Function ring::arithmetic::bigint::from_montgomery_amm

fn from_montgomery_amm<M>(
    limbs: BoxedLimbs<M>,
    m: &Modulus<'_, M>,
) -> Elem<M, Unencoded>

Does a Montgomery reduction on limbs assuming they are Montgomery-encoded (‘R’) and assuming they are the same size as m, but perhaps not reduced mod m. The result will be fully reduced mod m.