https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116093
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Based on my analysis in comment #1 makes this sound similar to the problem that is being fixed by r15-9397-g3f9dfb94eab1ab1bbf9a2b5e20d1f61e36516063 . Notice _5 = _2; there.