ValueToValueMap ⤅
};
+ 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 ⤅
+ };
+
+/// 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