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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
// Defines the class "ValueNumStore", which maintains value numbers for a compilation.
// Recall that "value numbering" assigns an integer value number to each expression. The "value
// number property" is that two expressions with the same value number will evaluate to the same value
// at runtime. Expressions with different value numbers may or may not be equivalent. This property
// of value numbers has obvious applications in redundancy-elimination optimizations.
//
// Since value numbers give us a way of talking about the (immutable) values to which expressions
// evaluate, they provide a good "handle" to use for attributing properties to values. For example,
// we might note that some value number represents some particular integer constant -- which has obvious
// application to constant propagation. Or that we know the exact type of some object reference,
// which might be used in devirtualization.
//
// Finally, we will also use value numbers to express control-flow-dependent assertions. Some test may
// imply that after the test, something new is known about a value: that an object reference is non-null
// after a dereference (since control flow continued because no exception was thrown); that an integer value
// is restricted to some subrange in after a comparison test; etc.
/*****************************************************************************/
#ifndef _VALUENUM_H_
#define _VALUENUM_H_
/*****************************************************************************/
#include "vartype.h"
// For "GT_COUNT"
#include "gentree.h"
// Defines the type ValueNum.
#include "valuenumtype.h"
// A "ValueNumStore" represents the "universe" of value numbers used in a single
// compilation.
// All members of the enumeration genTreeOps are also members of VNFunc.
// (Though some of these may be labeled "illegal").
enum VNFunc
{
// Implicitly, elements of genTreeOps here.
VNF_Boundary = GT_COUNT,
#define ValueNumFuncDef(nm, arity, commute, knownNonNull, sharedStatic) VNF_##nm,
#include "valuenumfuncs.h"
VNF_COUNT
};
// Given an "oper" and associated flags with it, transform the oper into a
// more accurate oper that can be used in evaluation. For example, (GT_ADD, unsigned)
// transforms to GT_ADD_UN.
VNFunc GetVNFuncForOper(genTreeOps oper, bool isUnsigned);
// An instance of this struct represents an application of the function symbol
// "m_func" to the first "m_arity" (<= 4) argument values in "m_args."
struct VNFuncApp
{
VNFunc m_func;
unsigned m_arity;
ValueNum m_args[4];
bool Equals(const VNFuncApp& funcApp)
{
if (m_func != funcApp.m_func) return false;
if (m_arity != funcApp.m_arity) return false;
for (unsigned i = 0; i < m_arity; i++)
{
if (m_args[i] != funcApp.m_args[i]) return false;
}
return true;
}
};
// A unique prefix character to use when dumping a tree's gtVN in the tree dumps
// We use this together with string concatenation to put this in printf format strings
// static const char* const VN_DumpPrefix = "$";
#define STR_VN "$"
class ValueNumStore
{
public:
// We will reserve "max unsigned" to represent "not a value number", for maps that might start uninitialized.
static const ValueNum NoVN = UINT32_MAX;
// A second special value, used to indicate that a function evaluation would cause infinite recursion.
static const ValueNum RecursiveVN = UINT32_MAX-1;
// ==================================================================================================
// VNMap - map from something to ValueNum, where something is typically a constant value or a VNFunc
// This class has two purposes - to abstract the implementation and to validate the ValueNums
// being stored or retrieved.
template <class fromType, class keyfuncs=LargePrimitiveKeyFuncs<fromType>>
class VNMap : public SimplerHashTable<fromType, keyfuncs, ValueNum, DefaultSimplerHashBehavior>
{
public:
VNMap(IAllocator* alloc) : SimplerHashTable<fromType, keyfuncs, ValueNum, DefaultSimplerHashBehavior>(alloc) {}
~VNMap()
{
~VNMap<fromType, keyfuncs>::SimplerHashTable();
}
bool Set(fromType k, ValueNum val)
{
assert(val != RecursiveVN);
return SimplerHashTable<fromType, keyfuncs, ValueNum, DefaultSimplerHashBehavior>::Set(k, val);
}
bool Lookup(fromType k, ValueNum* pVal = NULL) const
{
bool result = SimplerHashTable<fromType, keyfuncs, ValueNum, DefaultSimplerHashBehavior>::Lookup(k, pVal);
assert(!result || *pVal != RecursiveVN);
return result;
}
};
private:
Compiler* m_pComp;
// For allocations. (Other things?)
IAllocator* m_alloc;
// TODO-Cleanup: should transform "attribs" into a struct with bit fields. That would be simpler...
enum VNFOpAttrib
{
VNFOA_IllegalGenTreeOp = 0x1, // corresponds to a genTreeOps value that is not a legal VN func.
VNFOA_Commutative = 0x2, // 1 iff the function is commutative.
VNFOA_Arity = 0x4, // Bits 2..3 encode the arity.
VNFOA_AfterArity = 0x20, // Makes it clear what value the next flag(s) after Arity should have.
VNFOA_KnownNonNull = 0x20, // 1 iff the result is known to be non-null.
VNFOA_SharedStatic = 0x40, // 1 iff this VNF is represent one of the shared static jit helpers
};
static const unsigned VNFOA_ArityShift = 2;
static const unsigned VNFOA_ArityBits = 3;
static const unsigned VNFOA_MaxArity = (1 << VNFOA_ArityBits) - 1; // Max arity we can represent.
static const unsigned VNFOA_ArityMask = VNFOA_AfterArity - VNFOA_Arity;
// These enum constants are used to encode the cast operation in the lowest bits by VNForCastOper
enum VNFCastAttrib
{
VCA_UnsignedSrc = 0x01,
VCA_BitCount = 1, // the number of reserved bits
VCA_ReservedBits = 0x01, // i.e. (VCA_UnsignedSrc)
};
// An array of length GT_COUNT, mapping genTreeOp values to their VNFOpAttrib.
static UINT8* s_vnfOpAttribs;
// Returns "true" iff gtOper is a legal value number function.
// (Requires InitValueNumStoreStatics to have been run.)
static bool GenTreeOpIsLegalVNFunc(genTreeOps gtOper);
// Returns "true" iff "vnf" is a commutative (and thus binary) operator.
// (Requires InitValueNumStoreStatics to have been run.)
static bool VNFuncIsCommutative(VNFunc vnf);
// Returns "true" iff "vnf" is a comparison (and thus binary) operator.
static bool VNFuncIsComparison(VNFunc vnf);
// Returns "true" iff "vnf" can be evaluated for constant arguments.
static bool CanEvalForConstantArgs(VNFunc vnf);
// return vnf(v0)
template<typename T>
static T EvalOp(VNFunc vnf, T v0);
// If vnf(v0, v1) would raise an exception, sets *pExcSet to the singleton set containing the exception, and returns (T)0.
// Otherwise, returns vnf(v0, v1).
template<typename T>
T EvalOp(VNFunc vnf, T v0, T v1, ValueNum* pExcSet);
template<typename T>
static int EvalComparison(VNFunc vnf, T v0, T v1);
template<typename T>
static int EvalOrderedComparisonFloat(VNFunc vnf, T v0, T v1);
// return vnf(v0) or vnf(v0, v1), respectively (must, of course be unary/binary ops, respectively.)
// Should only be instantiated for integral types.
template<typename T>
static T EvalOpIntegral(VNFunc vnf, T v0);
template<typename T>
T EvalOpIntegral(VNFunc vnf, T v0, T v1, ValueNum* pExcSet);
// Should only instantiate (in a non-trivial way) for "int" and "INT64". Returns true iff dividing "v0" by "v1"
// would produce integer overflow (an ArithmeticException -- *not* division by zero, which is separate.)
template<typename T>
static bool IsOverflowIntDiv(T v0, T v1);
// Should only instantiate (in a non-trivial way) for integral types (signed/unsigned int32/int64).
// Returns true iff v is the zero of the appropriate type.
template<typename T>
static bool IsIntZero(T v);
// Given an constant value number return its value.
int GetConstantInt32(ValueNum argVN);
INT64 GetConstantInt64(ValueNum argVN);
double GetConstantDouble(ValueNum argVN);
// Assumes that all the ValueNum arguments of each of these functions have been shown to represent constants.
// Assumes that "vnf" is a operator of the appropriate arity (unary for the first, binary for the second).
// Assume that "CanEvalForConstantArgs(vnf)" is true.
// Returns the result of evaluating the function with those constant arguments.
ValueNum EvalFuncForConstantArgs(var_types typ, VNFunc vnf, ValueNum vn0);
ValueNum EvalFuncForConstantArgs(var_types typ, VNFunc vnf, ValueNum vn0, ValueNum vn1);
ValueNum EvalFuncForConstantFPArgs(var_types typ, VNFunc vnf, ValueNum vn0, ValueNum vn1);
ValueNum EvalCastForConstantArgs(var_types typ, VNFunc vnf, ValueNum vn0, ValueNum vn1);
#ifdef DEBUG
// This helps test some performance pathologies related to "evaluation" of VNF_MapSelect terms,
// especially relating to the heap. We count the number of applications of such terms we consider,
// and if this exceeds a limit, indicated by a COMPLUS_ variable, we assert.
unsigned m_numMapSels;
#endif
// This is the maximum number of MapSelect terms that can be "considered" as part of evaluation of a top-level MapSelect
// application.
unsigned m_mapSelectBudget;
public:
// Initializes any static variables of ValueNumStore.
static void InitValueNumStoreStatics();
// Initialize an empty ValueNumStore.
ValueNumStore(Compiler* comp, IAllocator* allocator);
// Returns "true" iff "vnf" (which may have been created by a cast from an integral value) represents
// a legal value number function.
// (Requires InitValueNumStoreStatics to have been run.)
static bool VNFuncIsLegal(VNFunc vnf)
{
return unsigned(vnf) > VNF_Boundary || GenTreeOpIsLegalVNFunc(static_cast<genTreeOps>(vnf));
}
// Returns the arity of "vnf".
static unsigned VNFuncArity(VNFunc vnf);
// Requires "gtOper" to be a genTreeOps legally representing a VNFunc, and returns that
// VNFunc.
// (Requires InitValueNumStoreStatics to have been run.)
static VNFunc GenTreeOpToVNFunc(genTreeOps gtOper)
{
assert(GenTreeOpIsLegalVNFunc(gtOper));
return static_cast<VNFunc>(gtOper);
}
#ifdef DEBUG
static void RunTests(Compiler* comp);
#endif // DEBUG
// This block of methods gets value numbers for constants of primitive types.
ValueNum VNForIntCon(INT32 cnsVal);
ValueNum VNForLongCon(INT64 cnsVal);
ValueNum VNForFloatCon(float cnsVal);
ValueNum VNForDoubleCon(double cnsVal);
ValueNum VNForByrefCon(INT64 byrefVal);
#ifdef _TARGET_64BIT_
ValueNum VNForPtrSizeIntCon(INT64 cnsVal) { return VNForLongCon(cnsVal); }
#else
ValueNum VNForPtrSizeIntCon(INT32 cnsVal) { return VNForIntCon(cnsVal); }
#endif
ValueNum VNForCastOper(var_types castToType, bool srcIsUnsigned = false);
// We keep handle values in a separate pool, so we don't confuse a handle with an int constant
// that happens to be the same...
ValueNum VNForHandle(ssize_t cnsVal, unsigned iconFlags);
// And the single constant for an object reference type.
static ValueNum VNForNull()
{
// We reserve Chunk 0 for "special" VNs. SRC_Null (== 0) is the VN of "null".
return ValueNum(SRC_Null);
}
// The zero map is the map that returns a zero "for the appropriate type" when indexed at any index.
static ValueNum VNForZeroMap()
{
// We reserve Chunk 0 for "special" VNs. Let SRC_ZeroMap (== 1) be the zero map.
return ValueNum(SRC_ZeroMap);
}
// The value number for the special "NotAField" field sequence.
static ValueNum VNForNotAField()
{
// We reserve Chunk 0 for "special" VNs. Let SRC_NotAField (== 2) be the "not a field seq".
return ValueNum(SRC_NotAField);
}
// The ROH map is the map for the "read-only heap". We assume that this is never mutated, and always
// has the same value number.
static ValueNum VNForROH()
{
// We reserve Chunk 0 for "special" VNs. Let SRC_ReadOnlyHeap (== 3) be the read-only heap.
return ValueNum(SRC_ReadOnlyHeap);
}
// A special value number for "void" -- sometimes a type-void thing is an argument to a
// GT_LIST, and we want the args to be non-NoVN.
static ValueNum VNForVoid()
{
// We reserve Chunk 0 for "special" VNs. Let SRC_Void (== 4) be the value for "void".
return ValueNum(SRC_Void);
}
static ValueNumPair VNPForVoid()
{
return ValueNumPair(VNForVoid(), VNForVoid());
}
// A special value number for the empty set of exceptions.
static ValueNum VNForEmptyExcSet()
{
// We reserve Chunk 0 for "special" VNs. Let SRC_EmptyExcSet (== 5) be the value for the empty set of exceptions.
return ValueNum(SRC_EmptyExcSet);
}
static ValueNumPair VNPForEmptyExcSet()
{
return ValueNumPair(VNForEmptyExcSet(), VNForEmptyExcSet());
}
// Returns the value number for zero of the given "typ".
// It has an unreached() for a "typ" that has no zero value, such as TYP_BYREF.
ValueNum VNZeroForType(var_types typ);
// Returns the value number for one of the given "typ".
// It returns NoVN for a "typ" that has no one value, such as TYP_REF.
ValueNum VNOneForType(var_types typ);
// Return the value number representing the singleton exception set containing the exception value "x".
ValueNum VNExcSetSingleton(ValueNum x);
ValueNumPair VNPExcSetSingleton(ValueNumPair x);
// Returns the VN representing the union of the two exception sets "xs0" and "xs1".
// These must be VNForEmtpyExcSet() or applications of VNF_ExcSetCons, obeying
// the ascending order invariant (which is preserved in the result.)
ValueNum VNExcSetUnion(ValueNum xs0, ValueNum xs1 DEBUG_ARG(bool topLevel = true));
ValueNumPair VNPExcSetUnion(ValueNumPair xs0vnp, ValueNumPair xs1vnp);
// Returns "true" iff "vn" is an application of "VNF_ValWithExc".
bool VNHasExc(ValueNum vn)
{
VNFuncApp funcApp;
return GetVNFunc(vn, &funcApp) && funcApp.m_func == VNF_ValWithExc;
}
// Requires that "vn" is *not* a "VNF_ValWithExc" appliation.
// If vn "excSet" is not "VNForEmptyExcSet()", return "VNF_ValWithExc(vn, excSet)". Otherwise,
// just return "vn".
ValueNum VNWithExc(ValueNum vn, ValueNum excSet);
ValueNumPair VNPWithExc(ValueNumPair vnp, ValueNumPair excSetVNP);
// If "vnWx" is a "VNF_ValWithExc(normal, excSet)" application, sets "*pvn" to "normal", and
// "*pvnx" to "excSet". Otherwise, just sets "*pvn" to "normal".
void VNUnpackExc(ValueNum vnWx, ValueNum* pvn, ValueNum* pvnx);
void VNPUnpackExc(ValueNumPair vnWx, ValueNumPair* pvn, ValueNumPair* pvnx);
// If "vn" is a "VNF_ValWithExc(norm, excSet)" value, returns the "norm" argument; otherwise,
// just returns "vn".
ValueNum VNNormVal(ValueNum vn);
ValueNumPair VNPNormVal(ValueNumPair vn);
// If "vn" is a "VNF_ValWithExc(norm, excSet)" value, returns the "excSet" argument; otherwise,
// just returns "EmptyExcSet()".
ValueNum VNExcVal(ValueNum vn);
ValueNumPair VNPExcVal(ValueNumPair vn);
// True "iff" vn is a value known to be non-null. (For example, the result of an allocation...)
bool IsKnownNonNull(ValueNum vn);
// True "iff" vn is a value returned by a call to a shared static helper.
bool IsSharedStatic(ValueNum vn);
// VN's for functions of other values.
// Four overloads, for arities 0, 1, 2, and 3. If we need other arities, we'll consider it.
ValueNum VNForFunc(var_types typ, VNFunc func);
ValueNum VNForFunc(var_types typ, VNFunc func, ValueNum opVNwx);
// This must not be used for VNF_MapSelect applications; instead use VNForMapSelect, below.
ValueNum VNForFunc(var_types typ, VNFunc func, ValueNum op1VNwx, ValueNum op2VNwx);
ValueNum VNForFunc(var_types typ, VNFunc func, ValueNum op1VNwx, ValueNum op2VNwx, ValueNum op3VNwx);
// The following four op VNForFunc is only used for VNF_PtrToArrElem, elemTypeEqVN, arrVN, inxVN, fldSeqVN
ValueNum VNForFunc(var_types typ, VNFunc func, ValueNum op1VNwx, ValueNum op2VNwx, ValueNum op3VNwx, ValueNum op4VNwx);
// This requires a "ValueNumKind" because it will attempt, given "select(phi(m1, ..., mk), ind)", to evaluate
// "select(m1, ind)", ..., "select(mk, ind)" to see if they agree. It needs to know which kind of value number
// (liberal/conservative) to read from the SSA def referenced in the phi argument.
ValueNum VNForMapSelect(ValueNumKind vnk, var_types typ, ValueNum op1VN, ValueNum op2VN);
// A method that does the work for VNForMapSelect and may call itself recursively.
ValueNum VNForMapSelectWork(ValueNumKind vnk,
var_types typ,
ValueNum op1VN,
ValueNum op2VN,
unsigned* pBudget,
bool* pUsedRecursiveVN);
// A specialized version of VNForFunc that is used for VNF_MapStore and provides some logging when verbose is set
ValueNum VNForMapStore(var_types typ, ValueNum arg0VN, ValueNum arg1VN, ValueNum arg2VN);
// These functions parallel the ones above, except that they take liberal/conservative VN pairs
// as arguments, and return such a pair (the pair of the function applied to the liberal args, and
// the function applied to the conservative args).
ValueNumPair VNPairForFunc(var_types typ, VNFunc func)
{
ValueNumPair res;
res.SetBoth(VNForFunc(typ, func));
return res;
}
ValueNumPair VNPairForFunc(var_types typ, VNFunc func, ValueNumPair opVN)
{
return ValueNumPair(VNForFunc(typ, func, opVN.GetLiberal()),
VNForFunc(typ, func, opVN.GetConservative()));
}
ValueNumPair VNPairForFunc(var_types typ, VNFunc func, ValueNumPair op1VN, ValueNumPair op2VN)
{
return ValueNumPair(VNForFunc(typ, func, op1VN.GetLiberal(), op2VN.GetLiberal()),
VNForFunc(typ, func, op1VN.GetConservative(), op2VN.GetConservative()));
}
ValueNumPair VNPairForFunc(var_types typ, VNFunc func, ValueNumPair op1VN, ValueNumPair op2VN, ValueNumPair op3VN)
{
return ValueNumPair(VNForFunc(typ, func, op1VN.GetLiberal(), op2VN.GetLiberal(), op3VN.GetLiberal()),
VNForFunc(typ, func, op1VN.GetConservative(), op2VN.GetConservative(), op3VN.GetConservative()));
}
ValueNumPair VNPairForFunc(var_types typ, VNFunc func, ValueNumPair op1VN, ValueNumPair op2VN, ValueNumPair op3VN, ValueNumPair op4VN)
{
return ValueNumPair(VNForFunc(typ, func, op1VN.GetLiberal(), op2VN.GetLiberal(), op3VN.GetLiberal(), op4VN.GetLiberal()),
VNForFunc(typ, func, op1VN.GetConservative(), op2VN.GetConservative(), op3VN.GetConservative(), op4VN.GetConservative()));
}
// Get a new, unique value number for an expression that we're not equating to some function.
ValueNum VNForExpr(var_types typ = TYP_UNKNOWN);
// This controls extra tracing of the "evaluation" of "VNF_MapSelect" functions.
#define FEATURE_VN_TRACE_APPLY_SELECTORS 1
// Return the value number corresponding to constructing "MapSelect(map, f0)", where "f0" is the
// (value number of) the first field in "fieldSeq". (The type of this application will be the type of "f0".)
// If there are no remaining fields in "fieldSeq", return that value number; otherwise, return VNApplySelectors
// applied to that value number and the remainder of "fieldSeq". When the 'fieldSeq' specifies a TYP_STRUCT
// then the size of the struct is returned by 'wbFinalStructSize' (when it is non-null)
ValueNum VNApplySelectors(ValueNumKind vnk, ValueNum map, FieldSeqNode* fieldSeq, size_t* wbFinalStructSize = nullptr);
// Used after VNApplySelectors has determined that "selectedVN" is contained in a Map using VNForMapSelect
// It determines whether the 'selectedVN' is of an appropriate type to be read using and indirection of 'indType'
// If it is appropriate type then 'selectedVN' is returned, otherwise it may insert a cast to indType
// or return a unique value number for an incompatible indType.
ValueNum VNApplySelectorsTypeCheck(ValueNum selectedVN, var_types indType, size_t structSize);
// Assumes that "map" represents a map that is addressable by the fields in "fieldSeq", to get
// to a value of the type of "rhs". Returns an expression for the RHS of an assignment to a location
// containing value "map" that will change the field addressed by "fieldSeq" to "rhs", leaving all other
// indices in "map" the same.
ValueNum VNApplySelectorsAssign(ValueNumKind vnk, ValueNum map, FieldSeqNode* fieldSeq, ValueNum rhs, var_types indType);
// Used after VNApplySelectorsAssign has determined that "elem" is to be writen into a Map using VNForMapStore
// It determines whether the 'elem' is of an appropriate type to be writen using using an indirection of 'indType'
// It may insert a cast to indType or return a unique value number for an incompatible indType.
ValueNum VNApplySelectorsAssignTypeCoerce(ValueNum elem, var_types indType);
ValueNumPair VNPairApplySelectors(ValueNumPair map, FieldSeqNode* fieldSeq, var_types indType);
ValueNumPair VNPairApplySelectorsAssign(ValueNumPair map, FieldSeqNode* fieldSeq, ValueNumPair rhs, var_types indType)
{
return ValueNumPair(VNApplySelectorsAssign(VNK_Liberal, map.GetLiberal(), fieldSeq, rhs.GetLiberal(), indType),
VNApplySelectorsAssign(VNK_Conservative, map.GetConservative(), fieldSeq, rhs.GetConservative(), indType));
}
// Compute the normal ValueNumber for a cast with no exceptions
ValueNum VNForCast(ValueNum srcVN, var_types castToType, var_types castFromType,
bool srcIsUnsigned = false);
// Compute the ValueNumberPair for a cast
ValueNumPair VNPairForCast(ValueNumPair srcVNPair, var_types castToType, var_types castFromType,
bool srcIsUnsigned = false,
bool hasOverflowCheck = false);
// PtrToLoc values need to express a field sequence as one of their arguments. VN for null represents
// empty sequence, otherwise, "FieldSeq(VN(FieldHandle), restOfSeq)".
ValueNum VNForFieldSeq(FieldSeqNode* fieldSeq);
// Requires that "vn" represents a field sequence, that is, is the result of a call to VNForFieldSeq.
// Returns the FieldSequence it represents.
FieldSeqNode* FieldSeqVNToFieldSeq(ValueNum vn);
// Both argument must represent field sequences; returns the value number representing the
// concatenation "fsVN1 || fsVN2".
ValueNum FieldSeqVNAppend(ValueNum fsVN1, ValueNum fsVN2);
// Requires "lclVarVN" be a value number for a GT_LCL_VAR pointer tree.
// Requires "fieldSeqVN" be a field sequence value number.
// Requires "typ" to be a TYP_REF/TYP_BYREF used for VNF_PtrToLoc.
// When "fieldSeqVN" is VNForNotAField, a unique VN is generated using m_uPtrToLocNotAFieldCount.
ValueNum VNForPtrToLoc(var_types typ, ValueNum lclVarVN, ValueNum fieldSeqVN);
// If "opA" has a PtrToLoc, PtrToArrElem, or PtrToStatic application as its value numbers, and "opB" is an integer with
// a "fieldSeq", returns the VN for the pointer form extended with the field sequence; or else NoVN.
ValueNum ExtendPtrVN(GenTreePtr opA, GenTreePtr opB);
// If "opA" has a PtrToLoc, PtrToArrElem, or PtrToStatic application as its value numbers, returns the VN for the pointer form
// extended with "fieldSeq"; or else NoVN.
ValueNum ExtendPtrVN(GenTreePtr opA, FieldSeqNode* fieldSeq);
// Queries on value numbers.
// All queries taking value numbers require that those value numbers are valid, that is, that
// they have been returned by previous "VNFor..." operations. They can assert false if this is
// not true.
// Returns TYP_UNKNOWN if the given value number has not been given a type.
var_types TypeOfVN(ValueNum vn);
// Returns true iff the VN represents a (non-handle) constant.
bool IsVNConstant(ValueNum vn);
// Returns true iff the VN represents an integeral constant.
bool IsVNInt32Constant(ValueNum vn);
struct ArrLenArithBoundInfo
{
// (vnArr.len - 1) > vnOp
// (vnArr.len arrOper arrOp) cmpOper cmpOp
ValueNum vnArray;
unsigned arrOper;
ValueNum arrOp;
unsigned cmpOper;
ValueNum cmpOp;
ArrLenArithBoundInfo()
: vnArray(NoVN)
, arrOper(GT_NONE)
, arrOp(NoVN)
, cmpOper(GT_NONE)
, cmpOp(NoVN)
{
}
#ifdef DEBUG
void dump(ValueNumStore* vnStore)
{
vnStore->vnDump(vnStore->m_pComp, cmpOp);
printf(" ");
printf(vnStore->VNFuncName((VNFunc) cmpOper));
printf(" ");
vnStore->vnDump(vnStore->m_pComp, vnArray);
if (arrOper != GT_NONE)
{
printf(vnStore->VNFuncName((VNFunc) arrOper));
vnStore->vnDump(vnStore->m_pComp, arrOp);
}
}
#endif
};
struct ConstantBoundInfo
{
// 100 > vnOp
int constVal;
unsigned cmpOper;
ValueNum cmpOpVN;
ConstantBoundInfo()
: constVal(0)
, cmpOper(GT_NONE)
, cmpOpVN(NoVN)
{
}
#ifdef DEBUG
void dump(ValueNumStore* vnStore)
{
vnStore->vnDump(vnStore->m_pComp, cmpOpVN);
printf(" ");
printf(vnStore->VNFuncName((VNFunc)cmpOper));
printf(" ");
printf("%d", constVal);
}
#endif
};
// Check if "vn" is "new [] (type handle, size)"
bool IsVNNewArr(ValueNum vn, VNFuncApp* funcApp);
// Check if "vn" IsVNNewArr and return <= 0 if arr size cannot be determined, else array size.
int GetNewArrSize(ValueNum vn);
// Check if "vn" is "a.len"
bool IsVNArrLen(ValueNum vn);
// If "vn" is VN(a.len) then return VN(a); NoVN if VN(a) can't be determined.
ValueNum GetArrForLenVn(ValueNum vn);
// Return true with any Relop except for == and != and one operand has to be a 32-bit integer constant.
bool IsVNConstantBound(ValueNum vn);
// If "vn" is constant bound, then populate the "info" fields for constVal, cmpOp, cmpOper.
void GetConstantBoundInfo(ValueNum vn, ConstantBoundInfo* info);
// If "vn" is of the form "var < a.len" or "a.len <= var" return true.
bool IsVNArrLenBound(ValueNum vn);
// If "vn" is arr len bound, then populate the "info" fields for the arrVn, cmpOp, cmpOper.
void GetArrLenBoundInfo(ValueNum vn, ArrLenArithBoundInfo* info);
// If "vn" is of the form "a.len +/- var" return true.
bool IsVNArrLenArith(ValueNum vn);
// If "vn" is arr len arith, then populate the "info" fields for arrOper, arrVn, arrOp.
void GetArrLenArithInfo(ValueNum vn, ArrLenArithBoundInfo* info);
// If "vn" is of the form "var < a.len +/- k" return true.
bool IsVNArrLenArithBound(ValueNum vn);
// If "vn" is arr len arith bound, then populate the "info" fields for cmpOp, cmpOper.
void GetArrLenArithBoundInfo(ValueNum vn, ArrLenArithBoundInfo* info);
// Returns the flags on the current handle. GTF_ICON_SCOPE_HDL for example.
unsigned GetHandleFlags(ValueNum vn);
// Returns true iff the VN represents a handle constant.
bool IsVNHandle(ValueNum vn);
// Convert a vartype_t to the value number's storage type for that vartype_t.
// For example, ValueNum of type TYP_LONG are stored in a map of INT64 variables.
// Lang is the language (C++) type for the corresponding vartype_t.
template <int N>
struct VarTypConv { };
private:
struct Chunk;
template <typename T>
static T CoerceTypRefToT(Chunk* c, unsigned offset);
// Get the actual value and coerce the actual type c->m_typ to the wanted type T.
template <typename T>
FORCEINLINE T SafeGetConstantValue(Chunk* c, unsigned offset);
template<typename T>
T ConstantValueInternal(ValueNum vn DEBUGARG(bool coerce))
{
Chunk* c = m_chunks.GetNoExpand(GetChunkNum(vn));
assert(c->m_attribs == CEA_Const || c->m_attribs == CEA_Handle);
unsigned offset = ChunkOffset(vn);
switch (c->m_typ)
{
case TYP_REF:
assert(0 <= offset && offset <= 1); // Null or exception.
__fallthrough;
case TYP_BYREF:
#ifndef PLATFORM_UNIX
assert(&typeid(T) == &typeid(size_t)); // We represent ref/byref constants as size_t's.
#endif // PLATFORM_UNIX
__fallthrough;
case TYP_INT:
case TYP_LONG:
case TYP_FLOAT:
case TYP_DOUBLE:
if (c->m_attribs == CEA_Handle)
{
C_ASSERT(offsetof(VNHandle, m_cnsVal) == 0);
return (T) reinterpret_cast<VNHandle*>(c->m_defs)[offset].m_cnsVal;
}
#ifdef DEBUG
if (!coerce)
{
T val1 = reinterpret_cast<T*>(c->m_defs)[offset];
T val2 = SafeGetConstantValue<T>(c, offset);
// Detect if there is a mismatch between the VN storage type and explicitly
// passed-in type T.
bool mismatch = false;
if (varTypeIsFloating(c->m_typ))
{
mismatch = (memcmp(&val1, &val2, sizeof(val1)) != 0);
}
else
{
mismatch = (val1 != val2);
}
if (mismatch)
{
assert(!"Called ConstantValue<T>(vn), but type(T) != type(vn); Use CoercedConstantValue instead.");
}
}
#endif
return SafeGetConstantValue<T>(c, offset);
default:
assert(false); // We do not record constants of this typ.
return (T)0;
}
}
public:
// Requires that "vn" is a constant, and that its type is compatible with the explicitly passed
// type "T". Also, note that "T" has to have an accurate storage size of the TypeOfVN(vn).
template<typename T>
T ConstantValue(ValueNum vn)
{
return ConstantValueInternal<T>(vn DEBUGARG(false));
}
// Requires that "vn" is a constant, and that its type can be coerced to the explicitly passed
// type "T".
template<typename T>
T CoercedConstantValue(ValueNum vn)
{
return ConstantValueInternal<T>(vn DEBUGARG(true));
}
// Given a value number "vn", go through the list of VNs that are handles
// to find if it is present, if so, return "true", else "false."
bool IsHandle(ValueNum vn);
// Requires "mthFunc" to be an intrinsic math function (one of the allowable values for the "gtMath" field
// of a GenTreeMath node). For unary ops, return the value number for the application of this function to
// "arg0VN". For binary ops, return the value number for the application of this function to "arg0VN" and
// "arg1VN".
ValueNum EvalMathFuncUnary(var_types typ, CorInfoIntrinsics mthFunc, ValueNum arg0VN);
ValueNum EvalMathFuncBinary(var_types typ, CorInfoIntrinsics mthFunc, ValueNum arg0VN, ValueNum arg1VN);
ValueNumPair EvalMathFuncUnary(var_types typ, CorInfoIntrinsics mthFunc, ValueNumPair arg0VNP)
{
return ValueNumPair(EvalMathFuncUnary(typ, mthFunc, arg0VNP.GetLiberal()),
EvalMathFuncUnary(typ, mthFunc, arg0VNP.GetConservative()));
}
ValueNumPair EvalMathFuncBinary(var_types typ, CorInfoIntrinsics mthFunc, ValueNumPair arg0VNP, ValueNumPair arg1VNP)
{
return ValueNumPair(EvalMathFuncBinary(typ, mthFunc, arg0VNP.GetLiberal(), arg1VNP.GetLiberal()),
EvalMathFuncBinary(typ, mthFunc, arg0VNP.GetConservative(), arg1VNP.GetConservative()));
}
// Returns "true" iff "vn" represents a function application.
bool IsVNFunc(ValueNum vn);
// If "vn" represents a function application, returns "true" and set "*funcApp" to
// the function application it represents; otherwise, return "false."
bool GetVNFunc(ValueNum vn, VNFuncApp* funcApp);
// Requires that "vn" represents a "heap address" the sum of a "TYP_REF" value and some integer
// value. Returns the TYP_REF value.
ValueNum VNForRefInAddr(ValueNum vn);
// Returns "true" iff "vn" is a valid value number -- one that has been previously returned.
bool VNIsValid(ValueNum vn);
#ifdef DEBUG
// This controls whether we recursively call vnDump on function arguments.
#define FEATURE_VN_DUMP_FUNC_ARGS 0
// Prints, to standard out, a representation of "vn".
void vnDump(Compiler* comp, ValueNum vn, bool isPtr = false);
// Requires "fieldSeq" to be a field sequence VNFuncApp.
// Prints a representation (comma-separated list of field names) on standard out.
void vnDumpFieldSeq(Compiler* comp, VNFuncApp* fieldSeq, bool isHead);
// Requires "mapSelect" to be a map select VNFuncApp.
// Prints a representation of a MapSelect operation on standard out.
void vnDumpMapSelect(Compiler* comp, VNFuncApp* mapSelect);
// Requires "mapStore" to be a map store VNFuncApp.
// Prints a representation of a MapStore operation on standard out.
void vnDumpMapStore(Compiler* comp, VNFuncApp* mapStore);
// Returns the string name of "vnf".
static const char* VNFuncName(VNFunc vnf);
// Used in the implementation of the above.
static const char* VNFuncNameArr[];
// Returns the string name of "vn" when it is a reserved value number, nullptr otherwise
static const char* reservedName(ValueNum vn);
#endif // DEBUG
// Returns true if "vn" is a reserved value number
static bool isReservedVN(ValueNum);
#define VALUENUM_SUPPORT_MERGE 0
// If we're going to support the Merge operation, and do it right, we really need to use an entire
// egraph data structure, so that we can do congruence closure, and discover congruences implied
// by the eq-class merge.
#if VALUENUM_SUPPORT_MERGE
// It may be that we provisionally give two expressions distinct value numbers, then later discover
// that the values of the expressions are provably equal. We allow the two value numbers to be
// "merged" -- after the merge, they represent the same abstract value.
void MergeVNs(ValueNum vn1, ValueNum vn2);
#endif
private:
// We will allocate value numbers in "chunks". Each chunk will have the same type and "constness".
static const unsigned LogChunkSize = 6;
static const unsigned ChunkSize = 1 << LogChunkSize;
static const unsigned ChunkOffsetMask = ChunkSize - 1;
// A "ChunkNum" is a zero-based index naming a chunk in the Store, or else the special "NoChunk" value.
typedef UINT32 ChunkNum;
static const ChunkNum NoChunk = UINT32_MAX;
// Returns the ChunkNum of the Chunk that holds "vn" (which is required to be a valid
// value number, i.e., one returned by some VN-producing method of this class).
static ChunkNum GetChunkNum(ValueNum vn)
{
return vn >> LogChunkSize;
}
// Returns the offset of the given "vn" within its chunk.
static unsigned ChunkOffset(ValueNum vn)
{
return vn & ChunkOffsetMask;
}
// The base VN of the next chunk to be allocated. Should always be a multiple of ChunkSize.
ValueNum m_nextChunkBase;
DECLARE_TYPED_ENUM(ChunkExtraAttribs,BYTE)
{
CEA_None, // No extra attributes.
CEA_Const, // This chunk contains constant values.
CEA_Handle, // This chunk contains handle constants.
CEA_Func0, // Represents functions of arity 0.
CEA_Func1, // ...arity 1.
CEA_Func2, // ...arity 2.
CEA_Func3, // ...arity 3.
CEA_Func4, // ...arity 4.
CEA_Count
}
END_DECLARE_TYPED_ENUM(ChunkExtraAttribs,BYTE);
// A "Chunk" holds "ChunkSize" value numbers, starting at "m_baseVN". All of these share the same
// "m_typ" and "m_attribs". These properties determine the interpretation of "m_defs", as discussed below.
struct Chunk
{
// If "m_defs" is non-null, it is an array of size ChunkSize, whose element type is determined by the other members.
// The "m_numUsed" field indicates the number of elements of "m_defs" that are already consumed (the next one to allocate).
void* m_defs;
unsigned m_numUsed;
// The value number of the first VN in the chunk.
ValueNum m_baseVN;
// The common attributes of this chunk.
var_types m_typ;
ChunkExtraAttribs m_attribs;
// Initialize a chunk, starting at "*baseVN", for the given "typ" and "attribs" (using "alloc" for allocations).
// (Increments "*baseVN" by ChunkSize.)
Chunk(IAllocator* alloc, ValueNum* baseVN, var_types typ, ChunkExtraAttribs attribs);
// Requires that "m_numUsed < ChunkSize." Returns the offset of the allocated VN within the chunk; the
// actual VN is this added to the "m_baseVN" of the chunk.
unsigned AllocVN()
{
assert(m_numUsed < ChunkSize);
return m_numUsed++;
}
template <int N>
struct Alloc
{
typedef typename ValueNumStore::VarTypConv<N>::Type Type;
};
};
struct VNHandle: public KeyFuncsDefEquals<VNHandle>
{
ssize_t m_cnsVal;
unsigned m_flags;
// Don't use a constructor to use the default copy constructor for hashtable rehash.
static void Initialize(VNHandle* handle, ssize_t m_cnsVal, unsigned m_flags)
{
handle->m_cnsVal = m_cnsVal;
handle->m_flags = m_flags;
}
bool operator==(const VNHandle& y) const
{
return m_cnsVal == y.m_cnsVal && m_flags == y.m_flags;
}
static unsigned GetHashCode(const VNHandle& val)
{
return static_cast<unsigned>(val.m_cnsVal);
}
};
struct VNDefFunc0Arg
{
VNFunc m_func;
VNDefFunc0Arg(VNFunc func) : m_func(func) {}
VNDefFunc0Arg(): m_func(VNF_COUNT) {}
bool operator==(const VNDefFunc0Arg& y) const
{
return m_func == y.m_func;
}
};
struct VNDefFunc1Arg: public VNDefFunc0Arg
{
ValueNum m_arg0;
VNDefFunc1Arg(VNFunc func, ValueNum arg0) : VNDefFunc0Arg(func), m_arg0(arg0) {}
VNDefFunc1Arg(): VNDefFunc0Arg(), m_arg0(ValueNumStore::NoVN) {}
bool operator==(const VNDefFunc1Arg& y) const
{
return VNDefFunc0Arg::operator==(y) && m_arg0 == y.m_arg0;
}
};
struct VNDefFunc2Arg : public VNDefFunc1Arg
{
ValueNum m_arg1;
VNDefFunc2Arg(VNFunc func, ValueNum arg0, ValueNum arg1) : VNDefFunc1Arg(func, arg0), m_arg1(arg1) {}
VNDefFunc2Arg(): m_arg1(ValueNumStore::NoVN) {}
bool operator==(const VNDefFunc2Arg& y) const
{
return VNDefFunc1Arg::operator==(y) && m_arg1 == y.m_arg1;
}
};
struct VNDefFunc3Arg : public VNDefFunc2Arg
{
ValueNum m_arg2;
VNDefFunc3Arg(VNFunc func, ValueNum arg0, ValueNum arg1, ValueNum arg2) : VNDefFunc2Arg(func, arg0, arg1), m_arg2(arg2) {}
VNDefFunc3Arg() : m_arg2(ValueNumStore::NoVN) {}
bool operator==(const VNDefFunc3Arg& y) const
{
return VNDefFunc2Arg::operator==(y) && m_arg2 == y.m_arg2;
}
};
struct VNDefFunc4Arg : public VNDefFunc3Arg
{
ValueNum m_arg3;
VNDefFunc4Arg(VNFunc func, ValueNum arg0, ValueNum arg1, ValueNum arg2, ValueNum arg3) : VNDefFunc3Arg(func, arg0, arg1, arg2), m_arg3(arg3) {}
VNDefFunc4Arg() : m_arg3(ValueNumStore::NoVN) {}
bool operator==(const VNDefFunc4Arg& y) const
{
return VNDefFunc3Arg::operator==(y) && m_arg3 == y.m_arg3;
}
};
// When we evaluate "select(m, i)", if "m" is a the value of a phi definition, we look at
// all the values of the phi args, and see if doing the "select" on each of them yields identical
// results. If so, that is the result of the entire "select" form. We have to be careful, however,
// because phis may be recursive in the presence of loop structures -- the VN for the phi may be (or be
// part of the definition of) the VN's of some of the arguments. But there will be at least one
// argument that does *not* depend on the outer phi VN -- after all, we had to get into the loop somehow.
// So we have to be careful about breaking infinite recursion. We can ignore "recursive" results -- if all the
// non-recursive results are the same, the recursion indicates that the loop structure didn't alter the result.
// This stack represents the set of outer phis such that select(phi, ind) is being evaluated.
ExpandArrayStack<VNDefFunc2Arg> m_fixedPointMapSels;
#ifdef DEBUG
// Returns "true" iff "m_fixedPointMapSels" is non-empty, and it's top element is
// "select(map, index)".
bool FixedPointMapSelsTopHasValue(ValueNum map, ValueNum index);
#endif
// Returns true if "sel(map, ind)" is a member of "m_fixedPointMapSels".
bool SelectIsBeingEvaluatedRecursively(ValueNum map, ValueNum ind);
// This is a map from "chunk number" to the attributes of the chunk.
ExpandArrayStack<Chunk*> m_chunks;
// These entries indicate the current allocation chunk, if any, for a <var_types, ChunkExtraAttribs> pair.
// If the value is NoChunk, it indicates that there is no current allocation chunk for that pair, otherwise
// it is the index in "m_chunks" of a chunk with the given attributes, in which the next allocation should
// be attempted.
ChunkNum m_curAllocChunk[TYP_COUNT][CEA_Count];
// Returns a (pointer to a) chunk in which a new value number may be allocated.
Chunk* GetAllocChunk(var_types typ, ChunkExtraAttribs attribs);
// First, we need mechanisms for mapping from constants to value numbers.
// For small integers, we'll use an array.
static const int SmallIntConstMin = -1;
static const int SmallIntConstMax = 10;
static const unsigned SmallIntConstNum = SmallIntConstMax - SmallIntConstMin + 1;
static bool IsSmallIntConst(int i) { return SmallIntConstMin <= i && i <= SmallIntConstMax; }
ValueNum m_VNsForSmallIntConsts[SmallIntConstNum];
struct ValueNumList
{
ValueNum vn;
ValueNumList* next;
ValueNumList(const ValueNum& v, ValueNumList* n = NULL) : vn(v), next(n) { }
};
// Keeps track of value numbers that are integer constants and also handles (GTG_ICON_HDL_MASK.)
ValueNumList* m_intConHandles;
typedef VNMap<INT32> IntToValueNumMap;
IntToValueNumMap* m_intCnsMap;
IntToValueNumMap* GetIntCnsMap()
{
if (m_intCnsMap == NULL) m_intCnsMap = new (m_alloc) IntToValueNumMap(m_alloc);
return m_intCnsMap;
}
ValueNum GetVNForIntCon(INT32 cnsVal)
{
ValueNum res;
if (GetIntCnsMap()->Lookup(cnsVal, &res))
{
return res;
}
else
{
Chunk* c = GetAllocChunk(TYP_INT, CEA_Const);
unsigned offsetWithinChunk = c->AllocVN();
res = c->m_baseVN + offsetWithinChunk;
reinterpret_cast<INT32*>(c->m_defs)[offsetWithinChunk] = cnsVal;
GetIntCnsMap()->Set(cnsVal, res);
return res;
}
}
typedef VNMap<INT64> LongToValueNumMap;
LongToValueNumMap* m_longCnsMap;
LongToValueNumMap* GetLongCnsMap()
{
if (m_longCnsMap == NULL) m_longCnsMap = new (m_alloc) LongToValueNumMap(m_alloc);
return m_longCnsMap;
}
typedef VNMap<VNHandle, VNHandle> HandleToValueNumMap;
HandleToValueNumMap* m_handleMap;
HandleToValueNumMap* GetHandleMap()
{
if (m_handleMap == NULL) m_handleMap = new (m_alloc) HandleToValueNumMap(m_alloc);
return m_handleMap;
}
struct LargePrimitiveKeyFuncsFloat : public LargePrimitiveKeyFuncs<float>
{
static bool Equals(float x, float y)
{
return *(unsigned*) &x == *(unsigned*) &y;
}
};
typedef VNMap<float, LargePrimitiveKeyFuncsFloat> FloatToValueNumMap;
FloatToValueNumMap* m_floatCnsMap;
FloatToValueNumMap* GetFloatCnsMap()
{
if (m_floatCnsMap == NULL) m_floatCnsMap = new (m_alloc) FloatToValueNumMap(m_alloc);
return m_floatCnsMap;
}
// In the JIT we need to distinguish -0.0 and 0.0 for optimizations.
struct LargePrimitiveKeyFuncsDouble : public LargePrimitiveKeyFuncs<double>
{
static bool Equals(double x, double y)
{
return *(__int64*) &x == *(__int64*) &y;
}
};
typedef VNMap<double, LargePrimitiveKeyFuncsDouble> DoubleToValueNumMap;
DoubleToValueNumMap* m_doubleCnsMap;
DoubleToValueNumMap* GetDoubleCnsMap()
{
if (m_doubleCnsMap == NULL) m_doubleCnsMap = new (m_alloc) DoubleToValueNumMap(m_alloc);
return m_doubleCnsMap;
}
LongToValueNumMap* m_byrefCnsMap;
LongToValueNumMap* GetByrefCnsMap()
{
if (m_byrefCnsMap == NULL) m_byrefCnsMap = new (m_alloc) LongToValueNumMap(m_alloc);
return m_byrefCnsMap;
}
struct VNDefFunc0ArgKeyFuncs: public KeyFuncsDefEquals<VNDefFunc1Arg>
{
static unsigned GetHashCode(VNDefFunc1Arg val)
{
return (val.m_func << 24) + val.m_arg0;
}
};
typedef VNMap<VNFunc> VNFunc0ToValueNumMap;
VNFunc0ToValueNumMap* m_VNFunc0Map;
VNFunc0ToValueNumMap* GetVNFunc0Map()
{
if (m_VNFunc0Map == NULL) m_VNFunc0Map = new (m_alloc) VNFunc0ToValueNumMap(m_alloc);
return m_VNFunc0Map;
}
struct VNDefFunc1ArgKeyFuncs: public KeyFuncsDefEquals<VNDefFunc1Arg>
{
static unsigned GetHashCode(VNDefFunc1Arg val)
{
return (val.m_func << 24) + val.m_arg0;
}
};
typedef VNMap<VNDefFunc1Arg, VNDefFunc1ArgKeyFuncs> VNFunc1ToValueNumMap;
VNFunc1ToValueNumMap* m_VNFunc1Map;
VNFunc1ToValueNumMap* GetVNFunc1Map()
{
if (m_VNFunc1Map == NULL) m_VNFunc1Map = new (m_alloc) VNFunc1ToValueNumMap(m_alloc);
return m_VNFunc1Map;
}
struct VNDefFunc2ArgKeyFuncs: public KeyFuncsDefEquals<VNDefFunc2Arg>
{
static unsigned GetHashCode(VNDefFunc2Arg val)
{
return (val.m_func << 24) + (val.m_arg0 << 8) + val.m_arg1;
}
};
typedef VNMap<VNDefFunc2Arg, VNDefFunc2ArgKeyFuncs> VNFunc2ToValueNumMap;
VNFunc2ToValueNumMap* m_VNFunc2Map;
VNFunc2ToValueNumMap* GetVNFunc2Map()
{
if (m_VNFunc2Map == NULL) m_VNFunc2Map = new (m_alloc) VNFunc2ToValueNumMap(m_alloc);
return m_VNFunc2Map;
}
struct VNDefFunc3ArgKeyFuncs: public KeyFuncsDefEquals<VNDefFunc3Arg>
{
static unsigned GetHashCode(VNDefFunc3Arg val)
{
return (val.m_func << 24) + (val.m_arg0 << 16) + (val.m_arg1 << 8) + val.m_arg2;
}
};
typedef VNMap<VNDefFunc3Arg, VNDefFunc3ArgKeyFuncs> VNFunc3ToValueNumMap;
VNFunc3ToValueNumMap* m_VNFunc3Map;
VNFunc3ToValueNumMap* GetVNFunc3Map()
{
if (m_VNFunc3Map == NULL) m_VNFunc3Map = new (m_alloc) VNFunc3ToValueNumMap(m_alloc);
return m_VNFunc3Map;
}
struct VNDefFunc4ArgKeyFuncs: public KeyFuncsDefEquals<VNDefFunc4Arg>
{
static unsigned GetHashCode(VNDefFunc4Arg val)
{
return (val.m_func << 24) + (val.m_arg0 << 16) + (val.m_arg1 << 8) + val.m_arg2 + (val.m_arg3 << 12);
}
};
typedef VNMap<VNDefFunc4Arg, VNDefFunc4ArgKeyFuncs> VNFunc4ToValueNumMap;
VNFunc4ToValueNumMap* m_VNFunc4Map;
VNFunc4ToValueNumMap* GetVNFunc4Map()
{
if (m_VNFunc4Map == NULL) m_VNFunc4Map = new (m_alloc) VNFunc4ToValueNumMap(m_alloc);
return m_VNFunc4Map;
}
enum SpecialRefConsts
{
SRC_Null,
SRC_ZeroMap,
SRC_NotAField,
SRC_ReadOnlyHeap,
SRC_Void,
SRC_EmptyExcSet,
SRC_NumSpecialRefConsts
};
// Counter to keep track of all the unique not a field sequences that have been assigned to
// PtrToLoc, because the ptr was added to an offset that was not a field.
unsigned m_uPtrToLocNotAFieldCount;
// The "values" of special ref consts will be all be "null" -- their differing meanings will
// be carried by the distinct value numbers.
static class Object* s_specialRefConsts[SRC_NumSpecialRefConsts];
static class Object* s_nullConst;
};
template <>
struct ValueNumStore::VarTypConv<TYP_INT> { typedef INT32 Type; typedef int Lang; };
template <>
struct ValueNumStore::VarTypConv<TYP_FLOAT> { typedef INT32 Type; typedef float Lang; };
template <>
struct ValueNumStore::VarTypConv<TYP_LONG> { typedef INT64 Type; typedef INT64 Lang; };
template <>
struct ValueNumStore::VarTypConv<TYP_DOUBLE> { typedef INT64 Type; typedef double Lang; };
template <>
struct ValueNumStore::VarTypConv<TYP_BYREF> { typedef INT64 Type; typedef void* Lang; };
template <>
struct ValueNumStore::VarTypConv<TYP_REF> { typedef class Object* Type; typedef class Object* Lang; };
// Get the actual value and coerce the actual type c->m_typ to the wanted type T.
template <typename T>
FORCEINLINE T ValueNumStore::SafeGetConstantValue(Chunk* c, unsigned offset)
{
switch (c->m_typ)
{
case TYP_REF:
return CoerceTypRefToT<T>(c, offset);
case TYP_BYREF:
return static_cast<T>(reinterpret_cast<VarTypConv<TYP_BYREF>::Type*>(c->m_defs)[offset]);
case TYP_INT:
return static_cast<T>(reinterpret_cast<VarTypConv<TYP_INT>::Type*>(c->m_defs)[offset]);
case TYP_LONG:
return static_cast<T>(reinterpret_cast<VarTypConv<TYP_LONG>::Type*>(c->m_defs)[offset]);
case TYP_FLOAT:
return static_cast<T>(reinterpret_cast<VarTypConv<TYP_FLOAT>::Lang*>(c->m_defs)[offset]);
case TYP_DOUBLE:
return static_cast<T>(reinterpret_cast<VarTypConv<TYP_DOUBLE>::Lang*>(c->m_defs)[offset]);
default:
assert(false);
return (T)0;
}
}
// Inline functions.
// static
inline bool ValueNumStore::GenTreeOpIsLegalVNFunc(genTreeOps gtOper)
{
return (s_vnfOpAttribs[gtOper] & VNFOA_IllegalGenTreeOp) == 0;
}
// static
inline bool ValueNumStore::VNFuncIsCommutative(VNFunc vnf)
{
return (s_vnfOpAttribs[vnf] & VNFOA_Commutative) != 0;
}
inline bool ValueNumStore::VNFuncIsComparison(VNFunc vnf)
{
if (vnf >= VNF_Boundary) return false;
genTreeOps gtOp = genTreeOps(vnf);
return GenTree::OperIsCompare(gtOp) != 0;
}
template <>
inline size_t ValueNumStore::CoerceTypRefToT(Chunk* c, unsigned offset)
{
return reinterpret_cast<size_t>(reinterpret_cast<VarTypConv<TYP_REF>::Type*>(c->m_defs)[offset]);
}
template <typename T>
inline T ValueNumStore::CoerceTypRefToT(Chunk* c, unsigned offset)
{
noway_assert(sizeof(T) >= sizeof(VarTypConv<TYP_REF>::Type));
unreached();
}
/*****************************************************************************/
#endif // _VALUENUM_H_
/*****************************************************************************/
|