Add a new SCEV representing signed division.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60407 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 55 insertions, 1 deletions

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index e16e990bad..f524daabf2 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -225,6 +225,7 @@ namespace llvm {
       return getMulExpr(Ops);
     }
     SCEVHandle getUDivExpr(const SCEVHandle &LHS, const SCEVHandle &RHS);
+    SCEVHandle getSDivExpr(const SCEVHandle &LHS, const SCEVHandle &RHS);
     SCEVHandle getAddRecExpr(const SCEVHandle &Start, const SCEVHandle &Step,
                              const Loop *L);
     SCEVHandle getAddRecExpr(std::vector<SCEVHandle> &Operands,
diff --git a/include/llvm/Analysis/ScalarEvolutionExpander.h b/include/llvm/Analysis/ScalarEvolutionExpander.h
index cd075ef643..7ecf5332ed 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpander.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpander.h
@@ -104,6 +104,8 @@ namespace llvm {
 
     Value *visitUDivExpr(SCEVUDivExpr *S);
 
+    Value *visitSDivExpr(SCEVSDivExpr *S);
+
     Value *visitAddRecExpr(SCEVAddRecExpr *S);
 
     Value *visitSMaxExpr(SCEVSMaxExpr *S);
diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 652a99d0fc..bedd075a10 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -25,7 +25,7 @@ namespace llvm {
     // These should be ordered in terms of increasing complexity to make the
     // folders simpler.
     scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr,
-    scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr, scUnknown,
+    scUDivExpr, scSDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr, scUnknown,
     scCouldNotCompute
   };
 
@@ -358,6 +358,55 @@ namespace llvm {
 
 
   //===--------------------------------------------------------------------===//
+  /// SCEVSDivExpr - This class represents a binary signed division operation.
+  ///
+  class SCEVSDivExpr : public SCEV {
+    friend class ScalarEvolution;
+
+    SCEVHandle LHS, RHS;
+    SCEVSDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs)
+      : SCEV(scSDivExpr), LHS(lhs), RHS(rhs) {}
+
+    virtual ~SCEVSDivExpr();
+  public:
+    const SCEVHandle &getLHS() const { return LHS; }
+    const SCEVHandle &getRHS() const { return RHS; }
+
+    virtual bool isLoopInvariant(const Loop *L) const {
+      return LHS->isLoopInvariant(L) && RHS->isLoopInvariant(L);
+    }
+
+    virtual bool hasComputableLoopEvolution(const Loop *L) const {
+      return LHS->hasComputableLoopEvolution(L) &&
+             RHS->hasComputableLoopEvolution(L);
+    }
+
+    SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
+                                                 const SCEVHandle &Conc,
+                                                 ScalarEvolution &SE) const {
+      SCEVHandle L = LHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
+      SCEVHandle R = RHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
+      if (L == LHS && R == RHS)
+        return this;
+      else
+        return SE.getSDivExpr(L, R);
+    }
+
+
+    virtual const Type *getType() const;
+
+    void print(std::ostream &OS) const;
+    void print(std::ostream *OS) const { if (OS) print(*OS); }
+
+    /// Methods for support type inquiry through isa, cast, and dyn_cast:
+    static inline bool classof(const SCEVSDivExpr *S) { return true; }
+    static inline bool classof(const SCEV *S) {
+      return S->getSCEVType() == scSDivExpr;
+    }
+  };
+
+
+  //===--------------------------------------------------------------------===//
   /// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
   /// count of the specified loop.
   ///
@@ -550,6 +599,8 @@ namespace llvm {
         return ((SC*)this)->visitMulExpr((SCEVMulExpr*)S);
       case scUDivExpr:
         return ((SC*)this)->visitUDivExpr((SCEVUDivExpr*)S);
+      case scSDivExpr:
+        return ((SC*)this)->visitSDivExpr((SCEVSDivExpr*)S);
       case scAddRecExpr:
         return ((SC*)this)->visitAddRecExpr((SCEVAddRecExpr*)S);
       case scSMaxExpr: