https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70557
--- Comment #13 from Siarhei Volkau <lis8215 at gmail dot com> --- Moreover, I think that the patches deal for limited possible cases. E.g. if upper or lower part of DI memory shall be set to zero the patch won't help. It seems feasible to make a special code path for zero reg promotion during regcprop pass.
