https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85030
--- Comment #4 from Vladimir Makarov <vmakarov at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #3) > 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. I'll look at this. LRA approach is different. It tries to transform RTL after each decision. Reload does not do changes until the very end. Therefore I think it will be a bit harder to fix it in LRA.