-
Notifications
You must be signed in to change notification settings - Fork 140
/
Copy pathCodeGenRA.cpp
3422 lines (3067 loc) · 136 KB
/
CodeGenRA.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) 2000, 2019 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at http://eclipse.org/legal/epl-2.0
* or the Apache License, Version 2.0 which accompanies this distribution
* and is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#include "codegen/CodeGenerator.hpp"
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <algorithm>
#include "codegen/BackingStore.hpp"
#include "codegen/CodeGenerator.hpp"
#include "codegen/CodeGenerator_inlines.hpp"
#include "env/FrontEnd.hpp"
#include "codegen/GCStackAtlas.hpp"
#include "codegen/Instruction.hpp"
#include "codegen/Linkage.hpp"
#include "codegen/Linkage_inlines.hpp"
#include "codegen/LinkageConventionsEnum.hpp"
#include "codegen/LiveReference.hpp"
#include "codegen/LiveRegister.hpp"
#include "codegen/Register.hpp"
#include "codegen/RegisterConstants.hpp"
#include "codegen/TreeEvaluator.hpp"
#include "compile/Compilation.hpp"
#include "control/Options.hpp"
#include "control/Options_inlines.hpp"
#include "env/CompilerEnv.hpp"
#include "env/IO.hpp"
#include "env/ObjectModel.hpp"
#include "env/StackMemoryRegion.hpp"
#include "env/TRMemory.hpp"
#include "il/AliasSetInterface.hpp"
#include "il/AutomaticSymbol.hpp"
#include "il/Block.hpp"
#include "il/DataTypes.hpp"
#include "il/ILOpCodes.hpp"
#include "il/ILOps.hpp"
#include "il/MethodSymbol.hpp"
#include "il/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/ParameterSymbol.hpp"
#include "il/ResolvedMethodSymbol.hpp"
#include "il/Symbol.hpp"
#include "il/SymbolReference.hpp"
#include "il/TreeTop.hpp"
#include "il/TreeTop_inlines.hpp"
#include "infra/Array.hpp"
#include "infra/Assert.hpp"
#include "infra/BitVector.hpp"
#include "infra/Cfg.hpp"
#include "infra/Flags.hpp"
#include "infra/Link.hpp"
#include "infra/List.hpp"
#include "infra/CfgEdge.hpp"
#include "infra/CfgNode.hpp"
#include "optimizer/Optimizations.hpp"
#include "optimizer/RegisterCandidate.hpp"
#include "optimizer/Structure.hpp"
#include "ras/Debug.hpp"
#define OPT_DETAILS "O^O CODE GENERATION: "
#define NUM_REGS_USED_BY_COMPLEX_OPCODES 3
namespace TR { class RealRegister; }
#if defined(DEBUG) || defined(PROD_WITH_ASSUMES)
void
OMR::CodeGenerator::checkForLiveRegisters(TR_LiveRegisters *liveRegisters)
{
TR_Debug * debug = self()->comp()->getDebug();
bool regsAreLive = false;
if (liveRegisters && liveRegisters->getFirstLiveRegister())
{
traceMsg(self()->comp(), "\n\n");
for (TR_LiveRegisterInfo *p = liveRegisters->getFirstLiveRegister(); p; p = p->getNext())
{
if (p->getNode())
traceMsg(self()->comp(), "Virtual register %s (for node [%s], ref count=%d) is live at end of method\n",
debug->getName(p->getRegister()), debug->getName(p->getNode()), p->getNode()->getReferenceCount());
else
traceMsg(self()->comp(), "Virtual register %s %p is live at end of method with node count %d\n", debug->getName(p->getRegister()), p->getRegister(), p->getNodeCount());
regsAreLive = true;
}
}
TR_ASSERT(!regsAreLive, "Virtual or real registers are live at end of method");
}
#endif
void
OMR::CodeGenerator::estimateRegisterPressure(TR::Node *node, int32_t ®isterPressure, int32_t &maxRegisterPressure, int32_t maxRegisters, TR_BitVector *valuesInGlobalRegs, bool isCold, vcount_t visitCount, TR::SymbolReference *symRef, bool &symRefIsLive, bool checkForIMuls, bool &vmThreadUsed)
{
if (node->getVisitCount() == visitCount)
{
node->setLocalIndex(node->getLocalIndex()-1);
if (node->getLocalIndex() == 0)
{
if (node->getOpCode().isLoadVar() &&
node->getSymbol()->isAutoOrParm() &&
valuesInGlobalRegs &&
valuesInGlobalRegs->get(node->getSymbolReference()->getReferenceNumber()))
{
//
// This node has already been counted in num registers live
//
}
else
{
if (!node->getOpCode().isLoadConst())
{
registerPressure--;
if ((node->getType().isInt64()) &&
self()->comp()->target().is32Bit())
registerPressure--;
}
if (node->getOpCode().isLoadVar() &&
node->getSymbolReference() == symRef)
{
symRefIsLive = false;
}
}
}
return;
}
node->setVisitCount(visitCount);
if (node->getReferenceCount() > 0)
node->setLocalIndex(node->getReferenceCount()-1);
else
node->setLocalIndex(0);
int32_t childCount;
for (childCount = node->getNumChildren()-1; childCount >= 0; childCount--)
self()->estimateRegisterPressure(node->getChild(childCount), registerPressure, maxRegisterPressure, maxRegisters, valuesInGlobalRegs, isCold, visitCount, symRef, symRefIsLive, checkForIMuls, vmThreadUsed);
bool highRegisterPressureOpCode = false;
if (node->getOpCode().isResolveCheck() ||
(node->getOpCode().isCall()) ||
node->getOpCodeValue() == TR::New ||
node->getOpCodeValue() == TR::newarray ||
node->getOpCodeValue() == TR::anewarray ||
node->getOpCodeValue() == TR::multianewarray ||
node->getOpCodeValue() == TR::MergeNew ||
node->getOpCodeValue() == TR::monent ||
node->getOpCodeValue() == TR::monexit ||
node->getOpCodeValue() == TR::checkcast ||
node->getOpCodeValue() == TR::instanceof ||
node->getOpCodeValue() == TR::arraycopy)
highRegisterPressureOpCode = true;
if (highRegisterPressureOpCode ||
node->getOpCodeValue() == TR::asynccheck)
vmThreadUsed = true;
// Allow these call-like opcodes in cold blocks
// as we can afford to spill in cold blocks
//
if (node->getLocalIndex() > 0)
{
if (node->getOpCode().isLoadVar() &&
node->getSymbol()->isAutoOrParm() &&
valuesInGlobalRegs &&
valuesInGlobalRegs->get(node->getSymbolReference()->getReferenceNumber()))
{
//
// This node has already been counted in num registers live
//
}
else
{
if (!node->getOpCode().isLoadConst())
{
bool gprCandidate = true;
TR::DataType dtype = node->getDataType();
if (dtype == TR::Float
|| dtype == TR::Double
#ifdef J9_PROJECT_SPECIFIC
|| dtype == TR::DecimalFloat
|| dtype == TR::DecimalDouble
|| dtype == TR::DecimalLongDouble
#endif
)
gprCandidate = false;
if (node->getDataType() == TR::Float
|| node->getDataType() == TR::Double
#ifdef J9_PROJECT_SPECIFIC
|| node->getDataType() == TR::DecimalFloat
|| node->getDataType() == TR::DecimalDouble
#endif
)
{
if (!gprCandidate)
registerPressure++;
}
#ifdef J9_PROJECT_SPECIFIC
else if (node->getDataType() == TR::DecimalLongDouble)
{
if (!gprCandidate)
registerPressure +=2;
}
#endif
else
{
if (gprCandidate)
{
registerPressure++;
if ((node->getType().isInt64()) &&
self()->comp()->target().is32Bit())
registerPressure++;
}
}
}
if (node->getOpCode().isLoadVar() &&
node->getSymbolReference() == symRef)
{
symRefIsLive = true;
}
if (!symRefIsLive)
{
//These opcodes result in high register usage
//
if (highRegisterPressureOpCode ||
((node->getType().isInt64()) &&
self()->comp()->target().is32Bit() &&
(node->getOpCode().isMul() ||
node->getOpCode().isDiv() ||
node->getOpCode().isRem() ||
node->getOpCode().isLeftShift() ||
node->getOpCode().isRightShift() ||
node->getOpCode().isBooleanCompare())))
{
if (!isCold)
{
if (registerPressure >= (maxRegisters - NUM_REGS_USED_BY_COMPLEX_OPCODES -1)) // Only allow if register pressure is known to be very low
{
maxRegisterPressure = maxRegisters;
}
}
}
else if (checkForIMuls &&
(node->getOpCode().isMul() ||
node->getOpCode().isDiv()))
{
if (!isCold)
{
maxRegisterPressure = maxRegisters;
}
}
else
{
if (registerPressure > maxRegisterPressure)
{
if (!isCold)
maxRegisterPressure = registerPressure;
}
}
}
}
}
}
int32_t
OMR::CodeGenerator::estimateRegisterPressure(TR::Block *block, vcount_t visitCount, int32_t maxStaticFrequency, int32_t maxFrequency, bool &vmThreadUsed, int32_t numGlobalRegs, TR_BitVector *valuesInGlobalRegs, TR::SymbolReference * symRef, bool checkForIMuls)
{
int32_t maxRegisterPressure = numGlobalRegs;
int32_t currRegisterPressure = numGlobalRegs;
block = block->startOfExtendedBlock();
TR::TreeTop *treeTop = block->getEntry()->getNextTreeTop();
bool isCold = false;
if (maxFrequency < 0)
{
maxFrequency = 0;
for (TR::CFGNode *node = self()->comp()->getFlowGraph()->getFirstNode(); node; node = node->getNext())
{
if (node->getFrequency() > maxFrequency)
maxFrequency = node->getFrequency();
}
}
//
// Use some measure for coldness
//
if (block->isCold() ||
((maxFrequency > 0) &&
(block->getFrequency()*100/maxFrequency < 20)))
isCold = true;
if (!isCold)
{
TR_BlockStructure *blockStructure = block->getStructureOf();
int32_t blockWeight = 1;
if (blockStructure &&
!block->isCold())
{
blockStructure->calculateFrequencyOfExecution(&blockWeight);
}
if ((maxStaticFrequency > 0) &&
(blockWeight*100/maxStaticFrequency < 20))
isCold = true;
}
bool symRefIsLive = false;
while (treeTop)
{
TR::Node *node = treeTop->getNode();
self()->estimateRegisterPressure(node, currRegisterPressure, maxRegisterPressure, self()->getMaximumNumbersOfAssignableGPRs(), valuesInGlobalRegs, isCold, visitCount, symRef, symRefIsLive, checkForIMuls, vmThreadUsed);
if (vmThreadUsed &&
(maxRegisterPressure >= self()->getMaximumNumbersOfAssignableGPRs()))
{
//dumpOptDetails("For global register candidate %d reg pressure reached limit %d at block_%d isCold %d maxFreq %d\n", rc->getSymbolReference()->getReferenceNumber(), maxRegisterPressure, liveBlockNum, isCold, maxFrequency);
break;
}
if (node->getOpCodeValue() == TR::BBStart)
{
if (!node->getBlock()->isExtensionOfPreviousBlock())
break;
//
// Use some measure for coldness
//
if (node->getBlock()->isCold() ||
((maxFrequency > 0) &&
(node->getBlock()->getFrequency()*100/maxFrequency < 20)))
isCold = true;
else
{
TR_BlockStructure *blockStructure = block->getStructureOf();
int32_t blockWeight = 1;
if (blockStructure &&
!block->isCold())
{
blockStructure->calculateFrequencyOfExecution(&blockWeight);
}
if ((maxStaticFrequency > 0) &&
(blockWeight*100/maxStaticFrequency < 20))
isCold = true;
else
isCold = false;
}
}
treeTop = treeTop->getNextTreeTop();
}
return maxRegisterPressure;
}
// Set the future use count on all registers, and keep track of what kind of registers
// need to be assigned.
//
TR_RegisterKinds
OMR::CodeGenerator::prepareRegistersForAssignment()
{
TR_Array<TR::Register *>& regArray=self()->getRegisterArray();
TR::Register *registerCursor;
TR_RegisterMask km, foundKindsMask = 0;
int i;
for (i=0; i < regArray.size(); i++)
{
registerCursor = regArray[i];
if (registerCursor->getKind() != TR_SSR)
registerCursor->setFutureUseCount(registerCursor->getTotalUseCount());
km = registerCursor->getKindAsMask();
if (!(foundKindsMask & km))
foundKindsMask |= km;
}
return TR_RegisterKinds(foundKindsMask);
}
TR_BackingStore *
OMR::CodeGenerator::allocateInternalPointerSpill(TR::AutomaticSymbol *pinningArrayPointer)
{
// Search for an existing free spill slot for this pinningArrayPointer
//
TR_BackingStore *spill = NULL;
for(auto i = self()->getInternalPointerSpillFreeList().begin(); i != self()->getInternalPointerSpillFreeList().end(); ++i)
{
if ((*i)->getSymbolReference()->getSymbol()->getAutoSymbol()->castToInternalPointerAutoSymbol()->getPinningArrayPointer() == pinningArrayPointer)
{
spill = *i;
_internalPointerSpillFreeList.remove(spill);
break;
}
}
// If there isn't an existing one, make a new one
//
if (!spill)
{
int32_t slot;
TR::AutomaticSymbol *spillSymbol =
TR::AutomaticSymbol::createInternalPointer(self()->trHeapMemory(),
TR::Address,
TR::Compiler->om.sizeofReferenceAddress(),
self()->fe());
spillSymbol->setSpillTempAuto();
spillSymbol->setPinningArrayPointer(pinningArrayPointer);
self()->comp()->getMethodSymbol()->addAutomatic(spillSymbol);
spill = new (self()->trHeapMemory()) TR_BackingStore(self()->comp()->getSymRefTab(), spillSymbol, 0);
slot = spill->getSymbolReference()->getCPIndex();
slot = (slot < 0) ? (-slot - 1) : slot;
self()->comp()->getJittedMethodSymbol()->getAutoSymRefs(slot).add(spill->getSymbolReference());
_allSpillList.push_front(spill);
}
spill->setIsOccupied();
return spill;
}
TR_BackingStore *
OMR::CodeGenerator::allocateSpill(bool containsCollectedReference, int32_t *offset, bool reuse)
{
return self()->allocateSpill((int32_t)(TR::Compiler->om.sizeofReferenceAddress()), containsCollectedReference, offset, reuse); // cast parameter explicitly
}
TR_BackingStore *
OMR::CodeGenerator::allocateSpill(int32_t dataSize, bool containsCollectedReference, int32_t *offset, bool reuse)
{
TR_ASSERT_FATAL(dataSize <= 16, "assertion failure");
TR_ASSERT_FATAL(!containsCollectedReference || (dataSize == TR::Compiler->om.sizeofReferenceAddress()), "assertion failure");
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\nallocateSpill(%d, %s, %s)", dataSize, containsCollectedReference? "collected":"uncollected", offset? "offset":"NULL");
if (offset && self()->comp()->getOption(TR_DisableHalfSlotSpills))
{
// Pretend the caller can't handle half-slot spills
*offset = 0;
offset = NULL;
}
TR_BackingStore *spill = NULL;
// mapStack will get confused if we put a 4-byte collected reference in an
// 8-byte spill temp. It will map the temp according to its GC map index
// multiplied by the size of a Java pointer, and that will only give it 4 bytes.
//
// TODO: Make mapStack smarter and support this in the GC maps.
//
bool try8ByteSpills = (dataSize < 16) && ((TR::Compiler->om.sizeofReferenceAddress() == 8) || !containsCollectedReference);
bool try16ByteSpills = (dataSize == 16);
if(reuse)
{
if (dataSize <= 4 && !self()->getSpill4FreeList().empty())
{
spill = self()->getSpill4FreeList().front();
self()->getSpill4FreeList().pop_front();
}
if (!spill && try8ByteSpills && !self()->getSpill8FreeList().empty())
{
spill = self()->getSpill8FreeList().front();
self()->getSpill8FreeList().pop_front();
}
if (!spill && try16ByteSpills && !self()->getSpill16FreeList().empty())
{
spill = self()->getSpill16FreeList().front();
self()->getSpill16FreeList().pop_front();
}
if (
(spill && self()->getTraceRAOption(TR_TraceRASpillTemps) && !performTransformation(self()->comp(), "O^O SPILL TEMPS: Reuse spill temp %s\n", self()->getDebug()->getName(spill->getSymbolReference()))))
{
// Discard the spill temp we popped and never use it again; allocate a
// new one instead, and later, where we would have returned this spill
// temp to the free list, we return the new one instead and continue
// using that one for future allocations.
//
// This approach was chosen because it tends to make lastOptTransformationIndex
// produce a smaller delta than if we had left the spill in the lists.
// TODO: Use the same size for the new spill temp so that it will be freed to
// the same list, thereby further reducing the delta.
//
spill = NULL;
}
}
TR::AutomaticSymbol *spillSymbol;
if (spill)
{
spillSymbol = spill->getSymbolReference()->getSymbol()->getAutoSymbol();
}
else
{
// Must allocate a new one
//
int spillSize = std::max(dataSize, static_cast<int32_t>(TR::Compiler->om.sizeofReferenceAddress()));
TR_ASSERT(4 <= spillSize && spillSize <= 16, "Spill temps should be between 4 and 16 bytes");
spillSymbol = TR::AutomaticSymbol::create(self()->trHeapMemory(),TR::NoType,spillSize);
spillSymbol->setSpillTempAuto();
self()->comp()->getMethodSymbol()->addAutomatic(spillSymbol);
spill = new (self()->trHeapMemory()) TR_BackingStore(self()->comp()->getSymRefTab(), spillSymbol, 0);
int32_t slot = spill->getSymbolReference()->getCPIndex();
slot = (slot < 0) ? (-slot - 1) : slot;
self()->comp()->getJittedMethodSymbol()->getAutoSymRefs(slot).add(spill->getSymbolReference());
_allSpillList.push_front(spill);
}
if (dataSize <= 4 && spillSymbol->getSize() == 8)
{
// We must only set the backing store half-occupied flags so that
// freeSpill will do the right thing.
//
if ( offset == NULL
|| spill->secondHalfIsOccupied()
|| !performTransformation(self()->comp(), "O^O HALF-SLOT SPILLS: Use second half of %s\n", self()->getDebug()->getName(spill->getSymbolReference())))
{
spill->setFirstHalfIsOccupied();
}
else
{
*offset = 4;
spill->setSecondHalfIsOccupied();
self()->getSpill4FreeList().push_front(spill);
}
}
else
{
spill->setIsOccupied();
}
if (containsCollectedReference && spillSymbol->getGCMapIndex() < 0)
{
spillSymbol->setGCMapIndex(self()->getStackAtlas()->assignGCIndex());
_collectedSpillList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> added to collectedSpillList");
}
spill->setContainsCollectedReference(containsCollectedReference);
TR_ASSERT(spill->isOccupied(), "assertion failure");
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\nallocateSpill returning (%s(%d%d), %d) ", self()->getDebug()->getName(spill->getSymbolReference()->getSymbol()), spill->firstHalfIsOccupied()?1:0, spill->secondHalfIsOccupied()?1:0, offset? *offset : 0);
return spill;
}
void
OMR::CodeGenerator::freeSpill(TR_BackingStore *spill, int32_t dataSize, int32_t offset)
{
TR_ASSERT(1 <= dataSize && dataSize <= 16, "assertion failure");
TR_ASSERT(offset == 0 || offset == 4, "assertion failure");
TR_ASSERT(dataSize + offset <= 16, "assertion failure");
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
{
traceMsg(self()->comp(), "\nfreeSpill(%s(%d%d), %d, %d, isLocked=%d)",
self()->getDebug()->getName(spill->getSymbolReference()->getSymbol()),
spill->firstHalfIsOccupied()?1:0,
spill->secondHalfIsOccupied()?1:0,
dataSize, offset, self()->isFreeSpillListLocked());
}
// Do not add a freed spill slot back onto the free list if the list is locked.
// This is to enforce re-use of the same spill slot for a virtual register
// while assigning non-linear control flow regions.
//
// However, we must still clear the occupied status of the temp.
//
bool updateFreeList = self()->isFreeSpillListLocked() ? false : true;
if (spill->getSymbolReference()->getSymbol()->getAutoSymbol()->isInternalPointer())
{
spill->setIsEmpty();
if (updateFreeList)
{
_internalPointerSpillFreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> Added to internalPointerSpillFreeList");
}
}
else if (dataSize <= 4 && spill->getSymbolReference()->getSymbol()->getSize() == 8)
{
if (offset == 0)
{
spill->setFirstHalfIsEmpty();
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> setFirstHalfIsEmpty");
}
else
{
TR_ASSERT(offset == 4, "assertion failure");
spill->setSecondHalfIsEmpty();
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> setSecondHalfIsEmpty");
}
if (spill->isEmpty())
{
TR_ASSERT(spill->isEmpty(), "assertion failure");
if (updateFreeList)
{
_spill4FreeList.remove(spill); // It may have been half-full before
_spill8FreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> moved to spill8FreeList");
}
}
else if (spill->firstHalfIsOccupied())
{
// TODO: Once every caller can cope with nonzero offsets, we should add first-half-occupied symbols into _spill4FreeList.
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> first half is still occupied; conservatively keeping out of spill4FreeList");
}
else
{
TR_ASSERT(spill->secondHalfIsOccupied(), "assertion failure");
if (updateFreeList)
{
// Half-free
_spill4FreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> moved to spill4FreeList");
}
}
}
else
{
spill->setIsEmpty();
if (updateFreeList)
{
if (spill->getSymbolReference()->getSymbol()->getSize() <= 4)
{
_spill4FreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> added to spill4FreeList");
}
else if (spill->getSymbolReference()->getSymbol()->getSize() == 8)
{
_spill8FreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> added to spill8FreeList");
}
else if (spill->getSymbolReference()->getSymbol()->getSize() == 16)
{
_spill16FreeList.push_front(spill);
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "\n -> added to spill16FreeList");
}
}
}
}
void
OMR::CodeGenerator::jettisonAllSpills()
{
if (self()->getTraceRAOption(TR_TraceRASpillTemps))
traceMsg(self()->comp(), "jettisonAllSpills: Clearing spill-temp freelists\n");
_spill4FreeList.clear();
_spill8FreeList.clear();
_spill16FreeList.clear();
_internalPointerSpillFreeList.clear();
}
TR::Register * OMR::CodeGenerator::allocateRegister(TR_RegisterKinds rk)
{
TR_ASSERT(rk != TR_SSR,"use allocatePseudoRegister for TR_SSR registers\n");
TR::Register * temp = new (self()->trHeapMemory()) TR::Register(rk);
self()->addAllocatedRegister(temp);
if (self()->getDebug())
self()->getDebug()->newRegister(temp);
return temp;
}
void
OMR::CodeGenerator::findAndFixCommonedReferences()
{
//
// TODO : Required to re-assess the feasibility of the spill
// strategy currently adopted at calls (potential GC points) where
// live references are stored in memory and restored when they need
// to be used. With register maps in place, the number of spills
// because of a call might possibly be reduced.
//
// When the above adjustment is made, it might be feasible for
// nodes to linked together across calls without necessarily incurring
// the cost of spilling the value (corresponding to the node)
// before a call. Might need to increase the strength of Local
// Dead Load Elimination in that case to perform linking of loads across
// calls.
//
//
if (debug("traceSpill"))
{
diagnostic("Start spilling at GC safe points\n");
self()->comp()->dumpMethodTrees("Trees before spilling");
}
self()->comp()->incVisitCount();
for (TR::TreeTop *tt = self()->comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
{
TR::Node *node = tt->getNode();
bool isSafePoint = node->canGCandReturn();
if (isSafePoint)
{
TR::Node *safePointNode;
if (node->getOpCodeValue() == TR::treetop ||
node->getOpCode().isResolveOrNullCheck())
{
safePointNode = node->getFirstChild();
}
else
{
safePointNode = node;
}
if (safePointNode->getVisitCount() != self()->comp()->getVisitCount())
{
// Remember the first available spill temp. Temps added to the available
// spill temp list by children of this node shouldn't be used to spill
// around this node, since the temp will have a new value stored before
// this treetop.
//
auto firstAvailableSpillTemp = _availableSpillTemps.begin();
// Find commoned references in the children of the safe point node.
// They must be spilled to temps to prepare for this possible GC.
//
self()->findCommonedReferences(safePointNode, tt);
// Now spill the live references to temps
//
if (!_liveReferenceList.empty())
{
self()->spillLiveReferencesToTemps(tt->getPrevTreeTop(), firstAvailableSpillTemp);
}
}
// Finally see if the safe point node itself is a commoned reference.
// If so, it will become a live reference for the next GC point.
//
if (node != safePointNode)
{
self()->findCommonedReferences(node, tt);
}
}
else
{
// Find commoned references in this tree.
//
self()->findCommonedReferences(node, tt);
}
}
if (debug("traceSpill"))
diagnostic("End spilling at GC safe points\n");
}
void
OMR::CodeGenerator::findCommonedReferences(TR::Node *node, TR::TreeTop *treeTop)
{
if (node->getVisitCount() == self()->comp()->getVisitCount())
return;
node->setVisitCount(self()->comp()->getVisitCount());
for (int32_t childCount = node->getNumChildren() - 1; childCount >= 0; childCount--)
{
TR::Node *child = node->getChild(childCount);
// Visit the children and add their children's references before adding
// them to the live reference list. This makes sure that the live reference
// list is kept in the order in which references must be processed.
//
if (child->getVisitCount() != self()->comp()->getVisitCount())
{
self()->findCommonedReferences(child, treeTop);
}
if (child->getDataType() == TR::Address &&
!child->getOpCode().isLoadConst() &&
child->getOpCodeValue() != TR::loadaddr)
{
TR::Symbol * sym = child->getOpCode().hasSymbolReference() ? child->getSymbol() : 0;
if (child->getReferenceCount() > 1)
{
// This is a reference that may be live across a possible GC
//
if (!sym || !sym->isNotCollected())
self()->processReference(child, node, treeTop);
}
else if (sym && sym->isSpillTempAuto())
{
// This is the only (and hence last) use of a spill temp so it can
// be released.
//
_availableSpillTemps.push_front(child->getSymbolReference());
if (debug("traceSpill"))
diagnostic("Release spill temp [%p] at node [%p]\n",child->getSymbolReference(),child);
}
}
}
}
void
OMR::CodeGenerator::processReference(TR::Node *reference, TR::Node *parent, TR::TreeTop *treeTop)
{
// The live reference list appender is used to add and remove elements from the
// live reference list, so that the list is maintained in the order in which
// elements are inserted.
//
// The list must be maintained in this order so that if both a parent and a
// child are in the live reference list, when it comes time to spill the
// original parent will be updated to reference the new copy of the child
// before a new copy of the parent is created.
//
auto iterator = _liveReferenceList.begin();
TR_LiveReference *cursor;
while (iterator != _liveReferenceList.end())
{
if ((*iterator)->getReferenceNode() == reference)
{
// if this is the last parent, then we have found all the parents of the
// reference and must remove this reference from the list because it can not
// be alive across any future calls that may be encountered.
if (reference->getReferenceCount() == (*iterator)->getNumberOfParents() + 1)
{
_liveReferenceList.erase(iterator);
// If this reference was to a spill temp, that temp can be freed
// up to be re-used
//
if (reference->getOpCode().hasSymbolReference())
{
TR::SymbolReference * symRef = reference->getSymbolReference();
if (symRef->getSymbol()->isSpillTempAuto())
{
_availableSpillTemps.push_front(symRef);
if (debug("traceSpill"))
diagnostic("Release spill temp [%p] at node [%p]\n",symRef,reference);
}
}
}
// otherwise we add it to the list so that we will be able to find it
// if it turns out to be alive across a GC safe point and we have to introduce
// a temp and fix up all the parents.
else
{
(*iterator)->addParentToList(parent);
self()->needSpillTemp(*iterator, parent, treeTop);
}
return;
}
++iterator;
}
cursor = new (self()->trHeapMemory()) TR_LiveReference(reference, parent, self()->trMemory());
_liveReferenceList.push_back(cursor);
self()->needSpillTemp(cursor, parent, treeTop);
}
void
OMR::CodeGenerator::spillLiveReferencesToTemps(TR::TreeTop *insertionTree, std::list<TR::SymbolReference*, TR::typed_allocator<TR::SymbolReference*, TR::Allocator> >::iterator firstAvailableSpillTemp)
{
if (debug("traceSpill") && !_liveReferenceList.empty())
diagnostic("Spill at GC safe node [%p]\n",insertionTree->getNextTreeTop()->getNode());
auto referenceIterator = _liveReferenceList.begin();
while (referenceIterator != _liveReferenceList.end())
{
TR::Node *originalReference = (*referenceIterator)->getReferenceNode();
// Find or allocate a spill temp.
// If the reference is to an existing spill temp there is no need to
// generate another store, we can just create another load after the
// GC point.
//
// If the reference is a simple load and the load is not killed before the
// first use after this GC point, there is no need for a spill temp, the
// original load can just be duplicated at the first use after this point.
//
// Otherwise pick up an available spill temp from the free list or create
// a new one.
bool storeSpillTemp = false;
TR::SymbolReference *tempSymRef = NULL;
if (originalReference->getOpCode().hasSymbolReference() &&
originalReference->getSymbol()->isSpillTempAuto())
{
tempSymRef = originalReference->getSymbolReference();
if (debug("traceSpill"))
diagnostic(" Re-use spill temp [%p] for reference [%p] without storing\n",tempSymRef,originalReference);
}
else if ((*referenceIterator)->needSpillTemp())
{
if (!_availableSpillTemps.empty())
{
tempSymRef = *firstAvailableSpillTemp;
firstAvailableSpillTemp = _availableSpillTemps.erase(firstAvailableSpillTemp);
if (debug("traceSpill"))
diagnostic(" Re-use available spill temp [%p] for reference [%p]\n",tempSymRef,originalReference);
}
else
{
int32_t slot;
TR::AutomaticSymbol *tempSym = TR::AutomaticSymbol::create(self()->trHeapMemory());
tempSym->setSize(TR::DataType::getSize(TR::Address));
tempSym->setSpillTempAuto();
tempSymRef = new (self()->trHeapMemory()) TR::SymbolReference(self()->comp()->getSymRefTab(), tempSym);
slot = tempSymRef->getCPIndex();
slot = (slot < 0) ? (-slot - 1) : slot;
self()->comp()->getJittedMethodSymbol()->getAutoSymRefs(slot).add(tempSymRef);
self()->comp()->getMethodSymbol()->addAutomatic(tempSym);
if (debug("traceSpill"))
diagnostic(" Create new spill temp [%p] for reference [%p]\n",tempSymRef,originalReference);
}
storeSpillTemp = true;
}
else
{
tempSymRef = NULL;
if (debug("traceSpill"))
diagnostic(" No need to spill live reference [%p]\n",originalReference);
}
// Create a copy of the reference for use by parents before the GC point.
// Reference count will be number of parents before the GC safe point; if
// there is a store to a spill temp the reference count will be incremented
// to take account of this extra reference.
//
TR::Node *newReference = TR::Node::copy(originalReference);
newReference->setReferenceCount((*referenceIterator)->getNumberOfParents());
// Go through the parent list changing them to point to the new reference
// node wherever they pointed to the original node
//
ListIterator<TR::Node> nodeIterator(&(*referenceIterator)->getParentList());
TR::Node *nodeCursor = nodeIterator.getFirst();
while (nodeCursor)
{
for (int32_t childCount = 0;
childCount < nodeCursor->getNumChildren();
++childCount)
{
if (nodeCursor->getChild(childCount) == originalReference)
{
nodeCursor->setChild(childCount, newReference);
}
}
nodeCursor = nodeIterator.getNext();
}
if (tempSymRef)
{
// There is a spill temp
// Store it before the GC point if necessary
//
if (storeSpillTemp)
{
// insert new TR::astore node into tree top list before the call
TR::TreeTop::create(self()->comp(), insertionTree, TR::Node::createWithSymRef(TR::astore, 1, 1, newReference, tempSymRef));
}
// Rewrite the original reference as an aload of the temp.
TR::Node::recreate(originalReference, TR::aload);
originalReference->setNumChildren(0);
originalReference->setSymbolReference(tempSymRef);
}
// The original reference is now only used by parents subsequent to the