http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54692
--- Comment #10 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2012-09-24 15:08:27 UTC --- (In reply to comment #6) > -O[[s0-9gf]] instead (also for -Ofast). "s/-O\([sg0-9]\|fast\) *//" should work.