Initial support for writing bitcode files. This currently only writes types,

the type symtab, and global/function protos, and is missing the important
size optimization, but it is a place to start.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36331 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 652 insertions, 0 deletions

diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
new file mode 100644
index 0000000..7ad7f36
--- /dev/null
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -0,0 +1,317 @@
+//===--- Bitcode/Writer/Writer.cpp - Bitcode Writer -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Bitcode writer implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitstreamWriter.h"
+#include "../LLVMBitCodes.h"
+#include "ValueEnumerator.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/TypeSymbolTable.h"
+#include "llvm/Support/MathExtras.h"
+using namespace llvm;
+
+static const unsigned CurVersion = 0;
+
+static void WriteStringRecord(unsigned Code, const std::string &Str, 
+                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
+  SmallVector<unsigned, 64> Vals;
+  
+  // Code: [strlen, strchar x N]
+  Vals.push_back(Str.size());
+  for (unsigned i = 0, e = Str.size(); i != e; ++i)
+    Vals.push_back(Str[i]);
+    
+  // Emit the finished record.
+  Stream.EmitRecord(Code, Vals, AbbrevToUse);
+}
+
+
+/// 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;
+  
+  // FIXME: Set up abbrevs now that we know the width of the type fields, etc.
+  
+  // 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()) {
+    case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
+    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::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
+    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
+    case Type::IntegerTyID:
+      // INTEGER: [width]
+      Code = bitc::TYPE_CODE_INTEGER;
+      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
+      break;
+    case Type::PointerTyID:
+      // POINTER: [pointee type]
+      Code = bitc::TYPE_CODE_POINTER;
+      TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
+      break;
+
+    case Type::FunctionTyID: {
+      const FunctionType *FT = cast<FunctionType>(T);
+      // FUNCTION: [isvararg, #pararms, paramty x N]
+      Code = bitc::TYPE_CODE_FUNCTION;
+      TypeVals.push_back(FT->isVarArg());
+      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
+      // FIXME: PARAM ATTR ID!
+      TypeVals.push_back(FT->getNumParams());
+      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
+        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
+      break;
+    }
+    case Type::StructTyID: {
+      const StructType *ST = cast<StructType>(T);
+      // STRUCT: [ispacked, #elts, eltty x N]
+      Code = bitc::TYPE_CODE_STRUCT;
+      TypeVals.push_back(ST->isPacked());
+      TypeVals.push_back(ST->getNumElements());
+      // 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));
+      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()));
+      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();
+}
+
+/// 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);
+
+  // FIXME: Set up the abbrev, we know how many types there are!
+  // FIXME: We know if the type names can use 7-bit ascii.
+  
+  SmallVector<unsigned, 64> NameVals;
+
+  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 
+       TI != TE; ++TI) {
+    unsigned AbbrevToUse = 0;
+
+    // TST_ENTRY: [typeid, namelen, namechar x N]
+    NameVals.push_back(VE.getTypeID(TI->second));
+    
+    const std::string &Str = TI->first;
+    NameVals.push_back(Str.size());
+    for (unsigned i = 0, e = Str.size(); i != e; ++i)
+      NameVals.push_back(Str[i]);
+  
+    // Emit the finished record.
+    Stream.EmitRecord(bitc::TST_ENTRY_CODE, NameVals, AbbrevToUse);
+    NameVals.clear();
+  }
+
+  Stream.ExitBlock();
+}
+
+static unsigned getEncodedLinkage(const GlobalValue *GV) {
+  switch (GV->getLinkage()) {
+  default: assert(0 && "Invalid linkage!");
+  case GlobalValue::ExternalLinkage:     return 0;
+  case GlobalValue::WeakLinkage:         return 1;
+  case GlobalValue::AppendingLinkage:    return 2;
+  case GlobalValue::InternalLinkage:     return 3;
+  case GlobalValue::LinkOnceLinkage:     return 4;
+  case GlobalValue::DLLImportLinkage:    return 5;
+  case GlobalValue::DLLExportLinkage:    return 6;
+  case GlobalValue::ExternalWeakLinkage: return 7;
+  }
+}
+
+static unsigned getEncodedVisibility(const GlobalValue *GV) {
+  switch (GV->getVisibility()) {
+  default: assert(0 && "Invalid visibility!");
+  case GlobalValue::DefaultVisibility: return 0;
+  case GlobalValue::HiddenVisibility:  return 1;
+  }
+}
+
+// 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.
+  std::map<std::string, unsigned> SectionMap;
+  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
+       GV != E; ++GV) {
+    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) {
+    if (!F->hasSection()) continue;
+    // Give section names unique ID's.
+    unsigned &Entry = SectionMap[F->getSection()];
+    if (Entry != 0) continue;
+    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
+                      0/*TODO*/, Stream);
+    Entry = SectionMap.size();
+  }
+  
+  // TODO: Emit abbrev, now that we know # sections.
+  
+  // 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) {
+    
+    // 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);
+    Vals.push_back(getEncodedVisibility(GV));
+    Vals.push_back(GV->isThreadLocal());
+    
+    unsigned AbbrevToUse = 0;
+    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, linkage, alignment, section,
+    //             visibility]
+    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(Log2_32(F->getAlignment())+1);
+    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
+    Vals.push_back(getEncodedVisibility(F));
+    
+    unsigned AbbrevToUse = 0;
+    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
+    Vals.clear();
+  }
+}
+
+
+/// WriteModule - Emit the specified module to the bitstream.
+static void WriteModule(const Module *M, BitstreamWriter &Stream) {
+  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 2);
+  
+  // Emit the version number if it is non-zero.
+  if (CurVersion) {
+    SmallVector<unsigned, 1> VersionVals;
+    VersionVals.push_back(CurVersion);
+    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, VersionVals);
+  }
+  
+  // Analyze the module, enumerating globals, functions, etc.
+  ValueEnumerator VE(M);
+  
+  // Emit information describing all of the types in the module.
+  WriteTypeTable(VE, Stream);
+  
+  // FIXME: Emit constants.
+  
+  // Emit top-level description of module, including target triple, inline asm,
+  // descriptors for global variables, and function prototype info.
+  WriteModuleInfo(M, VE, Stream);
+  
+  // Emit the type symbol table information.
+  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
+  Stream.ExitBlock();
+}
+
+/// WriteBitcodeToFile - Write the specified module to the specified output
+/// stream.
+void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
+  std::vector<unsigned char> Buffer;
+  BitstreamWriter Stream(Buffer);
+  
+  Buffer.reserve(256*1024);
+  
+  // 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);
+  
+  // Write the generated bitstream to "Out".
+  Out.write((char*)&Buffer.front(), Buffer.size());
+}
diff --git a/lib/Bitcode/Writer/Makefile b/lib/Bitcode/Writer/Makefile
new file mode 100644
index 0000000..c87387a
--- /dev/null
+++ b/lib/Bitcode/Writer/Makefile
@@ -0,0 +1,15 @@
+##===- lib/Bitcode/Reader/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file was developed by Chris Lattner and is distributed under
+# the University of Illinois Open Source License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+LIBRARYNAME = LLVMBitWriter
+BUILD_ARCHIVE = 1
+
+include $(LEVEL)/Makefile.common
+
diff --git a/lib/Bitcode/Writer/ValueEnumerator.cpp b/lib/Bitcode/Writer/ValueEnumerator.cpp
new file mode 100644
index 0000000..75a8c6d
--- /dev/null
+++ b/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -0,0 +1,235 @@
+//===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the ValueEnumerator class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueEnumerator.h"
+#include "llvm/Module.h"
+#include "llvm/TypeSymbolTable.h"
+#include "llvm/ValueSymbolTable.h"
+using namespace llvm;
+
+/// 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);
+
+  // 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());
+
+  // FIXME: Implement the 'string constant' optimization.
+
+  // Enumerate types used by the type symbol table.
+  EnumerateTypeSymbolTable(M->getTypeSymbolTable());
+
+  // Insert constants that are named at module level into the slot pool so that
+  // the module symbol table can refer to them...
+  EnumerateValueSymbolTable(M->getValueSymbolTable());
+  
+  // Enumerate types used by function bodies.
+  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
+    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)
+          EnumerateType((*OI)->getType());
+        EnumerateType(I->getType());
+      }
+  }
+    
+  
+  // FIXME: std::partition the type and value tables so that first-class types
+  // come earlier than aggregates.
+  
+  // FIXME: Sort type/value tables by frequency.
+}
+
+/// EnumerateTypeSymbolTable - Insert all of the types in the specified symbol
+/// table.
+void ValueEnumerator::EnumerateTypeSymbolTable(const TypeSymbolTable &TST) {
+  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); 
+       TI != TE; ++TI)
+    EnumerateType(TI->second);
+}
+
+/// 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());
+}
+
+void ValueEnumerator::EnumerateValue(const Value *V) {
+  assert(V->getType() != Type::VoidTy && "Can't insert void values!");
+  
+  // Check to see if it's already in!
+  unsigned &ValueID = ValueMap[V];
+  if (ValueID) {
+    // Increment use count.
+    Values[ValueID-1].second++;
+    return;
+  }
+  
+  // Add the value.
+  Values.push_back(std::make_pair(V, 1U));
+  ValueID = Values.size();
+
+  if (const Constant *C = dyn_cast<Constant>(V)) {
+    if (isa<GlobalValue>(C)) {
+      // Initializers for globals are handled explicitly elsewhere.
+    } else {
+      // This makes sure that if a constant has uses (for example an array of
+      // const ints), that they are inserted also.
+      for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
+           I != E; ++I)
+        EnumerateValue(*I);
+    }
+  }
+
+  EnumerateType(V->getType());
+}
+
+
+void ValueEnumerator::EnumerateType(const Type *Ty) {
+  unsigned &TypeID = TypeMap[Ty];
+  
+  if (TypeID) {
+    // If we've already seen this type, just increase its occurrence count.
+    Types[TypeID-1].second++;
+    return;
+  }
+  
+  // First time we saw this type, add it.
+  Types.push_back(std::make_pair(Ty, 1U));
+  TypeID = Types.size();
+  
+  // Enumerate subtypes.
+  for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
+       I != E; ++I)
+    EnumerateType(*I);
+}
+
+
+
+#if 0
+
+void SlotCalculator::incorporateFunction(const Function *F) {
+  SC_DEBUG("begin processFunction!\n");
+  
+  // Iterate over function arguments, adding them to the value table...
+  for(Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
+      I != E; ++I)
+    CreateFunctionValueSlot(I);
+  
+  SC_DEBUG("Inserting Instructions:\n");
+  
+  // Add all of the instructions to the type planes...
+  for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+    CreateFunctionValueSlot(BB);
+    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
+      if (I->getType() != Type::VoidTy)
+        CreateFunctionValueSlot(I);
+    }
+  }
+  
+  SC_DEBUG("end processFunction!\n");
+}
+
+void SlotCalculator::purgeFunction() {
+  SC_DEBUG("begin purgeFunction!\n");
+  
+  // Next, remove values from existing type planes
+  for (DenseMap<unsigned,unsigned,
+          ModuleLevelDenseMapKeyInfo>::iterator I = ModuleLevel.begin(),
+       E = ModuleLevel.end(); I != E; ++I) {
+    unsigned PlaneNo = I->first;
+    unsigned ModuleLev = I->second;
+    
+    // Pop all function-local values in this type-plane off of Table.
+    TypePlane &Plane = getPlane(PlaneNo);
+    assert(ModuleLev < Plane.size() && "module levels higher than elements?");
+    for (unsigned i = ModuleLev, e = Plane.size(); i != e; ++i) {
+      NodeMap.erase(Plane.back());       // Erase from nodemap
+      Plane.pop_back();                  // Shrink plane
+    }
+  }
+
+  ModuleLevel.clear();
+
+  // Finally, remove any type planes defined by the function...
+  while (Table.size() > NumModuleTypes) {
+    TypePlane &Plane = Table.back();
+    SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
+             << Plane.size() << "\n");
+    for (unsigned i = 0, e = Plane.size(); i != e; ++i)
+      NodeMap.erase(Plane[i]);   // Erase from nodemap
+    
+    Table.pop_back();                // Nuke the plane, we don't like it.
+  }
+  
+  SC_DEBUG("end purgeFunction!\n");
+}
+
+inline static bool hasImplicitNull(const Type* Ty) {
+  return Ty != Type::LabelTy && Ty != Type::VoidTy && !isa<OpaqueType>(Ty);
+}
+
+void SlotCalculator::CreateFunctionValueSlot(const Value *V) {
+  assert(!NodeMap.count(V) && "Function-local value can't be inserted!");
+  
+  const Type *Ty = V->getType();
+  assert(Ty != Type::VoidTy && "Can't insert void values!");
+  assert(!isa<Constant>(V) && "Not a function-local value!");
+  
+  unsigned TyPlane = getOrCreateTypeSlot(Ty);
+  if (Table.size() <= TyPlane)    // Make sure we have the type plane allocated.
+    Table.resize(TyPlane+1, TypePlane());
+  
+  // If this is the first value noticed of this type within this function,
+  // remember the module level for this type plane in ModuleLevel.  This reminds
+  // us to remove the values in purgeFunction and tells us how many to remove.
+  if (TyPlane < NumModuleTypes)
+    ModuleLevel.insert(std::make_pair(TyPlane, Table[TyPlane].size()));
+  
+  // If this is the first value to get inserted into the type plane, make sure
+  // to insert the implicit null value.
+  if (Table[TyPlane].empty()) {
+    // Label's and opaque types can't have a null value.
+    if (hasImplicitNull(Ty)) {
+      Value *ZeroInitializer = Constant::getNullValue(Ty);
+      
+      // If we are pushing zeroinit, it will be handled below.
+      if (V != ZeroInitializer) {
+        Table[TyPlane].push_back(ZeroInitializer);
+        NodeMap[ZeroInitializer] = 0;
+      }
+    }
+  }
+  
+  // Insert node into table and NodeMap...
+  NodeMap[V] = Table[TyPlane].size();
+  Table[TyPlane].push_back(V);
+  
+  SC_DEBUG("  Inserting value [" << TyPlane << "] = " << *V << " slot=" <<
+           NodeMap[V] << "\n");
+}
+
+#endif
diff --git a/lib/Bitcode/Writer/ValueEnumerator.h b/lib/Bitcode/Writer/ValueEnumerator.h
new file mode 100644
index 0000000..f407a26
--- /dev/null
+++ b/lib/Bitcode/Writer/ValueEnumerator.h
@@ -0,0 +1,85 @@
+//===-- Bitcode/Writer/ValueEnumerator.h - Number values --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class gives values and types Unique ID's.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef VALUE_ENUMERATOR_H
+#define VALUE_ENUMERATOR_H
+
+#include "llvm/ADT/DenseMap.h"
+#include <vector>
+
+namespace llvm {
+
+class Value;
+class Type;
+class Module;
+class Function;
+class TypeSymbolTable;
+class ValueSymbolTable;
+class ConstantArray;
+
+class ValueEnumerator {
+public:
+  // For each type, we remember its Type* and occurrence frequency.
+  typedef std::vector<std::pair<const Type*, unsigned> > TypeList;
+
+  // For each value, we remember its Value* and occurrence frequency.
+  typedef std::vector<std::pair<const Value*, unsigned> > ValueList;
+private:
+  TypeList Types;
+  
+  typedef DenseMap<const Type*, unsigned> TypeMapType;
+  TypeMapType TypeMap;
+
+  ValueList Values;
+  
+  typedef DenseMap<const Value*, unsigned> ValueMapType;
+  ValueMapType ValueMap;
+  
+  
+  ValueEnumerator(const ValueEnumerator &);  // DO NOT IMPLEMENT
+  void operator=(const ValueEnumerator &);   // DO NOT IMPLEMENT
+public:
+  ValueEnumerator(const Module *M);
+
+  unsigned getValueID(const Value *V) const {
+    ValueMapType::const_iterator I = ValueMap.find(V);
+    assert(I != ValueMap.end() && "Value not in slotcalculator!");
+    return I->second;
+  }
+  
+  unsigned getTypeID(const Type *T) const {
+    TypeMapType::const_iterator I = TypeMap.find(T);
+    assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
+    return I->second-1;
+  }
+
+
+  const TypeList &getTypes() const { return Types; }
+
+  /// 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 EnumerateValue(const Value *V);
+  void EnumerateType(const Type *T);
+  
+  void EnumerateTypeSymbolTable(const TypeSymbolTable &ST);
+  void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
+};
+
+} // End llvm namespace
+
+#endif