| //===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code to emit Constant Expr nodes as LLVM code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "CGObjCRuntime.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "llvm/Constants.h" |
| #include "llvm/Function.h" |
| #include "llvm/GlobalVariable.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Target/TargetData.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| namespace { |
| class VISIBILITY_HIDDEN ConstExprEmitter : |
| public StmtVisitor<ConstExprEmitter, llvm::Constant*> { |
| CodeGenModule &CGM; |
| CodeGenFunction *CGF; |
| public: |
| ConstExprEmitter(CodeGenModule &cgm, CodeGenFunction *cgf) |
| : CGM(cgm), CGF(cgf) { |
| } |
| |
| //===--------------------------------------------------------------------===// |
| // Visitor Methods |
| //===--------------------------------------------------------------------===// |
| |
| llvm::Constant *VisitStmt(Stmt *S) { |
| CGM.ErrorUnsupported(S, "constant expression"); |
| QualType T = cast<Expr>(S)->getType(); |
| return llvm::UndefValue::get(CGM.getTypes().ConvertType(T)); |
| } |
| |
| llvm::Constant *VisitParenExpr(ParenExpr *PE) { |
| return Visit(PE->getSubExpr()); |
| } |
| |
| // Leaves |
| llvm::Constant *VisitIntegerLiteral(const IntegerLiteral *E) { |
| return llvm::ConstantInt::get(E->getValue()); |
| } |
| llvm::Constant *VisitFloatingLiteral(const FloatingLiteral *E) { |
| return llvm::ConstantFP::get(E->getValue()); |
| } |
| llvm::Constant *VisitCharacterLiteral(const CharacterLiteral *E) { |
| return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); |
| } |
| llvm::Constant *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { |
| return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); |
| } |
| llvm::Constant *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { |
| return llvm::Constant::getNullValue(ConvertType(E->getType())); |
| } |
| llvm::Constant *VisitObjCStringLiteral(const ObjCStringLiteral *E) { |
| std::string S(E->getString()->getStrData(), |
| E->getString()->getByteLength()); |
| llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(S); |
| return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType())); |
| } |
| |
| llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { |
| return Visit(E->getInitializer()); |
| } |
| |
| llvm::Constant *VisitCastExpr(CastExpr* E) { |
| llvm::Constant *C = Visit(E->getSubExpr()); |
| |
| return EmitConversion(C, E->getSubExpr()->getType(), E->getType()); |
| } |
| |
| llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { |
| return Visit(DAE->getExpr()); |
| } |
| |
| llvm::Constant *EmitArrayInitialization(InitListExpr *ILE) { |
| std::vector<llvm::Constant*> Elts; |
| const llvm::ArrayType *AType = |
| cast<llvm::ArrayType>(ConvertType(ILE->getType())); |
| unsigned NumInitElements = ILE->getNumInits(); |
| // FIXME: Check for wide strings |
| if (NumInitElements > 0 && isa<StringLiteral>(ILE->getInit(0)) && |
| ILE->getType()->getArrayElementTypeNoTypeQual()->isCharType()) |
| return Visit(ILE->getInit(0)); |
| const llvm::Type *ElemTy = AType->getElementType(); |
| unsigned NumElements = AType->getNumElements(); |
| |
| // Initialising an array requires us to automatically |
| // initialise any elements that have not been initialised explicitly |
| unsigned NumInitableElts = std::min(NumInitElements, NumElements); |
| |
| // Copy initializer elements. |
| unsigned i = 0; |
| bool RewriteType = false; |
| for (; i < NumInitableElts; ++i) { |
| llvm::Constant *C = Visit(ILE->getInit(i)); |
| RewriteType |= (C->getType() != ElemTy); |
| Elts.push_back(C); |
| } |
| |
| // Initialize remaining array elements. |
| for (; i < NumElements; ++i) |
| Elts.push_back(llvm::Constant::getNullValue(ElemTy)); |
| |
| if (RewriteType) { |
| // FIXME: Try to avoid packing the array |
| std::vector<const llvm::Type*> Types; |
| for (unsigned i = 0; i < Elts.size(); ++i) |
| Types.push_back(Elts[i]->getType()); |
| const llvm::StructType *SType = llvm::StructType::get(Types, true); |
| return llvm::ConstantStruct::get(SType, Elts); |
| } |
| |
| return llvm::ConstantArray::get(AType, Elts); |
| } |
| |
| void InsertBitfieldIntoStruct(std::vector<llvm::Constant*>& Elts, |
| FieldDecl* Field, Expr* E) { |
| // Calculate the value to insert |
| llvm::Constant *C = Visit(E); |
| llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C); |
| if (!CI) { |
| CGM.ErrorUnsupported(E, "bitfield initialization"); |
| return; |
| } |
| llvm::APInt V = CI->getValue(); |
| |
| // Calculate information about the relevant field |
| const llvm::Type* Ty = CI->getType(); |
| const llvm::TargetData &TD = CGM.getTypes().getTargetData(); |
| unsigned size = TD.getTypeStoreSizeInBits(Ty); |
| unsigned fieldOffset = CGM.getTypes().getLLVMFieldNo(Field) * size; |
| CodeGenTypes::BitFieldInfo bitFieldInfo = |
| CGM.getTypes().getBitFieldInfo(Field); |
| fieldOffset += bitFieldInfo.Begin; |
| |
| // Find where to start the insertion |
| // FIXME: This is O(n^2) in the number of bit-fields! |
| // FIXME: This won't work if the struct isn't completely packed! |
| unsigned offset = 0, i = 0; |
| while (offset < (fieldOffset & -8)) |
| offset += TD.getTypeStoreSizeInBits(Elts[i++]->getType()); |
| |
| // Advance over 0 sized elements (must terminate in bounds since |
| // the bitfield must have a size). |
| while (TD.getTypeStoreSizeInBits(Elts[i]->getType()) == 0) |
| ++i; |
| |
| // Promote the size of V if necessary |
| // FIXME: This should never occur, but currently it can because |
| // initializer constants are cast to bool, and because clang is |
| // not enforcing bitfield width limits. |
| if (bitFieldInfo.Size > V.getBitWidth()) |
| V.zext(bitFieldInfo.Size); |
| |
| // Insert the bits into the struct |
| // FIXME: This algorthm is only correct on X86! |
| // FIXME: THis algorthm assumes bit-fields only have byte-size elements! |
| unsigned bitsToInsert = bitFieldInfo.Size; |
| unsigned curBits = std::min(8 - (fieldOffset & 7), bitsToInsert); |
| unsigned byte = V.getLoBits(curBits).getZExtValue() << (fieldOffset & 7); |
| do { |
| llvm::Constant* byteC = llvm::ConstantInt::get(llvm::Type::Int8Ty, byte); |
| Elts[i] = llvm::ConstantExpr::getOr(Elts[i], byteC); |
| ++i; |
| V = V.lshr(curBits); |
| bitsToInsert -= curBits; |
| |
| if (!bitsToInsert) |
| break; |
| |
| curBits = bitsToInsert > 8 ? 8 : bitsToInsert; |
| byte = V.getLoBits(curBits).getZExtValue(); |
| } while (true); |
| } |
| |
| llvm::Constant *EmitStructInitialization(InitListExpr *ILE) { |
| const llvm::StructType *SType = |
| cast<llvm::StructType>(ConvertType(ILE->getType())); |
| RecordDecl *RD = ILE->getType()->getAsRecordType()->getDecl(); |
| std::vector<llvm::Constant*> Elts; |
| |
| // Initialize the whole structure to zero. |
| for (unsigned i = 0; i < SType->getNumElements(); ++i) { |
| const llvm::Type *FieldTy = SType->getElementType(i); |
| Elts.push_back(llvm::Constant::getNullValue(FieldTy)); |
| } |
| |
| // Copy initializer elements. Skip padding fields. |
| unsigned EltNo = 0; // Element no in ILE |
| int FieldNo = 0; // Field no in RecordDecl |
| bool RewriteType = false; |
| while (EltNo < ILE->getNumInits() && FieldNo < RD->getNumMembers()) { |
| FieldDecl* curField = RD->getMember(FieldNo); |
| FieldNo++; |
| if (!curField->getIdentifier()) |
| continue; |
| |
| if (curField->isBitField()) { |
| InsertBitfieldIntoStruct(Elts, curField, ILE->getInit(EltNo)); |
| } else { |
| unsigned FieldNo = CGM.getTypes().getLLVMFieldNo(curField); |
| llvm::Constant* C = Visit(ILE->getInit(EltNo)); |
| RewriteType |= (C->getType() != Elts[FieldNo]->getType()); |
| Elts[FieldNo] = C; |
| } |
| EltNo++; |
| } |
| |
| if (RewriteType) { |
| // FIXME: Make this work for non-packed structs |
| assert(SType->isPacked() && "Cannot recreate unpacked structs"); |
| std::vector<const llvm::Type*> Types; |
| for (unsigned i = 0; i < Elts.size(); ++i) |
| Types.push_back(Elts[i]->getType()); |
| SType = llvm::StructType::get(Types, true); |
| } |
| |
| return llvm::ConstantStruct::get(SType, Elts); |
| } |
| |
| llvm::Constant *EmitUnionInitialization(InitListExpr *ILE) { |
| RecordDecl *RD = ILE->getType()->getAsRecordType()->getDecl(); |
| const llvm::Type *Ty = ConvertType(ILE->getType()); |
| |
| // Find the field decl we're initializing, if any |
| int FieldNo = 0; // Field no in RecordDecl |
| FieldDecl* curField = 0; |
| while (FieldNo < RD->getNumMembers()) { |
| curField = RD->getMember(FieldNo); |
| FieldNo++; |
| if (curField->getIdentifier()) |
| break; |
| } |
| |
| if (!curField || !curField->getIdentifier() || ILE->getNumInits() == 0) |
| return llvm::Constant::getNullValue(Ty); |
| |
| if (curField->isBitField()) { |
| // Create a dummy struct for bit-field insertion |
| unsigned NumElts = CGM.getTargetData().getABITypeSize(Ty) / 8; |
| llvm::Constant* NV = llvm::Constant::getNullValue(llvm::Type::Int8Ty); |
| std::vector<llvm::Constant*> Elts(NumElts, NV); |
| |
| InsertBitfieldIntoStruct(Elts, curField, ILE->getInit(0)); |
| const llvm::ArrayType *RetTy = |
| llvm::ArrayType::get(NV->getType(), NumElts); |
| return llvm::ConstantArray::get(RetTy, Elts); |
| } |
| |
| llvm::Constant *C = Visit(ILE->getInit(0)); |
| |
| // Build a struct with the union sub-element as the first member, |
| // and padded to the appropriate size |
| std::vector<llvm::Constant*> Elts; |
| std::vector<const llvm::Type*> Types; |
| Elts.push_back(C); |
| Types.push_back(C->getType()); |
| unsigned CurSize = CGM.getTargetData().getTypeStoreSize(C->getType()); |
| unsigned TotalSize = CGM.getTargetData().getTypeStoreSize(Ty); |
| while (CurSize < TotalSize) { |
| Elts.push_back(llvm::Constant::getNullValue(llvm::Type::Int8Ty)); |
| Types.push_back(llvm::Type::Int8Ty); |
| CurSize++; |
| } |
| |
| // This always generates a packed struct |
| // FIXME: Try to generate an unpacked struct when we can |
| llvm::StructType* STy = llvm::StructType::get(Types, true); |
| return llvm::ConstantStruct::get(STy, Elts); |
| } |
| |
| llvm::Constant *EmitVectorInitialization(InitListExpr *ILE) { |
| const llvm::VectorType *VType = |
| cast<llvm::VectorType>(ConvertType(ILE->getType())); |
| const llvm::Type *ElemTy = VType->getElementType(); |
| std::vector<llvm::Constant*> Elts; |
| unsigned NumElements = VType->getNumElements(); |
| unsigned NumInitElements = ILE->getNumInits(); |
| |
| unsigned NumInitableElts = std::min(NumInitElements, NumElements); |
| |
| // Copy initializer elements. |
| unsigned i = 0; |
| for (; i < NumInitableElts; ++i) { |
| llvm::Constant *C = Visit(ILE->getInit(i)); |
| Elts.push_back(C); |
| } |
| |
| for (; i < NumElements; ++i) |
| Elts.push_back(llvm::Constant::getNullValue(ElemTy)); |
| |
| return llvm::ConstantVector::get(VType, Elts); |
| } |
| |
| llvm::Constant *VisitInitListExpr(InitListExpr *ILE) { |
| if (ILE->getType()->isScalarType()) { |
| // We have a scalar in braces. Just use the first element. |
| if (ILE->getNumInits() > 0) |
| return Visit(ILE->getInit(0)); |
| |
| const llvm::Type* RetTy = CGM.getTypes().ConvertType(ILE->getType()); |
| return llvm::Constant::getNullValue(RetTy); |
| } |
| |
| if (ILE->getType()->isArrayType()) |
| return EmitArrayInitialization(ILE); |
| |
| if (ILE->getType()->isStructureType()) |
| return EmitStructInitialization(ILE); |
| |
| if (ILE->getType()->isUnionType()) |
| return EmitUnionInitialization(ILE); |
| |
| if (ILE->getType()->isVectorType()) |
| return EmitVectorInitialization(ILE); |
| |
| assert(0 && "Unable to handle InitListExpr"); |
| // Get rid of control reaches end of void function warning. |
| // Not reached. |
| return 0; |
| } |
| |
| llvm::Constant *VisitImplicitCastExpr(ImplicitCastExpr *ICExpr) { |
| Expr* SExpr = ICExpr->getSubExpr(); |
| QualType SType = SExpr->getType(); |
| llvm::Constant *C; // the intermediate expression |
| QualType T; // the type of the intermediate expression |
| if (SType->isArrayType()) { |
| // Arrays decay to a pointer to the first element |
| // VLAs would require special handling, but they can't occur here |
| C = EmitLValue(SExpr); |
| llvm::Constant *Idx0 = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); |
| llvm::Constant *Ops[] = {Idx0, Idx0}; |
| C = llvm::ConstantExpr::getGetElementPtr(C, Ops, 2); |
| T = CGM.getContext().getArrayDecayedType(SType); |
| } else if (SType->isFunctionType()) { |
| // Function types decay to a pointer to the function |
| C = EmitLValue(SExpr); |
| T = CGM.getContext().getPointerType(SType); |
| } else { |
| C = Visit(SExpr); |
| T = SType; |
| } |
| |
| // Perform the conversion; note that an implicit cast can both promote |
| // and convert an array/function |
| return EmitConversion(C, T, ICExpr->getType()); |
| } |
| |
| llvm::Constant *VisitStringLiteral(StringLiteral *E) { |
| assert(!E->getType()->isPointerType() && "Strings are always arrays"); |
| |
| // Otherwise this must be a string initializing an array in a static |
| // initializer. Don't emit it as the address of the string, emit the string |
| // data itself as an inline array. |
| return llvm::ConstantArray::get(CGM.GetStringForStringLiteral(E), false); |
| } |
| |
| llvm::Constant *VisitDeclRefExpr(DeclRefExpr *E) { |
| const ValueDecl *Decl = E->getDecl(); |
| if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(Decl)) |
| return llvm::ConstantInt::get(EC->getInitVal()); |
| assert(0 && "Unsupported decl ref type!"); |
| return 0; |
| } |
| |
| llvm::Constant *VisitSizeOfAlignOfTypeExpr(const SizeOfAlignOfTypeExpr *E) { |
| return EmitSizeAlignOf(E->getArgumentType(), E->getType(), E->isSizeOf()); |
| } |
| |
| llvm::Constant *VisitAddrLabelExpr(const AddrLabelExpr *E) { |
| assert(CGF && "Invalid address of label expression outside function."); |
| llvm::Constant *C = |
| llvm::ConstantInt::get(llvm::Type::Int32Ty, |
| CGF->GetIDForAddrOfLabel(E->getLabel())); |
| return llvm::ConstantExpr::getIntToPtr(C, ConvertType(E->getType())); |
| } |
| |
| // Unary operators |
| llvm::Constant *VisitUnaryPlus(const UnaryOperator *E) { |
| return Visit(E->getSubExpr()); |
| } |
| llvm::Constant *VisitUnaryMinus(const UnaryOperator *E) { |
| return llvm::ConstantExpr::getNeg(Visit(E->getSubExpr())); |
| } |
| llvm::Constant *VisitUnaryNot(const UnaryOperator *E) { |
| return llvm::ConstantExpr::getNot(Visit(E->getSubExpr())); |
| } |
| llvm::Constant *VisitUnaryLNot(const UnaryOperator *E) { |
| llvm::Constant *SubExpr = Visit(E->getSubExpr()); |
| |
| if (E->getSubExpr()->getType()->isRealFloatingType()) { |
| // Compare against 0.0 for fp scalars. |
| llvm::Constant *Zero = llvm::Constant::getNullValue(SubExpr->getType()); |
| SubExpr = llvm::ConstantExpr::getFCmp(llvm::FCmpInst::FCMP_UEQ, SubExpr, |
| Zero); |
| } else { |
| assert((E->getSubExpr()->getType()->isIntegerType() || |
| E->getSubExpr()->getType()->isPointerType()) && |
| "Unknown scalar type to convert"); |
| // Compare against an integer or pointer null. |
| llvm::Constant *Zero = llvm::Constant::getNullValue(SubExpr->getType()); |
| SubExpr = llvm::ConstantExpr::getICmp(llvm::ICmpInst::ICMP_EQ, SubExpr, |
| Zero); |
| } |
| |
| return llvm::ConstantExpr::getZExt(SubExpr, ConvertType(E->getType())); |
| } |
| llvm::Constant *VisitUnarySizeOf(const UnaryOperator *E) { |
| return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), true); |
| } |
| llvm::Constant *VisitUnaryAlignOf(const UnaryOperator *E) { |
| return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), false); |
| } |
| llvm::Constant *VisitUnaryAddrOf(const UnaryOperator *E) { |
| return EmitLValue(E->getSubExpr()); |
| } |
| llvm::Constant *VisitUnaryOffsetOf(const UnaryOperator *E) { |
| int64_t Val = E->evaluateOffsetOf(CGM.getContext()); |
| |
| assert(E->getType()->isIntegerType() && "Result type must be an integer!"); |
| |
| uint32_t ResultWidth = |
| static_cast<uint32_t>(CGM.getContext().getTypeSize(E->getType())); |
| return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); |
| } |
| |
| llvm::Constant *VisitUnaryExtension(const UnaryOperator *E) { |
| return Visit(E->getSubExpr()); |
| } |
| |
| // Binary operators |
| llvm::Constant *VisitBinOr(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| return llvm::ConstantExpr::getOr(LHS, RHS); |
| } |
| llvm::Constant *VisitBinSub(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| if (!isa<llvm::PointerType>(RHS->getType())) { |
| // pointer - int |
| if (isa<llvm::PointerType>(LHS->getType())) { |
| llvm::Constant *Idx = llvm::ConstantExpr::getNeg(RHS); |
| |
| return llvm::ConstantExpr::getGetElementPtr(LHS, &Idx, 1); |
| } |
| |
| // int - int |
| return llvm::ConstantExpr::getSub(LHS, RHS); |
| } |
| |
| assert(isa<llvm::PointerType>(LHS->getType())); |
| |
| const llvm::Type *ResultType = ConvertType(E->getType()); |
| const QualType Type = E->getLHS()->getType(); |
| const QualType ElementType = Type->getAsPointerType()->getPointeeType(); |
| |
| LHS = llvm::ConstantExpr::getPtrToInt(LHS, ResultType); |
| RHS = llvm::ConstantExpr::getPtrToInt(RHS, ResultType); |
| |
| llvm::Constant *sub = llvm::ConstantExpr::getSub(LHS, RHS); |
| llvm::Constant *size = EmitSizeAlignOf(ElementType, E->getType(), true); |
| return llvm::ConstantExpr::getSDiv(sub, size); |
| } |
| |
| llvm::Constant *VisitBinShl(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| // LLVM requires the LHS and RHS to be the same type: promote or truncate the |
| // RHS to the same size as the LHS. |
| if (LHS->getType() != RHS->getType()) |
| RHS = llvm::ConstantExpr::getIntegerCast(RHS, LHS->getType(), false); |
| |
| return llvm::ConstantExpr::getShl(LHS, RHS); |
| } |
| |
| llvm::Constant *VisitBinMul(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| return llvm::ConstantExpr::getMul(LHS, RHS); |
| } |
| |
| llvm::Constant *VisitBinDiv(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| if (LHS->getType()->isFPOrFPVector()) |
| return llvm::ConstantExpr::getFDiv(LHS, RHS); |
| else if (E->getType()->isUnsignedIntegerType()) |
| return llvm::ConstantExpr::getUDiv(LHS, RHS); |
| else |
| return llvm::ConstantExpr::getSDiv(LHS, RHS); |
| } |
| |
| llvm::Constant *VisitBinAdd(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| if (!E->getType()->isPointerType()) |
| return llvm::ConstantExpr::getAdd(LHS, RHS); |
| |
| llvm::Constant *Ptr, *Idx; |
| if (isa<llvm::PointerType>(LHS->getType())) { // pointer + int |
| Ptr = LHS; |
| Idx = RHS; |
| } else { // int + pointer |
| Ptr = RHS; |
| Idx = LHS; |
| } |
| |
| return llvm::ConstantExpr::getGetElementPtr(Ptr, &Idx, 1); |
| } |
| |
| llvm::Constant *VisitBinAnd(const BinaryOperator *E) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| |
| return llvm::ConstantExpr::getAnd(LHS, RHS); |
| } |
| |
| llvm::Constant *EmitCmp(const BinaryOperator *E, |
| llvm::CmpInst::Predicate SignedPred, |
| llvm::CmpInst::Predicate UnsignedPred, |
| llvm::CmpInst::Predicate FloatPred) { |
| llvm::Constant *LHS = Visit(E->getLHS()); |
| llvm::Constant *RHS = Visit(E->getRHS()); |
| llvm::Constant *Result; |
| if (LHS->getType()->isInteger() || |
| isa<llvm::PointerType>(LHS->getType())) { |
| if (E->getLHS()->getType()->isSignedIntegerType()) |
| Result = llvm::ConstantExpr::getICmp(SignedPred, LHS, RHS); |
| else |
| Result = llvm::ConstantExpr::getICmp(UnsignedPred, LHS, RHS); |
| } else if (LHS->getType()->isFloatingPoint()) { |
| Result = llvm::ConstantExpr::getFCmp(FloatPred, LHS, RHS); |
| } else { |
| CGM.ErrorUnsupported(E, "constant expression"); |
| Result = llvm::ConstantInt::getFalse(); |
| } |
| |
| const llvm::Type* ResultType = ConvertType(E->getType()); |
| return llvm::ConstantExpr::getZExtOrBitCast(Result, ResultType); |
| } |
| |
| llvm::Constant *VisitBinNE(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_NE, |
| llvm::CmpInst::FCMP_ONE); |
| } |
| |
| llvm::Constant *VisitBinEQ(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_EQ, |
| llvm::CmpInst::FCMP_OEQ); |
| } |
| |
| llvm::Constant *VisitBinLT(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_ULT, |
| llvm::CmpInst::FCMP_OLT); |
| } |
| |
| llvm::Constant *VisitBinLE(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_ULE, |
| llvm::CmpInst::FCMP_OLE); |
| } |
| |
| llvm::Constant *VisitBinGT(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_UGT, |
| llvm::CmpInst::FCMP_OGT); |
| } |
| |
| llvm::Constant *VisitBinGE(const BinaryOperator *E) { |
| return EmitCmp(E, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGE, |
| llvm::CmpInst::FCMP_OGE); |
| } |
| |
| llvm::Constant *VisitConditionalOperator(const ConditionalOperator *E) { |
| llvm::Constant *Cond = Visit(E->getCond()); |
| llvm::Constant *CondVal = EmitConversionToBool(Cond, E->getType()); |
| llvm::ConstantInt *CondValInt = dyn_cast<llvm::ConstantInt>(CondVal); |
| if (!CondValInt) { |
| CGM.ErrorUnsupported(E, "constant expression"); |
| return llvm::Constant::getNullValue(ConvertType(E->getType())); |
| } |
| if (CondValInt->isOne()) { |
| if (E->getLHS()) |
| return Visit(E->getLHS()); |
| return Cond; |
| } |
| |
| return Visit(E->getRHS()); |
| } |
| |
| llvm::Constant *VisitCallExpr(const CallExpr *E) { |
| if (const ImplicitCastExpr *IcExpr = |
| dyn_cast<const ImplicitCastExpr>(E->getCallee())) |
| if (const DeclRefExpr *DRExpr = |
| dyn_cast<const DeclRefExpr>(IcExpr->getSubExpr())) |
| if (const FunctionDecl *FDecl = |
| dyn_cast<const FunctionDecl>(DRExpr->getDecl())) |
| if (unsigned builtinID = FDecl->getIdentifier()->getBuiltinID()) |
| return EmitBuiltinExpr(builtinID, E); |
| |
| CGM.ErrorUnsupported(E, "constant call expression"); |
| return llvm::Constant::getNullValue(ConvertType(E->getType())); |
| } |
| |
| // Utility methods |
| const llvm::Type *ConvertType(QualType T) { |
| return CGM.getTypes().ConvertType(T); |
| } |
| |
| llvm::Constant *EmitConversionToBool(llvm::Constant *Src, QualType SrcType) { |
| assert(SrcType->isCanonical() && "EmitConversion strips typedefs"); |
| |
| if (SrcType->isRealFloatingType()) { |
| // Compare against 0.0 for fp scalars. |
| llvm::Constant *Zero = llvm::Constant::getNullValue(Src->getType()); |
| return llvm::ConstantExpr::getFCmp(llvm::FCmpInst::FCMP_UNE, Src, Zero); |
| } |
| |
| assert((SrcType->isIntegerType() || SrcType->isPointerType()) && |
| "Unknown scalar type to convert"); |
| |
| // Compare against an integer or pointer null. |
| llvm::Constant *Zero = llvm::Constant::getNullValue(Src->getType()); |
| return llvm::ConstantExpr::getICmp(llvm::ICmpInst::ICMP_NE, Src, Zero); |
| } |
| |
| llvm::Constant *EmitConversion(llvm::Constant *Src, QualType SrcType, |
| QualType DstType) { |
| SrcType = CGM.getContext().getCanonicalType(SrcType); |
| DstType = CGM.getContext().getCanonicalType(DstType); |
| if (SrcType == DstType) return Src; |
| |
| // Handle conversions to bool first, they are special: comparisons against 0. |
| if (DstType->isBooleanType()) |
| return EmitConversionToBool(Src, SrcType); |
| |
| const llvm::Type *DstTy = ConvertType(DstType); |
| |
| // Ignore conversions like int -> uint. |
| if (Src->getType() == DstTy) |
| return Src; |
| |
| // Handle pointer conversions next: pointers can only be converted to/from |
| // other pointers and integers. |
| if (isa<llvm::PointerType>(DstTy)) { |
| // The source value may be an integer, or a pointer. |
| if (isa<llvm::PointerType>(Src->getType())) |
| return llvm::ConstantExpr::getBitCast(Src, DstTy); |
| assert(SrcType->isIntegerType() &&"Not ptr->ptr or int->ptr conversion?"); |
| return llvm::ConstantExpr::getIntToPtr(Src, DstTy); |
| } |
| |
| if (isa<llvm::PointerType>(Src->getType())) { |
| // Must be an ptr to int cast. |
| assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); |
| return llvm::ConstantExpr::getPtrToInt(Src, DstTy); |
| } |
| |
| // A scalar source can be splatted to a vector of the same element type |
| if (isa<llvm::VectorType>(DstTy) && !isa<VectorType>(SrcType)) { |
| const llvm::VectorType *VT = cast<llvm::VectorType>(DstTy); |
| assert((VT->getElementType() == Src->getType()) && |
| "Vector element type must match scalar type to splat."); |
| unsigned NumElements = DstType->getAsVectorType()->getNumElements(); |
| llvm::SmallVector<llvm::Constant*, 16> Elements; |
| for (unsigned i = 0; i < NumElements; i++) |
| Elements.push_back(Src); |
| |
| return llvm::ConstantVector::get(&Elements[0], NumElements); |
| } |
| |
| if (isa<llvm::VectorType>(Src->getType()) || |
| isa<llvm::VectorType>(DstTy)) { |
| return llvm::ConstantExpr::getBitCast(Src, DstTy); |
| } |
| |
| // Finally, we have the arithmetic types: real int/float. |
| if (isa<llvm::IntegerType>(Src->getType())) { |
| bool InputSigned = SrcType->isSignedIntegerType(); |
| if (isa<llvm::IntegerType>(DstTy)) |
| return llvm::ConstantExpr::getIntegerCast(Src, DstTy, InputSigned); |
| else if (InputSigned) |
| return llvm::ConstantExpr::getSIToFP(Src, DstTy); |
| else |
| return llvm::ConstantExpr::getUIToFP(Src, DstTy); |
| } |
| |
| assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); |
| if (isa<llvm::IntegerType>(DstTy)) { |
| if (DstType->isSignedIntegerType()) |
| return llvm::ConstantExpr::getFPToSI(Src, DstTy); |
| else |
| return llvm::ConstantExpr::getFPToUI(Src, DstTy); |
| } |
| |
| assert(DstTy->isFloatingPoint() && "Unknown real conversion"); |
| if (DstTy->getTypeID() < Src->getType()->getTypeID()) |
| return llvm::ConstantExpr::getFPTrunc(Src, DstTy); |
| else |
| return llvm::ConstantExpr::getFPExtend(Src, DstTy); |
| } |
| |
| llvm::Constant *EmitSizeAlignOf(QualType TypeToSize, |
| QualType RetType, bool isSizeOf) { |
| std::pair<uint64_t, unsigned> Info = |
| CGM.getContext().getTypeInfo(TypeToSize); |
| |
| uint64_t Val = isSizeOf ? Info.first : Info.second; |
| Val /= 8; // Return size in bytes, not bits. |
| |
| assert(RetType->isIntegerType() && "Result type must be an integer!"); |
| |
| uint32_t ResultWidth = |
| static_cast<uint32_t>(CGM.getContext().getTypeSize(RetType)); |
| return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); |
| } |
| |
| llvm::Constant *EmitLValue(Expr *E) { |
| switch (E->getStmtClass()) { |
| default: break; |
| case Expr::ParenExprClass: |
| // Elide parenthesis |
| return EmitLValue(cast<ParenExpr>(E)->getSubExpr()); |
| case Expr::CompoundLiteralExprClass: { |
| // Note that due to the nature of compound literals, this is guaranteed |
| // to be the only use of the variable, so we just generate it here. |
| CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E); |
| llvm::Constant* C = Visit(CLE->getInitializer()); |
| C = new llvm::GlobalVariable(C->getType(),E->getType().isConstQualified(), |
| llvm::GlobalValue::InternalLinkage, |
| C, ".compoundliteral", &CGM.getModule()); |
| return C; |
| } |
| case Expr::DeclRefExprClass: { |
| ValueDecl *Decl = cast<DeclRefExpr>(E)->getDecl(); |
| if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Decl)) |
| return CGM.GetAddrOfFunction(FD); |
| if (const VarDecl* VD = dyn_cast<VarDecl>(Decl)) { |
| if (VD->isFileVarDecl()) |
| return CGM.GetAddrOfGlobalVar(VD); |
| else if (VD->isBlockVarDecl()) { |
| assert(CGF && "Can't access static local vars without CGF"); |
| return CGF->GetAddrOfStaticLocalVar(VD); |
| } |
| } |
| break; |
| } |
| case Expr::MemberExprClass: { |
| MemberExpr* ME = cast<MemberExpr>(E); |
| llvm::Constant *Base; |
| if (ME->isArrow()) |
| Base = Visit(ME->getBase()); |
| else |
| Base = EmitLValue(ME->getBase()); |
| |
| unsigned FieldNumber = CGM.getTypes().getLLVMFieldNo(ME->getMemberDecl()); |
| llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); |
| llvm::Constant *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, |
| FieldNumber); |
| llvm::Value *Ops[] = {Zero, Idx}; |
| return llvm::ConstantExpr::getGetElementPtr(Base, Ops, 2); |
| } |
| case Expr::ArraySubscriptExprClass: { |
| ArraySubscriptExpr* ASExpr = cast<ArraySubscriptExpr>(E); |
| llvm::Constant *Base = Visit(ASExpr->getBase()); |
| llvm::Constant *Index = Visit(ASExpr->getIdx()); |
| assert(!ASExpr->getBase()->getType()->isVectorType() && |
| "Taking the address of a vector component is illegal!"); |
| return llvm::ConstantExpr::getGetElementPtr(Base, &Index, 1); |
| } |
| case Expr::StringLiteralClass: |
| return CGM.GetAddrOfConstantStringFromLiteral(cast<StringLiteral>(E)); |
| case Expr::UnaryOperatorClass: { |
| UnaryOperator *Exp = cast<UnaryOperator>(E); |
| switch (Exp->getOpcode()) { |
| default: break; |
| case UnaryOperator::Extension: |
| // Extension is just a wrapper for expressions |
| return EmitLValue(Exp->getSubExpr()); |
| case UnaryOperator::Real: |
| case UnaryOperator::Imag: { |
| // The address of __real or __imag is just a GEP off the address |
| // of the internal expression |
| llvm::Constant* C = EmitLValue(Exp->getSubExpr()); |
| llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); |
| llvm::Constant *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, |
| Exp->getOpcode() == UnaryOperator::Imag); |
| llvm::Value *Ops[] = {Zero, Idx}; |
| return llvm::ConstantExpr::getGetElementPtr(C, Ops, 2); |
| } |
| case UnaryOperator::Deref: |
| // The address of a deref is just the value of the expression |
| return Visit(Exp->getSubExpr()); |
| } |
| break; |
| } |
| } |
| CGM.ErrorUnsupported(E, "constant l-value expression"); |
| llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType())); |
| return llvm::UndefValue::get(Ty); |
| } |
| |
| llvm::Constant *EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) |
| { |
| switch (BuiltinID) { |
| default: |
| CGM.ErrorUnsupported(E, "constant builtin function"); |
| return 0; |
| case Builtin::BI__builtin_huge_valf: { |
| const llvm::fltSemantics &Sem = |
| CGM.getContext().getFloatTypeSemantics(E->getType()); |
| return llvm::ConstantFP::get(llvm::APFloat::getInf(Sem)); |
| } |
| } |
| } |
| |
| }; |
| |
| } // end anonymous namespace. |
| |
| |
| llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E, |
| CodeGenFunction *CGF) { |
| QualType type = Context.getCanonicalType(E->getType()); |
| |
| if (type->isIntegerType()) { |
| llvm::APSInt Value(static_cast<uint32_t>(Context.getTypeSize(type))); |
| if (E->isIntegerConstantExpr(Value, Context)) { |
| return llvm::ConstantInt::get(Value); |
| } |
| } |
| |
| llvm::Constant* C = ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E)); |
| if (C->getType() == llvm::Type::Int1Ty) { |
| const llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType()); |
| C = llvm::ConstantExpr::getZExt(C, BoolTy); |
| } |
| return C; |
| } |