[Mesa-dev] [PATCH v2 6/6] i965/miptree: Remove the width/height < 32768 restrictions

[Eero Tamminen]

Hi,

On 25.10.2016 06:40, Jason Ekstrand wrote:
> These restrictions existed because intel_miptree_blit couldn't handle
> surfaces bigger than 32k.  How that we're chopping blits up into chunks, it
> can handle any size we throw at it so we can get rid of this restriction.
> This improves the terrain tests in synmark by 25-30% on my Sky Lake gt3.

I'm seeing ~30% improvement in instantiated terrain tests and ~40% 
improvement in tessellated terrain tests on SKL GT2.

I tried also our other regular benchmarks, but didn't see improvement in 
them.

It could help some games though, I vaguely remember Borderlands2 
complaining about too large miptree blit and many Unreal Engine v4 demos 
do that too.


	- Eero


> Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
> Reported-by: Ben Widawsky <ben at bwidawsk.net>
> ---
>  src/mesa/drivers/dri/i965/brw_tex_layout.c    | 3 +--
>  src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 6 ------
>  2 files changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_tex_layout.c b/src/mesa/drivers/dri/i965/brw_tex_layout.c
> index 4618bc0..768f8a8 100644
> --- a/src/mesa/drivers/dri/i965/brw_tex_layout.c
> +++ b/src/mesa/drivers/dri/i965/brw_tex_layout.c
> @@ -610,8 +610,7 @@ brw_miptree_choose_tiling(struct brw_context *brw,
>     if (minimum_pitch < 64)
>        return I915_TILING_NONE;
>
> -   if (ALIGN(minimum_pitch, 512) >= 32768 ||
> -       mt->total_width >= 32768 || mt->total_height >= 32768) {
> +   if (ALIGN(minimum_pitch, 512) >= 32768) {
>        perf_debug("%dx%d miptree too large to blit, falling back to untiled",
>                   mt->total_width, mt->total_height);
>        return I915_TILING_NONE;
> diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> index 551df4d..551812a 100644
> --- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> +++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
> @@ -2838,12 +2838,6 @@ static bool
>  can_blit_slice(struct intel_mipmap_tree *mt,
>                 unsigned int level, unsigned int slice)
>  {
> -   uint32_t image_x;
> -   uint32_t image_y;
> -   intel_miptree_get_image_offset(mt, level, slice, &image_x, &image_y);
> -   if (image_x >= 32768 || image_y >= 32768)
> -      return false;
> -
>     /* See intel_miptree_blit() for details on the 32k pitch limit. */
>     if (mt->pitch >= 32768)
>        return false;
>