On Wed, 2010-03-10 at 10:46 +0100, ext Ove Kaaven 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.
You can also put the CPU to a "fast floats" mode, see hd_fpu_set_mode() in http://maemo.gitorious.org/fremantle-hildon-desktop/hildon-desktop/blobs/master/src/main.c N900 has support for NEON instructions also. -Kimmo _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
