https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128218
--- Comment #5 from Harald Anlauf <anlauf at gcc dot gnu.org> --- (In reply to Harald Anlauf from comment #4) > IIRC there used to be an issue with the built-in memmove in early 16.x when > the size of the area was exactly 64 bytes. This was fixed later. Don't > remember the PR. > > Can you try a different size (like double or half the size)? > If that helps, then this is a known & resolved issue. Actually even the latest 16.2.1 produces the lengthy code, so this is only fixed in 17.
