Re: Popcount optimization for the slow-path lookups

> I don't think the proposed improvements are relevant for either of the
> machines you used for your benchmarks.  For x86, we've optimized our
> popcount code to use SSE4.2 or AVX-512, and for AArch64, we've optimized it
> to use Neon or SVE.  And for other systems, we still try to use
> __builtin_popcount() and friends in the fallback paths, which IIUC are
> available on both gcc and clang (and maybe elsewhere).  IMHO we need to run
> the benchmarks on a compiler/architecture combination where it would
> actually be used in practice.

Yes, I saw that the code is on a rather obscure path, but those machines were my only options for quick benchmarks.
I reasoned that the code path still exists, and eliminating branching there would be beneficial anyway
(most probably). But you are right, we need to test it on target architectures/compilers. I'll try to do with that.

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Cheers,

Andy