-
Notifications
You must be signed in to change notification settings - Fork 56
/
stringopts.cpp
1977 lines (1800 loc) · 69.3 KB
/
stringopts.cpp
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
/*
* Copyright (c) 2009, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "classfile/javaClasses.hpp"
#include "compiler/compileLog.hpp"
#include "opto/addnode.hpp"
#include "opto/callGenerator.hpp"
#include "opto/callnode.hpp"
#include "opto/divnode.hpp"
#include "opto/graphKit.hpp"
#include "opto/idealKit.hpp"
#include "opto/rootnode.hpp"
#include "opto/runtime.hpp"
#include "opto/stringopts.hpp"
#include "opto/subnode.hpp"
#include "runtime/sharedRuntime.hpp"
#define __ kit.
class StringConcat : public ResourceObj {
private:
PhaseStringOpts* _stringopts;
Node* _string_alloc;
AllocateNode* _begin; // The allocation the begins the pattern
CallStaticJavaNode* _end; // The final call of the pattern. Will either be
// SB.toString or or String.<init>(SB.toString)
bool _multiple; // indicates this is a fusion of two or more
// separate StringBuilders
Node* _arguments; // The list of arguments to be concatenated
GrowableArray<int> _mode; // into a String along with a mode flag
// indicating how to treat the value.
Node_List _constructors; // List of constructors (many in case of stacked concat)
Node_List _control; // List of control nodes that will be deleted
Node_List _uncommon_traps; // Uncommon traps that needs to be rewritten
// to restart at the initial JVMState.
public:
// Mode for converting arguments to Strings
enum {
StringMode,
IntMode,
CharMode,
StringNullCheckMode
};
StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
_stringopts(stringopts),
_string_alloc(NULL),
_begin(NULL),
_end(end),
_multiple(false) {
_arguments = new Node(1);
_arguments->del_req(0);
}
bool validate_mem_flow();
bool validate_control_flow();
void merge_add() {
#if 0
// XXX This is place holder code for reusing an existing String
// allocation but the logic for checking the state safety is
// probably inadequate at the moment.
CallProjections endprojs;
sc->end()->extract_projections(&endprojs, false);
if (endprojs.resproj != NULL) {
for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
if (use != NULL && use->method() != NULL &&
use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
// Found useless new String(sb.toString()) so reuse the newly allocated String
// when creating the result instead of allocating a new one.
sc->set_string_alloc(use->in(TypeFunc::Parms));
sc->set_end(use);
}
}
}
#endif
}
StringConcat* merge(StringConcat* other, Node* arg);
void set_allocation(AllocateNode* alloc) {
_begin = alloc;
}
void append(Node* value, int mode) {
_arguments->add_req(value);
_mode.append(mode);
}
void push(Node* value, int mode) {
_arguments->ins_req(0, value);
_mode.insert_before(0, mode);
}
void push_string(Node* value) {
push(value, StringMode);
}
void push_string_null_check(Node* value) {
push(value, StringNullCheckMode);
}
void push_int(Node* value) {
push(value, IntMode);
}
void push_char(Node* value) {
push(value, CharMode);
}
static bool is_SB_toString(Node* call) {
if (call->is_CallStaticJava()) {
CallStaticJavaNode* csj = call->as_CallStaticJava();
ciMethod* m = csj->method();
if (m != NULL &&
(m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
return true;
}
}
return false;
}
static Node* skip_string_null_check(Node* value) {
// Look for a diamond shaped Null check of toString() result
// (could be code from String.valueOf()):
// (Proj == NULL) ? "null":"CastPP(Proj)#NotNULL
if (value->is_Phi()) {
int true_path = value->as_Phi()->is_diamond_phi();
if (true_path != 0) {
// phi->region->if_proj->ifnode->bool
BoolNode* b = value->in(0)->in(1)->in(0)->in(1)->as_Bool();
Node* cmp = b->in(1);
Node* v1 = cmp->in(1);
Node* v2 = cmp->in(2);
// Null check of the return of toString which can simply be skipped.
if (b->_test._test == BoolTest::ne &&
v2->bottom_type() == TypePtr::NULL_PTR &&
value->in(true_path)->Opcode() == Op_CastPP &&
value->in(true_path)->in(1) == v1 &&
v1->is_Proj() && is_SB_toString(v1->in(0))) {
return v1;
}
}
}
return value;
}
Node* argument(int i) {
return _arguments->in(i);
}
Node* argument_uncast(int i) {
Node* arg = argument(i);
int amode = mode(i);
if (amode == StringConcat::StringMode ||
amode == StringConcat::StringNullCheckMode) {
arg = skip_string_null_check(arg);
}
return arg;
}
void set_argument(int i, Node* value) {
_arguments->set_req(i, value);
}
int num_arguments() {
return _mode.length();
}
int mode(int i) {
return _mode.at(i);
}
void add_control(Node* ctrl) {
assert(!_control.contains(ctrl), "only push once");
_control.push(ctrl);
}
void add_constructor(Node* init) {
assert(!_constructors.contains(init), "only push once");
_constructors.push(init);
}
CallStaticJavaNode* end() { return _end; }
AllocateNode* begin() { return _begin; }
Node* string_alloc() { return _string_alloc; }
void eliminate_unneeded_control();
void eliminate_initialize(InitializeNode* init);
void eliminate_call(CallNode* call);
void maybe_log_transform() {
CompileLog* log = _stringopts->C->log();
if (log != NULL) {
log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
num_arguments(),
_string_alloc != NULL,
_multiple);
JVMState* p = _begin->jvms();
while (p != NULL) {
log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
p = p->caller();
}
log->tail("replace_string_concat");
}
}
void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
for (uint u = 0; u < _uncommon_traps.size(); u++) {
Node* uct = _uncommon_traps.at(u);
// Build a new call using the jvms state of the allocate
address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
const TypePtr* no_memory_effects = NULL;
Compile* C = _stringopts->C;
CallStaticJavaNode* call = new CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
jvms->bci(), no_memory_effects);
for (int e = 0; e < TypeFunc::Parms; e++) {
call->init_req(e, uct->in(e));
}
// Set the trap request to record intrinsic failure if this trap
// is taken too many times. Ideally we would handle then traps by
// doing the original bookkeeping in the MDO so that if it caused
// the code to be thrown out we could still recompile and use the
// optimization. Failing the uncommon traps doesn't really mean
// that the optimization is a bad idea but there's no other way to
// do the MDO updates currently.
int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
Deoptimization::Action_make_not_entrant);
call->init_req(TypeFunc::Parms, __ intcon(trap_request));
kit.add_safepoint_edges(call);
_stringopts->gvn()->transform(call);
C->gvn_replace_by(uct, call);
uct->disconnect_inputs(NULL, C);
}
}
void cleanup() {
// disconnect the hook node
_arguments->disconnect_inputs(NULL, _stringopts->C);
}
};
void StringConcat::eliminate_unneeded_control() {
for (uint i = 0; i < _control.size(); i++) {
Node* n = _control.at(i);
if (n->is_Allocate()) {
eliminate_initialize(n->as_Allocate()->initialization());
}
if (n->is_Call()) {
if (n != _end) {
eliminate_call(n->as_Call());
}
} else if (n->is_IfTrue()) {
Compile* C = _stringopts->C;
C->gvn_replace_by(n, n->in(0)->in(0));
// get rid of the other projection
C->gvn_replace_by(n->in(0)->as_If()->proj_out(false), C->top());
}
}
}
StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
StringConcat* result = new StringConcat(_stringopts, _end);
for (uint x = 0; x < _control.size(); x++) {
Node* n = _control.at(x);
if (n->is_Call()) {
result->_control.push(n);
}
}
for (uint x = 0; x < other->_control.size(); x++) {
Node* n = other->_control.at(x);
if (n->is_Call()) {
result->_control.push(n);
}
}
assert(result->_control.contains(other->_end), "what?");
assert(result->_control.contains(_begin), "what?");
for (int x = 0; x < num_arguments(); x++) {
Node* argx = argument_uncast(x);
if (argx == arg) {
// replace the toString result with the all the arguments that
// made up the other StringConcat
for (int y = 0; y < other->num_arguments(); y++) {
result->append(other->argument(y), other->mode(y));
}
} else {
result->append(argx, mode(x));
}
}
result->set_allocation(other->_begin);
for (uint i = 0; i < _constructors.size(); i++) {
result->add_constructor(_constructors.at(i));
}
for (uint i = 0; i < other->_constructors.size(); i++) {
result->add_constructor(other->_constructors.at(i));
}
result->_multiple = true;
return result;
}
void StringConcat::eliminate_call(CallNode* call) {
Compile* C = _stringopts->C;
CallProjections projs;
call->extract_projections(&projs, false);
if (projs.fallthrough_catchproj != NULL) {
C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
}
if (projs.fallthrough_memproj != NULL) {
C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
}
if (projs.catchall_memproj != NULL) {
C->gvn_replace_by(projs.catchall_memproj, C->top());
}
if (projs.fallthrough_ioproj != NULL) {
C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
}
if (projs.catchall_ioproj != NULL) {
C->gvn_replace_by(projs.catchall_ioproj, C->top());
}
if (projs.catchall_catchproj != NULL) {
// EA can't cope with the partially collapsed graph this
// creates so put it on the worklist to be collapsed later.
for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
Node *use = i.get();
int opc = use->Opcode();
if (opc == Op_CreateEx || opc == Op_Region) {
_stringopts->record_dead_node(use);
}
}
C->gvn_replace_by(projs.catchall_catchproj, C->top());
}
if (projs.resproj != NULL) {
C->gvn_replace_by(projs.resproj, C->top());
}
C->gvn_replace_by(call, C->top());
}
void StringConcat::eliminate_initialize(InitializeNode* init) {
Compile* C = _stringopts->C;
// Eliminate Initialize node.
assert(init->outcnt() <= 2, "only a control and memory projection expected");
assert(init->req() <= InitializeNode::RawStores, "no pending inits");
Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
if (ctrl_proj != NULL) {
C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
}
Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
if (mem_proj != NULL) {
Node *mem = init->in(TypeFunc::Memory);
C->gvn_replace_by(mem_proj, mem);
}
C->gvn_replace_by(init, C->top());
init->disconnect_inputs(NULL, C);
}
Node_List PhaseStringOpts::collect_toString_calls() {
Node_List string_calls;
Node_List worklist;
_visited.clear();
// Prime the worklist
for (uint i = 1; i < C->root()->len(); i++) {
Node* n = C->root()->in(i);
if (n != NULL && !_visited.test_set(n->_idx)) {
worklist.push(n);
}
}
while (worklist.size() > 0) {
Node* ctrl = worklist.pop();
if (StringConcat::is_SB_toString(ctrl)) {
CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
string_calls.push(csj);
}
if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
worklist.push(ctrl->in(0));
}
if (ctrl->is_Region()) {
for (uint i = 1; i < ctrl->len(); i++) {
if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
worklist.push(ctrl->in(i));
}
}
}
}
return string_calls;
}
StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
ciMethod* m = call->method();
ciSymbol* string_sig;
ciSymbol* int_sig;
ciSymbol* char_sig;
if (m->holder() == C->env()->StringBuilder_klass()) {
string_sig = ciSymbol::String_StringBuilder_signature();
int_sig = ciSymbol::int_StringBuilder_signature();
char_sig = ciSymbol::char_StringBuilder_signature();
} else if (m->holder() == C->env()->StringBuffer_klass()) {
string_sig = ciSymbol::String_StringBuffer_signature();
int_sig = ciSymbol::int_StringBuffer_signature();
char_sig = ciSymbol::char_StringBuffer_signature();
} else {
return NULL;
}
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("considering toString call in ");
call->jvms()->dump_spec(tty); tty->cr();
}
#endif
StringConcat* sc = new StringConcat(this, call);
AllocateNode* alloc = NULL;
InitializeNode* init = NULL;
// possible opportunity for StringBuilder fusion
CallStaticJavaNode* cnode = call;
while (cnode) {
Node* recv = cnode->in(TypeFunc::Parms)->uncast();
if (recv->is_Proj()) {
recv = recv->in(0);
}
cnode = recv->isa_CallStaticJava();
if (cnode == NULL) {
alloc = recv->isa_Allocate();
if (alloc == NULL) {
break;
}
// Find the constructor call
Node* result = alloc->result_cast();
if (result == NULL || !result->is_CheckCastPP() || alloc->in(TypeFunc::Memory)->is_top()) {
// strange looking allocation
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("giving up because allocation looks strange ");
alloc->jvms()->dump_spec(tty); tty->cr();
}
#endif
break;
}
Node* constructor = NULL;
for (SimpleDUIterator i(result); i.has_next(); i.next()) {
CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
if (use != NULL &&
use->method() != NULL &&
!use->method()->is_static() &&
use->method()->name() == ciSymbol::object_initializer_name() &&
use->method()->holder() == m->holder()) {
// Matched the constructor.
ciSymbol* sig = use->method()->signature()->as_symbol();
if (sig == ciSymbol::void_method_signature() ||
sig == ciSymbol::int_void_signature() ||
sig == ciSymbol::string_void_signature()) {
if (sig == ciSymbol::string_void_signature()) {
// StringBuilder(String) so pick this up as the first argument
assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
if (type == TypePtr::NULL_PTR) {
// StringBuilder(null) throws exception.
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("giving up because StringBuilder(null) throws exception");
alloc->jvms()->dump_spec(tty); tty->cr();
}
#endif
return NULL;
}
// StringBuilder(str) argument needs null check.
sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
}
// The int variant takes an initial size for the backing
// array so just treat it like the void version.
constructor = use;
} else {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("unexpected constructor signature: %s", sig->as_utf8());
}
#endif
}
break;
}
}
if (constructor == NULL) {
// couldn't find constructor
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("giving up because couldn't find constructor ");
alloc->jvms()->dump_spec(tty); tty->cr();
}
#endif
break;
}
// Walked all the way back and found the constructor call so see
// if this call converted into a direct string concatenation.
sc->add_control(call);
sc->add_control(constructor);
sc->add_control(alloc);
sc->set_allocation(alloc);
sc->add_constructor(constructor);
if (sc->validate_control_flow() && sc->validate_mem_flow()) {
return sc;
} else {
return NULL;
}
} else if (cnode->method() == NULL) {
break;
} else if (!cnode->method()->is_static() &&
cnode->method()->holder() == m->holder() &&
cnode->method()->name() == ciSymbol::append_name() &&
(cnode->method()->signature()->as_symbol() == string_sig ||
cnode->method()->signature()->as_symbol() == char_sig ||
cnode->method()->signature()->as_symbol() == int_sig)) {
sc->add_control(cnode);
Node* arg = cnode->in(TypeFunc::Parms + 1);
if (cnode->method()->signature()->as_symbol() == int_sig) {
sc->push_int(arg);
} else if (cnode->method()->signature()->as_symbol() == char_sig) {
sc->push_char(arg);
} else {
if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
if (csj->method() != NULL &&
csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
arg->outcnt() == 1) {
// _control is the list of StringBuilder calls nodes which
// will be replaced by new String code after this optimization.
// Integer::toString() call is not part of StringBuilder calls
// chain. It could be eliminated only if its result is used
// only by this SB calls chain.
// Another limitation: it should be used only once because
// it is unknown that it is used only by this SB calls chain
// until all related SB calls nodes are collected.
assert(arg->unique_out() == cnode, "sanity");
sc->add_control(csj);
sc->push_int(csj->in(TypeFunc::Parms));
continue;
}
}
sc->push_string(arg);
}
continue;
} else {
// some unhandled signature
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("giving up because encountered unexpected signature ");
cnode->tf()->dump(); tty->cr();
cnode->in(TypeFunc::Parms + 1)->dump();
}
#endif
break;
}
}
return NULL;
}
PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
Phase(StringOpts),
_gvn(gvn) {
assert(OptimizeStringConcat, "shouldn't be here");
size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
ciSymbol::make("[I"), true);
if (size_table_field == NULL) {
// Something wrong so give up.
assert(false, "why can't we find Integer.sizeTable?");
return;
}
// Collect the types needed to talk about the various slices of memory
byte_adr_idx = C->get_alias_index(TypeAryPtr::BYTES);
// For each locally allocated StringBuffer see if the usages can be
// collapsed into a single String construction.
// Run through the list of allocation looking for SB.toString to see
// if it's possible to fuse the usage of the SB into a single String
// construction.
GrowableArray<StringConcat*> concats;
Node_List toStrings = collect_toString_calls();
while (toStrings.size() > 0) {
StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
if (sc != NULL) {
concats.push(sc);
}
}
// try to coalesce separate concats
restart:
for (int c = 0; c < concats.length(); c++) {
StringConcat* sc = concats.at(c);
for (int i = 0; i < sc->num_arguments(); i++) {
Node* arg = sc->argument_uncast(i);
if (arg->is_Proj() && StringConcat::is_SB_toString(arg->in(0))) {
CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
for (int o = 0; o < concats.length(); o++) {
if (c == o) continue;
StringConcat* other = concats.at(o);
if (other->end() == csj) {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print_cr("considering stacked concats");
}
#endif
StringConcat* merged = sc->merge(other, arg);
if (merged->validate_control_flow() && merged->validate_mem_flow()) {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print_cr("stacking would succeed");
}
#endif
if (c < o) {
concats.remove_at(o);
concats.at_put(c, merged);
} else {
concats.remove_at(c);
concats.at_put(o, merged);
}
goto restart;
} else {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print_cr("stacking would fail");
}
#endif
}
}
}
}
}
}
for (int c = 0; c < concats.length(); c++) {
StringConcat* sc = concats.at(c);
replace_string_concat(sc);
}
remove_dead_nodes();
}
void PhaseStringOpts::record_dead_node(Node* dead) {
dead_worklist.push(dead);
}
void PhaseStringOpts::remove_dead_nodes() {
// Delete any dead nodes to make things clean enough that escape
// analysis doesn't get unhappy.
while (dead_worklist.size() > 0) {
Node* use = dead_worklist.pop();
int opc = use->Opcode();
switch (opc) {
case Op_Region: {
uint i = 1;
for (i = 1; i < use->req(); i++) {
if (use->in(i) != C->top()) {
break;
}
}
if (i >= use->req()) {
for (SimpleDUIterator i(use); i.has_next(); i.next()) {
Node* m = i.get();
if (m->is_Phi()) {
dead_worklist.push(m);
}
}
C->gvn_replace_by(use, C->top());
}
break;
}
case Op_AddP:
case Op_CreateEx: {
// Recurisvely clean up references to CreateEx so EA doesn't
// get unhappy about the partially collapsed graph.
for (SimpleDUIterator i(use); i.has_next(); i.next()) {
Node* m = i.get();
if (m->is_AddP()) {
dead_worklist.push(m);
}
}
C->gvn_replace_by(use, C->top());
break;
}
case Op_Phi:
if (use->in(0) == C->top()) {
C->gvn_replace_by(use, C->top());
}
break;
}
}
}
bool StringConcat::validate_mem_flow() {
Compile* C = _stringopts->C;
for (uint i = 0; i < _control.size(); i++) {
#ifndef PRODUCT
Node_List path;
#endif
Node* curr = _control.at(i);
if (curr->is_Call() && curr != _begin) { // For all calls except the first allocation
// Now here's the main invariant in our case:
// For memory between the constructor, and appends, and toString we should only see bottom memory,
// produced by the previous call we know about.
if (!_constructors.contains(curr)) {
NOT_PRODUCT(path.push(curr);)
Node* mem = curr->in(TypeFunc::Memory);
assert(mem != NULL, "calls should have memory edge");
assert(!mem->is_Phi(), "should be handled by control flow validation");
NOT_PRODUCT(path.push(mem);)
while (mem->is_MergeMem()) {
for (uint i = 1; i < mem->req(); i++) {
if (i != Compile::AliasIdxBot && mem->in(i) != C->top()) {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("fusion has incorrect memory flow (side effects) for ");
_begin->jvms()->dump_spec(tty); tty->cr();
path.dump();
}
#endif
return false;
}
}
// skip through a potential MergeMem chain, linked through Bot
mem = mem->in(Compile::AliasIdxBot);
NOT_PRODUCT(path.push(mem);)
}
// now let it fall through, and see if we have a projection
if (mem->is_Proj()) {
// Should point to a previous known call
Node *prev = mem->in(0);
NOT_PRODUCT(path.push(prev);)
if (!prev->is_Call() || !_control.contains(prev)) {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("fusion has incorrect memory flow (unknown call) for ");
_begin->jvms()->dump_spec(tty); tty->cr();
path.dump();
}
#endif
return false;
}
} else {
assert(mem->is_Store() || mem->is_LoadStore(), "unexpected node type: %s", mem->Name());
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("fusion has incorrect memory flow (unexpected source) for ");
_begin->jvms()->dump_spec(tty); tty->cr();
path.dump();
}
#endif
return false;
}
} else {
// For memory that feeds into constructors it's more complicated.
// However the advantage is that any side effect that happens between the Allocate/Initialize and
// the constructor will have to be control-dependent on Initialize.
// So we actually don't have to do anything, since it's going to be caught by the control flow
// analysis.
#ifdef ASSERT
// Do a quick verification of the control pattern between the constructor and the initialize node
assert(curr->is_Call(), "constructor should be a call");
// Go up the control starting from the constructor call
Node* ctrl = curr->in(0);
IfNode* iff = NULL;
RegionNode* copy = NULL;
while (true) {
// skip known check patterns
if (ctrl->is_Region()) {
if (ctrl->as_Region()->is_copy()) {
copy = ctrl->as_Region();
ctrl = copy->is_copy();
} else { // a cast
assert(ctrl->req() == 3 &&
ctrl->in(1) != NULL && ctrl->in(1)->is_Proj() &&
ctrl->in(2) != NULL && ctrl->in(2)->is_Proj() &&
ctrl->in(1)->in(0) == ctrl->in(2)->in(0) &&
ctrl->in(1)->in(0) != NULL && ctrl->in(1)->in(0)->is_If(),
"must be a simple diamond");
Node* true_proj = ctrl->in(1)->is_IfTrue() ? ctrl->in(1) : ctrl->in(2);
for (SimpleDUIterator i(true_proj); i.has_next(); i.next()) {
Node* use = i.get();
assert(use == ctrl || use->is_ConstraintCast(),
"unexpected user: %s", use->Name());
}
iff = ctrl->in(1)->in(0)->as_If();
ctrl = iff->in(0);
}
} else if (ctrl->is_IfTrue()) { // null checks, class checks
iff = ctrl->in(0)->as_If();
// Verify that the other arm is an uncommon trap
Node* otherproj = iff->proj_out(1 - ctrl->as_Proj()->_con);
CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
assert(strcmp(call->_name, "uncommon_trap") == 0, "must be uncommon trap");
ctrl = iff->in(0);
} else {
break;
}
}
assert(ctrl->is_Proj(), "must be a projection");
assert(ctrl->in(0)->is_Initialize(), "should be initialize");
for (SimpleDUIterator i(ctrl); i.has_next(); i.next()) {
Node* use = i.get();
assert(use == copy || use == iff || use == curr || use->is_CheckCastPP() || use->is_Load(),
"unexpected user: %s", use->Name());
}
#endif // ASSERT
}
}
}
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print("fusion has correct memory flow for ");
_begin->jvms()->dump_spec(tty); tty->cr();
tty->cr();
}
#endif
return true;
}
bool StringConcat::validate_control_flow() {
// We found all the calls and arguments now lets see if it's
// safe to transform the graph as we would expect.
// Check to see if this resulted in too many uncommon traps previously
if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
Deoptimization::Reason_intrinsic)) {
return false;
}
// Walk backwards over the control flow from toString to the
// allocation and make sure all the control flow is ok. This
// means it's either going to be eliminated once the calls are
// removed or it can safely be transformed into an uncommon
// trap.
int null_check_count = 0;
Unique_Node_List ctrl_path;
assert(_control.contains(_begin), "missing");
assert(_control.contains(_end), "missing");
// Collect the nodes that we know about and will eliminate into ctrl_path
for (uint i = 0; i < _control.size(); i++) {
// Push the call and it's control projection
Node* n = _control.at(i);
if (n->is_Allocate()) {
AllocateNode* an = n->as_Allocate();
InitializeNode* init = an->initialization();
ctrl_path.push(init);
ctrl_path.push(init->as_Multi()->proj_out(0));
}
if (n->is_Call()) {
CallNode* cn = n->as_Call();
ctrl_path.push(cn);
ctrl_path.push(cn->proj_out(0));
ctrl_path.push(cn->proj_out(0)->unique_out());
Node* catchproj = cn->proj_out(0)->unique_out()->as_Catch()->proj_out_or_null(0);
if (catchproj != NULL) {
ctrl_path.push(catchproj);
}
} else {
ShouldNotReachHere();
}
}
// Skip backwards through the control checking for unexpected control flow
Node* ptr = _end;
bool fail = false;
while (ptr != _begin) {
if (ptr->is_Call() && ctrl_path.member(ptr)) {
ptr = ptr->in(0);
} else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
ptr = ptr->in(0)->in(0)->in(0);
assert(ctrl_path.member(ptr), "should be a known piece of control");
} else if (ptr->is_IfTrue()) {
IfNode* iff = ptr->in(0)->as_If();
BoolNode* b = iff->in(1)->isa_Bool();
if (b == NULL) {
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print_cr("unexpected input to IfNode");
iff->in(1)->dump();
tty->cr();
}
#endif
fail = true;
break;
}
Node* cmp = b->in(1);
Node* v1 = cmp->in(1);
Node* v2 = cmp->in(2);
Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
// Null check of the return of append which can simply be eliminated
if (b->_test._test == BoolTest::ne &&
v2->bottom_type() == TypePtr::NULL_PTR &&
v1->is_Proj() && ctrl_path.member(v1->in(0))) {
// NULL check of the return value of the append
null_check_count++;
if (otherproj->outcnt() == 1) {
CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
ctrl_path.push(call);
}
}
_control.push(ptr);
ptr = ptr->in(0)->in(0);
continue;
}
// A test which leads to an uncommon trap which should be safe.
// Later this trap will be converted into a trap that restarts
// at the beginning.
if (otherproj->outcnt() == 1) {
CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
// control flow leads to uct so should be ok
_uncommon_traps.push(call);
ctrl_path.push(call);
ptr = ptr->in(0)->in(0);
continue;
}
}
#ifndef PRODUCT
// Some unexpected control flow we don't know how to handle.
if (PrintOptimizeStringConcat) {
tty->print_cr("failing with unknown test");
b->dump();
cmp->dump();
v1->dump();
v2->dump();
tty->cr();
}
#endif
fail = true;
break;
} else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
ptr = ptr->in(0)->in(0);
} else if (ptr->is_Region()) {
Node* copy = ptr->as_Region()->is_copy();
if (copy != NULL) {
ptr = copy;
continue;
}
if (ptr->req() == 3 &&
ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
// Simple diamond.
// XXX should check for possibly merging stores. simple data merges are ok.
// The IGVN will make this simple diamond go away when it
// transforms the Region. Make sure it sees it.
Compile::current()->record_for_igvn(ptr);
ptr = ptr->in(1)->in(0)->in(0);
continue;
}
#ifndef PRODUCT
if (PrintOptimizeStringConcat) {
tty->print_cr("fusion would fail for region");