http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375
--- Comment #204 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- Here is a comparison of libxul sizes (in bytes, unstripped) for different compiler options: gcc (trunk): -O3 90213016 -O3 -flto 79682648 -O3 -flto / PGO 77250512 -Os 70431584 -Os -flto 62474008 clang (trunk): -O3 80574784 -O3 -flto 79394992 -Os 72452776 -Os -flto 65111640