[Mesa-dev] [PATCH] nir: add lowering for ffract

[Iago Toral]

Reviewed-by: Iago Toral Quiroga <itoral at igalia.com>

On Tue, 2015-09-15 at 17:40 -0400, Rob Clark wrote:
> From: Rob Clark <robclark at freedesktop.org>
> 
> Signed-off-by: Rob Clark <robclark at freedesktop.org>
> ---
>  src/glsl/nir/nir.h                | 3 +++
>  src/glsl/nir/nir_opt_algebraic.py | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
> index f0acd75..284fccd 100644
> --- a/src/glsl/nir/nir.h
> +++ b/src/glsl/nir/nir.h
> @@ -1440,6 +1440,9 @@ typedef struct nir_shader_compiler_options {
>      */
>     bool fdot_replicates;
>  
> +   /** lowers ffract to fsub+ffloor: */
> +   bool lower_ffract;
> +
>     /**
>      * Does the driver support real 32-bit integers?  (Otherwise, integers
>      * are simulated by floats.)
> diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
> index acc3b04..43558a5 100644
> --- a/src/glsl/nir/nir_opt_algebraic.py
> +++ b/src/glsl/nir/nir_opt_algebraic.py
> @@ -76,6 +76,7 @@ optimizations = [
>     (('flrp', a, a, b), a),
>     (('flrp', 0.0, a, b), ('fmul', a, b)),
>     (('flrp', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp'),
> +   (('ffract', a), ('fsub', a, ('ffloor', a)), 'options->lower_ffract'),
>     (('fadd', ('fmul', a, ('fadd', 1.0, ('fneg', c))), ('fmul', b, c)), ('flrp', a, b, c), '!options->lower_flrp'),
>     (('fadd', a, ('fmul', c, ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp'),
>     (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),