Function update_de 

const fn update_de<const LIMBS: usize>(
    d: &SignedInt<LIMBS>,
    e: &SignedInt<LIMBS>,
    m: &Uint<LIMBS>,
    mi: u64,
    t: [[i64; 2]; 2],
    shift: u32,
) -> (SignedInt<LIMBS>, SignedInt<LIMBS>)