despacer VS simde

Cool performance enhancement, with an accompanying implementation in a real-world library (https://github.com/lemire/despacer).

Still, what does it signal that vector extensions are required to get better string performance on x86? Wouldn't it be better if Intel invested their AVX transistor budget into simply making existing REPB prefixes a lot faster?

If you're looking for an example, perhaps the despacer problem might be one which doesn't get too complex. Do you know of a way to implement it on a GPU such that it'd run better than (or at least as good as) a CPU SIMD implementation would?

I was curious about these libraries a few weeks ago and did some searching. Is there one that's got a clearly dominating set of users or contributors?

I don't know what a good way to compare these might be, other than perhaps activity/contributor count.

[1] https://github.com/simd-everywhere/simde

[2] https://github.com/ermig1979/Simd

[3] https://github.com/google/highway

[4] https://gitlab.com/libeigen/eigen

[5] https://github.com/shibatch/sleef

I note that SIMDe doesn't have RISC-V support yet (but it does support Loongson LoongArch):

https://github.com/simd-everywhere/simde/

There are still a ton of things to do to get the Debian riscv64 port going too:

https://wiki.debian.org/PortsDocs/New

SIMDe is everything you're after: https://github.com/simd-everywhere/simde

> low level code that can run on multiple hardware architectures

I thought SIMD Everywhere was a pretty interesting project for that, lets you write x86 SSE/AVX code and run it on non-x86 architectures:

https://github.com/simd-everywhere/simde

> architecture-specific features such as SSE/AVX which is not portable.

I don’t have hands-on experience, but somewhere on HN I saw this: https://github.com/simd-everywhere/simde If starting a new cross-platform project today, I would try that library first, before doing the usual intrinsics.