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
);
584 *slot
= (void *) new_pair
;
588 /* Add expression E to the expression set of value id V. */
591 add_to_value (unsigned int v
, pre_expr e
)
595 gcc_assert (get_expr_value_id (e
) == v
);
597 if (v
>= VEC_length (bitmap_set_t
, value_expressions
))
599 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
603 set
= VEC_index (bitmap_set_t
, value_expressions
, v
);
606 set
= bitmap_set_new ();
607 VEC_replace (bitmap_set_t
, value_expressions
, v
, set
);
610 bitmap_insert_into_set_1 (set
, e
, v
, true);
613 /* Create a new bitmap set and return it. */
616 bitmap_set_new (void)
618 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
619 bitmap_initialize (&ret
->expressions
, &grand_bitmap_obstack
);
620 bitmap_initialize (&ret
->values
, &grand_bitmap_obstack
);
624 /* Return the value id for a PRE expression EXPR. */
627 get_expr_value_id (pre_expr expr
)
634 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
637 id
= get_or_alloc_constant_value_id (PRE_EXPR_CONSTANT (expr
));
638 add_to_value (id
, expr
);
643 return VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
645 return PRE_EXPR_NARY (expr
)->value_id
;
647 return PRE_EXPR_REFERENCE (expr
)->value_id
;
653 /* Remove an expression EXPR from a bitmapped set. */
656 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
658 unsigned int val
= get_expr_value_id (expr
);
659 if (!value_id_constant_p (val
))
661 bitmap_clear_bit (&set
->values
, val
);
662 bitmap_clear_bit (&set
->expressions
, get_expression_id (expr
));
667 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
668 unsigned int val
, bool allow_constants
)
670 if (allow_constants
|| !value_id_constant_p (val
))
672 /* We specifically expect this and only this function to be able to
673 insert constants into a set. */
674 bitmap_set_bit (&set
->values
, val
);
675 bitmap_set_bit (&set
->expressions
, get_or_alloc_expression_id (expr
));
679 /* Insert an expression EXPR into a bitmapped set. */
682 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
684 bitmap_insert_into_set_1 (set
, expr
, get_expr_value_id (expr
), false);
687 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
690 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
692 bitmap_copy (&dest
->expressions
, &orig
->expressions
);
693 bitmap_copy (&dest
->values
, &orig
->values
);
697 /* Free memory used up by SET. */
699 bitmap_set_free (bitmap_set_t set
)
701 bitmap_clear (&set
->expressions
);
702 bitmap_clear (&set
->values
);
706 /* Generate an topological-ordered array of bitmap set SET. */
708 static VEC(pre_expr
, heap
) *
709 sorted_array_from_bitmap_set (bitmap_set_t set
)
712 bitmap_iterator bi
, bj
;
713 VEC(pre_expr
, heap
) *result
;
715 /* Pre-allocate roughly enough space for the array. */
716 result
= VEC_alloc (pre_expr
, heap
, bitmap_count_bits (&set
->values
));
718 FOR_EACH_VALUE_ID_IN_SET (set
, i
, bi
)
720 /* The number of expressions having a given value is usually
721 relatively small. Thus, rather than making a vector of all
722 the expressions and sorting it by value-id, we walk the values
723 and check in the reverse mapping that tells us what expressions
724 have a given value, to filter those in our set. As a result,
725 the expressions are inserted in value-id order, which means
728 If this is somehow a significant lose for some cases, we can
729 choose which set to walk based on the set size. */
730 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, i
);
731 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bj
)
733 if (bitmap_bit_p (&set
->expressions
, j
))
734 VEC_safe_push (pre_expr
, heap
, result
, expression_for_id (j
));
741 /* Perform bitmapped set operation DEST &= ORIG. */
744 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
752 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
754 bitmap_and_into (&dest
->values
, &orig
->values
);
755 bitmap_copy (&temp
, &dest
->expressions
);
756 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
758 pre_expr expr
= expression_for_id (i
);
759 unsigned int value_id
= get_expr_value_id (expr
);
760 if (!bitmap_bit_p (&dest
->values
, value_id
))
761 bitmap_clear_bit (&dest
->expressions
, i
);
763 bitmap_clear (&temp
);
767 /* Subtract all values and expressions contained in ORIG from DEST. */
770 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
772 bitmap_set_t result
= bitmap_set_new ();
776 bitmap_and_compl (&result
->expressions
, &dest
->expressions
,
779 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
781 pre_expr expr
= expression_for_id (i
);
782 unsigned int value_id
= get_expr_value_id (expr
);
783 bitmap_set_bit (&result
->values
, value_id
);
789 /* Subtract all the values in bitmap set B from bitmap set A. */
792 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
798 bitmap_initialize (&temp
, &grand_bitmap_obstack
);
800 bitmap_copy (&temp
, &a
->expressions
);
801 EXECUTE_IF_SET_IN_BITMAP (&temp
, 0, i
, bi
)
803 pre_expr expr
= expression_for_id (i
);
804 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
805 bitmap_remove_from_set (a
, expr
);
807 bitmap_clear (&temp
);
811 /* Return true if bitmapped set SET contains the value VALUE_ID. */
814 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
816 if (value_id_constant_p (value_id
))
819 if (!set
|| bitmap_empty_p (&set
->expressions
))
822 return bitmap_bit_p (&set
->values
, value_id
);
826 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
828 return bitmap_bit_p (&set
->expressions
, get_expression_id (expr
));
831 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
834 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
837 bitmap_set_t exprset
;
841 if (value_id_constant_p (lookfor
))
844 if (!bitmap_set_contains_value (set
, lookfor
))
847 /* The number of expressions having a given value is usually
848 significantly less than the total number of expressions in SET.
849 Thus, rather than check, for each expression in SET, whether it
850 has the value LOOKFOR, we walk the reverse mapping that tells us
851 what expressions have a given value, and see if any of those
852 expressions are in our set. For large testcases, this is about
853 5-10x faster than walking the bitmap. If this is somehow a
854 significant lose for some cases, we can choose which set to walk
855 based on the set size. */
856 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
857 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
859 if (bitmap_clear_bit (&set
->expressions
, i
))
861 bitmap_set_bit (&set
->expressions
, get_expression_id (expr
));
867 /* Return true if two bitmap sets are equal. */
870 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
872 return bitmap_equal_p (&a
->values
, &b
->values
);
875 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
876 and add it otherwise. */
879 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
881 unsigned int val
= get_expr_value_id (expr
);
883 if (bitmap_set_contains_value (set
, val
))
884 bitmap_set_replace_value (set
, val
, expr
);
886 bitmap_insert_into_set (set
, expr
);
889 /* Insert EXPR into SET if EXPR's value is not already present in
893 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
895 unsigned int val
= get_expr_value_id (expr
);
897 gcc_checking_assert (expr
->id
== get_or_alloc_expression_id (expr
));
899 /* Constant values are always considered to be part of the set. */
900 if (value_id_constant_p (val
))
903 /* If the value membership changed, add the expression. */
904 if (bitmap_set_bit (&set
->values
, val
))
905 bitmap_set_bit (&set
->expressions
, expr
->id
);
908 /* Print out EXPR to outfile. */
911 print_pre_expr (FILE *outfile
, const pre_expr expr
)
916 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
919 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
924 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
925 fprintf (outfile
, "{%s,", tree_code_name
[nary
->opcode
]);
926 for (i
= 0; i
< nary
->length
; i
++)
928 print_generic_expr (outfile
, nary
->op
[i
], 0);
929 if (i
!= (unsigned) nary
->length
- 1)
930 fprintf (outfile
, ",");
932 fprintf (outfile
, "}");
938 vn_reference_op_t vro
;
940 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
941 fprintf (outfile
, "{");
943 VEC_iterate (vn_reference_op_s
, ref
->operands
, i
, vro
);
946 bool closebrace
= false;
947 if (vro
->opcode
!= SSA_NAME
948 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
950 fprintf (outfile
, "%s", tree_code_name
[vro
->opcode
]);
953 fprintf (outfile
, "<");
959 print_generic_expr (outfile
, vro
->op0
, 0);
962 fprintf (outfile
, ",");
963 print_generic_expr (outfile
, vro
->op1
, 0);
967 fprintf (outfile
, ",");
968 print_generic_expr (outfile
, vro
->op2
, 0);
972 fprintf (outfile
, ">");
973 if (i
!= VEC_length (vn_reference_op_s
, ref
->operands
) - 1)
974 fprintf (outfile
, ",");
976 fprintf (outfile
, "}");
979 fprintf (outfile
, "@");
980 print_generic_expr (outfile
, ref
->vuse
, 0);
986 void debug_pre_expr (pre_expr
);
988 /* Like print_pre_expr but always prints to stderr. */
990 debug_pre_expr (pre_expr e
)
992 print_pre_expr (stderr
, e
);
993 fprintf (stderr
, "\n");
996 /* Print out SET to OUTFILE. */
999 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
1000 const char *setname
, int blockindex
)
1002 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
1009 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
1011 const pre_expr expr
= expression_for_id (i
);
1014 fprintf (outfile
, ", ");
1016 print_pre_expr (outfile
, expr
);
1018 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
1021 fprintf (outfile
, " }\n");
1024 void debug_bitmap_set (bitmap_set_t
);
1027 debug_bitmap_set (bitmap_set_t set
)
1029 print_bitmap_set (stderr
, set
, "debug", 0);
1032 void debug_bitmap_sets_for (basic_block
);
1035 debug_bitmap_sets_for (basic_block bb
)
1037 print_bitmap_set (stderr
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
1040 print_bitmap_set (stderr
, EXP_GEN (bb
), "exp_gen", bb
->index
);
1041 print_bitmap_set (stderr
, PHI_GEN (bb
), "phi_gen", bb
->index
);
1042 print_bitmap_set (stderr
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
1043 print_bitmap_set (stderr
, ANTIC_IN (bb
), "antic_in", bb
->index
);
1044 if (do_partial_partial
)
1045 print_bitmap_set (stderr
, PA_IN (bb
), "pa_in", bb
->index
);
1046 print_bitmap_set (stderr
, NEW_SETS (bb
), "new_sets", bb
->index
);
1050 /* Print out the expressions that have VAL to OUTFILE. */
1053 print_value_expressions (FILE *outfile
, unsigned int val
)
1055 bitmap_set_t set
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1059 sprintf (s
, "%04d", val
);
1060 print_bitmap_set (outfile
, set
, s
, 0);
1066 debug_value_expressions (unsigned int val
)
1068 print_value_expressions (stderr
, val
);
1071 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
1075 get_or_alloc_expr_for_constant (tree constant
)
1077 unsigned int result_id
;
1078 unsigned int value_id
;
1079 struct pre_expr_d expr
;
1082 expr
.kind
= CONSTANT
;
1083 PRE_EXPR_CONSTANT (&expr
) = constant
;
1084 result_id
= lookup_expression_id (&expr
);
1086 return expression_for_id (result_id
);
1088 newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1089 newexpr
->kind
= CONSTANT
;
1090 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1091 alloc_expression_id (newexpr
);
1092 value_id
= get_or_alloc_constant_value_id (constant
);
1093 add_to_value (value_id
, newexpr
);
1097 /* Given a value id V, find the actual tree representing the constant
1098 value if there is one, and return it. Return NULL if we can't find
1102 get_constant_for_value_id (unsigned int v
)
1104 if (value_id_constant_p (v
))
1108 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, v
);
1110 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1112 pre_expr expr
= expression_for_id (i
);
1113 if (expr
->kind
== CONSTANT
)
1114 return PRE_EXPR_CONSTANT (expr
);
1120 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1121 Currently only supports constants and SSA_NAMES. */
1123 get_or_alloc_expr_for (tree t
)
1125 if (TREE_CODE (t
) == SSA_NAME
)
1126 return get_or_alloc_expr_for_name (t
);
1127 else if (is_gimple_min_invariant (t
))
1128 return get_or_alloc_expr_for_constant (t
);
1131 /* More complex expressions can result from SCCVN expression
1132 simplification that inserts values for them. As they all
1133 do not have VOPs the get handled by the nary ops struct. */
1134 vn_nary_op_t result
;
1135 unsigned int result_id
;
1136 vn_nary_op_lookup (t
, &result
);
1139 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1141 PRE_EXPR_NARY (e
) = result
;
1142 result_id
= lookup_expression_id (e
);
1145 pool_free (pre_expr_pool
, e
);
1146 e
= expression_for_id (result_id
);
1149 alloc_expression_id (e
);
1156 /* Return the folded version of T if T, when folded, is a gimple
1157 min_invariant. Otherwise, return T. */
1160 fully_constant_expression (pre_expr e
)
1168 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1169 switch (TREE_CODE_CLASS (nary
->opcode
))
1172 case tcc_comparison
:
1174 /* We have to go from trees to pre exprs to value ids to
1176 tree naryop0
= nary
->op
[0];
1177 tree naryop1
= nary
->op
[1];
1179 if (!is_gimple_min_invariant (naryop0
))
1181 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1182 unsigned int vrep0
= get_expr_value_id (rep0
);
1183 tree const0
= get_constant_for_value_id (vrep0
);
1185 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1187 if (!is_gimple_min_invariant (naryop1
))
1189 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1190 unsigned int vrep1
= get_expr_value_id (rep1
);
1191 tree const1
= get_constant_for_value_id (vrep1
);
1193 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1195 result
= fold_binary (nary
->opcode
, nary
->type
,
1197 if (result
&& is_gimple_min_invariant (result
))
1198 return get_or_alloc_expr_for_constant (result
);
1199 /* We might have simplified the expression to a
1200 SSA_NAME for example from x_1 * 1. But we cannot
1201 insert a PHI for x_1 unconditionally as x_1 might
1202 not be available readily. */
1206 if (nary
->opcode
!= REALPART_EXPR
1207 && nary
->opcode
!= IMAGPART_EXPR
1208 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1213 /* We have to go from trees to pre exprs to value ids to
1215 tree naryop0
= nary
->op
[0];
1216 tree const0
, result
;
1217 if (is_gimple_min_invariant (naryop0
))
1221 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1222 unsigned int vrep0
= get_expr_value_id (rep0
);
1223 const0
= get_constant_for_value_id (vrep0
);
1228 tree type1
= TREE_TYPE (nary
->op
[0]);
1229 const0
= fold_convert (type1
, const0
);
1230 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1232 if (result
&& is_gimple_min_invariant (result
))
1233 return get_or_alloc_expr_for_constant (result
);
1242 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1244 if ((folded
= fully_constant_vn_reference_p (ref
)))
1245 return get_or_alloc_expr_for_constant (folded
);
1254 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
1255 it has the value it would have in BLOCK. Set *SAME_VALID to true
1256 in case the new vuse doesn't change the value id of the OPERANDS. */
1259 translate_vuse_through_block (VEC (vn_reference_op_s
, heap
) *operands
,
1260 alias_set_type set
, tree type
, tree vuse
,
1261 basic_block phiblock
,
1262 basic_block block
, bool *same_valid
)
1264 gimple phi
= SSA_NAME_DEF_STMT (vuse
);
1271 if (gimple_bb (phi
) != phiblock
)
1274 use_oracle
= ao_ref_init_from_vn_reference (&ref
, set
, type
, operands
);
1276 /* Use the alias-oracle to find either the PHI node in this block,
1277 the first VUSE used in this block that is equivalent to vuse or
1278 the first VUSE which definition in this block kills the value. */
1279 if (gimple_code (phi
) == GIMPLE_PHI
)
1280 e
= find_edge (block
, phiblock
);
1281 else if (use_oracle
)
1282 while (!stmt_may_clobber_ref_p_1 (phi
, &ref
))
1284 vuse
= gimple_vuse (phi
);
1285 phi
= SSA_NAME_DEF_STMT (vuse
);
1286 if (gimple_bb (phi
) != phiblock
)
1288 if (gimple_code (phi
) == GIMPLE_PHI
)
1290 e
= find_edge (block
, phiblock
);
1301 bitmap visited
= NULL
;
1302 /* Try to find a vuse that dominates this phi node by skipping
1303 non-clobbering statements. */
1304 vuse
= get_continuation_for_phi (phi
, &ref
, &visited
);
1306 BITMAP_FREE (visited
);
1312 /* If we didn't find any, the value ID can't stay the same,
1313 but return the translated vuse. */
1314 *same_valid
= false;
1315 vuse
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1317 /* ??? We would like to return vuse here as this is the canonical
1318 upmost vdef that this reference is associated with. But during
1319 insertion of the references into the hash tables we only ever
1320 directly insert with their direct gimple_vuse, hence returning
1321 something else would make us not find the other expression. */
1322 return PHI_ARG_DEF (phi
, e
->dest_idx
);
1328 /* Like bitmap_find_leader, but checks for the value existing in SET1 *or*
1329 SET2. This is used to avoid making a set consisting of the union
1330 of PA_IN and ANTIC_IN during insert. */
1332 static inline pre_expr
1333 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1337 result
= bitmap_find_leader (set1
, val
, NULL
);
1338 if (!result
&& set2
)
1339 result
= bitmap_find_leader (set2
, val
, NULL
);
1343 /* Get the tree type for our PRE expression e. */
1346 get_expr_type (const pre_expr e
)
1351 return TREE_TYPE (PRE_EXPR_NAME (e
));
1353 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1355 return PRE_EXPR_REFERENCE (e
)->type
;
1357 return PRE_EXPR_NARY (e
)->type
;
1362 /* Get a representative SSA_NAME for a given expression.
1363 Since all of our sub-expressions are treated as values, we require
1364 them to be SSA_NAME's for simplicity.
1365 Prior versions of GVNPRE used to use "value handles" here, so that
1366 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1367 either case, the operands are really values (IE we do not expect
1368 them to be usable without finding leaders). */
1371 get_representative_for (const pre_expr e
)
1375 unsigned int value_id
= get_expr_value_id (e
);
1380 return PRE_EXPR_NAME (e
);
1382 return PRE_EXPR_CONSTANT (e
);
1386 /* Go through all of the expressions representing this value
1387 and pick out an SSA_NAME. */
1390 bitmap_set_t exprs
= VEC_index (bitmap_set_t
, value_expressions
,
1392 FOR_EACH_EXPR_ID_IN_SET (exprs
, i
, bi
)
1394 pre_expr rep
= expression_for_id (i
);
1395 if (rep
->kind
== NAME
)
1396 return PRE_EXPR_NAME (rep
);
1401 /* If we reached here we couldn't find an SSA_NAME. This can
1402 happen when we've discovered a value that has never appeared in
1403 the program as set to an SSA_NAME, most likely as the result of
1408 "Could not find SSA_NAME representative for expression:");
1409 print_pre_expr (dump_file
, e
);
1410 fprintf (dump_file
, "\n");
1413 exprtype
= get_expr_type (e
);
1415 /* Build and insert the assignment of the end result to the temporary
1416 that we will return. */
1417 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
1419 pretemp
= create_tmp_reg (exprtype
, "pretmp");
1420 add_referenced_var (pretemp
);
1423 name
= make_ssa_name (pretemp
, gimple_build_nop ());
1424 VN_INFO_GET (name
)->value_id
= value_id
;
1425 if (e
->kind
== CONSTANT
)
1426 VN_INFO (name
)->valnum
= PRE_EXPR_CONSTANT (e
);
1428 VN_INFO (name
)->valnum
= name
;
1430 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1433 fprintf (dump_file
, "Created SSA_NAME representative ");
1434 print_generic_expr (dump_file
, name
, 0);
1435 fprintf (dump_file
, " for expression:");
1436 print_pre_expr (dump_file
, e
);
1437 fprintf (dump_file
, "\n");
1446 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1447 basic_block pred
, basic_block phiblock
);
1449 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1450 the phis in PRED. Return NULL if we can't find a leader for each part
1451 of the translated expression. */
1454 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1455 basic_block pred
, basic_block phiblock
)
1462 bool changed
= false;
1463 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1464 vn_nary_op_t newnary
= XALLOCAVAR (struct vn_nary_op_s
,
1465 sizeof_vn_nary_op (nary
->length
));
1466 memcpy (newnary
, nary
, sizeof_vn_nary_op (nary
->length
));
1468 for (i
= 0; i
< newnary
->length
; i
++)
1470 if (TREE_CODE (newnary
->op
[i
]) != SSA_NAME
)
1474 pre_expr leader
, result
;
1475 unsigned int op_val_id
= VN_INFO (newnary
->op
[i
])->value_id
;
1476 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1477 result
= phi_translate (leader
, set1
, set2
, pred
, phiblock
);
1478 if (result
&& result
!= leader
)
1480 tree name
= get_representative_for (result
);
1483 newnary
->op
[i
] = name
;
1488 changed
|= newnary
->op
[i
] != nary
->op
[i
];
1494 unsigned int new_val_id
;
1496 tree result
= vn_nary_op_lookup_pieces (newnary
->length
,
1501 if (result
&& is_gimple_min_invariant (result
))
1502 return get_or_alloc_expr_for_constant (result
);
1504 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1509 PRE_EXPR_NARY (expr
) = nary
;
1510 constant
= fully_constant_expression (expr
);
1511 if (constant
!= expr
)
1514 new_val_id
= nary
->value_id
;
1515 get_or_alloc_expression_id (expr
);
1519 new_val_id
= get_next_value_id ();
1520 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1522 get_max_value_id() + 1);
1523 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;
1548 unsigned int i
, j
, n
;
1549 vn_reference_op_t operand
;
1550 vn_reference_t newref
;
1553 VEC_iterate (vn_reference_op_s
, operands
, i
, operand
); i
++, j
++)
1558 tree type
= operand
->type
;
1559 vn_reference_op_s newop
= *operand
;
1560 op
[0] = operand
->op0
;
1561 op
[1] = operand
->op1
;
1562 op
[2] = operand
->op2
;
1563 for (n
= 0; n
< 3; ++n
)
1565 unsigned int op_val_id
;
1568 if (TREE_CODE (op
[n
]) != SSA_NAME
)
1570 /* We can't possibly insert these. */
1572 && !is_gimple_min_invariant (op
[n
]))
1576 op_val_id
= VN_INFO (op
[n
])->value_id
;
1577 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1580 /* Make sure we do not recursively translate ourselves
1581 like for translating a[n_1] with the leader for
1582 n_1 being a[n_1]. */
1583 if (get_expression_id (leader
) != get_expression_id (expr
))
1585 opresult
= phi_translate (leader
, set1
, set2
,
1589 if (opresult
!= leader
)
1591 tree name
= get_representative_for (opresult
);
1594 changed
|= name
!= op
[n
];
1602 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1606 newoperands
= VEC_copy (vn_reference_op_s
, heap
, operands
);
1607 /* We may have changed from an SSA_NAME to a constant */
1608 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op
[0]) != SSA_NAME
)
1609 newop
.opcode
= TREE_CODE (op
[0]);
1614 /* If it transforms a non-constant ARRAY_REF into a constant
1615 one, adjust the constant offset. */
1616 if (newop
.opcode
== ARRAY_REF
1618 && TREE_CODE (op
[0]) == INTEGER_CST
1619 && TREE_CODE (op
[1]) == INTEGER_CST
1620 && TREE_CODE (op
[2]) == INTEGER_CST
)
1622 double_int off
= tree_to_double_int (op
[0]);
1623 off
= double_int_add (off
,
1625 (tree_to_double_int (op
[1])));
1626 off
= double_int_mul (off
, tree_to_double_int (op
[2]));
1627 if (double_int_fits_in_shwi_p (off
))
1628 newop
.off
= off
.low
;
1630 VEC_replace (vn_reference_op_s
, newoperands
, j
, &newop
);
1631 /* If it transforms from an SSA_NAME to an address, fold with
1632 a preceding indirect reference. */
1633 if (j
> 0 && op
[0] && TREE_CODE (op
[0]) == ADDR_EXPR
1634 && VEC_index (vn_reference_op_s
,
1635 newoperands
, j
- 1)->opcode
== MEM_REF
)
1636 vn_reference_fold_indirect (&newoperands
, &j
);
1638 if (i
!= VEC_length (vn_reference_op_s
, operands
))
1641 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1647 newvuse
= translate_vuse_through_block (newoperands
,
1648 ref
->set
, ref
->type
,
1649 vuse
, phiblock
, pred
,
1651 if (newvuse
== NULL_TREE
)
1653 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1658 if (changed
|| newvuse
!= vuse
)
1660 unsigned int new_val_id
;
1662 bool converted
= false;
1664 tree result
= vn_reference_lookup_pieces (newvuse
, ref
->set
,
1669 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1672 && !useless_type_conversion_p (ref
->type
, TREE_TYPE (result
)))
1674 result
= fold_build1 (VIEW_CONVERT_EXPR
, ref
->type
, result
);
1677 else if (!result
&& newref
1678 && !useless_type_conversion_p (ref
->type
, newref
->type
))
1680 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1684 if (result
&& is_gimple_min_invariant (result
))
1686 gcc_assert (!newoperands
);
1687 return get_or_alloc_expr_for_constant (result
);
1690 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1691 expr
->kind
= REFERENCE
;
1699 gcc_assert (CONVERT_EXPR_P (result
)
1700 || TREE_CODE (result
) == VIEW_CONVERT_EXPR
);
1702 nresult
= vn_nary_op_lookup_pieces (1, TREE_CODE (result
),
1704 &TREE_OPERAND (result
, 0),
1706 if (nresult
&& is_gimple_min_invariant (nresult
))
1707 return get_or_alloc_expr_for_constant (nresult
);
1712 PRE_EXPR_NARY (expr
) = nary
;
1713 constant
= fully_constant_expression (expr
);
1714 if (constant
!= expr
)
1717 new_val_id
= nary
->value_id
;
1718 get_or_alloc_expression_id (expr
);
1722 new_val_id
= get_next_value_id ();
1723 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1725 get_max_value_id() + 1);
1726 nary
= vn_nary_op_insert_pieces (1, TREE_CODE (result
),
1728 &TREE_OPERAND (result
, 0),
1731 PRE_EXPR_NARY (expr
) = nary
;
1732 constant
= fully_constant_expression (expr
);
1733 if (constant
!= expr
)
1735 get_or_alloc_expression_id (expr
);
1740 PRE_EXPR_REFERENCE (expr
) = newref
;
1741 constant
= fully_constant_expression (expr
);
1742 if (constant
!= expr
)
1745 new_val_id
= newref
->value_id
;
1746 get_or_alloc_expression_id (expr
);
1750 if (changed
|| !same_valid
)
1752 new_val_id
= get_next_value_id ();
1753 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1755 get_max_value_id() + 1);
1758 new_val_id
= ref
->value_id
;
1759 newref
= vn_reference_insert_pieces (newvuse
, ref
->set
,
1762 result
, new_val_id
);
1764 PRE_EXPR_REFERENCE (expr
) = newref
;
1765 constant
= fully_constant_expression (expr
);
1766 if (constant
!= expr
)
1768 get_or_alloc_expression_id (expr
);
1770 add_to_value (new_val_id
, expr
);
1772 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1782 tree name
= PRE_EXPR_NAME (expr
);
1784 def_stmt
= SSA_NAME_DEF_STMT (name
);
1785 if (gimple_code (def_stmt
) == GIMPLE_PHI
1786 && gimple_bb (def_stmt
) == phiblock
)
1791 e
= find_edge (pred
, gimple_bb (phi
));
1794 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1797 if (TREE_CODE (def
) == SSA_NAME
)
1798 def
= VN_INFO (def
)->valnum
;
1800 /* Handle constant. */
1801 if (is_gimple_min_invariant (def
))
1802 return get_or_alloc_expr_for_constant (def
);
1804 if (TREE_CODE (def
) == SSA_NAME
&& ssa_undefined_value_p (def
))
1807 newexpr
= get_or_alloc_expr_for_name (def
);
1818 /* Wrapper around phi_translate_1 providing caching functionality. */
1821 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1822 basic_block pred
, basic_block phiblock
)
1829 /* Constants contain no values that need translation. */
1830 if (expr
->kind
== CONSTANT
)
1833 if (value_id_constant_p (get_expr_value_id (expr
)))
1836 if (expr
->kind
!= NAME
)
1838 phitrans
= phi_trans_lookup (expr
, pred
);
1844 phitrans
= phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
);
1846 /* Don't add empty translations to the cache. Neither add
1847 translations of NAMEs as those are cheap to translate. */
1849 && expr
->kind
!= NAME
)
1850 phi_trans_add (expr
, phitrans
, pred
);
1856 /* For each expression in SET, translate the values through phi nodes
1857 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1858 expressions in DEST. */
1861 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1862 basic_block phiblock
)
1864 VEC (pre_expr
, heap
) *exprs
;
1868 if (gimple_seq_empty_p (phi_nodes (phiblock
)))
1870 bitmap_set_copy (dest
, set
);
1874 exprs
= sorted_array_from_bitmap_set (set
);
1875 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
1877 pre_expr translated
;
1878 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1882 /* We might end up with multiple expressions from SET being
1883 translated to the same value. In this case we do not want
1884 to retain the NARY or REFERENCE expression but prefer a NAME
1885 which would be the leader. */
1886 if (translated
->kind
== NAME
)
1887 bitmap_value_replace_in_set (dest
, translated
);
1889 bitmap_value_insert_into_set (dest
, translated
);
1891 VEC_free (pre_expr
, heap
, exprs
);
1894 /* Find the leader for a value (i.e., the name representing that
1895 value) in a given set, and return it. If STMT is non-NULL it
1896 makes sure the defining statement for the leader dominates it.
1897 Return NULL if no leader is found. */
1900 bitmap_find_leader (bitmap_set_t set
, unsigned int val
, gimple stmt
)
1902 if (value_id_constant_p (val
))
1906 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1908 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1910 pre_expr expr
= expression_for_id (i
);
1911 if (expr
->kind
== CONSTANT
)
1915 if (bitmap_set_contains_value (set
, val
))
1917 /* Rather than walk the entire bitmap of expressions, and see
1918 whether any of them has the value we are looking for, we look
1919 at the reverse mapping, which tells us the set of expressions
1920 that have a given value (IE value->expressions with that
1921 value) and see if any of those expressions are in our set.
1922 The number of expressions per value is usually significantly
1923 less than the number of expressions in the set. In fact, for
1924 large testcases, doing it this way is roughly 5-10x faster
1925 than walking the bitmap.
1926 If this is somehow a significant lose for some cases, we can
1927 choose which set to walk based on which set is smaller. */
1930 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1932 EXECUTE_IF_AND_IN_BITMAP (&exprset
->expressions
,
1933 &set
->expressions
, 0, i
, bi
)
1935 pre_expr val
= expression_for_id (i
);
1936 /* At the point where stmt is not null, there should always
1937 be an SSA_NAME first in the list of expressions. */
1940 gimple def_stmt
= SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val
));
1941 if (gimple_code (def_stmt
) != GIMPLE_PHI
1942 && gimple_bb (def_stmt
) == gimple_bb (stmt
)
1943 /* PRE insertions are at the end of the basic-block
1945 && (gimple_uid (def_stmt
) == 0
1946 || gimple_uid (def_stmt
) >= gimple_uid (stmt
)))
1955 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1956 BLOCK by seeing if it is not killed in the block. Note that we are
1957 only determining whether there is a store that kills it. Because
1958 of the order in which clean iterates over values, we are guaranteed
1959 that altered operands will have caused us to be eliminated from the
1960 ANTIC_IN set already. */
1963 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1965 tree vuse
= PRE_EXPR_REFERENCE (expr
)->vuse
;
1966 vn_reference_t refx
= PRE_EXPR_REFERENCE (expr
);
1968 gimple_stmt_iterator gsi
;
1969 unsigned id
= get_expression_id (expr
);
1976 /* Lookup a previously calculated result. */
1977 if (EXPR_DIES (block
)
1978 && bitmap_bit_p (EXPR_DIES (block
), id
* 2))
1979 return bitmap_bit_p (EXPR_DIES (block
), id
* 2 + 1);
1981 /* A memory expression {e, VUSE} dies in the block if there is a
1982 statement that may clobber e. If, starting statement walk from the
1983 top of the basic block, a statement uses VUSE there can be no kill
1984 inbetween that use and the original statement that loaded {e, VUSE},
1985 so we can stop walking. */
1986 ref
.base
= NULL_TREE
;
1987 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1989 tree def_vuse
, def_vdef
;
1990 def
= gsi_stmt (gsi
);
1991 def_vuse
= gimple_vuse (def
);
1992 def_vdef
= gimple_vdef (def
);
1994 /* Not a memory statement. */
1998 /* Not a may-def. */
2001 /* A load with the same VUSE, we're done. */
2002 if (def_vuse
== vuse
)
2008 /* Init ref only if we really need it. */
2009 if (ref
.base
== NULL_TREE
2010 && !ao_ref_init_from_vn_reference (&ref
, refx
->set
, refx
->type
,
2016 /* If the statement may clobber expr, it dies. */
2017 if (stmt_may_clobber_ref_p_1 (def
, &ref
))
2024 /* Remember the result. */
2025 if (!EXPR_DIES (block
))
2026 EXPR_DIES (block
) = BITMAP_ALLOC (&grand_bitmap_obstack
);
2027 bitmap_set_bit (EXPR_DIES (block
), id
* 2);
2029 bitmap_set_bit (EXPR_DIES (block
), id
* 2 + 1);
2035 /* Determine if OP is valid in SET1 U SET2, which it is when the union
2036 contains its value-id. */
2039 op_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, tree op
)
2041 if (op
&& TREE_CODE (op
) == SSA_NAME
)
2043 unsigned int value_id
= VN_INFO (op
)->value_id
;
2044 if (!bitmap_set_contains_value (set1
, value_id
)
2045 || (set2
&& !bitmap_set_contains_value (set2
, value_id
)))
2051 /* Determine if the expression EXPR is valid in SET1 U SET2.
2052 ONLY SET2 CAN BE NULL.
2053 This means that we have a leader for each part of the expression
2054 (if it consists of values), or the expression is an SSA_NAME.
2055 For loads/calls, we also see if the vuse is killed in this block. */
2058 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
2064 return bitmap_set_contains_expr (AVAIL_OUT (block
), expr
);
2068 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2069 for (i
= 0; i
< nary
->length
; i
++)
2070 if (!op_valid_in_sets (set1
, set2
, nary
->op
[i
]))
2072 /* If the NARY may trap make sure the block does not contain
2073 a possible exit point.
2074 ??? This is overly conservative if we translate AVAIL_OUT
2075 as the available expression might be after the exit point. */
2076 if (BB_MAY_NOTRETURN (block
)
2077 && vn_nary_may_trap (nary
))
2084 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2085 vn_reference_op_t vro
;
2088 FOR_EACH_VEC_ELT (vn_reference_op_s
, ref
->operands
, i
, vro
)
2090 if (!op_valid_in_sets (set1
, set2
, vro
->op0
)
2091 || !op_valid_in_sets (set1
, set2
, vro
->op1
)
2092 || !op_valid_in_sets (set1
, set2
, vro
->op2
))
2102 /* Clean the set of expressions that are no longer valid in SET1 or
2103 SET2. This means expressions that are made up of values we have no
2104 leaders for in SET1 or SET2. This version is used for partial
2105 anticipation, which means it is not valid in either ANTIC_IN or
2109 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
2111 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set1
);
2115 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
2117 if (!valid_in_sets (set1
, set2
, expr
, block
))
2118 bitmap_remove_from_set (set1
, expr
);
2120 VEC_free (pre_expr
, heap
, exprs
);
2123 /* Clean the set of expressions that are no longer valid in SET. This
2124 means expressions that are made up of values we have no leaders for
2128 clean (bitmap_set_t set
, basic_block block
)
2130 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set
);
2134 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
2136 if (!valid_in_sets (set
, NULL
, expr
, block
))
2137 bitmap_remove_from_set (set
, expr
);
2139 VEC_free (pre_expr
, heap
, exprs
);
2142 /* Clean the set of expressions that are no longer valid in SET because
2143 they are clobbered in BLOCK. */
2146 prune_clobbered_mems (bitmap_set_t set
, basic_block block
)
2148 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set
);
2152 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
2155 if (expr
->kind
!= REFERENCE
)
2158 ref
= PRE_EXPR_REFERENCE (expr
);
2161 gimple def_stmt
= SSA_NAME_DEF_STMT (ref
->vuse
);
2162 if (!gimple_nop_p (def_stmt
)
2163 && ((gimple_bb (def_stmt
) != block
2164 && !dominated_by_p (CDI_DOMINATORS
,
2165 block
, gimple_bb (def_stmt
)))
2166 || (gimple_bb (def_stmt
) == block
2167 && value_dies_in_block_x (expr
, block
))))
2168 bitmap_remove_from_set (set
, expr
);
2171 VEC_free (pre_expr
, heap
, exprs
);
2174 static sbitmap has_abnormal_preds
;
2176 /* List of blocks that may have changed during ANTIC computation and
2177 thus need to be iterated over. */
2179 static sbitmap changed_blocks
;
2181 /* Decide whether to defer a block for a later iteration, or PHI
2182 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2183 should defer the block, and true if we processed it. */
2186 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2187 basic_block block
, basic_block phiblock
)
2189 if (!BB_VISITED (phiblock
))
2191 SET_BIT (changed_blocks
, block
->index
);
2192 BB_VISITED (block
) = 0;
2193 BB_DEFERRED (block
) = 1;
2197 phi_translate_set (dest
, source
, block
, phiblock
);
2201 /* Compute the ANTIC set for BLOCK.
2203 If succs(BLOCK) > 1 then
2204 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2205 else if succs(BLOCK) == 1 then
2206 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2208 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2212 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2214 bool changed
= false;
2215 bitmap_set_t S
, old
, ANTIC_OUT
;
2221 old
= ANTIC_OUT
= S
= NULL
;
2222 BB_VISITED (block
) = 1;
2224 /* If any edges from predecessors are abnormal, antic_in is empty,
2226 if (block_has_abnormal_pred_edge
)
2227 goto maybe_dump_sets
;
2229 old
= ANTIC_IN (block
);
2230 ANTIC_OUT
= bitmap_set_new ();
2232 /* If the block has no successors, ANTIC_OUT is empty. */
2233 if (EDGE_COUNT (block
->succs
) == 0)
2235 /* If we have one successor, we could have some phi nodes to
2236 translate through. */
2237 else if (single_succ_p (block
))
2239 basic_block succ_bb
= single_succ (block
);
2241 /* We trade iterations of the dataflow equations for having to
2242 phi translate the maximal set, which is incredibly slow
2243 (since the maximal set often has 300+ members, even when you
2244 have a small number of blocks).
2245 Basically, we defer the computation of ANTIC for this block
2246 until we have processed it's successor, which will inevitably
2247 have a *much* smaller set of values to phi translate once
2248 clean has been run on it.
2249 The cost of doing this is that we technically perform more
2250 iterations, however, they are lower cost iterations.
2252 Timings for PRE on tramp3d-v4:
2253 without maximal set fix: 11 seconds
2254 with maximal set fix/without deferring: 26 seconds
2255 with maximal set fix/with deferring: 11 seconds
2258 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2262 goto maybe_dump_sets
;
2265 /* If we have multiple successors, we take the intersection of all of
2266 them. Note that in the case of loop exit phi nodes, we may have
2267 phis to translate through. */
2270 VEC(basic_block
, heap
) * worklist
;
2272 basic_block bprime
, first
= NULL
;
2274 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2275 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2278 && BB_VISITED (e
->dest
))
2280 else if (BB_VISITED (e
->dest
))
2281 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2284 /* Of multiple successors we have to have visited one already. */
2287 SET_BIT (changed_blocks
, block
->index
);
2288 BB_VISITED (block
) = 0;
2289 BB_DEFERRED (block
) = 1;
2291 VEC_free (basic_block
, heap
, worklist
);
2292 goto maybe_dump_sets
;
2295 if (!gimple_seq_empty_p (phi_nodes (first
)))
2296 phi_translate_set (ANTIC_OUT
, ANTIC_IN (first
), block
, first
);
2298 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2300 FOR_EACH_VEC_ELT (basic_block
, worklist
, i
, bprime
)
2302 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2304 bitmap_set_t tmp
= bitmap_set_new ();
2305 phi_translate_set (tmp
, ANTIC_IN (bprime
), block
, bprime
);
2306 bitmap_set_and (ANTIC_OUT
, tmp
);
2307 bitmap_set_free (tmp
);
2310 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2312 VEC_free (basic_block
, heap
, worklist
);
2315 /* Prune expressions that are clobbered in block and thus become
2316 invalid if translated from ANTIC_OUT to ANTIC_IN. */
2317 prune_clobbered_mems (ANTIC_OUT
, block
);
2319 /* Generate ANTIC_OUT - TMP_GEN. */
2320 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2322 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2323 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2326 /* Then union in the ANTIC_OUT - TMP_GEN values,
2327 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2328 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2329 bitmap_value_insert_into_set (ANTIC_IN (block
),
2330 expression_for_id (bii
));
2332 clean (ANTIC_IN (block
), block
);
2334 if (!bitmap_set_equal (old
, ANTIC_IN (block
)))
2337 SET_BIT (changed_blocks
, block
->index
);
2338 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2339 SET_BIT (changed_blocks
, e
->src
->index
);
2342 RESET_BIT (changed_blocks
, block
->index
);
2345 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2347 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2350 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2352 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2356 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2361 "Block %d was deferred for a future iteration.\n",
2366 bitmap_set_free (old
);
2368 bitmap_set_free (S
);
2370 bitmap_set_free (ANTIC_OUT
);
2374 /* Compute PARTIAL_ANTIC for BLOCK.
2376 If succs(BLOCK) > 1 then
2377 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2378 in ANTIC_OUT for all succ(BLOCK)
2379 else if succs(BLOCK) == 1 then
2380 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2382 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2387 compute_partial_antic_aux (basic_block block
,
2388 bool block_has_abnormal_pred_edge
)
2390 bool changed
= false;
2391 bitmap_set_t old_PA_IN
;
2392 bitmap_set_t PA_OUT
;
2395 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2397 old_PA_IN
= PA_OUT
= NULL
;
2399 /* If any edges from predecessors are abnormal, antic_in is empty,
2401 if (block_has_abnormal_pred_edge
)
2402 goto maybe_dump_sets
;
2404 /* If there are too many partially anticipatable values in the
2405 block, phi_translate_set can take an exponential time: stop
2406 before the translation starts. */
2408 && single_succ_p (block
)
2409 && bitmap_count_bits (&PA_IN (single_succ (block
))->values
) > max_pa
)
2410 goto maybe_dump_sets
;
2412 old_PA_IN
= PA_IN (block
);
2413 PA_OUT
= bitmap_set_new ();
2415 /* If the block has no successors, ANTIC_OUT is empty. */
2416 if (EDGE_COUNT (block
->succs
) == 0)
2418 /* If we have one successor, we could have some phi nodes to
2419 translate through. Note that we can't phi translate across DFS
2420 back edges in partial antic, because it uses a union operation on
2421 the successors. For recurrences like IV's, we will end up
2422 generating a new value in the set on each go around (i + 3 (VH.1)
2423 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2424 else if (single_succ_p (block
))
2426 basic_block succ
= single_succ (block
);
2427 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2428 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2430 /* If we have multiple successors, we take the union of all of
2434 VEC(basic_block
, heap
) * worklist
;
2438 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2439 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2441 if (e
->flags
& EDGE_DFS_BACK
)
2443 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2445 if (VEC_length (basic_block
, worklist
) > 0)
2447 FOR_EACH_VEC_ELT (basic_block
, worklist
, i
, bprime
)
2452 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2453 bitmap_value_insert_into_set (PA_OUT
,
2454 expression_for_id (i
));
2455 if (!gimple_seq_empty_p (phi_nodes (bprime
)))
2457 bitmap_set_t pa_in
= bitmap_set_new ();
2458 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2459 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2460 bitmap_value_insert_into_set (PA_OUT
,
2461 expression_for_id (i
));
2462 bitmap_set_free (pa_in
);
2465 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2466 bitmap_value_insert_into_set (PA_OUT
,
2467 expression_for_id (i
));
2470 VEC_free (basic_block
, heap
, worklist
);
2473 /* Prune expressions that are clobbered in block and thus become
2474 invalid if translated from PA_OUT to PA_IN. */
2475 prune_clobbered_mems (PA_OUT
, block
);
2477 /* PA_IN starts with PA_OUT - TMP_GEN.
2478 Then we subtract things from ANTIC_IN. */
2479 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2481 /* For partial antic, we want to put back in the phi results, since
2482 we will properly avoid making them partially antic over backedges. */
2483 bitmap_ior_into (&PA_IN (block
)->values
, &PHI_GEN (block
)->values
);
2484 bitmap_ior_into (&PA_IN (block
)->expressions
, &PHI_GEN (block
)->expressions
);
2486 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2487 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2489 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2491 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2494 SET_BIT (changed_blocks
, block
->index
);
2495 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2496 SET_BIT (changed_blocks
, e
->src
->index
);
2499 RESET_BIT (changed_blocks
, block
->index
);
2502 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2505 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2507 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2510 bitmap_set_free (old_PA_IN
);
2512 bitmap_set_free (PA_OUT
);
2516 /* Compute ANTIC and partial ANTIC sets. */
2519 compute_antic (void)
2521 bool changed
= true;
2522 int num_iterations
= 0;
2526 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2527 We pre-build the map of blocks with incoming abnormal edges here. */
2528 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2529 sbitmap_zero (has_abnormal_preds
);
2536 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2538 e
->flags
&= ~EDGE_DFS_BACK
;
2539 if (e
->flags
& EDGE_ABNORMAL
)
2541 SET_BIT (has_abnormal_preds
, block
->index
);
2546 BB_VISITED (block
) = 0;
2547 BB_DEFERRED (block
) = 0;
2549 /* While we are here, give empty ANTIC_IN sets to each block. */
2550 ANTIC_IN (block
) = bitmap_set_new ();
2551 PA_IN (block
) = bitmap_set_new ();
2554 /* At the exit block we anticipate nothing. */
2555 ANTIC_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2556 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2557 PA_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2559 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2560 sbitmap_ones (changed_blocks
);
2563 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2564 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2565 /* ??? We need to clear our PHI translation cache here as the
2566 ANTIC sets shrink and we restrict valid translations to
2567 those having operands with leaders in ANTIC. Same below
2568 for PA ANTIC computation. */
2571 for (i
= n_basic_blocks
- NUM_FIXED_BLOCKS
- 1; i
>= 0; i
--)
2573 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2575 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2576 changed
|= compute_antic_aux (block
,
2577 TEST_BIT (has_abnormal_preds
,
2581 /* Theoretically possible, but *highly* unlikely. */
2582 gcc_checking_assert (num_iterations
< 500);
2585 statistics_histogram_event (cfun
, "compute_antic iterations",
2588 if (do_partial_partial
)
2590 sbitmap_ones (changed_blocks
);
2591 mark_dfs_back_edges ();
2596 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2597 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2600 for (i
= n_basic_blocks
- NUM_FIXED_BLOCKS
- 1 ; i
>= 0; i
--)
2602 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2604 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2606 |= compute_partial_antic_aux (block
,
2607 TEST_BIT (has_abnormal_preds
,
2611 /* Theoretically possible, but *highly* unlikely. */
2612 gcc_checking_assert (num_iterations
< 500);
2614 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2617 sbitmap_free (has_abnormal_preds
);
2618 sbitmap_free (changed_blocks
);
2621 /* Return true if we can value number the call in STMT. This is true
2622 if we have a pure or constant call to a real function. */
2625 can_value_number_call (gimple stmt
)
2627 if (gimple_call_internal_p (stmt
))
2629 if (gimple_call_flags (stmt
) & (ECF_PURE
| ECF_CONST
))
2634 /* Return true if OP is a tree which we can perform PRE on.
2635 This may not match the operations we can value number, but in
2636 a perfect world would. */
2639 can_PRE_operation (tree op
)
2641 return UNARY_CLASS_P (op
)
2642 || BINARY_CLASS_P (op
)
2643 || COMPARISON_CLASS_P (op
)
2644 || TREE_CODE (op
) == MEM_REF
2645 || TREE_CODE (op
) == COMPONENT_REF
2646 || TREE_CODE (op
) == VIEW_CONVERT_EXPR
2647 || TREE_CODE (op
) == CALL_EXPR
2648 || TREE_CODE (op
) == ARRAY_REF
;
2652 /* Inserted expressions are placed onto this worklist, which is used
2653 for performing quick dead code elimination of insertions we made
2654 that didn't turn out to be necessary. */
2655 static bitmap inserted_exprs
;
2657 /* Pool allocated fake store expressions are placed onto this
2658 worklist, which, after performing dead code elimination, is walked
2659 to see which expressions need to be put into GC'able memory */
2660 static VEC(gimple
, heap
) *need_creation
;
2662 /* The actual worker for create_component_ref_by_pieces. */
2665 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2666 unsigned int *operand
, gimple_seq
*stmts
,
2669 vn_reference_op_t currop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2673 switch (currop
->opcode
)
2677 tree folded
, sc
= NULL_TREE
;
2678 unsigned int nargs
= 0;
2680 if (TREE_CODE (currop
->op0
) == FUNCTION_DECL
)
2684 pre_expr op0
= get_or_alloc_expr_for (currop
->op0
);
2685 fn
= find_or_generate_expression (block
, op0
, stmts
, domstmt
);
2691 pre_expr scexpr
= get_or_alloc_expr_for (currop
->op1
);
2692 sc
= find_or_generate_expression (block
, scexpr
, stmts
, domstmt
);
2696 args
= XNEWVEC (tree
, VEC_length (vn_reference_op_s
,
2697 ref
->operands
) - 1);
2698 while (*operand
< VEC_length (vn_reference_op_s
, ref
->operands
))
2700 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2710 folded
= build_call_array (currop
->type
,
2711 (TREE_CODE (fn
) == FUNCTION_DECL
2712 ? build_fold_addr_expr (fn
) : fn
),
2716 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2722 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2724 tree offset
= currop
->op0
;
2727 if (TREE_CODE (baseop
) == ADDR_EXPR
2728 && handled_component_p (TREE_OPERAND (baseop
, 0)))
2732 base
= get_addr_base_and_unit_offset (TREE_OPERAND (baseop
, 0),
2735 offset
= int_const_binop (PLUS_EXPR
, offset
,
2736 build_int_cst (TREE_TYPE (offset
),
2738 baseop
= build_fold_addr_expr (base
);
2740 return fold_build2 (MEM_REF
, currop
->type
, baseop
, offset
);
2743 case TARGET_MEM_REF
:
2745 pre_expr op0expr
, op1expr
;
2746 tree genop0
= NULL_TREE
, genop1
= NULL_TREE
;
2747 vn_reference_op_t nextop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2749 tree baseop
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2755 op0expr
= get_or_alloc_expr_for (currop
->op0
);
2756 genop0
= find_or_generate_expression (block
, op0expr
,
2763 op1expr
= get_or_alloc_expr_for (nextop
->op0
);
2764 genop1
= find_or_generate_expression (block
, op1expr
,
2769 return build5 (TARGET_MEM_REF
, currop
->type
,
2770 baseop
, currop
->op2
, genop0
, currop
->op1
, genop1
);
2776 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2782 case VIEW_CONVERT_EXPR
:
2785 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
,
2790 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2795 case WITH_SIZE_EXPR
:
2797 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2799 pre_expr op1expr
= get_or_alloc_expr_for (currop
->op0
);
2805 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2809 return fold_build2 (currop
->opcode
, currop
->type
, genop0
, genop1
);
2815 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2817 pre_expr op1expr
= get_or_alloc_expr_for (currop
->op0
);
2818 pre_expr op2expr
= get_or_alloc_expr_for (currop
->op1
);
2824 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2827 genop2
= find_or_generate_expression (block
, op2expr
, stmts
, domstmt
);
2830 folded
= fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, genop1
,
2835 /* For array ref vn_reference_op's, operand 1 of the array ref
2836 is op0 of the reference op and operand 3 of the array ref is
2838 case ARRAY_RANGE_REF
:
2842 tree genop1
= currop
->op0
;
2844 tree genop2
= currop
->op1
;
2846 tree genop3
= currop
->op2
;
2848 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2852 op1expr
= get_or_alloc_expr_for (genop1
);
2853 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2858 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (genop0
));
2859 /* Drop zero minimum index if redundant. */
2860 if (integer_zerop (genop2
)
2862 || integer_zerop (TYPE_MIN_VALUE (domain_type
))))
2866 op2expr
= get_or_alloc_expr_for (genop2
);
2867 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2875 tree elmt_type
= TREE_TYPE (TREE_TYPE (genop0
));
2876 /* We can't always put a size in units of the element alignment
2877 here as the element alignment may be not visible. See
2878 PR43783. Simply drop the element size for constant
2880 if (tree_int_cst_equal (genop3
, TYPE_SIZE_UNIT (elmt_type
)))
2884 genop3
= size_binop (EXACT_DIV_EXPR
, genop3
,
2885 size_int (TYPE_ALIGN_UNIT (elmt_type
)));
2886 op3expr
= get_or_alloc_expr_for (genop3
);
2887 genop3
= find_or_generate_expression (block
, op3expr
, stmts
,
2893 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2900 tree genop2
= currop
->op1
;
2902 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2906 /* op1 should be a FIELD_DECL, which are represented by
2911 op2expr
= get_or_alloc_expr_for (genop2
);
2912 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2918 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
,
2924 pre_expr op0expr
= get_or_alloc_expr_for (currop
->op0
);
2925 genop
= find_or_generate_expression (block
, op0expr
, stmts
, domstmt
);
2946 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2947 COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
2948 trying to rename aggregates into ssa form directly, which is a no no.
2950 Thus, this routine doesn't create temporaries, it just builds a
2951 single access expression for the array, calling
2952 find_or_generate_expression to build the innermost pieces.
2954 This function is a subroutine of create_expression_by_pieces, and
2955 should not be called on it's own unless you really know what you
2959 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2960 gimple_seq
*stmts
, gimple domstmt
)
2962 unsigned int op
= 0;
2963 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
, domstmt
);
2966 /* Find a leader for an expression, or generate one using
2967 create_expression_by_pieces if it's ANTIC but
2969 BLOCK is the basic_block we are looking for leaders in.
2970 EXPR is the expression to find a leader or generate for.
2971 STMTS is the statement list to put the inserted expressions on.
2972 Returns the SSA_NAME of the LHS of the generated expression or the
2974 DOMSTMT if non-NULL is a statement that should be dominated by
2975 all uses in the generated expression. If DOMSTMT is non-NULL this
2976 routine can fail and return NULL_TREE. Otherwise it will assert
2980 find_or_generate_expression (basic_block block
, pre_expr expr
,
2981 gimple_seq
*stmts
, gimple domstmt
)
2983 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
),
2984 get_expr_value_id (expr
), domstmt
);
2988 if (leader
->kind
== NAME
)
2989 genop
= PRE_EXPR_NAME (leader
);
2990 else if (leader
->kind
== CONSTANT
)
2991 genop
= PRE_EXPR_CONSTANT (leader
);
2994 /* If it's still NULL, it must be a complex expression, so generate
2995 it recursively. Not so if inserting expressions for values generated
3000 bitmap_set_t exprset
;
3001 unsigned int lookfor
= get_expr_value_id (expr
);
3002 bool handled
= false;
3006 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
3007 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
3009 pre_expr temp
= expression_for_id (i
);
3010 if (temp
->kind
!= NAME
)
3013 genop
= create_expression_by_pieces (block
, temp
, stmts
,
3015 get_expr_type (expr
));
3019 if (!handled
&& domstmt
)
3022 gcc_assert (handled
);
3027 #define NECESSARY GF_PLF_1
3029 /* Create an expression in pieces, so that we can handle very complex
3030 expressions that may be ANTIC, but not necessary GIMPLE.
3031 BLOCK is the basic block the expression will be inserted into,
3032 EXPR is the expression to insert (in value form)
3033 STMTS is a statement list to append the necessary insertions into.
3035 This function will die if we hit some value that shouldn't be
3036 ANTIC but is (IE there is no leader for it, or its components).
3037 This function may also generate expressions that are themselves
3038 partially or fully redundant. Those that are will be either made
3039 fully redundant during the next iteration of insert (for partially
3040 redundant ones), or eliminated by eliminate (for fully redundant
3043 If DOMSTMT is non-NULL then we make sure that all uses in the
3044 expressions dominate that statement. In this case the function
3045 can return NULL_TREE to signal failure. */
3048 create_expression_by_pieces (basic_block block
, pre_expr expr
,
3049 gimple_seq
*stmts
, gimple domstmt
, tree type
)
3053 gimple_seq forced_stmts
= NULL
;
3054 unsigned int value_id
;
3055 gimple_stmt_iterator gsi
;
3056 tree exprtype
= type
? type
: get_expr_type (expr
);
3062 /* We may hit the NAME/CONSTANT case if we have to convert types
3063 that value numbering saw through. */
3065 folded
= PRE_EXPR_NAME (expr
);
3068 folded
= PRE_EXPR_CONSTANT (expr
);
3072 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
3073 folded
= create_component_ref_by_pieces (block
, ref
, stmts
, domstmt
);
3078 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
3081 for (i
= 0; i
< nary
->length
; ++i
)
3083 pre_expr op
= get_or_alloc_expr_for (nary
->op
[i
]);
3084 genop
[i
] = find_or_generate_expression (block
, op
,
3088 /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It
3089 may have conversions stripped. */
3090 if (nary
->opcode
== POINTER_PLUS_EXPR
)
3093 genop
[i
] = fold_convert (nary
->type
, genop
[i
]);
3095 genop
[i
] = convert_to_ptrofftype (genop
[i
]);
3098 genop
[i
] = fold_convert (TREE_TYPE (nary
->op
[i
]), genop
[i
]);
3100 if (nary
->opcode
== CONSTRUCTOR
)
3102 VEC(constructor_elt
,gc
) *elts
= NULL
;
3103 for (i
= 0; i
< nary
->length
; ++i
)
3104 CONSTRUCTOR_APPEND_ELT (elts
, NULL_TREE
, genop
[i
]);
3105 folded
= build_constructor (nary
->type
, elts
);
3109 switch (nary
->length
)
3112 folded
= fold_build1 (nary
->opcode
, nary
->type
,
3116 folded
= fold_build2 (nary
->opcode
, nary
->type
,
3117 genop
[0], genop
[1]);
3120 folded
= fold_build3 (nary
->opcode
, nary
->type
,
3121 genop
[0], genop
[1], genop
[3]);
3133 if (!useless_type_conversion_p (exprtype
, TREE_TYPE (folded
)))
3134 folded
= fold_convert (exprtype
, folded
);
3136 /* Force the generated expression to be a sequence of GIMPLE
3138 We have to call unshare_expr because force_gimple_operand may
3139 modify the tree we pass to it. */
3140 folded
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
3143 /* If we have any intermediate expressions to the value sets, add them
3144 to the value sets and chain them in the instruction stream. */
3147 gsi
= gsi_start (forced_stmts
);
3148 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3150 gimple stmt
= gsi_stmt (gsi
);
3151 tree forcedname
= gimple_get_lhs (stmt
);
3154 if (TREE_CODE (forcedname
) == SSA_NAME
)
3156 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (forcedname
));
3157 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
3158 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
3159 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
3160 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
3162 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
3163 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
3165 mark_symbols_for_renaming (stmt
);
3167 gimple_seq_add_seq (stmts
, forced_stmts
);
3170 /* Build and insert the assignment of the end result to the temporary
3171 that we will return. */
3172 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
3173 pretemp
= create_tmp_reg (exprtype
, "pretmp");
3176 add_referenced_var (temp
);
3178 newstmt
= gimple_build_assign (temp
, folded
);
3179 name
= make_ssa_name (temp
, newstmt
);
3180 gimple_assign_set_lhs (newstmt
, name
);
3181 gimple_set_plf (newstmt
, NECESSARY
, false);
3183 gimple_seq_add_stmt (stmts
, newstmt
);
3184 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (name
));
3186 /* All the symbols in NEWEXPR should be put into SSA form. */
3187 mark_symbols_for_renaming (newstmt
);
3189 /* Fold the last statement. */
3190 gsi
= gsi_last (*stmts
);
3191 if (fold_stmt_inplace (&gsi
))
3192 update_stmt (gsi_stmt (gsi
));
3194 /* Add a value number to the temporary.
3195 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
3196 we are creating the expression by pieces, and this particular piece of
3197 the expression may have been represented. There is no harm in replacing
3199 VN_INFO_GET (name
)->valnum
= name
;
3200 value_id
= get_expr_value_id (expr
);
3201 VN_INFO (name
)->value_id
= value_id
;
3202 nameexpr
= get_or_alloc_expr_for_name (name
);
3203 add_to_value (value_id
, nameexpr
);
3204 if (NEW_SETS (block
))
3205 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
3206 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
3208 pre_stats
.insertions
++;
3209 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3211 fprintf (dump_file
, "Inserted ");
3212 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
3213 fprintf (dump_file
, " in predecessor %d\n", block
->index
);
3220 /* Returns true if we want to inhibit the insertions of PHI nodes
3221 for the given EXPR for basic block BB (a member of a loop).
3222 We want to do this, when we fear that the induction variable we
3223 create might inhibit vectorization. */
3226 inhibit_phi_insertion (basic_block bb
, pre_expr expr
)
3228 vn_reference_t vr
= PRE_EXPR_REFERENCE (expr
);
3229 VEC (vn_reference_op_s
, heap
) *ops
= vr
->operands
;
3230 vn_reference_op_t op
;
3233 /* If we aren't going to vectorize we don't inhibit anything. */
3234 if (!flag_tree_vectorize
)
3237 /* Otherwise we inhibit the insertion when the address of the
3238 memory reference is a simple induction variable. In other
3239 cases the vectorizer won't do anything anyway (either it's
3240 loop invariant or a complicated expression). */
3241 FOR_EACH_VEC_ELT (vn_reference_op_s
, ops
, i
, op
)
3246 /* Calls are not a problem. */
3250 case ARRAY_RANGE_REF
:
3251 if (TREE_CODE (op
->op0
) != SSA_NAME
)
3256 basic_block defbb
= gimple_bb (SSA_NAME_DEF_STMT (op
->op0
));
3258 /* Default defs are loop invariant. */
3261 /* Defined outside this loop, also loop invariant. */
3262 if (!flow_bb_inside_loop_p (bb
->loop_father
, defbb
))
3264 /* If it's a simple induction variable inhibit insertion,
3265 the vectorizer might be interested in this one. */
3266 if (simple_iv (bb
->loop_father
, bb
->loop_father
,
3267 op
->op0
, &iv
, true))
3269 /* No simple IV, vectorizer can't do anything, hence no
3270 reason to inhibit the transformation for this operand. */
3280 /* Insert the to-be-made-available values of expression EXPRNUM for each
3281 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
3282 merge the result with a phi node, given the same value number as
3283 NODE. Return true if we have inserted new stuff. */
3286 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
3289 pre_expr expr
= expression_for_id (exprnum
);
3291 unsigned int val
= get_expr_value_id (expr
);
3293 bool insertions
= false;
3298 tree type
= get_expr_type (expr
);
3302 /* Make sure we aren't creating an induction variable. */
3303 if (block
->loop_depth
> 0 && EDGE_COUNT (block
->preds
) == 2)
3305 bool firstinsideloop
= false;
3306 bool secondinsideloop
= false;
3307 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3308 EDGE_PRED (block
, 0)->src
);
3309 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
3310 EDGE_PRED (block
, 1)->src
);
3311 /* Induction variables only have one edge inside the loop. */
3312 if ((firstinsideloop
^ secondinsideloop
)
3313 && (expr
->kind
!= REFERENCE
3314 || inhibit_phi_insertion (block
, expr
)))
3316 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3317 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3322 /* Make the necessary insertions. */
3323 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3325 gimple_seq stmts
= NULL
;
3328 eprime
= avail
[bprime
->index
];
3330 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3332 builtexpr
= create_expression_by_pieces (bprime
,
3336 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3337 gsi_insert_seq_on_edge (pred
, stmts
);
3338 avail
[bprime
->index
] = get_or_alloc_expr_for_name (builtexpr
);
3341 else if (eprime
->kind
== CONSTANT
)
3343 /* Constants may not have the right type, fold_convert
3344 should give us back a constant with the right type.
3346 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3347 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3349 tree builtexpr
= fold_convert (type
, constant
);
3350 if (!is_gimple_min_invariant (builtexpr
))
3352 tree forcedexpr
= force_gimple_operand (builtexpr
,
3355 if (!is_gimple_min_invariant (forcedexpr
))
3357 if (forcedexpr
!= builtexpr
)
3359 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3360 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3364 gimple_stmt_iterator gsi
;
3365 gsi
= gsi_start (stmts
);
3366 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3368 gimple stmt
= gsi_stmt (gsi
);
3369 tree lhs
= gimple_get_lhs (stmt
);
3370 if (TREE_CODE (lhs
) == SSA_NAME
)
3371 bitmap_set_bit (inserted_exprs
,
3372 SSA_NAME_VERSION (lhs
));
3373 gimple_set_plf (stmt
, NECESSARY
, false);
3375 gsi_insert_seq_on_edge (pred
, stmts
);
3377 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3381 avail
[bprime
->index
] = get_or_alloc_expr_for_constant (builtexpr
);
3384 else if (eprime
->kind
== NAME
)
3386 /* We may have to do a conversion because our value
3387 numbering can look through types in certain cases, but
3388 our IL requires all operands of a phi node have the same
3390 tree name
= PRE_EXPR_NAME (eprime
);
3391 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3395 builtexpr
= fold_convert (type
, name
);
3396 forcedexpr
= force_gimple_operand (builtexpr
,
3400 if (forcedexpr
!= name
)
3402 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3403 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3408 gimple_stmt_iterator gsi
;
3409 gsi
= gsi_start (stmts
);
3410 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3412 gimple stmt
= gsi_stmt (gsi
);
3413 tree lhs
= gimple_get_lhs (stmt
);
3414 if (TREE_CODE (lhs
) == SSA_NAME
)
3415 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
3416 gimple_set_plf (stmt
, NECESSARY
, false);
3418 gsi_insert_seq_on_edge (pred
, stmts
);
3420 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3424 /* If we didn't want a phi node, and we made insertions, we still have
3425 inserted new stuff, and thus return true. If we didn't want a phi node,
3426 and didn't make insertions, we haven't added anything new, so return
3428 if (nophi
&& insertions
)
3430 else if (nophi
&& !insertions
)
3433 /* Now build a phi for the new variable. */
3434 if (!prephitemp
|| TREE_TYPE (prephitemp
) != type
)
3435 prephitemp
= create_tmp_var (type
, "prephitmp");
3438 add_referenced_var (temp
);
3440 if (TREE_CODE (type
) == COMPLEX_TYPE
3441 || TREE_CODE (type
) == VECTOR_TYPE
)
3442 DECL_GIMPLE_REG_P (temp
) = 1;
3443 phi
= create_phi_node (temp
, block
);
3445 gimple_set_plf (phi
, NECESSARY
, false);
3446 VN_INFO_GET (gimple_phi_result (phi
))->valnum
= gimple_phi_result (phi
);
3447 VN_INFO (gimple_phi_result (phi
))->value_id
= val
;
3448 bitmap_set_bit (inserted_exprs
, SSA_NAME_VERSION (gimple_phi_result (phi
)));
3449 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3451 pre_expr ae
= avail
[pred
->src
->index
];
3452 gcc_assert (get_expr_type (ae
) == type
3453 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3454 if (ae
->kind
== CONSTANT
)
3455 add_phi_arg (phi
, PRE_EXPR_CONSTANT (ae
), pred
, UNKNOWN_LOCATION
);
3457 add_phi_arg (phi
, PRE_EXPR_NAME (avail
[pred
->src
->index
]), pred
,
3461 newphi
= get_or_alloc_expr_for_name (gimple_phi_result (phi
));
3462 add_to_value (val
, newphi
);
3464 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3465 this insertion, since we test for the existence of this value in PHI_GEN
3466 before proceeding with the partial redundancy checks in insert_aux.
3468 The value may exist in AVAIL_OUT, in particular, it could be represented
3469 by the expression we are trying to eliminate, in which case we want the
3470 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3473 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3474 this block, because if it did, it would have existed in our dominator's
3475 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3478 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3479 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3481 bitmap_insert_into_set (NEW_SETS (block
),
3484 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3486 fprintf (dump_file
, "Created phi ");
3487 print_gimple_stmt (dump_file
, phi
, 0, 0);
3488 fprintf (dump_file
, " in block %d\n", block
->index
);
3496 /* Perform insertion of partially redundant values.
3497 For BLOCK, do the following:
3498 1. Propagate the NEW_SETS of the dominator into the current block.
3499 If the block has multiple predecessors,
3500 2a. Iterate over the ANTIC expressions for the block to see if
3501 any of them are partially redundant.
3502 2b. If so, insert them into the necessary predecessors to make
3503 the expression fully redundant.
3504 2c. Insert a new PHI merging the values of the predecessors.
3505 2d. Insert the new PHI, and the new expressions, into the
3507 3. Recursively call ourselves on the dominator children of BLOCK.
3509 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3510 do_regular_insertion and do_partial_insertion.
3515 do_regular_insertion (basic_block block
, basic_block dom
)
3517 bool new_stuff
= false;
3518 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3522 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
3524 if (expr
->kind
!= NAME
)
3528 bool by_some
= false;
3529 bool cant_insert
= false;
3530 bool all_same
= true;
3531 pre_expr first_s
= NULL
;
3534 pre_expr eprime
= NULL
;
3536 pre_expr edoubleprime
= NULL
;
3537 bool do_insertion
= false;
3539 val
= get_expr_value_id (expr
);
3540 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3542 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3544 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3545 fprintf (dump_file
, "Found fully redundant value\n");
3549 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3550 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3552 unsigned int vprime
;
3554 /* We should never run insertion for the exit block
3555 and so not come across fake pred edges. */
3556 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3558 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3561 /* eprime will generally only be NULL if the
3562 value of the expression, translated
3563 through the PHI for this predecessor, is
3564 undefined. If that is the case, we can't
3565 make the expression fully redundant,
3566 because its value is undefined along a
3567 predecessor path. We can thus break out
3568 early because it doesn't matter what the
3569 rest of the results are. */
3576 eprime
= fully_constant_expression (eprime
);
3577 vprime
= get_expr_value_id (eprime
);
3578 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3580 if (edoubleprime
== NULL
)
3582 avail
[bprime
->index
] = eprime
;
3587 avail
[bprime
->index
] = edoubleprime
;
3589 /* We want to perform insertions to remove a redundancy on
3590 a path in the CFG we want to optimize for speed. */
3591 if (optimize_edge_for_speed_p (pred
))
3592 do_insertion
= true;
3593 if (first_s
== NULL
)
3594 first_s
= edoubleprime
;
3595 else if (!pre_expr_eq (first_s
, edoubleprime
))
3599 /* If we can insert it, it's not the same value
3600 already existing along every predecessor, and
3601 it's defined by some predecessor, it is
3602 partially redundant. */
3603 if (!cant_insert
&& !all_same
&& by_some
)
3607 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3609 fprintf (dump_file
, "Skipping partial redundancy for "
3611 print_pre_expr (dump_file
, expr
);
3612 fprintf (dump_file
, " (%04d), no redundancy on to be "
3613 "optimized for speed edge\n", val
);
3616 else if (dbg_cnt (treepre_insert
))
3618 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3620 fprintf (dump_file
, "Found partial redundancy for "
3622 print_pre_expr (dump_file
, expr
);
3623 fprintf (dump_file
, " (%04d)\n",
3624 get_expr_value_id (expr
));
3626 if (insert_into_preds_of_block (block
,
3627 get_expression_id (expr
),
3632 /* If all edges produce the same value and that value is
3633 an invariant, then the PHI has the same value on all
3634 edges. Note this. */
3635 else if (!cant_insert
&& all_same
&& eprime
3636 && (edoubleprime
->kind
== CONSTANT
3637 || edoubleprime
->kind
== NAME
)
3638 && !value_id_constant_p (val
))
3642 bitmap_set_t exprset
= VEC_index (bitmap_set_t
,
3643 value_expressions
, val
);
3645 unsigned int new_val
= get_expr_value_id (edoubleprime
);
3646 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bi
)
3648 pre_expr expr
= expression_for_id (j
);
3650 if (expr
->kind
== NAME
)
3652 vn_ssa_aux_t info
= VN_INFO (PRE_EXPR_NAME (expr
));
3653 /* Just reset the value id and valnum so it is
3654 the same as the constant we have discovered. */
3655 if (edoubleprime
->kind
== CONSTANT
)
3657 info
->valnum
= PRE_EXPR_CONSTANT (edoubleprime
);
3658 pre_stats
.constified
++;
3661 info
->valnum
= VN_INFO (PRE_EXPR_NAME (edoubleprime
))->valnum
;
3662 info
->value_id
= new_val
;
3670 VEC_free (pre_expr
, heap
, exprs
);
3675 /* Perform insertion for partially anticipatable expressions. There
3676 is only one case we will perform insertion for these. This case is
3677 if the expression is partially anticipatable, and fully available.
3678 In this case, we know that putting it earlier will enable us to
3679 remove the later computation. */
3683 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3685 bool new_stuff
= false;
3686 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3690 FOR_EACH_VEC_ELT (pre_expr
, exprs
, i
, expr
)
3692 if (expr
->kind
!= NAME
)
3697 bool cant_insert
= false;
3700 pre_expr eprime
= NULL
;
3703 val
= get_expr_value_id (expr
);
3704 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3706 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3709 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3710 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3712 unsigned int vprime
;
3713 pre_expr edoubleprime
;
3715 /* We should never run insertion for the exit block
3716 and so not come across fake pred edges. */
3717 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3719 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3723 /* eprime will generally only be NULL if the
3724 value of the expression, translated
3725 through the PHI for this predecessor, is
3726 undefined. If that is the case, we can't
3727 make the expression fully redundant,
3728 because its value is undefined along a
3729 predecessor path. We can thus break out
3730 early because it doesn't matter what the
3731 rest of the results are. */
3738 eprime
= fully_constant_expression (eprime
);
3739 vprime
= get_expr_value_id (eprime
);
3740 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3742 if (edoubleprime
== NULL
)
3748 avail
[bprime
->index
] = edoubleprime
;
3751 /* If we can insert it, it's not the same value
3752 already existing along every predecessor, and
3753 it's defined by some predecessor, it is
3754 partially redundant. */
3755 if (!cant_insert
&& by_all
)
3758 bool do_insertion
= false;
3760 /* Insert only if we can remove a later expression on a path
3761 that we want to optimize for speed.
3762 The phi node that we will be inserting in BLOCK is not free,
3763 and inserting it for the sake of !optimize_for_speed successor
3764 may cause regressions on the speed path. */
3765 FOR_EACH_EDGE (succ
, ei
, block
->succs
)
3767 if (bitmap_set_contains_value (PA_IN (succ
->dest
), val
))
3769 if (optimize_edge_for_speed_p (succ
))
3770 do_insertion
= true;
3776 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3778 fprintf (dump_file
, "Skipping partial partial redundancy "
3780 print_pre_expr (dump_file
, expr
);
3781 fprintf (dump_file
, " (%04d), not partially anticipated "
3782 "on any to be optimized for speed edges\n", val
);
3785 else if (dbg_cnt (treepre_insert
))
3787 pre_stats
.pa_insert
++;
3788 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3790 fprintf (dump_file
, "Found partial partial redundancy "
3792 print_pre_expr (dump_file
, expr
);
3793 fprintf (dump_file
, " (%04d)\n",
3794 get_expr_value_id (expr
));
3796 if (insert_into_preds_of_block (block
,
3797 get_expression_id (expr
),
3806 VEC_free (pre_expr
, heap
, exprs
);
3811 insert_aux (basic_block block
)
3814 bool new_stuff
= false;
3819 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3824 bitmap_set_t newset
= NEW_SETS (dom
);
3827 /* Note that we need to value_replace both NEW_SETS, and
3828 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3829 represented by some non-simple expression here that we want
3830 to replace it with. */
3831 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3833 pre_expr expr
= expression_for_id (i
);
3834 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3835 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3838 if (!single_pred_p (block
))
3840 new_stuff
|= do_regular_insertion (block
, dom
);
3841 if (do_partial_partial
)
3842 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3846 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3848 son
= next_dom_son (CDI_DOMINATORS
, son
))
3850 new_stuff
|= insert_aux (son
);
3856 /* Perform insertion of partially redundant values. */
3861 bool new_stuff
= true;
3863 int num_iterations
= 0;
3866 NEW_SETS (bb
) = bitmap_set_new ();
3871 if (dump_file
&& dump_flags
& TDF_DETAILS
)
3872 fprintf (dump_file
, "Starting insert iteration %d\n", num_iterations
);
3873 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3875 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3879 /* Add OP to EXP_GEN (block), and possibly to the maximal set. */
3882 add_to_exp_gen (basic_block block
, tree op
)
3887 if (TREE_CODE (op
) == SSA_NAME
&& ssa_undefined_value_p (op
))
3889 result
= get_or_alloc_expr_for_name (op
);
3890 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3894 /* Create value ids for PHI in BLOCK. */
3897 make_values_for_phi (gimple phi
, basic_block block
)
3899 tree result
= gimple_phi_result (phi
);
3901 /* We have no need for virtual phis, as they don't represent
3902 actual computations. */
3903 if (is_gimple_reg (result
))
3905 pre_expr e
= get_or_alloc_expr_for_name (result
);
3906 add_to_value (get_expr_value_id (e
), e
);
3907 bitmap_insert_into_set (PHI_GEN (block
), e
);
3908 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3912 for (i
= 0; i
< gimple_phi_num_args (phi
); ++i
)
3914 tree arg
= gimple_phi_arg_def (phi
, i
);
3915 if (TREE_CODE (arg
) == SSA_NAME
)
3917 e
= get_or_alloc_expr_for_name (arg
);
3918 add_to_value (get_expr_value_id (e
), e
);
3925 /* Compute the AVAIL set for all basic blocks.
3927 This function performs value numbering of the statements in each basic
3928 block. The AVAIL sets are built from information we glean while doing
3929 this value numbering, since the AVAIL sets contain only one entry per
3932 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3933 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3936 compute_avail (void)
3939 basic_block block
, son
;
3940 basic_block
*worklist
;
3944 /* We pretend that default definitions are defined in the entry block.
3945 This includes function arguments and the static chain decl. */
3946 for (i
= 1; i
< num_ssa_names
; ++i
)
3948 tree name
= ssa_name (i
);
3951 || !SSA_NAME_IS_DEFAULT_DEF (name
)
3952 || has_zero_uses (name
)
3953 || !is_gimple_reg (name
))
3956 e
= get_or_alloc_expr_for_name (name
);
3957 add_to_value (get_expr_value_id (e
), e
);
3959 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3960 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3963 /* Allocate the worklist. */
3964 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3966 /* Seed the algorithm by putting the dominator children of the entry
3967 block on the worklist. */
3968 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3970 son
= next_dom_son (CDI_DOMINATORS
, son
))
3971 worklist
[sp
++] = son
;
3973 /* Loop until the worklist is empty. */
3976 gimple_stmt_iterator gsi
;
3979 unsigned int stmt_uid
= 1;
3981 /* Pick a block from the worklist. */
3982 block
= worklist
[--sp
];
3984 /* Initially, the set of available values in BLOCK is that of
3985 its immediate dominator. */
3986 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3988 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3990 /* Generate values for PHI nodes. */
3991 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3992 make_values_for_phi (gsi_stmt (gsi
), block
);
3994 BB_MAY_NOTRETURN (block
) = 0;
3996 /* Now compute value numbers and populate value sets with all
3997 the expressions computed in BLOCK. */
3998 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4003 stmt
= gsi_stmt (gsi
);
4004 gimple_set_uid (stmt
, stmt_uid
++);
4006 /* Cache whether the basic-block has any non-visible side-effect
4008 If this isn't a call or it is the last stmt in the
4009 basic-block then the CFG represents things correctly. */
4010 if (is_gimple_call (stmt
)
4011 && !stmt_ends_bb_p (stmt
))
4013 /* Non-looping const functions always return normally.
4014 Otherwise the call might not return or have side-effects
4015 that forbids hoisting possibly trapping expressions
4017 int flags
= gimple_call_flags (stmt
);
4018 if (!(flags
& ECF_CONST
)
4019 || (flags
& ECF_LOOPING_CONST_OR_PURE
))
4020 BB_MAY_NOTRETURN (block
) = 1;
4023 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
4025 pre_expr e
= get_or_alloc_expr_for_name (op
);
4027 add_to_value (get_expr_value_id (e
), e
);
4029 bitmap_insert_into_set (TMP_GEN (block
), e
);
4030 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
4033 if (gimple_has_volatile_ops (stmt
)
4034 || stmt_could_throw_p (stmt
))
4037 switch (gimple_code (stmt
))
4040 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4041 add_to_exp_gen (block
, op
);
4048 vn_reference_op_t vro
;
4049 pre_expr result
= NULL
;
4050 VEC(vn_reference_op_s
, heap
) *ops
= NULL
;
4052 if (!can_value_number_call (stmt
))
4055 copy_reference_ops_from_call (stmt
, &ops
);
4056 vn_reference_lookup_pieces (gimple_vuse (stmt
), 0,
4057 gimple_expr_type (stmt
),
4058 ops
, &ref
, VN_NOWALK
);
4059 VEC_free (vn_reference_op_s
, heap
, ops
);
4063 for (i
= 0; VEC_iterate (vn_reference_op_s
,
4067 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
4068 add_to_exp_gen (block
, vro
->op0
);
4069 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
4070 add_to_exp_gen (block
, vro
->op1
);
4071 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
4072 add_to_exp_gen (block
, vro
->op2
);
4075 /* If the value of the call is not invalidated in
4076 this block until it is computed, add the expression
4078 if (!gimple_vuse (stmt
)
4080 (SSA_NAME_DEF_STMT (gimple_vuse (stmt
))) == GIMPLE_PHI
4081 || gimple_bb (SSA_NAME_DEF_STMT
4082 (gimple_vuse (stmt
))) != block
)
4084 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4085 result
->kind
= REFERENCE
;
4087 PRE_EXPR_REFERENCE (result
) = ref
;
4089 get_or_alloc_expression_id (result
);
4090 add_to_value (get_expr_value_id (result
), result
);
4092 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4099 pre_expr result
= NULL
;
4100 switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)))
4104 case tcc_comparison
:
4109 vn_nary_op_lookup_pieces (gimple_num_ops (stmt
) - 1,
4110 gimple_assign_rhs_code (stmt
),
4111 gimple_expr_type (stmt
),
4112 gimple_assign_rhs1_ptr (stmt
),
4118 for (i
= 0; i
< nary
->length
; i
++)
4119 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
4120 add_to_exp_gen (block
, nary
->op
[i
]);
4122 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4123 result
->kind
= NARY
;
4125 PRE_EXPR_NARY (result
) = nary
;
4129 case tcc_declaration
:
4134 vn_reference_op_t vro
;
4136 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
4142 for (i
= 0; VEC_iterate (vn_reference_op_s
,
4146 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
4147 add_to_exp_gen (block
, vro
->op0
);
4148 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
4149 add_to_exp_gen (block
, vro
->op1
);
4150 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
4151 add_to_exp_gen (block
, vro
->op2
);
4154 /* If the value of the reference is not invalidated in
4155 this block until it is computed, add the expression
4157 if (gimple_vuse (stmt
))
4161 def_stmt
= SSA_NAME_DEF_STMT (gimple_vuse (stmt
));
4162 while (!gimple_nop_p (def_stmt
)
4163 && gimple_code (def_stmt
) != GIMPLE_PHI
4164 && gimple_bb (def_stmt
) == block
)
4166 if (stmt_may_clobber_ref_p
4167 (def_stmt
, gimple_assign_rhs1 (stmt
)))
4173 = SSA_NAME_DEF_STMT (gimple_vuse (def_stmt
));
4179 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
4180 result
->kind
= REFERENCE
;
4182 PRE_EXPR_REFERENCE (result
) = ref
;
4187 /* For any other statement that we don't
4188 recognize, simply add all referenced
4189 SSA_NAMEs to EXP_GEN. */
4190 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
4191 add_to_exp_gen (block
, op
);
4195 get_or_alloc_expression_id (result
);
4196 add_to_value (get_expr_value_id (result
), result
);
4198 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
4207 /* Put the dominator children of BLOCK on the worklist of blocks
4208 to compute available sets for. */
4209 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
4211 son
= next_dom_son (CDI_DOMINATORS
, son
))
4212 worklist
[sp
++] = son
;
4218 /* Insert the expression for SSA_VN that SCCVN thought would be simpler
4219 than the available expressions for it. The insertion point is
4220 right before the first use in STMT. Returns the SSA_NAME that should
4221 be used for replacement. */
4224 do_SCCVN_insertion (gimple stmt
, tree ssa_vn
)
4226 basic_block bb
= gimple_bb (stmt
);
4227 gimple_stmt_iterator gsi
;
4228 gimple_seq stmts
= NULL
;
4232 /* First create a value expression from the expression we want
4233 to insert and associate it with the value handle for SSA_VN. */
4234 e
= get_or_alloc_expr_for (vn_get_expr_for (ssa_vn
));
4238 /* Then use create_expression_by_pieces to generate a valid
4239 expression to insert at this point of the IL stream. */
4240 expr
= create_expression_by_pieces (bb
, e
, &stmts
, stmt
, NULL
);
4241 if (expr
== NULL_TREE
)
4243 gsi
= gsi_for_stmt (stmt
);
4244 gsi_insert_seq_before (&gsi
, stmts
, GSI_SAME_STMT
);
4249 /* Eliminate fully redundant computations. */
4254 VEC (gimple
, heap
) *to_remove
= NULL
;
4255 VEC (gimple
, heap
) *to_update
= NULL
;
4257 unsigned int todo
= 0;
4258 gimple_stmt_iterator gsi
;
4264 for (gsi
= gsi_start_bb (b
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4266 tree lhs
= NULL_TREE
;
4267 tree rhs
= NULL_TREE
;
4269 stmt
= gsi_stmt (gsi
);
4271 if (gimple_has_lhs (stmt
))
4272 lhs
= gimple_get_lhs (stmt
);
4274 if (gimple_assign_single_p (stmt
))
4275 rhs
= gimple_assign_rhs1 (stmt
);
4277 /* Lookup the RHS of the expression, see if we have an
4278 available computation for it. If so, replace the RHS with
4279 the available computation.
4282 We don't replace global register variable when it is a the RHS of
4283 a single assign. We do replace local register variable since gcc
4284 does not guarantee local variable will be allocated in register. */
4285 if (gimple_has_lhs (stmt
)
4286 && TREE_CODE (lhs
) == SSA_NAME
4287 && !gimple_assign_ssa_name_copy_p (stmt
)
4288 && (!gimple_assign_single_p (stmt
)
4289 || (!is_gimple_min_invariant (rhs
)
4290 && (gimple_assign_rhs_code (stmt
) != VAR_DECL
4291 || !is_global_var (rhs
)
4292 || !DECL_HARD_REGISTER (rhs
))))
4293 && !gimple_has_volatile_ops (stmt
)
4294 && !has_zero_uses (lhs
))
4297 pre_expr lhsexpr
= get_or_alloc_expr_for_name (lhs
);
4298 pre_expr sprimeexpr
;
4299 gimple orig_stmt
= stmt
;
4301 sprimeexpr
= bitmap_find_leader (AVAIL_OUT (b
),
4302 get_expr_value_id (lhsexpr
),
4307 if (sprimeexpr
->kind
== CONSTANT
)
4308 sprime
= PRE_EXPR_CONSTANT (sprimeexpr
);
4309 else if (sprimeexpr
->kind
== NAME
)
4310 sprime
= PRE_EXPR_NAME (sprimeexpr
);
4315 /* If there is no existing leader but SCCVN knows this
4316 value is constant, use that constant. */
4317 if (!sprime
&& is_gimple_min_invariant (VN_INFO (lhs
)->valnum
))
4319 sprime
= VN_INFO (lhs
)->valnum
;
4320 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
4321 TREE_TYPE (sprime
)))
4322 sprime
= fold_convert (TREE_TYPE (lhs
), sprime
);
4324 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4326 fprintf (dump_file
, "Replaced ");
4327 print_gimple_expr (dump_file
, stmt
, 0, 0);
4328 fprintf (dump_file
, " with ");
4329 print_generic_expr (dump_file
, sprime
, 0);
4330 fprintf (dump_file
, " in ");
4331 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4333 pre_stats
.eliminations
++;
4334 propagate_tree_value_into_stmt (&gsi
, sprime
);
4335 stmt
= gsi_stmt (gsi
);
4338 /* If we removed EH side-effects from the statement, clean
4339 its EH information. */
4340 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4342 bitmap_set_bit (need_eh_cleanup
,
4343 gimple_bb (stmt
)->index
);
4344 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4345 fprintf (dump_file
, " Removed EH side-effects.\n");
4350 /* If there is no existing usable leader but SCCVN thinks
4351 it has an expression it wants to use as replacement,
4353 if (!sprime
|| sprime
== lhs
)
4355 tree val
= VN_INFO (lhs
)->valnum
;
4357 && TREE_CODE (val
) == SSA_NAME
4358 && VN_INFO (val
)->needs_insertion
4359 && can_PRE_operation (vn_get_expr_for (val
)))
4360 sprime
= do_SCCVN_insertion (stmt
, val
);
4364 && (rhs
== NULL_TREE
4365 || TREE_CODE (rhs
) != SSA_NAME
4366 || may_propagate_copy (rhs
, sprime
)))
4368 bool can_make_abnormal_goto
4369 = is_gimple_call (stmt
)
4370 && stmt_can_make_abnormal_goto (stmt
);
4372 gcc_assert (sprime
!= rhs
);
4374 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4376 fprintf (dump_file
, "Replaced ");
4377 print_gimple_expr (dump_file
, stmt
, 0, 0);
4378 fprintf (dump_file
, " with ");
4379 print_generic_expr (dump_file
, sprime
, 0);
4380 fprintf (dump_file
, " in ");
4381 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4384 if (TREE_CODE (sprime
) == SSA_NAME
)
4385 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
4387 /* We need to make sure the new and old types actually match,
4388 which may require adding a simple cast, which fold_convert
4390 if ((!rhs
|| TREE_CODE (rhs
) != SSA_NAME
)
4391 && !useless_type_conversion_p (gimple_expr_type (stmt
),
4392 TREE_TYPE (sprime
)))
4393 sprime
= fold_convert (gimple_expr_type (stmt
), sprime
);
4395 pre_stats
.eliminations
++;
4396 propagate_tree_value_into_stmt (&gsi
, sprime
);
4397 stmt
= gsi_stmt (gsi
);
4400 /* If we removed EH side-effects from the statement, clean
4401 its EH information. */
4402 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
4404 bitmap_set_bit (need_eh_cleanup
,
4405 gimple_bb (stmt
)->index
);
4406 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4407 fprintf (dump_file
, " Removed EH side-effects.\n");
4410 /* Likewise for AB side-effects. */
4411 if (can_make_abnormal_goto
4412 && !stmt_can_make_abnormal_goto (stmt
))
4414 bitmap_set_bit (need_ab_cleanup
,
4415 gimple_bb (stmt
)->index
);
4416 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4417 fprintf (dump_file
, " Removed AB side-effects.\n");
4421 /* If the statement is a scalar store, see if the expression
4422 has the same value number as its rhs. If so, the store is
4424 else if (gimple_assign_single_p (stmt
)
4425 && !gimple_has_volatile_ops (stmt
)
4426 && !is_gimple_reg (gimple_assign_lhs (stmt
))
4427 && (TREE_CODE (rhs
) == SSA_NAME
4428 || is_gimple_min_invariant (rhs
)))
4431 val
= vn_reference_lookup (gimple_assign_lhs (stmt
),
4432 gimple_vuse (stmt
), VN_WALK
, NULL
);
4433 if (TREE_CODE (rhs
) == SSA_NAME
)
4434 rhs
= VN_INFO (rhs
)->valnum
;
4436 && operand_equal_p (val
, rhs
, 0))
4438 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4440 fprintf (dump_file
, "Deleted redundant store ");
4441 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4444 /* Queue stmt for removal. */
4445 VEC_safe_push (gimple
, heap
, to_remove
, stmt
);
4448 /* Visit COND_EXPRs and fold the comparison with the
4449 available value-numbers. */
4450 else if (gimple_code (stmt
) == GIMPLE_COND
)
4452 tree op0
= gimple_cond_lhs (stmt
);
4453 tree op1
= gimple_cond_rhs (stmt
);
4456 if (TREE_CODE (op0
) == SSA_NAME
)
4457 op0
= VN_INFO (op0
)->valnum
;
4458 if (TREE_CODE (op1
) == SSA_NAME
)
4459 op1
= VN_INFO (op1
)->valnum
;
4460 result
= fold_binary (gimple_cond_code (stmt
), boolean_type_node
,
4462 if (result
&& TREE_CODE (result
) == INTEGER_CST
)
4464 if (integer_zerop (result
))
4465 gimple_cond_make_false (stmt
);
4467 gimple_cond_make_true (stmt
);
4469 todo
= TODO_cleanup_cfg
;
4472 /* Visit indirect calls and turn them into direct calls if
4474 if (is_gimple_call (stmt
))
4476 tree orig_fn
= gimple_call_fn (stmt
);
4480 if (TREE_CODE (orig_fn
) == SSA_NAME
)
4481 fn
= VN_INFO (orig_fn
)->valnum
;
4482 else if (TREE_CODE (orig_fn
) == OBJ_TYPE_REF
4483 && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn
)) == SSA_NAME
)
4484 fn
= VN_INFO (OBJ_TYPE_REF_EXPR (orig_fn
))->valnum
;
4487 if (gimple_call_addr_fndecl (fn
) != NULL_TREE
4488 && useless_type_conversion_p (TREE_TYPE (orig_fn
),
4491 bool can_make_abnormal_goto
4492 = stmt_can_make_abnormal_goto (stmt
);
4493 bool was_noreturn
= gimple_call_noreturn_p (stmt
);
4495 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4497 fprintf (dump_file
, "Replacing call target with ");
4498 print_generic_expr (dump_file
, fn
, 0);
4499 fprintf (dump_file
, " in ");
4500 print_gimple_stmt (dump_file
, stmt
, 0, 0);
4503 gimple_call_set_fn (stmt
, fn
);
4504 VEC_safe_push (gimple
, heap
, to_update
, stmt
);
4506 /* When changing a call into a noreturn call, cfg cleanup
4507 is needed to fix up the noreturn call. */
4508 if (!was_noreturn
&& gimple_call_noreturn_p (stmt
))
4509 todo
|= TODO_cleanup_cfg
;
4511 /* If we removed EH side-effects from the statement, clean
4512 its EH information. */
4513 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
4515 bitmap_set_bit (need_eh_cleanup
,
4516 gimple_bb (stmt
)->index
);
4517 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4518 fprintf (dump_file
, " Removed EH side-effects.\n");
4521 /* Likewise for AB side-effects. */
4522 if (can_make_abnormal_goto
4523 && !stmt_can_make_abnormal_goto (stmt
))
4525 bitmap_set_bit (need_ab_cleanup
,
4526 gimple_bb (stmt
)->index
);
4527 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4528 fprintf (dump_file
, " Removed AB side-effects.\n");
4531 /* Changing an indirect call to a direct call may
4532 have exposed different semantics. This may
4533 require an SSA update. */
4534 todo
|= TODO_update_ssa_only_virtuals
;
4539 for (gsi
= gsi_start_phis (b
); !gsi_end_p (gsi
);)
4541 gimple stmt
, phi
= gsi_stmt (gsi
);
4542 tree sprime
= NULL_TREE
, res
= PHI_RESULT (phi
);
4543 pre_expr sprimeexpr
, resexpr
;
4544 gimple_stmt_iterator gsi2
;
4546 /* We want to perform redundant PHI elimination. Do so by
4547 replacing the PHI with a single copy if possible.
4548 Do not touch inserted, single-argument or virtual PHIs. */
4549 if (gimple_phi_num_args (phi
) == 1
4550 || !is_gimple_reg (res
))
4556 resexpr
= get_or_alloc_expr_for_name (res
);
4557 sprimeexpr
= bitmap_find_leader (AVAIL_OUT (b
),
4558 get_expr_value_id (resexpr
), NULL
);
4561 if (sprimeexpr
->kind
== CONSTANT
)
4562 sprime
= PRE_EXPR_CONSTANT (sprimeexpr
);
4563 else if (sprimeexpr
->kind
== NAME
)
4564 sprime
= PRE_EXPR_NAME (sprimeexpr
);
4568 if (!sprime
&& is_gimple_min_invariant (VN_INFO (res
)->valnum
))
4570 sprime
= VN_INFO (res
)->valnum
;
4571 if (!useless_type_conversion_p (TREE_TYPE (res
),
4572 TREE_TYPE (sprime
)))
4573 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4582 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4584 fprintf (dump_file
, "Replaced redundant PHI node defining ");
4585 print_generic_expr (dump_file
, res
, 0);
4586 fprintf (dump_file
, " with ");
4587 print_generic_expr (dump_file
, sprime
, 0);
4588 fprintf (dump_file
, "\n");
4591 remove_phi_node (&gsi
, false);
4593 if (!bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
))
4594 && TREE_CODE (sprime
) == SSA_NAME
)
4595 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
), NECESSARY
, true);
4597 if (!useless_type_conversion_p (TREE_TYPE (res
), TREE_TYPE (sprime
)))
4598 sprime
= fold_convert (TREE_TYPE (res
), sprime
);
4599 stmt
= gimple_build_assign (res
, sprime
);
4600 SSA_NAME_DEF_STMT (res
) = stmt
;
4601 gimple_set_plf (stmt
, NECESSARY
, gimple_plf (phi
, NECESSARY
));
4603 gsi2
= gsi_after_labels (b
);
4604 gsi_insert_before (&gsi2
, stmt
, GSI_NEW_STMT
);
4605 /* Queue the copy for eventual removal. */
4606 VEC_safe_push (gimple
, heap
, to_remove
, stmt
);
4607 /* If we inserted this PHI node ourself, it's not an elimination. */
4608 if (bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (res
)))
4611 pre_stats
.eliminations
++;
4615 /* We cannot remove stmts during BB walk, especially not release SSA
4616 names there as this confuses the VN machinery. The stmts ending
4617 up in to_remove are either stores or simple copies. */
4618 FOR_EACH_VEC_ELT (gimple
, to_remove
, i
, stmt
)
4620 tree lhs
= gimple_assign_lhs (stmt
);
4621 tree rhs
= gimple_assign_rhs1 (stmt
);
4622 use_operand_p use_p
;
4625 /* If there is a single use only, propagate the equivalency
4626 instead of keeping the copy. */
4627 if (TREE_CODE (lhs
) == SSA_NAME
4628 && TREE_CODE (rhs
) == SSA_NAME
4629 && single_imm_use (lhs
, &use_p
, &use_stmt
)
4630 && may_propagate_copy (USE_FROM_PTR (use_p
), rhs
))
4632 SET_USE (use_p
, rhs
);
4633 update_stmt (use_stmt
);
4634 if (bitmap_bit_p (inserted_exprs
, SSA_NAME_VERSION (lhs
))
4635 && TREE_CODE (rhs
) == SSA_NAME
)
4636 gimple_set_plf (SSA_NAME_DEF_STMT (rhs
), NECESSARY
, true);
4639 /* If this is a store or a now unused copy, remove it. */
4640 if (TREE_CODE (lhs
) != SSA_NAME
4641 || has_zero_uses (lhs
))
4643 basic_block bb
= gimple_bb (stmt
);
4644 gsi
= gsi_for_stmt (stmt
);
4645 unlink_stmt_vdef (stmt
);
4646 if (gsi_remove (&gsi
, true))
4647 bitmap_set_bit (need_eh_cleanup
, bb
->index
);
4648 if (TREE_CODE (lhs
) == SSA_NAME
)
4649 bitmap_clear_bit (inserted_exprs
, SSA_NAME_VERSION (lhs
));
4650 release_defs (stmt
);
4653 VEC_free (gimple
, heap
, to_remove
);
4655 /* We cannot update call statements with virtual operands during
4656 SSA walk. This might remove them which in turn makes our
4657 VN lattice invalid. */
4658 FOR_EACH_VEC_ELT (gimple
, to_update
, i
, stmt
)
4660 VEC_free (gimple
, heap
, to_update
);
4665 /* Borrow a bit of tree-ssa-dce.c for the moment.
4666 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4667 this may be a bit faster, and we may want critical edges kept split. */
4669 /* If OP's defining statement has not already been determined to be necessary,
4670 mark that statement necessary. Return the stmt, if it is newly
4673 static inline gimple
4674 mark_operand_necessary (tree op
)
4680 if (TREE_CODE (op
) != SSA_NAME
)
4683 stmt
= SSA_NAME_DEF_STMT (op
);
4686 if (gimple_plf (stmt
, NECESSARY
)
4687 || gimple_nop_p (stmt
))
4690 gimple_set_plf (stmt
, NECESSARY
, true);
4694 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4695 to insert PHI nodes sometimes, and because value numbering of casts isn't
4696 perfect, we sometimes end up inserting dead code. This simple DCE-like
4697 pass removes any insertions we made that weren't actually used. */
4700 remove_dead_inserted_code (void)
4707 worklist
= BITMAP_ALLOC (NULL
);
4708 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4710 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4711 if (gimple_plf (t
, NECESSARY
))
4712 bitmap_set_bit (worklist
, i
);
4714 while (!bitmap_empty_p (worklist
))
4716 i
= bitmap_first_set_bit (worklist
);
4717 bitmap_clear_bit (worklist
, i
);
4718 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4720 /* PHI nodes are somewhat special in that each PHI alternative has
4721 data and control dependencies. All the statements feeding the
4722 PHI node's arguments are always necessary. */
4723 if (gimple_code (t
) == GIMPLE_PHI
)
4727 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4729 tree arg
= PHI_ARG_DEF (t
, k
);
4730 if (TREE_CODE (arg
) == SSA_NAME
)
4732 gimple n
= mark_operand_necessary (arg
);
4734 bitmap_set_bit (worklist
, SSA_NAME_VERSION (arg
));
4740 /* Propagate through the operands. Examine all the USE, VUSE and
4741 VDEF operands in this statement. Mark all the statements
4742 which feed this statement's uses as necessary. */
4746 /* The operands of VDEF expressions are also needed as they
4747 represent potential definitions that may reach this
4748 statement (VDEF operands allow us to follow def-def
4751 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4753 gimple n
= mark_operand_necessary (use
);
4755 bitmap_set_bit (worklist
, SSA_NAME_VERSION (use
));
4760 EXECUTE_IF_SET_IN_BITMAP (inserted_exprs
, 0, i
, bi
)
4762 t
= SSA_NAME_DEF_STMT (ssa_name (i
));
4763 if (!gimple_plf (t
, NECESSARY
))
4765 gimple_stmt_iterator gsi
;
4767 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4769 fprintf (dump_file
, "Removing unnecessary insertion:");
4770 print_gimple_stmt (dump_file
, t
, 0, 0);
4773 gsi
= gsi_for_stmt (t
);
4774 if (gimple_code (t
) == GIMPLE_PHI
)
4775 remove_phi_node (&gsi
, true);
4778 gsi_remove (&gsi
, true);
4783 BITMAP_FREE (worklist
);
4786 /* Compute a reverse post-order in *POST_ORDER. If INCLUDE_ENTRY_EXIT is
4787 true, then then ENTRY_BLOCK and EXIT_BLOCK are included. Returns
4788 the number of visited blocks. */
4791 my_rev_post_order_compute (int *post_order
, bool include_entry_exit
)
4793 edge_iterator
*stack
;
4795 int post_order_num
= 0;
4798 if (include_entry_exit
)
4799 post_order
[post_order_num
++] = EXIT_BLOCK
;
4801 /* Allocate stack for back-tracking up CFG. */
4802 stack
= XNEWVEC (edge_iterator
, n_basic_blocks
+ 1);
4805 /* Allocate bitmap to track nodes that have been visited. */
4806 visited
= sbitmap_alloc (last_basic_block
);
4808 /* None of the nodes in the CFG have been visited yet. */
4809 sbitmap_zero (visited
);
4811 /* Push the last edge on to the stack. */
4812 stack
[sp
++] = ei_start (EXIT_BLOCK_PTR
->preds
);
4820 /* Look at the edge on the top of the stack. */
4822 src
= ei_edge (ei
)->src
;
4823 dest
= ei_edge (ei
)->dest
;
4825 /* Check if the edge destination has been visited yet. */
4826 if (src
!= ENTRY_BLOCK_PTR
&& ! TEST_BIT (visited
, src
->index
))
4828 /* Mark that we have visited the destination. */
4829 SET_BIT (visited
, src
->index
);
4831 if (EDGE_COUNT (src
->preds
) > 0)
4832 /* Since the DEST node has been visited for the first
4833 time, check its successors. */
4834 stack
[sp
++] = ei_start (src
->preds
);
4836 post_order
[post_order_num
++] = src
->index
;
4840 if (ei_one_before_end_p (ei
) && dest
!= EXIT_BLOCK_PTR
)
4841 post_order
[post_order_num
++] = dest
->index
;
4843 if (!ei_one_before_end_p (ei
))
4844 ei_next (&stack
[sp
- 1]);
4850 if (include_entry_exit
)
4851 post_order
[post_order_num
++] = ENTRY_BLOCK
;
4854 sbitmap_free (visited
);
4855 return post_order_num
;
4859 /* Initialize data structures used by PRE. */
4862 init_pre (bool do_fre
)
4866 next_expression_id
= 1;
4868 VEC_safe_push (pre_expr
, heap
, expressions
, NULL
);
4869 value_expressions
= VEC_alloc (bitmap_set_t
, heap
, get_max_value_id () + 1);
4870 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
4871 get_max_value_id() + 1);
4876 inserted_exprs
= BITMAP_ALLOC (NULL
);
4877 need_creation
= NULL
;
4878 pretemp
= NULL_TREE
;
4879 storetemp
= NULL_TREE
;
4880 prephitemp
= NULL_TREE
;
4882 connect_infinite_loops_to_exit ();
4883 memset (&pre_stats
, 0, sizeof (pre_stats
));
4886 postorder
= XNEWVEC (int, n_basic_blocks
- NUM_FIXED_BLOCKS
);
4887 my_rev_post_order_compute (postorder
, false);
4889 alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets
));
4891 calculate_dominance_info (CDI_POST_DOMINATORS
);
4892 calculate_dominance_info (CDI_DOMINATORS
);
4894 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4895 phi_translate_table
= htab_create (5110, expr_pred_trans_hash
,
4896 expr_pred_trans_eq
, free
);
4897 expression_to_id
= htab_create (num_ssa_names
* 3,
4900 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4901 sizeof (struct bitmap_set
), 30);
4902 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4903 sizeof (struct pre_expr_d
), 30);
4906 EXP_GEN (bb
) = bitmap_set_new ();
4907 PHI_GEN (bb
) = bitmap_set_new ();
4908 TMP_GEN (bb
) = bitmap_set_new ();
4909 AVAIL_OUT (bb
) = bitmap_set_new ();
4912 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4913 need_ab_cleanup
= BITMAP_ALLOC (NULL
);
4917 /* Deallocate data structures used by PRE. */
4920 fini_pre (bool do_fre
)
4922 bool do_eh_cleanup
= !bitmap_empty_p (need_eh_cleanup
);
4923 bool do_ab_cleanup
= !bitmap_empty_p (need_ab_cleanup
);
4926 VEC_free (bitmap_set_t
, heap
, value_expressions
);
4927 BITMAP_FREE (inserted_exprs
);
4928 VEC_free (gimple
, heap
, need_creation
);
4929 bitmap_obstack_release (&grand_bitmap_obstack
);
4930 free_alloc_pool (bitmap_set_pool
);
4931 free_alloc_pool (pre_expr_pool
);
4932 htab_delete (phi_translate_table
);
4933 htab_delete (expression_to_id
);
4934 VEC_free (unsigned, heap
, name_to_id
);
4936 free_aux_for_blocks ();
4938 free_dominance_info (CDI_POST_DOMINATORS
);
4941 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4944 gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup
);
4946 BITMAP_FREE (need_eh_cleanup
);
4947 BITMAP_FREE (need_ab_cleanup
);
4949 if (do_eh_cleanup
|| do_ab_cleanup
)
4950 cleanup_tree_cfg ();
4953 loop_optimizer_finalize ();
4956 /* Main entry point to the SSA-PRE pass. DO_FRE is true if the caller
4957 only wants to do full redundancy elimination. */
4960 execute_pre (bool do_fre
)
4962 unsigned int todo
= 0;
4964 do_partial_partial
=
4965 flag_tree_partial_pre
&& optimize_function_for_speed_p (cfun
);
4967 /* This has to happen before SCCVN runs because
4968 loop_optimizer_init may create new phis, etc. */
4970 loop_optimizer_init (LOOPS_NORMAL
);
4972 if (!run_scc_vn (do_fre
? VN_WALKREWRITE
: VN_WALK
))
4975 loop_optimizer_finalize ();
4983 /* Collect and value number expressions computed in each basic block. */
4986 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4992 print_bitmap_set (dump_file
, EXP_GEN (bb
), "exp_gen", bb
->index
);
4993 print_bitmap_set (dump_file
, PHI_GEN (bb
), "phi_gen", bb
->index
);
4994 print_bitmap_set (dump_file
, TMP_GEN (bb
), "tmp_gen", bb
->index
);
4995 print_bitmap_set (dump_file
, AVAIL_OUT (bb
), "avail_out", bb
->index
);
4999 /* Insert can get quite slow on an incredibly large number of basic
5000 blocks due to some quadratic behavior. Until this behavior is
5001 fixed, don't run it when he have an incredibly large number of
5002 bb's. If we aren't going to run insert, there is no point in
5003 computing ANTIC, either, even though it's plenty fast. */
5004 if (!do_fre
&& n_basic_blocks
< 4000)
5010 /* Make sure to remove fake edges before committing our inserts.
5011 This makes sure we don't end up with extra critical edges that
5012 we would need to split. */
5013 remove_fake_exit_edges ();
5014 gsi_commit_edge_inserts ();
5016 /* Remove all the redundant expressions. */
5017 todo
|= eliminate ();
5019 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
5020 statistics_counter_event (cfun
, "PA inserted", pre_stats
.pa_insert
);
5021 statistics_counter_event (cfun
, "New PHIs", pre_stats
.phis
);
5022 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
5023 statistics_counter_event (cfun
, "Constified", pre_stats
.constified
);
5025 clear_expression_ids ();
5028 remove_dead_inserted_code ();
5029 todo
|= TODO_verify_flow
;
5036 /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
5037 case we can merge the block with the remaining predecessor of the block.
5039 - call merge_blocks after each tail merge iteration
5040 - call merge_blocks after all tail merge iterations
5041 - mark TODO_cleanup_cfg when necessary
5042 - share the cfg cleanup with fini_pre. */
5043 todo
|= tail_merge_optimize (todo
);
5049 /* Gate and execute functions for PRE. */
5054 return execute_pre (false);
5060 return flag_tree_pre
!= 0;
5063 struct gimple_opt_pass pass_pre
=
5068 gate_pre
, /* gate */
5069 do_pre
, /* execute */
5072 0, /* static_pass_number */
5073 TV_TREE_PRE
, /* tv_id */
5074 PROP_no_crit_edges
| PROP_cfg
5075 | PROP_ssa
, /* properties_required */
5076 0, /* properties_provided */
5077 0, /* properties_destroyed */
5078 TODO_rebuild_alias
, /* todo_flags_start */
5079 TODO_update_ssa_only_virtuals
| TODO_ggc_collect
5080 | TODO_verify_ssa
/* todo_flags_finish */
5085 /* Gate and execute functions for FRE. */
5090 return execute_pre (true);
5096 return flag_tree_fre
!= 0;
5099 struct gimple_opt_pass pass_fre
=
5104 gate_fre
, /* gate */
5105 execute_fre
, /* execute */
5108 0, /* static_pass_number */
5109 TV_TREE_FRE
, /* tv_id */
5110 PROP_cfg
| PROP_ssa
, /* properties_required */
5111 0, /* properties_provided */
5112 0, /* properties_destroyed */
5113 0, /* todo_flags_start */
5114 TODO_ggc_collect
| TODO_verify_ssa
/* todo_flags_finish */