[Mesa-dev] [PATCH 5/9] glsl: use bitwise operators in varying_matches::compute_packing_class()

[Timothy Arceri]

On 19/12/17 07:47, Brian Paul wrote:
> The mix of bitwise operators with * and + to compute the packing_class
> values was a little weird.  Just use bitwise ops instead.
> ---
>   src/compiler/glsl/link_varyings.cpp | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp
> index 7821b1e..17d8653 100644
> --- a/src/compiler/glsl/link_varyings.cpp
> +++ b/src/compiler/glsl/link_varyings.cpp
> @@ -1982,11 +1982,12 @@ varying_matches::compute_packing_class(const ir_variable *var)
>       *
>       * Therefore, the packing class depends only on the interpolation type.
>       */
> -   unsigned packing_class = var->data.centroid | (var->data.sample << 1) |
> +   unsigned packing_class = (var->data.centroid << 0) |
> +                            (var->data.sample << 1) |
>                               (var->data.patch << 2) |
>                               (var->data.must_be_shader_input << 3);
> -   packing_class *= 8;
> -   packing_class += var->is_interpolation_flat()
> +   packing_class <<= 3;
> +   packing_class |= var->is_interpolation_flat()
>         ? unsigned(INTERP_MODE_FLAT) : var->data.interpolation;

Should we add assert(var->data.interpolation < 7); here somewhere?

Either way series:

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

>      return packing_class;
>   }
>