Re: document the fact that "Known Maximum Errors" might not be maximal

[Vincent Lefevre <vincent@vinc17.net>]

On 2024-02-16 11:02:40 +0100, Paul Zimmermann wrote:
>        Hi Vincent,
> 
> > Instead of saying that they are "documented elsewhere", shouldn't the
> > manual be updated?
> 
> this is one solution I proposed in
> https://sourceware.org/pipermail/libc-alpha/2023-December/153279.html,
> and Carlos answered:
> 
> > (a) There are known defects where ULPs may reach values that are not useful
> >     for talking about the library in general.
> > 
> > (b) There is value in being clear about the worst case known ULPs for an
> >     implementation of a given algorithm.
> > 
> > If a test is marked as XFAIL then it is clearly (a) and listing that worst
> > case ULPs in the manual may not be useful.
> 
> thus the proposed patch documents the existence of the "XFAIL" entries.

If I understand correctly, Carlos means (unintended) bugs, in which
case, values may even be completely wrong (as already seen). I think
that saying "documented elsewhere" is misleading. And note that bugs
are not specific to the math functions. Any buggy library function
will not behave as described in the manual. You should rather say
that the given bounds obviously do not take bugs into account, if
you think that this is worth recalling.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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