Something

            uint n = 32;
            uint sum = 0xC6EF3720;
            uint delta = 0x9E3779B9;

            while (n-- > 0)
            {
                data[1] -= ((data[0] << 4) + key[2]) ^ (data[0] + sum) ^ ((data[0] >> 5) + key[3]);
                data[0] -= ((data[1] << 4) + key[0]) ^ (data[1] + sum) ^ ((data[1] >> 5) + key[1]);
                sum -= delta;
            }