[Pixman] [PATCH 08/14] Add generic fast path for over_n_8888

[Siarhei Siamashka]

On Wed,  2 Oct 2013 00:00:28 +0100
Ben Avison <bavison at riscosopen.org> wrote:

> lowlevel-blt-bench results for over_n_8888 (on ARMv6):
>     Before          After
>     Mean   StdDev   Mean   StdDev  Confidence  Change
> L1  11.3   0.1      21.3   0.1     100.0%      +89.0%
> L2  10.0   0.1      17.5   0.5     100.0%      +73.9%
> M   8.6    0.0      14.1   0.0     100.0%      +63.0%
> HT  5.1    0.0      12.7   0.1     100.0%      +148.8%
> VT  4.9    0.0      12.4   0.1     100.0%      +151.3%
> R   4.8    0.0      12.0   0.1     100.0%      +148.6%
> RT  2.1    0.0      8.2    0.1     100.0%      +290.1%
> 
> Trimmed cairo-pref-traces does not show any significant change for this patch,
> reflecting the fact that over_n_8888 is barely used in the traces.

I guess that there must be some other good reason to have it added as
both generic fast patch and armv6 optimisation, which is just left out
from the commit message.

Maybe we are missing a cairo trace for some use case, which is
important for you?

> ---
>  pixman/pixman-fast-path.c |   41 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/pixman/pixman-fast-path.c b/pixman/pixman-fast-path.c
> index 5d52b4a..680149c 100644
> --- a/pixman/pixman-fast-path.c
> +++ b/pixman/pixman-fast-path.c
> @@ -1182,6 +1182,43 @@ fast_composite_src_memcpy (pixman_implementation_t *imp,
>      }
>  }
>  
> +static void
> +fast_composite_over_n_8888 (pixman_implementation_t *imp,
> +                            pixman_composite_info_t *info)
> +{
> +    PIXMAN_COMPOSITE_ARGS (info);
> +    uint32_t  src, srca;
> +    uint32_t *dst_line, *dst;
> +    int       dst_stride;
> +    int32_t   w;
> +
> +    src = _pixman_image_get_solid (imp, src_image, dest_image->bits.format);
> +
> +    srca = src >> 24;
> +    if (src == 0)
> +        return;
> +    if (srca == 0xff)
> +    {
> +        fast_composite_solid_fill (imp, info);
> +        return;
> +    }
> +
> +    PIXMAN_IMAGE_GET_LINE (dest_image, dest_x, dest_y, uint32_t, dst_stride, dst_line, 1);
> +
> +    while (height--)
> +    {
> +        dst = dst_line;
> +        dst_line += dst_stride;
> +        w = width;
> +
> +        while (w--)
> +        {
> +            *dst = over (src, *dst);
> +            dst++;
> +        }
> +    }
> +}
> +
>  FAST_NEAREST (8888_8888_cover, 8888, 8888, uint32_t, uint32_t, SRC, COVER)
>  FAST_NEAREST (8888_8888_none, 8888, 8888, uint32_t, uint32_t, SRC, NONE)
>  FAST_NEAREST (8888_8888_pad, 8888, 8888, uint32_t, uint32_t, SRC, PAD)
> @@ -1838,9 +1875,13 @@ static const pixman_fast_path_t c_fast_paths[] =
>      PIXMAN_STD_FAST_PATH (OVER, x8r8g8b8, a8, a8r8g8b8, fast_composite_over_x888_8_8888),
>      PIXMAN_STD_FAST_PATH (OVER, x8b8g8r8, a8, x8b8g8r8, fast_composite_over_x888_8_8888),
>      PIXMAN_STD_FAST_PATH (OVER, x8b8g8r8, a8, a8b8g8r8, fast_composite_over_x888_8_8888),
> +    PIXMAN_STD_FAST_PATH (OVER, solid, null, a8r8g8b8, fast_composite_over_n_8888),
> +    PIXMAN_STD_FAST_PATH (OVER, solid, null, x8r8g8b8, fast_composite_over_n_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8r8g8b8, null, a8r8g8b8, fast_composite_over_8888_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8r8g8b8, null, x8r8g8b8, fast_composite_over_8888_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8r8g8b8, null, r5g6b5, fast_composite_over_8888_0565),
> +    PIXMAN_STD_FAST_PATH (OVER, solid, null, a8b8g8r8, fast_composite_over_n_8888),
> +    PIXMAN_STD_FAST_PATH (OVER, solid, null, x8b8g8r8, fast_composite_over_n_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8b8g8r8, null, a8b8g8r8, fast_composite_over_8888_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8b8g8r8, null, x8b8g8r8, fast_composite_over_8888_8888),
>      PIXMAN_STD_FAST_PATH (OVER, a8b8g8r8, null, b5g6r5, fast_composite_over_8888_0565),


-- 
Best regards,
Siarhei Siamashka