//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// // // 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 Expr nodes with scalar LLVM types as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/RecordLayout.h" #include "clang/AST/StmtVisitor.h" #include "clang/Basic/TargetInfo.h" #include "llvm/Constants.h" #include "llvm/Function.h" #include "llvm/GlobalVariable.h" #include "llvm/Intrinsics.h" #include "llvm/Module.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/CFG.h" #include "llvm/Target/TargetData.h" #include using namespace clang; using namespace CodeGen; using llvm::Value; //===----------------------------------------------------------------------===// // Scalar Expression Emitter //===----------------------------------------------------------------------===// struct BinOpInfo { Value *LHS; Value *RHS; QualType Ty; // Computation Type. const BinaryOperator *E; }; namespace { class VISIBILITY_HIDDEN ScalarExprEmitter : public StmtVisitor { CodeGenFunction &CGF; CGBuilderTy &Builder; bool IgnoreResultAssign; public: ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira) { } //===--------------------------------------------------------------------===// // Utilities //===--------------------------------------------------------------------===// bool TestAndClearIgnoreResultAssign() { bool I = IgnoreResultAssign; IgnoreResultAssign = false; return I; } const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } Value *EmitLoadOfLValue(LValue LV, QualType T) { return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); } /// EmitLoadOfLValue - Given an expression with complex type that represents a /// value l-value, this method emits the address of the l-value, then loads /// and returns the result. Value *EmitLoadOfLValue(const Expr *E) { return EmitLoadOfLValue(EmitLValue(E), E->getType()); } /// EmitConversionToBool - Convert the specified expression value to a /// boolean (i1) truth value. This is equivalent to "Val != 0". Value *EmitConversionToBool(Value *Src, QualType DstTy); /// EmitScalarConversion - Emit a conversion from the specified type to the /// specified destination type, both of which are LLVM scalar types. Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); /// EmitComplexToScalarConversion - Emit a conversion from the specified /// complex type to the specified destination type, where the destination /// type is an LLVM scalar type. Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, QualType SrcTy, QualType DstTy); //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// Value *VisitStmt(Stmt *S) { S->dump(CGF.getContext().getSourceManager()); assert(0 && "Stmt can't have complex result type!"); return 0; } Value *VisitExpr(Expr *S); Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } // Leaves. Value *VisitIntegerLiteral(const IntegerLiteral *E) { return llvm::ConstantInt::get(E->getValue()); } Value *VisitFloatingLiteral(const FloatingLiteral *E) { return llvm::ConstantFP::get(E->getValue()); } Value *VisitCharacterLiteral(const CharacterLiteral *E) { return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); } Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); } Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { return llvm::Constant::getNullValue(ConvertType(E->getType())); } Value *VisitGNUNullExpr(const GNUNullExpr *E) { return llvm::Constant::getNullValue(ConvertType(E->getType())); } Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { return llvm::ConstantInt::get(ConvertType(E->getType()), CGF.getContext().typesAreCompatible( E->getArgType1(), E->getArgType2())); } Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { llvm::Value *V = llvm::ConstantInt::get(llvm::Type::Int32Ty, CGF.GetIDForAddrOfLabel(E->getLabel())); return Builder.CreateIntToPtr(V, ConvertType(E->getType())); } // l-values. Value *VisitDeclRefExpr(DeclRefExpr *E) { if (const EnumConstantDecl *EC = dyn_cast(E->getDecl())) return llvm::ConstantInt::get(EC->getInitVal()); return EmitLoadOfLValue(E); } Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { return CGF.EmitObjCSelectorExpr(E); } Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { return CGF.EmitObjCProtocolExpr(E); } Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { return EmitLoadOfLValue(E); } Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { return EmitLoadOfLValue(E); } Value *VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) { return EmitLoadOfLValue(E); } Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { return CGF.EmitObjCMessageExpr(E).getScalarVal(); } Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { return EmitLoadOfLValue(E); } Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return EmitLValue(E).getAddress(); } Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } Value *VisitInitListExpr(InitListExpr *E) { bool Ignore = TestAndClearIgnoreResultAssign(); (void)Ignore; assert (Ignore == false && "init list ignored"); unsigned NumInitElements = E->getNumInits(); if (E->hadArrayRangeDesignator()) { CGF.ErrorUnsupported(E, "GNU array range designator extension"); } const llvm::VectorType *VType = dyn_cast(ConvertType(E->getType())); // We have a scalar in braces. Just use the first element. if (!VType) return Visit(E->getInit(0)); unsigned NumVectorElements = VType->getNumElements(); const llvm::Type *ElementType = VType->getElementType(); // Emit individual vector element stores. llvm::Value *V = llvm::UndefValue::get(VType); // Emit initializers unsigned i; for (i = 0; i < NumInitElements; ++i) { Value *NewV = Visit(E->getInit(i)); Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); V = Builder.CreateInsertElement(V, NewV, Idx); } // Emit remaining default initializers for (/* Do not initialize i*/; i < NumVectorElements; ++i) { Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); V = Builder.CreateInsertElement(V, NewV, Idx); } return V; } Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { return llvm::Constant::getNullValue(ConvertType(E->getType())); } Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); Value *VisitCastExpr(const CastExpr *E) { // Make sure to evaluate VLA bounds now so that we have them for later. if (E->getType()->isVariablyModifiedType()) CGF.EmitVLASize(E->getType()); return EmitCastExpr(E->getSubExpr(), E->getType()); } Value *EmitCastExpr(const Expr *E, QualType T); Value *VisitCallExpr(const CallExpr *E) { if (E->getCallReturnType()->isReferenceType()) return EmitLoadOfLValue(E); return CGF.EmitCallExpr(E).getScalarVal(); } Value *VisitStmtExpr(const StmtExpr *E); Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); // Unary Operators. Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); Value *VisitUnaryPostDec(const UnaryOperator *E) { return VisitPrePostIncDec(E, false, false); } Value *VisitUnaryPostInc(const UnaryOperator *E) { return VisitPrePostIncDec(E, true, false); } Value *VisitUnaryPreDec(const UnaryOperator *E) { return VisitPrePostIncDec(E, false, true); } Value *VisitUnaryPreInc(const UnaryOperator *E) { return VisitPrePostIncDec(E, true, true); } Value *VisitUnaryAddrOf(const UnaryOperator *E) { return EmitLValue(E->getSubExpr()).getAddress(); } Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } Value *VisitUnaryPlus(const UnaryOperator *E) { // This differs from gcc, though, most likely due to a bug in gcc. TestAndClearIgnoreResultAssign(); return Visit(E->getSubExpr()); } Value *VisitUnaryMinus (const UnaryOperator *E); Value *VisitUnaryNot (const UnaryOperator *E); Value *VisitUnaryLNot (const UnaryOperator *E); Value *VisitUnaryReal (const UnaryOperator *E); Value *VisitUnaryImag (const UnaryOperator *E); Value *VisitUnaryExtension(const UnaryOperator *E) { return Visit(E->getSubExpr()); } Value *VisitUnaryOffsetOf(const UnaryOperator *E); // C++ Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { return Visit(DAE->getExpr()); } Value *VisitCXXThisExpr(CXXThisExpr *TE) { return CGF.LoadCXXThis(); } Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); } Value *VisitCXXNewExpr(const CXXNewExpr *E) { return CGF.EmitCXXNewExpr(E); } // Binary Operators. Value *EmitMul(const BinOpInfo &Ops) { if (CGF.getContext().getLangOptions().OverflowChecking && Ops.Ty->isSignedIntegerType()) return EmitOverflowCheckedBinOp(Ops); return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); } /// Create a binary op that checks for overflow. /// Currently only supports +, - and *. Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); Value *EmitDiv(const BinOpInfo &Ops); Value *EmitRem(const BinOpInfo &Ops); Value *EmitAdd(const BinOpInfo &Ops); Value *EmitSub(const BinOpInfo &Ops); Value *EmitShl(const BinOpInfo &Ops); Value *EmitShr(const BinOpInfo &Ops); Value *EmitAnd(const BinOpInfo &Ops) { return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); } Value *EmitXor(const BinOpInfo &Ops) { return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); } Value *EmitOr (const BinOpInfo &Ops) { return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); } BinOpInfo EmitBinOps(const BinaryOperator *E); Value *EmitCompoundAssign(const CompoundAssignOperator *E, Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); // Binary operators and binary compound assignment operators. #define HANDLEBINOP(OP) \ Value *VisitBin ## OP(const BinaryOperator *E) { \ return Emit ## OP(EmitBinOps(E)); \ } \ Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ } HANDLEBINOP(Mul); HANDLEBINOP(Div); HANDLEBINOP(Rem); HANDLEBINOP(Add); HANDLEBINOP(Sub); HANDLEBINOP(Shl); HANDLEBINOP(Shr); HANDLEBINOP(And); HANDLEBINOP(Xor); HANDLEBINOP(Or); #undef HANDLEBINOP // Comparisons. Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, unsigned SICmpOpc, unsigned FCmpOpc); #define VISITCOMP(CODE, UI, SI, FP) \ Value *VisitBin##CODE(const BinaryOperator *E) { \ return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ llvm::FCmpInst::FP); } VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); #undef VISITCOMP Value *VisitBinAssign (const BinaryOperator *E); Value *VisitBinLAnd (const BinaryOperator *E); Value *VisitBinLOr (const BinaryOperator *E); Value *VisitBinComma (const BinaryOperator *E); // Other Operators. Value *VisitBlockExpr(const BlockExpr *BE); Value *VisitConditionalOperator(const ConditionalOperator *CO); Value *VisitChooseExpr(ChooseExpr *CE); Value *VisitVAArgExpr(VAArgExpr *VE); Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { return CGF.EmitObjCStringLiteral(E); } }; } // end anonymous namespace. //===----------------------------------------------------------------------===// // Utilities //===----------------------------------------------------------------------===// /// EmitConversionToBool - Convert the specified expression value to a /// boolean (i1) truth value. This is equivalent to "Val != 0". Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); if (SrcType->isRealFloatingType()) { // Compare against 0.0 for fp scalars. llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); return Builder.CreateFCmpUNE(Src, Zero, "tobool"); } assert((SrcType->isIntegerType() || isa(Src->getType())) && "Unknown scalar type to convert"); // Because of the type rules of C, we often end up computing a logical value, // then zero extending it to int, then wanting it as a logical value again. // Optimize this common case. if (llvm::ZExtInst *ZI = dyn_cast(Src)) { if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { Value *Result = ZI->getOperand(0); // If there aren't any more uses, zap the instruction to save space. // Note that there can be more uses, for example if this // is the result of an assignment. if (ZI->use_empty()) ZI->eraseFromParent(); return Result; } } // Compare against an integer or pointer null. llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); return Builder.CreateICmpNE(Src, Zero, "tobool"); } /// EmitScalarConversion - Emit a conversion from the specified type to the /// specified destination type, both of which are LLVM scalar types. Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, QualType DstType) { SrcType = CGF.getContext().getCanonicalType(SrcType); DstType = CGF.getContext().getCanonicalType(DstType); if (SrcType == DstType) return Src; if (DstType->isVoidType()) return 0; // 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. Check for pointer types in // terms of LLVM, as some native types (like Obj-C id) may map to a // pointer type. if (isa(DstTy)) { // The source value may be an integer, or a pointer. if (isa(Src->getType())) return Builder.CreateBitCast(Src, DstTy, "conv"); assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); // First, convert to the correct width so that we control the kind of // extension. const llvm::Type *MiddleTy = llvm::IntegerType::get(CGF.LLVMPointerWidth); bool InputSigned = SrcType->isSignedIntegerType(); llvm::Value* IntResult = Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); // Then, cast to pointer. return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); } if (isa(Src->getType())) { // Must be an ptr to int cast. assert(isa(DstTy) && "not ptr->int?"); return Builder.CreatePtrToInt(Src, DstTy, "conv"); } // A scalar can be splatted to an extended vector of the same element type if (DstType->isExtVectorType() && !isa(SrcType)) { // Cast the scalar to element type QualType EltTy = DstType->getAsExtVectorType()->getElementType(); llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); // Insert the element in element zero of an undef vector llvm::Value *UnV = llvm::UndefValue::get(DstTy); llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); // Splat the element across to all elements llvm::SmallVector Args; unsigned NumElements = cast(DstTy)->getNumElements(); for (unsigned i = 0; i < NumElements; i++) Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0)); llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); return Yay; } // Allow bitcast from vector to integer/fp of the same size. if (isa(Src->getType()) || isa(DstTy)) return Builder.CreateBitCast(Src, DstTy, "conv"); // Finally, we have the arithmetic types: real int/float. if (isa(Src->getType())) { bool InputSigned = SrcType->isSignedIntegerType(); if (isa(DstTy)) return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); else if (InputSigned) return Builder.CreateSIToFP(Src, DstTy, "conv"); else return Builder.CreateUIToFP(Src, DstTy, "conv"); } assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); if (isa(DstTy)) { if (DstType->isSignedIntegerType()) return Builder.CreateFPToSI(Src, DstTy, "conv"); else return Builder.CreateFPToUI(Src, DstTy, "conv"); } assert(DstTy->isFloatingPoint() && "Unknown real conversion"); if (DstTy->getTypeID() < Src->getType()->getTypeID()) return Builder.CreateFPTrunc(Src, DstTy, "conv"); else return Builder.CreateFPExt(Src, DstTy, "conv"); } /// EmitComplexToScalarConversion - Emit a conversion from the specified /// complex type to the specified destination type, where the destination /// type is an LLVM scalar type. Value *ScalarExprEmitter:: EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, QualType SrcTy, QualType DstTy) { // Get the source element type. SrcTy = SrcTy->getAsComplexType()->getElementType(); // Handle conversions to bool first, they are special: comparisons against 0. if (DstTy->isBooleanType()) { // Complex != 0 -> (Real != 0) | (Imag != 0) Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); return Builder.CreateOr(Src.first, Src.second, "tobool"); } // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, // the imaginary part of the complex value is discarded and the value of the // real part is converted according to the conversion rules for the // corresponding real type. return EmitScalarConversion(Src.first, SrcTy, DstTy); } //===----------------------------------------------------------------------===// // Visitor Methods //===----------------------------------------------------------------------===// Value *ScalarExprEmitter::VisitExpr(Expr *E) { CGF.ErrorUnsupported(E, "scalar expression"); if (E->getType()->isVoidType()) return 0; return llvm::UndefValue::get(CGF.ConvertType(E->getType())); } Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { llvm::SmallVector indices; for (unsigned i = 2; i < E->getNumSubExprs(); i++) { indices.push_back(cast(CGF.EmitScalarExpr(E->getExpr(i)))); } Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); } Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { TestAndClearIgnoreResultAssign(); // Emit subscript expressions in rvalue context's. For most cases, this just // loads the lvalue formed by the subscript expr. However, we have to be // careful, because the base of a vector subscript is occasionally an rvalue, // so we can't get it as an lvalue. if (!E->getBase()->getType()->isVectorType()) return EmitLoadOfLValue(E); // Handle the vector case. The base must be a vector, the index must be an // integer value. Value *Base = Visit(E->getBase()); Value *Idx = Visit(E->getIdx()); bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); Idx = Builder.CreateIntCast(Idx, llvm::Type::Int32Ty, IdxSigned, "vecidxcast"); return Builder.CreateExtractElement(Base, Idx, "vecext"); } /// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but /// also handle things like function to pointer-to-function decay, and array to /// pointer decay. Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { const Expr *Op = E->getSubExpr(); // If this is due to array->pointer conversion, emit the array expression as // an l-value. if (Op->getType()->isArrayType()) { Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. // Note that VLA pointers are always decayed, so we don't need to do // anything here. if (!Op->getType()->isVariableArrayType()) { assert(isa(V->getType()) && "Expected pointer"); assert(isa(cast(V->getType()) ->getElementType()) && "Expected pointer to array"); V = Builder.CreateStructGEP(V, 0, "arraydecay"); } // The resultant pointer type can be implicitly casted to other pointer // types as well (e.g. void*) and can be implicitly converted to integer. const llvm::Type *DestTy = ConvertType(E->getType()); if (V->getType() != DestTy) { if (isa(DestTy)) V = Builder.CreateBitCast(V, DestTy, "ptrconv"); else { assert(isa(DestTy) && "Unknown array decay"); V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); } } return V; } return EmitCastExpr(Op, E->getType()); } // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts // have to handle a more broad range of conversions than explicit casts, as they // handle things like function to ptr-to-function decay etc. Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { if (!DestTy->isVoidType()) TestAndClearIgnoreResultAssign(); // Handle cases where the source is an non-complex type. if (!CGF.hasAggregateLLVMType(E->getType())) { Value *Src = Visit(const_cast(E)); // Use EmitScalarConversion to perform the conversion. return EmitScalarConversion(Src, E->getType(), DestTy); } if (E->getType()->isAnyComplexType()) { // Handle cases where the source is a complex type. bool IgnoreImag = true; bool IgnoreImagAssign = true; bool IgnoreReal = IgnoreResultAssign; bool IgnoreRealAssign = IgnoreResultAssign; if (DestTy->isBooleanType()) IgnoreImagAssign = IgnoreImag = false; else if (DestTy->isVoidType()) { IgnoreReal = IgnoreImag = false; IgnoreRealAssign = IgnoreImagAssign = true; } CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, IgnoreImagAssign); return EmitComplexToScalarConversion(V, E->getType(), DestTy); } // Okay, this is a cast from an aggregate. It must be a cast to void. Just // evaluate the result and return. CGF.EmitAggExpr(E, 0, false, true); return 0; } Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()).getScalarVal(); } Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { return Builder.CreateLoad(CGF.GetAddrOfBlockDecl(E), false, "tmp"); } //===----------------------------------------------------------------------===// // Unary Operators //===----------------------------------------------------------------------===// Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) { LValue LV = EmitLValue(E->getSubExpr()); QualType ValTy = E->getSubExpr()->getType(); Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); int AmountVal = isInc ? 1 : -1; if (ValTy->isPointerType() && ValTy->getAsPointerType()->isVariableArrayType()) { // The amount of the addition/subtraction needs to account for the VLA size CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); } Value *NextVal; if (const llvm::PointerType *PT = dyn_cast(InVal->getType())) { llvm::Constant *Inc =llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); if (!isa(PT->getElementType())) { NextVal = Builder.CreateGEP(InVal, Inc, "ptrincdec"); } else { const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); } } else if (InVal->getType() == llvm::Type::Int1Ty && isInc) { // Bool++ is an interesting case, due to promotion rules, we get: // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> // Bool = ((int)Bool+1) != 0 // An interesting aspect of this is that increment is always true. // Decrement does not have this property. NextVal = llvm::ConstantInt::getTrue(); } else { // Add the inc/dec to the real part. if (isa(InVal->getType())) NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); else if (InVal->getType() == llvm::Type::FloatTy) NextVal = llvm::ConstantFP::get(llvm::APFloat(static_cast(AmountVal))); else if (InVal->getType() == llvm::Type::DoubleTy) NextVal = llvm::ConstantFP::get(llvm::APFloat(static_cast(AmountVal))); else { llvm::APFloat F(static_cast(AmountVal)); bool ignored; F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, &ignored); NextVal = llvm::ConstantFP::get(F); } NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); } // Store the updated result through the lvalue. if (LV.isBitfield()) CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); else CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); // If this is a postinc, return the value read from memory, otherwise use the // updated value. return isPre ? NextVal : InVal; } Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { TestAndClearIgnoreResultAssign(); Value *Op = Visit(E->getSubExpr()); return Builder.CreateNeg(Op, "neg"); } Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { TestAndClearIgnoreResultAssign(); Value *Op = Visit(E->getSubExpr()); return Builder.CreateNot(Op, "neg"); } Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { // Compare operand to zero. Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); // Invert value. // TODO: Could dynamically modify easy computations here. For example, if // the operand is an icmp ne, turn into icmp eq. BoolVal = Builder.CreateNot(BoolVal, "lnot"); // ZExt result to the expr type. return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); } /// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of /// argument of the sizeof expression as an integer. Value * ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { QualType TypeToSize = E->getTypeOfArgument(); if (E->isSizeOf()) { if (const VariableArrayType *VAT = CGF.getContext().getAsVariableArrayType(TypeToSize)) { if (E->isArgumentType()) { // sizeof(type) - make sure to emit the VLA size. CGF.EmitVLASize(TypeToSize); } else { // C99 6.5.3.4p2: If the argument is an expression of type // VLA, it is evaluated. CGF.EmitAnyExpr(E->getArgumentExpr()); } return CGF.GetVLASize(VAT); } } // If this isn't sizeof(vla), the result must be constant; use the // constant folding logic so we don't have to duplicate it here. Expr::EvalResult Result; E->Evaluate(Result, CGF.getContext()); return llvm::ConstantInt::get(Result.Val.getInt()); } Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { Expr *Op = E->getSubExpr(); if (Op->getType()->isAnyComplexType()) return CGF.EmitComplexExpr(Op, false, true, false, true).first; return Visit(Op); } Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { Expr *Op = E->getSubExpr(); if (Op->getType()->isAnyComplexType()) return CGF.EmitComplexExpr(Op, true, false, true, false).second; // __imag on a scalar returns zero. Emit the subexpr to ensure side // effects are evaluated, but not the actual value. if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) CGF.EmitLValue(Op); else CGF.EmitScalarExpr(Op, true); return llvm::Constant::getNullValue(ConvertType(E->getType())); } Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); const llvm::Type* ResultType = ConvertType(E->getType()); return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); } //===----------------------------------------------------------------------===// // Binary Operators //===----------------------------------------------------------------------===// BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { TestAndClearIgnoreResultAssign(); BinOpInfo Result; Result.LHS = Visit(E->getLHS()); Result.RHS = Visit(E->getRHS()); Result.Ty = E->getType(); Result.E = E; return Result; } Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { bool Ignore = TestAndClearIgnoreResultAssign(); QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); BinOpInfo OpInfo; if (E->getComputationResultType()->isAnyComplexType()) { // This needs to go through the complex expression emitter, but // it's a tad complicated to do that... I'm leaving it out for now. // (Note that we do actually need the imaginary part of the RHS for // multiplication and division.) CGF.ErrorUnsupported(E, "complex compound assignment"); return llvm::UndefValue::get(CGF.ConvertType(E->getType())); } // Emit the RHS first. __block variables need to have the rhs evaluated // first, plus this should improve codegen a little. OpInfo.RHS = Visit(E->getRHS()); OpInfo.Ty = E->getComputationResultType(); OpInfo.E = E; // Load/convert the LHS. LValue LHSLV = EmitLValue(E->getLHS()); OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, E->getComputationLHSType()); // Expand the binary operator. Value *Result = (this->*Func)(OpInfo); // Convert the result back to the LHS type. Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); // Store the result value into the LHS lvalue. Bit-fields are // handled specially because the result is altered by the store, // i.e., [C99 6.5.16p1] 'An assignment expression has the value of // the left operand after the assignment...'. if (LHSLV.isBitfield()) { if (!LHSLV.isVolatileQualified()) { CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, &Result); return Result; } else CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); } else CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); if (Ignore) return 0; return EmitLoadOfLValue(LHSLV, E->getType()); } Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { if (Ops.LHS->getType()->isFPOrFPVector()) return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); else if (Ops.Ty->isUnsignedIntegerType()) return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); else return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); } Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { // Rem in C can't be a floating point type: C99 6.5.5p2. if (Ops.Ty->isUnsignedIntegerType()) return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); else return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); } Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { unsigned IID; unsigned OpID = 0; switch (Ops.E->getOpcode()) { case BinaryOperator::Add: case BinaryOperator::AddAssign: OpID = 1; IID = llvm::Intrinsic::sadd_with_overflow; break; case BinaryOperator::Sub: case BinaryOperator::SubAssign: OpID = 2; IID = llvm::Intrinsic::ssub_with_overflow; break; case BinaryOperator::Mul: case BinaryOperator::MulAssign: OpID = 3; IID = llvm::Intrinsic::smul_with_overflow; break; default: assert(false && "Unsupported operation for overflow detection"); IID = 0; } OpID <<= 1; OpID |= 1; const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); // Branch in case of overflow. llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); llvm::BasicBlock *continueBB = CGF.createBasicBlock("overflow.continue", CGF.CurFn); Builder.CreateCondBr(overflow, overflowBB, continueBB); // Handle overflow Builder.SetInsertPoint(overflowBB); // Handler is: // long long *__overflow_handler)(long long a, long long b, char op, // char width) std::vector handerArgTypes; handerArgTypes.push_back(llvm::Type::Int64Ty); handerArgTypes.push_back(llvm::Type::Int64Ty); handerArgTypes.push_back(llvm::Type::Int8Ty); handerArgTypes.push_back(llvm::Type::Int8Ty); llvm::FunctionType *handlerTy = llvm::FunctionType::get(llvm::Type::Int64Ty, handerArgTypes, false); llvm::Value *handlerFunction = CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", llvm::PointerType::getUnqual(handlerTy)); handlerFunction = Builder.CreateLoad(handlerFunction); llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, Builder.CreateSExt(Ops.LHS, llvm::Type::Int64Ty), Builder.CreateSExt(Ops.RHS, llvm::Type::Int64Ty), llvm::ConstantInt::get(llvm::Type::Int8Ty, OpID), llvm::ConstantInt::get(llvm::Type::Int8Ty, cast(opTy)->getBitWidth())); handlerResult = Builder.CreateTrunc(handlerResult, opTy); Builder.CreateBr(continueBB); // Set up the continuation Builder.SetInsertPoint(continueBB); // Get the correct result llvm::PHINode *phi = Builder.CreatePHI(opTy); phi->reserveOperandSpace(2); phi->addIncoming(result, initialBB); phi->addIncoming(handlerResult, overflowBB); return phi; } Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { if (!Ops.Ty->isPointerType()) { if (CGF.getContext().getLangOptions().OverflowChecking && Ops.Ty->isSignedIntegerType()) return EmitOverflowCheckedBinOp(Ops); return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); } if (Ops.Ty->getAsPointerType()->isVariableArrayType()) { // The amount of the addition needs to account for the VLA size CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); } Value *Ptr, *Idx; Expr *IdxExp; const PointerType *PT; if ((PT = Ops.E->getLHS()->getType()->getAsPointerType())) { Ptr = Ops.LHS; Idx = Ops.RHS; IdxExp = Ops.E->getRHS(); } else { // int + pointer PT = Ops.E->getRHS()->getType()->getAsPointerType(); assert(PT && "Invalid add expr"); Ptr = Ops.RHS; Idx = Ops.LHS; IdxExp = Ops.E->getLHS(); } unsigned Width = cast(Idx->getType())->getBitWidth(); if (Width < CGF.LLVMPointerWidth) { // Zero or sign extend the pointer value based on whether the index is // signed or not. const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); if (IdxExp->getType()->isSignedIntegerType()) Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); else Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); } const QualType ElementType = PT->getPointeeType(); // Handle interface types, which are not represented with a concrete // type. if (const ObjCInterfaceType *OIT = dyn_cast(ElementType)) { llvm::Value *InterfaceSize = llvm::ConstantInt::get(Idx->getType(), CGF.getContext().getTypeSize(OIT) / 8); Idx = Builder.CreateMul(Idx, InterfaceSize); const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); return Builder.CreateBitCast(Res, Ptr->getType()); } // Explicitly handle GNU void* and function pointer arithmetic // extensions. The GNU void* casts amount to no-ops since our void* // type is i8*, but this is future proof. if (ElementType->isVoidType() || ElementType->isFunctionType()) { const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); return Builder.CreateBitCast(Res, Ptr->getType()); } return Builder.CreateGEP(Ptr, Idx, "add.ptr"); } Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { if (!isa(Ops.LHS->getType())) { if (CGF.getContext().getLangOptions().OverflowChecking && Ops.Ty->isSignedIntegerType()) return EmitOverflowCheckedBinOp(Ops); return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); } if (Ops.E->getLHS()->getType()->getAsPointerType()->isVariableArrayType()) { // The amount of the addition needs to account for the VLA size for // ptr-int // The amount of the division needs to account for the VLA size for // ptr-ptr. CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); } const QualType LHSType = Ops.E->getLHS()->getType(); const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); if (!isa(Ops.RHS->getType())) { // pointer - int Value *Idx = Ops.RHS; unsigned Width = cast(Idx->getType())->getBitWidth(); if (Width < CGF.LLVMPointerWidth) { // Zero or sign extend the pointer value based on whether the index is // signed or not. const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); if (Ops.E->getRHS()->getType()->isSignedIntegerType()) Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); else Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); } Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); // Handle interface types, which are not represented with a concrete // type. if (const ObjCInterfaceType *OIT = dyn_cast(LHSElementType)) { llvm::Value *InterfaceSize = llvm::ConstantInt::get(Idx->getType(), CGF.getContext().getTypeSize(OIT) / 8); Idx = Builder.CreateMul(Idx, InterfaceSize); const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); return Builder.CreateBitCast(Res, Ops.LHS->getType()); } // Explicitly handle GNU void* and function pointer arithmetic // extensions. The GNU void* casts amount to no-ops since our // void* type is i8*, but this is future proof. if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); return Builder.CreateBitCast(Res, Ops.LHS->getType()); } return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); } else { // pointer - pointer Value *LHS = Ops.LHS; Value *RHS = Ops.RHS; uint64_t ElementSize; // Handle GCC extension for pointer arithmetic on void* and function pointer // types. if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { ElementSize = 1; } else { ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; } const llvm::Type *ResultType = ConvertType(Ops.Ty); LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); // Optimize out the shift for element size of 1. if (ElementSize == 1) return BytesBetween; // HACK: LLVM doesn't have an divide instruction that 'knows' there is no // remainder. As such, we handle common power-of-two cases here to generate // better code. See PR2247. if (llvm::isPowerOf2_64(ElementSize)) { Value *ShAmt = llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); } // Otherwise, do a full sdiv. Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); } } Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { // LLVM requires the LHS and RHS to be the same type: promote or truncate the // RHS to the same size as the LHS. Value *RHS = Ops.RHS; if (Ops.LHS->getType() != RHS->getType()) RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); return Builder.CreateShl(Ops.LHS, RHS, "shl"); } Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { // LLVM requires the LHS and RHS to be the same type: promote or truncate the // RHS to the same size as the LHS. Value *RHS = Ops.RHS; if (Ops.LHS->getType() != RHS->getType()) RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); if (Ops.Ty->isUnsignedIntegerType()) return Builder.CreateLShr(Ops.LHS, RHS, "shr"); return Builder.CreateAShr(Ops.LHS, RHS, "shr"); } Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, unsigned SICmpOpc, unsigned FCmpOpc) { TestAndClearIgnoreResultAssign(); Value *Result; QualType LHSTy = E->getLHS()->getType(); if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); if (LHS->getType()->isFloatingPoint()) { Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, LHS, RHS, "cmp"); } else if (LHSTy->isSignedIntegerType()) { Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, LHS, RHS, "cmp"); } else { // Unsigned integers and pointers. Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHS, RHS, "cmp"); } } else if (LHSTy->isVectorType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); if (LHS->getType()->isFPOrFPVector()) { Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, LHS, RHS, "cmp"); } else if (LHSTy->isUnsignedIntegerType()) { Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, LHS, RHS, "cmp"); } else { // Signed integers and pointers. Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, LHS, RHS, "cmp"); } return Result; } else { // Complex Comparison: can only be an equality comparison. CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); QualType CETy = LHSTy->getAsComplexType()->getElementType(); Value *ResultR, *ResultI; if (CETy->isRealFloatingType()) { ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, LHS.first, RHS.first, "cmp.r"); ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, LHS.second, RHS.second, "cmp.i"); } else { // Complex comparisons can only be equality comparisons. As such, signed // and unsigned opcodes are the same. ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHS.first, RHS.first, "cmp.r"); ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHS.second, RHS.second, "cmp.i"); } if (E->getOpcode() == BinaryOperator::EQ) { Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); } else { assert(E->getOpcode() == BinaryOperator::NE && "Complex comparison other than == or != ?"); Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); } } return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); } Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { bool Ignore = TestAndClearIgnoreResultAssign(); // __block variables need to have the rhs evaluated first, plus this should // improve codegen just a little. Value *RHS = Visit(E->getRHS()); LValue LHS = EmitLValue(E->getLHS()); // Store the value into the LHS. Bit-fields are handled specially // because the result is altered by the store, i.e., [C99 6.5.16p1] // 'An assignment expression has the value of the left operand after // the assignment...'. if (LHS.isBitfield()) { if (!LHS.isVolatileQualified()) { CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), &RHS); return RHS; } else CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); } else CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); if (Ignore) return 0; return EmitLoadOfLValue(LHS, E->getType()); } Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. // If we have 1 && X, just emit X without inserting the control flow. if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { if (Cond == 1) { // If we have 1 && X, just emit X. Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); // ZExt result to int. return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); } // 0 && RHS: If it is safe, just elide the RHS, and return 0. if (!CGF.ContainsLabel(E->getRHS())) return llvm::Constant::getNullValue(CGF.LLVMIntTy); } llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); // Branch on the LHS first. If it is false, go to the failure (cont) block. CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); // Any edges into the ContBlock are now from an (indeterminate number of) // edges from this first condition. All of these values will be false. Start // setting up the PHI node in the Cont Block for this. llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); PN->reserveOperandSpace(2); // Normal case, two inputs. for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); PI != PE; ++PI) PN->addIncoming(llvm::ConstantInt::getFalse(), *PI); CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); // Reaquire the RHS block, as there may be subblocks inserted. RHSBlock = Builder.GetInsertBlock(); // Emit an unconditional branch from this block to ContBlock. Insert an entry // into the phi node for the edge with the value of RHSCond. CGF.EmitBlock(ContBlock); PN->addIncoming(RHSCond, RHSBlock); // ZExt result to int. return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); } Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. // If we have 0 || X, just emit X without inserting the control flow. if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { if (Cond == -1) { // If we have 0 || X, just emit X. Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); // ZExt result to int. return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); } // 1 || RHS: If it is safe, just elide the RHS, and return 1. if (!CGF.ContainsLabel(E->getRHS())) return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); } llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); // Branch on the LHS first. If it is true, go to the success (cont) block. CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); // Any edges into the ContBlock are now from an (indeterminate number of) // edges from this first condition. All of these values will be true. Start // setting up the PHI node in the Cont Block for this. llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); PN->reserveOperandSpace(2); // Normal case, two inputs. for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); PI != PE; ++PI) PN->addIncoming(llvm::ConstantInt::getTrue(), *PI); // Emit the RHS condition as a bool value. CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); // Reaquire the RHS block, as there may be subblocks inserted. RHSBlock = Builder.GetInsertBlock(); // Emit an unconditional branch from this block to ContBlock. Insert an entry // into the phi node for the edge with the value of RHSCond. CGF.EmitBlock(ContBlock); PN->addIncoming(RHSCond, RHSBlock); // ZExt result to int. return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); } Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { CGF.EmitStmt(E->getLHS()); CGF.EnsureInsertPoint(); return Visit(E->getRHS()); } //===----------------------------------------------------------------------===// // Other Operators //===----------------------------------------------------------------------===// /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified /// expression is cheap enough and side-effect-free enough to evaluate /// unconditionally instead of conditionally. This is used to convert control /// flow into selects in some cases. static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { if (const ParenExpr *PE = dyn_cast(E)) return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); // TODO: Allow anything we can constant fold to an integer or fp constant. if (isa(E) || isa(E) || isa(E)) return true; // Non-volatile automatic variables too, to get "cond ? X : Y" where // X and Y are local variables. if (const DeclRefExpr *DRE = dyn_cast(E)) if (const VarDecl *VD = dyn_cast(DRE->getDecl())) if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) return true; return false; } Value *ScalarExprEmitter:: VisitConditionalOperator(const ConditionalOperator *E) { TestAndClearIgnoreResultAssign(); // If the condition constant folds and can be elided, try to avoid emitting // the condition and the dead arm. if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ Expr *Live = E->getLHS(), *Dead = E->getRHS(); if (Cond == -1) std::swap(Live, Dead); // If the dead side doesn't have labels we need, and if the Live side isn't // the gnu missing ?: extension (which we could handle, but don't bother // to), just emit the Live part. if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part Live) // Live part isn't missing. return Visit(Live); } // If this is a really simple expression (like x ? 4 : 5), emit this as a // select instead of as control flow. We can only do this if it is cheap and // safe to evaluate the LHS and RHS unconditionally. if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); llvm::Value *LHS = Visit(E->getLHS()); llvm::Value *RHS = Visit(E->getRHS()); return Builder.CreateSelect(CondV, LHS, RHS, "cond"); } llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); Value *CondVal = 0; // If we don't have the GNU missing condition extension, emit a branch on // bool the normal way. if (E->getLHS()) { // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for // the branch on bool. CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); } else { // Otherwise, for the ?: extension, evaluate the conditional and then // convert it to bool the hard way. We do this explicitly because we need // the unconverted value for the missing middle value of the ?:. CondVal = CGF.EmitScalarExpr(E->getCond()); // In some cases, EmitScalarConversion will delete the "CondVal" expression // if there are no extra uses (an optimization). Inhibit this by making an // extra dead use, because we're going to add a use of CondVal later. We // don't use the builder for this, because we don't want it to get optimized // away. This leaves dead code, but the ?: extension isn't common. new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", Builder.GetInsertBlock()); Value *CondBoolVal = CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), CGF.getContext().BoolTy); Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); } CGF.EmitBlock(LHSBlock); // Handle the GNU extension for missing LHS. Value *LHS; if (E->getLHS()) LHS = Visit(E->getLHS()); else // Perform promotions, to handle cases like "short ?: int" LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); LHSBlock = Builder.GetInsertBlock(); CGF.EmitBranch(ContBlock); CGF.EmitBlock(RHSBlock); Value *RHS = Visit(E->getRHS()); RHSBlock = Builder.GetInsertBlock(); CGF.EmitBranch(ContBlock); CGF.EmitBlock(ContBlock); if (!LHS || !RHS) { assert(E->getType()->isVoidType() && "Non-void value should have a value"); return 0; } // Create a PHI node for the real part. llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); PN->reserveOperandSpace(2); PN->addIncoming(LHS, LHSBlock); PN->addIncoming(RHS, RHSBlock); return PN; } Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { return Visit(E->getChosenSubExpr(CGF.getContext())); } Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); // If EmitVAArg fails, we fall back to the LLVM instruction. if (!ArgPtr) return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); // FIXME Volatility. return Builder.CreateLoad(ArgPtr); } Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { return CGF.BuildBlockLiteralTmp(BE); } //===----------------------------------------------------------------------===// // Entry Point into this File //===----------------------------------------------------------------------===// /// EmitScalarExpr - Emit the computation of the specified expression of /// scalar type, ignoring the result. Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { assert(E && !hasAggregateLLVMType(E->getType()) && "Invalid scalar expression to emit"); return ScalarExprEmitter(*this, IgnoreResultAssign) .Visit(const_cast(E)); } /// EmitScalarConversion - Emit a conversion from the specified type to the /// specified destination type, both of which are LLVM scalar types. Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy) { assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && "Invalid scalar expression to emit"); return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); } /// EmitComplexToScalarConversion - Emit a conversion from the specified /// complex type to the specified destination type, where the destination /// type is an LLVM scalar type. Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy, QualType DstTy) { assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && "Invalid complex -> scalar conversion"); return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, DstTy); } Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { assert(V1->getType() == V2->getType() && "Vector operands must be of the same type"); unsigned NumElements = cast(V1->getType())->getNumElements(); va_list va; va_start(va, V2); llvm::SmallVector Args; for (unsigned i = 0; i < NumElements; i++) { int n = va_arg(va, int); assert(n >= 0 && n < (int)NumElements * 2 && "Vector shuffle index out of bounds!"); Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); } const char *Name = va_arg(va, const char *); va_end(va); llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); return Builder.CreateShuffleVector(V1, V2, Mask, Name); } llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, unsigned NumVals, bool isSplat) { llvm::Value *Vec = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); for (unsigned i = 0, e = NumVals; i != e; ++i) { llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); } return Vec; }