From: Paul Zimmermann <Paul.Zimmermann@inria.fr>
To: newlib@sourceware.org
Subject: regression in tgamma?
Date: Wed, 16 Dec 2020 14:48:55 +0100 [thread overview]
Message-ID: <mw7dphdfp4.fsf@tomate.loria.fr> (raw)
Hi,
the regression I observed also concerns the binary32 code.
Consider the following code:
$ cat /tmp/test_tgamma.c
#include <stdio.h>
#include <math.h>
#ifdef NEWLIB
int errno;
int* __errno () { return &errno; }
#endif
int main()
{
float x = -0.0f;
float y = tgammaf (x);
printf ("x=%a y=%a\n", x, y);
{
double x = -0x1.53f198fe3b278p+7, y;
y = tgamma (x);
printf ("x=%a y=%a\n", x, y);
}
}
With commit a0d7982ff486292540078c0121a435013c5ee1ea it gives on x86_64/linux
(Intel(R) Core(TM) i5-4590):
$ gcc -no-pie -DNEWLIB /tmp/test_tgamma.c build/x86_64/newlib/libm/tmp/libm.a
$ ./a.out
x=-0x0p+0 y=inf
x=-0x1.53f198fe3b278p+7 y=0x1.fd6d312572d9cp-1015
and with commit 1f8e5847dff27e504949cd21bfeadb987d36ad19:
$ gcc -no-pie -DNEWLIB /tmp/test_tgamma.c build/x86_64/newlib/libm/tmp/libm.a
$ ./a.out
x=-0x0p+0 y=0x1p+0
x=-0x1.53f198fe3b278p+7 y=0x1p+0
Paul
next reply other threads:[~2020-12-16 13:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-16 13:48 Paul Zimmermann [this message]
2020-12-16 20:31 ` Jeff Johnston
2020-12-17 7:29 ` Paul Zimmermann
2020-12-17 16:13 ` Keith Packard
2020-12-17 18:27 ` Jeff Johnston
2020-12-17 19:16 ` Keith Packard
2020-12-17 21:28 ` Jeff Johnston
2020-12-18 6:36 ` Paul Zimmermann
2020-12-18 8:42 ` Corinna Vinschen
2020-12-18 8:54 ` Paul Zimmermann
2020-12-18 9:07 ` Corinna Vinschen
2020-12-18 17:42 ` Jeff Johnston
2020-12-18 8:37 ` Paul Zimmermann
-- strict thread matches above, loose matches on Subject: below --
2020-12-15 13:35 Paul Zimmermann
2020-12-15 17:11 ` Jeff Johnston
2020-12-16 6:36 ` Paul Zimmermann
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