https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103316
--- Comment #5 from Bill Schmidt <wschmidt at gcc dot gnu.org> --- At first glance, this is probably because vector.md's definition of vec_cmp<mode><mode> isn't defined for V1TImode. Probably needs to be changed to use VEC_IP rather than VEC_I and implement all the cases for 128-bit.