diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -698,8 +698,8 @@
           extents[pos] = getAffineConstantExpr(v.getShape()[idx], ctx);
       }
     }
-    assert(llvm::all_of(extents, [](AffineExpr e) { return e; }) &&
-           "expected extent along all dimensions.");
+    if (!llvm::all_of(extents, [](AffineExpr e) { return e; }))
+      return op.emitOpError("Some input dimensions are used by neither the LHS nor the RHS.");
 
     AffineMap resMap = op.getIndexingMaps()[2];
     auto extentsMap = AffineMap::get(/*dimCount=*/extents.size(),