[Mesa-dev] [PATCH 01/22] glsl: Reorder optimization-passes

[Matt Turner]

On Sat, Jan 3, 2015 at 11:18 AM, Thomas Helland
<thomashelland90 at gmail.com> wrote:
> This allows opt_algebraic to resolve open-coded
> saturates into ir_unop_saturate before we potentially
> mess it up by removing the min or max in min/max-pruning.
>
> Since we are now emitting more free saturates on i965
> this gives us some decrease in instruction count.
>
> total instructions in shared programs: 1317459 -> 1317065 (-0.03%)
> instructions in affected programs:     4084 -> 3690 (-9.65%)
> GAINED:                                0
> LOST:                                  0

You're definitely onto something here. On our collection of shaders:

total instructions in shared programs: 5876617 -> 5875919 (-0.01%)
instructions in affected programs:     9443 -> 8745 (-7.39%)

with some fragment shaders hurt in Natural Selection 2 and Kerbal Space program.

I'll investigate these.