recent fixes in devel tree

[Holger Bettag]

Dan Malek <dan at mvista.com> writes:

>
> Holger Bettag wrote:
>
> > P.S.: BTW, is there a general consensus wether or not AltiVec
> >       enhancements in the kernel would be a good thing.....
>
>
> What kind of enhancements?  I do a fair amount of audio/video
> processing on my G4 with the current gcc/Altivec tools.  I found only
> one minor bug in the exception handler that I fixed a while back.
>
> We have been discussing some of the vector load/store/touch as both
> enhancements to the kernel and glibc.  It is a little more challenging
> in the kernel because we would have to then keep some of the vector
> context around for the kernel, but in a very constrained case we could
> probably get some speed ups with that.
>
I know too little about the kernel to suggest specific tunings. I
thought along the lines you mention, inserting a 'data stream touch'
here and there for improved bus utilization, occasional use of AltiVec
code where it tends to speed things up a lot, like doing checksums for
software RAIDs or other fast I/O channels. Maybe 'generic' video
acceleration of the OpenFirmware framebuffer device, or something like
that. (Maybe I/O en-/decryption, if such functionality ever ends up in
the kernel.)

I mainly wanted to know wether there are efforts underway to make the
use of AltiVec in the kernel a no-brainer (like: "just pass -fvec and
use the AltiVec-'macros'!"), or wether it will be only for wizards at
the bleeding edge.

  Holger

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