[Mesa-dev] [PATCH v2] nir: add a comparison simplification

[Jason Ekstrand]

Assuming the thing I typed in my phone actually works, r-b. :-). I'm a bit 
surprised we didn't already have that one. It seems so obvious in hindsight.


On March 15, 2018 22:48:24 Timothy Arceri <tarceri at itsqueeze.com> wrote:

> These can be found in the Tomb Raider shaders, eliminating them
> helps unroll more loops.
> ---
>  src/compiler/nir/nir_opt_algebraic.py | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/src/compiler/nir/nir_opt_algebraic.py 
> b/src/compiler/nir/nir_opt_algebraic.py
> index c9575e6be4..2148bc121b 100644
> --- a/src/compiler/nir/nir_opt_algebraic.py
> +++ b/src/compiler/nir/nir_opt_algebraic.py
> @@ -152,6 +152,7 @@ optimizations = [
>     (('inot', ('ige', a, b)), ('ilt', a, b)),
>     (('inot', ('ieq', a, b)), ('ine', a, b)),
>     (('inot', ('ine', a, b)), ('ieq', a, b)),
> +   (('ine', ('b2i', 'a at bool'), 0), 'a'),
>
>     # 0.0 >= b2f(a)
>     # b2f(a) <= 0.0
> --
> 2.14.3
>