On Tue, Sep 08, 2020 at 11:43:30AM -0500, Qing Zhao wrote: > > On Sep 7, 2020, at 10:58 AM, H.J. Lu <hjl.to...@gmail.com> wrote: > > On Mon, Sep 7, 2020 at 7:06 AM Segher Boessenkool > > <seg...@kernel.crashing.org <mailto:seg...@kernel.crashing.org>> wrote: > >> On Fri, Sep 04, 2020 at 11:52:13AM -0700, H.J. Lu wrote: > >>> On Fri, Sep 4, 2020 at 11:09 AM Segher Boessenkool > >>> <seg...@kernel.crashing.org> wrote: > >>>> Very many normal returns do *not* pass through an epilogue, but are > >>>> simple_return. Disabling that is *much* more expensive than that 2%. > >>> > >>> Sibcall isn't covered. What other cases don't have an epilogue? > >> > >> Shrink-wrapped stuff. Quite important for performance. Not something > >> you can throw away. > > > > Qing, can you check how it interacts with shrink-wrap? > >>
<snip> > But I might miss some important issues here, please let me know what I am > missing here? Start looking at handle_simple_exit()? targetm.gen_simple_return()... Segher
