Bug#709756: (libc6 2.17 performance slowdown)

[Aurelien Jarno <aurelien@aurel32.net>]

On Sun, Jun 02, 2013 at 04:53:35PM +0100, Andrew M. Bishop wrote:
> I have done some more investigation and the cause of the slowdown
> appears to be this bug-fix to eglibc:
> 
> http://sourceware.org/bugzilla/show_bug.cgi?id=13658
> 
> My (possibly biased) summary of this change is that one user reported
> inaccurate sincos results for very large numbers so the eglibc library
> was changed so that *all* sin, cos and sincos functions now use soft
> maths functions rather than the FPU.
> 
> 
> Other people are reporting the slowdown as well and there is an eglibc
> bug report:
> 
> http://www.sourceware.org/bugzilla/show_bug.cgi?id=14412
> 
> No solution seems forthcoming and the bug is only marked as an
> "enhancement" rather than critical.

The problem is supposed to have been fixed in version 2.18. In practice
on my machine, I see that with version 2.18 the performances are almost
back to the 2.17 level, with version 2.19 the performances are slightly 
above 2.17.

I therefore guess that the problem is fixed and that the bug could be
closed. Could you please try and confirm?

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net