https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85030
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Trying to create BLKmode subreg of something (or subreg from BLKmode) is not going to work well, but don't know the LRA code enough to know how to safely get out to the point where we can error out on it.
