On Fri, Sep 25, 2015 at 7:34 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >> > What has changed between then and now? Also, do we not use >> > estimates/heuristics when not using a profile? >> >> Nothing has changed - splitting effectively never kicked in without a >> profile. Honza and I had discussed the idea that static profile >> heuristics could eventually be used to distinguish hot vs cold bbs, > > Yep, the basic idea was to move EH clenaups to the cold section for start. > The > cleanup code can get surprisingly large for some C++ apps. > >> but that hasn't happened. What I didn't notice until recently was the >> size increase in the .o files from varasm adding in unnecessary >> sections and labels when this option was on. Unless and until static > > Perhaps we also may just teach varasm to not output those when function is not > split. I am happy with the patch as it is because it is pointless to run the > code when no splitting happens.
Right, that will need to happen if splitting is tuned for static frequencies. For now I committed this patch. I also fixed the old change log entry that Bernd pointed out. Thanks, Teresa > > Honza >> heuristics are used to distinguish cold bbs in >> probably_never_executed_bb_p, I don't think it makes sense to do >> anything finer grained that just disabling the option. >> >> Teresa >> >> > >> > >> > Bernd >> >> >> >> -- >> Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413 -- Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
