aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm14/include/llvm/CodeGen/CodeGenPassBuilder.h
blob: 3664e90980583dc1f1fc546be2341647c51dfede (plain) (blame)
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
#pragma once

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

//===- Construction of codegen pass pipelines ------------------*- C++ -*--===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// Interfaces for registering analysis passes, producing common pass manager
/// configurations, and parsing of pass pipelines.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_CODEGENPASSBUILDER_H
#define LLVM_CODEGEN_CODEGENPASSBUILDER_H

#include "llvm/ADT/FunctionExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/CFLAndersAliasAnalysis.h"
#include "llvm/Analysis/CFLSteensAliasAnalysis.h"
#include "llvm/Analysis/ScopedNoAliasAA.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/TypeBasedAliasAnalysis.h"
#include "llvm/CodeGen/ExpandReductions.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachinePassManager.h"
#include "llvm/CodeGen/PreISelIntrinsicLowering.h"
#include "llvm/CodeGen/ReplaceWithVeclib.h"
#include "llvm/CodeGen/UnreachableBlockElim.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Verifier.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/CGPassBuilderOption.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Scalar/ConstantHoisting.h"
#include "llvm/Transforms/Scalar/LoopPassManager.h"
#include "llvm/Transforms/Scalar/LoopStrengthReduce.h"
#include "llvm/Transforms/Scalar/LowerConstantIntrinsics.h"
#include "llvm/Transforms/Scalar/MergeICmps.h"
#include "llvm/Transforms/Scalar/PartiallyInlineLibCalls.h"
#include "llvm/Transforms/Scalar/ScalarizeMaskedMemIntrin.h"
#include "llvm/Transforms/Utils.h"
#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
#include "llvm/Transforms/Utils/LowerInvoke.h"
#include <cassert>
#include <type_traits>
#include <utility>

namespace llvm {

// FIXME: Dummy target independent passes definitions that have not yet been
// ported to new pass manager. Once they do, remove these.
#define DUMMY_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)                      \
  struct PASS_NAME : public PassInfoMixin<PASS_NAME> {                         \
    template <typename... Ts> PASS_NAME(Ts &&...) {}                           \
    PreservedAnalyses run(Function &, FunctionAnalysisManager &) {             \
      return PreservedAnalyses::all();                                         \
    }                                                                          \
  };
#define DUMMY_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                        \
  struct PASS_NAME : public PassInfoMixin<PASS_NAME> {                         \
    template <typename... Ts> PASS_NAME(Ts &&...) {}                           \
    PreservedAnalyses run(Module &, ModuleAnalysisManager &) {                 \
      return PreservedAnalyses::all();                                         \
    }                                                                          \
  };
#define DUMMY_MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                \
  struct PASS_NAME : public PassInfoMixin<PASS_NAME> {                         \
    template <typename... Ts> PASS_NAME(Ts &&...) {}                           \
    Error run(Module &, MachineFunctionAnalysisManager &) {                    \
      return Error::success();                                                 \
    }                                                                          \
    PreservedAnalyses run(MachineFunction &,                                   \
                          MachineFunctionAnalysisManager &) {                  \
      llvm_unreachable("this api is to make new PM api happy");                \
    }                                                                          \
    static AnalysisKey Key;                                                    \
  };
#define DUMMY_MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)              \
  struct PASS_NAME : public PassInfoMixin<PASS_NAME> {                         \
    template <typename... Ts> PASS_NAME(Ts &&...) {}                           \
    PreservedAnalyses run(MachineFunction &,                                   \
                          MachineFunctionAnalysisManager &) {                  \
      return PreservedAnalyses::all();                                         \
    }                                                                          \
    static AnalysisKey Key;                                                    \
  };
#include "MachinePassRegistry.def"

/// This class provides access to building LLVM's passes.
///
/// Its members provide the baseline state available to passes during their
/// construction. The \c MachinePassRegistry.def file specifies how to construct
/// all of the built-in passes, and those may reference these members during
/// construction.
template <typename DerivedT> class CodeGenPassBuilder {
public:
  explicit CodeGenPassBuilder(LLVMTargetMachine &TM, CGPassBuilderOption Opts,
                              PassInstrumentationCallbacks *PIC)
      : TM(TM), Opt(Opts), PIC(PIC) {
    // Target could set CGPassBuilderOption::MISchedPostRA to true to achieve
    //     substitutePass(&PostRASchedulerID, &PostMachineSchedulerID)

    // Target should override TM.Options.EnableIPRA in their target-specific
    // LLVMTM ctor. See TargetMachine::setGlobalISel for example.
    if (Opt.EnableIPRA)
      TM.Options.EnableIPRA = *Opt.EnableIPRA;

    if (Opt.EnableGlobalISelAbort)
      TM.Options.GlobalISelAbort = *Opt.EnableGlobalISelAbort;

    if (!Opt.OptimizeRegAlloc)
      Opt.OptimizeRegAlloc = getOptLevel() != CodeGenOpt::None;
  }

  Error buildPipeline(ModulePassManager &MPM, MachineFunctionPassManager &MFPM,
                      raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
                      CodeGenFileType FileType) const;

  void registerModuleAnalyses(ModuleAnalysisManager &) const;
  void registerFunctionAnalyses(FunctionAnalysisManager &) const;
  void registerMachineFunctionAnalyses(MachineFunctionAnalysisManager &) const;
  std::pair<StringRef, bool> getPassNameFromLegacyName(StringRef) const;

  void registerAnalyses(MachineFunctionAnalysisManager &MFAM) const {
    registerModuleAnalyses(*MFAM.MAM);
    registerFunctionAnalyses(*MFAM.FAM);
    registerMachineFunctionAnalyses(MFAM);
  }

  PassInstrumentationCallbacks *getPassInstrumentationCallbacks() const {
    return PIC;
  }

protected:
  template <typename PassT> using has_key_t = decltype(PassT::Key);

  template <typename PassT>
  using is_module_pass_t = decltype(std::declval<PassT &>().run(
      std::declval<Module &>(), std::declval<ModuleAnalysisManager &>()));

  template <typename PassT>
  using is_function_pass_t = decltype(std::declval<PassT &>().run(
      std::declval<Function &>(), std::declval<FunctionAnalysisManager &>()));

  // Function object to maintain state while adding codegen IR passes.
  class AddIRPass {
  public:
    AddIRPass(ModulePassManager &MPM, bool DebugPM, bool Check = true)
        : MPM(MPM) {
      if (Check)
        AddingFunctionPasses = false;
    }
    ~AddIRPass() {
      MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
    }

    // Add Function Pass
    template <typename PassT>
    std::enable_if_t<is_detected<is_function_pass_t, PassT>::value>
    operator()(PassT &&Pass) {
      if (AddingFunctionPasses && !*AddingFunctionPasses)
        AddingFunctionPasses = true;
      FPM.addPass(std::forward<PassT>(Pass));
    }

    // Add Module Pass
    template <typename PassT>
    std::enable_if_t<is_detected<is_module_pass_t, PassT>::value &&
                     !is_detected<is_function_pass_t, PassT>::value>
    operator()(PassT &&Pass) {
      assert((!AddingFunctionPasses || !*AddingFunctionPasses) &&
             "could not add module pass after adding function pass");
      MPM.addPass(std::forward<PassT>(Pass));
    }

  private:
    ModulePassManager &MPM;
    FunctionPassManager FPM;
    // The codegen IR pipeline are mostly function passes with the exceptions of
    // a few loop and module passes. `AddingFunctionPasses` make sures that
    // we could only add module passes at the beginning of the pipeline. Once
    // we begin adding function passes, we could no longer add module passes.
    // This special-casing introduces less adaptor passes. If we have the need
    // of adding module passes after function passes, we could change the
    // implementation to accommodate that.
    Optional<bool> AddingFunctionPasses;
  };

  // Function object to maintain state while adding codegen machine passes.
  class AddMachinePass {
  public:
    AddMachinePass(MachineFunctionPassManager &PM) : PM(PM) {}

    template <typename PassT> void operator()(PassT &&Pass) {
      static_assert(
          is_detected<has_key_t, PassT>::value,
          "Machine function pass must define a static member variable `Key`.");
      for (auto &C : BeforeCallbacks)
        if (!C(&PassT::Key))
          return;
      PM.addPass(std::forward<PassT>(Pass));
      for (auto &C : AfterCallbacks)
        C(&PassT::Key);
    }

    template <typename PassT> void insertPass(AnalysisKey *ID, PassT Pass) {
      AfterCallbacks.emplace_back(
          [this, ID, Pass = std::move(Pass)](AnalysisKey *PassID) {
            if (PassID == ID)
              this->PM.addPass(std::move(Pass));
          });
    }

    void disablePass(AnalysisKey *ID) {
      BeforeCallbacks.emplace_back(
          [ID](AnalysisKey *PassID) { return PassID != ID; });
    }

    MachineFunctionPassManager releasePM() { return std::move(PM); }

  private:
    MachineFunctionPassManager &PM;
    SmallVector<llvm::unique_function<bool(AnalysisKey *)>, 4> BeforeCallbacks;
    SmallVector<llvm::unique_function<void(AnalysisKey *)>, 4> AfterCallbacks;
  };

  LLVMTargetMachine &TM;
  CGPassBuilderOption Opt;
  PassInstrumentationCallbacks *PIC;

  /// Target override these hooks to parse target-specific analyses.
  void registerTargetAnalysis(ModuleAnalysisManager &) const {}
  void registerTargetAnalysis(FunctionAnalysisManager &) const {}
  void registerTargetAnalysis(MachineFunctionAnalysisManager &) const {}
  std::pair<StringRef, bool> getTargetPassNameFromLegacyName(StringRef) const {
    return {"", false};
  }

  template <typename TMC> TMC &getTM() const { return static_cast<TMC &>(TM); }
  CodeGenOpt::Level getOptLevel() const { return TM.getOptLevel(); }

  /// Check whether or not GlobalISel should abort on error.
  /// When this is disabled, GlobalISel will fall back on SDISel instead of
  /// erroring out.
  bool isGlobalISelAbortEnabled() const {
    return TM.Options.GlobalISelAbort == GlobalISelAbortMode::Enable;
  }

  /// Check whether or not a diagnostic should be emitted when GlobalISel
  /// uses the fallback path. In other words, it will emit a diagnostic
  /// when GlobalISel failed and isGlobalISelAbortEnabled is false.
  bool reportDiagnosticWhenGlobalISelFallback() const {
    return TM.Options.GlobalISelAbort == GlobalISelAbortMode::DisableWithDiag;
  }

  /// addInstSelector - This method should install an instruction selector pass,
  /// which converts from LLVM code to machine instructions.
  Error addInstSelector(AddMachinePass &) const {
    return make_error<StringError>("addInstSelector is not overridden",
                                   inconvertibleErrorCode());
  }

  /// Add passes that optimize instruction level parallelism for out-of-order
  /// targets. These passes are run while the machine code is still in SSA
  /// form, so they can use MachineTraceMetrics to control their heuristics.
  ///
  /// All passes added here should preserve the MachineDominatorTree,
  /// MachineLoopInfo, and MachineTraceMetrics analyses.
  void addILPOpts(AddMachinePass &) const {}

  /// This method may be implemented by targets that want to run passes
  /// immediately before register allocation.
  void addPreRegAlloc(AddMachinePass &) const {}

  /// addPreRewrite - Add passes to the optimized register allocation pipeline
  /// after register allocation is complete, but before virtual registers are
  /// rewritten to physical registers.
  ///
  /// These passes must preserve VirtRegMap and LiveIntervals, and when running
  /// after RABasic or RAGreedy, they should take advantage of LiveRegMatrix.
  /// When these passes run, VirtRegMap contains legal physreg assignments for
  /// all virtual registers.
  ///
  /// Note if the target overloads addRegAssignAndRewriteOptimized, this may not
  /// be honored. This is also not generally used for the the fast variant,
  /// where the allocation and rewriting are done in one pass.
  void addPreRewrite(AddMachinePass &) const {}

  /// Add passes to be run immediately after virtual registers are rewritten
  /// to physical registers.
  void addPostRewrite(AddMachinePass &) const {}

  /// This method may be implemented by targets that want to run passes after
  /// register allocation pass pipeline but before prolog-epilog insertion.
  void addPostRegAlloc(AddMachinePass &) const {}

  /// This method may be implemented by targets that want to run passes after
  /// prolog-epilog insertion and before the second instruction scheduling pass.
  void addPreSched2(AddMachinePass &) const {}

  /// This pass may be implemented by targets that want to run passes
  /// immediately before machine code is emitted.
  void addPreEmitPass(AddMachinePass &) const {}

  /// Targets may add passes immediately before machine code is emitted in this
  /// callback. This is called even later than `addPreEmitPass`.
  // FIXME: Rename `addPreEmitPass` to something more sensible given its actual
  // position and remove the `2` suffix here as this callback is what
  // `addPreEmitPass` *should* be but in reality isn't.
  void addPreEmitPass2(AddMachinePass &) const {}

  /// {{@ For GlobalISel
  ///

  /// addPreISel - This method should add any "last minute" LLVM->LLVM
  /// passes (which are run just before instruction selector).
  void addPreISel(AddIRPass &) const {
    llvm_unreachable("addPreISel is not overridden");
  }

  /// This method should install an IR translator pass, which converts from
  /// LLVM code to machine instructions with possibly generic opcodes.
  Error addIRTranslator(AddMachinePass &) const {
    return make_error<StringError>("addIRTranslator is not overridden",
                                   inconvertibleErrorCode());
  }

  /// This method may be implemented by targets that want to run passes
  /// immediately before legalization.
  void addPreLegalizeMachineIR(AddMachinePass &) const {}

  /// This method should install a legalize pass, which converts the instruction
  /// sequence into one that can be selected by the target.
  Error addLegalizeMachineIR(AddMachinePass &) const {
    return make_error<StringError>("addLegalizeMachineIR is not overridden",
                                   inconvertibleErrorCode());
  }

  /// This method may be implemented by targets that want to run passes
  /// immediately before the register bank selection.
  void addPreRegBankSelect(AddMachinePass &) const {}

  /// This method should install a register bank selector pass, which
  /// assigns register banks to virtual registers without a register
  /// class or register banks.
  Error addRegBankSelect(AddMachinePass &) const {
    return make_error<StringError>("addRegBankSelect is not overridden",
                                   inconvertibleErrorCode());
  }

  /// This method may be implemented by targets that want to run passes
  /// immediately before the (global) instruction selection.
  void addPreGlobalInstructionSelect(AddMachinePass &) const {}

  /// This method should install a (global) instruction selector pass, which
  /// converts possibly generic instructions to fully target-specific
  /// instructions, thereby constraining all generic virtual registers to
  /// register classes.
  Error addGlobalInstructionSelect(AddMachinePass &) const {
    return make_error<StringError>(
        "addGlobalInstructionSelect is not overridden",
        inconvertibleErrorCode());
  }
  /// @}}

  /// High level function that adds all passes necessary to go from llvm IR
  /// representation to the MI representation.
  /// Adds IR based lowering and target specific optimization passes and finally
  /// the core instruction selection passes.
  void addISelPasses(AddIRPass &) const;

  /// Add the actual instruction selection passes. This does not include
  /// preparation passes on IR.
  Error addCoreISelPasses(AddMachinePass &) const;

  /// Add the complete, standard set of LLVM CodeGen passes.
  /// Fully developed targets will not generally override this.
  Error addMachinePasses(AddMachinePass &) const;

  /// Add passes to lower exception handling for the code generator.
  void addPassesToHandleExceptions(AddIRPass &) const;

  /// Add common target configurable passes that perform LLVM IR to IR
  /// transforms following machine independent optimization.
  void addIRPasses(AddIRPass &) const;

  /// Add pass to prepare the LLVM IR for code generation. This should be done
  /// before exception handling preparation passes.
  void addCodeGenPrepare(AddIRPass &) const;

  /// Add common passes that perform LLVM IR to IR transforms in preparation for
  /// instruction selection.
  void addISelPrepare(AddIRPass &) const;

  /// Methods with trivial inline returns are convenient points in the common
  /// codegen pass pipeline where targets may insert passes. Methods with
  /// out-of-line standard implementations are major CodeGen stages called by
  /// addMachinePasses. Some targets may override major stages when inserting
  /// passes is insufficient, but maintaining overriden stages is more work.
  ///

  /// addMachineSSAOptimization - Add standard passes that optimize machine
  /// instructions in SSA form.
  void addMachineSSAOptimization(AddMachinePass &) const;

  /// addFastRegAlloc - Add the minimum set of target-independent passes that
  /// are required for fast register allocation.
  Error addFastRegAlloc(AddMachinePass &) const;

  /// addOptimizedRegAlloc - Add passes related to register allocation.
  /// LLVMTargetMachine provides standard regalloc passes for most targets.
  void addOptimizedRegAlloc(AddMachinePass &) const;

  /// Add passes that optimize machine instructions after register allocation.
  void addMachineLateOptimization(AddMachinePass &) const;

  /// addGCPasses - Add late codegen passes that analyze code for garbage
  /// collection. This should return true if GC info should be printed after
  /// these passes.
  void addGCPasses(AddMachinePass &) const {}

  /// Add standard basic block placement passes.
  void addBlockPlacement(AddMachinePass &) const;

  using CreateMCStreamer =
      std::function<Expected<std::unique_ptr<MCStreamer>>(MCContext &)>;
  void addAsmPrinter(AddMachinePass &, CreateMCStreamer) const {
    llvm_unreachable("addAsmPrinter is not overridden");
  }

  /// Utilities for targets to add passes to the pass manager.
  ///

  /// createTargetRegisterAllocator - Create the register allocator pass for
  /// this target at the current optimization level.
  void addTargetRegisterAllocator(AddMachinePass &, bool Optimized) const;

  /// addMachinePasses helper to create the target-selected or overriden
  /// regalloc pass.
  void addRegAllocPass(AddMachinePass &, bool Optimized) const;

  /// Add core register alloator passes which do the actual register assignment
  /// and rewriting. \returns true if any passes were added.
  Error addRegAssignmentFast(AddMachinePass &) const;
  Error addRegAssignmentOptimized(AddMachinePass &) const;

private:
  DerivedT &derived() { return static_cast<DerivedT &>(*this); }
  const DerivedT &derived() const {
    return static_cast<const DerivedT &>(*this);
  }
};

template <typename Derived>
Error CodeGenPassBuilder<Derived>::buildPipeline(
    ModulePassManager &MPM, MachineFunctionPassManager &MFPM,
    raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
    CodeGenFileType FileType) const {
  AddIRPass addIRPass(MPM, Opt.DebugPM);
  addISelPasses(addIRPass);

  AddMachinePass addPass(MFPM);
  if (auto Err = addCoreISelPasses(addPass))
    return std::move(Err);

  if (auto Err = derived().addMachinePasses(addPass))
    return std::move(Err);

  derived().addAsmPrinter(
      addPass, [this, &Out, DwoOut, FileType](MCContext &Ctx) {
        return this->TM.createMCStreamer(Out, DwoOut, FileType, Ctx);
      });

  addPass(FreeMachineFunctionPass());
  return Error::success();
}

static inline AAManager registerAAAnalyses(CFLAAType UseCFLAA) {
  AAManager AA;

  // The order in which these are registered determines their priority when
  // being queried.

  switch (UseCFLAA) {
  case CFLAAType::Steensgaard:
    AA.registerFunctionAnalysis<CFLSteensAA>();
    break;
  case CFLAAType::Andersen:
    AA.registerFunctionAnalysis<CFLAndersAA>();
    break;
  case CFLAAType::Both:
    AA.registerFunctionAnalysis<CFLAndersAA>();
    AA.registerFunctionAnalysis<CFLSteensAA>();
    break;
  default:
    break;
  }

  // Basic AliasAnalysis support.
  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  // BasicAliasAnalysis wins if they disagree. This is intended to help
  // support "obvious" type-punning idioms.
  AA.registerFunctionAnalysis<TypeBasedAA>();
  AA.registerFunctionAnalysis<ScopedNoAliasAA>();
  AA.registerFunctionAnalysis<BasicAA>();

  return AA;
}

template <typename Derived>
void CodeGenPassBuilder<Derived>::registerModuleAnalyses(
    ModuleAnalysisManager &MAM) const {
#define MODULE_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR)                          \
  MAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
  derived().registerTargetAnalysis(MAM);
}

template <typename Derived>
void CodeGenPassBuilder<Derived>::registerFunctionAnalyses(
    FunctionAnalysisManager &FAM) const {
  FAM.registerPass([this] { return registerAAAnalyses(this->Opt.UseCFLAA); });

#define FUNCTION_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR)                        \
  FAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
  derived().registerTargetAnalysis(FAM);
}

template <typename Derived>
void CodeGenPassBuilder<Derived>::registerMachineFunctionAnalyses(
    MachineFunctionAnalysisManager &MFAM) const {
#define MACHINE_FUNCTION_ANALYSIS(NAME, PASS_NAME, CONSTRUCTOR)                \
  MFAM.registerPass([&] { return PASS_NAME CONSTRUCTOR; });
#include "MachinePassRegistry.def"
  derived().registerTargetAnalysis(MFAM);
}

// FIXME: For new PM, use pass name directly in commandline seems good.
// Translate stringfied pass name to its old commandline name. Returns the
// matching legacy name and a boolean value indicating if the pass is a machine
// pass.
template <typename Derived>
std::pair<StringRef, bool>
CodeGenPassBuilder<Derived>::getPassNameFromLegacyName(StringRef Name) const {
  std::pair<StringRef, bool> Ret;
  if (Name.empty())
    return Ret;

#define FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)                            \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, false};
#define DUMMY_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)                      \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, false};
#define MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                              \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, false};
#define DUMMY_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                        \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, false};
#define MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                      \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, true};
#define DUMMY_MACHINE_MODULE_PASS(NAME, PASS_NAME, CONSTRUCTOR)                \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, true};
#define MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)                    \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, true};
#define DUMMY_MACHINE_FUNCTION_PASS(NAME, PASS_NAME, CONSTRUCTOR)              \
  if (Name == NAME)                                                            \
    Ret = {#PASS_NAME, true};
#include "llvm/CodeGen/MachinePassRegistry.def"

  if (Ret.first.empty())
    Ret = derived().getTargetPassNameFromLegacyName(Name);

  if (Ret.first.empty())
    report_fatal_error(Twine('\"') + Twine(Name) +
                       Twine("\" pass could not be found."));

  return Ret;
}

template <typename Derived>
void CodeGenPassBuilder<Derived>::addISelPasses(AddIRPass &addPass) const {
  if (TM.useEmulatedTLS())
    addPass(LowerEmuTLSPass());

  addPass(PreISelIntrinsicLoweringPass());

  derived().addIRPasses(addPass);
  derived().addCodeGenPrepare(addPass);
  addPassesToHandleExceptions(addPass);
  derived().addISelPrepare(addPass);
}

/// Add common target configurable passes that perform LLVM IR to IR transforms
/// following machine independent optimization.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addIRPasses(AddIRPass &addPass) const {
  // Before running any passes, run the verifier to determine if the input
  // coming from the front-end and/or optimizer is valid.
  if (!Opt.DisableVerify)
    addPass(VerifierPass());

  // Run loop strength reduction before anything else.
  if (getOptLevel() != CodeGenOpt::None && !Opt.DisableLSR) {
    addPass(createFunctionToLoopPassAdaptor(
        LoopStrengthReducePass(), /*UseMemorySSA*/ true, Opt.DebugPM));
    // FIXME: use -stop-after so we could remove PrintLSR
    if (Opt.PrintLSR)
      addPass(PrintFunctionPass(dbgs(), "\n\n*** Code after LSR ***\n"));
  }

  if (getOptLevel() != CodeGenOpt::None) {
    // The MergeICmpsPass tries to create memcmp calls by grouping sequences of
    // loads and compares. ExpandMemCmpPass then tries to expand those calls
    // into optimally-sized loads and compares. The transforms are enabled by a
    // target lowering hook.
    if (!Opt.DisableMergeICmps)
      addPass(MergeICmpsPass());
    addPass(ExpandMemCmpPass());
  }

  // Run GC lowering passes for builtin collectors
  // TODO: add a pass insertion point here
  addPass(GCLoweringPass());
  addPass(ShadowStackGCLoweringPass());
  addPass(LowerConstantIntrinsicsPass());

  // Make sure that no unreachable blocks are instruction selected.
  addPass(UnreachableBlockElimPass());

  // Prepare expensive constants for SelectionDAG.
  if (getOptLevel() != CodeGenOpt::None && !Opt.DisableConstantHoisting)
    addPass(ConstantHoistingPass());

  // Replace calls to LLVM intrinsics (e.g., exp, log) operating on vector
  // operands with calls to the corresponding functions in a vector library.
  if (getOptLevel() != CodeGenOpt::None)
    addPass(ReplaceWithVeclib());

  if (getOptLevel() != CodeGenOpt::None && !Opt.DisablePartialLibcallInlining)
    addPass(PartiallyInlineLibCallsPass());

  // Instrument function entry and exit, e.g. with calls to mcount().
  addPass(EntryExitInstrumenterPass(/*PostInlining=*/true));

  // Add scalarization of target's unsupported masked memory intrinsics pass.
  // the unsupported intrinsic will be replaced with a chain of basic blocks,
  // that stores/loads element one-by-one if the appropriate mask bit is set.
  addPass(ScalarizeMaskedMemIntrinPass());

  // Expand reduction intrinsics into shuffle sequences if the target wants to.
  addPass(ExpandReductionsPass());
}

/// Turn exception handling constructs into something the code generators can
/// handle.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addPassesToHandleExceptions(
    AddIRPass &addPass) const {
  const MCAsmInfo *MCAI = TM.getMCAsmInfo();
  assert(MCAI && "No MCAsmInfo");
  switch (MCAI->getExceptionHandlingType()) {
  case ExceptionHandling::SjLj:
    // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both
    // Dwarf EH prepare needs to be run after SjLj prepare. Otherwise,
    // catch info can get misplaced when a selector ends up more than one block
    // removed from the parent invoke(s). This could happen when a landing
    // pad is shared by multiple invokes and is also a target of a normal
    // edge from elsewhere.
    addPass(SjLjEHPreparePass());
    LLVM_FALLTHROUGH;
  case ExceptionHandling::DwarfCFI:
  case ExceptionHandling::ARM:
  case ExceptionHandling::AIX:
    addPass(DwarfEHPass(getOptLevel()));
    break;
  case ExceptionHandling::WinEH:
    // We support using both GCC-style and MSVC-style exceptions on Windows, so
    // add both preparation passes. Each pass will only actually run if it
    // recognizes the personality function.
    addPass(WinEHPass());
    addPass(DwarfEHPass(getOptLevel()));
    break;
  case ExceptionHandling::Wasm:
    // Wasm EH uses Windows EH instructions, but it does not need to demote PHIs
    // on catchpads and cleanuppads because it does not outline them into
    // funclets. Catchswitch blocks are not lowered in SelectionDAG, so we
    // should remove PHIs there.
    addPass(WinEHPass(/*DemoteCatchSwitchPHIOnly=*/false));
    addPass(WasmEHPass());
    break;
  case ExceptionHandling::None:
    addPass(LowerInvokePass());

    // The lower invoke pass may create unreachable code. Remove it.
    addPass(UnreachableBlockElimPass());
    break;
  }
}

/// Add pass to prepare the LLVM IR for code generation. This should be done
/// before exception handling preparation passes.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addCodeGenPrepare(AddIRPass &addPass) const {
  if (getOptLevel() != CodeGenOpt::None && !Opt.DisableCGP)
    addPass(CodeGenPreparePass());
  // TODO: Default ctor'd RewriteSymbolPass is no-op.
  // addPass(RewriteSymbolPass());
}

/// Add common passes that perform LLVM IR to IR transforms in preparation for
/// instruction selection.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addISelPrepare(AddIRPass &addPass) const {
  derived().addPreISel(addPass);

  // Add both the safe stack and the stack protection passes: each of them will
  // only protect functions that have corresponding attributes.
  addPass(SafeStackPass());
  addPass(StackProtectorPass());

  if (Opt.PrintISelInput)
    addPass(PrintFunctionPass(dbgs(),
                              "\n\n*** Final LLVM Code input to ISel ***\n"));

  // All passes which modify the LLVM IR are now complete; run the verifier
  // to ensure that the IR is valid.
  if (!Opt.DisableVerify)
    addPass(VerifierPass());
}

template <typename Derived>
Error CodeGenPassBuilder<Derived>::addCoreISelPasses(
    AddMachinePass &addPass) const {
  // Enable FastISel with -fast-isel, but allow that to be overridden.
  TM.setO0WantsFastISel(Opt.EnableFastISelOption.getValueOr(true));

  // Determine an instruction selector.
  enum class SelectorType { SelectionDAG, FastISel, GlobalISel };
  SelectorType Selector;

  if (Opt.EnableFastISelOption && *Opt.EnableFastISelOption == true)
    Selector = SelectorType::FastISel;
  else if ((Opt.EnableGlobalISelOption &&
            *Opt.EnableGlobalISelOption == true) ||
           (TM.Options.EnableGlobalISel &&
            (!Opt.EnableGlobalISelOption ||
             *Opt.EnableGlobalISelOption == false)))
    Selector = SelectorType::GlobalISel;
  else if (TM.getOptLevel() == CodeGenOpt::None && TM.getO0WantsFastISel())
    Selector = SelectorType::FastISel;
  else
    Selector = SelectorType::SelectionDAG;

  // Set consistently TM.Options.EnableFastISel and EnableGlobalISel.
  if (Selector == SelectorType::FastISel) {
    TM.setFastISel(true);
    TM.setGlobalISel(false);
  } else if (Selector == SelectorType::GlobalISel) {
    TM.setFastISel(false);
    TM.setGlobalISel(true);
  }

  // Add instruction selector passes.
  if (Selector == SelectorType::GlobalISel) {
    if (auto Err = derived().addIRTranslator(addPass))
      return std::move(Err);

    derived().addPreLegalizeMachineIR(addPass);

    if (auto Err = derived().addLegalizeMachineIR(addPass))
      return std::move(Err);

    // Before running the register bank selector, ask the target if it
    // wants to run some passes.
    derived().addPreRegBankSelect(addPass);

    if (auto Err = derived().addRegBankSelect(addPass))
      return std::move(Err);

    derived().addPreGlobalInstructionSelect(addPass);

    if (auto Err = derived().addGlobalInstructionSelect(addPass))
      return std::move(Err);

    // Pass to reset the MachineFunction if the ISel failed.
    addPass(ResetMachineFunctionPass(reportDiagnosticWhenGlobalISelFallback(),
                                     isGlobalISelAbortEnabled()));

    // Provide a fallback path when we do not want to abort on
    // not-yet-supported input.
    if (!isGlobalISelAbortEnabled())
      if (auto Err = derived().addInstSelector(addPass))
        return std::move(Err);

  } else if (auto Err = derived().addInstSelector(addPass))
    return std::move(Err);

  // Expand pseudo-instructions emitted by ISel. Don't run the verifier before
  // FinalizeISel.
  addPass(FinalizeISelPass());

  // // Print the instruction selected machine code...
  // printAndVerify("After Instruction Selection");

  return Error::success();
}

/// Add the complete set of target-independent postISel code generator passes.
///
/// This can be read as the standard order of major LLVM CodeGen stages. Stages
/// with nontrivial configuration or multiple passes are broken out below in
/// add%Stage routines.
///
/// Any CodeGenPassBuilder<Derived>::addXX routine may be overriden by the
/// Target. The addPre/Post methods with empty header implementations allow
/// injecting target-specific fixups just before or after major stages.
/// Additionally, targets have the flexibility to change pass order within a
/// stage by overriding default implementation of add%Stage routines below. Each
/// technique has maintainability tradeoffs because alternate pass orders are
/// not well supported. addPre/Post works better if the target pass is easily
/// tied to a common pass. But if it has subtle dependencies on multiple passes,
/// the target should override the stage instead.
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addMachinePasses(
    AddMachinePass &addPass) const {
  // Add passes that optimize machine instructions in SSA form.
  if (getOptLevel() != CodeGenOpt::None) {
    derived().addMachineSSAOptimization(addPass);
  } else {
    // If the target requests it, assign local variables to stack slots relative
    // to one another and simplify frame index references where possible.
    addPass(LocalStackSlotPass());
  }

  if (TM.Options.EnableIPRA)
    addPass(RegUsageInfoPropagationPass());

  // Run pre-ra passes.
  derived().addPreRegAlloc(addPass);

  // Run register allocation and passes that are tightly coupled with it,
  // including phi elimination and scheduling.
  if (*Opt.OptimizeRegAlloc) {
    derived().addOptimizedRegAlloc(addPass);
  } else {
    if (auto Err = derived().addFastRegAlloc(addPass))
      return Err;
  }

  // Run post-ra passes.
  derived().addPostRegAlloc(addPass);

  addPass(RemoveRedundantDebugValuesPass());

  // Insert prolog/epilog code.  Eliminate abstract frame index references...
  if (getOptLevel() != CodeGenOpt::None) {
    addPass(PostRAMachineSinkingPass());
    addPass(ShrinkWrapPass());
  }

  addPass(PrologEpilogInserterPass());

  /// Add passes that optimize machine instructions after register allocation.
  if (getOptLevel() != CodeGenOpt::None)
    derived().addMachineLateOptimization(addPass);

  // Expand pseudo instructions before second scheduling pass.
  addPass(ExpandPostRAPseudosPass());

  // Run pre-sched2 passes.
  derived().addPreSched2(addPass);

  if (Opt.EnableImplicitNullChecks)
    addPass(ImplicitNullChecksPass());

  // Second pass scheduler.
  // Let Target optionally insert this pass by itself at some other
  // point.
  if (getOptLevel() != CodeGenOpt::None &&
      !TM.targetSchedulesPostRAScheduling()) {
    if (Opt.MISchedPostRA)
      addPass(PostMachineSchedulerPass());
    else
      addPass(PostRASchedulerPass());
  }

  // GC
  derived().addGCPasses(addPass);

  // Basic block placement.
  if (getOptLevel() != CodeGenOpt::None)
    derived().addBlockPlacement(addPass);

  // Insert before XRay Instrumentation.
  addPass(FEntryInserterPass());

  addPass(XRayInstrumentationPass());
  addPass(PatchableFunctionPass());

  derived().addPreEmitPass(addPass);

  if (TM.Options.EnableIPRA)
    // Collect register usage information and produce a register mask of
    // clobbered registers, to be used to optimize call sites.
    addPass(RegUsageInfoCollectorPass());

  addPass(FuncletLayoutPass());

  addPass(StackMapLivenessPass());
  addPass(LiveDebugValuesPass());

  if (TM.Options.EnableMachineOutliner && getOptLevel() != CodeGenOpt::None &&
      Opt.EnableMachineOutliner != RunOutliner::NeverOutline) {
    bool RunOnAllFunctions =
        (Opt.EnableMachineOutliner == RunOutliner::AlwaysOutline);
    bool AddOutliner = RunOnAllFunctions || TM.Options.SupportsDefaultOutlining;
    if (AddOutliner)
      addPass(MachineOutlinerPass(RunOnAllFunctions));
  }

  // Add passes that directly emit MI after all other MI passes.
  derived().addPreEmitPass2(addPass);

  return Error::success();
}

/// Add passes that optimize machine instructions in SSA form.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addMachineSSAOptimization(
    AddMachinePass &addPass) const {
  // Pre-ra tail duplication.
  addPass(EarlyTailDuplicatePass());

  // Optimize PHIs before DCE: removing dead PHI cycles may make more
  // instructions dead.
  addPass(OptimizePHIsPass());

  // This pass merges large allocas. StackSlotColoring is a different pass
  // which merges spill slots.
  addPass(StackColoringPass());

  // If the target requests it, assign local variables to stack slots relative
  // to one another and simplify frame index references where possible.
  addPass(LocalStackSlotPass());

  // With optimization, dead code should already be eliminated. However
  // there is one known exception: lowered code for arguments that are only
  // used by tail calls, where the tail calls reuse the incoming stack
  // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
  addPass(DeadMachineInstructionElimPass());

  // Allow targets to insert passes that improve instruction level parallelism,
  // like if-conversion. Such passes will typically need dominator trees and
  // loop info, just like LICM and CSE below.
  derived().addILPOpts(addPass);

  addPass(EarlyMachineLICMPass());
  addPass(MachineCSEPass());

  addPass(MachineSinkingPass());

  addPass(PeepholeOptimizerPass());
  // Clean-up the dead code that may have been generated by peephole
  // rewriting.
  addPass(DeadMachineInstructionElimPass());
}

//===---------------------------------------------------------------------===//
/// Register Allocation Pass Configuration
//===---------------------------------------------------------------------===//

/// Instantiate the default register allocator pass for this target for either
/// the optimized or unoptimized allocation path. This will be added to the pass
/// manager by addFastRegAlloc in the unoptimized case or addOptimizedRegAlloc
/// in the optimized case.
///
/// A target that uses the standard regalloc pass order for fast or optimized
/// allocation may still override this for per-target regalloc
/// selection. But -regalloc=... always takes precedence.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addTargetRegisterAllocator(
    AddMachinePass &addPass, bool Optimized) const {
  if (Optimized)
    addPass(RAGreedyPass());
  else
    addPass(RAFastPass());
}

/// Find and instantiate the register allocation pass requested by this target
/// at the current optimization level.  Different register allocators are
/// defined as separate passes because they may require different analysis.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addRegAllocPass(AddMachinePass &addPass,
                                                  bool Optimized) const {
  if (Opt.RegAlloc == RegAllocType::Default)
    // With no -regalloc= override, ask the target for a regalloc pass.
    derived().addTargetRegisterAllocator(addPass, Optimized);
  else if (Opt.RegAlloc == RegAllocType::Basic)
    addPass(RABasicPass());
  else if (Opt.RegAlloc == RegAllocType::Fast)
    addPass(RAFastPass());
  else if (Opt.RegAlloc == RegAllocType::Greedy)
    addPass(RAGreedyPass());
  else if (Opt.RegAlloc == RegAllocType::PBQP)
    addPass(RAPBQPPass());
  else
    llvm_unreachable("unknonwn register allocator type");
}

template <typename Derived>
Error CodeGenPassBuilder<Derived>::addRegAssignmentFast(
    AddMachinePass &addPass) const {
  if (Opt.RegAlloc != RegAllocType::Default &&
      Opt.RegAlloc != RegAllocType::Fast)
    return make_error<StringError>(
        "Must use fast (default) register allocator for unoptimized regalloc.",
        inconvertibleErrorCode());

  addRegAllocPass(addPass, false);
  return Error::success();
}

template <typename Derived>
Error CodeGenPassBuilder<Derived>::addRegAssignmentOptimized(
    AddMachinePass &addPass) const {
  // Add the selected register allocation pass.
  addRegAllocPass(addPass, true);

  // Allow targets to change the register assignments before rewriting.
  derived().addPreRewrite(addPass);

  // Finally rewrite virtual registers.
  addPass(VirtRegRewriterPass());
  // Perform stack slot coloring and post-ra machine LICM.
  //
  // FIXME: Re-enable coloring with register when it's capable of adding
  // kill markers.
  addPass(StackSlotColoringPass());

  return Error::success();
}

/// Add the minimum set of target-independent passes that are required for
/// register allocation. No coalescing or scheduling.
template <typename Derived>
Error CodeGenPassBuilder<Derived>::addFastRegAlloc(
    AddMachinePass &addPass) const {
  addPass(PHIEliminationPass());
  addPass(TwoAddressInstructionPass());
  return derived().addRegAssignmentFast(addPass);
}

/// Add standard target-independent passes that are tightly coupled with
/// optimized register allocation, including coalescing, machine instruction
/// scheduling, and register allocation itself.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addOptimizedRegAlloc(
    AddMachinePass &addPass) const {
  addPass(DetectDeadLanesPass());

  addPass(ProcessImplicitDefsPass());

  // Edge splitting is smarter with machine loop info.
  addPass(PHIEliminationPass());

  // Eventually, we want to run LiveIntervals before PHI elimination.
  if (Opt.EarlyLiveIntervals)
    addPass(LiveIntervalsPass());

  addPass(TwoAddressInstructionPass());
  addPass(RegisterCoalescerPass());

  // The machine scheduler may accidentally create disconnected components
  // when moving subregister definitions around, avoid this by splitting them to
  // separate vregs before. Splitting can also improve reg. allocation quality.
  addPass(RenameIndependentSubregsPass());

  // PreRA instruction scheduling.
  addPass(MachineSchedulerPass());

  if (derived().addRegAssignmentOptimized(addPass)) {
    // Allow targets to expand pseudo instructions depending on the choice of
    // registers before MachineCopyPropagation.
    derived().addPostRewrite(addPass);

    // Copy propagate to forward register uses and try to eliminate COPYs that
    // were not coalesced.
    addPass(MachineCopyPropagationPass());

    // Run post-ra machine LICM to hoist reloads / remats.
    //
    // FIXME: can this move into MachineLateOptimization?
    addPass(MachineLICMPass());
  }
}

//===---------------------------------------------------------------------===//
/// Post RegAlloc Pass Configuration
//===---------------------------------------------------------------------===//

/// Add passes that optimize machine instructions after register allocation.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addMachineLateOptimization(
    AddMachinePass &addPass) const {
  // Branch folding must be run after regalloc and prolog/epilog insertion.
  addPass(BranchFolderPass());

  // Tail duplication.
  // Note that duplicating tail just increases code size and degrades
  // performance for targets that require Structured Control Flow.
  // In addition it can also make CFG irreducible. Thus we disable it.
  if (!TM.requiresStructuredCFG())
    addPass(TailDuplicatePass());

  // Copy propagation.
  addPass(MachineCopyPropagationPass());
}

/// Add standard basic block placement passes.
template <typename Derived>
void CodeGenPassBuilder<Derived>::addBlockPlacement(
    AddMachinePass &addPass) const {
  addPass(MachineBlockPlacementPass());
  // Run a separate pass to collect block placement statistics.
  if (Opt.EnableBlockPlacementStats)
    addPass(MachineBlockPlacementStatsPass());
}

} // namespace llvm

#endif // LLVM_CODEGEN_CODEGENPASSBUILDER_H

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif