llvm-6502/tools/bugpoint/ExtractFunction.cpp
2003-03-07 18:17:13 +00:00

102 lines
4.0 KiB
C++

//===- ExtractFunction.cpp - Extract a function from Program --------------===//
//
// 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/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Type.h"
#include "llvm/Constant.h"
/// extractFunctionFromModule - This method is used to extract the specified
/// (non-external) function from the current program, slim down the module, and
/// then return it. This does not modify Program at all, it modifies a copy,
/// which it returns.
Module *BugDriver::extractFunctionFromModule(Function *F) const {
Module *Result = CloneModule(Program);
// Translate from the old module to the new copied module...
Module::iterator RFI = Result->begin(); // Get iterator to corresponding fn
std::advance(RFI, std::distance(Program->begin(), Module::iterator(F)));
// In addition to just parsing the input from GCC, we also want to spiff it up
// a little bit. Do this now.
//
PassManager Passes;
Passes.add(createFunctionExtractionPass(RFI)); // Extract the function
Passes.add(createGlobalDCEPass()); // Delete unreachable globals
Passes.add(createFunctionResolvingPass()); // Delete prototypes
Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
Passes.add(createVerifierPass());
Passes.run(*Result);
return Result;
}
/// 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);
// In addition to just parsing the input from GCC, we also want to spiff it up
// a little bit. Do this now.
//
PassManager Passes;
if (Simplification > 2)
Passes.add(createAggressiveDCEPass()); // Remove dead code...
//Passes.add(createInstructionCombiningPass());
if (Simplification > 1)
Passes.add(createDeadCodeEliminationPass());
if (Simplification)
Passes.add(createCFGSimplificationPass()); // Delete dead control flow
Passes.add(createVerifierPass());
Passes.run(*Result);
return Result;
}
/// 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() const {
PassManager CleanupPasses;
CleanupPasses.add(createFunctionResolvingPass());
CleanupPasses.add(createGlobalDCEPass());
CleanupPasses.add(createVerifierPass());
Module *M = CloneModule(Program);
CleanupPasses.run(*M);
return M;
}