https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96306
--- Comment #3 from Andrew Stubbs <ams at gcc dot gnu.org> --- TImode was added for use by a few instructions that take two 64-bit values in consecutive registers. It's also useful for the SLP fake vectorization stuff. It wasn't intended for use with user types; I probably ought to disable it, at least for now.
