llvm-6502/tools/bugpoint/ExtractFunction.cpp
2003-11-11 22:41:34 +00:00

139 lines
4.7 KiB
C++

//===- ExtractFunction.cpp - Extract a function from Program --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements a method that extracts a function from program, cleans
// it up, and returns it as a new module.
//
//===----------------------------------------------------------------------===//
#include "BugDriver.h"
#include "llvm/Constant.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/Type.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Target/TargetData.h"
#include "Support/CommandLine.h"
namespace llvm {
bool DisableSimplifyCFG = false;
} // End llvm namespace
using namespace llvm;
namespace {
cl::opt<bool>
NoADCE("disable-adce",
cl::desc("Do not use the -adce pass to reduce testcases"));
cl::opt<bool>
NoDCE ("disable-dce",
cl::desc("Do not use the -dce pass to reduce testcases"));
cl::opt<bool, true>
NoSCFG("disable-simplifycfg", cl::location(DisableSimplifyCFG),
cl::desc("Do not use the -simplifycfg pass to reduce testcases"));
}
namespace llvm {
/// deleteInstructionFromProgram - This method clones the current Program and
/// deletes the specified instruction from the cloned module. It then runs a
/// series of cleanup passes (ADCE and SimplifyCFG) to eliminate any code which
/// depends on the value. The modified module is then returned.
///
Module *BugDriver::deleteInstructionFromProgram(Instruction *I,
unsigned Simplification) const {
Module *Result = CloneModule(Program);
BasicBlock *PBB = I->getParent();
Function *PF = PBB->getParent();
Module::iterator RFI = Result->begin(); // Get iterator to corresponding fn
std::advance(RFI, std::distance(Program->begin(), Module::iterator(PF)));
Function::iterator RBI = RFI->begin(); // Get iterator to corresponding BB
std::advance(RBI, std::distance(PF->begin(), Function::iterator(PBB)));
BasicBlock::iterator RI = RBI->begin(); // Get iterator to corresponding inst
std::advance(RI, std::distance(PBB->begin(), BasicBlock::iterator(I)));
I = RI; // Got the corresponding instruction!
// If this instruction produces a value, replace any users with null values
if (I->getType() != Type::VoidTy)
I->replaceAllUsesWith(Constant::getNullValue(I->getType()));
// Remove the instruction from the program.
I->getParent()->getInstList().erase(I);
// Spiff up the output a little bit.
PassManager Passes;
// Make sure that the appropriate target data is always used...
Passes.add(new TargetData("bugpoint", Result));
if (Simplification > 2 && !NoADCE)
Passes.add(createAggressiveDCEPass()); // Remove dead code...
//Passes.add(createInstructionCombiningPass());
if (Simplification > 1 && !NoDCE)
Passes.add(createDeadCodeEliminationPass());
if (Simplification && !DisableSimplifyCFG)
Passes.add(createCFGSimplificationPass()); // Delete dead control flow
Passes.add(createVerifierPass());
Passes.run(*Result);
return Result;
}
static const PassInfo *getPI(Pass *P) {
const PassInfo *PI = P->getPassInfo();
delete P;
return PI;
}
/// performFinalCleanups - This method clones the current Program and performs
/// a series of cleanups intended to get rid of extra cruft on the module
/// before handing it to the user...
///
Module *BugDriver::performFinalCleanups(Module *M, bool MayModifySemantics) {
// Make all functions external, so GlobalDCE doesn't delete them...
for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
I->setLinkage(GlobalValue::ExternalLinkage);
std::vector<const PassInfo*> CleanupPasses;
CleanupPasses.push_back(getPI(createFunctionResolvingPass()));
CleanupPasses.push_back(getPI(createGlobalDCEPass()));
CleanupPasses.push_back(getPI(createDeadTypeEliminationPass()));
CleanupPasses.push_back(getPI(createDeadArgHackingPass()));
std::swap(Program, M);
std::string Filename;
bool Failed = runPasses(CleanupPasses, Filename);
std::swap(Program, M);
if (Failed) {
std::cerr << "Final cleanups failed. Sorry. :(\n";
} else {
delete M;
M = ParseInputFile(Filename);
if (M == 0) {
std::cerr << getToolName() << ": Error reading bytecode file '"
<< Filename << "'!\n";
exit(1);
}
}
return M;
}
} // End llvm namespace