[Mesa-dev] [PATCH] llvmpipe: don't use 3-component formats, except 32-bit x 3 formats

[Roland Scheidegger]

Am 10.06.2016 um 20:58 schrieb Brian Paul:
> This basically disallows all 8-bit x 3 and 16-bit x 3 formats for
> textures and render targets.  Some 3-component formats were already
> disallowed before.  This avoids problems with GL_ARB_copy_image.
> 
> v2: the previous version of this patch disallowed all 3-component formats
> 
> Reviewed-by: Charmaine Lee <charmainel at vmware.com>
> ---
>  src/gallium/drivers/llvmpipe/lp_screen.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/src/gallium/drivers/llvmpipe/lp_screen.c b/src/gallium/drivers/llvmpipe/lp_screen.c
> index f2a12a0..a44312c 100644
> --- a/src/gallium/drivers/llvmpipe/lp_screen.c
> +++ b/src/gallium/drivers/llvmpipe/lp_screen.c
> @@ -450,19 +450,20 @@ llvmpipe_is_format_supported( struct pipe_screen *_screen,
>        if (!format_desc->is_array && !format_desc->is_bitmask &&
>            format != PIPE_FORMAT_R11G11B10_FLOAT)
>           return FALSE;
> +   }
>  
> -      /*
> -       * XXX refuse formats known to crash in generate_unswizzled_blend().
> -       * These include all 3-channel 24bit RGB8 variants, plus 48bit
> -       * (except those using floats) 3-channel RGB16 variants (the latter
> -       * seems to be more of a llvm bug though).
> -       * The mesa state tracker only seems to use these for SINT/UINT formats.
> +   if ((bind & (PIPE_BIND_RENDER_TARGET | PIPE_BIND_SAMPLER_VIEW)) &&
> +       ((bind & PIPE_BIND_DISPLAY_TARGET) == 0)) {
> +      /* Disable all 3-channel formats, where channel size != 32 bits.
> +       * In some cases we run into crashes (in generate_unswizzled_blend()),
> +       * for 3-channel RGB16 variants, there was an apparent LLVM bug.
> +       * In any case, disabling the shallower 3-channel formats avoids a
> +       * number of issues with GL_ARB_copy_image support.
>         */
> -      if (format_desc->is_array && format_desc->nr_channels == 3) {
> -         if (format_desc->block.bits == 24 || (format_desc->block.bits == 48 &&
> -               !util_format_is_float(format))) {
> -            return FALSE;
> -         }
> +      if (format_desc->is_array &&
> +          format_desc->nr_channels == 3 &&
> +          format_desc->block.bits != 96) {
> +         return FALSE;
>        }
>     }
>  
> 

Reviewed-by: Roland Scheidegger <sroland at vmware.com>