Import LLVM, at r72732.vendor/llvm/llvm-r72732

1 files changed, 602 insertions, 0 deletions

diff --git a/tools/opt/opt.cpp b/tools/opt/opt.cpp
new file mode 100644
index 000000000000..680353ad2352
--- /dev/null
+++ b/tools/opt/opt.cpp
@@ -0,0 +1,602 @@
+//===- 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(&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(&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(&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(&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(&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;
+}