Factor out a common base class from SCEVTruncateExpr, SCEVZeroExtendExpr,

and SCEVSignExtendExpr.

llvm-svn: 69649

3 files changed, 48 insertions, 64 deletions

diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 1cfc6390ccb..d94a9ebcb57 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -73,16 +73,16 @@ namespace llvm {
   };
 
   //===--------------------------------------------------------------------===//
-  /// SCEVTruncateExpr - This class represents a truncation of an integer value
-  /// to a smaller integer value.
+  /// SCEVCastExpr - This is the base class for unary cast operator classes.
   ///
-  class SCEVTruncateExpr : public SCEV {
-    friend class ScalarEvolution;
-
+  class SCEVCastExpr : public SCEV {
+  protected:
     SCEVHandle Op;
     const Type *Ty;
-    SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
-    virtual ~SCEVTruncateExpr();
+
+    SCEVCastExpr(unsigned SCEVTy, const SCEVHandle &op, const Type *ty);
+    virtual ~SCEVCastExpr();
+
   public:
     const SCEVHandle &getOperand() const { return Op; }
     virtual const Type *getType() const { return Ty; }
@@ -95,6 +95,28 @@ namespace llvm {
       return Op->hasComputableLoopEvolution(L);
     }
 
+    virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
+    /// Methods for support type inquiry through isa, cast, and dyn_cast:
+    static inline bool classof(const SCEVCastExpr *S) { return true; }
+    static inline bool classof(const SCEV *S) {
+      return S->getSCEVType() == scTruncate ||
+             S->getSCEVType() == scZeroExtend ||
+             S->getSCEVType() == scSignExtend;
+    }
+  };
+
+  //===--------------------------------------------------------------------===//
+  /// SCEVTruncateExpr - This class represents a truncation of an integer value
+  /// to a smaller integer value.
+  ///
+  class SCEVTruncateExpr : public SCEVCastExpr {
+    friend class ScalarEvolution;
+
+    SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
+    virtual ~SCEVTruncateExpr();
+
+  public:
     SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
                                                  const SCEVHandle &Conc,
                                                  ScalarEvolution &SE) const {
@@ -104,8 +126,6 @@ namespace llvm {
       return SE.getTruncateExpr(H, Ty);
     }
 
-    virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
     virtual void print(raw_ostream &OS) const;
 
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
@@ -119,25 +139,13 @@ namespace llvm {
   /// SCEVZeroExtendExpr - This class represents a zero extension of a small
   /// integer value to a larger integer value.
   ///
-  class SCEVZeroExtendExpr : public SCEV {
+  class SCEVZeroExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVHandle Op;
-    const Type *Ty;
     SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty);
     virtual ~SCEVZeroExtendExpr();
-  public:
-    const SCEVHandle &getOperand() const { return Op; }
-    virtual const Type *getType() const { return Ty; }
-
-    virtual bool isLoopInvariant(const Loop *L) const {
-      return Op->isLoopInvariant(L);
-    }
-
-    virtual bool hasComputableLoopEvolution(const Loop *L) const {
-      return Op->hasComputableLoopEvolution(L);
-    }
 
+  public:
     SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
                                                  const SCEVHandle &Conc,
                                                  ScalarEvolution &SE) const {
@@ -147,8 +155,6 @@ namespace llvm {
       return SE.getZeroExtendExpr(H, Ty);
     }
 
-    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
     virtual void print(raw_ostream &OS) const;
 
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
@@ -162,25 +168,13 @@ namespace llvm {
   /// SCEVSignExtendExpr - This class represents a sign extension of a small
   /// integer value to a larger integer value.
   ///
-  class SCEVSignExtendExpr : public SCEV {
+  class SCEVSignExtendExpr : public SCEVCastExpr {
     friend class ScalarEvolution;
 
-    SCEVHandle Op;
-    const Type *Ty;
     SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty);
     virtual ~SCEVSignExtendExpr();
-  public:
-    const SCEVHandle &getOperand() const { return Op; }
-    virtual const Type *getType() const { return Ty; }
-
-    virtual bool isLoopInvariant(const Loop *L) const {
-      return Op->isLoopInvariant(L);
-    }
-
-    virtual bool hasComputableLoopEvolution(const Loop *L) const {
-      return Op->hasComputableLoopEvolution(L);
-    }
 
+  public:
     SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
                                                  const SCEVHandle &Conc,
                                                  ScalarEvolution &SE) const {
@@ -190,8 +184,6 @@ namespace llvm {
       return SE.getSignExtendExpr(H, Ty);
     }
 
-    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
     virtual void print(raw_ostream &OS) const;
 
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
@@ -207,8 +199,6 @@ namespace llvm {
   /// operators.
   ///
   class SCEVCommutativeExpr : public SCEV {
-    friend class ScalarEvolution;
-
     std::vector<SCEVHandle> Operands;
 
   protected:
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 5300dbe49f3..5308b8d0f53 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -190,6 +190,16 @@ void SCEVConstant::print(raw_ostream &OS) const {
   WriteAsOperand(OS, V, false);
 }
 
+SCEVCastExpr::SCEVCastExpr(unsigned SCEVTy,
+                           const SCEVHandle &op, const Type *ty)
+  : SCEV(SCEVTy), Op(op), Ty(ty) {}
+
+SCEVCastExpr::~SCEVCastExpr() {}
+
+bool SCEVCastExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
+  return Op->dominates(BB, DT);
+}
+
 // SCEVTruncates - Only allow the creation of one SCEVTruncateExpr for any
 // particular input.  Don't use a SCEVHandle here, or else the object will
 // never be deleted!
@@ -197,7 +207,7 @@ static ManagedStatic<std::map<std::pair<SCEV*, const Type*>,
                      SCEVTruncateExpr*> > SCEVTruncates;
 
 SCEVTruncateExpr::SCEVTruncateExpr(const SCEVHandle &op, const Type *ty)
-  : SCEV(scTruncate), Op(op), Ty(ty) {
+  : SCEVCastExpr(scTruncate, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot truncate non-integer value!");
@@ -207,10 +217,6 @@ SCEVTruncateExpr::~SCEVTruncateExpr() {
   SCEVTruncates->erase(std::make_pair(Op, Ty));
 }
 
-bool SCEVTruncateExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
-  return Op->dominates(BB, DT);
-}
-
 void SCEVTruncateExpr::print(raw_ostream &OS) const {
   OS << "(truncate " << *Op << " to " << *Ty << ")";
 }
@@ -222,7 +228,7 @@ static ManagedStatic<std::map<std::pair<SCEV*, const Type*>,
                      SCEVZeroExtendExpr*> > SCEVZeroExtends;
 
 SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty)
-  : SCEV(scZeroExtend), Op(op), Ty(ty) {
+  : SCEVCastExpr(scZeroExtend, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot zero extend non-integer value!");
@@ -232,10 +238,6 @@ SCEVZeroExtendExpr::~SCEVZeroExtendExpr() {
   SCEVZeroExtends->erase(std::make_pair(Op, Ty));
 }
 
-bool SCEVZeroExtendExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
-  return Op->dominates(BB, DT);
-}
-
 void SCEVZeroExtendExpr::print(raw_ostream &OS) const {
   OS << "(zeroextend " << *Op << " to " << *Ty << ")";
 }
@@ -247,7 +249,7 @@ static ManagedStatic<std::map<std::pair<SCEV*, const Type*>,
                      SCEVSignExtendExpr*> > SCEVSignExtends;
 
 SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty)
-  : SCEV(scSignExtend), Op(op), Ty(ty) {
+  : SCEVCastExpr(scSignExtend, op, ty) {
   assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
          (Ty->isInteger() || isa<PointerType>(Ty)) &&
          "Cannot sign extend non-integer value!");
@@ -257,10 +259,6 @@ SCEVSignExtendExpr::~SCEVSignExtendExpr() {
   SCEVSignExtends->erase(std::make_pair(Op, Ty));
 }
 
-bool SCEVSignExtendExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
-  return Op->dominates(BB, DT);
-}
-
 void SCEVSignExtendExpr::print(raw_ostream &OS) const {
   OS << "(signextend " << *Op << " to " << *Ty << ")";
 }
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 78198b5e0bf..c436cec26ed 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -300,12 +300,8 @@ static bool containsAddRecFromDifferentLoop(SCEVHandle S, Loop *L) {
     return containsAddRecFromDifferentLoop(DE->getLHS(), L) ||
            containsAddRecFromDifferentLoop(DE->getRHS(), L);
 #endif
-  if (const SCEVTruncateExpr *TE = dyn_cast<SCEVTruncateExpr>(S))
-    return containsAddRecFromDifferentLoop(TE->getOperand(), L);
-  if (const SCEVZeroExtendExpr *ZE = dyn_cast<SCEVZeroExtendExpr>(S))
-    return containsAddRecFromDifferentLoop(ZE->getOperand(), L);
-  if (const SCEVSignExtendExpr *SE = dyn_cast<SCEVSignExtendExpr>(S))
-    return containsAddRecFromDifferentLoop(SE->getOperand(), L);
+  if (const SCEVCastExpr *CE = dyn_cast<SCEVCastExpr>(S))
+    return containsAddRecFromDifferentLoop(CE->getOperand(), L);
   return false;
 }