[Bug tree-optimization/78604] [7 regression] test case gcc.target/powerpc/p8vector-vectorize-1.c fails starting with r242750

[meissner at gcc dot gnu.org]

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.