Fix a couple of bugs, add some new cool stuff.

1. Fix a todo in Parser::ParseTag, to recover better.  On code like
   that in test/Sema/decl-invalid.c it causes us to return a single
   error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
   declarator didn't have an identifier.  Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
   by a declspec or declarator.  This is mostly implemented for declspec,
   but could be improved, it is missing for declarator.

Thanks to Neil for pointing out this crash.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/CGExpr.cpp b/CodeGen/CGExpr.cpp
new file mode 100644
index 0000000..6d735e0
--- /dev/null
+++ b/CodeGen/CGExpr.cpp
@@ -0,0 +1,1480 @@
+//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and 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 "clang/AST/AST.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Support/MathExtras.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) {
+  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 Ty;
+  RValue Val = EmitExprWithUsualUnaryConversions(E, Ty);
+  return ConvertScalarValueToBool(Val, Ty);
+}
+
+/// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
+/// load the real and imaginary pieces, returning them as Real/Imag.
+void CodeGenFunction::EmitLoadOfComplex(RValue V,
+                                        llvm::Value *&Real, llvm::Value *&Imag){
+  llvm::Value *Ptr = V.getAggregateAddr();
+  
+  llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
+  llvm::Constant *One  = llvm::ConstantInt::get(llvm::Type::Int32Ty, 1);
+  llvm::Value *RealPtr = Builder.CreateGEP(Ptr, Zero, Zero, "realp");
+  llvm::Value *ImagPtr = Builder.CreateGEP(Ptr, Zero, One, "imagp");
+  
+  // FIXME: Handle volatility.
+  Real = Builder.CreateLoad(RealPtr, "real");
+  Imag = Builder.CreateLoad(ImagPtr, "imag");
+}
+
+/// EmitStoreOfComplex - Store the specified real/imag parts into the
+/// specified value pointer.
+void CodeGenFunction::EmitStoreOfComplex(llvm::Value *Real, llvm::Value *Imag,
+                                         llvm::Value *ResPtr) {
+  llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
+  llvm::Constant *One  = llvm::ConstantInt::get(llvm::Type::Int32Ty, 1);
+  llvm::Value *RealPtr = Builder.CreateGEP(ResPtr, Zero, Zero, "real");
+  llvm::Value *ImagPtr = Builder.CreateGEP(ResPtr, Zero, One, "imag");
+  
+  // FIXME: Handle volatility.
+  Builder.CreateStore(Real, RealPtr);
+  Builder.CreateStore(Imag, ImagPtr);
+}
+
+//===--------------------------------------------------------------------===//
+//                               Conversions
+//===--------------------------------------------------------------------===//
+
+/// EmitConversion - Convert the value specied by Val, whose type is ValTy, to
+/// the type specified by DstTy, following the rules of C99 6.3.
+RValue CodeGenFunction::EmitConversion(RValue Val, QualType ValTy,
+                                       QualType DstTy) {
+  ValTy = ValTy.getCanonicalType();
+  DstTy = DstTy.getCanonicalType();
+  if (ValTy == DstTy) return Val;
+
+  // Handle conversions to bool first, they are special: comparisons against 0.
+  if (const BuiltinType *DestBT = dyn_cast<BuiltinType>(DstTy))
+    if (DestBT->getKind() == BuiltinType::Bool)
+      return RValue::get(ConvertScalarValueToBool(Val, ValTy));
+  
+  // Handle pointer conversions next: pointers can only be converted to/from
+  // other pointers and integers.
+  if (isa<PointerType>(DstTy)) {
+    const llvm::Type *DestTy = ConvertType(DstTy);
+    
+    // The source value may be an integer, or a pointer.
+    assert(Val.isScalar() && "Can only convert from integer or pointer");
+    if (isa<llvm::PointerType>(Val.getVal()->getType()))
+      return RValue::get(Builder.CreateBitCast(Val.getVal(), DestTy, "conv"));
+    assert(ValTy->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
+    return RValue::get(Builder.CreateIntToPtr(Val.getVal(), DestTy, "conv"));
+  }
+  
+  if (isa<PointerType>(ValTy)) {
+    // Must be an ptr to int cast.
+    const llvm::Type *DestTy = ConvertType(DstTy);
+    assert(isa<llvm::IntegerType>(DestTy) && "not ptr->int?");
+    return RValue::get(Builder.CreateIntToPtr(Val.getVal(), DestTy, "conv"));
+  }
+  
+  // Finally, we have the arithmetic types: real int/float and complex
+  // int/float.  Handle real->real conversions first, they are the most
+  // common.
+  if (Val.isScalar() && DstTy->isRealType()) {
+    // We know that these are representable as scalars in LLVM, convert to LLVM
+    // types since they are easier to reason about.
+    llvm::Value *SrcVal = Val.getVal();
+    const llvm::Type *DestTy = ConvertType(DstTy);
+    if (SrcVal->getType() == DestTy) return Val;
+    
+    llvm::Value *Result;
+    if (isa<llvm::IntegerType>(SrcVal->getType())) {
+      bool InputSigned = ValTy->isSignedIntegerType();
+      if (isa<llvm::IntegerType>(DestTy))
+        Result = Builder.CreateIntCast(SrcVal, DestTy, InputSigned, "conv");
+      else if (InputSigned)
+        Result = Builder.CreateSIToFP(SrcVal, DestTy, "conv");
+      else
+        Result = Builder.CreateUIToFP(SrcVal, DestTy, "conv");
+    } else {
+      assert(SrcVal->getType()->isFloatingPoint() && "Unknown real conversion");
+      if (isa<llvm::IntegerType>(DestTy)) {
+        if (DstTy->isSignedIntegerType())
+          Result = Builder.CreateFPToSI(SrcVal, DestTy, "conv");
+        else
+          Result = Builder.CreateFPToUI(SrcVal, DestTy, "conv");
+      } else {
+        assert(DestTy->isFloatingPoint() && "Unknown real conversion");
+        if (DestTy->getTypeID() < SrcVal->getType()->getTypeID())
+          Result = Builder.CreateFPTrunc(SrcVal, DestTy, "conv");
+        else
+          Result = Builder.CreateFPExt(SrcVal, DestTy, "conv");
+      }
+    }
+    return RValue::get(Result);
+  }
+  
+  assert(0 && "FIXME: We don't support complex conversions yet!");
+}
+
+
+/// ConvertScalarValueToBool - Convert the specified expression value to a
+/// boolean (i1) truth value.  This is equivalent to "Val == 0".
+llvm::Value *CodeGenFunction::ConvertScalarValueToBool(RValue Val, QualType Ty){
+  Ty = Ty.getCanonicalType();
+  llvm::Value *Result;
+  if (const BuiltinType *BT = dyn_cast<BuiltinType>(Ty)) {
+    switch (BT->getKind()) {
+    default: assert(0 && "Unknown scalar value");
+    case BuiltinType::Bool:
+      Result = Val.getVal();
+      // Bool is already evaluated right.
+      assert(Result->getType() == llvm::Type::Int1Ty &&
+             "Unexpected bool value type!");
+      return Result;
+    case BuiltinType::Char_S:
+    case BuiltinType::Char_U:
+    case BuiltinType::SChar:
+    case BuiltinType::UChar:
+    case BuiltinType::Short:
+    case BuiltinType::UShort:
+    case BuiltinType::Int:
+    case BuiltinType::UInt:
+    case BuiltinType::Long:
+    case BuiltinType::ULong:
+    case BuiltinType::LongLong:
+    case BuiltinType::ULongLong:
+      // Code below handles simple integers.
+      break;
+    case BuiltinType::Float:
+    case BuiltinType::Double:
+    case BuiltinType::LongDouble: {
+      // Compare against 0.0 for fp scalars.
+      Result = Val.getVal();
+      llvm::Value *Zero = llvm::Constant::getNullValue(Result->getType());
+      // FIXME: llvm-gcc produces a une comparison: validate this is right.
+      Result = Builder.CreateFCmpUNE(Result, Zero, "tobool");
+      return Result;
+    }
+    }
+  } else if (isa<PointerType>(Ty) || 
+             cast<TagType>(Ty)->getDecl()->getKind() == Decl::Enum) {
+    // Code below handles this fine.
+  } else {
+    assert(isa<ComplexType>(Ty) && "Unknwon type!");
+    assert(0 && "FIXME: comparisons against complex not implemented yet");
+  }
+  
+  // Usual case for integers, pointers, and enums: compare against zero.
+  Result = Val.getVal();
+  
+  // 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>(Result)) {
+    if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) {
+      Result = ZI->getOperand(0);
+      ZI->eraseFromParent();
+      return Result;
+    }
+  }
+  
+  llvm::Value *Zero = llvm::Constant::getNullValue(Result->getType());
+  return Builder.CreateICmpNE(Result, Zero, "tobool");
+}
+
+//===----------------------------------------------------------------------===//
+//                         LValue Expression Emission
+//===----------------------------------------------------------------------===//
+
+/// 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:
+    fprintf(stderr, "Unimplemented lvalue expr!\n");
+    E->dump();
+    return LValue::MakeAddr(llvm::UndefValue::get(
+                              llvm::PointerType::get(llvm::Type::Int32Ty)));
+
+  case Expr::DeclRefExprClass: 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::UnaryOperatorClass: 
+    return EmitUnaryOpLValue(cast<UnaryOperator>(E));
+  case Expr::ArraySubscriptExprClass:
+    return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
+  }
+}
+
+/// 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) {
+  ExprType = ExprType.getCanonicalType();
+  
+  if (LV.isSimple()) {
+    llvm::Value *Ptr = LV.getAddress();
+    const llvm::Type *EltTy =
+      cast<llvm::PointerType>(Ptr->getType())->getElementType();
+    
+    // Simple scalar l-value.
+    if (EltTy->isFirstClassType())
+      return RValue::get(Builder.CreateLoad(Ptr, "tmp"));
+    
+    // Otherwise, we have an aggregate lvalue.
+    return RValue::getAggregate(Ptr);
+  }
+  
+  if (LV.isVectorElt()) {
+    llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(), "tmp");
+    return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
+                                                    "vecext"));
+  }
+  
+  assert(0 && "Bitfield ref not impl!");
+}
+
+RValue CodeGenFunction::EmitLoadOfLValue(const Expr *E) {
+  return EmitLoadOfLValue(EmitLValue(E), E->getType());
+}
+
+
+/// 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.isVectorElt()) {
+    // Read/modify/write the vector, inserting the new element.
+    // FIXME: Volatility.
+    llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(), "tmp");
+    Vec = Builder.CreateInsertElement(Vec, Src.getVal(),
+                                      Dst.getVectorIdx(), "vecins");
+    Builder.CreateStore(Vec, Dst.getVectorAddr());
+    return;
+  }
+  
+  assert(Dst.isSimple() && "FIXME: Don't support store to bitfield yet");
+  
+  llvm::Value *DstAddr = Dst.getAddress();
+  if (Src.isScalar()) {
+    // FIXME: Handle volatility etc.
+    const llvm::Type *SrcTy = Src.getVal()->getType();
+    const llvm::Type *AddrTy = 
+      cast<llvm::PointerType>(DstAddr->getType())->getElementType();
+    
+    if (AddrTy != SrcTy)
+      DstAddr = Builder.CreateBitCast(DstAddr, llvm::PointerType::get(SrcTy),
+                                      "storetmp");
+    Builder.CreateStore(Src.getVal(), DstAddr);
+    return;
+  }
+  
+  // Don't use memcpy for complex numbers.
+  if (Ty->isComplexType()) {
+    llvm::Value *Real, *Imag;
+    EmitLoadOfComplex(Src, Real, Imag);
+    EmitStoreOfComplex(Real, Imag, Dst.getAddress());
+    return;
+  }
+  
+  // Aggregate assignment turns into llvm.memcpy.
+  const llvm::Type *SBP = llvm::PointerType::get(llvm::Type::Int8Ty);
+  llvm::Value *SrcAddr = Src.getAggregateAddr();
+  
+  if (DstAddr->getType() != SBP)
+    DstAddr = Builder.CreateBitCast(DstAddr, SBP, "tmp");
+  if (SrcAddr->getType() != SBP)
+    SrcAddr = Builder.CreateBitCast(SrcAddr, SBP, "tmp");
+
+  unsigned Align = 1;   // FIXME: Compute type alignments.
+  unsigned Size = 1234; // FIXME: Compute type sizes.
+  
+  // FIXME: Handle variable sized types.
+  const llvm::Type *IntPtr = llvm::IntegerType::get(LLVMPointerWidth);
+  llvm::Value *SizeVal = llvm::ConstantInt::get(IntPtr, Size);
+  
+  llvm::Value *MemCpyOps[4] = {
+    DstAddr, SrcAddr, SizeVal,llvm::ConstantInt::get(llvm::Type::Int32Ty, Align)
+  };
+  
+  Builder.CreateCall(CGM.getMemCpyFn(), MemCpyOps, 4);
+}
+
+
+LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
+  const Decl *D = E->getDecl();
+  if (isa<BlockVarDecl>(D) || isa<ParmVarDecl>(D)) {
+    llvm::Value *V = LocalDeclMap[D];
+    assert(V && "BlockVarDecl not entered in LocalDeclMap?");
+    return LValue::MakeAddr(V);
+  } else if (isa<FunctionDecl>(D) || isa<FileVarDecl>(D)) {
+    return LValue::MakeAddr(CGM.GetAddrOfGlobalDecl(D));
+  }
+  assert(0 && "Unimp declref");
+}
+
+LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
+  // __extension__ doesn't affect lvalue-ness.
+  if (E->getOpcode() == UnaryOperator::Extension)
+    return EmitLValue(E->getSubExpr());
+  
+  assert(E->getOpcode() == UnaryOperator::Deref &&
+         "'*' is the only unary operator that produces an lvalue");
+  return LValue::MakeAddr(EmitExpr(E->getSubExpr()).getVal());
+}
+
+LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
+  assert(!E->isWide() && "FIXME: Wide strings not supported yet!");
+  const char *StrData = E->getStrData();
+  unsigned Len = E->getByteLength();
+  
+  // FIXME: Can cache/reuse these within the module.
+  llvm::Constant *C=llvm::ConstantArray::get(std::string(StrData, StrData+Len));
+  
+  // Create a global variable for this.
+  C = new llvm::GlobalVariable(C->getType(), true, 
+                               llvm::GlobalValue::InternalLinkage,
+                               C, ".str", CurFn->getParent());
+  llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty);
+  llvm::Constant *Zeros[] = { Zero, Zero };
+  C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2);
+  return LValue::MakeAddr(C);
+}
+
+LValue CodeGenFunction::EmitPreDefinedLValue(const PreDefinedExpr *E) {
+  std::string FunctionName(CurFuncDecl->getName());
+  std::string GlobalVarName;
+  
+  switch (E->getIdentType()) {
+    default:
+      assert(0 && "unknown pre-defined ident 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;
+  }
+  
+  GlobalVarName += CurFuncDecl->getName();
+  
+  // FIXME: Can cache/reuse these within the module.
+  llvm::Constant *C=llvm::ConstantArray::get(FunctionName);
+  
+  // Create a global variable for this.
+  C = new llvm::GlobalVariable(C->getType(), true, 
+                               llvm::GlobalValue::InternalLinkage,
+                               C, GlobalVarName, CurFn->getParent());
+  llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty);
+  llvm::Constant *Zeros[] = { Zero, Zero };
+  C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2);
+  return LValue::MakeAddr(C);
+}
+
+LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
+  // The index must always be a pointer or integer, neither of which is an
+  // aggregate.  Emit it.
+  QualType IdxTy;
+  llvm::Value *Idx = 
+    EmitExprWithUsualUnaryConversions(E->getIdx(), IdxTy).getVal();
+  
+  // 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 Base = EmitLValue(E->getBase());
+    assert(Base.isSimple() && "Can only subscript lvalue vectors here!");
+    // FIXME: This should properly sign/zero/extend or truncate Idx to i32.
+    return LValue::MakeVectorElt(Base.getAddress(), Idx);
+  }
+  
+  // At this point, the base must be a pointer or integer, neither of which are
+  // aggregates.  Emit it.
+  QualType BaseTy;
+  llvm::Value *Base =
+    EmitExprWithUsualUnaryConversions(E->getBase(), BaseTy).getVal();
+  
+  // Usually the base is the pointer type, but sometimes it is the index.
+  // Canonicalize to have the pointer as the base.
+  if (isa<llvm::PointerType>(Idx->getType())) {
+    std::swap(Base, Idx);
+    std::swap(BaseTy, IdxTy);
+  }
+  
+  // The pointer is now the base.  Extend or truncate the index type to 32 or
+  // 64-bits.
+  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.
+  if (!E->getType()->isConstantSizeType(getContext()))
+    assert(0 && "VLA idx not implemented");
+  return LValue::MakeAddr(Builder.CreateGEP(Base, Idx, "arrayidx"));
+}
+
+//===--------------------------------------------------------------------===//
+//                             Expression Emission
+//===--------------------------------------------------------------------===//
+
+RValue CodeGenFunction::EmitExpr(const Expr *E) {
+  assert(E && "Null expression?");
+  
+  switch (E->getStmtClass()) {
+  default:
+    fprintf(stderr, "Unimplemented expr!\n");
+    E->dump();
+    return RValue::get(llvm::UndefValue::get(llvm::Type::Int32Ty));
+    
+  // l-values.
+  case Expr::DeclRefExprClass:
+    // DeclRef's of EnumConstantDecl's are simple rvalues.
+    if (const EnumConstantDecl *EC = 
+          dyn_cast<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
+      return RValue::get(llvm::ConstantInt::get(EC->getInitVal()));
+    return EmitLoadOfLValue(E);
+  case Expr::ArraySubscriptExprClass:
+    return EmitArraySubscriptExprRV(cast<ArraySubscriptExpr>(E));
+  case Expr::PreDefinedExprClass:
+  case Expr::StringLiteralClass:
+    return RValue::get(EmitLValue(E).getAddress());
+    
+  // Leaf expressions.
+  case Expr::IntegerLiteralClass:
+    return EmitIntegerLiteral(cast<IntegerLiteral>(E)); 
+  case Expr::FloatingLiteralClass:
+    return EmitFloatingLiteral(cast<FloatingLiteral>(E));
+  case Expr::CharacterLiteralClass:
+    return EmitCharacterLiteral(cast<CharacterLiteral>(E));
+    
+  // Operators.  
+  case Expr::ParenExprClass:
+    return EmitExpr(cast<ParenExpr>(E)->getSubExpr());
+  case Expr::UnaryOperatorClass:
+    return EmitUnaryOperator(cast<UnaryOperator>(E));
+  case Expr::SizeOfAlignOfTypeExprClass:
+    return EmitSizeAlignOf(cast<SizeOfAlignOfTypeExpr>(E)->getArgumentType(),
+                           E->getType(),
+                           cast<SizeOfAlignOfTypeExpr>(E)->isSizeOf());
+  case Expr::ImplicitCastExprClass:
+    return EmitCastExpr(cast<ImplicitCastExpr>(E)->getSubExpr(), E->getType());
+  case Expr::CastExprClass: 
+    return EmitCastExpr(cast<CastExpr>(E)->getSubExpr(), E->getType());
+  case Expr::CallExprClass:
+    return EmitCallExpr(cast<CallExpr>(E));
+  case Expr::BinaryOperatorClass:
+    return EmitBinaryOperator(cast<BinaryOperator>(E));
+  
+  case Expr::ConditionalOperatorClass:
+    return EmitConditionalOperator(cast<ConditionalOperator>(E));
+  }
+  
+}
+
+RValue CodeGenFunction::EmitIntegerLiteral(const IntegerLiteral *E) {
+  return RValue::get(llvm::ConstantInt::get(E->getValue()));
+}
+RValue CodeGenFunction::EmitFloatingLiteral(const FloatingLiteral *E) {
+  return RValue::get(llvm::ConstantFP::get(ConvertType(E->getType()),
+                                           E->getValue()));
+}
+RValue CodeGenFunction::EmitCharacterLiteral(const CharacterLiteral *E) {
+  return RValue::get(llvm::ConstantInt::get(ConvertType(E->getType()),
+                                            E->getValue()));
+}
+
+RValue CodeGenFunction::EmitArraySubscriptExprRV(const ArraySubscriptExpr *E) {
+  // Emit subscript expressions in rvalue context's.  For most cases, this just
+  // loads the lvalue formed by the subscript expr.  However, we have to be
+  // careful, because the base of a vector subscript is occasionally an rvalue,
+  // so we can't get it as an lvalue.
+  if (!E->getBase()->getType()->isVectorType())
+    return EmitLoadOfLValue(E);
+
+  // Handle the vector case.  The base must be a vector, the index must be an
+  // integer value.
+  QualType BaseTy, IdxTy;
+  llvm::Value *Base =
+    EmitExprWithUsualUnaryConversions(E->getBase(), BaseTy).getVal();
+  llvm::Value *Idx = 
+    EmitExprWithUsualUnaryConversions(E->getIdx(), IdxTy).getVal();
+  
+  // FIXME: Convert Idx to i32 type.
+  
+  return RValue::get(Builder.CreateExtractElement(Base, Idx, "vecext"));
+}
+
+// EmitCastExpr - 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.
+RValue CodeGenFunction::EmitCastExpr(const Expr *Op, QualType DestTy) {
+  QualType SrcTy;
+  RValue Src = EmitExprWithUsualUnaryConversions(Op, SrcTy);
+  
+  // If the destination is void, just evaluate the source.
+  if (DestTy->isVoidType())
+    return RValue::getAggregate(0);
+  
+  return EmitConversion(Src, SrcTy, DestTy);
+}
+
+RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
+  QualType CalleeTy;
+  llvm::Value *Callee =
+    EmitExprWithUsualUnaryConversions(E->getCallee(), CalleeTy).getVal();
+  
+  // The callee type will always be a pointer to function type, get the function
+  // type.
+  CalleeTy = cast<PointerType>(CalleeTy.getCanonicalType())->getPointeeType();
+  
+  // Get information about the argument types.
+  FunctionTypeProto::arg_type_iterator ArgTyIt = 0, ArgTyEnd = 0;
+  
+  // Calling unprototyped functions provides no argument info.
+  if (const FunctionTypeProto *FTP = dyn_cast<FunctionTypeProto>(CalleeTy)) {
+    ArgTyIt  = FTP->arg_type_begin();
+    ArgTyEnd = FTP->arg_type_end();
+  }
+  
+  llvm::SmallVector<llvm::Value*, 16> Args;
+  
+  // FIXME: Handle struct return.
+  for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) {
+    QualType ArgTy;
+    RValue ArgVal = EmitExprWithUsualUnaryConversions(E->getArg(i), ArgTy);
+    
+    // If this argument has prototype information, convert it.
+    if (ArgTyIt != ArgTyEnd) {
+      ArgVal = EmitConversion(ArgVal, ArgTy, *ArgTyIt++);
+    } else {
+      // Otherwise, if passing through "..." or to a function with no prototype,
+      // perform the "default argument promotions" (C99 6.5.2.2p6), which
+      // includes the usual unary conversions, but also promotes float to
+      // double.
+      if (const BuiltinType *BT = 
+          dyn_cast<BuiltinType>(ArgTy.getCanonicalType())) {
+        if (BT->getKind() == BuiltinType::Float)
+          ArgVal = RValue::get(Builder.CreateFPExt(ArgVal.getVal(),
+                                                   llvm::Type::DoubleTy,"tmp"));
+      }
+    }
+    
+    
+    if (ArgVal.isScalar())
+      Args.push_back(ArgVal.getVal());
+    else  // Pass by-address.  FIXME: Set attribute bit on call.
+      Args.push_back(ArgVal.getAggregateAddr());
+  }
+  
+  llvm::Value *V = Builder.CreateCall(Callee, &Args[0], Args.size());
+  if (V->getType() != llvm::Type::VoidTy)
+    V->setName("call");
+  
+  // FIXME: Struct return;
+  return RValue::get(V);
+}
+
+
+//===----------------------------------------------------------------------===//
+//                           Unary Operator Emission
+//===----------------------------------------------------------------------===//
+
+RValue CodeGenFunction::EmitExprWithUsualUnaryConversions(const Expr *E, 
+                                                          QualType &ResTy) {
+  ResTy = E->getType().getCanonicalType();
+  
+  if (isa<FunctionType>(ResTy)) { // C99 6.3.2.1p4
+    // Functions are promoted to their address.
+    ResTy = getContext().getPointerType(ResTy);
+    return RValue::get(EmitLValue(E).getAddress());
+  } else if (const ArrayType *ary = dyn_cast<ArrayType>(ResTy)) {
+    // C99 6.3.2.1p3
+    ResTy = getContext().getPointerType(ary->getElementType());
+    
+    // FIXME: For now we assume that all source arrays map to LLVM arrays.  This
+    // will not true when we add support for VLAs.
+    llvm::Value *V = EmitLValue(E).getAddress();  // Bitfields can't be arrays.
+    
+    assert(isa<llvm::PointerType>(V->getType()) &&
+           isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
+                                ->getElementType()) &&
+           "Doesn't support VLAs yet!");
+    llvm::Constant *Idx0 = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
+    return RValue::get(Builder.CreateGEP(V, Idx0, Idx0, "arraydecay"));
+  } else if (ResTy->isPromotableIntegerType()) { // C99 6.3.1.1p2
+    // FIXME: this probably isn't right, pending clarification from Steve.
+    llvm::Value *Val = EmitExpr(E).getVal();
+    
+    // If the input is a signed integer, sign extend to the destination.
+    if (ResTy->isSignedIntegerType()) {
+      Val = Builder.CreateSExt(Val, LLVMIntTy, "promote");
+    } else {
+      // This handles unsigned types, including bool.
+      Val = Builder.CreateZExt(Val, LLVMIntTy, "promote");
+    }
+    ResTy = getContext().IntTy;
+    
+    return RValue::get(Val);
+  }
+  
+  // Otherwise, this is a float, double, int, struct, etc.
+  return EmitExpr(E);
+}
+
+
+RValue CodeGenFunction::EmitUnaryOperator(const UnaryOperator *E) {
+  switch (E->getOpcode()) {
+  default:
+    printf("Unimplemented unary expr!\n");
+    E->dump();
+    return RValue::get(llvm::UndefValue::get(llvm::Type::Int32Ty));
+  case UnaryOperator::PostInc:
+  case UnaryOperator::PostDec:
+  case UnaryOperator::PreInc :
+  case UnaryOperator::PreDec : return EmitUnaryIncDec(E);
+  case UnaryOperator::AddrOf : return EmitUnaryAddrOf(E);
+  case UnaryOperator::Deref  : return EmitLoadOfLValue(E);
+  case UnaryOperator::Plus   : return EmitUnaryPlus(E);
+  case UnaryOperator::Minus  : return EmitUnaryMinus(E);
+  case UnaryOperator::Not    : return EmitUnaryNot(E);
+  case UnaryOperator::LNot   : return EmitUnaryLNot(E);
+  case UnaryOperator::SizeOf :
+    return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), true);
+  case UnaryOperator::AlignOf :
+    return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), false);
+  // FIXME: real/imag
+  case UnaryOperator::Extension: return EmitExpr(E->getSubExpr());
+  }
+}
+
+RValue CodeGenFunction::EmitUnaryIncDec(const UnaryOperator *E) {
+  LValue LV = EmitLValue(E->getSubExpr());
+  RValue InVal = EmitLoadOfLValue(LV, E->getSubExpr()->getType());
+  
+  // We know the operand is real or pointer type, so it must be an LLVM scalar.
+  assert(InVal.isScalar() && "Unknown thing to increment");
+  llvm::Value *InV = InVal.getVal();
+
+  int AmountVal = 1;
+  if (E->getOpcode() == UnaryOperator::PreDec ||
+      E->getOpcode() == UnaryOperator::PostDec)
+    AmountVal = -1;
+  
+  llvm::Value *NextVal;
+  if (isa<llvm::IntegerType>(InV->getType())) {
+    NextVal = llvm::ConstantInt::get(InV->getType(), AmountVal);
+    NextVal = Builder.CreateAdd(InV, NextVal, AmountVal == 1 ? "inc" : "dec");
+  } else if (InV->getType()->isFloatingPoint()) {
+    NextVal = llvm::ConstantFP::get(InV->getType(), AmountVal);
+    NextVal = Builder.CreateAdd(InV, NextVal, AmountVal == 1 ? "inc" : "dec");
+  } else {
+    // FIXME: This is not right for pointers to VLA types.
+    assert(isa<llvm::PointerType>(InV->getType()));
+    NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal);
+    NextVal = Builder.CreateGEP(InV, NextVal, AmountVal == 1 ? "inc" : "dec");
+  }
+
+  RValue NextValToStore = RValue::get(NextVal);
+
+  // Store the updated result through the lvalue.
+  EmitStoreThroughLValue(NextValToStore, LV, E->getSubExpr()->getType());
+                         
+  // If this is a postinc, return the value read from memory, otherwise use the
+  // updated value.
+  if (E->getOpcode() == UnaryOperator::PreDec ||
+      E->getOpcode() == UnaryOperator::PreInc)
+    return NextValToStore;
+  else
+    return InVal;
+}
+
+/// C99 6.5.3.2
+RValue CodeGenFunction::EmitUnaryAddrOf(const UnaryOperator *E) {
+  // The address of the operand is just its lvalue.  It cannot be a bitfield.
+  return RValue::get(EmitLValue(E->getSubExpr()).getAddress());
+}
+
+RValue CodeGenFunction::EmitUnaryPlus(const UnaryOperator *E) {
+  // Unary plus just performs promotions on its arithmetic operand.
+  QualType Ty;
+  return EmitExprWithUsualUnaryConversions(E->getSubExpr(), Ty);
+}
+
+RValue CodeGenFunction::EmitUnaryMinus(const UnaryOperator *E) {
+  // Unary minus performs promotions, then negates its arithmetic operand.
+  QualType Ty;
+  RValue V = EmitExprWithUsualUnaryConversions(E->getSubExpr(), Ty);
+  
+  if (V.isScalar())
+    return RValue::get(Builder.CreateNeg(V.getVal(), "neg"));
+  
+  assert(0 && "FIXME: This doesn't handle complex operands yet");
+}
+
+RValue CodeGenFunction::EmitUnaryNot(const UnaryOperator *E) {
+  // Unary not performs promotions, then complements its integer operand.
+  QualType Ty;
+  RValue V = EmitExprWithUsualUnaryConversions(E->getSubExpr(), Ty);
+  
+  if (V.isScalar())
+    return RValue::get(Builder.CreateNot(V.getVal(), "neg"));
+                      
+  assert(0 && "FIXME: This doesn't handle integer complex operands yet (GNU)");
+}
+
+
+/// C99 6.5.3.3
+RValue CodeGenFunction::EmitUnaryLNot(const UnaryOperator *E) {
+  // Compare operand to zero.
+  llvm::Value *BoolVal = EvaluateExprAsBool(E->getSubExpr());
+  
+  // Invert value.
+  // TODO: Could dynamically modify easy computations here.  For example, if
+  // the operand is an icmp ne, turn into icmp eq.
+  BoolVal = Builder.CreateNot(BoolVal, "lnot");
+  
+  // ZExt result to int.
+  return RValue::get(Builder.CreateZExt(BoolVal, LLVMIntTy, "lnot.ext"));
+}
+
+/// EmitSizeAlignOf - Return the size or alignment of the 'TypeToSize' type as
+/// an integer (RetType).
+RValue CodeGenFunction::EmitSizeAlignOf(QualType TypeToSize,
+                                        QualType RetType, bool isSizeOf) {
+  /// FIXME: This doesn't handle VLAs yet!
+  std::pair<uint64_t, unsigned> Info =
+    getContext().getTypeInfo(TypeToSize, SourceLocation());
+  
+  uint64_t Val = isSizeOf ? Info.first : Info.second;
+  Val /= 8;  // Return size in bytes, not bits.
+  
+  assert(RetType->isIntegerType() && "Result type must be an integer!");
+
+  unsigned ResultWidth = getContext().getTypeSize(RetType, SourceLocation());
+  return RValue::get(llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)));
+}
+
+
+//===--------------------------------------------------------------------===//
+//                         Binary Operator Emission
+//===--------------------------------------------------------------------===//
+
+// FIXME describe.
+QualType CodeGenFunction::
+EmitUsualArithmeticConversions(const BinaryOperator *E, RValue &LHS, 
+                               RValue &RHS) {
+  QualType LHSType, RHSType;
+  LHS = EmitExprWithUsualUnaryConversions(E->getLHS(), LHSType);
+  RHS = EmitExprWithUsualUnaryConversions(E->getRHS(), RHSType);
+
+  // If both operands have the same source type, we're done already.
+  if (LHSType == RHSType) return LHSType;
+
+  // If either side is a non-arithmetic type (e.g. a pointer), we are done.
+  // The caller can deal with this (e.g. pointer + int).
+  if (!LHSType->isArithmeticType() || !RHSType->isArithmeticType())
+    return LHSType;
+
+  // At this point, we have two different arithmetic types. 
+  
+  // Handle complex types first (C99 6.3.1.8p1).
+  if (LHSType->isComplexType() || RHSType->isComplexType()) {
+    assert(0 && "FIXME: complex types unimp");
+#if 0
+    // if we have an integer operand, the result is the complex type.
+    if (rhs->isIntegerType())
+      return lhs;
+    if (lhs->isIntegerType())
+      return rhs;
+    return Context.maxComplexType(lhs, rhs);
+#endif
+  }
+  
+  // If neither operand is complex, they must be scalars.
+  llvm::Value *LHSV = LHS.getVal();
+  llvm::Value *RHSV = RHS.getVal();
+  
+  // If the LLVM types are already equal, then they only differed in sign, or it
+  // was something like char/signed char or double/long double.
+  if (LHSV->getType() == RHSV->getType())
+    return LHSType;
+  
+  // Now handle "real" floating types (i.e. float, double, long double).
+  if (LHSType->isRealFloatingType() || RHSType->isRealFloatingType()) {
+    // if we have an integer operand, the result is the real floating type, and
+    // the integer converts to FP.
+    if (RHSType->isIntegerType()) {
+      // Promote the RHS to an FP type of the LHS, with the sign following the
+      // RHS.
+      if (RHSType->isSignedIntegerType())
+        RHS = RValue::get(Builder.CreateSIToFP(RHSV,LHSV->getType(),"promote"));
+      else
+        RHS = RValue::get(Builder.CreateUIToFP(RHSV,LHSV->getType(),"promote"));
+      return LHSType;
+    }
+    
+    if (LHSType->isIntegerType()) {
+      // Promote the LHS to an FP type of the RHS, with the sign following the
+      // LHS.
+      if (LHSType->isSignedIntegerType())
+        LHS = RValue::get(Builder.CreateSIToFP(LHSV,RHSV->getType(),"promote"));
+      else
+        LHS = RValue::get(Builder.CreateUIToFP(LHSV,RHSV->getType(),"promote"));
+      return RHSType;
+    }
+    
+    // Otherwise, they are two FP types.  Promote the smaller operand to the
+    // bigger result.
+    QualType BiggerType = ASTContext::maxFloatingType(LHSType, RHSType);
+    
+    if (BiggerType == LHSType)
+      RHS = RValue::get(Builder.CreateFPExt(RHSV, LHSV->getType(), "promote"));
+    else
+      LHS = RValue::get(Builder.CreateFPExt(LHSV, RHSV->getType(), "promote"));
+    return BiggerType;
+  }
+  
+  // Finally, we have two integer types that are different according to C.  Do
+  // a sign or zero extension if needed.
+  
+  // Otherwise, one type is smaller than the other.  
+  QualType ResTy = ASTContext::maxIntegerType(LHSType, RHSType);
+  
+  if (LHSType == ResTy) {
+    if (RHSType->isSignedIntegerType())
+      RHS = RValue::get(Builder.CreateSExt(RHSV, LHSV->getType(), "promote"));
+    else
+      RHS = RValue::get(Builder.CreateZExt(RHSV, LHSV->getType(), "promote"));
+  } else {
+    assert(RHSType == ResTy && "Unknown conversion");
+    if (LHSType->isSignedIntegerType())
+      LHS = RValue::get(Builder.CreateSExt(LHSV, RHSV->getType(), "promote"));
+    else
+      LHS = RValue::get(Builder.CreateZExt(LHSV, RHSV->getType(), "promote"));
+  }  
+  return ResTy;
+}
+
+/// EmitCompoundAssignmentOperands - Compound assignment operations (like +=)
+/// are strange in that the result of the operation is not the same type as the
+/// intermediate computation.  This function emits the LHS and RHS operands of
+/// the compound assignment, promoting them to their common computation type.
+///
+/// Since the LHS is an lvalue, and the result is stored back through it, we
+/// return the lvalue as well as the LHS/RHS rvalues.  On return, the LHS and
+/// RHS values are both in the computation type for the operator.
+void CodeGenFunction::
+EmitCompoundAssignmentOperands(const CompoundAssignOperator *E,
+                               LValue &LHSLV, RValue &LHS, RValue &RHS) {
+  LHSLV = EmitLValue(E->getLHS());
+  
+  // Load the LHS and RHS operands.
+  QualType LHSTy = E->getLHS()->getType();
+  LHS = EmitLoadOfLValue(LHSLV, LHSTy);
+  QualType RHSTy;
+  RHS = EmitExprWithUsualUnaryConversions(E->getRHS(), RHSTy);
+  
+  // Shift operands do the usual unary conversions, but do not do the binary
+  // conversions.
+  if (E->isShiftAssignOp()) {
+    // FIXME: This is broken.  Implicit conversions should be made explicit,
+    // so that this goes away.  This causes us to reload the LHS.
+    LHS = EmitExprWithUsualUnaryConversions(E->getLHS(), LHSTy);
+  }
+  
+  // Convert the LHS and RHS to the common evaluation type.
+  LHS = EmitConversion(LHS, LHSTy, E->getComputationType());
+  RHS = EmitConversion(RHS, RHSTy, E->getComputationType());
+}
+
+/// EmitCompoundAssignmentResult - Given a result value in the computation type,
+/// truncate it down to the actual result type, store it through the LHS lvalue,
+/// and return it.
+RValue CodeGenFunction::
+EmitCompoundAssignmentResult(const CompoundAssignOperator *E,
+                             LValue LHSLV, RValue ResV) {
+  
+  // Truncate back to the destination type.
+  if (E->getComputationType() != E->getType())
+    ResV = EmitConversion(ResV, E->getComputationType(), E->getType());
+  
+  // Store the result value into the LHS.
+  EmitStoreThroughLValue(ResV, LHSLV, E->getType());
+  
+  // Return the result.
+  return ResV;
+}
+
+
+RValue CodeGenFunction::EmitBinaryOperator(const BinaryOperator *E) {
+  RValue LHS, RHS;
+  switch (E->getOpcode()) {
+  default:
+    fprintf(stderr, "Unimplemented binary expr!\n");
+    E->dump();
+    return RValue::get(llvm::UndefValue::get(llvm::Type::Int32Ty));
+  case BinaryOperator::Mul:
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitMul(LHS, RHS, E->getType());
+  case BinaryOperator::Div:
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitDiv(LHS, RHS, E->getType());
+  case BinaryOperator::Rem:
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitRem(LHS, RHS, E->getType());
+  case BinaryOperator::Add: {
+    QualType ExprTy = E->getType();
+    if (ExprTy->isPointerType()) {
+      Expr *LHSExpr = E->getLHS();
+      QualType LHSTy;
+      LHS = EmitExprWithUsualUnaryConversions(LHSExpr, LHSTy);
+      Expr *RHSExpr = E->getRHS();
+      QualType RHSTy;
+      RHS = EmitExprWithUsualUnaryConversions(RHSExpr, RHSTy);
+      return EmitPointerAdd(LHS, LHSTy, RHS, RHSTy, ExprTy);
+    } else {
+      EmitUsualArithmeticConversions(E, LHS, RHS);
+      return EmitAdd(LHS, RHS, ExprTy);
+    }
+  }
+  case BinaryOperator::Sub: {
+    QualType ExprTy = E->getType();
+    Expr *LHSExpr = E->getLHS();
+    if (LHSExpr->getType()->isPointerType()) {
+      QualType LHSTy;
+      LHS = EmitExprWithUsualUnaryConversions(LHSExpr, LHSTy);
+      Expr *RHSExpr = E->getRHS();
+      QualType RHSTy;
+      RHS = EmitExprWithUsualUnaryConversions(RHSExpr, RHSTy);
+      return EmitPointerSub(LHS, LHSTy, RHS, RHSTy, ExprTy);
+    } else {
+      EmitUsualArithmeticConversions(E, LHS, RHS);
+      return EmitSub(LHS, RHS, ExprTy);
+    }
+  }
+  case BinaryOperator::Shl:
+    EmitShiftOperands(E, LHS, RHS);
+    return EmitShl(LHS, RHS, E->getType());
+  case BinaryOperator::Shr:
+    EmitShiftOperands(E, LHS, RHS);
+    return EmitShr(LHS, RHS, E->getType());
+  case BinaryOperator::And:
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitAnd(LHS, RHS, E->getType());
+  case BinaryOperator::Xor:
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitXor(LHS, RHS, E->getType());
+  case BinaryOperator::Or :
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitOr(LHS, RHS, E->getType());
+  case BinaryOperator::LAnd: return EmitBinaryLAnd(E);
+  case BinaryOperator::LOr: return EmitBinaryLOr(E);
+  case BinaryOperator::LT:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_ULT,
+                             llvm::ICmpInst::ICMP_SLT,
+                             llvm::FCmpInst::FCMP_OLT);
+  case BinaryOperator::GT:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_UGT,
+                             llvm::ICmpInst::ICMP_SGT,
+                             llvm::FCmpInst::FCMP_OGT);
+  case BinaryOperator::LE:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_ULE,
+                             llvm::ICmpInst::ICMP_SLE,
+                             llvm::FCmpInst::FCMP_OLE);
+  case BinaryOperator::GE:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_UGE,
+                             llvm::ICmpInst::ICMP_SGE,
+                             llvm::FCmpInst::FCMP_OGE);
+  case BinaryOperator::EQ:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_EQ,
+                             llvm::ICmpInst::ICMP_EQ,
+                             llvm::FCmpInst::FCMP_OEQ);
+  case BinaryOperator::NE:
+    return EmitBinaryCompare(E, llvm::ICmpInst::ICMP_NE,
+                             llvm::ICmpInst::ICMP_NE, 
+                             llvm::FCmpInst::FCMP_UNE);
+  case BinaryOperator::Assign:
+    return EmitBinaryAssign(E);
+    
+  case BinaryOperator::MulAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitMul(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::DivAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitDiv(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::RemAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitRem(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::AddAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitAdd(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::SubAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitSub(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::ShlAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitShl(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::ShrAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitShr(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::AndAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitAnd(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::OrAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitOr(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::XorAssign: {
+    const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(E);
+    LValue LHSLV;
+    EmitCompoundAssignmentOperands(CAO, LHSLV, LHS, RHS);
+    LHS = EmitXor(LHS, RHS, CAO->getComputationType());
+    return EmitCompoundAssignmentResult(CAO, LHSLV, LHS);
+  }
+  case BinaryOperator::Comma: return EmitBinaryComma(E);
+  }
+}
+
+RValue CodeGenFunction::EmitMul(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateMul(LHS.getVal(), RHS.getVal(), "mul"));
+  
+  // Otherwise, this must be a complex number.
+  llvm::Value *LHSR, *LHSI, *RHSR, *RHSI;
+  
+  EmitLoadOfComplex(LHS, LHSR, LHSI);
+  EmitLoadOfComplex(RHS, RHSR, RHSI);
+  
+  llvm::Value *ResRl = Builder.CreateMul(LHSR, RHSR, "mul.rl");
+  llvm::Value *ResRr = Builder.CreateMul(LHSI, RHSI, "mul.rr");
+  llvm::Value *ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
+
+  llvm::Value *ResIl = Builder.CreateMul(LHSI, RHSR, "mul.il");
+  llvm::Value *ResIr = Builder.CreateMul(LHSR, RHSI, "mul.ir");
+  llvm::Value *ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
+  
+  llvm::Value *Res = CreateTempAlloca(ConvertType(ResTy));
+  EmitStoreOfComplex(ResR, ResI, Res);
+  return RValue::getAggregate(Res);
+}
+
+RValue CodeGenFunction::EmitDiv(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar()) {
+    llvm::Value *RV;
+    if (LHS.getVal()->getType()->isFloatingPoint())
+      RV = Builder.CreateFDiv(LHS.getVal(), RHS.getVal(), "div");
+    else if (ResTy->isUnsignedIntegerType())
+      RV = Builder.CreateUDiv(LHS.getVal(), RHS.getVal(), "div");
+    else
+      RV = Builder.CreateSDiv(LHS.getVal(), RHS.getVal(), "div");
+    return RValue::get(RV);
+  }
+  assert(0 && "FIXME: This doesn't handle complex operands yet");
+}
+
+RValue CodeGenFunction::EmitRem(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar()) {
+    llvm::Value *RV;
+    // Rem in C can't be a floating point type: C99 6.5.5p2.
+    if (ResTy->isUnsignedIntegerType())
+      RV = Builder.CreateURem(LHS.getVal(), RHS.getVal(), "rem");
+    else
+      RV = Builder.CreateSRem(LHS.getVal(), RHS.getVal(), "rem");
+    return RValue::get(RV);
+  }
+  
+  assert(0 && "FIXME: This doesn't handle complex operands yet");
+}
+
+RValue CodeGenFunction::EmitAdd(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateAdd(LHS.getVal(), RHS.getVal(), "add"));
+  
+  // Otherwise, this must be a complex number.
+  llvm::Value *LHSR, *LHSI, *RHSR, *RHSI;
+  
+  EmitLoadOfComplex(LHS, LHSR, LHSI);
+  EmitLoadOfComplex(RHS, RHSR, RHSI);
+  
+  llvm::Value *ResR = Builder.CreateAdd(LHSR, RHSR, "add.r");
+  llvm::Value *ResI = Builder.CreateAdd(LHSI, RHSI, "add.i");
+  
+  llvm::Value *Res = CreateTempAlloca(ConvertType(ResTy));
+  EmitStoreOfComplex(ResR, ResI, Res);
+  return RValue::getAggregate(Res);
+}
+
+RValue CodeGenFunction::EmitPointerAdd(RValue LHS, QualType LHSTy,
+                                       RValue RHS, QualType RHSTy,
+                                       QualType ResTy) {
+  llvm::Value *LHSValue = LHS.getVal();
+  llvm::Value *RHSValue = RHS.getVal();
+  if (LHSTy->isPointerType()) {
+    // pointer + int
+    return RValue::get(Builder.CreateGEP(LHSValue, RHSValue, "add.ptr"));
+  } else {
+    // int + pointer
+    return RValue::get(Builder.CreateGEP(RHSValue, LHSValue, "add.ptr"));
+  }
+}
+
+RValue CodeGenFunction::EmitSub(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateSub(LHS.getVal(), RHS.getVal(), "sub"));
+  
+  assert(0 && "FIXME: This doesn't handle complex operands yet");
+}
+
+RValue CodeGenFunction::EmitPointerSub(RValue LHS, QualType LHSTy,
+                                       RValue RHS, QualType RHSTy,
+                                       QualType ResTy) {
+  llvm::Value *LHSValue = LHS.getVal();
+  llvm::Value *RHSValue = RHS.getVal();
+  if (const PointerType *RHSPtrType =
+        dyn_cast<PointerType>(RHSTy.getTypePtr())) {
+    // pointer - pointer
+    const PointerType *LHSPtrType = cast<PointerType>(LHSTy.getTypePtr());
+    QualType LHSElementType = LHSPtrType->getPointeeType();
+    assert(LHSElementType == RHSPtrType->getPointeeType() &&
+      "can't subtract pointers with differing element types");
+    uint64_t ElementSize = getContext().getTypeSize(LHSElementType,
+                                                    SourceLocation()) / 8;
+    const llvm::Type *ResultType = ConvertType(ResTy);
+    llvm::Value *CastLHS = Builder.CreatePtrToInt(LHSValue, ResultType,
+                                                  "sub.ptr.lhs.cast");
+    llvm::Value *CastRHS = Builder.CreatePtrToInt(RHSValue, ResultType,
+                                                  "sub.ptr.rhs.cast");
+    llvm::Value *BytesBetween = Builder.CreateSub(CastLHS, CastRHS,
+                                                  "sub.ptr.sub");
+    
+    // HACK: LLVM doesn't have an divide instruction that 'knows' there is no
+    // remainder.  As such, we handle common power-of-two cases here to generate
+    // better code.
+    if (llvm::isPowerOf2_64(ElementSize)) {
+      llvm::Value *ShAmt =
+        llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize));
+      return RValue::get(Builder.CreateAShr(BytesBetween, ShAmt,"sub.ptr.shr"));
+    } else {
+      // Otherwise, do a full sdiv.
+      llvm::Value *BytesPerElement =
+        llvm::ConstantInt::get(ResultType, ElementSize);
+      return RValue::get(Builder.CreateSDiv(BytesBetween, BytesPerElement,
+                                            "sub.ptr.div"));
+    }
+  } else {
+    // pointer - int
+    llvm::Value *NegatedRHS = Builder.CreateNeg(RHSValue, "sub.ptr.neg");
+    return RValue::get(Builder.CreateGEP(LHSValue, NegatedRHS, "sub.ptr"));
+  }
+}
+
+void CodeGenFunction::EmitShiftOperands(const BinaryOperator *E,
+                                        RValue &LHS, RValue &RHS) {
+  // For shifts, integer promotions are performed, but the usual arithmetic 
+  // conversions are not.  The LHS and RHS need not have the same type.
+  QualType ResTy;
+  LHS = EmitExprWithUsualUnaryConversions(E->getLHS(), ResTy);
+  RHS = EmitExprWithUsualUnaryConversions(E->getRHS(), ResTy);
+}
+
+
+RValue CodeGenFunction::EmitShl(RValue LHSV, RValue RHSV, QualType ResTy) {
+  llvm::Value *LHS = LHSV.getVal(), *RHS = RHSV.getVal();
+  
+  // LLVM requires the LHS and RHS to be the same type, promote or truncate the
+  // RHS to the same size as the LHS.
+  if (LHS->getType() != RHS->getType())
+    RHS = Builder.CreateIntCast(RHS, LHS->getType(), false, "sh_prom");
+  
+  return RValue::get(Builder.CreateShl(LHS, RHS, "shl"));
+}
+
+RValue CodeGenFunction::EmitShr(RValue LHSV, RValue RHSV, QualType ResTy) {
+  llvm::Value *LHS = LHSV.getVal(), *RHS = RHSV.getVal();
+  
+  // LLVM requires the LHS and RHS to be the same type, promote or truncate the
+  // RHS to the same size as the LHS.
+  if (LHS->getType() != RHS->getType())
+    RHS = Builder.CreateIntCast(RHS, LHS->getType(), false, "sh_prom");
+  
+  if (ResTy->isUnsignedIntegerType())
+    return RValue::get(Builder.CreateLShr(LHS, RHS, "shr"));
+  else
+    return RValue::get(Builder.CreateAShr(LHS, RHS, "shr"));
+}
+
+RValue CodeGenFunction::EmitBinaryCompare(const BinaryOperator *E,
+                                          unsigned UICmpOpc, unsigned SICmpOpc,
+                                          unsigned FCmpOpc) {
+  RValue LHS, RHS;
+  EmitUsualArithmeticConversions(E, LHS, RHS);
+
+  llvm::Value *Result;
+  if (LHS.isScalar()) {
+    if (LHS.getVal()->getType()->isFloatingPoint()) {
+      Result = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
+                                  LHS.getVal(), RHS.getVal(), "cmp");
+    } else if (E->getLHS()->getType()->isUnsignedIntegerType()) {
+      // FIXME: This check isn't right for "unsigned short < int" where ushort
+      // promotes to int and does a signed compare.
+      Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
+                                  LHS.getVal(), RHS.getVal(), "cmp");
+    } else {
+      // Signed integers and pointers.
+      Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
+                                  LHS.getVal(), RHS.getVal(), "cmp");
+    }
+  } else {
+    // Struct/union/complex
+    llvm::Value *LHSR, *LHSI, *RHSR, *RHSI, *ResultR, *ResultI;
+    EmitLoadOfComplex(LHS, LHSR, LHSI);
+    EmitLoadOfComplex(RHS, RHSR, RHSI);
+
+    // FIXME: need to consider _Complex over integers too!
+
+    ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
+				 LHSR, RHSR, "cmp.r");
+    ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
+				 LHSI, RHSI, "cmp.i");
+    if (BinaryOperator::EQ == E->getOpcode()) {
+      Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
+    } else if (BinaryOperator::NE == E->getOpcode()) {
+      Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
+    } else {
+      assert(0 && "Complex comparison other than == or != ?");
+    }
+  }
+
+  // ZExt result to int.
+  return RValue::get(Builder.CreateZExt(Result, LLVMIntTy, "cmp.ext"));
+}
+
+RValue CodeGenFunction::EmitAnd(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateAnd(LHS.getVal(), RHS.getVal(), "and"));
+  
+  assert(0 && "FIXME: This doesn't handle complex integer operands yet (GNU)");
+}
+
+RValue CodeGenFunction::EmitXor(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateXor(LHS.getVal(), RHS.getVal(), "xor"));
+  
+  assert(0 && "FIXME: This doesn't handle complex integer operands yet (GNU)");
+}
+
+RValue CodeGenFunction::EmitOr(RValue LHS, RValue RHS, QualType ResTy) {
+  if (LHS.isScalar())
+    return RValue::get(Builder.CreateOr(LHS.getVal(), RHS.getVal(), "or"));
+  
+  assert(0 && "FIXME: This doesn't handle complex integer operands yet (GNU)");
+}
+
+RValue CodeGenFunction::EmitBinaryLAnd(const BinaryOperator *E) {
+  llvm::Value *LHSCond = EvaluateExprAsBool(E->getLHS());
+  
+  llvm::BasicBlock *ContBlock = new llvm::BasicBlock("land_cont");
+  llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("land_rhs");
+
+  llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock();
+  Builder.CreateCondBr(LHSCond, RHSBlock, ContBlock);
+  
+  EmitBlock(RHSBlock);
+  llvm::Value *RHSCond = EvaluateExprAsBool(E->getRHS());
+  
+  // Reaquire the RHS block, as there may be subblocks inserted.
+  RHSBlock = Builder.GetInsertBlock();
+  EmitBlock(ContBlock);
+  
+  // Create a PHI node.  If we just evaluted the LHS condition, the result is
+  // false.  If we evaluated both, the result is the RHS condition.
+  llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "land");
+  PN->reserveOperandSpace(2);
+  PN->addIncoming(llvm::ConstantInt::getFalse(), OrigBlock);
+  PN->addIncoming(RHSCond, RHSBlock);
+  
+  // ZExt result to int.
+  return RValue::get(Builder.CreateZExt(PN, LLVMIntTy, "land.ext"));
+}
+
+RValue CodeGenFunction::EmitBinaryLOr(const BinaryOperator *E) {
+  llvm::Value *LHSCond = EvaluateExprAsBool(E->getLHS());
+  
+  llvm::BasicBlock *ContBlock = new llvm::BasicBlock("lor_cont");
+  llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("lor_rhs");
+  
+  llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock();
+  Builder.CreateCondBr(LHSCond, ContBlock, RHSBlock);
+  
+  EmitBlock(RHSBlock);
+  llvm::Value *RHSCond = EvaluateExprAsBool(E->getRHS());
+  
+  // Reaquire the RHS block, as there may be subblocks inserted.
+  RHSBlock = Builder.GetInsertBlock();
+  EmitBlock(ContBlock);
+  
+  // Create a PHI node.  If we just evaluted the LHS condition, the result is
+  // true.  If we evaluated both, the result is the RHS condition.
+  llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "lor");
+  PN->reserveOperandSpace(2);
+  PN->addIncoming(llvm::ConstantInt::getTrue(), OrigBlock);
+  PN->addIncoming(RHSCond, RHSBlock);
+  
+  // ZExt result to int.
+  return RValue::get(Builder.CreateZExt(PN, LLVMIntTy, "lor.ext"));
+}
+
+RValue CodeGenFunction::EmitBinaryAssign(const BinaryOperator *E) {
+  LValue LHS = EmitLValue(E->getLHS());
+  
+  QualType RHSTy;
+  RValue RHS = EmitExprWithUsualUnaryConversions(E->getRHS(), RHSTy);
+  
+  // Convert the RHS to the type of the LHS.
+  RHS = EmitConversion(RHS, RHSTy, E->getType());
+  
+  // Store the value into the LHS.
+  EmitStoreThroughLValue(RHS, LHS, E->getType());
+  
+  // Return the converted RHS.
+  return RHS;
+}
+
+
+RValue CodeGenFunction::EmitBinaryComma(const BinaryOperator *E) {
+  EmitExpr(E->getLHS());
+  return EmitExpr(E->getRHS());
+}
+
+RValue CodeGenFunction::EmitConditionalOperator(const ConditionalOperator *E) {
+  llvm::BasicBlock *LHSBlock = new llvm::BasicBlock("cond.?");
+  llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("cond.:");
+  llvm::BasicBlock *ContBlock = new llvm::BasicBlock("cond.cont");
+  
+  llvm::Value *Cond = EvaluateExprAsBool(E->getCond());
+  Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
+  
+  // FIXME: Implement this for aggregate values.
+  
+  // FIXME: LHS & RHS need the "usual arithmetic conversions" but
+  // that's not possible with the current design.
+  
+  EmitBlock(LHSBlock);
+  QualType LHSTy;
+  llvm::Value *LHSValue = E->getLHS() ? // GNU extension
+      EmitExprWithUsualUnaryConversions(E->getLHS(), LHSTy).getVal() :
+      Cond;
+  Builder.CreateBr(ContBlock);
+  LHSBlock = Builder.GetInsertBlock();
+  
+  EmitBlock(RHSBlock);
+  QualType RHSTy;
+  llvm::Value *RHSValue =
+    EmitExprWithUsualUnaryConversions(E->getRHS(), RHSTy).getVal();
+  Builder.CreateBr(ContBlock);
+  RHSBlock = Builder.GetInsertBlock();
+  
+  const llvm::Type *LHSType = LHSValue->getType();
+  assert(LHSType == RHSValue->getType() && "?: LHS & RHS must have same type");
+  
+  EmitBlock(ContBlock);
+  llvm::PHINode *PN = Builder.CreatePHI(LHSType, "cond");
+  PN->reserveOperandSpace(2);
+  PN->addIncoming(LHSValue, LHSBlock);
+  PN->addIncoming(RHSValue, RHSBlock);
+  
+  return RValue::get(PN);
+}