https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102844
--- Comment #25 from Richard Biener <rguenth at gcc dot gnu.org> --- I'm not sure about the state of this bug - the issue reproduces on the GCC 10 branch with checking enabled and -O[2s] -fdisable-tree-fre4 -fno-strict-overflow It might be that using the backward threader from DOM (are we now doing that?) makes this truly fixed but I'm not sure the backward threader is resilent to the issue analyzed in comments #13 to #15. Eventually the NOCOPY special-casing could be removed as premature optimization (CFG cleanup will remove any copied forwarders), but then IIRC we have a hard limit on the number of blocks the threader handles.
