https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103316
--- Comment #16 from Segher Boessenkool <segher at gcc dot gnu.org> --- There are many patterns that use VEC_I, and not all have a V1TI variant currently, so adding V1TI to it is not suitable for now. It is better to add a new iterator for now. This whole thing desperately needs a big cleanup :-(