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* [Bug math/14638] New: fma produced wrong results for (0 * -1.0) + -0.0
@ 2012-09-27 20:45 law at redhat dot com
2012-09-29 18:34 ` [Bug math/14638] " jsm28 at gcc dot gnu.org
2014-06-17 4:17 ` fweimer at redhat dot com
0 siblings, 2 replies; 3+ messages in thread
From: law at redhat dot com @ 2012-09-27 20:45 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14638
Bug #: 14638
Summary: fma produced wrong results for (0 * -1.0) + -0.0
Product: glibc
Version: 2.17
Status: NEW
Severity: normal
Priority: P2
Component: math
AssignedTo: unassigned@sourceware.org
ReportedBy: law@redhat.com
Classification: Unclassified
The FMA implementation in sysdeps/ieee754/dbl-64/s_fma.c produces the wrong
result for this program when run on a x86_64 box that doesn't have fma3/fma4
support.
#include <assert.h>
#include <math.h>
#include <stdlib.h>
int main (void) {
double f1 = 0.0f;
double f2 = -1.0f;
double f3 = -0.0f;
double dresult = fma (f1, f2, f3);
if (! signbit (dresult))
abort ();
exit (0);
}
--
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^ permalink raw reply [flat|nested] 3+ messages in thread* [Bug math/14638] fma produced wrong results for (0 * -1.0) + -0.0 2012-09-27 20:45 [Bug math/14638] New: fma produced wrong results for (0 * -1.0) + -0.0 law at redhat dot com @ 2012-09-29 18:34 ` jsm28 at gcc dot gnu.org 2014-06-17 4:17 ` fweimer at redhat dot com 1 sibling, 0 replies; 3+ messages in thread From: jsm28 at gcc dot gnu.org @ 2012-09-29 18:34 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=14638 Joseph Myers <jsm28 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED --- Comment #1 from Joseph Myers <jsm28 at gcc dot gnu.org> 2012-09-29 18:34:30 UTC --- Fixed for 2.17 by: commit 8ec5b01346114da38e806ca1867da688d3a360e2 Author: Joseph Myers <joseph@codesourcery.com> Date: Sat Sep 29 18:31:54 2012 +0000 Fix sign of exact zero return from fma (bug 14638). -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug math/14638] fma produced wrong results for (0 * -1.0) + -0.0 2012-09-27 20:45 [Bug math/14638] New: fma produced wrong results for (0 * -1.0) + -0.0 law at redhat dot com 2012-09-29 18:34 ` [Bug math/14638] " jsm28 at gcc dot gnu.org @ 2014-06-17 4:17 ` fweimer at redhat dot com 1 sibling, 0 replies; 3+ messages in thread From: fweimer at redhat dot com @ 2014-06-17 4:17 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=14638 Florian Weimer <fweimer at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Flags| |security- -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-06-17 4:17 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-09-27 20:45 [Bug math/14638] New: fma produced wrong results for (0 * -1.0) + -0.0 law at redhat dot com 2012-09-29 18:34 ` [Bug math/14638] " jsm28 at gcc dot gnu.org 2014-06-17 4:17 ` fweimer at redhat dot com
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