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
))
1091 case tcc_expression
:
1092 if (nary
->opcode
== TRUTH_NOT_EXPR
)
1094 if (nary
->opcode
!= TRUTH_AND_EXPR
1095 && nary
->opcode
!= TRUTH_OR_EXPR
1096 && nary
->opcode
!= TRUTH_XOR_EXPR
)
1100 case tcc_comparison
:
1102 /* We have to go from trees to pre exprs to value ids to
1104 tree naryop0
= nary
->op
[0];
1105 tree naryop1
= nary
->op
[1];
1107 if (!is_gimple_min_invariant (naryop0
))
1109 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1110 unsigned int vrep0
= get_expr_value_id (rep0
);
1111 tree const0
= get_constant_for_value_id (vrep0
);
1113 naryop0
= fold_convert (TREE_TYPE (naryop0
), const0
);
1115 if (!is_gimple_min_invariant (naryop1
))
1117 pre_expr rep1
= get_or_alloc_expr_for (naryop1
);
1118 unsigned int vrep1
= get_expr_value_id (rep1
);
1119 tree const1
= get_constant_for_value_id (vrep1
);
1121 naryop1
= fold_convert (TREE_TYPE (naryop1
), const1
);
1123 result
= fold_binary (nary
->opcode
, nary
->type
,
1125 if (result
&& is_gimple_min_invariant (result
))
1126 return get_or_alloc_expr_for_constant (result
);
1127 /* We might have simplified the expression to a
1128 SSA_NAME for example from x_1 * 1. But we cannot
1129 insert a PHI for x_1 unconditionally as x_1 might
1130 not be available readily. */
1134 if (nary
->opcode
!= REALPART_EXPR
1135 && nary
->opcode
!= IMAGPART_EXPR
1136 && nary
->opcode
!= VIEW_CONVERT_EXPR
)
1142 /* We have to go from trees to pre exprs to value ids to
1144 tree naryop0
= nary
->op
[0];
1145 tree const0
, result
;
1146 if (is_gimple_min_invariant (naryop0
))
1150 pre_expr rep0
= get_or_alloc_expr_for (naryop0
);
1151 unsigned int vrep0
= get_expr_value_id (rep0
);
1152 const0
= get_constant_for_value_id (vrep0
);
1157 tree type1
= TREE_TYPE (nary
->op
[0]);
1158 const0
= fold_convert (type1
, const0
);
1159 result
= fold_unary (nary
->opcode
, nary
->type
, const0
);
1161 if (result
&& is_gimple_min_invariant (result
))
1162 return get_or_alloc_expr_for_constant (result
);
1171 vn_reference_t ref
= PRE_EXPR_REFERENCE (e
);
1172 VEC (vn_reference_op_s
, heap
) *operands
= ref
->operands
;
1173 vn_reference_op_t op
;
1175 /* Try to simplify the translated expression if it is
1176 a call to a builtin function with at most two arguments. */
1177 op
= VEC_index (vn_reference_op_s
, operands
, 0);
1178 if (op
->opcode
== CALL_EXPR
1179 && TREE_CODE (op
->op0
) == ADDR_EXPR
1180 && TREE_CODE (TREE_OPERAND (op
->op0
, 0)) == FUNCTION_DECL
1181 && DECL_BUILT_IN (TREE_OPERAND (op
->op0
, 0))
1182 && VEC_length (vn_reference_op_s
, operands
) >= 2
1183 && VEC_length (vn_reference_op_s
, operands
) <= 3)
1185 vn_reference_op_t arg0
, arg1
= NULL
;
1186 bool anyconst
= false;
1187 arg0
= VEC_index (vn_reference_op_s
, operands
, 1);
1188 if (VEC_length (vn_reference_op_s
, operands
) > 2)
1189 arg1
= VEC_index (vn_reference_op_s
, operands
, 2);
1190 if (TREE_CODE_CLASS (arg0
->opcode
) == tcc_constant
1191 || (arg0
->opcode
== ADDR_EXPR
1192 && is_gimple_min_invariant (arg0
->op0
)))
1195 && (TREE_CODE_CLASS (arg1
->opcode
) == tcc_constant
1196 || (arg1
->opcode
== ADDR_EXPR
1197 && is_gimple_min_invariant (arg1
->op0
))))
1201 tree folded
= build_call_expr (TREE_OPERAND (op
->op0
, 0),
1204 arg1
? arg1
->op0
: NULL
);
1206 && TREE_CODE (folded
) == NOP_EXPR
)
1207 folded
= TREE_OPERAND (folded
, 0);
1209 && is_gimple_min_invariant (folded
))
1210 return get_or_alloc_expr_for_constant (folded
);
1221 /* Translate the vuses in the VUSES vector backwards through phi nodes
1222 in PHIBLOCK, so that they have the value they would have in
1225 static VEC(tree
, gc
) *
1226 translate_vuses_through_block (VEC (tree
, gc
) *vuses
,
1227 basic_block phiblock
,
1231 VEC(tree
, gc
) *result
= NULL
;
1234 for (i
= 0; VEC_iterate (tree
, vuses
, i
, oldvuse
); i
++)
1236 gimple phi
= SSA_NAME_DEF_STMT (oldvuse
);
1237 if (gimple_code (phi
) == GIMPLE_PHI
1238 && gimple_bb (phi
) == phiblock
)
1240 edge e
= find_edge (block
, gimple_bb (phi
));
1243 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1247 result
= VEC_copy (tree
, gc
, vuses
);
1248 VEC_replace (tree
, result
, i
, def
);
1254 /* We avoid creating a new copy of the vuses unless something
1255 actually changed, so result can be NULL. */
1258 sort_vuses (result
);
1265 /* Like find_leader, but checks for the value existing in SET1 *or*
1266 SET2. This is used to avoid making a set consisting of the union
1267 of PA_IN and ANTIC_IN during insert. */
1269 static inline pre_expr
1270 find_leader_in_sets (unsigned int val
, bitmap_set_t set1
, bitmap_set_t set2
)
1274 result
= bitmap_find_leader (set1
, val
, NULL
);
1275 if (!result
&& set2
)
1276 result
= bitmap_find_leader (set2
, val
, NULL
);
1280 /* Get the tree type for our PRE expression e. */
1283 get_expr_type (const pre_expr e
)
1288 return TREE_TYPE (PRE_EXPR_NAME (e
));
1290 return TREE_TYPE (PRE_EXPR_CONSTANT (e
));
1293 vn_reference_op_t vro
;
1295 gcc_assert (PRE_EXPR_REFERENCE (e
)->operands
);
1296 vro
= VEC_index (vn_reference_op_s
,
1297 PRE_EXPR_REFERENCE (e
)->operands
,
1299 /* We don't store type along with COMPONENT_REF because it is
1300 always the same as FIELD_DECL's type. */
1303 gcc_assert (vro
->opcode
== COMPONENT_REF
);
1304 return TREE_TYPE (vro
->op0
);
1310 return PRE_EXPR_NARY (e
)->type
;
1315 /* Get a representative SSA_NAME for a given expression.
1316 Since all of our sub-expressions are treated as values, we require
1317 them to be SSA_NAME's for simplicity.
1318 Prior versions of GVNPRE used to use "value handles" here, so that
1319 an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
1320 either case, the operands are really values (IE we do not expect
1321 them to be usable without finding leaders). */
1324 get_representative_for (const pre_expr e
)
1328 unsigned int value_id
= get_expr_value_id (e
);
1333 return PRE_EXPR_NAME (e
);
1335 return PRE_EXPR_CONSTANT (e
);
1339 /* Go through all of the expressions representing this value
1340 and pick out an SSA_NAME. */
1343 bitmap_set_t exprs
= VEC_index (bitmap_set_t
, value_expressions
,
1345 FOR_EACH_EXPR_ID_IN_SET (exprs
, i
, bi
)
1347 pre_expr rep
= expression_for_id (i
);
1348 if (rep
->kind
== NAME
)
1349 return PRE_EXPR_NAME (rep
);
1354 /* If we reached here we couldn't find an SSA_NAME. This can
1355 happen when we've discovered a value that has never appeared in
1356 the program as set to an SSA_NAME, most likely as the result of
1361 "Could not find SSA_NAME representative for expression:");
1362 print_pre_expr (dump_file
, e
);
1363 fprintf (dump_file
, "\n");
1366 exprtype
= get_expr_type (e
);
1368 /* Build and insert the assignment of the end result to the temporary
1369 that we will return. */
1370 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
1372 pretemp
= create_tmp_var (exprtype
, "pretmp");
1373 get_var_ann (pretemp
);
1376 name
= make_ssa_name (pretemp
, gimple_build_nop ());
1377 VN_INFO_GET (name
)->value_id
= value_id
;
1378 if (e
->kind
== CONSTANT
)
1379 VN_INFO (name
)->valnum
= PRE_EXPR_CONSTANT (e
);
1381 VN_INFO (name
)->valnum
= name
;
1383 add_to_value (value_id
, get_or_alloc_expr_for_name (name
));
1386 fprintf (dump_file
, "Created SSA_NAME representative ");
1387 print_generic_expr (dump_file
, name
, 0);
1388 fprintf (dump_file
, " for expression:");
1389 print_pre_expr (dump_file
, e
);
1390 fprintf (dump_file
, "\n");
1399 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1400 the phis in PRED. SEEN is a bitmap saying which expression we have
1401 translated since we started translation of the toplevel expression.
1402 Return NULL if we can't find a leader for each part of the
1403 translated expression. */
1406 phi_translate_1 (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1407 basic_block pred
, basic_block phiblock
, bitmap seen
)
1409 pre_expr oldexpr
= expr
;
1415 if (value_id_constant_p (get_expr_value_id (expr
)))
1418 phitrans
= phi_trans_lookup (expr
, pred
);
1422 /* Prevent cycles when we have recursively dependent leaders. This
1423 can only happen when phi translating the maximal set. */
1426 unsigned int expr_id
= get_expression_id (expr
);
1427 if (bitmap_bit_p (seen
, expr_id
))
1429 bitmap_set_bit (seen
, expr_id
);
1434 /* Constants contain no values that need translation. */
1441 bool changed
= false;
1442 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1443 struct vn_nary_op_s newnary
;
1444 /* The NARY structure is only guaranteed to have been
1445 allocated to the nary->length operands. */
1446 memcpy (&newnary
, nary
, (sizeof (struct vn_nary_op_s
)
1447 - sizeof (tree
) * (4 - nary
->length
)));
1449 for (i
= 0; i
< newnary
.length
; i
++)
1451 if (TREE_CODE (newnary
.op
[i
]) != SSA_NAME
)
1455 unsigned int op_val_id
= VN_INFO (newnary
.op
[i
])->value_id
;
1456 pre_expr leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1457 pre_expr result
= phi_translate_1 (leader
, set1
, set2
,
1458 pred
, phiblock
, seen
);
1459 if (result
&& result
!= leader
)
1461 tree name
= get_representative_for (result
);
1464 newnary
.op
[i
] = name
;
1469 changed
|= newnary
.op
[i
] != nary
->op
[i
];
1476 tree result
= vn_nary_op_lookup_pieces (newnary
.length
,
1484 unsigned int new_val_id
;
1486 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1489 if (result
&& is_gimple_min_invariant (result
))
1490 return get_or_alloc_expr_for_constant (result
);
1495 PRE_EXPR_NARY (expr
) = nary
;
1496 constant
= fully_constant_expression (expr
);
1497 if (constant
!= expr
)
1500 new_val_id
= nary
->value_id
;
1501 get_or_alloc_expression_id (expr
);
1505 new_val_id
= get_next_value_id ();
1506 VEC_safe_grow_cleared (bitmap_set_t
, heap
,
1508 get_max_value_id() + 1);
1509 nary
= vn_nary_op_insert_pieces (newnary
.length
,
1516 result
, new_val_id
);
1517 PRE_EXPR_NARY (expr
) = nary
;
1518 constant
= fully_constant_expression (expr
);
1519 if (constant
!= expr
)
1521 get_or_alloc_expression_id (expr
);
1523 add_to_value (new_val_id
, expr
);
1525 phi_trans_add (oldexpr
, expr
, pred
);
1532 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1533 VEC (vn_reference_op_s
, heap
) *operands
= ref
->operands
;
1534 VEC (tree
, gc
) *vuses
= ref
->vuses
;
1535 VEC (tree
, gc
) *newvuses
= vuses
;
1536 VEC (vn_reference_op_s
, heap
) *newoperands
= NULL
;
1537 bool changed
= false;
1539 vn_reference_op_t operand
;
1540 vn_reference_t newref
;
1542 for (i
= 0; VEC_iterate (vn_reference_op_s
, operands
, i
, operand
); i
++)
1546 tree oldop0
= operand
->op0
;
1547 tree oldop1
= operand
->op1
;
1548 tree oldop2
= operand
->op2
;
1552 tree type
= operand
->type
;
1553 vn_reference_op_s newop
= *operand
;
1555 if (op0
&& TREE_CODE (op0
) == SSA_NAME
)
1557 unsigned int op_val_id
= VN_INFO (op0
)->value_id
;
1558 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1559 opresult
= phi_translate_1 (leader
, set1
, set2
,
1560 pred
, phiblock
, seen
);
1561 if (opresult
&& opresult
!= leader
)
1563 tree name
= get_representative_for (opresult
);
1571 changed
|= op0
!= oldop0
;
1573 if (op1
&& TREE_CODE (op1
) == SSA_NAME
)
1575 unsigned int op_val_id
= VN_INFO (op1
)->value_id
;
1576 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1577 opresult
= phi_translate_1 (leader
, set1
, set2
,
1578 pred
, phiblock
, seen
);
1579 if (opresult
&& opresult
!= leader
)
1581 tree name
= get_representative_for (opresult
);
1589 changed
|= op1
!= oldop1
;
1590 if (op2
&& TREE_CODE (op2
) == SSA_NAME
)
1592 unsigned int op_val_id
= VN_INFO (op2
)->value_id
;
1593 leader
= find_leader_in_sets (op_val_id
, set1
, set2
);
1594 opresult
= phi_translate_1 (leader
, set1
, set2
,
1595 pred
, phiblock
, seen
);
1596 if (opresult
&& opresult
!= leader
)
1598 tree name
= get_representative_for (opresult
);
1606 changed
|= op2
!= oldop2
;
1609 newoperands
= VEC_copy (vn_reference_op_s
, heap
, operands
);
1610 /* We may have changed from an SSA_NAME to a constant */
1611 if (newop
.opcode
== SSA_NAME
&& TREE_CODE (op0
) != SSA_NAME
)
1612 newop
.opcode
= TREE_CODE (op0
);
1617 VEC_replace (vn_reference_op_s
, newoperands
, i
, &newop
);
1619 if (i
!= VEC_length (vn_reference_op_s
, operands
))
1622 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1626 newvuses
= translate_vuses_through_block (vuses
, phiblock
, pred
);
1627 changed
|= newvuses
!= vuses
;
1631 unsigned int new_val_id
;
1634 tree result
= vn_reference_lookup_pieces (newvuses
,
1638 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1640 if (result
&& is_gimple_min_invariant (result
))
1642 gcc_assert (!newoperands
);
1643 return get_or_alloc_expr_for_constant (result
);
1646 expr
= (pre_expr
) pool_alloc (pre_expr_pool
);
1647 expr
->kind
= REFERENCE
;
1652 PRE_EXPR_REFERENCE (expr
) = newref
;
1653 constant
= fully_constant_expression (expr
);
1654 if (constant
!= expr
)
1657 new_val_id
= newref
->value_id
;
1658 get_or_alloc_expression_id (expr
);
1662 new_val_id
= get_next_value_id ();
1663 VEC_safe_grow_cleared (bitmap_set_t
, heap
, value_expressions
,
1664 get_max_value_id() + 1);
1665 newref
= vn_reference_insert_pieces (newvuses
,
1667 result
, new_val_id
);
1669 PRE_EXPR_REFERENCE (expr
) = newref
;
1670 constant
= fully_constant_expression (expr
);
1671 if (constant
!= expr
)
1673 get_or_alloc_expression_id (expr
);
1675 add_to_value (new_val_id
, expr
);
1677 VEC_free (vn_reference_op_s
, heap
, newoperands
);
1678 phi_trans_add (oldexpr
, expr
, pred
);
1688 tree name
= PRE_EXPR_NAME (expr
);
1690 def_stmt
= SSA_NAME_DEF_STMT (name
);
1691 if (gimple_code (def_stmt
) == GIMPLE_PHI
1692 && gimple_bb (def_stmt
) == phiblock
)
1697 e
= find_edge (pred
, gimple_bb (phi
));
1700 tree def
= PHI_ARG_DEF (phi
, e
->dest_idx
);
1703 /* Handle constant. */
1704 if (is_gimple_min_invariant (def
))
1705 return get_or_alloc_expr_for_constant (def
);
1707 if (TREE_CODE (def
) == SSA_NAME
&& ssa_undefined_value_p (def
))
1710 newexpr
= get_or_alloc_expr_for_name (def
);
1721 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
1723 Return NULL if we can't find a leader for each part of the
1724 translated expression. */
1727 phi_translate (pre_expr expr
, bitmap_set_t set1
, bitmap_set_t set2
,
1728 basic_block pred
, basic_block phiblock
)
1730 bitmap_clear (seen_during_translate
);
1731 return phi_translate_1 (expr
, set1
, set2
, pred
, phiblock
,
1732 seen_during_translate
);
1735 /* For each expression in SET, translate the values through phi nodes
1736 in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
1737 expressions in DEST. */
1740 phi_translate_set (bitmap_set_t dest
, bitmap_set_t set
, basic_block pred
,
1741 basic_block phiblock
)
1743 VEC (pre_expr
, heap
) *exprs
;
1747 if (!phi_nodes (phiblock
))
1749 bitmap_set_copy (dest
, set
);
1753 exprs
= sorted_array_from_bitmap_set (set
);
1754 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
1756 pre_expr translated
;
1757 translated
= phi_translate (expr
, set
, NULL
, pred
, phiblock
);
1759 /* Don't add empty translations to the cache */
1761 phi_trans_add (expr
, translated
, pred
);
1763 if (translated
!= NULL
)
1764 bitmap_value_insert_into_set (dest
, translated
);
1766 VEC_free (pre_expr
, heap
, exprs
);
1769 /* Find the leader for a value (i.e., the name representing that
1770 value) in a given set, and return it. If STMT is non-NULL it
1771 makes sure the defining statement for the leader dominates it.
1772 Return NULL if no leader is found. */
1775 bitmap_find_leader (bitmap_set_t set
, unsigned int val
, gimple stmt
)
1777 if (value_id_constant_p (val
))
1781 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1783 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
1785 pre_expr expr
= expression_for_id (i
);
1786 if (expr
->kind
== CONSTANT
)
1790 if (bitmap_set_contains_value (set
, val
))
1792 /* Rather than walk the entire bitmap of expressions, and see
1793 whether any of them has the value we are looking for, we look
1794 at the reverse mapping, which tells us the set of expressions
1795 that have a given value (IE value->expressions with that
1796 value) and see if any of those expressions are in our set.
1797 The number of expressions per value is usually significantly
1798 less than the number of expressions in the set. In fact, for
1799 large testcases, doing it this way is roughly 5-10x faster
1800 than walking the bitmap.
1801 If this is somehow a significant lose for some cases, we can
1802 choose which set to walk based on which set is smaller. */
1805 bitmap_set_t exprset
= VEC_index (bitmap_set_t
, value_expressions
, val
);
1807 EXECUTE_IF_AND_IN_BITMAP (exprset
->expressions
,
1808 set
->expressions
, 0, i
, bi
)
1810 pre_expr val
= expression_for_id (i
);
1811 /* At the point where stmt is not null, there should always
1812 be an SSA_NAME first in the list of expressions. */
1815 gimple def_stmt
= SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val
));
1816 if (gimple_code (def_stmt
) != GIMPLE_PHI
1817 && gimple_bb (def_stmt
) == gimple_bb (stmt
)
1818 && gimple_uid (def_stmt
) >= gimple_uid (stmt
))
1827 /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
1828 BLOCK by seeing if it is not killed in the block. Note that we are
1829 only determining whether there is a store that kills it. Because
1830 of the order in which clean iterates over values, we are guaranteed
1831 that altered operands will have caused us to be eliminated from the
1832 ANTIC_IN set already. */
1835 value_dies_in_block_x (pre_expr expr
, basic_block block
)
1839 VEC (tree
, gc
) *vuses
= PRE_EXPR_REFERENCE (expr
)->vuses
;
1841 /* Conservatively, a value dies if it's vuses are defined in this
1842 block, unless they come from phi nodes (which are merge operations,
1843 rather than stores. */
1844 for (i
= 0; VEC_iterate (tree
, vuses
, i
, vuse
); i
++)
1846 gimple def
= SSA_NAME_DEF_STMT (vuse
);
1848 if (gimple_bb (def
) != block
)
1850 if (gimple_code (def
) == GIMPLE_PHI
)
1858 #define union_contains_value(SET1, SET2, VAL) \
1859 (bitmap_set_contains_value ((SET1), (VAL)) \
1860 || ((SET2) && bitmap_set_contains_value ((SET2), (VAL))))
1862 /* Determine if vn_reference_op_t VRO is legal in SET1 U SET2.
1865 vro_valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
,
1866 vn_reference_op_t vro
)
1868 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
1870 struct pre_expr_d temp
;
1873 PRE_EXPR_NAME (&temp
) = vro
->op0
;
1874 temp
.id
= lookup_expression_id (&temp
);
1877 if (!union_contains_value (set1
, set2
,
1878 get_expr_value_id (&temp
)))
1881 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
1883 struct pre_expr_d temp
;
1886 PRE_EXPR_NAME (&temp
) = vro
->op1
;
1887 temp
.id
= lookup_expression_id (&temp
);
1890 if (!union_contains_value (set1
, set2
,
1891 get_expr_value_id (&temp
)))
1895 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
1897 struct pre_expr_d temp
;
1900 PRE_EXPR_NAME (&temp
) = vro
->op2
;
1901 temp
.id
= lookup_expression_id (&temp
);
1904 if (!union_contains_value (set1
, set2
,
1905 get_expr_value_id (&temp
)))
1912 /* Determine if the expression EXPR is valid in SET1 U SET2.
1913 ONLY SET2 CAN BE NULL.
1914 This means that we have a leader for each part of the expression
1915 (if it consists of values), or the expression is an SSA_NAME.
1916 For loads/calls, we also see if the vuses are killed in this block.
1920 valid_in_sets (bitmap_set_t set1
, bitmap_set_t set2
, pre_expr expr
,
1926 return bitmap_set_contains_expr (AVAIL_OUT (block
), expr
);
1930 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
1931 for (i
= 0; i
< nary
->length
; i
++)
1933 if (TREE_CODE (nary
->op
[i
]) == SSA_NAME
)
1935 struct pre_expr_d temp
;
1938 PRE_EXPR_NAME (&temp
) = nary
->op
[i
];
1939 temp
.id
= lookup_expression_id (&temp
);
1942 if (!union_contains_value (set1
, set2
,
1943 get_expr_value_id (&temp
)))
1952 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
1953 vn_reference_op_t vro
;
1956 for (i
= 0; VEC_iterate (vn_reference_op_s
, ref
->operands
, i
, vro
); i
++)
1958 if (!vro_valid_in_sets (set1
, set2
, vro
))
1961 return !value_dies_in_block_x (expr
, block
);
1968 /* Clean the set of expressions that are no longer valid in SET1 or
1969 SET2. This means expressions that are made up of values we have no
1970 leaders for in SET1 or SET2. This version is used for partial
1971 anticipation, which means it is not valid in either ANTIC_IN or
1975 dependent_clean (bitmap_set_t set1
, bitmap_set_t set2
, basic_block block
)
1977 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set1
);
1981 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
1983 if (!valid_in_sets (set1
, set2
, expr
, block
))
1984 bitmap_remove_from_set (set1
, expr
);
1986 VEC_free (pre_expr
, heap
, exprs
);
1989 /* Clean the set of expressions that are no longer valid in SET. This
1990 means expressions that are made up of values we have no leaders for
1994 clean (bitmap_set_t set
, basic_block block
)
1996 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (set
);
2000 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
2002 if (!valid_in_sets (set
, NULL
, expr
, block
))
2003 bitmap_remove_from_set (set
, expr
);
2005 VEC_free (pre_expr
, heap
, exprs
);
2008 static sbitmap has_abnormal_preds
;
2010 /* List of blocks that may have changed during ANTIC computation and
2011 thus need to be iterated over. */
2013 static sbitmap changed_blocks
;
2015 /* Decide whether to defer a block for a later iteration, or PHI
2016 translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
2017 should defer the block, and true if we processed it. */
2020 defer_or_phi_translate_block (bitmap_set_t dest
, bitmap_set_t source
,
2021 basic_block block
, basic_block phiblock
)
2023 if (!BB_VISITED (phiblock
))
2025 SET_BIT (changed_blocks
, block
->index
);
2026 BB_VISITED (block
) = 0;
2027 BB_DEFERRED (block
) = 1;
2031 phi_translate_set (dest
, source
, block
, phiblock
);
2035 /* Compute the ANTIC set for BLOCK.
2037 If succs(BLOCK) > 1 then
2038 ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
2039 else if succs(BLOCK) == 1 then
2040 ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
2042 ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
2046 compute_antic_aux (basic_block block
, bool block_has_abnormal_pred_edge
)
2048 bool changed
= false;
2049 bitmap_set_t S
, old
, ANTIC_OUT
;
2055 old
= ANTIC_OUT
= S
= NULL
;
2056 BB_VISITED (block
) = 1;
2058 /* If any edges from predecessors are abnormal, antic_in is empty,
2060 if (block_has_abnormal_pred_edge
)
2061 goto maybe_dump_sets
;
2063 old
= ANTIC_IN (block
);
2064 ANTIC_OUT
= bitmap_set_new ();
2066 /* If the block has no successors, ANTIC_OUT is empty. */
2067 if (EDGE_COUNT (block
->succs
) == 0)
2069 /* If we have one successor, we could have some phi nodes to
2070 translate through. */
2071 else if (single_succ_p (block
))
2073 basic_block succ_bb
= single_succ (block
);
2075 /* We trade iterations of the dataflow equations for having to
2076 phi translate the maximal set, which is incredibly slow
2077 (since the maximal set often has 300+ members, even when you
2078 have a small number of blocks).
2079 Basically, we defer the computation of ANTIC for this block
2080 until we have processed it's successor, which will inevitably
2081 have a *much* smaller set of values to phi translate once
2082 clean has been run on it.
2083 The cost of doing this is that we technically perform more
2084 iterations, however, they are lower cost iterations.
2086 Timings for PRE on tramp3d-v4:
2087 without maximal set fix: 11 seconds
2088 with maximal set fix/without deferring: 26 seconds
2089 with maximal set fix/with deferring: 11 seconds
2092 if (!defer_or_phi_translate_block (ANTIC_OUT
, ANTIC_IN (succ_bb
),
2096 goto maybe_dump_sets
;
2099 /* If we have multiple successors, we take the intersection of all of
2100 them. Note that in the case of loop exit phi nodes, we may have
2101 phis to translate through. */
2104 VEC(basic_block
, heap
) * worklist
;
2106 basic_block bprime
, first
;
2108 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2109 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2110 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2111 first
= VEC_index (basic_block
, worklist
, 0);
2113 if (phi_nodes (first
))
2115 bitmap_set_t from
= ANTIC_IN (first
);
2117 if (!BB_VISITED (first
))
2119 phi_translate_set (ANTIC_OUT
, from
, block
, first
);
2123 if (!BB_VISITED (first
))
2124 bitmap_set_copy (ANTIC_OUT
, maximal_set
);
2126 bitmap_set_copy (ANTIC_OUT
, ANTIC_IN (first
));
2129 for (i
= 1; VEC_iterate (basic_block
, worklist
, i
, bprime
); i
++)
2131 if (phi_nodes (bprime
))
2133 bitmap_set_t tmp
= bitmap_set_new ();
2134 bitmap_set_t from
= ANTIC_IN (bprime
);
2136 if (!BB_VISITED (bprime
))
2138 phi_translate_set (tmp
, from
, block
, bprime
);
2139 bitmap_set_and (ANTIC_OUT
, tmp
);
2140 bitmap_set_free (tmp
);
2144 if (!BB_VISITED (bprime
))
2145 bitmap_set_and (ANTIC_OUT
, maximal_set
);
2147 bitmap_set_and (ANTIC_OUT
, ANTIC_IN (bprime
));
2150 VEC_free (basic_block
, heap
, worklist
);
2153 /* Generate ANTIC_OUT - TMP_GEN. */
2154 S
= bitmap_set_subtract (ANTIC_OUT
, TMP_GEN (block
));
2156 /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
2157 ANTIC_IN (block
) = bitmap_set_subtract (EXP_GEN (block
),
2160 /* Then union in the ANTIC_OUT - TMP_GEN values,
2161 to get ANTIC_OUT U EXP_GEN - TMP_GEN */
2162 FOR_EACH_EXPR_ID_IN_SET (S
, bii
, bi
)
2163 bitmap_value_insert_into_set (ANTIC_IN (block
),
2164 expression_for_id (bii
));
2166 clean (ANTIC_IN (block
), block
);
2168 /* !old->expressions can happen when we deferred a block. */
2169 if (!old
->expressions
|| !bitmap_set_equal (old
, ANTIC_IN (block
)))
2172 SET_BIT (changed_blocks
, block
->index
);
2173 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2174 SET_BIT (changed_blocks
, e
->src
->index
);
2177 RESET_BIT (changed_blocks
, block
->index
);
2180 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2182 if (!BB_DEFERRED (block
) || BB_VISITED (block
))
2185 print_bitmap_set (dump_file
, ANTIC_OUT
, "ANTIC_OUT", block
->index
);
2187 print_bitmap_set (dump_file
, ANTIC_IN (block
), "ANTIC_IN",
2191 print_bitmap_set (dump_file
, S
, "S", block
->index
);
2196 "Block %d was deferred for a future iteration.\n",
2201 bitmap_set_free (old
);
2203 bitmap_set_free (S
);
2205 bitmap_set_free (ANTIC_OUT
);
2209 /* Compute PARTIAL_ANTIC for BLOCK.
2211 If succs(BLOCK) > 1 then
2212 PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
2213 in ANTIC_OUT for all succ(BLOCK)
2214 else if succs(BLOCK) == 1 then
2215 PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
2217 PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
2222 compute_partial_antic_aux (basic_block block
,
2223 bool block_has_abnormal_pred_edge
)
2225 bool changed
= false;
2226 bitmap_set_t old_PA_IN
;
2227 bitmap_set_t PA_OUT
;
2230 unsigned long max_pa
= PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH
);
2232 old_PA_IN
= PA_OUT
= NULL
;
2234 /* If any edges from predecessors are abnormal, antic_in is empty,
2236 if (block_has_abnormal_pred_edge
)
2237 goto maybe_dump_sets
;
2239 /* If there are too many partially anticipatable values in the
2240 block, phi_translate_set can take an exponential time: stop
2241 before the translation starts. */
2243 && single_succ_p (block
)
2244 && bitmap_count_bits (PA_IN (single_succ (block
))->values
) > max_pa
)
2245 goto maybe_dump_sets
;
2247 old_PA_IN
= PA_IN (block
);
2248 PA_OUT
= bitmap_set_new ();
2250 /* If the block has no successors, ANTIC_OUT is empty. */
2251 if (EDGE_COUNT (block
->succs
) == 0)
2253 /* If we have one successor, we could have some phi nodes to
2254 translate through. Note that we can't phi translate across DFS
2255 back edges in partial antic, because it uses a union operation on
2256 the successors. For recurrences like IV's, we will end up
2257 generating a new value in the set on each go around (i + 3 (VH.1)
2258 VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
2259 else if (single_succ_p (block
))
2261 basic_block succ
= single_succ (block
);
2262 if (!(single_succ_edge (block
)->flags
& EDGE_DFS_BACK
))
2263 phi_translate_set (PA_OUT
, PA_IN (succ
), block
, succ
);
2265 /* If we have multiple successors, we take the union of all of
2269 VEC(basic_block
, heap
) * worklist
;
2273 worklist
= VEC_alloc (basic_block
, heap
, EDGE_COUNT (block
->succs
));
2274 FOR_EACH_EDGE (e
, ei
, block
->succs
)
2276 if (e
->flags
& EDGE_DFS_BACK
)
2278 VEC_quick_push (basic_block
, worklist
, e
->dest
);
2280 if (VEC_length (basic_block
, worklist
) > 0)
2282 for (i
= 0; VEC_iterate (basic_block
, worklist
, i
, bprime
); i
++)
2287 FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime
), i
, bi
)
2288 bitmap_value_insert_into_set (PA_OUT
,
2289 expression_for_id (i
));
2290 if (phi_nodes (bprime
))
2292 bitmap_set_t pa_in
= bitmap_set_new ();
2293 phi_translate_set (pa_in
, PA_IN (bprime
), block
, bprime
);
2294 FOR_EACH_EXPR_ID_IN_SET (pa_in
, i
, bi
)
2295 bitmap_value_insert_into_set (PA_OUT
,
2296 expression_for_id (i
));
2297 bitmap_set_free (pa_in
);
2300 FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime
), i
, bi
)
2301 bitmap_value_insert_into_set (PA_OUT
,
2302 expression_for_id (i
));
2305 VEC_free (basic_block
, heap
, worklist
);
2308 /* PA_IN starts with PA_OUT - TMP_GEN.
2309 Then we subtract things from ANTIC_IN. */
2310 PA_IN (block
) = bitmap_set_subtract (PA_OUT
, TMP_GEN (block
));
2312 /* For partial antic, we want to put back in the phi results, since
2313 we will properly avoid making them partially antic over backedges. */
2314 bitmap_ior_into (PA_IN (block
)->values
, PHI_GEN (block
)->values
);
2315 bitmap_ior_into (PA_IN (block
)->expressions
, PHI_GEN (block
)->expressions
);
2317 /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
2318 bitmap_set_subtract_values (PA_IN (block
), ANTIC_IN (block
));
2320 dependent_clean (PA_IN (block
), ANTIC_IN (block
), block
);
2322 if (!bitmap_set_equal (old_PA_IN
, PA_IN (block
)))
2325 SET_BIT (changed_blocks
, block
->index
);
2326 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2327 SET_BIT (changed_blocks
, e
->src
->index
);
2330 RESET_BIT (changed_blocks
, block
->index
);
2333 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2336 print_bitmap_set (dump_file
, PA_OUT
, "PA_OUT", block
->index
);
2338 print_bitmap_set (dump_file
, PA_IN (block
), "PA_IN", block
->index
);
2341 bitmap_set_free (old_PA_IN
);
2343 bitmap_set_free (PA_OUT
);
2347 /* Compute ANTIC and partial ANTIC sets. */
2350 compute_antic (void)
2352 bool changed
= true;
2353 int num_iterations
= 0;
2357 /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
2358 We pre-build the map of blocks with incoming abnormal edges here. */
2359 has_abnormal_preds
= sbitmap_alloc (last_basic_block
);
2360 sbitmap_zero (has_abnormal_preds
);
2367 FOR_EACH_EDGE (e
, ei
, block
->preds
)
2369 e
->flags
&= ~EDGE_DFS_BACK
;
2370 if (e
->flags
& EDGE_ABNORMAL
)
2372 SET_BIT (has_abnormal_preds
, block
->index
);
2377 BB_VISITED (block
) = 0;
2378 BB_DEFERRED (block
) = 0;
2379 /* While we are here, give empty ANTIC_IN sets to each block. */
2380 ANTIC_IN (block
) = bitmap_set_new ();
2381 PA_IN (block
) = bitmap_set_new ();
2384 /* At the exit block we anticipate nothing. */
2385 ANTIC_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2386 BB_VISITED (EXIT_BLOCK_PTR
) = 1;
2387 PA_IN (EXIT_BLOCK_PTR
) = bitmap_set_new ();
2389 changed_blocks
= sbitmap_alloc (last_basic_block
+ 1);
2390 sbitmap_ones (changed_blocks
);
2393 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2394 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2397 for (i
= 0; i
< last_basic_block
- NUM_FIXED_BLOCKS
; i
++)
2399 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2401 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2402 changed
|= compute_antic_aux (block
,
2403 TEST_BIT (has_abnormal_preds
,
2407 #ifdef ENABLE_CHECKING
2408 /* Theoretically possible, but *highly* unlikely. */
2409 gcc_assert (num_iterations
< 500);
2413 statistics_histogram_event (cfun
, "compute_antic iterations",
2416 if (do_partial_partial
)
2418 sbitmap_ones (changed_blocks
);
2419 mark_dfs_back_edges ();
2424 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2425 fprintf (dump_file
, "Starting iteration %d\n", num_iterations
);
2428 for (i
= 0; i
< last_basic_block
- NUM_FIXED_BLOCKS
; i
++)
2430 if (TEST_BIT (changed_blocks
, postorder
[i
]))
2432 basic_block block
= BASIC_BLOCK (postorder
[i
]);
2434 |= compute_partial_antic_aux (block
,
2435 TEST_BIT (has_abnormal_preds
,
2439 #ifdef ENABLE_CHECKING
2440 /* Theoretically possible, but *highly* unlikely. */
2441 gcc_assert (num_iterations
< 500);
2444 statistics_histogram_event (cfun
, "compute_partial_antic iterations",
2447 sbitmap_free (has_abnormal_preds
);
2448 sbitmap_free (changed_blocks
);
2451 /* Return true if we can value number the call in STMT. This is true
2452 if we have a pure or constant call. */
2455 can_value_number_call (gimple stmt
)
2457 if (gimple_call_flags (stmt
) & (ECF_PURE
| ECF_CONST
))
2462 /* Return true if OP is an exception handler related operation, such as
2463 FILTER_EXPR or EXC_PTR_EXPR. */
2466 is_exception_related (gimple stmt
)
2468 return (is_gimple_assign (stmt
)
2469 && (gimple_assign_rhs_code (stmt
) == FILTER_EXPR
2470 || gimple_assign_rhs_code (stmt
) == EXC_PTR_EXPR
));
2473 /* Return true if OP is a tree which we can perform PRE on
2474 on. This may not match the operations we can value number, but in
2475 a perfect world would. */
2478 can_PRE_operation (tree op
)
2480 return UNARY_CLASS_P (op
)
2481 || BINARY_CLASS_P (op
)
2482 || COMPARISON_CLASS_P (op
)
2483 || TREE_CODE (op
) == INDIRECT_REF
2484 || TREE_CODE (op
) == COMPONENT_REF
2485 || TREE_CODE (op
) == VIEW_CONVERT_EXPR
2486 || TREE_CODE (op
) == CALL_EXPR
2487 || TREE_CODE (op
) == ARRAY_REF
;
2491 /* Inserted expressions are placed onto this worklist, which is used
2492 for performing quick dead code elimination of insertions we made
2493 that didn't turn out to be necessary. */
2494 static VEC(gimple
,heap
) *inserted_exprs
;
2496 /* Pool allocated fake store expressions are placed onto this
2497 worklist, which, after performing dead code elimination, is walked
2498 to see which expressions need to be put into GC'able memory */
2499 static VEC(gimple
, heap
) *need_creation
;
2501 /* The actual worker for create_component_ref_by_pieces. */
2504 create_component_ref_by_pieces_1 (basic_block block
, vn_reference_t ref
,
2505 unsigned int *operand
, gimple_seq
*stmts
,
2508 vn_reference_op_t currop
= VEC_index (vn_reference_op_s
, ref
->operands
,
2512 switch (currop
->opcode
)
2516 tree folded
, sc
= currop
->op1
;
2517 unsigned int nargs
= 0;
2518 tree
*args
= XNEWVEC (tree
, VEC_length (vn_reference_op_s
,
2519 ref
->operands
) - 1);
2520 while (*operand
< VEC_length (vn_reference_op_s
, ref
->operands
))
2522 args
[nargs
] = create_component_ref_by_pieces_1 (block
, ref
,
2527 folded
= build_call_array (currop
->type
,
2528 TREE_CODE (currop
->op0
) == FUNCTION_DECL
2529 ? build_fold_addr_expr (currop
->op0
)
2535 pre_expr scexpr
= get_or_alloc_expr_for (sc
);
2536 sc
= find_or_generate_expression (block
, scexpr
, stmts
, domstmt
);
2539 CALL_EXPR_STATIC_CHAIN (folded
) = sc
;
2547 gcc_assert (is_gimple_min_invariant (currop
->op0
));
2553 case VIEW_CONVERT_EXPR
:
2556 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
,
2561 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2566 case ALIGN_INDIRECT_REF
:
2567 case MISALIGNED_INDIRECT_REF
:
2571 tree genop1
= create_component_ref_by_pieces_1 (block
, ref
,
2576 genop1
= fold_convert (build_pointer_type (currop
->type
),
2579 if (currop
->opcode
== MISALIGNED_INDIRECT_REF
)
2580 folded
= fold_build2 (currop
->opcode
, currop
->type
,
2581 genop1
, currop
->op1
);
2583 folded
= fold_build1 (currop
->opcode
, currop
->type
,
2591 tree genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2593 pre_expr op1expr
= get_or_alloc_expr_for (currop
->op0
);
2594 pre_expr op2expr
= get_or_alloc_expr_for (currop
->op1
);
2600 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2603 genop2
= find_or_generate_expression (block
, op2expr
, stmts
, domstmt
);
2606 folded
= fold_build3 (BIT_FIELD_REF
, currop
->type
, genop0
, genop1
,
2611 /* For array ref vn_reference_op's, operand 1 of the array ref
2612 is op0 of the reference op and operand 3 of the array ref is
2614 case ARRAY_RANGE_REF
:
2618 tree genop1
= currop
->op0
;
2620 tree genop2
= currop
->op1
;
2623 genop0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2627 op1expr
= get_or_alloc_expr_for (genop1
);
2628 genop1
= find_or_generate_expression (block
, op1expr
, stmts
, domstmt
);
2633 op2expr
= get_or_alloc_expr_for (genop2
);
2634 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2640 genop3
= currop
->op2
;
2641 return build4 (currop
->opcode
, currop
->type
, genop0
, genop1
,
2648 tree genop2
= currop
->op1
;
2650 op0
= create_component_ref_by_pieces_1 (block
, ref
, operand
,
2654 /* op1 should be a FIELD_DECL, which are represented by
2659 op2expr
= get_or_alloc_expr_for (genop2
);
2660 genop2
= find_or_generate_expression (block
, op2expr
, stmts
,
2666 return fold_build3 (COMPONENT_REF
, TREE_TYPE (op1
), op0
, op1
,
2672 pre_expr op0expr
= get_or_alloc_expr_for (currop
->op0
);
2673 genop
= find_or_generate_expression (block
, op0expr
, stmts
, domstmt
);
2694 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
2695 COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
2696 trying to rename aggregates into ssa form directly, which is a no no.
2698 Thus, this routine doesn't create temporaries, it just builds a
2699 single access expression for the array, calling
2700 find_or_generate_expression to build the innermost pieces.
2702 This function is a subroutine of create_expression_by_pieces, and
2703 should not be called on it's own unless you really know what you
2707 create_component_ref_by_pieces (basic_block block
, vn_reference_t ref
,
2708 gimple_seq
*stmts
, gimple domstmt
)
2710 unsigned int op
= 0;
2711 return create_component_ref_by_pieces_1 (block
, ref
, &op
, stmts
, domstmt
);
2714 /* Find a leader for an expression, or generate one using
2715 create_expression_by_pieces if it's ANTIC but
2717 BLOCK is the basic_block we are looking for leaders in.
2718 EXPR is the expression to find a leader or generate for.
2719 STMTS is the statement list to put the inserted expressions on.
2720 Returns the SSA_NAME of the LHS of the generated expression or the
2722 DOMSTMT if non-NULL is a statement that should be dominated by
2723 all uses in the generated expression. If DOMSTMT is non-NULL this
2724 routine can fail and return NULL_TREE. Otherwise it will assert
2728 find_or_generate_expression (basic_block block
, pre_expr expr
,
2729 gimple_seq
*stmts
, gimple domstmt
)
2731 pre_expr leader
= bitmap_find_leader (AVAIL_OUT (block
),
2732 get_expr_value_id (expr
), domstmt
);
2736 if (leader
->kind
== NAME
)
2737 genop
= PRE_EXPR_NAME (leader
);
2738 else if (leader
->kind
== CONSTANT
)
2739 genop
= PRE_EXPR_CONSTANT (leader
);
2742 /* If it's still NULL, it must be a complex expression, so generate
2743 it recursively. Not so for FRE though. */
2747 bitmap_set_t exprset
;
2748 unsigned int lookfor
= get_expr_value_id (expr
);
2749 bool handled
= false;
2753 exprset
= VEC_index (bitmap_set_t
, value_expressions
, lookfor
);
2754 FOR_EACH_EXPR_ID_IN_SET (exprset
, i
, bi
)
2756 pre_expr temp
= expression_for_id (i
);
2757 if (temp
->kind
!= NAME
)
2760 genop
= create_expression_by_pieces (block
, temp
, stmts
,
2762 get_expr_type (expr
));
2766 if (!handled
&& domstmt
)
2769 gcc_assert (handled
);
2774 #define NECESSARY GF_PLF_1
2776 /* Create an expression in pieces, so that we can handle very complex
2777 expressions that may be ANTIC, but not necessary GIMPLE.
2778 BLOCK is the basic block the expression will be inserted into,
2779 EXPR is the expression to insert (in value form)
2780 STMTS is a statement list to append the necessary insertions into.
2782 This function will die if we hit some value that shouldn't be
2783 ANTIC but is (IE there is no leader for it, or its components).
2784 This function may also generate expressions that are themselves
2785 partially or fully redundant. Those that are will be either made
2786 fully redundant during the next iteration of insert (for partially
2787 redundant ones), or eliminated by eliminate (for fully redundant
2790 If DOMSTMT is non-NULL then we make sure that all uses in the
2791 expressions dominate that statement. In this case the function
2792 can return NULL_TREE to signal failure. */
2795 create_expression_by_pieces (basic_block block
, pre_expr expr
,
2796 gimple_seq
*stmts
, gimple domstmt
, tree type
)
2799 tree folded
, newexpr
;
2800 gimple_seq forced_stmts
;
2801 unsigned int value_id
;
2802 gimple_stmt_iterator gsi
;
2803 tree exprtype
= type
? type
: get_expr_type (expr
);
2809 /* We may hit the NAME/CONSTANT case if we have to convert types
2810 that value numbering saw through. */
2812 folded
= PRE_EXPR_NAME (expr
);
2815 folded
= PRE_EXPR_CONSTANT (expr
);
2819 vn_reference_t ref
= PRE_EXPR_REFERENCE (expr
);
2820 folded
= create_component_ref_by_pieces (block
, ref
, stmts
, domstmt
);
2825 vn_nary_op_t nary
= PRE_EXPR_NARY (expr
);
2826 switch (nary
->length
)
2830 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
2831 pre_expr op2
= get_or_alloc_expr_for (nary
->op
[1]);
2832 tree genop1
= find_or_generate_expression (block
, op1
,
2834 tree genop2
= find_or_generate_expression (block
, op2
,
2836 if (!genop1
|| !genop2
)
2838 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]),
2840 /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR. It
2841 may be a constant with the wrong type. */
2842 if (nary
->opcode
== POINTER_PLUS_EXPR
)
2843 genop2
= fold_convert (sizetype
, genop2
);
2845 genop2
= fold_convert (TREE_TYPE (nary
->op
[1]), genop2
);
2847 folded
= fold_build2 (nary
->opcode
, nary
->type
,
2853 pre_expr op1
= get_or_alloc_expr_for (nary
->op
[0]);
2854 tree genop1
= find_or_generate_expression (block
, op1
,
2858 genop1
= fold_convert (TREE_TYPE (nary
->op
[0]), genop1
);
2860 folded
= fold_build1 (nary
->opcode
, nary
->type
,
2872 folded
= fold_convert (exprtype
, folded
);
2873 /* Force the generated expression to be a sequence of GIMPLE
2875 We have to call unshare_expr because force_gimple_operand may
2876 modify the tree we pass to it. */
2877 newexpr
= force_gimple_operand (unshare_expr (folded
), &forced_stmts
,
2880 /* If we have any intermediate expressions to the value sets, add them
2881 to the value sets and chain them in the instruction stream. */
2884 gsi
= gsi_start (forced_stmts
);
2885 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
2887 gimple stmt
= gsi_stmt (gsi
);
2888 tree forcedname
= gimple_get_lhs (stmt
);
2891 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
2892 if (TREE_CODE (forcedname
) == SSA_NAME
)
2894 VN_INFO_GET (forcedname
)->valnum
= forcedname
;
2895 VN_INFO (forcedname
)->value_id
= get_next_value_id ();
2896 nameexpr
= get_or_alloc_expr_for_name (forcedname
);
2897 add_to_value (VN_INFO (forcedname
)->value_id
, nameexpr
);
2899 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2900 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2902 mark_symbols_for_renaming (stmt
);
2904 gimple_seq_add_seq (stmts
, forced_stmts
);
2907 /* Build and insert the assignment of the end result to the temporary
2908 that we will return. */
2909 if (!pretemp
|| exprtype
!= TREE_TYPE (pretemp
))
2911 pretemp
= create_tmp_var (exprtype
, "pretmp");
2912 get_var_ann (pretemp
);
2916 add_referenced_var (temp
);
2918 if (TREE_CODE (exprtype
) == COMPLEX_TYPE
2919 || TREE_CODE (exprtype
) == VECTOR_TYPE
)
2920 DECL_GIMPLE_REG_P (temp
) = 1;
2922 newstmt
= gimple_build_assign (temp
, newexpr
);
2923 name
= make_ssa_name (temp
, newstmt
);
2924 gimple_assign_set_lhs (newstmt
, name
);
2925 gimple_set_plf (newstmt
, NECESSARY
, false);
2927 gimple_seq_add_stmt (stmts
, newstmt
);
2928 VEC_safe_push (gimple
, heap
, inserted_exprs
, newstmt
);
2930 /* All the symbols in NEWEXPR should be put into SSA form. */
2931 mark_symbols_for_renaming (newstmt
);
2933 /* Add a value number to the temporary.
2934 The value may already exist in either NEW_SETS, or AVAIL_OUT, because
2935 we are creating the expression by pieces, and this particular piece of
2936 the expression may have been represented. There is no harm in replacing
2938 VN_INFO_GET (name
)->valnum
= name
;
2939 value_id
= get_expr_value_id (expr
);
2940 VN_INFO (name
)->value_id
= value_id
;
2941 nameexpr
= get_or_alloc_expr_for_name (name
);
2942 add_to_value (value_id
, nameexpr
);
2944 bitmap_value_replace_in_set (NEW_SETS (block
), nameexpr
);
2945 bitmap_value_replace_in_set (AVAIL_OUT (block
), nameexpr
);
2947 pre_stats
.insertions
++;
2948 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2950 fprintf (dump_file
, "Inserted ");
2951 print_gimple_stmt (dump_file
, newstmt
, 0, 0);
2952 fprintf (dump_file
, " in predecessor %d\n", block
->index
);
2959 /* Insert the to-be-made-available values of expression EXPRNUM for each
2960 predecessor, stored in AVAIL, into the predecessors of BLOCK, and
2961 merge the result with a phi node, given the same value number as
2962 NODE. Return true if we have inserted new stuff. */
2965 insert_into_preds_of_block (basic_block block
, unsigned int exprnum
,
2968 pre_expr expr
= expression_for_id (exprnum
);
2970 unsigned int val
= get_expr_value_id (expr
);
2972 bool insertions
= false;
2977 tree type
= get_expr_type (expr
);
2981 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2983 fprintf (dump_file
, "Found partial redundancy for expression ");
2984 print_pre_expr (dump_file
, expr
);
2985 fprintf (dump_file
, " (%04d)\n", val
);
2988 /* Make sure we aren't creating an induction variable. */
2989 if (block
->loop_depth
> 0 && EDGE_COUNT (block
->preds
) == 2
2990 && expr
->kind
!= REFERENCE
)
2992 bool firstinsideloop
= false;
2993 bool secondinsideloop
= false;
2994 firstinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2995 EDGE_PRED (block
, 0)->src
);
2996 secondinsideloop
= flow_bb_inside_loop_p (block
->loop_father
,
2997 EDGE_PRED (block
, 1)->src
);
2998 /* Induction variables only have one edge inside the loop. */
2999 if (firstinsideloop
^ secondinsideloop
)
3001 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3002 fprintf (dump_file
, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
3008 /* Make the necessary insertions. */
3009 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3011 gimple_seq stmts
= NULL
;
3014 eprime
= avail
[bprime
->index
];
3016 if (eprime
->kind
!= NAME
&& eprime
->kind
!= CONSTANT
)
3018 builtexpr
= create_expression_by_pieces (bprime
,
3022 gcc_assert (!(pred
->flags
& EDGE_ABNORMAL
));
3023 gsi_insert_seq_on_edge (pred
, stmts
);
3024 avail
[bprime
->index
] = get_or_alloc_expr_for_name (builtexpr
);
3027 else if (eprime
->kind
== CONSTANT
)
3029 /* Constants may not have the right type, fold_convert
3030 should give us back a constant with the right type.
3032 tree constant
= PRE_EXPR_CONSTANT (eprime
);
3033 if (!useless_type_conversion_p (type
, TREE_TYPE (constant
)))
3035 tree builtexpr
= fold_convert (type
, constant
);
3036 if (!is_gimple_min_invariant (builtexpr
))
3038 tree forcedexpr
= force_gimple_operand (builtexpr
,
3041 if (!is_gimple_min_invariant (forcedexpr
))
3043 if (forcedexpr
!= builtexpr
)
3045 VN_INFO_GET (forcedexpr
)->valnum
= PRE_EXPR_CONSTANT (eprime
);
3046 VN_INFO (forcedexpr
)->value_id
= get_expr_value_id (eprime
);
3050 gimple_stmt_iterator gsi
;
3051 gsi
= gsi_start (stmts
);
3052 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3054 gimple stmt
= gsi_stmt (gsi
);
3055 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
3056 gimple_set_plf (stmt
, NECESSARY
, false);
3058 gsi_insert_seq_on_edge (pred
, stmts
);
3060 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3065 else if (eprime
->kind
== NAME
)
3067 /* We may have to do a conversion because our value
3068 numbering can look through types in certain cases, but
3069 our IL requires all operands of a phi node have the same
3071 tree name
= PRE_EXPR_NAME (eprime
);
3072 if (!useless_type_conversion_p (type
, TREE_TYPE (name
)))
3076 builtexpr
= fold_convert (type
, name
);
3077 forcedexpr
= force_gimple_operand (builtexpr
,
3081 if (forcedexpr
!= name
)
3083 VN_INFO_GET (forcedexpr
)->valnum
= VN_INFO (name
)->valnum
;
3084 VN_INFO (forcedexpr
)->value_id
= VN_INFO (name
)->value_id
;
3089 gimple_stmt_iterator gsi
;
3090 gsi
= gsi_start (stmts
);
3091 for (; !gsi_end_p (gsi
); gsi_next (&gsi
))
3093 gimple stmt
= gsi_stmt (gsi
);
3094 VEC_safe_push (gimple
, heap
, inserted_exprs
, stmt
);
3095 gimple_set_plf (stmt
, NECESSARY
, false);
3097 gsi_insert_seq_on_edge (pred
, stmts
);
3099 avail
[bprime
->index
] = get_or_alloc_expr_for_name (forcedexpr
);
3103 /* If we didn't want a phi node, and we made insertions, we still have
3104 inserted new stuff, and thus return true. If we didn't want a phi node,
3105 and didn't make insertions, we haven't added anything new, so return
3107 if (nophi
&& insertions
)
3109 else if (nophi
&& !insertions
)
3112 /* Now build a phi for the new variable. */
3113 if (!prephitemp
|| TREE_TYPE (prephitemp
) != type
)
3115 prephitemp
= create_tmp_var (type
, "prephitmp");
3116 get_var_ann (prephitemp
);
3120 add_referenced_var (temp
);
3122 if (TREE_CODE (type
) == COMPLEX_TYPE
3123 || TREE_CODE (type
) == VECTOR_TYPE
)
3124 DECL_GIMPLE_REG_P (temp
) = 1;
3126 phi
= create_phi_node (temp
, block
);
3127 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3129 pre_expr ae
= avail
[pred
->src
->index
];
3130 gcc_assert (get_expr_type (ae
) == type
3131 || useless_type_conversion_p (type
, get_expr_type (ae
)));
3132 if (ae
->kind
== CONSTANT
)
3133 add_phi_arg (phi
, PRE_EXPR_CONSTANT (ae
), pred
);
3135 add_phi_arg (phi
, PRE_EXPR_NAME (avail
[pred
->src
->index
]), pred
);
3137 /* If the PHI node is already available, use it. */
3138 if ((res
= vn_phi_lookup (phi
)) != NULL_TREE
)
3140 gimple_stmt_iterator gsi
= gsi_for_stmt (phi
);
3141 remove_phi_node (&gsi
, true);
3143 add_to_value (val
, get_or_alloc_expr_for_name (res
));
3147 gimple_set_plf (phi
, NECESSARY
, false);
3148 VN_INFO_GET (gimple_phi_result (phi
))->valnum
= gimple_phi_result (phi
);
3149 VN_INFO (gimple_phi_result (phi
))->value_id
= val
;
3150 VEC_safe_push (gimple
, heap
, inserted_exprs
, phi
);
3152 newphi
= get_or_alloc_expr_for_name (gimple_phi_result (phi
));
3153 add_to_value (val
, newphi
);
3155 /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
3156 this insertion, since we test for the existence of this value in PHI_GEN
3157 before proceeding with the partial redundancy checks in insert_aux.
3159 The value may exist in AVAIL_OUT, in particular, it could be represented
3160 by the expression we are trying to eliminate, in which case we want the
3161 replacement to occur. If it's not existing in AVAIL_OUT, we want it
3164 Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
3165 this block, because if it did, it would have existed in our dominator's
3166 AVAIL_OUT, and would have been skipped due to the full redundancy check.
3169 bitmap_insert_into_set (PHI_GEN (block
), newphi
);
3170 bitmap_value_replace_in_set (AVAIL_OUT (block
),
3172 bitmap_insert_into_set (NEW_SETS (block
),
3175 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3177 fprintf (dump_file
, "Created phi ");
3178 print_gimple_stmt (dump_file
, phi
, 0, 0);
3179 fprintf (dump_file
, " in block %d\n", block
->index
);
3187 /* Perform insertion of partially redundant values.
3188 For BLOCK, do the following:
3189 1. Propagate the NEW_SETS of the dominator into the current block.
3190 If the block has multiple predecessors,
3191 2a. Iterate over the ANTIC expressions for the block to see if
3192 any of them are partially redundant.
3193 2b. If so, insert them into the necessary predecessors to make
3194 the expression fully redundant.
3195 2c. Insert a new PHI merging the values of the predecessors.
3196 2d. Insert the new PHI, and the new expressions, into the
3198 3. Recursively call ourselves on the dominator children of BLOCK.
3200 Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
3201 do_regular_insertion and do_partial_insertion.
3206 do_regular_insertion (basic_block block
, basic_block dom
)
3208 bool new_stuff
= false;
3209 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (ANTIC_IN (block
));
3213 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
3215 if (expr
->kind
!= NAME
)
3219 bool by_some
= false;
3220 bool cant_insert
= false;
3221 bool all_same
= true;
3222 pre_expr first_s
= NULL
;
3225 pre_expr eprime
= NULL
;
3227 pre_expr edoubleprime
= NULL
;
3229 val
= get_expr_value_id (expr
);
3230 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3232 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3234 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3235 fprintf (dump_file
, "Found fully redundant value\n");
3239 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3240 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3242 unsigned int vprime
;
3244 /* We should never run insertion for the exit block
3245 and so not come across fake pred edges. */
3246 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3248 eprime
= phi_translate (expr
, ANTIC_IN (block
), NULL
,
3251 /* eprime will generally only be NULL if the
3252 value of the expression, translated
3253 through the PHI for this predecessor, is
3254 undefined. If that is the case, we can't
3255 make the expression fully redundant,
3256 because its value is undefined along a
3257 predecessor path. We can thus break out
3258 early because it doesn't matter what the
3259 rest of the results are. */
3266 eprime
= fully_constant_expression (eprime
);
3267 vprime
= get_expr_value_id (eprime
);
3268 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3270 if (edoubleprime
== NULL
)
3272 avail
[bprime
->index
] = eprime
;
3277 avail
[bprime
->index
] = edoubleprime
;
3279 if (first_s
== NULL
)
3280 first_s
= edoubleprime
;
3281 else if (!pre_expr_eq (first_s
, edoubleprime
))
3285 /* If we can insert it, it's not the same value
3286 already existing along every predecessor, and
3287 it's defined by some predecessor, it is
3288 partially redundant. */
3289 if (!cant_insert
&& !all_same
&& by_some
&& dbg_cnt (treepre_insert
))
3291 if (insert_into_preds_of_block (block
, get_expression_id (expr
),
3295 /* If all edges produce the same value and that value is
3296 an invariant, then the PHI has the same value on all
3297 edges. Note this. */
3298 else if (!cant_insert
&& all_same
&& eprime
3299 && (edoubleprime
->kind
== CONSTANT
3300 || edoubleprime
->kind
== NAME
)
3301 && !value_id_constant_p (val
))
3305 bitmap_set_t exprset
= VEC_index (bitmap_set_t
,
3306 value_expressions
, val
);
3308 unsigned int new_val
= get_expr_value_id (edoubleprime
);
3309 FOR_EACH_EXPR_ID_IN_SET (exprset
, j
, bi
)
3311 pre_expr expr
= expression_for_id (j
);
3313 if (expr
->kind
== NAME
)
3315 vn_ssa_aux_t info
= VN_INFO (PRE_EXPR_NAME (expr
));
3316 /* Just reset the value id and valnum so it is
3317 the same as the constant we have discovered. */
3318 if (edoubleprime
->kind
== CONSTANT
)
3320 info
->valnum
= PRE_EXPR_CONSTANT (edoubleprime
);
3321 pre_stats
.constified
++;
3324 info
->valnum
= PRE_EXPR_NAME (edoubleprime
);
3325 info
->value_id
= new_val
;
3333 VEC_free (pre_expr
, heap
, exprs
);
3338 /* Perform insertion for partially anticipatable expressions. There
3339 is only one case we will perform insertion for these. This case is
3340 if the expression is partially anticipatable, and fully available.
3341 In this case, we know that putting it earlier will enable us to
3342 remove the later computation. */
3346 do_partial_partial_insertion (basic_block block
, basic_block dom
)
3348 bool new_stuff
= false;
3349 VEC (pre_expr
, heap
) *exprs
= sorted_array_from_bitmap_set (PA_IN (block
));
3353 for (i
= 0; VEC_iterate (pre_expr
, exprs
, i
, expr
); i
++)
3355 if (expr
->kind
!= NAME
)
3360 bool cant_insert
= false;
3363 pre_expr eprime
= NULL
;
3366 val
= get_expr_value_id (expr
);
3367 if (bitmap_set_contains_value (PHI_GEN (block
), val
))
3369 if (bitmap_set_contains_value (AVAIL_OUT (dom
), val
))
3372 avail
= XCNEWVEC (pre_expr
, last_basic_block
);
3373 FOR_EACH_EDGE (pred
, ei
, block
->preds
)
3375 unsigned int vprime
;
3376 pre_expr edoubleprime
;
3378 /* We should never run insertion for the exit block
3379 and so not come across fake pred edges. */
3380 gcc_assert (!(pred
->flags
& EDGE_FAKE
));
3382 eprime
= phi_translate (expr
, ANTIC_IN (block
),
3386 /* eprime will generally only be NULL if the
3387 value of the expression, translated
3388 through the PHI for this predecessor, is
3389 undefined. If that is the case, we can't
3390 make the expression fully redundant,
3391 because its value is undefined along a
3392 predecessor path. We can thus break out
3393 early because it doesn't matter what the
3394 rest of the results are. */
3401 eprime
= fully_constant_expression (eprime
);
3402 vprime
= get_expr_value_id (eprime
);
3403 edoubleprime
= bitmap_find_leader (AVAIL_OUT (bprime
),
3405 if (edoubleprime
== NULL
)
3411 avail
[bprime
->index
] = edoubleprime
;
3415 /* If we can insert it, it's not the same value
3416 already existing along every predecessor, and
3417 it's defined by some predecessor, it is
3418 partially redundant. */
3419 if (!cant_insert
&& by_all
&& dbg_cnt (treepre_insert
))
3421 pre_stats
.pa_insert
++;
3422 if (insert_into_preds_of_block (block
, get_expression_id (expr
),
3430 VEC_free (pre_expr
, heap
, exprs
);
3435 insert_aux (basic_block block
)
3438 bool new_stuff
= false;
3443 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3448 bitmap_set_t newset
= NEW_SETS (dom
);
3451 /* Note that we need to value_replace both NEW_SETS, and
3452 AVAIL_OUT. For both the case of NEW_SETS, the value may be
3453 represented by some non-simple expression here that we want
3454 to replace it with. */
3455 FOR_EACH_EXPR_ID_IN_SET (newset
, i
, bi
)
3457 pre_expr expr
= expression_for_id (i
);
3458 bitmap_value_replace_in_set (NEW_SETS (block
), expr
);
3459 bitmap_value_replace_in_set (AVAIL_OUT (block
), expr
);
3462 if (!single_pred_p (block
))
3464 new_stuff
|= do_regular_insertion (block
, dom
);
3465 if (do_partial_partial
)
3466 new_stuff
|= do_partial_partial_insertion (block
, dom
);
3470 for (son
= first_dom_son (CDI_DOMINATORS
, block
);
3472 son
= next_dom_son (CDI_DOMINATORS
, son
))
3474 new_stuff
|= insert_aux (son
);
3480 /* Perform insertion of partially redundant values. */
3485 bool new_stuff
= true;
3487 int num_iterations
= 0;
3490 NEW_SETS (bb
) = bitmap_set_new ();
3495 new_stuff
= insert_aux (ENTRY_BLOCK_PTR
);
3497 statistics_histogram_event (cfun
, "insert iterations", num_iterations
);
3501 /* Add OP to EXP_GEN (block), and possibly to the maximal set if it is
3502 not defined by a phi node.
3503 PHI nodes can't go in the maximal sets because they are not in
3504 TMP_GEN, so it is possible to get into non-monotonic situations
3505 during ANTIC calculation, because it will *add* bits. */
3508 add_to_exp_gen (basic_block block
, tree op
)
3513 if (TREE_CODE (op
) == SSA_NAME
&& ssa_undefined_value_p (op
))
3515 result
= get_or_alloc_expr_for_name (op
);
3516 bitmap_value_insert_into_set (EXP_GEN (block
), result
);
3517 if (TREE_CODE (op
) != SSA_NAME
3518 || gimple_code (SSA_NAME_DEF_STMT (op
)) != GIMPLE_PHI
)
3519 bitmap_value_insert_into_set (maximal_set
, result
);
3523 /* Create value ids for PHI in BLOCK. */
3526 make_values_for_phi (gimple phi
, basic_block block
)
3528 tree result
= gimple_phi_result (phi
);
3530 /* We have no need for virtual phis, as they don't represent
3531 actual computations. */
3532 if (is_gimple_reg (result
))
3534 pre_expr e
= get_or_alloc_expr_for_name (result
);
3535 add_to_value (get_expr_value_id (e
), e
);
3536 bitmap_insert_into_set (PHI_GEN (block
), e
);
3537 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3541 /* Compute the AVAIL set for all basic blocks.
3543 This function performs value numbering of the statements in each basic
3544 block. The AVAIL sets are built from information we glean while doing
3545 this value numbering, since the AVAIL sets contain only one entry per
3548 AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
3549 AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
3552 compute_avail (void)
3555 basic_block block
, son
;
3556 basic_block
*worklist
;
3560 /* For arguments with default definitions, we pretend they are
3561 defined in the entry block. */
3562 for (param
= DECL_ARGUMENTS (current_function_decl
);
3564 param
= TREE_CHAIN (param
))
3566 if (gimple_default_def (cfun
, param
) != NULL
)
3568 tree def
= gimple_default_def (cfun
, param
);
3569 pre_expr e
= get_or_alloc_expr_for_name (def
);
3571 add_to_value (get_expr_value_id (e
), e
);
3574 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3575 bitmap_value_insert_into_set (maximal_set
, e
);
3577 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3581 /* Likewise for the static chain decl. */
3582 if (cfun
->static_chain_decl
)
3584 param
= cfun
->static_chain_decl
;
3585 if (gimple_default_def (cfun
, param
) != NULL
)
3587 tree def
= gimple_default_def (cfun
, param
);
3588 pre_expr e
= get_or_alloc_expr_for_name (def
);
3590 add_to_value (get_expr_value_id (e
), e
);
3593 bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR
), e
);
3594 bitmap_value_insert_into_set (maximal_set
, e
);
3596 bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR
), e
);
3600 /* Allocate the worklist. */
3601 worklist
= XNEWVEC (basic_block
, n_basic_blocks
);
3603 /* Seed the algorithm by putting the dominator children of the entry
3604 block on the worklist. */
3605 for (son
= first_dom_son (CDI_DOMINATORS
, ENTRY_BLOCK_PTR
);
3607 son
= next_dom_son (CDI_DOMINATORS
, son
))
3608 worklist
[sp
++] = son
;
3610 /* Loop until the worklist is empty. */
3613 gimple_stmt_iterator gsi
;
3616 unsigned int stmt_uid
= 1;
3618 /* Pick a block from the worklist. */
3619 block
= worklist
[--sp
];
3621 /* Initially, the set of available values in BLOCK is that of
3622 its immediate dominator. */
3623 dom
= get_immediate_dominator (CDI_DOMINATORS
, block
);
3625 bitmap_set_copy (AVAIL_OUT (block
), AVAIL_OUT (dom
));
3627 /* Generate values for PHI nodes. */
3628 for (gsi
= gsi_start_phis (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3629 make_values_for_phi (gsi_stmt (gsi
), block
);
3631 /* Now compute value numbers and populate value sets with all
3632 the expressions computed in BLOCK. */
3633 for (gsi
= gsi_start_bb (block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3638 stmt
= gsi_stmt (gsi
);
3639 gimple_set_uid (stmt
, stmt_uid
++);
3641 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
)
3643 pre_expr e
= get_or_alloc_expr_for_name (op
);
3645 add_to_value (get_expr_value_id (e
), e
);
3647 bitmap_insert_into_set (TMP_GEN (block
), e
);
3648 bitmap_value_insert_into_set (AVAIL_OUT (block
), e
);
3651 if (gimple_has_volatile_ops (stmt
)
3652 || stmt_could_throw_p (stmt
))
3655 switch (gimple_code (stmt
))
3658 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_USE
)
3659 add_to_exp_gen (block
, op
);
3666 vn_reference_op_t vro
;
3667 pre_expr result
= NULL
;
3668 VEC(vn_reference_op_s
, heap
) *ops
= NULL
;
3670 if (!can_value_number_call (stmt
))
3673 copy_reference_ops_from_call (stmt
, &ops
);
3674 vn_reference_lookup_pieces (shared_vuses_from_stmt (stmt
),
3676 VEC_free (vn_reference_op_s
, heap
, ops
);
3680 for (i
= 0; VEC_iterate (vn_reference_op_s
,
3684 if (vro
->op0
&& TREE_CODE (vro
->op0
) == SSA_NAME
)
3685 add_to_exp_gen (block
, vro
->op0
);
3686 if (vro
->op1
&& TREE_CODE (vro
->op1
) == SSA_NAME
)
3687 add_to_exp_gen (block
, vro
->op1
);
3688 if (vro
->op2
&& TREE_CODE (vro
->op2
) == SSA_NAME
)
3689 add_to_exp_gen (block
, vro
->op2
);
3691 result
= (pre_expr
) pool_alloc (pre_expr_pool
);
3692 result
->kind
= REFERENCE
;
3694 PRE_EXPR_REFERENCE (result
) = ref
;
3696 get_or_alloc_expression_id (result
);
3697 add_to_value (get_expr_value_id (result
), result
);
3700 bitmap_value_insert_into_set (EXP_GEN (block
),
3702 bitmap_value_insert_into_set (maximal_set
, result
);
3709 pre_expr result
= NULL
;
3710 switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)))
3713 if (is_exception_related (stmt
))
3716 case tcc_comparison
:
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 */