llvm.org GIT mirror llvm / 13ace66 tools / opt / opt.cpp
13ace66

Tree @13ace66 (Download .tar.gz)

opt.cpp @13ace66raw · history · 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
//===- opt.cpp - The LLVM Modular Optimizer -------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Optimizations may be specified an arbitrary number of times on the command
// line, They are run in the order specified.
//
//===----------------------------------------------------------------------===//

#include "llvm/IR/LLVMContext.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/RegionPass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/DebugInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Module.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/LinkAllIR.h"
#include "llvm/LinkAllPasses.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/PassManager.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PassNameParser.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include <algorithm>
#include <memory>
using namespace llvm;

// The OptimizationList is automatically populated with registered Passes by the
// PassNameParser.
//
static cl::list<const PassInfo*, bool, PassNameParser>
PassList(cl::desc("Optimizations available:"));

// Other command line options...
//
static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
    cl::init("-"), cl::value_desc("filename"));

static cl::opt<std::string>
OutputFilename("o", cl::desc("Override output filename"),
               cl::value_desc("filename"));

static cl::opt<bool>
Force("f", cl::desc("Enable binary output on terminals"));

static cl::opt<bool>
PrintEachXForm("p", cl::desc("Print module after each transformation"));

static cl::opt<bool>
NoOutput("disable-output",
         cl::desc("Do not write result bitcode file"), cl::Hidden);

static cl::opt<bool>
OutputAssembly("S", cl::desc("Write output as LLVM assembly"));

static cl::opt<bool>
NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden);

static cl::opt<bool>
VerifyEach("verify-each", cl::desc("Verify after each transform"));

static cl::opt<bool>
StripDebug("strip-debug",
           cl::desc("Strip debugger symbol info from translation unit"));

static cl::opt<bool>
DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));

static cl::opt<bool>
DisableOptimizations("disable-opt",
                     cl::desc("Do not run any optimization passes"));

static cl::opt<bool>
DisableInternalize("disable-internalize",
                   cl::desc("Do not mark all symbols as internal"));

static cl::opt<bool>
StandardCompileOpts("std-compile-opts",
                   cl::desc("Include the standard compile time optimizations"));

static cl::opt<bool>
StandardLinkOpts("std-link-opts",
                 cl::desc("Include the standard link time optimizations"));

static cl::opt<bool>
OptLevelO1("O1",
           cl::desc("Optimization level 1. Similar to clang -O1"));

static cl::opt<bool>
OptLevelO2("O2",
           cl::desc("Optimization level 2. Similar to clang -O2"));

static cl::opt<bool>
OptLevelOs("Os",
           cl::desc("Like -O2 with extra optimizations for size. Similar to clang -Os"));

static cl::opt<bool>
OptLevelOz("Oz",
           cl::desc("Like -Os but reduces code size further. Similar to clang -Oz"));

static cl::opt<bool>
OptLevelO3("O3",
           cl::desc("Optimization level 3. Similar to clang -O3"));

static cl::opt<std::string>
TargetTriple("mtriple", cl::desc("Override target triple for module"));

static cl::opt<bool>
UnitAtATime("funit-at-a-time",
            cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"),
            cl::init(true));

static cl::opt<bool>
DisableSimplifyLibCalls("disable-simplify-libcalls",
                        cl::desc("Disable simplify-libcalls"));

static cl::opt<bool>
Quiet("q", cl::desc("Obsolete option"), cl::Hidden);

static cl::alias
QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));

static cl::opt<bool>
AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));

static cl::opt<bool>
PrintBreakpoints("print-breakpoints-for-testing",
                 cl::desc("Print select breakpoints location for testing"));

static cl::opt<std::string>
DefaultDataLayout("default-data-layout",
          cl::desc("data layout string to use if not specified by module"),
          cl::value_desc("layout-string"), cl::init(""));

// ---------- Define Printers for module and function passes ------------
namespace {

struct CallGraphSCCPassPrinter : public CallGraphSCCPass {
  static char ID;
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  std::string PassName;

  CallGraphSCCPassPrinter(const PassInfo *PI, raw_ostream &out) :
    CallGraphSCCPass(ID), PassToPrint(PI), Out(out) {
      std::string PassToPrintName =  PassToPrint->getPassName();
      PassName = "CallGraphSCCPass Printer: " + PassToPrintName;
    }

  virtual bool runOnSCC(CallGraphSCC &SCC) {
    if (!Quiet)
      Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n";

    // Get and print pass...
    for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
      Function *F = (*I)->getFunction();
      if (F)
        getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out,
                                                              F->getParent());
    }
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char CallGraphSCCPassPrinter::ID = 0;

struct ModulePassPrinter : public ModulePass {
  static char ID;
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  std::string PassName;

  ModulePassPrinter(const PassInfo *PI, raw_ostream &out)
    : ModulePass(ID), PassToPrint(PI), Out(out) {
      std::string PassToPrintName =  PassToPrint->getPassName();
      PassName = "ModulePass Printer: " + PassToPrintName;
    }

  virtual bool runOnModule(Module &M) {
    if (!Quiet)
      Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n";

    // Get and print pass...
    getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out, &M);
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char ModulePassPrinter::ID = 0;
struct FunctionPassPrinter : public FunctionPass {
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  static char ID;
  std::string PassName;

  FunctionPassPrinter(const PassInfo *PI, raw_ostream &out)
    : FunctionPass(ID), PassToPrint(PI), Out(out) {
      std::string PassToPrintName =  PassToPrint->getPassName();
      PassName = "FunctionPass Printer: " + PassToPrintName;
    }

  virtual bool runOnFunction(Function &F) {
    if (!Quiet)
      Out << "Printing analysis '" << PassToPrint->getPassName()
          << "' for function '" << F.getName() << "':\n";

    // Get and print pass...
    getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out,
            F.getParent());
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char FunctionPassPrinter::ID = 0;

struct LoopPassPrinter : public LoopPass {
  static char ID;
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  std::string PassName;

  LoopPassPrinter(const PassInfo *PI, raw_ostream &out) :
    LoopPass(ID), PassToPrint(PI), Out(out) {
      std::string PassToPrintName =  PassToPrint->getPassName();
      PassName = "LoopPass Printer: " + PassToPrintName;
    }


  virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
    if (!Quiet)
      Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n";

    // Get and print pass...
    getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out,
                        L->getHeader()->getParent()->getParent());
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char LoopPassPrinter::ID = 0;

struct RegionPassPrinter : public RegionPass {
  static char ID;
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  std::string PassName;

  RegionPassPrinter(const PassInfo *PI, raw_ostream &out) : RegionPass(ID),
    PassToPrint(PI), Out(out) {
    std::string PassToPrintName =  PassToPrint->getPassName();
    PassName = "RegionPass Printer: " + PassToPrintName;
  }

  virtual bool runOnRegion(Region *R, RGPassManager &RGM) {
    if (!Quiet) {
      Out << "Printing analysis '" << PassToPrint->getPassName() << "' for "
          << "region: '" << R->getNameStr() << "' in function '"
          << R->getEntry()->getParent()->getName() << "':\n";
    }
    // Get and print pass...
   getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out,
                       R->getEntry()->getParent()->getParent());
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char RegionPassPrinter::ID = 0;

struct BasicBlockPassPrinter : public BasicBlockPass {
  const PassInfo *PassToPrint;
  raw_ostream &Out;
  static char ID;
  std::string PassName;

  BasicBlockPassPrinter(const PassInfo *PI, raw_ostream &out)
    : BasicBlockPass(ID), PassToPrint(PI), Out(out) {
      std::string PassToPrintName =  PassToPrint->getPassName();
      PassName = "BasicBlockPass Printer: " + PassToPrintName;
    }

  virtual bool runOnBasicBlock(BasicBlock &BB) {
    if (!Quiet)
      Out << "Printing Analysis info for BasicBlock '" << BB.getName()
          << "': Pass " << PassToPrint->getPassName() << ":\n";

    // Get and print pass...
    getAnalysisID<Pass>(PassToPrint->getTypeInfo()).print(Out,
            BB.getParent()->getParent());
    return false;
  }

  virtual const char *getPassName() const { return PassName.c_str(); }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.addRequiredID(PassToPrint->getTypeInfo());
    AU.setPreservesAll();
  }
};

char BasicBlockPassPrinter::ID = 0;

struct BreakpointPrinter : public ModulePass {
  raw_ostream &Out;
  static char ID;

  BreakpointPrinter(raw_ostream &out)
    : ModulePass(ID), Out(out) {
    }

  void getContextName(DIDescriptor Context, std::string &N) {
    if (Context.isNameSpace()) {
      DINameSpace NS(Context);
      if (!NS.getName().empty()) {
        getContextName(NS.getContext(), N);
        N = N + NS.getName().str() + "::";
      }
    } else if (Context.isType()) {
      DIType TY(Context);
      if (!TY.getName().empty()) {
        getContextName(TY.getContext(), N);
        N = N + TY.getName().str() + "::";
      }
    }
  }

  virtual bool runOnModule(Module &M) {
    StringSet<> Processed;
    if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.sp"))
      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
        std::string Name;
        DISubprogram SP(NMD->getOperand(i));
        if (SP.Verify())
          getContextName(SP.getContext(), Name);
        Name = Name + SP.getDisplayName().str();
        if (!Name.empty() && Processed.insert(Name)) {
          Out << Name << "\n";
        }
      }
    return false;
  }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.setPreservesAll();
  }
};
 
} // anonymous namespace

char BreakpointPrinter::ID = 0;

static inline void addPass(PassManagerBase &PM, Pass *P) {
  // Add the pass to the pass manager...
  PM.add(P);

  // If we are verifying all of the intermediate steps, add the verifier...
  if (VerifyEach) PM.add(createVerifierPass());
}

/// AddOptimizationPasses - This routine adds optimization passes
/// based on selected optimization level, OptLevel. This routine
/// duplicates llvm-gcc behaviour.
///
/// OptLevel - Optimization Level
static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
                                  unsigned OptLevel, unsigned SizeLevel) {
  FPM.add(createVerifierPass());                  // Verify that input is correct

  PassManagerBuilder Builder;
  Builder.OptLevel = OptLevel;
  Builder.SizeLevel = SizeLevel;

  if (DisableInline) {
    // No inlining pass
  } else if (OptLevel > 1) {
    unsigned Threshold = 225;
    if (SizeLevel == 1)      // -Os
      Threshold = 75;
    else if (SizeLevel == 2) // -Oz
      Threshold = 25;
    if (OptLevel > 2)
      Threshold = 275;
    Builder.Inliner = createFunctionInliningPass(Threshold);
  } else {
    Builder.Inliner = createAlwaysInlinerPass();
  }
  Builder.DisableUnitAtATime = !UnitAtATime;
  Builder.DisableUnrollLoops = OptLevel == 0;
  Builder.DisableSimplifyLibCalls = DisableSimplifyLibCalls;
  
  Builder.populateFunctionPassManager(FPM);
  Builder.populateModulePassManager(MPM);
}

static void AddStandardCompilePasses(PassManagerBase &PM) {
  PM.add(createVerifierPass());                  // Verify that input is correct

  // If the -strip-debug command line option was specified, do it.
  if (StripDebug)
    addPass(PM, createStripSymbolsPass(true));

  if (DisableOptimizations) return;

  // -std-compile-opts adds the same module passes as -O3.
  PassManagerBuilder Builder;
  if (!DisableInline)
    Builder.Inliner = createFunctionInliningPass();
  Builder.OptLevel = 3;
  Builder.DisableSimplifyLibCalls = DisableSimplifyLibCalls;
  Builder.populateModulePassManager(PM);
}

static void AddStandardLinkPasses(PassManagerBase &PM) {
  PM.add(createVerifierPass());                  // Verify that input is correct

  // If the -strip-debug command line option was specified, do it.
  if (StripDebug)
    addPass(PM, createStripSymbolsPass(true));

  if (DisableOptimizations) return;

  PassManagerBuilder Builder;
  Builder.populateLTOPassManager(PM, /*Internalize=*/ !DisableInternalize,
                                 /*RunInliner=*/ !DisableInline);
}

//===----------------------------------------------------------------------===//
// CodeGen-related helper functions.
//
static TargetOptions GetTargetOptions() {
  TargetOptions Options;
  Options.LessPreciseFPMADOption = EnableFPMAD;
  Options.NoFramePointerElim = DisableFPElim;
  Options.NoFramePointerElimNonLeaf = DisableFPElimNonLeaf;
  Options.AllowFPOpFusion = FuseFPOps;
  Options.UnsafeFPMath = EnableUnsafeFPMath;
  Options.NoInfsFPMath = EnableNoInfsFPMath;
  Options.NoNaNsFPMath = EnableNoNaNsFPMath;
  Options.HonorSignDependentRoundingFPMathOption =
  EnableHonorSignDependentRoundingFPMath;
  Options.UseSoftFloat = GenerateSoftFloatCalls;
  if (FloatABIForCalls != FloatABI::Default)
    Options.FloatABIType = FloatABIForCalls;
  Options.NoZerosInBSS = DontPlaceZerosInBSS;
  Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
  Options.DisableTailCalls = DisableTailCalls;
  Options.StackAlignmentOverride = OverrideStackAlignment;
  Options.RealignStack = EnableRealignStack;
  Options.TrapFuncName = TrapFuncName;
  Options.PositionIndependentExecutable = EnablePIE;
  Options.EnableSegmentedStacks = SegmentedStacks;
  Options.UseInitArray = UseInitArray;
  Options.SSPBufferSize = SSPBufferSize;
  return Options;
}

CodeGenOpt::Level GetCodeGenOptLevel() {
  if (OptLevelO1)
    return CodeGenOpt::Less;
  if (OptLevelO2)
    return CodeGenOpt::Default;
  if (OptLevelO3)
    return CodeGenOpt::Aggressive;
  return CodeGenOpt::None;
}

// Returns the TargetMachine instance or zero if no triple is provided.
static TargetMachine* GetTargetMachine(Triple TheTriple) {
  std::string Error;
  const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple,
                                                         Error);
  // Some modules don't specify a triple, and this is okay.
  if (!TheTarget) {
    return 0;
  }

  // Package up features to be passed to target/subtarget
  std::string FeaturesStr;
  if (MAttrs.size()) {
    SubtargetFeatures Features;
    for (unsigned i = 0; i != MAttrs.size(); ++i)
      Features.AddFeature(MAttrs[i]);
    FeaturesStr = Features.getString();
  }

  return TheTarget->createTargetMachine(TheTriple.getTriple(),
                                        MCPU, FeaturesStr, GetTargetOptions(),
                                        RelocModel, CMModel,
                                        GetCodeGenOptLevel());
}

//===----------------------------------------------------------------------===//
// main for opt
//
int main(int argc, char **argv) {
  sys::PrintStackTraceOnErrorSignal();
  llvm::PrettyStackTraceProgram X(argc, argv);

  // Enable debug stream buffering.
  EnableDebugBuffering = true;

  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  LLVMContext &Context = getGlobalContext();

  InitializeAllTargets();
  InitializeAllTargetMCs();

  // Initialize passes
  PassRegistry &Registry = *PassRegistry::getPassRegistry();
  initializeCore(Registry);
  initializeDebugIRPass(Registry);
  initializeScalarOpts(Registry);
  initializeObjCARCOpts(Registry);
  initializeVectorization(Registry);
  initializeIPO(Registry);
  initializeAnalysis(Registry);
  initializeIPA(Registry);
  initializeTransformUtils(Registry);
  initializeInstCombine(Registry);
  initializeInstrumentation(Registry);
  initializeTarget(Registry);

  cl::ParseCommandLineOptions(argc, argv,
    "llvm .bc -> .bc modular optimizer and analysis printer\n");

  if (AnalyzeOnly && NoOutput) {
    errs() << argv[0] << ": analyze mode conflicts with no-output mode.\n";
    return 1;
  }

  SMDiagnostic Err;

  // Load the input module...
  OwningPtr<Module> M;
  M.reset(ParseIRFile(InputFilename, Err, Context));

  if (M.get() == 0) {
    Err.print(argv[0], errs());
    return 1;
  }

  // If we are supposed to override the target triple, do so now.
  if (!TargetTriple.empty())
    M->setTargetTriple(Triple::normalize(TargetTriple));

  // Figure out what stream we are supposed to write to...
  OwningPtr<tool_output_file> Out;
  if (NoOutput) {
    if (!OutputFilename.empty())
      errs() << "WARNING: The -o (output filename) option is ignored when\n"
                "the --disable-output option is used.\n";
  } else {
    // Default to standard output.
    if (OutputFilename.empty())
      OutputFilename = "-";

    std::string ErrorInfo;
    Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
                                   raw_fd_ostream::F_Binary));
    if (!ErrorInfo.empty()) {
      errs() << ErrorInfo << '\n';
      return 1;
    }
  }

  // If the output is set to be emitted to standard out, and standard out is a
  // console, print out a warning message and refuse to do it.  We don't
  // impress anyone by spewing tons of binary goo to a terminal.
  if (!Force && !NoOutput && !AnalyzeOnly && !OutputAssembly)
    if (CheckBitcodeOutputToConsole(Out->os(), !Quiet))
      NoOutput = true;

  // Create a PassManager to hold and optimize the collection of passes we are
  // about to build.
  //
  PassManager Passes;

  // Add an appropriate TargetLibraryInfo pass for the module's triple.
  TargetLibraryInfo *TLI = new TargetLibraryInfo(Triple(M->getTargetTriple()));

  // The -disable-simplify-libcalls flag actually disables all builtin optzns.
  if (DisableSimplifyLibCalls)
    TLI->disableAllFunctions();
  Passes.add(TLI);

  // Add an appropriate DataLayout instance for this module.
  DataLayout *TD = 0;
  const std::string &ModuleDataLayout = M.get()->getDataLayout();
  if (!ModuleDataLayout.empty())
    TD = new DataLayout(ModuleDataLayout);
  else if (!DefaultDataLayout.empty())
    TD = new DataLayout(DefaultDataLayout);

  if (TD)
    Passes.add(TD);

  Triple ModuleTriple(M->getTargetTriple());
  TargetMachine *Machine = 0;
  if (ModuleTriple.getArch())
    Machine = GetTargetMachine(Triple(ModuleTriple));
  OwningPtr<TargetMachine> TM(Machine);

  // Add internal analysis passes from the target machine.
  if (TM.get())
    TM->addAnalysisPasses(Passes);

  OwningPtr<FunctionPassManager> FPasses;
  if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) {
    FPasses.reset(new FunctionPassManager(M.get()));
    if (TD)
      FPasses->add(new DataLayout(*TD));
  }

  if (PrintBreakpoints) {
    // Default to standard output.
    if (!Out) {
      if (OutputFilename.empty())
        OutputFilename = "-";

      std::string ErrorInfo;
      Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
                                     raw_fd_ostream::F_Binary));
      if (!ErrorInfo.empty()) {
        errs() << ErrorInfo << '\n';
        return 1;
      }
    }
    Passes.add(new BreakpointPrinter(Out->os()));
    NoOutput = true;
  }

  // If the -strip-debug command line option was specified, add it.  If
  // -std-compile-opts was also specified, it will handle StripDebug.
  if (StripDebug && !StandardCompileOpts)
    addPass(Passes, createStripSymbolsPass(true));

  // Create a new optimization pass for each one specified on the command line
  for (unsigned i = 0; i < PassList.size(); ++i) {
    // Check to see if -std-compile-opts was specified before this option.  If
    // so, handle it.
    if (StandardCompileOpts &&
        StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
      AddStandardCompilePasses(Passes);
      StandardCompileOpts = false;
    }

    if (StandardLinkOpts &&
        StandardLinkOpts.getPosition() < PassList.getPosition(i)) {
      AddStandardLinkPasses(Passes);
      StandardLinkOpts = false;
    }

    if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
      AddOptimizationPasses(Passes, *FPasses, 1, 0);
      OptLevelO1 = false;
    }

    if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
      AddOptimizationPasses(Passes, *FPasses, 2, 0);
      OptLevelO2 = false;
    }

    if (OptLevelOs && OptLevelOs.getPosition() < PassList.getPosition(i)) {
      AddOptimizationPasses(Passes, *FPasses, 2, 1);
      OptLevelOs = false;
    }

    if (OptLevelOz && OptLevelOz.getPosition() < PassList.getPosition(i)) {
      AddOptimizationPasses(Passes, *FPasses, 2, 2);
      OptLevelOz = false;
    }

    if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
      AddOptimizationPasses(Passes, *FPasses, 3, 0);
      OptLevelO3 = false;
    }

    const PassInfo *PassInf = PassList[i];
    Pass *P = 0;
    if (PassInf->getNormalCtor())
      P = PassInf->getNormalCtor()();
    else
      errs() << argv[0] << ": cannot create pass: "
             << PassInf->getPassName() << "\n";
    if (P) {
      PassKind Kind = P->getPassKind();
      addPass(Passes, P);

      if (AnalyzeOnly) {
        switch (Kind) {
        case PT_BasicBlock:
          Passes.add(new BasicBlockPassPrinter(PassInf, Out->os()));
          break;
        case PT_Region:
          Passes.add(new RegionPassPrinter(PassInf, Out->os()));
          break;
        case PT_Loop:
          Passes.add(new LoopPassPrinter(PassInf, Out->os()));
          break;
        case PT_Function:
          Passes.add(new FunctionPassPrinter(PassInf, Out->os()));
          break;
        case PT_CallGraphSCC:
          Passes.add(new CallGraphSCCPassPrinter(PassInf, Out->os()));
          break;
        default:
          Passes.add(new ModulePassPrinter(PassInf, Out->os()));
          break;
        }
      }
    }

    if (PrintEachXForm)
      Passes.add(createPrintModulePass(&errs()));
  }

  // If -std-compile-opts was specified at the end of the pass list, add them.
  if (StandardCompileOpts) {
    AddStandardCompilePasses(Passes);
    StandardCompileOpts = false;
  }

  if (StandardLinkOpts) {
    AddStandardLinkPasses(Passes);
    StandardLinkOpts = false;
  }

  if (OptLevelO1)
    AddOptimizationPasses(Passes, *FPasses, 1, 0);

  if (OptLevelO2)
    AddOptimizationPasses(Passes, *FPasses, 2, 0);

  if (OptLevelOs)
    AddOptimizationPasses(Passes, *FPasses, 2, 1);

  if (OptLevelOz)
    AddOptimizationPasses(Passes, *FPasses, 2, 2);

  if (OptLevelO3)
    AddOptimizationPasses(Passes, *FPasses, 3, 0);

  if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) {
    FPasses->doInitialization();
    for (Module::iterator F = M->begin(), E = M->end(); F != E; ++F)
      FPasses->run(*F);
    FPasses->doFinalization();
  }

  // Check that the module is well formed on completion of optimization
  if (!NoVerify && !VerifyEach)
    Passes.add(createVerifierPass());

  // Write bitcode or assembly to the output as the last step...
  if (!NoOutput && !AnalyzeOnly) {
    if (OutputAssembly)
      Passes.add(createPrintModulePass(&Out->os()));
    else
      Passes.add(createBitcodeWriterPass(Out->os()));
  }

  // Before executing passes, print the final values of the LLVM options.
  cl::PrintOptionValues();

  // Now that we have all of the passes ready, run them.
  Passes.run(*M.get());

  // Declare success.
  if (!NoOutput || PrintBreakpoints)
    Out->keep();

  return 0;
}