https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84999
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- -m32 doesn't support __int128, nor int __attribute__((mode(TI))), and the __float128 vector comparison would be just a loophole to get at that support. C++ FE diagnoses this already: pr84999.c:5:5: error: could not find an integer type of the same size as ‘__float128’ and I think C FE should do the same.