https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99395
--- Comment #19 from rguenther at suse dot de <rguenther at suse dot de> --- On Wed, 31 Jan 2024, juzhe.zhong at rivai dot ai wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99395 > > --- Comment #18 from JuzheZhong <juzhe.zhong at rivai dot ai> --- > (In reply to rguent...@suse.de from comment #17) > > On Wed, 31 Jan 2024, juzhe.zhong at rivai dot ai wrote: > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99395 > > > > > > --- Comment #16 from JuzheZhong <juzhe.zhong at rivai dot ai> --- > > > (In reply to rguent...@suse.de from comment #15) > > > > On Wed, 31 Jan 2024, juzhe.zhong at rivai dot ai wrote: > > > > > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99395 > > > > > > > > > > --- Comment #14 from JuzheZhong <juzhe.zhong at rivai dot ai> --- > > > > > Thanks Richard. > > > > > > > > > > It seems that we can't fix this issue for now. Is that right ? > > > > > > > > > > If I understand correctly, do you mean we should wait after SLP > > > > > representations > > > > > are finished and then revisit this PR? > > > > > > > > Yes. > > > > > > It seems to be a big refactor work. > > > > It's not too bad if people wouldn't continue to add features not > > implementing SLP ... > > > > > I wonder I can do anything to help with SLP representations ? > > > > I hope to get back to this before stage1 re-opens and will post > > another request for testing. It's really mostly going to be making > > sure all paths have coverage which means testing all the various > > architectures - I can only easily test x86. There's a branch > > I worked on last year, refs/users/rguenth/heads/vect-force-slp, > > which I use to hunt down cases not supporting SLP (it's a bit > > overeager to trigger, and it has known holes so it's not really > > a good starting point yet for folks to try other archs). > > Ok. It seems that you almost done with that but needs more testing in > various targets. > > So, if I want to work on optimizing vectorization (start with TSVC), > I should avoid touching the failed vectorized due to data reference/dependence > analysis (e.g. this PR case, s116). It depends on the actual case - the one in this bug at least looks like half of it might be dealt with with the refactoring. > and avoid adding new features into loop vectorizer, e.g. min/max reduction > with > index (s315). It's fine to add features if they works with SLP as well ;) Note that in the future SLP will also do the "single lane" case but it doesn't do that on trunk. Some features are difficult with multi-lane SLP and probably not important in practice for that case, still handling single-lane SLP will be important as otherwise the feature is lost. > To not to make your SLP refactoring work heavier. > > Am I right ? Yes. I've got early break vectorization to chase now, I was "finished" with the parts I could exercise on x86_64 in autumn ...
