[Mesa-dev] [PATCH 4/4] R600/SI: Support AMDGPU.ddx/y intrinsics

[Michel Dänzer]

On Fre, 2013-02-22 at 09:05 -0800, Paul Berry wrote: 
> On 22 February 2013 08:02, Michel Dänzer <michel at daenzer.net> wrote:
>         From: Michel Dänzer <michel.daenzer at amd.com>
>         
>         Use LDS for calculating the deltas between neighbouring
>         pixels. Not sure the
>         sign of the delta is correct for both dimensions (the sign
>         doesn't seem to
>         matter for the relevant piglit tests), but it'll be easy to
>         fix that up if
>         not. 
> 
> 
> Is this the back-end code that implements the dFdx() and dFdy() GLSL
> functions?  If so, then there is a piglit test that verifies that the
> sign of the delta is correct for both dimensions.  It's in
> tests/fbo/fbo-deriv.c.

Ah, thanks, I'll look into that one. 

-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer