OpenMP and krita

[Cyrille Berger]

On Thursday 17 May 2007, Boudewijn Rempt wrote:
> Yes, that should be cool. Does OpenMP also use MMX and similar where
> possible?
no, it's not related :)

> Because that's where I see the biggest benefit for compositing. 
Well the benefit of SIMD instructions is around 40% and 50% maximum (due to 
the cost of loading in the SIMD registers). While multithreading can reduce 
the CPU cost to a maximum 1/N (with N the number of processor). And some 
composite operation doesn't benefit from SIMD at all, at least that's what my 
experiments show, and it seems to be confirmed by the gimp source code ;)

Anyway it needs experimenting, I am still working on SIMD library for Krita 
2 :)
-- 
Cyrille Berger