F13 glibc with nopl instructions - an explanation

[Daniel Drake]

Hi,

In the FESCO meeting today
(http://meetbot.fedoraproject.org/fedora-meeting/2010-06-08/fesco.2010-06-08-19.30.log.txt),
Fedora developers and some members of the OLPC community discussed the
loss of Geode LX (i.e. XO-1) support in F13.

It looks like we are all in agreement that the loss of support was
unintentional, but we postponed making a decision on the solution
because we realise that we don't fully understand the issue. The only
package we can see that uses nopl instructions is glibc -- why only
glibc? What changed to make that happen?

I've investigated and my explanation is here:
https://bugzilla.redhat.com/show_bug.cgi?id=579838#c10
https://bugzilla.redhat.com/show_bug.cgi?id=579838#c11

In a nutshell: glibc now is more agressive than most packages with its
optimizations, and takes an extra step to communicate the desired
processor optimizations to the assembler. (CPU-specific optimizations
in other packages are limited to the compiler and linker)

What are the next steps? Do we take this back to FESCO? When is the
next meeting?

Thanks,
Daniel