http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44786
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-08 14:06:31 UTC --- Indeed. I think it's meant to be useful for catching some of the problems that valgrind identifies, and valgrind has even more performance overhead. That said, although I haven't used it heavily clang's -fcatch-undefined-behavior has never caught any problems for me. YMMV.
