Questions about compilation and other questions

[Jim Gettys]

GCC has a mechanism for setting the flags used by default for a
particular installation of a compiler (the gcc specs file).  For those
people doing self-hosted development, it would indeed be good to craft a
Geode GX GCC specific configuration file for GCC to use. By default, it
uses a build-in spec file.  To see the built in defaults, type "gcc
-dumpspecs".  See section 3.15 of the gcc manual.
http://gcc.gnu.org/onlinedocs/

Knowing what flags are "best" obviously has value to us, though there
are always judgment calls about setting default options.

And there will certainly be specific packages where there is enough
performance to be gained to bother to compile with specific flags for
OLPC (e.g. codecs and similar CPU bound codes).   Those we should handle
separately from the trac bug.

Beyond this, what is probably more important in the long term is for
people who are friendly with gcc to work on a march=geode
implementation.  The code scheduling for floating point in particular
could be improved to give significant performance gain.

Also, if you have an FP intensive application, the performance
difference between single and double precision is larger than typical of
other x86 systems. Bothering to ensure single is used where feasible in
those particular applications may be helpful.

To capture this, I entered: http://dev.laptop.org/ticket/118
                                 Regards,
                                        - Jim


On Thu, 2006-09-21 at 21:32 +0800, Ivan Krstić wrote:
> Marcos Barbosa wrote:
> > * Why not to develop one toolchain for the OLPC?
> 
> Because it's a pain to maintain.
> 
> > * Which is the used window manager in the version of the Red Hat? It
> > was the Gnome? Now and the Matchbox? He is compatible with GTK?
> 
> It was never GNOME. The WM is sugar; GTK+ is the toolkit we support,
> yes, but that's not a window manager.
> 
-- 
Jim Gettys
One Laptop Per Child