That is unfortunate, like I said if the consensus is xsimd, let's move forward with that.
On Fri, Feb 12, 2021 at 2:45 AM Antoine Pitrou <anto...@python.org> wrote: > > There is an std::simd being envisioned. > https://en.cppreference.com/w/cpp/experimental/simd/simd > > The problem is that we need an implementation that's C++11- or > C++14-compliant, that works on major compilers, and that provides > accelerations for common instruction sets. It doesn't seem to be the > case currently. > https://github.com/VcDevel/std-simd > > Regards > > Antoine. > > > Le 12/02/2021 à 05:18, Micah Kornfield a écrit : > > I'm open to x-simd if others think it is the best option. I think the > last > > time this came up I expressed this opinion, but if possible it would be > > nice to use something that is on its way to become a standard to avoid > > abandonment issues but I don't know enough about the space to understand > if > > this is a real concern. > > > > On Tue, Feb 9, 2021 at 7:00 PM Yuqi Gu <yuqi...@linaro.org> wrote: > > > >> Thanks for comments on the SIMD related PR: > >> https://github.com/apache/arrow/pull/9424. > >> Agree to adopt the *xsimd *as the SIMD wrapper library for Arrow to > avoid a > >> large maintenance burden. It makes sense. > >> > >> It seems *ximd *is designed for mathematics calculating and it lacks the > >> functions like bit/byte shuffling, byte stream split encoding, ARM SVE > >> supporting, etc. > >> I'm absolutely willing to contribute the missing functions to *xsimd*. > >> > >> BRs, > >> Yuqi > >> > >> On Tue, 9 Feb 2021 at 22:08, Antoine Pitrou <anto...@python.org> wrote: > >> > >>> > >>> Le 09/02/2021 à 10:36, Antoine Pitrou a écrit : > >>>> > >>>> Note that we need to decouple the SIMD level available at compile-time > >>>> from the SIMD level available at runtime. That is, we typically build > >>>> optional AVX512 accelerations at compile-time, but only enable them at > >>>> runtime if the CPU supports AVX512 (and if the environment variable > >>>> ARROW_USER_SIMD_LEVEL wasn't forced to a lower value). > >>>> > >>>> From a quick glance, it's not obvious that xsimd supports that level > of > >>>> control. Though it may just be undocumented. I will check with the > >>>> authors, since I happen to know them. > >>> > >>> Ok, there shouldn't be any problem on that front. We just need to > >>> compile with the right compiler flags to select the desired SIMD level, > >>> like we already do currently when compiling multiple versions of a > >>> function. > >>> > >>> I'll note that xsimd isn't very complete. For example, it seems to > lack > >>> the functions required for byte stream split encoding and decoding. > >>> Those functions are exported by libsimdpp under the names "zip_lo" and > >>> "zip_hi". > >>> > >>> libsimdpp, on the other hand, seems to lack maintenance. It hasn't had > >>> a commit in one year, and issues and PRs seem to be unanswered. So > >>> perhaps xsimd is a better course, provided we want to contribute the > >>> missing functions. > >>> > >>> Regards > >>> > >>> Antoine. > >>> > >> > > >
