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From: Tim Prince <tprince@computer.org> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, Subject: Re: other/8484: gcc 3.2: log(0) => NaN ; -(Inf) => NaN; should return -Inf Date: Thu, 07 Nov 2002 22:06:00 -0000 [thread overview] Message-ID: <20021108060601.9662.qmail@sources.redhat.com> (raw) The following reply was made to PR other/8484; it has been noted by GNATS. From: Tim Prince <tprince@computer.org> To: kabal@ECE.McGill.CA, gcc-gnats@gcc.gnu.org Cc: Subject: Re: other/8484: gcc 3.2: log(0) => NaN ; -(Inf) => NaN; should return -Inf Date: Thu, 7 Nov 2002 22:04:24 -0800 On Wednesday 06 November 2002 13:01, kabal@ECE.McGill.CA wrote: > >Number: 8484 > >Category: other > >Synopsis: gcc 3.2: log(0) => NaN ; -(Inf) => NaN; should return -Inf > >Originator: Peter Kabal > >Release: gcc version 3.2 20020818 (prerelease) > >Organization: > >Environment: > > Cygwin under Windows XP pro > > >Description: > > Tests show that log(0) returns NaN and negating Inf also gives NaN. Under > previous 2.9x versions of gcc, these would both return -Inf. > > #include <math.h> > > int main (int argc, const char *argv[]) > > { > double dv; > > dv = -sqrt(1.0) / 0.0; > printf ("-sqrt(1) = %g\n", dv); > dv = log (0.0); > printf ("log(0) = %g\n", dv); > > return 0; > } I find it difficult to believe that the gcc version you use is directly responsible for the behavior of newlib printf(), if that's what you are claiming. gcc-3.3 with an old glibc on linux is giving me your expected result; gcc-3.3 on cygwin with the standard newlib is behaving as you report. Neither glibc nor newlib is under the influence of gcc maintainers. I doubt you will find a gcc maintainer willing to install the various gcc versions on cygwin, to see if they do in fact alter the behavior of newlib, nor do I see what you expect gcc to do about newlib. -- Tim Prince
next reply other threads:[~2002-11-08 6:06 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2002-11-07 22:06 Tim Prince [this message] -- strict thread matches above, loose matches on Subject: below -- 2002-11-06 13:06 kabal
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