svn commit: r215237 - head/lib/msun/src

[Alexander Best]

On Tue Nov 16 10, Bruce Evans wrote:
> On Tue, 16 Nov 2010, Bruce Evans wrote:
> 
> >...
> >I checked most cases specified in n1156.pdf and found only the following
> >non-conforming behaviour in FreeBSD:
> >
> >%C99 rule               -- pow(-Inf, y) returns -0 for y an odd integer < 
> >0.
> >%fdlibm rule(?)  *	17. -INF ** (anything)  = -0 ** (-anything)
> >
> >fdlibm error: returns +0 instead of -0.  I'm not sure if I matched the
> >rules correctly.
> 
> False alarm.  It actually returns -0 as specified.
> 
> >%C99 rule               -- pow(-1, +-Inf) returns 1.
> >%fdlibm rule     *	9.  +-1         ** +-INF is NAN
> >
> >fdlibm non-error: pow(-1, +-Inf) is NaN, not 1 as specified by C99.
> >fdlibm non-error: pow(1, +-Inf) is 1 as specified by C99, not NaN as
> >claimed in the comment.
> 
> So I didn't find any non-conforming behaviour in fdlibm except for not
> conforming to the new pow(-1, +-Inf) bug (which is required for conistency
> with old bugs).

thanks for all your work. i don't think there are a lot of people able to
understand the tiny details of arithmetics, so having your expertise is
invaluable. :)

if you are interested in solving two more msun mysteries, you might want to
have a look at #PR kern/133583 and standards/143358.

cheers.
alex

> 
> Bruce

-- 
a13x