[Mesa-dev] [PATCH 0/6][RFC] glsl: Expand opt_minmax get_range

[Matt Turner]

On Thu, Oct 30, 2014 at 10:57 AM, Thomas Helland
<thomashelland90 at gmail.com> wrote:
> Are the affected shaders from some commercial game that I might
> have in my steam-collection? Would be nice to extract a real-life
> shader that experiences this not-so-good behavior.

Yes.

Games with improvements:
  - Planeshift (one shader)
  - Dungeon Defenders (three shaders)
  - Guacamelee (two shaders)

Games with shaders hurt:
  - Civ 5, Stacking, Metro Last Light, Brutal Legend, The Cave, XCOM
Enemy Unknown, Guacamelee, Natural Selection 2

> I could try putting the saturate generation before this pass and write
> some shaders that exercise the regression we see here.
>
> Since freedreno implements saturates with min/max we should
> probably allow for splitting up saturates.
> Maybe we could add an "emitSaturate" option so that we can split
> up saturates if the backend does not support it?
> That way we can do what's best for each backend.

Yes, see the EmitNo* members of gl_shader_compiler_options in
src/mesa/main/mtypes.h.