On Wed, Mar 10, 2010 at 10:46 AM, Ove Kaaven <o...@arcticnet.no> wrote: > Alberto Mardegan skrev: >> Does anyone know any tricks to optimize certain operations on arrays of >> data? > > The answer to that is, obviously, to use the Cortex-A-series SIMD > engine, NEON. > > Supposedly you may be able to make gcc generate NEON instructions with > -mfpu=neon -ffast-math -ftree-vectorize (and perhaps -mfloat-abi=softfp, > but that's the default in the Fremantle SDK anyway), but it's still not > very good at it, so writing the asm by hand is still better... and I'm > not sure if it can automatically vectorize library calls like sqrt.
One has to be careful with that approach: Cortex-A9 SoC won't necessarily come with a NEON SIMD unit, as it's optional. So it'd be better to also include code that doesn't assume one has a NEON unit. Laurent _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
