//===- ExprTypeConvert.cpp - Code to change an LLVM Expr Type -------------===// // // 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 part of level raising that checks to see if it is // possible to coerce an entire expression tree into a different type. If // convertible, other routines from this file will do the conversion. // //===----------------------------------------------------------------------===// #include "TransformInternals.h" #include "llvm/Constants.h" #include "llvm/Instructions.h" #include "llvm/Analysis/Expressions.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Debug.h" #include using namespace llvm; static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty, ValueTypeCache &ConvertedTypes, const TargetData &TD); static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal, ValueMapCache &VMC, const TargetData &TD); // Peephole Malloc instructions: we take a look at the use chain of the // malloc instruction, and try to find out if the following conditions hold: // 1. The malloc is of the form: 'malloc [sbyte], uint ' // 2. The only users of the malloc are cast & add instructions // 3. Of the cast instructions, there is only one destination pointer type // [RTy] where the size of the pointed to object is equal to the number // of bytes allocated. // // If these conditions hold, we convert the malloc to allocate an [RTy] // element. TODO: This comment is out of date WRT arrays // static bool MallocConvertibleToType(MallocInst *MI, const Type *Ty, ValueTypeCache &CTMap, const TargetData &TD) { if (!isa(Ty)) return false; // Malloc always returns pointers // Deal with the type to allocate, not the pointer type... Ty = cast(Ty)->getElementType(); if (!Ty->isSized() || !MI->getType()->getElementType()->isSized()) return false; // Can only alloc something with a size // Analyze the number of bytes allocated... ExprType Expr = ClassifyExpr(MI->getArraySize()); // Get information about the base datatype being allocated, before & after uint64_t ReqTypeSize = TD.getTypeSize(Ty); if (ReqTypeSize == 0) return false; uint64_t OldTypeSize = TD.getTypeSize(MI->getType()->getElementType()); // Must have a scale or offset to analyze it... if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false; // Get the offset and scale of the allocation... int64_t OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0; int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) :(Expr.Var != 0); // The old type might not be of unit size, take old size into consideration // here... uint64_t Offset = OffsetVal * OldTypeSize; uint64_t Scale = ScaleVal * OldTypeSize; // In order to be successful, both the scale and the offset must be a multiple // of the requested data type's size. // if (Offset/ReqTypeSize*ReqTypeSize != Offset || Scale/ReqTypeSize*ReqTypeSize != Scale) return false; // Nope. return true; } static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty, const std::string &Name, ValueMapCache &VMC, const TargetData &TD){ BasicBlock *BB = MI->getParent(); BasicBlock::iterator It = BB->end(); // Analyze the number of bytes allocated... ExprType Expr = ClassifyExpr(MI->getArraySize()); const PointerType *AllocTy = cast(Ty); const Type *ElType = AllocTy->getElementType(); uint64_t DataSize = TD.getTypeSize(ElType); uint64_t OldTypeSize = TD.getTypeSize(MI->getType()->getElementType()); // Get the offset and scale coefficients that we are allocating... int64_t OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0); int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var !=0); // The old type might not be of unit size, take old size into consideration // here... unsigned Offset = OffsetVal * OldTypeSize / DataSize; unsigned Scale = ScaleVal * OldTypeSize / DataSize; // Locate the malloc instruction, because we may be inserting instructions It = MI; // If we have a scale, apply it first... if (Expr.Var) { // Expr.Var is not necessarily unsigned right now, insert a cast now. if (Expr.Var->getType() != Type::UIntTy) Expr.Var = new CastInst(Expr.Var, Type::UIntTy, Expr.Var->getName()+"-uint", It); if (Scale != 1) Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var, ConstantUInt::get(Type::UIntTy, Scale), Expr.Var->getName()+"-scl", It); } else { // If we are not scaling anything, just make the offset be the "var"... Expr.Var = ConstantUInt::get(Type::UIntTy, Offset); Offset = 0; Scale = 1; } // If we have an offset now, add it in... if (Offset != 0) { assert(Expr.Var && "Var must be nonnull by now!"); Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var, ConstantUInt::get(Type::UIntTy, Offset), Expr.Var->getName()+"-off", It); } assert(AllocTy == Ty); return new MallocInst(AllocTy->getElementType(), Expr.Var, Name); } // ExpressionConvertibleToType - Return true if it is possible bool llvm::ExpressionConvertibleToType(Value *V, const Type *Ty, ValueTypeCache &CTMap, const TargetData &TD) { // Expression type must be holdable in a register. if (!Ty->isFirstClassType()) return false; ValueTypeCache::iterator CTMI = CTMap.find(V); if (CTMI != CTMap.end()) return CTMI->second == Ty; // If it's a constant... all constants can be converted to a different // type. // if (isa(V) && !isa(V)) return true; CTMap[V] = Ty; if (V->getType() == Ty) return true; // Expression already correct type! Instruction *I = dyn_cast(V); if (I == 0) return false; // Otherwise, we can't convert! switch (I->getOpcode()) { case Instruction::Cast: // We can convert the expr if the cast destination type is losslessly // convertible to the requested type. if (!Ty->isLosslesslyConvertibleTo(I->getType())) return false; // We also do not allow conversion of a cast that casts from a ptr to array // of X to a *X. For example: cast [4 x %List *] * %val to %List * * // if (const PointerType *SPT = dyn_cast(I->getOperand(0)->getType())) if (const PointerType *DPT = dyn_cast(I->getType())) if (const ArrayType *AT = dyn_cast(SPT->getElementType())) if (AT->getElementType() == DPT->getElementType()) return false; break; case Instruction::Add: case Instruction::Sub: if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false; if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD) || !ExpressionConvertibleToType(I->getOperand(1), Ty, CTMap, TD)) return false; break; case Instruction::Shr: if (!Ty->isInteger()) return false; if (Ty->isSigned() != V->getType()->isSigned()) return false; // FALL THROUGH case Instruction::Shl: if (!Ty->isInteger()) return false; if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD)) return false; break; case Instruction::Load: { LoadInst *LI = cast(I); if (!ExpressionConvertibleToType(LI->getPointerOperand(), PointerType::get(Ty), CTMap, TD)) return false; break; } case Instruction::PHI: { PHINode *PN = cast(I); // Be conservative if we find a giant PHI node. if (PN->getNumIncomingValues() > 32) return false; for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i) if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD)) return false; break; } case Instruction::Malloc: if (!MallocConvertibleToType(cast(I), Ty, CTMap, TD)) return false; break; case Instruction::GetElementPtr: { // GetElementPtr's are directly convertible to a pointer type if they have // a number of zeros at the end. Because removing these values does not // change the logical offset of the GEP, it is okay and fair to remove them. // This can change this: // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **> // %t2 = cast %List * * %t1 to %List * // into // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *> // GetElementPtrInst *GEP = cast(I); const PointerType *PTy = dyn_cast(Ty); if (!PTy) return false; // GEP must always return a pointer... const Type *PVTy = PTy->getElementType(); // Check to see if there are zero elements that we can remove from the // index array. If there are, check to see if removing them causes us to // get to the right type... // std::vector Indices(GEP->idx_begin(), GEP->idx_end()); const Type *BaseType = GEP->getPointerOperand()->getType(); const Type *ElTy = 0; while (!Indices.empty() && Indices.back() == Constant::getNullValue(Indices.back()->getType())){ Indices.pop_back(); ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true); if (ElTy == PVTy) break; // Found a match!! ElTy = 0; } if (ElTy) break; // Found a number of zeros we can strip off! // Otherwise, we can convert a GEP from one form to the other iff the // current gep is of the form 'getelementptr sbyte*, long N // and we could convert this to an appropriate GEP for the new type. // if (GEP->getNumOperands() == 2 && GEP->getType() == PointerType::get(Type::SByteTy)) { // Do not Check to see if our incoming pointer can be converted // to be a ptr to an array of the right type... because in more cases than // not, it is simply not analyzable because of pointer/array // discrepancies. To fix this, we will insert a cast before the GEP. // // Check to see if 'N' is an expression that can be converted to // the appropriate size... if so, allow it. // std::vector Indices; const Type *ElTy = ConvertibleToGEP(PTy, I->getOperand(1), Indices, TD); if (ElTy == PVTy) { if (!ExpressionConvertibleToType(I->getOperand(0), PointerType::get(ElTy), CTMap, TD)) return false; // Can't continue, ExConToTy might have polluted set! break; } } // Otherwise, it could be that we have something like this: // getelementptr [[sbyte] *] * %reg115, long %reg138 ; [sbyte]** // and want to convert it into something like this: // getelemenptr [[int] *] * %reg115, long %reg138 ; [int]** // if (GEP->getNumOperands() == 2 && PTy->getElementType()->isSized() && TD.getTypeSize(PTy->getElementType()) == TD.getTypeSize(GEP->getType()->getElementType())) { const PointerType *NewSrcTy = PointerType::get(PVTy); if (!ExpressionConvertibleToType(I->getOperand(0), NewSrcTy, CTMap, TD)) return false; break; } return false; // No match, maybe next time. } case Instruction::Call: { if (isa(I->getOperand(0))) return false; // Don't even try to change direct calls. // If this is a function pointer, we can convert the return type if we can // convert the source function pointer. // const PointerType *PT = cast(I->getOperand(0)->getType()); const FunctionType *FT = cast(PT->getElementType()); std::vector ArgTys(FT->param_begin(), FT->param_end()); const FunctionType *NewTy = FunctionType::get(Ty, ArgTys, FT->isVarArg()); if (!ExpressionConvertibleToType(I->getOperand(0), PointerType::get(NewTy), CTMap, TD)) return false; break; } default: return false; } // Expressions are only convertible if all of the users of the expression can // have this value converted. This makes use of the map to avoid infinite // recursion. // for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It) if (!OperandConvertibleToType(*It, I, Ty, CTMap, TD)) return false; return true; } Value *llvm::ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC, const TargetData &TD) { if (V->getType() == Ty) return V; // Already where we need to be? ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V); if (VMCI != VMC.ExprMap.end()) { const Value *GV = VMCI->second; const Type *GTy = VMCI->second->getType(); assert(VMCI->second->getType() == Ty); if (Instruction *I = dyn_cast(V)) ValueHandle IHandle(VMC, I); // Remove I if it is unused now! return VMCI->second; } DEBUG(std::cerr << "CETT: " << (void*)V << " " << *V); Instruction *I = dyn_cast(V); if (I == 0) { Constant *CPV = cast(V); // Constants are converted by constant folding the cast that is required. // We assume here that all casts are implemented for constant prop. Value *Result = ConstantExpr::getCast(CPV, Ty); // Add the instruction to the expression map //VMC.ExprMap[V] = Result; return Result; } BasicBlock *BB = I->getParent(); std::string Name = I->getName(); if (!Name.empty()) I->setName(""); Instruction *Res; // Result of conversion ValueHandle IHandle(VMC, I); // Prevent I from being removed! Constant *Dummy = Constant::getNullValue(Ty); switch (I->getOpcode()) { case Instruction::Cast: assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0); Res = new CastInst(I->getOperand(0), Ty, Name); VMC.NewCasts.insert(ValueHandle(VMC, Res)); break; case Instruction::Add: case Instruction::Sub: Res = BinaryOperator::create(cast(I)->getOpcode(), Dummy, Dummy, Name); VMC.ExprMap[I] = Res; // Add node to expression eagerly Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD)); Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC, TD)); break; case Instruction::Shl: case Instruction::Shr: Res = new ShiftInst(cast(I)->getOpcode(), Dummy, I->getOperand(1), Name); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD)); break; case Instruction::Load: { LoadInst *LI = cast(I); Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(), PointerType::get(Ty), VMC, TD)); assert(Res->getOperand(0)->getType() == PointerType::get(Ty)); assert(Ty == Res->getType()); assert(Res->getType()->isFirstClassType() && "Load of structure or array!"); break; } case Instruction::PHI: { PHINode *OldPN = cast(I); PHINode *NewPN = new PHINode(Ty, Name); VMC.ExprMap[I] = NewPN; // Add node to expression eagerly while (OldPN->getNumOperands()) { BasicBlock *BB = OldPN->getIncomingBlock(0); Value *OldVal = OldPN->getIncomingValue(0); ValueHandle OldValHandle(VMC, OldVal); OldPN->removeIncomingValue(BB, false); Value *V = ConvertExpressionToType(OldVal, Ty, VMC, TD); NewPN->addIncoming(V, BB); } Res = NewPN; break; } case Instruction::Malloc: { Res = ConvertMallocToType(cast(I), Ty, Name, VMC, TD); break; } case Instruction::GetElementPtr: { // GetElementPtr's are directly convertible to a pointer type if they have // a number of zeros at the end. Because removing these values does not // change the logical offset of the GEP, it is okay and fair to remove them. // This can change this: // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **> // %t2 = cast %List * * %t1 to %List * // into // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *> // GetElementPtrInst *GEP = cast(I); // Check to see if there are zero elements that we can remove from the // index array. If there are, check to see if removing them causes us to // get to the right type... // std::vector Indices(GEP->idx_begin(), GEP->idx_end()); const Type *BaseType = GEP->getPointerOperand()->getType(); const Type *PVTy = cast(Ty)->getElementType(); Res = 0; while (!Indices.empty() && Indices.back() == Constant::getNullValue(Indices.back()->getType())){ Indices.pop_back(); if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) { if (Indices.size() == 0) Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP CAST else Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name); break; } } if (Res == 0 && GEP->getNumOperands() == 2 && GEP->getType() == PointerType::get(Type::SByteTy)) { // Otherwise, we can convert a GEP from one form to the other iff the // current gep is of the form 'getelementptr sbyte*, unsigned N // and we could convert this to an appropriate GEP for the new type. // const PointerType *NewSrcTy = PointerType::get(PVTy); BasicBlock::iterator It = I; // Check to see if 'N' is an expression that can be converted to // the appropriate size... if so, allow it. // std::vector Indices; const Type *ElTy = ConvertibleToGEP(NewSrcTy, I->getOperand(1), Indices, TD, &It); if (ElTy) { assert(ElTy == PVTy && "Internal error, setup wrong!"); Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy), Indices, Name); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), NewSrcTy, VMC, TD)); } } // Otherwise, it could be that we have something like this: // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]** // and want to convert it into something like this: // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]** // if (Res == 0) { const PointerType *NewSrcTy = PointerType::get(PVTy); std::vector Indices(GEP->idx_begin(), GEP->idx_end()); Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy), Indices, Name); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), NewSrcTy, VMC, TD)); } assert(Res && "Didn't find match!"); break; } case Instruction::Call: { assert(!isa(I->getOperand(0))); // If this is a function pointer, we can convert the return type if we can // convert the source function pointer. // const PointerType *PT = cast(I->getOperand(0)->getType()); const FunctionType *FT = cast(PT->getElementType()); std::vector ArgTys(FT->param_begin(), FT->param_end()); const FunctionType *NewTy = FunctionType::get(Ty, ArgTys, FT->isVarArg()); const PointerType *NewPTy = PointerType::get(NewTy); if (Ty == Type::VoidTy) Name = ""; // Make sure not to name calls that now return void! Res = new CallInst(Constant::getNullValue(NewPTy), std::vector(I->op_begin()+1, I->op_end()), Name); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),NewPTy,VMC,TD)); break; } default: assert(0 && "Expression convertible, but don't know how to convert?"); return 0; } assert(Res->getType() == Ty && "Didn't convert expr to correct type!"); BB->getInstList().insert(I, Res); // Add the instruction to the expression map VMC.ExprMap[I] = Res; //// WTF is this code! FIXME: remove this. unsigned NumUses = I->getNumUses(); for (unsigned It = 0; It < NumUses; ) { unsigned OldSize = NumUses; Value::use_iterator UI = I->use_begin(); std::advance(UI, It); ConvertOperandToType(*UI, I, Res, VMC, TD); NumUses = I->getNumUses(); if (NumUses == OldSize) ++It; } DEBUG(std::cerr << "ExpIn: " << (void*)I << " " << *I << "ExpOut: " << (void*)Res << " " << *Res); return Res; } // ValueConvertibleToType - Return true if it is possible bool llvm::ValueConvertibleToType(Value *V, const Type *Ty, ValueTypeCache &ConvertedTypes, const TargetData &TD) { ValueTypeCache::iterator I = ConvertedTypes.find(V); if (I != ConvertedTypes.end()) return I->second == Ty; ConvertedTypes[V] = Ty; // It is safe to convert the specified value to the specified type IFF all of // the uses of the value can be converted to accept the new typed value. // if (V->getType() != Ty) { for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) if (!OperandConvertibleToType(*I, V, Ty, ConvertedTypes, TD)) return false; } return true; } // OperandConvertibleToType - Return true if it is possible to convert operand // V of User (instruction) U to the specified type. This is true iff it is // possible to change the specified instruction to accept this. CTMap is a map // of converted types, so that circular definitions will see the future type of // the expression, not the static current type. // static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty, ValueTypeCache &CTMap, const TargetData &TD) { // if (V->getType() == Ty) return true; // Operand already the right type? // Expression type must be holdable in a register. if (!Ty->isFirstClassType()) return false; Instruction *I = dyn_cast(U); if (I == 0) return false; // We can't convert! switch (I->getOpcode()) { case Instruction::Cast: assert(I->getOperand(0) == V); // We can convert the expr if the cast destination type is losslessly // convertible to the requested type. // Also, do not change a cast that is a noop cast. For all intents and // purposes it should be eliminated. if (!Ty->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) || I->getType() == I->getOperand(0)->getType()) return false; // Do not allow a 'cast ushort %V to uint' to have it's first operand be // converted to a 'short' type. Doing so changes the way sign promotion // happens, and breaks things. Only allow the cast to take place if the // signedness doesn't change... or if the current cast is not a lossy // conversion. // if (!I->getType()->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) && I->getOperand(0)->getType()->isSigned() != Ty->isSigned()) return false; // We also do not allow conversion of a cast that casts from a ptr to array // of X to a *X. For example: cast [4 x %List *] * %val to %List * * // if (const PointerType *SPT = dyn_cast(I->getOperand(0)->getType())) if (const PointerType *DPT = dyn_cast(I->getType())) if (const ArrayType *AT = dyn_cast(SPT->getElementType())) if (AT->getElementType() == DPT->getElementType()) return false; return true; case Instruction::Add: if (isa(Ty)) { Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0); std::vector Indices; if (const Type *ETy = ConvertibleToGEP(Ty, IndexVal, Indices, TD)) { const Type *RetTy = PointerType::get(ETy); // Only successful if we can convert this type to the required type if (ValueConvertibleToType(I, RetTy, CTMap, TD)) { CTMap[I] = RetTy; return true; } // We have to return failure here because ValueConvertibleToType could // have polluted our map return false; } } // FALLTHROUGH case Instruction::Sub: { if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false; Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0); return ValueConvertibleToType(I, Ty, CTMap, TD) && ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD); } case Instruction::SetEQ: case Instruction::SetNE: { Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0); return ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD); } case Instruction::Shr: if (Ty->isSigned() != V->getType()->isSigned()) return false; // FALL THROUGH case Instruction::Shl: if (I->getOperand(1) == V) return false; // Cannot change shift amount type if (!Ty->isInteger()) return false; return ValueConvertibleToType(I, Ty, CTMap, TD); case Instruction::Free: assert(I->getOperand(0) == V); return isa(Ty); // Free can free any pointer type! case Instruction::Load: // Cannot convert the types of any subscripts... if (I->getOperand(0) != V) return false; if (const PointerType *PT = dyn_cast(Ty)) { LoadInst *LI = cast(I); const Type *LoadedTy = PT->getElementType(); // They could be loading the first element of a composite type... if (const CompositeType *CT = dyn_cast(LoadedTy)) { unsigned Offset = 0; // No offset, get first leaf. std::vector Indices; // Discarded... LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false); assert(Offset == 0 && "Offset changed from zero???"); } if (!LoadedTy->isFirstClassType()) return false; if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType())) return false; return ValueConvertibleToType(LI, LoadedTy, CTMap, TD); } return false; case Instruction::Store: { StoreInst *SI = cast(I); if (V == I->getOperand(0)) { ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1)); if (CTMI != CTMap.end()) { // Operand #1 is in the table already? // If so, check to see if it's Ty*, or, more importantly, if it is a // pointer to a structure where the first element is a Ty... this code // is necessary because we might be trying to change the source and // destination type of the store (they might be related) and the dest // pointer type might be a pointer to structure. Below we allow pointer // to structures where the 0th element is compatible with the value, // now we have to support the symmetrical part of this. // const Type *ElTy = cast(CTMI->second)->getElementType(); // Already a pointer to what we want? Trivially accept... if (ElTy == Ty) return true; // Tricky case now, if the destination is a pointer to structure, // obviously the source is not allowed to be a structure (cannot copy // a whole structure at a time), so the level raiser must be trying to // store into the first field. Check for this and allow it now: // if (const StructType *SElTy = dyn_cast(ElTy)) { unsigned Offset = 0; std::vector Indices; ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false); assert(Offset == 0 && "Offset changed!"); if (ElTy == 0) // Element at offset zero in struct doesn't exist! return false; // Can only happen for {}* if (ElTy == Ty) // Looks like the 0th element of structure is return true; // compatible! Accept now! // Otherwise we know that we can't work, so just stop trying now. return false; } } // Can convert the store if we can convert the pointer operand to match // the new value type... return ExpressionConvertibleToType(I->getOperand(1), PointerType::get(Ty), CTMap, TD); } else if (const PointerType *PT = dyn_cast(Ty)) { const Type *ElTy = PT->getElementType(); assert(V == I->getOperand(1)); if (isa(ElTy)) { // We can change the destination pointer if we can store our first // argument into the first element of the structure... // unsigned Offset = 0; std::vector Indices; ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false); assert(Offset == 0 && "Offset changed!"); if (ElTy == 0) // Element at offset zero in struct doesn't exist! return false; // Can only happen for {}* } // Must move the same amount of data... if (!ElTy->isSized() || TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType())) return false; // Can convert store if the incoming value is convertible and if the // result will preserve semantics... const Type *Op0Ty = I->getOperand(0)->getType(); if (!(Op0Ty->isIntegral() ^ ElTy->isIntegral()) && !(Op0Ty->isFloatingPoint() ^ ElTy->isFloatingPoint())) return ExpressionConvertibleToType(I->getOperand(0), ElTy, CTMap, TD); } return false; } case Instruction::GetElementPtr: if (V != I->getOperand(0) || !isa(Ty)) return false; // If we have a two operand form of getelementptr, this is really little // more than a simple addition. As with addition, check to see if the // getelementptr instruction can be changed to index into the new type. // if (I->getNumOperands() == 2) { const Type *OldElTy = cast(I->getType())->getElementType(); uint64_t DataSize = TD.getTypeSize(OldElTy); Value *Index = I->getOperand(1); Instruction *TempScale = 0; // If the old data element is not unit sized, we have to create a scale // instruction so that ConvertibleToGEP will know the REAL amount we are // indexing by. Note that this is never inserted into the instruction // stream, so we have to delete it when we're done. // if (DataSize != 1) { Value *CST; if (Index->getType()->isSigned()) CST = ConstantSInt::get(Index->getType(), DataSize); else CST = ConstantUInt::get(Index->getType(), DataSize); TempScale = BinaryOperator::create(Instruction::Mul, Index, CST); Index = TempScale; } // Check to see if the second argument is an expression that can // be converted to the appropriate size... if so, allow it. // std::vector Indices; const Type *ElTy = ConvertibleToGEP(Ty, Index, Indices, TD); delete TempScale; // Free our temporary multiply if we made it if (ElTy == 0) return false; // Cannot make conversion... return ValueConvertibleToType(I, PointerType::get(ElTy), CTMap, TD); } return false; case Instruction::PHI: { PHINode *PN = cast(I); // Be conservative if we find a giant PHI node. if (PN->getNumIncomingValues() > 32) return false; for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i) if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD)) return false; return ValueConvertibleToType(PN, Ty, CTMap, TD); } case Instruction::Call: { User::op_iterator OI = std::find(I->op_begin(), I->op_end(), V); assert (OI != I->op_end() && "Not using value!"); unsigned OpNum = OI - I->op_begin(); // Are we trying to change the function pointer value to a new type? if (OpNum == 0) { const PointerType *PTy = dyn_cast(Ty); if (PTy == 0) return false; // Can't convert to a non-pointer type... const FunctionType *FTy = dyn_cast(PTy->getElementType()); if (FTy == 0) return false; // Can't convert to a non ptr to function... // Do not allow converting to a call where all of the operands are ...'s if (FTy->getNumParams() == 0 && FTy->isVarArg()) return false; // Do not permit this conversion! // Perform sanity checks to make sure that new function type has the // correct number of arguments... // unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr // Cannot convert to a type that requires more fixed arguments than // the call provides... // if (NumArgs < FTy->getNumParams()) return false; // Unless this is a vararg function type, we cannot provide more arguments // than are desired... // if (!FTy->isVarArg() && NumArgs > FTy->getNumParams()) return false; // Okay, at this point, we know that the call and the function type match // number of arguments. Now we see if we can convert the arguments // themselves. Note that we do not require operands to be convertible, // we can insert casts if they are convertible but not compatible. The // reason for this is that we prefer to have resolved functions but casted // arguments if possible. // for (unsigned i = 0, NA = FTy->getNumParams(); i < NA; ++i) if (!FTy->getParamType(i)->isLosslesslyConvertibleTo(I->getOperand(i+1)->getType())) return false; // Operands must have compatible types! // Okay, at this point, we know that all of the arguments can be // converted. We succeed if we can change the return type if // necessary... // return ValueConvertibleToType(I, FTy->getReturnType(), CTMap, TD); } const PointerType *MPtr = cast(I->getOperand(0)->getType()); const FunctionType *FTy = cast(MPtr->getElementType()); if (!FTy->isVarArg()) return false; if ((OpNum-1) < FTy->getNumParams()) return false; // It's not in the varargs section... // If we get this far, we know the value is in the varargs section of the // function! We can convert if we don't reinterpret the value... // return Ty->isLosslesslyConvertibleTo(V->getType()); } } return false; } void llvm::ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC, const TargetData &TD) { ValueHandle VH(VMC, V); // FIXME: This is horrible! unsigned NumUses = V->getNumUses(); for (unsigned It = 0; It < NumUses; ) { unsigned OldSize = NumUses; Value::use_iterator UI = V->use_begin(); std::advance(UI, It); ConvertOperandToType(*UI, V, NewVal, VMC, TD); NumUses = V->getNumUses(); if (NumUses == OldSize) ++It; } } static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal, ValueMapCache &VMC, const TargetData &TD) { if (isa(U)) return; // Valuehandles don't let go of operands... if (VMC.OperandsMapped.count(U)) return; VMC.OperandsMapped.insert(U); ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U); if (VMCI != VMC.ExprMap.end()) return; Instruction *I = cast(U); // Only Instructions convertible BasicBlock *BB = I->getParent(); assert(BB != 0 && "Instruction not embedded in basic block!"); std::string Name = I->getName(); I->setName(""); Instruction *Res; // Result of conversion //std::cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I // << "BB Before: " << BB << endl; // Prevent I from being removed... ValueHandle IHandle(VMC, I); const Type *NewTy = NewVal->getType(); Constant *Dummy = (NewTy != Type::VoidTy) ? Constant::getNullValue(NewTy) : 0; switch (I->getOpcode()) { case Instruction::Cast: if (VMC.NewCasts.count(ValueHandle(VMC, I))) { // This cast has already had it's value converted, causing a new cast to // be created. We don't want to create YET ANOTHER cast instruction // representing the original one, so just modify the operand of this cast // instruction, which we know is newly created. I->setOperand(0, NewVal); I->setName(Name); // give I its name back return; } else { Res = new CastInst(NewVal, I->getType(), Name); } break; case Instruction::Add: if (isa(NewTy)) { Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0); std::vector Indices; BasicBlock::iterator It = I; if (const Type *ETy = ConvertibleToGEP(NewTy, IndexVal, Indices, TD,&It)){ // If successful, convert the add to a GEP //const Type *RetTy = PointerType::get(ETy); // First operand is actually the given pointer... Res = new GetElementPtrInst(NewVal, Indices, Name); assert(cast(Res->getType())->getElementType() == ETy && "ConvertibleToGEP broken!"); break; } } // FALLTHROUGH case Instruction::Sub: case Instruction::SetEQ: case Instruction::SetNE: { Res = BinaryOperator::create(cast(I)->getOpcode(), Dummy, Dummy, Name); VMC.ExprMap[I] = Res; // Add node to expression eagerly unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0; Value *OtherOp = I->getOperand(OtherIdx); Res->setOperand(!OtherIdx, NewVal); Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC, TD); Res->setOperand(OtherIdx, NewOther); break; } case Instruction::Shl: case Instruction::Shr: assert(I->getOperand(0) == OldVal); Res = new ShiftInst(cast(I)->getOpcode(), NewVal, I->getOperand(1), Name); break; case Instruction::Free: // Free can free any pointer type! assert(I->getOperand(0) == OldVal); Res = new FreeInst(NewVal); break; case Instruction::Load: { assert(I->getOperand(0) == OldVal && isa(NewVal->getType())); const Type *LoadedTy = cast(NewVal->getType())->getElementType(); Value *Src = NewVal; if (const CompositeType *CT = dyn_cast(LoadedTy)) { std::vector Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); unsigned Offset = 0; // No offset, get first leaf. LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false); assert(LoadedTy->isFirstClassType()); if (Indices.size() != 1) { // Do not generate load X, 0 // Insert the GEP instruction before this load. Src = new GetElementPtrInst(Src, Indices, Name+".idx", I); } } Res = new LoadInst(Src, Name); assert(Res->getType()->isFirstClassType() && "Load of structure or array!"); break; } case Instruction::Store: { if (I->getOperand(0) == OldVal) { // Replace the source value // Check to see if operand #1 has already been converted... ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(I->getOperand(1)); if (VMCI != VMC.ExprMap.end()) { // Comments describing this stuff are in the OperandConvertibleToType // switch statement for Store... // const Type *ElTy = cast(VMCI->second->getType())->getElementType(); Value *SrcPtr = VMCI->second; if (ElTy != NewTy) { // We check that this is a struct in the initial scan... const StructType *SElTy = cast(ElTy); std::vector Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); unsigned Offset = 0; const Type *Ty = getStructOffsetType(ElTy, Offset, Indices, TD,false); assert(Offset == 0 && "Offset changed!"); assert(NewTy == Ty && "Did not convert to correct type!"); // Insert the GEP instruction before this store. SrcPtr = new GetElementPtrInst(SrcPtr, Indices, SrcPtr->getName()+".idx", I); } Res = new StoreInst(NewVal, SrcPtr); VMC.ExprMap[I] = Res; } else { // Otherwise, we haven't converted Operand #1 over yet... const PointerType *NewPT = PointerType::get(NewTy); Res = new StoreInst(NewVal, Constant::getNullValue(NewPT)); VMC.ExprMap[I] = Res; Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC, TD)); } } else { // Replace the source pointer const Type *ValTy = cast(NewTy)->getElementType(); Value *SrcPtr = NewVal; if (isa(ValTy)) { std::vector Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); unsigned Offset = 0; ValTy = getStructOffsetType(ValTy, Offset, Indices, TD, false); assert(Offset == 0 && ValTy); // Insert the GEP instruction before this store. SrcPtr = new GetElementPtrInst(SrcPtr, Indices, SrcPtr->getName()+".idx", I); } Res = new StoreInst(Constant::getNullValue(ValTy), SrcPtr); VMC.ExprMap[I] = Res; Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC, TD)); } break; } case Instruction::GetElementPtr: { // Convert a one index getelementptr into just about anything that is // desired. // BasicBlock::iterator It = I; const Type *OldElTy = cast(I->getType())->getElementType(); uint64_t DataSize = TD.getTypeSize(OldElTy); Value *Index = I->getOperand(1); if (DataSize != 1) { // Insert a multiply of the old element type is not a unit size... Value *CST; if (Index->getType()->isSigned()) CST = ConstantSInt::get(Index->getType(), DataSize); else CST = ConstantUInt::get(Index->getType(), DataSize); Index = BinaryOperator::create(Instruction::Mul, Index, CST, "scale", It); } // Perform the conversion now... // std::vector Indices; const Type *ElTy = ConvertibleToGEP(NewVal->getType(),Index,Indices,TD,&It); assert(ElTy != 0 && "GEP Conversion Failure!"); Res = new GetElementPtrInst(NewVal, Indices, Name); assert(Res->getType() == PointerType::get(ElTy) && "ConvertibleToGet failed!"); } #if 0 if (I->getType() == PointerType::get(Type::SByteTy)) { // Convert a getelementptr sbyte * %reg111, uint 16 freely back to // anything that is a pointer type... // BasicBlock::iterator It = I; // Check to see if the second argument is an expression that can // be converted to the appropriate size... if so, allow it. // std::vector Indices; const Type *ElTy = ConvertibleToGEP(NewVal->getType(), I->getOperand(1), Indices, TD, &It); assert(ElTy != 0 && "GEP Conversion Failure!"); Res = new GetElementPtrInst(NewVal, Indices, Name); } else { // Convert a getelementptr ulong * %reg123, uint %N // to getelementptr long * %reg123, uint %N // ... where the type must simply stay the same size... // GetElementPtrInst *GEP = cast(I); std::vector Indices(GEP->idx_begin(), GEP->idx_end()); Res = new GetElementPtrInst(NewVal, Indices, Name); } #endif break; case Instruction::PHI: { PHINode *OldPN = cast(I); PHINode *NewPN = new PHINode(NewTy, Name); VMC.ExprMap[I] = NewPN; while (OldPN->getNumOperands()) { BasicBlock *BB = OldPN->getIncomingBlock(0); Value *OldVal = OldPN->getIncomingValue(0); ValueHandle OldValHandle(VMC, OldVal); OldPN->removeIncomingValue(BB, false); Value *V = ConvertExpressionToType(OldVal, NewTy, VMC, TD); NewPN->addIncoming(V, BB); } Res = NewPN; break; } case Instruction::Call: { Value *Meth = I->getOperand(0); std::vector Params(I->op_begin()+1, I->op_end()); if (Meth == OldVal) { // Changing the function pointer? const PointerType *NewPTy = cast(NewVal->getType()); const FunctionType *NewTy = cast(NewPTy->getElementType()); if (NewTy->getReturnType() == Type::VoidTy) Name = ""; // Make sure not to name a void call! // Get an iterator to the call instruction so that we can insert casts for // operands if need be. Note that we do not require operands to be // convertible, we can insert casts if they are convertible but not // compatible. The reason for this is that we prefer to have resolved // functions but casted arguments if possible. // BasicBlock::iterator It = I; // Convert over all of the call operands to their new types... but only // convert over the part that is not in the vararg section of the call. // for (unsigned i = 0; i != NewTy->getNumParams(); ++i) if (Params[i]->getType() != NewTy->getParamType(i)) { // Create a cast to convert it to the right type, we know that this // is a lossless cast... // Params[i] = new CastInst(Params[i], NewTy->getParamType(i), "callarg.cast." + Params[i]->getName(), It); } Meth = NewVal; // Update call destination to new value } else { // Changing an argument, must be in vararg area std::vector::iterator OI = std::find(Params.begin(), Params.end(), OldVal); assert (OI != Params.end() && "Not using value!"); *OI = NewVal; } Res = new CallInst(Meth, Params, Name); break; } default: assert(0 && "Expression convertible, but don't know how to convert?"); return; } // If the instruction was newly created, insert it into the instruction // stream. // BasicBlock::iterator It = I; assert(It != BB->end() && "Instruction not in own basic block??"); BB->getInstList().insert(It, Res); // Keep It pointing to old instruction DEBUG(std::cerr << "COT CREATED: " << (void*)Res << " " << *Res << "In: " << (void*)I << " " << *I << "Out: " << (void*)Res << " " << *Res); // Add the instruction to the expression map VMC.ExprMap[I] = Res; if (I->getType() != Res->getType()) ConvertValueToNewType(I, Res, VMC, TD); else { for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ) if (isa(*UI)) { ++UI; } else { Use &U = UI.getUse(); ++UI; // Do not invalidate UI. U.set(Res); } } } ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V) : Instruction(Type::VoidTy, UserOp1, &Op, 1, ""), Op(V, this), Cache(VMC) { //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V); } ValueHandle::ValueHandle(const ValueHandle &VH) : Instruction(Type::VoidTy, UserOp1, &Op, 1, ""), Op(VH.Op, this), Cache(VH.Cache) { //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V); } static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) { if (!I || !I->use_empty()) return; assert(I->getParent() && "Inst not in basic block!"); //DEBUG(std::cerr << "VH DELETING: " << (void*)I << " " << I); for (User::op_iterator OI = I->op_begin(), OE = I->op_end(); OI != OE; ++OI) if (Instruction *U = dyn_cast(OI)) { *OI = 0; RecursiveDelete(Cache, U); } I->getParent()->getInstList().remove(I); Cache.OperandsMapped.erase(I); Cache.ExprMap.erase(I); delete I; } ValueHandle::~ValueHandle() { if (Op->hasOneUse()) { Value *V = Op; Op.set(0); // Drop use! // Now we just need to remove the old instruction so we don't get infinite // loops. Note that we cannot use DCE because DCE won't remove a store // instruction, for example. // RecursiveDelete(Cache, dyn_cast(V)); } else { //DEBUG(std::cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " // << Operands[0]->getNumUses() << " " << Operands[0]); } }