| //===- LevelRaise.cpp - Code to change LLVM to higher level ---------------===// |
| // |
| // 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 the 'raising' part of the LevelChange API. This is |
| // useful because, in general, it makes the LLVM code terser and easier to |
| // analyze. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Transforms/Utils/Local.h" |
| #include "TransformInternals.h" |
| #include "llvm/iOther.h" |
| #include "llvm/iMemory.h" |
| #include "llvm/Pass.h" |
| #include "llvm/ConstantHandling.h" |
| #include "llvm/Analysis/Expressions.h" |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Transforms/Utils/BasicBlockUtils.h" |
| #include "Support/CommandLine.h" |
| #include "Support/Debug.h" |
| #include "Support/Statistic.h" |
| #include "Support/STLExtras.h" |
| #include <algorithm> |
| |
| namespace llvm { |
| |
| // StartInst - This enables the -raise-start-inst=foo option to cause the level |
| // raising pass to start at instruction "foo", which is immensely useful for |
| // debugging! |
| // |
| static cl::opt<std::string> |
| StartInst("raise-start-inst", cl::Hidden, cl::value_desc("inst name"), |
| cl::desc("Start raise pass at the instruction with the specified name")); |
| |
| static Statistic<> |
| NumLoadStorePeepholes("raise", "Number of load/store peepholes"); |
| |
| static Statistic<> |
| NumGEPInstFormed("raise", "Number of other getelementptr's formed"); |
| |
| static Statistic<> |
| NumExprTreesConv("raise", "Number of expression trees converted"); |
| |
| static Statistic<> |
| NumCastOfCast("raise", "Number of cast-of-self removed"); |
| |
| static Statistic<> |
| NumDCEorCP("raise", "Number of insts DCEd or constprop'd"); |
| |
| static Statistic<> |
| NumVarargCallChanges("raise", "Number of vararg call peepholes"); |
| |
| #define PRINT_PEEPHOLE(ID, NUM, I) \ |
| DEBUG(std::cerr << "Inst P/H " << ID << "[" << NUM << "] " << I) |
| |
| #define PRINT_PEEPHOLE1(ID, I1) do { PRINT_PEEPHOLE(ID, 0, I1); } while (0) |
| #define PRINT_PEEPHOLE2(ID, I1, I2) \ |
| do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); } while (0) |
| #define PRINT_PEEPHOLE3(ID, I1, I2, I3) \ |
| do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \ |
| PRINT_PEEPHOLE(ID, 2, I3); } while (0) |
| #define PRINT_PEEPHOLE4(ID, I1, I2, I3, I4) \ |
| do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \ |
| PRINT_PEEPHOLE(ID, 2, I3); PRINT_PEEPHOLE(ID, 3, I4); } while (0) |
| |
| namespace { |
| struct RPR : public FunctionPass { |
| virtual bool runOnFunction(Function &F); |
| |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesCFG(); |
| AU.addRequired<TargetData>(); |
| } |
| |
| private: |
| bool DoRaisePass(Function &F); |
| bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI); |
| }; |
| |
| RegisterOpt<RPR> X("raise", "Raise Pointer References"); |
| } |
| |
| |
| Pass *createRaisePointerReferencesPass() { |
| return new RPR(); |
| } |
| |
| |
| // isReinterpretingCast - Return true if the cast instruction specified will |
| // cause the operand to be "reinterpreted". A value is reinterpreted if the |
| // cast instruction would cause the underlying bits to change. |
| // |
| static inline bool isReinterpretingCast(const CastInst *CI) { |
| return!CI->getOperand(0)->getType()->isLosslesslyConvertibleTo(CI->getType()); |
| } |
| |
| |
| // Peephole optimize the following instructions: |
| // %t1 = cast ? to x * |
| // %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand |
| // |
| // Into: %t3 = getelementptr {<...>} * %SP, <element indices> |
| // %t2 = cast <eltype> * %t3 to {<...>}* |
| // |
| static bool HandleCastToPointer(BasicBlock::iterator BI, |
| const PointerType *DestPTy, |
| const TargetData &TD) { |
| CastInst &CI = cast<CastInst>(*BI); |
| if (CI.use_empty()) return false; |
| |
| // Scan all of the uses, looking for any uses that are not add or sub |
| // instructions. If we have non-adds, do not make this transformation. |
| // |
| bool HasSubUse = false; // Keep track of any subtracts... |
| for (Value::use_iterator I = CI.use_begin(), E = CI.use_end(); |
| I != E; ++I) |
| if (BinaryOperator *BO = dyn_cast<BinaryOperator>(*I)) { |
| if ((BO->getOpcode() != Instruction::Add && |
| BO->getOpcode() != Instruction::Sub) || |
| // Avoid add sbyte* %X, %X cases... |
| BO->getOperand(0) == BO->getOperand(1)) |
| return false; |
| else |
| HasSubUse |= BO->getOpcode() == Instruction::Sub; |
| } else { |
| return false; |
| } |
| |
| std::vector<Value*> Indices; |
| Value *Src = CI.getOperand(0); |
| const Type *Result = ConvertibleToGEP(DestPTy, Src, Indices, TD, &BI); |
| if (Result == 0) return false; // Not convertible... |
| |
| // Cannot handle subtracts if there is more than one index required... |
| if (HasSubUse && Indices.size() != 1) return false; |
| |
| PRINT_PEEPHOLE2("cast-add-to-gep:in", Src, CI); |
| |
| // If we have a getelementptr capability... transform all of the |
| // add instruction uses into getelementptr's. |
| while (!CI.use_empty()) { |
| BinaryOperator *I = cast<BinaryOperator>(*CI.use_begin()); |
| assert((I->getOpcode() == Instruction::Add || |
| I->getOpcode() == Instruction::Sub) && |
| "Use is not a valid add instruction!"); |
| |
| // Get the value added to the cast result pointer... |
| Value *OtherPtr = I->getOperand((I->getOperand(0) == &CI) ? 1 : 0); |
| |
| Instruction *GEP = new GetElementPtrInst(OtherPtr, Indices, I->getName()); |
| PRINT_PEEPHOLE1("cast-add-to-gep:i", I); |
| |
| // If the instruction is actually a subtract, we are guaranteed to only have |
| // one index (from code above), so we just need to negate the pointer index |
| // long value. |
| if (I->getOpcode() == Instruction::Sub) { |
| Instruction *Neg = BinaryOperator::createNeg(GEP->getOperand(1), |
| GEP->getOperand(1)->getName()+".neg", I); |
| GEP->setOperand(1, Neg); |
| } |
| |
| if (GEP->getType() == I->getType()) { |
| // Replace the old add instruction with the shiny new GEP inst |
| ReplaceInstWithInst(I, GEP); |
| } else { |
| // If the type produced by the gep instruction differs from the original |
| // add instruction type, insert a cast now. |
| // |
| |
| // Insert the GEP instruction before the old add instruction... |
| I->getParent()->getInstList().insert(I, GEP); |
| |
| PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP); |
| GEP = new CastInst(GEP, I->getType()); |
| |
| // Replace the old add instruction with the shiny new GEP inst |
| ReplaceInstWithInst(I, GEP); |
| } |
| |
| PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP); |
| } |
| return true; |
| } |
| |
| // Peephole optimize the following instructions: |
| // %t1 = cast ulong <const int> to {<...>} * |
| // %t2 = add {<...>} * %SP, %t1 ;; Constant must be 2nd operand |
| // |
| // or |
| // %t1 = cast {<...>}* %SP to int* |
| // %t5 = cast ulong <const int> to int* |
| // %t2 = add int* %t1, %t5 ;; int is same size as field |
| // |
| // Into: %t3 = getelementptr {<...>} * %SP, <element indices> |
| // %t2 = cast <eltype> * %t3 to {<...>}* |
| // |
| static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, |
| Value *AddOp1, CastInst *AddOp2, |
| const TargetData &TD) { |
| const CompositeType *CompTy; |
| Value *OffsetVal = AddOp2->getOperand(0); |
| Value *SrcPtr = 0; // Of type pointer to struct... |
| |
| if ((CompTy = getPointedToComposite(AddOp1->getType()))) { |
| SrcPtr = AddOp1; // Handle the first case... |
| } else if (CastInst *AddOp1c = dyn_cast<CastInst>(AddOp1)) { |
| SrcPtr = AddOp1c->getOperand(0); // Handle the second case... |
| CompTy = getPointedToComposite(SrcPtr->getType()); |
| } |
| |
| // Only proceed if we have detected all of our conditions successfully... |
| if (!CompTy || !SrcPtr || !OffsetVal->getType()->isInteger()) |
| return false; |
| |
| std::vector<Value*> Indices; |
| if (!ConvertibleToGEP(SrcPtr->getType(), OffsetVal, Indices, TD, &BI)) |
| return false; // Not convertible... perhaps next time |
| |
| if (getPointedToComposite(AddOp1->getType())) { // case 1 |
| PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, *BI); |
| } else { |
| PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, *BI); |
| } |
| |
| GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices, |
| AddOp2->getName(), BI); |
| |
| Instruction *NCI = new CastInst(GEP, AddOp1->getType()); |
| ReplaceInstWithInst(BB->getInstList(), BI, NCI); |
| PRINT_PEEPHOLE2("add-to-gep:out", GEP, NCI); |
| return true; |
| } |
| |
| bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { |
| Instruction *I = BI; |
| const TargetData &TD = getAnalysis<TargetData>(); |
| |
| if (CastInst *CI = dyn_cast<CastInst>(I)) { |
| Value *Src = CI->getOperand(0); |
| Instruction *SrcI = dyn_cast<Instruction>(Src); // Nonnull if instr source |
| const Type *DestTy = CI->getType(); |
| |
| // Peephole optimize the following instruction: |
| // %V2 = cast <ty> %V to <ty> |
| // |
| // Into: <nothing> |
| // |
| if (DestTy == Src->getType()) { // Check for a cast to same type as src!! |
| PRINT_PEEPHOLE1("cast-of-self-ty", CI); |
| CI->replaceAllUsesWith(Src); |
| if (!Src->hasName() && CI->hasName()) { |
| std::string Name = CI->getName(); |
| CI->setName(""); |
| Src->setName(Name, &BB->getParent()->getSymbolTable()); |
| } |
| |
| // DCE the instruction now, to avoid having the iterative version of DCE |
| // have to worry about it. |
| // |
| BI = BB->getInstList().erase(BI); |
| |
| ++NumCastOfCast; |
| return true; |
| } |
| |
| // Check to see if it's a cast of an instruction that does not depend on the |
| // specific type of the operands to do it's job. |
| if (!isReinterpretingCast(CI)) { |
| ValueTypeCache ConvertedTypes; |
| |
| // Check to see if we can convert the source of the cast to match the |
| // destination type of the cast... |
| // |
| ConvertedTypes[CI] = CI->getType(); // Make sure the cast doesn't change |
| if (ExpressionConvertibleToType(Src, DestTy, ConvertedTypes, TD)) { |
| PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent()); |
| |
| DEBUG(std::cerr << "\nCONVERTING SRC EXPR TYPE:\n"); |
| { // ValueMap must be destroyed before function verified! |
| ValueMapCache ValueMap; |
| Value *E = ConvertExpressionToType(Src, DestTy, ValueMap, TD); |
| |
| if (Constant *CPV = dyn_cast<Constant>(E)) |
| CI->replaceAllUsesWith(CPV); |
| |
| PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E); |
| DEBUG(std::cerr << "DONE CONVERTING SRC EXPR TYPE: \n" |
| << BB->getParent()); |
| } |
| |
| DEBUG(assert(verifyFunction(*BB->getParent()) == false && |
| "Function broken!")); |
| BI = BB->begin(); // Rescan basic block. BI might be invalidated. |
| ++NumExprTreesConv; |
| return true; |
| } |
| |
| // Check to see if we can convert the users of the cast value to match the |
| // source type of the cast... |
| // |
| ConvertedTypes.clear(); |
| // Make sure the source doesn't change type |
| ConvertedTypes[Src] = Src->getType(); |
| if (ValueConvertibleToType(CI, Src->getType(), ConvertedTypes, TD)) { |
| PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent()); |
| |
| DEBUG(std::cerr << "\nCONVERTING EXPR TYPE:\n"); |
| { // ValueMap must be destroyed before function verified! |
| ValueMapCache ValueMap; |
| ConvertValueToNewType(CI, Src, ValueMap, TD); // This will delete CI! |
| } |
| |
| PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src); |
| DEBUG(std::cerr << "DONE CONVERTING EXPR TYPE: \n\n" << BB->getParent()); |
| |
| DEBUG(assert(verifyFunction(*BB->getParent()) == false && |
| "Function broken!")); |
| BI = BB->begin(); // Rescan basic block. BI might be invalidated. |
| ++NumExprTreesConv; |
| return true; |
| } |
| } |
| |
| // Otherwise find out it this cast is a cast to a pointer type, which is |
| // then added to some other pointer, then loaded or stored through. If |
| // so, convert the add into a getelementptr instruction... |
| // |
| if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) { |
| if (HandleCastToPointer(BI, DestPTy, TD)) { |
| BI = BB->begin(); // Rescan basic block. BI might be invalidated. |
| ++NumGEPInstFormed; |
| return true; |
| } |
| } |
| |
| // Check to see if we are casting from a structure pointer to a pointer to |
| // the first element of the structure... to avoid munching other peepholes, |
| // we only let this happen if there are no add uses of the cast. |
| // |
| // Peephole optimize the following instructions: |
| // %t1 = cast {<...>} * %StructPtr to <ty> * |
| // |
| // Into: %t2 = getelementptr {<...>} * %StructPtr, <0, 0, 0, ...> |
| // %t1 = cast <eltype> * %t1 to <ty> * |
| // |
| if (const CompositeType *CTy = getPointedToComposite(Src->getType())) |
| if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) { |
| |
| // Loop over uses of the cast, checking for add instructions. If an add |
| // exists, this is probably a part of a more complex GEP, so we don't |
| // want to mess around with the cast. |
| // |
| bool HasAddUse = false; |
| for (Value::use_iterator I = CI->use_begin(), E = CI->use_end(); |
| I != E; ++I) |
| if (isa<Instruction>(*I) && |
| cast<Instruction>(*I)->getOpcode() == Instruction::Add) { |
| HasAddUse = true; break; |
| } |
| |
| // If it doesn't have an add use, check to see if the dest type is |
| // losslessly convertible to one of the types in the start of the struct |
| // type. |
| // |
| if (!HasAddUse) { |
| const Type *DestPointedTy = DestPTy->getElementType(); |
| unsigned Depth = 1; |
| const CompositeType *CurCTy = CTy; |
| const Type *ElTy = 0; |
| |
| // Build the index vector, full of all zeros |
| std::vector<Value*> Indices; |
| Indices.push_back(ConstantSInt::get(Type::LongTy, 0)); |
| while (CurCTy && !isa<PointerType>(CurCTy)) { |
| if (const StructType *CurSTy = dyn_cast<StructType>(CurCTy)) { |
| // Check for a zero element struct type... if we have one, bail. |
| if (CurSTy->getElementTypes().size() == 0) break; |
| |
| // Grab the first element of the struct type, which must lie at |
| // offset zero in the struct. |
| // |
| ElTy = CurSTy->getElementTypes()[0]; |
| } else { |
| ElTy = cast<ArrayType>(CurCTy)->getElementType(); |
| } |
| |
| // Insert a zero to index through this type... |
| Indices.push_back(Constant::getNullValue(CurCTy->getIndexType())); |
| |
| // Did we find what we're looking for? |
| if (ElTy->isLosslesslyConvertibleTo(DestPointedTy)) break; |
| |
| // Nope, go a level deeper. |
| ++Depth; |
| CurCTy = dyn_cast<CompositeType>(ElTy); |
| ElTy = 0; |
| } |
| |
| // Did we find what we were looking for? If so, do the transformation |
| if (ElTy) { |
| PRINT_PEEPHOLE1("cast-for-first:in", CI); |
| |
| std::string Name = CI->getName(); CI->setName(""); |
| |
| // Insert the new T cast instruction... stealing old T's name |
| GetElementPtrInst *GEP = new GetElementPtrInst(Src, Indices, |
| Name, BI); |
| |
| // Make the old cast instruction reference the new GEP instead of |
| // the old src value. |
| // |
| CI->setOperand(0, GEP); |
| |
| PRINT_PEEPHOLE2("cast-for-first:out", GEP, CI); |
| ++NumGEPInstFormed; |
| return true; |
| } |
| } |
| } |
| |
| } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) { |
| Value *Val = SI->getOperand(0); |
| Value *Pointer = SI->getPointerOperand(); |
| |
| // Peephole optimize the following instructions: |
| // %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertible to T2 |
| // store <T2> %V, <T2>* %t |
| // |
| // Into: |
| // %t = cast <T2> %V to <T1> |
| // store <T1> %t2, <T1>* %P |
| // |
| // Note: This is not taken care of by expr conversion because there might |
| // not be a cast available for the store to convert the incoming value of. |
| // This code is basically here to make sure that pointers don't have casts |
| // if possible. |
| // |
| if (CastInst *CI = dyn_cast<CastInst>(Pointer)) |
| if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType |
| if (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType())) |
| // convertible types? |
| if (Val->getType()->isLosslesslyConvertibleTo(CSPT->getElementType())) { |
| PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI); |
| |
| // Insert the new T cast instruction... stealing old T's name |
| std::string Name(CI->getName()); CI->setName(""); |
| CastInst *NCI = new CastInst(Val, CSPT->getElementType(), |
| Name, BI); |
| |
| // Replace the old store with a new one! |
| ReplaceInstWithInst(BB->getInstList(), BI, |
| SI = new StoreInst(NCI, CastSrc)); |
| PRINT_PEEPHOLE3("st-src-cast:out", NCI, CastSrc, SI); |
| ++NumLoadStorePeepholes; |
| return true; |
| } |
| |
| } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) { |
| Value *Pointer = LI->getOperand(0); |
| const Type *PtrElType = |
| cast<PointerType>(Pointer->getType())->getElementType(); |
| |
| // Peephole optimize the following instructions: |
| // %Val = cast <T1>* to <T2>* ;; If T1 is losslessly convertible to T2 |
| // %t = load <T2>* %P |
| // |
| // Into: |
| // %t = load <T1>* %P |
| // %Val = cast <T1> to <T2> |
| // |
| // Note: This is not taken care of by expr conversion because there might |
| // not be a cast available for the store to convert the incoming value of. |
| // This code is basically here to make sure that pointers don't have casts |
| // if possible. |
| // |
| if (CastInst *CI = dyn_cast<CastInst>(Pointer)) |
| if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType |
| if (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType())) |
| // convertible types? |
| if (PtrElType->isLosslesslyConvertibleTo(CSPT->getElementType())) { |
| PRINT_PEEPHOLE2("load-src-cast:in ", Pointer, LI); |
| |
| // Create the new load instruction... loading the pre-casted value |
| LoadInst *NewLI = new LoadInst(CastSrc, LI->getName(), BI); |
| |
| // Insert the new T cast instruction... stealing old T's name |
| CastInst *NCI = new CastInst(NewLI, LI->getType(), CI->getName()); |
| |
| // Replace the old store with a new one! |
| ReplaceInstWithInst(BB->getInstList(), BI, NCI); |
| PRINT_PEEPHOLE3("load-src-cast:out", NCI, CastSrc, NewLI); |
| ++NumLoadStorePeepholes; |
| return true; |
| } |
| |
| } else if (I->getOpcode() == Instruction::Add && |
| isa<CastInst>(I->getOperand(1))) { |
| |
| if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0), |
| cast<CastInst>(I->getOperand(1)), TD)) { |
| ++NumGEPInstFormed; |
| return true; |
| } |
| } else if (CallInst *CI = dyn_cast<CallInst>(I)) { |
| // If we have a call with all varargs arguments, convert the call to use the |
| // actual argument types present... |
| // |
| const PointerType *PTy = cast<PointerType>(CI->getCalledValue()->getType()); |
| const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); |
| |
| // Is the call to a vararg variable with no real parameters? |
| if (FTy->isVarArg() && FTy->getNumParams() == 0 && |
| !CI->getCalledFunction()) { |
| // If so, insert a new cast instruction, casting it to a function type |
| // that matches the current arguments... |
| // |
| std::vector<const Type *> Params; // Parameter types... |
| for (unsigned i = 1, e = CI->getNumOperands(); i != e; ++i) |
| Params.push_back(CI->getOperand(i)->getType()); |
| |
| FunctionType *NewFT = FunctionType::get(FTy->getReturnType(), |
| Params, false); |
| PointerType *NewPFunTy = PointerType::get(NewFT); |
| |
| // Create a new cast, inserting it right before the function call... |
| Value *NewCast; |
| Constant *ConstantCallSrc = 0; |
| if (Constant *CS = dyn_cast<Constant>(CI->getCalledValue())) |
| ConstantCallSrc = CS; |
| else if (GlobalValue *GV = dyn_cast<GlobalValue>(CI->getCalledValue())) |
| ConstantCallSrc = ConstantPointerRef::get(GV); |
| |
| if (ConstantCallSrc) |
| NewCast = ConstantExpr::getCast(ConstantCallSrc, NewPFunTy); |
| else |
| NewCast = new CastInst(CI->getCalledValue(), NewPFunTy, |
| CI->getCalledValue()->getName()+"_c",CI); |
| |
| // Create a new call instruction... |
| CallInst *NewCall = new CallInst(NewCast, |
| std::vector<Value*>(CI->op_begin()+1, CI->op_end())); |
| ++BI; |
| ReplaceInstWithInst(CI, NewCall); |
| |
| ++NumVarargCallChanges; |
| return true; |
| } |
| |
| } |
| |
| return false; |
| } |
| |
| |
| |
| |
| bool RPR::DoRaisePass(Function &F) { |
| bool Changed = false; |
| for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) |
| for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) { |
| DEBUG(std::cerr << "Processing: " << *BI); |
| if (dceInstruction(BI) || doConstantPropagation(BI)) { |
| Changed = true; |
| ++NumDCEorCP; |
| DEBUG(std::cerr << "***\t\t^^-- Dead code eliminated!\n"); |
| } else if (PeepholeOptimize(BB, BI)) { |
| Changed = true; |
| } else { |
| ++BI; |
| } |
| } |
| |
| return Changed; |
| } |
| |
| |
| // runOnFunction - Raise a function representation to a higher level. |
| bool RPR::runOnFunction(Function &F) { |
| DEBUG(std::cerr << "\n\n\nStarting to work on Function '" << F.getName() |
| << "'\n"); |
| |
| // Insert casts for all incoming pointer pointer values that are treated as |
| // arrays... |
| // |
| bool Changed = false, LocalChange; |
| |
| // If the StartInst option was specified, then Peephole optimize that |
| // instruction first if it occurs in this function. |
| // |
| if (!StartInst.empty()) { |
| for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) |
| for (BasicBlock::iterator BI = BB->begin(); BI != BB->end(); ++BI) |
| if (BI->getName() == StartInst) { |
| bool SavedDebug = DebugFlag; // Save the DEBUG() controlling flag. |
| DebugFlag = true; // Turn on DEBUG's |
| Changed |= PeepholeOptimize(BB, BI); |
| DebugFlag = SavedDebug; // Restore DebugFlag to previous state |
| } |
| } |
| |
| do { |
| DEBUG(std::cerr << "Looping: \n" << F); |
| |
| // Iterate over the function, refining it, until it converges on a stable |
| // state |
| LocalChange = false; |
| while (DoRaisePass(F)) LocalChange = true; |
| Changed |= LocalChange; |
| |
| } while (LocalChange); |
| |
| return Changed; |
| } |
| |
| } // End llvm namespace |