https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120578
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- 2**30*2 is an integer overflow . So yes this is invalid and undefined behavior.