2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
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"
29 #include "basic-block.h"
30 #include "diagnostic.h"
31 #include "tree-inline.h"
32 #include "tree-flow.h"
34 #include "tree-dump.h"
38 #include "tree-iterator.h"
40 #include "alloc-pool.h"
42 #include "tree-pass.h"
45 #include "langhooks.h"
47 #include "tree-ssa-sccvn.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 iterative_hash_expr (PRE_EXPR_NAME (e
), 0);
221 return vn_nary_op_compute_hash (PRE_EXPR_NARY (e
));
223 return vn_reference_compute_hash (PRE_EXPR_REFERENCE (e
));
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
;
239 /* Allocate an expression id for EXPR. */
241 static inline unsigned int
242 alloc_expression_id (pre_expr expr
)
245 /* Make sure we won't overflow. */
246 gcc_assert (next_expression_id
+ 1 > next_expression_id
);
247 expr
->id
= next_expression_id
++;
248 VEC_safe_push (pre_expr
, heap
, expressions
, expr
);
249 slot
= htab_find_slot (expression_to_id
, expr
, INSERT
);
252 return next_expression_id
- 1;
255 /* Return the expression id for tree EXPR. */
257 static inline unsigned int
258 get_expression_id (const pre_expr expr
)
263 static inline unsigned int
264 lookup_expression_id (const pre_expr expr
)
268 slot
= htab_find_slot (expression_to_id
, expr
, NO_INSERT
);
271 return ((pre_expr
)*slot
)->id
;
274 /* Return the existing expression id for EXPR, or create one if one
275 does not exist yet. */
277 static inline unsigned int
278 get_or_alloc_expression_id (pre_expr expr
)
280 unsigned int id
= lookup_expression_id (expr
);
282 return alloc_expression_id (expr
);
283 return expr
->id
= id
;
286 /* Return the expression that has expression id ID */
288 static inline pre_expr
289 expression_for_id (unsigned int id
)
291 return VEC_index (pre_expr
, expressions
, id
);
294 /* Free the expression id field in all of our expressions,
295 and then destroy the expressions array. */
298 clear_expression_ids (void)
300 VEC_free (pre_expr
, heap
, expressions
);
303 static alloc_pool pre_expr_pool
;
305 /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
308 get_or_alloc_expr_for_name (tree name
)
310 pre_expr result
= (pre_expr
) pool_alloc (pre_expr_pool
);
311 unsigned int result_id
;
315 PRE_EXPR_NAME (result
) = name
;
316 result_id
= lookup_expression_id (result
);
319 pool_free (pre_expr_pool
, result
);
320 result
= expression_for_id (result_id
);
323 get_or_alloc_expression_id (result
);
327 static bool in_fre
= false;
329 /* An unordered bitmap set. One bitmap tracks values, the other,
331 typedef struct bitmap_set
337 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
338 EXECUTE_IF_SET_IN_BITMAP((set)->expressions, 0, (id), (bi))
340 /* Mapping from value id to expressions with that value_id. */
341 DEF_VEC_P (bitmap_set_t
);
342 DEF_VEC_ALLOC_P (bitmap_set_t
, heap
);
343 static VEC(bitmap_set_t
, heap
) *value_expressions
;
345 /* Sets that we need to keep track of. */
346 typedef struct bb_bitmap_sets
348 /* The EXP_GEN set, which represents expressions/values generated in
350 bitmap_set_t exp_gen
;
352 /* The PHI_GEN set, which represents PHI results generated in a
354 bitmap_set_t phi_gen
;
356 /* The TMP_GEN set, which represents results/temporaries generated
357 in a basic block. IE the LHS of an expression. */
358 bitmap_set_t tmp_gen
;
360 /* The AVAIL_OUT set, which represents which values are available in
361 a given basic block. */
362 bitmap_set_t avail_out
;
364 /* The ANTIC_IN set, which represents which values are anticipatable
365 in a given basic block. */
366 bitmap_set_t antic_in
;
368 /* The PA_IN set, which represents which values are
369 partially anticipatable in a given basic block. */
372 /* The NEW_SETS set, which is used during insertion to augment the
373 AVAIL_OUT set of blocks with the new insertions performed during
374 the current iteration. */
375 bitmap_set_t new_sets
;
377 /* True if we have visited this block during ANTIC calculation. */
378 unsigned int visited
:1;
380 /* True we have deferred processing this block during ANTIC
381 calculation until its successor is processed. */
382 unsigned int deferred
: 1;
385 #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
386 #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
387 #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
388 #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
389 #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
390 #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
391 #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
392 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
393 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
396 /* Maximal set of values, used to initialize the ANTIC problem, which
397 is an intersection problem. */
398 static bitmap_set_t maximal_set
;
400 /* Basic block list in postorder. */
401 static int *postorder
;
403 /* This structure is used to keep track of statistics on what
404 optimization PRE was able to perform. */
407 /* The number of RHS computations eliminated by PRE. */
410 /* The number of new expressions/temporaries generated by PRE. */
413 /* The number of inserts found due to partial anticipation */
416 /* The number of new PHI nodes added by PRE. */
419 /* The number of values found constant. */
424 static bool do_partial_partial
;
425 static pre_expr
bitmap_find_leader (bitmap_set_t
, unsigned int, gimple
);
426 static void bitmap_value_insert_into_set (bitmap_set_t
, pre_expr
);
427 static void bitmap_value_replace_in_set (bitmap_set_t
, pre_expr
);
428 static void bitmap_set_copy (bitmap_set_t
, bitmap_set_t
);
429 static bool bitmap_set_contains_value (bitmap_set_t
, unsigned int);
430 static void bitmap_insert_into_set (bitmap_set_t
, pre_expr
);
431 static void bitmap_insert_into_set_1 (bitmap_set_t
, pre_expr
, bool);
432 static bitmap_set_t
bitmap_set_new (void);
433 static tree
create_expression_by_pieces (basic_block
, pre_expr
, gimple_seq
*,
435 static tree
find_or_generate_expression (basic_block
, pre_expr
, gimple_seq
*,
438 /* We can add and remove elements and entries to and from sets
439 and hash tables, so we use alloc pools for them. */
441 static alloc_pool bitmap_set_pool
;
442 static bitmap_obstack grand_bitmap_obstack
;
444 /* To avoid adding 300 temporary variables when we only need one, we
445 only create one temporary variable, on demand, and build ssa names
446 off that. We do have to change the variable if the types don't
447 match the current variable's type. */
449 static tree storetemp
;
450 static tree prephitemp
;
452 /* Set of blocks with statements that have had its EH information
454 static bitmap need_eh_cleanup
;
456 /* Which expressions have been seen during a given phi translation. */
457 static bitmap seen_during_translate
;
459 /* The phi_translate_table caches phi translations for a given
460 expression and predecessor. */
462 static htab_t phi_translate_table
;
464 /* A three tuple {e, pred, v} used to cache phi translations in the
465 phi_translate_table. */
467 typedef struct expr_pred_trans_d
469 /* The expression. */
472 /* The predecessor block along which we translated the expression. */
475 /* The value that resulted from the translation. */
478 /* The hashcode for the expression, pred pair. This is cached for
481 } *expr_pred_trans_t
;
482 typedef const struct expr_pred_trans_d
*const_expr_pred_trans_t
;
484 /* Return the hash value for a phi translation table entry. */
487 expr_pred_trans_hash (const void *p
)
489 const_expr_pred_trans_t
const ve
= (const_expr_pred_trans_t
) p
;
493 /* Return true if two phi translation table entries are the same.
494 P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
497 expr_pred_trans_eq (const void *p1
, const void *p2
)
499 const_expr_pred_trans_t
const ve1
= (const_expr_pred_trans_t
) p1
;
500 const_expr_pred_trans_t
const ve2
= (const_expr_pred_trans_t
) p2
;
501 basic_block b1
= ve1
->pred
;
502 basic_block b2
= ve2
->pred
;
504 /* If they are not translations for the same basic block, they can't
508 return pre_expr_eq (ve1
->e
, ve2
->e
);
511 /* Search in the phi translation table for the translation of
512 expression E in basic block PRED.
513 Return the translated value, if found, NULL otherwise. */
515 static inline pre_expr
516 phi_trans_lookup (pre_expr e
, basic_block pred
)
519 struct expr_pred_trans_d ept
;
523 ept
.hashcode
= iterative_hash_hashval_t (pre_expr_hash (e
), pred
->index
);
524 slot
= htab_find_slot_with_hash (phi_translate_table
, &ept
, ept
.hashcode
,
529 return ((expr_pred_trans_t
) *slot
)->v
;
533 /* Add the tuple mapping from {expression E, basic block PRED} to
534 value V, to the phi translation table. */
537 phi_trans_add (pre_expr e
, pre_expr v
, basic_block pred
)
540 expr_pred_trans_t new_pair
= XNEW (struct expr_pred_trans_d
);
542 new_pair
->pred
= pred
;
544 new_pair
->hashcode
= iterative_hash_hashval_t (pre_expr_hash (e
),
547 slot
= htab_find_slot_with_hash (phi_translate_table
, new_pair
,
548 new_pair
->hashcode
, INSERT
);
551 *slot
= (void *) new_pair
;
555 /* Add expression E to the expression set of value id V. */
558 add_to_value (unsigned int v
, pre_expr e
)
562 if (v
>= VEC_length (bitmap_set_t
, value_expressions
))
564 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
568 set
= VEC_index (bitmap_set_t
, value_expressions
, v
);
571 set
= bitmap_set_new ();
572 VEC_replace (bitmap_set_t
, value_expressions
, v
, set
);
575 bitmap_insert_into_set_1 (set
, e
, true);
578 /* Create a new bitmap set and return it. */
581 bitmap_set_new (void)
583 bitmap_set_t ret
= (bitmap_set_t
) pool_alloc (bitmap_set_pool
);
584 ret
->expressions
= BITMAP_ALLOC (&grand_bitmap_obstack
);
585 ret
->values
= BITMAP_ALLOC (&grand_bitmap_obstack
);
589 /* Return the value id for a PRE expression EXPR. */
592 get_expr_value_id (pre_expr expr
)
599 id
= get_constant_value_id (PRE_EXPR_CONSTANT (expr
));
602 id
= get_or_alloc_constant_value_id (PRE_EXPR_CONSTANT (expr
));
603 add_to_value (id
, expr
);
608 return VN_INFO (PRE_EXPR_NAME (expr
))->value_id
;
610 return PRE_EXPR_NARY (expr
)->value_id
;
612 return PRE_EXPR_REFERENCE (expr
)->value_id
;
618 /* Remove an expression EXPR from a bitmapped set. */
621 bitmap_remove_from_set (bitmap_set_t set
, pre_expr expr
)
623 unsigned int val
= get_expr_value_id (expr
);
624 if (!value_id_constant_p (val
))
626 bitmap_clear_bit (set
->values
, val
);
627 bitmap_clear_bit (set
->expressions
, get_expression_id (expr
));
632 bitmap_insert_into_set_1 (bitmap_set_t set
, pre_expr expr
,
633 bool allow_constants
)
635 unsigned int val
= get_expr_value_id (expr
);
636 if (allow_constants
|| !value_id_constant_p (val
))
638 /* We specifically expect this and only this function to be able to
639 insert constants into a set. */
640 bitmap_set_bit (set
->values
, val
);
641 bitmap_set_bit (set
->expressions
, get_or_alloc_expression_id (expr
));
645 /* Insert an expression EXPR into a bitmapped set. */
648 bitmap_insert_into_set (bitmap_set_t set
, pre_expr expr
)
650 bitmap_insert_into_set_1 (set
, expr
, false);
653 /* Copy a bitmapped set ORIG, into bitmapped set DEST. */
656 bitmap_set_copy (bitmap_set_t dest
, bitmap_set_t orig
)
658 bitmap_copy (dest
->expressions
, orig
->expressions
);
659 bitmap_copy (dest
->values
, orig
->values
);
663 /* Free memory used up by SET. */
665 bitmap_set_free (bitmap_set_t set
)
667 BITMAP_FREE (set
->expressions
);
668 BITMAP_FREE (set
->values
);
672 /* A comparison function for use in qsort to top sort a bitmap set. Simply
673 subtracts value ids, since they are created with leaves before
674 their parent users (IE topological order). */
677 value_id_compare (const void *pa
, const void *pb
)
679 const unsigned int vha
= get_expr_value_id (*((const pre_expr
*)pa
));
680 const unsigned int vhb
= get_expr_value_id (*((const pre_expr
*)pb
));
685 /* Generate an topological-ordered array of bitmap set SET. */
687 static VEC(pre_expr
, heap
) *
688 sorted_array_from_bitmap_set (bitmap_set_t set
)
692 VEC(pre_expr
, heap
) *result
= NULL
;
694 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
695 VEC_safe_push (pre_expr
, heap
, result
, expression_for_id (i
));
697 qsort (VEC_address (pre_expr
, result
), VEC_length (pre_expr
, result
),
698 sizeof (pre_expr
), value_id_compare
);
703 /* Perform bitmapped set operation DEST &= ORIG. */
706 bitmap_set_and (bitmap_set_t dest
, bitmap_set_t orig
)
713 bitmap temp
= BITMAP_ALLOC (&grand_bitmap_obstack
);
715 bitmap_and_into (dest
->values
, orig
->values
);
716 bitmap_copy (temp
, dest
->expressions
);
717 EXECUTE_IF_SET_IN_BITMAP (temp
, 0, i
, bi
)
719 pre_expr expr
= expression_for_id (i
);
720 unsigned int value_id
= get_expr_value_id (expr
);
721 if (!bitmap_bit_p (dest
->values
, value_id
))
722 bitmap_clear_bit (dest
->expressions
, i
);
728 /* Subtract all values and expressions contained in ORIG from DEST. */
731 bitmap_set_subtract (bitmap_set_t dest
, bitmap_set_t orig
)
733 bitmap_set_t result
= bitmap_set_new ();
737 bitmap_and_compl (result
->expressions
, dest
->expressions
,
740 FOR_EACH_EXPR_ID_IN_SET (result
, i
, bi
)
742 pre_expr expr
= expression_for_id (i
);
743 unsigned int value_id
= get_expr_value_id (expr
);
744 bitmap_set_bit (result
->values
, value_id
);
750 /* Subtract all the values in bitmap set B from bitmap set A. */
753 bitmap_set_subtract_values (bitmap_set_t a
, bitmap_set_t b
)
757 bitmap temp
= BITMAP_ALLOC (&grand_bitmap_obstack
);
759 bitmap_copy (temp
, a
->expressions
);
760 EXECUTE_IF_SET_IN_BITMAP (temp
, 0, i
, bi
)
762 pre_expr expr
= expression_for_id (i
);
763 if (bitmap_set_contains_value (b
, get_expr_value_id (expr
)))
764 bitmap_remove_from_set (a
, expr
);
770 /* Return true if bitmapped set SET contains the value VALUE_ID. */
773 bitmap_set_contains_value (bitmap_set_t set
, unsigned int value_id
)
775 if (value_id_constant_p (value_id
))
778 if (!set
|| bitmap_empty_p (set
->expressions
))
781 return bitmap_bit_p (set
->values
, value_id
);
785 bitmap_set_contains_expr (bitmap_set_t set
, const pre_expr expr
)
787 return bitmap_bit_p (set
->expressions
, get_expression_id (expr
));
790 /* Replace an instance of value LOOKFOR with expression EXPR in SET. */
793 bitmap_set_replace_value (bitmap_set_t set
, unsigned int lookfor
,
796 bitmap_set_t exprset
;
800 if (value_id_constant_p (lookfor
))
803 if (!bitmap_set_contains_value (set
, lookfor
))
806 /* The number of expressions having a given value is usually
807 significantly less than the total number of expressions in SET.
808 Thus, rather than check, for each expression in SET, whether it
809 has the value LOOKFOR, we walk the reverse mapping that tells us
810 what expressions have a given value, and see if any of those
811 expressions are in our set. For large testcases, this is about
812 5-10x faster than walking the bitmap. If this is somehow a
813 significant lose for some cases, we can choose which set to walk
814 based on the set size. */
815 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
816 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
818 if (bitmap_bit_p (set
->expressions
, i
))
820 bitmap_clear_bit (set
->expressions
, i
);
821 bitmap_set_bit (set
->expressions
, get_expression_id (expr
));
827 /* Return true if two bitmap sets are equal. */
830 bitmap_set_equal (bitmap_set_t a
, bitmap_set_t b
)
832 return bitmap_equal_p (a
->values
, b
->values
);
835 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
836 and add it otherwise. */
839 bitmap_value_replace_in_set (bitmap_set_t set
, pre_expr expr
)
841 unsigned int val
= get_expr_value_id (expr
);
843 if (bitmap_set_contains_value (set
, val
))
844 bitmap_set_replace_value (set
, val
, expr
);
846 bitmap_insert_into_set (set
, expr
);
849 /* Insert EXPR into SET if EXPR's value is not already present in
853 bitmap_value_insert_into_set (bitmap_set_t set
, pre_expr expr
)
855 unsigned int val
= get_expr_value_id (expr
);
857 if (value_id_constant_p (val
))
860 if (!bitmap_set_contains_value (set
, val
))
861 bitmap_insert_into_set (set
, expr
);
864 /* Print out EXPR to outfile. */
867 print_pre_expr (FILE *outfile
, const pre_expr expr
)
872 print_generic_expr (outfile
, PRE_EXPR_CONSTANT (expr
), 0);
875 print_generic_expr (outfile
, PRE_EXPR_NAME (expr
), 0);
880 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
881 fprintf (outfile
, "{%s,", tree_code_name
[nary
->opcode
]);
882 for (i
= 0; i
< nary
->length
; i
++)
884 print_generic_expr (outfile
, nary
->op
[i
], 0);
885 if (i
!= (unsigned) nary
->length
- 1)
886 fprintf (outfile
, ",");
888 fprintf (outfile
, "}");
894 vn_reference_op_t vro
;
896 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
897 fprintf (outfile
, "{");
899 VEC_iterate (vn_reference_op_s
, ref
->operands
, i
, vro
);
902 if (vro
->opcode
!= SSA_NAME
903 && TREE_CODE_CLASS (vro
->opcode
) != tcc_declaration
)
904 fprintf (outfile
, "%s ", tree_code_name
[vro
->opcode
]);
908 fprintf (outfile
, "<");
909 print_generic_expr (outfile
, vro
->op0
, 0);
912 fprintf (outfile
, ",");
913 print_generic_expr (outfile
, vro
->op1
, 0);
916 fprintf (outfile
, ">");
918 if (i
!= VEC_length (vn_reference_op_s
, ref
->operands
) - 1)
919 fprintf (outfile
, ",");
921 fprintf (outfile
, "}");
926 void debug_pre_expr (pre_expr
);
928 /* Like print_pre_expr but always prints to stderr. */
930 debug_pre_expr (pre_expr e
)
932 print_pre_expr (stderr
, e
);
933 fprintf (stderr
, "\n");
936 /* Print out SET to OUTFILE. */
939 print_bitmap_set (FILE *outfile
, bitmap_set_t set
,
940 const char *setname
, int blockindex
)
942 fprintf (outfile
, "%s[%d] := { ", setname
, blockindex
);
949 FOR_EACH_EXPR_ID_IN_SET (set
, i
, bi
)
951 const pre_expr expr
= expression_for_id (i
);
954 fprintf (outfile
, ", ");
956 print_pre_expr (outfile
, expr
);
958 fprintf (outfile
, " (%04d)", get_expr_value_id (expr
));
961 fprintf (outfile
, " }\n");
964 void debug_bitmap_set (bitmap_set_t
);
967 debug_bitmap_set (bitmap_set_t set
)
969 print_bitmap_set (stderr
, set
, "debug", 0);
972 /* Print out the expressions that have VAL to OUTFILE. */
975 print_value_expressions (FILE *outfile
, unsigned int val
)
977 bitmap_set_t set
= VEC_index (bitmap_set_t
, value_expressions
, val
);
981 sprintf (s
, "%04d", val
);
982 print_bitmap_set (outfile
, set
, s
, 0);
988 debug_value_expressions (unsigned int val
)
990 print_value_expressions (stderr
, val
);
993 /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
997 get_or_alloc_expr_for_constant (tree constant
)
999 unsigned int result_id
;
1000 unsigned int value_id
;
1001 pre_expr newexpr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1002 newexpr
->kind
= CONSTANT
;
1003 PRE_EXPR_CONSTANT (newexpr
) = constant
;
1004 result_id
= lookup_expression_id (newexpr
);
1007 pool_free (pre_expr_pool
, newexpr
);
1008 newexpr
= expression_for_id (result_id
);
1011 value_id
= get_or_alloc_constant_value_id (constant
);
1012 get_or_alloc_expression_id (newexpr
);
1013 add_to_value (value_id
, newexpr
);
1017 /* Given a value id V, find the actual tree representing the constant
1018 value if there is one, and return it. Return NULL if we can't find
1022 get_constant_for_value_id (unsigned int v
)
1024 if (value_id_constant_p (v
))
1028 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, v
);
1030 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1032 pre_expr expr
= expression_for_id (i
);
1033 if (expr
->kind
== CONSTANT
)
1034 return PRE_EXPR_CONSTANT (expr
);
1040 /* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
1041 Currently only supports constants and SSA_NAMES. */
1043 get_or_alloc_expr_for (tree t
)
1045 if (TREE_CODE (t
) == SSA_NAME
)
1046 return get_or_alloc_expr_for_name (t
);
1047 else if (is_gimple_min_invariant (t
))
1048 return get_or_alloc_expr_for_constant (t
);
1051 /* More complex expressions can result from SCCVN expression
1052 simplification that inserts values for them. As they all
1053 do not have VOPs the get handled by the nary ops struct. */
1054 vn_nary_op_t result
;
1055 unsigned int result_id
;
1056 vn_nary_op_lookup (t
, &result
);
1059 pre_expr e
= (pre_expr
) pool_alloc (pre_expr_pool
);
1061 PRE_EXPR_NARY (e
) = result
;
1062 result_id
= lookup_expression_id (e
);
1065 pool_free (pre_expr_pool
, e
);
1066 e
= expression_for_id (result_id
);
1069 alloc_expression_id (e
);
1076 /* Return the folded version of T if T, when folded, is a gimple
1077 min_invariant. Otherwise, return T. */
1080 fully_constant_expression (pre_expr e
)
1088 vn_nary_op_t nary
= PRE_EXPR_NARY (e
);
1089 switch (TREE_CODE_CLASS (nary
->opcode
))
1093 /* We have to go from trees to pre exprs to value ids to
1095 tree naryop0
= nary
->op
[0];
1096 tree naryop1
= nary
->op
[1];
1097 tree const0
, const1
, result
;
1098 if (is_gimple_min_invariant (naryop0
))
1102 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1103 unsigned int vrep0
= get_expr_value_id (rep0
);
1104 const0
= get_constant_for_value_id (vrep0
);
1106 if (is_gimple_min_invariant (naryop1
))
1110 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1111 unsigned int vrep1
= get_expr_value_id (rep1
);
1112 const1
= get_constant_for_value_id (vrep1
);
1115 if (const0
&& const1
)
1117 tree type1
= TREE_TYPE (nary
->op
[0]);
1118 tree type2
= TREE_TYPE (nary
->op
[1]);
1119 const0
= fold_convert (type1
, const0
);
1120 const1
= fold_convert (type2
, const1
);
1121 result
= fold_binary (nary
->opcode
, nary
->type
, const0
,
1124 if (result
&& is_gimple_min_invariant (result
))
1125 return get_or_alloc_expr_for_constant (result
);
1130 /* We have to go from trees to pre exprs to value ids to
1132 tree naryop0
= nary
->op
[0];
1133 tree const0
, result
;
1134 if (is_gimple_min_invariant (naryop0
))
1138 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1139 unsigned int vrep0
= get_expr_value_id (rep0
);
1140 const0
= get_constant_for_value_id (vrep0
);
1145 tree type1
= TREE_TYPE (nary
->op
[0]);
1146 const0
= fold_convert (type1
, const0
);
1147 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1150 if (result
&& is_gimple_min_invariant (result
))
1151 return get_or_alloc_expr_for_constant (result
);
1160 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1161 VEC (vn_reference_op_s
, heap
) *operands
= ref
->operands
;
1162 vn_reference_op_t op
;
1164 /* Try to simplify the translated expression if it is
1165 a call to a builtin function with at most two arguments. */
1166 op
= VEC_index (vn_reference_op_s
, operands
, 0);
1167 if (op
->opcode
== CALL_EXPR
1168 && TREE_CODE (op
->op0
) == ADDR_EXPR
1169 && TREE_CODE (TREE_OPERAND (op
->op0
, 0)) == FUNCTION_DECL
1170 && DECL_BUILT_IN (TREE_OPERAND (op
->op0
, 0))
1171 && VEC_length (vn_reference_op_s
, operands
) >= 2
1172 && VEC_length (vn_reference_op_s
, operands
) <= 3)
1174 vn_reference_op_t arg0
, arg1
= NULL
;
1175 bool anyconst
= false;
1176 arg0
= VEC_index (vn_reference_op_s
, operands
, 1);
1177 if (VEC_length (vn_reference_op_s
, operands
) > 2)
1178 arg1
= VEC_index (vn_reference_op_s
, operands
, 2);
1179 if (TREE_CODE_CLASS (arg0
->opcode
) == tcc_constant
1180 || (arg0
->opcode
== ADDR_EXPR
1181 && is_gimple_min_invariant (arg0
->op0
)))
1184 && (TREE_CODE_CLASS (arg1
->opcode
) == tcc_constant
1185 || (arg1
->opcode
== ADDR_EXPR
1186 && is_gimple_min_invariant (arg1
->op0
))))
1190 tree folded
= build_call_expr (TREE_OPERAND (op
->op0
, 0),
1193 arg1
? arg1
->op0
: NULL
);
1195 && TREE_CODE (folded
) == NOP_EXPR
)
1196 folded
= TREE_OPERAND (folded
, 0);
1198 && is_gimple_min_invariant (folded
))
1199 return get_or_alloc_expr_for_constant (folded
);
1210 /* Translate the vuses in the VUSES vector backwards through phi nodes
1211 in PHIBLOCK, so that they have the value they would have in
1214 static VEC(tree
, gc
) *
1215 translate_vuses_through_block (VEC (tree
, gc
) *vuses
,
1216 basic_block phiblock
,
1220 VEC(tree
, gc
) *result
= NULL
;
1223 for (i
= 0; VEC_iterate (tree
, vuses
, i
, oldvuse
); i
++)
1225 gimple phi
= SSA_NAME_DEF_STMT (oldvuse
);
1226 if (gimple_code (phi
) == GIMPLE_PHI
1227 && gimple_bb (phi
) == phiblock
)
1229 edge e
= find_edge (block
, gimple_bb (phi
));
1232 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1236 result
= VEC_copy (tree
, gc
, vuses
);
1237 VEC_replace (tree
, result
, i
, def
);
1243 /* We avoid creating a new copy of the vuses unless something
1244 actually changed, so result can be NULL. */
1247 sort_vuses (result
);
1254 /* Like find_leader, but checks for the value existing in SET1 *or*
1255 SET2. This is used to avoid making a set consisting of the union
1256 of PA_IN and ANTIC_IN during insert. */
1258 static inline pre_expr
1259 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1263 result
= bitmap_find_leader (set1
, val
, NULL
);
1264 if (!result
&& set2
)
1265 result
= bitmap_find_leader (set2
, val
, NULL
);
1269 /* Get the tree type for our PRE expression e. */
1272 get_expr_type (const pre_expr e
)
1277 return TREE_TYPE (PRE_EXPR_NAME (e
));
1279 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1282 vn_reference_op_t vro
;
1284 gcc_assert (PRE_EXPR_REFERENCE (e
)->operands
);
1285 vro
= VEC_index (vn_reference_op_s
,
1286 PRE_EXPR_REFERENCE (e
)->operands
,
1288 /* We don't store type along with COMPONENT_REF because it is
1289 always the same as FIELD_DECL's type. */
1292 gcc_assert (vro
->opcode
== COMPONENT_REF
);
1293 return TREE_TYPE (vro
->op0
);
1299 return PRE_EXPR_NARY (e
)->type
;
1304 /* Get a representative SSA_NAME for a given expression.
1305 Since all of our sub-expressions are treated as values, we require
1306 them to be SSA_NAME's for simplicity.
1307 Prior versions of GVNPRE used to use "value handles" here, so that
1308 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1309 either case, the operands are really values (IE we do not expect
1310 them to be usable without finding leaders). */
1313 get_representative_for (const pre_expr e
)
1317 unsigned int value_id
= get_expr_value_id (e
);
1322 return PRE_EXPR_NAME (e
);
1324 return PRE_EXPR_CONSTANT (e
);
1328 /* Go through all of the expressions representing this value
1329 and pick out an SSA_NAME. */
1332 bitmap_set_t exprs
= VEC_index (bitmap_set_t
, value_expressions
,
1334 FOR_EACH_EXPR_ID_IN_SET (exprs
, i
, bi
)
1336 pre_expr rep
= expression_for_id (i
);
1337 if (rep
->kind
== NAME
)
1338 return PRE_EXPR_NAME (rep
);
1343 /* If we reached here we couldn't find an SSA_NAME. This can
1344 happen when we've discovered a value that has never appeared in
1345 the program as set to an SSA_NAME, most likely as the result of
1350 "Could not find SSA_NAME representative for expression:");
1351 print_pre_expr (dump_file
, e
);
1352 fprintf (dump_file
, "\n");
1355 exprtype
= get_expr_type (e
);
1357 /* Build and insert the assignment of the end result to the temporary
1358 that we will return. */
1359 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
1361 pretemp
= create_tmp_var (exprtype
, "pretmp");
1362 get_var_ann (pretemp
);
1365 name
= make_ssa_name (pretemp
, gimple_build_nop ());
1366 VN_INFO_GET (name
)->value_id
= value_id
;
1367 if (e
->kind
== CONSTANT
)
1368 VN_INFO (name
)->valnum
= PRE_EXPR_CONSTANT (e
);
1370 VN_INFO (name
)->valnum
= name
;
1372 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1375 fprintf (dump_file
, "Created SSA_NAME representative ");
1376 print_generic_expr (dump_file
, name
, 0);
1377 fprintf (dump_file
, " for expression:");
1378 print_pre_expr (dump_file
, e
);
1379 fprintf (dump_file
, "\n");
1388 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1389 the phis in PRED. SEEN is a bitmap saying which expression we have
1390 translated since we started translation of the toplevel expression.
1391 Return NULL if we can't find a leader for each part of the
1392 translated expression. */
1395 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1396 basic_block pred
, basic_block phiblock
, bitmap seen
)
1398 pre_expr oldexpr
= expr
;
1404 if (value_id_constant_p (get_expr_value_id (expr
)))
1407 phitrans
= phi_trans_lookup (expr
, pred
);
1411 /* Prevent cycles when we have recursively dependent leaders. This
1412 can only happen when phi translating the maximal set. */
1415 unsigned int expr_id
= get_expression_id (expr
);
1416 if (bitmap_bit_p (seen
, expr_id
))
1418 bitmap_set_bit (seen
, expr_id
);
1423 /* Constants contain no values that need translation. */
1430 bool changed
= false;
1431 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1432 struct vn_nary_op_s newnary
;
1433 /* The NARY structure is only guaranteed to have been
1434 allocated to the nary->length operands. */
1435 memcpy (&newnary
, nary
, (sizeof (struct vn_nary_op_s
)
1436 - sizeof (tree
) * (4 - nary
->length
)));
1438 for (i
= 0; i
< newnary
.length
; i
++)
1440 if (TREE_CODE (newnary
.op
[i
]) != SSA_NAME
)
1444 unsigned int op_val_id
= VN_INFO (newnary
.op
[i
])->value_id
;
1445 pre_expr leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1446 pre_expr result
= phi_translate_1 (leader
, set1
, set2
,
1447 pred
, phiblock
, seen
);
1448 if (result
&& result
!= leader
)
1450 tree name
= get_representative_for (result
);
1453 newnary
.op
[i
] = name
;
1458 changed
|= newnary
.op
[i
] != nary
->op
[i
];
1465 tree result
= vn_nary_op_lookup_pieces (newnary
.length
,
1473 unsigned int new_val_id
;
1475 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1478 if (result
&& is_gimple_min_invariant (result
))
1479 return get_or_alloc_expr_for_constant (result
);
1484 PRE_EXPR_NARY (expr
) = nary
;
1485 constant
= fully_constant_expression (expr
);
1486 if (constant
!= expr
)
1489 new_val_id
= nary
->value_id
;
1490 get_or_alloc_expression_id (expr
);
1494 new_val_id
= get_next_value_id ();
1495 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1497 get_max_value_id() + 1);
1498 nary
= vn_nary_op_insert_pieces (newnary
.length
,
1505 result
, new_val_id
);
1506 PRE_EXPR_NARY (expr
) = nary
;
1507 constant
= fully_constant_expression (expr
);
1508 if (constant
!= expr
)
1510 get_or_alloc_expression_id (expr
);
1512 add_to_value (new_val_id
, expr
);
1514 phi_trans_add (oldexpr
, expr
, pred
);
1521 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1522 VEC (vn_reference_op_s
, heap
) *operands
= ref
->operands
;
1523 VEC (tree
, gc
) *vuses
= ref
->vuses
;
1524 VEC (tree
, gc
) *newvuses
= vuses
;
1525 VEC (vn_reference_op_s
, heap
) *newoperands
= NULL
;
1526 bool changed
= false;
1528 vn_reference_op_t operand
;
1529 vn_reference_t newref
;
1531 for (i
= 0; VEC_iterate (vn_reference_op_s
, operands
, i
, operand
); i
++)
1535 tree oldop0
= operand
->op0
;
1536 tree oldop1
= operand
->op1
;
1537 tree oldop2
= operand
->op2
;
1541 tree type
= operand
->type
;
1542 vn_reference_op_s newop
= *operand
;
1544 if (op0
&& TREE_CODE (op0
) == SSA_NAME
)
1546 unsigned int op_val_id
= VN_INFO (op0
)->value_id
;
1547 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1548 opresult
= phi_translate_1 (leader
, set1
, set2
,
1549 pred
, phiblock
, seen
);
1550 if (opresult
&& opresult
!= leader
)
1552 tree name
= get_representative_for (opresult
);
1560 changed
|= op0
!= oldop0
;
1562 if (op1
&& TREE_CODE (op1
) == SSA_NAME
)
1564 unsigned int op_val_id
= VN_INFO (op1
)->value_id
;
1565 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1566 opresult
= phi_translate_1 (leader
, set1
, set2
,
1567 pred
, phiblock
, seen
);
1568 if (opresult
&& opresult
!= leader
)
1570 tree name
= get_representative_for (opresult
);
1578 changed
|= op1
!= oldop1
;
1579 if (op2
&& TREE_CODE (op2
) == SSA_NAME
)
1581 unsigned int op_val_id
= VN_INFO (op2
)->value_id
;
1582 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1583 opresult
= phi_translate_1 (leader
, set1
, set2
,
1584 pred
, phiblock
, seen
);
1585 if (opresult
&& opresult
!= leader
)
1587 tree name
= get_representative_for (opresult
);
1595 changed
|= op2
!= oldop2
;
1598 newoperands
= VEC_copy (vn_reference_op_s
, heap
, operands
);
1599 /* We may have changed from an SSA_NAME to a constant */
1600 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op0
) != SSA_NAME
)
1601 newop
.opcode
= TREE_CODE (op0
);
1606 VEC_replace (vn_reference_op_s
, newoperands
, i
, &newop
);
1608 if (i
!= VEC_length (vn_reference_op_s
, operands
))
1611 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1615 newvuses
= translate_vuses_through_block (vuses
, phiblock
, pred
);
1616 changed
|= newvuses
!= vuses
;
1620 unsigned int new_val_id
;
1623 tree result
= vn_reference_lookup_pieces (newvuses
,
1627 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1629 if (result
&& is_gimple_min_invariant (result
))
1631 gcc_assert (!newoperands
);
1632 return get_or_alloc_expr_for_constant (result
);
1635 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1636 expr
->kind
= REFERENCE
;
1641 PRE_EXPR_REFERENCE (expr
) = newref
;
1642 constant
= fully_constant_expression (expr
);
1643 if (constant
!= expr
)
1646 new_val_id
= newref
->value_id
;
1647 get_or_alloc_expression_id (expr
);
1651 new_val_id
= get_next_value_id ();
1652 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
1653 get_max_value_id() + 1);
1654 newref
= vn_reference_insert_pieces (newvuses
,
1656 result
, new_val_id
);
1658 PRE_EXPR_REFERENCE (expr
) = newref
;
1659 constant
= fully_constant_expression (expr
);
1660 if (constant
!= expr
)
1662 get_or_alloc_expression_id (expr
);
1664 add_to_value (new_val_id
, expr
);
1666 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1667 phi_trans_add (oldexpr
, expr
, pred
);
1677 tree name
= PRE_EXPR_NAME (expr
);
1679 def_stmt
= SSA_NAME_DEF_STMT (name
);
1680 if (gimple_code (def_stmt
) == GIMPLE_PHI
1681 && gimple_bb (def_stmt
) == phiblock
)
1686 e
= find_edge (pred
, gimple_bb (phi
));
1689 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1692 /* Handle constant. */
1693 if (is_gimple_min_invariant (def
))
1694 return get_or_alloc_expr_for_constant (def
);
1696 if (TREE_CODE (def
) == SSA_NAME
&& ssa_undefined_value_p (def
))
1699 newexpr
= get_or_alloc_expr_for_name (def
);
1710 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1712 Return NULL if we can't find a leader for each part of the
1713 translated expression. */
1716 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1717 basic_block pred
, basic_block phiblock
)
1719 bitmap_clear (seen_during_translate
);
1720 return phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
,
1721 seen_during_translate
);
1724 /* For each expression in SET, translate the values through phi nodes
1725 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1726 expressions in DEST. */
1729 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1730 basic_block phiblock
)
1732 VEC (pre_expr
, heap
) *exprs
;
1736 if (!phi_nodes (phiblock
))
1738 bitmap_set_copy (dest
, set
);
1742 exprs
= sorted_array_from_bitmap_set (set
);
1743 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
1745 pre_expr translated
;
1746 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1748 /* Don't add constants or empty translations to the cache, since
1749 we won't look them up that way, or use the result, anyway. */
1750 if (translated
&& !value_id_constant_p (get_expr_value_id (translated
)))
1751 phi_trans_add (expr
, translated
, pred
);
1753 if (translated
!= NULL
)
1754 bitmap_value_insert_into_set (dest
, translated
);
1756 VEC_free (pre_expr
, heap
, exprs
);
1759 /* Find the leader for a value (i.e., the name representing that
1760 value) in a given set, and return it. If STMT is non-NULL it
1761 makes sure the defining statement for the leader dominates it.
1762 Return NULL if no leader is found. */
1765 bitmap_find_leader (bitmap_set_t set
, unsigned int val
, gimple stmt
)
1767 if (value_id_constant_p (val
))
1771 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1773 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1775 pre_expr expr
= expression_for_id (i
);
1776 if (expr
->kind
== CONSTANT
)
1780 if (bitmap_set_contains_value (set
, val
))
1782 /* Rather than walk the entire bitmap of expressions, and see
1783 whether any of them has the value we are looking for, we look
1784 at the reverse mapping, which tells us the set of expressions
1785 that have a given value (IE value->expressions with that
1786 value) and see if any of those expressions are in our set.
1787 The number of expressions per value is usually significantly
1788 less than the number of expressions in the set. In fact, for
1789 large testcases, doing it this way is roughly 5-10x faster
1790 than walking the bitmap.
1791 If this is somehow a significant lose for some cases, we can
1792 choose which set to walk based on which set is smaller. */
1795 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1797 EXECUTE_IF_AND_IN_BITMAP (exprset
->expressions
,
1798 set
->expressions
, 0, i
, bi
)
1800 pre_expr val
= expression_for_id (i
);
1801 /* At the point where stmt is not null, there should always
1802 be an SSA_NAME first in the list of expressions. */
1805 gimple def_stmt
= SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val
));
1806 if (gimple_code (def_stmt
) != GIMPLE_PHI
1807 && gimple_bb (def_stmt
) == gimple_bb (stmt
)
1808 && gimple_uid (def_stmt
) >= gimple_uid (stmt
))
1817 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1818 BLOCK by seeing if it is not killed in the block. Note that we are
1819 only determining whether there is a store that kills it. Because
1820 of the order in which clean iterates over values, we are guaranteed
1821 that altered operands will have caused us to be eliminated from the
1822 ANTIC_IN set already. */
1825 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1829 VEC (tree
, gc
) *vuses
= PRE_EXPR_REFERENCE (expr
)->vuses
;
1831 /* Conservatively, a value dies if it's vuses are defined in this
1832 block, unless they come from phi nodes (which are merge operations,
1833 rather than stores. */
1834 for (i
= 0; VEC_iterate (tree
, vuses
, i
, vuse
); i
++)
1836 gimple def
= SSA_NAME_DEF_STMT (vuse
);
1838 if (gimple_bb (def
) != block
)
1840 if (gimple_code (def
) == GIMPLE_PHI
)
1848 #define union_contains_value(SET1, SET2, VAL) \
1849 (bitmap_set_contains_value ((SET1), (VAL)) \
1850 || ((SET2) && bitmap_set_contains_value ((SET2), (VAL))))
1852 /* Determine if vn_reference_op_t VRO is legal in SET1 U SET2.
1855 vro_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
,
1856 vn_reference_op_t vro
)
1858 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
1860 struct pre_expr_d temp
;
1863 PRE_EXPR_NAME (&temp
) = vro
->op0
;
1864 temp
.id
= lookup_expression_id (&temp
);
1867 if (!union_contains_value (set1
, set2
,
1868 get_expr_value_id (&temp
)))
1871 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
1873 struct pre_expr_d temp
;
1876 PRE_EXPR_NAME (&temp
) = vro
->op1
;
1877 temp
.id
= lookup_expression_id (&temp
);
1880 if (!union_contains_value (set1
, set2
,
1881 get_expr_value_id (&temp
)))
1885 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
1887 struct pre_expr_d temp
;
1890 PRE_EXPR_NAME (&temp
) = vro
->op2
;
1891 temp
.id
= lookup_expression_id (&temp
);
1894 if (!union_contains_value (set1
, set2
,
1895 get_expr_value_id (&temp
)))
1902 /* Determine if the expression EXPR is valid in SET1 U SET2.
1903 ONLY SET2 CAN BE NULL.
1904 This means that we have a leader for each part of the expression
1905 (if it consists of values), or the expression is an SSA_NAME.
1906 For loads/calls, we also see if the vuses are killed in this block.
1910 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
1916 return bitmap_set_contains_expr (AVAIL_OUT (block
), expr
);
1920 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1921 for (i
= 0; i
< nary
->length
; i
++)
1923 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
1925 struct pre_expr_d temp
;
1928 PRE_EXPR_NAME (&temp
) = nary
->op
[i
];
1929 temp
.id
= lookup_expression_id (&temp
);
1932 if (!union_contains_value (set1
, set2
,
1933 get_expr_value_id (&temp
)))
1942 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1943 vn_reference_op_t vro
;
1946 for (i
= 0; VEC_iterate (vn_reference_op_s
, ref
->operands
, i
, vro
); i
++)
1948 if (!vro_valid_in_sets (set1
, set2
, vro
))
1951 return !value_dies_in_block_x (expr
, block
);
1958 /* Clean the set of expressions that are no longer valid in SET1 or
1959 SET2. This means expressions that are made up of values we have no
1960 leaders for in SET1 or SET2. This version is used for partial
1961 anticipation, which means it is not valid in either ANTIC_IN or
1965 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
1967 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set1
);
1971 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
1973 if (!valid_in_sets (set1
, set2
, expr
, block
))
1974 bitmap_remove_from_set (set1
, expr
);
1976 VEC_free (pre_expr
, heap
, exprs
);
1979 /* Clean the set of expressions that are no longer valid in SET. This
1980 means expressions that are made up of values we have no leaders for
1984 clean (bitmap_set_t set
, basic_block block
)
1986 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set
);
1990 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
1992 if (!valid_in_sets (set
, NULL
, expr
, block
))
1993 bitmap_remove_from_set (set
, expr
);
1995 VEC_free (pre_expr
, heap
, exprs
);
1998 static sbitmap has_abnormal_preds
;
2000 /* List of blocks that may have changed during ANTIC computation and
2001 thus need to be iterated over. */
2003 static sbitmap changed_blocks
;
2005 /* Decide whether to defer a block for a later iteration, or PHI
2006 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2007 should defer the block, and true if we processed it. */
2010 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2011 basic_block block
, basic_block phiblock
)
2013 if (!BB_VISITED (phiblock
))
2015 SET_BIT (changed_blocks
, block
->index
);
2016 BB_VISITED (block
) = 0;
2017 BB_DEFERRED (block
) = 1;
2021 phi_translate_set (dest
, source
, block
, phiblock
);
2025 /* Compute the ANTIC set for BLOCK.
2027 If succs(BLOCK) > 1 then
2028 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2029 else if succs(BLOCK) == 1 then
2030 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2032 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2036 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2038 bool changed
= false;
2039 bitmap_set_t S
, old
, ANTIC_OUT
;
2045 old
= ANTIC_OUT
= S
= NULL
;
2046 BB_VISITED (block
) = 1;
2048 /* If any edges from predecessors are abnormal, antic_in is empty,
2050 if (block_has_abnormal_pred_edge
)
2051 goto maybe_dump_sets
;
2053 old
= ANTIC_IN (block
);
2054 ANTIC_OUT
= bitmap_set_new ();
2056 /* If the block has no successors, ANTIC_OUT is empty. */
2057 if (EDGE_COUNT (block
->succs
) == 0)
2059 /* If we have one successor, we could have some phi nodes to
2060 translate through. */
2061 else if (single_succ_p (block
))
2063 basic_block succ_bb
= single_succ (block
);
2065 /* We trade iterations of the dataflow equations for having to
2066 phi translate the maximal set, which is incredibly slow
2067 (since the maximal set often has 300+ members, even when you
2068 have a small number of blocks).
2069 Basically, we defer the computation of ANTIC for this block
2070 until we have processed it's successor, which will inevitably
2071 have a *much* smaller set of values to phi translate once
2072 clean has been run on it.
2073 The cost of doing this is that we technically perform more
2074 iterations, however, they are lower cost iterations.
2076 Timings for PRE on tramp3d-v4:
2077 without maximal set fix: 11 seconds
2078 with maximal set fix/without deferring: 26 seconds
2079 with maximal set fix/with deferring: 11 seconds
2082 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2086 goto maybe_dump_sets
;
2089 /* If we have multiple successors, we take the intersection of all of
2090 them. Note that in the case of loop exit phi nodes, we may have
2091 phis to translate through. */
2094 VEC(basic_block
, heap
) * worklist
;
2096 basic_block bprime
, first
;
2098 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2099 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2100 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2101 first
= VEC_index (basic_block
, worklist
, 0);
2103 if (phi_nodes (first
))
2105 bitmap_set_t from
= ANTIC_IN (first
);
2107 if (!BB_VISITED (first
))
2109 phi_translate_set (ANTIC_OUT
, from
, block
, first
);
2113 if (!BB_VISITED (first
))
2114 bitmap_set_copy (ANTIC_OUT
, maximal_set
);
2116 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2119 for (i
= 1; VEC_iterate (basic_block
, worklist
, i
, bprime
); i
++)
2121 if (phi_nodes (bprime
))
2123 bitmap_set_t tmp
= bitmap_set_new ();
2124 bitmap_set_t from
= ANTIC_IN (bprime
);
2126 if (!BB_VISITED (bprime
))
2128 phi_translate_set (tmp
, from
, block
, bprime
);
2129 bitmap_set_and (ANTIC_OUT
, tmp
);
2130 bitmap_set_free (tmp
);
2134 if (!BB_VISITED (bprime
))
2135 bitmap_set_and (ANTIC_OUT
, maximal_set
);
2137 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2140 VEC_free (basic_block
, heap
, worklist
);
2143 /* Generate ANTIC_OUT - TMP_GEN. */
2144 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2146 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2147 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2150 /* Then union in the ANTIC_OUT - TMP_GEN values,
2151 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2152 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2153 bitmap_value_insert_into_set (ANTIC_IN (block
),
2154 expression_for_id (bii
));
2156 clean (ANTIC_IN (block
), block
);
2158 /* !old->expressions can happen when we deferred a block. */
2159 if (!old
->expressions
|| !bitmap_set_equal (old
, ANTIC_IN (block
)))
2162 SET_BIT (changed_blocks
, block
->index
);
2163 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2164 SET_BIT (changed_blocks
, e
->src
->index
);
2167 RESET_BIT (changed_blocks
, block
->index
);
2170 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2172 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2175 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2177 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2181 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2186 "Block %d was deferred for a future iteration.\n",
2191 bitmap_set_free (old
);
2193 bitmap_set_free (S
);
2195 bitmap_set_free (ANTIC_OUT
);
2199 /* Compute PARTIAL_ANTIC for BLOCK.
2201 If succs(BLOCK) > 1 then
2202 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2203 in ANTIC_OUT for all succ(BLOCK)
2204 else if succs(BLOCK) == 1 then
2205 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2207 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2212 compute_partial_antic_aux (basic_block block
,
2213 bool block_has_abnormal_pred_edge
)
2215 bool changed
= false;
2216 bitmap_set_t old_PA_IN
;
2217 bitmap_set_t PA_OUT
;
2220 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2222 old_PA_IN
= PA_OUT
= NULL
;
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 /* If there are too many partially anticipatable values in the
2230 block, phi_translate_set can take an exponential time: stop
2231 before the translation starts. */
2233 && single_succ_p (block
)
2234 && bitmap_count_bits (PA_IN (single_succ (block
))->values
) > max_pa
)
2235 goto maybe_dump_sets
;
2237 old_PA_IN
= PA_IN (block
);
2238 PA_OUT
= bitmap_set_new ();
2240 /* If the block has no successors, ANTIC_OUT is empty. */
2241 if (EDGE_COUNT (block
->succs
) == 0)
2243 /* If we have one successor, we could have some phi nodes to
2244 translate through. Note that we can't phi translate across DFS
2245 back edges in partial antic, because it uses a union operation on
2246 the successors. For recurrences like IV's, we will end up
2247 generating a new value in the set on each go around (i + 3 (VH.1)
2248 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2249 else if (single_succ_p (block
))
2251 basic_block succ
= single_succ (block
);
2252 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2253 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2255 /* If we have multiple successors, we take the union of all of
2259 VEC(basic_block
, heap
) * worklist
;
2263 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2264 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2266 if (e
->flags
& EDGE_DFS_BACK
)
2268 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2270 if (VEC_length (basic_block
, worklist
) > 0)
2272 for (i
= 0; VEC_iterate (basic_block
, worklist
, i
, bprime
); i
++)
2277 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2278 bitmap_value_insert_into_set (PA_OUT
,
2279 expression_for_id (i
));
2280 if (phi_nodes (bprime
))
2282 bitmap_set_t pa_in
= bitmap_set_new ();
2283 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2284 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2285 bitmap_value_insert_into_set (PA_OUT
,
2286 expression_for_id (i
));
2287 bitmap_set_free (pa_in
);
2290 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2291 bitmap_value_insert_into_set (PA_OUT
,
2292 expression_for_id (i
));
2295 VEC_free (basic_block
, heap
, worklist
);
2298 /* PA_IN starts with PA_OUT - TMP_GEN.
2299 Then we subtract things from ANTIC_IN. */
2300 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2302 /* For partial antic, we want to put back in the phi results, since
2303 we will properly avoid making them partially antic over backedges. */
2304 bitmap_ior_into (PA_IN (block
)->values
, PHI_GEN (block
)->values
);
2305 bitmap_ior_into (PA_IN (block
)->expressions
, PHI_GEN (block
)->expressions
);
2307 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2308 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2310 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2312 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2315 SET_BIT (changed_blocks
, block
->index
);
2316 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2317 SET_BIT (changed_blocks
, e
->src
->index
);
2320 RESET_BIT (changed_blocks
, block
->index
);
2323 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2326 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2328 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2331 bitmap_set_free (old_PA_IN
);
2333 bitmap_set_free (PA_OUT
);
2337 /* Compute ANTIC and partial ANTIC sets. */
2340 compute_antic (void)
2342 bool changed
= true;
2343 int num_iterations
= 0;
2347 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2348 We pre-build the map of blocks with incoming abnormal edges here. */
2349 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2350 sbitmap_zero (has_abnormal_preds
);
2357 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2359 e
->flags
&= ~EDGE_DFS_BACK
;
2360 if (e
->flags
& EDGE_ABNORMAL
)
2362 SET_BIT (has_abnormal_preds
, block
->index
);
2367 BB_VISITED (block
) = 0;
2368 BB_DEFERRED (block
) = 0;
2369 /* While we are here, give empty ANTIC_IN sets to each block. */
2370 ANTIC_IN (block
) = bitmap_set_new ();
2371 PA_IN (block
) = bitmap_set_new ();
2374 /* At the exit block we anticipate nothing. */
2375 ANTIC_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2376 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2377 PA_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2379 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2380 sbitmap_ones (changed_blocks
);
2383 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2384 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2387 for (i
= 0; i
< last_basic_block
- NUM_FIXED_BLOCKS
; i
++)
2389 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2391 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2392 changed
|= compute_antic_aux (block
,
2393 TEST_BIT (has_abnormal_preds
,
2397 #ifdef ENABLE_CHECKING
2398 /* Theoretically possible, but *highly* unlikely. */
2399 gcc_assert (num_iterations
< 500);
2403 statistics_histogram_event (cfun
, "compute_antic iterations",
2406 if (do_partial_partial
)
2408 sbitmap_ones (changed_blocks
);
2409 mark_dfs_back_edges ();
2414 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2415 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2418 for (i
= 0; i
< last_basic_block
- NUM_FIXED_BLOCKS
; i
++)
2420 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2422 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2424 |= compute_partial_antic_aux (block
,
2425 TEST_BIT (has_abnormal_preds
,
2429 #ifdef ENABLE_CHECKING
2430 /* Theoretically possible, but *highly* unlikely. */
2431 gcc_assert (num_iterations
< 500);
2434 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2437 sbitmap_free (has_abnormal_preds
);
2438 sbitmap_free (changed_blocks
);
2441 /* Return true if we can value number the call in STMT. This is true
2442 if we have a pure or constant call. */
2445 can_value_number_call (gimple stmt
)
2447 if (gimple_call_flags (stmt
) & (ECF_PURE
| ECF_CONST
))
2452 /* Return true if OP is an exception handler related operation, such as
2453 FILTER_EXPR or EXC_PTR_EXPR. */
2456 is_exception_related (gimple stmt
)
2458 return (is_gimple_assign (stmt
)
2459 && (gimple_assign_rhs_code (stmt
) == FILTER_EXPR
2460 || gimple_assign_rhs_code (stmt
) == EXC_PTR_EXPR
));
2463 /* Return true if OP is a tree which we can perform PRE on
2464 on. This may not match the operations we can value number, but in
2465 a perfect world would. */
2468 can_PRE_operation (tree op
)
2470 return UNARY_CLASS_P (op
)
2471 || BINARY_CLASS_P (op
)
2472 || COMPARISON_CLASS_P (op
)
2473 || TREE_CODE (op
) == INDIRECT_REF
2474 || TREE_CODE (op
) == COMPONENT_REF
2475 || TREE_CODE (op
) == VIEW_CONVERT_EXPR
2476 || TREE_CODE (op
) == CALL_EXPR
2477 || TREE_CODE (op
) == ARRAY_REF
;
2481 /* Inserted expressions are placed onto this worklist, which is used
2482 for performing quick dead code elimination of insertions we made
2483 that didn't turn out to be necessary. */
2484 static VEC(gimple
,heap
) *inserted_exprs
;
2486 /* Pool allocated fake store expressions are placed onto this
2487 worklist, which, after performing dead code elimination, is walked
2488 to see which expressions need to be put into GC'able memory */
2489 static VEC(gimple
, heap
) *need_creation
;
2491 /* The actual worker for create_component_ref_by_pieces. */
2494 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2495 unsigned int *operand
, gimple_seq
*stmts
,
2498 vn_reference_op_t currop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2502 switch (currop
->opcode
)
2506 tree folded
, sc
= currop
->op1
;
2507 unsigned int nargs
= 0;
2508 tree
*args
= XNEWVEC (tree
, VEC_length (vn_reference_op_s
,
2509 ref
->operands
) - 1);
2510 while (*operand
< VEC_length (vn_reference_op_s
, ref
->operands
))
2512 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2517 folded
= build_call_array (currop
->type
,
2518 TREE_CODE (currop
->op0
) == FUNCTION_DECL
2519 ? build_fold_addr_expr (currop
->op0
)
2525 pre_expr scexpr
= get_or_alloc_expr_for (sc
);
2526 sc
= find_or_generate_expression (block
, scexpr
, stmts
, domstmt
);
2529 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2537 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2543 case VIEW_CONVERT_EXPR
:
2546 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
,
2551 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2556 case ALIGN_INDIRECT_REF
:
2557 case MISALIGNED_INDIRECT_REF
:
2561 tree genop1
= create_component_ref_by_pieces_1 (block
, ref
,
2566 genop1
= fold_convert (build_pointer_type (currop
->type
),
2569 if (currop
->opcode
== MISALIGNED_INDIRECT_REF
)
2570 folded
= fold_build2 (currop
->opcode
, currop
->type
,
2571 genop1
, currop
->op1
);
2573 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2581 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2583 pre_expr op1expr
= get_or_alloc_expr_for (currop
->op0
);
2584 pre_expr op2expr
= get_or_alloc_expr_for (currop
->op1
);
2590 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2593 genop2
= find_or_generate_expression (block
, op2expr
, stmts
, domstmt
);
2596 folded
= fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, genop1
,
2601 /* For array ref vn_reference_op's, operand 1 of the array ref
2602 is op0 of the reference op and operand 3 of the array ref is
2604 case ARRAY_RANGE_REF
:
2608 tree genop1
= currop
->op0
;
2610 tree genop2
= currop
->op1
;
2613 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2617 op1expr
= get_or_alloc_expr_for (genop1
);
2618 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2623 op2expr
= get_or_alloc_expr_for (genop2
);
2624 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2630 genop3
= currop
->op2
;
2631 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2638 tree genop2
= currop
->op1
;
2640 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2644 /* op1 should be a FIELD_DECL, which are represented by
2649 op2expr
= get_or_alloc_expr_for (genop2
);
2650 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2656 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
,
2662 pre_expr op0expr
= get_or_alloc_expr_for (currop
->op0
);
2663 genop
= find_or_generate_expression (block
, op0expr
, stmts
, domstmt
);
2684 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2685 COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
2686 trying to rename aggregates into ssa form directly, which is a no no.
2688 Thus, this routine doesn't create temporaries, it just builds a
2689 single access expression for the array, calling
2690 find_or_generate_expression to build the innermost pieces.
2692 This function is a subroutine of create_expression_by_pieces, and
2693 should not be called on it's own unless you really know what you
2697 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2698 gimple_seq
*stmts
, gimple domstmt
)
2700 unsigned int op
= 0;
2701 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
, domstmt
);
2704 /* Find a leader for an expression, or generate one using
2705 create_expression_by_pieces if it's ANTIC but
2707 BLOCK is the basic_block we are looking for leaders in.
2708 EXPR is the expression to find a leader or generate for.
2709 STMTS is the statement list to put the inserted expressions on.
2710 Returns the SSA_NAME of the LHS of the generated expression or the
2712 DOMSTMT if non-NULL is a statement that should be dominated by
2713 all uses in the generated expression. If DOMSTMT is non-NULL this
2714 routine can fail and return NULL_TREE. Otherwise it will assert
2718 find_or_generate_expression (basic_block block
, pre_expr expr
,
2719 gimple_seq
*stmts
, gimple domstmt
)
2721 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
),
2722 get_expr_value_id (expr
), domstmt
);
2726 if (leader
->kind
== NAME
)
2727 genop
= PRE_EXPR_NAME (leader
);
2728 else if (leader
->kind
== CONSTANT
)
2729 genop
= PRE_EXPR_CONSTANT (leader
);
2732 /* If it's still NULL, it must be a complex expression, so generate
2733 it recursively. Not so for FRE though. */
2737 bitmap_set_t exprset
;
2738 unsigned int lookfor
= get_expr_value_id (expr
);
2739 bool handled
= false;
2743 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
2744 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
2746 pre_expr temp
= expression_for_id (i
);
2747 if (temp
->kind
!= NAME
)
2750 genop
= create_expression_by_pieces (block
, temp
, stmts
,
2752 get_expr_type (expr
));
2756 if (!handled
&& domstmt
)
2759 gcc_assert (handled
);
2764 #define NECESSARY GF_PLF_1
2766 /* Create an expression in pieces, so that we can handle very complex
2767 expressions that may be ANTIC, but not necessary GIMPLE.
2768 BLOCK is the basic block the expression will be inserted into,
2769 EXPR is the expression to insert (in value form)
2770 STMTS is a statement list to append the necessary insertions into.
2772 This function will die if we hit some value that shouldn't be
2773 ANTIC but is (IE there is no leader for it, or its components).
2774 This function may also generate expressions that are themselves
2775 partially or fully redundant. Those that are will be either made
2776 fully redundant during the next iteration of insert (for partially
2777 redundant ones), or eliminated by eliminate (for fully redundant
2780 If DOMSTMT is non-NULL then we make sure that all uses in the
2781 expressions dominate that statement. In this case the function
2782 can return NULL_TREE to signal failure. */
2785 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2786 gimple_seq
*stmts
, gimple domstmt
, tree type
)
2789 tree folded
, newexpr
;
2790 gimple_seq forced_stmts
;
2791 unsigned int value_id
;
2792 gimple_stmt_iterator gsi
;
2793 tree exprtype
= type
? type
: get_expr_type (expr
);
2799 /* We may hit the NAME/CONSTANT case if we have to convert types
2800 that value numbering saw through. */
2802 folded
= PRE_EXPR_NAME (expr
);
2805 folded
= PRE_EXPR_CONSTANT (expr
);
2809 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2810 folded
= create_component_ref_by_pieces (block
, ref
, stmts
, domstmt
);
2815 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2816 switch (nary
->length
)
2820 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
2821 pre_expr op2
= get_or_alloc_expr_for (nary
->op
[1]);
2822 tree genop1
= find_or_generate_expression (block
, op1
,
2824 tree genop2
= find_or_generate_expression (block
, op2
,
2826 if (!genop1
|| !genop2
)
2828 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]),
2830 /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR. It
2831 may be a constant with the wrong type. */
2832 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2833 genop2
= fold_convert (sizetype
, genop2
);
2835 genop2
= fold_convert (TREE_TYPE (nary
->op
[1]), genop2
);
2837 folded
= fold_build2 (nary
->opcode
, nary
->type
,
2843 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
2844 tree genop1
= find_or_generate_expression (block
, op1
,
2848 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]), genop1
);
2850 folded
= fold_build1 (nary
->opcode
, nary
->type
,
2862 folded
= fold_convert (exprtype
, folded
);
2863 /* Force the generated expression to be a sequence of GIMPLE
2865 We have to call unshare_expr because force_gimple_operand may
2866 modify the tree we pass to it. */
2867 newexpr
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
2870 /* If we have any intermediate expressions to the value sets, add them
2871 to the value sets and chain them in the instruction stream. */
2874 gsi
= gsi_start (forced_stmts
);
2875 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2877 gimple stmt
= gsi_stmt (gsi
);
2878 tree forcedname
= gimple_get_lhs (stmt
);
2881 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
2882 if (TREE_CODE (forcedname
) == SSA_NAME
)
2884 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2885 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2886 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2887 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2889 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2890 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2892 mark_symbols_for_renaming (stmt
);
2894 gimple_seq_add_seq (stmts
, forced_stmts
);
2897 /* Build and insert the assignment of the end result to the temporary
2898 that we will return. */
2899 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
2901 pretemp
= create_tmp_var (exprtype
, "pretmp");
2902 get_var_ann (pretemp
);
2906 add_referenced_var (temp
);
2908 if (TREE_CODE (exprtype
) == COMPLEX_TYPE
2909 || TREE_CODE (exprtype
) == VECTOR_TYPE
)
2910 DECL_GIMPLE_REG_P (temp
) = 1;
2912 newstmt
= gimple_build_assign (temp
, newexpr
);
2913 name
= make_ssa_name (temp
, newstmt
);
2914 gimple_assign_set_lhs (newstmt
, name
);
2915 gimple_set_plf (newstmt
, NECESSARY
, false);
2917 gimple_seq_add_stmt (stmts
, newstmt
);
2918 VEC_safe_push (gimple
, heap
, inserted_exprs
, newstmt
);
2920 /* All the symbols in NEWEXPR should be put into SSA form. */
2921 mark_symbols_for_renaming (newstmt
);
2923 /* Add a value number to the temporary.
2924 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2925 we are creating the expression by pieces, and this particular piece of
2926 the expression may have been represented. There is no harm in replacing
2928 VN_INFO_GET (name
)->valnum
= name
;
2929 value_id
= get_expr_value_id (expr
);
2930 VN_INFO (name
)->value_id
= value_id
;
2931 nameexpr
= get_or_alloc_expr_for_name (name
);
2932 add_to_value (value_id
, nameexpr
);
2934 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2935 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2937 pre_stats
.insertions
++;
2938 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2940 fprintf (dump_file
, "Inserted ");
2941 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
2942 fprintf (dump_file
, " in predecessor %d\n", block
->index
);
2949 /* Insert the to-be-made-available values of expression EXPRNUM for each
2950 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2951 merge the result with a phi node, given the same value number as
2952 NODE. Return true if we have inserted new stuff. */
2955 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2958 pre_expr expr
= expression_for_id (exprnum
);
2960 unsigned int val
= get_expr_value_id (expr
);
2962 bool insertions
= false;
2967 tree type
= get_expr_type (expr
);
2971 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2973 fprintf (dump_file
, "Found partial redundancy for expression ");
2974 print_pre_expr (dump_file
, expr
);
2975 fprintf (dump_file
, " (%04d)\n", val
);
2978 /* Make sure we aren't creating an induction variable. */
2979 if (block
->loop_depth
> 0 && EDGE_COUNT (block
->preds
) == 2
2980 && expr
->kind
!= REFERENCE
)
2982 bool firstinsideloop
= false;
2983 bool secondinsideloop
= false;
2984 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2985 EDGE_PRED (block
, 0)->src
);
2986 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2987 EDGE_PRED (block
, 1)->src
);
2988 /* Induction variables only have one edge inside the loop. */
2989 if (firstinsideloop
^ secondinsideloop
)
2991 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2992 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
2998 /* Make the necessary insertions. */
2999 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3001 gimple_seq stmts
= NULL
;
3004 eprime
= avail
[bprime
->index
];
3006 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3008 builtexpr
= create_expression_by_pieces (bprime
,
3012 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3013 gsi_insert_seq_on_edge (pred
, stmts
);
3014 avail
[bprime
->index
] = get_or_alloc_expr_for_name (builtexpr
);
3017 else if (eprime
->kind
== CONSTANT
)
3019 /* Constants may not have the right type, fold_convert
3020 should give us back a constant with the right type.
3022 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3023 if (TREE_TYPE (constant
) != type
)
3025 tree builtexpr
= fold_convert (type
, constant
);
3026 if (is_gimple_min_invariant (builtexpr
))
3028 PRE_EXPR_CONSTANT (eprime
) = builtexpr
;
3032 tree forcedexpr
= force_gimple_operand (builtexpr
,
3035 if (is_gimple_min_invariant (forcedexpr
))
3037 PRE_EXPR_CONSTANT (eprime
) = forcedexpr
;
3041 if (forcedexpr
!= builtexpr
)
3043 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3044 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3048 gimple_stmt_iterator gsi
;
3049 gsi
= gsi_start (stmts
);
3050 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3052 gimple stmt
= gsi_stmt (gsi
);
3053 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
3054 gimple_set_plf (stmt
, NECESSARY
, false);
3056 gsi_insert_seq_on_edge (pred
, stmts
);
3058 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3063 else if (eprime
->kind
== NAME
)
3065 /* We may have to do a conversion because our value
3066 numbering can look through types in certain cases, but
3067 our IL requires all operands of a phi node have the same
3069 tree name
= PRE_EXPR_NAME (eprime
);
3070 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3074 builtexpr
= fold_convert (type
, name
);
3075 forcedexpr
= force_gimple_operand (builtexpr
,
3079 if (forcedexpr
!= name
)
3081 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3082 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3087 gimple_stmt_iterator gsi
;
3088 gsi
= gsi_start (stmts
);
3089 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3091 gimple stmt
= gsi_stmt (gsi
);
3092 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
3093 gimple_set_plf (stmt
, NECESSARY
, false);
3095 gsi_insert_seq_on_edge (pred
, stmts
);
3097 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3101 /* If we didn't want a phi node, and we made insertions, we still have
3102 inserted new stuff, and thus return true. If we didn't want a phi node,
3103 and didn't make insertions, we haven't added anything new, so return
3105 if (nophi
&& insertions
)
3107 else if (nophi
&& !insertions
)
3110 /* Now build a phi for the new variable. */
3111 if (!prephitemp
|| TREE_TYPE (prephitemp
) != type
)
3113 prephitemp
= create_tmp_var (type
, "prephitmp");
3114 get_var_ann (prephitemp
);
3118 add_referenced_var (temp
);
3120 if (TREE_CODE (type
) == COMPLEX_TYPE
3121 || TREE_CODE (type
) == VECTOR_TYPE
)
3122 DECL_GIMPLE_REG_P (temp
) = 1;
3124 phi
= create_phi_node (temp
, block
);
3125 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3127 pre_expr ae
= avail
[pred
->src
->index
];
3128 gcc_assert (get_expr_type (ae
) == type
3129 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3130 if (ae
->kind
== CONSTANT
)
3131 add_phi_arg (phi
, PRE_EXPR_CONSTANT (ae
), pred
);
3133 add_phi_arg (phi
, PRE_EXPR_NAME (avail
[pred
->src
->index
]), pred
);
3135 /* If the PHI node is already available, use it. */
3136 if ((res
= vn_phi_lookup (phi
)) != NULL_TREE
)
3138 gimple_stmt_iterator gsi
= gsi_for_stmt (phi
);
3139 remove_phi_node (&gsi
, true);
3141 add_to_value (val
, get_or_alloc_expr_for_name (res
));
3145 gimple_set_plf (phi
, NECESSARY
, false);
3146 VN_INFO_GET (gimple_phi_result (phi
))->valnum
= gimple_phi_result (phi
);
3147 VN_INFO (gimple_phi_result (phi
))->value_id
= val
;
3148 VEC_safe_push (gimple
, heap
, inserted_exprs
, phi
);
3150 newphi
= get_or_alloc_expr_for_name (gimple_phi_result (phi
));
3151 add_to_value (val
, newphi
);
3153 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3154 this insertion, since we test for the existence of this value in PHI_GEN
3155 before proceeding with the partial redundancy checks in insert_aux.
3157 The value may exist in AVAIL_OUT, in particular, it could be represented
3158 by the expression we are trying to eliminate, in which case we want the
3159 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3162 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3163 this block, because if it did, it would have existed in our dominator's
3164 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3167 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3168 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3170 bitmap_insert_into_set (NEW_SETS (block
),
3173 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3175 fprintf (dump_file
, "Created phi ");
3176 print_gimple_stmt (dump_file
, phi
, 0, 0);
3177 fprintf (dump_file
, " in block %d\n", block
->index
);
3185 /* Perform insertion of partially redundant values.
3186 For BLOCK, do the following:
3187 1. Propagate the NEW_SETS of the dominator into the current block.
3188 If the block has multiple predecessors,
3189 2a. Iterate over the ANTIC expressions for the block to see if
3190 any of them are partially redundant.
3191 2b. If so, insert them into the necessary predecessors to make
3192 the expression fully redundant.
3193 2c. Insert a new PHI merging the values of the predecessors.
3194 2d. Insert the new PHI, and the new expressions, into the
3196 3. Recursively call ourselves on the dominator children of BLOCK.
3198 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3199 do_regular_insertion and do_partial_insertion.
3204 do_regular_insertion (basic_block block
, basic_block dom
)
3206 bool new_stuff
= false;
3207 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3211 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
3213 if (expr
->kind
!= NAME
)
3217 bool by_some
= false;
3218 bool cant_insert
= false;
3219 bool all_same
= true;
3220 pre_expr first_s
= NULL
;
3223 pre_expr eprime
= NULL
;
3225 pre_expr edoubleprime
;
3227 val
= get_expr_value_id (expr
);
3228 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3230 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3232 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3233 fprintf (dump_file
, "Found fully redundant value\n");
3237 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3238 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3240 unsigned int vprime
;
3242 /* We should never run insertion for the exit block
3243 and so not come across fake pred edges. */
3244 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3246 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3249 /* eprime will generally only be NULL if the
3250 value of the expression, translated
3251 through the PHI for this predecessor, is
3252 undefined. If that is the case, we can't
3253 make the expression fully redundant,
3254 because its value is undefined along a
3255 predecessor path. We can thus break out
3256 early because it doesn't matter what the
3257 rest of the results are. */
3264 eprime
= fully_constant_expression (eprime
);
3265 vprime
= get_expr_value_id (eprime
);
3266 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3268 if (edoubleprime
== NULL
)
3270 avail
[bprime
->index
] = eprime
;
3275 avail
[bprime
->index
] = edoubleprime
;
3277 if (first_s
== NULL
)
3278 first_s
= edoubleprime
;
3279 else if (!pre_expr_eq (first_s
, edoubleprime
))
3283 /* If we can insert it, it's not the same value
3284 already existing along every predecessor, and
3285 it's defined by some predecessor, it is
3286 partially redundant. */
3287 if (!cant_insert
&& !all_same
&& by_some
&& dbg_cnt (treepre_insert
))
3289 if (insert_into_preds_of_block (block
, get_expression_id (expr
),
3293 /* If all edges produce the same value and that value is
3294 an invariant, then the PHI has the same value on all
3295 edges. Note this. */
3296 else if (!cant_insert
&& all_same
&& eprime
3297 && (edoubleprime
->kind
== CONSTANT
3298 || edoubleprime
->kind
== NAME
)
3299 && !value_id_constant_p (val
))
3303 bitmap_set_t exprset
= VEC_index (bitmap_set_t
,
3304 value_expressions
, val
);
3306 unsigned int new_val
= get_expr_value_id (edoubleprime
);
3307 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bi
)
3309 pre_expr expr
= expression_for_id (j
);
3311 if (expr
->kind
== NAME
)
3313 vn_ssa_aux_t info
= VN_INFO (PRE_EXPR_NAME (expr
));
3314 /* Just reset the value id and valnum so it is
3315 the same as the constant we have discovered. */
3316 if (edoubleprime
->kind
== CONSTANT
)
3318 info
->valnum
= PRE_EXPR_CONSTANT (edoubleprime
);
3319 pre_stats
.constified
++;
3322 info
->valnum
= PRE_EXPR_NAME (edoubleprime
);
3323 info
->value_id
= new_val
;
3331 VEC_free (pre_expr
, heap
, exprs
);
3336 /* Perform insertion for partially anticipatable expressions. There
3337 is only one case we will perform insertion for these. This case is
3338 if the expression is partially anticipatable, and fully available.
3339 In this case, we know that putting it earlier will enable us to
3340 remove the later computation. */
3344 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3346 bool new_stuff
= false;
3347 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3351 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
3353 if (expr
->kind
!= NAME
)
3358 bool cant_insert
= false;
3361 pre_expr eprime
= NULL
;
3364 val
= get_expr_value_id (expr
);
3365 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3367 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3370 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3371 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3373 unsigned int vprime
;
3374 pre_expr edoubleprime
;
3376 /* We should never run insertion for the exit block
3377 and so not come across fake pred edges. */
3378 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3380 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3384 /* eprime will generally only be NULL if the
3385 value of the expression, translated
3386 through the PHI for this predecessor, is
3387 undefined. If that is the case, we can't
3388 make the expression fully redundant,
3389 because its value is undefined along a
3390 predecessor path. We can thus break out
3391 early because it doesn't matter what the
3392 rest of the results are. */
3399 eprime
= fully_constant_expression (eprime
);
3400 vprime
= get_expr_value_id (eprime
);
3401 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3403 if (edoubleprime
== NULL
)
3409 avail
[bprime
->index
] = edoubleprime
;
3413 /* If we can insert it, it's not the same value
3414 already existing along every predecessor, and
3415 it's defined by some predecessor, it is
3416 partially redundant. */
3417 if (!cant_insert
&& by_all
&& dbg_cnt (treepre_insert
))
3419 pre_stats
.pa_insert
++;
3420 if (insert_into_preds_of_block (block
, get_expression_id (expr
),
3428 VEC_free (pre_expr
, heap
, exprs
);
3433 insert_aux (basic_block block
)
3436 bool new_stuff
= false;
3441 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3446 bitmap_set_t newset
= NEW_SETS (dom
);
3449 /* Note that we need to value_replace both NEW_SETS, and
3450 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3451 represented by some non-simple expression here that we want
3452 to replace it with. */
3453 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3455 pre_expr expr
= expression_for_id (i
);
3456 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3457 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3460 if (!single_pred_p (block
))
3462 new_stuff
|= do_regular_insertion (block
, dom
);
3463 if (do_partial_partial
)
3464 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3468 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3470 son
= next_dom_son (CDI_DOMINATORS
, son
))
3472 new_stuff
|= insert_aux (son
);
3478 /* Perform insertion of partially redundant values. */
3483 bool new_stuff
= true;
3485 int num_iterations
= 0;
3488 NEW_SETS (bb
) = bitmap_set_new ();
3493 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3495 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3499 /* Add OP to EXP_GEN (block), and possibly to the maximal set if it is
3500 not defined by a phi node.
3501 PHI nodes can't go in the maximal sets because they are not in
3502 TMP_GEN, so it is possible to get into non-monotonic situations
3503 during ANTIC calculation, because it will *add* bits. */
3506 add_to_exp_gen (basic_block block
, tree op
)
3511 if (TREE_CODE (op
) == SSA_NAME
&& ssa_undefined_value_p (op
))
3513 result
= get_or_alloc_expr_for_name (op
);
3514 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3515 if (TREE_CODE (op
) != SSA_NAME
3516 || gimple_code (SSA_NAME_DEF_STMT (op
)) != GIMPLE_PHI
)
3517 bitmap_value_insert_into_set (maximal_set
, result
);
3521 /* Create value ids for PHI in BLOCK. */
3524 make_values_for_phi (gimple phi
, basic_block block
)
3526 tree result
= gimple_phi_result (phi
);
3528 /* We have no need for virtual phis, as they don't represent
3529 actual computations. */
3530 if (is_gimple_reg (result
))
3532 pre_expr e
= get_or_alloc_expr_for_name (result
);
3533 add_to_value (get_expr_value_id (e
), e
);
3534 bitmap_insert_into_set (PHI_GEN (block
), e
);
3535 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3539 /* Compute the AVAIL set for all basic blocks.
3541 This function performs value numbering of the statements in each basic
3542 block. The AVAIL sets are built from information we glean while doing
3543 this value numbering, since the AVAIL sets contain only one entry per
3546 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3547 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3550 compute_avail (void)
3553 basic_block block
, son
;
3554 basic_block
*worklist
;
3558 /* For arguments with default definitions, we pretend they are
3559 defined in the entry block. */
3560 for (param
= DECL_ARGUMENTS (current_function_decl
);
3562 param
= TREE_CHAIN (param
))
3564 if (gimple_default_def (cfun
, param
) != NULL
)
3566 tree def
= gimple_default_def (cfun
, param
);
3567 pre_expr e
= get_or_alloc_expr_for_name (def
);
3569 add_to_value (get_expr_value_id (e
), e
);
3572 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3573 bitmap_value_insert_into_set (maximal_set
, e
);
3575 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3579 /* Likewise for the static chain decl. */
3580 if (cfun
->static_chain_decl
)
3582 param
= cfun
->static_chain_decl
;
3583 if (gimple_default_def (cfun
, param
) != NULL
)
3585 tree def
= gimple_default_def (cfun
, param
);
3586 pre_expr e
= get_or_alloc_expr_for_name (def
);
3588 add_to_value (get_expr_value_id (e
), e
);
3591 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3592 bitmap_value_insert_into_set (maximal_set
, e
);
3594 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3598 /* Allocate the worklist. */
3599 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3601 /* Seed the algorithm by putting the dominator children of the entry
3602 block on the worklist. */
3603 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3605 son
= next_dom_son (CDI_DOMINATORS
, son
))
3606 worklist
[sp
++] = son
;
3608 /* Loop until the worklist is empty. */
3611 gimple_stmt_iterator gsi
;
3614 unsigned int stmt_uid
= 1;
3616 /* Pick a block from the worklist. */
3617 block
= worklist
[--sp
];
3619 /* Initially, the set of available values in BLOCK is that of
3620 its immediate dominator. */
3621 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3623 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3625 /* Generate values for PHI nodes. */
3626 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3627 make_values_for_phi (gsi_stmt (gsi
), block
);
3629 /* Now compute value numbers and populate value sets with all
3630 the expressions computed in BLOCK. */
3631 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3636 stmt
= gsi_stmt (gsi
);
3637 gimple_set_uid (stmt
, stmt_uid
++);
3639 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3641 pre_expr e
= get_or_alloc_expr_for_name (op
);
3643 add_to_value (get_expr_value_id (e
), e
);
3646 bitmap_insert_into_set (TMP_GEN (block
), e
);
3647 bitmap_value_insert_into_set (maximal_set
, e
);
3649 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3652 if (gimple_has_volatile_ops (stmt
)
3653 || stmt_could_throw_p (stmt
))
3656 switch (gimple_code (stmt
))
3659 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3660 add_to_exp_gen (block
, op
);
3667 vn_reference_op_t vro
;
3668 pre_expr result
= NULL
;
3669 VEC(vn_reference_op_s
, heap
) *ops
= NULL
;
3671 if (!can_value_number_call (stmt
))
3674 copy_reference_ops_from_call (stmt
, &ops
);
3675 vn_reference_lookup_pieces (shared_vuses_from_stmt (stmt
),
3677 VEC_free (vn_reference_op_s
, heap
, ops
);
3681 for (i
= 0; VEC_iterate (vn_reference_op_s
,
3685 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
3686 add_to_exp_gen (block
, vro
->op0
);
3687 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
3688 add_to_exp_gen (block
, vro
->op1
);
3689 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
3690 add_to_exp_gen (block
, vro
->op2
);
3692 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3693 result
->kind
= REFERENCE
;
3695 PRE_EXPR_REFERENCE (result
) = ref
;
3697 get_or_alloc_expression_id (result
);
3698 add_to_value (get_expr_value_id (result
), result
);
3701 bitmap_value_insert_into_set (EXP_GEN (block
),
3703 bitmap_value_insert_into_set (maximal_set
, result
);
3710 pre_expr result
= NULL
;
3711 switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)))
3714 if (is_exception_related (stmt
))
3721 vn_nary_op_lookup_pieces (gimple_num_ops (stmt
) - 1,
3722 gimple_assign_rhs_code (stmt
),
3723 gimple_expr_type (stmt
),
3724 gimple_assign_rhs1 (stmt
),
3725 gimple_assign_rhs2 (stmt
),
3726 NULL_TREE
, NULL_TREE
, &nary
);
3731 for (i
= 0; i
< nary
->length
; i
++)
3732 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
3733 add_to_exp_gen (block
, nary
->op
[i
]);
3735 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3736 result
->kind
= NARY
;
3738 PRE_EXPR_NARY (result
) = nary
;
3742 case tcc_declaration
:
3747 vn_reference_op_t vro
;
3749 vn_reference_lookup (gimple_assign_rhs1 (stmt
),
3750 shared_vuses_from_stmt (stmt
),
3755 for (i
= 0; VEC_iterate (vn_reference_op_s
,
3759 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
3760 add_to_exp_gen (block
, vro
->op0
);
3761 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
3762 add_to_exp_gen (block
, vro
->op1
);
3763 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
3764 add_to_exp_gen (block
, vro
->op2
);
3766 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3767 result
->kind
= REFERENCE
;
3769 PRE_EXPR_REFERENCE (result
) = ref
;
3774 /* For any other statement that we don't
3775 recognize, simply add all referenced
3776 SSA_NAMEs to EXP_GEN. */
3777 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3778 add_to_exp_gen (block
, op
);
3782 get_or_alloc_expression_id (result
);
3783 add_to_value (get_expr_value_id (result
), result
);
3786 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3787 bitmap_value_insert_into_set (maximal_set
, result
);
3797 /* Put the dominator children of BLOCK on the worklist of blocks
3798 to compute available sets for. */
3799 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3801 son
= next_dom_son (CDI_DOMINATORS
, son
))
3802 worklist
[sp
++] = son
;
3808 /* Insert the expression for SSA_VN that SCCVN thought would be simpler
3809 than the available expressions for it. The insertion point is
3810 right before the first use in STMT. Returns the SSA_NAME that should
3811 be used for replacement. */
3814 do_SCCVN_insertion (gimple stmt
, tree ssa_vn
)
3816 basic_block bb
= gimple_bb (stmt
);
3817 gimple_stmt_iterator gsi
;
3818 gimple_seq stmts
= NULL
;
3822 /* First create a value expression from the expression we want
3823 to insert and associate it with the value handle for SSA_VN. */
3824 e
= get_or_alloc_expr_for (vn_get_expr_for (ssa_vn
));
3828 /* Then use create_expression_by_pieces to generate a valid
3829 expression to insert at this point of the IL stream. */
3830 expr
= create_expression_by_pieces (bb
, e
, &stmts
, stmt
, NULL
);
3831 if (expr
== NULL_TREE
)
3833 gsi
= gsi_for_stmt (stmt
);
3834 gsi_insert_seq_before (&gsi
, stmts
, GSI_SAME_STMT
);
3839 /* Eliminate fully redundant computations. */
3845 unsigned int todo
= 0;
3849 gimple_stmt_iterator i
;
3851 for (i
= gsi_start_bb (b
); !gsi_end_p (i
); gsi_next (&i
))
3853 gimple stmt
= gsi_stmt (i
);
3855 /* Lookup the RHS of the expression, see if we have an
3856 available computation for it. If so, replace the RHS with
3857 the available computation. */
3858 if (gimple_has_lhs (stmt
)
3859 && TREE_CODE (gimple_get_lhs (stmt
)) == SSA_NAME
3860 && !gimple_assign_ssa_name_copy_p (stmt
)
3861 && (!gimple_assign_single_p (stmt
)
3862 || !is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
3863 && !gimple_has_volatile_ops (stmt
)
3864 && !has_zero_uses (gimple_get_lhs (stmt
)))
3866 tree lhs
= gimple_get_lhs (stmt
);
3867 tree rhs
= NULL_TREE
;
3869 pre_expr lhsexpr
= get_or_alloc_expr_for_name (lhs
);
3870 pre_expr sprimeexpr
;
3872 if (gimple_assign_single_p (stmt
))
3873 rhs
= gimple_assign_rhs1 (stmt
);
3875 sprimeexpr
= bitmap_find_leader (AVAIL_OUT (b
),
3876 get_expr_value_id (lhsexpr
),
3881 if (sprimeexpr
->kind
== CONSTANT
)
3882 sprime
= PRE_EXPR_CONSTANT (sprimeexpr
);
3883 else if (sprimeexpr
->kind
== NAME
)
3884 sprime
= PRE_EXPR_NAME (sprimeexpr
);
3889 /* If there is no existing leader but SCCVN knows this
3890 value is constant, use that constant. */
3891 if (!sprime
&& is_gimple_min_invariant (VN_INFO (lhs
)->valnum
))
3893 sprime
= fold_convert (TREE_TYPE (lhs
),
3894 VN_INFO (lhs
)->valnum
);
3896 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3898 fprintf (dump_file
, "Replaced ");
3899 print_gimple_expr (dump_file
, stmt
, 0, 0);
3900 fprintf (dump_file
, " with ");
3901 print_generic_expr (dump_file
, sprime
, 0);
3902 fprintf (dump_file
, " in ");
3903 print_gimple_stmt (dump_file
, stmt
, 0, 0);
3905 pre_stats
.eliminations
++;
3906 propagate_tree_value_into_stmt (&i
, sprime
);
3907 stmt
= gsi_stmt (i
);
3912 /* If there is no existing usable leader but SCCVN thinks
3913 it has an expression it wants to use as replacement,
3915 if (!sprime
|| sprime
== lhs
)
3917 tree val
= VN_INFO (lhs
)->valnum
;
3919 && TREE_CODE (val
) == SSA_NAME
3920 && VN_INFO (val
)->needs_insertion
3921 && can_PRE_operation (vn_get_expr_for (val
)))
3922 sprime
= do_SCCVN_insertion (stmt
, val
);
3926 && (rhs
== NULL_TREE
3927 || TREE_CODE (rhs
) != SSA_NAME
3928 || may_propagate_copy (rhs
, sprime
)))
3930 gcc_assert (sprime
!= rhs
);
3932 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3934 fprintf (dump_file
, "Replaced ");
3935 print_gimple_expr (dump_file
, stmt
, 0, 0);
3936 fprintf (dump_file
, " with ");
3937 print_generic_expr (dump_file
, sprime
, 0);
3938 fprintf (dump_file
, " in ");
3939 print_gimple_stmt (dump_file
, stmt
, 0, 0);
3942 if (TREE_CODE (sprime
) == SSA_NAME
)
3943 gimple_set_plf (SSA_NAME_DEF_STMT (sprime
),
3945 /* We need to make sure the new and old types actually match,
3946 which may require adding a simple cast, which fold_convert
3948 if ((!rhs
|| TREE_CODE (rhs
) != SSA_NAME
)
3949 && !useless_type_conversion_p (gimple_expr_type (stmt
),
3950 TREE_TYPE (sprime
)))
3951 sprime
= fold_convert (gimple_expr_type (stmt
), sprime
);
3953 pre_stats
.eliminations
++;
3954 propagate_tree_value_into_stmt (&i
, sprime
);
3955 stmt
= gsi_stmt (i
);
3958 /* If we removed EH side effects from the statement, clean
3959 its EH information. */
3960 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
3962 bitmap_set_bit (need_eh_cleanup
,
3963 gimple_bb (stmt
)->index
);
3964 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3965 fprintf (dump_file
, " Removed EH side effects.\n");
3969 /* Visit COND_EXPRs and fold the comparison with the
3970 available value-numbers. */
3971 else if (gimple_code (stmt
) == GIMPLE_COND
)
3973 tree op0
= gimple_cond_lhs (stmt
);
3974 tree op1
= gimple_cond_rhs (stmt
);
3977 if (TREE_CODE (op0
) == SSA_NAME
)
3978 op0
= VN_INFO (op0
)->valnum
;
3979 if (TREE_CODE (op1
) == SSA_NAME
)
3980 op1
= VN_INFO (op1
)->valnum
;
3981 result
= fold_binary (gimple_cond_code (stmt
), boolean_type_node
,
3983 if (result
&& TREE_CODE (result
) == INTEGER_CST
)
3985 if (integer_zerop (result
))
3986 gimple_cond_make_false (stmt
);
3988 gimple_cond_make_true (stmt
);
3990 todo
= TODO_cleanup_cfg
;
3999 /* Borrow a bit of tree-ssa-dce.c for the moment.
4000 XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
4001 this may be a bit faster, and we may want critical edges kept split. */
4003 /* If OP's defining statement has not already been determined to be necessary,
4004 mark that statement necessary. Return the stmt, if it is newly
4007 static inline gimple
4008 mark_operand_necessary (tree op
)
4014 if (TREE_CODE (op
) != SSA_NAME
)
4017 stmt
= SSA_NAME_DEF_STMT (op
);
4020 if (gimple_plf (stmt
, NECESSARY
)
4021 || gimple_nop_p (stmt
))
4024 gimple_set_plf (stmt
, NECESSARY
, true);
4028 /* Because we don't follow exactly the standard PRE algorithm, and decide not
4029 to insert PHI nodes sometimes, and because value numbering of casts isn't
4030 perfect, we sometimes end up inserting dead code. This simple DCE-like
4031 pass removes any insertions we made that weren't actually used. */
4034 remove_dead_inserted_code (void)
4036 VEC(gimple
,heap
) *worklist
= NULL
;
4040 worklist
= VEC_alloc (gimple
, heap
, VEC_length (gimple
, inserted_exprs
));
4041 for (i
= 0; VEC_iterate (gimple
, inserted_exprs
, i
, t
); i
++)
4043 if (gimple_plf (t
, NECESSARY
))
4044 VEC_quick_push (gimple
, worklist
, t
);
4046 while (VEC_length (gimple
, worklist
) > 0)
4048 t
= VEC_pop (gimple
, worklist
);
4050 /* PHI nodes are somewhat special in that each PHI alternative has
4051 data and control dependencies. All the statements feeding the
4052 PHI node's arguments are always necessary. */
4053 if (gimple_code (t
) == GIMPLE_PHI
)
4057 VEC_reserve (gimple
, heap
, worklist
, gimple_phi_num_args (t
));
4058 for (k
= 0; k
< gimple_phi_num_args (t
); k
++)
4060 tree arg
= PHI_ARG_DEF (t
, k
);
4061 if (TREE_CODE (arg
) == SSA_NAME
)
4063 gimple n
= mark_operand_necessary (arg
);
4065 VEC_quick_push (gimple
, worklist
, n
);
4071 /* Propagate through the operands. Examine all the USE, VUSE and
4072 VDEF operands in this statement. Mark all the statements
4073 which feed this statement's uses as necessary. */
4077 /* The operands of VDEF expressions are also needed as they
4078 represent potential definitions that may reach this
4079 statement (VDEF operands allow us to follow def-def
4082 FOR_EACH_SSA_TREE_OPERAND (use
, t
, iter
, SSA_OP_ALL_USES
)
4084 gimple n
= mark_operand_necessary (use
);
4086 VEC_safe_push (gimple
, heap
, worklist
, n
);
4091 for (i
= 0; VEC_iterate (gimple
, inserted_exprs
, i
, t
); i
++)
4093 if (!gimple_plf (t
, NECESSARY
))
4095 gimple_stmt_iterator gsi
;
4097 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4099 fprintf (dump_file
, "Removing unnecessary insertion:");
4100 print_gimple_stmt (dump_file
, t
, 0, 0);
4103 gsi
= gsi_for_stmt (t
);
4104 if (gimple_code (t
) == GIMPLE_PHI
)
4105 remove_phi_node (&gsi
, true);
4107 gsi_remove (&gsi
, true);
4111 VEC_free (gimple
, heap
, worklist
);
4114 /* Initialize data structures used by PRE. */
4117 init_pre (bool do_fre
)
4121 next_expression_id
= 1;
4123 VEC_safe_push (pre_expr
, heap
, expressions
, NULL
);
4124 value_expressions
= VEC_alloc (bitmap_set_t
, heap
, get_max_value_id () + 1);
4125 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
4126 get_max_value_id() + 1);
4130 inserted_exprs
= NULL
;
4131 need_creation
= NULL
;
4132 pretemp
= NULL_TREE
;
4133 storetemp
= NULL_TREE
;
4134 prephitemp
= NULL_TREE
;
4136 connect_infinite_loops_to_exit ();
4137 memset (&pre_stats
, 0, sizeof (pre_stats
));
4140 postorder
= XNEWVEC (int, n_basic_blocks
- NUM_FIXED_BLOCKS
);
4141 post_order_compute (postorder
, false, false);
4144 bb
->aux
= XCNEWVEC (struct bb_bitmap_sets
, 1);
4146 calculate_dominance_info (CDI_POST_DOMINATORS
);
4147 calculate_dominance_info (CDI_DOMINATORS
);
4149 bitmap_obstack_initialize (&grand_bitmap_obstack
);
4150 phi_translate_table
= htab_create (5110, expr_pred_trans_hash
,
4151 expr_pred_trans_eq
, free
);
4152 expression_to_id
= htab_create (num_ssa_names
* 3,
4155 seen_during_translate
= BITMAP_ALLOC (&grand_bitmap_obstack
);
4156 bitmap_set_pool
= create_alloc_pool ("Bitmap sets",
4157 sizeof (struct bitmap_set
), 30);
4158 pre_expr_pool
= create_alloc_pool ("pre_expr nodes",
4159 sizeof (struct pre_expr_d
), 30);
4162 EXP_GEN (bb
) = bitmap_set_new ();
4163 PHI_GEN (bb
) = bitmap_set_new ();
4164 TMP_GEN (bb
) = bitmap_set_new ();
4165 AVAIL_OUT (bb
) = bitmap_set_new ();
4167 maximal_set
= in_fre
? NULL
: bitmap_set_new ();
4169 need_eh_cleanup
= BITMAP_ALLOC (NULL
);
4173 /* Deallocate data structures used by PRE. */
4176 fini_pre (bool do_fre
)
4181 VEC_free (bitmap_set_t
, heap
, value_expressions
);
4182 VEC_free (gimple
, heap
, inserted_exprs
);
4183 VEC_free (gimple
, heap
, need_creation
);
4184 bitmap_obstack_release (&grand_bitmap_obstack
);
4185 free_alloc_pool (bitmap_set_pool
);
4186 free_alloc_pool (pre_expr_pool
);
4187 htab_delete (phi_translate_table
);
4188 htab_delete (expression_to_id
);
4196 free_dominance_info (CDI_POST_DOMINATORS
);
4198 if (!bitmap_empty_p (need_eh_cleanup
))
4200 gimple_purge_all_dead_eh_edges (need_eh_cleanup
);
4201 cleanup_tree_cfg ();
4204 BITMAP_FREE (need_eh_cleanup
);
4207 loop_optimizer_finalize ();
4210 /* Main entry point to the SSA-PRE pass. DO_FRE is true if the caller
4211 only wants to do full redundancy elimination. */
4214 execute_pre (bool do_fre ATTRIBUTE_UNUSED
)
4216 unsigned int todo
= 0;
4218 do_partial_partial
= optimize
> 2;
4220 /* This has to happen before SCCVN runs because
4221 loop_optimizer_init may create new phis, etc. */
4223 loop_optimizer_init (LOOPS_NORMAL
);
4225 if (!run_scc_vn (do_fre
))
4229 remove_dead_inserted_code ();
4230 loop_optimizer_finalize ();
4238 /* Collect and value number expressions computed in each basic block. */
4241 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4247 print_bitmap_set (dump_file
, EXP_GEN (bb
), "exp_gen", bb
->index
);
4248 print_bitmap_set (dump_file
, TMP_GEN (bb
), "tmp_gen",
4250 print_bitmap_set (dump_file
, AVAIL_OUT (bb
), "avail_out",
4255 /* Insert can get quite slow on an incredibly large number of basic
4256 blocks due to some quadratic behavior. Until this behavior is
4257 fixed, don't run it when he have an incredibly large number of
4258 bb's. If we aren't going to run insert, there is no point in
4259 computing ANTIC, either, even though it's plenty fast. */
4260 if (!do_fre
&& n_basic_blocks
< 4000)
4266 /* Remove all the redundant expressions. */
4267 todo
|= eliminate ();
4269 statistics_counter_event (cfun
, "Insertions", pre_stats
.insertions
);
4270 statistics_counter_event (cfun
, "PA inserted", pre_stats
.pa_insert
);
4271 statistics_counter_event (cfun
, "New PHIs", pre_stats
.phis
);
4272 statistics_counter_event (cfun
, "Eliminated", pre_stats
.eliminations
);
4273 statistics_counter_event (cfun
, "Constified", pre_stats
.constified
);
4275 /* Make sure to remove fake edges before committing our inserts.
4276 This makes sure we don't end up with extra critical edges that
4277 we would need to split. */
4278 remove_fake_exit_edges ();
4279 gsi_commit_edge_inserts ();
4281 clear_expression_ids ();
4284 remove_dead_inserted_code ();
4291 /* Gate and execute functions for PRE. */
4296 return TODO_rebuild_alias
| execute_pre (false);
4302 /* PRE tends to generate bigger code. */
4303 return flag_tree_pre
!= 0 && optimize_function_for_speed_p (cfun
);
4306 struct gimple_opt_pass pass_pre
=
4311 gate_pre
, /* gate */
4312 do_pre
, /* execute */
4315 0, /* static_pass_number */
4316 TV_TREE_PRE
, /* tv_id */
4317 PROP_no_crit_edges
| PROP_cfg
4318 | PROP_ssa
| PROP_alias
, /* properties_required */
4319 0, /* properties_provided */
4320 0, /* properties_destroyed */
4321 0, /* todo_flags_start */
4322 TODO_update_ssa_only_virtuals
| TODO_dump_func
| TODO_ggc_collect
4323 | TODO_verify_ssa
/* todo_flags_finish */
4328 /* Gate and execute functions for FRE. */
4333 return execute_pre (true);
4339 return flag_tree_fre
!= 0;
4342 struct gimple_opt_pass pass_fre
=
4347 gate_fre
, /* gate */
4348 execute_fre
, /* execute */
4351 0, /* static_pass_number */
4352 TV_TREE_FRE
, /* tv_id */
4353 PROP_cfg
| PROP_ssa
| PROP_alias
, /* properties_required */
4354 0, /* properties_provided */
4355 0, /* properties_destroyed */
4356 0, /* todo_flags_start */
4357 TODO_dump_func
| TODO_ggc_collect
| TODO_verify_ssa
/* todo_flags_finish */