vendor/llvm/llvm-r72732

1 files changed, 1449 insertions, 0 deletions

diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
new file mode 100644
index 0000000000000..bfc029c1f2771
--- /dev/null
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -0,0 +1,1449 @@
+//===--- 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 "llvm/Bitcode/ReaderWriter.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/MDNode.h"
+#include "llvm/Module.h"
+#include "llvm/TypeSymbolTable.h"
+#include "llvm/ValueSymbolTable.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/System/Program.h"
+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_CAST_ABBREV,
+  FUNCTION_INST_RET_VOID_ABBREV,
+  FUNCTION_INST_RET_VAL_ABBREV,
+  FUNCTION_INST_UNREACHABLE_ABBREV
+};
+
+
+static unsigned GetEncodedCastOpcode(unsigned Opcode) {
+  switch (Opcode) {
+  default: assert(0 && "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: assert(0 && "Unknown binary instruction!");
+  case Instruction::Add:  return bitc::BINOP_ADD;
+  case Instruction::Sub:  return bitc::BINOP_SUB;
+  case Instruction::Mul:  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, const std::string &Str, 
+                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
+  SmallVector<unsigned, 64> Vals;
+  
+  // Code: [strchar x N]
+  for (unsigned i = 0, e = Str.size(); i != e; ++i)
+    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();
+}
+
+/// 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, 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);
+  
+  // Abbrev for TYPE_CODE_STRUCT.
+  Abbv = new BitCodeAbbrev();
+  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
+  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) {
+    const Type *T = TypeList[i].first;
+    int AbbrevToUse = 0;
+    unsigned Code = 0;
+    
+    switch (T->getTypeID()) {
+    default: assert(0 && "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::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
+    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
+    case Type::IntegerTyID:
+      // INTEGER: [width]
+      Code = bitc::TYPE_CODE_INTEGER;
+      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
+      break;
+    case Type::PointerTyID: {
+      const 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: {
+      const 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: {
+      const StructType *ST = cast<StructType>(T);
+      // STRUCT: [ispacked, eltty x N]
+      Code = bitc::TYPE_CODE_STRUCT;
+      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: {
+      const 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: {
+      const 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();
+}
+
+static unsigned getEncodedLinkage(const GlobalValue *GV) {
+  switch (GV->getLinkage()) {
+  default: assert(0 && "Invalid linkage!");
+  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
+  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;
+  }
+}
+
+static unsigned getEncodedVisibility(const GlobalValue *GV) {
+  switch (GV->getVisibility()) {
+  default: assert(0 && "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]
+    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) {
+      Vals.push_back(getEncodedVisibility(GV));
+      Vals.push_back(GV->isThreadLocal());
+    } 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]
+    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);
+    
+    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 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;
+  unsigned MDString8Abbrev = 0;
+  unsigned MDString6Abbrev = 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);
+
+    // Abbrev for CST_CODE_MDSTRING.
+    Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_MDSTRING));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+    MDString8Abbrev = Stream.EmitAbbrev(Abbv);
+    // Abbrev for CST_CODE_MDSTRING.
+    Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_MDSTRING));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
+    MDString6Abbrev = Stream.EmitAbbrev(Abbv);
+  }  
+  
+  SmallVector<uint64_t, 64> Record;
+
+  const ValueEnumerator::ValueList &Vals = VE.getValues();
+  const 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()));
+      
+      // 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) {
+        int64_t V = IV->getSExtValue();
+        if (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;
+      const Type *Ty = CFP->getType();
+      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
+        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
+      } else if (Ty == Type::X86_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 == Type::FP128Ty || Ty == Type::PPC_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()) {
+      // Emit constant strings specially.
+      unsigned NumOps = C->getNumOperands();
+      // If this is a null-terminated string, use the denser CSTRING encoding.
+      if (C->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>(C->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)));
+        }
+        break;
+      case Instruction::GetElementPtr:
+        Code = bitc::CST_CODE_CE_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:
+      case Instruction::VICmp:
+      case Instruction::VFCmp:
+        if (isa<VectorType>(C->getOperand(0)->getType())
+            && (CE->getOpcode() == Instruction::ICmp
+                || CE->getOpcode() == Instruction::FCmp)) {
+          // compare returning vector of Int1Ty
+          assert(0 && "Unsupported constant!");
+        } else {
+          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 MDString *S = dyn_cast<MDString>(C)) {
+      Code = bitc::CST_CODE_MDSTRING;
+      AbbrevToUse = MDString6Abbrev;
+      for (unsigned i = 0, e = S->size(); i != e; ++i) {
+        char V = S->begin()[i];
+        Record.push_back(V);
+
+        if (!BitCodeAbbrevOp::isChar6(V))
+          AbbrevToUse = MDString8Abbrev;
+      }
+    } else if (const MDNode *N = dyn_cast<MDNode>(C)) {
+      Code = bitc::CST_CODE_MDNODE;
+      for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
+        if (N->getElement(i)) {
+          Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
+          Record.push_back(VE.getValueID(N->getElement(i)));
+        } else {
+          Record.push_back(VE.getTypeID(Type::VoidTy));
+          Record.push_back(0);
+        }
+      }
+    } else {
+      assert(0 && "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;
+  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()));
+    }
+    break;
+
+  case Instruction::GetElementPtr:
+    Code = bitc::FUNC_CODE_INST_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:
+  case Instruction::VICmp:
+  case Instruction::VFCmp:
+    if (I.getOpcode() == Instruction::ICmp
+        || I.getOpcode() == Instruction::FCmp) {
+      // compare returning Int1Ty or vector of Int1Ty
+      Code = bitc::FUNC_CODE_INST_CMP2;
+    } else {
+      Code = bitc::FUNC_CODE_INST_CMP;
+    }
+    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::Invoke: {
+    const InvokeInst *II = cast<InvokeInst>(&I);
+    const Value *Callee(II->getCalledValue());
+    const PointerType *PTy = cast<PointerType>(Callee->getType());
+    const 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+3)));  // fixed param.
+
+    // Emit type/value pairs for varargs params.
+    if (FTy->isVarArg()) {
+      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
+           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:
+    Code = bitc::FUNC_CODE_INST_PHI;
+    Vals.push_back(VE.getTypeID(I.getType()));
+    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
+      Vals.push_back(VE.getValueID(I.getOperand(i)));
+    break;
+    
+  case Instruction::Malloc:
+    Code = bitc::FUNC_CODE_INST_MALLOC;
+    Vals.push_back(VE.getTypeID(I.getType()));
+    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
+    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
+    break;
+    
+  case Instruction::Free:
+    Code = bitc::FUNC_CODE_INST_FREE;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    break;
+    
+  case Instruction::Alloca:
+    Code = bitc::FUNC_CODE_INST_ALLOCA;
+    Vals.push_back(VE.getTypeID(I.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_STORE2;
+    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 PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
+    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+
+    Code = bitc::FUNC_CODE_INST_CALL;
+    
+    const CallInst *CI = cast<CallInst>(&I);
+    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
+    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
+    PushValueAndType(CI->getOperand(0), 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(I.getOperand(i+1)));  // fixed param.
+      
+    // Emit type/value pairs for varargs params.
+    if (FTy->isVarArg()) {
+      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
+      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
+           i != e; ++i)
+        PushValueAndType(I.getOperand(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);
+  
+  // Keep a running idea of what the instruction ID is. 
+  unsigned InstID = CstEnd;
+  
+  // 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() != Type::VoidTy)
+        ++InstID;
+    }
+  
+  // Emit names for all the instructions etc.
+  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
+    
+  VE.purgeFunction();
+  Stream.ExitBlock();
+}
+
+/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
+static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
+                                 const ValueEnumerator &VE,
+                                 BitstreamWriter &Stream) {
+  if (TST.empty()) return;
+  
+  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 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 (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();
+  }
+  
+  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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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)
+      assert(0 && "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);
+  
+  // If we have any aggregate values in the value table, purge them - these can
+  // only be used to initialize global variables.  Doing so makes the value
+  // namespace smaller for code in functions.
+  int NumNonAggregates = VE.PurgeAggregateValues();
+  if (NumNonAggregates != -1) {
+    SmallVector<unsigned, 1> Vals;
+    Vals.push_back(NumNonAggregates);
+    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
+  }
+  
+  // Emit function bodies.
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
+    if (!I->isDeclaration())
+      WriteFunction(*I, VE, Stream);
+  
+  // Emit the type symbol table information.
+  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, 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 std::string &TT) {
+  unsigned CPUType = ~0U;
+  
+  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  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_POWERPC    = 18
+  };
+  
+  if (TT.find("x86_64-") == 0)
+    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
+  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
+           TT[4] == '-' && TT[1] - '3' < 6)
+    CPUType = DARWIN_CPU_TYPE_X86;
+  else if (TT.find("powerpc-") == 0)
+    CPUType = DARWIN_CPU_TYPE_POWERPC;
+  else if (TT.find("powerpc64-") == 0)
+    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
+  
+  // 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::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
+  raw_os_ostream RawOut(Out);
+  // If writing to stdout, set binary mode.
+  if (llvm::cout == Out)
+    sys::Program::ChangeStdoutToBinary();
+  WriteBitcodeToFile(M, RawOut);
+}
+
+/// WriteBitcodeToFile - Write the specified module to the specified output
+/// stream.
+void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
+  std::vector<unsigned char> Buffer;
+  BitstreamWriter Stream(Buffer);
+  
+  Buffer.reserve(256*1024);
+
+  WriteBitcodeToStream( M, Stream );
+  
+  // If writing to stdout, set binary mode.
+  if (&llvm::outs() == &Out)
+    sys::Program::ChangeStdoutToBinary();
+
+  // Write the generated bitstream to "Out".
+  Out.write((char*)&Buffer.front(), Buffer.size());
+  
+  // Make sure it hits disk now.
+  Out.flush();
+}
+
+/// WriteBitcodeToStream - Write the specified module to the specified output
+/// stream.
+void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
+  // If this is darwin, emit a file header and trailer if needed.
+  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
+  if (isDarwin)
+    EmitDarwinBCHeader(Stream, M->getTargetTriple());
+  
+  // 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 (isDarwin)
+    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
+}