https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115832
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #3) > I looked at the output of -ftime-report, there does not seen anything that > sticks out really. Plus with -fsanitize=undefined just means there will > almost definitely be much more basic blocks and many more registers alive. And _GLIBCXX_DEBUG means there is A LOT more work being done on every step of the algorithm.