diff --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -691,6 +691,9 @@
     return;
   }
 
+  lhs = binExpr.getLHS();
+  rhs = binExpr.getRHS();
+
   auto rhsConst = rhs.dyn_cast<AffineConstantExpr>();
   if (!rhsConst)
     return;