https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88713
--- Comment #31 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Chris Elrod from comment #30) > gcc caclulates the rsqrt directly No, vrsqrt14ps is just the first step in calculating sqrt here (slightly different formula than rsqrt). vrcp14ps shows that it is computing an inverse later. What we need to understand is why gcc doesn't try to generate rsqrt (which would also have vrsqrt14ps, but a slightly different formula without the comparison with 0 and masking, and without needing an inversion afterwards).
