> AIUI, neither ORDERED nor UNEQ trap on signalling NaNs. Without this, > the follow-on patch would fold > > (and (ordered x y) (uneq x y)) -> (eq x y) > > which is the same thing for quiet NaNs but not for signalling NaNs.
Note that GCC defaults to -fno-signaling-nans and the transformation would be valid in this mode. -- Eric Botcazou
