Start basic support for LLVM 2.9 bitcode writer.

Change-Id: I6a54158a32e485f506f0b991f89125b8a0e60267
diff --git a/Android.mk b/Android.mk
index deae802..49e1a68 100644
--- a/Android.mk
+++ b/Android.mk
@@ -38,6 +38,7 @@
 	libLLVMLinker   \
 	libLLVMipo	\
 	libLLVMBitWriter	\
+	libLLVMBitWriter_2_9  \
 	libLLVMBitReader	\
 	libLLVMARMCodeGen	\
 	libLLVMARMAsmPrinter	\
@@ -249,3 +250,8 @@
 include $(BUILD_HOST_EXECUTABLE)
 
 endif  # TARGET_BUILD_APPS
+
+#=====================================================================
+# Include Subdirectories
+#=====================================================================
+include $(call all-makefiles-under,$(LOCAL_PATH))
diff --git a/BitWriter_2_9/Android.mk b/BitWriter_2_9/Android.mk
new file mode 100644
index 0000000..28d3133
--- /dev/null
+++ b/BitWriter_2_9/Android.mk
@@ -0,0 +1,26 @@
+LOCAL_PATH:= $(call my-dir)
+
+LLVM_ROOT_PATH := $(LOCAL_PATH)/../../../../external/llvm
+include $(LLVM_ROOT_PATH)/llvm.mk
+
+LOCAL_CFLAGS += $(local_cflags_for_slang)
+
+bitcode_writer_2_9_SRC_FILES :=	\
+	BitcodeWriter.cpp	\
+	BitcodeWriterPass.cpp	\
+	ValueEnumerator.cpp
+
+# For the host
+# =====================================================
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := $(bitcode_writer_2_9_SRC_FILES)
+
+LOCAL_MODULE:= libLLVMBitWriter_2_9
+
+LOCAL_MODULE_TAGS := optional
+
+include $(LLVM_HOST_BUILD_MK)
+include $(LLVM_GEN_INTRINSICS_MK)
+include $(BUILD_HOST_STATIC_LIBRARY)
+
diff --git a/BitWriter_2_9/BitcodeWriter.cpp b/BitWriter_2_9/BitcodeWriter.cpp
new file mode 100644
index 0000000..38a12d7
--- /dev/null
+++ b/BitWriter_2_9/BitcodeWriter.cpp
@@ -0,0 +1,1696 @@
+//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Bitcode writer implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ReaderWriter_2_9.h"
+#include "llvm/Bitcode/BitstreamWriter.h"
+#include "llvm/Bitcode/LLVMBitCodes.h"
+#include "ValueEnumerator.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+#include "llvm/Operator.h"
+#include "llvm/ValueSymbolTable.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Program.h"
+#include <cctype>
+#include <map>
+using namespace llvm;
+
+/// These are manifest constants used by the bitcode writer. They do not need to
+/// be kept in sync with the reader, but need to be consistent within this file.
+enum {
+  CurVersion = 0,
+
+  // VALUE_SYMTAB_BLOCK abbrev id's.
+  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
+  VST_ENTRY_7_ABBREV,
+  VST_ENTRY_6_ABBREV,
+  VST_BBENTRY_6_ABBREV,
+
+  // CONSTANTS_BLOCK abbrev id's.
+  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
+  CONSTANTS_INTEGER_ABBREV,
+  CONSTANTS_CE_CAST_Abbrev,
+  CONSTANTS_NULL_Abbrev,
+
+  // FUNCTION_BLOCK abbrev id's.
+  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
+  FUNCTION_INST_BINOP_ABBREV,
+  FUNCTION_INST_BINOP_FLAGS_ABBREV,
+  FUNCTION_INST_CAST_ABBREV,
+  FUNCTION_INST_RET_VOID_ABBREV,
+  FUNCTION_INST_RET_VAL_ABBREV,
+  FUNCTION_INST_UNREACHABLE_ABBREV
+};
+
+
+static unsigned GetEncodedCastOpcode(unsigned Opcode) {
+  switch (Opcode) {
+  default: llvm_unreachable("Unknown cast instruction!");
+  case Instruction::Trunc   : return bitc::CAST_TRUNC;
+  case Instruction::ZExt    : return bitc::CAST_ZEXT;
+  case Instruction::SExt    : return bitc::CAST_SEXT;
+  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
+  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
+  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
+  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
+  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
+  case Instruction::FPExt   : return bitc::CAST_FPEXT;
+  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
+  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
+  case Instruction::BitCast : return bitc::CAST_BITCAST;
+  }
+}
+
+static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
+  switch (Opcode) {
+  default: llvm_unreachable("Unknown binary instruction!");
+  case Instruction::Add:
+  case Instruction::FAdd: return bitc::BINOP_ADD;
+  case Instruction::Sub:
+  case Instruction::FSub: return bitc::BINOP_SUB;
+  case Instruction::Mul:
+  case Instruction::FMul: return bitc::BINOP_MUL;
+  case Instruction::UDiv: return bitc::BINOP_UDIV;
+  case Instruction::FDiv:
+  case Instruction::SDiv: return bitc::BINOP_SDIV;
+  case Instruction::URem: return bitc::BINOP_UREM;
+  case Instruction::FRem:
+  case Instruction::SRem: return bitc::BINOP_SREM;
+  case Instruction::Shl:  return bitc::BINOP_SHL;
+  case Instruction::LShr: return bitc::BINOP_LSHR;
+  case Instruction::AShr: return bitc::BINOP_ASHR;
+  case Instruction::And:  return bitc::BINOP_AND;
+  case Instruction::Or:   return bitc::BINOP_OR;
+  case Instruction::Xor:  return bitc::BINOP_XOR;
+  }
+}
+
+static void WriteStringRecord(unsigned Code, StringRef Str,
+                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
+  SmallVector<unsigned, 64> Vals;
+
+  // Code: [strchar x N]
+  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
+      AbbrevToUse = 0;
+    Vals.push_back(Str[i]);
+  }
+
+  // Emit the finished record.
+  Stream.EmitRecord(Code, Vals, AbbrevToUse);
+}
+
+// Emit information about parameter attributes.
+static void WriteAttributeTable(const ValueEnumerator &VE,
+                                BitstreamWriter &Stream) {
+  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
+  if (Attrs.empty()) return;
+
+  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
+
+  SmallVector<uint64_t, 64> Record;
+  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
+    const AttrListPtr &A = Attrs[i];
+    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
+      const AttributeWithIndex &PAWI = A.getSlot(i);
+      Record.push_back(PAWI.Index);
+
+      // FIXME: remove in LLVM 3.0
+      // Store the alignment in the bitcode as a 16-bit raw value instead of a
+      // 5-bit log2 encoded value. Shift the bits above the alignment up by
+      // 11 bits.
+      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
+      if (PAWI.Attrs & Attribute::Alignment)
+        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
+      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
+
+      Record.push_back(FauxAttr);
+    }
+
+    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
+    Record.clear();
+  }
+
+  Stream.ExitBlock();
+}
+
+static void WriteTypeSymbolTable(const ValueEnumerator &VE,
+                                 BitstreamWriter &Stream) {
+  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
+  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID_OLD, 3);
+
+  // 7-bit fixed width VST_CODE_ENTRY strings.
+  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
+  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
+
+  SmallVector<unsigned, 64> NameVals;
+
+  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
+    Type *T = TypeList[i];
+
+    switch (T->getTypeID()) {
+    case Type::StructTyID: {
+      StructType *ST = cast<StructType>(T);
+      if (ST->isAnonymous()) {
+        // Skip anonymous struct definitions in type symbol table
+        // FIXME(srhines)
+        break;
+      }
+
+      // TST_ENTRY: [typeid, namechar x N]
+      NameVals.push_back(i);
+
+      const std::string &Str = ST->getName();
+      bool is7Bit = true;
+      for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+        NameVals.push_back((unsigned char)Str[i]);
+        if (Str[i] & 128)
+          is7Bit = false;
+      }
+
+      // Emit the finished record.
+      Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
+      NameVals.clear();
+
+      break;
+    }
+    default: break;
+    }
+  }
+
+#if 0
+  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
+       TI != TE; ++TI) {
+    // TST_ENTRY: [typeid, namechar x N]
+    NameVals.push_back(VE.getTypeID(TI->second));
+
+    const std::string &Str = TI->first;
+    bool is7Bit = true;
+    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+      NameVals.push_back((unsigned char)Str[i]);
+      if (Str[i] & 128)
+        is7Bit = false;
+    }
+
+    // Emit the finished record.
+    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
+    NameVals.clear();
+  }
+#endif
+
+  Stream.ExitBlock();
+}
+
+/// WriteTypeTable - Write out the type table for a module.
+static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
+  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
+
+  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_OLD, 4 /*count from # abbrevs */);
+  SmallVector<uint64_t, 64> TypeVals;
+
+  // Abbrev for TYPE_CODE_POINTER.
+  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
+  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
+
+  // Abbrev for TYPE_CODE_FUNCTION.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
+  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
+
+#if 0
+  // Abbrev for TYPE_CODE_STRUCT_ANON.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
+
+  // Abbrev for TYPE_CODE_STRUCT_NAME.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
+  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
+
+  // Abbrev for TYPE_CODE_STRUCT_NAMED.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
+#endif
+
+  // Abbrev for TYPE_CODE_STRUCT.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_OLD));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
+
+  // Abbrev for TYPE_CODE_ARRAY.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
+  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                            Log2_32_Ceil(VE.getTypes().size()+1)));
+  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
+
+  // Emit an entry count so the reader can reserve space.
+  TypeVals.push_back(TypeList.size());
+  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
+  TypeVals.clear();
+
+  // Loop over all of the types, emitting each in turn.
+  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
+    Type *T = TypeList[i];
+    int AbbrevToUse = 0;
+    unsigned Code = 0;
+
+    switch (T->getTypeID()) {
+    default: llvm_unreachable("Unknown type!");
+    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
+    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
+    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
+    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
+    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
+    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
+    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
+    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
+    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
+    case Type::IntegerTyID:
+      // INTEGER: [width]
+      Code = bitc::TYPE_CODE_INTEGER;
+      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
+      break;
+    case Type::PointerTyID: {
+      PointerType *PTy = cast<PointerType>(T);
+      // POINTER: [pointee type, address space]
+      Code = bitc::TYPE_CODE_POINTER;
+      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
+      unsigned AddressSpace = PTy->getAddressSpace();
+      TypeVals.push_back(AddressSpace);
+      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
+      break;
+    }
+    case Type::FunctionTyID: {
+      FunctionType *FT = cast<FunctionType>(T);
+      // FUNCTION: [isvararg, attrid, retty, paramty x N]
+      Code = bitc::TYPE_CODE_FUNCTION;
+      TypeVals.push_back(FT->isVarArg());
+      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
+      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
+      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
+        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
+      AbbrevToUse = FunctionAbbrev;
+      break;
+    }
+    case Type::StructTyID: {
+      StructType *ST = cast<StructType>(T);
+      // STRUCT: [ispacked, eltty x N]
+      TypeVals.push_back(ST->isPacked());
+      // Output all of the element types.
+      for (StructType::element_iterator I = ST->element_begin(),
+           E = ST->element_end(); I != E; ++I)
+        TypeVals.push_back(VE.getTypeID(*I));
+      AbbrevToUse = StructAbbrev;
+      break;
+    }
+    case Type::ArrayTyID: {
+      ArrayType *AT = cast<ArrayType>(T);
+      // ARRAY: [numelts, eltty]
+      Code = bitc::TYPE_CODE_ARRAY;
+      TypeVals.push_back(AT->getNumElements());
+      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
+      AbbrevToUse = ArrayAbbrev;
+      break;
+    }
+    case Type::VectorTyID: {
+      VectorType *VT = cast<VectorType>(T);
+      // VECTOR [numelts, eltty]
+      Code = bitc::TYPE_CODE_VECTOR;
+      TypeVals.push_back(VT->getNumElements());
+      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
+      break;
+    }
+    }
+
+    // Emit the finished record.
+    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
+    TypeVals.clear();
+  }
+
+  Stream.ExitBlock();
+
+  WriteTypeSymbolTable(VE, Stream);
+}
+
+static unsigned getEncodedLinkage(const GlobalValue *GV) {
+  switch (GV->getLinkage()) {
+  default: llvm_unreachable("Invalid linkage!");
+  case GlobalValue::ExternalLinkage:                 return 0;
+  case GlobalValue::WeakAnyLinkage:                  return 1;
+  case GlobalValue::AppendingLinkage:                return 2;
+  case GlobalValue::InternalLinkage:                 return 3;
+  case GlobalValue::LinkOnceAnyLinkage:              return 4;
+  case GlobalValue::DLLImportLinkage:                return 5;
+  case GlobalValue::DLLExportLinkage:                return 6;
+  case GlobalValue::ExternalWeakLinkage:             return 7;
+  case GlobalValue::CommonLinkage:                   return 8;
+  case GlobalValue::PrivateLinkage:                  return 9;
+  case GlobalValue::WeakODRLinkage:                  return 10;
+  case GlobalValue::LinkOnceODRLinkage:              return 11;
+  case GlobalValue::AvailableExternallyLinkage:      return 12;
+  case GlobalValue::LinkerPrivateLinkage:            return 13;
+  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
+  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
+  }
+}
+
+static unsigned getEncodedVisibility(const GlobalValue *GV) {
+  switch (GV->getVisibility()) {
+  default: llvm_unreachable("Invalid visibility!");
+  case GlobalValue::DefaultVisibility:   return 0;
+  case GlobalValue::HiddenVisibility:    return 1;
+  case GlobalValue::ProtectedVisibility: return 2;
+  }
+}
+
+// Emit top-level description of module, including target triple, inline asm,
+// descriptors for global variables, and function prototype info.
+static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
+                            BitstreamWriter &Stream) {
+  // Emit the list of dependent libraries for the Module.
+  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
+    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
+
+  // Emit various pieces of data attached to a module.
+  if (!M->getTargetTriple().empty())
+    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
+                      0/*TODO*/, Stream);
+  if (!M->getDataLayout().empty())
+    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
+                      0/*TODO*/, Stream);
+  if (!M->getModuleInlineAsm().empty())
+    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
+                      0/*TODO*/, Stream);
+
+  // Emit information about sections and GC, computing how many there are. Also
+  // compute the maximum alignment value.
+  std::map<std::string, unsigned> SectionMap;
+  std::map<std::string, unsigned> GCMap;
+  unsigned MaxAlignment = 0;
+  unsigned MaxGlobalType = 0;
+  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
+       GV != E; ++GV) {
+    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
+    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
+
+    if (!GV->hasSection()) continue;
+    // Give section names unique ID's.
+    unsigned &Entry = SectionMap[GV->getSection()];
+    if (Entry != 0) continue;
+    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
+                      0/*TODO*/, Stream);
+    Entry = SectionMap.size();
+  }
+  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
+    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
+    if (F->hasSection()) {
+      // Give section names unique ID's.
+      unsigned &Entry = SectionMap[F->getSection()];
+      if (!Entry) {
+        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
+                          0/*TODO*/, Stream);
+        Entry = SectionMap.size();
+      }
+    }
+    if (F->hasGC()) {
+      // Same for GC names.
+      unsigned &Entry = GCMap[F->getGC()];
+      if (!Entry) {
+        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
+                          0/*TODO*/, Stream);
+        Entry = GCMap.size();
+      }
+    }
+  }
+
+  // Emit abbrev for globals, now that we know # sections and max alignment.
+  unsigned SimpleGVarAbbrev = 0;
+  if (!M->global_empty()) {
+    // Add an abbrev for common globals with no visibility or thread localness.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                              Log2_32_Ceil(MaxGlobalType+1)));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
+    if (MaxAlignment == 0)                                      // Alignment.
+      Abbv->Add(BitCodeAbbrevOp(0));
+    else {
+      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
+      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                               Log2_32_Ceil(MaxEncAlignment+1)));
+    }
+    if (SectionMap.empty())                                    // Section.
+      Abbv->Add(BitCodeAbbrevOp(0));
+    else
+      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                               Log2_32_Ceil(SectionMap.size()+1)));
+    // Don't bother emitting vis + thread local.
+    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
+  }
+
+  // Emit the global variable information.
+  SmallVector<unsigned, 64> Vals;
+  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
+       GV != E; ++GV) {
+    unsigned AbbrevToUse = 0;
+
+    // GLOBALVAR: [type, isconst, initid,
+    //             linkage, alignment, section, visibility, threadlocal,
+    //             unnamed_addr]
+    Vals.push_back(VE.getTypeID(GV->getType()));
+    Vals.push_back(GV->isConstant());
+    Vals.push_back(GV->isDeclaration() ? 0 :
+                   (VE.getValueID(GV->getInitializer()) + 1));
+    Vals.push_back(getEncodedLinkage(GV));
+    Vals.push_back(Log2_32(GV->getAlignment())+1);
+    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
+    if (GV->isThreadLocal() ||
+        GV->getVisibility() != GlobalValue::DefaultVisibility ||
+        GV->hasUnnamedAddr()) {
+      Vals.push_back(getEncodedVisibility(GV));
+      Vals.push_back(GV->isThreadLocal());
+      Vals.push_back(GV->hasUnnamedAddr());
+    } else {
+      AbbrevToUse = SimpleGVarAbbrev;
+    }
+
+    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
+    Vals.clear();
+  }
+
+  // Emit the function proto information.
+  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
+    // FUNCTION:  [type, callingconv, isproto, paramattr,
+    //             linkage, alignment, section, visibility, gc, unnamed_addr]
+    Vals.push_back(VE.getTypeID(F->getType()));
+    Vals.push_back(F->getCallingConv());
+    Vals.push_back(F->isDeclaration());
+    Vals.push_back(getEncodedLinkage(F));
+    Vals.push_back(VE.getAttributeID(F->getAttributes()));
+    Vals.push_back(Log2_32(F->getAlignment())+1);
+    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
+    Vals.push_back(getEncodedVisibility(F));
+    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
+    Vals.push_back(F->hasUnnamedAddr());
+
+    unsigned AbbrevToUse = 0;
+    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
+    Vals.clear();
+  }
+
+  // Emit the alias information.
+  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
+       AI != E; ++AI) {
+    Vals.push_back(VE.getTypeID(AI->getType()));
+    Vals.push_back(VE.getValueID(AI->getAliasee()));
+    Vals.push_back(getEncodedLinkage(AI));
+    Vals.push_back(getEncodedVisibility(AI));
+    unsigned AbbrevToUse = 0;
+    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
+    Vals.clear();
+  }
+}
+
+static uint64_t GetOptimizationFlags(const Value *V) {
+  uint64_t Flags = 0;
+
+  if (const OverflowingBinaryOperator *OBO =
+        dyn_cast<OverflowingBinaryOperator>(V)) {
+    if (OBO->hasNoSignedWrap())
+      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
+    if (OBO->hasNoUnsignedWrap())
+      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
+  } else if (const PossiblyExactOperator *PEO =
+               dyn_cast<PossiblyExactOperator>(V)) {
+    if (PEO->isExact())
+      Flags |= 1 << bitc::PEO_EXACT;
+  }
+
+  return Flags;
+}
+
+static void WriteMDNode(const MDNode *N,
+                        const ValueEnumerator &VE,
+                        BitstreamWriter &Stream,
+                        SmallVector<uint64_t, 64> &Record) {
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+    if (N->getOperand(i)) {
+      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
+      Record.push_back(VE.getValueID(N->getOperand(i)));
+    } else {
+      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
+      Record.push_back(0);
+    }
+  }
+  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
+                                           bitc::METADATA_NODE;
+  Stream.EmitRecord(MDCode, Record, 0);
+  Record.clear();
+}
+
+static void WriteModuleMetadata(const Module *M,
+                                const ValueEnumerator &VE,
+                                BitstreamWriter &Stream) {
+  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
+  bool StartedMetadataBlock = false;
+  unsigned MDSAbbrev = 0;
+  SmallVector<uint64_t, 64> Record;
+  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+
+    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
+      if (!N->isFunctionLocal() || !N->getFunction()) {
+        if (!StartedMetadataBlock) {
+          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+          StartedMetadataBlock = true;
+        }
+        WriteMDNode(N, VE, Stream, Record);
+      }
+    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
+      if (!StartedMetadataBlock)  {
+        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+
+        // Abbrev for METADATA_STRING.
+        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+        MDSAbbrev = Stream.EmitAbbrev(Abbv);
+        StartedMetadataBlock = true;
+      }
+
+      // Code: [strchar x N]
+      Record.append(MDS->begin(), MDS->end());
+
+      // Emit the finished record.
+      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
+      Record.clear();
+    }
+  }
+
+  // Write named metadata.
+  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
+       E = M->named_metadata_end(); I != E; ++I) {
+    const NamedMDNode *NMD = I;
+    if (!StartedMetadataBlock)  {
+      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+      StartedMetadataBlock = true;
+    }
+
+    // Write name.
+    StringRef Str = NMD->getName();
+    for (unsigned i = 0, e = Str.size(); i != e; ++i)
+      Record.push_back(Str[i]);
+    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
+    Record.clear();
+
+    // Write named metadata operands.
+    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
+      Record.push_back(VE.getValueID(NMD->getOperand(i)));
+    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
+    Record.clear();
+  }
+
+  if (StartedMetadataBlock)
+    Stream.ExitBlock();
+}
+
+static void WriteFunctionLocalMetadata(const Function &F,
+                                       const ValueEnumerator &VE,
+                                       BitstreamWriter &Stream) {
+  bool StartedMetadataBlock = false;
+  SmallVector<uint64_t, 64> Record;
+  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
+  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
+    if (const MDNode *N = Vals[i])
+      if (N->isFunctionLocal() && N->getFunction() == &F) {
+        if (!StartedMetadataBlock) {
+          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+          StartedMetadataBlock = true;
+        }
+        WriteMDNode(N, VE, Stream, Record);
+      }
+
+  if (StartedMetadataBlock)
+    Stream.ExitBlock();
+}
+
+static void WriteMetadataAttachment(const Function &F,
+                                    const ValueEnumerator &VE,
+                                    BitstreamWriter &Stream) {
+  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
+
+  SmallVector<uint64_t, 64> Record;
+
+  // Write metadata attachments
+  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
+  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
+
+  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
+    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
+         I != E; ++I) {
+      MDs.clear();
+      I->getAllMetadataOtherThanDebugLoc(MDs);
+
+      // If no metadata, ignore instruction.
+      if (MDs.empty()) continue;
+
+      Record.push_back(VE.getInstructionID(I));
+
+      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
+        Record.push_back(MDs[i].first);
+        Record.push_back(VE.getValueID(MDs[i].second));
+      }
+      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
+      Record.clear();
+    }
+
+  Stream.ExitBlock();
+}
+
+static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
+  SmallVector<uint64_t, 64> Record;
+
+  // Write metadata kinds
+  // METADATA_KIND - [n x [id, name]]
+  SmallVector<StringRef, 4> Names;
+  M->getMDKindNames(Names);
+
+  if (Names.empty()) return;
+
+  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+
+  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
+    Record.push_back(MDKindID);
+    StringRef KName = Names[MDKindID];
+    Record.append(KName.begin(), KName.end());
+
+    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
+    Record.clear();
+  }
+
+  Stream.ExitBlock();
+}
+
+static void WriteConstants(unsigned FirstVal, unsigned LastVal,
+                           const ValueEnumerator &VE,
+                           BitstreamWriter &Stream, bool isGlobal) {
+  if (FirstVal == LastVal) return;
+
+  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
+
+  unsigned AggregateAbbrev = 0;
+  unsigned String8Abbrev = 0;
+  unsigned CString7Abbrev = 0;
+  unsigned CString6Abbrev = 0;
+  // If this is a constant pool for the module, emit module-specific abbrevs.
+  if (isGlobal) {
+    // Abbrev for CST_CODE_AGGREGATE.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
+    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
+
+    // Abbrev for CST_CODE_STRING.
+    Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+    String8Abbrev = Stream.EmitAbbrev(Abbv);
+    // Abbrev for CST_CODE_CSTRING.
+    Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
+    CString7Abbrev = Stream.EmitAbbrev(Abbv);
+    // Abbrev for CST_CODE_CSTRING.
+    Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
+    CString6Abbrev = Stream.EmitAbbrev(Abbv);
+  }
+
+  SmallVector<uint64_t, 64> Record;
+
+  const ValueEnumerator::ValueList &Vals = VE.getValues();
+  Type *LastTy = 0;
+  for (unsigned i = FirstVal; i != LastVal; ++i) {
+    const Value *V = Vals[i].first;
+    // If we need to switch types, do so now.
+    if (V->getType() != LastTy) {
+      LastTy = V->getType();
+      Record.push_back(VE.getTypeID(LastTy));
+      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
+                        CONSTANTS_SETTYPE_ABBREV);
+      Record.clear();
+    }
+
+    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
+      Record.push_back(unsigned(IA->hasSideEffects()) |
+                       unsigned(IA->isAlignStack()) << 1);
+
+      // Add the asm string.
+      const std::string &AsmStr = IA->getAsmString();
+      Record.push_back(AsmStr.size());
+      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
+        Record.push_back(AsmStr[i]);
+
+      // Add the constraint string.
+      const std::string &ConstraintStr = IA->getConstraintString();
+      Record.push_back(ConstraintStr.size());
+      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
+        Record.push_back(ConstraintStr[i]);
+      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
+      Record.clear();
+      continue;
+    }
+    const Constant *C = cast<Constant>(V);
+    unsigned Code = -1U;
+    unsigned AbbrevToUse = 0;
+    if (C->isNullValue()) {
+      Code = bitc::CST_CODE_NULL;
+    } else if (isa<UndefValue>(C)) {
+      Code = bitc::CST_CODE_UNDEF;
+    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
+      if (IV->getBitWidth() <= 64) {
+        uint64_t V = IV->getSExtValue();
+        if ((int64_t)V >= 0)
+          Record.push_back(V << 1);
+        else
+          Record.push_back((-V << 1) | 1);
+        Code = bitc::CST_CODE_INTEGER;
+        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
+      } else {                             // Wide integers, > 64 bits in size.
+        // We have an arbitrary precision integer value to write whose
+        // bit width is > 64. However, in canonical unsigned integer
+        // format it is likely that the high bits are going to be zero.
+        // So, we only write the number of active words.
+        unsigned NWords = IV->getValue().getActiveWords();
+        const uint64_t *RawWords = IV->getValue().getRawData();
+        for (unsigned i = 0; i != NWords; ++i) {
+          int64_t V = RawWords[i];
+          if (V >= 0)
+            Record.push_back(V << 1);
+          else
+            Record.push_back((-V << 1) | 1);
+        }
+        Code = bitc::CST_CODE_WIDE_INTEGER;
+      }
+    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+      Code = bitc::CST_CODE_FLOAT;
+      Type *Ty = CFP->getType();
+      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
+        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
+      } else if (Ty->isX86_FP80Ty()) {
+        // api needed to prevent premature destruction
+        // bits are not in the same order as a normal i80 APInt, compensate.
+        APInt api = CFP->getValueAPF().bitcastToAPInt();
+        const uint64_t *p = api.getRawData();
+        Record.push_back((p[1] << 48) | (p[0] >> 16));
+        Record.push_back(p[0] & 0xffffLL);
+      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
+        APInt api = CFP->getValueAPF().bitcastToAPInt();
+        const uint64_t *p = api.getRawData();
+        Record.push_back(p[0]);
+        Record.push_back(p[1]);
+      } else {
+        assert (0 && "Unknown FP type!");
+      }
+    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
+      const ConstantArray *CA = cast<ConstantArray>(C);
+      // Emit constant strings specially.
+      unsigned NumOps = CA->getNumOperands();
+      // If this is a null-terminated string, use the denser CSTRING encoding.
+      if (CA->getOperand(NumOps-1)->isNullValue()) {
+        Code = bitc::CST_CODE_CSTRING;
+        --NumOps;  // Don't encode the null, which isn't allowed by char6.
+      } else {
+        Code = bitc::CST_CODE_STRING;
+        AbbrevToUse = String8Abbrev;
+      }
+      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
+      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
+      for (unsigned i = 0; i != NumOps; ++i) {
+        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
+        Record.push_back(V);
+        isCStr7 &= (V & 128) == 0;
+        if (isCStrChar6)
+          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
+      }
+
+      if (isCStrChar6)
+        AbbrevToUse = CString6Abbrev;
+      else if (isCStr7)
+        AbbrevToUse = CString7Abbrev;
+    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
+               isa<ConstantVector>(V)) {
+      Code = bitc::CST_CODE_AGGREGATE;
+      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
+        Record.push_back(VE.getValueID(C->getOperand(i)));
+      AbbrevToUse = AggregateAbbrev;
+    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+      switch (CE->getOpcode()) {
+      default:
+        if (Instruction::isCast(CE->getOpcode())) {
+          Code = bitc::CST_CODE_CE_CAST;
+          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
+          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
+          Record.push_back(VE.getValueID(C->getOperand(0)));
+          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
+        } else {
+          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
+          Code = bitc::CST_CODE_CE_BINOP;
+          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
+          Record.push_back(VE.getValueID(C->getOperand(0)));
+          Record.push_back(VE.getValueID(C->getOperand(1)));
+          uint64_t Flags = GetOptimizationFlags(CE);
+          if (Flags != 0)
+            Record.push_back(Flags);
+        }
+        break;
+      case Instruction::GetElementPtr:
+        Code = bitc::CST_CODE_CE_GEP;
+        if (cast<GEPOperator>(C)->isInBounds())
+          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
+        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
+          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
+          Record.push_back(VE.getValueID(C->getOperand(i)));
+        }
+        break;
+      case Instruction::Select:
+        Code = bitc::CST_CODE_CE_SELECT;
+        Record.push_back(VE.getValueID(C->getOperand(0)));
+        Record.push_back(VE.getValueID(C->getOperand(1)));
+        Record.push_back(VE.getValueID(C->getOperand(2)));
+        break;
+      case Instruction::ExtractElement:
+        Code = bitc::CST_CODE_CE_EXTRACTELT;
+        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
+        Record.push_back(VE.getValueID(C->getOperand(0)));
+        Record.push_back(VE.getValueID(C->getOperand(1)));
+        break;
+      case Instruction::InsertElement:
+        Code = bitc::CST_CODE_CE_INSERTELT;
+        Record.push_back(VE.getValueID(C->getOperand(0)));
+        Record.push_back(VE.getValueID(C->getOperand(1)));
+        Record.push_back(VE.getValueID(C->getOperand(2)));
+        break;
+      case Instruction::ShuffleVector:
+        // If the return type and argument types are the same, this is a
+        // standard shufflevector instruction.  If the types are different,
+        // then the shuffle is widening or truncating the input vectors, and
+        // the argument type must also be encoded.
+        if (C->getType() == C->getOperand(0)->getType()) {
+          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
+        } else {
+          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
+          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
+        }
+        Record.push_back(VE.getValueID(C->getOperand(0)));
+        Record.push_back(VE.getValueID(C->getOperand(1)));
+        Record.push_back(VE.getValueID(C->getOperand(2)));
+        break;
+      case Instruction::ICmp:
+      case Instruction::FCmp:
+        Code = bitc::CST_CODE_CE_CMP;
+        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
+        Record.push_back(VE.getValueID(C->getOperand(0)));
+        Record.push_back(VE.getValueID(C->getOperand(1)));
+        Record.push_back(CE->getPredicate());
+        break;
+      }
+    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
+      Code = bitc::CST_CODE_BLOCKADDRESS;
+      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
+      Record.push_back(VE.getValueID(BA->getFunction()));
+      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
+    } else {
+#ifndef NDEBUG
+      C->dump();
+#endif
+      llvm_unreachable("Unknown constant!");
+    }
+    Stream.EmitRecord(Code, Record, AbbrevToUse);
+    Record.clear();
+  }
+
+  Stream.ExitBlock();
+}
+
+static void WriteModuleConstants(const ValueEnumerator &VE,
+                                 BitstreamWriter &Stream) {
+  const ValueEnumerator::ValueList &Vals = VE.getValues();
+
+  // Find the first constant to emit, which is the first non-globalvalue value.
+  // We know globalvalues have been emitted by WriteModuleInfo.
+  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+    if (!isa<GlobalValue>(Vals[i].first)) {
+      WriteConstants(i, Vals.size(), VE, Stream, true);
+      return;
+    }
+  }
+}
+
+/// PushValueAndType - The file has to encode both the value and type id for
+/// many values, because we need to know what type to create for forward
+/// references.  However, most operands are not forward references, so this type
+/// field is not needed.
+///
+/// This function adds V's value ID to Vals.  If the value ID is higher than the
+/// instruction ID, then it is a forward reference, and it also includes the
+/// type ID.
+static bool PushValueAndType(const Value *V, unsigned InstID,
+                             SmallVector<unsigned, 64> &Vals,
+                             ValueEnumerator &VE) {
+  unsigned ValID = VE.getValueID(V);
+  Vals.push_back(ValID);
+  if (ValID >= InstID) {
+    Vals.push_back(VE.getTypeID(V->getType()));
+    return true;
+  }
+  return false;
+}
+
+/// WriteInstruction - Emit an instruction to the specified stream.
+static void WriteInstruction(const Instruction &I, unsigned InstID,
+                             ValueEnumerator &VE, BitstreamWriter &Stream,
+                             SmallVector<unsigned, 64> &Vals) {
+  unsigned Code = 0;
+  unsigned AbbrevToUse = 0;
+  VE.setInstructionID(&I);
+  switch (I.getOpcode()) {
+  default:
+    if (Instruction::isCast(I.getOpcode())) {
+      Code = bitc::FUNC_CODE_INST_CAST;
+      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
+        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
+      Vals.push_back(VE.getTypeID(I.getType()));
+      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
+    } else {
+      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
+      Code = bitc::FUNC_CODE_INST_BINOP;
+      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
+        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
+      Vals.push_back(VE.getValueID(I.getOperand(1)));
+      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
+      uint64_t Flags = GetOptimizationFlags(&I);
+      if (Flags != 0) {
+        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
+          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
+        Vals.push_back(Flags);
+      }
+    }
+    break;
+
+  case Instruction::GetElementPtr:
+    Code = bitc::FUNC_CODE_INST_GEP;
+    if (cast<GEPOperator>(&I)->isInBounds())
+      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
+    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
+      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
+    break;
+  case Instruction::ExtractValue: {
+    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
+    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
+      Vals.push_back(*i);
+    break;
+  }
+  case Instruction::InsertValue: {
+    Code = bitc::FUNC_CODE_INST_INSERTVAL;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
+    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
+    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
+      Vals.push_back(*i);
+    break;
+  }
+  case Instruction::Select:
+    Code = bitc::FUNC_CODE_INST_VSELECT;
+    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
+    Vals.push_back(VE.getValueID(I.getOperand(2)));
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    break;
+  case Instruction::ExtractElement:
+    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    Vals.push_back(VE.getValueID(I.getOperand(1)));
+    break;
+  case Instruction::InsertElement:
+    Code = bitc::FUNC_CODE_INST_INSERTELT;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    Vals.push_back(VE.getValueID(I.getOperand(1)));
+    Vals.push_back(VE.getValueID(I.getOperand(2)));
+    break;
+  case Instruction::ShuffleVector:
+    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    Vals.push_back(VE.getValueID(I.getOperand(1)));
+    Vals.push_back(VE.getValueID(I.getOperand(2)));
+    break;
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    // compare returning Int1Ty or vector of Int1Ty
+    Code = bitc::FUNC_CODE_INST_CMP2;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    Vals.push_back(VE.getValueID(I.getOperand(1)));
+    Vals.push_back(cast<CmpInst>(I).getPredicate());
+    break;
+
+  case Instruction::Ret:
+    {
+      Code = bitc::FUNC_CODE_INST_RET;
+      unsigned NumOperands = I.getNumOperands();
+      if (NumOperands == 0)
+        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
+      else if (NumOperands == 1) {
+        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
+          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
+      } else {
+        for (unsigned i = 0, e = NumOperands; i != e; ++i)
+          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
+      }
+    }
+    break;
+  case Instruction::Br:
+    {
+      Code = bitc::FUNC_CODE_INST_BR;
+      BranchInst &II = cast<BranchInst>(I);
+      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
+      if (II.isConditional()) {
+        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
+        Vals.push_back(VE.getValueID(II.getCondition()));
+      }
+    }
+    break;
+  case Instruction::Switch:
+    Code = bitc::FUNC_CODE_INST_SWITCH;
+    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
+    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
+      Vals.push_back(VE.getValueID(I.getOperand(i)));
+    break;
+  case Instruction::IndirectBr:
+    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
+    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
+    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
+      Vals.push_back(VE.getValueID(I.getOperand(i)));
+    break;
+
+  case Instruction::Invoke: {
+    const InvokeInst *II = cast<InvokeInst>(&I);
+    const Value *Callee(II->getCalledValue());
+    PointerType *PTy = cast<PointerType>(Callee->getType());
+    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+    Code = bitc::FUNC_CODE_INST_INVOKE;
+
+    Vals.push_back(VE.getAttributeID(II->getAttributes()));
+    Vals.push_back(II->getCallingConv());
+    Vals.push_back(VE.getValueID(II->getNormalDest()));
+    Vals.push_back(VE.getValueID(II->getUnwindDest()));
+    PushValueAndType(Callee, InstID, Vals, VE);
+
+    // Emit value #'s for the fixed parameters.
+    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
+      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
+
+    // Emit type/value pairs for varargs params.
+    if (FTy->isVarArg()) {
+      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
+           i != e; ++i)
+        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
+    }
+    break;
+  }
+  case Instruction::Unwind:
+    Code = bitc::FUNC_CODE_INST_UNWIND;
+    break;
+  case Instruction::Unreachable:
+    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
+    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
+    break;
+
+  case Instruction::PHI: {
+    const PHINode &PN = cast<PHINode>(I);
+    Code = bitc::FUNC_CODE_INST_PHI;
+    Vals.push_back(VE.getTypeID(PN.getType()));
+    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
+      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
+      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
+    }
+    break;
+  }
+
+  case Instruction::Alloca:
+    Code = bitc::FUNC_CODE_INST_ALLOCA;
+    Vals.push_back(VE.getTypeID(I.getType()));
+    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
+    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
+    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
+    break;
+
+  case Instruction::Load:
+    Code = bitc::FUNC_CODE_INST_LOAD;
+    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
+      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
+
+    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
+    Vals.push_back(cast<LoadInst>(I).isVolatile());
+    break;
+  case Instruction::Store:
+    Code = bitc::FUNC_CODE_INST_STORE;
+    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
+    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
+    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
+    Vals.push_back(cast<StoreInst>(I).isVolatile());
+    break;
+  case Instruction::Call: {
+    const CallInst &CI = cast<CallInst>(I);
+    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
+    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+
+    Code = bitc::FUNC_CODE_INST_CALL;
+
+    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
+    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
+    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
+
+    // Emit value #'s for the fixed parameters.
+    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
+      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
+
+    // Emit type/value pairs for varargs params.
+    if (FTy->isVarArg()) {
+      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
+           i != e; ++i)
+        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
+    }
+    break;
+  }
+  case Instruction::VAArg:
+    Code = bitc::FUNC_CODE_INST_VAARG;
+    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
+    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
+    Vals.push_back(VE.getTypeID(I.getType())); // restype.
+    break;
+  }
+
+  Stream.EmitRecord(Code, Vals, AbbrevToUse);
+  Vals.clear();
+}
+
+// Emit names for globals/functions etc.
+static void WriteValueSymbolTable(const ValueSymbolTable &VST,
+                                  const ValueEnumerator &VE,
+                                  BitstreamWriter &Stream) {
+  if (VST.empty()) return;
+  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
+
+  // FIXME: Set up the abbrev, we know how many values there are!
+  // FIXME: We know if the type names can use 7-bit ascii.
+  SmallVector<unsigned, 64> NameVals;
+
+  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
+       SI != SE; ++SI) {
+
+    const ValueName &Name = *SI;
+
+    // Figure out the encoding to use for the name.
+    bool is7Bit = true;
+    bool isChar6 = true;
+    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
+         C != E; ++C) {
+      if (isChar6)
+        isChar6 = BitCodeAbbrevOp::isChar6(*C);
+      if ((unsigned char)*C & 128) {
+        is7Bit = false;
+        break;  // don't bother scanning the rest.
+      }
+    }
+
+    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
+
+    // VST_ENTRY:   [valueid, namechar x N]
+    // VST_BBENTRY: [bbid, namechar x N]
+    unsigned Code;
+    if (isa<BasicBlock>(SI->getValue())) {
+      Code = bitc::VST_CODE_BBENTRY;
+      if (isChar6)
+        AbbrevToUse = VST_BBENTRY_6_ABBREV;
+    } else {
+      Code = bitc::VST_CODE_ENTRY;
+      if (isChar6)
+        AbbrevToUse = VST_ENTRY_6_ABBREV;
+      else if (is7Bit)
+        AbbrevToUse = VST_ENTRY_7_ABBREV;
+    }
+
+    NameVals.push_back(VE.getValueID(SI->getValue()));
+    for (const char *P = Name.getKeyData(),
+         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
+      NameVals.push_back((unsigned char)*P);
+
+    // Emit the finished record.
+    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
+    NameVals.clear();
+  }
+  Stream.ExitBlock();
+}
+
+/// WriteFunction - Emit a function body to the module stream.
+static void WriteFunction(const Function &F, ValueEnumerator &VE,
+                          BitstreamWriter &Stream) {
+  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
+  VE.incorporateFunction(F);
+
+  SmallVector<unsigned, 64> Vals;
+
+  // Emit the number of basic blocks, so the reader can create them ahead of
+  // time.
+  Vals.push_back(VE.getBasicBlocks().size());
+  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
+  Vals.clear();
+
+  // If there are function-local constants, emit them now.
+  unsigned CstStart, CstEnd;
+  VE.getFunctionConstantRange(CstStart, CstEnd);
+  WriteConstants(CstStart, CstEnd, VE, Stream, false);
+
+  // If there is function-local metadata, emit it now.
+  WriteFunctionLocalMetadata(F, VE, Stream);
+
+  // Keep a running idea of what the instruction ID is.
+  unsigned InstID = CstEnd;
+
+  bool NeedsMetadataAttachment = false;
+
+  DebugLoc LastDL;
+
+  // Finally, emit all the instructions, in order.
+  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
+    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
+         I != E; ++I) {
+      WriteInstruction(*I, InstID, VE, Stream, Vals);
+
+      if (!I->getType()->isVoidTy())
+        ++InstID;
+
+      // If the instruction has metadata, write a metadata attachment later.
+      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
+
+      // If the instruction has a debug location, emit it.
+      DebugLoc DL = I->getDebugLoc();
+      if (DL.isUnknown()) {
+        // nothing todo.
+      } else if (DL == LastDL) {
+        // Just repeat the same debug loc as last time.
+        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
+      } else {
+        MDNode *Scope, *IA;
+        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
+
+        Vals.push_back(DL.getLine());
+        Vals.push_back(DL.getCol());
+        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
+        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
+        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
+        Vals.clear();
+
+        LastDL = DL;
+      }
+    }
+
+  // Emit names for all the instructions etc.
+  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
+
+  if (NeedsMetadataAttachment)
+    WriteMetadataAttachment(F, VE, Stream);
+  VE.purgeFunction();
+  Stream.ExitBlock();
+}
+
+// Emit blockinfo, which defines the standard abbreviations etc.
+static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
+  // We only want to emit block info records for blocks that have multiple
+  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
+  // blocks can defined their abbrevs inline.
+  Stream.EnterBlockInfoBlock(2);
+
+  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+                                   Abbv) != VST_ENTRY_8_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  { // 7-bit fixed width VST_ENTRY strings.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
+    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+                                   Abbv) != VST_ENTRY_7_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // 6-bit char6 VST_ENTRY strings.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
+    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+                                   Abbv) != VST_ENTRY_6_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // 6-bit char6 VST_BBENTRY strings.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
+    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+                                   Abbv) != VST_BBENTRY_6_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+
+
+  { // SETTYPE abbrev for CONSTANTS_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
+                              Log2_32_Ceil(VE.getTypes().size()+1)));
+    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
+                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  { // INTEGER abbrev for CONSTANTS_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
+                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  { // CE_CAST abbrev for CONSTANTS_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
+                              Log2_32_Ceil(VE.getTypes().size()+1)));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
+
+    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
+                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // NULL abbrev for CONSTANTS_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
+    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
+                                   Abbv) != CONSTANTS_NULL_Abbrev)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  // FIXME: This should only use space for first class types!
+
+  { // INST_LOAD abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_BINOP abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_CAST abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
+                              Log2_32_Ceil(VE.getTypes().size()+1)));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  { // INST_RET abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_RET abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+
+  Stream.ExitBlock();
+}
+
+
+/// WriteModule - Emit the specified module to the bitstream.
+static void WriteModule(const Module *M, BitstreamWriter &Stream) {
+  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
+
+  // Emit the version number if it is non-zero.
+  if (CurVersion) {
+    SmallVector<unsigned, 1> Vals;
+    Vals.push_back(CurVersion);
+    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
+  }
+
+  // Analyze the module, enumerating globals, functions, etc.
+  ValueEnumerator VE(M);
+
+  // Emit blockinfo, which defines the standard abbreviations etc.
+  WriteBlockInfo(VE, Stream);
+
+  // Emit information about parameter attributes.
+  WriteAttributeTable(VE, Stream);
+
+  // Emit information describing all of the types in the module.
+  WriteTypeTable(VE, Stream);
+
+  // Emit top-level description of module, including target triple, inline asm,
+  // descriptors for global variables, and function prototype info.
+  WriteModuleInfo(M, VE, Stream);
+
+  // Emit constants.
+  WriteModuleConstants(VE, Stream);
+
+  // Emit metadata.
+  WriteModuleMetadata(M, VE, Stream);
+
+  // Emit function bodies.
+  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
+    if (!F->isDeclaration())
+      WriteFunction(*F, VE, Stream);
+
+  // Emit metadata.
+  WriteModuleMetadataStore(M, Stream);
+
+  // Emit names for globals/functions etc.
+  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
+
+  Stream.ExitBlock();
+}
+
+/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
+/// header and trailer to make it compatible with the system archiver.  To do
+/// this we emit the following header, and then emit a trailer that pads the
+/// file out to be a multiple of 16 bytes.
+///
+/// struct bc_header {
+///   uint32_t Magic;         // 0x0B17C0DE
+///   uint32_t Version;       // Version, currently always 0.
+///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
+///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
+///   uint32_t CPUType;       // CPU specifier.
+///   ... potentially more later ...
+/// };
+enum {
+  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
+  DarwinBCHeaderSize = 5*4
+};
+
+static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
+  unsigned CPUType = ~0U;
+
+  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
+  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
+  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
+  // specific constants here because they are implicitly part of the Darwin ABI.
+  enum {
+    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
+    DARWIN_CPU_TYPE_X86        = 7,
+    DARWIN_CPU_TYPE_ARM        = 12,
+    DARWIN_CPU_TYPE_POWERPC    = 18
+  };
+
+  Triple::ArchType Arch = TT.getArch();
+  if (Arch == Triple::x86_64)
+    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
+  else if (Arch == Triple::x86)
+    CPUType = DARWIN_CPU_TYPE_X86;
+  else if (Arch == Triple::ppc)
+    CPUType = DARWIN_CPU_TYPE_POWERPC;
+  else if (Arch == Triple::ppc64)
+    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
+  else if (Arch == Triple::arm || Arch == Triple::thumb)
+    CPUType = DARWIN_CPU_TYPE_ARM;
+
+  // Traditional Bitcode starts after header.
+  unsigned BCOffset = DarwinBCHeaderSize;
+
+  Stream.Emit(0x0B17C0DE, 32);
+  Stream.Emit(0         , 32);  // Version.
+  Stream.Emit(BCOffset  , 32);
+  Stream.Emit(0         , 32);  // Filled in later.
+  Stream.Emit(CPUType   , 32);
+}
+
+/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
+/// finalize the header.
+static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
+  // Update the size field in the header.
+  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
+
+  // If the file is not a multiple of 16 bytes, insert dummy padding.
+  while (BufferSize & 15) {
+    Stream.Emit(0, 8);
+    ++BufferSize;
+  }
+}
+
+
+/// WriteBitcodeToFile - Write the specified module to the specified output
+/// stream.
+void llvm_2_9::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
+  std::vector<unsigned char> Buffer;
+  BitstreamWriter Stream(Buffer);
+
+  Buffer.reserve(256*1024);
+
+  WriteBitcodeToStream( M, Stream );
+
+  // Write the generated bitstream to "Out".
+  Out.write((char*)&Buffer.front(), Buffer.size());
+}
+
+/// WriteBitcodeToStream - Write the specified module to the specified output
+/// stream.
+void llvm_2_9::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
+  // If this is darwin or another generic macho target, emit a file header and
+  // trailer if needed.
+  Triple TT(M->getTargetTriple());
+  if (TT.isOSDarwin())
+    EmitDarwinBCHeader(Stream, TT);
+
+  // Emit the file header.
+  Stream.Emit((unsigned)'B', 8);
+  Stream.Emit((unsigned)'C', 8);
+  Stream.Emit(0x0, 4);
+  Stream.Emit(0xC, 4);
+  Stream.Emit(0xE, 4);
+  Stream.Emit(0xD, 4);
+
+  // Emit the module.
+  WriteModule(M, Stream);
+
+  if (TT.isOSDarwin())
+    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
+}
diff --git a/BitWriter_2_9/BitcodeWriterPass.cpp b/BitWriter_2_9/BitcodeWriterPass.cpp
new file mode 100644
index 0000000..df33de6
--- /dev/null
+++ b/BitWriter_2_9/BitcodeWriterPass.cpp
@@ -0,0 +1,41 @@
+//===--- Bitcode/Writer/BitcodeWriterPass.cpp - Bitcode Writer ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// BitcodeWriterPass implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ReaderWriter_2_9.h"
+#include "llvm/Pass.h"
+using namespace llvm;
+
+namespace {
+  class WriteBitcodePass : public ModulePass {
+    raw_ostream &OS; // raw_ostream to print on
+  public:
+    static char ID; // Pass identification, replacement for typeid
+    explicit WriteBitcodePass(raw_ostream &o)
+      : ModulePass(ID), OS(o) {}
+
+    const char *getPassName() const { return "Bitcode Writer"; }
+
+    bool runOnModule(Module &M) {
+      llvm_2_9::WriteBitcodeToFile(&M, OS);
+      return false;
+    }
+  };
+}
+
+char WriteBitcodePass::ID = 0;
+
+/// createBitcodeWriterPass - Create and return a pass that writes the module
+/// to the specified ostream.
+llvm::ModulePass *llvm_2_9::createBitcodeWriterPass(llvm::raw_ostream &Str) {
+  return new WriteBitcodePass(Str);
+}
diff --git a/BitWriter_2_9/CMakeLists.txt b/BitWriter_2_9/CMakeLists.txt
new file mode 100644
index 0000000..f097b09
--- /dev/null
+++ b/BitWriter_2_9/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_llvm_library(LLVMBitWriter
+  BitWriter.cpp
+  BitcodeWriter.cpp
+  BitcodeWriterPass.cpp
+  ValueEnumerator.cpp
+  )
diff --git a/BitWriter_2_9/Makefile b/BitWriter_2_9/Makefile
new file mode 100644
index 0000000..7b0bd72
--- /dev/null
+++ b/BitWriter_2_9/Makefile
@@ -0,0 +1,15 @@
+##===- lib/Bitcode/Reader/Makefile -------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+LIBRARYNAME = LLVMBitWriter
+BUILD_ARCHIVE = 1
+
+include $(LEVEL)/Makefile.common
+
diff --git a/BitWriter_2_9/ReaderWriter_2_9.h b/BitWriter_2_9/ReaderWriter_2_9.h
new file mode 100644
index 0000000..bb82fa3
--- /dev/null
+++ b/BitWriter_2_9/ReaderWriter_2_9.h
@@ -0,0 +1,147 @@
+//===-- llvm/Bitcode/ReaderWriter.h - Bitcode reader/writers ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This header defines interfaces to read and write LLVM bitcode files/streams.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BITCODE_2_9_H
+#define LLVM_BITCODE_2_9_H
+
+#include <string>
+
+namespace llvm {
+  class Module;
+  class MemoryBuffer;
+  class ModulePass;
+  class BitstreamWriter;
+  class LLVMContext;
+  class raw_ostream;
+} // End llvm namespace
+
+namespace llvm_2_9 {
+  /// getLazyBitcodeModule - Read the header of the specified bitcode buffer
+  /// and prepare for lazy deserialization of function bodies.  If successful,
+  /// this takes ownership of 'buffer' and returns a non-null pointer.  On
+  /// error, this returns null, *does not* take ownership of Buffer, and fills
+  /// in *ErrMsg with an error description if ErrMsg is non-null.
+  llvm::Module *getLazyBitcodeModule(llvm::MemoryBuffer *Buffer,
+                               llvm::LLVMContext& Context,
+                               std::string *ErrMsg = 0);
+
+  /// getBitcodeTargetTriple - Read the header of the specified bitcode
+  /// buffer and extract just the triple information. If successful,
+  /// this returns a string and *does not* take ownership
+  /// of 'buffer'. On error, this returns "", and fills in *ErrMsg
+  /// if ErrMsg is non-null.
+  std::string getBitcodeTargetTriple(llvm::MemoryBuffer *Buffer,
+                                     llvm::LLVMContext& Context,
+                                     std::string *ErrMsg = 0);
+
+  /// ParseBitcodeFile - Read the specified bitcode file, returning the module.
+  /// If an error occurs, this returns null and fills in *ErrMsg if it is
+  /// non-null.  This method *never* takes ownership of Buffer.
+  llvm::Module *ParseBitcodeFile(llvm::MemoryBuffer *Buffer, llvm::LLVMContext& Context,
+                           std::string *ErrMsg = 0);
+
+  /// WriteBitcodeToFile - Write the specified module to the specified
+  /// raw output stream.  For streams where it matters, the given stream
+  /// should be in "binary" mode.
+  void WriteBitcodeToFile(const llvm::Module *M, llvm::raw_ostream &Out);
+
+  /// WriteBitcodeToStream - Write the specified module to the specified
+  /// raw output stream.
+  void WriteBitcodeToStream(const llvm::Module *M, llvm::BitstreamWriter &Stream);
+
+  /// createBitcodeWriterPass - Create and return a pass that writes the module
+  /// to the specified ostream.
+  llvm::ModulePass *createBitcodeWriterPass(llvm::raw_ostream &Str);
+
+
+  /// isBitcodeWrapper - Return true if the given bytes are the magic bytes
+  /// for an LLVM IR bitcode wrapper.
+  ///
+  static inline bool isBitcodeWrapper(const unsigned char *BufPtr,
+                                      const unsigned char *BufEnd) {
+    // See if you can find the hidden message in the magic bytes :-).
+    // (Hint: it's a little-endian encoding.)
+    return BufPtr != BufEnd &&
+           BufPtr[0] == 0xDE &&
+           BufPtr[1] == 0xC0 &&
+           BufPtr[2] == 0x17 &&
+           BufPtr[3] == 0x0B;
+  }
+
+  /// isRawBitcode - Return true if the given bytes are the magic bytes for
+  /// raw LLVM IR bitcode (without a wrapper).
+  ///
+  static inline bool isRawBitcode(const unsigned char *BufPtr,
+                                  const unsigned char *BufEnd) {
+    // These bytes sort of have a hidden message, but it's not in
+    // little-endian this time, and it's a little redundant.
+    return BufPtr != BufEnd &&
+           BufPtr[0] == 'B' &&
+           BufPtr[1] == 'C' &&
+           BufPtr[2] == 0xc0 &&
+           BufPtr[3] == 0xde;
+  }
+
+  /// isBitcode - Return true if the given bytes are the magic bytes for
+  /// LLVM IR bitcode, either with or without a wrapper.
+  ///
+  static bool inline isBitcode(const unsigned char *BufPtr,
+                               const unsigned char *BufEnd) {
+    return isBitcodeWrapper(BufPtr, BufEnd) ||
+           isRawBitcode(BufPtr, BufEnd);
+  }
+
+  /// SkipBitcodeWrapperHeader - Some systems wrap bc files with a special
+  /// header for padding or other reasons.  The format of this header is:
+  ///
+  /// struct bc_header {
+  ///   uint32_t Magic;         // 0x0B17C0DE
+  ///   uint32_t Version;       // Version, currently always 0.
+  ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
+  ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
+  ///   ... potentially other gunk ...
+  /// };
+  ///
+  /// This function is called when we find a file with a matching magic number.
+  /// In this case, skip down to the subsection of the file that is actually a
+  /// BC file.
+  static inline bool SkipBitcodeWrapperHeader(unsigned char *&BufPtr,
+                                              unsigned char *&BufEnd) {
+    enum {
+      KnownHeaderSize = 4*4,  // Size of header we read.
+      OffsetField = 2*4,      // Offset in bytes to Offset field.
+      SizeField = 3*4         // Offset in bytes to Size field.
+    };
+
+    // Must contain the header!
+    if (BufEnd-BufPtr < KnownHeaderSize) return true;
+
+    unsigned Offset = ( BufPtr[OffsetField  ]        |
+                       (BufPtr[OffsetField+1] << 8)  |
+                       (BufPtr[OffsetField+2] << 16) |
+                       (BufPtr[OffsetField+3] << 24));
+    unsigned Size   = ( BufPtr[SizeField    ]        |
+                       (BufPtr[SizeField  +1] << 8)  |
+                       (BufPtr[SizeField  +2] << 16) |
+                       (BufPtr[SizeField  +3] << 24));
+
+    // Verify that Offset+Size fits in the file.
+    if (Offset+Size > unsigned(BufEnd-BufPtr))
+      return true;
+    BufPtr += Offset;
+    BufEnd = BufPtr+Size;
+    return false;
+  }
+} // End llvm_2_9 namespace
+
+#endif
diff --git a/BitWriter_2_9/ValueEnumerator.cpp b/BitWriter_2_9/ValueEnumerator.cpp
new file mode 100644
index 0000000..db766b1
--- /dev/null
+++ b/BitWriter_2_9/ValueEnumerator.cpp
@@ -0,0 +1,494 @@
+//===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the ValueEnumerator class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueEnumerator.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/ValueSymbolTable.h"
+#include "llvm/Instructions.h"
+#include <algorithm>
+using namespace llvm;
+
+static bool isIntegerValue(const std::pair<const Value*, unsigned> &V) {
+  return V.first->getType()->isIntegerTy();
+}
+
+/// ValueEnumerator - Enumerate module-level information.
+ValueEnumerator::ValueEnumerator(const Module *M) {
+  // Enumerate the global variables.
+  for (Module::const_global_iterator I = M->global_begin(),
+         E = M->global_end(); I != E; ++I)
+    EnumerateValue(I);
+
+  // Enumerate the functions.
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+    EnumerateValue(I);
+    EnumerateAttributes(cast<Function>(I)->getAttributes());
+  }
+
+  // Enumerate the aliases.
+  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+       I != E; ++I)
+    EnumerateValue(I);
+
+  // Remember what is the cutoff between globalvalue's and other constants.
+  unsigned FirstConstant = Values.size();
+
+  // Enumerate the global variable initializers.
+  for (Module::const_global_iterator I = M->global_begin(),
+         E = M->global_end(); I != E; ++I)
+    if (I->hasInitializer())
+      EnumerateValue(I->getInitializer());
+
+  // Enumerate the aliasees.
+  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+       I != E; ++I)
+    EnumerateValue(I->getAliasee());
+
+  // Insert constants and metadata that are named at module level into the slot 
+  // pool so that the module symbol table can refer to them...
+  EnumerateValueSymbolTable(M->getValueSymbolTable());
+  EnumerateNamedMetadata(M);
+
+  SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
+
+  // Enumerate types used by function bodies and argument lists.
+  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
+
+    for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
+         I != E; ++I)
+      EnumerateType(I->getType());
+
+    for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+      for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I){
+        for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
+             OI != E; ++OI) {
+          if (MDNode *MD = dyn_cast<MDNode>(*OI))
+            if (MD->isFunctionLocal() && MD->getFunction())
+              // These will get enumerated during function-incorporation.
+              continue;
+          EnumerateOperandType(*OI);
+        }
+        EnumerateType(I->getType());
+        if (const CallInst *CI = dyn_cast<CallInst>(I))
+          EnumerateAttributes(CI->getAttributes());
+        else if (const InvokeInst *II = dyn_cast<InvokeInst>(I))
+          EnumerateAttributes(II->getAttributes());
+
+        // Enumerate metadata attached with this instruction.
+        MDs.clear();
+        I->getAllMetadataOtherThanDebugLoc(MDs);
+        for (unsigned i = 0, e = MDs.size(); i != e; ++i)
+          EnumerateMetadata(MDs[i].second);
+        
+        if (!I->getDebugLoc().isUnknown()) {
+          MDNode *Scope, *IA;
+          I->getDebugLoc().getScopeAndInlinedAt(Scope, IA, I->getContext());
+          if (Scope) EnumerateMetadata(Scope);
+          if (IA) EnumerateMetadata(IA);
+        }
+      }
+  }
+
+  // Optimize constant ordering.
+  OptimizeConstants(FirstConstant, Values.size());
+}
+
+
+unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
+  InstructionMapType::const_iterator I = InstructionMap.find(Inst);
+  assert(I != InstructionMap.end() && "Instruction is not mapped!");
+  return I->second;
+}
+
+void ValueEnumerator::setInstructionID(const Instruction *I) {
+  InstructionMap[I] = InstructionCount++;
+}
+
+unsigned ValueEnumerator::getValueID(const Value *V) const {
+  if (isa<MDNode>(V) || isa<MDString>(V)) {
+    ValueMapType::const_iterator I = MDValueMap.find(V);
+    assert(I != MDValueMap.end() && "Value not in slotcalculator!");
+    return I->second-1;
+  }
+
+  ValueMapType::const_iterator I = ValueMap.find(V);
+  assert(I != ValueMap.end() && "Value not in slotcalculator!");
+  return I->second-1;
+}
+
+// Optimize constant ordering.
+namespace {
+  struct CstSortPredicate {
+    ValueEnumerator &VE;
+    explicit CstSortPredicate(ValueEnumerator &ve) : VE(ve) {}
+    bool operator()(const std::pair<const Value*, unsigned> &LHS,
+                    const std::pair<const Value*, unsigned> &RHS) {
+      // Sort by plane.
+      if (LHS.first->getType() != RHS.first->getType())
+        return VE.getTypeID(LHS.first->getType()) <
+               VE.getTypeID(RHS.first->getType());
+      // Then by frequency.
+      return LHS.second > RHS.second;
+    }
+  };
+}
+
+/// OptimizeConstants - Reorder constant pool for denser encoding.
+void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
+  if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
+
+  CstSortPredicate P(*this);
+  std::stable_sort(Values.begin()+CstStart, Values.begin()+CstEnd, P);
+
+  // Ensure that integer constants are at the start of the constant pool.  This
+  // is important so that GEP structure indices come before gep constant exprs.
+  std::partition(Values.begin()+CstStart, Values.begin()+CstEnd,
+                 isIntegerValue);
+
+  // Rebuild the modified portion of ValueMap.
+  for (; CstStart != CstEnd; ++CstStart)
+    ValueMap[Values[CstStart].first] = CstStart+1;
+}
+
+
+/// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
+/// table into the values table.
+void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
+  for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
+       VI != VE; ++VI)
+    EnumerateValue(VI->getValue());
+}
+
+/// EnumerateNamedMetadata - Insert all of the values referenced by
+/// named metadata in the specified module.
+void ValueEnumerator::EnumerateNamedMetadata(const Module *M) {
+  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
+       E = M->named_metadata_end(); I != E; ++I)
+    EnumerateNamedMDNode(I);
+}
+
+void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
+  for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
+    EnumerateMetadata(MD->getOperand(i));
+}
+
+/// EnumerateMDNodeOperands - Enumerate all non-function-local values
+/// and types referenced by the given MDNode.
+void ValueEnumerator::EnumerateMDNodeOperands(const MDNode *N) {
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+    if (Value *V = N->getOperand(i)) {
+      if (isa<MDNode>(V) || isa<MDString>(V))
+        EnumerateMetadata(V);
+      else if (!isa<Instruction>(V) && !isa<Argument>(V))
+        EnumerateValue(V);
+    } else
+      EnumerateType(Type::getVoidTy(N->getContext()));
+  }
+}
+
+void ValueEnumerator::EnumerateMetadata(const Value *MD) {
+  assert((isa<MDNode>(MD) || isa<MDString>(MD)) && "Invalid metadata kind");
+
+  // Enumerate the type of this value.
+  EnumerateType(MD->getType());
+
+  const MDNode *N = dyn_cast<MDNode>(MD);
+
+  // In the module-level pass, skip function-local nodes themselves, but
+  // do walk their operands.
+  if (N && N->isFunctionLocal() && N->getFunction()) {
+    EnumerateMDNodeOperands(N);
+    return;
+  }
+
+  // Check to see if it's already in!
+  unsigned &MDValueID = MDValueMap[MD];
+  if (MDValueID) {
+    // Increment use count.
+    MDValues[MDValueID-1].second++;
+    return;
+  }
+  MDValues.push_back(std::make_pair(MD, 1U));
+  MDValueID = MDValues.size();
+
+  // Enumerate all non-function-local operands.
+  if (N)
+    EnumerateMDNodeOperands(N);
+}
+
+/// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
+/// information reachable from the given MDNode.
+void ValueEnumerator::EnumerateFunctionLocalMetadata(const MDNode *N) {
+  assert(N->isFunctionLocal() && N->getFunction() &&
+         "EnumerateFunctionLocalMetadata called on non-function-local mdnode!");
+
+  // Enumerate the type of this value.
+  EnumerateType(N->getType());
+
+  // Check to see if it's already in!
+  unsigned &MDValueID = MDValueMap[N];
+  if (MDValueID) {
+    // Increment use count.
+    MDValues[MDValueID-1].second++;
+    return;
+  }
+  MDValues.push_back(std::make_pair(N, 1U));
+  MDValueID = MDValues.size();
+
+  // To incoroporate function-local information visit all function-local
+  // MDNodes and all function-local values they reference.
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+    if (Value *V = N->getOperand(i)) {
+      if (MDNode *O = dyn_cast<MDNode>(V)) {
+        if (O->isFunctionLocal() && O->getFunction())
+          EnumerateFunctionLocalMetadata(O);
+      } else if (isa<Instruction>(V) || isa<Argument>(V))
+        EnumerateValue(V);
+    }
+
+  // Also, collect all function-local MDNodes for easy access.
+  FunctionLocalMDs.push_back(N);
+}
+
+void ValueEnumerator::EnumerateValue(const Value *V) {
+  assert(!V->getType()->isVoidTy() && "Can't insert void values!");
+  assert(!isa<MDNode>(V) && !isa<MDString>(V) &&
+         "EnumerateValue doesn't handle Metadata!");
+
+  // Check to see if it's already in!
+  unsigned &ValueID = ValueMap[V];
+  if (ValueID) {
+    // Increment use count.
+    Values[ValueID-1].second++;
+    return;
+  }
+
+  // Enumerate the type of this value.
+  EnumerateType(V->getType());
+
+  if (const Constant *C = dyn_cast<Constant>(V)) {
+    if (isa<GlobalValue>(C)) {
+      // Initializers for globals are handled explicitly elsewhere.
+    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
+      // Do not enumerate the initializers for an array of simple characters.
+      // The initializers just pollute the value table, and we emit the strings
+      // specially.
+    } else if (C->getNumOperands()) {
+      // If a constant has operands, enumerate them.  This makes sure that if a
+      // constant has uses (for example an array of const ints), that they are
+      // inserted also.
+
+      // We prefer to enumerate them with values before we enumerate the user
+      // itself.  This makes it more likely that we can avoid forward references
+      // in the reader.  We know that there can be no cycles in the constants
+      // graph that don't go through a global variable.
+      for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
+           I != E; ++I)
+        if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
+          EnumerateValue(*I);
+
+      // Finally, add the value.  Doing this could make the ValueID reference be
+      // dangling, don't reuse it.
+      Values.push_back(std::make_pair(V, 1U));
+      ValueMap[V] = Values.size();
+      return;
+    }
+  }
+
+  // Add the value.
+  Values.push_back(std::make_pair(V, 1U));
+  ValueID = Values.size();
+}
+
+
+void ValueEnumerator::EnumerateType(Type *Ty) {
+  unsigned *TypeID = &TypeMap[Ty];
+
+  // We've already seen this type.
+  if (*TypeID)
+    return;
+
+  // If it is a non-anonymous struct, mark the type as being visited so that we
+  // don't recursively visit it.  This is safe because we allow forward
+  // references of these in the bitcode reader.
+  if (StructType *STy = dyn_cast<StructType>(Ty))
+    if (!STy->isAnonymous())
+      *TypeID = ~0U;
+  
+  // Enumerate all of the subtypes before we enumerate this type.  This ensures
+  // that the type will be enumerated in an order that can be directly built.
+  for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
+       I != E; ++I)
+    EnumerateType(*I);
+  
+  // Refresh the TypeID pointer in case the table rehashed.
+  TypeID = &TypeMap[Ty];
+  
+  // Check to see if we got the pointer another way.  This can happen when
+  // enumerating recursive types that hit the base case deeper than they start.
+  //
+  // If this is actually a struct that we are treating as forward ref'able,
+  // then emit the definition now that all of its contents are available.
+  if (*TypeID && *TypeID != ~0U)
+    return;
+  
+  // Add this type now that its contents are all happily enumerated.
+  Types.push_back(Ty);
+  
+  *TypeID = Types.size();
+}
+
+// Enumerate the types for the specified value.  If the value is a constant,
+// walk through it, enumerating the types of the constant.
+void ValueEnumerator::EnumerateOperandType(const Value *V) {
+  EnumerateType(V->getType());
+  
+  if (const Constant *C = dyn_cast<Constant>(V)) {
+    // If this constant is already enumerated, ignore it, we know its type must
+    // be enumerated.
+    if (ValueMap.count(V)) return;
+
+    // This constant may have operands, make sure to enumerate the types in
+    // them.
+    for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
+      const Value *Op = C->getOperand(i);
+      
+      // Don't enumerate basic blocks here, this happens as operands to
+      // blockaddress.
+      if (isa<BasicBlock>(Op)) continue;
+      
+      EnumerateOperandType(Op);
+    }
+
+    if (const MDNode *N = dyn_cast<MDNode>(V)) {
+      for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+        if (Value *Elem = N->getOperand(i))
+          EnumerateOperandType(Elem);
+    }
+  } else if (isa<MDString>(V) || isa<MDNode>(V))
+    EnumerateMetadata(V);
+}
+
+void ValueEnumerator::EnumerateAttributes(const AttrListPtr &PAL) {
+  if (PAL.isEmpty()) return;  // null is always 0.
+  // Do a lookup.
+  unsigned &Entry = AttributeMap[PAL.getRawPointer()];
+  if (Entry == 0) {
+    // Never saw this before, add it.
+    Attributes.push_back(PAL);
+    Entry = Attributes.size();
+  }
+}
+
+void ValueEnumerator::incorporateFunction(const Function &F) {
+  InstructionCount = 0;
+  NumModuleValues = Values.size();
+  NumModuleMDValues = MDValues.size();
+
+  // Adding function arguments to the value table.
+  for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
+       I != E; ++I)
+    EnumerateValue(I);
+
+  FirstFuncConstantID = Values.size();
+
+  // Add all function-level constants to the value table.
+  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
+    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I)
+      for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
+           OI != E; ++OI) {
+        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
+            isa<InlineAsm>(*OI))
+          EnumerateValue(*OI);
+      }
+    BasicBlocks.push_back(BB);
+    ValueMap[BB] = BasicBlocks.size();
+  }
+
+  // Optimize the constant layout.
+  OptimizeConstants(FirstFuncConstantID, Values.size());
+
+  // Add the function's parameter attributes so they are available for use in
+  // the function's instruction.
+  EnumerateAttributes(F.getAttributes());
+
+  FirstInstID = Values.size();
+
+  SmallVector<MDNode *, 8> FnLocalMDVector;
+  // Add all of the instructions.
+  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
+    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
+      for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
+           OI != E; ++OI) {
+        if (MDNode *MD = dyn_cast<MDNode>(*OI))
+          if (MD->isFunctionLocal() && MD->getFunction())
+            // Enumerate metadata after the instructions they might refer to.
+            FnLocalMDVector.push_back(MD);
+      }
+
+      SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
+      I->getAllMetadataOtherThanDebugLoc(MDs);
+      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
+        MDNode *N = MDs[i].second;
+        if (N->isFunctionLocal() && N->getFunction())
+          FnLocalMDVector.push_back(N);
+      }
+        
+      if (!I->getType()->isVoidTy())
+        EnumerateValue(I);
+    }
+  }
+
+  // Add all of the function-local metadata.
+  for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i)
+    EnumerateFunctionLocalMetadata(FnLocalMDVector[i]);
+}
+
+void ValueEnumerator::purgeFunction() {
+  /// Remove purged values from the ValueMap.
+  for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
+    ValueMap.erase(Values[i].first);
+  for (unsigned i = NumModuleMDValues, e = MDValues.size(); i != e; ++i)
+    MDValueMap.erase(MDValues[i].first);
+  for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
+    ValueMap.erase(BasicBlocks[i]);
+
+  Values.resize(NumModuleValues);
+  MDValues.resize(NumModuleMDValues);
+  BasicBlocks.clear();
+  FunctionLocalMDs.clear();
+}
+
+static void IncorporateFunctionInfoGlobalBBIDs(const Function *F,
+                                 DenseMap<const BasicBlock*, unsigned> &IDMap) {
+  unsigned Counter = 0;
+  for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+    IDMap[BB] = ++Counter;
+}
+
+/// getGlobalBasicBlockID - This returns the function-specific ID for the
+/// specified basic block.  This is relatively expensive information, so it
+/// should only be used by rare constructs such as address-of-label.
+unsigned ValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const {
+  unsigned &Idx = GlobalBasicBlockIDs[BB];
+  if (Idx != 0)
+    return Idx-1;
+
+  IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
+  return getGlobalBasicBlockID(BB);
+}
+
diff --git a/BitWriter_2_9/ValueEnumerator.h b/BitWriter_2_9/ValueEnumerator.h
new file mode 100644
index 0000000..b6fc920
--- /dev/null
+++ b/BitWriter_2_9/ValueEnumerator.h
@@ -0,0 +1,153 @@
+//===-- Bitcode/Writer/ValueEnumerator.h - Number values --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class gives values and types Unique ID's.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef VALUE_ENUMERATOR_H
+#define VALUE_ENUMERATOR_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Attributes.h"
+#include <vector>
+
+namespace llvm {
+
+class Type;
+class Value;
+class Instruction;
+class BasicBlock;
+class Function;
+class Module;
+class MDNode;
+class NamedMDNode;
+class AttrListPtr;
+class ValueSymbolTable;
+class MDSymbolTable;
+
+class ValueEnumerator {
+public:
+  typedef std::vector<Type*> TypeList;
+
+  // For each value, we remember its Value* and occurrence frequency.
+  typedef std::vector<std::pair<const Value*, unsigned> > ValueList;
+private:
+  typedef DenseMap<Type*, unsigned> TypeMapType;
+  TypeMapType TypeMap;
+  TypeList Types;
+
+  typedef DenseMap<const Value*, unsigned> ValueMapType;
+  ValueMapType ValueMap;
+  ValueList Values;
+  ValueList MDValues;
+  SmallVector<const MDNode *, 8> FunctionLocalMDs;
+  ValueMapType MDValueMap;
+  
+  typedef DenseMap<void*, unsigned> AttributeMapType;
+  AttributeMapType AttributeMap;
+  std::vector<AttrListPtr> Attributes;
+  
+  /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
+  /// the "getGlobalBasicBlockID" method.
+  mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
+  
+  typedef DenseMap<const Instruction*, unsigned> InstructionMapType;
+  InstructionMapType InstructionMap;
+  unsigned InstructionCount;
+
+  /// BasicBlocks - This contains all the basic blocks for the currently
+  /// incorporated function.  Their reverse mapping is stored in ValueMap.
+  std::vector<const BasicBlock*> BasicBlocks;
+  
+  /// When a function is incorporated, this is the size of the Values list
+  /// before incorporation.
+  unsigned NumModuleValues;
+
+  /// When a function is incorporated, this is the size of the MDValues list
+  /// before incorporation.
+  unsigned NumModuleMDValues;
+
+  unsigned FirstFuncConstantID;
+  unsigned FirstInstID;
+  
+  ValueEnumerator(const ValueEnumerator &);  // DO NOT IMPLEMENT
+  void operator=(const ValueEnumerator &);   // DO NOT IMPLEMENT
+public:
+  ValueEnumerator(const Module *M);
+
+  unsigned getValueID(const Value *V) const;
+
+  unsigned getTypeID(Type *T) const {
+    TypeMapType::const_iterator I = TypeMap.find(T);
+    assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
+    return I->second-1;
+  }
+
+  unsigned getInstructionID(const Instruction *I) const;
+  void setInstructionID(const Instruction *I);
+
+  unsigned getAttributeID(const AttrListPtr &PAL) const {
+    if (PAL.isEmpty()) return 0;  // Null maps to zero.
+    AttributeMapType::const_iterator I = AttributeMap.find(PAL.getRawPointer());
+    assert(I != AttributeMap.end() && "Attribute not in ValueEnumerator!");
+    return I->second;
+  }
+
+  /// getFunctionConstantRange - Return the range of values that corresponds to
+  /// function-local constants.
+  void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
+    Start = FirstFuncConstantID;
+    End = FirstInstID;
+  }
+  
+  const ValueList &getValues() const { return Values; }
+  const ValueList &getMDValues() const { return MDValues; }
+  const SmallVector<const MDNode *, 8> &getFunctionLocalMDValues() const { 
+    return FunctionLocalMDs;
+  }
+  const TypeList &getTypes() const { return Types; }
+  const std::vector<const BasicBlock*> &getBasicBlocks() const {
+    return BasicBlocks; 
+  }
+  const std::vector<AttrListPtr> &getAttributes() const {
+    return Attributes;
+  }
+  
+  /// getGlobalBasicBlockID - This returns the function-specific ID for the
+  /// specified basic block.  This is relatively expensive information, so it
+  /// should only be used by rare constructs such as address-of-label.
+  unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
+
+  /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
+  /// use these two methods to get its data into the ValueEnumerator!
+  ///
+  void incorporateFunction(const Function &F);
+  void purgeFunction();
+
+private:
+  void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
+    
+  void EnumerateMDNodeOperands(const MDNode *N);
+  void EnumerateMetadata(const Value *MD);
+  void EnumerateFunctionLocalMetadata(const MDNode *N);
+  void EnumerateNamedMDNode(const NamedMDNode *NMD);
+  void EnumerateValue(const Value *V);
+  void EnumerateType(Type *T);
+  void EnumerateOperandType(const Value *V);
+  void EnumerateAttributes(const AttrListPtr &PAL);
+  
+  void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
+  void EnumerateNamedMetadata(const Module *M);
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/slang_backend.cpp b/slang_backend.cpp
index 0eeaeaf..659d0ce 100644
--- a/slang_backend.cpp
+++ b/slang_backend.cpp
@@ -52,8 +52,8 @@
 
 #include "llvm/MC/SubtargetFeature.h"
 
-#include "slang.h"
 #include "slang_assert.h"
+#include "BitWriter_2_9/ReaderWriter_2_9.h"
 
 namespace slang {
 
@@ -320,7 +320,12 @@
     }
     case Slang::OT_Bitcode: {
       llvm::PassManager *BCEmitPM = new llvm::PassManager();
-      BCEmitPM->add(llvm::createBitcodeWriterPass(FormattedOutStream));
+      if (getTargetAPI() < SLANG_ICS_TARGET_API) {
+        // Pre-ICS targets must use the LLVM 2.9 BitcodeWriter
+        BCEmitPM->add(llvm_2_9::createBitcodeWriterPass(FormattedOutStream));
+      } else {
+        BCEmitPM->add(llvm::createBitcodeWriterPass(FormattedOutStream));
+      }
       BCEmitPM->run(*mpModule);
       break;
     }
diff --git a/slang_backend.h b/slang_backend.h
index 6cec9c3..052be4b 100644
--- a/slang_backend.h
+++ b/slang_backend.h
@@ -25,6 +25,7 @@
 
 #include "slang.h"
 #include "slang_pragma_recorder.h"
+#include "slang_version.h"
 
 namespace llvm {
   class formatted_raw_ostream;
@@ -80,6 +81,10 @@
 
   PragmaList *mPragmas;
 
+  virtual unsigned int getTargetAPI() const {
+    return SLANG_MAXIMUM_TARGET_API;
+  }
+
   // This handler will be invoked before Clang translates @Ctx to LLVM IR. This
   // give you an opportunity to modified the IR in AST level (scope information,
   // unoptimized IR, etc.). After the return from this method, slang will start
diff --git a/slang_rs.cpp b/slang_rs.cpp
index cbde576..bf2cadd 100644
--- a/slang_rs.cpp
+++ b/slang_rs.cpp
@@ -283,11 +283,10 @@
   mAllowRSPrefix = AllowRSPrefix;
 
   mTargetAPI = TargetAPI;
-  if (mTargetAPI < RS_MINIMUM_TARGET_API ||
-      mTargetAPI > RS_MAXIMUM_TARGET_API) {
+  if (mTargetAPI < SLANG_MINIMUM_TARGET_API ||
+      mTargetAPI > SLANG_MAXIMUM_TARGET_API) {
     getDiagnostics().Report(mDiagErrorTargetAPIRange) << mTargetAPI
-                                                      << RS_MINIMUM_TARGET_API
-                                                      << RS_MAXIMUM_TARGET_API;
+        << SLANG_MINIMUM_TARGET_API << SLANG_MAXIMUM_TARGET_API;
     return false;
   }
 
diff --git a/slang_rs.h b/slang_rs.h
index 1f0483a..323bfaa 100644
--- a/slang_rs.h
+++ b/slang_rs.h
@@ -27,7 +27,7 @@
 #include "llvm/ADT/StringMap.h"
 
 #include "slang_rs_reflect_utils.h"
-#include "slang_rs_version.h"
+#include "slang_version.h"
 
 namespace clang {
   class FunctionDecl;
diff --git a/slang_rs_backend.h b/slang_rs_backend.h
index d399e13..1395594 100644
--- a/slang_rs_backend.h
+++ b/slang_rs_backend.h
@@ -59,6 +59,10 @@
   void AnnotateFunction(clang::FunctionDecl *FD);
 
  protected:
+  virtual unsigned int getTargetAPI() const {
+    return mContext->getTargetAPI();
+  }
+
   virtual void HandleTopLevelDecl(clang::DeclGroupRef D);
 
   virtual void HandleTranslationUnitPre(clang::ASTContext &C);
diff --git a/slang_rs_reflection.cpp b/slang_rs_reflection.cpp
index 7ec4750..8083322 100644
--- a/slang_rs_reflection.cpp
+++ b/slang_rs_reflection.cpp
@@ -34,7 +34,7 @@
 #include "slang_rs_export_foreach.h"
 #include "slang_rs_export_func.h"
 #include "slang_rs_reflect_utils.h"
-#include "slang_rs_version.h"
+#include "slang_version.h"
 #include "slang_utils.h"
 
 #define RS_SCRIPT_CLASS_NAME_PREFIX      "ScriptC_"
@@ -625,7 +625,7 @@
     genExportVariable(C, *I);
 
   // Reflect export for each functions (only available on ICS+)
-  if (mRSContext->getTargetAPI() >= RS_ICS_TARGET_API) {
+  if (mRSContext->getTargetAPI() >= SLANG_ICS_TARGET_API) {
     for (RSContext::const_export_foreach_iterator
              I = mRSContext->export_foreach_begin(),
              E = mRSContext->export_foreach_end();
diff --git a/slang_rs_version.h b/slang_version.h
similarity index 67%
rename from slang_rs_version.h
rename to slang_version.h
index 2bb725d..2df3ec8 100644
--- a/slang_rs_version.h
+++ b/slang_version.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_VERSION_H_  // NOLINT
-#define _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_VERSION_H_
+#ifndef _FRAMEWORKS_COMPILE_SLANG_SLANG_VERSION_H_  // NOLINT
+#define _FRAMEWORKS_COMPILE_SLANG_SLANG_VERSION_H_
 
 // API levels used by the standard Android SDK.
 //
@@ -23,9 +23,10 @@
 // 13 - Honeycomb MR2
 // 14 - Ice Cream Sandwich
 // ...
-#define RS_MINIMUM_TARGET_API 12
-#define RS_MAXIMUM_TARGET_API RS_VERSION
+#define SLANG_MINIMUM_TARGET_API 12
+#define SLANG_MAXIMUM_TARGET_API RS_VERSION
+// Note that RS_VERSION is defined at build time (see Android.mk for details).
 
-#define RS_ICS_TARGET_API 14
+#define SLANG_ICS_TARGET_API 14
 
-#endif  // _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_VERSION_H_  NOLINT
+#endif  // _FRAMEWORKS_COMPILE_SLANG_SLANG_VERSION_H_  NOLINT