remove unions from LLVM IR. They are severely buggy and not

being actively maintained, improved, or extended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112356 91177308-0d34-0410-b5e6-96231b3b80d8

20 files changed, 18 insertions, 538 deletions

diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 90696b9..032753a 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -573,7 +573,6 @@ lltok::Kind LLLexer::LexIdentifier() {
 
   KEYWORD(type);
   KEYWORD(opaque);
-  KEYWORD(union);
 
   KEYWORD(eq); KEYWORD(ne); KEYWORD(slt); KEYWORD(sgt); KEYWORD(sle);
   KEYWORD(sge); KEYWORD(ult); KEYWORD(ugt); KEYWORD(ule); KEYWORD(uge);
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 7766ad6..f21a065 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -1359,11 +1359,6 @@ bool LLParser::ParseTypeRec(PATypeHolder &Result) {
     if (ParseStructType(Result, false))
       return true;
     break;
-  case lltok::kw_union:
-    // TypeRec ::= 'union' '{' ... '}'
-    if (ParseUnionType(Result))
-      return true;
-    break;
   case lltok::lsquare:
     // TypeRec ::= '[' ... ']'
     Lex.Lex(); // eat the lsquare.
@@ -1673,38 +1668,6 @@ bool LLParser::ParseStructType(PATypeHolder &Result, bool Packed) {
   return false;
 }
 
-/// ParseUnionType
-///   TypeRec
-///     ::= 'union' '{' TypeRec (',' TypeRec)* '}'
-bool LLParser::ParseUnionType(PATypeHolder &Result) {
-  assert(Lex.getKind() == lltok::kw_union);
-  Lex.Lex(); // Consume the 'union'
-
-  if (ParseToken(lltok::lbrace, "'{' expected after 'union'")) return true;
-
-  SmallVector<PATypeHolder, 8> ParamsList;
-  do {
-    LocTy EltTyLoc = Lex.getLoc();
-    if (ParseTypeRec(Result)) return true;
-    ParamsList.push_back(Result);
-
-    if (Result->isVoidTy())
-      return Error(EltTyLoc, "union element can not have void type");
-    if (!UnionType::isValidElementType(Result))
-      return Error(EltTyLoc, "invalid element type for union");
-
-  } while (EatIfPresent(lltok::comma)) ;
-
-  if (ParseToken(lltok::rbrace, "expected '}' at end of union"))
-    return true;
-
-  SmallVector<const Type*, 8> ParamsListTy;
-  for (unsigned i = 0, e = ParamsList.size(); i != e; ++i)
-    ParamsListTy.push_back(ParamsList[i].get());
-  Result = HandleUpRefs(UnionType::get(&ParamsListTy[0], ParamsListTy.size()));
-  return false;
-}
-
 /// ParseArrayVectorType - Parse an array or vector type, assuming the first
 /// token has already been consumed.
 ///   TypeRec
@@ -2656,16 +2619,8 @@ bool LLParser::ConvertValIDToValue(const Type *Ty, ValID &ID, Value *&V,
     V = Constant::getNullValue(Ty);
     return false;
   case ValID::t_Constant:
-    if (ID.ConstantVal->getType() != Ty) {
-      // Allow a constant struct with a single member to be converted
-      // to a union, if the union has a member which is the same type
-      // as the struct member.
-      if (const UnionType* utype = dyn_cast<UnionType>(Ty)) {
-        return ParseUnionValue(utype, ID, V);
-      }
-
+    if (ID.ConstantVal->getType() != Ty)
       return Error(ID.Loc, "constant expression type mismatch");
-    }
 
     V = ID.ConstantVal;
     return false;
@@ -2696,22 +2651,6 @@ bool LLParser::ParseTypeAndBasicBlock(BasicBlock *&BB, LocTy &Loc,
   return false;
 }
 
-bool LLParser::ParseUnionValue(const UnionType* utype, ValID &ID, Value *&V) {
-  if (const StructType* stype = dyn_cast<StructType>(ID.ConstantVal->getType())) {
-    if (stype->getNumContainedTypes() != 1)
-      return Error(ID.Loc, "constant expression type mismatch");
-    int index = utype->getElementTypeIndex(stype->getContainedType(0));
-    if (index < 0)
-      return Error(ID.Loc, "initializer type is not a member of the union");
-
-    V = ConstantUnion::get(
-        utype, cast<Constant>(ID.ConstantVal->getOperand(0)));
-    return false;
-  }
-
-  return Error(ID.Loc, "constant expression type mismatch");
-}
-
 
 /// FunctionHeader
 ///   ::= OptionalLinkage OptionalVisibility OptionalCallingConv OptRetAttrs
diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h
index 5ac7337..404cec3 100644
--- a/lib/AsmParser/LLParser.h
+++ b/lib/AsmParser/LLParser.h
@@ -32,7 +32,6 @@ namespace llvm {
   class GlobalValue;
   class MDString;
   class MDNode;
-  class UnionType;
 
   /// ValID - Represents a reference of a definition of some sort with no type.
   /// There are several cases where we have to parse the value but where the
@@ -229,7 +228,6 @@ namespace llvm {
     }
     bool ParseTypeRec(PATypeHolder &H);
     bool ParseStructType(PATypeHolder &H, bool Packed);
-    bool ParseUnionType(PATypeHolder &H);
     bool ParseArrayVectorType(PATypeHolder &H, bool isVector);
     bool ParseFunctionType(PATypeHolder &Result);
     PATypeHolder HandleUpRefs(const Type *Ty);
@@ -298,7 +296,6 @@ namespace llvm {
       return ParseTypeAndBasicBlock(BB, Loc, PFS);
     }
 
-    bool ParseUnionValue(const UnionType* utype, ValID &ID, Value *&V);
 
     struct ParamInfo {
       LocTy Loc;
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index e266db9..61f93a4 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -98,7 +98,6 @@ namespace lltok {
 
     kw_type,
     kw_opaque,
-    kw_union,
 
     kw_eq, kw_ne, kw_slt, kw_sgt, kw_sle, kw_sge, kw_ult, kw_ugt, kw_ule,
     kw_uge, kw_oeq, kw_one, kw_olt, kw_ogt, kw_ole, kw_oge, kw_ord, kw_uno,
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index fd7fe90..cb7f2f4 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -297,8 +297,6 @@ void BitcodeReaderValueList::ResolveConstantForwardRefs() {
       } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
         NewC = ConstantStruct::get(Context, &NewOps[0], NewOps.size(),
                                          UserCS->getType()->isPacked());
-      } else if (ConstantUnion *UserCU = dyn_cast<ConstantUnion>(UserC)) {
-        NewC = ConstantUnion::get(UserCU->getType(), NewOps[0]);
       } else if (isa<ConstantVector>(UserC)) {
         NewC = ConstantVector::get(&NewOps[0], NewOps.size());
       } else {
@@ -591,13 +589,6 @@ bool BitcodeReader::ParseTypeTable() {
       ResultTy = StructType::get(Context, EltTys, Record[0]);
       break;
     }
-    case bitc::TYPE_CODE_UNION: {  // UNION: [eltty x N]
-      SmallVector<const Type*, 8> EltTys;
-      for (unsigned i = 0, e = Record.size(); i != e; ++i)
-        EltTys.push_back(getTypeByID(Record[i], true));
-      ResultTy = UnionType::get(&EltTys[0], EltTys.size());
-      break;
-    }
     case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
       if (Record.size() < 2)
         return Error("Invalid ARRAY type record");
@@ -1014,11 +1005,6 @@ bool BitcodeReader::ParseConstants() {
           Elts.push_back(ValueList.getConstantFwdRef(Record[i],
                                                      STy->getElementType(i)));
         V = ConstantStruct::get(STy, Elts);
-      } else if (const UnionType *UnTy = dyn_cast<UnionType>(CurTy)) {
-        uint64_t Index = Record[0];
-        Constant *Val = ValueList.getConstantFwdRef(Record[1],
-                                        UnTy->getElementType(Index));
-        V = ConstantUnion::get(UnTy, Val);
       } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
         const Type *EltTy = ATy->getElementType();
         for (unsigned i = 0; i != Size; ++i)
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 390e482..07727f3 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -181,14 +181,6 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
                             Log2_32_Ceil(VE.getTypes().size()+1)));
   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 
-  // Abbrev for TYPE_CODE_UNION.
-  Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_UNION));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
-                            Log2_32_Ceil(VE.getTypes().size()+1)));
-  unsigned UnionAbbrev = Stream.EmitAbbrev(Abbv);
-
   // Abbrev for TYPE_CODE_ARRAY.
   Abbv = new BitCodeAbbrev();
   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
@@ -258,17 +250,6 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
       AbbrevToUse = StructAbbrev;
       break;
     }
-    case Type::UnionTyID: {
-      const UnionType *UT = cast<UnionType>(T);
-      // UNION: [eltty x N]
-      Code = bitc::TYPE_CODE_UNION;
-      // Output all of the element types.
-      for (UnionType::element_iterator I = UT->element_begin(),
-           E = UT->element_end(); I != E; ++I)
-        TypeVals.push_back(VE.getTypeID(*I));
-      AbbrevToUse = UnionAbbrev;
-      break;
-    }
     case Type::ArrayTyID: {
       const ArrayType *AT = cast<ArrayType>(T);
       // ARRAY: [numelts, eltty]
@@ -811,20 +792,6 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
         Record.push_back(VE.getValueID(C->getOperand(i)));
       AbbrevToUse = AggregateAbbrev;
-    } else if (isa<ConstantUnion>(C)) {
-      Code = bitc::CST_CODE_AGGREGATE;
-
-      // Unions only have one entry but we must send type along with it.
-      const Type *EntryKind = C->getOperand(0)->getType();
-
-      const UnionType *UnTy = cast<UnionType>(C->getType());
-      int UnionIndex = UnTy->getElementTypeIndex(EntryKind);
-      assert(UnionIndex != -1 && "Constant union contains invalid entry");
-
-      Record.push_back(UnionIndex);
-      Record.push_back(VE.getValueID(C->getOperand(0)));
-
-      AbbrevToUse = AggregateAbbrev;
     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
       switch (CE->getOpcode()) {
       default:
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index fa0b97f..2571341 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1433,21 +1433,6 @@ static void EmitGlobalConstantStruct(const ConstantStruct *CS,
          "Layout of constant struct may be incorrect!");
 }
 
-static void EmitGlobalConstantUnion(const ConstantUnion *CU, 
-                                    unsigned AddrSpace, AsmPrinter &AP) {
-  const TargetData *TD = AP.TM.getTargetData();
-  unsigned Size = TD->getTypeAllocSize(CU->getType());
-
-  const Constant *Contents = CU->getOperand(0);
-  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
-    
-  // Print the actually filled part
-  EmitGlobalConstantImpl(Contents, AddrSpace, AP);
-
-  // And pad with enough zeroes
-  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
-}
-
 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
                                  AsmPrinter &AP) {
   // FP Constants are printed as integer constants to avoid losing
@@ -1573,9 +1558,6 @@ static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
     return;
   }
   
-  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
-    return EmitGlobalConstantUnion(CVU, AddrSpace, AP);
-  
   if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
     return EmitGlobalConstantVector(V, AddrSpace, AP);
   
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 17cc6bf..abffeb0 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2804,11 +2804,6 @@ void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
       }
 
       Ty = StTy->getElementType(Field);
-    } else if (const UnionType *UnTy = dyn_cast<UnionType>(Ty)) {
-      unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
-      
-      // Offset canonically 0 for unions, but type changes
-      Ty = UnTy->getElementType(Field);
     } else {
       Ty = cast<SequentialType>(Ty)->getElementType();
 
diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index 69fce44..f35c96d 100644
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -454,15 +454,6 @@ uint64_t TargetData::getTypeSizeInBits(const Type *Ty) const {
   case Type::StructTyID:
     // Get the layout annotation... which is lazily created on demand.
     return getStructLayout(cast<StructType>(Ty))->getSizeInBits();
-  case Type::UnionTyID: {
-    const UnionType *UnTy = cast<UnionType>(Ty);
-    uint64_t Size = 0;
-    for (UnionType::element_iterator i = UnTy->element_begin(),
-             e = UnTy->element_end(); i != e; ++i) {
-      Size = std::max(Size, getTypeSizeInBits(*i));
-    }
-    return Size;
-  }
   case Type::IntegerTyID:
     return cast<IntegerType>(Ty)->getBitWidth();
   case Type::VoidTyID:
@@ -519,17 +510,6 @@ unsigned TargetData::getAlignment(const Type *Ty, bool abi_or_pref) const {
     unsigned Align = getAlignmentInfo(AGGREGATE_ALIGN, 0, abi_or_pref, Ty);
     return std::max(Align, Layout->getAlignment());
   }
-  case Type::UnionTyID: {
-    const UnionType *UnTy = cast<UnionType>(Ty);
-    unsigned Align = 1;
-
-    // Unions need the maximum alignment of all their entries
-    for (UnionType::element_iterator i = UnTy->element_begin(), 
-             e = UnTy->element_end(); i != e; ++i) {
-      Align = std::max(Align, getAlignment(*i, abi_or_pref));
-    }
-    return Align;
-  }
   case Type::IntegerTyID:
   case Type::VoidTyID:
     AlignType = INTEGER_ALIGN;
@@ -614,11 +594,6 @@ uint64_t TargetData::getIndexedOffset(const Type *ptrTy, Value* const* Indices,
 
       // Update Ty to refer to current element
       Ty = STy->getElementType(FieldNo);
-    } else if (const UnionType *UnTy = dyn_cast<UnionType>(*TI)) {
-        unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue();
-
-        // Offset into union is canonically 0, but type changes
-        Ty = UnTy->getElementType(FieldNo);
     } else {
       // Update Ty to refer to current element
       Ty = cast<SequentialType>(Ty)->getElementType();
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index d7075b9..cac824b 100644
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -220,20 +220,6 @@ bool FunctionComparator::isEquivalentType(const Type *Ty1,
     return true;
   }
 
-  case Type::UnionTyID: {
-    const UnionType *UTy1 = cast<UnionType>(Ty1);
-    const UnionType *UTy2 = cast<UnionType>(Ty2);
-
-    if (UTy1->getNumElements() != UTy2->getNumElements())
-      return false;
-
-    for (unsigned i = 0, e = UTy1->getNumElements(); i != e; ++i) {
-      if (!isEquivalentType(UTy1->getElementType(i), UTy2->getElementType(i)))
-        return false;
-    }
-    return true;
-  }
-
   case Type::FunctionTyID: {
     const FunctionType *FTy1 = cast<FunctionType>(Ty1);
     const FunctionType *FTy2 = cast<FunctionType>(Ty2);
diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index c7f27c6..ab9dd3e 100644
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -238,21 +238,6 @@ void TypePrinting::CalcTypeName(const Type *Ty,
       OS << '>';
     break;
   }
-  case Type::UnionTyID: {
-    const UnionType *UTy = cast<UnionType>(Ty);
-    OS << "union {";
-    for (StructType::element_iterator I = UTy->element_begin(),
-         E = UTy->element_end(); I != E; ++I) {
-      OS << ' ';
-      CalcTypeName(*I, TypeStack, OS);
-      if (llvm::next(I) == UTy->element_end())
-        OS << ' ';
-      else
-        OS << ',';
-    }
-    OS << '}';
-    break;
-  }
   case Type::PointerTyID: {
     const PointerType *PTy = cast<PointerType>(Ty);
     CalcTypeName(PTy->getElementType(), TypeStack, OS);
@@ -1042,16 +1027,6 @@ static void WriteConstantInternal(raw_ostream &Out, const Constant *CV,
     return;
   }
 
-  if (const ConstantUnion *CU = dyn_cast<ConstantUnion>(CV)) {
-    Out << "{ ";
-    TypePrinter.print(CU->getOperand(0)->getType(), Out);
-    Out << ' ';
-    WriteAsOperandInternal(Out, CU->getOperand(0), &TypePrinter, Machine,
-                           Context);
-    Out << " }";
-    return;
-  }
-  
   if (const ConstantVector *CP = dyn_cast<ConstantVector>(CV)) {
     const Type *ETy = CP->getType()->getElementType();
     assert(CP->getNumOperands() > 0 &&
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 3567266..9a91daf 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -357,22 +357,6 @@ static Constant *getFoldedSizeOf(const Type *Ty, const Type *DestTy,
       }
     }
 
-  if (const UnionType *UTy = dyn_cast<UnionType>(Ty)) {
-    unsigned NumElems = UTy->getNumElements();
-    // Check for a union with all members having the same size.
-    Constant *MemberSize =
-      getFoldedSizeOf(UTy->getElementType(0), DestTy, true);
-    bool AllSame = true;
-    for (unsigned i = 1; i != NumElems; ++i)
-      if (MemberSize !=
-          getFoldedSizeOf(UTy->getElementType(i), DestTy, true)) {
-        AllSame = false;
-        break;
-      }
-    if (AllSame)
-      return MemberSize;
-  }
-
   // Pointer size doesn't depend on the pointee type, so canonicalize them
   // to an arbitrary pointee.
   if (const PointerType *PTy = dyn_cast<PointerType>(Ty))
@@ -438,24 +422,6 @@ static Constant *getFoldedAlignOf(const Type *Ty, const Type *DestTy,
       return MemberAlign;
   }
 
-  if (const UnionType *UTy = dyn_cast<UnionType>(Ty)) {
-    // Union alignment is the maximum alignment of any member.
-    // Without target data, we can't compare much, but we can check to see
-    // if all the members have the same alignment.
-    unsigned NumElems = UTy->getNumElements();
-    // Check for a union with all members having the same alignment.
-    Constant *MemberAlign =
-      getFoldedAlignOf(UTy->getElementType(0), DestTy, true);
-    bool AllSame = true;
-    for (unsigned i = 1; i != NumElems; ++i)
-      if (MemberAlign != getFoldedAlignOf(UTy->getElementType(i), DestTy, true)) {
-        AllSame = false;
-        break;
-      }
-    if (AllSame)
-      return MemberAlign;
-  }
-
   // Pointer alignment doesn't depend on the pointee type, so canonicalize them
   // to an arbitrary pointee.
   if (const PointerType *PTy = dyn_cast<PointerType>(Ty))
@@ -909,8 +875,6 @@ Constant *llvm::ConstantFoldInsertValueInstruction(Constant *Agg,
     unsigned numOps;
     if (const ArrayType *AR = dyn_cast<ArrayType>(AggTy))
       numOps = AR->getNumElements();
-    else if (AggTy->isUnionTy())
-      numOps = 1;
     else
       numOps = cast<StructType>(AggTy)->getNumElements();
     
@@ -927,10 +891,6 @@ Constant *llvm::ConstantFoldInsertValueInstruction(Constant *Agg,
     
     if (const StructType* ST = dyn_cast<StructType>(AggTy))
       return ConstantStruct::get(ST->getContext(), Ops, ST->isPacked());
-    if (const UnionType* UT = dyn_cast<UnionType>(AggTy)) {
-      assert(Ops.size() == 1 && "Union can only contain a single value!");
-      return ConstantUnion::get(UT, Ops[0]);
-    }
     return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
   }
   
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index c0fa92d..16eaca8 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -59,7 +59,6 @@ Constant *Constant::getNullValue(const Type *Ty) {
   case Type::PointerTyID:
     return ConstantPointerNull::get(cast<PointerType>(Ty));
   case Type::StructTyID:
-  case Type::UnionTyID:
   case Type::ArrayTyID:
   case Type::VectorTyID:
     return ConstantAggregateZero::get(Ty);
@@ -587,27 +586,6 @@ Constant* ConstantStruct::get(LLVMContext &Context,
   return get(Context, std::vector<Constant*>(Vals, Vals+NumVals), Packed);
 }
 
-ConstantUnion::ConstantUnion(const UnionType *T, Constant* V)
-  : Constant(T, ConstantUnionVal,
-             OperandTraits<ConstantUnion>::op_end(this) - 1, 1) {
-  Use *OL = OperandList;
-  assert(T->getElementTypeIndex(V->getType()) >= 0 &&
-      "Initializer for union element isn't a member of union type!");
-  *OL = V;
-}
-
-// ConstantUnion accessors.
-Constant* ConstantUnion::get(const UnionType* T, Constant* V) {
-  LLVMContextImpl* pImpl = T->getContext().pImpl;
-  
-  // Create a ConstantAggregateZero value if all elements are zeros...
-  if (!V->isNullValue())
-    return pImpl->UnionConstants.getOrCreate(T, V);
-
-  return ConstantAggregateZero::get(T);
-}
-
-
 ConstantVector::ConstantVector(const VectorType *T,
                                const std::vector<Constant*> &V)
   : Constant(T, ConstantVectorVal,
@@ -946,8 +924,7 @@ bool ConstantFP::isValueValidForType(const Type *Ty, const APFloat& Val) {
 //                      Factory Function Implementation
 
 ConstantAggregateZero* ConstantAggregateZero::get(const Type* Ty) {
-  assert((Ty->isStructTy() || Ty->isUnionTy()
-         || Ty->isArrayTy() || Ty->isVectorTy()) &&
+  assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
          "Cannot create an aggregate zero of non-aggregate type!");
   
   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
@@ -1034,13 +1011,6 @@ void ConstantStruct::destroyConstant() {
 
 // destroyConstant - Remove the constant from the constant table...
 //
-void ConstantUnion::destroyConstant() {
-  getRawType()->getContext().pImpl->UnionConstants.remove(this);
-  destroyConstantImpl();
-}
-
-// destroyConstant - Remove the constant from the constant table...
-//
 void ConstantVector::destroyConstant() {
   getRawType()->getContext().pImpl->VectorConstants.remove(this);
   destroyConstantImpl();
@@ -2117,55 +2087,6 @@ void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
   destroyConstant();
 }
 
-void ConstantUnion::replaceUsesOfWithOnConstant(Value *From, Value *To,
-                                                 Use *U) {
-  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
-  Constant *ToC = cast<Constant>(To);
-
-  assert(U == OperandList && "Union constants can only have one use!");
-  assert(getNumOperands() == 1 && "Union constants can only have one use!");
-  assert(getOperand(0) == From && "ReplaceAllUsesWith broken!");
-
-  std::pair<LLVMContextImpl::UnionConstantsTy::MapKey, ConstantUnion*> Lookup;
-  Lookup.first.first = cast<UnionType>(getRawType());
-  Lookup.second = this;
-  Lookup.first.second = ToC;
-
-  LLVMContextImpl *pImpl = getRawType()->getContext().pImpl;
-
-  Constant *Replacement = 0;
-  if (ToC->isNullValue()) {
-    Replacement = ConstantAggregateZero::get(getRawType());
-  } else {
-    // Check to see if we have this union type already.
-    bool Exists;
-    LLVMContextImpl::UnionConstantsTy::MapTy::iterator I =
-      pImpl->UnionConstants.InsertOrGetItem(Lookup, Exists);
-    
-    if (Exists) {
-      Replacement = I->second;
-    } else {
-      // Okay, the new shape doesn't exist in the system yet.  Instead of
-      // creating a new constant union, inserting it, replaceallusesof'ing the
-      // old with the new, then deleting the old... just update the current one
-      // in place!
-      pImpl->UnionConstants.MoveConstantToNewSlot(this, I);
-      
-      // Update to the new value.
-      setOperand(0, ToC);
-      return;
-    }
-  }
-  
-  assert(Replacement != this && "I didn't contain From!");
-  
-  // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(Replacement);
-  
-  // Delete the old constant!
-  destroyConstant();
-}
-
 void ConstantVector::replaceUsesOfWithOnConstant(Value *From, Value *To,
                                                  Use *U) {
   assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
diff --git a/lib/VMCore/ConstantsContext.h b/lib/VMCore/ConstantsContext.h
index b86ea60..1c04c3e 100644
--- a/lib/VMCore/ConstantsContext.h
+++ b/lib/VMCore/ConstantsContext.h
@@ -511,14 +511,6 @@ struct ConstantKeyData<ConstantStruct> {
   }
 };
 
-template<>
-struct ConstantKeyData<ConstantUnion> {
-  typedef Constant* ValType;
-  static ValType getValType(ConstantUnion *CU) {
-    return cast<Constant>(CU->getOperand(0));
-  }
-};
-
 // ConstantPointerNull does not take extra "value" argument...
 template<class ValType>
 struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
diff --git a/lib/VMCore/Core.cpp b/lib/VMCore/Core.cpp
index e884404..5aad19d 100644
--- a/lib/VMCore/Core.cpp
+++ b/lib/VMCore/Core.cpp
@@ -156,8 +156,6 @@ LLVMTypeKind LLVMGetTypeKind(LLVMTypeRef Ty) {
     return LLVMFunctionTypeKind;
   case Type::StructTyID:
     return LLVMStructTypeKind;
-  case Type::UnionTyID:
-    return LLVMUnionTypeKind;
   case Type::ArrayTyID:
     return LLVMArrayTypeKind;
   case Type::PointerTyID:
@@ -316,34 +314,6 @@ LLVMBool LLVMIsPackedStruct(LLVMTypeRef StructTy) {
   return unwrap<StructType>(StructTy)->isPacked();
 }
 
-/*--.. Operations on union types ..........................................--*/
-
-LLVMTypeRef LLVMUnionTypeInContext(LLVMContextRef C, LLVMTypeRef *ElementTypes,
-                                   unsigned ElementCount) {
-  SmallVector<const Type*, 8> Tys;
-  for (LLVMTypeRef *I = ElementTypes,
-                   *E = ElementTypes + ElementCount; I != E; ++I)
-    Tys.push_back(unwrap(*I));
-  
-  return wrap(UnionType::get(&Tys[0], Tys.size()));
-}
-
-LLVMTypeRef LLVMUnionType(LLVMTypeRef *ElementTypes, unsigned ElementCount) {
-  return LLVMUnionTypeInContext(LLVMGetGlobalContext(), ElementTypes,
-                                ElementCount);
-}
-
-unsigned LLVMCountUnionElementTypes(LLVMTypeRef UnionTy) {
-  return unwrap<UnionType>(UnionTy)->getNumElements();
-}
-
-void LLVMGetUnionElementTypes(LLVMTypeRef UnionTy, LLVMTypeRef *Dest) {
-  UnionType *Ty = unwrap<UnionType>(UnionTy);
-  for (FunctionType::param_iterator I = Ty->element_begin(),
-                                    E = Ty->element_end(); I != E; ++I)
-    *Dest++ = wrap(*I);
-}
-
 /*--.. Operations on array, pointer, and vector types (sequence types) .....--*/
 
 LLVMTypeRef LLVMArrayType(LLVMTypeRef ElementType, unsigned ElementCount) {
@@ -628,10 +598,6 @@ LLVMValueRef LLVMConstVector(LLVMValueRef *ScalarConstantVals, unsigned Size) {
   return wrap(ConstantVector::get(
                             unwrap<Constant>(ScalarConstantVals, Size), Size));
 }
-LLVMValueRef LLVMConstUnion(LLVMTypeRef Ty, LLVMValueRef Val) {
-  return wrap(ConstantUnion::get(unwrap<UnionType>(Ty), unwrap<Constant>(Val)));
-}
-
 /*--.. Constant expressions ................................................--*/
 
 LLVMOpcode LLVMGetConstOpcode(LLVMValueRef ConstantVal) {
diff --git a/lib/VMCore/LLVMContextImpl.cpp b/lib/VMCore/LLVMContextImpl.cpp
index 9e41a08..93a075f 100644
--- a/lib/VMCore/LLVMContextImpl.cpp
+++ b/lib/VMCore/LLVMContextImpl.cpp
@@ -57,14 +57,11 @@ LLVMContextImpl::~LLVMContextImpl() {
                 DropReferences());
   std::for_each(StructConstants.map_begin(), StructConstants.map_end(),
                 DropReferences());
-  std::for_each(UnionConstants.map_begin(), UnionConstants.map_end(),
-                DropReferences());
   std::for_each(VectorConstants.map_begin(), VectorConstants.map_end(),
                 DropReferences());
   ExprConstants.freeConstants();
   ArrayConstants.freeConstants();
   StructConstants.freeConstants();
-  UnionConstants.freeConstants();
   VectorConstants.freeConstants();
   AggZeroConstants.freeConstants();
   NullPtrConstants.freeConstants();
diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 4876f5d..51b2992 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -144,10 +144,6 @@ public:
     ConstantStruct, true /*largekey*/> StructConstantsTy;
   StructConstantsTy StructConstants;
   
-  typedef ConstantUniqueMap<Constant*, UnionType, ConstantUnion>
-      UnionConstantsTy;
-  UnionConstantsTy UnionConstants;
-  
   typedef ConstantUniqueMap<std::vector<Constant*>, VectorType,
                             ConstantVector> VectorConstantsTy;
   VectorConstantsTy VectorConstants;
@@ -192,7 +188,6 @@ public:
   TypeMap<PointerValType, PointerType> PointerTypes;
   TypeMap<FunctionValType, FunctionType> FunctionTypes;
   TypeMap<StructValType, StructType> StructTypes;
-  TypeMap<UnionValType, UnionType> UnionTypes;
   TypeMap<IntegerValType, IntegerType> IntegerTypes;
 
   // Opaque types are not structurally uniqued, so don't use TypeMap.
diff --git a/lib/VMCore/Type.cpp b/lib/VMCore/Type.cpp
index 0c9b0ea..c55e626 100644
--- a/lib/VMCore/Type.cpp
+++ b/lib/VMCore/Type.cpp
@@ -50,7 +50,7 @@ void AbstractTypeUser::setType(Value *V, const Type *NewTy) {
 
 /// Because of the way Type subclasses are allocated, this function is necessary
 /// to use the correct kind of "delete" operator to deallocate the Type object.
-/// Some type objects (FunctionTy, StructTy, UnionTy) allocate additional space
+/// Some type objects (FunctionTy, StructTy) allocate additional space
 /// after the space for their derived type to hold the contained types array of
 /// PATypeHandles. Using this allocation scheme means all the PATypeHandles are
 /// allocated with the type object, decreasing allocations and eliminating the
@@ -66,8 +66,7 @@ void Type::destroy() const {
   // Structures and Functions allocate their contained types past the end of
   // the type object itself. These need to be destroyed differently than the
   // other types.
-  if (this->isFunctionTy() || this->isStructTy() ||
-      this->isUnionTy()) {
+  if (this->isFunctionTy() || this->isStructTy()) {
     // First, make sure we destruct any PATypeHandles allocated by these
     // subclasses.  They must be manually destructed. 
     for (unsigned i = 0; i < NumContainedTys; ++i)
@@ -77,10 +76,10 @@ void Type::destroy() const {
     // to delete this as an array of char.
     if (this->isFunctionTy())
       static_cast<const FunctionType*>(this)->FunctionType::~FunctionType();
-    else if (this->isStructTy())
+    else {
+      assert(isStructTy());
       static_cast<const StructType*>(this)->StructType::~StructType();
-    else
-      static_cast<const UnionType*>(this)->UnionType::~UnionType();
+    }
 
     // Finally, remove the memory as an array deallocation of the chars it was
     // constructed from.
@@ -234,7 +233,7 @@ bool Type::isSizedDerivedType() const {
   if (const VectorType *PTy = dyn_cast<VectorType>(this))
     return PTy->getElementType()->isSized();
 
-  if (!this->isStructTy() && !this->isUnionTy()) 
+  if (!this->isStructTy()) 
     return false;
 
   // Okay, our struct is sized if all of the elements are...
@@ -319,31 +318,6 @@ const Type *StructType::getTypeAtIndex(unsigned Idx) const {
 }
 
 
-bool UnionType::indexValid(const Value *V) const {
-  // Union indexes require 32-bit integer constants.
-  if (V->getType()->isIntegerTy(32))
-    if (const ConstantInt *CU = dyn_cast<ConstantInt>(V))
-      return indexValid(CU->getZExtValue());
-  return false;
-}
-
-bool UnionType::indexValid(unsigned V) const {
-  return V < NumContainedTys;
-}
-
-// getTypeAtIndex - Given an index value into the type, return the type of the
-// element.  For a structure type, this must be a constant value...
-//
-const Type *UnionType::getTypeAtIndex(const Value *V) const {
-  unsigned Idx = (unsigned)cast<ConstantInt>(V)->getZExtValue();
-  return getTypeAtIndex(Idx);
-}
-
-const Type *UnionType::getTypeAtIndex(unsigned Idx) const {
-  assert(indexValid(Idx) && "Invalid structure index!");
-  return ContainedTys[Idx];
-}
-
 //===----------------------------------------------------------------------===//
 //                          Primitive 'Type' data
 //===----------------------------------------------------------------------===//
@@ -507,23 +481,6 @@ StructType::StructType(LLVMContext &C,
   setAbstract(isAbstract);
 }
 
-UnionType::UnionType(LLVMContext &C,const Type* const* Types, unsigned NumTypes)
-  : CompositeType(C, UnionTyID) {
-  ContainedTys = reinterpret_cast<PATypeHandle*>(this + 1);
-  NumContainedTys = NumTypes;
-  bool isAbstract = false;
-  for (unsigned i = 0; i < NumTypes; ++i) {
-    assert(Types[i] && "<null> type for union field!");
-    assert(isValidElementType(Types[i]) &&
-           "Invalid type for union element!");
-    new (&ContainedTys[i]) PATypeHandle(Types[i], this);
-    isAbstract |= Types[i]->isAbstract();
-  }
-
-  // Calculate whether or not this type is abstract
-  setAbstract(isAbstract);
-}
-
 ArrayType::ArrayType(const Type *ElType, uint64_t NumEl)
   : SequentialType(ArrayTyID, ElType) {
   NumElements = NumEl;
@@ -711,15 +668,6 @@ static bool TypesEqual(const Type *Ty, const Type *Ty2,
     return true;
   }
   
-  if (const UnionType *UTy = dyn_cast<UnionType>(Ty)) {
-    const UnionType *UTy2 = cast<UnionType>(Ty2);
-    if (UTy->getNumElements() != UTy2->getNumElements()) return false;
-    for (unsigned i = 0, e = UTy2->getNumElements(); i != e; ++i)
-      if (!TypesEqual(UTy->getElementType(i), UTy2->getElementType(i), EqTypes))
-        return false;
-    return true;
-  }
-  
   if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
     const ArrayType *ATy2 = cast<ArrayType>(Ty2);
     return ATy->getNumElements() == ATy2->getNumElements() &&
@@ -987,60 +935,6 @@ bool StructType::isValidElementType(const Type *ElemTy) {
 
 
 //===----------------------------------------------------------------------===//
-// Union Type Factory...
-//
-
-UnionType *UnionType::get(const Type* const* Types, unsigned NumTypes) {
-  assert(NumTypes > 0 && "union must have at least one member type!");
-  UnionValType UTV(Types, NumTypes);
-  UnionType *UT = 0;
-  
-  LLVMContextImpl *pImpl = Types[0]->getContext().pImpl;
-  
-  UT = pImpl->UnionTypes.get(UTV);
-    
-  if (!UT) {
-    // Value not found.  Derive a new type!
-    UT = (UnionType*) operator new(sizeof(UnionType) +
-                                   sizeof(PATypeHandle) * NumTypes);
-    new (UT) UnionType(Types[0]->getContext(), Types, NumTypes);
-    pImpl->UnionTypes.add(UTV, UT);
-  }
-#ifdef DEBUG_MERGE_TYPES
-  DEBUG(dbgs() << "Derived new type: " << *UT << "\n");
-#endif
-  return UT;
-}
-
-UnionType *UnionType::get(const Type *type, ...) {
-  va_list ap;
-  SmallVector<const llvm::Type*, 8> UnionFields;
-  va_start(ap, type);
-  while (type) {
-    UnionFields.push_back(type);
-    type = va_arg(ap, llvm::Type*);
-  }
-  unsigned NumTypes = UnionFields.size();
-  assert(NumTypes > 0 && "union must have at least one member type!");
-  return llvm::UnionType::get(&UnionFields[0], NumTypes);
-}
-
-bool UnionType::isValidElementType(const Type *ElemTy) {
-  return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
-         !ElemTy->isMetadataTy() && !ElemTy->isFunctionTy();
-}
-
-int UnionType::getElementTypeIndex(const Type *ElemTy) const {
-  int index = 0;
-  for (UnionType::element_iterator I = element_begin(), E = element_end();
-       I != E; ++I, ++index) {
-     if (ElemTy == *I) return index;
-  }
-  
-  return -1;
-}
-
-//===----------------------------------------------------------------------===//
 // Pointer Type Factory...
 //
 
@@ -1291,21 +1185,6 @@ void StructType::typeBecameConcrete(const DerivedType *AbsTy) {
 // concrete - this could potentially change us from an abstract type to a
 // concrete type.
 //
-void UnionType::refineAbstractType(const DerivedType *OldType,
-                                    const Type *NewType) {
-  LLVMContextImpl *pImpl = OldType->getContext().pImpl;
-  pImpl->UnionTypes.RefineAbstractType(this, OldType, NewType);
-}
-
-void UnionType::typeBecameConcrete(const DerivedType *AbsTy) {
-  LLVMContextImpl *pImpl = AbsTy->getContext().pImpl;
-  pImpl->UnionTypes.TypeBecameConcrete(this, AbsTy);
-}
-
-// refineAbstractType - Called when a contained type is found to be more
-// concrete - this could potentially change us from an abstract type to a
-// concrete type.
-//
 void PointerType::refineAbstractType(const DerivedType *OldType,
                                      const Type *NewType) {
   LLVMContextImpl *pImpl = OldType->getContext().pImpl;
diff --git a/lib/VMCore/TypesContext.h b/lib/VMCore/TypesContext.h
index f19b80a..5a90917 100644
--- a/lib/VMCore/TypesContext.h
+++ b/lib/VMCore/TypesContext.h
@@ -180,32 +180,6 @@ public:
   }
 };
 
-// UnionValType - Define a class to hold the key that goes into the TypeMap
-//
-class UnionValType {
-  std::vector<const Type*> ElTypes;
-public:
-  UnionValType(const Type* const* Types, unsigned NumTypes)
-    : ElTypes(&Types[0], &Types[NumTypes]) {}
-
-  static UnionValType get(const UnionType *UT) {
-    std::vector<const Type *> ElTypes;
-    ElTypes.reserve(UT->getNumElements());
-    for (unsigned i = 0, e = UT->getNumElements(); i != e; ++i)
-      ElTypes.push_back(UT->getElementType(i));
-
-    return UnionValType(&ElTypes[0], ElTypes.size());
-  }
-
-  static unsigned hashTypeStructure(const UnionType *UT) {
-    return UT->getNumElements();
-  }
-
-  inline bool operator<(const UnionValType &UTV) const {
-    return (ElTypes < UTV.ElTypes);
-  }
-};
-
 // FunctionValType - Define a class to hold the key that goes into the TypeMap
 //
 class FunctionValType {
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 185b03d..e3ecc97 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -1560,7 +1560,8 @@ void Verifier::VerifyType(const Type *Ty) {
               "Function type with invalid parameter type", ElTy, FTy);
       VerifyType(ElTy);
     }
-  } break;
+    break;
+  }
   case Type::StructTyID: {
     const StructType *STy = cast<StructType>(Ty);
     for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
@@ -1569,34 +1570,29 @@ void Verifier::VerifyType(const Type *Ty) {
               "Structure type with invalid element type", ElTy, STy);
       VerifyType(ElTy);
     }
-  } break;
-  case Type::UnionTyID: {
-    const UnionType *UTy = cast<UnionType>(Ty);
-    for (unsigned i = 0, e = UTy->getNumElements(); i != e; ++i) {
-      const Type *ElTy = UTy->getElementType(i);
-      Assert2(UnionType::isValidElementType(ElTy),
-              "Union type with invalid element type", ElTy, UTy);
-      VerifyType(ElTy);
-    }
-  } break;
+    break;
+  }
   case Type::ArrayTyID: {
     const ArrayType *ATy = cast<ArrayType>(Ty);
     Assert1(ArrayType::isValidElementType(ATy->getElementType()),
             "Array type with invalid element type", ATy);
     VerifyType(ATy->getElementType());
-  } break;
+    break;
+  }
   case Type::PointerTyID: {
     const PointerType *PTy = cast<PointerType>(Ty);
     Assert1(PointerType::isValidElementType(PTy->getElementType()),
             "Pointer type with invalid element type", PTy);
     VerifyType(PTy->getElementType());
-  } break;
+    break;
+  }
   case Type::VectorTyID: {
     const VectorType *VTy = cast<VectorType>(Ty);
     Assert1(VectorType::isValidElementType(VTy->getElementType()),
             "Vector type with invalid element type", VTy);
     VerifyType(VTy->getElementType());
-  } break;
+    break;
+  }
   default:
     break;
   }