GTA03 = has FPU?

[Nicolas Dufresne]

Have a look at this:

http://wiki.openmoko.org/wiki/GTA03

To save you time, the new processor (similar Samsung) will have a
integrated 3D accelerator and VFP instruction set. The VFP (Vector
Floating-Point) is a floating point unit combined with SIMD (Single
Instruction Multi Data). It got introduce by ARM since ARMv5, the GTA02
is ARMv4.  It's not as good as the Neon instruction set, that is
available in ARMv7 that can be found on TI OMAP3 but if the everything
is compiled with good flags, VFP will give a big boost Cairo
application.

Cairo path are all float based, so I guess this cannot be changed, but
you may be able to improve performance by rewriting libpixman with fix
point routine. You may also have a look at DirectFB Cairo, which uses
DirectFB fixpoint software routine.

Nicolas


Le dimanche 01 mars 2009 à 21:52 +0100, Anton Persson a écrit :

> Oh, I forgot; IF the GTA03 _doesn't_ have a FPU, do anyone know a good
> and cool
> vector based GFX-lib that _doesn't_ use floats? (Maybe I need to write
> one, if
> there isn't, and if the GTA03 won't have a proper FPU..)
> 
> A nice SVG-based (but converted to fixed-point math) GUI with more
> focus on
> finger-friendlyness would be nice, and maybe worth writing.
> 
>     /Anton
> 
> 
> On Sun, Mar 1, 2009 at 9:50 PM, Anton Persson <don.juanton at gmail.com>
> wrote:
> 
>         Hi, 
>         
>         will the GTA03 have a FPU?
>         
>         The reason I'm wondering is because of, well, it sucks if it
>         doesn't.. We all
>         want to run all available standard Linux apps on this thing,
>         but many applications
>         _require_ floating point math, especially for graphics! I've
>         been working
>         a lot (a lot meaning, whenever I don't have to take care of my
>         "real" job, and
>         my family.. :-P) on my program "SATAN" and I got pretty good
>         performance
>         out of it now.. The problem though is that it is GTK- and
>         Cairo-based and that
>         these libraries use floats quite extensively.. This really
>         hurts performance
>         on the OpenMoko and makes the application feel really sluggish
>         when you
>         want to interact with the GUI. I haven't done any real
>         benchmarks, but I do
>         know that the floating point version of SATAN is totally
>         UNUSABLE on the
>         OpenMoko, but the fixed-point math version works "OK" (except
>         the GUI then..).
>         
>            Best regards
>              Anton
> 
> 
> 
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