On Thu, 2 Jul 2026, Kyrylo Tkachov wrote: > > > > On 2 Jul 2026, at 09:00, Richard Biener <[email protected]> wrote: > > > > On Wed, 1 Jul 2026, Jeffrey Law wrote: > > > >> > >> > >> On 7/1/2026 9:43 AM, Kyrylo Tkachov wrote: > >>>> What I would suggest would be to look at the code we generate for the > >>>> split-paths tests before/after removal and make sure we're not missing > >>>> something. The tests, more likely than not, test that split-paths > >>>> triggered rather than looking at the final assembly codes. > >>> So out of all split-path tests only one shows a difference with > >>> -fsplit-paths vs -fno-split-paths: split-paths-6.c where -fno-split-paths > >>> gives +3 aarch64 instructions, but this is a downstream artifact. > >>> In the source: > >>> void givehelp (int interactive) > >>> { > >>> if (interactive) > >>> while ((--((_impure_ptr->_stdin))->_r < 0 > >>> ? __srget_r (_impure_ptr, _impure_ptr->_stdin) > >>> : (int) (*((_impure_ptr->_stdin))->_p++)) != ' ‘); > >>> } > >>> > >>> -fsplit-paths triggers once but the duplication is later remerged but the > >>> edge probabilities end up different and then loop rotation ends up making > >>> different layout decisions. > >>> So I don’t think it’s a very deliberate effect. > >> Yea, that's sounds more like a random downstream effect than something > >> intentional. I don't really recall split-path-6, though a reasonable > >> assumption would be that I was playing around with the original patch and > >> included some tests I found when experimenting with the patch's behavior. > > > > Can we preserve testcases as compile-only btw? Some might have been > > introduced for ICEs, some for overall expected optimization (with > > no path splitting). > > > > You mean put them in the torture suite without the scans for expected > dump/assembly?
Yes, or just remove the scans for expected dump/assembly (if those are related to path splitting). > Thanks, > Kyrill > > > Richard. > > > >> > >> Jeff > >> > >> > > > > -- > > Richard Biener <[email protected]> > > SUSE Software Solutions Germany GmbH, > > Frankenstrasse 146, 90461 Nuernberg, Germany; > > GF: Jochen Jaser, Andrew McDonald; (HRB 36809, AG Nuernberg) > > > -- Richard Biener <[email protected]> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Jochen Jaser, Andrew McDonald; (HRB 36809, AG Nuernberg)
