[Mesa-dev] [PATCH 0/4] Clean up dFdy() bug fix.

[Paul Berry]

On 18 July 2012 15:11, Kenneth Graunke <kenneth at whitecape.org> wrote:

> On 07/18/2012 12:16 PM, Paul Berry wrote:
> > This patch series cleans up a bug fix I made to Mesa on June 22
> > (commit 82d2596: i965: Compute dFdy() correctly for FBOs).  The bug
> > was that the i965 driver wasn't adjusting the dFdy() logic to account
> > for the fact that window system framebuffers use flipped Y coordinates
> > compared to FBOs.  The fix was to compile fragment shaders differently
> > when they are used for FBOs vs window system framebuffers.
> >
> > Commit 82d2596 conservatively assumed that all fragment shader
> > programs might use dFdy(), so it recompiled all of them when switching
> > between FBOs and window system framebuffers.  For shaders that don't
> > use dFdy(), the recompile is an unnecessary performance hit.  This
> > patch series adds accounting to core mesa to keep track of whether or
> > not a shader uses dFdy(), and changes the i965 back-end to only
> > recompile shaders that actually need it.
> >
> > Patches 1-3 may be of interest to non-i965 developers, since the
> > accounting in core Mesa applies to all back-ends.
> >
> > [PATCH 1/4] mesa: Add UsesDFdy to struct gl_fragment_program.
> > [PATCH 2/4] mesa: Set UsesDFdy appropriately for assembly programs.
> > [PATCH 3/4] glsl: Set UsesDFdy appropriately for GLSL shaders.
> > [PATCH 4/4] i965: Avoid unnecessary recompiles for shaders that don't
> use dFdy().
>
> Looks fine to me, but please get Ian's ack before pushing.
>

Ian, any comments?


>
> For the series:
> Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
>
>
>
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