https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78604
--- Comment #6 from Michael Meissner <meissner at gcc dot gnu.org> --- Unless -ffast-math or -fno-honor-nans is used, you cannot invert < to >=, because you will get a different result if either operand is a NaN. However, the basic code for vector compares hasn't changed much since the early power7 days.
