[Pixman] [PATCH 3/5] ARMv6: New blit routines

[Siarhei Siamashka]

On Sat, 19 Jan 2013 16:16:51 +0000
Ben Avison <bavison at riscosopen.org> wrote:

> These are usable either as various composite operations, or via the
> top-level function pixman_blt() which now does some blitting for the
> first time on an ARMv6 platform (previously it just returned FALSE).

Hi, generally the results are quite good and show an improvement.
Just one thing looks a bit odd.

> src_8888_8888
> 
>     Before          After
>     Mean   StdDev   Mean   StdDev  Confidence  Change
> L1  414.5  9.4      445.8  3.6     100.0%      +7.6%
> L2  93.3   20.7     114.5  12.9    100.0%      +22.7%
> M   57.0   0.2      89.2   0.5     100.0%      +56.4%

89.2 MPix/s * 32bpp = ~357 MB/s

> HT  28.7   0.3      39.6   0.4     100.0%      +37.9%
> VT  25.5   0.2      35.3   0.4     100.0%      +38.4%
> R   20.1   0.1      33.8   0.3     100.0%      +67.8%
> RT  7.8    0.2      12.7   0.4     100.0%      +62.7%
> 
> src_0565_0565
> 
>     Before          After
>     Mean   StdDev   Mean   StdDev  Confidence  Change
> L1  397.4  6.1      412.5  5.2     100.0%      +3.8%
> L2  143.2  10.9     141.9  6.5     68.9%       -0.9%  (insignificant)
> M   90.7   0.4      133.5  0.7     100.0%      +47.1%

133.5 MPix/s * 16bpp = ~267 MB/s

Seems to be a much less efficient use of memory bandwidth here
compared to src_8888_8888?

> HT  38.6   0.3      53.7   0.7     100.0%      +39.0%
> VT  33.0   0.3      47.3   0.6     100.0%      +43.3%
> R   25.7   0.2      42.1   0.5     100.0%      +64.1%
> RT  8.0    0.2      13.3   0.3     100.0%      +65.6%
> 
> src_8_8
> 
>     Before          After
>     Mean   StdDev   Mean   StdDev  Confidence  Change
> L1  716.5  9.8      768.2  20.4    100.0%      +7.2%
> L2  246.2  12.7     260.5  8.8     100.0%      +5.8%
> M   146.8  0.7      227.9  0.7     100.0%      +55.2%
> HT  44.9   0.6      62.1   1.0     100.0%      +38.2%
> VT  35.6   0.4      53.4   0.7     100.0%      +50.0%
> R   29.7   0.3      48.2   0.6     100.0%      +62.2%
> RT  8.6    0.2      12.9   0.4     100.0%      +49.3%

-- 
Best regards,
Siarhei Siamashka