Re: Make PHP JIT to generate AVX2/AVX3 for performance improvement?

On Tue, Oct 31, 2023, 3:57 PM tag Knife <fenniclog@gmail.com> wrote: > > Hi Guys, > > > > A quick question: is it possible to enable AVX2/AVX3 in PHP JIT generated > > code, and hence can get some performance improvement? > > Just check the community first: if anyone has already tried that or got > > some experiences? before we dive into this investigation. > > We are discussing if we could get some extra performance via new AVX > > instructions in PHP program execution. > > > > Thanks. > > > > AVX3 might be too new to just flat out generate for it. But > It can be quite simple for the JIT compiler to be aware of what > features flags are enabled on a CPU and generate compatible > instructions that will run on that CPU. > it is not really new, however the gain for most cases are not necessarily significant but for specific cases. For most usages in php, at a request level, the gain will be barely measurable. Also for latest avx, most hosting servers won't have them anyway. I would think some specific APIs to prepare specific data to be processed using the best available runtime intrinsics would bring much more than in JIT. As a sidenote, most libraries used by php, where larger intrinsics vectors bring something, implement them already. best, Pierre >