rotl64
*v1 = rotl64(*v1, 13) ^ *v0;
*v3 = rotl64(*v3, 16) ^ *v2;
*v0 = rotl64(*v0, 32);
*v1 = rotl64(*v1, 17) ^ *v2;
*v3 = rotl64(*v3, 21) ^ *v0;
*v2 = rotl64(*v2, 32);