https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109031
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #5) > Both testcases I tested all exited with a non-zero value even at -O0 ... Ok, I missed you need to pass an argument to the program. Anyways I think this might be an uninitialized variable causing the difference but I am not 100% sure.