https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125852
--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> --- The other thing I found with my changes to cfgcleanup(and other related changes) was that it changes the EBB. So the it might the case the 2 basic blocks are no longer part of the same EBB which is required for late combine and cse and a few other rtl passes to work. I have not figured that part out yet either.
