X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FScalarEvolutionExpressions.h;h=eac91131ad535c53ec2fcaf42199c313abfc6ea6;hb=b075ed3b90fa2a520aeb15802fddf3460d865f91;hp=bd15ae12c85bf4b997bb69bec64bda710340d6e8;hpb=a9e4d3f37590bb326e6c5a3ea02ee1aa3db681ea;p=oota-llvm.git

diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index bd15ae12c85..eac91131ad5 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -549,12 +549,14 @@ namespace llvm {
     T.visitAll(Root);
   }
 
-  /// The ScevRewriter takes a scalar evolution expression and copies all its
+  /// The SCEVRewriter takes a scalar evolution expression and copies all its
   /// components. The result after a rewrite is an identical SCEV.
-  struct ScevRewriter
-    : public SCEVVisitor<ScevRewriter, const SCEV*> {
+  struct SCEVRewriter
+    : public SCEVVisitor<SCEVRewriter, const SCEV*> {
   public:
-    ScevRewriter(ScalarEvolution &S) : SE(S) {}
+    SCEVRewriter(ScalarEvolution &S) : SE(S) {}
+
+    virtual ~SCEVRewriter() {}
 
     virtual const SCEV *visitConstant(const SCEVConstant *Constant) {
       return Constant;
@@ -629,17 +631,17 @@ namespace llvm {
 
   typedef DenseMap<const Value*, Value*> ValueToValueMap;
 
-  /// The ScevParameterRewriter takes a scalar evolution expression and updates
+  /// The SCEVParameterRewriter takes a scalar evolution expression and updates
   /// the SCEVUnknown components following the Map (Value -> Value).
-  struct ScevParameterRewriter: public ScevRewriter {
+  struct SCEVParameterRewriter: public SCEVRewriter {
   public:
     static const SCEV *rewrite(const SCEV *Scev, ScalarEvolution &SE,
                                ValueToValueMap &Map) {
-      ScevParameterRewriter Rewriter(SE, Map);
+      SCEVParameterRewriter Rewriter(SE, Map);
       return Rewriter.visit(Scev);
     }
-    ScevParameterRewriter(ScalarEvolution &S, ValueToValueMap &M)
-      : ScevRewriter(S), Map(M) {}
+    SCEVParameterRewriter(ScalarEvolution &S, ValueToValueMap &M)
+      : SCEVRewriter(S), Map(M) {}
 
     virtual const SCEV *visitUnknown(const SCEVUnknown *Expr) {
       Value *V = Expr->getValue();
@@ -652,6 +654,45 @@ namespace llvm {
     ValueToValueMap &Map;
   };
 
+  typedef DenseMap<const Loop*, const SCEV*> LoopToScevMapT;
+
+  /// The SCEVApplyRewriter takes a scalar evolution expression and applies
+  /// the Map (Loop -> SCEV) to all AddRecExprs.
+  struct SCEVApplyRewriter: public SCEVRewriter {
+  public:
+    static const SCEV *rewrite(const SCEV *Scev, LoopToScevMapT &Map,
+                               ScalarEvolution &SE) {
+      SCEVApplyRewriter Rewriter(SE, Map);
+      return Rewriter.visit(Scev);
+    }
+    SCEVApplyRewriter(ScalarEvolution &S, LoopToScevMapT &M)
+      : SCEVRewriter(S), Map(M) {}
+
+    virtual const SCEV *visitAddRecExpr(const SCEVAddRecExpr *Expr) {
+      SmallVector<const SCEV *, 2> Operands;
+      for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+        Operands.push_back(visit(Expr->getOperand(i)));
+
+      const Loop *L = Expr->getLoop();
+      const SCEV *Res = SE.getAddRecExpr(Operands, L, Expr->getNoWrapFlags());
+
+      if (0 == Map.count(L))
+        return Res;
+
+      const SCEVAddRecExpr *Rec = (const SCEVAddRecExpr *) Res;
+      return Rec->evaluateAtIteration(Map[L], SE);
+    }
+
+  private:
+    LoopToScevMapT &Map;
+  };
+
+/// Applies the Map (Loop -> SCEV) to the given Scev.
+static inline const SCEV *apply(const SCEV *Scev, LoopToScevMapT &Map,
+                                ScalarEvolution &SE) {
+  return SCEVApplyRewriter::rewrite(Scev, Map, SE);
+}
+
 }
 
 #endif