Re: ARM NEON optimisations for gf-complete/jerasure/ceph-erasure

[Janne Grunau <j@jannau.net>]

Hi Kevin,

On 2014-09-16 11:25:12 -0700, Kevin Greenan wrote:
> 
> I feel that separating the arch-specific implementations out and have a
> default 'generic' implementation would be a huge improvement.  Note that
> gf-complete was in active development for some time before including the
> SIMD code.  In hindsight, we should have done this separation back in 2012,
> but had some time pressure due to a paper deadline and limited time
> available to the contributors.
> 
> Also, I agree w.r.t. the preprocessor stuff.  Going with SIMD/NOSIMD is
> fine by me.

I created a pull request with my neon optimisations, the SSE -> SIMD 
rename and some minor fixes.

The neon methods all reside in their own files, I didn't come up with 
good solution for the init / scratch_size functions, so I added 
arm-specific defines there.

> Also, there should be very little "SIMD" work with jerasure, as gf-complete
> is the Galois field backend, so I would not worry too much about that.

Yes, there was no SIMD work in jerasure.

Please have a look at 
https://bitbucket.org/jimplank/gf-complete/pull-request/25/arm-neon-optimisations 
I'll be available to address review comments and suggestions.

regards

Janne