maskl(i[, kind]) has its leftmost i bits set to 1, and the remaining bits set to 0.
Fortran 2008 and later
result = maskl(i[, kind])
i - Shall be of type integer.kind - Shall be a scalar constant expression of type integer.The return value is of type integer. If kind is present, it specifies the kind value of the return type; otherwise, it is of the default integer kind.