Re: gawk 3.1.5h test results on interix

[Martin Koeppe]

On Tue, 16 Oct 2007, Aharon Robbins wrote:

> Greetings. Re this:
>
> > I just test built gawk 3.1.5h on interix 3.5. Building was fine, but 2
> > tests failed, see below.
> >
> > Martin
> >
> >
> > --- fmtspcl.ok  Mon Oct 15 09:12:50 2007
> > +++ _fmtspcl    Mon Oct 15 09:12:50 2007
> > @@ -5,5 +5,10 @@
> >   gawk: ./fmtspcl.awk:6: warning: [s]printf: value NaN is out of range for `%d' 
> > format
> >   gawk: ./fmtspcl.awk:6: warning: [s]printf: value NaN is out of range for `%x' 
> > format
> >   gawk: ./fmtspcl.awk:6: warning: [s]printf: value NaN is out of range for `%d' 
> > format
> > +sprintf(%f,NaN) = NaN (!= -NaN)
> > +sprintf(%s,NaN) = NaN (!= -NaN)
> > +sprintf(%g,NaN) = NaN (!= -NaN)
> >   gawk: ./fmtspcl.awk:6: warning: [s]printf: value NaN is out of range for `%x' 
> > format
> > +sprintf(%x,NaN) = NaN (!= -NaN)
> >   gawk: ./fmtspcl.awk:6: warning: [s]printf: value NaN is out of range for `%d' 
> > format
> > +sprintf(%d,NaN) = NaN (!= -NaN)
>
> It would appear that your library doesn't distinguish negative and positive NAN 
> values.
> Is that true?

Yes, I verified that now. Interix libc printf doesn't distinguish 
between NaN and -NaN, it always prints "NaN".

> Andy:
> This seems rather bewildering to me (that 'sprintf("%f",-nan)' 
> returned '-NaN' in the first instance inside BEGIN, but then behaved 
> differently inside the display function).  I hope that I'm reading 
> the code improperly. Does anybody else understand what's going on 
> here?

But Andy is also right. NaN or -NaN isn't the problem, the test 
compensates for it. The real problem is that log(0) isn't -Inf but NaN 
for me. The reason is, however, the libm I'm using. If I use the 
system libm, everything is fine, also the tweakfld test. The system 
libm has other problems with single precision floats, that's why I'm 
now using libm from newlib.

Unfortunaly, newlib's libm has a bug which I just found now. For 
log(0) the docs says it returns -Inf, but the source says it returns 
NaN.

Thank you both.

On Interix there is a problem with "long double", for details see:
http://www.debian-interix.net/techdocs/#ldbl

Apparently, this is not the case here, but just to verify: Does gawk 
make use of "long double" anywhere, besides in the configure script?


Martin


> > --- tweakfld.ok Fri Aug 11 14:05:50 2006
> > +++ _tweakfld   Mon Oct 15 09:13:45 2007
>
> It seems that your library for sin and cos return small values where other
> systems return zero. This code is a bit hard to follow, since it came in
> a bug report, but that's what it looks like to me.
>
> In any case, I think that for most things the version you've built should
> be fine.  The tweakfld test is an old one --- if an older version of gawk
> also fails on it under Interix then I don't think it's an issue.
>
> Thanks,
>
> Arnold