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* [Bug math/4108] New: erfcf returns incorrectly rounded results compared to erfc @ 2007-02-28 2:34 myles at peakstreaminc dot com 2007-02-28 2:35 ` [Bug math/4108] " myles at peakstreaminc dot com 0 siblings, 1 reply; 5+ messages in thread From: myles at peakstreaminc dot com @ 2007-02-28 2:34 UTC (permalink / raw) To: glibc-bugs In the attached program results from erfc are compared with results from erfcf and large differences are flagged. The errors occur for values near 4.0 and 8.0, but slightly under. Two examples: x: 3.9311595 (407b981e) float(erfc): 2.7055004e-08 (32e86695) erfcf: 2.705503e -08 (32e866a4) diff: 2.6645353e-14 (45 ULP) x: 7.9999866 (40ffffe4) float(erfc): 1.1226714e-29 (f63b46e) erfcf: 1.1226756e -29 (f63b4a7) diff: 4.2882034e-35 (114 ULP) It is possible the values for erfc are incorrect, as I don't have another source to check that. Also happens on x86_64-redhat-linux -- Summary: erfcf returns incorrectly rounded results compared to erfc Product: glibc Version: 2.3.4 Status: NEW Severity: normal Priority: P2 Component: math AssignedTo: aj at suse dot de ReportedBy: myles at peakstreaminc dot com CC: glibc-bugs at sources dot redhat dot com GCC build triplet: i386-redhat-linux GCC host triplet: i386-redhat-linux GCC target triplet: i386-redhat-linux http://sourceware.org/bugzilla/show_bug.cgi?id=4108 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug math/4108] erfcf returns incorrectly rounded results compared to erfc 2007-02-28 2:34 [Bug math/4108] New: erfcf returns incorrectly rounded results compared to erfc myles at peakstreaminc dot com @ 2007-02-28 2:35 ` myles at peakstreaminc dot com 0 siblings, 0 replies; 5+ messages in thread From: myles at peakstreaminc dot com @ 2007-02-28 2:35 UTC (permalink / raw) To: glibc-bugs ------- Additional Comments From myles at peakstreaminc dot com 2007-02-28 02:35 ------- Created an attachment (id=1585) --> (http://sourceware.org/bugzilla/attachment.cgi?id=1585&action=view) Program (C++) that compares erfcf and erfc results This program may be compiled with g++, e.g. gcc version 3.4.5 20051201 (Red Hat 3.4.5-2) -- http://sourceware.org/bugzilla/show_bug.cgi?id=4108 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <bug-4108-131@http.sourceware.org/bugzilla/>]
* [Bug math/4108] erfcf returns incorrectly rounded results compared to erfc [not found] <bug-4108-131@http.sourceware.org/bugzilla/> @ 2012-02-26 14:00 ` jsm28 at gcc dot gnu.org 2012-02-26 16:34 ` jsm28 at gcc dot gnu.org 2012-03-01 21:19 ` jsm28 at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: jsm28 at gcc dot gnu.org @ 2012-02-26 14:00 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=4108 Joseph Myers <jsm28 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|aj at suse dot de |unassigned at sourceware | |dot org --- Comment #2 from Joseph Myers <jsm28 at gcc dot gnu.org> 2012-02-26 14:00:40 UTC --- Confirmed in essence (the numbers of ULPs given in this report don't seem right, though). erfcf (0X1.F7303CP+1) should be 0X1.D0CD2AP-26 but glibc gives 0X1.D0CD46P-26. erfcf (0X1.FFFFC8P+2) should be 0X1.C768DCP-97 but glibc gives 0X1.C7694EP-97. Probably same cause as bug 2541. -- 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] 5+ messages in thread
* [Bug math/4108] erfcf returns incorrectly rounded results compared to erfc [not found] <bug-4108-131@http.sourceware.org/bugzilla/> 2012-02-26 14:00 ` jsm28 at gcc dot gnu.org @ 2012-02-26 16:34 ` jsm28 at gcc dot gnu.org 2012-03-01 21:19 ` jsm28 at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: jsm28 at gcc dot gnu.org @ 2012-02-26 16:34 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=4108 Joseph Myers <jsm28 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED AssignedTo|unassigned at sourceware |jsm28 at gcc dot gnu.org |dot org | --- Comment #3 from Joseph Myers <jsm28 at gcc dot gnu.org> 2012-02-26 16:33:28 UTC --- Patch submitted: http://sourceware.org/ml/libc-alpha/2012-02/msg00640.html -- 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] 5+ messages in thread
* [Bug math/4108] erfcf returns incorrectly rounded results compared to erfc [not found] <bug-4108-131@http.sourceware.org/bugzilla/> 2012-02-26 14:00 ` jsm28 at gcc dot gnu.org 2012-02-26 16:34 ` jsm28 at gcc dot gnu.org @ 2012-03-01 21:19 ` jsm28 at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: jsm28 at gcc dot gnu.org @ 2012-03-01 21:19 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=4108 Joseph Myers <jsm28 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED --- Comment #4 from Joseph Myers <jsm28 at gcc dot gnu.org> 2012-03-01 21:18:28 UTC --- Fixed by: commit 7b1902cb3e64d340247638a8781770c3a4d850ce Author: Joseph Myers <joseph@codesourcery.com> Date: Thu Mar 1 21:15:38 2012 +0000 Improve erfc accuracy. -- 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] 5+ messages in thread
end of thread, other threads:[~2012-03-01 21:19 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2007-02-28 2:34 [Bug math/4108] New: erfcf returns incorrectly rounded results compared to erfc myles at peakstreaminc dot com 2007-02-28 2:35 ` [Bug math/4108] " myles at peakstreaminc dot com [not found] <bug-4108-131@http.sourceware.org/bugzilla/> 2012-02-26 14:00 ` jsm28 at gcc dot gnu.org 2012-02-26 16:34 ` jsm28 at gcc dot gnu.org 2012-03-01 21:19 ` jsm28 at gcc dot gnu.org
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