Hi Siarhei, > On the last weekend I tried to get familiar with powerpc altivec assembly and > added some optimization for sbc encoder. Experimental patch is attached. It > handles 4 subbands case only, so is not that much useful in practice. There > are no problems supporting 8 subbands too, but I was just running out of > time. The patch merges processing of 4 blocks into the single block of code. > It's something that is also in my todo list for ARM NEON. But while this merge > is mostly "nice to have" optimization for ARM, it is much more important for > PowerPC because of a huge multiply-accumulate latency. > > And bluez a2dp seems to work fine on ppc64 linux (playstation3). > > In order to activate altivec code, -maltivec option needs to be added to > gcc compilation flags. > > Benchmark result: > > time ./sbcenc -s4 somefile.au > /dev/null > > before: > real 0m13.999s > user 0m13.468s > sys 0m0.523s > > after: > real 0m5.714s > user 0m5.199s > sys 0m0.519s > > 3.2GHz CPU in playstation3 uses roughly 1.5% of cpu resources on sbc encoding > without any optimizations. cpu usage is down to something like 0.6% after this > optimization is applied. please redo the patch and include a proper commit message. For example the details from the email would be perfect for a commit message. It doesn't need to be that verbose, but a little bit more would be nice. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
