| //===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// | 
 | // | 
 | //                     The LLVM Compiler Infrastructure | 
 | // | 
 | // This file is distributed under the University of Illinois Open Source | 
 | // License. See LICENSE.TXT for details. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 | // | 
 | // This contains code to emit Expr nodes with scalar LLVM types as LLVM code. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #include "CodeGenFunction.h" | 
 | #include "CodeGenModule.h" | 
 | #include "clang/AST/ASTContext.h" | 
 | #include "clang/AST/DeclObjC.h" | 
 | #include "clang/AST/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/Support/Compiler.h" | 
 | #include <cstdarg> | 
 |  | 
 | using namespace clang; | 
 | using namespace CodeGen; | 
 | using llvm::Value; | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                         Scalar Expression Emitter | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | struct BinOpInfo { | 
 |   Value *LHS; | 
 |   Value *RHS; | 
 |   QualType Ty;  // Computation Type. | 
 |   const BinaryOperator *E; | 
 | }; | 
 |  | 
 | namespace { | 
 | class VISIBILITY_HIDDEN ScalarExprEmitter | 
 |   : public StmtVisitor<ScalarExprEmitter, Value*> { | 
 |   CodeGenFunction &CGF; | 
 |   CGBuilderTy &Builder; | 
 |  | 
 | public: | 
 |  | 
 |   ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf),  | 
 |     Builder(CGF.Builder) { | 
 |   } | 
 |    | 
 |   //===--------------------------------------------------------------------===// | 
 |   //                               Utilities | 
 |   //===--------------------------------------------------------------------===// | 
 |  | 
 |   const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } | 
 |   LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } | 
 |  | 
 |   Value *EmitLoadOfLValue(LValue LV, QualType T) { | 
 |     return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); | 
 |   } | 
 |      | 
 |   /// EmitLoadOfLValue - Given an expression with complex type that represents a | 
 |   /// value l-value, this method emits the address of the l-value, then loads | 
 |   /// and returns the result. | 
 |   Value *EmitLoadOfLValue(const Expr *E) { | 
 |     // FIXME: Volatile | 
 |     return EmitLoadOfLValue(EmitLValue(E), E->getType()); | 
 |   } | 
 |      | 
 |   /// EmitConversionToBool - Convert the specified expression value to a | 
 |   /// boolean (i1) truth value.  This is equivalent to "Val != 0". | 
 |   Value *EmitConversionToBool(Value *Src, QualType DstTy); | 
 |      | 
 |   /// EmitScalarConversion - Emit a conversion from the specified type to the | 
 |   /// specified destination type, both of which are LLVM scalar types. | 
 |   Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); | 
 |  | 
 |   /// EmitComplexToScalarConversion - Emit a conversion from the specified | 
 |   /// complex type to the specified destination type, where the destination | 
 |   /// type is an LLVM scalar type. | 
 |   Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, | 
 |                                        QualType SrcTy, QualType DstTy); | 
 |      | 
 |   //===--------------------------------------------------------------------===// | 
 |   //                            Visitor Methods | 
 |   //===--------------------------------------------------------------------===// | 
 |  | 
 |   Value *VisitStmt(Stmt *S) { | 
 |     S->dump(CGF.getContext().getSourceManager()); | 
 |     assert(0 && "Stmt can't have complex result type!"); | 
 |     return 0; | 
 |   } | 
 |   Value *VisitExpr(Expr *S); | 
 |   Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } | 
 |  | 
 |   // Leaves. | 
 |   Value *VisitIntegerLiteral(const IntegerLiteral *E) { | 
 |     return llvm::ConstantInt::get(E->getValue()); | 
 |   } | 
 |   Value *VisitFloatingLiteral(const FloatingLiteral *E) { | 
 |     return llvm::ConstantFP::get(E->getValue()); | 
 |   } | 
 |   Value *VisitCharacterLiteral(const CharacterLiteral *E) { | 
 |     return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); | 
 |   } | 
 |   Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { | 
 |     return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); | 
 |   } | 
 |   Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { | 
 |     return llvm::Constant::getNullValue(ConvertType(E->getType())); | 
 |   } | 
 |   Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { | 
 |     return llvm::ConstantInt::get(ConvertType(E->getType()), | 
 |                                   CGF.getContext().typesAreCompatible( | 
 |                                     E->getArgType1(), E->getArgType2())); | 
 |   } | 
 |   Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); | 
 |   Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { | 
 |     llvm::Value *V =  | 
 |       llvm::ConstantInt::get(llvm::Type::Int32Ty, | 
 |                              CGF.GetIDForAddrOfLabel(E->getLabel())); | 
 |      | 
 |     return Builder.CreateIntToPtr(V, ConvertType(E->getType())); | 
 |   } | 
 |      | 
 |   // l-values. | 
 |   Value *VisitDeclRefExpr(DeclRefExpr *E) { | 
 |     if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) | 
 |       return llvm::ConstantInt::get(EC->getInitVal()); | 
 |     return EmitLoadOfLValue(E); | 
 |   } | 
 |   Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {  | 
 |     return CGF.EmitObjCSelectorExpr(E);  | 
 |   } | 
 |   Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {  | 
 |     return CGF.EmitObjCProtocolExpr(E);  | 
 |   } | 
 |   Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {  | 
 |     return EmitLoadOfLValue(E); | 
 |   } | 
 |   Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { | 
 |     return EmitLoadOfLValue(E); | 
 |   } | 
 |   Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { | 
 |     return CGF.EmitObjCMessageExpr(E).getScalarVal(); | 
 |   } | 
 |  | 
 |   Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); | 
 |   Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); | 
 |   Value *VisitMemberExpr(Expr *E)           { return EmitLoadOfLValue(E); } | 
 |   Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } | 
 |   Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { | 
 |     return EmitLoadOfLValue(E); | 
 |   } | 
 |   Value *VisitStringLiteral(Expr *E)  { return EmitLValue(E).getAddress(); } | 
 |   Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } | 
 |  | 
 |   Value *VisitInitListExpr(InitListExpr *E) { | 
 |     unsigned NumInitElements = E->getNumInits(); | 
 |      | 
 |     const llvm::VectorType *VType =  | 
 |       dyn_cast<llvm::VectorType>(ConvertType(E->getType())); | 
 |      | 
 |     // We have a scalar in braces. Just use the first element. | 
 |     if (!VType)  | 
 |       return Visit(E->getInit(0)); | 
 |      | 
 |     if (E->hadDesignators()) { | 
 |       CGF.ErrorUnsupported(E, "initializer list with designators"); | 
 |       return llvm::UndefValue::get(CGF.ConvertType(E->getType())); | 
 |     } | 
 |      | 
 |     unsigned NumVectorElements = VType->getNumElements(); | 
 |     const llvm::Type *ElementType = VType->getElementType(); | 
 |  | 
 |     // Emit individual vector element stores. | 
 |     llvm::Value *V = llvm::UndefValue::get(VType); | 
 |      | 
 |     // Emit initializers | 
 |     unsigned i; | 
 |     for (i = 0; i < NumInitElements; ++i) { | 
 |       Value *NewV = Visit(E->getInit(i)); | 
 |       Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); | 
 |       V = Builder.CreateInsertElement(V, NewV, Idx); | 
 |     } | 
 |      | 
 |     // Emit remaining default initializers | 
 |     for (/* Do not initialize i*/; i < NumVectorElements; ++i) { | 
 |       Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); | 
 |       llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); | 
 |       V = Builder.CreateInsertElement(V, NewV, Idx); | 
 |     } | 
 |      | 
 |     return V; | 
 |   } | 
 |    | 
 |   Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); | 
 |   Value *VisitCastExpr(const CastExpr *E) {  | 
 |     return EmitCastExpr(E->getSubExpr(), E->getType()); | 
 |   } | 
 |   Value *EmitCastExpr(const Expr *E, QualType T); | 
 |  | 
 |   Value *VisitCallExpr(const CallExpr *E) { | 
 |     return CGF.EmitCallExpr(E).getScalarVal(); | 
 |   } | 
 |  | 
 |   Value *VisitStmtExpr(const StmtExpr *E); | 
 |    | 
 |   // Unary Operators. | 
 |   Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); | 
 |   Value *VisitUnaryPostDec(const UnaryOperator *E) { | 
 |     return VisitPrePostIncDec(E, false, false); | 
 |   } | 
 |   Value *VisitUnaryPostInc(const UnaryOperator *E) { | 
 |     return VisitPrePostIncDec(E, true, false); | 
 |   } | 
 |   Value *VisitUnaryPreDec(const UnaryOperator *E) { | 
 |     return VisitPrePostIncDec(E, false, true); | 
 |   } | 
 |   Value *VisitUnaryPreInc(const UnaryOperator *E) { | 
 |     return VisitPrePostIncDec(E, true, true); | 
 |   } | 
 |   Value *VisitUnaryAddrOf(const UnaryOperator *E) { | 
 |     return EmitLValue(E->getSubExpr()).getAddress(); | 
 |   } | 
 |   Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } | 
 |   Value *VisitUnaryPlus(const UnaryOperator *E) { | 
 |     return Visit(E->getSubExpr()); | 
 |   } | 
 |   Value *VisitUnaryMinus    (const UnaryOperator *E); | 
 |   Value *VisitUnaryNot      (const UnaryOperator *E); | 
 |   Value *VisitUnaryLNot     (const UnaryOperator *E); | 
 |   Value *VisitUnaryReal     (const UnaryOperator *E); | 
 |   Value *VisitUnaryImag     (const UnaryOperator *E); | 
 |   Value *VisitUnaryExtension(const UnaryOperator *E) { | 
 |     return Visit(E->getSubExpr()); | 
 |   } | 
 |   Value *VisitUnaryOffsetOf(const UnaryOperator *E); | 
 |   Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { | 
 |     return Visit(DAE->getExpr()); | 
 |   } | 
 |      | 
 |   // Binary Operators. | 
 |   Value *EmitMul(const BinOpInfo &Ops) { | 
 |     return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); | 
 |   } | 
 |   Value *EmitDiv(const BinOpInfo &Ops); | 
 |   Value *EmitRem(const BinOpInfo &Ops); | 
 |   Value *EmitAdd(const BinOpInfo &Ops); | 
 |   Value *EmitSub(const BinOpInfo &Ops); | 
 |   Value *EmitShl(const BinOpInfo &Ops); | 
 |   Value *EmitShr(const BinOpInfo &Ops); | 
 |   Value *EmitAnd(const BinOpInfo &Ops) { | 
 |     return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); | 
 |   } | 
 |   Value *EmitXor(const BinOpInfo &Ops) { | 
 |     return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); | 
 |   } | 
 |   Value *EmitOr (const BinOpInfo &Ops) { | 
 |     return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); | 
 |   } | 
 |  | 
 |   BinOpInfo EmitBinOps(const BinaryOperator *E); | 
 |   Value *EmitCompoundAssign(const CompoundAssignOperator *E, | 
 |                             Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); | 
 |  | 
 |   // Binary operators and binary compound assignment operators. | 
 | #define HANDLEBINOP(OP) \ | 
 |   Value *VisitBin ## OP(const BinaryOperator *E) {                         \ | 
 |     return Emit ## OP(EmitBinOps(E));                                      \ | 
 |   }                                                                        \ | 
 |   Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) {       \ | 
 |     return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP);          \ | 
 |   } | 
 |   HANDLEBINOP(Mul); | 
 |   HANDLEBINOP(Div); | 
 |   HANDLEBINOP(Rem); | 
 |   HANDLEBINOP(Add); | 
 |   HANDLEBINOP(Sub); | 
 |   HANDLEBINOP(Shl); | 
 |   HANDLEBINOP(Shr); | 
 |   HANDLEBINOP(And); | 
 |   HANDLEBINOP(Xor); | 
 |   HANDLEBINOP(Or); | 
 | #undef HANDLEBINOP | 
 |  | 
 |   // Comparisons. | 
 |   Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, | 
 |                      unsigned SICmpOpc, unsigned FCmpOpc); | 
 | #define VISITCOMP(CODE, UI, SI, FP) \ | 
 |     Value *VisitBin##CODE(const BinaryOperator *E) { \ | 
 |       return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ | 
 |                          llvm::FCmpInst::FP); } | 
 |   VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); | 
 |   VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); | 
 |   VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); | 
 |   VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); | 
 |   VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); | 
 |   VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); | 
 | #undef VISITCOMP | 
 |    | 
 |   Value *VisitBinAssign     (const BinaryOperator *E); | 
 |  | 
 |   Value *VisitBinLAnd       (const BinaryOperator *E); | 
 |   Value *VisitBinLOr        (const BinaryOperator *E); | 
 |   Value *VisitBinComma      (const BinaryOperator *E); | 
 |  | 
 |   // Other Operators. | 
 |   Value *VisitConditionalOperator(const ConditionalOperator *CO); | 
 |   Value *VisitChooseExpr(ChooseExpr *CE); | 
 |   Value *VisitOverloadExpr(OverloadExpr *OE); | 
 |   Value *VisitVAArgExpr(VAArgExpr *VE); | 
 |   Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { | 
 |     return CGF.EmitObjCStringLiteral(E); | 
 |   } | 
 |   Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E); | 
 | }; | 
 | }  // end anonymous namespace. | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                                Utilities | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | /// EmitConversionToBool - Convert the specified expression value to a | 
 | /// boolean (i1) truth value.  This is equivalent to "Val != 0". | 
 | Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { | 
 |   assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); | 
 |    | 
 |   if (SrcType->isRealFloatingType()) { | 
 |     // Compare against 0.0 for fp scalars. | 
 |     llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); | 
 |     return Builder.CreateFCmpUNE(Src, Zero, "tobool"); | 
 |   } | 
 |    | 
 |   assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && | 
 |          "Unknown scalar type to convert"); | 
 |    | 
 |   // Because of the type rules of C, we often end up computing a logical value, | 
 |   // then zero extending it to int, then wanting it as a logical value again. | 
 |   // Optimize this common case. | 
 |   if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { | 
 |     if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { | 
 |       Value *Result = ZI->getOperand(0); | 
 |       // If there aren't any more uses, zap the instruction to save space. | 
 |       // Note that there can be more uses, for example if this | 
 |       // is the result of an assignment. | 
 |       if (ZI->use_empty()) | 
 |         ZI->eraseFromParent(); | 
 |       return Result; | 
 |     } | 
 |   } | 
 |    | 
 |   // Compare against an integer or pointer null. | 
 |   llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); | 
 |   return Builder.CreateICmpNE(Src, Zero, "tobool"); | 
 | } | 
 |  | 
 | /// EmitScalarConversion - Emit a conversion from the specified type to the | 
 | /// specified destination type, both of which are LLVM scalar types. | 
 | Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, | 
 |                                                QualType DstType) { | 
 |   SrcType = CGF.getContext().getCanonicalType(SrcType); | 
 |   DstType = CGF.getContext().getCanonicalType(DstType); | 
 |   if (SrcType == DstType) return Src; | 
 |    | 
 |   if (DstType->isVoidType()) return 0; | 
 |  | 
 |   // Handle conversions to bool first, they are special: comparisons against 0. | 
 |   if (DstType->isBooleanType()) | 
 |     return EmitConversionToBool(Src, SrcType); | 
 |    | 
 |   const llvm::Type *DstTy = ConvertType(DstType); | 
 |  | 
 |   // Ignore conversions like int -> uint. | 
 |   if (Src->getType() == DstTy) | 
 |     return Src; | 
 |  | 
 |   // Handle pointer conversions next: pointers can only be converted | 
 |   // to/from other pointers and integers. Check for pointer types in | 
 |   // terms of LLVM, as some native types (like Obj-C id) may map to a | 
 |   // pointer type. | 
 |   if (isa<llvm::PointerType>(DstTy)) { | 
 |     // The source value may be an integer, or a pointer. | 
 |     if (isa<llvm::PointerType>(Src->getType())) | 
 |       return Builder.CreateBitCast(Src, DstTy, "conv"); | 
 |     assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); | 
 |     return Builder.CreateIntToPtr(Src, DstTy, "conv"); | 
 |   } | 
 |    | 
 |   if (isa<llvm::PointerType>(Src->getType())) { | 
 |     // Must be an ptr to int cast. | 
 |     assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); | 
 |     return Builder.CreatePtrToInt(Src, DstTy, "conv"); | 
 |   } | 
 |    | 
 |   // A scalar can be splatted to an extended vector of the same element type | 
 |   if (DstType->isExtVectorType() && !isa<VectorType>(SrcType) && | 
 |       cast<llvm::VectorType>(DstTy)->getElementType() == Src->getType()) | 
 |     return CGF.EmitVector(&Src, DstType->getAsVectorType()->getNumElements(),  | 
 |                           true); | 
 |  | 
 |   // Allow bitcast from vector to integer/fp of the same size. | 
 |   if (isa<llvm::VectorType>(Src->getType()) || | 
 |       isa<llvm::VectorType>(DstTy)) | 
 |     return Builder.CreateBitCast(Src, DstTy, "conv"); | 
 |        | 
 |   // Finally, we have the arithmetic types: real int/float. | 
 |   if (isa<llvm::IntegerType>(Src->getType())) { | 
 |     bool InputSigned = SrcType->isSignedIntegerType(); | 
 |     if (isa<llvm::IntegerType>(DstTy)) | 
 |       return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); | 
 |     else if (InputSigned) | 
 |       return Builder.CreateSIToFP(Src, DstTy, "conv"); | 
 |     else | 
 |       return Builder.CreateUIToFP(Src, DstTy, "conv"); | 
 |   } | 
 |    | 
 |   assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); | 
 |   if (isa<llvm::IntegerType>(DstTy)) { | 
 |     if (DstType->isSignedIntegerType()) | 
 |       return Builder.CreateFPToSI(Src, DstTy, "conv"); | 
 |     else | 
 |       return Builder.CreateFPToUI(Src, DstTy, "conv"); | 
 |   } | 
 |  | 
 |   assert(DstTy->isFloatingPoint() && "Unknown real conversion"); | 
 |   if (DstTy->getTypeID() < Src->getType()->getTypeID()) | 
 |     return Builder.CreateFPTrunc(Src, DstTy, "conv"); | 
 |   else | 
 |     return Builder.CreateFPExt(Src, DstTy, "conv"); | 
 | } | 
 |  | 
 | /// EmitComplexToScalarConversion - Emit a conversion from the specified | 
 | /// complex type to the specified destination type, where the destination | 
 | /// type is an LLVM scalar type. | 
 | Value *ScalarExprEmitter:: | 
 | EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, | 
 |                               QualType SrcTy, QualType DstTy) { | 
 |   // Get the source element type. | 
 |   SrcTy = SrcTy->getAsComplexType()->getElementType(); | 
 |    | 
 |   // Handle conversions to bool first, they are special: comparisons against 0. | 
 |   if (DstTy->isBooleanType()) { | 
 |     //  Complex != 0  -> (Real != 0) | (Imag != 0) | 
 |     Src.first  = EmitScalarConversion(Src.first, SrcTy, DstTy); | 
 |     Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); | 
 |     return Builder.CreateOr(Src.first, Src.second, "tobool"); | 
 |   } | 
 |    | 
 |   // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, | 
 |   // the imaginary part of the complex value is discarded and the value of the | 
 |   // real part is converted according to the conversion rules for the | 
 |   // corresponding real type.  | 
 |   return EmitScalarConversion(Src.first, SrcTy, DstTy); | 
 | } | 
 |  | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                            Visitor Methods | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | Value *ScalarExprEmitter::VisitExpr(Expr *E) { | 
 |   CGF.ErrorUnsupported(E, "scalar expression"); | 
 |   if (E->getType()->isVoidType()) | 
 |     return 0; | 
 |   return llvm::UndefValue::get(CGF.ConvertType(E->getType())); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { | 
 |   llvm::SmallVector<llvm::Constant*, 32> indices; | 
 |   for (unsigned i = 2; i < E->getNumSubExprs(); i++) { | 
 |     indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); | 
 |   } | 
 |   Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); | 
 |   Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); | 
 |   Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); | 
 |   return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { | 
 |   // 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()); | 
 |    | 
 |   // FIXME: Convert Idx to i32 type. | 
 |   return Builder.CreateExtractElement(Base, Idx, "vecext"); | 
 | } | 
 |  | 
 | /// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but | 
 | /// also handle things like function to pointer-to-function decay, and array to | 
 | /// pointer decay. | 
 | Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { | 
 |   const Expr *Op = E->getSubExpr(); | 
 |    | 
 |   // If this is due to array->pointer conversion, emit the array expression as | 
 |   // an l-value. | 
 |   if (Op->getType()->isArrayType()) { | 
 |     // FIXME: For now we assume that all source arrays map to LLVM arrays.  This | 
 |     // will not true when we add support for VLAs. | 
 |     Value *V = EmitLValue(Op).getAddress();  // Bitfields can't be arrays. | 
 |      | 
 |     if (!(isa<llvm::PointerType>(V->getType()) && | 
 |           isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) | 
 |                                ->getElementType()))) { | 
 |       CGF.ErrorUnsupported(E, "variable-length array cast", true); | 
 |       if (E->getType()->isVoidType()) | 
 |         return 0; | 
 |       return llvm::UndefValue::get(CGF.ConvertType(E->getType())); | 
 |     } | 
 |     V = Builder.CreateStructGEP(V, 0, "arraydecay"); | 
 |      | 
 |     // The resultant pointer type can be implicitly casted to other pointer | 
 |     // types as well (e.g. void*) and can be implicitly converted to integer. | 
 |     const llvm::Type *DestTy = ConvertType(E->getType()); | 
 |     if (V->getType() != DestTy) { | 
 |       if (isa<llvm::PointerType>(DestTy)) | 
 |         V = Builder.CreateBitCast(V, DestTy, "ptrconv"); | 
 |       else { | 
 |         assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); | 
 |         V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); | 
 |       } | 
 |     } | 
 |     return V; | 
 |      | 
 |   } else if (E->getType()->isReferenceType()) { | 
 |     return EmitLValue(Op).getAddress(); | 
 |   } | 
 |    | 
 |   return EmitCastExpr(Op, E->getType()); | 
 | } | 
 |  | 
 |  | 
 | // VisitCastExpr - Emit code for an explicit or implicit cast.  Implicit casts | 
 | // have to handle a more broad range of conversions than explicit casts, as they | 
 | // handle things like function to ptr-to-function decay etc. | 
 | Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { | 
 |   // Handle cases where the source is an non-complex type. | 
 |    | 
 |   if (!CGF.hasAggregateLLVMType(E->getType())) { | 
 |     Value *Src = Visit(const_cast<Expr*>(E)); | 
 |  | 
 |     // Use EmitScalarConversion to perform the conversion. | 
 |     return EmitScalarConversion(Src, E->getType(), DestTy); | 
 |   } | 
 |    | 
 |   if (E->getType()->isAnyComplexType()) { | 
 |     // Handle cases where the source is a complex type. | 
 |     return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(), | 
 |                                          DestTy); | 
 |   } | 
 |  | 
 |   // Okay, this is a cast from an aggregate.  It must be a cast to void.  Just | 
 |   // evaluate the result and return. | 
 |   CGF.EmitAggExpr(E, 0, false); | 
 |   return 0; | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { | 
 |   return CGF.EmitCompoundStmt(*E->getSubStmt(), | 
 |                               !E->getType()->isVoidType()).getScalarVal(); | 
 | } | 
 |  | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                             Unary Operators | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, | 
 |                                              bool isInc, bool isPre) { | 
 |   LValue LV = EmitLValue(E->getSubExpr()); | 
 |   // FIXME: Handle volatile! | 
 |   Value *InVal = CGF.EmitLoadOfLValue(LV, // false | 
 |                                      E->getSubExpr()->getType()).getScalarVal(); | 
 |    | 
 |   int AmountVal = isInc ? 1 : -1; | 
 |    | 
 |   Value *NextVal; | 
 |   if (isa<llvm::PointerType>(InVal->getType())) { | 
 |     // FIXME: This isn't right for VLAs. | 
 |     NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); | 
 |     NextVal = Builder.CreateGEP(InVal, NextVal, "ptrincdec"); | 
 |   } else { | 
 |     // Add the inc/dec to the real part. | 
 |     if (isa<llvm::IntegerType>(InVal->getType())) | 
 |       NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); | 
 |     else if (InVal->getType() == llvm::Type::FloatTy) | 
 |       NextVal =  | 
 |         llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); | 
 |     else if (InVal->getType() == llvm::Type::DoubleTy) | 
 |       NextVal =  | 
 |         llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); | 
 |     else { | 
 |       llvm::APFloat F(static_cast<float>(AmountVal)); | 
 |       bool ignored; | 
 |       F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, | 
 |                 &ignored); | 
 |       NextVal = llvm::ConstantFP::get(F); | 
 |     } | 
 |     NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); | 
 |   } | 
 |    | 
 |   // Store the updated result through the lvalue. | 
 |   CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV,  | 
 |                              E->getSubExpr()->getType()); | 
 |  | 
 |   // If this is a postinc, return the value read from memory, otherwise use the | 
 |   // updated value. | 
 |   return isPre ? NextVal : InVal; | 
 | } | 
 |  | 
 |  | 
 | Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { | 
 |   Value *Op = Visit(E->getSubExpr()); | 
 |   return Builder.CreateNeg(Op, "neg"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { | 
 |   Value *Op = Visit(E->getSubExpr()); | 
 |   return Builder.CreateNot(Op, "neg"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { | 
 |   // Compare operand to zero. | 
 |   Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); | 
 |    | 
 |   // Invert value. | 
 |   // TODO: Could dynamically modify easy computations here.  For example, if | 
 |   // the operand is an icmp ne, turn into icmp eq. | 
 |   BoolVal = Builder.CreateNot(BoolVal, "lnot"); | 
 |    | 
 |   // ZExt result to int. | 
 |   return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext"); | 
 | } | 
 |  | 
 | /// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of | 
 | /// argument of the sizeof expression as an integer. | 
 | Value * | 
 | ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { | 
 |   QualType RetType = E->getType(); | 
 |   assert(RetType->isIntegerType() && "Result type must be an integer!"); | 
 |   uint32_t ResultWidth =  | 
 |     static_cast<uint32_t>(CGF.getContext().getTypeSize(RetType)); | 
 |  | 
 |   QualType TypeToSize = E->getTypeOfArgument(); | 
 |   // sizeof(void) and __alignof__(void) = 1 as a gcc extension. Also | 
 |   // for function types. | 
 |   // FIXME: what is alignof a function type in gcc? | 
 |   if (TypeToSize->isVoidType() || TypeToSize->isFunctionType()) | 
 |     return llvm::ConstantInt::get(llvm::APInt(ResultWidth, 1)); | 
 |    | 
 |   /// FIXME: This doesn't handle VLAs yet! | 
 |   std::pair<uint64_t, unsigned> Info = CGF.getContext().getTypeInfo(TypeToSize); | 
 |    | 
 |   uint64_t Val = E->isSizeOf() ? Info.first : Info.second; | 
 |   Val /= 8;  // Return size in bytes, not bits. | 
 |    | 
 |   return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { | 
 |   Expr *Op = E->getSubExpr(); | 
 |   if (Op->getType()->isAnyComplexType()) | 
 |     return CGF.EmitComplexExpr(Op).first; | 
 |   return Visit(Op); | 
 | } | 
 | Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { | 
 |   Expr *Op = E->getSubExpr(); | 
 |   if (Op->getType()->isAnyComplexType()) | 
 |     return CGF.EmitComplexExpr(Op).second; | 
 |    | 
 |   // __imag on a scalar returns zero.  Emit it the subexpr to ensure side | 
 |   // effects are evaluated. | 
 |   CGF.EmitScalarExpr(Op); | 
 |   return llvm::Constant::getNullValue(ConvertType(E->getType())); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) | 
 | { | 
 |   int64_t Val = E->evaluateOffsetOf(CGF.getContext()); | 
 |    | 
 |   assert(E->getType()->isIntegerType() && "Result type must be an integer!"); | 
 |    | 
 |   uint32_t ResultWidth = | 
 |     static_cast<uint32_t>(CGF.getContext().getTypeSize(E->getType())); | 
 |   return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); | 
 | } | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                           Binary Operators | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { | 
 |   BinOpInfo Result; | 
 |   Result.LHS = Visit(E->getLHS()); | 
 |   Result.RHS = Visit(E->getRHS()); | 
 |   Result.Ty  = E->getType(); | 
 |   Result.E = E; | 
 |   return Result; | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, | 
 |                       Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { | 
 |   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); | 
 |  | 
 |   BinOpInfo OpInfo; | 
 |  | 
 |   // Load the LHS and RHS operands. | 
 |   LValue LHSLV = EmitLValue(E->getLHS()); | 
 |   OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); | 
 |  | 
 |   // Determine the computation type.  If the RHS is complex, then this is one of | 
 |   // the add/sub/mul/div operators.  All of these operators can be computed in | 
 |   // with just their real component even though the computation domain really is | 
 |   // complex. | 
 |   QualType ComputeType = E->getComputationType(); | 
 |    | 
 |   // If the computation type is complex, then the RHS is complex.  Emit the RHS. | 
 |   if (const ComplexType *CT = ComputeType->getAsComplexType()) { | 
 |     ComputeType = CT->getElementType(); | 
 |      | 
 |     // Emit the RHS, only keeping the real component. | 
 |     OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first; | 
 |     RHSTy = RHSTy->getAsComplexType()->getElementType(); | 
 |   } else { | 
 |     // Otherwise the RHS is a simple scalar value. | 
 |     OpInfo.RHS = Visit(E->getRHS()); | 
 |   } | 
 |    | 
 |   QualType LComputeTy, RComputeTy, ResultTy; | 
 |  | 
 |   // Compound assignment does not contain enough information about all | 
 |   // the types involved for pointer arithmetic cases. Figure it out | 
 |   // here for now. | 
 |   if (E->getLHS()->getType()->isPointerType()) { | 
 |     // Pointer arithmetic cases: ptr +=,-= int and ptr -= ptr,  | 
 |     assert((E->getOpcode() == BinaryOperator::AddAssign || | 
 |             E->getOpcode() == BinaryOperator::SubAssign) && | 
 |            "Invalid compound assignment operator on pointer type."); | 
 |     LComputeTy = E->getLHS()->getType(); | 
 |      | 
 |     if (E->getRHS()->getType()->isPointerType()) {     | 
 |       // Degenerate case of (ptr -= ptr) allowed by GCC implicit cast | 
 |       // extension, the conversion from the pointer difference back to | 
 |       // the LHS type is handled at the end. | 
 |       assert(E->getOpcode() == BinaryOperator::SubAssign && | 
 |              "Invalid compound assignment operator on pointer type."); | 
 |       RComputeTy = E->getLHS()->getType(); | 
 |       ResultTy = CGF.getContext().getPointerDiffType(); | 
 |     } else { | 
 |       RComputeTy = E->getRHS()->getType(); | 
 |       ResultTy = LComputeTy; | 
 |     } | 
 |   } else if (E->getRHS()->getType()->isPointerType()) { | 
 |     // Degenerate case of (int += ptr) allowed by GCC implicit cast | 
 |     // extension. | 
 |     assert(E->getOpcode() == BinaryOperator::AddAssign && | 
 |            "Invalid compound assignment operator on pointer type."); | 
 |     LComputeTy = E->getLHS()->getType(); | 
 |     RComputeTy = E->getRHS()->getType(); | 
 |     ResultTy = RComputeTy; | 
 |   } else { | 
 |     LComputeTy = RComputeTy = ResultTy = ComputeType; | 
 |   } | 
 |  | 
 |   // Convert the LHS/RHS values to the computation type. | 
 |   OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, LComputeTy); | 
 |   OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, RComputeTy); | 
 |   OpInfo.Ty = ResultTy; | 
 |   OpInfo.E = E; | 
 |    | 
 |   // Expand the binary operator. | 
 |   Value *Result = (this->*Func)(OpInfo); | 
 |    | 
 |   // Convert the result back to the LHS type. | 
 |   Result = EmitScalarConversion(Result, ResultTy, LHSTy); | 
 |    | 
 |   // Store the result value into the LHS lvalue. | 
 |   CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); | 
 |  | 
 |   // For bitfields, we need the value in the bitfield. Note that | 
 |   // property references do not reload their value (even though the | 
 |   // setter may have changed it). | 
 |   // FIXME: This adds an extra bitfield load | 
 |   if (LHSLV.isBitfield()) | 
 |     Result = EmitLoadOfLValue(LHSLV, LHSTy); | 
 |   return Result; | 
 | } | 
 |  | 
 |  | 
 | Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { | 
 |   if (Ops.LHS->getType()->isFPOrFPVector()) | 
 |     return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); | 
 |   else if (Ops.Ty->isUnsignedIntegerType()) | 
 |     return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); | 
 |   else | 
 |     return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { | 
 |   // Rem in C can't be a floating point type: C99 6.5.5p2. | 
 |   if (Ops.Ty->isUnsignedIntegerType()) | 
 |     return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); | 
 |   else | 
 |     return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); | 
 | } | 
 |  | 
 |  | 
 | Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { | 
 |   if (!Ops.Ty->isPointerType()) | 
 |     return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); | 
 |    | 
 |   // FIXME: What about a pointer to a VLA? | 
 |   Value *Ptr, *Idx; | 
 |   Expr *IdxExp; | 
 |   if (isa<llvm::PointerType>(Ops.LHS->getType())) {  // pointer + int | 
 |     Ptr = Ops.LHS; | 
 |     Idx = Ops.RHS; | 
 |     IdxExp = Ops.E->getRHS(); | 
 |   } else {                                           // int + pointer | 
 |     Ptr = Ops.RHS; | 
 |     Idx = Ops.LHS; | 
 |     IdxExp = Ops.E->getLHS(); | 
 |   } | 
 |  | 
 |   unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); | 
 |   if (Width < CGF.LLVMPointerWidth) { | 
 |     // Zero or sign extend the pointer value based on whether the index is | 
 |     // signed or not. | 
 |     const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); | 
 |     if (IdxExp->getType()->isSignedIntegerType()) | 
 |       Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); | 
 |     else | 
 |       Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); | 
 |   } | 
 |    | 
 |   return Builder.CreateGEP(Ptr, Idx, "add.ptr"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { | 
 |   if (!isa<llvm::PointerType>(Ops.LHS->getType())) | 
 |     return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); | 
 |  | 
 |   if (!isa<llvm::PointerType>(Ops.RHS->getType())) { | 
 |     // pointer - int | 
 |     Value *Idx = Ops.RHS; | 
 |     unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); | 
 |     if (Width < CGF.LLVMPointerWidth) { | 
 |       // Zero or sign extend the pointer value based on whether the index is | 
 |       // signed or not. | 
 |       const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); | 
 |       if (Ops.E->getRHS()->getType()->isSignedIntegerType()) | 
 |         Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); | 
 |       else | 
 |         Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); | 
 |     } | 
 |     Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); | 
 |      | 
 |     // FIXME: The pointer could point to a VLA. | 
 |     // The GNU void* - int case is automatically handled here because | 
 |     // our LLVM type for void* is i8*. | 
 |     return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); | 
 |   } else { | 
 |     // pointer - pointer | 
 |     Value *LHS = Ops.LHS; | 
 |     Value *RHS = Ops.RHS; | 
 |    | 
 |     const QualType LHSType = Ops.E->getLHS()->getType(); | 
 |     const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); | 
 |     uint64_t ElementSize; | 
 |  | 
 |     // Handle GCC extension for pointer arithmetic on void* types. | 
 |     if (LHSElementType->isVoidType()) { | 
 |       ElementSize = 1; | 
 |     } else { | 
 |       ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; | 
 |     } | 
 |      | 
 |     const llvm::Type *ResultType = ConvertType(Ops.Ty); | 
 |     LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); | 
 |     RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); | 
 |     Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); | 
 |      | 
 |     // HACK: LLVM doesn't have an divide instruction that 'knows' there is no | 
 |     // remainder.  As such, we handle common power-of-two cases here to generate | 
 |     // better code. See PR2247. | 
 |     if (llvm::isPowerOf2_64(ElementSize)) { | 
 |       Value *ShAmt = | 
 |         llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); | 
 |       return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); | 
 |     } | 
 |      | 
 |     // Otherwise, do a full sdiv. | 
 |     Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); | 
 |     return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); | 
 |   } | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { | 
 |   // LLVM requires the LHS and RHS to be the same type: promote or truncate the | 
 |   // RHS to the same size as the LHS. | 
 |   Value *RHS = Ops.RHS; | 
 |   if (Ops.LHS->getType() != RHS->getType()) | 
 |     RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); | 
 |    | 
 |   return Builder.CreateShl(Ops.LHS, RHS, "shl"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { | 
 |   // LLVM requires the LHS and RHS to be the same type: promote or truncate the | 
 |   // RHS to the same size as the LHS. | 
 |   Value *RHS = Ops.RHS; | 
 |   if (Ops.LHS->getType() != RHS->getType()) | 
 |     RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); | 
 |    | 
 |   if (Ops.Ty->isUnsignedIntegerType()) | 
 |     return Builder.CreateLShr(Ops.LHS, RHS, "shr"); | 
 |   return Builder.CreateAShr(Ops.LHS, RHS, "shr"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, | 
 |                                       unsigned SICmpOpc, unsigned FCmpOpc) { | 
 |   Value *Result; | 
 |   QualType LHSTy = E->getLHS()->getType(); | 
 |   if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { | 
 |     Value *LHS = Visit(E->getLHS()); | 
 |     Value *RHS = Visit(E->getRHS()); | 
 |      | 
 |     if (LHS->getType()->isFloatingPoint()) { | 
 |       Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } else if (LHSTy->isSignedIntegerType()) { | 
 |       Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } else { | 
 |       // Unsigned integers and pointers. | 
 |       Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } | 
 |   } else if (LHSTy->isVectorType()) { | 
 |     Value *LHS = Visit(E->getLHS()); | 
 |     Value *RHS = Visit(E->getRHS()); | 
 |      | 
 |     if (LHS->getType()->isFPOrFPVector()) { | 
 |       Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } else if (LHSTy->isUnsignedIntegerType()) { | 
 |       Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } else { | 
 |       // Signed integers and pointers. | 
 |       Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, | 
 |                                   LHS, RHS, "cmp"); | 
 |     } | 
 |     return Result; | 
 |   } else { | 
 |     // Complex Comparison: can only be an equality comparison. | 
 |     CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); | 
 |     CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); | 
 |      | 
 |     QualType CETy = LHSTy->getAsComplexType()->getElementType(); | 
 |      | 
 |     Value *ResultR, *ResultI; | 
 |     if (CETy->isRealFloatingType()) { | 
 |       ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, | 
 |                                    LHS.first, RHS.first, "cmp.r"); | 
 |       ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, | 
 |                                    LHS.second, RHS.second, "cmp.i"); | 
 |     } else { | 
 |       // Complex comparisons can only be equality comparisons.  As such, signed | 
 |       // and unsigned opcodes are the same. | 
 |       ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, | 
 |                                    LHS.first, RHS.first, "cmp.r"); | 
 |       ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, | 
 |                                    LHS.second, RHS.second, "cmp.i"); | 
 |     } | 
 |      | 
 |     if (E->getOpcode() == BinaryOperator::EQ) { | 
 |       Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); | 
 |     } else { | 
 |       assert(E->getOpcode() == BinaryOperator::NE && | 
 |              "Complex comparison other than == or != ?"); | 
 |       Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); | 
 |     } | 
 |   } | 
 |    | 
 |   // ZExt result to int. | 
 |   return Builder.CreateZExt(Result, CGF.LLVMIntTy, "cmp.ext"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { | 
 |   LValue LHS = EmitLValue(E->getLHS()); | 
 |   Value *RHS = Visit(E->getRHS()); | 
 |    | 
 |   // Store the value into the LHS. | 
 |   // FIXME: Volatility! | 
 |   CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); | 
 |  | 
 |   // For bitfields, we need the value in the bitfield. Note that | 
 |   // property references do not reload their value (even though the | 
 |   // setter may have changed it). | 
 |   // FIXME: This adds an extra bitfield load | 
 |   if (LHS.isBitfield()) | 
 |     return EmitLoadOfLValue(LHS, E->getLHS()->getType()); | 
 |  | 
 |   // Return the RHS. | 
 |   return RHS; | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { | 
 |   Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); | 
 |    | 
 |   if (llvm::ConstantInt *LHSCst = dyn_cast<llvm::ConstantInt>(LHSCond)) { | 
 |     // If we have 0 && RHS, see if we can elide RHS, if so, just return LHSCond. | 
 |     if (LHSCst->getZExtValue() == 0) { | 
 |       if (!CGF.ContainsLabel(E->getRHS())) | 
 |         // Elide RHS, return 0 | 
 |         return llvm::Constant::getNullValue(CGF.LLVMIntTy); | 
 |     } else { | 
 |       // If we have 1 && X, just emit X without inserting the control flow. | 
 |       Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); | 
 |       // ZExt result to int. | 
 |       return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); | 
 |     } | 
 |   } | 
 |    | 
 |   llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("land_cont"); | 
 |   llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("land_rhs"); | 
 |    | 
 |   llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); | 
 |   Builder.CreateCondBr(LHSCond, RHSBlock, ContBlock); | 
 |    | 
 |   CGF.EmitBlock(RHSBlock); | 
 |   Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); | 
 |    | 
 |   // Reaquire the RHS block, as there may be subblocks inserted. | 
 |   RHSBlock = Builder.GetInsertBlock(); | 
 |   CGF.EmitBlock(ContBlock); | 
 |    | 
 |   // Create a PHI node.  If we just evaluted the LHS condition, the result is | 
 |   // false.  If we evaluated both, the result is the RHS condition. | 
 |   llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "land"); | 
 |   PN->reserveOperandSpace(2); | 
 |   PN->addIncoming(llvm::ConstantInt::getFalse(), OrigBlock); | 
 |   PN->addIncoming(RHSCond, RHSBlock); | 
 |    | 
 |   // ZExt result to int. | 
 |   return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { | 
 |   Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); | 
 |    | 
 |   if (llvm::ConstantInt *LHSCst = dyn_cast<llvm::ConstantInt>(LHSCond)) { | 
 |     // If we have 1 || RHS, see if we can elide RHS, if so, just return LHSCond. | 
 |     if (LHSCst->getZExtValue() != 0) { | 
 |       if (!CGF.ContainsLabel(E->getRHS())) | 
 |         // Elide RHS, return 1 | 
 |         return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); | 
 |     } else { | 
 |       // If we have 0 || X, just emit X without inserting the control flow. | 
 |       Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); | 
 |       // ZExt result to int. | 
 |       return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); | 
 |     } | 
 |   } | 
 |    | 
 |   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor_cont"); | 
 |   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor_rhs"); | 
 |    | 
 |   llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); | 
 |   Builder.CreateCondBr(LHSCond, ContBlock, RHSBlock); | 
 |    | 
 |   CGF.EmitBlock(RHSBlock); | 
 |   Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); | 
 |    | 
 |   // Reaquire the RHS block, as there may be subblocks inserted. | 
 |   RHSBlock = Builder.GetInsertBlock(); | 
 |   CGF.EmitBlock(ContBlock); | 
 |    | 
 |   // Create a PHI node.  If we just evaluted the LHS condition, the result is | 
 |   // true.  If we evaluated both, the result is the RHS condition. | 
 |   llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "lor"); | 
 |   PN->reserveOperandSpace(2); | 
 |   PN->addIncoming(llvm::ConstantInt::getTrue(), OrigBlock); | 
 |   PN->addIncoming(RHSCond, RHSBlock); | 
 |    | 
 |   // ZExt result to int. | 
 |   return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { | 
 |   CGF.EmitStmt(E->getLHS()); | 
 |   return Visit(E->getRHS()); | 
 | } | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                             Other Operators | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | Value *ScalarExprEmitter:: | 
 | VisitConditionalOperator(const ConditionalOperator *E) { | 
 |   // Evaluate the conditional, then convert it to bool.  We do this explicitly | 
 |   // because we need the unconverted value if this is a GNU ?: expression with | 
 |   // missing middle value. | 
 |   Value *CondVal = CGF.EmitScalarExpr(E->getCond()); | 
 |  | 
 |   // If the condition folded to a constant, try to elide the dead side.  We | 
 |   // can't do this if the dead side contains a label. | 
 |   if (llvm::ConstantInt *CondCI = dyn_cast<llvm::ConstantInt>(CondVal)) { | 
 |     Expr *Live = E->getLHS(), *Dead = E->getRHS(); | 
 |     if (CondCI->getZExtValue() == 0) | 
 |       std::swap(Live, Dead); | 
 |     if (!Dead || !CGF.ContainsLabel(Dead)) { | 
 |       // Emit the live side. | 
 |       if (Live) | 
 |         return Visit(Live); | 
 |       // Perform promotions, to handle cases like "short ?: int" | 
 |       return EmitScalarConversion(CondVal, E->getCond()->getType(), | 
 |                                   E->getType()); | 
 |     }    | 
 |   } | 
 |    | 
 |   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.?"); | 
 |   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.:"); | 
 |   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.cont"); | 
 |    | 
 |   Value *CondBoolVal =CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), | 
 |                                                CGF.getContext().BoolTy); | 
 |   Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); | 
 |    | 
 |   CGF.EmitBlock(LHSBlock); | 
 |    | 
 |   // Handle the GNU extension for missing LHS. | 
 |   Value *LHS; | 
 |   if (E->getLHS()) | 
 |     LHS = Visit(E->getLHS()); | 
 |   else    // Perform promotions, to handle cases like "short ?: int" | 
 |     LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); | 
 |    | 
 |   LHSBlock = Builder.GetInsertBlock(); | 
 |   CGF.EmitBranch(ContBlock); | 
 |    | 
 |   CGF.EmitBlock(RHSBlock); | 
 |    | 
 |   Value *RHS = Visit(E->getRHS()); | 
 |   RHSBlock = Builder.GetInsertBlock(); | 
 |   CGF.EmitBranch(ContBlock); | 
 |    | 
 |   CGF.EmitBlock(ContBlock); | 
 |    | 
 |   if (!LHS || !RHS) { | 
 |     assert(E->getType()->isVoidType() && "Non-void value should have a value"); | 
 |     return 0; | 
 |   } | 
 |    | 
 |   // Create a PHI node for the real part. | 
 |   llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); | 
 |   PN->reserveOperandSpace(2); | 
 |   PN->addIncoming(LHS, LHSBlock); | 
 |   PN->addIncoming(RHS, RHSBlock); | 
 |   return PN; | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { | 
 |   // Emit the LHS or RHS as appropriate. | 
 |   return | 
 |     Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitOverloadExpr(OverloadExpr *E) { | 
 |   return CGF.EmitCallExpr(E->getFn(), E->arg_begin(), | 
 |                           E->arg_end(CGF.getContext())).getScalarVal(); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { | 
 |   llvm::Value *ArgValue = EmitLValue(VE->getSubExpr()).getAddress(); | 
 |  | 
 |   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: volatile? | 
 |   return Builder.CreateLoad(ArgPtr); | 
 | } | 
 |  | 
 | Value *ScalarExprEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { | 
 |   std::string str; | 
 |   CGF.getContext().getObjCEncodingForType(E->getEncodedType(), str); | 
 |    | 
 |   llvm::Constant *C = llvm::ConstantArray::get(str); | 
 |   C = new llvm::GlobalVariable(C->getType(), true,  | 
 |                                llvm::GlobalValue::InternalLinkage, | 
 |                                C, ".str", &CGF.CGM.getModule()); | 
 |   llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); | 
 |   llvm::Constant *Zeros[] = { Zero, Zero }; | 
 |   C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2); | 
 |    | 
 |   return C; | 
 | } | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //                         Entry Point into this File | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | /// EmitComplexExpr - Emit the computation of the specified expression of | 
 | /// complex type, ignoring the result. | 
 | Value *CodeGenFunction::EmitScalarExpr(const Expr *E) { | 
 |   assert(E && !hasAggregateLLVMType(E->getType()) && | 
 |          "Invalid scalar expression to emit"); | 
 |    | 
 |   return ScalarExprEmitter(*this).Visit(const_cast<Expr*>(E)); | 
 | } | 
 |  | 
 | /// EmitScalarConversion - Emit a conversion from the specified type to the | 
 | /// specified destination type, both of which are LLVM scalar types. | 
 | Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, | 
 |                                              QualType DstTy) { | 
 |   assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && | 
 |          "Invalid scalar expression to emit"); | 
 |   return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); | 
 | } | 
 |  | 
 | /// EmitComplexToScalarConversion - Emit a conversion from the specified | 
 | /// complex type to the specified destination type, where the destination | 
 | /// type is an LLVM scalar type. | 
 | Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, | 
 |                                                       QualType SrcTy, | 
 |                                                       QualType DstTy) { | 
 |   assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && | 
 |          "Invalid complex -> scalar conversion"); | 
 |   return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, | 
 |                                                                 DstTy); | 
 | } | 
 |  | 
 | Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { | 
 |   assert(V1->getType() == V2->getType() && | 
 |          "Vector operands must be of the same type"); | 
 |   unsigned NumElements =  | 
 |     cast<llvm::VectorType>(V1->getType())->getNumElements(); | 
 |    | 
 |   va_list va; | 
 |   va_start(va, V2); | 
 |    | 
 |   llvm::SmallVector<llvm::Constant*, 16> Args; | 
 |   for (unsigned i = 0; i < NumElements; i++) { | 
 |     int n = va_arg(va, int); | 
 |     assert(n >= 0 && n < (int)NumElements * 2 &&  | 
 |            "Vector shuffle index out of bounds!"); | 
 |     Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); | 
 |   } | 
 |    | 
 |   const char *Name = va_arg(va, const char *); | 
 |   va_end(va); | 
 |    | 
 |   llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); | 
 |    | 
 |   return Builder.CreateShuffleVector(V1, V2, Mask, Name); | 
 | } | 
 |  | 
 | llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals,  | 
 |                                          unsigned NumVals, bool isSplat) { | 
 |   llvm::Value *Vec | 
 |     = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); | 
 |    | 
 |   for (unsigned i = 0, e = NumVals; i != e; ++i) { | 
 |     llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; | 
 |     llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); | 
 |     Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); | 
 |   } | 
 |    | 
 |   return Vec;   | 
 | } |