I "implemented" your code into cpuminer on an EC2 yesterday and can confirm the 220kh/s. Very nice! 
Thanks for your work on this and for sharing.  Very .

Although it seems to slow down over time but IIRC you mentioned that in the readme. After a restart of the miner it's running normal again.

Now if only cryptocurrencies all around wouldn't be crashing like no tomorrow right now...