X-Authentication-Warning:	delorie.com: mailnull set sender to djgpp-workers-bounces using -f
Date:	Sun, 3 Mar 2002 13:35:41 +0200 (IST)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	djgpp-workers AT delorie DOT com
Subject:	Re: libm signed/unsigned warnings
In-Reply-To:	<200203031015.g23AFf901564@mother.ludd.luth.se>
Message-ID:	<Pine.SUN.3.91.1020303133142.705F-100000@is>
MIME-Version:	1.0
Reply-To:	djgpp-workers AT delorie DOT com
Errors-To:	nobody AT delorie DOT com
X-Mailing-List:	djgpp-workers AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On Sun, 3 Mar 2002, Martin Str|mberg wrote:

> According to Eli Zaretskii:
> > Please run the cygnus test suite after the changes, and compare the
> > results with tests/cygnus/standard.results.  Any changes should be
> > scrutinized.
> 
> Ouch! Only recompiling (djlsr203) libm with gcc 3.04 increases the
> failures from 397 to 491. CVS head gives 451. My changes take this
> number down to 430.

Sigh.  I was afraid this would be the case.

> So it seems I mamanged to improve something but I
> don't know why.

The only way to find the problems is to debug each case of failure 
individually, unfortunately.

One troublesome issue is aggressive optimizations of the newer compilers: 
libm.a sources sometimes depend on certain subexpressions not being 
optimized away, even though rules of algebra suggest they could be.  Try 
building libm.a without optimizations and see if things change.

Also, some ``failures'' are actually due to changes in low bits of the 
result, like bit 62 of a double.  These can be generally disregarded, 
especially in low-accuracy functions such as j0 etc. (you will see that 
standard.results reports lots of inaccurate results for those).

- Raw text -