https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109005
--- Comment #17 from Marc Poulhiès <dkm at gcc dot gnu.org> --- FWIW, can confirm the above fix works for the small reproducer (x86_64-linux) /* Bail out if the representative is BLKmode as we will not be able to vectorize this. */ - if (TYPE_MODE (TREE_TYPE (rep_decl)) == E_BLKmode) + if (!is_gimple_reg_type (TREE_TYPE (rep_decl))) return NULL_TREE;