X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FLevelRaise.cpp;h=edc42b7a56c650bd0e128477bc19c78c68f62230;hb=d21cd809b656d3011ec089536857e048e037159c;hp=4828f753e862cf7a8a9930b39caad497631b9bf0;hpb=bd70bb94d6b3e39c3f483920d71383766a699c9d;p=oota-llvm.git diff --git a/lib/Transforms/LevelRaise.cpp b/lib/Transforms/LevelRaise.cpp index 4828f753e86..edc42b7a56c 100644 --- a/lib/Transforms/LevelRaise.cpp +++ b/lib/Transforms/LevelRaise.cpp @@ -1,4 +1,11 @@ -//===- LevelRaise.cpp - Code to change LLVM to higher level -----------------=// +//===- 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 @@ -6,29 +13,48 @@ // //===----------------------------------------------------------------------===// -#include "llvm/Transforms/LevelChange.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Transforms/Utils/Local.h" #include "TransformInternals.h" -#include "llvm/Method.h" -#include "llvm/Support/STLExtras.h" #include "llvm/iOther.h" #include "llvm/iMemory.h" -#include "llvm/ConstPoolVals.h" -#include "llvm/Optimizations/ConstantHandling.h" -#include "llvm/Optimizations/DCE.h" -#include "llvm/Optimizations/ConstantProp.h" -#include "llvm/Analysis/Expressions.h" +#include "llvm/Pass.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "Support/CommandLine.h" +#include "Support/Debug.h" +#include "Support/Statistic.h" +#include "Support/STLExtras.h" #include +using 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 +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"); -#include "llvm/Assembly/Writer.h" +static Statistic<> +NumExprTreesConv("raise", "Number of expression trees converted"); -#define DEBUG_PEEPHOLE_INSTS 1 +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"); -#ifdef DEBUG_PEEPHOLE_INSTS #define PRINT_PEEPHOLE(ID, NUM, I) \ - cerr << "Inst P/H " << ID << "[" << NUM << "] " << I; -#else -#define PRINT_PEEPHOLE(ID, NUM, I) -#endif + 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) \ @@ -40,18 +66,124 @@ 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(); + } + + private: + bool DoRaisePass(Function &F); + bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI); + }; + + RegisterOpt X("raise", "Raise Pointer References"); +} + + +Pass *llvm::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()->isLosslesslyConvertableTo(CI->getType()); + 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, +// %t2 = cast * %t3 to {<...>}* +// +static bool HandleCastToPointer(BasicBlock::iterator BI, + const PointerType *DestPTy, + const TargetData &TD) { + CastInst &CI = cast(*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(*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 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(*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 to {<...>} * @@ -66,10 +198,11 @@ static inline bool isReinterpretingCast(const CastInst *CI) { // %t2 = cast * %t3 to {<...>}* // static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, - Value *AddOp1, CastInst *AddOp2) { + Value *AddOp1, CastInst *AddOp2, + const TargetData &TD) { const CompositeType *CompTy; Value *OffsetVal = AddOp2->getOperand(0); - Value *SrcPtr; // Of type pointer to struct... + Value *SrcPtr = 0; // Of type pointer to struct... if ((CompTy = getPointedToComposite(AddOp1->getType()))) { SrcPtr = AddOp1; // Handle the first case... @@ -79,12 +212,12 @@ static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, } // Only proceed if we have detected all of our conditions successfully... - if (!CompTy || !SrcPtr || !OffsetVal->getType()->isIntegral()) + if (!CompTy || !SrcPtr || !OffsetVal->getType()->isInteger()) return false; - vector Indices; - if (!ConvertableToGEP(SrcPtr->getType(), OffsetVal, Indices, &BI)) - return false; // Not convertable... perhaps next time + std::vector 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); @@ -93,8 +226,7 @@ static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, } GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices, - AddOp2->getName()); - BI = BB->getInstList().insert(BI, GEP)+1; + AddOp2->getName(), BI); Instruction *NCI = new CastInst(GEP, AddOp1->getType()); ReplaceInstWithInst(BB->getInstList(), BI, NCI); @@ -102,8 +234,9 @@ static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, return true; } -static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { - Instruction *I = *BI; +bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { + Instruction *I = BI; + const TargetData &TD = getAnalysis(); if (CastInst *CI = dyn_cast(I)) { Value *Src = CI->getOperand(0); @@ -119,74 +252,84 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { PRINT_PEEPHOLE1("cast-of-self-ty", CI); CI->replaceAllUsesWith(Src); if (!Src->hasName() && CI->hasName()) { - string Name = CI->getName(); + std::string Name = CI->getName(); CI->setName(""); - Src->setName(Name, BB->getParent()->getSymbolTable()); + 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; } - // Peephole optimize the following instructions: - // %tmp = cast %V to - // %V = cast %tmp to ; Where ty & ty2 are same size - // - // Into: cast %V to - // - if (SrcI) - if (CastInst *CSrc = dyn_cast(SrcI)) - if (isReinterpretingCast(CI) + isReinterpretingCast(CSrc) < 2) { - // We can only do c-c elimination if, at most, one cast does a - // reinterpretation of the input data. - // - // If legal, make this cast refer the the original casts argument! - // - PRINT_PEEPHOLE2("cast-cast:in ", CI, CSrc); - CI->setOperand(0, CSrc->getOperand(0)); - PRINT_PEEPHOLE1("cast-cast:out", CI); - 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; - if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) { - PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", Src, CI); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "\nCONVERTING EXPR TYPE:\n"; -#endif - ValueMapCache ValueMap; - ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI! - - BI = BB->begin(); // Rescan basic block. BI might be invalidated. - PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DONE CONVERTING EXPR TYPE: \n\n";// << BB->getParent(); -#endif - return true; - } else { - ConvertedTypes.clear(); - if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) { - PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", Src, CI); + // 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()); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "\nCONVERTING SRC EXPR TYPE:\n"; -#endif + DEBUG(std::cerr << "\nCONVERTING SRC EXPR TYPE:\n"); + { // ValueMap must be destroyed before function verified! ValueMapCache ValueMap; - Value *E = ConvertExpressionToType(Src, DestTy, ValueMap); - if (ConstPoolVal *CPV = dyn_cast(E)) - CI->replaceAllUsesWith(CPV); + Value *E = ConvertExpressionToType(Src, DestTy, ValueMap, TD); - BI = BB->begin(); // Rescan basic block. BI might be invalidated. + if (Constant *CPV = dyn_cast(E)) + CI->replaceAllUsesWith(CPV); + PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DONE CONVERTING SRC EXPR TYPE: \n\n";// << BB->getParent(); -#endif - return true; + DEBUG(std::cerr << "DONE CONVERTING SRC EXPR TYPE: \n" + << BB->getParent()); } + + 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()); + + 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(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 @@ -199,7 +342,6 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { // Into: %t2 = getelementptr {<...>} * %StructPtr, <0, 0, 0, ...> // %t1 = cast * %t1 to * // -#if 1 if (const CompositeType *CTy = getPointedToComposite(Src->getType())) if (const PointerType *DestPTy = dyn_cast(DestTy)) { @@ -216,36 +358,40 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { } // If it doesn't have an add use, check to see if the dest type is - // losslessly convertable to one of the types in the start of the struct + // losslessly convertible to one of the types in the start of the struct // type. // if (!HasAddUse) { - const Type *DestPointedTy = DestPTy->getValueType(); + const Type *DestPointedTy = DestPTy->getElementType(); unsigned Depth = 1; const CompositeType *CurCTy = CTy; const Type *ElTy = 0; // Build the index vector, full of all zeros - vector Indices; + std::vector Indices; - while (CurCTy) { + Indices.push_back(ConstantSInt::get(Type::LongTy, 0)); // FIXME, PR82 + while (CurCTy && !isa(CurCTy)) { + const Type *IdxType; if (const StructType *CurSTy = dyn_cast(CurCTy)) { // Check for a zero element struct type... if we have one, bail. - if (CurSTy->getElementTypes().size() == 0) break; + if (CurSTy->getNumElements() == 0) break; // Grab the first element of the struct type, which must lie at // offset zero in the struct. // - ElTy = CurSTy->getElementTypes()[0]; + ElTy = CurSTy->getElementType(0); + IdxType = Type::UByteTy; // FIXME when PR82 is fixed. } else { ElTy = cast(CurCTy)->getElementType(); + IdxType = Type::LongTy; // FIXME when PR82 is fixed. } // Insert a zero to index through this type... - Indices.push_back(ConstPoolUInt::get(CurCTy->getIndexType(), 0)); + Indices.push_back(Constant::getNullValue(IdxType)); // Did we find what we're looking for? - if (ElTy->isLosslesslyConvertableTo(DestPointedTy)) break; + if (ElTy->isLosslesslyConvertibleTo(DestPointedTy)) break; // Nope, go a level deeper. ++Depth; @@ -257,11 +403,11 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { 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, - CI->getName()); - CI->setName(""); - BI = BB->getInstList().insert(BI, GEP)+1; + Name, BI); // Make the old cast instruction reference the new GEP instead of // the old src value. @@ -269,139 +415,144 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { CI->setOperand(0, GEP); PRINT_PEEPHOLE2("cast-for-first:out", GEP, CI); + ++NumGEPInstFormed; return true; } } } -#endif -#if 1 } else if (StoreInst *SI = dyn_cast(I)) { Value *Val = SI->getOperand(0); Value *Pointer = SI->getPointerOperand(); // Peephole optimize the following instructions: - // %t1 = getelementptr {<...>} * %StructPtr, - // store %v, * %t1 - // - // Into: store %v, {<...>} * %StructPtr, - // - if (GetElementPtrInst *GEP = dyn_cast(Pointer)) { - // Append any indices that the store instruction has onto the end of the - // ones that the GEP is carrying... - // - vector Indices(GEP->copyIndices()); - Indices.insert(Indices.end(), SI->idx_begin(), SI->idx_end()); - - PRINT_PEEPHOLE2("gep-store:in", GEP, SI); - ReplaceInstWithInst(BB->getInstList(), BI, - SI = new StoreInst(Val, GEP->getPointerOperand(), - Indices)); - PRINT_PEEPHOLE1("gep-store:out", SI); - return true; - } - - // Peephole optimize the following instructions: - // %t = cast * %P to * ;; If T1 is losslessly convertable to T2 + // %t = cast * %P to * ;; If T1 is losslessly convertible to T2 // store %V, * %t // // Into: // %t = cast %V to // store %t2, * %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(Pointer)) if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType - if (PointerType *CSPT = dyn_cast(CastSrc->getType())) - // convertable types? - if (Val->getType()->isLosslesslyConvertableTo(CSPT->getValueType()) && - !SI->hasIndices()) { // No subscripts yet! + if (const PointerType *CSPT = dyn_cast(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 - CastInst *NCI = new CastInst(Val, CSPT->getValueType(), - CI->getName()); - CI->setName(""); - BI = BB->getInstList().insert(BI, NCI)+1; + 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(I)) { - Value *Pointer = LI->getPointerOperand(); + Value *Pointer = LI->getOperand(0); + const Type *PtrElType = + cast(Pointer->getType())->getElementType(); // Peephole optimize the following instructions: - // %t1 = getelementptr {<...>} * %StructPtr, - // %V = load * %t1 - // - // Into: load {<...>} * %StructPtr, + // %Val = cast * to * ;; If T1 is losslessly convertible to T2 + // %t = load * %P // - if (GetElementPtrInst *GEP = dyn_cast(Pointer)) { - // Append any indices that the load instruction has onto the end of the - // ones that the GEP is carrying... - // - vector Indices(GEP->copyIndices()); - Indices.insert(Indices.end(), LI->idx_begin(), LI->idx_end()); - - PRINT_PEEPHOLE2("gep-load:in", GEP, LI); - ReplaceInstWithInst(BB->getInstList(), BI, - LI = new LoadInst(GEP->getPointerOperand(), - Indices)); - PRINT_PEEPHOLE1("gep-load:out", LI); - return true; - } - - - // Peephole optimize the following instructions: - // %t1 = cast * %t0 to * - // %V = load * %t1 - // - // Into: %t1 = load * %t0 - // %V = cast %t1 to + // Into: + // %t = load * %P + // %Val = cast to // - // The idea behind this transformation is that if the expression type - // conversion engine could not convert the cast into some other nice form, - // that there is something fundementally wrong with the current shape of - // the program. Move the cast through the load and try again. This will - // leave the original cast instruction, to presumably become dead. + // 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(Pointer)) { - Value *SrcVal = CI->getOperand(0); - const PointerType *SrcTy = dyn_cast(SrcVal->getType()); - const Type *ElTy = SrcTy ? SrcTy->getValueType() : 0; - - // Make sure that nothing will be lost in the new cast... - if (!LI->hasIndices() && SrcTy && - ElTy->isLosslesslyConvertableTo(LI->getType())) { - PRINT_PEEPHOLE2("CL-LoadCast:in ", CI, LI); - - string CName = CI->getName(); CI->setName(""); - LoadInst *NLI = new LoadInst(SrcVal, LI->getName()); - LI->setName(""); // Take over the old load's name + if (CastInst *CI = dyn_cast(Pointer)) + if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType + if (const PointerType *CSPT = dyn_cast(CastSrc->getType())) + // convertible types? + if (PtrElType->isLosslesslyConvertibleTo(CSPT->getElementType())) { + PRINT_PEEPHOLE2("load-src-cast:in ", Pointer, LI); - // Insert the load before the old load - BI = BB->getInstList().insert(BI, NLI)+1; + // 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 load with a new cast... - ReplaceInstWithInst(BB->getInstList(), BI, - CI = new CastInst(NLI, LI->getType(), CName)); - PRINT_PEEPHOLE2("CL-LoadCast:out", NLI, CI); + // 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; + } - return true; - } - } } else if (I->getOpcode() == Instruction::Add && isa(I->getOperand(1))) { if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0), - cast(I->getOperand(1)))) + cast(I->getOperand(1)), TD)) { + ++NumGEPInstFormed; + return true; + } + } else if (CallInst *CI = dyn_cast(I)) { + // If we have a call with all varargs arguments, convert the call to use the + // actual argument types present... + // + const PointerType *PTy = cast(CI->getCalledValue()->getType()); + const FunctionType *FTy = cast(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 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(CI->getCalledValue())) + ConstantCallSrc = CS; + else if (GlobalValue *GV = dyn_cast(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); + + // Strip off unneeded CPR's. + if (ConstantPointerRef *CPR = dyn_cast(NewCast)) + NewCast = CPR->getValue(); + + // Create a new call instruction... + CallInst *NewCall = new CallInst(NewCast, + std::vector(CI->op_begin()+1, CI->op_end())); + ++BI; + ReplaceInstWithInst(CI, NewCall); + + ++NumVarargCallChanges; return true; + } -#endif } return false; @@ -410,166 +561,61 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { -static bool DoRaisePass(Method *M) { +bool RPR::DoRaisePass(Function &F) { bool Changed = false; - for (Method::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) { - BasicBlock *BB = *MI; - BasicBlock::InstListType &BIL = BB->getInstList(); - + for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) { - if (opt::DeadCodeElimination::dceInstruction(BIL, BI) || - opt::ConstantPropogation::doConstantPropogation(BB, BI)) { + DEBUG(std::cerr << "Processing: " << *BI); + if (dceInstruction(BI) || doConstantPropagation(BI)) { Changed = true; -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DeadCode Elinated!\n"; -#endif - } else if (PeepholeOptimize(BB, BI)) + ++NumDCEorCP; + DEBUG(std::cerr << "***\t\t^^-- Dead code eliminated!\n"); + } else if (PeepholeOptimize(BB, BI)) { Changed = true; - else + } else { ++BI; + } } - } - return Changed; -} - - - - -// DoInsertArrayCast - If the argument value has a pointer type, and if the -// argument value is used as an array, insert a cast before the specified -// basic block iterator that casts the value to an array pointer. Return the -// new cast instruction (in the CastResult var), or null if no cast is inserted. -// -static bool DoInsertArrayCast(Value *V, BasicBlock *BB, - BasicBlock::iterator InsertBefore) { - const PointerType *ThePtrType = dyn_cast(V->getType()); - if (!ThePtrType) return false; - - const Type *ElTy = ThePtrType->getValueType(); - if (isa(ElTy) || isa(ElTy)) return false; - - unsigned ElementSize = TD.getTypeSize(ElTy); - bool InsertCast = false; - - for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) { - Instruction *Inst = cast(*I); - switch (Inst->getOpcode()) { - case Instruction::Cast: // There is already a cast instruction! - if (const PointerType *PT = dyn_cast(Inst->getType())) - if (const ArrayType *AT = dyn_cast(PT->getValueType())) - if (AT->getElementType() == ThePtrType->getValueType()) { - // Cast already exists! Don't mess around with it. - return false; // No changes made to program though... - } - break; - case Instruction::Add: { // Analyze pointer arithmetic... - Value *OtherOp = Inst->getOperand(Inst->getOperand(0) == V); - analysis::ExprType Expr = analysis::ClassifyExpression(OtherOp); - - // This looks like array addressing iff: - // A. The constant of the index is larger than the size of the element - // type. - // B. The scale factor is >= the size of the type. - // - if (Expr.Offset && getConstantValue(Expr.Offset) >= (int)ElementSize) // A - InsertCast = true; - - if (Expr.Scale && getConstantValue(Expr.Scale) >= (int)ElementSize) // B - InsertCast = true; - - break; - } - default: break; // Not an interesting use... - } - } - - if (!InsertCast) return false; // There is no reason to insert a cast! - - // Calculate the destination pointer type - const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy)); - - // Check to make sure that all uses of the value can be converted over to use - // the newly typed value. - // - ValueTypeCache ConvertedTypes; - if (!ValueConvertableToType(V, DestTy, ConvertedTypes)) { - cerr << "FAILED to convert types of values for " << V << "\n"; - ConvertedTypes.clear(); - ValueConvertableToType(V, DestTy, ConvertedTypes); - return false; - } - ConvertedTypes.clear(); - - // Insert a cast! - CastInst *TheCast = - new CastInst(ConstPoolVal::getNullConstant(V->getType()), DestTy, - V->getName()); - BB->getInstList().insert(InsertBefore, TheCast); - - cerr << "Inserting cast for " << V << endl; - - // Convert users of the old value over to use the cast result... - ValueMapCache VMC; - ConvertValueToNewType(V, TheCast, VMC); - - // The cast is the only thing that is allowed to reference the value... - TheCast->setOperand(0, V); - - cerr << "Inserted ptr-array cast: " << TheCast; - return true; // Made a change! -} - - -// DoInsertArrayCasts - Loop over all "incoming" values in the specified method, -// inserting a cast for pointer values that are used as arrays. For our -// purposes, an incoming value is considered to be either a value that is -// either a method parameter, or a pointer returned from a function call. -// -static bool DoInsertArrayCasts(Method *M) { - assert(!M->isExternal() && "Can't handle external methods!"); - - // Insert casts for all arguments to the function... - bool Changed = false; - BasicBlock *CurBB = M->front(); - - for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(), - AE = M->getArgumentList().end(); AI != AE; ++AI) { - - Changed |= DoInsertArrayCast(*AI, CurBB, CurBB->begin()); - } - - // TODO: insert casts for alloca, malloc, and function call results. Also, - // look for pointers that already have casts, to add to the map. return Changed; } - - -// RaisePointerReferences::doit - Raise a method representation to a higher -// level. -// -bool RaisePointerReferences::doit(Method *M) { - if (M->isExternal()) return false; - -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n"; -#endif +// 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 { - LocalChange = DoInsertArrayCasts(M); + DEBUG(std::cerr << "Looping: \n" << F); - // Iterate over the method, refining it, until it converges on a stable + // Iterate over the function, refining it, until it converges on a stable // state - while (DoRaisePass(M)) LocalChange = true; + LocalChange = false; + while (DoRaisePass(F)) LocalChange = true; Changed |= LocalChange; } while (LocalChange); return Changed; } +