[Mesa-dev] [PATCH 1/2] i965: Change intel_disable_rb_aux_buffer into get_drawbuffer_index().

[Nanley Chery]

On Thu, Oct 05, 2017 at 10:02:39PM -0700, Kenneth Graunke wrote:
> The bulk of the work in intel_disable_rb_aux_buffer() is finding the
> drawbuffer index for the given BO.  After that, disabling the auxiliary
> buffers is an easy one liner.
> 
> This lets us ask whether a texture is also bound as a renderbuffer
> before making any decisions.  We'll use this in the next patch.
> 
> Cc: nanleychery at gmail.com
> Cc: jason at jlekstrand.net
> ---
>  src/mesa/drivers/dri/i965/brw_draw.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_draw.c b/src/mesa/drivers/dri/i965/brw_draw.c
> index c7ed7284501..cab3758d7b5 100644
> --- a/src/mesa/drivers/dri/i965/brw_draw.c
> +++ b/src/mesa/drivers/dri/i965/brw_draw.c
> @@ -336,22 +336,21 @@ brw_merge_inputs(struct brw_context *brw,
>     }
>  }
>  
> -static bool
> -intel_disable_rb_aux_buffer(struct brw_context *brw, const struct brw_bo *bo)
> +static int
> +get_drawbuffer_index(struct brw_context *brw, const struct brw_bo *bo)

We can now make brw point to a const struct.

>  {
>     const struct gl_framebuffer *fb = brw->ctx.DrawBuffer;
> -   bool found = false;
>  
>     for (unsigned i = 0; i < fb->_NumColorDrawBuffers; i++) {
>        const struct intel_renderbuffer *irb =
>           intel_renderbuffer(fb->_ColorDrawBuffers[i]);
>  
>        if (irb && irb->mt->bo == bo) {
> -         found = brw->draw_aux_buffer_disabled[i] = true;
> +         return i;
>        }
>     }
>  
> -   return found;
> +   return -1;
>  }
>  
>  /**
> @@ -382,13 +381,14 @@ brw_predraw_resolve_inputs(struct brw_context *brw)
>        struct gl_sampler_object *sampler = _mesa_get_samplerobj(ctx, i);
>        enum isl_format view_format =
>           translate_tex_format(brw, tex_obj->_Format, sampler->sRGBDecode);
> +      int drawbuf_idx = get_drawbuffer_index(brw, tex_obj->mt->bo);
>  
>        bool aux_supported;
>        intel_miptree_prepare_texture(brw, tex_obj->mt, view_format,
>                                      &aux_supported);
>  
> -      if (!aux_supported && devinfo->gen >= 9 &&
> -          intel_disable_rb_aux_buffer(brw, tex_obj->mt->bo)) {
> +      if (!aux_supported && devinfo->gen >= 9 && drawbuf_idx != -1) {
> +         brw->draw_aux_buffer_disabled[i] = true;

Don't we want to index this array with drawbuf_idx? Maybe I don't
understand how the texunit and drawbuffer arrays are related.. I'll do
some reading.

>           perf_debug("Sampling renderbuffer with non-compressible format - "
>                      "turning off compression\n");
>        }
> @@ -413,9 +413,11 @@ brw_predraw_resolve_inputs(struct brw_context *brw)
>  
>              if (tex_obj && tex_obj->mt) {
>                 intel_miptree_prepare_image(brw, tex_obj->mt);
> +               int drawbuf_idx = get_drawbuffer_index(brw, tex_obj->mt->bo);
>  
>                 if (tex_obj->mt->aux_usage == ISL_AUX_USAGE_CCS_E &&
> -                   intel_disable_rb_aux_buffer(brw, tex_obj->mt->bo)) {
> +                   drawbuf_idx != -1) {
> +                  brw->draw_aux_buffer_disabled[i] = true;

You're using the index of the shader stage here.

>                    perf_debug("Using renderbuffer as shader image - turning "
>                               "off lossless compression\n");
>                 }
> -- 
> 2.14.2
>