Thanks for the hwf-ppc.c. I've pulled the latest from upstream, applied the patches, and gotten the updated library built. Will let you know of any feedback from our performance team.

We are trying to apply patches in order to conduct internal testing. They did apply successfully. However, we can't get the result to link because _gcry_hwf_detect_ppc is undefined. Is there a hwf-ppc.c somewhere?

I don't know. That would make it a relatively easy transplant. We've also used the Cryptogams code as a reference for Golang enhancements, if that helps. I'd welcome guidance on the matter from a maintainer.