sum_element_type);
    else
      result_type = UnrankedTensorType::get(sum_element_type);

    // Convert if we need enlarge the element type's bitwidth.
    if (input_element_type != sum_element_type)
      input_value = rewriter.create<ConvertOp>(op.getLoc(), input_value,
                                               sum_element_type);

    // Create the ReduceWindow op.

      [&](RankedTensorType new_element_type) -> bool {
    DCOMMENT("\t\tConsidering " << new_element_type << " with old "
                                << *potential_element_type);
    if (!new_element_type || !new_element_type.hasStaticShape()) return false;
    if (!*potential_element_type) {
      DCOMMENT("\t\tUpdating potential_element_type " << new_element_type);
      *potential_element_type = new_element_type;