https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61626
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- 0x7FFFFFFFFFFFFFFF is not exactly presentably in 64bit (double) precision floating point. But is 80bit (the underlying precision of x86/x87). So yes this is exactly the same issue as bug 323.
