https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794
--- Comment #2 from Aldy Hernandez <aldyh at redhat dot com> --- I haven't looked at this, but there's a pending patch with more restrictions for loop threading in the presence of loops. Does this help? https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581637.html We really shouldn't be destroying loop info. On Sat, Oct 16, 2021, 07:01 pinskia at gcc dot gnu.org < gcc-bugzi...@gcc.gnu.org> wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 > > Andrew Pinski <pinskia at gcc dot gnu.org> changed: > > What |Removed |Added > > ---------------------------------------------------------------------------- > CC| |aldyh at gcc dot gnu.org > > --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- > Jump threading really messes up the loop here ... > about to thread: path: 4 -> 6, 6 -> 7, 7 -> 3, > just threaded: path: 4 -> 9, 6 -> 7, 7 -> 3, > > I don't know what else to say. Maybe move ethread after evpr? > > Note with -fno-thread-jumps, evpr is able to figure out the induction > variable > goes from [-100, -1] . It does look like jump threading is full on > messing up > how induction variable detection works; we get two a = a +1; statement > after > the jump threading improvements. > Maybe there is another bug about that case already. > > -- > You are receiving this mail because: > You are on the CC list for the bug. > >
