//===--- 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 "clang/Frontend/CodeGenOptions.h" #include "CodeGenFunction.h" #include "CGCXXABI.h" #include "CGObjCRuntime.h" #include "CodeGenModule.h" #include "CGDebugInfo.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 //===----------------------------------------------------------------------===// namespace { 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. }; static bool MustVisitNullValue(const Expr *E) { // If a null pointer expression's type is the C++0x nullptr_t, then // it's not necessarily a simple constant and it must be evaluated // for its potential side effects. return E->getType()->isNullPtrType(); } 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; } 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) { return CGF.EmitLoadOfLValue(LV).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)); } /// 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); /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. Value *EmitFloatToBoolConversion(Value *V) { // Compare against 0.0 for fp scalars. llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); return Builder.CreateFCmpUNE(V, Zero, "tobool"); } /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. Value *EmitPointerToBoolConversion(Value *V) { Value *Zero = llvm::ConstantPointerNull::get( cast(V->getType())); return Builder.CreateICmpNE(V, Zero, "tobool"); } Value *EmitIntToBoolConversion(Value *V) { // 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(V)) { if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 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; } } return Builder.CreateIsNotNull(V, "tobool"); } //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// Value *Visit(Expr *E) { return StmtVisitor::Visit(E); } Value *VisitStmt(Stmt *S) { S->dump(CGF.getContext().getSourceManager()); llvm_unreachable("Stmt can't have complex result type!"); } Value *VisitExpr(Expr *S); Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { return Visit(E->getReplacement()); } Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { return Visit(GE->getResultExpr()); } // Leaves. Value *VisitIntegerLiteral(const IntegerLiteral *E) { return Builder.getInt(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 *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *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 *VisitOffsetOfExpr(OffsetOfExpr *E); Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); return Builder.CreateBitCast(V, ConvertType(E->getType())); } Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); } Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) { return CGF.EmitPseudoObjectRValue(E).getScalarVal(); } Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { if (E->isGLValue()) return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); // Otherwise, assume the mapping is the scalar directly. return CGF.getOpaqueRValueMapping(E).getScalarVal(); } // l-values. Value *VisitDeclRefExpr(DeclRefExpr *E) { if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { if (result.isReference()) return EmitLoadOfLValue(result.getReferenceLValue(CGF, E)); return result.getValue(); } 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 *VisitObjCMessageExpr(ObjCMessageExpr *E) { if (E->getMethodDecl() && E->getMethodDecl()->getResultType()->isReferenceType()) return EmitLoadOfLValue(E); return CGF.EmitObjCMessageExpr(E).getScalarVal(); } Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { LValue LV = CGF.EmitObjCIsaExpr(E); Value *V = CGF.EmitLoadOfLValue(LV).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 *VisitExplicitCastExpr(ExplicitCastExpr *E) { if (E->getType()->isVariablyModifiedType()) CGF.EmitVariablyModifiedType(E->getType()); return VisitCastExpr(E); } Value *VisitCastExpr(CastExpr *E); Value *VisitCallExpr(const CallExpr *E) { if (E->getCallReturnType()->isReferenceType()) return EmitLoadOfLValue(E); return CGF.EmitCallExpr(E).getScalarVal(); } Value *VisitStmtExpr(const StmtExpr *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 *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, llvm::Value *InVal, llvm::Value *NextVal, bool IsInc); llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre); Value *VisitUnaryAddrOf(const UnaryOperator *E) { if (isa(E->getType())) // never sugared return CGF.CGM.getMemberPointerConstant(E); return EmitLValue(E->getSubExpr()).getAddress(); } Value *VisitUnaryDeref(const UnaryOperator *E) { if (E->getType()->isVoidType()) return Visit(E->getSubExpr()); // the actual value should be unused 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()); } // C++ Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { return EmitLoadOfLValue(E); } Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { return Visit(DAE->getExpr()); } Value *VisitCXXThisExpr(CXXThisExpr *TE) { return CGF.LoadCXXThis(); } Value *VisitExprWithCleanups(ExprWithCleanups *E) { CGF.enterFullExpression(E); CodeGenFunction::RunCleanupsScope Scope(CGF); return Visit(E->getSubExpr()); } 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 Builder.getInt1(E->getValue()); } Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); } Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); } Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); } 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; } Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { return Builder.getInt1(E->getValue()); } // Binary Operators. Value *EmitMul(const BinOpInfo &Ops) { if (Ops.Ty->isSignedIntegerOrEnumerationType()) { switch (CGF.getContext().getLangOpts().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"); } bool isTrapvOverflowBehavior() { return CGF.getContext().getLangOpts().getSignedOverflowBehavior() == LangOptions::SOB_Trapping; } /// Create a binary op that checks for overflow. /// Currently only supports +, - and *. Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); // Emit the overflow BB when -ftrapv option is activated. void EmitOverflowBB(llvm::BasicBlock *overflowBB) { Builder.SetInsertPoint(overflowBB); llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); Builder.CreateCall(Trap); Builder.CreateUnreachable(); } // Check for undefined division and modulus behaviors. void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, llvm::Value *Zero,bool isDiv); 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 *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); Value *VisitChooseExpr(ChooseExpr *CE); Value *VisitVAArgExpr(VAArgExpr *VE); Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { return CGF.EmitObjCStringLiteral(E); } Value *VisitObjCNumericLiteral(ObjCNumericLiteral *E) { return CGF.EmitObjCNumericLiteral(E); } Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) { return CGF.EmitObjCArrayLiteral(E); } Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { return CGF.EmitObjCDictionaryLiteral(E); } Value *VisitAsTypeExpr(AsTypeExpr *CE); Value *VisitAtomicExpr(AtomicExpr *AE); }; } // 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()) return EmitFloatToBoolConversion(Src); if (const MemberPointerType *MPT = dyn_cast(SrcType)) return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); assert((SrcType->isIntegerType() || isa(Src->getType())) && "Unknown scalar type to convert"); if (isa(Src->getType())) return EmitIntToBoolConversion(Src); assert(isa(Src->getType())); return EmitPointerToBoolConversion(Src); } /// 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; llvm::Type *SrcTy = Src->getType(); // Floating casts might be a bit special: if we're doing casts to / from half // FP, we should go via special intrinsics. if (SrcType->isHalfType()) { Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); SrcType = CGF.getContext().FloatTy; SrcTy = CGF.FloatTy; } // Handle conversions to bool first, they are special: comparisons against 0. if (DstType->isBooleanType()) return EmitConversionToBool(Src, SrcType); llvm::Type *DstTy = ConvertType(DstType); // Ignore conversions like int -> uint. if (SrcTy == 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(SrcTy)) 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. llvm::Type *MiddleTy = CGF.IntPtrTy; bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); llvm::Value* IntResult = Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); // Then, cast to pointer. return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); } if (isa(SrcTy)) { // 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 = Builder.getInt32(0); UnV = Builder.CreateInsertElement(UnV, Elt, Idx); // Splat the element across to all elements unsigned NumElements = cast(DstTy)->getNumElements(); llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, Builder.getInt32(0)); llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); return Yay; } // Allow bitcast from vector to integer/fp of the same size. if (isa(SrcTy) || isa(DstTy)) return Builder.CreateBitCast(Src, DstTy, "conv"); // Finally, we have the arithmetic types: real int/float. Value *Res = NULL; llvm::Type *ResTy = DstTy; // Cast to half via float if (DstType->isHalfType()) DstTy = CGF.FloatTy; if (isa(SrcTy)) { bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); if (isa(DstTy)) Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); else if (InputSigned) Res = Builder.CreateSIToFP(Src, DstTy, "conv"); else Res = Builder.CreateUIToFP(Src, DstTy, "conv"); } else if (isa(DstTy)) { assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); if (DstType->isSignedIntegerOrEnumerationType()) Res = Builder.CreateFPToSI(Src, DstTy, "conv"); else Res = Builder.CreateFPToUI(Src, DstTy, "conv"); } else { assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && "Unknown real conversion"); if (DstTy->getTypeID() < SrcTy->getTypeID()) Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); else Res = Builder.CreateFPExt(Src, DstTy, "conv"); } if (DstTy != ResTy) { assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); } return Res; } /// 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) { if (const MemberPointerType *MPT = Ty->getAs()) return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); return llvm::Constant::getNullValue(ConvertType(Ty)); } //===----------------------------------------------------------------------===// // 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; 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. SmallVector concat; for (unsigned i = 0; i != LHSElts; ++i) { concat.push_back(Builder.getInt32(2*i)); concat.push_back(Builder.getInt32(2*i+1)); } Value* CV = llvm::ConstantVector::get(concat); LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); LHSElts *= 2; } else { Mask = RHS; } 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. Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(), EltMask); 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 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 *IIndx = Builder.getInt32(i); Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "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, Builder.getInt32(3), "cmp_shuf_idx"); newIndx = Builder.CreateSub(Indx, Builder.getInt32(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, IIndx, "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::VectorType *VTy = cast(V1->getType()); SmallVector indices; for (unsigned i = 2; i < E->getNumSubExprs(); i++) { unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); if (VTy->getNumElements() == 3 && Idx > 3) Idx -= 1; indices.push_back(Builder.getInt32(Idx)); } Value *SV = llvm::ConstantVector::get(indices); return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); } Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { llvm::APSInt Value; if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) { if (E->isArrow()) CGF.EmitScalarExpr(E->getBase()); else EmitLValue(E->getBase()); return Builder.getInt(Value); } // Emit debug info for aggregate now, if it was delayed to reduce // debug info size. CGDebugInfo *DI = CGF.getDebugInfo(); if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) { QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); if (const PointerType * PTy = dyn_cast(PQTy)) if (FieldDecl *M = dyn_cast(E->getMemberDecl())) DI->getOrCreateRecordType(PTy->getPointeeType(), M->getParent()->getLocation()); } 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()->isSignedIntegerOrEnumerationType(); 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, 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"); llvm::VectorType *VType = dyn_cast(ConvertType(E->getType())); if (!VType) { if (NumInitElements == 0) { // C++11 value-initialization for the scalar. return EmitNullValue(E->getType()); } // We have a scalar in braces. Just use the first element. 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); SmallVector Args; 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); Args.resize(ResElts, 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(Builder.getInt32(ResElts + C->getZExtValue())); Args.resize(ResElts, 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); V = Builder.CreateShuffleVector(LHS, RHS, Mask); ++CurIdx; continue; } } } V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), "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); 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(Builder.getInt32(j)); } } for (unsigned j = 0, je = InitElts; j != je; ++j) Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); Args.resize(ResElts, 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(Builder.getInt32(j)); Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); llvm::Constant *Mask = llvm::ConstantVector::get(Args); Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), Mask, "vext"); Args.clear(); for (unsigned j = 0; j != CurIdx; ++j) Args.push_back(Builder.getInt32(j)); for (unsigned j = 0; j != InitElts; ++j) Args.push_back(Builder.getInt32(j+Offset)); Args.resize(ResElts, 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); 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. llvm::Type *EltTy = VType->getElementType(); // Emit remaining default initializers for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { Value *Idx = Builder.getInt32(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() == 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 glvalue casts are never null. if (ICE->getValueKind() != VK_RValue) 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::VisitCastExpr(CastExpr *CE) { Expr *E = CE->getSubExpr(); QualType DestTy = CE->getType(); 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 CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); case CK_LValueBitCast: case CK_ObjCObjectLValueCast: { Value *V = EmitLValue(E).getAddress(); V = Builder.CreateBitCast(V, ConvertType(CGF.getContext().getPointerType(DestTy))); return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy)); } case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: case CK_AnyPointerToBlockPointerCast: case CK_BitCast: { Value *Src = Visit(const_cast(E)); return Builder.CreateBitCast(Src, ConvertType(DestTy)); } case CK_AtomicToNonAtomic: case CK_NonAtomicToAtomic: case CK_NoOp: case CK_UserDefinedConversion: return Visit(const_cast(E)); case CK_BaseToDerived: { const CXXRecordDecl *DerivedClassDecl = DestTy->getCXXRecordDeclForPointerType(); return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, CE->path_begin(), CE->path_end(), ShouldNullCheckClassCastValue(CE)); } case CK_UncheckedDerivedToBase: case CK_DerivedToBase: { const RecordType *DerivedClassTy = E->getType()->getAs()->getPointeeType()->getAs(); CXXRecordDecl *DerivedClassDecl = cast(DerivedClassTy->getDecl()); return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, CE->path_begin(), CE->path_end(), ShouldNullCheckClassCastValue(CE)); } case CK_Dynamic: { Value *V = Visit(const_cast(E)); const CXXDynamicCastExpr *DCE = cast(CE); return CGF.EmitDynamicCast(V, DCE); } case 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"); } // Make sure the array decay ends up being the right type. This matters if // the array type was of an incomplete type. return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); } case CK_FunctionToPointerDecay: return EmitLValue(E).getAddress(); case CK_NullToPointer: if (MustVisitNullValue(E)) (void) Visit(E); return llvm::ConstantPointerNull::get( cast(ConvertType(DestTy))); case CK_NullToMemberPointer: { if (MustVisitNullValue(E)) (void) Visit(E); const MemberPointerType *MPT = CE->getType()->getAs(); return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); } case CK_ReinterpretMemberPointer: case CK_BaseToDerivedMemberPointer: case CK_DerivedToBaseMemberPointer: { Value *Src = Visit(E); // Note that the AST doesn't distinguish between checked and // unchecked member pointer conversions, so we always have to // implement checked conversions here. This is inefficient when // actual control flow may be required in order to perform the // check, which it is for data member pointers (but not member // function pointers on Itanium and ARM). return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); } case CK_ARCProduceObject: return CGF.EmitARCRetainScalarExpr(E); case CK_ARCConsumeObject: return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); case CK_ARCReclaimReturnedObject: { llvm::Value *value = Visit(E); value = CGF.EmitARCRetainAutoreleasedReturnValue(value); return CGF.EmitObjCConsumeObject(E->getType(), value); } case CK_ARCExtendBlockObject: return CGF.EmitARCExtendBlockObject(E); case CK_CopyAndAutoreleaseBlockObject: return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType()); case CK_FloatingRealToComplex: case CK_FloatingComplexCast: case CK_IntegralRealToComplex: case CK_IntegralComplexCast: case CK_IntegralComplexToFloatingComplex: case CK_FloatingComplexToIntegralComplex: case CK_ConstructorConversion: case CK_ToUnion: llvm_unreachable("scalar cast to non-scalar value"); case CK_LValueToRValue: assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); return Visit(const_cast(E)); case CK_IntegralToPointer: { Value *Src = Visit(const_cast(E)); // First, convert to the correct width so that we control the kind of // extension. llvm::Type *MiddleTy = CGF.IntPtrTy; bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); llvm::Value* IntResult = Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); } case CK_PointerToIntegral: assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); case CK_ToVoid: { CGF.EmitIgnoredExpr(E); return 0; } case CK_VectorSplat: { llvm::Type *DstTy = ConvertType(DestTy); Value *Elt = Visit(const_cast(E)); Elt = EmitScalarConversion(Elt, E->getType(), DestTy->getAs()->getElementType()); // Insert the element in element zero of an undef vector llvm::Value *UnV = llvm::UndefValue::get(DstTy); llvm::Value *Idx = Builder.getInt32(0); UnV = Builder.CreateInsertElement(UnV, Elt, Idx); // Splat the element across to all elements unsigned NumElements = cast(DstTy)->getNumElements(); llvm::Constant *Zero = Builder.getInt32(0); llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, Zero); llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); return Yay; } case CK_IntegralCast: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingCast: return EmitScalarConversion(Visit(E), E->getType(), DestTy); case CK_IntegralToBoolean: return EmitIntToBoolConversion(Visit(E)); case CK_PointerToBoolean: return EmitPointerToBoolConversion(Visit(E)); case CK_FloatingToBoolean: return EmitFloatToBoolConversion(Visit(E)); case CK_MemberPointerToBoolean: { llvm::Value *MemPtr = Visit(E); const MemberPointerType *MPT = E->getType()->getAs(); return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); } case CK_FloatingComplexToReal: case CK_IntegralComplexToReal: return CGF.EmitComplexExpr(E, false, true).first; case CK_FloatingComplexToBoolean: case CK_IntegralComplexToBoolean: { CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); // TODO: kill this function off, inline appropriate case here return EmitComplexToScalarConversion(V, E->getType(), DestTy); } } llvm_unreachable("unknown scalar cast"); } Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { CodeGenFunction::StmtExprEvaluation eval(CGF); return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) .getScalarVal(); } //===----------------------------------------------------------------------===// // Unary Operators //===----------------------------------------------------------------------===// llvm::Value *ScalarExprEmitter:: EmitAddConsiderOverflowBehavior(const UnaryOperator *E, llvm::Value *InVal, llvm::Value *NextVal, bool IsInc) { switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); case LangOptions::SOB_Defined: return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); case LangOptions::SOB_Trapping: BinOpInfo BinOp; BinOp.LHS = InVal; BinOp.RHS = NextVal; BinOp.Ty = E->getType(); BinOp.Opcode = BO_Add; BinOp.E = E; return EmitOverflowCheckedBinOp(BinOp); } llvm_unreachable("Unknown SignedOverflowBehaviorTy"); } llvm::Value * ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre) { QualType type = E->getSubExpr()->getType(); llvm::Value *value = EmitLoadOfLValue(LV); llvm::Value *input = value; llvm::PHINode *atomicPHI = 0; int amount = (isInc ? 1 : -1); if (const AtomicType *atomicTy = type->getAs()) { llvm::BasicBlock *startBB = Builder.GetInsertBlock(); llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); Builder.CreateBr(opBB); Builder.SetInsertPoint(opBB); atomicPHI = Builder.CreatePHI(value->getType(), 2); atomicPHI->addIncoming(value, startBB); type = atomicTy->getValueType(); value = atomicPHI; } // Special case of integer increment that we have to check first: bool++. // 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. if (isInc && type->isBooleanType()) { value = Builder.getTrue(); // Most common case by far: integer increment. } else if (type->isIntegerType()) { llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); // Note that signed integer inc/dec with width less than int can't // overflow because of promotion rules; we're just eliding a few steps here. if (type->isSignedIntegerOrEnumerationType() && value->getType()->getPrimitiveSizeInBits() >= CGF.IntTy->getBitWidth()) value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); else value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); // Next most common: pointer increment. } else if (const PointerType *ptr = type->getAs()) { QualType type = ptr->getPointeeType(); // VLA types don't have constant size. if (const VariableArrayType *vla = CGF.getContext().getAsVariableArrayType(type)) { llvm::Value *numElts = CGF.getVLASize(vla).first; if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) value = Builder.CreateGEP(value, numElts, "vla.inc"); else value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); // Arithmetic on function pointers (!) is just +-1. } else if (type->isFunctionType()) { llvm::Value *amt = Builder.getInt32(amount); value = CGF.EmitCastToVoidPtr(value); if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) value = Builder.CreateGEP(value, amt, "incdec.funcptr"); else value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); value = Builder.CreateBitCast(value, input->getType()); // For everything else, we can just do a simple increment. } else { llvm::Value *amt = Builder.getInt32(amount); if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) value = Builder.CreateGEP(value, amt, "incdec.ptr"); else value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); } // Vector increment/decrement. } else if (type->isVectorType()) { if (type->hasIntegerRepresentation()) { llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); } else { value = Builder.CreateFAdd( value, llvm::ConstantFP::get(value->getType(), amount), isInc ? "inc" : "dec"); } // Floating point. } else if (type->isRealFloatingType()) { // Add the inc/dec to the real part. llvm::Value *amt; if (type->isHalfType()) { // Another special case: half FP increment should be done via float value = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), input); } if (value->getType()->isFloatTy()) amt = llvm::ConstantFP::get(VMContext, llvm::APFloat(static_cast(amount))); else if (value->getType()->isDoubleTy()) amt = llvm::ConstantFP::get(VMContext, llvm::APFloat(static_cast(amount))); else { llvm::APFloat F(static_cast(amount)); bool ignored; F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, &ignored); amt = llvm::ConstantFP::get(VMContext, F); } value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); if (type->isHalfType()) value = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), value); // Objective-C pointer types. } else { const ObjCObjectPointerType *OPT = type->castAs(); value = CGF.EmitCastToVoidPtr(value); CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); if (!isInc) size = -size; llvm::Value *sizeValue = llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); else value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); value = Builder.CreateBitCast(value, input->getType()); } if (atomicPHI) { llvm::BasicBlock *opBB = Builder.GetInsertBlock(); llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI, value, llvm::SequentiallyConsistent); atomicPHI->addIncoming(old, opBB); llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); Builder.CreateCondBr(success, contBB, opBB); Builder.SetInsertPoint(contBB); return isPre ? value : input; } // Store the updated result through the lvalue. if (LV.isBitField()) CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); else CGF.EmitStoreThroughLValue(RValue::get(value), LV); // If this is a postinc, return the value read from memory, otherwise use the // updated value. return isPre ? value : input; } 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 = BO_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) { // Perform vector logical not on comparison with zero vector. if (E->getType()->isExtVectorType()) { Value *Oper = Visit(E->getSubExpr()); Value *Zero = llvm::Constant::getNullValue(Oper->getType()); Value *Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp"); return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); } // 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(OffsetOfExpr *E) { // Try folding the offsetof to a constant. llvm::APSInt Value; if (E->EvaluateAsInt(Value, CGF.getContext())) return Builder.getInt(Value); // Loop over the components of the offsetof to compute the value. unsigned n = E->getNumComponents(); llvm::Type* ResultType = ConvertType(E->getType()); llvm::Value* Result = llvm::Constant::getNullValue(ResultType); QualType CurrentType = E->getTypeSourceInfo()->getType(); for (unsigned i = 0; i != n; ++i) { OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); llvm::Value *Offset = 0; switch (ON.getKind()) { case OffsetOfExpr::OffsetOfNode::Array: { // Compute the index Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); // Save the element type CurrentType = CGF.getContext().getAsArrayType(CurrentType)->getElementType(); // Compute the element size llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); // Multiply out to compute the result Offset = Builder.CreateMul(Idx, ElemSize); break; } case OffsetOfExpr::OffsetOfNode::Field: { FieldDecl *MemberDecl = ON.getField(); RecordDecl *RD = CurrentType->getAs()->getDecl(); const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); // Compute the index of the field in its parent. unsigned i = 0; // FIXME: It would be nice if we didn't have to loop here! for (RecordDecl::field_iterator Field = RD->field_begin(), FieldEnd = RD->field_end(); Field != FieldEnd; (void)++Field, ++i) { if (*Field == MemberDecl) break; } assert(i < RL.getFieldCount() && "offsetof field in wrong type"); // Compute the offset to the field int64_t OffsetInt = RL.getFieldOffset(i) / CGF.getContext().getCharWidth(); Offset = llvm::ConstantInt::get(ResultType, OffsetInt); // Save the element type. CurrentType = MemberDecl->getType(); break; } case OffsetOfExpr::OffsetOfNode::Identifier: llvm_unreachable("dependent __builtin_offsetof"); case OffsetOfExpr::OffsetOfNode::Base: { if (ON.getBase()->isVirtual()) { CGF.ErrorUnsupported(E, "virtual base in offsetof"); continue; } RecordDecl *RD = CurrentType->getAs()->getDecl(); const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); // Save the element type. CurrentType = ON.getBase()->getType(); // Compute the offset to the base. const RecordType *BaseRT = CurrentType->getAs(); CXXRecordDecl *BaseRD = cast(BaseRT->getDecl()); int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) / CGF.getContext().getCharWidth(); Offset = llvm::ConstantInt::get(ResultType, OffsetInt); break; } } Result = Builder.CreateAdd(Result, Offset); } return Result; } /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of /// argument of the sizeof expression as an integer. Value * ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( const UnaryExprOrTypeTraitExpr *E) { QualType TypeToSize = E->getTypeOfArgument(); if (E->getKind() == UETT_SizeOf) { if (const VariableArrayType *VAT = CGF.getContext().getAsVariableArrayType(TypeToSize)) { if (E->isArgumentType()) { // sizeof(type) - make sure to emit the VLA size. CGF.EmitVariablyModifiedType(TypeToSize); } else { // C99 6.5.3.4p2: If the argument is an expression of type // VLA, it is evaluated. CGF.EmitIgnoredExpr(E->getArgumentExpr()); } QualType eltType; llvm::Value *numElts; llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); llvm::Value *size = numElts; // Scale the number of non-VLA elements by the non-VLA element size. CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); if (!eltSize.isOne()) size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); return size; } } // 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. return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext())); } Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { Expr *Op = E->getSubExpr(); if (Op->getType()->isAnyComplexType()) { // If it's an l-value, load through the appropriate subobject l-value. // Note that we have to ask E because Op might be an l-value that // this won't work for, e.g. an Obj-C property. if (E->isGLValue()) return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); // Otherwise, calculate and project. return CGF.EmitComplexExpr(Op, false, true).first; } return Visit(Op); } Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { Expr *Op = E->getSubExpr(); if (Op->getType()->isAnyComplexType()) { // If it's an l-value, load through the appropriate subobject l-value. // Note that we have to ask E because Op might be an l-value that // this won't work for, e.g. an Obj-C property. if (Op->isGLValue()) return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); // Otherwise, calculate and project. return CGF.EmitComplexExpr(Op, true, false).second; } // __imag on a scalar returns zero. Emit the subexpr to ensure side // effects are evaluated, but not the actual value. if (Op->isGLValue()) CGF.EmitLValue(Op); else CGF.EmitScalarExpr(Op, true); return llvm::Constant::getNullValue(ConvertType(E->getType())); } //===----------------------------------------------------------------------===// // 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); OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, E->getComputationLHSType()); llvm::PHINode *atomicPHI = 0; if (const AtomicType *atomicTy = OpInfo.Ty->getAs()) { // FIXME: For floating point types, we should be saving and restoring the // floating point environment in the loop. llvm::BasicBlock *startBB = Builder.GetInsertBlock(); llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); Builder.CreateBr(opBB); Builder.SetInsertPoint(opBB); atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2); atomicPHI->addIncoming(OpInfo.LHS, startBB); OpInfo.Ty = atomicTy->getValueType(); OpInfo.LHS = atomicPHI; } // Expand the binary operator. Result = (this->*Func)(OpInfo); // Convert the result back to the LHS type. Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); if (atomicPHI) { llvm::BasicBlock *opBB = Builder.GetInsertBlock(); llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI, Result, llvm::SequentiallyConsistent); atomicPHI->addIncoming(old, opBB); llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); Builder.CreateCondBr(success, contBB, opBB); Builder.SetInsertPoint(contBB); return LHSLV; } // 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, &Result); else CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 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; // The result of an assignment in C is the assigned r-value. if (!CGF.getContext().getLangOpts().CPlusPlus) 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); } void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) { llvm::Function::iterator insertPt = Builder.GetInsertBlock(); llvm::BasicBlock *contBB = CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn, llvm::next(insertPt)); llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); llvm::IntegerType *Ty = cast(Zero->getType()); if (Ops.Ty->hasSignedIntegerRepresentation()) { llvm::Value *IntMin = Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), overflowBB, contBB); } else { CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), overflowBB, contBB); } EmitOverflowBB(overflowBB); Builder.SetInsertPoint(contBB); } Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { if (isTrapvOverflowBehavior()) { llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); if (Ops.Ty->isIntegerType()) EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); else if (Ops.Ty->isRealFloatingType()) { llvm::Function::iterator insertPt = Builder.GetInsertBlock(); llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn, llvm::next(insertPt)); llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), overflowBB, DivCont); EmitOverflowBB(overflowBB); Builder.SetInsertPoint(DivCont); } } if (Ops.LHS->getType()->isFPOrFPVectorTy()) { llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); if (CGF.getContext().getLangOpts().OpenCL) { // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp llvm::Type *ValTy = Val->getType(); if (ValTy->isFloatTy() || (isa(ValTy) && cast(ValTy)->getElementType()->isFloatTy())) CGF.SetFPAccuracy(Val, 2.5); } return Val; } else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 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 (isTrapvOverflowBehavior()) { llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); if (Ops.Ty->isIntegerType()) EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); } if (Ops.Ty->hasUnsignedIntegerRepresentation()) 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 BO_Add: case BO_AddAssign: OpID = 1; IID = llvm::Intrinsic::sadd_with_overflow; break; case BO_Sub: case BO_SubAssign: OpID = 2; IID = llvm::Intrinsic::ssub_with_overflow; break; case BO_Mul: case BO_MulAssign: OpID = 3; IID = llvm::Intrinsic::smul_with_overflow; break; default: llvm_unreachable("Unsupported operation for overflow detection"); } OpID <<= 1; OpID |= 1; llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 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::Function::iterator insertPt = initialBB; llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, llvm::next(insertPt)); llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); Builder.CreateCondBr(overflow, overflowBB, continueBB); // Handle overflow with llvm.trap. const std::string *handlerName = &CGF.getContext().getLangOpts().OverflowHandler; if (handlerName->empty()) { EmitOverflowBB(overflowBB); Builder.SetInsertPoint(continueBB); return result; } // If an overflow handler is set, then we want to call it and then use its // result, if it returns. Builder.SetInsertPoint(overflowBB); // Get the overflow handler. llvm::Type *Int8Ty = CGF.Int8Ty; llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; llvm::FunctionType *handlerTy = llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); // Sign extend the args to 64-bit, so that we can use the same handler for // all types of overflow. llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); // Call the handler with the two arguments, the operation, and the size of // the result. llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, Builder.getInt8(OpID), Builder.getInt8(cast(opTy)->getBitWidth())); // Truncate the result back to the desired size. handlerResult = Builder.CreateTrunc(handlerResult, opTy); Builder.CreateBr(continueBB); Builder.SetInsertPoint(continueBB); llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); phi->addIncoming(result, initialBB); phi->addIncoming(handlerResult, overflowBB); return phi; } /// Emit pointer + index arithmetic. static Value *emitPointerArithmetic(CodeGenFunction &CGF, const BinOpInfo &op, bool isSubtraction) { // Must have binary (not unary) expr here. Unary pointer // increment/decrement doesn't use this path. const BinaryOperator *expr = cast(op.E); Value *pointer = op.LHS; Expr *pointerOperand = expr->getLHS(); Value *index = op.RHS; Expr *indexOperand = expr->getRHS(); // In a subtraction, the LHS is always the pointer. if (!isSubtraction && !pointer->getType()->isPointerTy()) { std::swap(pointer, index); std::swap(pointerOperand, indexOperand); } unsigned width = cast(index->getType())->getBitWidth(); if (width != CGF.PointerWidthInBits) { // Zero-extend or sign-extend the pointer value according to // whether the index is signed or not. bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, "idx.ext"); } // If this is subtraction, negate the index. if (isSubtraction) index = CGF.Builder.CreateNeg(index, "idx.neg"); const PointerType *pointerType = pointerOperand->getType()->getAs(); if (!pointerType) { QualType objectType = pointerOperand->getType() ->castAs() ->getPointeeType(); llvm::Value *objectSize = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); index = CGF.Builder.CreateMul(index, objectSize); Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); result = CGF.Builder.CreateGEP(result, index, "add.ptr"); return CGF.Builder.CreateBitCast(result, pointer->getType()); } QualType elementType = pointerType->getPointeeType(); if (const VariableArrayType *vla = CGF.getContext().getAsVariableArrayType(elementType)) { // The element count here is the total number of non-VLA elements. llvm::Value *numElements = CGF.getVLASize(vla).first; // Effectively, the multiply by the VLA size is part of the GEP. // GEP indexes are signed, and scaling an index isn't permitted to // signed-overflow, so we use the same semantics for our explicit // multiply. We suppress this if overflow is not undefined behavior. if (CGF.getLangOpts().isSignedOverflowDefined()) { index = CGF.Builder.CreateMul(index, numElements, "vla.index"); pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); } else { index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); } return pointer; } // 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()) { Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); result = CGF.Builder.CreateGEP(result, index, "add.ptr"); return CGF.Builder.CreateBitCast(result, pointer->getType()); } if (CGF.getLangOpts().isSignedOverflowDefined()) return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); } Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { if (op.LHS->getType()->isPointerTy() || op.RHS->getType()->isPointerTy()) return emitPointerArithmetic(CGF, op, /*subtraction*/ false); if (op.Ty->isSignedIntegerOrEnumerationType()) { switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); case LangOptions::SOB_Defined: return Builder.CreateAdd(op.LHS, op.RHS, "add"); case LangOptions::SOB_Trapping: return EmitOverflowCheckedBinOp(op); } } if (op.LHS->getType()->isFPOrFPVectorTy()) return Builder.CreateFAdd(op.LHS, op.RHS, "add"); return Builder.CreateAdd(op.LHS, op.RHS, "add"); } Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { // The LHS is always a pointer if either side is. if (!op.LHS->getType()->isPointerTy()) { if (op.Ty->isSignedIntegerOrEnumerationType()) { switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { case LangOptions::SOB_Undefined: return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); case LangOptions::SOB_Defined: return Builder.CreateSub(op.LHS, op.RHS, "sub"); case LangOptions::SOB_Trapping: return EmitOverflowCheckedBinOp(op); } } if (op.LHS->getType()->isFPOrFPVectorTy()) return Builder.CreateFSub(op.LHS, op.RHS, "sub"); return Builder.CreateSub(op.LHS, op.RHS, "sub"); } // If the RHS is not a pointer, then we have normal pointer // arithmetic. if (!op.RHS->getType()->isPointerTy()) return emitPointerArithmetic(CGF, op, /*subtraction*/ true); // Otherwise, this is a pointer subtraction. // Do the raw subtraction part. llvm::Value *LHS = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); llvm::Value *RHS = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); // Okay, figure out the element size. const BinaryOperator *expr = cast(op.E); QualType elementType = expr->getLHS()->getType()->getPointeeType(); llvm::Value *divisor = 0; // For a variable-length array, this is going to be non-constant. if (const VariableArrayType *vla = CGF.getContext().getAsVariableArrayType(elementType)) { llvm::Value *numElements; llvm::tie(numElements, elementType) = CGF.getVLASize(vla); divisor = numElements; // Scale the number of non-VLA elements by the non-VLA element size. CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); if (!eltSize.isOne()) divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); // For everything elese, we can just compute it, safe in the // assumption that Sema won't let anything through that we can't // safely compute the size of. } else { CharUnits elementSize; // Handle GCC extension for pointer arithmetic on void* and // function pointer types. if (elementType->isVoidType() || elementType->isFunctionType()) elementSize = CharUnits::One(); else elementSize = CGF.getContext().getTypeSizeInChars(elementType); // Don't even emit the divide for element size of 1. if (elementSize.isOne()) return diffInChars; divisor = CGF.CGM.getSize(elementSize); } // 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. return Builder.CreateExactSDiv(diffInChars, divisor, "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->hasUnsignedIntegerRepresentation()) return Builder.CreateLShr(Ops.LHS, RHS, "shr"); return Builder.CreateAShr(Ops.LHS, RHS, "shr"); } enum IntrinsicType { VCMPEQ, VCMPGT }; // return corresponding comparison intrinsic for given vector type static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, BuiltinType::Kind ElemKind) { switch (ElemKind) { default: llvm_unreachable("unexpected element type"); case BuiltinType::Char_U: case BuiltinType::UChar: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : llvm::Intrinsic::ppc_altivec_vcmpgtub_p; case BuiltinType::Char_S: case BuiltinType::SChar: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; case BuiltinType::UShort: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; case BuiltinType::Short: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; case BuiltinType::UInt: case BuiltinType::ULong: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; case BuiltinType::Int: case BuiltinType::Long: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; case BuiltinType::Float: return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; } } Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, unsigned SICmpOpc, unsigned FCmpOpc) { TestAndClearIgnoreResultAssign(); Value *Result; QualType LHSTy = E->getLHS()->getType(); if (const MemberPointerType *MPT = LHSTy->getAs()) { assert(E->getOpcode() == BO_EQ || E->getOpcode() == BO_NE); Value *LHS = CGF.EmitScalarExpr(E->getLHS()); Value *RHS = CGF.EmitScalarExpr(E->getRHS()); Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); } else if (!LHSTy->isAnyComplexType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); // If AltiVec, the comparison results in a numeric type, so we use // intrinsics comparing vectors and giving 0 or 1 as a result if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { // constants for mapping CR6 register bits to predicate result enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; // in several cases vector arguments order will be reversed Value *FirstVecArg = LHS, *SecondVecArg = RHS; QualType ElTy = LHSTy->getAs()->getElementType(); const BuiltinType *BTy = ElTy->getAs(); BuiltinType::Kind ElementKind = BTy->getKind(); switch(E->getOpcode()) { default: llvm_unreachable("is not a comparison operation"); case BO_EQ: CR6 = CR6_LT; ID = GetIntrinsic(VCMPEQ, ElementKind); break; case BO_NE: CR6 = CR6_EQ; ID = GetIntrinsic(VCMPEQ, ElementKind); break; case BO_LT: CR6 = CR6_LT; ID = GetIntrinsic(VCMPGT, ElementKind); std::swap(FirstVecArg, SecondVecArg); break; case BO_GT: CR6 = CR6_LT; ID = GetIntrinsic(VCMPGT, ElementKind); break; case BO_LE: if (ElementKind == BuiltinType::Float) { CR6 = CR6_LT; ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; std::swap(FirstVecArg, SecondVecArg); } else { CR6 = CR6_EQ; ID = GetIntrinsic(VCMPGT, ElementKind); } break; case BO_GE: if (ElementKind == BuiltinType::Float) { CR6 = CR6_LT; ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; } else { CR6 = CR6_EQ; ID = GetIntrinsic(VCMPGT, ElementKind); std::swap(FirstVecArg, SecondVecArg); } break; } Value *CR6Param = Builder.getInt32(CR6); llvm::Function *F = CGF.CGM.getIntrinsic(ID); Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); } if (LHS->getType()->isFPOrFPVectorTy()) { Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, LHS, RHS, "cmp"); } else if (LHSTy->hasSignedIntegerRepresentation()) { 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() == BO_EQ) { Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); } else { assert(E->getOpcode() == BO_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(); Value *RHS; LValue LHS; switch (E->getLHS()->getType().getObjCLifetime()) { case Qualifiers::OCL_Strong: llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); break; case Qualifiers::OCL_Autoreleasing: llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); break; case Qualifiers::OCL_Weak: RHS = Visit(E->getRHS()); LHS = EmitCheckedLValue(E->getLHS()); RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); break; // No reason to do any of these differently. case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: // __block variables need to have the rhs evaluated first, plus // this should improve codegen just a little. RHS = Visit(E->getRHS()); 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, &RHS); else CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); } // If the result is clearly ignored, return now. if (Ignore) return 0; // The result of an assignment in C is the assigned r-value. if (!CGF.getContext().getLangOpts().CPlusPlus) 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); } Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { // Perform vector logical and on comparisons with zero vectors. if (E->getType()->isVectorType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); Value *And = Builder.CreateAnd(LHS, RHS); return Builder.CreateSExt(And, Zero->getType(), "sext"); } 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. bool LHSCondVal; if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { if (LHSCondVal) { // 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"); CodeGenFunction::ConditionalEvaluation eval(CGF); // 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), 2, "", ContBlock); for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); PI != PE; ++PI) PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); eval.begin(CGF); CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); eval.end(CGF); // 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. if (CGF.getDebugInfo()) // There is no need to emit line number for unconditional branch. Builder.SetCurrentDebugLocation(llvm::DebugLoc()); CGF.EmitBlock(ContBlock); PN->addIncoming(RHSCond, RHSBlock); // ZExt result to int. return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); } Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { // Perform vector logical or on comparisons with zero vectors. if (E->getType()->isVectorType()) { Value *LHS = Visit(E->getLHS()); Value *RHS = Visit(E->getRHS()); Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); Value *Or = Builder.CreateOr(LHS, RHS); return Builder.CreateSExt(Or, Zero->getType(), "sext"); } 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. bool LHSCondVal; if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { if (!LHSCondVal) { // 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"); CodeGenFunction::ConditionalEvaluation eval(CGF); // 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), 2, "", ContBlock); for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); PI != PE; ++PI) PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); eval.begin(CGF); // Emit the RHS condition as a bool value. CGF.EmitBlock(RHSBlock); Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); eval.end(CGF); // 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.EmitIgnoredExpr(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) { E = E->IgnoreParens(); // Anything that is an integer or floating point constant is fine. if (E->isConstantInitializer(CGF.getContext(), false)) 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:: VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { TestAndClearIgnoreResultAssign(); // Bind the common expression if necessary. CodeGenFunction::OpaqueValueMapping binding(CGF, E); Expr *condExpr = E->getCond(); Expr *lhsExpr = E->getTrueExpr(); Expr *rhsExpr = E->getFalseExpr(); // If the condition constant folds and can be elided, try to avoid emitting // the condition and the dead arm. bool CondExprBool; if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { Expr *live = lhsExpr, *dead = rhsExpr; if (!CondExprBool) std::swap(live, dead); // If the dead side doesn't have labels we need, just emit the Live part. if (!CGF.ContainsLabel(dead)) { Value *Result = Visit(live); // If the live part is a throw expression, it acts like it has a void // type, so evaluating it returns a null Value*. However, a conditional // with non-void type must return a non-null Value*. if (!Result && !E->getType()->isVoidType()) Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); return Result; } } // OpenCL: If the condition is a vector, we can treat this condition like // the select function. if (CGF.getContext().getLangOpts().OpenCL && condExpr->getType()->isVectorType()) { llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); llvm::Value *LHS = Visit(lhsExpr); llvm::Value *RHS = Visit(rhsExpr); llvm::Type *condType = ConvertType(condExpr->getType()); llvm::VectorType *vecTy = cast(condType); unsigned numElem = vecTy->getNumElements(); llvm::Type *elemType = vecTy->getElementType(); llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy); llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); llvm::Value *tmp = Builder.CreateSExt(TestMSB, llvm::VectorType::get(elemType, numElem), "sext"); llvm::Value *tmp2 = Builder.CreateNot(tmp); // Cast float to int to perform ANDs if necessary. llvm::Value *RHSTmp = RHS; llvm::Value *LHSTmp = LHS; bool wasCast = false; llvm::VectorType *rhsVTy = cast(RHS->getType()); if (rhsVTy->getElementType()->isFloatTy()) { RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); wasCast = true; } llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); if (wasCast) tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); return tmp5; } // 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 (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); llvm::Value *LHS = Visit(lhsExpr); llvm::Value *RHS = Visit(rhsExpr); if (!LHS) { // If the conditional has void type, make sure we return a null Value*. assert(!RHS && "LHS and RHS types must match"); return 0; } 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"); CodeGenFunction::ConditionalEvaluation eval(CGF); CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); CGF.EmitBlock(LHSBlock); eval.begin(CGF); Value *LHS = Visit(lhsExpr); eval.end(CGF); LHSBlock = Builder.GetInsertBlock(); Builder.CreateBr(ContBlock); CGF.EmitBlock(RHSBlock); eval.begin(CGF); Value *RHS = Visit(rhsExpr); eval.end(CGF); RHSBlock = Builder.GetInsertBlock(); 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(), 2, "cond"); 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 *block) { return CGF.EmitBlockLiteral(block); } Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); llvm::Type *DstTy = ConvertType(E->getType()); // Going from vec4->vec3 or vec3->vec4 is a special case and requires // a shuffle vector instead of a bitcast. llvm::Type *SrcTy = Src->getType(); if (isa(DstTy) && isa(SrcTy)) { unsigned numElementsDst = cast(DstTy)->getNumElements(); unsigned numElementsSrc = cast(SrcTy)->getNumElements(); if ((numElementsDst == 3 && numElementsSrc == 4) || (numElementsDst == 4 && numElementsSrc == 3)) { // In the case of going from int4->float3, a bitcast is needed before // doing a shuffle. llvm::Type *srcElemTy = cast(SrcTy)->getElementType(); llvm::Type *dstElemTy = cast(DstTy)->getElementType(); if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { // Create a float type of the same size as the source or destination. llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, numElementsSrc); Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); } llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); SmallVector Args; Args.push_back(Builder.getInt32(0)); Args.push_back(Builder.getInt32(1)); Args.push_back(Builder.getInt32(2)); if (numElementsDst == 4) Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); llvm::Constant *Mask = llvm::ConstantVector::get(Args); return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); } } return Builder.CreateBitCast(Src, DstTy, "astype"); } Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { return CGF.EmitAtomicExpr(E).getScalarVal(); } //===----------------------------------------------------------------------===// // 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"); if (isa(E)) disableDebugInfo(); Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) .Visit(const_cast(E)); if (isa(E)) enableDebugInfo(); return V; } /// 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 llvm::Type *ClassPtrTy = ConvertType(E->getType()); Expr *BaseExpr = E->getBase(); if (BaseExpr->isRValue()) { V = CreateMemTemp(E->getType(), "resval"); llvm::Value *Src = EmitScalarExpr(BaseExpr); Builder.CreateStore(Src, V); V = ScalarExprEmitter(*this).EmitLoadOfLValue( MakeNaturalAlignAddrLValue(V, 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); return MakeNaturalAlignAddrLValue(V, E->getType()); } LValue CodeGenFunction::EmitCompoundAssignmentLValue( const CompoundAssignOperator *E) { ScalarExprEmitter Scalar(*this); Value *Result = 0; switch (E->getOpcode()) { #define COMPOUND_OP(Op) \ case BO_##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 BO_PtrMemD: case BO_PtrMemI: case BO_Mul: case BO_Div: case BO_Rem: case BO_Add: case BO_Sub: case BO_Shl: case BO_Shr: case BO_LT: case BO_GT: case BO_LE: case BO_GE: case BO_EQ: case BO_NE: case BO_And: case BO_Xor: case BO_Or: case BO_LAnd: case BO_LOr: case BO_Assign: case BO_Comma: llvm_unreachable("Not valid compound assignment operators"); } llvm_unreachable("Unhandled compound assignment operator"); }