[Bitcode] Store type IDs for values

[nikic]

Summary

This is the next step towards supporting bitcode auto upgrade with opaque pointers. The ValueList now stores the Value* together with its associated type ID, which allows inspecting the original pointer element type of arbitrary values.

This is a largely mechanical change threading the type ID through various places. I've left TODOTypeID placeholders in a number of places where determining the type ID is either non-trivial or requires allocating a new type ID not present in the original bitcode. For this reason, the new type IDs are also not used for anything yet (apart from propagation). They will get used once the TODOs are resolved.

[aeubanks]

could you give an example of what this will be used for?

[nikic]

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

5226

@aeubanks For example, here we'd write Ty = getTypeByID(ResTypeID). Similar for other remaining uses of getPointerElementType().

[aeubanks]

llvm/lib/Bitcode/Reader/ValueList.cpp

125

should this also check TyID?

llvm/lib/Bitcode/Reader/ValueList.h

29–30

could you add a comment about what the unsigned represents?

[nikic]

llvm/lib/Bitcode/Reader/ValueList.cpp

125

I'm not entirely sure here, but I think not, as multiple type IDs may encode the same type, and these would be technically compatible.

I'll check this again once the full propagation is implemented, as we can currently get a dummy ID here.

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

public:
   void setStripDebugInfo() override;
 
 private:
   std::vector<StructType *> IdentifiedStructTypes;
   StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
   StructType *createIdentifiedStructType(LLVMContext &Context);
 
   static constexpr unsigned InvalidTypeID = ~0u;
+  /// Placeholder for value type IDs we don't yet determine.
+  static constexpr unsigned TODOTypeID = InvalidTypeID - 1;
 
   Type *getTypeByID(unsigned ID);
   Type *getPtrElementTypeByID(unsigned ID);
-  unsigned getContainedTypeID(unsigned ID, unsigned Idx);
+  unsigned getContainedTypeID(unsigned ID, unsigned Idx = 0);
 
-  Value *getFnValueByID(unsigned ID, Type *Ty) {
+  Value *getFnValueByID(unsigned ID, Type *Ty, unsigned TyID) {
     if (Ty && Ty->isMetadataTy())
       return MetadataAsValue::get(Ty->getContext(), getFnMetadataByID(ID));
-    return ValueList.getValueFwdRef(ID, Ty);
+    return ValueList.getValueFwdRef(ID, Ty, TyID);
   }
 
   Metadata *getFnMetadataByID(unsigned ID) {
     return MDLoader->getMetadataFwdRefOrLoad(ID);
   }
 
   BasicBlock *getBasicBlock(unsigned ID) const {
     if (ID >= FunctionBBs.size()) return nullptr; // Invalid ID
     return FunctionBBs[ID];
   }
 
   AttributeList getAttributes(unsigned i) const {
     if (i-1 < MAttributes.size())
       return MAttributes[i-1];
     return AttributeList();
   }
 
   /// Read a value/type pair out of the specified record from slot 'Slot'.
   /// Increment Slot past the number of slots used in the record. Return true on
   /// failure.
   bool getValueTypePair(const SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
-                        unsigned InstNum, Value *&ResVal) {
+                        unsigned InstNum, Value *&ResVal, unsigned &TypeID) {
     if (Slot == Record.size()) return true;
     unsigned ValNo = (unsigned)Record[Slot++];
     // Adjust the ValNo, if it was encoded relative to the InstNum.
     if (UseRelativeIDs)
       ValNo = InstNum - ValNo;
     if (ValNo < InstNum) {
       // If this is not a forward reference, just return the value we already
       // have.
-      ResVal = getFnValueByID(ValNo, nullptr);
+      TypeID = ValueList.getTypeID(ValNo);
+      ResVal = getFnValueByID(ValNo, nullptr, TypeID);
       return ResVal == nullptr;
     }
     if (Slot == Record.size())
       return true;
 
-    unsigned TypeNo = (unsigned)Record[Slot++];
-    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
+    TypeID = (unsigned)Record[Slot++];
+    ResVal = getFnValueByID(ValNo, getTypeByID(TypeID), TypeID);
     return ResVal == nullptr;
   }
 
   /// Read a value out of the specified record from slot 'Slot'. Increment Slot
   /// past the number of slots used by the value in the record. Return true if
   /// there is an error.
   bool popValue(const SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
-                unsigned InstNum, Type *Ty, Value *&ResVal) {
-    if (getValue(Record, Slot, InstNum, Ty, ResVal))
+                unsigned InstNum, Type *Ty, unsigned TyID, Value *&ResVal) {
+    if (getValue(Record, Slot, InstNum, Ty, TyID, ResVal))
       return true;
     // All values currently take a single record slot.
     ++Slot;
     return false;
   }
 
   /// Like popValue, but does not increment the Slot number.
   bool getValue(const SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                unsigned InstNum, Type *Ty, Value *&ResVal) {
-    ResVal = getValue(Record, Slot, InstNum, Ty);
+                unsigned InstNum, Type *Ty, unsigned TyID,  Value *&ResVal) {
+    ResVal = getValue(Record, Slot, InstNum, Ty, TyID);
     return ResVal == nullptr;
   }
 
   /// Version of getValue that returns ResVal directly, or 0 if there is an
   /// error.
   Value *getValue(const SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                  unsigned InstNum, Type *Ty) {
+                  unsigned InstNum, Type *Ty, unsigned TyID) {
     if (Slot == Record.size()) return nullptr;
     unsigned ValNo = (unsigned)Record[Slot];
     // Adjust the ValNo, if it was encoded relative to the InstNum.
     if (UseRelativeIDs)
       ValNo = InstNum - ValNo;
-    return getFnValueByID(ValNo, Ty);
+    return getFnValueByID(ValNo, Ty, TyID);
   }
 
   /// Like getValue, but decodes signed VBRs.
   Value *getValueSigned(const SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                        unsigned InstNum, Type *Ty) {
+                        unsigned InstNum, Type *Ty, unsigned TyID) {
     if (Slot == Record.size()) return nullptr;
     unsigned ValNo = (unsigned)decodeSignRotatedValue(Record[Slot]);
     // Adjust the ValNo, if it was encoded relative to the InstNum.
     if (UseRelativeIDs)
       ValNo = InstNum - ValNo;
-    return getFnValueByID(ValNo, Ty);
+    return getFnValueByID(ValNo, Ty, TyID);
   }
 
   /// Upgrades old-style typeless byval/sret/inalloca attributes by adding the
   /// corresponding argument's pointee type. Also upgrades intrinsics that now
   /// require an elementtype attribute.
   void propagateAttributeTypes(CallBase *CB, ArrayRef<Type *> ArgsTys);
 
   /// Converts alignment exponent (i.e. power of two (or zero)) to the
if (Type *Ty = TypeList[ID])
     return Ty;
 
   // If we have a forward reference, the only possible case is when it is to a
   // named struct.  Just create a placeholder for now.
   return TypeList[ID] = createIdentifiedStructType(Context);
 }
 
 unsigned BitcodeReader::getContainedTypeID(unsigned ID, unsigned Idx) {
+  if (ID == TODOTypeID)
+    return TODOTypeID;
+
   auto It = ContainedTypeIDs.find(ID);
   if (It == ContainedTypeIDs.end())
     return InvalidTypeID;
 
   if (Idx >= It->second.size())
     return InvalidTypeID;
 
   return It->second[Idx];

 
 Error BitcodeReader::parseConstants() {
   if (Error Err = Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
     return Err;
 
   SmallVector<uint64_t, 64> Record;
 
   // Read all the records for this value table.
+  unsigned CurTyID = TODOTypeID;
   Type *CurTy = Type::getInt32Ty(Context);
   Type *CurElemTy = nullptr;
   unsigned NextCstNo = ValueList.size();
 
   struct DelayedShufTy {
     VectorType *OpTy;
+    unsigned OpTyID;
     VectorType *RTy;
     uint64_t Op0Idx;
     uint64_t Op1Idx;
     uint64_t Op2Idx;
     unsigned CstNo;
   };
   std::vector<DelayedShufTy> DelayedShuffles;
   struct DelayedSelTy {
     Type *OpTy;
+    unsigned OpTyID;
     uint64_t Op0Idx;
     uint64_t Op1Idx;
     uint64_t Op2Idx;
     unsigned CstNo;
   };
   std::vector<DelayedSelTy> DelayedSelectors;
 
   while (true) {
case BitstreamEntry::EndBlock:
       // Once all the constants have been read, go through and resolve forward
       // references.
       //
       // We have to treat shuffles specially because they don't have three
       // operands anymore.  We need to convert the shuffle mask into an array,
       // and we can't convert a forward reference.
       for (auto &DelayedShuffle : DelayedShuffles) {
         VectorType *OpTy = DelayedShuffle.OpTy;
+        unsigned OpTyID = DelayedShuffle.OpTyID;
         VectorType *RTy = DelayedShuffle.RTy;
         uint64_t Op0Idx = DelayedShuffle.Op0Idx;
         uint64_t Op1Idx = DelayedShuffle.Op1Idx;
         uint64_t Op2Idx = DelayedShuffle.Op2Idx;
         uint64_t CstNo = DelayedShuffle.CstNo;
-        Constant *Op0 = ValueList.getConstantFwdRef(Op0Idx, OpTy);
-        Constant *Op1 = ValueList.getConstantFwdRef(Op1Idx, OpTy);
+        Constant *Op0 = ValueList.getConstantFwdRef(Op0Idx, OpTy, OpTyID);
+        Constant *Op1 = ValueList.getConstantFwdRef(Op1Idx, OpTy, OpTyID);
         Type *ShufTy =
             VectorType::get(Type::getInt32Ty(Context), RTy->getElementCount());
-        Constant *Op2 = ValueList.getConstantFwdRef(Op2Idx, ShufTy);
+        Constant *Op2 = ValueList.getConstantFwdRef(Op2Idx, ShufTy, TODOTypeID);
         if (!ShuffleVectorInst::isValidOperands(Op0, Op1, Op2))
           return error("Invalid shufflevector operands");
         SmallVector<int, 16> Mask;
         ShuffleVectorInst::getShuffleMask(Op2, Mask);
         Value *V = ConstantExpr::getShuffleVector(Op0, Op1, Mask);
-        ValueList.assignValue(CstNo, V);
+        ValueList.assignValue(CstNo, V, TODOTypeID);
       }
       for (auto &DelayedSelector : DelayedSelectors) {
         Type *OpTy = DelayedSelector.OpTy;
+        unsigned OpTyID = DelayedSelector.OpTyID;
         Type *SelectorTy = Type::getInt1Ty(Context);
         uint64_t Op0Idx = DelayedSelector.Op0Idx;
         uint64_t Op1Idx = DelayedSelector.Op1Idx;
         uint64_t Op2Idx = DelayedSelector.Op2Idx;
         uint64_t CstNo = DelayedSelector.CstNo;
-        Constant *Op1 = ValueList.getConstantFwdRef(Op1Idx, OpTy);
-        Constant *Op2 = ValueList.getConstantFwdRef(Op2Idx, OpTy);
+        Constant *Op1 = ValueList.getConstantFwdRef(Op1Idx, OpTy, OpTyID);
+        Constant *Op2 = ValueList.getConstantFwdRef(Op2Idx, OpTy, OpTyID);
         // The selector might be an i1 or an <n x i1>
         // Get the type from the ValueList before getting a forward ref.
         if (VectorType *VTy = dyn_cast<VectorType>(OpTy)) {
           Value *V = ValueList[Op0Idx];
           assert(V);
           if (SelectorTy != V->getType())
             SelectorTy = VectorType::get(SelectorTy, VTy->getElementCount());
         }
-        Constant *Op0 = ValueList.getConstantFwdRef(Op0Idx, SelectorTy);
+        Constant *Op0 =
+            ValueList.getConstantFwdRef(Op0Idx, SelectorTy, TODOTypeID);
         Value *V = ConstantExpr::getSelect(Op0, Op1, Op2);
-        ValueList.assignValue(CstNo, V);
+        ValueList.assignValue(CstNo, V, TODOTypeID);
       }
 
       if (NextCstNo != ValueList.size())
         return error("Invalid constant reference");
 
       ValueList.resolveConstantForwardRefs();
       return Error::success();
     case BitstreamEntry::Record:
case bitc::CST_CODE_POISON:    // POISON
       break;
     case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
       if (Record.empty())
         return error("Invalid record");
       if (Record[0] >= TypeList.size() || !TypeList[Record[0]])
         return error("Invalid record");
       if (TypeList[Record[0]] == VoidType)
         return error("Invalid constant type");
-      CurTy = TypeList[Record[0]];
-      CurElemTy = getPtrElementTypeByID(Record[0]);
+      CurTyID = Record[0];
+      CurTy = TypeList[CurTyID];
+      CurElemTy = getPtrElementTypeByID(CurTyID);
       continue;  // Skip the ValueList manipulation.
     case bitc::CST_CODE_NULL:      // NULL
       if (CurTy->isVoidTy() || CurTy->isFunctionTy() || CurTy->isLabelTy())
         return error("Invalid type for a constant null value");
       V = Constant::getNullValue(CurTy);
       break;
     case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
       if (!CurTy->isIntegerTy() || Record.empty())
case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
       if (Record.empty())
         return error("Invalid record");
 
       unsigned Size = Record.size();
       SmallVector<Constant*, 16> Elts;
 
       if (StructType *STy = dyn_cast<StructType>(CurTy)) {
         for (unsigned i = 0; i != Size; ++i)
-          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
-                                                     STy->getElementType(i)));
+          Elts.push_back(ValueList.getConstantFwdRef(
+              Record[i], STy->getElementType(i),
+              getContainedTypeID(CurTyID, i)));
         V = ConstantStruct::get(STy, Elts);
       } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
         Type *EltTy = ATy->getElementType();
+        unsigned EltTyID = getContainedTypeID(CurTyID);
         for (unsigned i = 0; i != Size; ++i)
-          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
+          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy,
+                                                     EltTyID));
         V = ConstantArray::get(ATy, Elts);
       } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
         Type *EltTy = VTy->getElementType();
+        unsigned EltTyID = getContainedTypeID(CurTyID);
         for (unsigned i = 0; i != Size; ++i)
-          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
+          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy,
+                                                     EltTyID));
         V = ConstantVector::get(Elts);
       } else {
         V = UndefValue::get(CurTy);
       }
       break;
     }
     case bitc::CST_CODE_STRING:    // STRING: [values]
     case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
while (true) {
     }
     case bitc::CST_CODE_CE_UNOP: {  // CE_UNOP: [opcode, opval]
       if (Record.size() < 2)
         return error("Invalid record");
       int Opc = getDecodedUnaryOpcode(Record[0], CurTy);
       if (Opc < 0) {
         V = UndefValue::get(CurTy);  // Unknown unop.
       } else {
-        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
+        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy, CurTyID);
         unsigned Flags = 0;
         V = ConstantExpr::get(Opc, LHS, Flags);
       }
       break;
     }
     case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
       if (Record.size() < 3)
         return error("Invalid 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);
+        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy, CurTyID);
+        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy, CurTyID);
         unsigned Flags = 0;
         if (Record.size() >= 4) {
           if (Opc == Instruction::Add ||
               Opc == Instruction::Sub ||
               Opc == Instruction::Mul ||
               Opc == Instruction::Shl) {
             if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
               Flags |= OverflowingBinaryOperator::NoSignedWrap;
while (true) {
     }
     case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
       if (Record.size() < 3)
         return error("Invalid record");
       int Opc = getDecodedCastOpcode(Record[0]);
       if (Opc < 0) {
         V = UndefValue::get(CurTy);  // Unknown cast.
       } else {
-        Type *OpTy = getTypeByID(Record[1]);
+        unsigned OpTyID = Record[1];
+        Type *OpTy = getTypeByID(OpTyID);
         if (!OpTy)
           return error("Invalid record");
-        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
+        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy, OpTyID);
         V = UpgradeBitCastExpr(Opc, Op, CurTy);
         if (!V) V = ConstantExpr::getCast(Opc, Op, CurTy);
       }
       break;
     }
     case bitc::CST_CODE_CE_INBOUNDS_GEP: // [ty, n x operands]
     case bitc::CST_CODE_CE_GEP: // [ty, n x operands]
     case bitc::CST_CODE_CE_GEP_WITH_INRANGE_INDEX: { // [ty, flags, n x
case bitc::CST_CODE_CE_GEP_WITH_INRANGE_INDEX: { // [ty, flags, n x
         InBounds = Op & 1;
         InRangeIndex = Op >> 1;
       } else if (BitCode == bitc::CST_CODE_CE_INBOUNDS_GEP)
         InBounds = true;
 
       SmallVector<Constant*, 16> Elts;
       unsigned BaseTypeID = Record[OpNum];
       while (OpNum != Record.size()) {
-        Type *ElTy = getTypeByID(Record[OpNum++]);
+        unsigned ElTyID = Record[OpNum++];
+        Type *ElTy = getTypeByID(ElTyID);
         if (!ElTy)
           return error("Invalid record");
-        Elts.push_back(ValueList.getConstantFwdRef(Record[OpNum++], ElTy));
+        Elts.push_back(ValueList.getConstantFwdRef(Record[OpNum++], ElTy,
+                                                   ElTyID));
       }
 
       if (Elts.size() < 1)
         return error("Invalid gep with no operands");
 
       Type *BaseType = getTypeByID(BaseTypeID);
       if (isa<VectorType>(BaseType)) {
         BaseTypeID = getContainedTypeID(BaseTypeID, 0);
case bitc::CST_CODE_CE_GEP_WITH_INRANGE_INDEX: { // [ty, flags, n x
                                          InBounds, InRangeIndex);
       break;
     }
     case bitc::CST_CODE_CE_SELECT: {  // CE_SELECT: [opval#, opval#, opval#]
       if (Record.size() < 3)
         return error("Invalid record");
 
       DelayedSelectors.push_back(
-          {CurTy, Record[0], Record[1], Record[2], NextCstNo});
-      (void)ValueList.getConstantFwdRef(NextCstNo, CurTy);
+          {CurTy, CurTyID, Record[0], Record[1], Record[2], NextCstNo});
+      (void)ValueList.getConstantFwdRef(NextCstNo, CurTy, CurTyID);
       ++NextCstNo;
       continue;
     }
     case bitc::CST_CODE_CE_EXTRACTELT
         : { // CE_EXTRACTELT: [opty, opval, opty, opval]
       if (Record.size() < 3)
         return error("Invalid record");
+      unsigned OpTyID = Record[0];
       VectorType *OpTy =
-        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
+        dyn_cast_or_null<VectorType>(getTypeByID(OpTyID));
       if (!OpTy)
         return error("Invalid record");
-      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy, OpTyID);
       Constant *Op1 = nullptr;
       if (Record.size() == 4) {
-        Type *IdxTy = getTypeByID(Record[2]);
+        unsigned IdxTyID = Record[2];
+        Type *IdxTy = getTypeByID(IdxTyID);
         if (!IdxTy)
           return error("Invalid record");
-        Op1 = ValueList.getConstantFwdRef(Record[3], IdxTy);
+        Op1 = ValueList.getConstantFwdRef(Record[3], IdxTy, IdxTyID);
       } else {
         // Deprecated, but still needed to read old bitcode files.
-        Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
+        Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context),
+                                          TODOTypeID);
       }
       if (!Op1)
         return error("Invalid record");
       V = ConstantExpr::getExtractElement(Op0, Op1);
       break;
     }
     case bitc::CST_CODE_CE_INSERTELT
         : { // CE_INSERTELT: [opval, opval, opty, opval]
       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
       if (Record.size() < 3 || !OpTy)
         return error("Invalid record");
-      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy, CurTyID);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
-                                                  OpTy->getElementType());
+                                                  OpTy->getElementType(),
+                                                  getContainedTypeID(CurTyID));
       Constant *Op2 = nullptr;
       if (Record.size() == 4) {
-        Type *IdxTy = getTypeByID(Record[2]);
+        unsigned IdxTyID = Record[2];
+        Type *IdxTy = getTypeByID(IdxTyID);
         if (!IdxTy)
           return error("Invalid record");
-        Op2 = ValueList.getConstantFwdRef(Record[3], IdxTy);
+        Op2 = ValueList.getConstantFwdRef(Record[3], IdxTy, IdxTyID);
       } else {
         // Deprecated, but still needed to read old bitcode files.
-        Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
+        Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context),
+                                          TODOTypeID);
       }
       if (!Op2)
         return error("Invalid record");
       V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
       break;
     }
     case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
       if (Record.size() < 3 || !OpTy)
         return error("Invalid record");
       DelayedShuffles.push_back(
-          {OpTy, OpTy, Record[0], Record[1], Record[2], NextCstNo});
+          {OpTy, CurTyID, OpTy, Record[0], Record[1], Record[2], NextCstNo});
       ++NextCstNo;
       continue;
     }
     case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
       VectorType *RTy = dyn_cast<VectorType>(CurTy);
       VectorType *OpTy =
         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
       if (Record.size() < 4 || !RTy || !OpTy)
         return error("Invalid record");
       DelayedShuffles.push_back(
-          {OpTy, RTy, Record[1], Record[2], Record[3], NextCstNo});
+          {OpTy, CurTyID, RTy, Record[1], Record[2], Record[3], NextCstNo});
       ++NextCstNo;
       continue;
     }
     case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
       if (Record.size() < 4)
         return error("Invalid record");
-      Type *OpTy = getTypeByID(Record[0]);
+      unsigned OpTyID = Record[0];
+      Type *OpTy = getTypeByID(OpTyID);
       if (!OpTy)
         return error("Invalid record");
-      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
-      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
+      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy, OpTyID);
+      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy, OpTyID);
 
       if (OpTy->isFPOrFPVectorTy())
         V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
       else
         V = ConstantExpr::getICmp(Record[3], Op0, Op1);
       break;
     }
     // This maintains backward compatibility, pre-asm dialect keywords.
case bitc::CST_CODE_INLINEASM: {
       UpgradeInlineAsmString(&AsmStr);
       V = InlineAsm::get(FnTy, AsmStr, ConstrStr, HasSideEffects, IsAlignStack,
                          InlineAsm::AsmDialect(AsmDialect), CanThrow);
       break;
     }
     case bitc::CST_CODE_BLOCKADDRESS:{
       if (Record.size() < 3)
         return error("Invalid record");
-      Type *FnTy = getTypeByID(Record[0]);
+      unsigned FnTyID = Record[0];
+      Type *FnTy = getTypeByID(FnTyID);
       if (!FnTy)
         return error("Invalid record");
-      Function *Fn =
-        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
+      Function *Fn = dyn_cast_or_null<Function>(
+          ValueList.getConstantFwdRef(Record[1], FnTy, FnTyID));
       if (!Fn)
         return error("Invalid record");
 
       // If the function is already parsed we can insert the block address right
       // away.
       BasicBlock *BB;
       unsigned BBID = Record[2];
       if (!BBID)
case bitc::CST_CODE_BLOCKADDRESS:{
         BB = FwdBBs[BBID];
       }
       V = BlockAddress::get(Fn, BB);
       break;
     }
     case bitc::CST_CODE_DSO_LOCAL_EQUIVALENT: {
       if (Record.size() < 2)
         return error("Invalid record");
-      Type *GVTy = getTypeByID(Record[0]);
+      unsigned GVTyID = Record[0];
+      Type *GVTy = getTypeByID(GVTyID);
       if (!GVTy)
         return error("Invalid record");
       GlobalValue *GV = dyn_cast_or_null<GlobalValue>(
-          ValueList.getConstantFwdRef(Record[1], GVTy));
+          ValueList.getConstantFwdRef(Record[1], GVTy, GVTyID));
       if (!GV)
         return error("Invalid record");
 
       V = DSOLocalEquivalent::get(GV);
       break;
     }
     case bitc::CST_CODE_NO_CFI_VALUE: {
       if (Record.size() < 2)
         return error("Invalid record");
-      Type *GVTy = getTypeByID(Record[0]);
+      unsigned GVTyID = Record[0];
+      Type *GVTy = getTypeByID(GVTyID);
       if (!GVTy)
         return error("Invalid record");
       GlobalValue *GV = dyn_cast_or_null<GlobalValue>(
-          ValueList.getConstantFwdRef(Record[1], GVTy));
+          ValueList.getConstantFwdRef(Record[1], GVTy, GVTyID));
       if (!GV)
         return error("Invalid record");
       V = NoCFIValue::get(GV);
       break;
     }
     }
 
-    ValueList.assignValue(NextCstNo, V);
+    ValueList.assignValue(NextCstNo, V, CurTyID);
     ++NextCstNo;
   }
 }
 
 Error BitcodeReader::parseUseLists() {
   if (Error Err = Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
     return Err;
 
Error BitcodeReader::parseGlobalVarRecord(ArrayRef<uint64_t> Record) {
   // dllstorageclass, comdat, attributes, preemption specifier,
   // partition strtab offset, partition strtab size] (name in VST)
   // v2: [strtab_offset, strtab_size, v1]
   StringRef Name;
   std::tie(Name, Record) = readNameFromStrtab(Record);
 
   if (Record.size() < 6)
     return error("Invalid record");
-  Type *Ty = getTypeByID(Record[0]);
+  unsigned TyID = Record[0];
+  Type *Ty = getTypeByID(TyID);
   if (!Ty)
     return error("Invalid record");
   bool isConstant = Record[1] & 1;
   bool explicitType = Record[1] & 2;
   unsigned AddressSpace;
   if (explicitType) {
     AddressSpace = Record[1] >> 2;
   } else {
Error BitcodeReader::parseGlobalVarRecord(ArrayRef<uint64_t> Record) {
   NewGV->setVisibility(Visibility);
   NewGV->setUnnamedAddr(UnnamedAddr);
 
   if (Record.size() > 10)
     NewGV->setDLLStorageClass(getDecodedDLLStorageClass(Record[10]));
   else
     upgradeDLLImportExportLinkage(NewGV, RawLinkage);
 
-  ValueList.push_back(NewGV);
+  ValueList.push_back(NewGV, TyID);
 
   // Remember which value to use for the global initializer.
   if (unsigned InitID = Record[2])
     GlobalInits.push_back(std::make_pair(NewGV, InitID - 1));
 
   if (Record.size() > 11) {
     if (unsigned ComdatID = Record[11]) {
       if (ComdatID > ComdatList.size())
Error BitcodeReader::parseFunctionRecord(ArrayRef<uint64_t> Record) {
 
   // Check whether we have enough values to read a partition name. Also make
   // sure Strtab has enough values.
   if (Record.size() > 18 && Strtab.data() &&
       Record[17] + Record[18] <= Strtab.size()) {
     Func->setPartition(StringRef(Strtab.data() + Record[17], Record[18]));
   }
 
-  ValueList.push_back(Func);
+  ValueList.push_back(Func, TODOTypeID);
 
   if (OperandInfo.PersonalityFn || OperandInfo.Prefix || OperandInfo.Prologue)
     FunctionOperands.push_back(OperandInfo);
 
   // 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) {
     Func->setIsMaterializable(true);
Error BitcodeReader::parseGlobalIndirectSymbolRecord(
 
   // Check whether we have enough values to read a partition name.
   if (OpNum + 1 < Record.size()) {
     NewGA->setPartition(
         StringRef(Strtab.data() + Record[OpNum], Record[OpNum + 1]));
     OpNum += 2;
   }
 
-  ValueList.push_back(NewGA);
+  ValueList.push_back(NewGA, TypeID);
   IndirectSymbolInits.push_back(std::make_pair(NewGA, Val));
   return Error::success();
 }
 
 Error BitcodeReader::parseModule(uint64_t ResumeBit,
                                  bool ShouldLazyLoadMetadata,
                                  DataLayoutCallbackTy DataLayoutCallback) {
   if (ResumeBit) {
Error BitcodeReader::parseFunctionBody(Function *F) {
   // Add all the function arguments to the value table.
 #ifndef NDEBUG
   unsigned ArgNo = 0;
   FunctionType *FTy = FunctionTypes[F];
 #endif
   for (Argument &I : F->args()) {
     assert(I.getType() == FTy->getParamType(ArgNo++) &&
            "Incorrect fully specified type for Function Argument");
-    ValueList.push_back(&I);
+    ValueList.push_back(&I, TODOTypeID);
   }
   unsigned NextValueNo = ValueList.size();
   BasicBlock *CurBB = nullptr;
   unsigned CurBBNo = 0;
 
   DebugLoc LastLoc;
   auto getLastInstruction = [&]() -> Instruction * {
     if (CurBB && !CurBB->empty())
while (true) {
     case BitstreamEntry::Record:
       // The interesting case.
       break;
     }
 
     // Read a record.
     Record.clear();
     Instruction *I = nullptr;
+    unsigned ResTypeID = InvalidTypeID;
     Expected<unsigned> MaybeBitCode = Stream.readRecord(Entry.ID, Record);
     if (!MaybeBitCode)
       return MaybeBitCode.takeError();
     switch (unsigned BitCode = MaybeBitCode.get()) {
     default: // Default behavior: reject
       return error("Invalid value");
     case bitc::FUNC_CODE_DECLAREBLOCKS: {   // DECLAREBLOCKS: [nblocks]
       if (Record.empty() || Record[0] == 0)
case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
                                 isImplicitCode);
       I->setDebugLoc(LastLoc);
       I = nullptr;
       continue;
     }
     case bitc::FUNC_CODE_INST_UNOP: {    // UNOP: [opval, ty, opcode]
       unsigned OpNum = 0;
       Value *LHS;
-      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
+      unsigned TypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS, TypeID) ||
           OpNum+1 > Record.size())
         return error("Invalid record");
 
       int Opc = getDecodedUnaryOpcode(Record[OpNum++], LHS->getType());
       if (Opc == -1)
         return error("Invalid record");
       I = UnaryOperator::Create((Instruction::UnaryOps)Opc, LHS);
+      ResTypeID = TypeID;
       InstructionList.push_back(I);
       if (OpNum < Record.size()) {
         if (isa<FPMathOperator>(I)) {
           FastMathFlags FMF = getDecodedFastMathFlags(Record[OpNum]);
           if (FMF.any())
             I->setFastMathFlags(FMF);
         }
       }
       break;
     }
     case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
       unsigned OpNum = 0;
       Value *LHS, *RHS;
-      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
-          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
+      unsigned TypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS, TypeID) ||
+          popValue(Record, OpNum, NextValueNo, LHS->getType(), TypeID, RHS) ||
           OpNum+1 > Record.size())
         return error("Invalid record");
 
       int Opc = getDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
       if (Opc == -1)
         return error("Invalid record");
       I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
+      ResTypeID = TypeID;
       InstructionList.push_back(I);
       if (OpNum < Record.size()) {
         if (Opc == Instruction::Add ||
             Opc == Instruction::Sub ||
             Opc == Instruction::Mul ||
             Opc == Instruction::Shl) {
           if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
             cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
         }
 
       }
       break;
     }
     case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
       unsigned OpNum = 0;
       Value *Op;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+      unsigned OpTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID) ||
           OpNum+2 != Record.size())
         return error("Invalid record");
 
-      Type *ResTy = getTypeByID(Record[OpNum]);
+      ResTypeID = Record[OpNum];
+      Type *ResTy = getTypeByID(ResTypeID);
       int Opc = getDecodedCastOpcode(Record[OpNum + 1]);
       if (Opc == -1 || !ResTy)
         return error("Invalid record");
       Instruction *Temp = nullptr;
       if ((I = UpgradeBitCastInst(Opc, Op, ResTy, Temp))) {
         if (Temp) {
           InstructionList.push_back(Temp);
           assert(CurBB && "No current BB?");
case bitc::FUNC_CODE_INST_GEP: { // GEP: type, [n x operands]
         InBounds = Record[OpNum++];
         Ty = getTypeByID(Record[OpNum++]);
       } else {
         InBounds = BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD;
         Ty = nullptr;
       }
 
       Value *BasePtr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
+      unsigned BasePtrTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr, BasePtrTypeID))
         return error("Invalid record");
 
       if (!Ty) {
         Ty = BasePtr->getType()->getScalarType()->getPointerElementType();
       } else if (!cast<PointerType>(BasePtr->getType()->getScalarType())
                       ->isOpaqueOrPointeeTypeMatches(Ty)) {
         return error(
             "Explicit gep type does not match pointee type of pointer operand");
       }
 
       SmallVector<Value*, 16> GEPIdx;
       while (OpNum != Record.size()) {
         Value *Op;
-        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+        unsigned OpTypeID;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
           return error("Invalid record");
         GEPIdx.push_back(Op);
       }
 
       I = GetElementPtrInst::Create(Ty, BasePtr, GEPIdx);
+      ResTypeID = TODOTypeID;
 
       InstructionList.push_back(I);
       if (InBounds)
         cast<GetElementPtrInst>(I)->setIsInBounds(true);
       break;
     }
 
     case bitc::FUNC_CODE_INST_EXTRACTVAL: {
                                        // EXTRACTVAL: [opty, opval, n x indices]
       unsigned OpNum = 0;
       Value *Agg;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
+      unsigned AggTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Agg, AggTypeID))
         return error("Invalid record");
       Type *Ty = Agg->getType();
 
       unsigned RecSize = Record.size();
       if (OpNum == RecSize)
         return error("EXTRACTVAL: Invalid instruction with 0 indices");
 
       SmallVector<unsigned, 4> EXTRACTVALIdx;
+      ResTypeID = AggTypeID;
       for (; OpNum != RecSize; ++OpNum) {
         bool IsArray = Ty->isArrayTy();
         bool IsStruct = Ty->isStructTy();
         uint64_t Index = Record[OpNum];
 
         if (!IsStruct && !IsArray)
           return error("EXTRACTVAL: Invalid type");
         if ((unsigned)Index != Index)
           return error("Invalid value");
         if (IsStruct && Index >= Ty->getStructNumElements())
           return error("EXTRACTVAL: Invalid struct index");
         if (IsArray && Index >= Ty->getArrayNumElements())
           return error("EXTRACTVAL: Invalid array index");
         EXTRACTVALIdx.push_back((unsigned)Index);
 
-        if (IsStruct)
+        if (IsStruct) {
           Ty = Ty->getStructElementType(Index);
-        else
+          ResTypeID = getContainedTypeID(ResTypeID, Index);
+        } else {
           Ty = Ty->getArrayElementType();
+          ResTypeID = getContainedTypeID(ResTypeID);
+        }
       }
 
       I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_INSERTVAL: {
                            // INSERTVAL: [opty, opval, opty, opval, n x indices]
       unsigned OpNum = 0;
       Value *Agg;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
+      unsigned AggTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Agg, AggTypeID))
         return error("Invalid record");
       Value *Val;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
+      unsigned ValTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Val, ValTypeID))
         return error("Invalid record");
 
       unsigned RecSize = Record.size();
       if (OpNum == RecSize)
         return error("INSERTVAL: Invalid instruction with 0 indices");
 
       SmallVector<unsigned, 4> INSERTVALIdx;
       Type *CurTy = Agg->getType();
case bitc::FUNC_CODE_INST_INSERTVAL: {
         else
           CurTy = CurTy->getArrayElementType();
       }
 
       if (CurTy != Val->getType())
         return error("Inserted value type doesn't match aggregate type");
 
       I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
+      ResTypeID = AggTypeID;
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
       // obsolete form of select
       // handles select i1 ... in old bitcode
       unsigned OpNum = 0;
       Value *TrueVal, *FalseVal, *Cond;
-      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
-          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
-          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
+      unsigned TypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal, TypeID) ||
+          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), TypeID,
+                   FalseVal) ||
+          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context),
+                   TODOTypeID, Cond))
         return error("Invalid record");
 
       I = SelectInst::Create(Cond, TrueVal, FalseVal);
+      ResTypeID = TypeID;
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
       // new form of select
       // handles select i1 or select [N x i1]
       unsigned OpNum = 0;
       Value *TrueVal, *FalseVal, *Cond;
-      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
-          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
-          getValueTypePair(Record, OpNum, NextValueNo, Cond))
+      unsigned ValTypeID, CondTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal, ValTypeID) ||
+          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), ValTypeID,
+                   FalseVal) ||
+          getValueTypePair(Record, OpNum, NextValueNo, Cond, CondTypeID))
         return error("Invalid record");
 
       // select condition can be either i1 or [N x i1]
       if (VectorType* vector_type =
           dyn_cast<VectorType>(Cond->getType())) {
         // expect <n x i1>
         if (vector_type->getElementType() != Type::getInt1Ty(Context))
           return error("Invalid type for value");
       } else {
         // expect i1
         if (Cond->getType() != Type::getInt1Ty(Context))
           return error("Invalid type for value");
       }
 
       I = SelectInst::Create(Cond, TrueVal, FalseVal);
+      ResTypeID = ValTypeID;
       InstructionList.push_back(I);
       if (OpNum < Record.size() && isa<FPMathOperator>(I)) {
         FastMathFlags FMF = getDecodedFastMathFlags(Record[OpNum]);
         if (FMF.any())
           I->setFastMathFlags(FMF);
       }
       break;
     }
 
     case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
       unsigned OpNum = 0;
       Value *Vec, *Idx;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
-          getValueTypePair(Record, OpNum, NextValueNo, Idx))
+      unsigned VecTypeID, IdxTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec, VecTypeID) ||
+          getValueTypePair(Record, OpNum, NextValueNo, Idx, IdxTypeID))
         return error("Invalid record");
       if (!Vec->getType()->isVectorTy())
         return error("Invalid type for value");
       I = ExtractElementInst::Create(Vec, Idx);
+      ResTypeID = getContainedTypeID(VecTypeID);
       InstructionList.push_back(I);
       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))
+      unsigned VecTypeID, IdxTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec, VecTypeID))
         return error("Invalid record");
       if (!Vec->getType()->isVectorTy())
         return error("Invalid type for value");
       if (popValue(Record, OpNum, NextValueNo,
-                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
-          getValueTypePair(Record, OpNum, NextValueNo, Idx))
+                   cast<VectorType>(Vec->getType())->getElementType(),
+                   getContainedTypeID(VecTypeID), Elt) ||
+          getValueTypePair(Record, OpNum, NextValueNo, Idx, IdxTypeID))
         return error("Invalid record");
       I = InsertElementInst::Create(Vec, Elt, Idx);
+      ResTypeID = VecTypeID;
       InstructionList.push_back(I);
       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) ||
-          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
+      unsigned Vec1TypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1, Vec1TypeID) ||
+          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec1TypeID,
+                   Vec2))
         return error("Invalid record");
 
-      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
+      unsigned MaskTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Mask, MaskTypeID))
         return error("Invalid record");
       if (!Vec1->getType()->isVectorTy() || !Vec2->getType()->isVectorTy())
         return error("Invalid type for value");
 
       I = new ShuffleVectorInst(Vec1, Vec2, Mask);
+      ResTypeID = TODOTypeID;
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
       // Old form of ICmp/FCmp returning bool
       // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
       // both legal on vectors but had different behaviour.
     case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
       // FCmp/ICmp returning bool or vector of bool
 
       unsigned OpNum = 0;
       Value *LHS, *RHS;
-      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
-          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS))
+      unsigned LHSTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS, LHSTypeID) ||
+          popValue(Record, OpNum, NextValueNo, LHS->getType(), LHSTypeID, RHS))
         return error("Invalid record");
 
       if (OpNum >= Record.size())
         return error(
             "Invalid record: operand number exceeded available operands");
 
       unsigned PredVal = Record[OpNum];
       bool IsFP = LHS->getType()->isFPOrFPVectorTy();
       FastMathFlags FMF;
       if (IsFP && Record.size() > OpNum+1)
         FMF = getDecodedFastMathFlags(Record[++OpNum]);
 
       if (OpNum+1 != Record.size())
         return error("Invalid record");
 
       if (LHS->getType()->isFPOrFPVectorTy())
         I = new FCmpInst((FCmpInst::Predicate)PredVal, LHS, RHS);
       else
         I = new ICmpInst((ICmpInst::Predicate)PredVal, LHS, RHS);
+      ResTypeID = TODOTypeID;
 
       if (FMF.any())
         I->setFastMathFlags(FMF);
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
       {
         unsigned Size = Record.size();
         if (Size == 0) {
           I = ReturnInst::Create(Context);
           InstructionList.push_back(I);
           break;
         }
 
         unsigned OpNum = 0;
         Value *Op = nullptr;
-        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+        unsigned OpTypeID;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
           return error("Invalid record");
         if (OpNum != Record.size())
           return error("Invalid record");
 
         I = ReturnInst::Create(Context, Op);
         InstructionList.push_back(I);
         break;
       }
     case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
       if (Record.size() != 1 && Record.size() != 3)
         return error("Invalid record");
       BasicBlock *TrueDest = getBasicBlock(Record[0]);
       if (!TrueDest)
         return error("Invalid record");
 
       if (Record.size() == 1) {
         I = BranchInst::Create(TrueDest);
         InstructionList.push_back(I);
       }
       else {
         BasicBlock *FalseDest = getBasicBlock(Record[1]);
         Value *Cond = getValue(Record, 2, NextValueNo,
-                               Type::getInt1Ty(Context));
+                               Type::getInt1Ty(Context), TODOTypeID);
         if (!FalseDest || !Cond)
           return error("Invalid record");
         I = BranchInst::Create(TrueDest, FalseDest, Cond);
         InstructionList.push_back(I);
       }
       break;
     }
     case bitc::FUNC_CODE_INST_CLEANUPRET: { // CLEANUPRET: [val] or [val,bb#]
       if (Record.size() != 1 && Record.size() != 2)
         return error("Invalid record");
       unsigned Idx = 0;
-      Value *CleanupPad =
-          getValue(Record, Idx++, NextValueNo, Type::getTokenTy(Context));
+      Value *CleanupPad = getValue(
+          Record, Idx++, NextValueNo, Type::getTokenTy(Context), TODOTypeID);
       if (!CleanupPad)
         return error("Invalid record");
       BasicBlock *UnwindDest = nullptr;
       if (Record.size() == 2) {
         UnwindDest = getBasicBlock(Record[Idx++]);
         if (!UnwindDest)
           return error("Invalid record");
       }
 
       I = CleanupReturnInst::Create(CleanupPad, UnwindDest);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_CATCHRET: { // CATCHRET: [val,bb#]
       if (Record.size() != 2)
         return error("Invalid record");
       unsigned Idx = 0;
-      Value *CatchPad =
-          getValue(Record, Idx++, NextValueNo, Type::getTokenTy(Context));
+      Value *CatchPad = getValue(
+          Record, Idx++, NextValueNo, Type::getTokenTy(Context), TODOTypeID);
       if (!CatchPad)
         return error("Invalid record");
       BasicBlock *BB = getBasicBlock(Record[Idx++]);
       if (!BB)
         return error("Invalid record");
 
       I = CatchReturnInst::Create(CatchPad, BB);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_CATCHSWITCH: { // CATCHSWITCH: [tok,num,(bb)*,bb?]
       // We must have, at minimum, the outer scope and the number of arguments.
       if (Record.size() < 2)
         return error("Invalid record");
 
       unsigned Idx = 0;
 
-      Value *ParentPad =
-          getValue(Record, Idx++, NextValueNo, Type::getTokenTy(Context));
+      Value *ParentPad = getValue(
+          Record, Idx++, NextValueNo, Type::getTokenTy(Context), TODOTypeID);
 
       unsigned NumHandlers = Record[Idx++];
 
       SmallVector<BasicBlock *, 2> Handlers;
       for (unsigned Op = 0; Op != NumHandlers; ++Op) {
         BasicBlock *BB = getBasicBlock(Record[Idx++]);
         if (!BB)
           return error("Invalid record");
case bitc::FUNC_CODE_INST_CATCHSWITCH: { // CATCHSWITCH: [tok,num,(bb)*,bb?]
       if (Record.size() != Idx)
         return error("Invalid record");
 
       auto *CatchSwitch =
           CatchSwitchInst::Create(ParentPad, UnwindDest, NumHandlers);
       for (BasicBlock *Handler : Handlers)
         CatchSwitch->addHandler(Handler);
       I = CatchSwitch;
+      ResTypeID = TODOTypeID;
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_CATCHPAD:
     case bitc::FUNC_CODE_INST_CLEANUPPAD: { // [tok,num,(ty,val)*]
       // We must have, at minimum, the outer scope and the number of arguments.
       if (Record.size() < 2)
         return error("Invalid record");
 
       unsigned Idx = 0;
 
-      Value *ParentPad =
-          getValue(Record, Idx++, NextValueNo, Type::getTokenTy(Context));
+      Value *ParentPad = getValue(
+          Record, Idx++, NextValueNo, Type::getTokenTy(Context), TODOTypeID);
 
       unsigned NumArgOperands = Record[Idx++];
 
       SmallVector<Value *, 2> Args;
       for (unsigned Op = 0; Op != NumArgOperands; ++Op) {
         Value *Val;
-        if (getValueTypePair(Record, Idx, NextValueNo, Val))
+        unsigned ValTypeID;
+        if (getValueTypePair(Record, Idx, NextValueNo, Val, ValTypeID))
           return error("Invalid record");
         Args.push_back(Val);
       }
 
       if (Record.size() != Idx)
         return error("Invalid record");
 
       if (BitCode == bitc::FUNC_CODE_INST_CLEANUPPAD)
         I = CleanupPadInst::Create(ParentPad, Args);
       else
         I = CatchPadInst::Create(ParentPad, Args);
+      ResTypeID = TODOTypeID;
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
       // Check magic
       if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
         // "New" SwitchInst format with case ranges. The changes to write this
         // format were reverted but we still recognize bitcode that uses it.
         // Hopefully someday we will have support for case ranges and can use
         // this format again.
 
-        Type *OpTy = getTypeByID(Record[1]);
+        unsigned OpTyID = Record[1];
+        Type *OpTy = getTypeByID(OpTyID);
         unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
 
-        Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
+        Value *Cond = getValue(Record, 2, NextValueNo, OpTy, OpTyID);
         BasicBlock *Default = getBasicBlock(Record[3]);
         if (!OpTy || !Cond || !Default)
           return error("Invalid record");
 
         unsigned NumCases = Record[4];
 
         SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
         InstructionList.push_back(SI);
case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
         I = SI;
         break;
       }
 
       // Old SwitchInst format without case ranges.
 
       if (Record.size() < 3 || (Record.size() & 1) == 0)
         return error("Invalid record");
-      Type *OpTy = getTypeByID(Record[0]);
-      Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
+      unsigned OpTyID = Record[0];
+      Type *OpTy = getTypeByID(OpTyID);
+      Value *Cond = getValue(Record, 1, NextValueNo, OpTy, OpTyID);
       BasicBlock *Default = getBasicBlock(Record[2]);
       if (!OpTy || !Cond || !Default)
         return error("Invalid record");
       unsigned NumCases = (Record.size()-3)/2;
       SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
       InstructionList.push_back(SI);
       for (unsigned i = 0, e = NumCases; i != e; ++i) {
-        ConstantInt *CaseVal =
-          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
+        ConstantInt *CaseVal = dyn_cast_or_null<ConstantInt>(
+            getFnValueByID(Record[3+i*2], OpTy, OpTyID));
         BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
         if (!CaseVal || !DestBB) {
           delete SI;
           return error("Invalid record");
         }
         SI->addCase(CaseVal, DestBB);
       }
       I = SI;
       break;
     }
     case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
       if (Record.size() < 2)
         return error("Invalid record");
-      Type *OpTy = getTypeByID(Record[0]);
-      Value *Address = getValue(Record, 1, NextValueNo, OpTy);
+      unsigned OpTyID = Record[0];
+      Type *OpTy = getTypeByID(OpTyID);
+      Value *Address = getValue(Record, 1, NextValueNo, OpTy, OpTyID);
       if (!OpTy || !Address)
         return error("Invalid record");
       unsigned NumDests = Record.size()-2;
       IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
       InstructionList.push_back(IBI);
       for (unsigned i = 0, e = NumDests; i != e; ++i) {
         if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
           IBI->addDestination(DestBB);
case bitc::FUNC_CODE_INST_INVOKE: {
       FunctionType *FTy = nullptr;
       if ((CCInfo >> 13) & 1) {
         FTy = dyn_cast<FunctionType>(getTypeByID(Record[OpNum++]));
         if (!FTy)
           return error("Explicit invoke type is not a function type");
       }
 
       Value *Callee;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
+      unsigned CalleeTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Callee, CalleeTypeID))
         return error("Invalid record");
 
       PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
       if (!CalleeTy)
         return error("Callee is not a pointer");
       if (!FTy) {
         FTy =
             dyn_cast<FunctionType>(Callee->getType()->getPointerElementType());
         if (!FTy)
           return error("Callee is not of pointer to function type");
       } else if (!CalleeTy->isOpaqueOrPointeeTypeMatches(FTy))
         return error("Explicit invoke type does not match pointee type of "
                      "callee operand");
       if (Record.size() < FTy->getNumParams() + OpNum)
         return error("Insufficient operands to call");
 
       SmallVector<Value*, 16> Ops;
       SmallVector<Type *, 16> ArgsTys;
       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
         Ops.push_back(getValue(Record, OpNum, NextValueNo,
-                               FTy->getParamType(i)));
+                               FTy->getParamType(i), TODOTypeID));
         ArgsTys.push_back(FTy->getParamType(i));
         if (!Ops.back())
           return error("Invalid record");
       }
 
       if (!FTy->isVarArg()) {
         if (Record.size() != OpNum)
           return error("Invalid record");
       } else {
         // Read type/value pairs for varargs params.
         while (OpNum != Record.size()) {
           Value *Op;
-          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+          unsigned OpTypeID;
+          if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
             return error("Invalid record");
           Ops.push_back(Op);
           ArgsTys.push_back(Op->getType());
         }
       }
 
       I = InvokeInst::Create(FTy, Callee, NormalBB, UnwindBB, Ops,
                              OperandBundles);
+      ResTypeID = TODOTypeID;
       OperandBundles.clear();
       InstructionList.push_back(I);
       cast<InvokeInst>(I)->setCallingConv(
           static_cast<CallingConv::ID>(CallingConv::MaxID & CCInfo));
       cast<InvokeInst>(I)->setAttributes(PAL);
       propagateAttributeTypes(cast<CallBase>(I), ArgsTys);
 
       break;
     }
     case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
       unsigned Idx = 0;
       Value *Val = nullptr;
-      if (getValueTypePair(Record, Idx, NextValueNo, Val))
+      unsigned ValTypeID;
+      if (getValueTypePair(Record, Idx, NextValueNo, Val, ValTypeID))
         return error("Invalid record");
       I = ResumeInst::Create(Val);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_CALLBR: {
       // CALLBR: [attr, cc, norm, transfs, fty, fnid, args]
       unsigned OpNum = 0;
case bitc::FUNC_CODE_INST_CALLBR: {
       FunctionType *FTy = nullptr;
       if ((CCInfo >> bitc::CALL_EXPLICIT_TYPE) & 1) {
         FTy = dyn_cast<FunctionType>(getTypeByID(Record[OpNum++]));
         if (!FTy)
           return error("Explicit call type is not a function type");
       }
 
       Value *Callee;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
+      unsigned CalleeTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Callee, CalleeTypeID))
         return error("Invalid record");
 
       PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
       if (!OpTy)
         return error("Callee is not a pointer type");
       if (!FTy) {
         FTy =
             dyn_cast<FunctionType>(Callee->getType()->getPointerElementType());
         if (!FTy)
           return error("Callee is not of pointer to function type");
       } else if (!OpTy->isOpaqueOrPointeeTypeMatches(FTy))
         return error("Explicit call type does not match pointee type of "
                      "callee operand");
       if (Record.size() < FTy->getNumParams() + OpNum)
         return error("Insufficient operands to call");
 
       SmallVector<Value*, 16> Args;
       SmallVector<Type *, 16> ArgsTys;
       // Read the fixed params.
       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
         Value *Arg;
         if (FTy->getParamType(i)->isLabelTy())
           Arg = getBasicBlock(Record[OpNum]);
         else
-          Arg = getValue(Record, OpNum, NextValueNo, FTy->getParamType(i));
+          Arg = getValue(Record, OpNum, NextValueNo, FTy->getParamType(i),
+                         TODOTypeID);
         if (!Arg)
           return error("Invalid record");
         Args.push_back(Arg);
         ArgsTys.push_back(Arg->getType());
       }
 
       // Read type/value pairs for varargs params.
       if (!FTy->isVarArg()) {
         if (OpNum != Record.size())
           return error("Invalid record");
       } else {
         while (OpNum != Record.size()) {
           Value *Op;
-          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+          unsigned OpTypeID;
+          if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
             return error("Invalid record");
           Args.push_back(Op);
           ArgsTys.push_back(Op->getType());
         }
       }
 
       I = CallBrInst::Create(FTy, Callee, DefaultDest, IndirectDests, Args,
                              OperandBundles);
+      ResTypeID = TODOTypeID;
       OperandBundles.clear();
       InstructionList.push_back(I);
       cast<CallBrInst>(I)->setCallingConv(
           static_cast<CallingConv::ID>((0x7ff & CCInfo) >> bitc::CALL_CCONV));
       cast<CallBrInst>(I)->setAttributes(PAL);
       propagateAttributeTypes(cast<CallBase>(I), ArgsTys);
       break;
     }
     case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
       I = new UnreachableInst(Context);
       InstructionList.push_back(I);
       break;
     case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
       if (Record.empty())
         return error("Invalid record");
       // The first record specifies the type.
-      Type *Ty = getTypeByID(Record[0]);
+      unsigned TyID = Record[0];
+      Type *Ty = getTypeByID(TyID);
       if (!Ty)
         return error("Invalid record");
 
       // Phi arguments are pairs of records of [value, basic block].
       // There is an optional final record for fast-math-flags if this phi has a
       // floating-point type.
       size_t NumArgs = (Record.size() - 1) / 2;
       PHINode *PN = PHINode::Create(Ty, NumArgs);
       if ((Record.size() - 1) % 2 == 1 && !isa<FPMathOperator>(PN))
         return error("Invalid record");
       InstructionList.push_back(PN);
 
       for (unsigned i = 0; i != NumArgs; i++) {
         Value *V;
         // With the new function encoding, it is possible that operands have
         // negative IDs (for forward references).  Use a signed VBR
         // representation to keep the encoding small.
         if (UseRelativeIDs)
-          V = getValueSigned(Record, i * 2 + 1, NextValueNo, Ty);
+          V = getValueSigned(Record, i * 2 + 1, NextValueNo, Ty, TyID);
         else
-          V = getValue(Record, i * 2 + 1, NextValueNo, Ty);
+          V = getValue(Record, i * 2 + 1, NextValueNo, Ty, TyID);
         BasicBlock *BB = getBasicBlock(Record[i * 2 + 2]);
         if (!V || !BB)
           return error("Invalid record");
         PN->addIncoming(V, BB);
       }
       I = PN;
+      ResTypeID = TyID;
 
       // If there are an even number of records, the final record must be FMF.
       if (Record.size() % 2 == 0) {
         assert(isa<FPMathOperator>(I) && "Unexpected phi type");
         FastMathFlags FMF = getDecodedFastMathFlags(Record[Record.size() - 1]);
         if (FMF.any())
           I->setFastMathFlags(FMF);
       }
 
       break;
     }
 
     case bitc::FUNC_CODE_INST_LANDINGPAD:
     case bitc::FUNC_CODE_INST_LANDINGPAD_OLD: {
       // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
       unsigned Idx = 0;
       if (BitCode == bitc::FUNC_CODE_INST_LANDINGPAD) {
         if (Record.size() < 3)
           return error("Invalid record");
       } else {
         assert(BitCode == bitc::FUNC_CODE_INST_LANDINGPAD_OLD);
         if (Record.size() < 4)
           return error("Invalid record");
       }
-      Type *Ty = getTypeByID(Record[Idx++]);
+      ResTypeID = Record[Idx++];
+      Type *Ty = getTypeByID(ResTypeID);
       if (!Ty)
         return error("Invalid record");
       if (BitCode == bitc::FUNC_CODE_INST_LANDINGPAD_OLD) {
         Value *PersFn = nullptr;
-        if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
+        unsigned PersFnTypeID;
+        if (getValueTypePair(Record, Idx, NextValueNo, PersFn, PersFnTypeID))
           return error("Invalid record");
 
         if (!F->hasPersonalityFn())
           F->setPersonalityFn(cast<Constant>(PersFn));
         else if (F->getPersonalityFn() != cast<Constant>(PersFn))
           return error("Personality function mismatch");
       }
 
       bool IsCleanup = !!Record[Idx++];
       unsigned NumClauses = Record[Idx++];
       LandingPadInst *LP = LandingPadInst::Create(Ty, NumClauses);
       LP->setCleanup(IsCleanup);
       for (unsigned J = 0; J != NumClauses; ++J) {
         LandingPadInst::ClauseType CT =
           LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
         Value *Val;
+        unsigned ValTypeID;
 
-        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
+        if (getValueTypePair(Record, Idx, NextValueNo, Val, ValTypeID)) {
           delete LP;
           return error("Invalid record");
         }
 
         assert((CT != LandingPadInst::Catch ||
                 !isa<ArrayType>(Val->getType())) &&
                "Catch clause has a invalid type!");
         assert((CT != LandingPadInst::Filter ||
case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
       const bool InAlloca = Bitfield::get<APV::UsedWithInAlloca>(Rec);
       const bool SwiftError = Bitfield::get<APV::SwiftError>(Rec);
       Type *Ty = getTypeByID(Record[0]);
       if (!Bitfield::get<APV::ExplicitType>(Rec)) {
         Ty = getPtrElementTypeByID(Record[0]);
         if (!Ty)
           return error("Missing element type for old-style alloca");
       }
-      Type *OpTy = getTypeByID(Record[1]);
-      Value *Size = getFnValueByID(Record[2], OpTy);
+      unsigned OpTyID = Record[1];
+      Type *OpTy = getTypeByID(OpTyID);
+      Value *Size = getFnValueByID(Record[2], OpTy, OpTyID);
       MaybeAlign Align;
       uint64_t AlignExp =
           Bitfield::get<APV::AlignLower>(Rec) |
           (Bitfield::get<APV::AlignUpper>(Rec) << APV::AlignLower::Bits);
       if (Error Err = parseAlignmentValue(AlignExp, Align)) {
         return Err;
       }
       if (!Ty || !Size)
         return error("Invalid record");
 
       // FIXME: Make this an optional field.
       const DataLayout &DL = TheModule->getDataLayout();
       unsigned AS = DL.getAllocaAddrSpace();
 
       SmallPtrSet<Type *, 4> Visited;
       if (!Align && !Ty->isSized(&Visited))
         return error("alloca of unsized type");
       if (!Align)
         Align = DL.getPrefTypeAlign(Ty);
 
       AllocaInst *AI = new AllocaInst(Ty, AS, Size, *Align);
       AI->setUsedWithInAlloca(InAlloca);
       AI->setSwiftError(SwiftError);
       I = AI;
+      ResTypeID = TODOTypeID;
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
       unsigned OpNum = 0;
       Value *Op;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+      unsigned OpTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID) ||
           (OpNum + 2 != Record.size() && OpNum + 3 != Record.size()))
         return error("Invalid record");
 
       if (!isa<PointerType>(Op->getType()))
         return error("Load operand is not a pointer type");
 
       Type *Ty = nullptr;
       if (OpNum + 3 == Record.size()) {
-        Ty = getTypeByID(Record[OpNum++]);
+        ResTypeID = Record[OpNum++];
+        Ty = getTypeByID(ResTypeID);
       } else {
+        ResTypeID = getContainedTypeID(OpTypeID);
         Ty = Op->getType()->getPointerElementType();
       }
 
       if (Error Err = typeCheckLoadStoreInst(Ty, Op->getType()))
         return Err;
 
       MaybeAlign Align;
       if (Error Err = parseAlignmentValue(Record[OpNum], Align))
         return Err;
       SmallPtrSet<Type *, 4> Visited;
       if (!Align && !Ty->isSized(&Visited))
         return error("load of unsized type");
       if (!Align)
         Align = TheModule->getDataLayout().getABITypeAlign(Ty);
       I = new LoadInst(Ty, Op, "", Record[OpNum + 1], *Align);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_LOADATOMIC: {
        // LOADATOMIC: [opty, op, align, vol, ordering, ssid]
       unsigned OpNum = 0;
       Value *Op;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
+      unsigned OpTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID) ||
           (OpNum + 4 != Record.size() && OpNum + 5 != Record.size()))
         return error("Invalid record");
 
       if (!isa<PointerType>(Op->getType()))
         return error("Load operand is not a pointer type");
 
       Type *Ty = nullptr;
       if (OpNum + 5 == Record.size()) {
-        Ty = getTypeByID(Record[OpNum++]);
+        ResTypeID = Record[OpNum++];
+        Ty = getTypeByID(ResTypeID);
       } else {
+        ResTypeID = getContainedTypeID(OpTypeID);
         Ty = Op->getType()->getPointerElementType();
       }
 
       if (Error Err = typeCheckLoadStoreInst(Ty, Op->getType()))
         return Err;
 
       AtomicOrdering Ordering = getDecodedOrdering(Record[OpNum + 2]);
       if (Ordering == AtomicOrdering::NotAtomic ||
case bitc::FUNC_CODE_INST_LOADATOMIC: {
       I = new LoadInst(Ty, Op, "", Record[OpNum + 1], *Align, Ordering, SSID);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_STORE:
     case bitc::FUNC_CODE_INST_STORE_OLD: { // STORE2:[ptrty, ptr, val, align, vol]
       unsigned OpNum = 0;
       Value *Val, *Ptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
+      unsigned PtrTypeID, ValTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, PtrTypeID) ||
           (BitCode == bitc::FUNC_CODE_INST_STORE
-               ? getValueTypePair(Record, OpNum, NextValueNo, Val)
+               ? getValueTypePair(Record, OpNum, NextValueNo, Val, ValTypeID)
                : popValue(Record, OpNum, NextValueNo,
-                          Ptr->getType()->getPointerElementType(), Val)) ||
+                          Ptr->getType()->getPointerElementType(),
+                          getContainedTypeID(PtrTypeID), Val)) ||
           OpNum + 2 != Record.size())
         return error("Invalid record");
 
       if (Error Err = typeCheckLoadStoreInst(Val->getType(), Ptr->getType()))
         return Err;
       MaybeAlign Align;
       if (Error Err = parseAlignmentValue(Record[OpNum], Align))
         return Err;
       SmallPtrSet<Type *, 4> Visited;
       if (!Align && !Val->getType()->isSized(&Visited))
         return error("store of unsized type");
       if (!Align)
         Align = TheModule->getDataLayout().getABITypeAlign(Val->getType());
       I = new StoreInst(Val, Ptr, Record[OpNum + 1], *Align);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_STOREATOMIC:
     case bitc::FUNC_CODE_INST_STOREATOMIC_OLD: {
       // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, ssid]
       unsigned OpNum = 0;
       Value *Val, *Ptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
+      unsigned PtrTypeID, ValTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, PtrTypeID) ||
           !isa<PointerType>(Ptr->getType()) ||
           (BitCode == bitc::FUNC_CODE_INST_STOREATOMIC
-               ? getValueTypePair(Record, OpNum, NextValueNo, Val)
+               ? getValueTypePair(Record, OpNum, NextValueNo, Val, ValTypeID)
                : popValue(Record, OpNum, NextValueNo,
-                          Ptr->getType()->getPointerElementType(), Val)) ||
+                          Ptr->getType()->getPointerElementType(),
+                          getContainedTypeID(PtrTypeID), Val)) ||
           OpNum + 4 != Record.size())
         return error("Invalid record");
 
       if (Error Err = typeCheckLoadStoreInst(Val->getType(), Ptr->getType()))
         return Err;
       AtomicOrdering Ordering = getDecodedOrdering(Record[OpNum + 2]);
       if (Ordering == AtomicOrdering::NotAtomic ||
           Ordering == AtomicOrdering::Acquire ||
case bitc::FUNC_CODE_INST_STOREATOMIC_OLD: {
       break;
     }
     case bitc::FUNC_CODE_INST_CMPXCHG_OLD: {
       // CMPXCHG_OLD: [ptrty, ptr, cmp, val, vol, ordering, synchscope,
       // failure_ordering?, weak?]
       const size_t NumRecords = Record.size();
       unsigned OpNum = 0;
       Value *Ptr = nullptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr))
+      unsigned PtrTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, PtrTypeID))
         return error("Invalid record");
 
       if (!isa<PointerType>(Ptr->getType()))
         return error("Cmpxchg operand is not a pointer type");
 
       Value *Cmp = nullptr;
+      unsigned CmpTypeID = getContainedTypeID(PtrTypeID);
       if (popValue(Record, OpNum, NextValueNo,
                    cast<PointerType>(Ptr->getType())->getPointerElementType(),
-                   Cmp))
+                   CmpTypeID, Cmp))
         return error("Invalid record");
 
       Value *New = nullptr;
-      if (popValue(Record, OpNum, NextValueNo, Cmp->getType(), New) ||
+      if (popValue(Record, OpNum, NextValueNo, Cmp->getType(), CmpTypeID,
+                   New) ||
           NumRecords < OpNum + 3 || NumRecords > OpNum + 5)
         return error("Invalid record");
 
       const AtomicOrdering SuccessOrdering =
           getDecodedOrdering(Record[OpNum + 1]);
       if (SuccessOrdering == AtomicOrdering::NotAtomic ||
           SuccessOrdering == AtomicOrdering::Unordered)
         return error("Invalid record");
case bitc::FUNC_CODE_INST_CMPXCHG_OLD: {
           FailureOrdering == AtomicOrdering::Unordered)
         return error("Invalid record");
 
       const Align Alignment(
           TheModule->getDataLayout().getTypeStoreSize(Cmp->getType()));
 
       I = new AtomicCmpXchgInst(Ptr, Cmp, New, Alignment, SuccessOrdering,
                                 FailureOrdering, SSID);
+      ResTypeID = TODOTypeID;
       cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
 
       if (NumRecords < 8) {
         // Before weak cmpxchgs existed, the instruction simply returned the
         // value loaded from memory, so bitcode files from that era will be
         // expecting the first component of a modern cmpxchg.
         CurBB->getInstList().push_back(I);
         I = ExtractValueInst::Create(I, 0);
+        ResTypeID = TODOTypeID;
       } else {
         cast<AtomicCmpXchgInst>(I)->setWeak(Record[OpNum + 4]);
       }
 
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_CMPXCHG: {
       // CMPXCHG: [ptrty, ptr, cmp, val, vol, success_ordering, synchscope,
       // failure_ordering, weak, align?]
       const size_t NumRecords = Record.size();
       unsigned OpNum = 0;
       Value *Ptr = nullptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr))
+      unsigned PtrTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, PtrTypeID))
         return error("Invalid record");
 
       if (!isa<PointerType>(Ptr->getType()))
         return error("Cmpxchg operand is not a pointer type");
 
       Value *Cmp = nullptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Cmp))
+      unsigned CmpTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Cmp, CmpTypeID))
         return error("Invalid record");
 
       Value *Val = nullptr;
-      if (popValue(Record, OpNum, NextValueNo, Cmp->getType(), Val))
+      if (popValue(Record, OpNum, NextValueNo, Cmp->getType(), CmpTypeID, Val))
         return error("Invalid record");
 
       if (NumRecords < OpNum + 3 || NumRecords > OpNum + 6)
         return error("Invalid record");
 
       const bool IsVol = Record[OpNum];
 
       const AtomicOrdering SuccessOrdering =
case bitc::FUNC_CODE_INST_CMPXCHG: {
       if (!Alignment)
         Alignment =
             Align(TheModule->getDataLayout().getTypeStoreSize(Cmp->getType()));
 
       I = new AtomicCmpXchgInst(Ptr, Cmp, Val, *Alignment, SuccessOrdering,
                                 FailureOrdering, SSID);
       cast<AtomicCmpXchgInst>(I)->setVolatile(IsVol);
       cast<AtomicCmpXchgInst>(I)->setWeak(IsWeak);
+      ResTypeID = TODOTypeID;
 
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_ATOMICRMW_OLD:
     case bitc::FUNC_CODE_INST_ATOMICRMW: {
       // ATOMICRMW_OLD: [ptrty, ptr, val, op, vol, ordering, ssid, align?]
       // ATOMICRMW: [ptrty, ptr, valty, val, op, vol, ordering, ssid, align?]
       const size_t NumRecords = Record.size();
       unsigned OpNum = 0;
 
       Value *Ptr = nullptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr))
+      unsigned PtrTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, PtrTypeID))
         return error("Invalid record");
 
       if (!isa<PointerType>(Ptr->getType()))
         return error("Invalid record");
 
       Value *Val = nullptr;
       if (BitCode == bitc::FUNC_CODE_INST_ATOMICRMW_OLD) {
         if (popValue(Record, OpNum, NextValueNo,
                      cast<PointerType>(Ptr->getType())->getPointerElementType(),
-                     Val))
+                     getContainedTypeID(PtrTypeID), Val))
           return error("Invalid record");
       } else {
-        if (getValueTypePair(Record, OpNum, NextValueNo, Val))
+        unsigned ValTypeID;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Val, ValTypeID))
           return error("Invalid record");
       }
 
       if (!(NumRecords == (OpNum + 4) || NumRecords == (OpNum + 5)))
         return error("Invalid record");
 
       const AtomicRMWInst::BinOp Operation =
           getDecodedRMWOperation(Record[OpNum]);
case bitc::FUNC_CODE_INST_ATOMICRMW: {
           return Err;
       }
 
       if (!Alignment)
         Alignment =
             Align(TheModule->getDataLayout().getTypeStoreSize(Val->getType()));
 
       I = new AtomicRMWInst(Operation, Ptr, Val, *Alignment, Ordering, SSID);
+      ResTypeID = TODOTypeID;
       cast<AtomicRMWInst>(I)->setVolatile(IsVol);
 
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, ssid]
       if (2 != Record.size())
         return error("Invalid record");
case bitc::FUNC_CODE_INST_CALL: {
       FunctionType *FTy = nullptr;
       if ((CCInfo >> bitc::CALL_EXPLICIT_TYPE) & 1) {
         FTy = dyn_cast<FunctionType>(getTypeByID(Record[OpNum++]));
         if (!FTy)
           return error("Explicit call type is not a function type");
       }
 
       Value *Callee;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
+      unsigned CalleeTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Callee, CalleeTypeID))
         return error("Invalid record");
 
       PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
       if (!OpTy)
         return error("Callee is not a pointer type");
       if (!FTy) {
         FTy =
             dyn_cast<FunctionType>(Callee->getType()->getPointerElementType());
         if (!FTy)
           return error("Callee is not of pointer to function type");
       } else if (!OpTy->isOpaqueOrPointeeTypeMatches(FTy))
         return error("Explicit call type does not match pointee type of "
                      "callee operand");
       if (Record.size() < FTy->getNumParams() + OpNum)
         return error("Insufficient operands to call");
 
       SmallVector<Value*, 16> Args;
       SmallVector<Type *, 16> ArgsTys;
       // Read the fixed params.
       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
         if (FTy->getParamType(i)->isLabelTy())
           Args.push_back(getBasicBlock(Record[OpNum]));
         else
           Args.push_back(getValue(Record, OpNum, NextValueNo,
-                                  FTy->getParamType(i)));
+                                  FTy->getParamType(i), TODOTypeID));
         ArgsTys.push_back(FTy->getParamType(i));
         if (!Args.back())
           return error("Invalid record");
       }
 
       // Read type/value pairs for varargs params.
       if (!FTy->isVarArg()) {
         if (OpNum != Record.size())
           return error("Invalid record");
       } else {
         while (OpNum != Record.size()) {
           Value *Op;
-          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+          unsigned OpTypeID;
+          if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
             return error("Invalid record");
           Args.push_back(Op);
           ArgsTys.push_back(Op->getType());
         }
       }
 
       I = CallInst::Create(FTy, Callee, Args, OperandBundles);
+      ResTypeID = TODOTypeID;
       OperandBundles.clear();
       InstructionList.push_back(I);
       cast<CallInst>(I)->setCallingConv(
           static_cast<CallingConv::ID>((0x7ff & CCInfo) >> bitc::CALL_CCONV));
       CallInst::TailCallKind TCK = CallInst::TCK_None;
       if (CCInfo & 1 << bitc::CALL_TAIL)
         TCK = CallInst::TCK_Tail;
       if (CCInfo & (1 << bitc::CALL_MUSTTAIL))
case bitc::FUNC_CODE_INST_CALL: {
                        "floating-point scalar or vector return type");
         I->setFastMathFlags(FMF);
       }
       break;
     }
     case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
       if (Record.size() < 3)
         return error("Invalid record");
-      Type *OpTy = getTypeByID(Record[0]);
-      Value *Op = getValue(Record, 1, NextValueNo, OpTy);
-      Type *ResTy = getTypeByID(Record[2]);
+      unsigned OpTyID = Record[0];
+      Type *OpTy = getTypeByID(OpTyID);
+      Value *Op = getValue(Record, 1, NextValueNo, OpTy, OpTyID);
+      ResTypeID = Record[2];
+      Type *ResTy = getTypeByID(ResTypeID);
       if (!OpTy || !Op || !ResTy)
         return error("Invalid record");
       I = new VAArgInst(Op, ResTy);
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_OPERAND_BUNDLE: {
       // A call or an invoke can be optionally prefixed with some variable
       // number of operand bundle blocks.  These blocks are read into
       // OperandBundles and consumed at the next call or invoke instruction.
 
       if (Record.empty() || Record[0] >= BundleTags.size())
         return error("Invalid record");
 
       std::vector<Value *> Inputs;
 
       unsigned OpNum = 1;
       while (OpNum != Record.size()) {
         Value *Op;
-        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+        unsigned OpTypeID;
+        if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
           return error("Invalid record");
         Inputs.push_back(Op);
       }
 
       OperandBundles.emplace_back(BundleTags[Record[0]], std::move(Inputs));
       continue;
     }
 
     case bitc::FUNC_CODE_INST_FREEZE: { // FREEZE: [opty,opval]
       unsigned OpNum = 0;
       Value *Op = nullptr;
-      if (getValueTypePair(Record, OpNum, NextValueNo, Op))
+      unsigned OpTypeID;
+      if (getValueTypePair(Record, OpNum, NextValueNo, Op, OpTypeID))
         return error("Invalid record");
       if (OpNum != Record.size())
         return error("Invalid record");
 
       I = new FreezeInst(Op);
+      ResTypeID = OpTypeID;
       InstructionList.push_back(I);
       break;
     }
     }
 
     // Add instruction to end of current BB.  If there is no current BB, reject
     // this file.
     if (!CurBB) {
       I->deleteValue();
       return error("Invalid instruction with no BB");
     }
     if (!OperandBundles.empty()) {
       I->deleteValue();
       return error("Operand bundles found with no consumer");
     }
     CurBB->getInstList().push_back(I);
 
     // If this was a terminator instruction, move to the next block.
     if (I->isTerminator()) {
       ++CurBBNo;
       CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : nullptr;
     }
 
     // Non-void values get registered in the value table for future use.
-    if (!I->getType()->isVoidTy())
-      ValueList.assignValue(NextValueNo++, I);
+    if (!I->getType()->isVoidTy()) {
+      assert(ResTypeID != InvalidTypeID && "Should have ID for non-void type");
+      ValueList.assignValue(NextValueNo++, I, ResTypeID);
+    }
   }
 
 OutOfRecordLoop:
 
   if (!OperandBundles.empty())
     return error("Operand bundles found with no consumer");
 
   // Check the function list for unresolved values.

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

auto dropRecord = [&] {
       MetadataList.assignValue(MDNode::get(Context, None), NextMetadataNo);
       NextMetadataNo++;
     };
     if (Record.size() != 2) {
       dropRecord();
       break;
     }
 
-    Type *Ty = getTypeByID(Record[0]);
+    unsigned TyID = Record[0];
+    Type *Ty = getTypeByID(TyID);
     if (Ty->isMetadataTy() || Ty->isVoidTy()) {
       dropRecord();
       break;
     }
 
     MetadataList.assignValue(
-        LocalAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
+        LocalAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty, TyID)),
         NextMetadataNo);
     NextMetadataNo++;
     break;
   }
   case bitc::METADATA_OLD_NODE: {
     // Deprecated, but still needed to read old bitcode files.
     if (Record.size() % 2 == 1)
       return error("Invalid record");
 
     unsigned Size = Record.size();
     SmallVector<Metadata *, 8> Elts;
     for (unsigned i = 0; i != Size; i += 2) {
-      Type *Ty = getTypeByID(Record[i]);
+      unsigned TyID = Record[i];
+      Type *Ty = getTypeByID(TyID);
       if (!Ty)
         return error("Invalid record");
       if (Ty->isMetadataTy())
         Elts.push_back(getMD(Record[i + 1]));
       else if (!Ty->isVoidTy()) {
-        auto *MD =
-            ValueAsMetadata::get(ValueList.getValueFwdRef(Record[i + 1], Ty));
+        auto *MD = ValueAsMetadata::get(
+            ValueList.getValueFwdRef(Record[i + 1], Ty, TyID));
         assert(isa<ConstantAsMetadata>(MD) &&
                "Expected non-function-local metadata");
         Elts.push_back(MD);
       } else
         Elts.push_back(nullptr);
     }
     MetadataList.assignValue(MDNode::get(Context, Elts), NextMetadataNo);
     NextMetadataNo++;
     break;
   }
   case bitc::METADATA_VALUE: {
     if (Record.size() != 2)
       return error("Invalid record");
 
-    Type *Ty = getTypeByID(Record[0]);
+    unsigned TyID = Record[0];
+    Type *Ty = getTypeByID(TyID);
     if (Ty->isMetadataTy() || Ty->isVoidTy())
       return error("Invalid record");
 
     MetadataList.assignValue(
-        ValueAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
+        ValueAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty, TyID)),
         NextMetadataNo);
     NextMetadataNo++;
     break;
   }
   case bitc::METADATA_DISTINCT_NODE:
     IsDistinct = true;
     LLVM_FALLTHROUGH;
   case bitc::METADATA_NODE: {

llvm/lib/Bitcode/Reader/ValueList.h

 namespace llvm {
 
 class Constant;
 class LLVMContext;
 class Type;
 class Value;
 
 class BitcodeReaderValueList {
-  std::vector<WeakTrackingVH> ValuePtrs;
+  /// Maps Value ID to pair of Value* and Type ID.
+  std::vector<std::pair<WeakTrackingVH, unsigned>> ValuePtrs;
 
   /// As we resolve forward-referenced constants, we add information about them
   /// to this vector.  This allows us to resolve them in bulk instead of
   /// resolving each reference at a time.  See the code in
   /// ResolveConstantForwardRefs for more information about this.
   ///
   /// The key of this vector is the placeholder constant, the value is the slot
   /// number that holds the resolved value.
~BitcodeReaderValueList() {
     assert(ResolveConstants.empty() && "Constants not resolved?");
   }
 
   // vector compatibility methods
   unsigned size() const { return ValuePtrs.size(); }
   void resize(unsigned N) {
     ValuePtrs.resize(N);
   }
-  void push_back(Value *V) { ValuePtrs.emplace_back(V); }
+  void push_back(Value *V, unsigned TypeID) {
+    ValuePtrs.emplace_back(V, TypeID);
+  }
 
   void clear() {
     assert(ResolveConstants.empty() && "Constants not resolved?");
     ValuePtrs.clear();
   }
 
   Value *operator[](unsigned i) const {
     assert(i < ValuePtrs.size());
-    return ValuePtrs[i];
+    return ValuePtrs[i].first;
+  }
+
+  unsigned getTypeID(unsigned ValNo) const {
+    assert(ValNo < ValuePtrs.size());
+    return ValuePtrs[ValNo].second;
   }
 
-  Value *back() const { return ValuePtrs.back(); }
+  Value *back() const { return ValuePtrs.back().first; }
   void pop_back() {
     ValuePtrs.pop_back();
   }
   bool empty() const { return ValuePtrs.empty(); }
 
   void shrinkTo(unsigned N) {
     assert(N <= size() && "Invalid shrinkTo request!");
     ValuePtrs.resize(N);
   }
 
-  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
-  Value *getValueFwdRef(unsigned Idx, Type *Ty);
+  Constant *getConstantFwdRef(unsigned Idx, Type *Ty, unsigned TyID);
+  Value *getValueFwdRef(unsigned Idx, Type *Ty, unsigned TyID);
 
-  void assignValue(unsigned Idx, Value *V);
+  void assignValue(unsigned Idx, Value *V, unsigned TypeID);
 
   /// Once all constants are read, this method bulk resolves any forward
   /// references.
   void resolveConstantForwardRefs();
 };
 
 } // end namespace llvm
 
 #endif // LLVM_LIB_BITCODE_READER_VALUELIST_H

llvm/lib/Bitcode/Reader/ValueList.cpp

 // FIXME: can we inherit this from ConstantExpr?
 template <>
 struct OperandTraits<ConstantPlaceHolder>
     : public FixedNumOperandTraits<ConstantPlaceHolder, 1> {};
 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
 
 } // end namespace llvm
 
-void BitcodeReaderValueList::assignValue(unsigned Idx, Value *V) {
+void BitcodeReaderValueList::assignValue(unsigned Idx, Value *V,
+                                         unsigned TypeID) {
   if (Idx == size()) {
-    push_back(V);
+    push_back(V, TypeID);
     return;
   }
 
   if (Idx >= size())
     resize(Idx + 1);
 
-  WeakTrackingVH &OldV = ValuePtrs[Idx];
-  if (!OldV) {
-    OldV = V;
+  auto &Old = ValuePtrs[Idx];
+  if (!Old.first) {
+    Old.first = V;
+    Old.second = TypeID;
     return;
   }
 
   // Handle constants and non-constants (e.g. instrs) differently for
   // efficiency.
-  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
+  if (Constant *PHC = dyn_cast<Constant>(&*Old.first)) {
     ResolveConstants.push_back(std::make_pair(PHC, Idx));
-    OldV = V;
+    Old.first = V;
+    Old.second = TypeID;
   } else {
     // If there was a forward reference to this value, replace it.
-    Value *PrevVal = OldV;
-    OldV->replaceAllUsesWith(V);
+    Value *PrevVal = Old.first;
+    Old.first->replaceAllUsesWith(V);
     PrevVal->deleteValue();
   }
 }
 
-Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx, Type *Ty) {
+Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx, Type *Ty,
+                                                    unsigned TyID) {
   // Bail out for a clearly invalid value.
   if (Idx >= RefsUpperBound)
     return nullptr;
 
   if (Idx >= size())
     resize(Idx + 1);
 
-  if (Value *V = ValuePtrs[Idx]) {
+  if (Value *V = ValuePtrs[Idx].first) {
     if (Ty != V->getType())
       report_fatal_error("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, Context);
-  ValuePtrs[Idx] = C;
+  ValuePtrs[Idx] = {C, TyID};
   return C;
 }
 
-Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
+Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty,
+                                              unsigned TyID) {
   // Bail out for a clearly invalid value.
   if (Idx >= RefsUpperBound)
     return nullptr;
 
   if (Idx >= size())
     resize(Idx + 1);
 
-  if (Value *V = ValuePtrs[Idx]) {
+  if (Value *V = ValuePtrs[Idx].first) {
     // If the types don't match, it's invalid.
     if (Ty && Ty != V->getType())
       return nullptr;
     return V;
   }
 
   // No type specified, must be invalid reference.
   if (!Ty)
     return nullptr;
 
   // Create and return a placeholder, which will later be RAUW'd.
   Value *V = new Argument(Ty);
-  ValuePtrs[Idx] = V;
+  ValuePtrs[Idx] = {V, TyID};
   return V;
 }
 
 /// Once all constants are read, this method bulk resolves any forward
 /// references.  The idea behind this is that we sometimes get constants (such
 /// as large arrays) which reference *many* forward ref constants.  Replacing
 /// each of these causes a lot of thrashing when building/reuniquing the
 /// constant.  Instead of doing this, we look at all the uses and rewrite all