http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57300
--- Comment #14 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > I agree that possibly bogus IL is a smoking gun that waits for this kind > of bugs to appear. If we do not want to pay the price of removing > notes can we at least have a flag that tells whether the NOTE problem > is up-to-date (and add verification that it indeed is - at least has > no bogus notes - when that flag is set)? We could introduce > a new PROP_rtl_notes for that. We cannot be sure that the NOTE problem is up-to-date since DF doesn't update them on the fly; it's correct only right after calling df_analyze. > As for the case in question in PR57281 - it shouldn't be hard for > postreload to remove REG_DEAD notes from all uses when it propagates > equivalencies, no? All the dataflow stuff is now handled by DF and I don't think that we should go backwards by asking again individual passes to fiddle with it. > Btw, as alternative to computing the NOTE problem at the start of split > we can also remove all notes which should be cheaper. Yes, that's another possibility.
