Bug#617894: [ARMel] tgammal isn't accurate enough
Package: libc6
Version: 2.11.2-13
The following piece of code :
#include <stdio.h>
#include <math.h>
int
main (int argc,
char* argv[])
{
long double x = 6.0;
printf ("tgammal (%20Lf)=%20Lf\n", x, tgammal (x));
return 0;
}
Prints, on an x86 debian unstable (eglibc 2.11.2-11) :
tgammal ( 6.000000)= 120.000000
And on an ARMel debian unstable (eglibc 2.11.2-13) :
tgammal (6.00000000000000000000)=119.99999999999997157829
That last results if of too poor precision for sage
(http://www.sagemath.org), which I'm porting to the platform.
The box used to run ubuntu, where the problem occurred too
(https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/713985).
Snark on #sage-devel
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