Import Clang, at r72732.vendor/clang/clang-r72732

1 files changed, 1324 insertions, 0 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
new file mode 100644
index 000000000000..c5f23879d1c3
--- /dev/null
+++ b/lib/CodeGen/CGExpr.cpp
@@ -0,0 +1,1324 @@
+//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
+//
+//                     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 as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "CGCall.h"
+#include "CGObjCRuntime.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
+#include "llvm/Target/TargetData.h"
+using namespace clang;
+using namespace CodeGen;
+
+//===--------------------------------------------------------------------===//
+//                        Miscellaneous Helper Methods
+//===--------------------------------------------------------------------===//
+
+/// CreateTempAlloca - This creates a alloca and inserts it into the entry
+/// block.
+llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
+                                                    const char *Name) {
+  if (!Builder.isNamePreserving())
+    Name = "";
+  return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
+}
+
+/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
+/// expression and compare the result against zero, returning an Int1Ty value.
+llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
+  QualType BoolTy = getContext().BoolTy;
+  if (!E->getType()->isAnyComplexType())
+    return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
+
+  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
+}
+
+/// EmitAnyExpr - Emit code to compute the specified expression which can have
+/// any type.  The result is returned as an RValue struct.  If this is an
+/// aggregate expression, the aggloc/agglocvolatile arguments indicate where
+/// the result should be returned.
+RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc, 
+                                    bool isAggLocVolatile, bool IgnoreResult) {
+  if (!hasAggregateLLVMType(E->getType()))
+    return RValue::get(EmitScalarExpr(E, IgnoreResult));
+  else if (E->getType()->isAnyComplexType())
+    return RValue::getComplex(EmitComplexExpr(E, false, false,
+                                              IgnoreResult, IgnoreResult));
+  
+  EmitAggExpr(E, AggLoc, isAggLocVolatile, IgnoreResult);
+  return RValue::getAggregate(AggLoc, isAggLocVolatile);
+}
+
+/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result
+/// will always be accessible even if no aggregate location is
+/// provided.
+RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E, llvm::Value *AggLoc, 
+                                          bool isAggLocVolatile) {
+  if (!AggLoc && hasAggregateLLVMType(E->getType()) && 
+      !E->getType()->isAnyComplexType())
+    AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
+  return EmitAnyExpr(E, AggLoc, isAggLocVolatile);
+}
+
+RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
+                                                   QualType DestType) {
+  RValue Val;
+  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
+    // Emit the expr as an lvalue.
+    LValue LV = EmitLValue(E);
+    if (LV.isSimple())
+      return RValue::get(LV.getAddress());
+    Val = EmitLoadOfLValue(LV, E->getType());
+  } else {
+    Val = EmitAnyExprToTemp(E);
+  }
+
+  if (Val.isAggregate()) {
+    Val = RValue::get(Val.getAggregateAddr());
+  } else {
+    // Create a temporary variable that we can bind the reference to.
+    llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), 
+                                         "reftmp");
+    if (Val.isScalar())
+      EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
+    else
+      StoreComplexToAddr(Val.getComplexVal(), Temp, false);
+    Val = RValue::get(Temp);
+  }
+
+  return Val;
+}
+
+
+/// getAccessedFieldNo - Given an encoded value and a result number, return
+/// the input field number being accessed.
+unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx, 
+                                             const llvm::Constant *Elts) {
+  if (isa<llvm::ConstantAggregateZero>(Elts))
+    return 0;
+  
+  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
+}
+
+
+//===----------------------------------------------------------------------===//
+//                         LValue Expression Emission
+//===----------------------------------------------------------------------===//
+
+RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
+  if (Ty->isVoidType()) {
+    return RValue::get(0);
+  } else if (const ComplexType *CTy = Ty->getAsComplexType()) {
+    const llvm::Type *EltTy = ConvertType(CTy->getElementType());
+    llvm::Value *U = llvm::UndefValue::get(EltTy);
+    return RValue::getComplex(std::make_pair(U, U));
+  } else if (hasAggregateLLVMType(Ty)) {
+    const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
+    return RValue::getAggregate(llvm::UndefValue::get(LTy));
+  } else {
+    return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
+  }
+}
+
+RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
+                                              const char *Name) {
+  ErrorUnsupported(E, Name);
+  return GetUndefRValue(E->getType());
+}
+
+LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
+                                              const char *Name) {
+  ErrorUnsupported(E, Name);
+  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
+  return LValue::MakeAddr(llvm::UndefValue::get(Ty),
+                          E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+/// EmitLValue - Emit code to compute a designator that specifies the location
+/// of the expression.
+///
+/// This can return one of two things: a simple address or a bitfield
+/// reference.  In either case, the LLVM Value* in the LValue structure is
+/// guaranteed to be an LLVM pointer type.
+///
+/// If this returns a bitfield reference, nothing about the pointee type of
+/// the LLVM value is known: For example, it may not be a pointer to an
+/// integer.
+///
+/// If this returns a normal address, and if the lvalue's C type is fixed
+/// size, this method guarantees that the returned pointer type will point to
+/// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
+/// variable length type, this is not possible.
+///
+LValue CodeGenFunction::EmitLValue(const Expr *E) {
+  switch (E->getStmtClass()) {
+  default: return EmitUnsupportedLValue(E, "l-value expression");
+
+  case Expr::BinaryOperatorClass: 
+    return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
+  case Expr::CallExprClass: 
+  case Expr::CXXOperatorCallExprClass:
+    return EmitCallExprLValue(cast<CallExpr>(E));
+  case Expr::VAArgExprClass:
+    return EmitVAArgExprLValue(cast<VAArgExpr>(E));
+  case Expr::DeclRefExprClass: 
+  case Expr::QualifiedDeclRefExprClass:
+    return EmitDeclRefLValue(cast<DeclRefExpr>(E));
+  case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
+  case Expr::PredefinedExprClass:
+    return EmitPredefinedLValue(cast<PredefinedExpr>(E));
+  case Expr::StringLiteralClass:
+    return EmitStringLiteralLValue(cast<StringLiteral>(E));
+  case Expr::ObjCEncodeExprClass:
+    return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
+
+  case Expr::BlockDeclRefExprClass: 
+    return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
+
+  case Expr::CXXConditionDeclExprClass:
+    return EmitCXXConditionDeclLValue(cast<CXXConditionDeclExpr>(E));
+  case Expr::CXXTemporaryObjectExprClass:
+  case Expr::CXXConstructExprClass:
+    return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
+  case Expr::CXXBindTemporaryExprClass:
+    return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
+
+  case Expr::ObjCMessageExprClass:
+    return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
+  case Expr::ObjCIvarRefExprClass: 
+    return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
+  case Expr::ObjCPropertyRefExprClass:
+    return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
+  case Expr::ObjCKVCRefExprClass:
+    return EmitObjCKVCRefLValue(cast<ObjCKVCRefExpr>(E));
+  case Expr::ObjCSuperExprClass:
+    return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
+
+  case Expr::StmtExprClass:
+    return EmitStmtExprLValue(cast<StmtExpr>(E));
+  case Expr::UnaryOperatorClass: 
+    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
+  case Expr::ArraySubscriptExprClass:
+    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
+  case Expr::ExtVectorElementExprClass:
+    return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
+  case Expr::MemberExprClass: return EmitMemberExpr(cast<MemberExpr>(E));
+  case Expr::CompoundLiteralExprClass:
+    return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
+  case Expr::ConditionalOperatorClass:
+    return EmitConditionalOperator(cast<ConditionalOperator>(E));
+  case Expr::ChooseExprClass:
+    return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
+  case Expr::ImplicitCastExprClass:
+  case Expr::CStyleCastExprClass:
+  case Expr::CXXFunctionalCastExprClass:
+  case Expr::CXXStaticCastExprClass:
+  case Expr::CXXDynamicCastExprClass:
+  case Expr::CXXReinterpretCastExprClass:
+  case Expr::CXXConstCastExprClass:
+    return EmitCastLValue(cast<CastExpr>(E));
+  }
+}
+
+llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
+                                               QualType Ty) {
+  llvm::Value *V = Builder.CreateLoad(Addr, Volatile, "tmp");
+
+  // Bool can have different representation in memory than in registers.
+  if (Ty->isBooleanType())
+    if (V->getType() != llvm::Type::Int1Ty)
+      V = Builder.CreateTrunc(V, llvm::Type::Int1Ty, "tobool");
+  
+  return V;
+}
+
+void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
+                                        bool Volatile, QualType Ty) {
+  
+  if (Ty->isBooleanType()) {
+    // Bool can have different representation in memory than in registers.
+    const llvm::Type *SrcTy = Value->getType();
+    const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
+    if (DstPtr->getElementType() != SrcTy) {
+      const llvm::Type *MemTy = 
+        llvm::PointerType::get(SrcTy, DstPtr->getAddressSpace());
+      Addr = Builder.CreateBitCast(Addr, MemTy, "storetmp");
+    }
+  }
+  
+  Builder.CreateStore(Value, Addr, Volatile);  
+}
+
+/// EmitLoadOfLValue - Given an expression that represents a value lvalue,
+/// this method emits the address of the lvalue, then loads the result as an
+/// rvalue, returning the rvalue.
+RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
+  if (LV.isObjCWeak()) {
+    // load of a __weak object. 
+    llvm::Value *AddrWeakObj = LV.getAddress();
+    llvm::Value *read_weak = CGM.getObjCRuntime().EmitObjCWeakRead(*this, 
+                                                                   AddrWeakObj);
+    return RValue::get(read_weak);
+  }
+      
+  if (LV.isSimple()) {
+    llvm::Value *Ptr = LV.getAddress();
+    const llvm::Type *EltTy =
+      cast<llvm::PointerType>(Ptr->getType())->getElementType();
+    
+    // Simple scalar l-value.
+    if (EltTy->isSingleValueType())
+      return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(), 
+                                          ExprType));
+    
+    assert(ExprType->isFunctionType() && "Unknown scalar value");
+    return RValue::get(Ptr);
+  }
+  
+  if (LV.isVectorElt()) {
+    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
+                                          LV.isVolatileQualified(), "tmp");
+    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
+                                                    "vecext"));
+  }
+
+  // If this is a reference to a subset of the elements of a vector, either
+  // shuffle the input or extract/insert them as appropriate.
+  if (LV.isExtVectorElt())
+    return EmitLoadOfExtVectorElementLValue(LV, ExprType);
+
+  if (LV.isBitfield())
+    return EmitLoadOfBitfieldLValue(LV, ExprType);
+
+  if (LV.isPropertyRef())
+    return EmitLoadOfPropertyRefLValue(LV, ExprType);
+
+  assert(LV.isKVCRef() && "Unknown LValue type!");
+  return EmitLoadOfKVCRefLValue(LV, ExprType);
+}
+
+RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
+                                                 QualType ExprType) {
+  unsigned StartBit = LV.getBitfieldStartBit();
+  unsigned BitfieldSize = LV.getBitfieldSize();
+  llvm::Value *Ptr = LV.getBitfieldAddr();
+
+  const llvm::Type *EltTy = 
+    cast<llvm::PointerType>(Ptr->getType())->getElementType();
+  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
+
+  // In some cases the bitfield may straddle two memory locations.
+  // Currently we load the entire bitfield, then do the magic to
+  // sign-extend it if necessary. This results in somewhat more code
+  // than necessary for the common case (one load), since two shifts
+  // accomplish both the masking and sign extension.
+  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
+  llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
+  
+  // Shift to proper location.
+  if (StartBit)
+    Val = Builder.CreateLShr(Val, llvm::ConstantInt::get(EltTy, StartBit), 
+                             "bf.lo");
+  
+  // Mask off unused bits.
+  llvm::Constant *LowMask = 
+    llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, LowBits));
+  Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
+  
+  // Fetch the high bits if necessary.
+  if (LowBits < BitfieldSize) {
+    unsigned HighBits = BitfieldSize - LowBits;
+    llvm::Value *HighPtr = 
+      Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
+                        "bf.ptr.hi");    
+    llvm::Value *HighVal = Builder.CreateLoad(HighPtr, 
+                                              LV.isVolatileQualified(),
+                                              "tmp");
+    
+    // Mask off unused bits.
+    llvm::Constant *HighMask = 
+      llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, HighBits));
+    HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
+
+    // Shift to proper location and or in to bitfield value.
+    HighVal = Builder.CreateShl(HighVal, 
+                                llvm::ConstantInt::get(EltTy, LowBits));
+    Val = Builder.CreateOr(Val, HighVal, "bf.val");
+  }
+
+  // Sign extend if necessary.
+  if (LV.isBitfieldSigned()) {
+    llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy, 
+                                                    EltTySize - BitfieldSize);
+    Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits), 
+                             ExtraBits, "bf.val.sext");
+  }
+
+  // The bitfield type and the normal type differ when the storage sizes
+  // differ (currently just _Bool).
+  Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
+
+  return RValue::get(Val);
+}
+
+RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
+                                                    QualType ExprType) {
+  return EmitObjCPropertyGet(LV.getPropertyRefExpr());
+}
+
+RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
+                                               QualType ExprType) {
+  return EmitObjCPropertyGet(LV.getKVCRefExpr());
+}
+
+// If this is a reference to a subset of the elements of a vector, create an
+// appropriate shufflevector.
+RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
+                                                         QualType ExprType) {
+  llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
+                                        LV.isVolatileQualified(), "tmp");
+  
+  const llvm::Constant *Elts = LV.getExtVectorElts();
+  
+  // If the result of the expression is a non-vector type, we must be
+  // extracting a single element.  Just codegen as an extractelement.
+  const VectorType *ExprVT = ExprType->getAsVectorType();
+  if (!ExprVT) {
+    unsigned InIdx = getAccessedFieldNo(0, Elts);
+    llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
+    return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
+  }
+
+  // Always use shuffle vector to try to retain the original program structure
+  unsigned NumResultElts = ExprVT->getNumElements();
+  
+  llvm::SmallVector<llvm::Constant*, 4> Mask;
+  for (unsigned i = 0; i != NumResultElts; ++i) {
+    unsigned InIdx = getAccessedFieldNo(i, Elts);
+    Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
+  }
+  
+  llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
+  Vec = Builder.CreateShuffleVector(Vec,
+                                    llvm::UndefValue::get(Vec->getType()),
+                                    MaskV, "tmp");
+  return RValue::get(Vec);
+}
+
+
+
+/// EmitStoreThroughLValue - Store the specified rvalue into the specified
+/// lvalue, where both are guaranteed to the have the same type, and that type
+/// is 'Ty'.
+void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst, 
+                                             QualType Ty) {
+  if (!Dst.isSimple()) {
+    if (Dst.isVectorElt()) {
+      // Read/modify/write the vector, inserting the new element.
+      llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
+                                            Dst.isVolatileQualified(), "tmp");
+      Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
+                                        Dst.getVectorIdx(), "vecins");
+      Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
+      return;
+    }
+  
+    // If this is an update of extended vector elements, insert them as
+    // appropriate.
+    if (Dst.isExtVectorElt())
+      return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
+
+    if (Dst.isBitfield())
+      return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
+
+    if (Dst.isPropertyRef())
+      return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
+
+    if (Dst.isKVCRef())
+      return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
+
+    assert(0 && "Unknown LValue type");
+  }
+  
+  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
+    // load of a __weak object. 
+    llvm::Value *LvalueDst = Dst.getAddress();
+    llvm::Value *src = Src.getScalarVal();
+     CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
+    return;
+  }
+  
+  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
+    // load of a __strong object. 
+    llvm::Value *LvalueDst = Dst.getAddress();
+    llvm::Value *src = Src.getScalarVal();
+#if 0
+    // FIXME. We cannot positively determine if we have an 'ivar' assignment,
+    // object assignment or an unknown assignment. For now, generate call to
+    // objc_assign_strongCast assignment which is a safe, but consevative
+    // assumption.
+    if (Dst.isObjCIvar())
+      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst);
+    else
+      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
+#endif
+    if (Dst.isGlobalObjCRef())
+      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
+    else
+      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
+    return;
+  }
+  
+  assert(Src.isScalar() && "Can't emit an agg store with this method");
+  EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
+                    Dst.isVolatileQualified(), Ty);
+}
+
+void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
+                                                     QualType Ty, 
+                                                     llvm::Value **Result) {
+  unsigned StartBit = Dst.getBitfieldStartBit();
+  unsigned BitfieldSize = Dst.getBitfieldSize();
+  llvm::Value *Ptr = Dst.getBitfieldAddr();
+
+  const llvm::Type *EltTy = 
+    cast<llvm::PointerType>(Ptr->getType())->getElementType();
+  unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
+
+  // Get the new value, cast to the appropriate type and masked to
+  // exactly the size of the bit-field.
+  llvm::Value *SrcVal = Src.getScalarVal();
+  llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
+  llvm::Constant *Mask = 
+    llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
+  NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
+
+  // Return the new value of the bit-field, if requested.
+  if (Result) {
+    // Cast back to the proper type for result.
+    const llvm::Type *SrcTy = SrcVal->getType();
+    llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
+                                                  "bf.reload.val");
+
+    // Sign extend if necessary.
+    if (Dst.isBitfieldSigned()) {
+      unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
+      llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
+                                                      SrcTySize - BitfieldSize);
+      SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits), 
+                                    ExtraBits, "bf.reload.sext");
+    }
+
+    *Result = SrcTrunc;
+  }
+
+  // In some cases the bitfield may straddle two memory locations.
+  // Emit the low part first and check to see if the high needs to be
+  // done.
+  unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
+  llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
+                                           "bf.prev.low");
+
+  // Compute the mask for zero-ing the low part of this bitfield.
+  llvm::Constant *InvMask = 
+    llvm::ConstantInt::get(~llvm::APInt::getBitsSet(EltTySize, StartBit, 
+                                                    StartBit + LowBits));
+  
+  // Compute the new low part as
+  //   LowVal = (LowVal & InvMask) | (NewVal << StartBit),
+  // with the shift of NewVal implicitly stripping the high bits.
+  llvm::Value *NewLowVal = 
+    Builder.CreateShl(NewVal, llvm::ConstantInt::get(EltTy, StartBit), 
+                      "bf.value.lo");  
+  LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
+  LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
+    
+  // Write back.
+  Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
+
+  // If the low part doesn't cover the bitfield emit a high part.
+  if (LowBits < BitfieldSize) {
+    unsigned HighBits = BitfieldSize - LowBits;
+    llvm::Value *HighPtr = 
+      Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
+                        "bf.ptr.hi");    
+    llvm::Value *HighVal = Builder.CreateLoad(HighPtr, 
+                                              Dst.isVolatileQualified(),
+                                              "bf.prev.hi");
+    
+    // Compute the mask for zero-ing the high part of this bitfield.
+    llvm::Constant *InvMask = 
+      llvm::ConstantInt::get(~llvm::APInt::getLowBitsSet(EltTySize, HighBits));
+  
+    // Compute the new high part as
+    //   HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
+    // where the high bits of NewVal have already been cleared and the
+    // shift stripping the low bits.
+    llvm::Value *NewHighVal = 
+      Builder.CreateLShr(NewVal, llvm::ConstantInt::get(EltTy, LowBits), 
+                        "bf.value.high");  
+    HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
+    HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
+    
+    // Write back.
+    Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
+  }
+}
+
+void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
+                                                        LValue Dst,
+                                                        QualType Ty) {
+  EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
+}
+
+void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
+                                                   LValue Dst,
+                                                   QualType Ty) {
+  EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
+}
+
+void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
+                                                               LValue Dst,
+                                                               QualType Ty) {
+  // This access turns into a read/modify/write of the vector.  Load the input
+  // value now.
+  llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
+                                        Dst.isVolatileQualified(), "tmp");
+  const llvm::Constant *Elts = Dst.getExtVectorElts();
+  
+  llvm::Value *SrcVal = Src.getScalarVal();
+  
+  if (const VectorType *VTy = Ty->getAsVectorType()) {
+    unsigned NumSrcElts = VTy->getNumElements();
+    unsigned NumDstElts =
+       cast<llvm::VectorType>(Vec->getType())->getNumElements();
+    if (NumDstElts == NumSrcElts) {
+      // Use shuffle vector is the src and destination are the same number
+      // of elements
+      llvm::SmallVector<llvm::Constant*, 4> Mask;
+      for (unsigned i = 0; i != NumSrcElts; ++i) {
+        unsigned InIdx = getAccessedFieldNo(i, Elts);
+        Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
+      }
+    
+      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
+      Vec = Builder.CreateShuffleVector(SrcVal,
+                                        llvm::UndefValue::get(Vec->getType()),
+                                        MaskV, "tmp");
+    }
+    else if (NumDstElts > NumSrcElts) {
+      // Extended the source vector to the same length and then shuffle it
+      // into the destination.
+      // FIXME: since we're shuffling with undef, can we just use the indices
+      //        into that?  This could be simpler.
+      llvm::SmallVector<llvm::Constant*, 4> ExtMask;
+      unsigned i;
+      for (i = 0; i != NumSrcElts; ++i)
+        ExtMask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
+      for (; i != NumDstElts; ++i)
+        ExtMask.push_back(llvm::UndefValue::get(llvm::Type::Int32Ty));
+      llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
+                                                        ExtMask.size());
+      llvm::Value *ExtSrcVal = 
+        Builder.CreateShuffleVector(SrcVal,
+                                    llvm::UndefValue::get(SrcVal->getType()),
+                                    ExtMaskV, "tmp");
+      // build identity
+      llvm::SmallVector<llvm::Constant*, 4> Mask;
+      for (unsigned i = 0; i != NumDstElts; ++i) {
+        Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
+      }
+      // modify when what gets shuffled in
+      for (unsigned i = 0; i != NumSrcElts; ++i) {
+        unsigned Idx = getAccessedFieldNo(i, Elts);
+        Mask[Idx] =llvm::ConstantInt::get(llvm::Type::Int32Ty, i+NumDstElts);
+      }
+      llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
+      Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
+    }
+    else {
+      // We should never shorten the vector
+      assert(0 && "unexpected shorten vector length");
+    }
+  } else {
+    // If the Src is a scalar (not a vector) it must be updating one element.
+    unsigned InIdx = getAccessedFieldNo(0, Elts);
+    llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
+    Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
+  }
+  
+  Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
+}
+
+LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
+  const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
+  
+  if (VD && (VD->isBlockVarDecl() || isa<ParmVarDecl>(VD) ||
+        isa<ImplicitParamDecl>(VD))) {
+    LValue LV;
+    bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
+    if (VD->hasExternalStorage()) {
+      llvm::Value *V = CGM.GetAddrOfGlobalVar(VD);
+      if (VD->getType()->isReferenceType())
+        V = Builder.CreateLoad(V, "tmp");
+      LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers(),
+                            getContext().getObjCGCAttrKind(E->getType()));
+    }
+    else {
+      llvm::Value *V = LocalDeclMap[VD];
+      assert(V && "DeclRefExpr not entered in LocalDeclMap?");
+      // local variables do not get their gc attribute set.
+      QualType::GCAttrTypes attr = QualType::GCNone;
+      // local static?
+      if (!NonGCable)
+        attr = getContext().getObjCGCAttrKind(E->getType());
+      if (VD->hasAttr<BlocksAttr>()) {
+        bool needsCopyDispose = BlockRequiresCopying(VD->getType());
+        const llvm::Type *PtrStructTy = V->getType();
+        const llvm::Type *Ty = PtrStructTy;
+        Ty = llvm::PointerType::get(Ty, 0);
+        V = Builder.CreateStructGEP(V, 1, "forwarding");
+        V = Builder.CreateBitCast(V, Ty);
+        V = Builder.CreateLoad(V, false);
+        V = Builder.CreateBitCast(V, PtrStructTy);
+        V = Builder.CreateStructGEP(V, needsCopyDispose*2 + 4, "x");
+      }
+      if (VD->getType()->isReferenceType())
+        V = Builder.CreateLoad(V, "tmp");
+      LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers(), attr);
+    }
+    LValue::SetObjCNonGC(LV, NonGCable);
+    return LV;
+  } else if (VD && VD->isFileVarDecl()) {
+    llvm::Value *V = CGM.GetAddrOfGlobalVar(VD);
+    if (VD->getType()->isReferenceType())
+      V = Builder.CreateLoad(V, "tmp");
+    LValue LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers(),
+                                 getContext().getObjCGCAttrKind(E->getType()));
+    if (LV.isObjCStrong())
+      LV.SetGlobalObjCRef(LV, true);
+    return LV;
+  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl())) {
+    llvm::Value* V = CGM.GetAddrOfFunction(GlobalDecl(FD));
+    if (!FD->hasPrototype()) {
+      if (const FunctionProtoType *Proto =
+              FD->getType()->getAsFunctionProtoType()) {
+        // Ugly case: for a K&R-style definition, the type of the definition
+        // isn't the same as the type of a use.  Correct for this with a
+        // bitcast.
+        QualType NoProtoType =
+            getContext().getFunctionNoProtoType(Proto->getResultType());
+        NoProtoType = getContext().getPointerType(NoProtoType);
+        V = Builder.CreateBitCast(V, ConvertType(NoProtoType), "tmp");
+      }
+    }
+    return LValue::MakeAddr(V, E->getType().getCVRQualifiers(),
+                            getContext().getObjCGCAttrKind(E->getType()));
+  }
+  else if (const ImplicitParamDecl *IPD =
+      dyn_cast<ImplicitParamDecl>(E->getDecl())) {
+    llvm::Value *V = LocalDeclMap[IPD];
+    assert(V && "BlockVarDecl not entered in LocalDeclMap?");
+    return LValue::MakeAddr(V, E->getType().getCVRQualifiers(),
+                            getContext().getObjCGCAttrKind(E->getType()));
+  }
+  assert(0 && "Unimp declref");
+  //an invalid LValue, but the assert will
+  //ensure that this point is never reached.
+  return LValue();
+}
+
+LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
+  return LValue::MakeAddr(GetAddrOfBlockDecl(E), 
+                          E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
+  // __extension__ doesn't affect lvalue-ness.
+  if (E->getOpcode() == UnaryOperator::Extension)
+    return EmitLValue(E->getSubExpr());
+  
+  QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
+  switch (E->getOpcode()) {
+  default: assert(0 && "Unknown unary operator lvalue!");
+  case UnaryOperator::Deref:
+    {
+      QualType T =
+        E->getSubExpr()->getType()->getAsPointerType()->getPointeeType();
+      LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()),
+                                   ExprTy->getAsPointerType()->getPointeeType()
+                                      .getCVRQualifiers(), 
+                                   getContext().getObjCGCAttrKind(T));
+     // We should not generate __weak write barrier on indirect reference
+     // of a pointer to object; as in void foo (__weak id *param); *param = 0;
+     // But, we continue to generate __strong write barrier on indirect write
+     // into a pointer to object.
+     if (getContext().getLangOptions().ObjC1 &&
+         getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
+         LV.isObjCWeak())
+       LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
+     return LV;
+    }
+  case UnaryOperator::Real:
+  case UnaryOperator::Imag:
+    LValue LV = EmitLValue(E->getSubExpr());
+    unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
+    return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
+                                                    Idx, "idx"),
+                            ExprTy.getCVRQualifiers());
+  }
+}
+
+LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
+  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E), 0);
+}
+
+LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
+  return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E), 0);
+}
+
+
+LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
+  std::string GlobalVarName;
+
+  switch (Type) {
+  default:
+    assert(0 && "Invalid type");
+  case PredefinedExpr::Func:
+    GlobalVarName = "__func__.";
+    break;
+  case PredefinedExpr::Function:
+    GlobalVarName = "__FUNCTION__.";
+    break;
+  case PredefinedExpr::PrettyFunction:
+    // FIXME:: Demangle C++ method names
+    GlobalVarName = "__PRETTY_FUNCTION__.";
+    break;
+  }
+
+  // FIXME: This isn't right at all.  The logic for computing this should go
+  // into a method on PredefinedExpr.  This would allow sema and codegen to be
+  // consistent for things like sizeof(__func__) etc.
+  std::string FunctionName;
+  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurCodeDecl)) {
+    FunctionName = CGM.getMangledName(FD);
+  } else {
+    // Just get the mangled name; skipping the asm prefix if it
+    // exists.
+    FunctionName = CurFn->getName();
+    if (FunctionName[0] == '\01')
+      FunctionName = FunctionName.substr(1, std::string::npos);
+  }
+
+  GlobalVarName += FunctionName;
+  llvm::Constant *C = 
+    CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
+  return LValue::MakeAddr(C, 0);
+}
+
+LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {  
+  switch (E->getIdentType()) {
+  default:
+    return EmitUnsupportedLValue(E, "predefined expression");
+  case PredefinedExpr::Func:
+  case PredefinedExpr::Function:
+  case PredefinedExpr::PrettyFunction:
+    return EmitPredefinedFunctionName(E->getIdentType());
+  }
+}
+
+LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
+  // The index must always be an integer, which is not an aggregate.  Emit it.
+  llvm::Value *Idx = EmitScalarExpr(E->getIdx());
+  
+  // If the base is a vector type, then we are forming a vector element lvalue
+  // with this subscript.
+  if (E->getBase()->getType()->isVectorType()) {
+    // Emit the vector as an lvalue to get its address.
+    LValue LHS = EmitLValue(E->getBase());
+    assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
+    // FIXME: This should properly sign/zero/extend or truncate Idx to i32.
+    return LValue::MakeVectorElt(LHS.getAddress(), Idx,
+      E->getBase()->getType().getCVRQualifiers());
+  }
+  
+  // The base must be a pointer, which is not an aggregate.  Emit it.
+  llvm::Value *Base = EmitScalarExpr(E->getBase());
+  
+  // Extend or truncate the index type to 32 or 64-bits.
+  QualType IdxTy  = E->getIdx()->getType();
+  bool IdxSigned = IdxTy->isSignedIntegerType();
+  unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
+  if (IdxBitwidth != LLVMPointerWidth)
+    Idx = Builder.CreateIntCast(Idx, llvm::IntegerType::get(LLVMPointerWidth),
+                                IdxSigned, "idxprom");
+
+  // We know that the pointer points to a type of the correct size,
+  // unless the size is a VLA or Objective-C interface.
+  llvm::Value *Address = 0;
+  if (const VariableArrayType *VAT = 
+        getContext().getAsVariableArrayType(E->getType())) {
+    llvm::Value *VLASize = VLASizeMap[VAT];
+    
+    Idx = Builder.CreateMul(Idx, VLASize);
+    
+    QualType BaseType = getContext().getBaseElementType(VAT);
+  
+    uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
+    Idx = Builder.CreateUDiv(Idx,
+                             llvm::ConstantInt::get(Idx->getType(), 
+                                                    BaseTypeSize));
+    Address = Builder.CreateGEP(Base, Idx, "arrayidx");
+  } else if (const ObjCInterfaceType *OIT = 
+             dyn_cast<ObjCInterfaceType>(E->getType())) {
+    llvm::Value *InterfaceSize = 
+      llvm::ConstantInt::get(Idx->getType(),
+                             getContext().getTypeSize(OIT) / 8);
+    
+    Idx = Builder.CreateMul(Idx, InterfaceSize);
+
+    llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy), 
+                                Idx, "arrayidx");
+    Address = Builder.CreateBitCast(Address, Base->getType());
+  } else {
+    Address = Builder.CreateGEP(Base, Idx, "arrayidx");
+  }
+  
+  QualType T = E->getBase()->getType()->getAsPointerType()->getPointeeType();
+  LValue LV = LValue::MakeAddr(Address,
+                               T.getCVRQualifiers(),
+                               getContext().getObjCGCAttrKind(T));
+  if (getContext().getLangOptions().ObjC1 &&
+      getContext().getLangOptions().getGCMode() != LangOptions::NonGC)
+    LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
+  return LV;
+}
+
+static 
+llvm::Constant *GenerateConstantVector(llvm::SmallVector<unsigned, 4> &Elts) {
+  llvm::SmallVector<llvm::Constant *, 4> CElts;
+  
+  for (unsigned i = 0, e = Elts.size(); i != e; ++i)
+    CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, Elts[i]));
+
+  return llvm::ConstantVector::get(&CElts[0], CElts.size());
+}
+
+LValue CodeGenFunction::
+EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
+  // Emit the base vector as an l-value.
+  LValue Base;
+
+  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
+  if (!E->isArrow()) {
+    assert(E->getBase()->getType()->isVectorType());
+    Base = EmitLValue(E->getBase());
+  } else {
+    const PointerType *PT = E->getBase()->getType()->getAsPointerType();
+    llvm::Value *Ptr = EmitScalarExpr(E->getBase());
+    Base = LValue::MakeAddr(Ptr, PT->getPointeeType().getCVRQualifiers());
+  }
+
+  // Encode the element access list into a vector of unsigned indices.
+  llvm::SmallVector<unsigned, 4> Indices;
+  E->getEncodedElementAccess(Indices);
+
+  if (Base.isSimple()) {
+    llvm::Constant *CV = GenerateConstantVector(Indices);
+    return LValue::MakeExtVectorElt(Base.getAddress(), CV,
+                                    Base.getQualifiers());
+  }
+  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
+
+  llvm::Constant *BaseElts = Base.getExtVectorElts();
+  llvm::SmallVector<llvm::Constant *, 4> CElts;
+
+  for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
+    if (isa<llvm::ConstantAggregateZero>(BaseElts))
+      CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0));
+    else
+      CElts.push_back(BaseElts->getOperand(Indices[i]));
+  }
+  llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
+  return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
+                                  Base.getQualifiers());
+}
+
+LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
+  bool isUnion = false;
+  bool isIvar = false;
+  bool isNonGC = false;
+  Expr *BaseExpr = E->getBase();
+  llvm::Value *BaseValue = NULL;
+  unsigned CVRQualifiers=0;
+
+  // If this is s.x, emit s as an lvalue.  If it is s->x, emit s as a scalar.
+  if (E->isArrow()) {
+    BaseValue = EmitScalarExpr(BaseExpr);
+    const PointerType *PTy = 
+      BaseExpr->getType()->getAsPointerType();
+    if (PTy->getPointeeType()->isUnionType())
+      isUnion = true;
+    CVRQualifiers = PTy->getPointeeType().getCVRQualifiers();
+  } else if (isa<ObjCPropertyRefExpr>(BaseExpr) ||
+             isa<ObjCKVCRefExpr>(BaseExpr)) {
+    RValue RV = EmitObjCPropertyGet(BaseExpr);
+    BaseValue = RV.getAggregateAddr();
+    if (BaseExpr->getType()->isUnionType())
+      isUnion = true;
+    CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
+  } else {
+    LValue BaseLV = EmitLValue(BaseExpr);
+    if (BaseLV.isObjCIvar())
+      isIvar = true;
+    if (BaseLV.isNonGC())
+      isNonGC = true;
+    // FIXME: this isn't right for bitfields.
+    BaseValue = BaseLV.getAddress();
+    if (BaseExpr->getType()->isUnionType())
+      isUnion = true;
+    CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
+  }
+
+  FieldDecl *Field = dyn_cast<FieldDecl>(E->getMemberDecl());
+  // FIXME: Handle non-field member expressions
+  assert(Field && "No code generation for non-field member references");
+  LValue MemExpLV = EmitLValueForField(BaseValue, Field, isUnion,
+                                       CVRQualifiers);
+  LValue::SetObjCIvar(MemExpLV, isIvar);
+  LValue::SetObjCNonGC(MemExpLV, isNonGC);
+  return MemExpLV;
+}
+
+LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
+                                              FieldDecl* Field,
+                                              unsigned CVRQualifiers) {
+   unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
+  // FIXME: CodeGenTypes should expose a method to get the appropriate type for
+  // FieldTy (the appropriate type is ABI-dependent).
+  const llvm::Type *FieldTy = 
+    CGM.getTypes().ConvertTypeForMem(Field->getType());
+  const llvm::PointerType *BaseTy =
+  cast<llvm::PointerType>(BaseValue->getType());
+  unsigned AS = BaseTy->getAddressSpace();
+  BaseValue = Builder.CreateBitCast(BaseValue,
+                                    llvm::PointerType::get(FieldTy, AS),
+                                    "tmp");
+  llvm::Value *V = Builder.CreateGEP(BaseValue,
+                              llvm::ConstantInt::get(llvm::Type::Int32Ty, idx),
+                              "tmp");
+  
+  CodeGenTypes::BitFieldInfo bitFieldInfo = 
+    CGM.getTypes().getBitFieldInfo(Field);
+  return LValue::MakeBitfield(V, bitFieldInfo.Begin, bitFieldInfo.Size,
+                              Field->getType()->isSignedIntegerType(),
+                            Field->getType().getCVRQualifiers()|CVRQualifiers);
+}
+
+LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
+                                           FieldDecl* Field,
+                                           bool isUnion,
+                                           unsigned CVRQualifiers)
+{
+  if (Field->isBitField())
+    return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
+  
+  unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
+  llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
+
+  // Match union field type.
+  if (isUnion) {
+    const llvm::Type *FieldTy = 
+      CGM.getTypes().ConvertTypeForMem(Field->getType());
+    const llvm::PointerType * BaseTy = 
+      cast<llvm::PointerType>(BaseValue->getType());
+    unsigned AS = BaseTy->getAddressSpace();
+    V = Builder.CreateBitCast(V, 
+                              llvm::PointerType::get(FieldTy, AS), 
+                              "tmp");
+  }
+  if (Field->getType()->isReferenceType())
+    V = Builder.CreateLoad(V, "tmp");
+
+  QualType::GCAttrTypes attr = QualType::GCNone;
+  if (CGM.getLangOptions().ObjC1 &&
+      CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
+    QualType Ty = Field->getType();
+    attr = Ty.getObjCGCAttr();
+    if (attr != QualType::GCNone) {
+      // __weak attribute on a field is ignored.
+      if (attr == QualType::Weak)
+        attr = QualType::GCNone;
+    }
+    else if (getContext().isObjCObjectPointerType(Ty))
+      attr = QualType::Strong;
+  }
+  LValue LV =  
+    LValue::MakeAddr(V, 
+                     Field->getType().getCVRQualifiers()|CVRQualifiers,
+                     attr);
+  return LV;
+}
+
+LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
+  const llvm::Type *LTy = ConvertType(E->getType());
+  llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
+
+  const Expr* InitExpr = E->getInitializer();
+  LValue Result = LValue::MakeAddr(DeclPtr, E->getType().getCVRQualifiers());
+
+  if (E->getType()->isComplexType()) {
+    EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
+  } else if (hasAggregateLLVMType(E->getType())) {
+    EmitAnyExpr(InitExpr, DeclPtr, false);
+  } else {
+    EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
+  }
+
+  return Result;
+}
+
+LValue CodeGenFunction::EmitConditionalOperator(const ConditionalOperator* E) {
+  // We don't handle vectors yet.
+  if (E->getType()->isVectorType())
+    return EmitUnsupportedLValue(E, "conditional operator");
+
+  // ?: here should be an aggregate.
+  assert((hasAggregateLLVMType(E->getType()) && 
+          !E->getType()->isAnyComplexType()) &&
+         "Unexpected conditional operator!");
+
+  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
+  EmitAggExpr(E, Temp, false);
+
+  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+ 
+}
+
+/// EmitCastLValue - Casts are never lvalues.  If a cast is needed by the code
+/// generator in an lvalue context, then it must mean that we need the address
+/// of an aggregate in order to access one of its fields.  This can happen for
+/// all the reasons that casts are permitted with aggregate result, including
+/// noop aggregate casts, and cast from scalar to union.
+LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
+  // If this is an aggregate-to-aggregate cast, just use the input's address as
+  // the lvalue.
+  if (getContext().hasSameUnqualifiedType(E->getType(),
+                                          E->getSubExpr()->getType()))
+    return EmitLValue(E->getSubExpr());
+
+  // Otherwise, we must have a cast from scalar to union.
+  assert(E->getType()->isUnionType() && "Expected scalar-to-union cast");
+  
+  // Casts are only lvalues when the source and destination types are the same.
+  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
+  EmitAnyExpr(E->getSubExpr(), Temp, false);
+  
+  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+//===--------------------------------------------------------------------===//
+//                             Expression Emission
+//===--------------------------------------------------------------------===//
+
+
+RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
+  // Builtins never have block type.
+  if (E->getCallee()->getType()->isBlockPointerType())
+    return EmitBlockCallExpr(E);
+
+  if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
+    return EmitCXXMemberCallExpr(CE);
+  
+  const Decl *TargetDecl = 0;
+  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
+    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
+      TargetDecl = DRE->getDecl();
+      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
+        if (unsigned builtinID = FD->getBuiltinID(getContext()))
+          return EmitBuiltinExpr(FD, builtinID, E);
+    }
+  }
+
+  if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E)) {
+    if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
+      return EmitCXXOperatorMemberCallExpr(CE, MD);
+  }
+      
+  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
+  return EmitCall(Callee, E->getCallee()->getType(),
+                  E->arg_begin(), E->arg_end(), TargetDecl);
+}
+
+LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
+  // Comma expressions just emit their LHS then their RHS as an l-value.
+  if (E->getOpcode() == BinaryOperator::Comma) {
+    EmitAnyExpr(E->getLHS());
+    return EmitLValue(E->getRHS());
+  }
+  
+  // Can only get l-value for binary operator expressions which are a
+  // simple assignment of aggregate type.
+  if (E->getOpcode() != BinaryOperator::Assign)
+    return EmitUnsupportedLValue(E, "binary l-value expression");
+
+  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
+  EmitAggExpr(E, Temp, false);
+  // FIXME: Are these qualifiers correct?
+  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
+  RValue RV = EmitCallExpr(E);
+
+  if (RV.isScalar()) {
+    assert(E->getCallReturnType()->isReferenceType() &&
+           "Can't have a scalar return unless the return type is a "
+           "reference type!");
+    
+    return LValue::MakeAddr(RV.getScalarVal(), E->getType().getCVRQualifiers(), 
+                            getContext().getObjCGCAttrKind(E->getType()));
+  }
+  
+  return LValue::MakeAddr(RV.getAggregateAddr(),
+                          E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
+  // FIXME: This shouldn't require another copy.
+  llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
+  EmitAggExpr(E, Temp, false);
+  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
+}
+
+LValue
+CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) {
+  EmitLocalBlockVarDecl(*E->getVarDecl());
+  return EmitDeclRefLValue(E);
+}
+
+LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
+  llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
+  EmitCXXConstructExpr(Temp, E);
+  return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
+}
+
+LValue
+CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
+  LValue LV = EmitLValue(E->getSubExpr());
+  
+  PushCXXTemporary(E->getTemporary(), LV.getAddress());
+  
+  return LV;
+}
+
+LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
+  // Can only get l-value for message expression returning aggregate type
+  RValue RV = EmitObjCMessageExpr(E);
+  // FIXME: can this be volatile?
+  return LValue::MakeAddr(RV.getAggregateAddr(),
+                          E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
+                                             const ObjCIvarDecl *Ivar) {
+  return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
+}
+
+LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
+                                          llvm::Value *BaseValue,
+                                          const ObjCIvarDecl *Ivar,
+                                          unsigned CVRQualifiers) {
+  return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
+                                                   Ivar, CVRQualifiers);
+}
+
+LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
+  // FIXME: A lot of the code below could be shared with EmitMemberExpr.
+  llvm::Value *BaseValue = 0;
+  const Expr *BaseExpr = E->getBase();
+  unsigned CVRQualifiers = 0;
+  QualType ObjectTy;
+  if (E->isArrow()) {
+    BaseValue = EmitScalarExpr(BaseExpr);
+    const PointerType *PTy = BaseExpr->getType()->getAsPointerType();
+    ObjectTy = PTy->getPointeeType();
+    CVRQualifiers = ObjectTy.getCVRQualifiers();
+  } else {
+    LValue BaseLV = EmitLValue(BaseExpr);
+    // FIXME: this isn't right for bitfields.
+    BaseValue = BaseLV.getAddress();
+    ObjectTy = BaseExpr->getType();
+    CVRQualifiers = ObjectTy.getCVRQualifiers();
+  }
+
+  return EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(), CVRQualifiers);
+}
+
+LValue 
+CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
+  // This is a special l-value that just issues sends when we load or
+  // store through it.
+  return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
+}
+
+LValue 
+CodeGenFunction::EmitObjCKVCRefLValue(const ObjCKVCRefExpr *E) {
+  // This is a special l-value that just issues sends when we load or
+  // store through it.
+  return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
+}
+
+LValue
+CodeGenFunction::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
+  return EmitUnsupportedLValue(E, "use of super");
+}
+
+LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
+  
+  // Can only get l-value for message expression returning aggregate type
+  RValue RV = EmitAnyExprToTemp(E);
+  // FIXME: can this be volatile?
+  return LValue::MakeAddr(RV.getAggregateAddr(),
+                          E->getType().getCVRQualifiers(),
+                          getContext().getObjCGCAttrKind(E->getType()));
+}
+
+
+RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType, 
+                                 CallExpr::const_arg_iterator ArgBeg,
+                                 CallExpr::const_arg_iterator ArgEnd,
+                                 const Decl *TargetDecl) {
+  // Get the actual function type. The callee type will always be a
+  // pointer to function type or a block pointer type.
+  assert(CalleeType->isFunctionPointerType() && 
+         "Call must have function pointer type!");
+
+  QualType FnType = CalleeType->getAsPointerType()->getPointeeType();
+  QualType ResultType = FnType->getAsFunctionType()->getResultType();
+
+  CallArgList Args;
+  EmitCallArgs(Args, FnType->getAsFunctionProtoType(), ArgBeg, ArgEnd);
+
+  return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args), 
+                  Callee, Args, TargetDecl);
+}