Re: Altivec Linear Algebra Help

FROM : gabe taubman
DATE : Sun Oct 17 20:23:32 2004

Thanks for the links!  I was also wondering if anyone knows if this
would be a useful way of utilizing AltiVec.  For instance, the
programs people write with this library are most likely not
multiplying thousands of matrices in a row.  However, it being a
graphics package, they will be multiplying LOTS of vectors by matrices
one by one, just not all in a bunch.

On the Vector Libraries page, I read the stuff about cBLAS and it
seems to have Matrix*Vector and stuff like that.  So let's say that i
comment out the function overload for Matrix * Vector and I replace it
with one that uses the cBLAS version (gemv I think it is) and they do
it just once.  Will there be any significant speed up or is it just
not worth it?

Thanks!
gabe


On Sun, 17 Oct 2004 16:52:14 +1000, Steven Marcus
<steven.<email_removed>> wrote:
> Here are a couple of links you might find helpful:
>
> 1) http://developer.apple.com/hardware/ve/vector_libraries.html
> 2) http://hpc.sourceforge.net/
> 3) http://developer.apple.com/hardware/ve/index.html
>
> #1 introduces the Apple vector/matrix libraries which are altivec accelerated
> #2 has a reference to macstl which has accelerated numerics classes for C++
> #3 is the Velocity Engine / Altivec homepage
>
> good luck!
>
>
>
>
> On Sun, 17 Oct 2004 00:38:48 -0400, gabe taubman <<email_removed>> wrote:
> > Hi,
> > I'm part of the mac team porting an open source 3d graphics library to
> > OS X.  It has its own built in linear algebra package.  I was
> > wondering if instead of using its own matrix multiplication calls
> > (etc) I could use the altivec ones instead.
> >
> > >From what I've read about altivec, is that the structure of the
> > matrices and vectors would have to be changed into ones recognized by
> > altivec, otherwise we'd lose tons of speed just transforming data
> > around.  If anyone has any advice, or comments on whether or not this
> > is worthwhile I'd be very grateful.  I'd really like to make this
> > library great for OS X and it seems this is a good way to start.
> >
> > Thanks!
> > gabe taubman
> > _______________________________________________
> > MacOSX-dev mailing list
> > <email_removed>
> > http://www.omnigroup.com/mailman/listinfo/macosx-dev
> >
>