https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61296
--- Comment #15 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Jakub Jelinek from comment #13) > Read the sources? It really depends on many factors. There are int max_align_compat = optimize_size ? BITS_PER_WORD : MIN (256, MAX_OFILE_ALIGNMENT); With -Os, we aren't compatible with the older GCC anyway.