diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 88a4a27..8c64366 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -53,12 +53,15 @@
         delete this;
     }
 
+    const ScalarEvolution* parent;
+
     SCEV(const SCEV &);            // DO NOT IMPLEMENT
     void operator=(const SCEV &);  // DO NOT IMPLEMENT
   protected:
     virtual ~SCEV();
   public:
-    explicit SCEV(unsigned SCEVTy) : SCEVType(SCEVTy), RefCount(0) {}
+    explicit SCEV(unsigned SCEVTy, const ScalarEvolution* p) : 
+      SCEVType(SCEVTy), RefCount(0), parent(p) {}
 
     unsigned getSCEVType() const { return SCEVType; }
 
@@ -126,7 +129,7 @@
   /// None of the standard SCEV operations are valid on this class, it is just a
   /// marker.
   struct SCEVCouldNotCompute : public SCEV {
-    SCEVCouldNotCompute();
+    SCEVCouldNotCompute(const ScalarEvolution* p);
     ~SCEVCouldNotCompute();
 
     // None of these methods are valid for this object.
@@ -205,13 +208,13 @@
   template<>
   struct DenseMapInfo<SCEVHandle> {
     static inline SCEVHandle getEmptyKey() {
-      static SCEVCouldNotCompute Empty;
+      static SCEVCouldNotCompute Empty(0);
       if (Empty.RefCount == 0)
         Empty.addRef();
       return &Empty;
     }
     static inline SCEVHandle getTombstoneKey() {
-      static SCEVCouldNotCompute Tombstone;
+      static SCEVCouldNotCompute Tombstone(0);
       if (Tombstone.RefCount == 0)
         Tombstone.addRef();
       return &Tombstone;
diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index ced220a..2842356 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -36,7 +36,8 @@
     friend class ScalarEvolution;
 
     ConstantInt *V;
-    explicit SCEVConstant(ConstantInt *v) : SCEV(scConstant), V(v) {}
+    explicit SCEVConstant(ConstantInt *v, const ScalarEvolution* p) :
+      SCEV(scConstant, p), V(v) {}
 
     virtual ~SCEVConstant();
   public:
@@ -79,7 +80,8 @@
     SCEVHandle Op;
     const Type *Ty;
 
-    SCEVCastExpr(unsigned SCEVTy, const SCEVHandle &op, const Type *ty);
+    SCEVCastExpr(unsigned SCEVTy, const SCEVHandle &op, const Type *ty,
+                 const ScalarEvolution* p);
     virtual ~SCEVCastExpr();
 
   public:
@@ -112,7 +114,8 @@
   class SCEVTruncateExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
+    SCEVTruncateExpr(const SCEVHandle &op, const Type *ty,
+                     const ScalarEvolution* p);
     virtual ~SCEVTruncateExpr();
 
   public:
@@ -141,7 +144,8 @@
   class SCEVZeroExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty);
+    SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty,
+                       const ScalarEvolution* p);
     virtual ~SCEVZeroExtendExpr();
 
   public:
@@ -170,7 +174,8 @@
   class SCEVSignExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty);
+    SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty,
+                       const ScalarEvolution* p);
     virtual ~SCEVSignExtendExpr();
 
   public:
@@ -201,8 +206,9 @@
   protected:
     SmallVector<SCEVHandle, 8> Operands;
 
-    SCEVNAryExpr(enum SCEVTypes T, const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEV(T), Operands(ops.begin(), ops.end()) {}
+    SCEVNAryExpr(enum SCEVTypes T, const SmallVectorImpl<SCEVHandle> &ops,
+                 const ScalarEvolution* p)
+      : SCEV(T, p), Operands(ops.begin(), ops.end()) {}
     virtual ~SCEVNAryExpr() {}
 
   public:
@@ -259,8 +265,10 @@
   ///
   class SCEVCommutativeExpr : public SCEVNAryExpr {
   protected:
-    SCEVCommutativeExpr(enum SCEVTypes T, const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEVNAryExpr(T, ops) {}
+    SCEVCommutativeExpr(enum SCEVTypes T,
+                        const SmallVectorImpl<SCEVHandle> &ops,
+                        const ScalarEvolution* p)
+      : SCEVNAryExpr(T, ops, p) {}
     ~SCEVCommutativeExpr();
 
   public:
@@ -289,8 +297,9 @@
   class SCEVAddExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVAddExpr(const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEVCommutativeExpr(scAddExpr, ops) {
+    explicit SCEVAddExpr(const SmallVectorImpl<SCEVHandle> &ops,
+                         const ScalarEvolution* p)
+      : SCEVCommutativeExpr(scAddExpr, ops, p) {
     }
 
   public:
@@ -309,8 +318,9 @@
   class SCEVMulExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVMulExpr(const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEVCommutativeExpr(scMulExpr, ops) {
+    explicit SCEVMulExpr(const SmallVectorImpl<SCEVHandle> &ops,
+                         const ScalarEvolution* p)
+      : SCEVCommutativeExpr(scMulExpr, ops, p) {
     }
 
   public:
@@ -331,8 +341,9 @@
     friend class ScalarEvolution;
 
     SCEVHandle LHS, RHS;
-    SCEVUDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs)
-      : SCEV(scUDivExpr), LHS(lhs), RHS(rhs) {}
+    SCEVUDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs,
+                 const ScalarEvolution* p)
+      : SCEV(scUDivExpr, p), LHS(lhs), RHS(rhs) {}
 
     virtual ~SCEVUDivExpr();
   public:
@@ -387,8 +398,9 @@
 
     const Loop *L;
 
-    SCEVAddRecExpr(const SmallVectorImpl<SCEVHandle> &ops, const Loop *l)
-      : SCEVNAryExpr(scAddRecExpr, ops), L(l) {
+    SCEVAddRecExpr(const SmallVectorImpl<SCEVHandle> &ops, const Loop *l,
+                   const ScalarEvolution* p)
+      : SCEVNAryExpr(scAddRecExpr, ops, p), L(l) {
       for (size_t i = 0, e = Operands.size(); i != e; ++i)
         assert(Operands[i]->isLoopInvariant(l) &&
                "Operands of AddRec must be loop-invariant!");
@@ -463,8 +475,9 @@
   class SCEVSMaxExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVSMaxExpr(const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEVCommutativeExpr(scSMaxExpr, ops) {
+    explicit SCEVSMaxExpr(const SmallVectorImpl<SCEVHandle> &ops,
+                          const ScalarEvolution* p)
+      : SCEVCommutativeExpr(scSMaxExpr, ops, p) {
     }
 
   public:
@@ -484,8 +497,9 @@
   class SCEVUMaxExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVUMaxExpr(const SmallVectorImpl<SCEVHandle> &ops)
-      : SCEVCommutativeExpr(scUMaxExpr, ops) {
+    explicit SCEVUMaxExpr(const SmallVectorImpl<SCEVHandle> &ops,
+                          const ScalarEvolution* p)
+      : SCEVCommutativeExpr(scUMaxExpr, ops, p) {
     }
 
   public:
@@ -508,7 +522,8 @@
     friend class ScalarEvolution;
 
     Value *V;
-    explicit SCEVUnknown(Value *v) : SCEV(scUnknown), V(v) {}
+    explicit SCEVUnknown(Value *v, const ScalarEvolution* p) :
+      SCEV(scUnknown, p), V(v) {}
 
   protected:
     ~SCEVUnknown();
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 18c136f..94b75ba 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -133,7 +133,8 @@
   return false;
 }
 
-SCEVCouldNotCompute::SCEVCouldNotCompute() : SCEV(scCouldNotCompute) {}
+SCEVCouldNotCompute::SCEVCouldNotCompute(const ScalarEvolution* p) :
+  SCEV(scCouldNotCompute, p) {}
 SCEVCouldNotCompute::~SCEVCouldNotCompute() {}
 
 bool SCEVCouldNotCompute::isLoopInvariant(const Loop *L) const {
@@ -179,7 +180,7 @@
 
 SCEVHandle ScalarEvolution::getConstant(ConstantInt *V) {
   SCEVConstant *&R = (*SCEVConstants)[V];
-  if (R == 0) R = new SCEVConstant(V);
+  if (R == 0) R = new SCEVConstant(V, this);
   return R;
 }
 
@@ -199,8 +200,9 @@
 }
 
 SCEVCastExpr::SCEVCastExpr(unsigned SCEVTy,
-                           const SCEVHandle &op, const Type *ty)
-  : SCEV(SCEVTy), Op(op), Ty(ty) {}
+                           const SCEVHandle &op, const Type *ty,
+                           const ScalarEvolution* p)
+  : SCEV(SCEVTy, p), Op(op), Ty(ty) {}
 
 SCEVCastExpr::~SCEVCastExpr() {}
 
@@ -214,8 +216,9 @@
 static ManagedStatic<std::map<std::pair<const SCEV*, const Type*>, 
                      SCEVTruncateExpr*> > SCEVTruncates;
 
-SCEVTruncateExpr::SCEVTruncateExpr(const SCEVHandle &op, const Type *ty)
-  : SCEVCastExpr(scTruncate, op, ty) {
+SCEVTruncateExpr::SCEVTruncateExpr(const SCEVHandle &op, const Type *ty,
+                                   const ScalarEvolution* p)
+  : SCEVCastExpr(scTruncate, op, ty, p) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot truncate non-integer value!");
@@ -235,8 +238,9 @@
 static ManagedStatic<std::map<std::pair<const SCEV*, const Type*>,
                      SCEVZeroExtendExpr*> > SCEVZeroExtends;
 
-SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty)
-  : SCEVCastExpr(scZeroExtend, op, ty) {
+SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty,
+                                       const ScalarEvolution* p)
+  : SCEVCastExpr(scZeroExtend, op, ty, p) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot zero extend non-integer value!");
@@ -256,8 +260,9 @@
 static ManagedStatic<std::map<std::pair<const SCEV*, const Type*>,
                      SCEVSignExtendExpr*> > SCEVSignExtends;
 
-SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty)
-  : SCEVCastExpr(scSignExtend, op, ty) {
+SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty,
+                                       const ScalarEvolution* p)
+  : SCEVCastExpr(scSignExtend, op, ty, p) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot sign extend non-integer value!");
@@ -787,7 +792,7 @@
   }
 
   SCEVTruncateExpr *&Result = (*SCEVTruncates)[std::make_pair(Op, Ty)];
-  if (Result == 0) Result = new SCEVTruncateExpr(Op, Ty);
+  if (Result == 0) Result = new SCEVTruncateExpr(Op, Ty, this);
   return Result;
 }
 
@@ -875,7 +880,7 @@
     }
 
   SCEVZeroExtendExpr *&Result = (*SCEVZeroExtends)[std::make_pair(Op, Ty)];
-  if (Result == 0) Result = new SCEVZeroExtendExpr(Op, Ty);
+  if (Result == 0) Result = new SCEVZeroExtendExpr(Op, Ty, this);
   return Result;
 }
 
@@ -947,7 +952,7 @@
     }
 
   SCEVSignExtendExpr *&Result = (*SCEVSignExtends)[std::make_pair(Op, Ty)];
-  if (Result == 0) Result = new SCEVSignExtendExpr(Op, Ty);
+  if (Result == 0) Result = new SCEVSignExtendExpr(Op, Ty, this);
   return Result;
 }
 
@@ -1409,7 +1414,7 @@
   std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
   SCEVCommutativeExpr *&Result = (*SCEVCommExprs)[std::make_pair(scAddExpr,
                                                                  SCEVOps)];
-  if (Result == 0) Result = new SCEVAddExpr(Ops);
+  if (Result == 0) Result = new SCEVAddExpr(Ops, this);
   return Result;
 }
 
@@ -1575,7 +1580,7 @@
   SCEVCommutativeExpr *&Result = (*SCEVCommExprs)[std::make_pair(scMulExpr,
                                                                  SCEVOps)];
   if (Result == 0)
-    Result = new SCEVMulExpr(Ops);
+    Result = new SCEVMulExpr(Ops, this);
   return Result;
 }
 
@@ -1666,7 +1671,7 @@
   }
 
   SCEVUDivExpr *&Result = (*SCEVUDivs)[std::make_pair(LHS, RHS)];
-  if (Result == 0) Result = new SCEVUDivExpr(LHS, RHS);
+  if (Result == 0) Result = new SCEVUDivExpr(LHS, RHS, this);
   return Result;
 }
 
@@ -1720,7 +1725,7 @@
 
   std::vector<const SCEV*> SCEVOps(Operands.begin(), Operands.end());
   SCEVAddRecExpr *&Result = (*SCEVAddRecExprs)[std::make_pair(L, SCEVOps)];
-  if (Result == 0) Result = new SCEVAddRecExpr(Operands, L);
+  if (Result == 0) Result = new SCEVAddRecExpr(Operands, L, this);
   return Result;
 }
 
@@ -1807,7 +1812,7 @@
   std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
   SCEVCommutativeExpr *&Result = (*SCEVCommExprs)[std::make_pair(scSMaxExpr,
                                                                  SCEVOps)];
-  if (Result == 0) Result = new SCEVSMaxExpr(Ops);
+  if (Result == 0) Result = new SCEVSMaxExpr(Ops, this);
   return Result;
 }
 
@@ -1894,7 +1899,7 @@
   std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
   SCEVCommutativeExpr *&Result = (*SCEVCommExprs)[std::make_pair(scUMaxExpr,
                                                                  SCEVOps)];
-  if (Result == 0) Result = new SCEVUMaxExpr(Ops);
+  if (Result == 0) Result = new SCEVUMaxExpr(Ops, this);
   return Result;
 }
 
@@ -1904,7 +1909,7 @@
   if (isa<ConstantPointerNull>(V))
     return getIntegerSCEV(0, V->getType());
   SCEVUnknown *&Result = (*SCEVUnknowns)[V];
-  if (Result == 0) Result = new SCEVUnknown(V);
+  if (Result == 0) Result = new SCEVUnknown(V, this);
   return Result;
 }
 
@@ -3978,7 +3983,7 @@
 //===----------------------------------------------------------------------===//
 
 ScalarEvolution::ScalarEvolution()
-  : FunctionPass(&ID), CouldNotCompute(new SCEVCouldNotCompute()) {
+  : FunctionPass(&ID), CouldNotCompute(new SCEVCouldNotCompute(0)) {
 }
 
 bool ScalarEvolution::runOnFunction(Function &F) {