Stage two of getting CFE top correct.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@39734 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/CGDecl.cpp b/CodeGen/CGDecl.cpp
new file mode 100644
index 0000000..822aca3
--- /dev/null
+++ b/CodeGen/CGDecl.cpp
@@ -0,0 +1,119 @@
+//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
+//
+//                     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 Decl nodes as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "clang/AST/AST.h"
+#include "llvm/Type.h"
+using namespace clang;
+using namespace CodeGen;
+
+
+void CodeGenFunction::EmitDecl(const Decl &D) {
+
+  switch (D.getKind()) {
+  default: assert(0 && "Unknown decl kind!");
+  case Decl::FileVariable:
+    assert(0 && "Should not see file-scope variables inside a function!");
+  case Decl::ParmVariable:
+    assert(0 && "Parmdecls should not be in declstmts!");
+  case Decl::Typedef:   // typedef int X;
+  case Decl::Function:  // void X();
+  case Decl::Struct:    // struct X;
+  case Decl::Union:     // union X;
+  case Decl::Class:     // class X;
+  case Decl::Enum:      // enum X;
+    // None of these decls require codegen support.
+    return;
+    
+  case Decl::BlockVariable:
+    return EmitBlockVarDecl(cast<BlockVarDecl>(D));
+  case Decl::EnumConstant:
+    return EmitEnumConstantDecl(cast<EnumConstantDecl>(D));
+  }
+}
+
+void CodeGenFunction::EmitEnumConstantDecl(const EnumConstantDecl &D) {
+  assert(0 && "FIXME: Enum constant decls not implemented yet!");  
+}
+
+/// EmitBlockVarDecl - This method handles emission of any variable declaration
+/// inside a function, including static vars etc.
+void CodeGenFunction::EmitBlockVarDecl(const BlockVarDecl &D) {
+  switch (D.getStorageClass()) {
+  case VarDecl::Static:
+    assert(0 && "FIXME: local static vars not implemented yet");
+  case VarDecl::Extern:
+    assert(0 && "FIXME: should call up to codegenmodule");
+  default:
+    assert((D.getStorageClass() == VarDecl::None ||
+            D.getStorageClass() == VarDecl::Auto ||
+            D.getStorageClass() == VarDecl::Register) &&
+           "Unknown storage class");
+    return EmitLocalBlockVarDecl(D);
+  }
+}
+
+/// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a
+/// variable declaration with auto, register, or no storage class specifier.
+/// These turn into simple stack objects.
+void CodeGenFunction::EmitLocalBlockVarDecl(const BlockVarDecl &D) {
+  QualType Ty = D.getCanonicalType();
+
+  llvm::Value *DeclPtr;
+  if (Ty->isConstantSizeType()) {
+    // A normal fixed sized variable becomes an alloca in the entry block.
+    const llvm::Type *LTy = ConvertType(Ty);
+    // TODO: Alignment
+    DeclPtr = CreateTempAlloca(LTy, D.getName());
+  } else {
+    // TODO: Create a dynamic alloca.
+    assert(0 && "FIXME: Local VLAs not implemented yet");
+  }
+  
+  llvm::Value *&DMEntry = LocalDeclMap[&D];
+  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
+  DMEntry = DeclPtr;
+  
+  // FIXME: Evaluate initializer.
+}
+
+/// Emit an alloca for the specified parameter and set up LocalDeclMap.
+void CodeGenFunction::EmitParmDecl(const ParmVarDecl &D, llvm::Value *Arg) {
+  QualType Ty = D.getCanonicalType();
+  
+  llvm::Value *DeclPtr;
+  if (!Ty->isConstantSizeType()) {
+    // Variable sized values always are passed by-reference.
+    DeclPtr = Arg;
+  } else {
+    // A fixed sized first class variable becomes an alloca in the entry block.
+    const llvm::Type *LTy = ConvertType(Ty);
+    if (LTy->isFirstClassType()) {
+      // TODO: Alignment
+      DeclPtr = new llvm::AllocaInst(LTy, 0, std::string(D.getName())+".addr",
+                                     AllocaInsertPt);
+      
+      // Store the initial value into the alloca.
+      Builder.CreateStore(Arg, DeclPtr);
+    } else {
+      // Otherwise, if this is an aggregate, just use the input pointer.
+      DeclPtr = Arg;
+    }
+    Arg->setName(D.getName());
+  }
+
+  llvm::Value *&DMEntry = LocalDeclMap[&D];
+  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
+  DMEntry = DeclPtr;
+}
+
diff --git a/CodeGen/CGExpr.cpp b/CodeGen/CGExpr.cpp
new file mode 100644
index 0000000..936770e
--- /dev/null
+++ b/CodeGen/CGExpr.cpp
@@ -0,0 +1,1211 @@
+//===--- 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"
+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.CreatePtrToInt(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::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::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())
+    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::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));
+    
+  // Operators.  
+  case Expr::ParenExprClass:
+    return EmitExpr(cast<ParenExpr>(E)->getSubExpr());
+  case Expr::UnaryOperatorClass:
+    return EmitUnaryOperator(cast<UnaryOperator>(E));
+  case Expr::CastExprClass: 
+    return EmitCastExpr(cast<CastExpr>(E));
+  case Expr::CallExprClass:
+    return EmitCallExpr(cast<CallExpr>(E));
+  case Expr::BinaryOperatorClass:
+    return EmitBinaryOperator(cast<BinaryOperator>(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::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"));
+}
+
+
+RValue CodeGenFunction::EmitCastExpr(const CastExpr *E) {
+  QualType SrcTy;
+  RValue Src = EmitExprWithUsualUnaryConversions(E->getSubExpr(), SrcTy);
+  
+  // If the destination is void, just evaluate the source.
+  if (E->getType()->isVoidType())
+    return RValue::getAggregate(0);
+  
+  return EmitConversion(Src, SrcTy, E->getType());
+}
+
+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));
+  // FIXME: pre/post inc/dec
+  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);
+  // FIXME: SIZEOF/ALIGNOF(expr).
+  // FIXME: real/imag
+  case UnaryOperator::Extension: return EmitExpr(E->getSubExpr());
+  }
+}
+
+/// 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"));
+}
+
+
+//===--------------------------------------------------------------------===//
+//                         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:
+    // FIXME: This doesn't handle ptr+int etc yet.
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitAdd(LHS, RHS, E->getType());
+  case BinaryOperator::Sub:
+    // FIXME: This doesn't handle ptr-int etc yet.
+    EmitUsualArithmeticConversions(E, LHS, RHS);
+    return EmitSub(LHS, RHS, E->getType());
+  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"));
+  
+  assert(0 && "FIXME: This doesn't handle complex operands yet");
+}
+
+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::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");
+}
+
+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
+    assert(0 && "Aggregate comparisons not implemented yet!");
+  }
+  
+  // 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());
+}
diff --git a/CodeGen/CGStmt.cpp b/CodeGen/CGStmt.cpp
new file mode 100644
index 0000000..fb2f784
--- /dev/null
+++ b/CodeGen/CGStmt.cpp
@@ -0,0 +1,284 @@
+//===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===//
+//
+//                     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 Stmt nodes as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "clang/AST/AST.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+using namespace clang;
+using namespace CodeGen;
+
+//===----------------------------------------------------------------------===//
+//                              Statement Emission
+//===----------------------------------------------------------------------===//
+
+void CodeGenFunction::EmitStmt(const Stmt *S) {
+  assert(S && "Null statement?");
+  
+  switch (S->getStmtClass()) {
+  default:
+    // Must be an expression in a stmt context.  Emit the value and ignore the
+    // result.
+    if (const Expr *E = dyn_cast<Expr>(S)) {
+      EmitExpr(E);
+    } else {
+      printf("Unimplemented stmt!\n");
+      S->dump();
+    }
+    break;
+  case Stmt::NullStmtClass: break;
+  case Stmt::CompoundStmtClass: EmitCompoundStmt(cast<CompoundStmt>(*S)); break;
+  case Stmt::LabelStmtClass:    EmitLabelStmt(cast<LabelStmt>(*S));       break;
+  case Stmt::GotoStmtClass:     EmitGotoStmt(cast<GotoStmt>(*S));         break;
+
+  case Stmt::IfStmtClass:       EmitIfStmt(cast<IfStmt>(*S));             break;
+  case Stmt::WhileStmtClass:    EmitWhileStmt(cast<WhileStmt>(*S));       break;
+  case Stmt::DoStmtClass:       EmitDoStmt(cast<DoStmt>(*S));             break;
+  case Stmt::ForStmtClass:      EmitForStmt(cast<ForStmt>(*S));           break;
+    
+  case Stmt::ReturnStmtClass:   EmitReturnStmt(cast<ReturnStmt>(*S));     break;
+  case Stmt::DeclStmtClass:     EmitDeclStmt(cast<DeclStmt>(*S));         break;
+  }
+}
+
+void CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S) {
+  // FIXME: handle vla's etc.
+  
+  for (CompoundStmt::const_body_iterator I = S.body_begin(), E = S.body_end();
+       I != E; ++I)
+    EmitStmt(*I);
+}
+
+void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB) {
+  // Emit a branch from this block to the next one if this was a real block.  If
+  // this was just a fall-through block after a terminator, don't emit it.
+  llvm::BasicBlock *LastBB = Builder.GetInsertBlock();
+  
+  if (LastBB->getTerminator()) {
+    // If the previous block is already terminated, don't touch it.
+  } else if (LastBB->empty() && LastBB->getValueName() == 0) {
+    // If the last block was an empty placeholder, remove it now.
+    // TODO: cache and reuse these.
+    Builder.GetInsertBlock()->eraseFromParent();
+  } else {
+    // Otherwise, create a fall-through branch.
+    Builder.CreateBr(BB);
+  }
+  CurFn->getBasicBlockList().push_back(BB);
+  Builder.SetInsertPoint(BB);
+}
+
+void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) {
+  llvm::BasicBlock *NextBB = getBasicBlockForLabel(&S);
+  
+  EmitBlock(NextBB);
+  EmitStmt(S.getSubStmt());
+}
+
+void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
+  Builder.CreateBr(getBasicBlockForLabel(S.getLabel()));
+  
+  // Emit a block after the branch so that dead code after a goto has some place
+  // to go.
+  Builder.SetInsertPoint(new llvm::BasicBlock("", CurFn));
+}
+
+void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
+  // C99 6.8.4.1: The first substatement is executed if the expression compares
+  // unequal to 0.  The condition must be a scalar type.
+  llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+  
+  llvm::BasicBlock *ContBlock = new llvm::BasicBlock("ifend");
+  llvm::BasicBlock *ThenBlock = new llvm::BasicBlock("ifthen");
+  llvm::BasicBlock *ElseBlock = ContBlock;
+  
+  if (S.getElse())
+    ElseBlock = new llvm::BasicBlock("ifelse");
+  
+  // Insert the conditional branch.
+  Builder.CreateCondBr(BoolCondVal, ThenBlock, ElseBlock);
+  
+  // Emit the 'then' code.
+  EmitBlock(ThenBlock);
+  EmitStmt(S.getThen());
+  Builder.CreateBr(ContBlock);
+  
+  // Emit the 'else' code if present.
+  if (const Stmt *Else = S.getElse()) {
+    EmitBlock(ElseBlock);
+    EmitStmt(Else);
+    Builder.CreateBr(ContBlock);
+  }
+  
+  // Emit the continuation block for code after the if.
+  EmitBlock(ContBlock);
+}
+
+void CodeGenFunction::EmitWhileStmt(const WhileStmt &S) {
+  // FIXME: Handle continue/break.
+  
+  // Emit the header for the loop, insert it, which will create an uncond br to
+  // it.
+  llvm::BasicBlock *LoopHeader = new llvm::BasicBlock("whilecond");
+  EmitBlock(LoopHeader);
+  
+  // Evaluate the conditional in the while header.  C99 6.8.5.1: The evaluation
+  // of the controlling expression takes place before each execution of the loop
+  // body. 
+  llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+  
+  // TODO: while(1) is common, avoid extra exit blocks, etc.  Be sure
+  // to correctly handle break/continue though.
+  
+  // Create an exit block for when the condition fails, create a block for the
+  // body of the loop.
+  llvm::BasicBlock *ExitBlock = new llvm::BasicBlock("whileexit");
+  llvm::BasicBlock *LoopBody  = new llvm::BasicBlock("whilebody");
+  
+  // As long as the condition is true, go to the loop body.
+  Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock);
+  
+  // Emit the loop body.
+  EmitBlock(LoopBody);
+  EmitStmt(S.getBody());
+  
+  // Cycle to the condition.
+  Builder.CreateBr(LoopHeader);
+  
+  // Emit the exit block.
+  EmitBlock(ExitBlock);
+}
+
+void CodeGenFunction::EmitDoStmt(const DoStmt &S) {
+  // FIXME: Handle continue/break.
+  // TODO: "do {} while (0)" is common in macros, avoid extra blocks.  Be sure
+  // to correctly handle break/continue though.
+
+  // Emit the body for the loop, insert it, which will create an uncond br to
+  // it.
+  llvm::BasicBlock *LoopBody = new llvm::BasicBlock("dobody");
+  llvm::BasicBlock *AfterDo = new llvm::BasicBlock("afterdo");
+  EmitBlock(LoopBody);
+  
+  // Emit the body of the loop into the block.
+  EmitStmt(S.getBody());
+  
+  // C99 6.8.5.2: "The evaluation of the controlling expression takes place
+  // after each execution of the loop body."
+  
+  // Evaluate the conditional in the while header.
+  // C99 6.8.5p2/p4: The first substatement is executed if the expression
+  // compares unequal to 0.  The condition must be a scalar type.
+  llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+  
+  // As long as the condition is true, iterate the loop.
+  Builder.CreateCondBr(BoolCondVal, LoopBody, AfterDo);
+  
+  // Emit the exit block.
+  EmitBlock(AfterDo);
+}
+
+void CodeGenFunction::EmitForStmt(const ForStmt &S) {
+  // FIXME: Handle continue/break.
+  // FIXME: What do we do if the increment (f.e.) contains a stmt expression,
+  // which contains a continue/break?
+  
+  // Evaluate the first part before the loop.
+  if (S.getInit())
+    EmitStmt(S.getInit());
+
+  // Start the loop with a block that tests the condition.
+  llvm::BasicBlock *CondBlock = new llvm::BasicBlock("forcond");
+  llvm::BasicBlock *AfterFor = 0;
+  EmitBlock(CondBlock);
+
+  // Evaluate the condition if present.  If not, treat it as a non-zero-constant
+  // according to 6.8.5.3p2, aka, true.
+  if (S.getCond()) {
+    // C99 6.8.5p2/p4: The first substatement is executed if the expression
+    // compares unequal to 0.  The condition must be a scalar type.
+    llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+    
+    // As long as the condition is true, iterate the loop.
+    llvm::BasicBlock *ForBody = new llvm::BasicBlock("forbody");
+    AfterFor = new llvm::BasicBlock("afterfor");
+    Builder.CreateCondBr(BoolCondVal, ForBody, AfterFor);
+    EmitBlock(ForBody);    
+  } else {
+    // Treat it as a non-zero constant.  Don't even create a new block for the
+    // body, just fall into it.
+  }
+
+  // If the condition is true, execute the body of the for stmt.
+  EmitStmt(S.getBody());
+  
+  // If there is an increment, emit it next.
+  if (S.getInc())
+    EmitExpr(S.getInc());
+      
+  // Finally, branch back up to the condition for the next iteration.
+  Builder.CreateBr(CondBlock);
+
+  // Emit the fall-through block if there is any.
+  if (AfterFor) 
+    EmitBlock(AfterFor);
+  else
+    EmitBlock(new llvm::BasicBlock());
+}
+
+/// EmitReturnStmt - Note that due to GCC extensions, this can have an operand
+/// if the function returns void, or may be missing one if the function returns
+/// non-void.  Fun stuff :).
+void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) {
+  RValue RetVal;
+  
+  // Emit the result value, even if unused, to evalute the side effects.
+  const Expr *RV = S.getRetValue();
+  if (RV)
+    RetVal = EmitExpr(RV);
+  
+  QualType FnRetTy = CurFuncDecl->getType().getCanonicalType();
+  FnRetTy = cast<FunctionType>(FnRetTy)->getResultType();
+  
+  if (FnRetTy->isVoidType()) {
+    // If the function returns void, emit ret void, and ignore the retval.
+    Builder.CreateRetVoid();
+  } else if (RV == 0) {
+    // "return;" in a function that returns a value.
+    const llvm::Type *RetTy = CurFn->getFunctionType()->getReturnType();
+    if (RetTy == llvm::Type::VoidTy)
+      Builder.CreateRetVoid();   // struct return etc.
+    else
+      Builder.CreateRet(llvm::UndefValue::get(RetTy));
+  } else {
+    // Do implicit conversions to the returned type.
+    RetVal = EmitConversion(RetVal, RV->getType(), FnRetTy);
+    
+    if (RetVal.isScalar()) {
+      Builder.CreateRet(RetVal.getVal());
+    } else {
+      llvm::Value *SRetPtr = CurFn->arg_begin();
+      EmitStoreThroughLValue(RetVal, LValue::MakeAddr(SRetPtr), FnRetTy);
+    }
+  }
+  
+  // Emit a block after the branch so that dead code after a return has some
+  // place to go.
+  EmitBlock(new llvm::BasicBlock());
+}
+
+void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) {
+  for (const Decl *Decl = S.getDecl(); Decl; Decl = Decl->getNextDeclarator())
+    EmitDecl(*Decl);
+}
\ No newline at end of file
diff --git a/CodeGen/CodeGenFunction.cpp b/CodeGen/CodeGenFunction.cpp
new file mode 100644
index 0000000..662c3b5
--- /dev/null
+++ b/CodeGen/CodeGenFunction.cpp
@@ -0,0 +1,98 @@
+//===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===//
+//
+//                     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 coordinates the per-function state used while generating code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/AST/AST.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/Analysis/Verifier.h"
+using namespace clang;
+using namespace CodeGen;
+
+CodeGenFunction::CodeGenFunction(CodeGenModule &cgm) 
+  : CGM(cgm), Target(CGM.getContext().Target) {}
+
+ASTContext &CodeGenFunction::getContext() const {
+  return CGM.getContext();
+}
+
+
+llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) {
+  llvm::BasicBlock *&BB = LabelMap[S];
+  if (BB) return BB;
+  
+  // Create, but don't insert, the new block.
+  return BB = new llvm::BasicBlock(S->getName());
+}
+
+
+const llvm::Type *CodeGenFunction::ConvertType(QualType T) {
+  return CGM.getTypes().ConvertType(T);
+}
+
+bool CodeGenFunction::hasAggregateLLVMType(QualType T) {
+  return !T->isRealType() && !T->isPointerType() && !T->isVoidType() &&
+         !T->isVectorType();
+}
+
+
+void CodeGenFunction::GenerateCode(const FunctionDecl *FD) {
+  LLVMIntTy = ConvertType(getContext().IntTy);
+  LLVMPointerWidth = Target.getPointerWidth(SourceLocation());
+  
+  CurFn = cast<llvm::Function>(CGM.GetAddrOfGlobalDecl(FD));
+  CurFuncDecl = FD;
+  
+  // TODO: Set up linkage and many other things.
+  assert(CurFn->isDeclaration() && "Function already has body?");
+  
+  llvm::BasicBlock *EntryBB = new llvm::BasicBlock("entry", CurFn);
+  
+  Builder.SetInsertPoint(EntryBB);
+
+  // Create a marker to make it easy to insert allocas into the entryblock
+  // later.
+  llvm::Value *Undef = llvm::UndefValue::get(llvm::Type::Int32Ty);
+  AllocaInsertPt = Builder.CreateBitCast(Undef,llvm::Type::Int32Ty, "allocapt");
+  
+  // Emit allocs for param decls.  Give the LLVM Argument nodes names.
+  llvm::Function::arg_iterator AI = CurFn->arg_begin();
+  
+  // Name the struct return argument.
+  if (hasAggregateLLVMType(FD->getResultType())) {
+    AI->setName("agg.result");
+    ++AI;
+  }
+  
+  for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i, ++AI) {
+    assert(AI != CurFn->arg_end() && "Argument mismatch!");
+    EmitParmDecl(*FD->getParamDecl(i), AI);
+  }
+  
+  // Emit the function body.
+  EmitStmt(FD->getBody());
+  
+  // Emit a return for code that falls off the end.
+  // FIXME: if this is C++ main, this should return 0.
+  if (CurFn->getReturnType() == llvm::Type::VoidTy)
+    Builder.CreateRetVoid();
+  else
+    Builder.CreateRet(llvm::UndefValue::get(CurFn->getReturnType()));
+  
+  // Verify that the function is well formed.
+  assert(!verifyFunction(*CurFn));
+}
+
diff --git a/CodeGen/CodeGenFunction.h b/CodeGen/CodeGenFunction.h
new file mode 100644
index 0000000..acefedf
--- /dev/null
+++ b/CodeGen/CodeGenFunction.h
@@ -0,0 +1,354 @@
+//===--- CodeGenFunction.h - Per-Function state for LLVM CodeGen ----------===//
+//
+//                     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 is the internal per-function state used for llvm translation. 
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_CODEGENFUNCTION_H
+#define CODEGEN_CODEGENFUNCTION_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/LLVMBuilder.h"
+#include <vector>
+
+namespace llvm {
+  class Module;
+}
+
+namespace clang {
+  class ASTContext;
+  class Decl;
+  class FunctionDecl;
+  class TargetInfo;
+  class QualType;
+  class FunctionTypeProto;
+  
+  class Stmt;
+  class CompoundStmt;
+  class LabelStmt;
+  class GotoStmt;
+  class IfStmt;
+  class WhileStmt;
+  class DoStmt;
+  class ForStmt;
+  class ReturnStmt;
+  class DeclStmt;
+  
+  class Expr;
+  class DeclRefExpr;
+  class StringLiteral;
+  class IntegerLiteral;
+  class FloatingLiteral;
+  class CastExpr;
+  class CallExpr;
+  class UnaryOperator;
+  class BinaryOperator;
+  class CompoundAssignOperator;
+  class ArraySubscriptExpr;
+  
+  class BlockVarDecl;
+  class EnumConstantDecl;
+  class ParmVarDecl;
+namespace CodeGen {
+  class CodeGenModule;
+  
+
+/// RValue - This trivial value class is used to represent the result of an
+/// expression that is evaluated.  It can be one of two things: either a simple
+/// LLVM SSA value, or the address of an aggregate value in memory.  These two
+/// possibilities are discriminated by isAggregate/isScalar.
+class RValue {
+  llvm::Value *V;
+  // TODO: Encode this into the low bit of pointer for more efficient
+  // return-by-value.
+  bool IsAggregate;
+  
+  // FIXME: Aggregate rvalues need to retain information about whether they are
+  // volatile or not.
+public:
+  
+  bool isAggregate() const { return IsAggregate; }
+  bool isScalar() const { return !IsAggregate; }
+  
+  /// getVal() - Return the Value* of this scalar value.
+  llvm::Value *getVal() const {
+    assert(!isAggregate() && "Not a scalar!");
+    return V;
+  }
+
+  /// getAggregateAddr() - Return the Value* of the address of the aggregate.
+  llvm::Value *getAggregateAddr() const {
+    assert(isAggregate() && "Not an aggregate!");
+    return V;
+  }
+  
+  static RValue get(llvm::Value *V) {
+    RValue ER;
+    ER.V = V;
+    ER.IsAggregate = false;
+    return ER;
+  }
+  static RValue getAggregate(llvm::Value *V) {
+    RValue ER;
+    ER.V = V;
+    ER.IsAggregate = true;
+    return ER;
+  }
+};
+
+
+/// LValue - This represents an lvalue references.  Because C/C++ allow
+/// bitfields, this is not a simple LLVM pointer, it may be a pointer plus a
+/// bitrange.
+class LValue {
+  // FIXME: Volatility.  Restrict?
+  // alignment?
+  
+  enum {
+    Simple,    // This is a normal l-value, use getAddress().
+    VectorElt, // This is a vector element l-value (V[i]), use getVector*
+    BitField   // This is a bitfield l-value, use getBitfield*.
+  } LVType;
+  
+  llvm::Value *V;
+  
+  union {
+    llvm::Value *VectorIdx;
+  };
+public:
+  bool isSimple() const { return LVType == Simple; }
+  bool isVectorElt() const { return LVType == VectorElt; }
+  bool isBitfield() const { return LVType == BitField; }
+  
+  // simple lvalue
+  llvm::Value *getAddress() const { assert(isSimple()); return V; }
+  // vector elt lvalue
+  llvm::Value *getVectorAddr() const { assert(isVectorElt()); return V; }
+  llvm::Value *getVectorIdx() const { assert(isVectorElt()); return VectorIdx; }
+  
+  static LValue MakeAddr(llvm::Value *V) {
+    LValue R;
+    R.LVType = Simple;
+    R.V = V;
+    return R;
+  }
+  
+  static LValue MakeVectorElt(llvm::Value *Vec, llvm::Value *Idx) {
+    LValue R;
+    R.LVType = VectorElt;
+    R.V = Vec;
+    R.VectorIdx = Idx;
+    return R;
+  }
+  
+};
+
+/// CodeGenFunction - This class organizes the per-function state that is used
+/// while generating LLVM code.
+class CodeGenFunction {
+  CodeGenModule &CGM;  // Per-module state.
+  TargetInfo &Target;
+  llvm::LLVMBuilder Builder;
+  
+  const FunctionDecl *CurFuncDecl;
+  llvm::Function *CurFn;
+
+  /// AllocaInsertPoint - This is an instruction in the entry block before which
+  /// we prefer to insert allocas.
+  llvm::Instruction *AllocaInsertPt;
+  
+  const llvm::Type *LLVMIntTy;
+  unsigned LLVMPointerWidth;
+  
+  /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
+  /// decls.
+  llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
+
+  /// LabelMap - This keeps track of the LLVM basic block for each C label.
+  llvm::DenseMap<const LabelStmt*, llvm::BasicBlock*> LabelMap;
+public:
+  CodeGenFunction(CodeGenModule &cgm);
+  
+  ASTContext &getContext() const;
+
+  void GenerateCode(const FunctionDecl *FD);
+  
+  const llvm::Type *ConvertType(QualType T);
+  
+  /// hasAggregateLLVMType - Return true if the specified AST type will map into
+  /// an aggregate LLVM type or is void.
+  static bool hasAggregateLLVMType(QualType T);
+  
+  /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
+  /// label maps to.
+  llvm::BasicBlock *getBasicBlockForLabel(const LabelStmt *S);
+  
+  
+  void EmitBlock(llvm::BasicBlock *BB);
+
+  //===--------------------------------------------------------------------===//
+  //                                  Helpers
+  //===--------------------------------------------------------------------===//
+  
+  /// CreateTempAlloca - This creates a alloca and inserts it into the entry
+  /// block.
+  llvm::AllocaInst *CreateTempAlloca(const llvm::Type *Ty,
+                                     const char *Name = "tmp");
+  
+  /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
+  /// expression and compare the result against zero, returning an Int1Ty value.
+  llvm::Value *EvaluateExprAsBool(const Expr *E);
+
+  
+  /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
+  /// load the real and imaginary pieces, returning them as Real/Imag.
+  void EmitLoadOfComplex(RValue V, llvm::Value *&Real, llvm::Value *&Imag);
+  
+  /// EmitStoreOfComplex - Store the specified real/imag parts into the
+  /// specified value pointer.
+  void EmitStoreOfComplex(llvm::Value *Real, llvm::Value *Imag,
+                          llvm::Value *ResPtr);
+
+  //===--------------------------------------------------------------------===//
+  //                                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 EmitConversion(RValue Val, QualType ValTy, QualType DstTy);
+  
+  /// ConvertScalarValueToBool - Convert the specified expression value to a
+  /// boolean (i1) truth value.  This is equivalent to "Val == 0".
+  llvm::Value *ConvertScalarValueToBool(RValue Val, QualType Ty);
+  
+  //===--------------------------------------------------------------------===//
+  //                            Declaration Emission
+  //===--------------------------------------------------------------------===//
+  
+  void EmitDecl(const Decl &D);
+  void EmitEnumConstantDecl(const EnumConstantDecl &D);
+  void EmitBlockVarDecl(const BlockVarDecl &D);
+  void EmitLocalBlockVarDecl(const BlockVarDecl &D);
+  void EmitParmDecl(const ParmVarDecl &D, llvm::Value *Arg);
+  
+  //===--------------------------------------------------------------------===//
+  //                             Statement Emission
+  //===--------------------------------------------------------------------===//
+
+  void EmitStmt(const Stmt *S);
+  void EmitCompoundStmt(const CompoundStmt &S);
+  void EmitLabelStmt(const LabelStmt &S);
+  void EmitGotoStmt(const GotoStmt &S);
+  void EmitIfStmt(const IfStmt &S);
+  void EmitWhileStmt(const WhileStmt &S);
+  void EmitDoStmt(const DoStmt &S);
+  void EmitForStmt(const ForStmt &S);
+  void EmitReturnStmt(const ReturnStmt &S);
+  void EmitDeclStmt(const DeclStmt &S);
+
+  //===--------------------------------------------------------------------===//
+  //                         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 EmitLValue(const Expr *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 EmitLoadOfLValue(const Expr *E);
+  RValue EmitLoadOfLValue(LValue V, QualType LVType);
+
+  /// 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 EmitStoreThroughLValue(RValue Src, LValue Dst, QualType Ty);
+  
+  LValue EmitDeclRefLValue(const DeclRefExpr *E);
+  LValue EmitStringLiteralLValue(const StringLiteral *E);
+  LValue EmitUnaryOpLValue(const UnaryOperator *E);
+  LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E);
+    
+  //===--------------------------------------------------------------------===//
+  //                             Expression Emission
+  //===--------------------------------------------------------------------===//
+
+  RValue EmitExprWithUsualUnaryConversions(const Expr *E, QualType &ResTy);
+  QualType EmitUsualArithmeticConversions(const BinaryOperator *E,
+                                          RValue &LHS, RValue &RHS);
+  void EmitShiftOperands(const BinaryOperator *E, RValue &LHS, RValue &RHS);
+
+  void EmitCompoundAssignmentOperands(const CompoundAssignOperator *CAO,
+                                      LValue &LHSLV, RValue &LHS, RValue &RHS);
+  RValue EmitCompoundAssignmentResult(const CompoundAssignOperator *E,
+                                      LValue LHSLV, RValue ResV);
+  
+  
+  RValue EmitExpr(const Expr *E);
+  RValue EmitIntegerLiteral(const IntegerLiteral *E);
+  RValue EmitFloatingLiteral(const FloatingLiteral *E);
+  
+  RValue EmitCastExpr(const CastExpr *E);
+  RValue EmitCallExpr(const CallExpr *E);
+  RValue EmitArraySubscriptExprRV(const ArraySubscriptExpr *E);
+
+  // Unary Operators.
+  RValue EmitUnaryOperator(const UnaryOperator *E);
+  // FIXME: pre/post inc/dec
+  RValue EmitUnaryAddrOf  (const UnaryOperator *E);
+  RValue EmitUnaryPlus    (const UnaryOperator *E);
+  RValue EmitUnaryMinus   (const UnaryOperator *E);
+  RValue EmitUnaryNot     (const UnaryOperator *E);
+  RValue EmitUnaryLNot    (const UnaryOperator *E);
+  // FIXME: SIZEOF/ALIGNOF(expr).
+  // FIXME: real/imag
+  
+  // Binary Operators.
+  RValue EmitBinaryOperator(const BinaryOperator *E);
+  RValue EmitBinaryMul(const BinaryOperator *E);
+  RValue EmitBinaryDiv(const BinaryOperator *E);
+  RValue EmitBinaryRem(const BinaryOperator *E);
+  RValue EmitMul(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitDiv(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitRem(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitAdd(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitSub(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitShl(RValue LHS, RValue RHS, QualType ResTy);
+  RValue EmitShr(RValue LHS, RValue RHS, QualType ResTy);
+  RValue EmitBinaryCompare(const BinaryOperator *E, unsigned UICmpOpc,
+                           unsigned SICmpOpc, unsigned FCmpOpc);
+  RValue EmitAnd(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitOr (RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitXor(RValue LHS, RValue RHS, QualType EltTy);
+  RValue EmitBinaryLAnd(const BinaryOperator *E);
+  RValue EmitBinaryLOr(const BinaryOperator *E);
+  
+  RValue EmitBinaryAssign(const BinaryOperator *E);
+  RValue EmitBinaryComma(const BinaryOperator *E);
+};
+}  // end namespace CodeGen
+}  // end namespace clang
+
+#endif
diff --git a/CodeGen/CodeGenModule.cpp b/CodeGen/CodeGenModule.cpp
new file mode 100644
index 0000000..cdc3e63
--- /dev/null
+++ b/CodeGen/CodeGenModule.cpp
@@ -0,0 +1,68 @@
+//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
+//
+//                     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 coordinates the per-module state used while generating code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenModule.h"
+#include "CodeGenFunction.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Intrinsics.h"
+using namespace clang;
+using namespace CodeGen;
+
+
+CodeGenModule::CodeGenModule(ASTContext &C, llvm::Module &M)
+  : Context(C), TheModule(M), Types(C.Target) {}
+
+llvm::Constant *CodeGenModule::GetAddrOfGlobalDecl(const Decl *D) {
+  // See if it is already in the map.
+  llvm::Constant *&Entry = GlobalDeclMap[D];
+  if (Entry) return Entry;
+  
+  QualType ASTTy = cast<ValueDecl>(D)->getType();
+  const llvm::Type *Ty = getTypes().ConvertType(ASTTy);
+  if (isa<FunctionDecl>(D)) {
+    const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
+    // FIXME: param attributes for sext/zext etc.
+    return Entry = new llvm::Function(FTy, llvm::Function::ExternalLinkage,
+                                      D->getName(), &getModule());
+  }
+  
+  assert(isa<FileVarDecl>(D) && "Unknown global decl!");
+  
+  return Entry = new llvm::GlobalVariable(Ty, false, 
+                                          llvm::GlobalValue::ExternalLinkage,
+                                          0, D->getName(), &getModule());
+}
+
+void CodeGenModule::EmitFunction(FunctionDecl *FD) {
+  // If this is not a prototype, emit the body.
+  if (FD->getBody())
+    CodeGenFunction(*this).GenerateCode(FD);
+}
+
+
+
+llvm::Function *CodeGenModule::getMemCpyFn() {
+  if (MemCpyFn) return MemCpyFn;
+  llvm::Intrinsic::ID IID;
+  switch (Context.Target.getPointerWidth(SourceLocation())) {
+  default: assert(0 && "Unknown ptr width");
+  case 32: IID = llvm::Intrinsic::memcpy_i32; break;
+  case 64: IID = llvm::Intrinsic::memcpy_i64; break;
+  }
+  return MemCpyFn = llvm::Intrinsic::getDeclaration(&TheModule, IID);
+}
diff --git a/CodeGen/CodeGenModule.h b/CodeGen/CodeGenModule.h
new file mode 100644
index 0000000..885fb97
--- /dev/null
+++ b/CodeGen/CodeGenModule.h
@@ -0,0 +1,60 @@
+//===--- CodeGenModule.h - Per-Module state for LLVM CodeGen --------------===//
+//
+//                     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 is the internal per-translation-unit state used for llvm translation. 
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_CODEGENMODULE_H
+#define CODEGEN_CODEGENMODULE_H
+
+#include "CodeGenTypes.h"
+#include "llvm/ADT/DenseMap.h"
+
+namespace llvm {
+  class Module;
+  class Constant;
+  class Function;
+}
+
+namespace clang {
+  class ASTContext;
+  class FunctionDecl;
+  class Decl;
+    
+namespace CodeGen {
+
+/// CodeGenModule - This class organizes the cross-module state that is used
+/// while generating LLVM code.
+class CodeGenModule {
+  ASTContext &Context;
+  llvm::Module &TheModule;
+  CodeGenTypes Types;
+
+  llvm::Function *MemCpyFn;
+  llvm::DenseMap<const Decl*, llvm::Constant*> GlobalDeclMap;
+public:
+  CodeGenModule(ASTContext &C, llvm::Module &M);
+  
+  ASTContext &getContext() const { return Context; }
+  llvm::Module &getModule() const { return TheModule; }
+  CodeGenTypes &getTypes() { return Types; }
+  
+  llvm::Constant *GetAddrOfGlobalDecl(const Decl *D);
+  
+  llvm::Function *getMemCpyFn();
+  
+  void EmitFunction(FunctionDecl *FD);
+  
+  void PrintStats() {}
+};
+}  // end namespace CodeGen
+}  // end namespace clang
+
+#endif
diff --git a/CodeGen/CodeGenTypes.cpp b/CodeGen/CodeGenTypes.cpp
new file mode 100644
index 0000000..f0b7790
--- /dev/null
+++ b/CodeGen/CodeGenTypes.cpp
@@ -0,0 +1,151 @@
+//===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===//
+//
+//                     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 is the code that handles AST -> LLVM type lowering. 
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenTypes.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/AST/AST.h"
+#include "llvm/DerivedTypes.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+
+/// ConvertType - Convert the specified type to its LLVM form.
+const llvm::Type *CodeGenTypes::ConvertType(QualType T) {
+  // FIXME: Cache these, move the CodeGenModule, expand, etc.
+  const clang::Type &Ty = *T.getCanonicalType();
+  
+  switch (Ty.getTypeClass()) {
+  case Type::Builtin: {
+    switch (cast<BuiltinType>(Ty).getKind()) {
+    case BuiltinType::Void:
+      // LLVM void type can only be used as the result of a function call.  Just
+      // map to the same as char.
+    case BuiltinType::Char_S:
+    case BuiltinType::Char_U:
+    case BuiltinType::SChar:
+    case BuiltinType::UChar:
+      return llvm::IntegerType::get(Target.getCharWidth(SourceLocation()));
+
+    case BuiltinType::Bool:
+      // FIXME: This is very strange.  We want scalars to be i1, but in memory
+      // they can be i1 or i32.  Should the codegen handle this issue?
+      return llvm::Type::Int1Ty;
+      
+    case BuiltinType::Short:
+    case BuiltinType::UShort:
+      return llvm::IntegerType::get(Target.getShortWidth(SourceLocation()));
+      
+    case BuiltinType::Int:
+    case BuiltinType::UInt:
+      return llvm::IntegerType::get(Target.getIntWidth(SourceLocation()));
+
+    case BuiltinType::Long:
+    case BuiltinType::ULong:
+      return llvm::IntegerType::get(Target.getLongWidth(SourceLocation()));
+
+    case BuiltinType::LongLong:
+    case BuiltinType::ULongLong:
+      return llvm::IntegerType::get(Target.getLongLongWidth(SourceLocation()));
+      
+    case BuiltinType::Float:      return llvm::Type::FloatTy;
+    case BuiltinType::Double:     return llvm::Type::DoubleTy;
+    case BuiltinType::LongDouble:
+      // FIXME: mapping long double onto double.
+      return llvm::Type::DoubleTy;
+    }
+    break;
+  }
+  case Type::Complex: {
+    std::vector<const llvm::Type*> Elts;
+    Elts.push_back(ConvertType(cast<ComplexType>(Ty).getElementType()));
+    Elts.push_back(Elts[0]);
+    return llvm::StructType::get(Elts);
+  }
+  case Type::Pointer: {
+    const PointerType &P = cast<PointerType>(Ty);
+    return llvm::PointerType::get(ConvertType(P.getPointeeType())); 
+  }
+  case Type::Reference: {
+    const ReferenceType &R = cast<ReferenceType>(Ty);
+    return llvm::PointerType::get(ConvertType(R.getReferenceeType()));
+  }
+    
+  case Type::Array: {
+    const ArrayType &A = cast<ArrayType>(Ty);
+    assert(A.getSizeModifier() == ArrayType::Normal &&
+           A.getIndexTypeQualifier() == 0 &&
+           "FIXME: We only handle trivial array types so far!");
+    
+    llvm::APSInt Size(32);
+    if (A.getSize() && A.getSize()->isIntegerConstantExpr(Size)) {
+      const llvm::Type *EltTy = ConvertType(A.getElementType());
+      return llvm::ArrayType::get(EltTy, Size.getZExtValue());
+    } else {
+      assert(0 && "FIXME: VLAs not implemented yet!");
+    }
+  }
+  case Type::Vector: {
+    const VectorType &VT = cast<VectorType>(Ty);
+    return llvm::VectorType::get(ConvertType(VT.getElementType()),
+                                 VT.getNumElements());
+  }
+  case Type::FunctionNoProto:
+  case Type::FunctionProto: {
+    const FunctionType &FP = cast<FunctionType>(Ty);
+    const llvm::Type *ResultType;
+    
+    if (FP.getResultType()->isVoidType())
+      ResultType = llvm::Type::VoidTy;    // Result of function uses llvm void.
+    else
+      ResultType = ConvertType(FP.getResultType());
+    
+    // FIXME: Convert argument types.
+    bool isVarArg;
+    std::vector<const llvm::Type*> ArgTys;
+    
+    // Struct return passes the struct byref.
+    if (!ResultType->isFirstClassType() && ResultType != llvm::Type::VoidTy) {
+      ArgTys.push_back(llvm::PointerType::get(ResultType));
+      ResultType = llvm::Type::VoidTy;
+    }
+    
+    if (const FunctionTypeProto *FTP = dyn_cast<FunctionTypeProto>(&FP)) {
+      DecodeArgumentTypes(*FTP, ArgTys);
+      isVarArg = FTP->isVariadic();
+    } else {
+      isVarArg = true;
+    }
+    
+    return llvm::FunctionType::get(ResultType, ArgTys, isVarArg, 0);
+  }
+  case Type::TypeName:
+  case Type::Tagged:
+    break;
+  }
+  
+  // FIXME: implement.
+  return llvm::OpaqueType::get();
+}
+
+void CodeGenTypes::DecodeArgumentTypes(const FunctionTypeProto &FTP, 
+                                       std::vector<const llvm::Type*> &ArgTys) {
+  for (unsigned i = 0, e = FTP.getNumArgs(); i != e; ++i) {
+    const llvm::Type *Ty = ConvertType(FTP.getArgType(i));
+    if (Ty->isFirstClassType())
+      ArgTys.push_back(Ty);
+    else
+      ArgTys.push_back(llvm::PointerType::get(Ty));
+  }
+}
+
diff --git a/CodeGen/CodeGenTypes.h b/CodeGen/CodeGenTypes.h
new file mode 100644
index 0000000..dd322a1
--- /dev/null
+++ b/CodeGen/CodeGenTypes.h
@@ -0,0 +1,47 @@
+//===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- C++ -*-===//
+//
+//                     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 is the code that handles AST -> LLVM type lowering. 
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_CODEGENTYPES_H
+#define CODEGEN_CODEGENTYPES_H
+
+#include <vector>
+
+namespace llvm {
+  class Type;
+}
+
+namespace clang {
+  class TargetInfo;
+  class QualType;
+  class FunctionTypeProto;
+  
+namespace CodeGen {
+  
+/// CodeGenTypes - This class organizes the cross-module state that is used
+/// while lowering AST types to LLVM types.
+class CodeGenTypes {
+  TargetInfo &Target;
+  
+public:
+  CodeGenTypes(TargetInfo &target) : Target(target) {}
+  
+  TargetInfo &getTarget() const { return Target; }
+  
+  const llvm::Type *ConvertType(QualType T);
+  void DecodeArgumentTypes(const FunctionTypeProto &FTP, 
+                           std::vector<const llvm::Type*> &ArgTys);
+};
+}  // end namespace CodeGen
+}  // end namespace clang
+
+#endif
diff --git a/CodeGen/Makefile b/CodeGen/Makefile
new file mode 100644
index 0000000..5e6f705
--- /dev/null
+++ b/CodeGen/Makefile
@@ -0,0 +1,23 @@
+##===- clang/CodeGen/Makefile ------------------------------*- Makefile -*-===##
+# 
+#                     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 implements the AST -> LLVM code generation library for the 
+# C-Language front-end.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+LIBRARYNAME := clangCodeGen
+BUILD_ARCHIVE = 1
+CXXFLAGS = -fno-rtti
+
+CPPFLAGS += -I$(PROJ_SRC_DIR)/../include
+
+include $(LEVEL)/Makefile.common
+
diff --git a/CodeGen/ModuleBuilder.cpp b/CodeGen/ModuleBuilder.cpp
new file mode 100644
index 0000000..16b13d1
--- /dev/null
+++ b/CodeGen/ModuleBuilder.cpp
@@ -0,0 +1,39 @@
+//===--- ModuleBuilder.cpp - Emit LLVM Code from ASTs ---------------------===//
+//
+//                     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 builds an AST and converts it to LLVM Code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CodeGen/ModuleBuilder.h"
+#include "CodeGenModule.h"
+using namespace clang;
+
+
+/// Init - Create an ModuleBuilder with the specified ASTContext.
+clang::CodeGen::BuilderTy *
+clang::CodeGen::Init(ASTContext &Context, llvm::Module &M) {
+  return new CodeGenModule(Context, M);
+}
+
+void clang::CodeGen::Terminate(BuilderTy *B) {
+  delete static_cast<CodeGenModule*>(B);
+}
+
+/// CodeGenFunction - Convert the AST node for a FunctionDecl into LLVM.
+///
+void clang::CodeGen::CodeGenFunction(BuilderTy *B, FunctionDecl *D) {
+  static_cast<CodeGenModule*>(B)->EmitFunction(D);
+}
+
+/// PrintStats - Emit statistic information to stderr.
+///
+void clang::CodeGen::PrintStats(BuilderTy *B) {
+  static_cast<CodeGenModule*>(B)->PrintStats();
+}