On September 27, 2021 6:07:40 PM GMT+02:00, Aldy Hernandez via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > >On 9/27/21 5:27 PM, Aldy Hernandez wrote: >> >> >> On 9/27/21 5:01 PM, Jeff Law wrote: >>> >>> >>> On 9/24/2021 9:46 AM, Aldy Hernandez wrote: > >>> And the big question, is the pass running after VRP2 doing anything >>> particularly useful? Do we want to try and kill it now, or later? >> >> Interesting question. Perhaps if we convert DOM threading to a hybrid >> model, it will render the post-VRP threader completely useless. Huhh... >> That could kill 2 birds with one stone... we get rid of a threading >> pass, and we don't need to worry about as much about the super-fast ranger. > >These are just a few of the threading passes at -O2: > >a.c.192t.thread3 <-- bck threader >a.c.193t.dom3 <-- fwd threader >a.c.194t.strlen1 >a.c.195t.thread4 <-- bck threader >a.c.196t.vrp2 >a.c.197t.vrp-thread2 <-- fwd threader > >That's almost 4 back to back threaders! > >*pause for effect*
We've always known we have too many of these once Jeff triplicated all the backwards threading ones. I do hope we manage to reduce the number for GCC 12. Esp. If the new ones are slower because they no longer use simple lattices. Richard. >Aldy >
