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* [Bug math/26982] New: [x86_64] x86_64 lgamma has too large ULP error
@ 2020-11-30 10:27 zimmerma+gcc at loria dot fr
2020-12-01 23:51 ` [Bug math/26982] " woodard at redhat dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: zimmerma+gcc at loria dot fr @ 2020-11-30 10:27 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=26982
Bug ID: 26982
Summary: [x86_64] x86_64 lgamma has too large ULP error
Product: glibc
Version: 2.32
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: math
Assignee: unassigned at sourceware dot org
Reporter: zimmerma+gcc at loria dot fr
CC: joseph at codesourcery dot com
Target Milestone: ---
$ cat test.c
#include <stdio.h>
#include <math.h>
int main()
{
double x = -0x1.f60c969a239f2p+1, y;
y = lgamma (x);
printf ("x=%a y=%a\n", x, y);
}
$ gcc -fno-builtin test.c -lm
$ ./a.out
x=-0x1.f60c969a239f2p+1 y=-0x1.fd3d359162ae4p-2
The correctly rounded result is -0x1.fd3d359162adap-2, thus the error is 10
ulps, which is larger than the maximum accepted limit of 9 ulps.
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^ permalink raw reply [flat|nested] 4+ messages in thread* [Bug math/26982] [x86_64] x86_64 lgamma has too large ULP error 2020-11-30 10:27 [Bug math/26982] New: [x86_64] x86_64 lgamma has too large ULP error zimmerma+gcc at loria dot fr @ 2020-12-01 23:51 ` woodard at redhat dot com 2020-12-04 17:29 ` zimmerma+gcc at loria dot fr 2021-01-05 14:57 ` zimmerma+gcc at loria dot fr 2 siblings, 0 replies; 4+ messages in thread From: woodard at redhat dot com @ 2020-12-01 23:51 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=26982 Ben Woodard <woodard at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |woodard at redhat dot com -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug math/26982] [x86_64] x86_64 lgamma has too large ULP error 2020-11-30 10:27 [Bug math/26982] New: [x86_64] x86_64 lgamma has too large ULP error zimmerma+gcc at loria dot fr 2020-12-01 23:51 ` [Bug math/26982] " woodard at redhat dot com @ 2020-12-04 17:29 ` zimmerma+gcc at loria dot fr 2021-01-05 14:57 ` zimmerma+gcc at loria dot fr 2 siblings, 0 replies; 4+ messages in thread From: zimmerma+gcc at loria dot fr @ 2020-12-04 17:29 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=26982 --- Comment #1 from Paul Zimmermann <zimmerma+gcc at loria dot fr> --- I also get an error of 11.8884 ulps in the binary128 format for x=-0x3.ec1bd0fc6a9c6bf9b04c0bcd1a96p+0 (from https://members.loria.fr/PZimmermann/papers/accuracy.pdf) -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug math/26982] [x86_64] x86_64 lgamma has too large ULP error 2020-11-30 10:27 [Bug math/26982] New: [x86_64] x86_64 lgamma has too large ULP error zimmerma+gcc at loria dot fr 2020-12-01 23:51 ` [Bug math/26982] " woodard at redhat dot com 2020-12-04 17:29 ` zimmerma+gcc at loria dot fr @ 2021-01-05 14:57 ` zimmerma+gcc at loria dot fr 2 siblings, 0 replies; 4+ messages in thread From: zimmerma+gcc at loria dot fr @ 2021-01-05 14:57 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=26982 --- Comment #2 from Paul Zimmermann <zimmerma+gcc at loria dot fr> --- for long double on x86_64 (ldbl-96) I get an error of 11.4817 ulps for x = -0x3.ec953aa5efab0258p+0l with glibc 2.32. -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-01-05 14:57 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-11-30 10:27 [Bug math/26982] New: [x86_64] x86_64 lgamma has too large ULP error zimmerma+gcc at loria dot fr 2020-12-01 23:51 ` [Bug math/26982] " woodard at redhat dot com 2020-12-04 17:29 ` zimmerma+gcc at loria dot fr 2021-01-05 14:57 ` zimmerma+gcc at loria dot fr
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