, is
3738 undefined. If that is the case, we can't
3739 make the expression fully redundant,
3740 because its value is undefined along a
3741 predecessor path. We can thus break out
3742 early because it doesn't matter what the
3743 rest of the results are. */
3750 eprime
= fully_constant_expression (eprime
);
3751 vprime
= get_expr_value_id (eprime
);
3752 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3754 if (edoubleprime
== NULL
)
3760 avail
[bprime
->index
] = edoubleprime
;
3764 /* If we can insert it, it's not the same value
3765 already existing along every predecessor, and
3766 it's defined by some predecessor, it is
3767 partially redundant. */
3768 if (!cant_insert
&& by_all
&& dbg_cnt (treepre_insert
))
3770 pre_stats
.pa_insert
++;
3771 if (insert_into_preds_of_block (block
, get_expression_id (expr
),
3779 VEC_free (pre_expr
, heap
, exprs
);
3784 insert_aux (basic_block block
)
3787 bool new_stuff
= false;
3792 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3797 bitmap_set_t newset
= NEW_SETS (dom
);
3800 /* Note that we need to value_replace both NEW_SETS, and
3801 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3802 represented by some non-simple expression here that we want
3803 to replace it with. */
3804 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3806 pre_expr expr
= expression_for_id (i
);
3807 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3808 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3811 if (!single_pred_p (block
))
3813 new_stuff
|= do_regular_insertion (block
, dom
);
3814 if (do_partial_partial
)
3815 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3819 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3821 son
= next_dom_son (CDI_DOMINATORS
, son
))
3823 new_stuff
|= insert_aux (son
);
3829 /* Perform insertion of partially redundant values. */
3834 bool new_stuff
= true;
3836 int num_iterations
= 0;
3839 NEW_SETS (bb
) = bitmap_set_new ();
3844 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3846 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3850 /* Add OP to EXP_GEN (block), and possibly to the maximal set. */
3853 add_to_exp_gen (basic_block block
, tree op
)
3858 if (TREE_CODE (op
) == SSA_NAME
&& ssa_undefined_value_p (op
))
3860 result
= get_or_alloc_expr_for_name (op
);
3861 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3865 /* Create value ids for PHI in BLOCK. */
3868 make_values_for_phi (gimple phi
, basic_block block
)
3870 tree result
= gimple_phi_result (phi
);
3872 /* We have no need for virtual phis, as they don't represent
3873 actual computations. */
3874 if (is_gimple_reg (result
))
3876 pre_expr e
= get_or_alloc_expr_for_name (result
);
3877 add_to_value (get_expr_value_id (e
), e
);
3878 bitmap_insert_into_set (PHI_GEN (block
), e
);
3879 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3883 for (i
= 0; i
< gimple_phi_num_args (phi
); ++i
)
3885 tree arg
= gimple_phi_arg_def (phi
, i
);
3886 if (TREE_CODE (arg
) == SSA_NAME
)
3888 e
= get_or_alloc_expr_for_name (arg
);
3889 add_to_value (get_expr_value_id (e
), e
);
3896 /* Compute the AVAIL set for all basic blocks.
3898 This function performs value numbering of the statements in each basic
3899 block. The AVAIL sets are built from information we glean while doing
3900 this value numbering, since the AVAIL sets contain only one entry per
3903 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3904 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3907 compute_avail (void)
3910 basic_block block
, son
;
3911 basic_block
*worklist
;
3915 /* We pretend that default definitions are defined in the entry block.
3916 This includes function arguments and the static chain decl. */
3917 for (i
= 1; i
< num_ssa_names
; ++i
)
3919 tree name
= ssa_name (i
);
3922 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3923 || has_zero_uses (name
)
3924 || !is_gimple_reg (name
))
3927 e
= get_or_alloc_expr_for_name (name
);
3928 add_to_value (get_expr_value_id (e
), e
);
3930 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3931 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3934 /* Allocate the worklist. */
3935 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3937 /* Seed the algorithm by putting the dominator children of the entry
3938 block on the worklist. */
3939 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3941 son
= next_dom_son (CDI_DOMINATORS
, son
))
3942 worklist
[sp
++] = son
;
3944 /* Loop until the worklist is empty. */
3947 gimple_stmt_iterator gsi
;
3950 unsigned int stmt_uid
= 1;
3952 /* Pick a block from the worklist. */
3953 block
= worklist
[--sp
];
3955 /* Initially, the set of available values in BLOCK is that of
3956 its immediate dominator. */
3957 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3959 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3961 /* Generate values for PHI nodes. */
3962 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3963 make_values_for_phi (gsi_stmt (gsi
), block
);
3965 BB_MAY_NOTRETURN (block
) = 0;
3967 /* Now compute value numbers and populate value sets with all
3968 the expressions computed in BLOCK. */
3969 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3974 stmt
= gsi_stmt (gsi
);
3975 gimple_set_uid (stmt
, stmt_uid
++);
3977 /* Cache whether the basic-block has any non-visible side-effect
3979 If this isn't a call or it is the last stmt in the
3980 basic-block then the CFG represents things correctly. */
3981 if (is_gimple_call (stmt
)
3982 && !stmt_ends_bb_p (stmt
))
3984 /* Non-looping const functions always return normally.
3985 Otherwise the call might not return or have side-effects
3986 that forbids hoisting possibly trapping expressions
3988 int flags
= gimple_call_flags (stmt
);
3989 if (!(flags
& ECF_CONST
)
3990 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
3991 BB_MAY_NOTRETURN (block
) = 1;
3994 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3996 pre_expr e
= get_or_alloc_expr_for_name (op
);
3998 add_to_value (get_expr_value_id (e
), e
);
4000 bitmap_insert_into_set (TMP_GEN (block
), e
);
4001 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
4004 if (gimple_has_volatile_ops (stmt
)
4005 || stmt_could_throw_p (stmt
))
4008 switch (gimple_code (stmt
))
4011 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4012 add_to_exp_gen (block
, op
);
4019 vn_reference_op_t vro
;
4020 pre_expr result
= NULL
;
4021 VEC(vn_reference_op_s
, heap
) *ops
= NULL
;
4023 if (!can_value_number_call (stmt
))
4026 copy_reference_ops_from_call (stmt
, &ops
);
4027 vn_reference_lookup_pieces (gimple_vuse (stmt
), 0,
4028 gimple_expr_type (stmt
),
4029 ops
, &ref
, VN_NOWALK
);
4030 VEC_free (vn_reference_op_s
, heap
, ops
);
4034 for (i
= 0; VEC_iterate (vn_reference_op_s
,
4038 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
4039 add_to_exp_gen (block
, vro
->op0
);
4040 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
4041 add_to_exp_gen (block
, vro
->op1
);
4042 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
4043 add_to_exp_gen (block
, vro
->op2
);
4045 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4046 result
->kind
= REFERENCE
;
4048 PRE_EXPR_REFERENCE (result
) = ref
;
4050 get_or_alloc_expression_id (result
);
4051 add_to_value (get_expr_value_id (result
), result
);
4053 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4059 pre_expr result
= NULL
;
4060 switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)))
4064 case tcc_comparison
:
4069 vn_nary_op_lookup_pieces (gimple_num_ops (stmt
) - 1,
4070 gimple_assign_rhs_code (stmt
),
4071 gimple_expr_type (stmt
),
4072 gimple_assign_rhs1 (stmt
),
4073 gimple_assign_rhs2 (stmt
),
4074 NULL_TREE
, NULL_TREE
, &nary
);
4079 for (i
= 0; i
< nary
->length
; i
++)
4080 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
4081 add_to_exp_gen (block
, nary
->op
[i
]);
4083 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4084 result
->kind
= NARY
;
4086 PRE_EXPR_NARY (result
) = nary
;
4090 case tcc_declaration
:
4095 vn_reference_op_t vro
;
4097 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
4103 for (i
= 0; VEC_iterate (vn_reference_op_s
,
4107 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
4108 add_to_exp_gen (block
, vro
->op0
);
4109 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
4110 add_to_exp_gen (block
, vro
->op1
);
4111 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
4112 add_to_exp_gen (block
, vro
->op2
);
4114 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4115 result
->kind
= REFERENCE
;
4117 PRE_EXPR_REFERENCE (result
) = ref
;
4122 /* For any other statement that we don't
4123 recognize, simply add all referenced
4124 SSA_NAMEs to EXP_GEN. */
4125 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4126 add_to_exp_gen (block
, op
);
4130 get_or_alloc_expression_id (result
);
4131 add_to_value (get_expr_value_id (result
), result
);
4133 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4142 /* Put the dominator children of BLOCK on the worklist of blocks
4143 to compute available sets for. */
4144 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4146 son
= next_dom_son (CDI_DOMINATORS
, son
))
4147 worklist
[sp
++] = son
;
4153 /* Insert the expression for SSA_VN that SCCVN thought would be simpler
4154 than the available expressions for it. The insertion point is
4155 right before the first use in STMT. Returns the SSA_NAME that should
4156 be used for replacement. */
4159 do_SCCVN_insertion (gimple stmt
, tree ssa_vn
)
4161 basic_block bb
= gimple_bb (stmt
);
4162 gimple_stmt_iterator gsi
;
4163 gimple_seq stmts
= NULL
;
4167 /* First create a value expression from the expression we want
4168 to insert and associate it with the value handle for SSA_VN. */
4169 e
= get_or_alloc_expr_for (vn_get_expr_for (ssa_vn
));
4173 /* Then use create_expression_by_pieces to generate a valid
4174 expression to insert at this point of the IL stream. */
4175 expr
= create_expression_by_pieces (bb
, e
, &stmts
, stmt
, NULL
);
4176 if (expr
== NULL_TREE
)
4178 gsi
= gsi_for_stmt (stmt
);
4179 gsi_insert_seq_before (&gsi
, stmts
, GSI_SAME_STMT
);
4184 /* Eliminate fully redundant computations. */
4189 VEC (gimple
, heap
) *to_remove
= NULL
;
4191 unsigned int todo
= 0;
4192 gimple_stmt_iterator gsi
;
4198 for (gsi
= gsi_start_bb (b
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4200 stmt
= gsi_stmt (gsi
);
4202 /* Lookup the RHS of the expression, see if we have an
4203 available computation for it. If so, replace the RHS with
4204 the available computation. */
4205 if (gimple_has_lhs (stmt
)
4206 && TREE_CODE (gimple_get_lhs (stmt
)) == SSA_NAME
4207 && !gimple_assign_ssa_name_copy_p (stmt
)
4208 && (!gimple_assign_single_p (stmt
)
4209 || !is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
4210 && !gimple_has_volatile_ops (stmt
)
4211 && !has_zero_uses (gimple_get_lhs (stmt
)))
4213 tree lhs
= gimple_get_lhs (stmt
);
4214 tree rhs
= NULL_TREE
;
4216 pre_expr lhsexpr
= get_or_alloc_expr_for_name (lhs
);
4217 pre_expr sprimeexpr
;
4219 if (gimple_assign_single_p (stmt
))
4220 rhs
= gimple_assign_rhs1 (stmt
);
4222 sprimeexpr
= bitmap_find_leader (AVAIL_OUT (b
),
4223 get_expr_value_id (lhsexpr
),
4228 if (sprimeexpr
->kind
== CONSTANT
)
4229 sprime
= PRE_EXPR_CONSTANT (sprimeexpr
);
4230 else if (sprimeexpr
->kind
== NAME
)
4231 sprime
= PRE_EXPR_NAME (sprimeexpr
);
4236 /* If there is no existing leader but SCCVN knows this
4237 value is constant, use that constant. */
4238 if (!sprime
&& is_gimple_min_invariant (VN_INFO (lhs
)->valnum
))
4240 sprime
= VN_INFO (lhs
)->valnum
;
4241 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4242 TREE_TYPE (sprime
)))
4243 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4245 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4247 fprintf (dump_file
, "Replaced ");
4248 print_gimple_expr (dump_file
, stmt
, 0, 0);
4249 fprintf (dump_file
, " with ");
4250 print_generic_expr (dump_file
, sprime
, 0);
4251 fprintf (dump_file
, " in ");
4252 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4254 pre_stats
.eliminations
++;
4255 propagate_tree_value_into_stmt (&gsi
, sprime
);
4256 stmt
= gsi_stmt (gsi
);
4261 /* If there is no existing usable leader but SCCVN thinks
4262 it has an expression it wants to use as replacement,
4264 if (!sprime
|| sprime
== lhs
)
4266 tree val
= VN_INFO (lhs
)->valnum
;
4268 && TREE_CODE (val
) == SSA_NAME
4269 && VN_INFO (val
)->needs_insertion
4270 && can_PRE_operation (vn_get_expr_for (val
)))
4271 sprime
= do_SCCVN_insertion (stmt
, val
);
4275 && (rhs
== NULL_TREE
4276 || TREE_CODE (rhs
) != SSA_NAME
4277 || may_propagate_copy (rhs
, sprime
)))
4279 bool can_make_abnormal_goto
4280 = is_gimple_call (stmt
)
4281 && stmt_can_make_abnormal_goto (stmt
);
4283 gcc_assert (sprime
!= rhs
);
4285 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4287 fprintf (dump_file
, "Replaced ");
4288 print_gimple_expr (dump_file
, stmt
, 0, 0);
4289 fprintf (dump_file
, " with ");
4290 print_generic_expr (dump_file
, sprime
, 0);
4291 fprintf (dump_file
, " in ");
4292 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4295 if (TREE_CODE (sprime
) == SSA_NAME
)
4296 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4298 /* We need to make sure the new and old types actually match,
4299 which may require adding a simple cast, which fold_convert
4301 if ((!rhs
|| TREE_CODE (rhs
) != SSA_NAME
)
4302 && !useless_type_conversion_p (gimple_expr_type (stmt
),
4303 TREE_TYPE (sprime
)))
4304 sprime
= fold_convert (gimple_expr_type (stmt
), sprime
);
4306 pre_stats
.eliminations
++;
4307 propagate_tree_value_into_stmt (&gsi
, sprime
);
4308 stmt
= gsi_stmt (gsi
);
4311 /* If we removed EH side-effects from the statement, clean
4312 its EH information. */
4313 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
4315 bitmap_set_bit (need_eh_cleanup
,
4316 gimple_bb (stmt
)->index
);
4317 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4318 fprintf (dump_file
, " Removed EH side-effects.\n");
4321 /* Likewise for AB side-effects. */
4322 if (can_make_abnormal_goto
4323 && !stmt_can_make_abnormal_goto (stmt
))
4325 bitmap_set_bit (need_ab_cleanup
,
4326 gimple_bb (stmt
)->index
);
4327 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4328 fprintf (dump_file
, " Removed AB side-effects.\n");
4332 /* If the statement is a scalar store, see if the expression
4333 has the same value number as its rhs. If so, the store is
4335 else if (gimple_assign_single_p (stmt
)
4336 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4337 && (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
4338 || is_gimple_min_invariant (gimple_assign_rhs1 (stmt
))))
4340 tree rhs
= gimple_assign_rhs1 (stmt
);
4342 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4343 gimple_vuse (stmt
), VN_WALK
, NULL
);
4344 if (TREE_CODE (rhs
) == SSA_NAME
)
4345 rhs
= VN_INFO (rhs
)->valnum
;
4347 && operand_equal_p (val
, rhs
, 0))
4349 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4351 fprintf (dump_file
, "Deleted redundant store ");
4352 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4355 /* Queue stmt for removal. */
4356 VEC_safe_push (gimple
, heap
, to_remove
, stmt
);
4359 /* Visit COND_EXPRs and fold the comparison with the
4360 available value-numbers. */
4361 else if (gimple_code (stmt
) == GIMPLE_COND
)
4363 tree op0
= gimple_cond_lhs (stmt
);
4364 tree op1
= gimple_cond_rhs (stmt
);
4367 if (TREE_CODE (op0
) == SSA_NAME
)
4368 op0
= VN_INFO (op0
)->valnum
;
4369 if (TREE_CODE (op1
) == SSA_NAME
)
4370 op1
= VN_INFO (op1
)->valnum
;
4371 result
= fold_binary (gimple_cond_code (stmt
), boolean_type_node
,
4373 if (result
&& TREE_CODE (result
) == INTEGER_CST
)
4375 if (integer_zerop (result
))
4376 gimple_cond_make_false (stmt
);
4378 gimple_cond_make_true (stmt
);
4380 todo
= TODO_cleanup_cfg
;
4383 /* Visit indirect calls and turn them into direct calls if
4385 if (is_gimple_call (stmt
))
4387 tree orig_fn
= gimple_call_fn (stmt
);
4391 if (TREE_CODE (orig_fn
) == SSA_NAME
)
4392 fn
= VN_INFO (orig_fn
)->valnum
;
4393 else if (TREE_CODE (orig_fn
) == OBJ_TYPE_REF
4394 && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn
)) == SSA_NAME
)
4395 fn
= VN_INFO (OBJ_TYPE_REF_EXPR (orig_fn
))->valnum
;
4398 if (gimple_call_addr_fndecl (fn
) != NULL_TREE
4399 && useless_type_conversion_p (TREE_TYPE (orig_fn
),
4402 bool can_make_abnormal_goto
4403 = stmt_can_make_abnormal_goto (stmt
);
4404 bool was_noreturn
= gimple_call_noreturn_p (stmt
);
4406 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4408 fprintf (dump_file
, "Replacing call target with ");
4409 print_generic_expr (dump_file
, fn
, 0);
4410 fprintf (dump_file
, " in ");
4411 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4414 gimple_call_set_fn (stmt
, fn
);
4417 /* When changing a call into a noreturn call, cfg cleanup
4418 is needed to fix up the noreturn call. */
4419 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4420 todo
|= TODO_cleanup_cfg
;
4422 /* If we removed EH side-effects from the statement, clean
4423 its EH information. */
4424 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
4426 bitmap_set_bit (need_eh_cleanup
,
4427 gimple_bb (stmt
)->index
);
4428 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4429 fprintf (dump_file
, " Removed EH side-effects.\n");
4432 /* Likewise for AB side-effects. */
4433 if (can_make_abnormal_goto
4434 && !stmt_can_make_abnormal_goto (stmt
))
4436 bitmap_set_bit (need_ab_cleanup
,
4437 gimple_bb (stmt
)->index
);
4438 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4439 fprintf (dump_file
, " Removed AB side-effects.\n");
4442 /* Changing an indirect call to a direct call may
4443 have exposed different semantics. This may
4444 require an SSA update. */
4445 todo
|= TODO_update_ssa_only_virtuals
;
4450 for (gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4452 gimple stmt
, phi
= gsi_stmt (gsi
);
4453 tree sprime
= NULL_TREE
, res
= PHI_RESULT (phi
);
4454 pre_expr sprimeexpr
, resexpr
;
4455 gimple_stmt_iterator gsi2
;
4457 /* We want to perform redundant PHI elimination. Do so by
4458 replacing the PHI with a single copy if possible.
4459 Do not touch inserted, single-argument or virtual PHIs. */
4460 if (gimple_phi_num_args (phi
) == 1
4461 || !is_gimple_reg (res
))
4467 resexpr
= get_or_alloc_expr_for_name (res
);
4468 sprimeexpr
= bitmap_find_leader (AVAIL_OUT (b
),
4469 get_expr_value_id (resexpr
), NULL
);
4472 if (sprimeexpr
->kind
== CONSTANT
)
4473 sprime
= PRE_EXPR_CONSTANT (sprimeexpr
);
4474 else if (sprimeexpr
->kind
== NAME
)
4475 sprime
= PRE_EXPR_NAME (sprimeexpr
);
4479 if (!sprime
&& is_gimple_min_invariant (VN_INFO (res
)->valnum
))
4481 sprime
= VN_INFO (res
)->valnum
;
4482 if (!useless_type_conversion_p (TREE_TYPE (res
),
4483 TREE_TYPE (sprime
)))
4484 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4493 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4495 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4496 print_generic_expr (dump_file
, res
, 0);
4497 fprintf (dump_file
, " with ");
4498 print_generic_expr (dump_file
, sprime
, 0);
4499 fprintf (dump_file
, "\n");
4502 remove_phi_node (&gsi
, false);
4504 if (!bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4505 && TREE_CODE (sprime
) == SSA_NAME
)
4506 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4508 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4509 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4510 stmt
= gimple_build_assign (res
, sprime
);
4511 SSA_NAME_DEF_STMT (res
) = stmt
;
4512 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4514 gsi2
= gsi_after_labels (b
);
4515 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4516 /* Queue the copy for eventual removal. */
4517 VEC_safe_push (gimple
, heap
, to_remove
, stmt
);
4518 /* If we inserted this PHI node ourself, it's not an elimination. */
4519 if (bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4522 pre_stats
.eliminations
++;
4526 /* We cannot remove stmts during BB walk, especially not release SSA
4527 names there as this confuses the VN machinery. The stmts ending
4528 up in to_remove are either stores or simple copies. */
4529 FOR_EACH_VEC_ELT (gimple
, to_remove
, i
, stmt
)
4531 tree lhs
= gimple_assign_lhs (stmt
);
4532 tree rhs
= gimple_assign_rhs1 (stmt
);
4533 use_operand_p use_p
;
4536 /* If there is a single use only, propagate the equivalency
4537 instead of keeping the copy. */
4538 if (TREE_CODE (lhs
) == SSA_NAME
4539 && TREE_CODE (rhs
) == SSA_NAME
4540 && single_imm_use (lhs
, &use_p
, &use_stmt
)
4541 && may_propagate_copy (USE_FROM_PTR (use_p
), rhs
))
4543 SET_USE (use_p
, rhs
);
4544 update_stmt (use_stmt
);
4545 if (bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (lhs
))
4546 && TREE_CODE (rhs
) == SSA_NAME
)
4547 gimple_set_plf (SSA_NAME_DEF_STMT (rhs
), NECESSARY
, true);
4550 /* If this is a store or a now unused copy, remove it. */
4551 if (TREE_CODE (lhs
) != SSA_NAME
4552 || has_zero_uses (lhs
))
4554 basic_block bb
= gimple_bb (stmt
);
4555 gsi
= gsi_for_stmt (stmt
);
4556 unlink_stmt_vdef (stmt
);
4557 gsi_remove (&gsi
, true);
4558 if (gimple_purge_dead_eh_edges (bb
))
4559 todo
|= TODO_cleanup_cfg
;
4560 if (TREE_CODE (lhs
) == SSA_NAME
)
4561 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4562 release_defs (stmt
);
4565 VEC_free (gimple
, heap
, to_remove
);
4570 /* Borrow a bit of tree-ssa-dce.c for the moment.
4571 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4572 this may be a bit faster, and we may want critical edges kept split. */
4574 /* If OP's defining statement has not already been determined to be necessary,
4575 mark that statement necessary. Return the stmt, if it is newly
4578 static inline gimple
4579 mark_operand_necessary (tree op
)
4585 if (TREE_CODE (op
) != SSA_NAME
)
4588 stmt
= SSA_NAME_DEF_STMT (op
);
4591 if (gimple_plf (stmt
, NECESSARY
)
4592 || gimple_nop_p (stmt
))
4595 gimple_set_plf (stmt
, NECESSARY
, true);
4599 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4600 to insert PHI nodes sometimes, and because value numbering of casts isn't
4601 perfect, we sometimes end up inserting dead code. This simple DCE-like
4602 pass removes any insertions we made that weren't actually used. */
4605 remove_dead_inserted_code (void)
4612 worklist
= BITMAP_ALLOC (NULL
);
4613 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4615 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4616 if (gimple_plf (t
, NECESSARY
))
4617 bitmap_set_bit (worklist
, i
);
4619 while (!bitmap_empty_p (worklist
))
4621 i
= bitmap_first_set_bit (worklist
);
4622 bitmap_clear_bit (worklist
, i
);
4623 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4625 /* PHI nodes are somewhat special in that each PHI alternative has
4626 data and control dependencies. All the statements feeding the
4627 PHI node's arguments are always necessary. */
4628 if (gimple_code (t
) == GIMPLE_PHI
)
4632 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4634 tree arg
= PHI_ARG_DEF (t
, k
);
4635 if (TREE_CODE (arg
) == SSA_NAME
)
4637 gimple n
= mark_operand_necessary (arg
);
4639 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4645 /* Propagate through the operands. Examine all the USE, VUSE and
4646 VDEF operands in this statement. Mark all the statements
4647 which feed this statement's uses as necessary. */
4651 /* The operands of VDEF expressions are also needed as they
4652 represent potential definitions that may reach this
4653 statement (VDEF operands allow us to follow def-def
4656 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4658 gimple n
= mark_operand_necessary (use
);
4660 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4665 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4667 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4668 if (!gimple_plf (t
, NECESSARY
))
4670 gimple_stmt_iterator gsi
;
4672 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4674 fprintf (dump_file
, "Removing unnecessary insertion:");
4675 print_gimple_stmt (dump_file
, t
, 0, 0);
4678 gsi
= gsi_for_stmt (t
);
4679 if (gimple_code (t
) == GIMPLE_PHI
)
4680 remove_phi_node (&gsi
, true);
4683 gsi_remove (&gsi
, true);
4688 BITMAP_FREE (worklist
);
4691 /* Compute a reverse post-order in *POST_ORDER. If INCLUDE_ENTRY_EXIT is
4692 true, then then ENTRY_BLOCK and EXIT_BLOCK are included. Returns
4693 the number of visited blocks. */
4696 my_rev_post_order_compute (int *post_order
, bool include_entry_exit
)
4698 edge_iterator
*stack
;
4700 int post_order_num
= 0;
4703 if (include_entry_exit
)
4704 post_order
[post_order_num
++] = EXIT_BLOCK
;
4706 /* Allocate stack for back-tracking up CFG. */
4707 stack
= XNEWVEC (edge_iterator
, n_basic_blocks
+ 1);
4710 /* Allocate bitmap to track nodes that have been visited. */
4711 visited
= sbitmap_alloc (last_basic_block
);
4713 /* None of the nodes in the CFG have been visited yet. */
4714 sbitmap_zero (visited
);
4716 /* Push the last edge on to the stack. */
4717 stack
[sp
++] = ei_start (EXIT_BLOCK_PTR
->preds
);
4725 /* Look at the edge on the top of the stack. */
4727 src
= ei_edge (ei
)->src
;
4728 dest
= ei_edge (ei
)->dest
;
4730 /* Check if the edge destination has been visited yet. */
4731 if (src
!= ENTRY_BLOCK_PTR
&& ! TEST_BIT (visited
, src
->index
))
4733 /* Mark that we have visited the destination. */
4734 SET_BIT (visited
, src
->index
);
4736 if (EDGE_COUNT (src
->preds
) > 0)
4737 /* Since the DEST node has been visited for the first
4738 time, check its successors. */
4739 stack
[sp
++] = ei_start (src
->preds
);
4741 post_order
[post_order_num
++] = src
->index
;
4745 if (ei_one_before_end_p (ei
) && dest
!= EXIT_BLOCK_PTR
)
4746 post_order
[post_order_num
++] = dest
->index
;
4748 if (!ei_one_before_end_p (ei
))
4749 ei_next (&stack
[sp
- 1]);
4755 if (include_entry_exit
)
4756 post_order
[post_order_num
++] = ENTRY_BLOCK
;
4759 sbitmap_free (visited
);
4760 return post_order_num
;
4764 /* Initialize data structures used by PRE. */
4767 init_pre (bool do_fre
)
4771 next_expression_id
= 1;
4773 VEC_safe_push (pre_expr
, heap
, expressions
, NULL
);
4774 value_expressions
= VEC_alloc (bitmap_set_t
, heap
, get_max_value_id () + 1);
4775 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
4776 get_max_value_id() + 1);
4781 inserted_exprs
= BITMAP_ALLOC (NULL
);
4782 need_creation
= NULL
;
4783 pretemp
= NULL_TREE
;
4784 storetemp
= NULL_TREE
;
4785 prephitemp
= NULL_TREE
;
4787 connect_infinite_loops_to_exit ();
4788 memset (&pre_stats
, 0, sizeof (pre_stats
));
4791 postorder
= XNEWVEC (int, n_basic_blocks
- NUM_FIXED_BLOCKS
);
4792 my_rev_post_order_compute (postorder
, false);
4794 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4796 calculate_dominance_info (CDI_POST_DOMINATORS
);
4797 calculate_dominance_info (CDI_DOMINATORS
);
4799 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4800 phi_translate_table
= htab_create (5110, expr_pred_trans_hash
,
4801 expr_pred_trans_eq
, free
);
4802 expression_to_id
= htab_create (num_ssa_names
* 3,
4805 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4806 sizeof (struct bitmap_set
), 30);
4807 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4808 sizeof (struct pre_expr_d
), 30);
4811 EXP_GEN (bb
) = bitmap_set_new ();
4812 PHI_GEN (bb
) = bitmap_set_new ();
4813 TMP_GEN (bb
) = bitmap_set_new ();
4814 AVAIL_OUT (bb
) = bitmap_set_new ();
4817 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4818 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4822 /* Deallocate data structures used by PRE. */
4825 fini_pre (bool do_fre
)
4828 VEC_free (bitmap_set_t
, heap
, value_expressions
);
4829 BITMAP_FREE (inserted_exprs
);
4830 VEC_free (gimple
, heap
, need_creation
);
4831 bitmap_obstack_release (&grand_bitmap_obstack
);
4832 free_alloc_pool (bitmap_set_pool
);
4833 free_alloc_pool (pre_expr_pool
);
4834 htab_delete (phi_translate_table
);
4835 htab_delete (expression_to_id
);
4836 VEC_free (unsigned, heap
, name_to_id
);
4838 free_aux_for_blocks ();
4840 free_dominance_info (CDI_POST_DOMINATORS
);
4842 if (!bitmap_empty_p (need_eh_cleanup
))
4844 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4845 cleanup_tree_cfg ();
4848 BITMAP_FREE (need_eh_cleanup
);
4850 if (!bitmap_empty_p (need_ab_cleanup
))
4852 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4853 cleanup_tree_cfg ();
4856 BITMAP_FREE (need_ab_cleanup
);
4859 loop_optimizer_finalize ();
4862 /* Main entry point to the SSA-PRE pass. DO_FRE is true if the caller
4863 only wants to do full redundancy elimination. */
4866 execute_pre (bool do_fre
)
4868 unsigned int todo
= 0;
4870 do_partial_partial
= optimize
> 2 && optimize_function_for_speed_p (cfun
);
4872 /* This has to happen before SCCVN runs because
4873 loop_optimizer_init may create new phis, etc. */
4875 loop_optimizer_init (LOOPS_NORMAL
);
4877 if (!run_scc_vn (do_fre
? VN_WALKREWRITE
: VN_WALK
))
4880 loop_optimizer_finalize ();
4888 /* Collect and value number expressions computed in each basic block. */
4891 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4897 print_bitmap_set (dump_file
, EXP_GEN (bb
), "exp_gen", bb
->index
);
4898 print_bitmap_set (dump_file
, PHI_GEN (bb
), "phi_gen", bb
->index
);
4899 print_bitmap_set (dump_file
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
4900 print_bitmap_set (dump_file
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
4904 /* Insert can get quite slow on an incredibly large number of basic
4905 blocks due to some quadratic behavior. Until this behavior is
4906 fixed, don't run it when he have an incredibly large number of
4907 bb's. If we aren't going to run insert, there is no point in
4908 computing ANTIC, either, even though it's plenty fast. */
4909 if (!do_fre
&& n_basic_blocks
< 4000)
4915 /* Make sure to remove fake edges before committing our inserts.
4916 This makes sure we don't end up with extra critical edges that
4917 we would need to split. */
4918 remove_fake_exit_edges ();
4919 gsi_commit_edge_inserts ();
4921 /* Remove all the redundant expressions. */
4922 todo
|= eliminate ();
4924 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4925 statistics_counter_event (cfun
, "PA inserted", pre_stats
.pa_insert
);
4926 statistics_counter_event (cfun
, "New PHIs", pre_stats
.phis
);
4927 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4928 statistics_counter_event (cfun
, "Constified", pre_stats
.constified
);
4930 clear_expression_ids ();
4934 remove_dead_inserted_code ();
4935 todo
|= TODO_verify_flow
;
4944 /* Gate and execute functions for PRE. */
4949 return execute_pre (false);
4955 return flag_tree_pre
!= 0;
4958 struct gimple_opt_pass pass_pre
=
4963 gate_pre
, /* gate */
4964 do_pre
, /* execute */
4967 0, /* static_pass_number */
4968 TV_TREE_PRE
, /* tv_id */
4969 PROP_no_crit_edges
| PROP_cfg
4970 | PROP_ssa
, /* properties_required */
4971 0, /* properties_provided */
4972 0, /* properties_destroyed */
4973 TODO_rebuild_alias
, /* todo_flags_start */
4974 TODO_update_ssa_only_virtuals
| TODO_dump_func
| TODO_ggc_collect
4975 | TODO_verify_ssa
/* todo_flags_finish */
4980 /* Gate and execute functions for FRE. */
4985 return execute_pre (true);
4991 return flag_tree_fre
!= 0;
4994 struct gimple_opt_pass pass_fre
=
4999 gate_fre
, /* gate */
5000 execute_fre
, /* execute */
5003 0, /* static_pass_number */
5004 TV_TREE_FRE
, /* tv_id */
5005 PROP_cfg
| PROP_ssa
, /* properties_required */
5006 0, /* properties_provided */
5007 0, /* properties_destroyed */
5008 0, /* todo_flags_start */
5009 TODO_dump_func
| TODO_ggc_collect
| TODO_verify_ssa
/* todo_flags_finish */