[Mesa-dev] [PATCH] i965/blorp: do not use unnecessary hw-blending support

[Pohjolainen, Topi]

On Mon, Jan 27, 2014 at 10:20:54AM -0800, Eric Anholt wrote:
> Topi Pohjolainen <topi.pohjolainen at intel.com> writes:
> 
> > This is really not needed as blorp blit programs already sample
> > XRGB normally and get alpha channel set to 1.0 automatically by
> > the sampler engine. This is simply copied directly to the payload
> > of the render target write message and hence there is no need for
> > any additional blending support from the pixel processing pipeline.
> >
> > Fixes recently modified piglit test gl-3.2-layered-rendering-blit
> > on IVB. No regressions on IVB.
> 
> What about when you have a RGB-but-not-alpha gl format that's been
> promoted to an ARGB Mesa and BRW surface format?  I don't think blorp's
> samplers have any overrides going on there.

I relied on the restriction that only blits from RGBX to RGBA and vice
versa are allowed. Otherwise the formats must match.