[Mesa-dev] [PATCH 03/18] mesa: Optimize unbind_texobj_from_texunits()

[Brian Paul]

On 01/21/2014 03:35 PM, Fredrik Höglund wrote:
> The texture can only be bound to the index that corresponds to its
> target, so there is no need to loop over all possible indices
> for every unit and checking if the texture is bound to it.
> ---
>   src/mesa/main/texobj.c |   20 ++++++++++----------
>   1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/src/mesa/main/texobj.c b/src/mesa/main/texobj.c
> index fbbc577..5a3cfb2 100644
> --- a/src/mesa/main/texobj.c
> +++ b/src/mesa/main/texobj.c
> @@ -1084,19 +1084,19 @@ static void
>   unbind_texobj_from_texunits(struct gl_context *ctx,
>                               struct gl_texture_object *texObj)
>   {
> -   GLuint u, tex;
> +   const GLuint index = texObj->TargetIndex;
> +   GLuint u;
>
>      for (u = 0; u < Elements(ctx->Texture.Unit); u++) {
>         struct gl_texture_unit *unit = &ctx->Texture.Unit[u];
> -      for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
> -         if (texObj == unit->CurrentTex[tex]) {
> -            _mesa_reference_texobj(&unit->CurrentTex[tex],
> -                                   ctx->Shared->DefaultTex[tex]);
> -            ASSERT(unit->CurrentTex[tex]);
> -            unit->_BoundTextures ^= (1 << tex);
> -            break;
> -         }
> -      }
> +
> +      if (texObj != unit->CurrentTex[index])
> +         continue;
> +
> +      _mesa_reference_texobj(&unit->CurrentTex[index],
> +                             ctx->Shared->DefaultTex[index]);
> +      ASSERT(unit->CurrentTex[index]);
> +      unit->_BoundTextures ^= (1 << index);
>      }
>   }

I guess I'd like to see the last part written as:

   if (texObj == unit->CurrentTex[index]) {
      /* Bind the default texture for this unit/target */
      _mesa_reference_texobj(&unit->CurrentTex[index],
                             ctx->Shared->DefaultTex[index]);
      unit->_BoundTextures &= ~(1 << index);
   }

I try to only use continue when really needed.  I don't think the 
assertion is needed since we wouldn't have created the context if we 
failed to create any DefaultTex.

-Brian