https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98167
--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> --- -fno-trapping-math tells us we are not concerned about FP exception flags (so say spurious FP_INEXACT is OK), -fno-signalling-nans is needed as well I guess. Oh, and in practice performing the multiplication for elements that are NaN or denormal might trigger very slow paths in the CPU which means the optimization could be a pessimization runtime wise. Eventually zeroing the unused lanes in one(?) of the operands is enough to avoid that (for denormal, I guess 0 * NaN is still NaN).
