!fixup Diff -> Op.

Author: fhahn

llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp

@@ -1249,7 +1249,7 @@ Value *SCEVExpander::tryToReuseLCSSAPhi(const SCEVAddRecExpr *S) {
     // offset, if the offset is simpler.
     const SCEV *Diff = SE.getMinusSCEV(S, ExitSCEV);
     const SCEV *Op = Diff;
-    match(Diff, m_scev_Add(m_SCEVConstant(), m_SCEV(Op)));
+    match(Op, m_scev_Add(m_SCEVConstant(), m_SCEV(Op)));
     match(Op, m_scev_Mul(m_scev_AllOnes(), m_SCEV(Op)));
     match(Op, m_scev_PtrToInt(m_SCEV(Op)));
     if (!isa<SCEVConstant, SCEVUnknown>(Op))