ExtractFunction.cpp revision 5da69c79f9c4490c6657c207430dfeb1060fc4dd
1afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner//===- ExtractFunction.cpp - Extract a function from Program --------------===// 27c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// 37c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// The LLVM Compiler Infrastructure 47c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// 57c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// This file was developed by the LLVM research group and is distributed under 67c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// the University of Illinois Open Source License. See LICENSE.TXT for details. 77c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell// 87c0e022c5c4be4b11e199a53f73bbdd84e34aa80John Criswell//===----------------------------------------------------------------------===// 9afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner// 10afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner// This file implements a method that extracts a function from program, cleans 11afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner// it up, and returns it as a new module. 12afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner// 13afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner//===----------------------------------------------------------------------===// 14afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner 15afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner#include "BugDriver.h" 16e49603d79d220a795bd50684c8b1f503ee40f97fMisha Brukman#include "llvm/Constant.h" 17afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner#include "llvm/Module.h" 18afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner#include "llvm/PassManager.h" 19d1a85a744cc1001c2b7fc37cf37aca266964f519Brian Gaeke#include "llvm/Pass.h" 20e49603d79d220a795bd50684c8b1f503ee40f97fMisha Brukman#include "llvm/Type.h" 21e49603d79d220a795bd50684c8b1f503ee40f97fMisha Brukman#include "llvm/Analysis/Verifier.h" 22afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner#include "llvm/Transforms/IPO.h" 236520785dcd22012535934098942d57c07c7631c2Chris Lattner#include "llvm/Transforms/Scalar.h" 24afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner#include "llvm/Transforms/Utils/Cloning.h" 255da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner#include "llvm/Target/TargetData.h" 266db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner#include "Support/CommandLine.h" 276db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner 2847ae4a1cee5eec5767a11403c0fac7c91ec45461Chris Lattnerbool DisableSimplifyCFG = false; 2947ae4a1cee5eec5767a11403c0fac7c91ec45461Chris Lattner 306db70ef879916e6115ac97eb76e4fea973652e2cChris Lattnernamespace { 316db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner cl::opt<bool> 326db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner NoADCE("disable-adce", 336db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner cl::desc("Do not use the -adce pass to reduce testcases")); 346db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner cl::opt<bool> 356db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner NoDCE ("disable-dce", 366db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner cl::desc("Do not use the -dce pass to reduce testcases")); 3747ae4a1cee5eec5767a11403c0fac7c91ec45461Chris Lattner cl::opt<bool, true> 3847ae4a1cee5eec5767a11403c0fac7c91ec45461Chris Lattner NoSCFG("disable-simplifycfg", cl::location(DisableSimplifyCFG), 396db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner cl::desc("Do not use the -simplifycfg pass to reduce testcases")); 40dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner cl::opt<bool> 41dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner NoFinalCleanup("disable-final-cleanup", 42dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner cl::desc("Disable the final cleanup phase of narrowing")); 436db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner} 44afade9294af43c6b947b9aeaa1555883d5f853e3Chris Lattner 456520785dcd22012535934098942d57c07c7631c2Chris Lattner/// deleteInstructionFromProgram - This method clones the current Program and 466520785dcd22012535934098942d57c07c7631c2Chris Lattner/// deletes the specified instruction from the cloned module. It then runs a 476520785dcd22012535934098942d57c07c7631c2Chris Lattner/// series of cleanup passes (ADCE and SimplifyCFG) to eliminate any code which 486520785dcd22012535934098942d57c07c7631c2Chris Lattner/// depends on the value. The modified module is then returned. 496520785dcd22012535934098942d57c07c7631c2Chris Lattner/// 506520785dcd22012535934098942d57c07c7631c2Chris LattnerModule *BugDriver::deleteInstructionFromProgram(Instruction *I, 516520785dcd22012535934098942d57c07c7631c2Chris Lattner unsigned Simplification) const { 526520785dcd22012535934098942d57c07c7631c2Chris Lattner Module *Result = CloneModule(Program); 536520785dcd22012535934098942d57c07c7631c2Chris Lattner 546520785dcd22012535934098942d57c07c7631c2Chris Lattner BasicBlock *PBB = I->getParent(); 556520785dcd22012535934098942d57c07c7631c2Chris Lattner Function *PF = PBB->getParent(); 566520785dcd22012535934098942d57c07c7631c2Chris Lattner 576520785dcd22012535934098942d57c07c7631c2Chris Lattner Module::iterator RFI = Result->begin(); // Get iterator to corresponding fn 586520785dcd22012535934098942d57c07c7631c2Chris Lattner std::advance(RFI, std::distance(Program->begin(), Module::iterator(PF))); 596520785dcd22012535934098942d57c07c7631c2Chris Lattner 606520785dcd22012535934098942d57c07c7631c2Chris Lattner Function::iterator RBI = RFI->begin(); // Get iterator to corresponding BB 616520785dcd22012535934098942d57c07c7631c2Chris Lattner std::advance(RBI, std::distance(PF->begin(), Function::iterator(PBB))); 626520785dcd22012535934098942d57c07c7631c2Chris Lattner 636520785dcd22012535934098942d57c07c7631c2Chris Lattner BasicBlock::iterator RI = RBI->begin(); // Get iterator to corresponding inst 646520785dcd22012535934098942d57c07c7631c2Chris Lattner std::advance(RI, std::distance(PBB->begin(), BasicBlock::iterator(I))); 656520785dcd22012535934098942d57c07c7631c2Chris Lattner I = RI; // Got the corresponding instruction! 666520785dcd22012535934098942d57c07c7631c2Chris Lattner 676520785dcd22012535934098942d57c07c7631c2Chris Lattner // If this instruction produces a value, replace any users with null values 686520785dcd22012535934098942d57c07c7631c2Chris Lattner if (I->getType() != Type::VoidTy) 696520785dcd22012535934098942d57c07c7631c2Chris Lattner I->replaceAllUsesWith(Constant::getNullValue(I->getType())); 706520785dcd22012535934098942d57c07c7631c2Chris Lattner 716520785dcd22012535934098942d57c07c7631c2Chris Lattner // Remove the instruction from the program. 726520785dcd22012535934098942d57c07c7631c2Chris Lattner I->getParent()->getInstList().erase(I); 736520785dcd22012535934098942d57c07c7631c2Chris Lattner 7444be25716628941b4cccccf56a28ee0ba2606850Chris Lattner // Spiff up the output a little bit. 756520785dcd22012535934098942d57c07c7631c2Chris Lattner PassManager Passes; 765da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner // Make sure that the appropriate target data is always used... 775da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner Passes.add(new TargetData("bugpoint", Result)); 785da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner 796db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner if (Simplification > 2 && !NoADCE) 806520785dcd22012535934098942d57c07c7631c2Chris Lattner Passes.add(createAggressiveDCEPass()); // Remove dead code... 816520785dcd22012535934098942d57c07c7631c2Chris Lattner //Passes.add(createInstructionCombiningPass()); 826db70ef879916e6115ac97eb76e4fea973652e2cChris Lattner if (Simplification > 1 && !NoDCE) 836520785dcd22012535934098942d57c07c7631c2Chris Lattner Passes.add(createDeadCodeEliminationPass()); 8447ae4a1cee5eec5767a11403c0fac7c91ec45461Chris Lattner if (Simplification && !DisableSimplifyCFG) 856520785dcd22012535934098942d57c07c7631c2Chris Lattner Passes.add(createCFGSimplificationPass()); // Delete dead control flow 8610f22cb1a0f2755050218cd0e07221a0985c6b63Chris Lattner 8710f22cb1a0f2755050218cd0e07221a0985c6b63Chris Lattner Passes.add(createVerifierPass()); 886520785dcd22012535934098942d57c07c7631c2Chris Lattner Passes.run(*Result); 896520785dcd22012535934098942d57c07c7631c2Chris Lattner return Result; 906520785dcd22012535934098942d57c07c7631c2Chris Lattner} 91ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner 92ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner/// performFinalCleanups - This method clones the current Program and performs 93ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner/// a series of cleanups intended to get rid of extra cruft on the module 94ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner/// before handing it to the user... 95ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner/// 96587a6ce4b99346b5e785d0a5c360c6c6687b036aChris LattnerModule *BugDriver::performFinalCleanups(Module *InM) const { 97587a6ce4b99346b5e785d0a5c360c6c6687b036aChris Lattner Module *M = InM ? InM : CloneModule(Program); 9828b8ed90c75ce6c271500fa778fef252f267a5ffChris Lattner 99dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner // Allow disabling these passes if they crash bugpoint. 100dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner // 101dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner // FIXME: This should eventually run these passes in a pass list to prevent 102dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner // them from being able to crash bugpoint at all! 103dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner // 104dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner if (NoFinalCleanup) return M; 105dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner 10628b8ed90c75ce6c271500fa778fef252f267a5ffChris Lattner // Make all functions external, so GlobalDCE doesn't delete them... 10728b8ed90c75ce6c271500fa778fef252f267a5ffChris Lattner for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) 10828b8ed90c75ce6c271500fa778fef252f267a5ffChris Lattner I->setLinkage(GlobalValue::ExternalLinkage); 109dbe48dcaec69ff78e39e2d5faf4323ade6fffb04Chris Lattner 110ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner PassManager CleanupPasses; 1115da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner // Make sure that the appropriate target data is always used... 1125da69c79f9c4490c6657c207430dfeb1060fc4ddChris Lattner CleanupPasses.add(new TargetData("bugpoint", M)); 113ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner CleanupPasses.add(createFunctionResolvingPass()); 114ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner CleanupPasses.add(createGlobalDCEPass()); 11516608b4c853ba883ac4bf5c642c4a9b4977a4fbaChris Lattner CleanupPasses.add(createDeadTypeEliminationPass()); 116587a6ce4b99346b5e785d0a5c360c6c6687b036aChris Lattner CleanupPasses.add(createDeadArgEliminationPass(InM == 0)); 11710f22cb1a0f2755050218cd0e07221a0985c6b63Chris Lattner CleanupPasses.add(createVerifierPass()); 118ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner CleanupPasses.run(*M); 119ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner return M; 120ba386d943f4a83095d9c625cb0d46c1afe45ed1fChris Lattner} 121