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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp | 2006 |
1 files changed, 2006 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp new file mode 100644 index 0000000..2108414 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp @@ -0,0 +1,2006 @@ +//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +#include "CGObjCRuntime.h" +#include "CodeGenModule.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/RecordLayout.h" +#include "clang/AST/StmtVisitor.h" +#include "clang/Basic/TargetInfo.h" +#include "llvm/Constants.h" +#include "llvm/Function.h" +#include "llvm/GlobalVariable.h" +#include "llvm/Intrinsics.h" +#include "llvm/Module.h" +#include "llvm/Support/CFG.h" +#include "llvm/Target/TargetData.h" +#include <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 ScalarExprEmitter + : public StmtVisitor<ScalarExprEmitter, Value*> { + CodeGenFunction &CGF; + CGBuilderTy &Builder; + bool IgnoreResultAssign; + llvm::LLVMContext &VMContext; +public: + + ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) + : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), + VMContext(cgf.getLLVMContext()) { + } + + //===--------------------------------------------------------------------===// + // Utilities + //===--------------------------------------------------------------------===// + + bool TestAndClearIgnoreResultAssign() { + bool I = IgnoreResultAssign; + IgnoreResultAssign = false; + return I; + } + + const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } + LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } + LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } + + Value *EmitLoadOfLValue(LValue LV, QualType T) { + return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); + } + + /// EmitLoadOfLValue - Given an expression with complex type that represents a + /// value l-value, this method emits the address of the l-value, then loads + /// and returns the result. + Value *EmitLoadOfLValue(const Expr *E) { + return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); + } + + /// EmitConversionToBool - Convert the specified expression value to a + /// boolean (i1) truth value. This is equivalent to "Val != 0". + Value *EmitConversionToBool(Value *Src, QualType DstTy); + + /// EmitScalarConversion - Emit a conversion from the specified type to the + /// specified destination type, both of which are LLVM scalar types. + Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); + + /// EmitComplexToScalarConversion - Emit a conversion from the specified + /// complex type to the specified destination type, where the destination type + /// is an LLVM scalar type. + Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, + QualType SrcTy, QualType DstTy); + + /// EmitNullValue - Emit a value that corresponds to null for the given type. + Value *EmitNullValue(QualType Ty); + + //===--------------------------------------------------------------------===// + // Visitor Methods + //===--------------------------------------------------------------------===// + + Value *VisitStmt(Stmt *S) { + S->dump(CGF.getContext().getSourceManager()); + assert(0 && "Stmt can't have complex result type!"); + return 0; + } + Value *VisitExpr(Expr *S); + + Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } + + // Leaves. + Value *VisitIntegerLiteral(const IntegerLiteral *E) { + return llvm::ConstantInt::get(VMContext, E->getValue()); + } + Value *VisitFloatingLiteral(const FloatingLiteral *E) { + return llvm::ConstantFP::get(VMContext, E->getValue()); + } + Value *VisitCharacterLiteral(const CharacterLiteral *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); + } + Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); + } + Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { + return EmitNullValue(E->getType()); + } + Value *VisitGNUNullExpr(const GNUNullExpr *E) { + return EmitNullValue(E->getType()); + } + Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), + CGF.getContext().typesAreCompatible( + E->getArgType1(), E->getArgType2())); + } + Value *VisitOffsetOfExpr(const OffsetOfExpr *E); + Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); + Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { + llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); + return Builder.CreateBitCast(V, ConvertType(E->getType())); + } + + // l-values. + Value *VisitDeclRefExpr(DeclRefExpr *E) { + Expr::EvalResult Result; + if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { + assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); + return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); + } + return EmitLoadOfLValue(E); + } + Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { + return CGF.EmitObjCSelectorExpr(E); + } + Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { + return CGF.EmitObjCProtocolExpr(E); + } + Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCImplicitSetterGetterRefExpr( + ObjCImplicitSetterGetterRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { + return CGF.EmitObjCMessageExpr(E).getScalarVal(); + } + + Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { + LValue LV = CGF.EmitObjCIsaExpr(E); + Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); + return V; + } + + Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); + Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); + Value *VisitMemberExpr(MemberExpr *E); + Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { + return EmitLoadOfLValue(E); + } + + Value *VisitInitListExpr(InitListExpr *E); + + Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { + return CGF.CGM.EmitNullConstant(E->getType()); + } + Value *VisitCastExpr(CastExpr *E) { + // Make sure to evaluate VLA bounds now so that we have them for later. + if (E->getType()->isVariablyModifiedType()) + CGF.EmitVLASize(E->getType()); + + return EmitCastExpr(E); + } + Value *EmitCastExpr(CastExpr *E); + + Value *VisitCallExpr(const CallExpr *E) { + if (E->getCallReturnType()->isReferenceType()) + return EmitLoadOfLValue(E); + + return CGF.EmitCallExpr(E).getScalarVal(); + } + + Value *VisitStmtExpr(const StmtExpr *E); + + Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); + + // Unary Operators. + Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) { + LValue LV = EmitLValue(E->getSubExpr()); + return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre); + } + Value *VisitUnaryPostDec(const UnaryOperator *E) { + return VisitPrePostIncDec(E, false, false); + } + Value *VisitUnaryPostInc(const UnaryOperator *E) { + return VisitPrePostIncDec(E, true, false); + } + Value *VisitUnaryPreDec(const UnaryOperator *E) { + return VisitPrePostIncDec(E, false, true); + } + Value *VisitUnaryPreInc(const UnaryOperator *E) { + return VisitPrePostIncDec(E, true, true); + } + Value *VisitUnaryAddrOf(const UnaryOperator *E) { + return EmitLValue(E->getSubExpr()).getAddress(); + } + Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitUnaryPlus(const UnaryOperator *E) { + // This differs from gcc, though, most likely due to a bug in gcc. + TestAndClearIgnoreResultAssign(); + return Visit(E->getSubExpr()); + } + Value *VisitUnaryMinus (const UnaryOperator *E); + Value *VisitUnaryNot (const UnaryOperator *E); + Value *VisitUnaryLNot (const UnaryOperator *E); + Value *VisitUnaryReal (const UnaryOperator *E); + Value *VisitUnaryImag (const UnaryOperator *E); + Value *VisitUnaryExtension(const UnaryOperator *E) { + return Visit(E->getSubExpr()); + } + Value *VisitUnaryOffsetOf(const UnaryOperator *E); + + // C++ + Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { + return Visit(DAE->getExpr()); + } + Value *VisitCXXThisExpr(CXXThisExpr *TE) { + return CGF.LoadCXXThis(); + } + + Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { + return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); + } + Value *VisitCXXNewExpr(const CXXNewExpr *E) { + return CGF.EmitCXXNewExpr(E); + } + Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { + CGF.EmitCXXDeleteExpr(E); + return 0; + } + Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { + return llvm::ConstantInt::get(Builder.getInt1Ty(), + E->EvaluateTrait(CGF.getContext())); + } + + Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { + // C++ [expr.pseudo]p1: + // The result shall only be used as the operand for the function call + // operator (), and the result of such a call has type void. The only + // effect is the evaluation of the postfix-expression before the dot or + // arrow. + CGF.EmitScalarExpr(E->getBase()); + return 0; + } + + Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { + return EmitNullValue(E->getType()); + } + + Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { + CGF.EmitCXXThrowExpr(E); + return 0; + } + + // Binary Operators. + Value *EmitMul(const BinOpInfo &Ops) { + if (CGF.getContext().getLangOptions().OverflowChecking + && Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + if (Ops.LHS->getType()->isFPOrFPVectorTy()) + return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); + return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); + } + /// Create a binary op that checks for overflow. + /// Currently only supports +, - and *. + Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); + Value *EmitDiv(const BinOpInfo &Ops); + Value *EmitRem(const BinOpInfo &Ops); + Value *EmitAdd(const BinOpInfo &Ops); + Value *EmitSub(const BinOpInfo &Ops); + Value *EmitShl(const BinOpInfo &Ops); + Value *EmitShr(const BinOpInfo &Ops); + Value *EmitAnd(const BinOpInfo &Ops) { + return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); + } + Value *EmitXor(const BinOpInfo &Ops) { + return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); + } + Value *EmitOr (const BinOpInfo &Ops) { + return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); + } + + BinOpInfo EmitBinOps(const BinaryOperator *E); + LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*F)(const BinOpInfo &), + Value *&BitFieldResult); + + Value *EmitCompoundAssign(const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); + + // Binary operators and binary compound assignment operators. +#define HANDLEBINOP(OP) \ + Value *VisitBin ## OP(const BinaryOperator *E) { \ + return Emit ## OP(EmitBinOps(E)); \ + } \ + Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ + return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ + } + HANDLEBINOP(Mul) + HANDLEBINOP(Div) + HANDLEBINOP(Rem) + HANDLEBINOP(Add) + HANDLEBINOP(Sub) + HANDLEBINOP(Shl) + HANDLEBINOP(Shr) + HANDLEBINOP(And) + HANDLEBINOP(Xor) + HANDLEBINOP(Or) +#undef HANDLEBINOP + + // Comparisons. + Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, + unsigned SICmpOpc, unsigned FCmpOpc); +#define VISITCOMP(CODE, UI, SI, FP) \ + Value *VisitBin##CODE(const BinaryOperator *E) { \ + return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ + llvm::FCmpInst::FP); } + VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) + VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) + VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) + VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) + VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) + VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) +#undef VISITCOMP + + Value *VisitBinAssign (const BinaryOperator *E); + + Value *VisitBinLAnd (const BinaryOperator *E); + Value *VisitBinLOr (const BinaryOperator *E); + Value *VisitBinComma (const BinaryOperator *E); + + Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } + + // Other Operators. + Value *VisitBlockExpr(const BlockExpr *BE); + Value *VisitConditionalOperator(const ConditionalOperator *CO); + Value *VisitChooseExpr(ChooseExpr *CE); + Value *VisitVAArgExpr(VAArgExpr *VE); + Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { + return CGF.EmitObjCStringLiteral(E); + } +}; +} // end anonymous namespace. + +//===----------------------------------------------------------------------===// +// Utilities +//===----------------------------------------------------------------------===// + +/// EmitConversionToBool - Convert the specified expression value to a +/// boolean (i1) truth value. This is equivalent to "Val != 0". +Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { + assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); + + if (SrcType->isRealFloatingType()) { + // Compare against 0.0 for fp scalars. + llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); + return Builder.CreateFCmpUNE(Src, Zero, "tobool"); + } + + if (SrcType->isMemberPointerType()) { + // Compare against -1. + llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); + return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); + } + + assert((SrcType->isIntegerType() || isa<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::getInt1Ty(CGF.getLLVMContext())) { + Value *Result = ZI->getOperand(0); + // If there aren't any more uses, zap the instruction to save space. + // Note that there can be more uses, for example if this + // is the result of an assignment. + if (ZI->use_empty()) + ZI->eraseFromParent(); + return Result; + } + } + + // Compare against an integer or pointer null. + llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); + return Builder.CreateICmpNE(Src, Zero, "tobool"); +} + +/// EmitScalarConversion - Emit a conversion from the specified type to the +/// specified destination type, both of which are LLVM scalar types. +Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, + QualType DstType) { + SrcType = CGF.getContext().getCanonicalType(SrcType); + DstType = CGF.getContext().getCanonicalType(DstType); + if (SrcType == DstType) return Src; + + if (DstType->isVoidType()) return 0; + + llvm::LLVMContext &VMContext = CGF.getLLVMContext(); + + // 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?"); + // First, convert to the correct width so that we control the kind of + // extension. + const llvm::Type *MiddleTy = + llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); + bool InputSigned = SrcType->isSignedIntegerType(); + llvm::Value* IntResult = + Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); + // Then, cast to pointer. + return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); + } + + if (isa<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() && !SrcType->isVectorType()) { + // Cast the scalar to element type + QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); + llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); + + // Insert the element in element zero of an undef vector + llvm::Value *UnV = llvm::UndefValue::get(DstTy); + llvm::Value *Idx = + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); + UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); + + // Splat the element across to all elements + llvm::SmallVector<llvm::Constant*, 16> Args; + unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); + for (unsigned i = 0; i < NumElements; i++) + Args.push_back(llvm::ConstantInt::get( + llvm::Type::getInt32Ty(VMContext), 0)); + + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); + llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); + return Yay; + } + + // Allow bitcast from vector to integer/fp of the same size. + if (isa<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()->isFloatingPointTy() && "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->isFloatingPointTy() && "Unknown real conversion"); + if (DstTy->getTypeID() < Src->getType()->getTypeID()) + return Builder.CreateFPTrunc(Src, DstTy, "conv"); + else + return Builder.CreateFPExt(Src, DstTy, "conv"); +} + +/// EmitComplexToScalarConversion - Emit a conversion from the specified complex +/// type to the specified destination type, where the destination type is an +/// LLVM scalar type. +Value *ScalarExprEmitter:: +EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, + QualType SrcTy, QualType DstTy) { + // Get the source element type. + SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); + + // Handle conversions to bool first, they are special: comparisons against 0. + if (DstTy->isBooleanType()) { + // Complex != 0 -> (Real != 0) | (Imag != 0) + Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); + Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); + return Builder.CreateOr(Src.first, Src.second, "tobool"); + } + + // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, + // the imaginary part of the complex value is discarded and the value of the + // real part is converted according to the conversion rules for the + // corresponding real type. + return EmitScalarConversion(Src.first, SrcTy, DstTy); +} + +Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { + const llvm::Type *LTy = ConvertType(Ty); + + if (!Ty->isMemberPointerType()) + return llvm::Constant::getNullValue(LTy); + + assert(!Ty->isMemberFunctionPointerType() && + "member function pointers are not scalar!"); + + // Itanium C++ ABI 2.3: + // A NULL pointer is represented as -1. + return llvm::ConstantInt::get(LTy, -1ULL, /*isSigned=*/true); +} + +//===----------------------------------------------------------------------===// +// Visitor Methods +//===----------------------------------------------------------------------===// + +Value *ScalarExprEmitter::VisitExpr(Expr *E) { + CGF.ErrorUnsupported(E, "scalar expression"); + if (E->getType()->isVoidType()) + return 0; + return llvm::UndefValue::get(CGF.ConvertType(E->getType())); +} + +Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { + 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::VisitMemberExpr(MemberExpr *E) { + Expr::EvalResult Result; + if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { + if (E->isArrow()) + CGF.EmitScalarExpr(E->getBase()); + else + EmitLValue(E->getBase()); + return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); + } + return EmitLoadOfLValue(E); +} + +Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { + TestAndClearIgnoreResultAssign(); + + // Emit subscript expressions in rvalue context's. For most cases, this just + // loads the lvalue formed by the subscript expr. However, we have to be + // careful, because the base of a vector subscript is occasionally an rvalue, + // so we can't get it as an lvalue. + if (!E->getBase()->getType()->isVectorType()) + return EmitLoadOfLValue(E); + + // Handle the vector case. The base must be a vector, the index must be an + // integer value. + Value *Base = Visit(E->getBase()); + Value *Idx = Visit(E->getIdx()); + bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); + Idx = Builder.CreateIntCast(Idx, + llvm::Type::getInt32Ty(CGF.getLLVMContext()), + IdxSigned, + "vecidxcast"); + return Builder.CreateExtractElement(Base, Idx, "vecext"); +} + +static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, + unsigned Off, const llvm::Type *I32Ty) { + int MV = SVI->getMaskValue(Idx); + if (MV == -1) + return llvm::UndefValue::get(I32Ty); + return llvm::ConstantInt::get(I32Ty, Off+MV); +} + +Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { + bool Ignore = TestAndClearIgnoreResultAssign(); + (void)Ignore; + assert (Ignore == false && "init list ignored"); + unsigned NumInitElements = E->getNumInits(); + + if (E->hadArrayRangeDesignator()) + CGF.ErrorUnsupported(E, "GNU array range designator extension"); + + const llvm::VectorType *VType = + dyn_cast<llvm::VectorType>(ConvertType(E->getType())); + + // We have a scalar in braces. Just use the first element. + if (!VType) + return Visit(E->getInit(0)); + + unsigned ResElts = VType->getNumElements(); + const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); + + // Loop over initializers collecting the Value for each, and remembering + // whether the source was swizzle (ExtVectorElementExpr). This will allow + // us to fold the shuffle for the swizzle into the shuffle for the vector + // initializer, since LLVM optimizers generally do not want to touch + // shuffles. + unsigned CurIdx = 0; + bool VIsUndefShuffle = false; + llvm::Value *V = llvm::UndefValue::get(VType); + for (unsigned i = 0; i != NumInitElements; ++i) { + Expr *IE = E->getInit(i); + Value *Init = Visit(IE); + llvm::SmallVector<llvm::Constant*, 16> Args; + + const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(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<ExtVectorElementExpr>(IE)) { + llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); + + if (EI->getVectorOperandType()->getNumElements() == ResElts) { + llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); + Value *LHS = 0, *RHS = 0; + if (CurIdx == 0) { + // insert into undef -> shuffle (src, undef) + Args.push_back(C); + for (unsigned j = 1; j != ResElts; ++j) + Args.push_back(llvm::UndefValue::get(I32Ty)); + + LHS = EI->getVectorOperand(); + RHS = V; + VIsUndefShuffle = true; + } else if (VIsUndefShuffle) { + // insert into undefshuffle && size match -> shuffle (v, src) + llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); + for (unsigned j = 0; j != CurIdx; ++j) + Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); + Args.push_back(llvm::ConstantInt::get(I32Ty, + ResElts + C->getZExtValue())); + for (unsigned j = CurIdx + 1; j != ResElts; ++j) + Args.push_back(llvm::UndefValue::get(I32Ty)); + + LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); + RHS = EI->getVectorOperand(); + VIsUndefShuffle = false; + } + if (!Args.empty()) { + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); + V = Builder.CreateShuffleVector(LHS, RHS, Mask); + ++CurIdx; + continue; + } + } + } + Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); + V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); + VIsUndefShuffle = false; + ++CurIdx; + continue; + } + + unsigned InitElts = VVT->getNumElements(); + + // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's + // input is the same width as the vector being constructed, generate an + // optimized shuffle of the swizzle input into the result. + unsigned Offset = (CurIdx == 0) ? 0 : ResElts; + if (isa<ExtVectorElementExpr>(IE)) { + llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); + Value *SVOp = SVI->getOperand(0); + const llvm::VectorType *OpTy = cast<llvm::VectorType>(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<llvm::ShuffleVectorInst>(V), j, 0, + I32Ty)); + } else { + Args.push_back(llvm::ConstantInt::get(I32Ty, j)); + } + } + for (unsigned j = 0, je = InitElts; j != je; ++j) + Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); + for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) + Args.push_back(llvm::UndefValue::get(I32Ty)); + + if (VIsUndefShuffle) + V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); + + Init = SVOp; + } + } + + // Extend init to result vector length, and then shuffle its contribution + // to the vector initializer into V. + if (Args.empty()) { + for (unsigned j = 0; j != InitElts; ++j) + Args.push_back(llvm::ConstantInt::get(I32Ty, j)); + for (unsigned j = InitElts; j != ResElts; ++j) + Args.push_back(llvm::UndefValue::get(I32Ty)); + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); + Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), + Mask, "vext"); + + Args.clear(); + for (unsigned j = 0; j != CurIdx; ++j) + Args.push_back(llvm::ConstantInt::get(I32Ty, j)); + for (unsigned j = 0; j != InitElts; ++j) + Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); + for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) + Args.push_back(llvm::UndefValue::get(I32Ty)); + } + + // If V is undef, make sure it ends up on the RHS of the shuffle to aid + // merging subsequent shuffles into this one. + if (CurIdx == 0) + std::swap(V, Init); + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); + V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); + VIsUndefShuffle = isa<llvm::UndefValue>(Init); + CurIdx += InitElts; + } + + // FIXME: evaluate codegen vs. shuffling against constant null vector. + // Emit remaining default initializers. + const llvm::Type *EltTy = VType->getElementType(); + + // Emit remaining default initializers + for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { + Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); + llvm::Value *Init = llvm::Constant::getNullValue(EltTy); + V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); + } + return V; +} + +static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { + const Expr *E = CE->getSubExpr(); + + if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) + return false; + + if (isa<CXXThisExpr>(E)) { + // We always assume that 'this' is never null. + return false; + } + + if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { + // And that lvalue casts are never null. + if (ICE->isLvalueCast()) + return false; + } + + return true; +} + +// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts +// have to handle a more broad range of conversions than explicit casts, as they +// handle things like function to ptr-to-function decay etc. +Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { + Expr *E = CE->getSubExpr(); + QualType DestTy = CE->getType(); + CastExpr::CastKind Kind = CE->getCastKind(); + + if (!DestTy->isVoidType()) + TestAndClearIgnoreResultAssign(); + + // Since almost all cast kinds apply to scalars, this switch doesn't have + // a default case, so the compiler will warn on a missing case. The cases + // are in the same order as in the CastKind enum. + switch (Kind) { + case CastExpr::CK_Unknown: + // FIXME: All casts should have a known kind! + //assert(0 && "Unknown cast kind!"); + break; + + case CastExpr::CK_AnyPointerToObjCPointerCast: + case CastExpr::CK_AnyPointerToBlockPointerCast: + case CastExpr::CK_BitCast: { + Value *Src = Visit(const_cast<Expr*>(E)); + return Builder.CreateBitCast(Src, ConvertType(DestTy)); + } + case CastExpr::CK_NoOp: + case CastExpr::CK_UserDefinedConversion: + return Visit(const_cast<Expr*>(E)); + + case CastExpr::CK_BaseToDerived: { + const CXXRecordDecl *DerivedClassDecl = + DestTy->getCXXRecordDeclForPointerType(); + + return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, + CE->getBasePath(), + ShouldNullCheckClassCastValue(CE)); + } + case CastExpr::CK_UncheckedDerivedToBase: + case CastExpr::CK_DerivedToBase: { + const RecordType *DerivedClassTy = + E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); + CXXRecordDecl *DerivedClassDecl = + cast<CXXRecordDecl>(DerivedClassTy->getDecl()); + + return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, + CE->getBasePath(), + ShouldNullCheckClassCastValue(CE)); + } + case CastExpr::CK_Dynamic: { + Value *V = Visit(const_cast<Expr*>(E)); + const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); + return CGF.EmitDynamicCast(V, DCE); + } + case CastExpr::CK_ToUnion: + assert(0 && "Should be unreachable!"); + break; + + case CastExpr::CK_ArrayToPointerDecay: { + assert(E->getType()->isArrayType() && + "Array to pointer decay must have array source type!"); + + Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. + + // Note that VLA pointers are always decayed, so we don't need to do + // anything here. + if (!E->getType()->isVariableArrayType()) { + assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); + assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) + ->getElementType()) && + "Expected pointer to array"); + V = Builder.CreateStructGEP(V, 0, "arraydecay"); + } + + return V; + } + case CastExpr::CK_FunctionToPointerDecay: + return EmitLValue(E).getAddress(); + + case CastExpr::CK_NullToMemberPointer: + return CGF.CGM.EmitNullConstant(DestTy); + + case CastExpr::CK_BaseToDerivedMemberPointer: + case CastExpr::CK_DerivedToBaseMemberPointer: { + Value *Src = Visit(E); + + // See if we need to adjust the pointer. + const CXXRecordDecl *BaseDecl = + cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> + getClass()->getAs<RecordType>()->getDecl()); + const CXXRecordDecl *DerivedDecl = + cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> + getClass()->getAs<RecordType>()->getDecl()); + if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) + std::swap(DerivedDecl, BaseDecl); + + if (llvm::Constant *Adj = + CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, + CE->getBasePath())) { + if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) + Src = Builder.CreateSub(Src, Adj, "adj"); + else + Src = Builder.CreateAdd(Src, Adj, "adj"); + } + return Src; + } + + case CastExpr::CK_ConstructorConversion: + assert(0 && "Should be unreachable!"); + break; + + case CastExpr::CK_IntegralToPointer: { + Value *Src = Visit(const_cast<Expr*>(E)); + + // First, convert to the correct width so that we control the kind of + // extension. + const llvm::Type *MiddleTy = + llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); + bool InputSigned = E->getType()->isSignedIntegerType(); + llvm::Value* IntResult = + Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); + + return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); + } + case CastExpr::CK_PointerToIntegral: { + Value *Src = Visit(const_cast<Expr*>(E)); + return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); + } + case CastExpr::CK_ToVoid: { + CGF.EmitAnyExpr(E, 0, false, true); + return 0; + } + case CastExpr::CK_VectorSplat: { + const llvm::Type *DstTy = ConvertType(DestTy); + Value *Elt = Visit(const_cast<Expr*>(E)); + + // Insert the element in element zero of an undef vector + llvm::Value *UnV = llvm::UndefValue::get(DstTy); + llvm::Value *Idx = + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); + UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); + + // Splat the element across to all elements + llvm::SmallVector<llvm::Constant*, 16> Args; + unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); + for (unsigned i = 0; i < NumElements; i++) + Args.push_back(llvm::ConstantInt::get( + llvm::Type::getInt32Ty(VMContext), 0)); + + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); + llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); + return Yay; + } + case CastExpr::CK_IntegralCast: + case CastExpr::CK_IntegralToFloating: + case CastExpr::CK_FloatingToIntegral: + case CastExpr::CK_FloatingCast: + return EmitScalarConversion(Visit(E), E->getType(), DestTy); + + case CastExpr::CK_MemberPointerToBoolean: + return CGF.EvaluateExprAsBool(E); + } + + // Handle cases where the source is an non-complex type. + + if (!CGF.hasAggregateLLVMType(E->getType())) { + Value *Src = Visit(const_cast<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. + bool IgnoreImag = true; + bool IgnoreImagAssign = true; + bool IgnoreReal = IgnoreResultAssign; + bool IgnoreRealAssign = IgnoreResultAssign; + if (DestTy->isBooleanType()) + IgnoreImagAssign = IgnoreImag = false; + else if (DestTy->isVoidType()) { + IgnoreReal = IgnoreImag = false; + IgnoreRealAssign = IgnoreImagAssign = true; + } + CodeGenFunction::ComplexPairTy V + = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, + IgnoreImagAssign); + return EmitComplexToScalarConversion(V, E->getType(), DestTy); + } + + // Okay, this is a cast from an aggregate. It must be a cast to void. Just + // evaluate the result and return. + CGF.EmitAggExpr(E, 0, false, true); + return 0; +} + +Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { + return CGF.EmitCompoundStmt(*E->getSubStmt(), + !E->getType()->isVoidType()).getScalarVal(); +} + +Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { + llvm::Value *V = CGF.GetAddrOfBlockDecl(E); + if (E->getType().isObjCGCWeak()) + return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); + return Builder.CreateLoad(V, "tmp"); +} + +//===----------------------------------------------------------------------===// +// Unary Operators +//===----------------------------------------------------------------------===// + +Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { + TestAndClearIgnoreResultAssign(); + Value *Op = Visit(E->getSubExpr()); + if (Op->getType()->isFPOrFPVectorTy()) + return Builder.CreateFNeg(Op, "neg"); + return Builder.CreateNeg(Op, "neg"); +} + +Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { + TestAndClearIgnoreResultAssign(); + Value *Op = Visit(E->getSubExpr()); + return Builder.CreateNot(Op, "neg"); +} + +Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { + // Compare operand to zero. + Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); + + // Invert value. + // TODO: Could dynamically modify easy computations here. For example, if + // the operand is an icmp ne, turn into icmp eq. + BoolVal = Builder.CreateNot(BoolVal, "lnot"); + + // ZExt result to the expr type. + return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); +} + +Value *ScalarExprEmitter::VisitOffsetOfExpr(const OffsetOfExpr *E) { + Expr::EvalResult Result; + if(E->Evaluate(Result, CGF.getContext())) + return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); + + // FIXME: Cannot support code generation for non-constant offsetof. + unsigned DiagID = CGF.CGM.getDiags().getCustomDiagID(Diagnostic::Error, + "cannot compile non-constant __builtin_offsetof"); + CGF.CGM.getDiags().Report(CGF.getContext().getFullLoc(E->getLocStart()), + DiagID) + << E->getSourceRange(); + + return llvm::Constant::getNullValue(ConvertType(E->getType())); +} + +/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of +/// argument of the sizeof expression as an integer. +Value * +ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { + QualType TypeToSize = E->getTypeOfArgument(); + if (E->isSizeOf()) { + if (const VariableArrayType *VAT = + CGF.getContext().getAsVariableArrayType(TypeToSize)) { + if (E->isArgumentType()) { + // sizeof(type) - make sure to emit the VLA size. + CGF.EmitVLASize(TypeToSize); + } else { + // C99 6.5.3.4p2: If the argument is an expression of type + // VLA, it is evaluated. + CGF.EmitAnyExpr(E->getArgumentExpr()); + } + + return CGF.GetVLASize(VAT); + } + } + + // If this isn't sizeof(vla), the result must be constant; use the constant + // folding logic so we don't have to duplicate it here. + Expr::EvalResult Result; + E->Evaluate(Result, CGF.getContext()); + return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); +} + +Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { + Expr *Op = E->getSubExpr(); + if (Op->getType()->isAnyComplexType()) + return CGF.EmitComplexExpr(Op, false, true, false, true).first; + return Visit(Op); +} +Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { + Expr *Op = E->getSubExpr(); + if (Op->getType()->isAnyComplexType()) + return CGF.EmitComplexExpr(Op, true, false, true, false).second; + + // __imag on a scalar returns zero. Emit the subexpr to ensure side + // effects are evaluated, but not the actual value. + if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) + CGF.EmitLValue(Op); + else + CGF.EmitScalarExpr(Op, true); + return llvm::Constant::getNullValue(ConvertType(E->getType())); +} + +Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { + Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); + const llvm::Type* ResultType = ConvertType(E->getType()); + return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); +} + +//===----------------------------------------------------------------------===// +// Binary Operators +//===----------------------------------------------------------------------===// + +BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { + TestAndClearIgnoreResultAssign(); + BinOpInfo Result; + Result.LHS = Visit(E->getLHS()); + Result.RHS = Visit(E->getRHS()); + Result.Ty = E->getType(); + Result.E = E; + return Result; +} + +LValue ScalarExprEmitter::EmitCompoundAssignLValue( + const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), + Value *&BitFieldResult) { + QualType LHSTy = E->getLHS()->getType(); + BitFieldResult = 0; + 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"); + 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.E = E; + // Load/convert the LHS. + LValue LHSLV = EmitCheckedLValue(E->getLHS()); + OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); + OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, + E->getComputationLHSType()); + + // Expand the binary operator. + Value *Result = (this->*Func)(OpInfo); + + // Convert the result back to the LHS type. + Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); + + // Store the result value into the LHS lvalue. Bit-fields are handled + // specially because the result is altered by the store, i.e., [C99 6.5.16p1] + // 'An assignment expression has the value of the left operand after the + // assignment...'. + if (LHSLV.isBitField()) { + if (!LHSLV.isVolatileQualified()) { + CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, + &Result); + BitFieldResult = Result; + return LHSLV; + } else + CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); + } else + CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); + return LHSLV; +} + +Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { + bool Ignore = TestAndClearIgnoreResultAssign(); + Value *BitFieldResult; + LValue LHSLV = EmitCompoundAssignLValue(E, Func, BitFieldResult); + if (BitFieldResult) + return BitFieldResult; + + if (Ignore) + return 0; + return EmitLoadOfLValue(LHSLV, E->getType()); +} + + +Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { + if (Ops.LHS->getType()->isFPOrFPVectorTy()) + return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); + else if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); + else + return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); +} + +Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { + // Rem in C can't be a floating point type: C99 6.5.5p2. + if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); + else + return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); +} + +Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { + unsigned IID; + unsigned OpID = 0; + + switch (Ops.E->getOpcode()) { + case BinaryOperator::Add: + case BinaryOperator::AddAssign: + OpID = 1; + IID = llvm::Intrinsic::sadd_with_overflow; + break; + case BinaryOperator::Sub: + case BinaryOperator::SubAssign: + OpID = 2; + IID = llvm::Intrinsic::ssub_with_overflow; + break; + case BinaryOperator::Mul: + case BinaryOperator::MulAssign: + OpID = 3; + IID = llvm::Intrinsic::smul_with_overflow; + break; + default: + assert(false && "Unsupported operation for overflow detection"); + IID = 0; + } + OpID <<= 1; + OpID |= 1; + + const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); + + llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); + + Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); + Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); + Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); + + // Branch in case of overflow. + llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); + llvm::BasicBlock *overflowBB = + CGF.createBasicBlock("overflow", CGF.CurFn); + llvm::BasicBlock *continueBB = + CGF.createBasicBlock("overflow.continue", CGF.CurFn); + + Builder.CreateCondBr(overflow, overflowBB, continueBB); + + // Handle overflow + + Builder.SetInsertPoint(overflowBB); + + // Handler is: + // long long *__overflow_handler)(long long a, long long b, char op, + // char width) + std::vector<const llvm::Type*> handerArgTypes; + handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); + handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); + handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); + handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); + llvm::FunctionType *handlerTy = llvm::FunctionType::get( + llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); + llvm::Value *handlerFunction = + CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", + llvm::PointerType::getUnqual(handlerTy)); + handlerFunction = Builder.CreateLoad(handlerFunction); + + llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, + Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), + Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), + llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), + llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), + cast<llvm::IntegerType>(opTy)->getBitWidth())); + + handlerResult = Builder.CreateTrunc(handlerResult, opTy); + + Builder.CreateBr(continueBB); + + // Set up the continuation + Builder.SetInsertPoint(continueBB); + // Get the correct result + llvm::PHINode *phi = Builder.CreatePHI(opTy); + phi->reserveOperandSpace(2); + phi->addIncoming(result, initialBB); + phi->addIncoming(handlerResult, overflowBB); + + return phi; +} + +Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { + if (!Ops.Ty->isAnyPointerType()) { + if (CGF.getContext().getLangOptions().OverflowChecking && + Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + + if (Ops.LHS->getType()->isFPOrFPVectorTy()) + return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); + + // Signed integer overflow is undefined behavior. + if (Ops.Ty->isSignedIntegerType()) + return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); + + return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); + } + + if (Ops.Ty->isPointerType() && + Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { + // The amount of the addition needs to account for the VLA size + CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); + } + Value *Ptr, *Idx; + Expr *IdxExp; + const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); + const ObjCObjectPointerType *OPT = + Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); + if (PT || OPT) { + Ptr = Ops.LHS; + Idx = Ops.RHS; + IdxExp = Ops.E->getRHS(); + } else { // int + pointer + PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); + OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); + assert((PT || OPT) && "Invalid add expr"); + 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(VMContext, CGF.LLVMPointerWidth); + if (IdxExp->getType()->isSignedIntegerType()) + Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); + else + Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); + } + const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); + // Handle interface types, which are not represented with a concrete type. + if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { + llvm::Value *InterfaceSize = + llvm::ConstantInt::get(Idx->getType(), + CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); + Idx = Builder.CreateMul(Idx, InterfaceSize); + const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); + Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); + Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ptr->getType()); + } + + // Explicitly handle GNU void* and function pointer arithmetic extensions. The + // GNU void* casts amount to no-ops since our void* type is i8*, but this is + // future proof. + if (ElementType->isVoidType() || ElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); + Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); + Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ptr->getType()); + } + + return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); +} + +Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { + if (!isa<llvm::PointerType>(Ops.LHS->getType())) { + if (CGF.getContext().getLangOptions().OverflowChecking + && Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + + if (Ops.LHS->getType()->isFPOrFPVectorTy()) + return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); + + // Signed integer overflow is undefined behavior. + if (Ops.Ty->isSignedIntegerType()) + return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); + + return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); + } + + if (Ops.E->getLHS()->getType()->isPointerType() && + Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { + // The amount of the addition needs to account for the VLA size for + // ptr-int + // The amount of the division needs to account for the VLA size for + // ptr-ptr. + CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); + } + + const QualType LHSType = Ops.E->getLHS()->getType(); + const QualType LHSElementType = LHSType->getPointeeType(); + 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(VMContext, CGF.LLVMPointerWidth); + if (Ops.E->getRHS()->getType()->isSignedIntegerType()) + Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); + else + Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); + } + Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); + + // Handle interface types, which are not represented with a concrete type. + if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { + llvm::Value *InterfaceSize = + llvm::ConstantInt::get(Idx->getType(), + CGF.getContext(). + getTypeSizeInChars(OIT).getQuantity()); + Idx = Builder.CreateMul(Idx, InterfaceSize); + const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); + Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); + Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ops.LHS->getType()); + } + + // Explicitly handle GNU void* and function pointer arithmetic + // extensions. The GNU void* casts amount to no-ops since our void* type is + // i8*, but this is future proof. + if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); + Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); + Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); + return Builder.CreateBitCast(Res, Ops.LHS->getType()); + } + + return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); + } else { + // pointer - pointer + Value *LHS = Ops.LHS; + Value *RHS = Ops.RHS; + + CharUnits ElementSize; + + // Handle GCC extension for pointer arithmetic on void* and function pointer + // types. + if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { + ElementSize = CharUnits::One(); + } else { + ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); + } + + const llvm::Type *ResultType = ConvertType(Ops.Ty); + LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); + RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); + Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); + + // Optimize out the shift for element size of 1. + if (ElementSize.isOne()) + return BytesBetween; + + // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since + // pointer difference in C is only defined in the case where both operands + // are pointing to elements of an array. + Value *BytesPerElt = + llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); + return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); + } +} + +Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { + // LLVM requires the LHS and RHS to be the same type: promote or truncate the + // RHS to the same size as the LHS. + Value *RHS = Ops.RHS; + if (Ops.LHS->getType() != RHS->getType()) + RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); + + if (CGF.CatchUndefined + && isa<llvm::IntegerType>(Ops.LHS->getType())) { + unsigned Width = cast<llvm::IntegerType>(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<llvm::IntegerType>(Ops.LHS->getType())) { + unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); + llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); + CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, + llvm::ConstantInt::get(RHS->getType(), Width)), + Cont, CGF.getTrapBB()); + CGF.EmitBlock(Cont); + } + + if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateLShr(Ops.LHS, RHS, "shr"); + return Builder.CreateAShr(Ops.LHS, RHS, "shr"); +} + +Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, + unsigned SICmpOpc, unsigned FCmpOpc) { + TestAndClearIgnoreResultAssign(); + Value *Result; + QualType LHSTy = E->getLHS()->getType(); + if (LHSTy->isMemberFunctionPointerType()) { + Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); + Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); + llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); + LHSFunc = Builder.CreateLoad(LHSFunc); + llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); + RHSFunc = Builder.CreateLoad(RHSFunc); + Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHSFunc, RHSFunc, "cmp.func"); + Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); + Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHSFunc, NullPtr, "cmp.null"); + llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); + LHSAdj = Builder.CreateLoad(LHSAdj); + llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); + RHSAdj = Builder.CreateLoad(RHSAdj); + Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHSAdj, RHSAdj, "cmp.adj"); + if (E->getOpcode() == BinaryOperator::EQ) { + Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); + Result = Builder.CreateAnd(Result, ResultF, "and.f"); + } else { + assert(E->getOpcode() == BinaryOperator::NE && + "Member pointer comparison other than == or != ?"); + Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); + Result = Builder.CreateOr(Result, ResultF, "or.f"); + } + } else if (!LHSTy->isAnyComplexType()) { + Value *LHS = Visit(E->getLHS()); + Value *RHS = Visit(E->getRHS()); + + if (LHS->getType()->isFPOrFPVectorTy()) { + Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, + LHS, RHS, "cmp"); + } else if (LHSTy->isSignedIntegerType()) { + Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, + LHS, RHS, "cmp"); + } else { + // Unsigned integers and pointers. + Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS, RHS, "cmp"); + } + + // If this is a vector comparison, sign extend the result to the appropriate + // vector integer type and return it (don't convert to bool). + if (LHSTy->isVectorType()) + return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); + + } else { + // Complex Comparison: can only be an equality comparison. + CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); + CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); + + QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); + + Value *ResultR, *ResultI; + if (CETy->isRealFloatingType()) { + ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, + LHS.first, RHS.first, "cmp.r"); + ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, + LHS.second, RHS.second, "cmp.i"); + } else { + // Complex comparisons can only be equality comparisons. As such, signed + // and unsigned opcodes are the same. + ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS.first, RHS.first, "cmp.r"); + ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS.second, RHS.second, "cmp.i"); + } + + if (E->getOpcode() == BinaryOperator::EQ) { + Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); + } else { + assert(E->getOpcode() == BinaryOperator::NE && + "Complex comparison other than == or != ?"); + Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); + } + } + + return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); +} + +Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { + bool Ignore = TestAndClearIgnoreResultAssign(); + + // __block variables need to have the rhs evaluated first, plus this should + // improve codegen just a little. + Value *RHS = Visit(E->getRHS()); + LValue LHS = EmitCheckedLValue(E->getLHS()); + + // Store the value into the LHS. Bit-fields are handled specially + // because the result is altered by the store, i.e., [C99 6.5.16p1] + // 'An assignment expression has the value of the left operand after + // the assignment...'. + if (LHS.isBitField()) { + if (!LHS.isVolatileQualified()) { + CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), + &RHS); + return RHS; + } else + CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); + } else + CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); + if (Ignore) + return 0; + return EmitLoadOfLValue(LHS, E->getType()); +} + +Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { + const llvm::Type *ResTy = ConvertType(E->getType()); + + // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. + // If we have 1 && X, just emit X without inserting the control flow. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { + if (Cond == 1) { // If we have 1 && X, just emit X. + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + // ZExt result to int or bool. + return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); + } + + // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. + if (!CGF.ContainsLabel(E->getRHS())) + return llvm::Constant::getNullValue(ResTy); + } + + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); + + // Branch on the LHS first. If it is false, go to the failure (cont) block. + CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); + + // Any edges into the ContBlock are now from an (indeterminate number of) + // edges from this first condition. All of these values will be false. Start + // setting up the PHI node in the Cont Block for this. + llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), + "", ContBlock); + PN->reserveOperandSpace(2); // Normal case, two inputs. + for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); + PI != PE; ++PI) + PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); + + CGF.BeginConditionalBranch(); + CGF.EmitBlock(RHSBlock); + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + CGF.EndConditionalBranch(); + + // Reaquire the RHS block, as there may be subblocks inserted. + RHSBlock = Builder.GetInsertBlock(); + + // Emit an unconditional branch from this block to ContBlock. Insert an entry + // into the phi node for the edge with the value of RHSCond. + CGF.EmitBlock(ContBlock); + PN->addIncoming(RHSCond, RHSBlock); + + // ZExt result to int. + return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); +} + +Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { + const llvm::Type *ResTy = ConvertType(E->getType()); + + // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. + // If we have 0 || X, just emit X without inserting the control flow. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { + if (Cond == -1) { // If we have 0 || X, just emit X. + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + // ZExt result to int or bool. + return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); + } + + // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. + if (!CGF.ContainsLabel(E->getRHS())) + return llvm::ConstantInt::get(ResTy, 1); + } + + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); + + // Branch on the LHS first. If it is true, go to the success (cont) block. + CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); + + // Any edges into the ContBlock are now from an (indeterminate number of) + // edges from this first condition. All of these values will be true. Start + // setting up the PHI node in the Cont Block for this. + llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), + "", ContBlock); + PN->reserveOperandSpace(2); // Normal case, two inputs. + for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); + PI != PE; ++PI) + PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); + + CGF.BeginConditionalBranch(); + + // Emit the RHS condition as a bool value. + CGF.EmitBlock(RHSBlock); + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + + CGF.EndConditionalBranch(); + + // Reaquire the RHS block, as there may be subblocks inserted. + RHSBlock = Builder.GetInsertBlock(); + + // Emit an unconditional branch from this block to ContBlock. Insert an entry + // into the phi node for the edge with the value of RHSCond. + CGF.EmitBlock(ContBlock); + PN->addIncoming(RHSCond, RHSBlock); + + // ZExt result to int. + return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); +} + +Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { + CGF.EmitStmt(E->getLHS()); + CGF.EnsureInsertPoint(); + return Visit(E->getRHS()); +} + +//===----------------------------------------------------------------------===// +// Other Operators +//===----------------------------------------------------------------------===// + +/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified +/// expression is cheap enough and side-effect-free enough to evaluate +/// unconditionally instead of conditionally. This is used to convert control +/// flow into selects in some cases. +static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, + CodeGenFunction &CGF) { + if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) + return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); + + // TODO: Allow anything we can constant fold to an integer or fp constant. + if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || + isa<FloatingLiteral>(E)) + return true; + + // Non-volatile automatic variables too, to get "cond ? X : Y" where + // X and Y are local variables. + if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) + if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) + if (VD->hasLocalStorage() && !(CGF.getContext() + .getCanonicalType(VD->getType()) + .isVolatileQualified())) + return true; + + return false; +} + + +Value *ScalarExprEmitter:: +VisitConditionalOperator(const ConditionalOperator *E) { + TestAndClearIgnoreResultAssign(); + // If the condition constant folds and can be elided, try to avoid emitting + // the condition and the dead arm. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ + Expr *Live = E->getLHS(), *Dead = E->getRHS(); + if (Cond == -1) + std::swap(Live, Dead); + + // If the dead side doesn't have labels we need, and if the Live side isn't + // the gnu missing ?: extension (which we could handle, but don't bother + // to), just emit the Live part. + if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part + Live) // Live part isn't missing. + return Visit(Live); + } + + + // If this is a really simple expression (like x ? 4 : 5), emit this as a + // select instead of as control flow. We can only do this if it is cheap and + // safe to evaluate the LHS and RHS unconditionally. + if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), + CGF) && + isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { + llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); + llvm::Value *LHS = Visit(E->getLHS()); + llvm::Value *RHS = Visit(E->getRHS()); + return Builder.CreateSelect(CondV, LHS, RHS, "cond"); + } + + + llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); + Value *CondVal = 0; + + // If we don't have the GNU missing condition extension, emit a branch on bool + // the normal way. + if (E->getLHS()) { + // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for + // the branch on bool. + CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); + } else { + // Otherwise, for the ?: extension, evaluate the conditional and then + // convert it to bool the hard way. We do this explicitly because we need + // the unconverted value for the missing middle value of the ?:. + CondVal = CGF.EmitScalarExpr(E->getCond()); + + // In some cases, EmitScalarConversion will delete the "CondVal" expression + // if there are no extra uses (an optimization). Inhibit this by making an + // extra dead use, because we're going to add a use of CondVal later. We + // don't use the builder for this, because we don't want it to get optimized + // away. This leaves dead code, but the ?: extension isn't common. + new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", + Builder.GetInsertBlock()); + + Value *CondBoolVal = + CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), + CGF.getContext().BoolTy); + Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); + } + + CGF.BeginConditionalBranch(); + CGF.EmitBlock(LHSBlock); + + // Handle the GNU extension for missing LHS. + Value *LHS; + if (E->getLHS()) + LHS = Visit(E->getLHS()); + else // Perform promotions, to handle cases like "short ?: int" + LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); + + CGF.EndConditionalBranch(); + LHSBlock = Builder.GetInsertBlock(); + CGF.EmitBranch(ContBlock); + + CGF.BeginConditionalBranch(); + CGF.EmitBlock(RHSBlock); + + Value *RHS = Visit(E->getRHS()); + CGF.EndConditionalBranch(); + RHSBlock = Builder.GetInsertBlock(); + CGF.EmitBranch(ContBlock); + + CGF.EmitBlock(ContBlock); + + // If the LHS or RHS is a throw expression, it will be legitimately null. + if (!LHS) + return RHS; + if (!RHS) + return LHS; + + // Create a PHI node for the real part. + llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); + PN->reserveOperandSpace(2); + PN->addIncoming(LHS, LHSBlock); + PN->addIncoming(RHS, RHSBlock); + return PN; +} + +Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { + return Visit(E->getChosenSubExpr(CGF.getContext())); +} + +Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { + llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); + llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); + + // If EmitVAArg fails, we fall back to the LLVM instruction. + if (!ArgPtr) + return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); + + // FIXME Volatility. + return Builder.CreateLoad(ArgPtr); +} + +Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { + return CGF.BuildBlockLiteralTmp(BE); +} + +//===----------------------------------------------------------------------===// +// Entry Point into this File +//===----------------------------------------------------------------------===// + +/// EmitScalarExpr - Emit the computation of the specified expression of scalar +/// type, ignoring the result. +Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { + assert(E && !hasAggregateLLVMType(E->getType()) && + "Invalid scalar expression to emit"); + + return ScalarExprEmitter(*this, IgnoreResultAssign) + .Visit(const_cast<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); +} + +LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { + llvm::Value *V; + // object->isa or (*object).isa + // Generate code as for: *(Class*)object + // build Class* type + const llvm::Type *ClassPtrTy = ConvertType(E->getType()); + + Expr *BaseExpr = E->getBase(); + if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { + V = CreateTempAlloca(ClassPtrTy, "resval"); + llvm::Value *Src = EmitScalarExpr(BaseExpr); + Builder.CreateStore(Src, V); + LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); + V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); + } + else { + if (E->isArrow()) + V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); + else + V = EmitLValue(BaseExpr).getAddress(); + } + + // build Class* type + ClassPtrTy = ClassPtrTy->getPointerTo(); + V = Builder.CreateBitCast(V, ClassPtrTy); + LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); + return LV; +} + + +LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( + const CompoundAssignOperator *E) { + ScalarExprEmitter Scalar(*this); + Value *BitFieldResult = 0; + switch (E->getOpcode()) { +#define COMPOUND_OP(Op) \ + case BinaryOperator::Op##Assign: \ + return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ + BitFieldResult) + COMPOUND_OP(Mul); + COMPOUND_OP(Div); + COMPOUND_OP(Rem); + COMPOUND_OP(Add); + COMPOUND_OP(Sub); + COMPOUND_OP(Shl); + COMPOUND_OP(Shr); + COMPOUND_OP(And); + COMPOUND_OP(Xor); + COMPOUND_OP(Or); +#undef COMPOUND_OP + + case BinaryOperator::PtrMemD: + case BinaryOperator::PtrMemI: + case BinaryOperator::Mul: + case BinaryOperator::Div: + case BinaryOperator::Rem: + case BinaryOperator::Add: + case BinaryOperator::Sub: + case BinaryOperator::Shl: + case BinaryOperator::Shr: + case BinaryOperator::LT: + case BinaryOperator::GT: + case BinaryOperator::LE: + case BinaryOperator::GE: + case BinaryOperator::EQ: + case BinaryOperator::NE: + case BinaryOperator::And: + case BinaryOperator::Xor: + case BinaryOperator::Or: + case BinaryOperator::LAnd: + case BinaryOperator::LOr: + case BinaryOperator::Assign: + case BinaryOperator::Comma: + assert(false && "Not valid compound assignment operators"); + break; + } + + llvm_unreachable("Unhandled compound assignment operator"); +} |
