lib/Transforms/IPO/PassManagerBuilder.cpp - platform/external/llvm - Git at Google

 //===- PassManagerBuilder.cpp - Build Standard Pass -----------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the PassManagerBuilder class, which is used to set up a
 // "standard" optimization sequence suitable for languages like C and C++.
 //
 //===----------------------------------------------------------------------===//


 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm-c/Transforms/PassManagerBuilder.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/Verifier.h"
 #include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Vectorize.h"

 using namespace llvm;

 static cl::opt<bool>
 RunLoopVectorization("vectorize-loops",
                      cl::desc("Run the Loop vectorization passes"));

 static cl::opt<bool>
 RunBBVectorization("vectorize", cl::desc("Run the BB vectorization passes"));

 static cl::opt<bool>
 UseGVNAfterVectorization("use-gvn-after-vectorization",
   cl::init(false), cl::Hidden,
   cl::desc("Run GVN instead of Early CSE after vectorization passes"));

 static cl::opt<bool> UseNewSROA("use-new-sroa",
   cl::init(true), cl::Hidden,
   cl::desc("Enable the new, experimental SROA pass"));

 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
     LibraryInfo = 0;
     Inliner = 0;
     DisableSimplifyLibCalls = false;
     DisableUnitAtATime = false;
     DisableUnrollLoops = false;
     Vectorize = RunBBVectorization;
     LoopVectorize = RunLoopVectorization;
 }

 PassManagerBuilder::~PassManagerBuilder() {
   delete LibraryInfo;
   delete Inliner;
 }

 /// Set of global extensions, automatically added as part of the standard set.
 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;

 void PassManagerBuilder::addGlobalExtension(
     PassManagerBuilder::ExtensionPointTy Ty,
     PassManagerBuilder::ExtensionFn Fn) {
   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
 }

 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
   Extensions.push_back(std::make_pair(Ty, Fn));
 }

 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
                                            PassManagerBase &PM) const {
   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
     if ((*GlobalExtensions)[i].first == ETy)
       (*GlobalExtensions)[i].second(*this, PM);
   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
     if (Extensions[i].first == ETy)
       Extensions[i].second(*this, PM);
 }

 void
 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
   // BasicAliasAnalysis wins if they disagree. This is intended to help
   // support "obvious" type-punning idioms.
   PM.add(createTypeBasedAliasAnalysisPass());
   PM.add(createBasicAliasAnalysisPass());
 }

 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
   addExtensionsToPM(EP_EarlyAsPossible, FPM);

   // Add LibraryInfo if we have some.
   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));

   if (OptLevel == 0) return;

   addInitialAliasAnalysisPasses(FPM);

   FPM.add(createCFGSimplificationPass());
   if (UseNewSROA)
     FPM.add(createSROAPass());
   else
     FPM.add(createScalarReplAggregatesPass());
   FPM.add(createEarlyCSEPass());
   FPM.add(createLowerExpectIntrinsicPass());
 }

 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
   // If all optimizations are disabled, just run the always-inline pass.
   if (OptLevel == 0) {
     if (Inliner) {
       MPM.add(Inliner);
       Inliner = 0;
     }

     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
     // pass manager, but we don't want to add extensions into that pass manager.
     // To prevent this we must insert a no-op module pass to reset the pass
     // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
     if (!GlobalExtensions->empty() || !Extensions.empty())
       MPM.add(createBarrierNoopPass());

     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
     return;
   }

   // Add LibraryInfo if we have some.
   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));

   addInitialAliasAnalysisPasses(MPM);

   if (!DisableUnitAtATime) {
     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);

     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars

     MPM.add(createIPSCCPPass());              // IP SCCP
     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination

     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
   }

   // Start of CallGraph SCC passes.
   if (!DisableUnitAtATime)
     MPM.add(createPruneEHPass());             // Remove dead EH info
   if (Inliner) {
     MPM.add(Inliner);
     Inliner = 0;
   }
   if (!DisableUnitAtATime)
     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
   if (OptLevel > 2)
     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args

   // Start of function pass.
   // Break up aggregate allocas, using SSAUpdater.
   if (UseNewSROA)
     MPM.add(createSROAPass(/*RequiresDomTree*/ false));
   else
     MPM.add(createScalarReplAggregatesPass(-1, false));
   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
   if (!DisableSimplifyLibCalls)
     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
   MPM.add(createJumpThreadingPass());         // Thread jumps.
   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
   MPM.add(createInstructionCombiningPass());  // Combine silly seq's

   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(SizeLevel || OptLevel < 3));
   MPM.add(createInstructionCombiningPass());
   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
   MPM.add(createLoopDeletionPass());          // Delete dead loops

   if (LoopVectorize && OptLevel > 2)
     MPM.add(createLoopVectorizePass());

   if (!DisableUnrollLoops)
     MPM.add(createLoopUnrollPass());          // Unroll small loops
   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);

   if (OptLevel > 1)
     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(createJumpThreadingPass());         // Thread jumps
   MPM.add(createCorrelatedValuePropagationPass());
   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores

   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);

   if (Vectorize) {
     MPM.add(createBBVectorizePass());
     MPM.add(createInstructionCombiningPass());
     if (OptLevel > 1 && UseGVNAfterVectorization)
       MPM.add(createGVNPass());                   // Remove redundancies
     else
       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies

     // BBVectorize may have significantly shortened a loop body; unroll again.
     if (!DisableUnrollLoops)
       MPM.add(createLoopUnrollPass());
   }

   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
   MPM.add(createInstructionCombiningPass());  // Clean up after everything.

   if (!DisableUnitAtATime) {
     // FIXME: We shouldn't bother with this anymore.
     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes

     // GlobalOpt already deletes dead functions and globals, at -O2 try a
     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
     if (OptLevel > 1) {
       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
       MPM.add(createConstantMergePass());     // Merge dup global constants
     }
   }
   addExtensionsToPM(EP_OptimizerLast, MPM);
 }

 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
                                                 bool Internalize,
                                                 bool RunInliner,
                                                 bool DisableGVNLoadPRE) {
   // Provide AliasAnalysis services for optimizations.
   addInitialAliasAnalysisPasses(PM);

   // Now that composite has been compiled, scan through the module, looking
   // for a main function.  If main is defined, mark all other functions
   // internal.
   if (Internalize) {
     std::vector<const char*> E;
     E.push_back("main");
     PM.add(createInternalizePass(E));
   }

   // Propagate constants at call sites into the functions they call.  This
   // opens opportunities for globalopt (and inlining) by substituting function
   // pointers passed as arguments to direct uses of functions.
   PM.add(createIPSCCPPass());

   // Now that we internalized some globals, see if we can hack on them!
   PM.add(createGlobalOptimizerPass());

   // Linking modules together can lead to duplicated global constants, only
   // keep one copy of each constant.
   PM.add(createConstantMergePass());

   // Remove unused arguments from functions.
   PM.add(createDeadArgEliminationPass());

   // Reduce the code after globalopt and ipsccp.  Both can open up significant
   // simplification opportunities, and both can propagate functions through
   // function pointers.  When this happens, we often have to resolve varargs
   // calls, etc, so let instcombine do this.
   PM.add(createInstructionCombiningPass());

   // Inline small functions
   if (RunInliner)
     PM.add(createFunctionInliningPass());

   PM.add(createPruneEHPass());   // Remove dead EH info.

   // Optimize globals again if we ran the inliner.
   if (RunInliner)
     PM.add(createGlobalOptimizerPass());
   PM.add(createGlobalDCEPass()); // Remove dead functions.

   // If we didn't decide to inline a function, check to see if we can
   // transform it to pass arguments by value instead of by reference.
   PM.add(createArgumentPromotionPass());

   // The IPO passes may leave cruft around.  Clean up after them.
   PM.add(createInstructionCombiningPass());
   PM.add(createJumpThreadingPass());
   // Break up allocas
   if (UseNewSROA)
     PM.add(createSROAPass());
   else
     PM.add(createScalarReplAggregatesPass());

   // Run a few AA driven optimizations here and now, to cleanup the code.
   PM.add(createFunctionAttrsPass()); // Add nocapture.
   PM.add(createGlobalsModRefPass()); // IP alias analysis.

   PM.add(createLICMPass());                 // Hoist loop invariants.
   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
   // Nuke dead stores.
   PM.add(createDeadStoreEliminationPass());

   // Cleanup and simplify the code after the scalar optimizations.
   PM.add(createInstructionCombiningPass());

   PM.add(createJumpThreadingPass());

   // Delete basic blocks, which optimization passes may have killed.
   PM.add(createCFGSimplificationPass());

   // Now that we have optimized the program, discard unreachable functions.
   PM.add(createGlobalDCEPass());
 }

 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
   PassManagerBuilder *PMB = new PassManagerBuilder();
   return wrap(PMB);
 }

 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
   PassManagerBuilder *Builder = unwrap(PMB);
   delete Builder;
 }

 void
 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
                                   unsigned OptLevel) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->OptLevel = OptLevel;
 }

 void
 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
                                    unsigned SizeLevel) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->SizeLevel = SizeLevel;
 }

 void
 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
                                             LLVMBool Value) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->DisableUnitAtATime = Value;
 }

 void
 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
                                             LLVMBool Value) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->DisableUnrollLoops = Value;
 }

 void
 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
                                                  LLVMBool Value) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->DisableSimplifyLibCalls = Value;
 }

 void
 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
                                               unsigned Threshold) {
   PassManagerBuilder *Builder = unwrap(PMB);
   Builder->Inliner = createFunctionInliningPass(Threshold);
 }

 void
 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
                                                   LLVMPassManagerRef PM) {
   PassManagerBuilder *Builder = unwrap(PMB);
   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
   Builder->populateFunctionPassManager(*FPM);
 }

 void
 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
                                                 LLVMPassManagerRef PM) {
   PassManagerBuilder *Builder = unwrap(PMB);
   PassManagerBase *MPM = unwrap(PM);
   Builder->populateModulePassManager(*MPM);
 }

 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
                                                   LLVMPassManagerRef PM,
                                                   LLVMBool Internalize,
                                                   LLVMBool RunInliner) {
   PassManagerBuilder *Builder = unwrap(PMB);
   PassManagerBase *LPM = unwrap(PM);
   Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
 }
	//===- PassManagerBuilder.cpp - Build Standard Pass -----------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file defines the PassManagerBuilder class, which is used to set up a
	// "standard" optimization sequence suitable for languages like C and C++.
	//
	//===----------------------------------------------------------------------===//


	#include "llvm/Transforms/IPO/PassManagerBuilder.h"
	#include "llvm-c/Transforms/PassManagerBuilder.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/Analysis/Passes.h"
	#include "llvm/Analysis/Verifier.h"
	#include "llvm/PassManager.h"
	#include "llvm/Support/CommandLine.h"
	#include "llvm/Support/ManagedStatic.h"
	#include "llvm/Target/TargetLibraryInfo.h"
	#include "llvm/Transforms/IPO.h"
	#include "llvm/Transforms/Scalar.h"
	#include "llvm/Transforms/Vectorize.h"

	using namespace llvm;

	static cl::opt<bool>
	RunLoopVectorization("vectorize-loops",
	cl::desc("Run the Loop vectorization passes"));

	static cl::opt<bool>
	RunBBVectorization("vectorize", cl::desc("Run the BB vectorization passes"));

	static cl::opt<bool>
	UseGVNAfterVectorization("use-gvn-after-vectorization",
	cl::init(false), cl::Hidden,
	cl::desc("Run GVN instead of Early CSE after vectorization passes"));

	static cl::opt<bool> UseNewSROA("use-new-sroa",
	cl::init(true), cl::Hidden,
	cl::desc("Enable the new, experimental SROA pass"));

	PassManagerBuilder::PassManagerBuilder() {
	OptLevel = 2;
	SizeLevel = 0;
	LibraryInfo = 0;
	Inliner = 0;
	DisableSimplifyLibCalls = false;
	DisableUnitAtATime = false;
	DisableUnrollLoops = false;
	Vectorize = RunBBVectorization;
	LoopVectorize = RunLoopVectorization;
	}

	PassManagerBuilder::~PassManagerBuilder() {
	delete LibraryInfo;
	delete Inliner;
	}

	/// Set of global extensions, automatically added as part of the standard set.
	static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
	PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;

	void PassManagerBuilder::addGlobalExtension(
	PassManagerBuilder::ExtensionPointTy Ty,
	PassManagerBuilder::ExtensionFn Fn) {
	GlobalExtensions->push_back(std::make_pair(Ty, Fn));
	}

	void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
	Extensions.push_back(std::make_pair(Ty, Fn));
	}

	void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
	PassManagerBase &PM) const {
	for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
	if ((*GlobalExtensions)[i].first == ETy)
	(GlobalExtensions)[i].second(this, PM);
	for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
	if (Extensions[i].first == ETy)
	Extensions[i].second(*this, PM);
	}

	void
	PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
	// Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
	// BasicAliasAnalysis wins if they disagree. This is intended to help
	// support "obvious" type-punning idioms.
	PM.add(createTypeBasedAliasAnalysisPass());
	PM.add(createBasicAliasAnalysisPass());
	}

	void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
	addExtensionsToPM(EP_EarlyAsPossible, FPM);

	// Add LibraryInfo if we have some.
	if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));

	if (OptLevel == 0) return;

	addInitialAliasAnalysisPasses(FPM);

	FPM.add(createCFGSimplificationPass());
	if (UseNewSROA)
	FPM.add(createSROAPass());
	else
	FPM.add(createScalarReplAggregatesPass());
	FPM.add(createEarlyCSEPass());
	FPM.add(createLowerExpectIntrinsicPass());
	}

	void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
	// If all optimizations are disabled, just run the always-inline pass.
	if (OptLevel == 0) {
	if (Inliner) {
	MPM.add(Inliner);
	Inliner = 0;
	}

	// FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
	// pass manager, but we don't want to add extensions into that pass manager.
	// To prevent this we must insert a no-op module pass to reset the pass
	// manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
	if (!GlobalExtensions->empty() \|\| !Extensions.empty())
	MPM.add(createBarrierNoopPass());

	addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
	return;
	}

	// Add LibraryInfo if we have some.
	if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));

	addInitialAliasAnalysisPasses(MPM);

	if (!DisableUnitAtATime) {
	addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);

	MPM.add(createGlobalOptimizerPass()); // Optimize out global vars

	MPM.add(createIPSCCPPass()); // IP SCCP
	MPM.add(createDeadArgEliminationPass()); // Dead argument elimination

	MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
	MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE
	}

	// Start of CallGraph SCC passes.
	if (!DisableUnitAtATime)
	MPM.add(createPruneEHPass()); // Remove dead EH info
	if (Inliner) {
	MPM.add(Inliner);
	Inliner = 0;
	}
	if (!DisableUnitAtATime)
	MPM.add(createFunctionAttrsPass()); // Set readonly/readnone attrs
	if (OptLevel > 2)
	MPM.add(createArgumentPromotionPass()); // Scalarize uninlined fn args

	// Start of function pass.
	// Break up aggregate allocas, using SSAUpdater.
	if (UseNewSROA)
	MPM.add(createSROAPass(/RequiresDomTree/ false));
	else
	MPM.add(createScalarReplAggregatesPass(-1, false));
	MPM.add(createEarlyCSEPass()); // Catch trivial redundancies
	if (!DisableSimplifyLibCalls)
	MPM.add(createSimplifyLibCallsPass()); // Library Call Optimizations
	MPM.add(createJumpThreadingPass()); // Thread jumps.
	MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
	MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
	MPM.add(createInstructionCombiningPass()); // Combine silly seq's

	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(SizeLevel \|\| OptLevel < 3));
	MPM.add(createInstructionCombiningPass());
	MPM.add(createIndVarSimplifyPass()); // Canonicalize indvars
	MPM.add(createLoopIdiomPass()); // Recognize idioms like memset.
	MPM.add(createLoopDeletionPass()); // Delete dead loops

	if (LoopVectorize && OptLevel > 2)
	MPM.add(createLoopVectorizePass());

	if (!DisableUnrollLoops)
	MPM.add(createLoopUnrollPass()); // Unroll small loops
	addExtensionsToPM(EP_LoopOptimizerEnd, MPM);

	if (OptLevel > 1)
	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(createJumpThreadingPass()); // Thread jumps
	MPM.add(createCorrelatedValuePropagationPass());
	MPM.add(createDeadStoreEliminationPass()); // Delete dead stores

	addExtensionsToPM(EP_ScalarOptimizerLate, MPM);

	if (Vectorize) {
	MPM.add(createBBVectorizePass());
	MPM.add(createInstructionCombiningPass());
	if (OptLevel > 1 && UseGVNAfterVectorization)
	MPM.add(createGVNPass()); // Remove redundancies
	else
	MPM.add(createEarlyCSEPass()); // Catch trivial redundancies

	// BBVectorize may have significantly shortened a loop body; unroll again.
	if (!DisableUnrollLoops)
	MPM.add(createLoopUnrollPass());
	}

	MPM.add(createAggressiveDCEPass()); // Delete dead instructions
	MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
	MPM.add(createInstructionCombiningPass()); // Clean up after everything.

	if (!DisableUnitAtATime) {
	// FIXME: We shouldn't bother with this anymore.
	MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes

	// GlobalOpt already deletes dead functions and globals, at -O2 try a
	// late pass of GlobalDCE. It is capable of deleting dead cycles.
	if (OptLevel > 1) {
	MPM.add(createGlobalDCEPass()); // Remove dead fns and globals.
	MPM.add(createConstantMergePass()); // Merge dup global constants
	}
	}
	addExtensionsToPM(EP_OptimizerLast, MPM);
	}

	void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
	bool Internalize,
	bool RunInliner,
	bool DisableGVNLoadPRE) {
	// Provide AliasAnalysis services for optimizations.
	addInitialAliasAnalysisPasses(PM);

	// Now that composite has been compiled, scan through the module, looking
	// for a main function. If main is defined, mark all other functions
	// internal.
	if (Internalize) {
	std::vector<const char*> E;
	E.push_back("main");
	PM.add(createInternalizePass(E));
	}

	// Propagate constants at call sites into the functions they call. This
	// opens opportunities for globalopt (and inlining) by substituting function
	// pointers passed as arguments to direct uses of functions.
	PM.add(createIPSCCPPass());

	// Now that we internalized some globals, see if we can hack on them!
	PM.add(createGlobalOptimizerPass());

	// Linking modules together can lead to duplicated global constants, only
	// keep one copy of each constant.
	PM.add(createConstantMergePass());

	// Remove unused arguments from functions.
	PM.add(createDeadArgEliminationPass());

	// Reduce the code after globalopt and ipsccp. Both can open up significant
	// simplification opportunities, and both can propagate functions through
	// function pointers. When this happens, we often have to resolve varargs
	// calls, etc, so let instcombine do this.
	PM.add(createInstructionCombiningPass());

	// Inline small functions
	if (RunInliner)
	PM.add(createFunctionInliningPass());

	PM.add(createPruneEHPass()); // Remove dead EH info.

	// Optimize globals again if we ran the inliner.
	if (RunInliner)
	PM.add(createGlobalOptimizerPass());
	PM.add(createGlobalDCEPass()); // Remove dead functions.

	// If we didn't decide to inline a function, check to see if we can
	// transform it to pass arguments by value instead of by reference.
	PM.add(createArgumentPromotionPass());

	// The IPO passes may leave cruft around. Clean up after them.
	PM.add(createInstructionCombiningPass());
	PM.add(createJumpThreadingPass());
	// Break up allocas
	if (UseNewSROA)
	PM.add(createSROAPass());
	else
	PM.add(createScalarReplAggregatesPass());

	// Run a few AA driven optimizations here and now, to cleanup the code.
	PM.add(createFunctionAttrsPass()); // Add nocapture.
	PM.add(createGlobalsModRefPass()); // IP alias analysis.

	PM.add(createLICMPass()); // Hoist loop invariants.
	PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
	PM.add(createMemCpyOptPass()); // Remove dead memcpys.
	// Nuke dead stores.
	PM.add(createDeadStoreEliminationPass());

	// Cleanup and simplify the code after the scalar optimizations.
	PM.add(createInstructionCombiningPass());

	PM.add(createJumpThreadingPass());

	// Delete basic blocks, which optimization passes may have killed.
	PM.add(createCFGSimplificationPass());

	// Now that we have optimized the program, discard unreachable functions.
	PM.add(createGlobalDCEPass());
	}

	LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
	PassManagerBuilder *PMB = new PassManagerBuilder();
	return wrap(PMB);
	}

	void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
	PassManagerBuilder *Builder = unwrap(PMB);
	delete Builder;
	}

	void
	LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
	unsigned OptLevel) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->OptLevel = OptLevel;
	}

	void
	LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
	unsigned SizeLevel) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->SizeLevel = SizeLevel;
	}

	void
	LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
	LLVMBool Value) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->DisableUnitAtATime = Value;
	}

	void
	LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
	LLVMBool Value) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->DisableUnrollLoops = Value;
	}

	void
	LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
	LLVMBool Value) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->DisableSimplifyLibCalls = Value;
	}

	void
	LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
	unsigned Threshold) {
	PassManagerBuilder *Builder = unwrap(PMB);
	Builder->Inliner = createFunctionInliningPass(Threshold);
	}

	void
	LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
	LLVMPassManagerRef PM) {
	PassManagerBuilder *Builder = unwrap(PMB);
	FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
	Builder->populateFunctionPassManager(*FPM);
	}

	void
	LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
	LLVMPassManagerRef PM) {
	PassManagerBuilder *Builder = unwrap(PMB);
	PassManagerBase *MPM = unwrap(PM);
	Builder->populateModulePassManager(*MPM);
	}

	void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
	LLVMPassManagerRef PM,
	LLVMBool Internalize,
	LLVMBool RunInliner) {
	PassManagerBuilder *Builder = unwrap(PMB);
	PassManagerBase *LPM = unwrap(PM);
	Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
	}