GMP on the Cell processor

[Michael Abshoff]

Torbjorn Granlund wrote:
>   On a similar note, is there a version of GMP for the Altivec
>   which is this vector extension for some (but not all) PowerPC
>   CPU's ?
>
> GMP 4.2 makes use of Altivec when it is available.  (There are some
> flaws in configure that made the altivec recognition unreliable,
> though.)
>

The Cell is a hyprid of a dual Core PowerCore (in order) and up to 8 SPEs
(also in order). The great performance for numerical applications comes
from the fact that you can achieve up to 200 GFlops *single* precision and
about 1/14 of that for *double* precision with hand tuned code that uses
all the SPEs in parallel. The Power Core just feeds the SPEs. The SPEs
also supposedly provide integer operations and because each SPE has 128
128bit registers there is certainly potential. Cell blades are rather
costly (dual Cell from IBM at around ~15K$), but you can get a PCI-Express
card with a single Cell for around 4K$. To play around there is also an
emulator (free as in beer) and a toolchain based on gcc (free as in
freedom ;) that lets you play around provided you have some decent
hardware (1.5GHZ PPC, x86, x86-64, 1+G Ram). The emulator supposedly gives
you something that is very close (~2%) to the physical CPU because it also
takes into consideration DMA transfers, cache misses and all the other fun
stuff.

I am currently starting to play around with the emulator for some
numerical  project group I am working with, but provided somebody does
start to port I would certainly be willing to test & debug and maybe code
a little. I will also have (limited) access to some real hardware in the
future. Because I also do work on other open source projects I do not have
whole lot of time to do so.

If you own a PS3 you can install Linux and have access to 6 SPEs because
the hypervisor of the PS3 only gives you access to those 6 while the 7th
is reserved for hypervisor. But it is a relatively cheap way to get one's
hands on some real Cell hardware.

Hope that helps,

Michael

> --
> Torbjörn
> _______________________________________________
> gmp-discuss mailing list
> gmp-discuss at swox.com
> https://gmplib.org/mailman/listinfo/gmp-discuss
>