https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82831
--- Comment #11 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > I know you have some skill. Do you think problem is in traces how are traced > (more precisely why are the problematic blocks selected as hot)? > Or merging of the traces? I know it's problematic to reproduce as it happens > in profiled bootstrap, but I would appreciate any help ;) Yes, this could be during the connection of the traces, which involves copying basic blocks. When you do this, you redirect edges, which in turns changes the dominance relationship and thus can turn a hot block into a cold block.
