https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71831
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- One of the reasons is that -O0 should mean short compile time. If you schedule the objsz pass at -O0, you might slow down the compilation, especially on larger functions. The glibc headers won't use it at -O0 anyway, so what would it be good for?
