On Mon, Feb 13, 2017 at 05:08:07PM +0100, Andrew - wrote: > Is this the expected behaviour when std::isinf(-inf) yields 0 or -1 > instead of 1? It returns a bool, not a number. > Granted, -Ofast is allowed to disregard some standards in favor of > performance... but is it allowed to produce code that is plain wrong? -Ofast includes -ffast-math which includes -ffinite-math-only. Nothing is wrong here, everything works as designed, the only thing plain wrong is using infinities when you promised not to :-) > Furthermore, std::isinf sometimes takes the output of isinf from the > math library without casting it to bool, which, as far as I know, > doesn`t comply to the standard. Yeah this looks weird. > The question is whether I should report any of this as a GCC bug. I think you should yes. Segher
