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Re: [graphite] Use params for the size of loop blocking tiles
On Sat, 21 Feb 2009, Sebastian Pop wrote:
> On Sat, Feb 21, 2009 at 04:25, Richard Guenther <rguenther@suse.de> wrote:
> > - /* TODO: - Calculate the stride size automatically. */
> > - int stride_size = 64;
> > + int stride_size = PARAM_VALUE (PARAM_LOOP_BLOCK_TILE_SIZE);
> >
> > So - why is it now 51 and it was 64?
>
> 51 is more magic than 64.
> 51 is better to avoid cache padding problems and it avoids
> to fill up the cache. Would a simpler patch like the one
> attached be ok for trunk?
Yes.
Thanks,
Richard.
> > And why is the TODO removed?
>
> It shouldn't have been removed.
>
> > I think stride size should be computed based on CPU cache
> > parameters and the number of streams.
>
> Agreed.
>
> > Thus, I don't think a user-controllable param makes much sense here.
>
> Ok. So we don't want programmers to play with this.
>
> At least we do want to play with it a little bit, so in the graphite
> branch it makes sense to have this parameter. I committed a similar
> patch to the branch.
>
> Sebastian
>
--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
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