https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97163
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Well, libcpp isn't using the standard Altivec intrinsics, but their gcc underlying implementation. Looking at clang altivec.h, I see they use vector keyword everywhere and not sure what exactly they map it to under the hood, but clearly not to altivec attribute, and they have different __builtin_* calls to implement e.g. vsx_ld and the like.
