Jun 13, 2024

There are also significant CPU-specific optimizations that you can set via the command line. These provide hash function vectorization at different levels. For example: --enable-sse4 is the most basic and should be available on any supported CPU. --enable-avx2 and --enable-avx512 are also extremely common. I have been testing on a 7 year old machine that has sse4 and avx2 but not avx512. That allows 4 and and 8 lane vectorization, but not 16 lanes (avx512). If you set these then the build will enable them. However, these are implemented such that portability is still enabled. This hurts performance, and so I have made a minor modification to one file locally...