//===--- 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 "CGObjCRuntime.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/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. BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform const Expr *E; // Entire expr, for error unsupported. May not be binop. }; namespace { class ScalarExprEmitter : public StmtVisitor { CodeGenFunction &CGF; CGBuilderTy &Builder; bool IgnoreResultAssign; llvm::LLVMContext &VMContext; public: ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), VMContext(cgf.getLLVMContext()) { } //===--------------------------------------------------------------------===// // 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); } LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(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(EmitCheckedLValue(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); /// EmitNullValue - Emit a value that corresponds to null for the given type. Value *EmitNullValue(QualType Ty); //===--------------------------------------------------------------------===// // 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(VMContext, E->getValue()); } Value *VisitFloatingLiteral(const FloatingLiteral *E) { return llvm::ConstantFP::get(VMContext, 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 *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { return EmitNullValue(E->getType()); } Value *VisitGNUNullExpr(const GNUNullExpr *E) { return EmitNullValue(E->getType()); } Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { return llvm::ConstantInt::get(ConvertType(E->getType()), CGF.getContext().typesAreCompatible( E->getArgType1(), E->getArgType2())); } Value *VisitOffsetOfExpr(const OffsetOfExpr *E); Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); return Builder.CreateBitCast(V, ConvertType(E->getType())); } // l-values. Value *VisitDeclRefExpr(DeclRefExpr *E) { Expr::EvalResult Result; if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); } 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 *VisitObjCImplicitSetterGetterRefExpr( ObjCImplicitSetterGetterRefExpr *E) { return EmitLoadOfLValue(E); } Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { return CGF.EmitObjCMessageExpr(E).getScalarVal(); } Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { LValue LV = CGF.EmitObjCIsaExpr(E); Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); return V; } Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); Value *VisitMemberExpr(MemberExpr *E); Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { return EmitLoadOfLValue(E); } Value *VisitInitListExpr(InitListExpr *E); Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { return CGF.CGM.EmitNullConstant(E->getType()); } Value *VisitCastExpr(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); } Value *EmitCastExpr(CastExpr *E); 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 *VisitUnaryPostDec(const UnaryOperator *E) { LValue LV = EmitLValue(E->getSubExpr()); return EmitScalarPrePostIncDec(E, LV, false, false); } Value *VisitUnaryPostInc(const UnaryOperator *E) { LValue LV = EmitLValue(E->getSubExpr()); return EmitScalarPrePostIncDec(E, LV, true, false); } Value *VisitUnaryPreDec(const UnaryOperator *E) { LValue LV = EmitLValue(E->getSubExpr()); return EmitScalarPrePostIncDec(E, LV, false, true); } Value *VisitUnaryPreInc(const UnaryOperator *E) { LValue LV = EmitLValue(E->getSubExpr()); return EmitScalarPrePostIncDec(E, LV, true, true); } llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre); 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); } Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { CGF.EmitCXXDeleteExpr(E); return 0; } Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { return llvm::ConstantInt::get(Builder.getInt1Ty(), E->EvaluateTrait(CGF.getContext())); } Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { // C++ [expr.pseudo]p1: // The result shall only be used as the operand for the function call // operator (), and the result of such a call has type void. The only // effect is the evaluation of the postfix-expression before the dot or // arrow. CGF.EmitScalarExpr(E->getBase()); return 0; } Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { return EmitNullValue(E->getType()); } Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); return 0; } // Binary Operators. Value *EmitMul(const BinOpInfo &Ops) { if (Ops.Ty->isSignedIntegerType()) { switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); case LangOptions::SOB_Defined: return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); case LangOptions::SOB_Trapping: return EmitOverflowCheckedBinOp(Ops); } } if (Ops.LHS->getType()->isFPOrFPVectorTy()) return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 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); LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, Value *(ScalarExprEmitter::*F)(const BinOpInfo &), Value *&Result); 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); Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(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"); } if (SrcType->isMemberPointerType()) { // Compare against -1. llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); return Builder.CreateICmpNE(Src, NegativeOne, "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::getInt1Ty(CGF.getLLVMContext())) { 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 = CGF.IntPtrTy; 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() && !SrcType->isVectorType()) { // Cast the scalar to element type QualType EltTy = DstType->getAs()->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(CGF.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(CGF.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()->isFloatingPointTy() && "Unknown real conversion"); if (isa(DstTy)) { if (DstType->isSignedIntegerType()) return Builder.CreateFPToSI(Src, DstTy, "conv"); else return Builder.CreateFPToUI(Src, DstTy, "conv"); } assert(DstTy->isFloatingPointTy() && "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->getAs()->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); } Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { const llvm::Type *LTy = ConvertType(Ty); if (!Ty->isMemberPointerType()) return llvm::Constant::getNullValue(LTy); assert(!Ty->isMemberFunctionPointerType() && "member function pointers are not scalar!"); // Itanium C++ ABI 2.3: // A NULL pointer is represented as -1. return llvm::ConstantInt::get(LTy, -1ULL, /*isSigned=*/true); } //===----------------------------------------------------------------------===// // 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) { // Vector Mask Case if (E->getNumSubExprs() == 2 || (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); Value *Mask; const llvm::VectorType *LTy = cast(LHS->getType()); unsigned LHSElts = LTy->getNumElements(); if (E->getNumSubExprs() == 3) { Mask = CGF.EmitScalarExpr(E->getExpr(2)); // Shuffle LHS & RHS into one input vector. llvm::SmallVector concat; for (unsigned i = 0; i != LHSElts; ++i) { concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); } Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); LHSElts *= 2; } else { Mask = RHS; } const llvm::VectorType *MTy = cast(Mask->getType()); llvm::Constant* EltMask; // Treat vec3 like vec4. if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) EltMask = llvm::ConstantInt::get(MTy->getElementType(), (1 << llvm::Log2_32(LHSElts+2))-1); else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) EltMask = llvm::ConstantInt::get(MTy->getElementType(), (1 << llvm::Log2_32(LHSElts+1))-1); else EltMask = llvm::ConstantInt::get(MTy->getElementType(), (1 << llvm::Log2_32(LHSElts))-1); // Mask off the high bits of each shuffle index. llvm::SmallVector MaskV; for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) MaskV.push_back(EltMask); Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); // newv = undef // mask = mask & maskbits // for each elt // n = extract mask i // x = extract val n // newv = insert newv, x, i const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), MTy->getNumElements()); Value* NewV = llvm::UndefValue::get(RTy); for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); // Handle vec3 special since the index will be off by one for the RHS. if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { Value *cmpIndx, *newIndx; cmpIndx = Builder.CreateICmpUGT(Indx, llvm::ConstantInt::get(CGF.Int32Ty, 3), "cmp_shuf_idx"); newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), "shuf_idx_adj"); Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); } Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); } return NewV; } Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); // Handle vec3 special since the index will be off by one for the RHS. llvm::SmallVector indices; for (unsigned i = 2; i < E->getNumSubExprs(); i++) { llvm::Constant *C = cast(CGF.EmitScalarExpr(E->getExpr(i))); const llvm::VectorType *VTy = cast(V1->getType()); if (VTy->getNumElements() == 3) { if (llvm::ConstantInt *CI = dyn_cast(C)) { uint64_t cVal = CI->getZExtValue(); if (cVal > 3) { C = llvm::ConstantInt::get(C->getType(), cVal-1); } } } indices.push_back(C); } Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); } Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { Expr::EvalResult Result; if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { if (E->isArrow()) CGF.EmitScalarExpr(E->getBase()); else EmitLValue(E->getBase()); return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); } return EmitLoadOfLValue(E); } 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, CGF.Int32Ty, IdxSigned, "vecidxcast"); return Builder.CreateExtractElement(Base, Idx, "vecext"); } static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, unsigned Off, const llvm::Type *I32Ty) { int MV = SVI->getMaskValue(Idx); if (MV == -1) return llvm::UndefValue::get(I32Ty); return llvm::ConstantInt::get(I32Ty, Off+MV); } Value *ScalarExprEmitter::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 ResElts = VType->getNumElements(); // Loop over initializers collecting the Value for each, and remembering // whether the source was swizzle (ExtVectorElementExpr). This will allow // us to fold the shuffle for the swizzle into the shuffle for the vector // initializer, since LLVM optimizers generally do not want to touch // shuffles. unsigned CurIdx = 0; bool VIsUndefShuffle = false; llvm::Value *V = llvm::UndefValue::get(VType); for (unsigned i = 0; i != NumInitElements; ++i) { Expr *IE = E->getInit(i); Value *Init = Visit(IE); llvm::SmallVector Args; const llvm::VectorType *VVT = dyn_cast(Init->getType()); // Handle scalar elements. If the scalar initializer is actually one // element of a different vector of the same width, use shuffle instead of // extract+insert. if (!VVT) { if (isa(IE)) { llvm::ExtractElementInst *EI = cast(Init); if (EI->getVectorOperandType()->getNumElements() == ResElts) { llvm::ConstantInt *C = cast(EI->getIndexOperand()); Value *LHS = 0, *RHS = 0; if (CurIdx == 0) { // insert into undef -> shuffle (src, undef) Args.push_back(C); for (unsigned j = 1; j != ResElts; ++j) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); LHS = EI->getVectorOperand(); RHS = V; VIsUndefShuffle = true; } else if (VIsUndefShuffle) { // insert into undefshuffle && size match -> shuffle (v, src) llvm::ShuffleVectorInst *SVV = cast(V); for (unsigned j = 0; j != CurIdx; ++j) Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, ResElts + C->getZExtValue())); for (unsigned j = CurIdx + 1; j != ResElts; ++j) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); LHS = cast(V)->getOperand(0); RHS = EI->getVectorOperand(); VIsUndefShuffle = false; } if (!Args.empty()) { llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); V = Builder.CreateShuffleVector(LHS, RHS, Mask); ++CurIdx; continue; } } } Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); VIsUndefShuffle = false; ++CurIdx; continue; } unsigned InitElts = VVT->getNumElements(); // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's // input is the same width as the vector being constructed, generate an // optimized shuffle of the swizzle input into the result. unsigned Offset = (CurIdx == 0) ? 0 : ResElts; if (isa(IE)) { llvm::ShuffleVectorInst *SVI = cast(Init); Value *SVOp = SVI->getOperand(0); const llvm::VectorType *OpTy = cast(SVOp->getType()); if (OpTy->getNumElements() == ResElts) { for (unsigned j = 0; j != CurIdx; ++j) { // If the current vector initializer is a shuffle with undef, merge // this shuffle directly into it. if (VIsUndefShuffle) { Args.push_back(getMaskElt(cast(V), j, 0, CGF.Int32Ty)); } else { Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); } } for (unsigned j = 0, je = InitElts; j != je; ++j) Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); if (VIsUndefShuffle) V = cast(V)->getOperand(0); Init = SVOp; } } // Extend init to result vector length, and then shuffle its contribution // to the vector initializer into V. if (Args.empty()) { for (unsigned j = 0; j != InitElts; ++j) Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); for (unsigned j = InitElts; j != ResElts; ++j) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), Mask, "vext"); Args.clear(); for (unsigned j = 0; j != CurIdx; ++j) Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); for (unsigned j = 0; j != InitElts; ++j) Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); } // If V is undef, make sure it ends up on the RHS of the shuffle to aid // merging subsequent shuffles into this one. if (CurIdx == 0) std::swap(V, Init); llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); VIsUndefShuffle = isa(Init); CurIdx += InitElts; } // FIXME: evaluate codegen vs. shuffling against constant null vector. // Emit remaining default initializers. const llvm::Type *EltTy = VType->getElementType(); // Emit remaining default initializers for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); llvm::Value *Init = llvm::Constant::getNullValue(EltTy); V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); } return V; } static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { const Expr *E = CE->getSubExpr(); if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) return false; if (isa(E)) { // We always assume that 'this' is never null. return false; } if (const ImplicitCastExpr *ICE = dyn_cast(CE)) { // And that lvalue casts are never null. if (ICE->isLvalueCast()) return false; } return true; } // 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(CastExpr *CE) { Expr *E = CE->getSubExpr(); QualType DestTy = CE->getType(); CastExpr::CastKind Kind = CE->getCastKind(); if (!DestTy->isVoidType()) TestAndClearIgnoreResultAssign(); // Since almost all cast kinds apply to scalars, this switch doesn't have // a default case, so the compiler will warn on a missing case. The cases // are in the same order as in the CastKind enum. switch (Kind) { case CastExpr::CK_Unknown: // FIXME: All casts should have a known kind! //assert(0 && "Unknown cast kind!"); break; case CastExpr::CK_LValueBitCast: { Value *V = EmitLValue(E).getAddress(); V = Builder.CreateBitCast(V, ConvertType(CGF.getContext().getPointerType(DestTy))); // FIXME: Are the qualifiers correct here? return EmitLoadOfLValue(LValue::MakeAddr(V, CGF.MakeQualifiers(DestTy)), DestTy); } case CastExpr::CK_AnyPointerToObjCPointerCast: case CastExpr::CK_AnyPointerToBlockPointerCast: case CastExpr::CK_BitCast: { Value *Src = Visit(const_cast(E)); return Builder.CreateBitCast(Src, ConvertType(DestTy)); } case CastExpr::CK_NoOp: case CastExpr::CK_UserDefinedConversion: return Visit(const_cast(E)); case CastExpr::CK_BaseToDerived: { const CXXRecordDecl *DerivedClassDecl = DestTy->getCXXRecordDeclForPointerType(); return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, CE->getBasePath(), ShouldNullCheckClassCastValue(CE)); } case CastExpr::CK_UncheckedDerivedToBase: case CastExpr::CK_DerivedToBase: { const RecordType *DerivedClassTy = E->getType()->getAs()->getPointeeType()->getAs(); CXXRecordDecl *DerivedClassDecl = cast(DerivedClassTy->getDecl()); return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, CE->getBasePath(), ShouldNullCheckClassCastValue(CE)); } case CastExpr::CK_Dynamic: { Value *V = Visit(const_cast(E)); const CXXDynamicCastExpr *DCE = cast(CE); return CGF.EmitDynamicCast(V, DCE); } case CastExpr::CK_ToUnion: assert(0 && "Should be unreachable!"); break; case CastExpr::CK_ArrayToPointerDecay: { assert(E->getType()->isArrayType() && "Array to pointer decay must have array source type!"); Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. // Note that VLA pointers are always decayed, so we don't need to do // anything here. if (!E->getType()->isVariableArrayType()) { assert(isa(V->getType()) && "Expected pointer"); assert(isa(cast(V->getType()) ->getElementType()) && "Expected pointer to array"); V = Builder.CreateStructGEP(V, 0, "arraydecay"); } return V; } case CastExpr::CK_FunctionToPointerDecay: return EmitLValue(E).getAddress(); case CastExpr::CK_NullToMemberPointer: return CGF.CGM.EmitNullConstant(DestTy); case CastExpr::CK_BaseToDerivedMemberPointer: case CastExpr::CK_DerivedToBaseMemberPointer: { Value *Src = Visit(E); // See if we need to adjust the pointer. const CXXRecordDecl *BaseDecl = cast(E->getType()->getAs()-> getClass()->getAs()->getDecl()); const CXXRecordDecl *DerivedDecl = cast(CE->getType()->getAs()-> getClass()->getAs()->getDecl()); if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) std::swap(DerivedDecl, BaseDecl); if (llvm::Constant *Adj = CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, CE->getBasePath())){ if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) Src = Builder.CreateNSWSub(Src, Adj, "adj"); else Src = Builder.CreateNSWAdd(Src, Adj, "adj"); } return Src; } case CastExpr::CK_ConstructorConversion: assert(0 && "Should be unreachable!"); break; case CastExpr::CK_IntegralToPointer: { Value *Src = Visit(const_cast(E)); // First, convert to the correct width so that we control the kind of // extension. const llvm::Type *MiddleTy = CGF.IntPtrTy; bool InputSigned = E->getType()->isSignedIntegerType(); llvm::Value* IntResult = Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); } case CastExpr::CK_PointerToIntegral: { Value *Src = Visit(const_cast(E)); return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); } case CastExpr::CK_ToVoid: { CGF.EmitAnyExpr(E, 0, false, true); return 0; } case CastExpr::CK_VectorSplat: { const llvm::Type *DstTy = ConvertType(DestTy); Value *Elt = Visit(const_cast(E)); // Insert the element in element zero of an undef vector llvm::Value *UnV = llvm::UndefValue::get(DstTy); llvm::Value *Idx = llvm::ConstantInt::get(CGF.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(CGF.Int32Ty, 0)); llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); return Yay; } case CastExpr::CK_IntegralCast: case CastExpr::CK_IntegralToFloating: case CastExpr::CK_FloatingToIntegral: case CastExpr::CK_FloatingCast: return EmitScalarConversion(Visit(E), E->getType(), DestTy); case CastExpr::CK_MemberPointerToBoolean: return CGF.EvaluateExprAsBool(E); } // 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) { llvm::Value *V = CGF.GetAddrOfBlockDecl(E); if (E->getType().isObjCGCWeak()) return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); return Builder.CreateLoad(V, "tmp"); } //===----------------------------------------------------------------------===// // Unary Operators //===----------------------------------------------------------------------===// llvm::Value *ScalarExprEmitter:: EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre) { QualType ValTy = E->getSubExpr()->getType(); llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); int AmountVal = isInc ? 1 : -1; if (ValTy->isPointerType() && ValTy->getAs()->isVariableArrayType()) { // The amount of the addition/subtraction needs to account for the VLA size CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); } llvm::Value *NextVal; if (const llvm::PointerType *PT = dyn_cast(InVal->getType())) { llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); if (!isa(PT->getElementType())) { QualType PTEE = ValTy->getPointeeType(); if (const ObjCObjectType *OIT = PTEE->getAs()) { // Handle interface types, which are not represented with a concrete // type. int size = CGF.getContext().getTypeSize(OIT) / 8; if (!isInc) size = -size; Inc = llvm::ConstantInt::get(Inc->getType(), size); const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); InVal = Builder.CreateBitCast(InVal, i8Ty); NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); llvm::Value *lhs = LV.getAddress(); lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); LV = LValue::MakeAddr(lhs, CGF.MakeQualifiers(ValTy)); } else NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); } else { const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); } } else if (InVal->getType()->isIntegerTy(1) && 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(VMContext); } else if (isa(InVal->getType())) { NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); if (!ValTy->isSignedIntegerType()) // Unsigned integer inc is always two's complement. NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); else { switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); break; case LangOptions::SOB_Defined: NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); break; case LangOptions::SOB_Trapping: BinOpInfo BinOp; BinOp.LHS = InVal; BinOp.RHS = NextVal; BinOp.Ty = E->getType(); BinOp.Opcode = BinaryOperator::Add; BinOp.E = E; return EmitOverflowCheckedBinOp(BinOp); } } } else { // Add the inc/dec to the real part. if (InVal->getType()->isFloatTy()) NextVal = llvm::ConstantFP::get(VMContext, llvm::APFloat(static_cast(AmountVal))); else if (InVal->getType()->isDoubleTy()) NextVal = llvm::ConstantFP::get(VMContext, 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(VMContext, F); } NextVal = Builder.CreateFAdd(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(); // Emit unary minus with EmitSub so we handle overflow cases etc. BinOpInfo BinOp; BinOp.RHS = Visit(E->getSubExpr()); if (BinOp.RHS->getType()->isFPOrFPVectorTy()) BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); else BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); BinOp.Ty = E->getType(); BinOp.Opcode = BinaryOperator::Sub; BinOp.E = E; return EmitSub(BinOp); } 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"); } Value *ScalarExprEmitter::VisitOffsetOfExpr(const OffsetOfExpr *E) { Expr::EvalResult Result; if(E->Evaluate(Result, CGF.getContext())) return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); // FIXME: Cannot support code generation for non-constant offsetof. unsigned DiagID = CGF.CGM.getDiags().getCustomDiagID(Diagnostic::Error, "cannot compile non-constant __builtin_offsetof"); CGF.CGM.getDiags().Report(CGF.getContext().getFullLoc(E->getLocStart()), DiagID) << E->getSourceRange(); return llvm::Constant::getNullValue(ConvertType(E->getType())); } /// 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(VMContext, 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.Opcode = E->getOpcode(); Result.E = E; return Result; } LValue ScalarExprEmitter::EmitCompoundAssignLValue( const CompoundAssignOperator *E, Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), Value *&Result) { QualType LHSTy = E->getLHS()->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"); Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); return LValue(); } // 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.Opcode = E->getOpcode(); OpInfo.E = E; // Load/convert the LHS. LValue LHSLV = EmitCheckedLValue(E->getLHS()); OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, E->getComputationLHSType()); // Expand the binary operator. 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()) CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, &Result); else CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); return LHSLV; } Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { bool Ignore = TestAndClearIgnoreResultAssign(); Value *RHS; LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); // If the result is clearly ignored, return now. if (Ignore) return 0; // Objective-C property assignment never reloads the value following a store. if (LHS.isPropertyRef() || LHS.isKVCRef()) return RHS; // If the lvalue is non-volatile, return the computed value of the assignment. if (!LHS.isVolatileQualified()) return RHS; // Otherwise, reload the value. return EmitLoadOfLValue(LHS, E->getType()); } Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { if (Ops.LHS->getType()->isFPOrFPVectorTy()) 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.Opcode) { 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(CGF.Int64Ty); handerArgTypes.push_back(CGF.Int64Ty); handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); llvm::FunctionType *handlerTy = llvm::FunctionType::get(CGF.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, CGF.Int64Ty), Builder.CreateSExt(Ops.RHS, CGF.Int64Ty), llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 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->isAnyPointerType()) { if (Ops.Ty->isSignedIntegerType()) { switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); case LangOptions::SOB_Defined: return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); case LangOptions::SOB_Trapping: return EmitOverflowCheckedBinOp(Ops); } } if (Ops.LHS->getType()->isFPOrFPVectorTy()) return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); } // Must have binary (not unary) expr here. Unary pointer decrement doesn't // use this path. const BinaryOperator *BinOp = cast(Ops.E); if (Ops.Ty->isPointerType() && Ops.Ty->getAs()->isVariableArrayType()) { // The amount of the addition needs to account for the VLA size CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); } Value *Ptr, *Idx; Expr *IdxExp; const PointerType *PT = BinOp->getLHS()->getType()->getAs(); const ObjCObjectPointerType *OPT = BinOp->getLHS()->getType()->getAs(); if (PT || OPT) { Ptr = Ops.LHS; Idx = Ops.RHS; IdxExp = BinOp->getRHS(); } else { // int + pointer PT = BinOp->getRHS()->getType()->getAs(); OPT = BinOp->getRHS()->getType()->getAs(); assert((PT || OPT) && "Invalid add expr"); Ptr = Ops.RHS; Idx = Ops.LHS; IdxExp = BinOp->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 = CGF.IntPtrTy; if (IdxExp->getType()->isSignedIntegerType()) Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); else Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); } const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); // Handle interface types, which are not represented with a concrete type. if (const ObjCObjectType *OIT = ElementType->getAs()) { llvm::Value *InterfaceSize = llvm::ConstantInt::get(Idx->getType(), CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); Idx = Builder.CreateMul(Idx, InterfaceSize); const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 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::Type::getInt8PtrTy(VMContext); Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); return Builder.CreateBitCast(Res, Ptr->getType()); } return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); } Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { if (!isa(Ops.LHS->getType())) { if (Ops.Ty->isSignedIntegerType()) { switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); case LangOptions::SOB_Defined: return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); case LangOptions::SOB_Trapping: return EmitOverflowCheckedBinOp(Ops); } } if (Ops.LHS->getType()->isFPOrFPVectorTy()) return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); } // Must have binary (not unary) expr here. Unary pointer increment doesn't // use this path. const BinaryOperator *BinOp = cast(Ops.E); if (BinOp->getLHS()->getType()->isPointerType() && BinOp->getLHS()->getType()->getAs()->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(BinOp, "VLA pointer subtraction"); } const QualType LHSType = BinOp->getLHS()->getType(); const QualType LHSElementType = LHSType->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 = CGF.IntPtrTy; if (BinOp->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 ObjCObjectType *OIT = LHSElementType->getAs()) { llvm::Value *InterfaceSize = llvm::ConstantInt::get(Idx->getType(), CGF.getContext(). getTypeSizeInChars(OIT).getQuantity()); Idx = Builder.CreateMul(Idx, InterfaceSize); const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 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::Type::getInt8PtrTy(VMContext); Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); return Builder.CreateBitCast(Res, Ops.LHS->getType()); } return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); } else { // pointer - pointer Value *LHS = Ops.LHS; Value *RHS = Ops.RHS; CharUnits ElementSize; // Handle GCC extension for pointer arithmetic on void* and function pointer // types. if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { ElementSize = CharUnits::One(); } else { ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); } 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.isOne()) return BytesBetween; // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since // pointer difference in C is only defined in the case where both operands // are pointing to elements of an array. Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); return Builder.CreateExactSDiv(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"); if (CGF.CatchUndefined && isa(Ops.LHS->getType())) { unsigned Width = cast(Ops.LHS->getType())->getBitWidth(); llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, llvm::ConstantInt::get(RHS->getType(), Width)), Cont, CGF.getTrapBB()); CGF.EmitBlock(Cont); } 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 (CGF.CatchUndefined && isa(Ops.LHS->getType())) { unsigned Width = cast(Ops.LHS->getType())->getBitWidth(); llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, llvm::ConstantInt::get(RHS->getType(), Width)), Cont, CGF.getTrapBB()); CGF.EmitBlock(Cont); } 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->isMemberFunctionPointerType()) { Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); LHSFunc = Builder.CreateLoad(LHSFunc); llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); RHSFunc = Builder.CreateLoad(RHSFunc); Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHSFunc, RHSFunc, "cmp.func"); Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHSFunc, NullPtr, "cmp.null"); llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); LHSAdj = Builder.CreateLoad(LHSAdj); llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); RHSAdj = Builder.CreateLoad(RHSAdj); Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, LHSAdj, RHSAdj, "cmp.adj"); if (E->getOpcode() == BinaryOperator::EQ) { Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); Result = Builder.CreateAnd(Result, ResultF, "and.f"); } else { assert(E->getOpcode() == BinaryOperator::NE && "Member pointer comparison other than == or != ?"); Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); Result = Builder.CreateOr(Result, ResultF, "or.f"); } } else if (!LHSTy->isAnyComplexType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); if (LHS->getType()->isFPOrFPVectorTy()) { 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"); } // If this is a vector comparison, sign extend the result to the appropriate // vector integer type and return it (don't convert to bool). if (LHSTy->isVectorType()) return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); } 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->getAs()->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 = EmitCheckedLValue(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()) CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), &RHS); else CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); // If the result is clearly ignored, return now. if (Ignore) return 0; // Objective-C property assignment never reloads the value following a store. if (LHS.isPropertyRef() || LHS.isKVCRef()) return RHS; // If the lvalue is non-volatile, return the computed value of the assignment. if (!LHS.isVolatileQualified()) return RHS; // Otherwise, reload the value. return EmitLoadOfLValue(LHS, E->getType()); } Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { const llvm::Type *ResTy = ConvertType(E->getType()); // 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 or bool. return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); } // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. if (!CGF.ContainsLabel(E->getRHS())) return llvm::Constant::getNullValue(ResTy); } 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::getInt1Ty(VMContext), "", 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(VMContext), *PI); CGF.BeginConditionalBranch(); CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); CGF.EndConditionalBranch(); // 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.CreateZExtOrBitCast(PN, ResTy, "land.ext"); } Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { const llvm::Type *ResTy = ConvertType(E->getType()); // 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 or bool. return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); } // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. if (!CGF.ContainsLabel(E->getRHS())) return llvm::ConstantInt::get(ResTy, 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::getInt1Ty(VMContext), "", 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(VMContext), *PI); CGF.BeginConditionalBranch(); // Emit the RHS condition as a bool value. CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); CGF.EndConditionalBranch(); // 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.CreateZExtOrBitCast(PN, ResTy, "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, CodeGenFunction &CGF) { if (const ParenExpr *PE = dyn_cast(E)) return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); // 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() && !(CGF.getContext() .getCanonicalType(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(), CGF) && isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 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.BeginConditionalBranch(); 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()); CGF.EndConditionalBranch(); LHSBlock = Builder.GetInsertBlock(); CGF.EmitBranch(ContBlock); CGF.BeginConditionalBranch(); CGF.EmitBlock(RHSBlock); Value *RHS = Visit(E->getRHS()); CGF.EndConditionalBranch(); RHSBlock = Builder.GetInsertBlock(); CGF.EmitBranch(ContBlock); CGF.EmitBlock(ContBlock); // If the LHS or RHS is a throw expression, it will be legitimately null. if (!LHS) return RHS; if (!RHS) return LHS; // 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); } llvm::Value *CodeGenFunction:: EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre) { return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); } LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { llvm::Value *V; // object->isa or (*object).isa // Generate code as for: *(Class*)object // build Class* type const llvm::Type *ClassPtrTy = ConvertType(E->getType()); Expr *BaseExpr = E->getBase(); if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { V = CreateTempAlloca(ClassPtrTy, "resval"); llvm::Value *Src = EmitScalarExpr(BaseExpr); Builder.CreateStore(Src, V); LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); } else { if (E->isArrow()) V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); else V = EmitLValue(BaseExpr).getAddress(); } // build Class* type ClassPtrTy = ClassPtrTy->getPointerTo(); V = Builder.CreateBitCast(V, ClassPtrTy); LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); return LV; } LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( const CompoundAssignOperator *E) { ScalarExprEmitter Scalar(*this); Value *Result = 0; switch (E->getOpcode()) { #define COMPOUND_OP(Op) \ case BinaryOperator::Op##Assign: \ return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ Result) COMPOUND_OP(Mul); COMPOUND_OP(Div); COMPOUND_OP(Rem); COMPOUND_OP(Add); COMPOUND_OP(Sub); COMPOUND_OP(Shl); COMPOUND_OP(Shr); COMPOUND_OP(And); COMPOUND_OP(Xor); COMPOUND_OP(Or); #undef COMPOUND_OP case BinaryOperator::PtrMemD: case BinaryOperator::PtrMemI: case BinaryOperator::Mul: case BinaryOperator::Div: case BinaryOperator::Rem: case BinaryOperator::Add: case BinaryOperator::Sub: case BinaryOperator::Shl: case BinaryOperator::Shr: case BinaryOperator::LT: case BinaryOperator::GT: case BinaryOperator::LE: case BinaryOperator::GE: case BinaryOperator::EQ: case BinaryOperator::NE: case BinaryOperator::And: case BinaryOperator::Xor: case BinaryOperator::Or: case BinaryOperator::LAnd: case BinaryOperator::LOr: case BinaryOperator::Assign: case BinaryOperator::Comma: assert(false && "Not valid compound assignment operators"); break; } llvm_unreachable("Unhandled compound assignment operator"); }