Reverting dtor devirtualization patch.

_sabre_: it has a major problem: by the time ~Value is run, all of the "parts" of the derived classes have been destroyed
_sabre_: the vtable lives to fight another day

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44760 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 197 insertions, 295 deletions

diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
index ad9ad42..d45a1c4 100644
--- a/lib/VMCore/BasicBlock.cpp
+++ b/lib/VMCore/BasicBlock.cpp
@@ -30,9 +30,31 @@ ilist_traits<Instruction>::getSymTab(BasicBlock *BB) {
   return 0;
 }
 
-DummyInst::DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd, 0, 0) {
-  // This should not be garbage monitored.
-  LeakDetector::removeGarbageObject(this);
+
+namespace {
+  /// DummyInst - An instance of this class is used to mark the end of the
+  /// instruction list.  This is not a real instruction.
+  struct VISIBILITY_HIDDEN DummyInst : public Instruction {
+    DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd, 0, 0) {
+      // This should not be garbage monitored.
+      LeakDetector::removeGarbageObject(this);
+    }
+
+    Instruction *clone() const {
+      assert(0 && "Cannot clone EOL");abort();
+      return 0;
+    }
+    const char *getOpcodeName() const { return "*end-of-list-inst*"; }
+
+    // Methods for support type inquiry through isa, cast, and dyn_cast...
+    static inline bool classof(const DummyInst *) { return true; }
+    static inline bool classof(const Instruction *I) {
+      return I->getOpcode() == OtherOpsEnd;
+    }
+    static inline bool classof(const Value *V) {
+      return isa<Instruction>(V) && classof(cast<Instruction>(V));
+    }
+  };
 }
 
 Instruction *ilist_traits<Instruction>::createSentinel() {
@@ -66,12 +88,10 @@ BasicBlock::BasicBlock(const std::string &Name, Function *NewParent,
 }
 
 
-void BasicBlock::destroyThis(BasicBlock*v)
-{
-  assert(v->getParent() == 0 && "BasicBlock still linked into the program!");
-  v->dropAllReferences();
-  v->InstList.clear();
-  Value::destroyThis(v);	
+BasicBlock::~BasicBlock() {
+  assert(getParent() == 0 && "BasicBlock still linked into the program!");
+  dropAllReferences();
+  InstList.clear();
 }
 
 void BasicBlock::setParent(Function *parent) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index fb51c3f..49c27b8 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -356,9 +356,8 @@ ConstantArray::ConstantArray(const ArrayType *T,
   }
 }
 
-void ConstantArray::destroyThis(ConstantArray*v) {
-  delete [] v->OperandList;
-  Constant::destroyThis(v);
+ConstantArray::~ConstantArray() {
+  delete [] OperandList;
 }
 
 ConstantStruct::ConstantStruct(const StructType *T,
@@ -380,9 +379,8 @@ ConstantStruct::ConstantStruct(const StructType *T,
   }
 }
 
-void ConstantStruct::destroyThis(ConstantStruct*v) {
-  delete [] v->OperandList;
-  Constant::destroyThis(v);
+ConstantStruct::~ConstantStruct() {
+  delete [] OperandList;
 }
 
 
@@ -401,67 +399,124 @@ ConstantVector::ConstantVector(const VectorType *T,
   }
 }
 
-void ConstantVector::destroyThis(ConstantVector*v) {
-  delete [] v->OperandList;
-  Constant::destroyThis(v);
+ConstantVector::~ConstantVector() {
+  delete [] OperandList;
 }
 
-UnaryConstantExpr::UnaryConstantExpr(unsigned Opcode, 
-                                     Constant *C, const Type *Ty)
-  : ConstantExpr(Ty, Opcode, &Op, 1), Op(C, this) {
-}
+// We declare several classes private to this file, so use an anonymous
+// namespace
+namespace {
 
-SelectConstantExpr::SelectConstantExpr(Constant *C1, 
-                                       Constant *C2, Constant *C3)
-  : ConstantExpr(C2->getType(), Instruction::Select, Ops, 3) {
-  Ops[0].init(C1, this);
-  Ops[1].init(C2, this);
-  Ops[2].init(C3, this);
-}
+/// UnaryConstantExpr - This class is private to Constants.cpp, and is used
+/// behind the scenes to implement unary constant exprs.
+class VISIBILITY_HIDDEN UnaryConstantExpr : public ConstantExpr {
+  Use Op;
+public:
+  UnaryConstantExpr(unsigned Opcode, Constant *C, const Type *Ty)
+    : ConstantExpr(Ty, Opcode, &Op, 1), Op(C, this) {}
+};
 
-ExtractElementConstantExpr::ExtractElementConstantExpr(Constant *C1, 
-                                                       Constant *C2)
-  : ConstantExpr(cast<VectorType>(C1->getType())->getElementType(), 
-                 Instruction::ExtractElement, Ops, 2) {
-  Ops[0].init(C1, this);
-  Ops[1].init(C2, this);
-}
+/// BinaryConstantExpr - This class is private to Constants.cpp, and is used
+/// behind the scenes to implement binary constant exprs.
+class VISIBILITY_HIDDEN BinaryConstantExpr : public ConstantExpr {
+  Use Ops[2];
+public:
+  BinaryConstantExpr(unsigned Opcode, Constant *C1, Constant *C2)
+    : ConstantExpr(C1->getType(), Opcode, Ops, 2) {
+    Ops[0].init(C1, this);
+    Ops[1].init(C2, this);
+  }
+};
 
-InsertElementConstantExpr::InsertElementConstantExpr(Constant *C1, 
-                                                     Constant *C2, 
-                                                     Constant *C3)
-  : ConstantExpr(C1->getType(), Instruction::InsertElement, Ops, 3) {
-  Ops[0].init(C1, this);
-  Ops[1].init(C2, this);
-  Ops[2].init(C3, this);
-}
+/// SelectConstantExpr - This class is private to Constants.cpp, and is used
+/// behind the scenes to implement select constant exprs.
+class VISIBILITY_HIDDEN SelectConstantExpr : public ConstantExpr {
+  Use Ops[3];
+public:
+  SelectConstantExpr(Constant *C1, Constant *C2, Constant *C3)
+    : ConstantExpr(C2->getType(), Instruction::Select, Ops, 3) {
+    Ops[0].init(C1, this);
+    Ops[1].init(C2, this);
+    Ops[2].init(C3, this);
+  }
+};
 
-ShuffleVectorConstantExpr::ShuffleVectorConstantExpr(Constant *C1, 
-                                                     Constant *C2, 
-                                                     Constant *C3)
-  : ConstantExpr(C1->getType(), Instruction::ShuffleVector, Ops, 3) {
-  Ops[0].init(C1, this);
-  Ops[1].init(C2, this);
-  Ops[2].init(C3, this);
-}
+/// ExtractElementConstantExpr - This class is private to
+/// Constants.cpp, and is used behind the scenes to implement
+/// extractelement constant exprs.
+class VISIBILITY_HIDDEN ExtractElementConstantExpr : public ConstantExpr {
+  Use Ops[2];
+public:
+  ExtractElementConstantExpr(Constant *C1, Constant *C2)
+    : ConstantExpr(cast<VectorType>(C1->getType())->getElementType(), 
+                   Instruction::ExtractElement, Ops, 2) {
+    Ops[0].init(C1, this);
+    Ops[1].init(C2, this);
+  }
+};
 
-CompareConstantExpr::CompareConstantExpr(unsigned opc, unsigned short pred, 
-                                         Constant* LHS, Constant* RHS)
-  : ConstantExpr(Type::Int1Ty, opc, Ops, 2), predicate(pred) {
-  OperandList[0].init(LHS, this);
-  OperandList[1].init(RHS, this);
-}
+/// InsertElementConstantExpr - This class is private to
+/// Constants.cpp, and is used behind the scenes to implement
+/// insertelement constant exprs.
+class VISIBILITY_HIDDEN InsertElementConstantExpr : public ConstantExpr {
+  Use Ops[3];
+public:
+  InsertElementConstantExpr(Constant *C1, Constant *C2, Constant *C3)
+    : ConstantExpr(C1->getType(), Instruction::InsertElement, 
+                   Ops, 3) {
+    Ops[0].init(C1, this);
+    Ops[1].init(C2, this);
+    Ops[2].init(C3, this);
+  }
+};
+
+/// ShuffleVectorConstantExpr - This class is private to
+/// Constants.cpp, and is used behind the scenes to implement
+/// shufflevector constant exprs.
+class VISIBILITY_HIDDEN ShuffleVectorConstantExpr : public ConstantExpr {
+  Use Ops[3];
+public:
+  ShuffleVectorConstantExpr(Constant *C1, Constant *C2, Constant *C3)
+  : ConstantExpr(C1->getType(), Instruction::ShuffleVector, 
+                 Ops, 3) {
+    Ops[0].init(C1, this);
+    Ops[1].init(C2, this);
+    Ops[2].init(C3, this);
+  }
+};
+
+/// GetElementPtrConstantExpr - This class is private to Constants.cpp, and is
+/// used behind the scenes to implement getelementpr constant exprs.
+struct VISIBILITY_HIDDEN GetElementPtrConstantExpr : public ConstantExpr {
+  GetElementPtrConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
+                            const Type *DestTy)
+    : ConstantExpr(DestTy, Instruction::GetElementPtr,
+                   new Use[IdxList.size()+1], IdxList.size()+1) {
+    OperandList[0].init(C, this);
+    for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
+      OperandList[i+1].init(IdxList[i], this);
+  }
+  ~GetElementPtrConstantExpr() {
+    delete [] OperandList;
+  }
+};
+
+// CompareConstantExpr - This class is private to Constants.cpp, and is used
+// behind the scenes to implement ICmp and FCmp constant expressions. This is
+// needed in order to store the predicate value for these instructions.
+struct VISIBILITY_HIDDEN CompareConstantExpr : public ConstantExpr {
+  unsigned short predicate;
+  Use Ops[2];
+  CompareConstantExpr(Instruction::OtherOps opc, unsigned short pred, 
+                      Constant* LHS, Constant* RHS)
+    : ConstantExpr(Type::Int1Ty, opc, Ops, 2), predicate(pred) {
+    OperandList[0].init(LHS, this);
+    OperandList[1].init(RHS, this);
+  }
+};
+
+} // end anonymous namespace
 
-GetElementPtrConstantExpr::GetElementPtrConstantExpr(Constant *C, 
-                                                const std::vector<Constant*> 
-                                                &IdxList, const Type *DestTy)
-: ConstantExpr(DestTy, Instruction::GetElementPtr,
-			   new Use[IdxList.size()+1], IdxList.size()+1) 
-{
-  OperandList[0].init(C, this);
-  for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
-    OperandList[i+1].init(IdxList[i], this);
-}
 
 // Utility function for determining if a ConstantExpr is a CastOp or not. This
 // can't be inline because we don't want to #include Instruction.h into
diff --git a/lib/VMCore/Function.cpp b/lib/VMCore/Function.cpp
index b1405e5..04db3aa 100644
--- a/lib/VMCore/Function.cpp
+++ b/lib/VMCore/Function.cpp
@@ -287,17 +287,16 @@ Function::Function(const FunctionType *Ty, LinkageTypes Linkage,
     ParentModule->getFunctionList().push_back(this);
 }
 
-void Function::destroyThis(Function*v) {
-  v->dropAllReferences();    // After this it is safe to delete instructions.
+Function::~Function() {
+  dropAllReferences();    // After this it is safe to delete instructions.
 
   // Delete all of the method arguments and unlink from symbol table...
-  v->ArgumentList.clear();
-  delete v->SymTab;
+  ArgumentList.clear();
+  delete SymTab;
 
   // Drop our reference to the parameter attributes, if any.
-  if (v->ParamAttrs)
-    v->ParamAttrs->dropRef();
-  GlobalValue::destroyThis(v);
+  if (ParamAttrs)
+    ParamAttrs->dropRef();
 }
 
 void Function::BuildLazyArguments() const {
diff --git a/lib/VMCore/InlineAsm.cpp b/lib/VMCore/InlineAsm.cpp
index 4b42237..ca4ecad 100644
--- a/lib/VMCore/InlineAsm.cpp
+++ b/lib/VMCore/InlineAsm.cpp
@@ -17,6 +17,12 @@
 #include <cctype>
 using namespace llvm;
 
+// Implement the first virtual method in this class in this file so the
+// InlineAsm vtable is emitted here.
+InlineAsm::~InlineAsm() {
+}
+
+
 // NOTE: when memoizing the function type, we have to be careful to handle the
 // case when the type gets refined.
 
diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index fdee5e8..7fc6245 100644
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -46,8 +46,8 @@ Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
 
 
 // Out of line virtual method, so the vtable, etc has a home.
-void Instruction::destroyThis(Instruction*v) {
-  assert(v->Parent == 0 && "Instruction still linked in the program!");
+Instruction::~Instruction() {
+  assert(Parent == 0 && "Instruction still linked in the program!");
 }
 
 
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 84adc50..0df0466 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -67,6 +67,20 @@ bool CallSite::onlyReadsMemory() const {
 }
 
 
+
+//===----------------------------------------------------------------------===//
+//                            TerminatorInst Class
+//===----------------------------------------------------------------------===//
+
+// Out of line virtual method, so the vtable, etc has a home.
+TerminatorInst::~TerminatorInst() {
+}
+
+// Out of line virtual method, so the vtable, etc has a home.
+UnaryInstruction::~UnaryInstruction() {
+}
+
+
 //===----------------------------------------------------------------------===//
 //                               PHINode Class
 //===----------------------------------------------------------------------===//
@@ -82,9 +96,8 @@ PHINode::PHINode(const PHINode &PN)
   }
 }
 
-void PHINode::destroyThis(PHINode*v) {
-  delete [] v->OperandList;
-  Instruction::destroyThis(v);
+PHINode::~PHINode() {
+  delete [] OperandList;
 }
 
 // removeIncomingValue - Remove an incoming value.  This is useful if a
@@ -201,11 +214,10 @@ Value *PHINode::hasConstantValue(bool AllowNonDominatingInstruction) const {
 //                        CallInst Implementation
 //===----------------------------------------------------------------------===//
 
-void CallInst::destroyThis(CallInst*v) {
-  delete [] v->OperandList;
-  if (v->ParamAttrs)
-    v->ParamAttrs->dropRef();
-  Instruction::destroyThis(v);
+CallInst::~CallInst() {
+  delete [] OperandList;
+  if (ParamAttrs)
+    ParamAttrs->dropRef();
 }
 
 void CallInst::init(Value *Func, Value* const *Params, unsigned NumParams) {
@@ -394,11 +406,10 @@ bool CallInst::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
 //                        InvokeInst Implementation
 //===----------------------------------------------------------------------===//
 
-void InvokeInst::destroyThis(InvokeInst*v) {
-  delete [] v->OperandList;
-  if (v->ParamAttrs)
-    v->ParamAttrs->dropRef();
-  TerminatorInst::destroyThis(v);
+InvokeInst::~InvokeInst() {
+  delete [] OperandList;
+  if (ParamAttrs)
+    ParamAttrs->dropRef();
 }
 
 void InvokeInst::init(Value *Fn, BasicBlock *IfNormal, BasicBlock *IfException,
@@ -672,6 +683,10 @@ AllocationInst::AllocationInst(const Type *Ty, Value *ArraySize, unsigned iTy,
   setName(Name);
 }
 
+// Out of line virtual method, so the vtable, etc has a home.
+AllocationInst::~AllocationInst() {
+}
+
 bool AllocationInst::isArrayAllocation() const {
   if (ConstantInt *CI = dyn_cast<ConstantInt>(getOperand(0)))
     return CI->getZExtValue() != 1;
@@ -936,8 +951,8 @@ GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,
   setName(Name);
 }
 
-void GetElementPtrInst::destroyThis(GetElementPtrInst*v) {
-  delete[] v->OperandList;
+GetElementPtrInst::~GetElementPtrInst() {
+  delete[] OperandList;
 }
 
 // getIndexedType - Returns the type of the element that would be loaded with
@@ -2454,9 +2469,8 @@ SwitchInst::SwitchInst(const SwitchInst &SI)
   }
 }
 
-void SwitchInst::destroyThis(SwitchInst*v) {
-  delete [] v->OperandList;
-  TerminatorInst::destroyThis(v);
+SwitchInst::~SwitchInst() {
+  delete [] OperandList;
 }
 
 
diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp
index cbedcfa..de6c16b 100644
--- a/lib/VMCore/Value.cpp
+++ b/lib/VMCore/Value.cpp
@@ -18,11 +18,6 @@
 #include "llvm/ValueSymbolTable.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/LeakDetector.h"
-#include "llvm/Constants.h"
-#include "llvm/InlineAsm.h"
-#include "llvm/Instructions.h"
-#include "llvm/IntrinsicInst.h"
-#include "llvm/InstrTypes.h"
 #include <algorithm>
 using namespace llvm;
 
@@ -44,194 +39,7 @@ Value::Value(const Type *ty, unsigned scid)
            "Cannot create non-first-class values except for constants!");
 }
 
-Value::~Value() 
-{
-  switch(SubclassID)
-  {
-  case ArgumentVal:
-    Argument::destroyThis(cast<Argument>(this));
-    break;
-  case BasicBlockVal:
-    BasicBlock::destroyThis(cast<BasicBlock>(this));
-    break;
-  case FunctionVal:
-    Function::destroyThis(cast<Function>(this));
-    break;
-  case GlobalAliasVal:
-    GlobalAlias::destroyThis(cast<GlobalAlias>(this));
-    break;
-  case GlobalVariableVal:
-    GlobalVariable::destroyThis(cast<GlobalVariable>(this));
-    break;
-  case UndefValueVal:
-    UndefValue::destroyThis(cast<UndefValue>(this));
-    break;
-  case ConstantExprVal:
-    {
-      ConstantExpr* CE = dyn_cast<ConstantExpr>(this);
-      if(CE->getOpcode() == Instruction::GetElementPtr)
-      {
-        GetElementPtrConstantExpr* GECE = 
-          dyn_cast<GetElementPtrConstantExpr>(CE);
-        GetElementPtrConstantExpr::destroyThis(GECE);
-      }
-      else if(CE->getOpcode() == Instruction::ExtractElement)
-      {
-        ExtractElementConstantExpr* EECE = 
-          dyn_cast<ExtractElementConstantExpr>(CE);
-        ExtractElementConstantExpr::destroyThis(EECE);
-      }
-      else if(CE->getOpcode() == Instruction::InsertElement)
-      {
-        InsertElementConstantExpr* IECE = 
-          dyn_cast<InsertElementConstantExpr>(CE);
-        InsertElementConstantExpr::destroyThis(IECE);
-      }
-      else if(CE->getOpcode() == Instruction::Select)
-      {
-        SelectConstantExpr* SCE = dyn_cast<SelectConstantExpr>(CE);
-        SelectConstantExpr::destroyThis(SCE);
-      }
-      else if(CE->getOpcode() == Instruction::ShuffleVector)
-      {
-        ShuffleVectorConstantExpr* SVCE = 
-          dyn_cast<ShuffleVectorConstantExpr>(CE);
-        ShuffleVectorConstantExpr::destroyThis(SVCE);
-      }
-      else if(BinaryConstantExpr* BCE = dyn_cast<BinaryConstantExpr>(this))
-        BinaryConstantExpr::destroyThis(BCE);
-      else if(UnaryConstantExpr* UCE = dyn_cast<UnaryConstantExpr>(this))
-        UnaryConstantExpr::destroyThis(UCE);
-      else if(CompareConstantExpr* CCE = dyn_cast<CompareConstantExpr>(this))
-        CompareConstantExpr::destroyThis(CCE);
-      else
-        assert(0 && "Unknown ConstantExpr-inherited class in ~Value.");
-    }
-    break;
-  case ConstantAggregateZeroVal:
-    ConstantAggregateZero::destroyThis(cast<ConstantAggregateZero>(this));
-    break;
-  case ConstantIntVal:          
-    ConstantInt::destroyThis(cast<ConstantInt>(this));
-    break;
-  case ConstantFPVal:         
-    ConstantFP::destroyThis(cast<ConstantFP>(this));
-    break;
-  case ConstantArrayVal:      
-    ConstantArray::destroyThis(cast<ConstantArray>(this));
-    break;
-  case ConstantStructVal:       
-    ConstantStruct::destroyThis(cast<ConstantStruct>(this));
-    break;
-  case ConstantVectorVal:     
-    ConstantVector::destroyThis(cast<ConstantVector>(this));
-    break;
-  case ConstantPointerNullVal:   
-    ConstantPointerNull::destroyThis(cast<ConstantPointerNull>(this));
-    break;
-  case InlineAsmVal:         
-    InlineAsm::destroyThis(cast<InlineAsm>(this));
-    break;
-
-  default:
-    if (BinaryOperator *BO = dyn_cast<BinaryOperator>(this))
-      BinaryOperator::destroyThis(BO);
-    else if (CallInst *CI = dyn_cast<CallInst>(this))
-      CallInst::destroyThis(CI);
-    else if (CmpInst *CI = dyn_cast<CmpInst>(this))
-    {
-      if (FCmpInst *FCI = dyn_cast<FCmpInst>(CI))
-        FCmpInst::destroyThis(FCI);
-      else if (ICmpInst *ICI = dyn_cast<ICmpInst>(CI))
-        ICmpInst::destroyThis(ICI);
-      else
-        assert(0 && "Unknown CmpInst-inherited class in ~Value.");
-    }
-    else if (ExtractElementInst *EEI = dyn_cast<ExtractElementInst>(this))
-      ExtractElementInst::destroyThis(EEI);
-    else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(this))
-      GetElementPtrInst::destroyThis(GEP);
-    else if (InsertElementInst* IE = dyn_cast<InsertElementInst>(this))
-      InsertElementInst::destroyThis(IE);
-    else if (PHINode *PN = dyn_cast<PHINode>(this))
-      PHINode::destroyThis(PN);
-    else if (SelectInst *SI = dyn_cast<SelectInst>(this))
-      SelectInst::destroyThis(SI);
-    else if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(this))
-      ShuffleVectorInst::destroyThis(SVI);
-    else if (StoreInst *SI = dyn_cast<StoreInst>(this))
-      StoreInst::destroyThis(SI);
-    else if (TerminatorInst *TI = dyn_cast<TerminatorInst>(this))
-    {
-      if (BranchInst* BI = dyn_cast<BranchInst>(TI))
-        BranchInst::destroyThis(BI);
-      else if (InvokeInst* II = dyn_cast<InvokeInst>(TI))
-        InvokeInst::destroyThis(II);
-      else if (ReturnInst* RI = dyn_cast<ReturnInst>(TI))
-        ReturnInst::destroyThis(RI);
-      else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI))
-        SwitchInst::destroyThis(SI);
-      else if (UnreachableInst *UI = dyn_cast<UnreachableInst>(TI))
-        UnreachableInst::destroyThis(UI);
-      else if (UnwindInst *UI = dyn_cast<UnwindInst>(TI))
-        UnwindInst::destroyThis(UI);
-      else
-        assert(0 && "Unknown TerminatorInst-inherited class in ~Value.");
-    } else if(UnaryInstruction* UI = dyn_cast<UnaryInstruction>(this)) {
-      if(AllocationInst* AI = dyn_cast<AllocationInst>(UI)) {
-        if(AllocaInst* AI = dyn_cast<AllocaInst>(UI))
-          AllocaInst::destroyThis(AI);
-        else if(MallocInst* MI = dyn_cast<MallocInst>(UI))
-          MallocInst::destroyThis(MI);
-        else
-          assert(0 && "Unknown AllocationInst-inherited class in ~Value.");
-      } else if(CastInst* CI = dyn_cast<CastInst>(this)) {
-        if(BitCastInst* BCI = dyn_cast<BitCastInst>(CI))
-          BitCastInst::destroyThis(BCI);
-        else if(FPExtInst* FPEI = dyn_cast<FPExtInst>(CI))
-          FPExtInst::destroyThis(FPEI);
-        else if(FPToSIInst* FPSII = dyn_cast<FPToSIInst>(CI))
-          FPToSIInst::destroyThis(FPSII);
-        else if(FPToUIInst* FPUII = dyn_cast<FPToUIInst>(CI))
-          FPToUIInst::destroyThis(FPUII);
-        else if(FPTruncInst* FPTI = dyn_cast<FPTruncInst>(CI))
-          FPTruncInst::destroyThis(FPTI);
-        else if(IntToPtrInst* I2PI = dyn_cast<IntToPtrInst>(CI))
-          IntToPtrInst::destroyThis(I2PI);
-        else if(PtrToIntInst* P2II = dyn_cast<PtrToIntInst>(CI))
-          PtrToIntInst::destroyThis(P2II);
-        else if(SExtInst* SEI = dyn_cast<SExtInst>(CI))
-          SExtInst::destroyThis(SEI);
-        else if(SIToFPInst* SIFPI = dyn_cast<SIToFPInst>(CI))
-          SIToFPInst::destroyThis(SIFPI);
-        else if(TruncInst* TI = dyn_cast<TruncInst>(CI))
-          TruncInst::destroyThis(TI);
-        else if(UIToFPInst* UIFPI = dyn_cast<UIToFPInst>(CI))
-          UIToFPInst::destroyThis(UIFPI);
-        else if(ZExtInst* ZEI = dyn_cast<ZExtInst>(CI))
-          ZExtInst::destroyThis(ZEI);
-        else
-          assert(0 && "Unknown CastInst-inherited class in ~Value.");
-      }
-      else if(FreeInst* FI = dyn_cast<FreeInst>(this))
-        FreeInst::destroyThis(FI);
-      else if(LoadInst* LI = dyn_cast<LoadInst>(this))
-        LoadInst::destroyThis(LI);
-      else if(VAArgInst* VAI = dyn_cast<VAArgInst>(this))
-        VAArgInst::destroyThis(VAI);
-      else
-        assert(0 && "Unknown UnaryInstruction-inherited class in ~Value.");
-    }
-    else if (DummyInst *DI = dyn_cast<DummyInst>(this))
-      DummyInst::destroyThis(DI);
-    else
-      assert(0 && "Unknown Instruction-inherited class in ~Value.");
-    break;
-  }
-}
-
-void Value::destroyThis(Value*v)
-{
+Value::~Value() {
 #ifndef NDEBUG      // Only in -g mode...
   // Check to make sure that there are no uses of this value that are still
   // around when the value is destroyed.  If there are, then we have a dangling
@@ -239,22 +47,22 @@ void Value::destroyThis(Value*v)
   // still being referenced.  The value in question should be printed as
   // a <badref>
   //
-  if (!v->use_empty()) {
-    DOUT << "While deleting: " << *v->Ty << " %" << v->Name << "\n";
-    for (use_iterator I = v->use_begin(), E = v->use_end(); I != E; ++I)
+  if (!use_empty()) {
+    DOUT << "While deleting: " << *Ty << " %" << Name << "\n";
+    for (use_iterator I = use_begin(), E = use_end(); I != E; ++I)
       DOUT << "Use still stuck around after Def is destroyed:"
            << **I << "\n";
   }
 #endif
-  assert(v->use_empty() && "Uses remain when a value is destroyed!");
+  assert(use_empty() && "Uses remain when a value is destroyed!");
 
   // If this value is named, destroy the name.  This should not be in a symtab
   // at this point.
-  if (v->Name)
-    v->Name->Destroy();
+  if (Name)
+    Name->Destroy();
   
   // There should be no uses of this object anymore, remove it.
-  LeakDetector::removeGarbageObject(v);
+  LeakDetector::removeGarbageObject(this);
 }
 
 /// hasNUses - Return true if this Value has exactly N users.