[PATCH v3] Add nextup and nextdown math functions

[Joseph Myers]

On Tue, 7 Jun 2016, Rical Jasan wrote:

> I don't believe quiet NaNs are mentioned, though, so if that just means
> a normal NaN that doesn't make noise by signalling like a sNaN, it might
> not hurt to introduce that language in the Infinity and NaN section.

NaNs are quiet by default, as per the usage in the C standard.  Yes, maybe 
the glibc manual needs to say a bit more there.

> nextup(-Inf) is more interesting :), as well as the subnormal, but is
> the zero behaviour you just described abnormal in some way? That seems

The point is that it's not about an ordering (-DBL_TRUE_MIN, -0.0, 0.0, 
DBL_TRUE_MIN) that has both -0.0 and +0.0 (like for the totalorder 
function in TS 18661-1) and goes from one to the other - but about going 
to the next value that is strictly greater or less than the argument 
(depending on the function).  And saying that then leaves the choice of 
-0.0 or +0.0 as ambiguous, so it needs to be specified.

-- 
Joseph S. Myers
joseph@codesourcery.com