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. >
