diff --git a/mlir/lib/Analysis/FlatLinearValueConstraints.cpp b/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
--- a/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
+++ b/mlir/lib/Analysis/FlatLinearValueConstraints.cpp
@@ -457,7 +457,7 @@
                                            SmallVectorImpl<AffineMap> *lbMaps,
                                            SmallVectorImpl<AffineMap> *ubMaps,
                                            bool closedUB) {
-  assert(num < getNumDimVars() && "invalid range");
+  assert(offset + num <= getNumDimVars() && "invalid range");
 
   // Basic simplification.
   normalizeConstraintsByGCD();