[Mesa-dev] [PATCH 01/14] i965: Don't tile 1D miptrees.

[Kenneth Graunke]

On Friday, February 06, 2015 07:23:15 PM Francisco Jerez wrote:
> It doesn't really improve locality of texture fetches, quite the
> opposite it's a waste of memory bandwidth and space due to tile
> alignment.
> ---
>  src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> index 64752dd..311b204 100644
> --- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> +++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> @@ -488,6 +488,10 @@ intel_miptree_choose_tiling(struct brw_context *brw,
>         base_format == GL_DEPTH_STENCIL_EXT)
>        return I915_TILING_Y;
>  
> +   if (mt->target == GL_TEXTURE_1D ||
> +       mt->target == GL_TEXTURE_1D_ARRAY)
> +      return I915_TILING_NONE;
> +
>     int minimum_pitch = mt->total_width * mt->cpp;
>  
>     /* If the width is much smaller than a tile, don't bother tiling. */
> 

What do you think about checking mt->logical_height0 == 1 instead?
GLES doesn't have 1D textures, but people might use a 2D texture with
height 1, and I think the same logic applies.

I've also been thinking of trying to make core Mesa hide 1D textures and
simply turn them into 2D textures with height = 1, so drivers don't have
to deal with them.

Either way, this seems like a good idea to me.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20150206/d0d3ca08/attachment.sig>