forked from illumos/gcc
/
ipa.c
1458 lines (1291 loc) · 42.1 KB
/
ipa.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* Basic IPA optimizations and utilities.
Copyright (C) 2003-2015 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "hash-set.h"
#include "machmode.h"
#include "vec.h"
#include "double-int.h"
#include "input.h"
#include "alias.h"
#include "symtab.h"
#include "options.h"
#include "wide-int.h"
#include "inchash.h"
#include "tree.h"
#include "fold-const.h"
#include "calls.h"
#include "stringpool.h"
#include "predict.h"
#include "basic-block.h"
#include "hash-map.h"
#include "is-a.h"
#include "plugin-api.h"
#include "hard-reg-set.h"
#include "input.h"
#include "function.h"
#include "ipa-ref.h"
#include "cgraph.h"
#include "tree-pass.h"
#include "gimple-expr.h"
#include "gimplify.h"
#include "flags.h"
#include "target.h"
#include "tree-iterator.h"
#include "ipa-utils.h"
#include "alloc-pool.h"
#include "symbol-summary.h"
#include "ipa-prop.h"
#include "ipa-inline.h"
#include "tree-inline.h"
#include "profile.h"
#include "params.h"
#include "internal-fn.h"
#include "tree-ssa-alias.h"
#include "gimple.h"
#include "dbgcnt.h"
/* Return true when NODE has ADDR reference. */
static bool
has_addr_references_p (struct cgraph_node *node,
void *data ATTRIBUTE_UNUSED)
{
int i;
struct ipa_ref *ref = NULL;
for (i = 0; node->iterate_referring (i, ref); i++)
if (ref->use == IPA_REF_ADDR)
return true;
return false;
}
/* Look for all functions inlined to NODE and update their inlined_to pointers
to INLINED_TO. */
static void
update_inlined_to_pointer (struct cgraph_node *node, struct cgraph_node *inlined_to)
{
struct cgraph_edge *e;
for (e = node->callees; e; e = e->next_callee)
if (e->callee->global.inlined_to)
{
e->callee->global.inlined_to = inlined_to;
update_inlined_to_pointer (e->callee, inlined_to);
}
}
/* Add symtab NODE to queue starting at FIRST.
The queue is linked via AUX pointers and terminated by pointer to 1.
We enqueue nodes at two occasions: when we find them reachable or when we find
their bodies needed for further clonning. In the second case we mark them
by pointer to 2 after processing so they are re-queue when they become
reachable. */
static void
enqueue_node (symtab_node *node, symtab_node **first,
hash_set<symtab_node *> *reachable)
{
/* Node is still in queue; do nothing. */
if (node->aux && node->aux != (void *) 2)
return;
/* Node was already processed as unreachable, re-enqueue
only if it became reachable now. */
if (node->aux == (void *)2 && !reachable->contains (node))
return;
node->aux = *first;
*first = node;
}
/* Process references. */
static void
process_references (symtab_node *snode,
symtab_node **first,
bool before_inlining_p,
hash_set<symtab_node *> *reachable)
{
int i;
struct ipa_ref *ref = NULL;
for (i = 0; snode->iterate_reference (i, ref); i++)
{
symtab_node *node = ref->referred;
symtab_node *body = node->ultimate_alias_target ();
if (node->definition && !node->in_other_partition
&& ((!DECL_EXTERNAL (node->decl) || node->alias)
|| (((before_inlining_p
&& ((TREE_CODE (node->decl) != FUNCTION_DECL
&& optimize)
|| (TREE_CODE (node->decl) == FUNCTION_DECL
&& opt_for_fn (body->decl, optimize))
|| (symtab->state < IPA_SSA
&& lookup_attribute
("always_inline",
DECL_ATTRIBUTES (body->decl))))))
/* We use variable constructors during late compilation for
constant folding. Keep references alive so partitioning
knows about potential references. */
|| (TREE_CODE (node->decl) == VAR_DECL
&& flag_wpa
&& ctor_for_folding (node->decl)
!= error_mark_node))))
{
/* Be sure that we will not optimize out alias target
body. */
if (DECL_EXTERNAL (node->decl)
&& node->alias
&& before_inlining_p)
reachable->add (body);
reachable->add (node);
}
enqueue_node (node, first, reachable);
}
}
/* EDGE is an polymorphic call. If BEFORE_INLINING_P is set, mark
all its potential targets as reachable to permit later inlining if
devirtualization happens. After inlining still keep their declarations
around, so we can devirtualize to a direct call.
Also try to make trivial devirutalization when no or only one target is
possible. */
static void
walk_polymorphic_call_targets (hash_set<void *> *reachable_call_targets,
struct cgraph_edge *edge,
symtab_node **first,
hash_set<symtab_node *> *reachable,
bool before_inlining_p)
{
unsigned int i;
void *cache_token;
bool final;
vec <cgraph_node *>targets
= possible_polymorphic_call_targets
(edge, &final, &cache_token);
if (!reachable_call_targets->add (cache_token))
{
for (i = 0; i < targets.length (); i++)
{
struct cgraph_node *n = targets[i];
/* Do not bother to mark virtual methods in anonymous namespace;
either we will find use of virtual table defining it, or it is
unused. */
if (TREE_CODE (TREE_TYPE (n->decl)) == METHOD_TYPE
&& type_in_anonymous_namespace_p
(method_class_type (TREE_TYPE (n->decl))))
continue;
symtab_node *body = n->function_symbol ();
/* Prior inlining, keep alive bodies of possible targets for
devirtualization. */
if (n->definition
&& (before_inlining_p
&& opt_for_fn (body->decl, optimize)
&& opt_for_fn (body->decl, flag_devirtualize)))
{
/* Be sure that we will not optimize out alias target
body. */
if (DECL_EXTERNAL (n->decl)
&& n->alias
&& before_inlining_p)
reachable->add (body);
reachable->add (n);
}
/* Even after inlining we want to keep the possible targets in the
boundary, so late passes can still produce direct call even if
the chance for inlining is lost. */
enqueue_node (n, first, reachable);
}
}
/* Very trivial devirtualization; when the type is
final or anonymous (so we know all its derivation)
and there is only one possible virtual call target,
make the edge direct. */
if (final)
{
if (targets.length () <= 1 && dbg_cnt (devirt))
{
cgraph_node *target, *node = edge->caller;
if (targets.length () == 1)
target = targets[0];
else
target = cgraph_node::get_create
(builtin_decl_implicit (BUILT_IN_UNREACHABLE));
if (dump_enabled_p ())
{
location_t locus;
if (edge->call_stmt)
locus = gimple_location (edge->call_stmt);
else
locus = UNKNOWN_LOCATION;
dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, locus,
"devirtualizing call in %s/%i to %s/%i\n",
edge->caller->name (), edge->caller->order,
target->name (),
target->order);
}
edge = edge->make_direct (target);
if (inline_summaries)
inline_update_overall_summary (node);
else if (edge->call_stmt)
{
edge->redirect_call_stmt_to_callee ();
/* Call to __builtin_unreachable shouldn't be instrumented. */
if (!targets.length ())
gimple_call_set_with_bounds (edge->call_stmt, false);
}
}
}
}
/* Perform reachability analysis and reclaim all unreachable nodes.
The algorithm is basically mark&sweep but with some extra refinements:
- reachable extern inline functions needs special handling; the bodies needs
to stay in memory until inlining in hope that they will be inlined.
After inlining we release their bodies and turn them into unanalyzed
nodes even when they are reachable.
- virtual functions are kept in callgraph even if they seem unreachable in
hope calls to them will be devirtualized.
Again we remove them after inlining. In late optimization some
devirtualization may happen, but it is not important since we won't inline
the call. In theory early opts and IPA should work out all important cases.
- virtual clones needs bodies of their origins for later materialization;
this means that we want to keep the body even if the origin is unreachable
otherwise. To avoid origin from sitting in the callgraph and being
walked by IPA passes, we turn them into unanalyzed nodes with body
defined.
We maintain set of function declaration where body needs to stay in
body_needed_for_clonning
Inline clones represent special case: their declaration match the
declaration of origin and cgraph_remove_node already knows how to
reshape callgraph and preserve body when offline copy of function or
inline clone is being removed.
- C++ virtual tables keyed to other unit are represented as DECL_EXTERNAL
variables with DECL_INITIAL set. We finalize these and keep reachable
ones around for constant folding purposes. After inlining we however
stop walking their references to let everything static referneced by them
to be removed when it is otherwise unreachable.
We maintain queue of both reachable symbols (i.e. defined symbols that needs
to stay) and symbols that are in boundary (i.e. external symbols referenced
by reachable symbols or origins of clones). The queue is represented
as linked list by AUX pointer terminated by 1.
At the end we keep all reachable symbols. For symbols in boundary we always
turn definition into a declaration, but we may keep function body around
based on body_needed_for_clonning
All symbols that enter the queue have AUX pointer non-zero and are in the
boundary. Pointer set REACHABLE is used to track reachable symbols.
Every symbol can be visited twice - once as part of boundary and once
as real reachable symbol. enqueue_node needs to decide whether the
node needs to be re-queued for second processing. For this purpose
we set AUX pointer of processed symbols in the boundary to constant 2. */
bool
symbol_table::remove_unreachable_nodes (FILE *file)
{
symtab_node *first = (symtab_node *) (void *) 1;
struct cgraph_node *node, *next;
varpool_node *vnode, *vnext;
bool changed = false;
hash_set<symtab_node *> reachable;
hash_set<tree> body_needed_for_clonning;
hash_set<void *> reachable_call_targets;
bool before_inlining_p = symtab->state < (!optimize ? IPA_SSA
: IPA_SSA_AFTER_INLINING);
timevar_push (TV_IPA_UNREACHABLE);
build_type_inheritance_graph ();
if (file)
fprintf (file, "\nReclaiming functions:");
#ifdef ENABLE_CHECKING
FOR_EACH_FUNCTION (node)
gcc_assert (!node->aux);
FOR_EACH_VARIABLE (vnode)
gcc_assert (!vnode->aux);
#endif
/* Mark functions whose bodies are obviously needed.
This is mostly when they can be referenced externally. Inline clones
are special since their declarations are shared with master clone and thus
cgraph_can_remove_if_no_direct_calls_and_refs_p should not be called on them. */
FOR_EACH_FUNCTION (node)
{
node->used_as_abstract_origin = false;
if (node->definition
&& !node->global.inlined_to
&& !node->in_other_partition
&& !node->can_remove_if_no_direct_calls_and_refs_p ())
{
gcc_assert (!node->global.inlined_to);
reachable.add (node);
enqueue_node (node, &first, &reachable);
}
else
gcc_assert (!node->aux);
}
/* Mark variables that are obviously needed. */
FOR_EACH_DEFINED_VARIABLE (vnode)
if (!vnode->can_remove_if_no_refs_p()
&& !vnode->in_other_partition)
{
reachable.add (vnode);
enqueue_node (vnode, &first, &reachable);
}
/* Perform reachability analysis. */
while (first != (symtab_node *) (void *) 1)
{
bool in_boundary_p = !reachable.contains (first);
symtab_node *node = first;
first = (symtab_node *)first->aux;
/* If we are processing symbol in boundary, mark its AUX pointer for
possible later re-processing in enqueue_node. */
if (in_boundary_p)
{
node->aux = (void *)2;
if (node->alias && node->analyzed)
enqueue_node (node->get_alias_target (), &first, &reachable);
}
else
{
if (TREE_CODE (node->decl) == FUNCTION_DECL
&& DECL_ABSTRACT_ORIGIN (node->decl))
{
struct cgraph_node *origin_node
= cgraph_node::get (DECL_ABSTRACT_ORIGIN (node->decl));
if (origin_node && !origin_node->used_as_abstract_origin)
{
origin_node->used_as_abstract_origin = true;
gcc_assert (!origin_node->prev_sibling_clone);
gcc_assert (!origin_node->next_sibling_clone);
for (cgraph_node *n = origin_node->clones; n;
n = n->next_sibling_clone)
if (n->decl == DECL_ABSTRACT_ORIGIN (node->decl))
n->used_as_abstract_origin = true;
}
}
/* If any symbol in a comdat group is reachable, force
all externally visible symbols in the same comdat
group to be reachable as well. Comdat-local symbols
can be discarded if all uses were inlined. */
if (node->same_comdat_group)
{
symtab_node *next;
for (next = node->same_comdat_group;
next != node;
next = next->same_comdat_group)
if (!next->comdat_local_p ()
&& !reachable.add (next))
enqueue_node (next, &first, &reachable);
}
/* Mark references as reachable. */
process_references (node, &first, before_inlining_p, &reachable);
}
if (cgraph_node *cnode = dyn_cast <cgraph_node *> (node))
{
/* Mark the callees reachable unless they are direct calls to extern
inline functions we decided to not inline. */
if (!in_boundary_p)
{
struct cgraph_edge *e;
/* Keep alive possible targets for devirtualization. */
if (opt_for_fn (cnode->decl, optimize)
&& opt_for_fn (cnode->decl, flag_devirtualize))
{
struct cgraph_edge *next;
for (e = cnode->indirect_calls; e; e = next)
{
next = e->next_callee;
if (e->indirect_info->polymorphic)
walk_polymorphic_call_targets (&reachable_call_targets,
e, &first, &reachable,
before_inlining_p);
}
}
for (e = cnode->callees; e; e = e->next_callee)
{
symtab_node *body = e->callee->function_symbol ();
if (e->callee->definition
&& !e->callee->in_other_partition
&& (!e->inline_failed
|| !DECL_EXTERNAL (e->callee->decl)
|| e->callee->alias
|| (before_inlining_p
&& (opt_for_fn (body->decl, optimize)
|| (symtab->state < IPA_SSA
&& lookup_attribute
("always_inline",
DECL_ATTRIBUTES (body->decl)))))))
{
/* Be sure that we will not optimize out alias target
body. */
if (DECL_EXTERNAL (e->callee->decl)
&& e->callee->alias
&& before_inlining_p)
reachable.add (body);
reachable.add (e->callee);
}
enqueue_node (e->callee, &first, &reachable);
}
/* When inline clone exists, mark body to be preserved so when removing
offline copy of the function we don't kill it. */
if (cnode->global.inlined_to)
body_needed_for_clonning.add (cnode->decl);
/* For instrumentation clones we always need original
function node for proper LTO privatization. */
if (cnode->instrumentation_clone
&& cnode->definition)
{
gcc_assert (cnode->instrumented_version || in_lto_p);
if (cnode->instrumented_version)
{
enqueue_node (cnode->instrumented_version, &first,
&reachable);
reachable.add (cnode->instrumented_version);
}
}
/* For non-inline clones, force their origins to the boundary and ensure
that body is not removed. */
while (cnode->clone_of)
{
bool noninline = cnode->clone_of->decl != cnode->decl;
cnode = cnode->clone_of;
if (noninline)
{
body_needed_for_clonning.add (cnode->decl);
enqueue_node (cnode, &first, &reachable);
}
}
}
else if (cnode->thunk.thunk_p)
enqueue_node (cnode->callees->callee, &first, &reachable);
/* If any reachable function has simd clones, mark them as
reachable as well. */
if (cnode->simd_clones)
{
cgraph_node *next;
for (next = cnode->simd_clones;
next;
next = next->simdclone->next_clone)
if (in_boundary_p
|| !reachable.add (next))
enqueue_node (next, &first, &reachable);
}
}
/* When we see constructor of external variable, keep referred nodes in the
boundary. This will also hold initializers of the external vars NODE
refers to. */
varpool_node *vnode = dyn_cast <varpool_node *> (node);
if (vnode
&& DECL_EXTERNAL (node->decl)
&& !vnode->alias
&& in_boundary_p)
{
struct ipa_ref *ref = NULL;
for (int i = 0; node->iterate_reference (i, ref); i++)
enqueue_node (ref->referred, &first, &reachable);
}
}
/* Remove unreachable functions. */
for (node = first_function (); node; node = next)
{
next = next_function (node);
/* If node is not needed at all, remove it. */
if (!node->aux)
{
if (file)
fprintf (file, " %s/%i", node->name (), node->order);
node->remove ();
changed = true;
}
/* If node is unreachable, remove its body. */
else if (!reachable.contains (node))
{
/* We keep definitions of thunks and aliases in the boundary so
we can walk to the ultimate alias targets and function symbols
reliably. */
if (node->alias || node->thunk.thunk_p)
;
else if (!body_needed_for_clonning.contains (node->decl)
&& !node->alias && !node->thunk.thunk_p)
node->release_body ();
else if (!node->clone_of)
gcc_assert (in_lto_p || DECL_RESULT (node->decl));
if (node->definition && !node->alias && !node->thunk.thunk_p)
{
if (file)
fprintf (file, " %s/%i", node->name (), node->order);
node->body_removed = true;
node->analyzed = false;
node->definition = false;
node->cpp_implicit_alias = false;
node->alias = false;
node->thunk.thunk_p = false;
node->weakref = false;
/* After early inlining we drop always_inline attributes on
bodies of functions that are still referenced (have their
address taken). */
DECL_ATTRIBUTES (node->decl)
= remove_attribute ("always_inline",
DECL_ATTRIBUTES (node->decl));
if (!node->in_other_partition)
node->local.local = false;
node->remove_callees ();
node->remove_all_references ();
changed = true;
if (node->thunk.thunk_p
&& node->thunk.add_pointer_bounds_args)
{
node->thunk.thunk_p = false;
node->thunk.add_pointer_bounds_args = false;
}
}
}
else
gcc_assert (node->clone_of || !node->has_gimple_body_p ()
|| in_lto_p || DECL_RESULT (node->decl));
}
/* Inline clones might be kept around so their materializing allows further
cloning. If the function the clone is inlined into is removed, we need
to turn it into normal cone. */
FOR_EACH_FUNCTION (node)
{
if (node->global.inlined_to
&& !node->callers)
{
gcc_assert (node->clones);
node->global.inlined_to = NULL;
update_inlined_to_pointer (node, node);
}
node->aux = NULL;
}
/* Remove unreachable variables. */
if (file)
fprintf (file, "\nReclaiming variables:");
for (vnode = first_variable (); vnode; vnode = vnext)
{
vnext = next_variable (vnode);
if (!vnode->aux
/* For can_refer_decl_in_current_unit_p we want to track for
all external variables if they are defined in other partition
or not. */
&& (!flag_ltrans || !DECL_EXTERNAL (vnode->decl)))
{
struct ipa_ref *ref = NULL;
/* First remove the aliases, so varpool::remove can possibly lookup
the constructor and save it for future use. */
while (vnode->iterate_direct_aliases (0, ref))
{
if (file)
fprintf (file, " %s/%i", ref->referred->name (),
ref->referred->order);
ref->referring->remove ();
}
if (file)
fprintf (file, " %s/%i", vnode->name (), vnode->order);
vnext = next_variable (vnode);
vnode->remove ();
changed = true;
}
else if (!reachable.contains (vnode) && !vnode->alias)
{
tree init;
if (vnode->definition)
{
if (file)
fprintf (file, " %s", vnode->name ());
changed = true;
}
/* Keep body if it may be useful for constant folding. */
if ((init = ctor_for_folding (vnode->decl)) == error_mark_node
&& !POINTER_BOUNDS_P (vnode->decl))
vnode->remove_initializer ();
else
DECL_INITIAL (vnode->decl) = init;
vnode->body_removed = true;
vnode->definition = false;
vnode->analyzed = false;
vnode->aux = NULL;
vnode->remove_from_same_comdat_group ();
vnode->remove_all_references ();
}
else
vnode->aux = NULL;
}
/* Now update address_taken flags and try to promote functions to be local. */
if (file)
fprintf (file, "\nClearing address taken flags:");
FOR_EACH_DEFINED_FUNCTION (node)
if (node->address_taken
&& !node->used_from_other_partition)
{
if (!node->call_for_symbol_and_aliases
(has_addr_references_p, NULL, true)
&& (!node->instrumentation_clone
|| !node->instrumented_version
|| !node->instrumented_version->address_taken))
{
if (file)
fprintf (file, " %s", node->name ());
node->address_taken = false;
changed = true;
if (node->local_p ())
{
node->local.local = true;
if (file)
fprintf (file, " (local)");
}
}
}
if (file)
fprintf (file, "\n");
#ifdef ENABLE_CHECKING
symtab_node::verify_symtab_nodes ();
#endif
/* If we removed something, perhaps profile could be improved. */
if (changed && optimize && inline_edge_summary_vec.exists ())
FOR_EACH_DEFINED_FUNCTION (node)
ipa_propagate_frequency (node);
timevar_pop (TV_IPA_UNREACHABLE);
return changed;
}
/* Process references to VNODE and set flags WRITTEN, ADDRESS_TAKEN, READ
as needed, also clear EXPLICIT_REFS if the references to given variable
do not need to be explicit. */
void
process_references (varpool_node *vnode,
bool *written, bool *address_taken,
bool *read, bool *explicit_refs)
{
int i;
struct ipa_ref *ref;
if (!vnode->all_refs_explicit_p ()
|| TREE_THIS_VOLATILE (vnode->decl))
*explicit_refs = false;
for (i = 0; vnode->iterate_referring (i, ref)
&& *explicit_refs && (!*written || !*address_taken || !*read); i++)
switch (ref->use)
{
case IPA_REF_ADDR:
*address_taken = true;
break;
case IPA_REF_LOAD:
*read = true;
break;
case IPA_REF_STORE:
*written = true;
break;
case IPA_REF_ALIAS:
process_references (dyn_cast<varpool_node *> (ref->referring), written,
address_taken, read, explicit_refs);
break;
case IPA_REF_CHKP:
gcc_unreachable ();
}
}
/* Set TREE_READONLY bit. */
bool
set_readonly_bit (varpool_node *vnode, void *data ATTRIBUTE_UNUSED)
{
TREE_READONLY (vnode->decl) = true;
return false;
}
/* Set writeonly bit and clear the initalizer, since it will not be needed. */
bool
set_writeonly_bit (varpool_node *vnode, void *data)
{
vnode->writeonly = true;
if (optimize)
{
DECL_INITIAL (vnode->decl) = NULL;
if (!vnode->alias)
{
if (vnode->num_references ())
*(bool *)data = true;
vnode->remove_all_references ();
}
}
return false;
}
/* Clear addressale bit of VNODE. */
bool
clear_addressable_bit (varpool_node *vnode, void *data ATTRIBUTE_UNUSED)
{
vnode->address_taken = false;
TREE_ADDRESSABLE (vnode->decl) = 0;
return false;
}
/* Discover variables that have no longer address taken or that are read only
and update their flags.
Return true when unreachable symbol removan should be done.
FIXME: This can not be done in between gimplify and omp_expand since
readonly flag plays role on what is shared and what is not. Currently we do
this transformation as part of whole program visibility and re-do at
ipa-reference pass (to take into account clonning), but it would
make sense to do it before early optimizations. */
bool
ipa_discover_readonly_nonaddressable_vars (void)
{
bool remove_p = false;
varpool_node *vnode;
if (dump_file)
fprintf (dump_file, "Clearing variable flags:");
FOR_EACH_VARIABLE (vnode)
if (!vnode->alias
&& (TREE_ADDRESSABLE (vnode->decl)
|| !vnode->writeonly
|| !TREE_READONLY (vnode->decl)))
{
bool written = false;
bool address_taken = false;
bool read = false;
bool explicit_refs = true;
process_references (vnode, &written, &address_taken, &read,
&explicit_refs);
if (!explicit_refs)
continue;
if (!address_taken)
{
if (TREE_ADDRESSABLE (vnode->decl) && dump_file)
fprintf (dump_file, " %s (non-addressable)", vnode->name ());
vnode->call_for_symbol_and_aliases (clear_addressable_bit, NULL,
true);
}
if (!address_taken && !written
/* Making variable in explicit section readonly can cause section
type conflict.
See e.g. gcc.c-torture/compile/pr23237.c */
&& vnode->get_section () == NULL)
{
if (!TREE_READONLY (vnode->decl) && dump_file)
fprintf (dump_file, " %s (read-only)", vnode->name ());
vnode->call_for_symbol_and_aliases (set_readonly_bit, NULL, true);
}
if (!vnode->writeonly && !read && !address_taken && written)
{
if (dump_file)
fprintf (dump_file, " %s (write-only)", vnode->name ());
vnode->call_for_symbol_and_aliases (set_writeonly_bit, &remove_p,
true);
}
}
if (dump_file)
fprintf (dump_file, "\n");
return remove_p;
}
/* Free inline summary. */
namespace {
const pass_data pass_data_ipa_free_inline_summary =
{
SIMPLE_IPA_PASS, /* type */
"free-inline-summary", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_IPA_FREE_INLINE_SUMMARY, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
/* Early optimizations may make function unreachable. We can not
remove unreachable functions as part of the ealry opts pass because
TODOs are run before subpasses. Do it here. */
( TODO_remove_functions | TODO_dump_symtab ), /* todo_flags_finish */
};
class pass_ipa_free_inline_summary : public simple_ipa_opt_pass
{
public:
pass_ipa_free_inline_summary (gcc::context *ctxt)
: simple_ipa_opt_pass (pass_data_ipa_free_inline_summary, ctxt)
{}
/* opt_pass methods: */
virtual unsigned int execute (function *)
{
inline_free_summary ();
return 0;
}
}; // class pass_ipa_free_inline_summary
} // anon namespace
simple_ipa_opt_pass *
make_pass_ipa_free_inline_summary (gcc::context *ctxt)
{
return new pass_ipa_free_inline_summary (ctxt);
}
/* Generate and emit a static constructor or destructor. WHICH must
be one of 'I' (for a constructor), 'D' (for a destructor), 'P'
(for chp static vars constructor) or 'B' (for chkp static bounds
constructor). BODY is a STATEMENT_LIST containing GENERIC
statements. PRIORITY is the initialization priority for this
constructor or destructor.
FINAL specify whether the externally visible name for collect2 should
be produced. */
static void
cgraph_build_static_cdtor_1 (char which, tree body, int priority, bool final)
{
static int counter = 0;
char which_buf[16];
tree decl, name, resdecl;
/* The priority is encoded in the constructor or destructor name.
collect2 will sort the names and arrange that they are called at
program startup. */
if (final)
sprintf (which_buf, "%c_%.5d_%d", which, priority, counter++);
else
/* Proudce sane name but one not recognizable by collect2, just for the
case we fail to inline the function. */
sprintf (which_buf, "sub_%c_%.5d_%d", which, priority, counter++);
name = get_file_function_name (which_buf);
decl = build_decl (input_location, FUNCTION_DECL, name,
build_function_type_list (void_type_node, NULL_TREE));
current_function_decl = decl;
resdecl = build_decl (input_location,
RESULT_DECL, NULL_TREE, void_type_node);
DECL_ARTIFICIAL (resdecl) = 1;
DECL_RESULT (decl) = resdecl;
DECL_CONTEXT (resdecl) = decl;
allocate_struct_function (decl, false);
TREE_STATIC (decl) = 1;
TREE_USED (decl) = 1;
DECL_ARTIFICIAL (decl) = 1;
DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
DECL_SAVED_TREE (decl) = body;
if (!targetm.have_ctors_dtors && final)
{
TREE_PUBLIC (decl) = 1;
DECL_PRESERVE_P (decl) = 1;
}
DECL_UNINLINABLE (decl) = 1;
DECL_INITIAL (decl) = make_node (BLOCK);
TREE_USED (DECL_INITIAL (decl)) = 1;
DECL_SOURCE_LOCATION (decl) = input_location;
cfun->function_end_locus = input_location;
switch (which)
{
case 'I':
DECL_STATIC_CONSTRUCTOR (decl) = 1;
decl_init_priority_insert (decl, priority);
break;
case 'P':
DECL_STATIC_CONSTRUCTOR (decl) = 1;
DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("chkp ctor"),
NULL,
NULL_TREE);
decl_init_priority_insert (decl, priority);
break;
case 'B':
DECL_STATIC_CONSTRUCTOR (decl) = 1;
DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("bnd_legacy"),
NULL,
NULL_TREE);
decl_init_priority_insert (decl, priority);
break;
case 'D':
DECL_STATIC_DESTRUCTOR (decl) = 1;
decl_fini_priority_insert (decl, priority);
break;
default:
gcc_unreachable ();
}
gimplify_function_tree (decl);
cgraph_node::add_new_function (decl, false);
set_cfun (NULL);
current_function_decl = NULL;
}
/* Generate and emit a static constructor or destructor. WHICH must
be one of 'I' (for a constructor), 'D' (for a destructor), 'P'
(for chkp static vars constructor) or 'B' (for chkp static bounds
constructor). BODY is a STATEMENT_LIST containing GENERIC
statements. PRIORITY is the initialization priority for this
constructor or destructor. */
void
cgraph_build_static_cdtor (char which, tree body, int priority)
{
cgraph_build_static_cdtor_1 (which, body, priority, false);
}