cmph is not the fastest library for MPHF, mostly because it uses a slow ranking function to turn a PHF into a MPHF.

I wrote a small library some time ago that performs much faster, both for in-memory construction and lookups, [1, see the linked paper for benchmarks], unfortunately I have no time to maintain it but I recently found out that some projects are using it, so it wasn't all wasted time :)

[1] https://github.com/ot/emphf

</shameless plug>