Date: Sat, 13 Nov 2010 08:46:45 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Alexander Best <arundel@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Ulrich Spoerlein <uqs@freebsd.org> Subject: Re: svn commit: r215237 - head/lib/msun/src Message-ID: <20101113164645.GB69612@troutmask.apl.washington.edu> In-Reply-To: <20101113125648.GA25183@freebsd.org> References: <201011131054.oADAsA7I045096@svn.freebsd.org> <20101113125648.GA25183@freebsd.org>
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On Sat, Nov 13, 2010 at 12:56:48PM +0000, Alexander Best wrote: > On Sat Nov 13 10, Ulrich Spoerlein wrote: > > Author: uqs > > Date: Sat Nov 13 10:54:10 2010 > > New Revision: 215237 > > URL: http://svn.freebsd.org/changeset/base/215237 > > > > Log: > > Fix bug in jn(3) and jnf(3) that led to -inf results > > thank you very much for fixing this long outstanding issue. > you might want to have a look at [1], where two more issues have been reported. > > cheers. > alex > > [1] http://mailman.oakapple.net/pipermail/numeric-interest/2010-September/thread.html > Ulrich, thanks. Of the two remaining issues, I can verify one is indeed an issue. laptop:kargl[204] cat mn.c #include <stdio.h> #include <math.h> static const double z = 0.; int main(void) { double x, y; x = -1. / z; y = exp( 0.5 * log(x)); printf("pow(%f, 0.5) = %le, %le\n", x, pow(x, 0.5), y); y = exp(-0.5 * log(x)); printf("pow(%f, -0.5) = %le, %le\n", x, pow(x, -0.5), y); return 0; } laptop:kargl[205] cc -o z mn.c -fno-builtin -lm && ./z pow(-inf, 0.5) = inf, nan pow(-inf, -0.5) = 0.000000e+00, nan -- Steve
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