X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FLevelRaise.cpp;h=f246116a2ee7822ee0ce363d5f56ecb05d98a88e;hb=c966a2acee176369be2f901e32c346c176b7f772;hp=c672c4e5015ff5b311b926b2f4ca8365b40fa09d;hpb=44480b52b956af36a599eebcf07dbf54c68ac043;p=oota-llvm.git diff --git a/lib/Transforms/LevelRaise.cpp b/lib/Transforms/LevelRaise.cpp index c672c4e5015..f246116a2ee 100644 --- a/lib/Transforms/LevelRaise.cpp +++ b/lib/Transforms/LevelRaise.cpp @@ -6,29 +6,51 @@ // //===----------------------------------------------------------------------===// -#include "llvm/Transforms/LevelChange.h" +#include "llvm/Transforms/RaisePointerReferences.h" +#include "llvm/Transforms/Utils/Local.h" #include "TransformInternals.h" -#include "llvm/Method.h" #include "llvm/iOther.h" #include "llvm/iMemory.h" -#include "llvm/ConstantVals.h" -#include "llvm/Optimizations/ConstantHandling.h" -#include "llvm/Optimizations/DCE.h" -#include "llvm/Optimizations/ConstantProp.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/STLExtras.h" +#include "Support/Statistic.h" +#include "Support/CommandLine.h" #include +using std::cerr; -#include "llvm/Assembly/Writer.h" +// 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"); + +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 DEBUG_PEEPHOLE_INSTS 1 -#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) \ @@ -50,7 +72,6 @@ static inline bool isReinterpretingCast(const CastInst *CI) { } - // Peephole optimize the following instructions: // %t1 = cast ? to x * // %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand @@ -60,68 +81,62 @@ static inline bool isReinterpretingCast(const CastInst *CI) { // static bool HandleCastToPointer(BasicBlock::iterator BI, const PointerType *DestPTy) { - CastInst *CI = cast(*BI); + CastInst &CI = cast(*BI); + if (CI.use_empty()) return false; // Scan all of the uses, looking for any uses that are not add // instructions. If we have non-adds, do not make this transformation. // - for (Value::use_iterator I = CI->use_begin(), E = CI->use_end(); + 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) + if (BO->getOpcode() != Instruction::Add || + // Avoid add sbyte* %X, %X cases... + BO->getOperand(0) == BO->getOperand(1)) return false; } else { return false; } } - vector Indices; - Value *Src = CI->getOperand(0); + std::vector Indices; + Value *Src = CI.getOperand(0); const Type *Result = ConvertableToGEP(DestPTy, Src, Indices, &BI); - const PointerType *UsedType = DestPTy; - - // If we fail, check to see if we have an pointer source type that, if - // converted to an unsized array type, would work. In this case, we propogate - // the cast forward to the input of the add instruction. - // - if (Result == 0 && getPointedToComposite(DestPTy) == 0) { - // Make an unsized array and try again... - UsedType = PointerType::get(ArrayType::get(DestPTy->getElementType())); - Result = ConvertableToGEP(UsedType, Src, Indices, &BI); - } - if (Result == 0) return false; // Not convertable... 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. - for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end(); - UI != E; ++UI) { - Instruction *I = cast(*UI); + while (!CI.use_empty()) { + BinaryOperator *I = cast(*CI.use_begin()); assert(I->getOpcode() == Instruction::Add && I->getNumOperands() == 2 && "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); + Value *OtherPtr = I->getOperand((I->getOperand(0) == &CI) ? 1 : 0); - BasicBlock *BB = I->getParent(); - BasicBlock::iterator AddIt = find(BB->getInstList().begin(), - BB->getInstList().end(), I); + Instruction *GEP = new GetElementPtrInst(OtherPtr, Indices, I->getName()); + PRINT_PEEPHOLE1("cast-add-to-gep:i", I); - if (UsedType != DestPTy) { - // Insert a cast of the incoming value to something addressable... - CastInst *C = new CastInst(OtherPtr, UsedType, OtherPtr->getName()); - AddIt = BB->getInstList().insert(AddIt, C)+1; - OtherPtr = C; - } + 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. + // - GetElementPtrInst *GEP = new GetElementPtrInst(OtherPtr, Indices); + // 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:i", I); - - // Replace the old add instruction with the shiny new GEP inst - ReplaceInstWithInst(BB->getInstList(), AddIt, GEP); PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP); } return true; @@ -153,10 +168,10 @@ 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; + std::vector Indices; if (!ConvertableToGEP(SrcPtr->getType(), OffsetVal, Indices, &BI)) return false; // Not convertable... perhaps next time @@ -167,8 +182,7 @@ 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); @@ -177,7 +191,7 @@ static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI, } static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { - Instruction *I = *BI; + Instruction *I = BI; if (CastInst *CI = dyn_cast(I)) { Value *Src = CI->getOperand(0); @@ -193,54 +207,48 @@ 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()); } + + // 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; + // Check to see if we can convert the source of the cast to match the // destination type of the cast... // - ValueTypeCache ConvertedTypes; - if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) { - PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", Src, CI); + ConvertedTypes[CI] = CI->getType(); // Make sure the cast doesn't change + if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) { + PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent()); + + DEBUG(cerr << "\nCONVERTING SRC EXPR TYPE:\n"); + { // ValueMap must be destroyed before function verified! + ValueMapCache ValueMap; + Value *E = ConvertExpressionToType(Src, DestTy, ValueMap); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "\nCONVERTING EXPR TYPE:\n"; -#endif - ValueMapCache ValueMap; - ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI! + if (Constant *CPV = dyn_cast(E)) + CI->replaceAllUsesWith(CPV); + + PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E); + DEBUG(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. - PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DONE CONVERTING EXPR TYPE: \n\n";// << BB->getParent(); -#endif + ++NumExprTreesConv; return true; } @@ -248,22 +256,24 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { // source type of the cast... // ConvertedTypes.clear(); - if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) { - PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", Src, CI); - -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "\nCONVERTING SRC EXPR TYPE:\n"; -#endif - ValueMapCache ValueMap; - Value *E = ConvertExpressionToType(Src, DestTy, ValueMap); - if (Constant *CPV = dyn_cast(E)) - CI->replaceAllUsesWith(CPV); + // Make sure the source doesn't change type + ConvertedTypes[Src] = Src->getType(); + if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) { + PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent()); + + DEBUG(cerr << "\nCONVERTING EXPR TYPE:\n"); + { // ValueMap must be destroyed before function verified! + ValueMapCache ValueMap; + ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI! + } + PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src); + DEBUG(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. - PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E); -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DONE CONVERTING SRC EXPR TYPE: \n\n";// << BB->getParent(); -#endif + ++NumExprTreesConv; return true; } } @@ -275,6 +285,7 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { if (const PointerType *DestPTy = dyn_cast(DestTy)) { if (HandleCastToPointer(BI, DestPTy)) { BI = BB->begin(); // Rescan basic block. BI might be invalidated. + ++NumGEPInstFormed; return true; } } @@ -289,7 +300,6 @@ 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)) { @@ -316,9 +326,9 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { const Type *ElTy = 0; // Build the index vector, full of all zeros - vector Indices; - - while (CurCTy) { + std::vector Indices; + Indices.push_back(ConstantSInt::get(Type::LongTy, 0)); + while (CurCTy && !isa(CurCTy)) { 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; @@ -332,7 +342,7 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { } // Insert a zero to index through this type... - Indices.push_back(ConstantUInt::get(CurCTy->getIndexType(), 0)); + Indices.push_back(Constant::getNullValue(CurCTy->getIndexType())); // Did we find what we're looking for? if (ElTy->isLosslesslyConvertableTo(DestPointedTy)) break; @@ -347,11 +357,11 @@ 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. @@ -359,38 +369,16 @@ 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 // store %V, * %t @@ -399,61 +387,111 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { // %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())) + if (const PointerType *CSPT = dyn_cast(CastSrc->getType())) // convertable types? - if (Val->getType()->isLosslesslyConvertableTo(CSPT->getElementType()) && - !SI->hasIndices()) { // No subscripts yet! + if (Val->getType()->isLosslesslyConvertableTo(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(), - CI->getName()); - CI->setName(""); - BI = BB->getInstList().insert(BI, NCI)+1; + 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)) { -#if 0 - 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 + // %Val = cast * to * ;; If T1 is losslessly convertable to T2 + // %t = load * %P // - // Into: load {<...>} * %StructPtr, + // Into: + // %t = load * %P + // %Val = cast to // - 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; - } -#endif + // 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 (const PointerType *CSPT = dyn_cast(CastSrc->getType())) + // convertable types? + if (PtrElType->isLosslesslyConvertableTo(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(I->getOperand(1))) { if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0), - cast(I->getOperand(1)))) + cast(I->getOperand(1)))) { + ++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) { + // 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... + CastInst *NewCast = new CastInst(CI->getCalledValue(), NewPFunTy, + CI->getCalledValue()->getName(), CI); + + // 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; @@ -462,179 +500,83 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) { -static bool DoRaisePass(Method *M) { +static bool 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(cerr << "Processing: " << *BI); + if (dceInstruction(BI) || doConstantPropogation(BI)) { Changed = true; -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "DeadCode Elinated!\n"; -#endif - } else if (PeepholeOptimize(BB, BI)) + ++NumDCEorCP; + DEBUG(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->getElementType(); - if (isa(ElTy) || - (isa(ElTy) && cast(ElTy)->isUnsized())) - 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->getElementType())) - if (AT->getElementType() == ThePtrType->getElementType()) { - // 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 << " to " << DestTy << "\n"; - ConvertedTypes.clear(); - ValueConvertableToType(V, DestTy, ConvertedTypes); - return false; - } - ConvertedTypes.clear(); - - // Insert a cast! - CastInst *TheCast = - new CastInst(Constant::getNullConstant(V->getType()), DestTy, V->getName()); - BB->getInstList().insert(InsertBefore, TheCast); - -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "Inserting cast for " << V << endl; -#endif - - // 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); - -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "Inserted ptr-array cast: " << TheCast; -#endif - 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. - -#ifdef DEBUG_PEEPHOLE_INSTS - if (Changed) cerr << "Inserted casts:\n" << M; -#endif return Changed; } - - -// RaisePointerReferences::doit - Raise a method representation to a higher +// RaisePointerReferences::doit - Raise a function 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 +static bool doRPR(Function &F) { + DEBUG(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 { -#ifdef DEBUG_PEEPHOLE_INSTS - cerr << "Looping: \n" << M; -#endif - LocalChange = DoInsertArrayCasts(M); + DEBUG(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; } + +namespace { + struct RaisePointerReferences : public FunctionPass { + + // FIXME: constructor should save and use target data here!! + RaisePointerReferences(const TargetData &TD) {} + + virtual bool runOnFunction(Function &F) { return doRPR(F); } + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.preservesCFG(); + } + }; +} + +Pass *createRaisePointerReferencesPass(const TargetData &TD) { + return new RaisePointerReferences(TD); +} + +static RegisterOpt +X("raise", "Raise Pointer References", createRaisePointerReferencesPass);