// {sub} the subdiagonal alignment. "LEFT" means rows will be padded to the
    // left, "RIGHT" means rows will be padded ot the right.  The default is
    // "RIGHT_LEFT".
    StringRef align = op->getAttrOfType<StringAttr>("align").getValue();
    enum Alignment { kLeft, kRight };

    // default is RIGHT_LEFT
    Alignment superdiagonal_align = kRight;
    Alignment subdiagonal_align = kLeft;