[Mesa-dev] [PATCH 07/15] i965/blorp: Use 16 pixel dispatch on Gen7 when there is a WM program.
kenneth at whitecape.org
Wed May 23 10:22:54 PDT 2012
On 05/23/2012 07:45 AM, Paul Berry wrote:
> On 22 May 2012 13:02, Eric Anholt <eric at anholt.net
> <mailto:eric at anholt.net>> wrote:
> On Fri, 11 May 2012 11:03:50 -0700, Paul Berry
> <stereotype441 at gmail.com <mailto:stereotype441 at gmail.com>> wrote:
> > When executing a blorp operation on Gen7 that does not need a WM
> > program (i.e. a HiZ operation), we use 32-pixel dispatch mode because
> > it's faster. However, when executing a blorp operation that does
> > a WM program, we need to use 16-pixel dispatch, because blorp WM
> > programs are compiled assuming 16-pixel dispatch.
> I didn't think dispatch mode means anything unless you're actually
> dispatching a thread (though I could see how having no dispatch mode set
> might anger things). Basically, I'm thinking just always set 16, unless
> there is some efficiency reason I don't know of.
> I don't honestly know. Chad, I inherited the 32-pixel dispatch from
> your HiZ code, and assumed you did it on purpose because it was faster.
> But I didn't actually do any tests. Do you have any thoughts about this?
I recall Chad saying that not setting thread dispatch broke horribly, so
since he had enable thread dispatch, he picked the widest mode.
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