https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105950
--- Comment #19 from John Kanapes <jkanapes at yahoo dot com> --- Aaaah. So it's different than the other gcc flags... I just linked libubsan... No compilation errors. At runtime it SIGILLS at the same gdb point as before... Same as the rest of the recommended flags. BTW since -O3 is the highest gcc optimization, gcc could print a warning: Warning -Ox is deprecated. Downgrading to -O3;-) Otherwise in a few years you will find code compiled with -O20 and then it is the sky. It just takes 1 coder to use it in open source, and since gcc seems to take it, all the other coders will copy it:(
