[Ffmpeg-devel] [PATCH] put_mpeg4_qpel16_h_lowpass altivec, take 2

Guillaume POIRIER poirierg
Wed Jan 24 09:43:39 CET 2007


On 11/27/06, Brian Foley <bfoley at compsoc.nuigalway.ie> wrote:
> On Sun, Nov 26, 2006 at 09:15:26PM +0100, Guillaume POIRIER wrote:
> > Hi,
> >
> > >I suspect Shark and simg4 are probably as good or better for
> > >profiling anyway.
> >
> > Well, one thing that no Apple CHUD tools seem to be able to do is
> > tracking down access to un-initialized memory, which valgrind does to
> > the best of my knowledge.
> Yes, I think Apple's tools are the way to go. I'm just not terribly
> familiar with using them for optimisation on the single instruction
> level like this.
> Valgrind's great for certain kinds of profiling, but it's not much use
> here. The sort of thing we care about here are pipeline stalls,
> functional unit utilisation, and of course cache behaviour. Thanks to
> its translate-everything-into-uops approach, Valgrind can only really
> give meaningful information about the cache behaviour.
> Besides, my main development machine is running MacOS, which doesn't
> have a fully working Valgrind port anyways. The only access I have to
> Linux/PPC is through emulation using qemu, and that's both slow and not
> cycle-accurate either.
> Cheers,
> Brian.

Brian, did you have some time to work on your patch?
There hasn't been activity about it here for about 2 months!!!


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