tools/opt/opt.cpp

   1 //===- opt.cpp - The LLVM Modular Optimizer -------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Optimizations may be specified an arbitrary number of times on the command
  11 // line, They are run in the order specified.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Module.h"
  16 #include "llvm/ModuleProvider.h"
  17 #include "llvm/PassManager.h"
  18 #include "llvm/CallGraphSCCPass.h"
  19 #include "llvm/Bitcode/ReaderWriter.h"
  20 #include "llvm/Assembly/PrintModulePass.h"
  21 #include "llvm/Analysis/Verifier.h"
  22 #include "llvm/Analysis/LoopPass.h"
  23 #include "llvm/Analysis/CallGraph.h"
  24 #include "llvm/Target/TargetData.h"
  25 #include "llvm/Target/TargetMachine.h"
  26 #include "llvm/Support/PassNameParser.h"
  27 #include "llvm/System/Signals.h"
  28 #include "llvm/Support/ManagedStatic.h"
  29 #include "llvm/Support/MemoryBuffer.h"
  30 #include "llvm/Support/PluginLoader.h"
  31 #include "llvm/Support/Streams.h"
  32 #include "llvm/Support/SystemUtils.h"
  33 #include "llvm/Support/raw_ostream.h"
  34 #include "llvm/LinkAllPasses.h"
  35 #include "llvm/LinkAllVMCore.h"
  36 #include <iostream>
  37 #include <fstream>
  38 #include <memory>
  39 #include <algorithm>
  40 using namespace llvm;
  41
  42 // The OptimizationList is automatically populated with registered Passes by the
  43 // PassNameParser.
  44 //
  45 static cl::list<const PassInfo*, bool, PassNameParser>
  46 PassList(cl::desc("Optimizations available:"));
  47
  48 // Other command line options...
  49 //
  50 static cl::opt<std::string>
  51 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
  52     cl::init("-"), cl::value_desc("filename"));
  53
  54 static cl::opt<std::string>
  55 OutputFilename("o", cl::desc("Override output filename"),
  56                cl::value_desc("filename"), cl::init("-"));
  57
  58 static cl::opt<bool>
  59 Force("f", cl::desc("Overwrite output files"));
  60
  61 static cl::opt<bool>
  62 PrintEachXForm("p", cl::desc("Print module after each transformation"));
  63
  64 static cl::opt<bool>
  65 NoOutput("disable-output",
  66          cl::desc("Do not write result bitcode file"), cl::Hidden);
  67
  68 static cl::opt<bool>
  69 NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden);
  70
  71 static cl::opt<bool>
  72 VerifyEach("verify-each", cl::desc("Verify after each transform"));
  73
  74 static cl::opt<bool>
  75 StripDebug("strip-debug",
  76            cl::desc("Strip debugger symbol info from translation unit"));
  77
  78 static cl::opt<bool>
  79 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
  80
  81 static cl::opt<bool>
  82 DisableOptimizations("disable-opt",
  83                      cl::desc("Do not run any optimization passes"));
  84
  85 static cl::opt<bool>
  86 StandardCompileOpts("std-compile-opts",
  87                    cl::desc("Include the standard compile time optimizations"));
  88
  89 static cl::opt<bool>
  90 OptLevelO1("O1",
  91            cl::desc("Optimization level 1. Similar to llvm-gcc -O1"));
  92
  93 static cl::opt<bool>
  94 OptLevelO2("O2",
  95            cl::desc("Optimization level 2. Similar to llvm-gcc -O2"));
  96
  97 static cl::opt<bool>
  98 OptLevelO3("O3",
  99            cl::desc("Optimization level 3. Similar to llvm-gcc -O3"));
 100
 101 static cl::opt<bool>
 102 UnitAtATime("funit-at-a-time",
 103             cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"));
 104
 105 static cl::opt<bool>
 106 DisableSimplifyLibCalls("disable-simplify-libcalls",
 107                         cl::desc("Disable simplify-libcalls"));
 108
 109 static cl::opt<bool>
 110 Quiet("q", cl::desc("Obsolete option"), cl::Hidden);
 111
 112 static cl::alias
 113 QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));
 114
 115 static cl::opt<bool>
 116 AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));
 117
 118 // ---------- Define Printers for module and function passes ------------
 119 namespace {
 120
 121 struct CallGraphSCCPassPrinter : public CallGraphSCCPass {
 122   static char ID;
 123   const PassInfo *PassToPrint;
 124   CallGraphSCCPassPrinter(const PassInfo *PI) :
 125     CallGraphSCCPass(&ID), PassToPrint(PI) {}
 126
 127   virtual bool runOnSCC(const std::vector<CallGraphNode *>&SCC) {
 128     if (!Quiet) {
 129       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 130
 131       for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
 132         Function *F = SCC[i]->getFunction();
 133         if (F)
 134           getAnalysisID<Pass>(PassToPrint).print(cout, F->getParent());
 135       }
 136     }
 137     // Get and print pass...
 138     return false;
 139   }
 140
 141   virtual const char *getPassName() const { return "'Pass' Printer"; }
 142
 143   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 144     AU.addRequiredID(PassToPrint);
 145     AU.setPreservesAll();
 146   }
 147 };
 148
 149 char CallGraphSCCPassPrinter::ID = 0;
 150
 151 struct ModulePassPrinter : public ModulePass {
 152   static char ID;
 153   const PassInfo *PassToPrint;
 154   ModulePassPrinter(const PassInfo *PI) : ModulePass(&ID),
 155                                           PassToPrint(PI) {}
 156
 157   virtual bool runOnModule(Module &M) {
 158     if (!Quiet) {
 159       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 160       getAnalysisID<Pass>(PassToPrint).print(cout, &M);
 161     }
 162
 163     // Get and print pass...
 164     return false;
 165   }
 166
 167   virtual const char *getPassName() const { return "'Pass' Printer"; }
 168
 169   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 170     AU.addRequiredID(PassToPrint);
 171     AU.setPreservesAll();
 172   }
 173 };
 174
 175 char ModulePassPrinter::ID = 0;
 176 struct FunctionPassPrinter : public FunctionPass {
 177   const PassInfo *PassToPrint;
 178   static char ID;
 179   FunctionPassPrinter(const PassInfo *PI) : FunctionPass(&ID),
 180                                             PassToPrint(PI) {}
 181
 182   virtual bool runOnFunction(Function &F) {
 183     if (!Quiet) {
 184       cout << "Printing analysis '" << PassToPrint->getPassName()
 185            << "' for function '" << F.getName() << "':\n";
 186     }
 187     // Get and print pass...
 188     getAnalysisID<Pass>(PassToPrint).print(cout, F.getParent());
 189     return false;
 190   }
 191
 192   virtual const char *getPassName() const { return "FunctionPass Printer"; }
 193
 194   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 195     AU.addRequiredID(PassToPrint);
 196     AU.setPreservesAll();
 197   }
 198 };
 199
 200 char FunctionPassPrinter::ID = 0;
 201
 202 struct LoopPassPrinter : public LoopPass {
 203   static char ID;
 204   const PassInfo *PassToPrint;
 205   LoopPassPrinter(const PassInfo *PI) :
 206     LoopPass(&ID), PassToPrint(PI) {}
 207
 208   virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
 209     if (!Quiet) {
 210       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 211       getAnalysisID<Pass>(PassToPrint).print(cout,
 212                                   L->getHeader()->getParent()->getParent());
 213     }
 214     // Get and print pass...
 215     return false;
 216   }
 217
 218   virtual const char *getPassName() const { return "'Pass' Printer"; }
 219
 220   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 221     AU.addRequiredID(PassToPrint);
 222     AU.setPreservesAll();
 223   }
 224 };
 225
 226 char LoopPassPrinter::ID = 0;
 227
 228 struct BasicBlockPassPrinter : public BasicBlockPass {
 229   const PassInfo *PassToPrint;
 230   static char ID;
 231   BasicBlockPassPrinter(const PassInfo *PI)
 232     : BasicBlockPass(&ID), PassToPrint(PI) {}
 233
 234   virtual bool runOnBasicBlock(BasicBlock &BB) {
 235     if (!Quiet) {
 236       cout << "Printing Analysis info for BasicBlock '" << BB.getName()
 237            << "': Pass " << PassToPrint->getPassName() << ":\n";
 238     }
 239
 240     // Get and print pass...
 241     getAnalysisID<Pass>(PassToPrint).print(cout, BB.getParent()->getParent());
 242     return false;
 243   }
 244
 245   virtual const char *getPassName() const { return "BasicBlockPass Printer"; }
 246
 247   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 248     AU.addRequiredID(PassToPrint);
 249     AU.setPreservesAll();
 250   }
 251 };
 252
 253 char BasicBlockPassPrinter::ID = 0;
 254 inline void addPass(PassManager &PM, Pass *P) {
 255   // Add the pass to the pass manager...
 256   PM.add(P);
 257
 258   // If we are verifying all of the intermediate steps, add the verifier...
 259   if (VerifyEach) PM.add(createVerifierPass());
 260 }
 261
 262 /// AddOptimizationPasses - This routine adds optimization passes
 263 /// based on selected optimization level, OptLevel. This routine
 264 /// duplicates llvm-gcc behaviour.
 265 ///
 266 /// OptLevel - Optimization Level
 267 void AddOptimizationPasses(PassManager &MPM, FunctionPassManager &FPM,
 268                            unsigned OptLevel) {
 269
 270   if (OptLevel == 0)
 271     return;
 272
 273   FPM.add(createCFGSimplificationPass());
 274   if (OptLevel == 1)
 275     FPM.add(createPromoteMemoryToRegisterPass());
 276   else
 277     FPM.add(createScalarReplAggregatesPass());
 278   FPM.add(createInstructionCombiningPass());
 279
 280   if (UnitAtATime)
 281     MPM.add(createRaiseAllocationsPass());      // call %malloc -> malloc inst
 282   MPM.add(createCFGSimplificationPass());       // Clean up disgusting code
 283   MPM.add(createPromoteMemoryToRegisterPass()); // Kill useless allocas
 284   if (UnitAtATime) {
 285     MPM.add(createGlobalOptimizerPass());       // OptLevel out global vars
 286     MPM.add(createGlobalDCEPass());             // Remove unused fns and globs
 287     MPM.add(createIPConstantPropagationPass()); // IP Constant Propagation
 288     MPM.add(createDeadArgEliminationPass());    // Dead argument elimination
 289   }
 290   MPM.add(createInstructionCombiningPass());    // Clean up after IPCP & DAE
 291   MPM.add(createCFGSimplificationPass());       // Clean up after IPCP & DAE
 292   if (UnitAtATime) {
 293     MPM.add(createPruneEHPass());               // Remove dead EH info
 294     MPM.add(createFunctionAttrsPass());         // Deduce function attrs
 295   }
 296   if (OptLevel > 1)
 297     MPM.add(createFunctionInliningPass());      // Inline small functions
 298   if (OptLevel > 2)
 299     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 300   if (!DisableSimplifyLibCalls)
 301     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 302   MPM.add(createInstructionCombiningPass());  // Cleanup for scalarrepl.
 303   MPM.add(createJumpThreadingPass());         // Thread jumps.
 304   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 305   MPM.add(createScalarReplAggregatesPass());  // Break up aggregate allocas
 306   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 307   MPM.add(createCondPropagationPass());       // Propagate conditionals
 308   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 309   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 310   MPM.add(createReassociatePass());           // Reassociate expressions
 311   MPM.add(createLoopRotatePass());            // Rotate Loop
 312   MPM.add(createLICMPass());                  // Hoist loop invariants
 313   MPM.add(createLoopUnswitchPass());
 314   MPM.add(createLoopIndexSplitPass());        // Split loop index
 315   MPM.add(createInstructionCombiningPass());
 316   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 317   MPM.add(createLoopDeletionPass());          // Delete dead loops
 318   if (OptLevel > 1)
 319     MPM.add(createLoopUnrollPass());          // Unroll small loops
 320   MPM.add(createInstructionCombiningPass());  // Clean up after the unroller
 321   MPM.add(createGVNPass());                   // Remove redundancies
 322   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 323   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 324
 325   // Run instcombine after redundancy elimination to exploit opportunities
 326   // opened up by them.
 327   MPM.add(createInstructionCombiningPass());
 328   MPM.add(createCondPropagationPass());       // Propagate conditionals
 329   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 330   MPM.add(createAggressiveDCEPass());   // Delete dead instructions
 331   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 332
 333   if (UnitAtATime) {
 334     MPM.add(createStripDeadPrototypesPass());   // Get rid of dead prototypes
 335     MPM.add(createDeadTypeEliminationPass());   // Eliminate dead types
 336   }
 337
 338   if (OptLevel > 1 && UnitAtATime)
 339     MPM.add(createConstantMergePass());       // Merge dup global constants
 340
 341   return;
 342 }
 343
 344 void AddStandardCompilePasses(PassManager &PM) {
 345   PM.add(createVerifierPass());                  // Verify that input is correct
 346
 347   addPass(PM, createLowerSetJmpPass());          // Lower llvm.setjmp/.longjmp
 348
 349   // If the -strip-debug command line option was specified, do it.
 350   if (StripDebug)
 351     addPass(PM, createStripSymbolsPass(true));
 352
 353   if (DisableOptimizations) return;
 354
 355   addPass(PM, createRaiseAllocationsPass());     // call %malloc -> malloc inst
 356   addPass(PM, createCFGSimplificationPass());    // Clean up disgusting code
 357   addPass(PM, createPromoteMemoryToRegisterPass());// Kill useless allocas
 358   addPass(PM, createGlobalOptimizerPass());      // Optimize out global vars
 359   addPass(PM, createGlobalDCEPass());            // Remove unused fns and globs
 360   addPass(PM, createIPConstantPropagationPass());// IP Constant Propagation
 361   addPass(PM, createDeadArgEliminationPass());   // Dead argument elimination
 362   addPass(PM, createInstructionCombiningPass()); // Clean up after IPCP & DAE
 363   addPass(PM, createCFGSimplificationPass());    // Clean up after IPCP & DAE
 364
 365   addPass(PM, createPruneEHPass());              // Remove dead EH info
 366   addPass(PM, createFunctionAttrsPass());        // Deduce function attrs
 367
 368   if (!DisableInline)
 369     addPass(PM, createFunctionInliningPass());   // Inline small functions
 370   addPass(PM, createArgumentPromotionPass());    // Scalarize uninlined fn args
 371
 372   addPass(PM, createSimplifyLibCallsPass());     // Library Call Optimizations
 373   addPass(PM, createInstructionCombiningPass()); // Cleanup for scalarrepl.
 374   addPass(PM, createJumpThreadingPass());        // Thread jumps.
 375   addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
 376   addPass(PM, createScalarReplAggregatesPass()); // Break up aggregate allocas
 377   addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
 378   addPass(PM, createCondPropagationPass());      // Propagate conditionals
 379
 380   addPass(PM, createTailCallEliminationPass());  // Eliminate tail calls
 381   addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
 382   addPass(PM, createReassociatePass());          // Reassociate expressions
 383   addPass(PM, createLoopRotatePass());
 384   addPass(PM, createLICMPass());                 // Hoist loop invariants
 385   addPass(PM, createLoopUnswitchPass());         // Unswitch loops.
 386   addPass(PM, createLoopIndexSplitPass());       // Index split loops.
 387   // FIXME : Removing instcombine causes nestedloop regression.
 388   addPass(PM, createInstructionCombiningPass());
 389   addPass(PM, createIndVarSimplifyPass());       // Canonicalize indvars
 390   addPass(PM, createLoopDeletionPass());         // Delete dead loops
 391   addPass(PM, createLoopUnrollPass());           // Unroll small loops
 392   addPass(PM, createInstructionCombiningPass()); // Clean up after the unroller
 393   addPass(PM, createGVNPass());                  // Remove redundancies
 394   addPass(PM, createMemCpyOptPass());            // Remove memcpy / form memset
 395   addPass(PM, createSCCPPass());                 // Constant prop with SCCP
 396
 397   // Run instcombine after redundancy elimination to exploit opportunities
 398   // opened up by them.
 399   addPass(PM, createInstructionCombiningPass());
 400   addPass(PM, createCondPropagationPass());      // Propagate conditionals
 401
 402   addPass(PM, createDeadStoreEliminationPass()); // Delete dead stores
 403   addPass(PM, createAggressiveDCEPass());        // Delete dead instructions
 404   addPass(PM, createCFGSimplificationPass());    // Merge & remove BBs
 405   addPass(PM, createStripDeadPrototypesPass());  // Get rid of dead prototypes
 406   addPass(PM, createDeadTypeEliminationPass());  // Eliminate dead types
 407   addPass(PM, createConstantMergePass());        // Merge dup global constants
 408 }
 409
 410 } // anonymous namespace
 411
 412
 413 //===----------------------------------------------------------------------===//
 414 // main for opt
 415 //
 416 int main(int argc, char **argv) {
 417   llvm_shutdown_obj X;  // Call llvm_shutdown() on exit.
 418   try {
 419     cl::ParseCommandLineOptions(argc, argv,
 420       "llvm .bc -> .bc modular optimizer and analysis printer\n");
 421     sys::PrintStackTraceOnErrorSignal();
 422
 423     // Allocate a full target machine description only if necessary.
 424     // FIXME: The choice of target should be controllable on the command line.
 425     std::auto_ptr<TargetMachine> target;
 426
 427     std::string ErrorMessage;
 428
 429     // Load the input module...
 430     std::auto_ptr<Module> M;
 431     if (MemoryBuffer *Buffer
 432           = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
 433       M.reset(ParseBitcodeFile(Buffer, &ErrorMessage));
 434       delete Buffer;
 435     }
 436
 437     if (M.get() == 0) {
 438       cerr << argv[0] << ": ";
 439       if (ErrorMessage.size())
 440         cerr << ErrorMessage << "\n";
 441       else
 442         cerr << "bitcode didn't read correctly.\n";
 443       return 1;
 444     }
 445
 446     // Figure out what stream we are supposed to write to...
 447     // FIXME: cout is not binary!
 448     std::ostream *Out = &std::cout;  // Default to printing to stdout...
 449     if (OutputFilename != "-") {
 450       if (!Force && std::ifstream(OutputFilename.c_str())) {
 451         // If force is not specified, make sure not to overwrite a file!
 452         cerr << argv[0] << ": error opening '" << OutputFilename
 453              << "': file exists!\n"
 454              << "Use -f command line argument to force output\n";
 455         return 1;
 456       }
 457       std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 458                                    std::ios::binary;
 459       Out = new std::ofstream(OutputFilename.c_str(), io_mode);
 460
 461       if (!Out->good()) {
 462         cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
 463         return 1;
 464       }
 465
 466       // Make sure that the Output file gets unlinked from the disk if we get a
 467       // SIGINT
 468       sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 469     }
 470
 471     // If the output is set to be emitted to standard out, and standard out is a
 472     // console, print out a warning message and refuse to do it.  We don't
 473     // impress anyone by spewing tons of binary goo to a terminal.
 474     if (!Force && !NoOutput && CheckBitcodeOutputToConsole(Out,!Quiet)) {
 475       NoOutput = true;
 476     }
 477
 478     // Create a PassManager to hold and optimize the collection of passes we are
 479     // about to build...
 480     //
 481     PassManager Passes;
 482
 483     // Add an appropriate TargetData instance for this module...
 484     Passes.add(new TargetData(M.get()));
 485
 486     FunctionPassManager *FPasses = NULL;
 487     if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
 488       FPasses = new FunctionPassManager(new ExistingModuleProvider(M.get()));
 489       FPasses->add(new TargetData(M.get()));
 490     }
 491
 492     // If the -strip-debug command line option was specified, add it.  If
 493     // -std-compile-opts was also specified, it will handle StripDebug.
 494     if (StripDebug && !StandardCompileOpts)
 495       addPass(Passes, createStripSymbolsPass(true));
 496
 497     // Create a new optimization pass for each one specified on the command line
 498     for (unsigned i = 0; i < PassList.size(); ++i) {
 499       // Check to see if -std-compile-opts was specified before this option.  If
 500       // so, handle it.
 501       if (StandardCompileOpts &&
 502           StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
 503         AddStandardCompilePasses(Passes);
 504         StandardCompileOpts = false;
 505       }
 506
 507       if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
 508         AddOptimizationPasses(Passes, *FPasses, 1);
 509         OptLevelO1 = false;
 510       }
 511
 512       if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
 513         AddOptimizationPasses(Passes, *FPasses, 2);
 514         OptLevelO2 = false;
 515       }
 516
 517       if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
 518         AddOptimizationPasses(Passes, *FPasses, 3);
 519         OptLevelO3 = false;
 520       }
 521
 522       const PassInfo *PassInf = PassList[i];
 523       Pass *P = 0;
 524       if (PassInf->getNormalCtor())
 525         P = PassInf->getNormalCtor()();
 526       else
 527         cerr << argv[0] << ": cannot create pass: "
 528              << PassInf->getPassName() << "\n";
 529       if (P) {
 530         bool isBBPass = dynamic_cast<BasicBlockPass*>(P) != 0;
 531         bool isLPass = !isBBPass && dynamic_cast<LoopPass*>(P) != 0;
 532         bool isFPass = !isLPass && dynamic_cast<FunctionPass*>(P) != 0;
 533         bool isCGSCCPass = !isFPass && dynamic_cast<CallGraphSCCPass*>(P) != 0;
 534
 535         addPass(Passes, P);
 536
 537         if (AnalyzeOnly) {
 538           if (isBBPass)
 539             Passes.add(new BasicBlockPassPrinter(PassInf));
 540           else if (isLPass)
 541             Passes.add(new LoopPassPrinter(PassInf));
 542           else if (isFPass)
 543             Passes.add(new FunctionPassPrinter(PassInf));
 544           else if (isCGSCCPass)
 545             Passes.add(new CallGraphSCCPassPrinter(PassInf));
 546           else
 547             Passes.add(new ModulePassPrinter(PassInf));
 548         }
 549       }
 550
 551       if (PrintEachXForm)
 552         Passes.add(createPrintModulePass(&errs()));
 553     }
 554
 555     // If -std-compile-opts was specified at the end of the pass list, add them.
 556     if (StandardCompileOpts) {
 557       AddStandardCompilePasses(Passes);
 558       StandardCompileOpts = false;
 559     }
 560
 561     if (OptLevelO1) {
 562         AddOptimizationPasses(Passes, *FPasses, 1);
 563       }
 564
 565     if (OptLevelO2) {
 566         AddOptimizationPasses(Passes, *FPasses, 2);
 567       }
 568
 569     if (OptLevelO3) {
 570         AddOptimizationPasses(Passes, *FPasses, 3);
 571       }
 572
 573     if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
 574       for (Module::iterator I = M.get()->begin(), E = M.get()->end();
 575            I != E; ++I)
 576         FPasses->run(*I);
 577     }
 578
 579     // Check that the module is well formed on completion of optimization
 580     if (!NoVerify && !VerifyEach)
 581       Passes.add(createVerifierPass());
 582
 583     // Write bitcode out to disk or cout as the last step...
 584     if (!NoOutput && !AnalyzeOnly)
 585       Passes.add(CreateBitcodeWriterPass(*Out));
 586
 587     // Now that we have all of the passes ready, run them.
 588     Passes.run(*M.get());
 589
 590     // Delete the ofstream.
 591     if (Out != &std::cout)
 592       delete Out;
 593     return 0;
 594
 595   } catch (const std::string& msg) {
 596     cerr << argv[0] << ": " << msg << "\n";
 597   } catch (...) {
 598     cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
 599   }
 600   llvm_shutdown();
 601   return 1;
 602 }