Creating 2.1 release branch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_21@41920 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1721 insertions, 0 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
new file mode 100644
index 0000000000..9e4a3dee60
--- /dev/null
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -0,0 +1,1721 @@
+//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
+//
+//                     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 header defines the BitcodeReader class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "BitcodeReader.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+#include "llvm/ParameterAttributes.h"
+#include "llvm/AutoUpgrade.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/MemoryBuffer.h"
+using namespace llvm;
+
+void BitcodeReader::FreeState() {
+  delete Buffer;
+  Buffer = 0;
+  std::vector<PATypeHolder>().swap(TypeList);
+  ValueList.clear();
+  std::vector<const ParamAttrsList*>().swap(ParamAttrs);
+  std::vector<BasicBlock*>().swap(FunctionBBs);
+  std::vector<Function*>().swap(FunctionsWithBodies);
+  DeferredFunctionInfo.clear();
+}
+
+//===----------------------------------------------------------------------===//
+//  Helper functions to implement forward reference resolution, etc.
+//===----------------------------------------------------------------------===//
+
+/// ConvertToString - Convert a string from a record into an std::string, return
+/// true on failure.
+template<typename StrTy>
+static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
+                            StrTy &Result) {
+  if (Idx > Record.size())
+    return true;
+  
+  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
+    Result += (char)Record[i];
+  return false;
+}
+
+static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
+  switch (Val) {
+  default: // Map unknown/new linkages to external
+  case 0: return GlobalValue::ExternalLinkage;
+  case 1: return GlobalValue::WeakLinkage;
+  case 2: return GlobalValue::AppendingLinkage;
+  case 3: return GlobalValue::InternalLinkage;
+  case 4: return GlobalValue::LinkOnceLinkage;
+  case 5: return GlobalValue::DLLImportLinkage;
+  case 6: return GlobalValue::DLLExportLinkage;
+  case 7: return GlobalValue::ExternalWeakLinkage;
+  }
+}
+
+static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
+  switch (Val) {
+  default: // Map unknown visibilities to default.
+  case 0: return GlobalValue::DefaultVisibility;
+  case 1: return GlobalValue::HiddenVisibility;
+  case 2: return GlobalValue::ProtectedVisibility;
+  }
+}
+
+static int GetDecodedCastOpcode(unsigned Val) {
+  switch (Val) {
+  default: return -1;
+  case bitc::CAST_TRUNC   : return Instruction::Trunc;
+  case bitc::CAST_ZEXT    : return Instruction::ZExt;
+  case bitc::CAST_SEXT    : return Instruction::SExt;
+  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
+  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
+  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
+  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
+  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
+  case bitc::CAST_FPEXT   : return Instruction::FPExt;
+  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
+  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
+  case bitc::CAST_BITCAST : return Instruction::BitCast;
+  }
+}
+static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
+  switch (Val) {
+  default: return -1;
+  case bitc::BINOP_ADD:  return Instruction::Add;
+  case bitc::BINOP_SUB:  return Instruction::Sub;
+  case bitc::BINOP_MUL:  return Instruction::Mul;
+  case bitc::BINOP_UDIV: return Instruction::UDiv;
+  case bitc::BINOP_SDIV:
+    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
+  case bitc::BINOP_UREM: return Instruction::URem;
+  case bitc::BINOP_SREM:
+    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
+  case bitc::BINOP_SHL:  return Instruction::Shl;
+  case bitc::BINOP_LSHR: return Instruction::LShr;
+  case bitc::BINOP_ASHR: return Instruction::AShr;
+  case bitc::BINOP_AND:  return Instruction::And;
+  case bitc::BINOP_OR:   return Instruction::Or;
+  case bitc::BINOP_XOR:  return Instruction::Xor;
+  }
+}
+
+
+namespace {
+  /// @brief A class for maintaining the slot number definition
+  /// as a placeholder for the actual definition for forward constants defs.
+  class ConstantPlaceHolder : public ConstantExpr {
+    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
+    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
+  public:
+    Use Op;
+    ConstantPlaceHolder(const Type *Ty)
+      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
+        Op(UndefValue::get(Type::Int32Ty), this) {
+    }
+  };
+}
+
+Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
+                                                    const Type *Ty) {
+  if (Idx >= size()) {
+    // Insert a bunch of null values.
+    Uses.resize(Idx+1);
+    OperandList = &Uses[0];
+    NumOperands = Idx+1;
+  }
+
+  if (Value *V = Uses[Idx]) {
+    assert(Ty == V->getType() && "Type mismatch in constant table!");
+    return cast<Constant>(V);
+  }
+
+  // Create and return a placeholder, which will later be RAUW'd.
+  Constant *C = new ConstantPlaceHolder(Ty);
+  Uses[Idx].init(C, this);
+  return C;
+}
+
+Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
+  if (Idx >= size()) {
+    // Insert a bunch of null values.
+    Uses.resize(Idx+1);
+    OperandList = &Uses[0];
+    NumOperands = Idx+1;
+  }
+  
+  if (Value *V = Uses[Idx]) {
+    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
+    return V;
+  }
+  
+  // No type specified, must be invalid reference.
+  if (Ty == 0) return 0;
+  
+  // Create and return a placeholder, which will later be RAUW'd.
+  Value *V = new Argument(Ty);
+  Uses[Idx].init(V, this);
+  return V;
+}
+
+
+const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
+  // If the TypeID is in range, return it.
+  if (ID < TypeList.size())
+    return TypeList[ID].get();
+  if (!isTypeTable) return 0;
+  
+  // The type table allows forward references.  Push as many Opaque types as
+  // needed to get up to ID.
+  while (TypeList.size() <= ID)
+    TypeList.push_back(OpaqueType::get());
+  return TypeList.back().get();
+}
+
+//===----------------------------------------------------------------------===//
+//  Functions for parsing blocks from the bitcode file
+//===----------------------------------------------------------------------===//
+
+bool BitcodeReader::ParseParamAttrBlock() {
+  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
+    return Error("Malformed block record");
+  
+  if (!ParamAttrs.empty())
+    return Error("Multiple PARAMATTR blocks found!");
+  
+  SmallVector<uint64_t, 64> Record;
+  
+  ParamAttrsVector Attrs;
+  
+  // Read all the records.
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of PARAMATTR block");
+      return false;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      // No known subblocks, always skip them.
+      Stream.ReadSubBlockID();
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    switch (Stream.ReadRecord(Code, Record)) {
+    default:  // Default behavior: ignore.
+      break;
+    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
+      if (Record.size() & 1)
+        return Error("Invalid ENTRY record");
+
+      ParamAttrsWithIndex PAWI;
+      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
+        PAWI.index = Record[i];
+        PAWI.attrs = Record[i+1];
+        Attrs.push_back(PAWI);
+      }
+      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
+      Attrs.clear();
+      break;
+    }
+    }    
+  }
+}
+
+
+bool BitcodeReader::ParseTypeTable() {
+  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
+    return Error("Malformed block record");
+  
+  if (!TypeList.empty())
+    return Error("Multiple TYPE_BLOCKs found!");
+
+  SmallVector<uint64_t, 64> Record;
+  unsigned NumRecords = 0;
+
+  // Read all the records for this type table.
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (NumRecords != TypeList.size())
+        return Error("Invalid type forward reference in TYPE_BLOCK");
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of type table block");
+      return false;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      // No known subblocks, always skip them.
+      Stream.ReadSubBlockID();
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    const Type *ResultTy = 0;
+    switch (Stream.ReadRecord(Code, Record)) {
+    default:  // Default behavior: unknown type.
+      ResultTy = 0;
+      break;
+    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
+      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
+      // type list.  This allows us to reserve space.
+      if (Record.size() < 1)
+        return Error("Invalid TYPE_CODE_NUMENTRY record");
+      TypeList.reserve(Record[0]);
+      continue;
+    case bitc::TYPE_CODE_VOID:      // VOID
+      ResultTy = Type::VoidTy;
+      break;
+    case bitc::TYPE_CODE_FLOAT:     // FLOAT
+      ResultTy = Type::FloatTy;
+      break;
+    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
+      ResultTy = Type::DoubleTy;
+      break;
+    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
+      ResultTy = Type::X86_FP80Ty;
+      break;
+    case bitc::TYPE_CODE_FP128:     // FP128
+      ResultTy = Type::FP128Ty;
+      break;
+    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
+      ResultTy = Type::PPC_FP128Ty;
+      break;
+    case bitc::TYPE_CODE_LABEL:     // LABEL
+      ResultTy = Type::LabelTy;
+      break;
+    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
+      ResultTy = 0;
+      break;
+    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
+      if (Record.size() < 1)
+        return Error("Invalid Integer type record");
+      
+      ResultTy = IntegerType::get(Record[0]);
+      break;
+    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
+      if (Record.size() < 1)
+        return Error("Invalid POINTER type record");
+      ResultTy = PointerType::get(getTypeByID(Record[0], true));
+      break;
+    case bitc::TYPE_CODE_FUNCTION: {
+      // FUNCTION: [vararg, attrid, retty, paramty x N]
+      if (Record.size() < 3)
+        return Error("Invalid FUNCTION type record");
+      std::vector<const Type*> ArgTys;
+      for (unsigned i = 3, e = Record.size(); i != e; ++i)
+        ArgTys.push_back(getTypeByID(Record[i], true));
+      
+      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
+                                   Record[0], getParamAttrs(Record[1]));
+      break;
+    }
+    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
+      if (Record.size() < 1)
+        return Error("Invalid STRUCT type record");
+      std::vector<const Type*> EltTys;
+      for (unsigned i = 1, e = Record.size(); i != e; ++i)
+        EltTys.push_back(getTypeByID(Record[i], true));
+      ResultTy = StructType::get(EltTys, Record[0]);
+      break;
+    }
+    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
+      if (Record.size() < 2)
+        return Error("Invalid ARRAY type record");
+      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
+      break;
+    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
+      if (Record.size() < 2)
+        return Error("Invalid VECTOR type record");
+      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
+      break;
+    }
+    
+    if (NumRecords == TypeList.size()) {
+      // If this is a new type slot, just append it.
+      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
+      ++NumRecords;
+    } else if (ResultTy == 0) {
+      // Otherwise, this was forward referenced, so an opaque type was created,
+      // but the result type is actually just an opaque.  Leave the one we
+      // created previously.
+      ++NumRecords;
+    } else {
+      // Otherwise, this was forward referenced, so an opaque type was created.
+      // Resolve the opaque type to the real type now.
+      assert(NumRecords < TypeList.size() && "Typelist imbalance");
+      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
+     
+      // Don't directly push the new type on the Tab. Instead we want to replace
+      // the opaque type we previously inserted with the new concrete value. The
+      // refinement from the abstract (opaque) type to the new type causes all
+      // uses of the abstract type to use the concrete type (NewTy). This will
+      // also cause the opaque type to be deleted.
+      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
+      
+      // This should have replaced the old opaque type with the new type in the
+      // value table... or with a preexisting type that was already in the
+      // system.  Let's just make sure it did.
+      assert(TypeList[NumRecords-1].get() != OldTy &&
+             "refineAbstractType didn't work!");
+    }
+  }
+}
+
+
+bool BitcodeReader::ParseTypeSymbolTable() {
+  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
+    return Error("Malformed block record");
+  
+  SmallVector<uint64_t, 64> Record;
+  
+  // Read all the records for this type table.
+  std::string TypeName;
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of type symbol table block");
+      return false;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      // No known subblocks, always skip them.
+      Stream.ReadSubBlockID();
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    switch (Stream.ReadRecord(Code, Record)) {
+    default:  // Default behavior: unknown type.
+      break;
+    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
+      if (ConvertToString(Record, 1, TypeName))
+        return Error("Invalid TST_ENTRY record");
+      unsigned TypeID = Record[0];
+      if (TypeID >= TypeList.size())
+        return Error("Invalid Type ID in TST_ENTRY record");
+
+      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
+      TypeName.clear();
+      break;
+    }
+  }
+}
+
+bool BitcodeReader::ParseValueSymbolTable() {
+  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
+    return Error("Malformed block record");
+
+  SmallVector<uint64_t, 64> Record;
+  
+  // Read all the records for this value table.
+  SmallString<128> ValueName;
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of value symbol table block");
+      return false;
+    }    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      // No known subblocks, always skip them.
+      Stream.ReadSubBlockID();
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    switch (Stream.ReadRecord(Code, Record)) {
+    default:  // Default behavior: unknown type.
+      break;
+    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
+      if (ConvertToString(Record, 1, ValueName))
+        return Error("Invalid TST_ENTRY record");
+      unsigned ValueID = Record[0];
+      if (ValueID >= ValueList.size())
+        return Error("Invalid Value ID in VST_ENTRY record");
+      Value *V = ValueList[ValueID];
+      
+      V->setName(&ValueName[0], ValueName.size());
+      ValueName.clear();
+      break;
+    }
+    case bitc::VST_CODE_BBENTRY: {
+      if (ConvertToString(Record, 1, ValueName))
+        return Error("Invalid VST_BBENTRY record");
+      BasicBlock *BB = getBasicBlock(Record[0]);
+      if (BB == 0)
+        return Error("Invalid BB ID in VST_BBENTRY record");
+      
+      BB->setName(&ValueName[0], ValueName.size());
+      ValueName.clear();
+      break;
+    }
+    }
+  }
+}
+
+/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
+/// the LSB for dense VBR encoding.
+static uint64_t DecodeSignRotatedValue(uint64_t V) {
+  if ((V & 1) == 0)
+    return V >> 1;
+  if (V != 1) 
+    return -(V >> 1);
+  // There is no such thing as -0 with integers.  "-0" really means MININT.
+  return 1ULL << 63;
+}
+
+/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
+/// values and aliases that we can.
+bool BitcodeReader::ResolveGlobalAndAliasInits() {
+  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
+  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
+  
+  GlobalInitWorklist.swap(GlobalInits);
+  AliasInitWorklist.swap(AliasInits);
+
+  while (!GlobalInitWorklist.empty()) {
+    unsigned ValID = GlobalInitWorklist.back().second;
+    if (ValID >= ValueList.size()) {
+      // Not ready to resolve this yet, it requires something later in the file.
+      GlobalInits.push_back(GlobalInitWorklist.back());
+    } else {
+      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
+        GlobalInitWorklist.back().first->setInitializer(C);
+      else
+        return Error("Global variable initializer is not a constant!");
+    }
+    GlobalInitWorklist.pop_back(); 
+  }
+
+  while (!AliasInitWorklist.empty()) {
+    unsigned ValID = AliasInitWorklist.back().second;
+    if (ValID >= ValueList.size()) {
+      AliasInits.push_back(AliasInitWorklist.back());
+    } else {
+      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
+        AliasInitWorklist.back().first->setAliasee(C);
+      else
+        return Error("Alias initializer is not a constant!");
+    }
+    AliasInitWorklist.pop_back(); 
+  }
+  return false;
+}
+
+
+bool BitcodeReader::ParseConstants() {
+  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
+    return Error("Malformed block record");
+
+  SmallVector<uint64_t, 64> Record;
+  
+  // Read all the records for this value table.
+  const Type *CurTy = Type::Int32Ty;
+  unsigned NextCstNo = ValueList.size();
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (NextCstNo != ValueList.size())
+        return Error("Invalid constant reference!");
+      
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of constants block");
+      return false;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      // No known subblocks, always skip them.
+      Stream.ReadSubBlockID();
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    Value *V = 0;
+    switch (Stream.ReadRecord(Code, Record)) {
+    default:  // Default behavior: unknown constant
+    case bitc::CST_CODE_UNDEF:     // UNDEF
+      V = UndefValue::get(CurTy);
+      break;
+    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
+      if (Record.empty())
+        return Error("Malformed CST_SETTYPE record");
+      if (Record[0] >= TypeList.size())
+        return Error("Invalid Type ID in CST_SETTYPE record");
+      CurTy = TypeList[Record[0]];
+      continue;  // Skip the ValueList manipulation.
+    case bitc::CST_CODE_NULL:      // NULL
+      V = Constant::getNullValue(CurTy);
+      break;
+    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
+      if (!isa<IntegerType>(CurTy) || Record.empty())
+        return Error("Invalid CST_INTEGER record");
+      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
+      break;
+    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
+      if (!isa<IntegerType>(CurTy) || Record.empty())
+        return Error("Invalid WIDE_INTEGER record");
+      
+      unsigned NumWords = Record.size();
+      SmallVector<uint64_t, 8> Words;
+      Words.resize(NumWords);
+      for (unsigned i = 0; i != NumWords; ++i)
+        Words[i] = DecodeSignRotatedValue(Record[i]);
+      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
+                                 NumWords, &Words[0]));
+      break;
+    }
+    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
+      if (Record.empty())
+        return Error("Invalid FLOAT record");
+      if (CurTy == Type::FloatTy)
+        V = ConstantFP::get(CurTy, APFloat(APInt(32, (uint32_t)Record[0])));
+      else if (CurTy == Type::DoubleTy)
+        V = ConstantFP::get(CurTy, APFloat(APInt(64, Record[0])));
+      else if (CurTy == Type::X86_FP80Ty)
+        V = ConstantFP::get(CurTy, APFloat(APInt(80, 2, &Record[0])));
+      else if (CurTy == Type::FP128Ty)
+        V = ConstantFP::get(CurTy, APFloat(APInt(128, 2, &Record[0])));
+      else if (CurTy == Type::PPC_FP128Ty)
+        assert(0 && "PowerPC long double constants not handled yet.");
+      else
+        V = UndefValue::get(CurTy);
+      break;
+    }
+      
+    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
+      if (Record.empty())
+        return Error("Invalid CST_AGGREGATE record");
+      
+      unsigned Size = Record.size();
+      std::vector<Constant*> Elts;
+      
+      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
+        for (unsigned i = 0; i != Size; ++i)
+          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
+                                                     STy->getElementType(i)));
+        V = ConstantStruct::get(STy, Elts);
+      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
+        const Type *EltTy = ATy->getElementType();
+        for (unsigned i = 0; i != Size; ++i)
+          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
+        V = ConstantArray::get(ATy, Elts);
+      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
+        const Type *EltTy = VTy->getElementType();
+        for (unsigned i = 0; i != Size; ++i)
+          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
+        V = ConstantVector::get(Elts);
+      } else {
+        V = UndefValue::get(CurTy);
+      }
+      break;
+    }
+    case bitc::CST_CODE_STRING: { // STRING: [values]
+      if (Record.empty())
+        return Error("Invalid CST_AGGREGATE record");
+
+      const ArrayType *ATy = cast<ArrayType>(CurTy);
+      const Type *EltTy = ATy->getElementType();
+      
+      unsigned Size = Record.size();
+      std::vector<Constant*> Elts;
+      for (unsigned i = 0; i != Size; ++i)
+        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
+      V = ConstantArray::get(ATy, Elts);
+      break;
+    }
+    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
+      if (Record.empty())
+        return Error("Invalid CST_AGGREGATE record");
+      
+      const ArrayType *ATy = cast<ArrayType>(CurTy);
+      const Type *EltTy = ATy->getElementType();
+      
+      unsigned Size = Record.size();
+      std::vector<Constant*> Elts;
+      for (unsigned i = 0; i != Size; ++i)
+        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
+      Elts.push_back(Constant::getNullValue(EltTy));
+      V = ConstantArray::get(ATy, Elts);
+      break;
+    }
+    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
+      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
+      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
+      if (Opc < 0) {
+        V = UndefValue::get(CurTy);  // Unknown binop.
+      } else {
+        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
+        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
+        V = ConstantExpr::get(Opc, LHS, RHS);
+      }
+      break;
+    }  
+    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
+      if (Record.size() < 3) return Error("Invalid CE_CAST record");
+      int Opc = GetDecodedCastOpcode(Record[0]);
+      if (Opc < 0) {
+        V = UndefValue::get(CurTy);  // Unknown cast.
+      } else {
+        const Type *OpTy = getTypeByID(Record[1]);
+        if (!OpTy) return Error("Invalid CE_CAST record");
+        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
+        V = ConstantExpr::getCast(Opc, Op, CurTy);
+      }
+      break;
+    }  
+    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
+      if (Record.size() & 1) return Error("Invalid CE_GEP record");
+      SmallVector<Constant*, 16> Elts;
+      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
+        const Type *ElTy = getTypeByID(Record[i]);
+        if (!ElTy) return Error("Invalid CE_GEP record");
+        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
+      }
+      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
+      break;
+    }
+    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
+      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
+      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
+                                                              Type::Int1Ty),
+                                  ValueList.getConstantFwdRef(Record[1],CurTy),
+                                  ValueList.getConstantFwdRef(Record[2],CurTy));
+      break;
+    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
+      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
+      const VectorType *OpTy = 
+        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
+      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
+      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
+                                                  OpTy->getElementType());
+      V = ConstantExpr::getExtractElement(Op0, Op1);
+      break;
+    }
+    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
+      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
+      if (Record.size() < 3 || OpTy == 0)
+        return Error("Invalid CE_INSERTELT record");
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
+      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
+                                                  OpTy->getElementType());
+      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
+      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
+      break;
+    }
+    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
+      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
+      if (Record.size() < 3 || OpTy == 0)
+        return Error("Invalid CE_INSERTELT record");
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
+      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
+      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
+      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
+      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
+      break;
+    }
+    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
+      if (Record.size() < 4) return Error("Invalid CE_CMP record");
+      const Type *OpTy = getTypeByID(Record[0]);
+      if (OpTy == 0) return Error("Invalid CE_CMP record");
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
+      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
+
+      if (OpTy->isFloatingPoint())
+        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
+      else
+        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
+      break;
+    }
+    case bitc::CST_CODE_INLINEASM: {
+      if (Record.size() < 2) return Error("Invalid INLINEASM record");
+      std::string AsmStr, ConstrStr;
+      bool HasSideEffects = Record[0];
+      unsigned AsmStrSize = Record[1];
+      if (2+AsmStrSize >= Record.size())
+        return Error("Invalid INLINEASM record");
+      unsigned ConstStrSize = Record[2+AsmStrSize];
+      if (3+AsmStrSize+ConstStrSize > Record.size())
+        return Error("Invalid INLINEASM record");
+      
+      for (unsigned i = 0; i != AsmStrSize; ++i)
+        AsmStr += (char)Record[2+i];
+      for (unsigned i = 0; i != ConstStrSize; ++i)
+        ConstrStr += (char)Record[3+AsmStrSize+i];
+      const PointerType *PTy = cast<PointerType>(CurTy);
+      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
+                         AsmStr, ConstrStr, HasSideEffects);
+      break;
+    }
+    }
+    
+    ValueList.AssignValue(V, NextCstNo);
+    ++NextCstNo;
+  }
+}
+
+/// RememberAndSkipFunctionBody - When we see the block for a function body,
+/// remember where it is and then skip it.  This lets us lazily deserialize the
+/// functions.
+bool BitcodeReader::RememberAndSkipFunctionBody() {
+  // Get the function we are talking about.
+  if (FunctionsWithBodies.empty())
+    return Error("Insufficient function protos");
+  
+  Function *Fn = FunctionsWithBodies.back();
+  FunctionsWithBodies.pop_back();
+  
+  // Save the current stream state.
+  uint64_t CurBit = Stream.GetCurrentBitNo();
+  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
+  
+  // Set the functions linkage to GhostLinkage so we know it is lazily
+  // deserialized.
+  Fn->setLinkage(GlobalValue::GhostLinkage);
+  
+  // Skip over the function block for now.
+  if (Stream.SkipBlock())
+    return Error("Malformed block record");
+  return false;
+}
+
+bool BitcodeReader::ParseModule(const std::string &ModuleID) {
+  // Reject multiple MODULE_BLOCK's in a single bitstream.
+  if (TheModule)
+    return Error("Multiple MODULE_BLOCKs in same stream");
+  
+  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
+    return Error("Malformed block record");
+
+  // Otherwise, create the module.
+  TheModule = new Module(ModuleID);
+  
+  SmallVector<uint64_t, 64> Record;
+  std::vector<std::string> SectionTable;
+
+  // Read all the records for this module.
+  while (!Stream.AtEndOfStream()) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of module block");
+
+      // Patch the initializers for globals and aliases up.
+      ResolveGlobalAndAliasInits();
+      if (!GlobalInits.empty() || !AliasInits.empty())
+        return Error("Malformed global initializer set");
+      if (!FunctionsWithBodies.empty())
+        return Error("Too few function bodies found");
+
+      // Look for intrinsic functions which need to be upgraded at some point
+      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
+           FI != FE; ++FI) {
+        if (Function* NewFn = UpgradeIntrinsicFunction(FI))
+          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
+      }
+
+      // Force deallocation of memory for these vectors to favor the client that
+      // want lazy deserialization.
+      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
+      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
+      std::vector<Function*>().swap(FunctionsWithBodies);
+      return false;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      switch (Stream.ReadSubBlockID()) {
+      default:  // Skip unknown content.
+        if (Stream.SkipBlock())
+          return Error("Malformed block record");
+        break;
+      case bitc::BLOCKINFO_BLOCK_ID:
+        if (Stream.ReadBlockInfoBlock())
+          return Error("Malformed BlockInfoBlock");
+        break;
+      case bitc::PARAMATTR_BLOCK_ID:
+        if (ParseParamAttrBlock())
+          return true;
+        break;
+      case bitc::TYPE_BLOCK_ID:
+        if (ParseTypeTable())
+          return true;
+        break;
+      case bitc::TYPE_SYMTAB_BLOCK_ID:
+        if (ParseTypeSymbolTable())
+          return true;
+        break;
+      case bitc::VALUE_SYMTAB_BLOCK_ID:
+        if (ParseValueSymbolTable())
+          return true;
+        break;
+      case bitc::CONSTANTS_BLOCK_ID:
+        if (ParseConstants() || ResolveGlobalAndAliasInits())
+          return true;
+        break;
+      case bitc::FUNCTION_BLOCK_ID:
+        // If this is the first function body we've seen, reverse the
+        // FunctionsWithBodies list.
+        if (!HasReversedFunctionsWithBodies) {
+          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
+          HasReversedFunctionsWithBodies = true;
+        }
+        
+        if (RememberAndSkipFunctionBody())
+          return true;
+        break;
+      }
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    switch (Stream.ReadRecord(Code, Record)) {
+    default: break;  // Default behavior, ignore unknown content.
+    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
+      if (Record.size() < 1)
+        return Error("Malformed MODULE_CODE_VERSION");
+      // Only version #0 is supported so far.
+      if (Record[0] != 0)
+        return Error("Unknown bitstream version!");
+      break;
+    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
+      std::string S;
+      if (ConvertToString(Record, 0, S))
+        return Error("Invalid MODULE_CODE_TRIPLE record");
+      TheModule->setTargetTriple(S);
+      break;
+    }
+    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
+      std::string S;
+      if (ConvertToString(Record, 0, S))
+        return Error("Invalid MODULE_CODE_DATALAYOUT record");
+      TheModule->setDataLayout(S);
+      break;
+    }
+    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
+      std::string S;
+      if (ConvertToString(Record, 0, S))
+        return Error("Invalid MODULE_CODE_ASM record");
+      TheModule->setModuleInlineAsm(S);
+      break;
+    }
+    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
+      std::string S;
+      if (ConvertToString(Record, 0, S))
+        return Error("Invalid MODULE_CODE_DEPLIB record");
+      TheModule->addLibrary(S);
+      break;
+    }
+    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
+      std::string S;
+      if (ConvertToString(Record, 0, S))
+        return Error("Invalid MODULE_CODE_SECTIONNAME record");
+      SectionTable.push_back(S);
+      break;
+    }
+    // GLOBALVAR: [type, isconst, initid, 
+    //             linkage, alignment, section, visibility, threadlocal]
+    case bitc::MODULE_CODE_GLOBALVAR: {
+      if (Record.size() < 6)
+        return Error("Invalid MODULE_CODE_GLOBALVAR record");
+      const Type *Ty = getTypeByID(Record[0]);
+      if (!isa<PointerType>(Ty))
+        return Error("Global not a pointer type!");
+      Ty = cast<PointerType>(Ty)->getElementType();
+      
+      bool isConstant = Record[1];
+      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
+      unsigned Alignment = (1 << Record[4]) >> 1;
+      std::string Section;
+      if (Record[5]) {
+        if (Record[5]-1 >= SectionTable.size())
+          return Error("Invalid section ID");
+        Section = SectionTable[Record[5]-1];
+      }
+      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
+      if (Record.size() > 6)
+        Visibility = GetDecodedVisibility(Record[6]);
+      bool isThreadLocal = false;
+      if (Record.size() > 7)
+        isThreadLocal = Record[7];
+
+      GlobalVariable *NewGV =
+        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
+      NewGV->setAlignment(Alignment);
+      if (!Section.empty())
+        NewGV->setSection(Section);
+      NewGV->setVisibility(Visibility);
+      NewGV->setThreadLocal(isThreadLocal);
+      
+      ValueList.push_back(NewGV);
+      
+      // Remember which value to use for the global initializer.
+      if (unsigned InitID = Record[2])
+        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
+      break;
+    }
+    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
+    //             alignment, section, visibility]
+    case bitc::MODULE_CODE_FUNCTION: {
+      if (Record.size() < 8)
+        return Error("Invalid MODULE_CODE_FUNCTION record");
+      const Type *Ty = getTypeByID(Record[0]);
+      if (!isa<PointerType>(Ty))
+        return Error("Function not a pointer type!");
+      const FunctionType *FTy =
+        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
+      if (!FTy)
+        return Error("Function not a pointer to function type!");
+
+      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
+                                    "", TheModule);
+
+      Func->setCallingConv(Record[1]);
+      bool isProto = Record[2];
+      Func->setLinkage(GetDecodedLinkage(Record[3]));
+      
+      assert(Func->getFunctionType()->getParamAttrs() == 
+             getParamAttrs(Record[4]));
+      
+      Func->setAlignment((1 << Record[5]) >> 1);
+      if (Record[6]) {
+        if (Record[6]-1 >= SectionTable.size())
+          return Error("Invalid section ID");
+        Func->setSection(SectionTable[Record[6]-1]);
+      }
+      Func->setVisibility(GetDecodedVisibility(Record[7]));
+      
+      ValueList.push_back(Func);
+      
+      // If this is a function with a body, remember the prototype we are
+      // creating now, so that we can match up the body with them later.
+      if (!isProto)
+        FunctionsWithBodies.push_back(Func);
+      break;
+    }
+    // ALIAS: [alias type, aliasee val#, linkage]
+    case bitc::MODULE_CODE_ALIAS: {
+      if (Record.size() < 3)
+        return Error("Invalid MODULE_ALIAS record");
+      const Type *Ty = getTypeByID(Record[0]);
+      if (!isa<PointerType>(Ty))
+        return Error("Function not a pointer type!");
+      
+      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
+                                           "", 0, TheModule);
+      ValueList.push_back(NewGA);
+      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
+      break;
+    }
+    /// MODULE_CODE_PURGEVALS: [numvals]
+    case bitc::MODULE_CODE_PURGEVALS:
+      // Trim down the value list to the specified size.
+      if (Record.size() < 1 || Record[0] > ValueList.size())
+        return Error("Invalid MODULE_PURGEVALS record");
+      ValueList.shrinkTo(Record[0]);
+      break;
+    }
+    Record.clear();
+  }
+  
+  return Error("Premature end of bitstream");
+}
+
+
+bool BitcodeReader::ParseBitcode() {
+  TheModule = 0;
+  
+  if (Buffer->getBufferSize() & 3)
+    return Error("Bitcode stream should be a multiple of 4 bytes in length");
+  
+  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
+  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
+  
+  // Sniff for the signature.
+  if (Stream.Read(8) != 'B' ||
+      Stream.Read(8) != 'C' ||
+      Stream.Read(4) != 0x0 ||
+      Stream.Read(4) != 0xC ||
+      Stream.Read(4) != 0xE ||
+      Stream.Read(4) != 0xD)
+    return Error("Invalid bitcode signature");
+  
+  // We expect a number of well-defined blocks, though we don't necessarily
+  // need to understand them all.
+  while (!Stream.AtEndOfStream()) {
+    unsigned Code = Stream.ReadCode();
+    
+    if (Code != bitc::ENTER_SUBBLOCK)
+      return Error("Invalid record at top-level");
+    
+    unsigned BlockID = Stream.ReadSubBlockID();
+    
+    // We only know the MODULE subblock ID.
+    switch (BlockID) {
+    case bitc::BLOCKINFO_BLOCK_ID:
+      if (Stream.ReadBlockInfoBlock())
+        return Error("Malformed BlockInfoBlock");
+      break;
+    case bitc::MODULE_BLOCK_ID:
+      if (ParseModule(Buffer->getBufferIdentifier()))
+        return true;
+      break;
+    default:
+      if (Stream.SkipBlock())
+        return Error("Malformed block record");
+      break;
+    }
+  }
+  
+  return false;
+}
+
+
+/// ParseFunctionBody - Lazily parse the specified function body block.
+bool BitcodeReader::ParseFunctionBody(Function *F) {
+  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
+    return Error("Malformed block record");
+  
+  unsigned ModuleValueListSize = ValueList.size();
+  
+  // Add all the function arguments to the value table.
+  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
+    ValueList.push_back(I);
+  
+  unsigned NextValueNo = ValueList.size();
+  BasicBlock *CurBB = 0;
+  unsigned CurBBNo = 0;
+
+  // Read all the records.
+  SmallVector<uint64_t, 64> Record;
+  while (1) {
+    unsigned Code = Stream.ReadCode();
+    if (Code == bitc::END_BLOCK) {
+      if (Stream.ReadBlockEnd())
+        return Error("Error at end of function block");
+      break;
+    }
+    
+    if (Code == bitc::ENTER_SUBBLOCK) {
+      switch (Stream.ReadSubBlockID()) {
+      default:  // Skip unknown content.
+        if (Stream.SkipBlock())
+          return Error("Malformed block record");
+        break;
+      case bitc::CONSTANTS_BLOCK_ID:
+        if (ParseConstants()) return true;
+        NextValueNo = ValueList.size();
+        break;
+      case bitc::VALUE_SYMTAB_BLOCK_ID:
+        if (ParseValueSymbolTable()) return true;
+        break;
+      }
+      continue;
+    }
+    
+    if (Code == bitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      continue;
+    }
+    
+    // Read a record.
+    Record.clear();
+    Instruction *I = 0;
+    switch (Stream.ReadRecord(Code, Record)) {
+    default: // Default behavior: reject
+      return Error("Unknown instruction");
+    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
+      if (Record.size() < 1 || Record[0] == 0)
+        return Error("Invalid DECLAREBLOCKS record");
+      // Create all the basic blocks for the function.
+      FunctionBBs.resize(Record[0]);
+      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
+        FunctionBBs[i] = new BasicBlock("", F);
+      CurBB = FunctionBBs[0];
+      continue;
+      
+    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
+      unsigned OpNum = 0;
+      Value *LHS, *RHS;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
+          getValue(Record, OpNum, LHS->getType(), RHS) ||
+          OpNum+1 != Record.size())
+        return Error("Invalid BINOP record");
+      
+      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
+      if (Opc == -1) return Error("Invalid BINOP record");
+      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
+      unsigned OpNum = 0;
+      Value *Op;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+          OpNum+2 != Record.size())
+        return Error("Invalid CAST record");
+      
+      const Type *ResTy = getTypeByID(Record[OpNum]);
+      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
+      if (Opc == -1 || ResTy == 0)
+        return Error("Invalid CAST record");
+      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
+      unsigned OpNum = 0;
+      Value *BasePtr;
+      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
+        return Error("Invalid GEP record");
+
+      SmallVector<Value*, 16> GEPIdx;
+      while (OpNum != Record.size()) {
+        Value *Op;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+          return Error("Invalid GEP record");
+        GEPIdx.push_back(Op);
+      }
+
+      I = new GetElementPtrInst(BasePtr, GEPIdx.begin(), GEPIdx.end());
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
+      unsigned OpNum = 0;
+      Value *TrueVal, *FalseVal, *Cond;
+      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
+          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
+          getValue(Record, OpNum, Type::Int1Ty, Cond))
+        return Error("Invalid SELECT record");
+      
+      I = new SelectInst(Cond, TrueVal, FalseVal);
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
+      unsigned OpNum = 0;
+      Value *Vec, *Idx;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
+          getValue(Record, OpNum, Type::Int32Ty, Idx))
+        return Error("Invalid EXTRACTELT record");
+      I = new ExtractElementInst(Vec, Idx);
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
+      unsigned OpNum = 0;
+      Value *Vec, *Elt, *Idx;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
+          getValue(Record, OpNum, 
+                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
+          getValue(Record, OpNum, Type::Int32Ty, Idx))
+        return Error("Invalid INSERTELT record");
+      I = new InsertElementInst(Vec, Elt, Idx);
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
+      unsigned OpNum = 0;
+      Value *Vec1, *Vec2, *Mask;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
+          getValue(Record, OpNum, Vec1->getType(), Vec2))
+        return Error("Invalid SHUFFLEVEC record");
+
+      const Type *MaskTy =
+        VectorType::get(Type::Int32Ty, 
+                        cast<VectorType>(Vec1->getType())->getNumElements());
+
+      if (getValue(Record, OpNum, MaskTy, Mask))
+        return Error("Invalid SHUFFLEVEC record");
+      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
+      unsigned OpNum = 0;
+      Value *LHS, *RHS;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
+          getValue(Record, OpNum, LHS->getType(), RHS) ||
+          OpNum+1 != Record.size())
+        return Error("Invalid CMP record");
+      
+      if (LHS->getType()->isFPOrFPVector())
+        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
+      else
+        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
+      break;
+    }
+    
+    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
+      if (Record.size() == 0) {
+        I = new ReturnInst();
+        break;
+      } else {
+        unsigned OpNum = 0;
+        Value *Op;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+            OpNum != Record.size())
+          return Error("Invalid RET record");
+        I = new ReturnInst(Op);
+        break;
+      }
+    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
+      if (Record.size() != 1 && Record.size() != 3)
+        return Error("Invalid BR record");
+      BasicBlock *TrueDest = getBasicBlock(Record[0]);
+      if (TrueDest == 0)
+        return Error("Invalid BR record");
+
+      if (Record.size() == 1)
+        I = new BranchInst(TrueDest);
+      else {
+        BasicBlock *FalseDest = getBasicBlock(Record[1]);
+        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
+        if (FalseDest == 0 || Cond == 0)
+          return Error("Invalid BR record");
+        I = new BranchInst(TrueDest, FalseDest, Cond);
+      }
+      break;
+    }
+    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
+      if (Record.size() < 3 || (Record.size() & 1) == 0)
+        return Error("Invalid SWITCH record");
+      const Type *OpTy = getTypeByID(Record[0]);
+      Value *Cond = getFnValueByID(Record[1], OpTy);
+      BasicBlock *Default = getBasicBlock(Record[2]);
+      if (OpTy == 0 || Cond == 0 || Default == 0)
+        return Error("Invalid SWITCH record");
+      unsigned NumCases = (Record.size()-3)/2;
+      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
+      for (unsigned i = 0, e = NumCases; i != e; ++i) {
+        ConstantInt *CaseVal = 
+          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
+        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
+        if (CaseVal == 0 || DestBB == 0) {
+          delete SI;
+          return Error("Invalid SWITCH record!");
+        }
+        SI->addCase(CaseVal, DestBB);
+      }
+      I = SI;
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
+      if (Record.size() < 4) return Error("Invalid INVOKE record");
+      unsigned CCInfo = Record[1];
+      BasicBlock *NormalBB = getBasicBlock(Record[2]);
+      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
+      
+      unsigned OpNum = 4;
+      Value *Callee;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
+        return Error("Invalid INVOKE record");
+      
+      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
+      const FunctionType *FTy = !CalleeTy ? 0 :
+        dyn_cast<FunctionType>(CalleeTy->getElementType());
+
+      // Check that the right number of fixed parameters are here.
+      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
+          Record.size() < OpNum+FTy->getNumParams())
+        return Error("Invalid INVOKE record");
+      
+      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
+
+      SmallVector<Value*, 16> Ops;
+      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
+        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
+        if (Ops.back() == 0) return Error("Invalid INVOKE record");
+      }
+      
+      if (!FTy->isVarArg()) {
+        if (Record.size() != OpNum)
+          return Error("Invalid INVOKE record");
+      } else {
+        // Read type/value pairs for varargs params.
+        while (OpNum != Record.size()) {
+          Value *Op;
+          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+            return Error("Invalid INVOKE record");
+          Ops.push_back(Op);
+        }
+      }
+      
+      I = new InvokeInst(Callee, NormalBB, UnwindBB, Ops.begin(), Ops.end());
+      cast<InvokeInst>(I)->setCallingConv(CCInfo);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
+      I = new UnwindInst();
+      break;
+    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
+      I = new UnreachableInst();
+      break;
+    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
+      if (Record.size() < 1 || ((Record.size()-1)&1))
+        return Error("Invalid PHI record");
+      const Type *Ty = getTypeByID(Record[0]);
+      if (!Ty) return Error("Invalid PHI record");
+      
+      PHINode *PN = new PHINode(Ty);
+      PN->reserveOperandSpace(Record.size()-1);
+      
+      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
+        Value *V = getFnValueByID(Record[1+i], Ty);
+        BasicBlock *BB = getBasicBlock(Record[2+i]);
+        if (!V || !BB) return Error("Invalid PHI record");
+        PN->addIncoming(V, BB);
+      }
+      I = PN;
+      break;
+    }
+      
+    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
+      if (Record.size() < 3)
+        return Error("Invalid MALLOC record");
+      const PointerType *Ty =
+        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
+      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
+      unsigned Align = Record[2];
+      if (!Ty || !Size) return Error("Invalid MALLOC record");
+      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
+      unsigned OpNum = 0;
+      Value *Op;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+          OpNum != Record.size())
+        return Error("Invalid FREE record");
+      I = new FreeInst(Op);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
+      if (Record.size() < 3)
+        return Error("Invalid ALLOCA record");
+      const PointerType *Ty =
+        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
+      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
+      unsigned Align = Record[2];
+      if (!Ty || !Size) return Error("Invalid ALLOCA record");
+      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
+      unsigned OpNum = 0;
+      Value *Op;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+          OpNum+2 != Record.size())
+        return Error("Invalid LOAD record");
+      
+      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
+      unsigned OpNum = 0;
+      Value *Val, *Ptr;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
+          getValue(Record, OpNum, PointerType::get(Val->getType()), Ptr) ||
+          OpNum+2 != Record.size())
+        return Error("Invalid STORE record");
+      
+      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
+      if (Record.size() < 2)
+        return Error("Invalid CALL record");
+      
+      unsigned CCInfo = Record[1];
+      
+      unsigned OpNum = 2;
+      Value *Callee;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
+        return Error("Invalid CALL record");
+      
+      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
+      const FunctionType *FTy = 0;
+      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
+      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
+        return Error("Invalid CALL record");
+      
+      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
+      
+      SmallVector<Value*, 16> Args;
+      // Read the fixed params.
+      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
+        Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
+        if (Args.back() == 0) return Error("Invalid CALL record");
+      }
+      
+      // Read type/value pairs for varargs params.
+      if (!FTy->isVarArg()) {
+        if (OpNum != Record.size())
+          return Error("Invalid CALL record");
+      } else {
+        while (OpNum != Record.size()) {
+          Value *Op;
+          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+            return Error("Invalid CALL record");
+          Args.push_back(Op);
+        }
+      }
+      
+      I = new CallInst(Callee, Args.begin(), Args.end());
+      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
+      cast<CallInst>(I)->setTailCall(CCInfo & 1);
+      break;
+    }
+    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
+      if (Record.size() < 3)
+        return Error("Invalid VAARG record");
+      const Type *OpTy = getTypeByID(Record[0]);
+      Value *Op = getFnValueByID(Record[1], OpTy);
+      const Type *ResTy = getTypeByID(Record[2]);
+      if (!OpTy || !Op || !ResTy)
+        return Error("Invalid VAARG record");
+      I = new VAArgInst(Op, ResTy);
+      break;
+    }
+    }
+
+    // Add instruction to end of current BB.  If there is no current BB, reject
+    // this file.
+    if (CurBB == 0) {
+      delete I;
+      return Error("Invalid instruction with no BB");
+    }
+    CurBB->getInstList().push_back(I);
+    
+    // If this was a terminator instruction, move to the next block.
+    if (isa<TerminatorInst>(I)) {
+      ++CurBBNo;
+      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
+    }
+    
+    // Non-void values get registered in the value table for future use.
+    if (I && I->getType() != Type::VoidTy)
+      ValueList.AssignValue(I, NextValueNo++);
+  }
+  
+  // Check the function list for unresolved values.
+  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
+    if (A->getParent() == 0) {
+      // We found at least one unresolved value.  Nuke them all to avoid leaks.
+      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
+        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
+          A->replaceAllUsesWith(UndefValue::get(A->getType()));
+          delete A;
+        }
+      }
+      return Error("Never resolved value found in function!");
+    }
+  }
+  
+  // Trim the value list down to the size it was before we parsed this function.
+  ValueList.shrinkTo(ModuleValueListSize);
+  std::vector<BasicBlock*>().swap(FunctionBBs);
+  
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// ModuleProvider implementation
+//===----------------------------------------------------------------------===//
+
+
+bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
+  // If it already is material, ignore the request.
+  if (!F->hasNotBeenReadFromBitcode()) return false;
+  
+  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII = 
+    DeferredFunctionInfo.find(F);
+  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
+  
+  // Move the bit stream to the saved position of the deferred function body and
+  // restore the real linkage type for the function.
+  Stream.JumpToBit(DFII->second.first);
+  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
+  
+  if (ParseFunctionBody(F)) {
+    if (ErrInfo) *ErrInfo = ErrorString;
+    return true;
+  }
+
+  // Upgrade any old intrinsic calls in the function.
+  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
+       E = UpgradedIntrinsics.end(); I != E; ++I) {
+    if (I->first != I->second) {
+      for (Value::use_iterator UI = I->first->use_begin(),
+           UE = I->first->use_end(); UI != UE; ) {
+        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
+          UpgradeIntrinsicCall(CI, I->second);
+      }
+    }
+  }
+  
+  return false;
+}
+
+void BitcodeReader::dematerializeFunction(Function *F) {
+  // If this function isn't materialized, or if it is a proto, this is a noop.
+  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
+    return;
+  
+  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
+  
+  // Just forget the function body, we can remat it later.
+  F->deleteBody();
+  F->setLinkage(GlobalValue::GhostLinkage);
+}
+
+
+Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
+  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I = 
+       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
+       ++I) {
+    Function *F = I->first;
+    if (F->hasNotBeenReadFromBitcode() &&
+        materializeFunction(F, ErrInfo))
+      return 0;
+  }
+
+  // Upgrade any intrinsic calls that slipped through (should not happen!) and 
+  // delete the old functions to clean up. We can't do this unless the entire 
+  // module is materialized because there could always be another function body 
+  // with calls to the old function.
+  for (std::vector<std::pair<Function*, Function*> >::iterator I =
+       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
+    if (I->first != I->second) {
+      for (Value::use_iterator UI = I->first->use_begin(),
+           UE = I->first->use_end(); UI != UE; ) {
+        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
+          UpgradeIntrinsicCall(CI, I->second);
+      }
+      ValueList.replaceUsesOfWith(I->first, I->second);
+      I->first->eraseFromParent();
+    }
+  }
+  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
+  
+  return TheModule;
+}
+
+
+/// This method is provided by the parent ModuleProvde class and overriden
+/// here. It simply releases the module from its provided and frees up our
+/// state.
+/// @brief Release our hold on the generated module
+Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
+  // Since we're losing control of this Module, we must hand it back complete
+  Module *M = ModuleProvider::releaseModule(ErrInfo);
+  FreeState();
+  return M;
+}
+
+
+//===----------------------------------------------------------------------===//
+// External interface
+//===----------------------------------------------------------------------===//
+
+/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
+///
+ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
+                                               std::string *ErrMsg) {
+  BitcodeReader *R = new BitcodeReader(Buffer);
+  if (R->ParseBitcode()) {
+    if (ErrMsg)
+      *ErrMsg = R->getErrorString();
+    
+    // Don't let the BitcodeReader dtor delete 'Buffer'.
+    R->releaseMemoryBuffer();
+    delete R;
+    return 0;
+  }
+  return R;
+}
+
+/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
+/// If an error occurs, return null and fill in *ErrMsg if non-null.
+Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
+  BitcodeReader *R;
+  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
+  if (!R) return 0;
+  
+  // Read in the entire module.
+  Module *M = R->materializeModule(ErrMsg);
+
+  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
+  // there was an error.
+  R->releaseMemoryBuffer();
+  
+  // If there was no error, tell ModuleProvider not to delete it when its dtor
+  // is run.
+  if (M)
+    M = R->releaseModule(ErrMsg);
+  
+  delete R;
+  return M;
+}