On Thu, 25 May 2023 at 16:14, Jeff Law via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > > > On 5/25/23 07:50, Richard Biener wrote: > > On Thu, May 25, 2023 at 3:32 PM Jeff Law via Gcc-patches > > <gcc-patches@gcc.gnu.org> wrote: > >> > >> > >> > >> On 5/25/23 07:01, Richard Biener via Gcc-patches wrote: > >>> On Thu, May 25, 2023 at 2:36 PM Manolis Tsamis <manolis.tsa...@vrull.eu> > >>> wrote: > >>>> > >>>> Implementation of the new RISC-V optimization pass for memory offset > >>>> calculations, documentation and testcases. > >>> > >>> Why do fwprop or combine not what you want to do?
At least for stack variables, the virtual-stack-vars is not resolved until reload. So combine will be running much too early to be of any use (and I haven't recently looked at whether one of the propagation passes runs after). Philipp. > >> I think a lot of them end up coming from register elimination. > > > > Why isn't this a problem for other targets then? Or maybe it is and this > > shouldn't be a machine specific pass? Maybe postreload-gcse should > > perform strength reduction (I can't think of any other post reload pass > > that would do something even remotely related). > It is to some degree. I ran into similar problems at my prior employer. > We ended up working around it in the target files in a different way > -- which didn't work when I quickly tried it on RISC-V. > > Seems like it would be worth another investigative step as part of the > evaluation of this patch. I wasn't at 100% when I did that poking > around many months ago. > > Jeff
