Convert SCEV from FoldingSetNode to FastFoldingSetNode. This eliminates

a bunch of redundent code in Profile methods, and prepares for upcoming
changes to do improved memoization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75494 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 78 insertions, 110 deletions

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index ba53550499..0224c00ba1 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -42,7 +42,7 @@ namespace llvm {
   /// are opaque objects that the client is not allowed to do much with
   /// directly.
   ///
-  class SCEV : public FoldingSetNode {
+  class SCEV : public FastFoldingSetNode {
     const unsigned SCEVType;      // The SCEV baseclass this node corresponds to
 
     SCEV(const SCEV &);            // DO NOT IMPLEMENT
@@ -50,10 +50,8 @@ namespace llvm {
   protected:
     virtual ~SCEV();
   public:
-    explicit SCEV(unsigned SCEVTy) :
-      SCEVType(SCEVTy) {}
-
-    virtual void Profile(FoldingSetNodeID &ID) const = 0;
+    explicit SCEV(const FoldingSetNodeID &ID, unsigned SCEVTy) :
+      FastFoldingSetNode(ID), SCEVType(SCEVTy) {}
 
     unsigned getSCEVType() const { return SCEVType; }
 
@@ -129,7 +127,6 @@ namespace llvm {
     SCEVCouldNotCompute();
 
     // None of these methods are valid for this object.
-    virtual void Profile(FoldingSetNodeID &ID) const;
     virtual bool isLoopInvariant(const Loop *L) const;
     virtual const Type *getType() const;
     virtual bool hasComputableLoopEvolution(const Loop *L) const;
diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index a8fa4bbc5f..1c900cabfa 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -37,11 +37,9 @@ namespace llvm {
     friend class ScalarEvolution;
 
     ConstantInt *V;
-    explicit SCEVConstant(ConstantInt *v) :
-      SCEV(scConstant), V(v) {}
+    SCEVConstant(const FoldingSetNodeID &ID, ConstantInt *v) :
+      SCEV(ID, scConstant), V(v) {}
   public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
-
     ConstantInt *getValue() const { return V; }
 
     virtual bool isLoopInvariant(const Loop *L) const {
@@ -81,11 +79,10 @@ namespace llvm {
     const SCEV *Op;
     const Type *Ty;
 
-    SCEVCastExpr(unsigned SCEVTy, const SCEV *op, const Type *ty);
+    SCEVCastExpr(const FoldingSetNodeID &ID,
+                 unsigned SCEVTy, const SCEV *op, const Type *ty);
 
   public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
-
     const SCEV *getOperand() const { return Op; }
     virtual const Type *getType() const { return Ty; }
 
@@ -115,7 +112,8 @@ namespace llvm {
   class SCEVTruncateExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVTruncateExpr(const SCEV *op, const Type *ty);
+    SCEVTruncateExpr(const FoldingSetNodeID &ID,
+                     const SCEV *op, const Type *ty);
 
   public:
     const SCEV *replaceSymbolicValuesWithConcrete(const SCEV *Sym,
@@ -143,7 +141,8 @@ namespace llvm {
   class SCEVZeroExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVZeroExtendExpr(const SCEV *op, const Type *ty);
+    SCEVZeroExtendExpr(const FoldingSetNodeID &ID,
+                       const SCEV *op, const Type *ty);
 
   public:
     const SCEV *replaceSymbolicValuesWithConcrete(const SCEV *Sym,
@@ -171,7 +170,8 @@ namespace llvm {
   class SCEVSignExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVSignExtendExpr(const SCEV *op, const Type *ty);
+    SCEVSignExtendExpr(const FoldingSetNodeID &ID,
+                       const SCEV *op, const Type *ty);
 
   public:
     const SCEV *replaceSymbolicValuesWithConcrete(const SCEV *Sym,
@@ -201,12 +201,11 @@ namespace llvm {
   protected:
     SmallVector<const SCEV *, 8> Operands;
 
-    SCEVNAryExpr(enum SCEVTypes T, const SmallVectorImpl<const SCEV *> &ops)
-      : SCEV(T), Operands(ops.begin(), ops.end()) {}
+    SCEVNAryExpr(const FoldingSetNodeID &ID,
+                 enum SCEVTypes T, const SmallVectorImpl<const SCEV *> &ops)
+      : SCEV(ID, T), Operands(ops.begin(), ops.end()) {}
 
   public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
-
     unsigned getNumOperands() const { return (unsigned)Operands.size(); }
     const SCEV *getOperand(unsigned i) const {
       assert(i < Operands.size() && "Operand index out of range!");
@@ -262,9 +261,10 @@ namespace llvm {
   ///
   class SCEVCommutativeExpr : public SCEVNAryExpr {
   protected:
-    SCEVCommutativeExpr(enum SCEVTypes T,
+    SCEVCommutativeExpr(const FoldingSetNodeID &ID,
+                        enum SCEVTypes T,
                         const SmallVectorImpl<const SCEV *> &ops)
-      : SCEVNAryExpr(T, ops) {}
+      : SCEVNAryExpr(ID, T, ops) {}
 
   public:
     const SCEV *replaceSymbolicValuesWithConcrete(const SCEV *Sym,
@@ -292,8 +292,9 @@ namespace llvm {
   class SCEVAddExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVAddExpr(const SmallVectorImpl<const SCEV *> &ops)
-      : SCEVCommutativeExpr(scAddExpr, ops) {
+    SCEVAddExpr(const FoldingSetNodeID &ID,
+                const SmallVectorImpl<const SCEV *> &ops)
+      : SCEVCommutativeExpr(ID, scAddExpr, ops) {
     }
 
   public:
@@ -312,8 +313,9 @@ namespace llvm {
   class SCEVMulExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVMulExpr(const SmallVectorImpl<const SCEV *> &ops)
-      : SCEVCommutativeExpr(scMulExpr, ops) {
+    SCEVMulExpr(const FoldingSetNodeID &ID,
+                const SmallVectorImpl<const SCEV *> &ops)
+      : SCEVCommutativeExpr(ID, scMulExpr, ops) {
     }
 
   public:
@@ -335,12 +337,10 @@ namespace llvm {
 
     const SCEV *LHS;
     const SCEV *RHS;
-    SCEVUDivExpr(const SCEV *lhs, const SCEV *rhs)
-      : SCEV(scUDivExpr), LHS(lhs), RHS(rhs) {}
+    SCEVUDivExpr(const FoldingSetNodeID &ID, const SCEV *lhs, const SCEV *rhs)
+      : SCEV(ID, scUDivExpr), LHS(lhs), RHS(rhs) {}
 
   public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
-
     const SCEV *getLHS() const { return LHS; }
     const SCEV *getRHS() const { return RHS; }
 
@@ -392,16 +392,15 @@ namespace llvm {
 
     const Loop *L;
 
-    SCEVAddRecExpr(const SmallVectorImpl<const SCEV *> &ops, const Loop *l)
-      : SCEVNAryExpr(scAddRecExpr, ops), L(l) {
+    SCEVAddRecExpr(const FoldingSetNodeID &ID,
+                   const SmallVectorImpl<const SCEV *> &ops, const Loop *l)
+      : SCEVNAryExpr(ID, scAddRecExpr, ops), 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!");
     }
 
   public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
-
     const SCEV *getStart() const { return Operands[0]; }
     const Loop *getLoop() const { return L; }
 
@@ -454,6 +453,12 @@ namespace llvm {
                                                  const SCEV *Conc,
                                                  ScalarEvolution &SE) const;
 
+    /// getPostIncExpr - Return an expression representing the value of
+    /// this expression one iteration of the loop ahead.
+    const SCEV *getPostIncExpr(ScalarEvolution &SE) const {
+      return SE.getAddExpr(this, getStepRecurrence(SE));
+    }
+
     virtual void print(raw_ostream &OS) const;
 
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
@@ -470,8 +475,9 @@ namespace llvm {
   class SCEVSMaxExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVSMaxExpr(const SmallVectorImpl<const SCEV *> &ops)
-      : SCEVCommutativeExpr(scSMaxExpr, ops) {
+    SCEVSMaxExpr(const FoldingSetNodeID &ID,
+                 const SmallVectorImpl<const SCEV *> &ops)
+      : SCEVCommutativeExpr(ID, scSMaxExpr, ops) {
     }
 
   public:
@@ -491,8 +497,9 @@ namespace llvm {
   class SCEVUMaxExpr : public SCEVCommutativeExpr {
     friend class ScalarEvolution;
 
-    explicit SCEVUMaxExpr(const SmallVectorImpl<const SCEV *> &ops)
-      : SCEVCommutativeExpr(scUMaxExpr, ops) {
+    SCEVUMaxExpr(const FoldingSetNodeID &ID,
+                 const SmallVectorImpl<const SCEV *> &ops)
+      : SCEVCommutativeExpr(ID, scUMaxExpr, ops) {
     }
 
   public:
@@ -515,12 +522,10 @@ namespace llvm {
     friend class ScalarEvolution;
 
     Value *V;
-    explicit SCEVUnknown(Value *v) :
-      SCEV(scUnknown), V(v) {}
-      
-  public:
-    virtual void Profile(FoldingSetNodeID &ID) const;
+    SCEVUnknown(const FoldingSetNodeID &ID, Value *v) :
+      SCEV(ID, scUnknown), V(v) {}
 
+  public:
     Value *getValue() const { return V; }
 
     virtual bool isLoopInvariant(const Loop *L) const;
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index fc7d286aaf..815a6f21cd 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -145,11 +145,7 @@ bool SCEV::isAllOnesValue() const {
 }
 
 SCEVCouldNotCompute::SCEVCouldNotCompute() :
-  SCEV(scCouldNotCompute) {}
-
-void SCEVCouldNotCompute::Profile(FoldingSetNodeID &ID) const {
-  LLVM_UNREACHABLE("Attempt to use a SCEVCouldNotCompute object!");
-}
+  SCEV(FoldingSetNodeID(), scCouldNotCompute) {}
 
 bool SCEVCouldNotCompute::isLoopInvariant(const Loop *L) const {
   LLVM_UNREACHABLE("Attempt to use a SCEVCouldNotCompute object!");
@@ -189,7 +185,7 @@ const SCEV *ScalarEvolution::getConstant(ConstantInt *V) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVConstant>();
-  new (S) SCEVConstant(V);
+  new (S) SCEVConstant(ID, V);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -203,33 +199,23 @@ ScalarEvolution::getConstant(const Type *Ty, uint64_t V, bool isSigned) {
   return getConstant(ConstantInt::get(cast<IntegerType>(Ty), V, isSigned));
 }
 
-void SCEVConstant::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(scConstant);
-  ID.AddPointer(V);
-}
-
 const Type *SCEVConstant::getType() const { return V->getType(); }
 
 void SCEVConstant::print(raw_ostream &OS) const {
   WriteAsOperand(OS, V, false);
 }
 
-SCEVCastExpr::SCEVCastExpr(unsigned SCEVTy,
-                           const SCEV *op, const Type *ty)
-  : SCEV(SCEVTy), Op(op), Ty(ty) {}
-
-void SCEVCastExpr::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(getSCEVType());
-  ID.AddPointer(Op);
-  ID.AddPointer(Ty);
-}
+SCEVCastExpr::SCEVCastExpr(const FoldingSetNodeID &ID,
+                           unsigned SCEVTy, const SCEV *op, const Type *ty)
+  : SCEV(ID, SCEVTy), Op(op), Ty(ty) {}
 
 bool SCEVCastExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
   return Op->dominates(BB, DT);
 }
 
-SCEVTruncateExpr::SCEVTruncateExpr(const SCEV *op, const Type *ty)
-  : SCEVCastExpr(scTruncate, op, ty) {
+SCEVTruncateExpr::SCEVTruncateExpr(const FoldingSetNodeID &ID,
+                                   const SCEV *op, const Type *ty)
+  : SCEVCastExpr(ID, scTruncate, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot truncate non-integer value!");
@@ -239,8 +225,9 @@ void SCEVTruncateExpr::print(raw_ostream &OS) const {
   OS << "(trunc " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
 }
 
-SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEV *op, const Type *ty)
-  : SCEVCastExpr(scZeroExtend, op, ty) {
+SCEVZeroExtendExpr::SCEVZeroExtendExpr(const FoldingSetNodeID &ID,
+                                       const SCEV *op, const Type *ty)
+  : SCEVCastExpr(ID, scZeroExtend, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot zero extend non-integer value!");
@@ -250,8 +237,9 @@ void SCEVZeroExtendExpr::print(raw_ostream &OS) const {
   OS << "(zext " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
 }
 
-SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEV *op, const Type *ty)
-  : SCEVCastExpr(scSignExtend, op, ty) {
+SCEVSignExtendExpr::SCEVSignExtendExpr(const FoldingSetNodeID &ID,
+                                       const SCEV *op, const Type *ty)
+  : SCEVCastExpr(ID, scSignExtend, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot sign extend non-integer value!");
@@ -303,13 +291,6 @@ SCEVCommutativeExpr::replaceSymbolicValuesWithConcrete(
   return this;
 }
 
-void SCEVNAryExpr::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(getSCEVType());
-  ID.AddInteger(Operands.size());
-  for (unsigned i = 0, e = Operands.size(); i != e; ++i)
-    ID.AddPointer(Operands[i]);
-}
-
 bool SCEVNAryExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
     if (!getOperand(i)->dominates(BB, DT))
@@ -318,12 +299,6 @@ bool SCEVNAryExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
   return true;
 }
 
-void SCEVUDivExpr::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(scUDivExpr);
-  ID.AddPointer(LHS);
-  ID.AddPointer(RHS);
-}
-
 bool SCEVUDivExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
   return LHS->dominates(BB, DT) && RHS->dominates(BB, DT);
 }
@@ -341,14 +316,6 @@ const Type *SCEVUDivExpr::getType() const {
   return RHS->getType();
 }
 
-void SCEVAddRecExpr::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(scAddRecExpr);
-  ID.AddInteger(Operands.size());
-  for (unsigned i = 0, e = Operands.size(); i != e; ++i)
-    ID.AddPointer(Operands[i]);
-  ID.AddPointer(L);
-}
-
 const SCEV *
 SCEVAddRecExpr::replaceSymbolicValuesWithConcrete(const SCEV *Sym,
                                                   const SCEV *Conc,
@@ -399,11 +366,6 @@ void SCEVAddRecExpr::print(raw_ostream &OS) const {
   OS << "}<" << L->getHeader()->getName() + ">";
 }
 
-void SCEVUnknown::Profile(FoldingSetNodeID &ID) const {
-  ID.AddInteger(scUnknown);
-  ID.AddPointer(V);
-}
-
 bool SCEVUnknown::isLoopInvariant(const Loop *L) const {
   // All non-instruction values are loop invariant.  All instructions are loop
   // invariant if they are not contained in the specified loop.
@@ -749,6 +711,13 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
          "This is not a conversion to a SCEVable type!");
   Ty = getEffectiveSCEVType(Ty);
 
+  FoldingSetNodeID ID;
+  ID.AddInteger(scTruncate);
+  ID.AddPointer(Op);
+  ID.AddPointer(Ty);
+  void *IP = 0;
+  if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
+
   // Fold if the operand is constant.
   if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op))
     return getConstant(
@@ -774,14 +743,11 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
     return getAddRecExpr(Operands, AddRec->getLoop());
   }
 
-  FoldingSetNodeID ID;
-  ID.AddInteger(scTruncate);
-  ID.AddPointer(Op);
-  ID.AddPointer(Ty);
-  void *IP = 0;
+  // The cast wasn't folded; create an explicit cast node.
+  // Recompute the insert position, as it may have been invalidated.
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVTruncateExpr>();
-  new (S) SCEVTruncateExpr(Op, Ty);
+  new (S) SCEVTruncateExpr(ID, Op, Ty);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -877,7 +843,7 @@ const SCEV *ScalarEvolution::getZeroExtendExpr(const SCEV *Op,
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVZeroExtendExpr>();
-  new (S) SCEVZeroExtendExpr(Op, Ty);
+  new (S) SCEVZeroExtendExpr(ID, Op, Ty);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -957,7 +923,7 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVSignExtendExpr>();
-  new (S) SCEVSignExtendExpr(Op, Ty);
+  new (S) SCEVSignExtendExpr(ID, Op, Ty);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1426,7 +1392,7 @@ const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV *> &Ops) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVAddExpr>();
-  new (S) SCEVAddExpr(Ops);
+  new (S) SCEVAddExpr(ID, Ops);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1597,7 +1563,7 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVMulExpr>();
-  new (S) SCEVMulExpr(Ops);
+  new (S) SCEVMulExpr(ID, Ops);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1696,7 +1662,7 @@ const SCEV *ScalarEvolution::getUDivExpr(const SCEV *LHS,
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVUDivExpr>();
-  new (S) SCEVUDivExpr(LHS, RHS);
+  new (S) SCEVUDivExpr(ID, LHS, RHS);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1779,7 +1745,7 @@ ScalarEvolution::getAddRecExpr(SmallVectorImpl<const SCEV *> &Operands,
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVAddRecExpr>();
-  new (S) SCEVAddRecExpr(Operands, L);
+  new (S) SCEVAddRecExpr(ID, Operands, L);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1876,7 +1842,7 @@ ScalarEvolution::getSMaxExpr(SmallVectorImpl<const SCEV *> &Ops) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVSMaxExpr>();
-  new (S) SCEVSMaxExpr(Ops);
+  new (S) SCEVSMaxExpr(ID, Ops);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -1973,7 +1939,7 @@ ScalarEvolution::getUMaxExpr(SmallVectorImpl<const SCEV *> &Ops) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVUMaxExpr>();
-  new (S) SCEVUMaxExpr(Ops);
+  new (S) SCEVUMaxExpr(ID, Ops);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }
@@ -2002,7 +1968,7 @@ const SCEV *ScalarEvolution::getUnknown(Value *V) {
   void *IP = 0;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
   SCEV *S = SCEVAllocator.Allocate<SCEVUnknown>();
-  new (S) SCEVUnknown(V);
+  new (S) SCEVUnknown(ID, V);
   UniqueSCEVs.InsertNode(S, IP);
   return S;
 }