llvm.org GIT mirror llvm / release_25 tools / opt / opt.cpp
release_25

Tree @release_25 (Download .tar.gz)

opt.cpp @release_25raw · 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
//===- 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/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/PassManager.h"
#include "llvm/CallGraphSCCPass.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/PassNameParser.h"
#include "llvm/System/Signals.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Support/Streams.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/LinkAllPasses.h"
#include "llvm/LinkAllVMCore.h"
#include <iostream>
#include <fstream>
#include <memory>
#include <algorithm>
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"), cl::init("-"));

static cl::opt<bool>
Force("f", cl::desc("Overwrite output files"));

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

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

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

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

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

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"));

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

struct CallGraphSCCPassPrinter : public CallGraphSCCPass {
  static char ID;
  const PassInfo *PassToPrint;
  CallGraphSCCPassPrinter(const PassInfo *PI) : 
    CallGraphSCCPass((intptr_t)&ID), PassToPrint(PI) {}

  virtual bool runOnSCC(const std::vector<CallGraphNode *>&SCC) {
    if (!Quiet) {
      cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";

      for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
        Function *F = SCC[i]->getFunction();
        if (F) 
          getAnalysisID<Pass>(PassToPrint).print(cout, F->getParent());
      }
    }
    // Get and print pass...
    return false;
  }
  
  virtual const char *getPassName() const { return "'Pass' Printer"; }

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

char CallGraphSCCPassPrinter::ID = 0;

struct ModulePassPrinter : public ModulePass {
  static char ID;
  const PassInfo *PassToPrint;
  ModulePassPrinter(const PassInfo *PI) : ModulePass((intptr_t)&ID),
                                          PassToPrint(PI) {}

  virtual bool runOnModule(Module &M) {
    if (!Quiet) {
      cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
      getAnalysisID<Pass>(PassToPrint).print(cout, &M);
    }

    // Get and print pass...
    return false;
  }

  virtual const char *getPassName() const { return "'Pass' Printer"; }

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

char ModulePassPrinter::ID = 0;
struct FunctionPassPrinter : public FunctionPass {
  const PassInfo *PassToPrint;
  static char ID;
  FunctionPassPrinter(const PassInfo *PI) : FunctionPass((intptr_t)&ID),
                                            PassToPrint(PI) {}

  virtual bool runOnFunction(Function &F) {
    if (!Quiet) { 
      cout << "Printing analysis '" << PassToPrint->getPassName()
           << "' for function '" << F.getName() << "':\n";
    }
    // Get and print pass...
    getAnalysisID<Pass>(PassToPrint).print(cout, F.getParent());
    return false;
  }

  virtual const char *getPassName() const { return "FunctionPass Printer"; }

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

char FunctionPassPrinter::ID = 0;

struct LoopPassPrinter : public LoopPass {
  static char ID;
  const PassInfo *PassToPrint;
  LoopPassPrinter(const PassInfo *PI) : 
    LoopPass((intptr_t)&ID), PassToPrint(PI) {}

  virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
    if (!Quiet) {
      cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
      getAnalysisID<Pass>(PassToPrint).print(cout, 
                                  L->getHeader()->getParent()->getParent());
    }
    // Get and print pass...
    return false;
  }
  
  virtual const char *getPassName() const { return "'Pass' Printer"; }

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

char LoopPassPrinter::ID = 0;

struct BasicBlockPassPrinter : public BasicBlockPass {
  const PassInfo *PassToPrint;
  static char ID;
  BasicBlockPassPrinter(const PassInfo *PI) 
    : BasicBlockPass((intptr_t)&ID), PassToPrint(PI) {}

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

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

  virtual const char *getPassName() const { return "BasicBlockPass Printer"; }

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

char BasicBlockPassPrinter::ID = 0;
inline void addPass(PassManager &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
void AddOptimizationPasses(PassManager &MPM, FunctionPassManager &FPM,
                           unsigned OptLevel) {

  if (OptLevel == 0) 
    return;

  FPM.add(createCFGSimplificationPass());
  if (OptLevel == 1)
    FPM.add(createPromoteMemoryToRegisterPass());
  else
    FPM.add(createScalarReplAggregatesPass());
  FPM.add(createInstructionCombiningPass());

  if (UnitAtATime)
    MPM.add(createRaiseAllocationsPass());      // call %malloc -> malloc inst
  MPM.add(createCFGSimplificationPass());       // Clean up disgusting code
  MPM.add(createPromoteMemoryToRegisterPass()); // Kill useless allocas
  if (UnitAtATime) {
    MPM.add(createGlobalOptimizerPass());       // OptLevel out global vars
    MPM.add(createGlobalDCEPass());             // Remove unused fns and globs
    MPM.add(createIPConstantPropagationPass()); // IP Constant Propagation
    MPM.add(createDeadArgEliminationPass());    // Dead argument elimination
  }
  MPM.add(createInstructionCombiningPass());    // Clean up after IPCP & DAE
  MPM.add(createCFGSimplificationPass());       // Clean up after IPCP & DAE
  if (UnitAtATime) {
    MPM.add(createPruneEHPass());               // Remove dead EH info
    MPM.add(createFunctionAttrsPass());         // Deduce function attrs
  }
  if (OptLevel > 1)
    MPM.add(createFunctionInliningPass());      // Inline small functions
  if (OptLevel > 2)
    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
  if (!DisableSimplifyLibCalls)
    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
  MPM.add(createInstructionCombiningPass());  // Cleanup for scalarrepl.
  MPM.add(createJumpThreadingPass());         // Thread jumps.
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createScalarReplAggregatesPass());  // Break up aggregate allocas
  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
  MPM.add(createCondPropagationPass());       // Propagate conditionals
  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createReassociatePass());           // Reassociate expressions
  MPM.add(createLoopRotatePass());            // Rotate Loop
  MPM.add(createLICMPass());                  // Hoist loop invariants
  MPM.add(createLoopUnswitchPass());
  MPM.add(createLoopIndexSplitPass());        // Split loop index
  MPM.add(createInstructionCombiningPass());  
  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
  MPM.add(createLoopDeletionPass());          // Delete dead loops
  if (OptLevel > 1)
    MPM.add(createLoopUnrollPass());          // Unroll small loops
  MPM.add(createInstructionCombiningPass());  // Clean up after the unroller
  MPM.add(createGVNPass());                   // Remove redundancies
  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
  MPM.add(createSCCPPass());                  // Constant prop with SCCP
  
  // Run instcombine after redundancy elimination to exploit opportunities
  // opened up by them.
  MPM.add(createInstructionCombiningPass());
  MPM.add(createCondPropagationPass());       // Propagate conditionals
  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
  MPM.add(createAggressiveDCEPass());   // Delete dead instructions
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  
  if (UnitAtATime) {
    MPM.add(createStripDeadPrototypesPass());   // Get rid of dead prototypes
    MPM.add(createDeadTypeEliminationPass());   // Eliminate dead types
  }
  
  if (OptLevel > 1 && UnitAtATime)
    MPM.add(createConstantMergePass());       // Merge dup global constants 
  
  return;
}

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

  addPass(PM, createLowerSetJmpPass());          // Lower llvm.setjmp/.longjmp

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

  if (DisableOptimizations) return;

  addPass(PM, createRaiseAllocationsPass());     // call %malloc -> malloc inst
  addPass(PM, createCFGSimplificationPass());    // Clean up disgusting code
  addPass(PM, createPromoteMemoryToRegisterPass());// Kill useless allocas
  addPass(PM, createGlobalOptimizerPass());      // Optimize out global vars
  addPass(PM, createGlobalDCEPass());            // Remove unused fns and globs
  addPass(PM, createIPConstantPropagationPass());// IP Constant Propagation
  addPass(PM, createDeadArgEliminationPass());   // Dead argument elimination
  addPass(PM, createInstructionCombiningPass()); // Clean up after IPCP & DAE
  addPass(PM, createCFGSimplificationPass());    // Clean up after IPCP & DAE

  addPass(PM, createPruneEHPass());              // Remove dead EH info
  addPass(PM, createFunctionAttrsPass());        // Deduce function attrs

  if (!DisableInline)
    addPass(PM, createFunctionInliningPass());   // Inline small functions
  addPass(PM, createArgumentPromotionPass());    // Scalarize uninlined fn args

  addPass(PM, createSimplifyLibCallsPass());     // Library Call Optimizations
  addPass(PM, createInstructionCombiningPass()); // Cleanup for scalarrepl.
  addPass(PM, createJumpThreadingPass());        // Thread jumps.
  addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
  addPass(PM, createScalarReplAggregatesPass()); // Break up aggregate allocas
  addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
  addPass(PM, createCondPropagationPass());      // Propagate conditionals

  addPass(PM, createTailCallEliminationPass());  // Eliminate tail calls
  addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
  addPass(PM, createReassociatePass());          // Reassociate expressions
  addPass(PM, createLoopRotatePass());
  addPass(PM, createLICMPass());                 // Hoist loop invariants
  addPass(PM, createLoopUnswitchPass());         // Unswitch loops.
  addPass(PM, createLoopIndexSplitPass());       // Index split loops.
  // FIXME : Removing instcombine causes nestedloop regression.
  addPass(PM, createInstructionCombiningPass());
  addPass(PM, createIndVarSimplifyPass());       // Canonicalize indvars
  addPass(PM, createLoopDeletionPass());         // Delete dead loops
  addPass(PM, createLoopUnrollPass());           // Unroll small loops
  addPass(PM, createInstructionCombiningPass()); // Clean up after the unroller
  addPass(PM, createGVNPass());                  // Remove redundancies
  addPass(PM, createMemCpyOptPass());            // Remove memcpy / form memset
  addPass(PM, createSCCPPass());                 // Constant prop with SCCP

  // Run instcombine after redundancy elimination to exploit opportunities
  // opened up by them.
  addPass(PM, createInstructionCombiningPass());
  addPass(PM, createCondPropagationPass());      // Propagate conditionals

  addPass(PM, createDeadStoreEliminationPass()); // Delete dead stores
  addPass(PM, createAggressiveDCEPass());        // Delete dead instructions
  addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
  addPass(PM, createStripDeadPrototypesPass());  // Get rid of dead prototypes
  addPass(PM, createDeadTypeEliminationPass());  // Eliminate dead types
  addPass(PM, createConstantMergePass());        // Merge dup global constants
}

} // anonymous namespace


//===----------------------------------------------------------------------===//
// main for opt
//
int main(int argc, char **argv) {
  llvm_shutdown_obj X;  // Call llvm_shutdown() on exit.
  try {
    cl::ParseCommandLineOptions(argc, argv,
      "llvm .bc -> .bc modular optimizer and analysis printer\n");
    sys::PrintStackTraceOnErrorSignal();

    // Allocate a full target machine description only if necessary.
    // FIXME: The choice of target should be controllable on the command line.
    std::auto_ptr<TargetMachine> target;

    std::string ErrorMessage;

    // Load the input module...
    std::auto_ptr<Module> M;
    if (MemoryBuffer *Buffer
          = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
      M.reset(ParseBitcodeFile(Buffer, &ErrorMessage));
      delete Buffer;
    }
    
    if (M.get() == 0) {
      cerr << argv[0] << ": ";
      if (ErrorMessage.size())
        cerr << ErrorMessage << "\n";
      else
        cerr << "bitcode didn't read correctly.\n";
      return 1;
    }

    // Figure out what stream we are supposed to write to...
    // FIXME: cout is not binary!
    std::ostream *Out = &std::cout;  // Default to printing to stdout...
    if (OutputFilename != "-") {
      if (!Force && std::ifstream(OutputFilename.c_str())) {
        // If force is not specified, make sure not to overwrite a file!
        cerr << argv[0] << ": error opening '" << OutputFilename
             << "': file exists!\n"
             << "Use -f command line argument to force output\n";
        return 1;
      }
      std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
                                   std::ios::binary;
      Out = new std::ofstream(OutputFilename.c_str(), io_mode);

      if (!Out->good()) {
        cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
        return 1;
      }

      // Make sure that the Output file gets unlinked from the disk if we get a
      // SIGINT
      sys::RemoveFileOnSignal(sys::Path(OutputFilename));
    }

    // 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 && CheckBitcodeOutputToConsole(Out,!Quiet)) {
      NoOutput = true;
    }

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

    // Add an appropriate TargetData instance for this module...
    Passes.add(new TargetData(M.get()));

    FunctionPassManager *FPasses = NULL;
    if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
      FPasses = new FunctionPassManager(new ExistingModuleProvider(M.get()));
      FPasses->add(new TargetData(M.get()));
    }
      
    // 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 (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
        AddOptimizationPasses(Passes, *FPasses, 1);
        OptLevelO1 = false;
      }

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

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

      const PassInfo *PassInf = PassList[i];
      Pass *P = 0;
      if (PassInf->getNormalCtor())
        P = PassInf->getNormalCtor()();
      else
        cerr << argv[0] << ": cannot create pass: "
             << PassInf->getPassName() << "\n";
      if (P) {
        bool isBBPass = dynamic_cast<BasicBlockPass*>(P) != 0;
        bool isLPass = !isBBPass && dynamic_cast<LoopPass*>(P) != 0;
        bool isFPass = !isLPass && dynamic_cast<FunctionPass*>(P) != 0;
        bool isCGSCCPass = !isFPass && dynamic_cast<CallGraphSCCPass*>(P) != 0;

        addPass(Passes, P);

        if (AnalyzeOnly) {
          if (isBBPass)
            Passes.add(new BasicBlockPassPrinter(PassInf));
          else if (isLPass)
            Passes.add(new LoopPassPrinter(PassInf));
          else if (isFPass)
            Passes.add(new FunctionPassPrinter(PassInf));
          else if (isCGSCCPass)
            Passes.add(new CallGraphSCCPassPrinter(PassInf));
          else
            Passes.add(new ModulePassPrinter(PassInf));
        }
      }
      
      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 (OptLevelO1) {
        AddOptimizationPasses(Passes, *FPasses, 1);
      }

    if (OptLevelO2) {
        AddOptimizationPasses(Passes, *FPasses, 2);
      }

    if (OptLevelO3) {
        AddOptimizationPasses(Passes, *FPasses, 3);
      }

    if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
      for (Module::iterator I = M.get()->begin(), E = M.get()->end();
           I != E; ++I)
        FPasses->run(*I);
    }

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

    // Write bitcode out to disk or cout as the last step...
    if (!NoOutput && !AnalyzeOnly)
      Passes.add(CreateBitcodeWriterPass(*Out));

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

    // Delete the ofstream.
    if (Out != &std::cout) 
      delete Out;
    return 0;

  } catch (const std::string& msg) {
    cerr << argv[0] << ": " << msg << "\n";
  } catch (...) {
    cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
  }
  llvm_shutdown();
  return 1;
}