Bug#709756: (libc6 2.17 performance slowdown)

[debbugs@gedanken.org.uk (Andrew M. Bishop)]

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.

-- 
Andrew Bishop