Your message dated Thu, 17 Dec 2015 19:47:53 +0100
with message-id <[email protected]>
and subject line Re: Bug#687545: libc6: Incorrect decimal printf output of tiny
long double values on PowerPC
has caused the Debian Bug report #687545,
regarding libc6: Incorrect decimal printf output of tiny long double values on
PowerPC
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
687545: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=687545
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: libc6
Version: 2.13-35
Severity: normal
The minimum positive long double value is not output correctly by
printf with the decimal conversion specifiers (e, f, g) on PowerPC
(where long double is implemented with a double-double arithmetic).
See the testcase below. There may be the same problem with other
tiny values.
#include <stdio.h>
#include <math.h>
int main (void)
{
double d;
long double e;
d = nextafter (0.0, 1.0);
printf ("d = %e = %f = %g = %a\n", d, d, d, d);
e = d;
printf ("e = %Le = %Lf = %Lg = %La\n", e, e, e, e);
d = e;
printf ("d = %e = %f = %g = %a\n", d, d, d, d);
printf ("d = %.330f\n", d);
printf ("e = %.330Lf\n", e);
return 0;
}
I get:
d = 4.940656e-324 = 0.000000 = 4.94066e-324 = 0x0.0000000000001p-1022
e = 4.450148e-308 = 0.000000 = 4.45015e-308 = 0x0.0000000000001p-1022
d = 4.940656e-324 = 0.000000 = 4.94066e-324 = 0x0.0000000000001p-1022
d =
0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004940656
e =
0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000044501477170144027661805
Note that 4.450148e-308 / 4.940656e-324 is about 2^53, where 53 is the
precision of a double. I suspect that the glibc code doesn't handle
small values such that one of the double's in the representation is 0.
-- System Information:
Debian Release: wheezy/sid
APT prefers testing
APT policy: (900, 'testing'), (900, 'stable'), (200, 'unstable')
Architecture: powerpc (ppc)
Kernel: Linux 2.6.26-1-powerpc
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages libc6 depends on:
ii libc-bin 2.13-35
ii libgcc1 1:4.7.1-7
libc6 recommends no packages.
Versions of packages libc6 suggests:
ii debconf [debconf-2.0] 1.5.46
pn glibc-doc <none>
ii locales 2.13-35
-- debconf information:
glibc/upgrade: true
glibc/disable-screensaver:
* glibc/restart-failed:
* glibc/restart-services: spamassassin openbsd-inetd exim4 cron atd
* libraries/restart-without-asking: true
-- debsums errors found:
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 5250 package
'inn2':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 8462 package
'libgdbmg1':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 11058
package 'libnewt0':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 13393
package 'docbook-mathml':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 22784
package 'libpcd':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 31190
package 'inn2-inews':
missing architecture
dpkg-query: warning: parsing file '/var/lib/dpkg/status' near line 33324
package 'libisc4':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 5250
package 'inn2':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 8462
package 'libgdbmg1':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 11058
package 'libnewt0':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 13393
package 'docbook-mathml':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 22784
package 'libpcd':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 31190
package 'inn2-inews':
missing architecture
dpkg-divert: warning: parsing file '/var/lib/dpkg/status' near line 33324
package 'libisc4':
missing architecture
--- End Message ---
--- Begin Message ---
Version: 2.19-18
On 2012-09-13 18:29, Vincent Lefevre wrote:
> Package: libc6
> Version: 2.13-35
> Severity: normal
>
> The minimum positive long double value is not output correctly by
> printf with the decimal conversion specifiers (e, f, g) on PowerPC
> (where long double is implemented with a double-double arithmetic).
> See the testcase below. There may be the same problem with other
> tiny values.
>
> #include <stdio.h>
> #include <math.h>
>
> int main (void)
> {
> double d;
> long double e;
>
> d = nextafter (0.0, 1.0);
> printf ("d = %e = %f = %g = %a\n", d, d, d, d);
> e = d;
> printf ("e = %Le = %Lf = %Lg = %La\n", e, e, e, e);
> d = e;
> printf ("d = %e = %f = %g = %a\n", d, d, d, d);
> printf ("d = %.330f\n", d);
> printf ("e = %.330Lf\n", e);
> return 0;
> }
>
> I get:
>
> d = 4.940656e-324 = 0.000000 = 4.94066e-324 = 0x0.0000000000001p-1022
> e = 4.450148e-308 = 0.000000 = 4.45015e-308 = 0x0.0000000000001p-1022
> d = 4.940656e-324 = 0.000000 = 4.94066e-324 = 0x0.0000000000001p-1022
> d =
> 0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004940656
> e =
> 0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000044501477170144027661805
>
> Note that 4.450148e-308 / 4.940656e-324 is about 2^53, where 53 is the
> precision of a double. I suspect that the glibc code doesn't handle
> small values such that one of the double's in the representation is 0.
This bug is reproducible in wheezy but not in jessie. I therefore
conclude that the bug has been fixed in between and I am closing it with
this mail.
--
Aurelien Jarno GPG: 4096R/1DDD8C9B
[email protected] http://www.aurel32.net
--- End Message ---
