[FFmpeg-devel] [PATCH] swscale/x86/rgb2rgb: add AVX512ICL versions of shuffle_bytes

[Shreesh Adiga]

> Thanks for the patch. Could you please compile and run
> tests/checkasm/checkasm with "--test=sw_rgb --bench" and paste the
> results for the shuffle_bytes functions, to see if there's a speed up
> compared to the AVX2 implementation?

I ran the command "tests/checkasm/checkasm --test=sw_rgb --bench" and I see
the below output:
benchmarking with native FFmpeg timers
nop: 45.0
checkasm: using random seed 17575157
checkasm: bench runs 1024 (1 << 10)
SSE2:
 - sw_rgb.uyvytoyuv422       [OK]
 - sw_rgb.interleave_bytes   [OK]
 - sw_rgb.deinterleave_bytes [OK]
 - sw_rgb.rgb_to_y           [OK]
 - sw_rgb.rgb_to_uv          [OK]
SSSE3:
 - sw_rgb.shuffle_bytes_2103 [OK]
 - sw_rgb.shuffle_bytes_0321 [OK]
 - sw_rgb.shuffle_bytes_1230 [OK]
 - sw_rgb.shuffle_bytes_3012 [OK]
 - sw_rgb.shuffle_bytes_3210 [OK]
 - sw_rgb.rgb_to_y           [OK]
 - sw_rgb.rgb_to_uv          [OK]
AVX:
 - sw_rgb.uyvytoyuv422       [OK]
 - sw_rgb.deinterleave_bytes [OK]
 - sw_rgb.rgb_to_y           [OK]
 - sw_rgb.rgb_to_uv          [OK]
AVX2:
 - sw_rgb.shuffle_bytes_2103 [OK]
 - sw_rgb.shuffle_bytes_0321 [OK]
 - sw_rgb.shuffle_bytes_1230 [OK]
 - sw_rgb.shuffle_bytes_3012 [OK]
 - sw_rgb.shuffle_bytes_3210 [OK]
 - sw_rgb.uyvytoyuv422       [OK]
 - sw_rgb.rgb_to_y           [OK]
 - sw_rgb.rgb_to_uv          [OK]
AVX-512ICL:
 - sw_rgb.shuffle_bytes_2103 [OK]
 - sw_rgb.shuffle_bytes_0321 [OK]
 - sw_rgb.shuffle_bytes_1230 [OK]
 - sw_rgb.shuffle_bytes_3012 [OK]
 - sw_rgb.shuffle_bytes_3210 [OK]
checkasm: all 184 tests passed
shuffle_bytes_0321_c:                                   45.0 ( 1.00x)
shuffle_bytes_0321_ssse3:                               11.2 ( 4.00x)
shuffle_bytes_0321_avx2:                                11.2 ( 4.00x)
shuffle_bytes_0321_avx512icl:                           11.2 ( 4.00x)
shuffle_bytes_1230_c:                                   67.5 ( 1.00x)
shuffle_bytes_1230_ssse3:                               11.2 ( 6.00x)
shuffle_bytes_1230_avx2:                                11.2 ( 6.00x)
shuffle_bytes_1230_avx512icl:                            0.0 ( 0.00x)
shuffle_bytes_2103_c:                                   45.0 ( 1.00x)
shuffle_bytes_2103_ssse3:                               11.2 ( 4.00x)
shuffle_bytes_2103_avx2:                                 0.0 ( 0.00x)
shuffle_bytes_2103_avx512icl:                            0.0 ( 0.00x)
shuffle_bytes_3012_c:                                   67.5 ( 1.00x)
shuffle_bytes_3012_ssse3:                               11.2 ( 6.00x)
shuffle_bytes_3012_avx2:                                11.2 ( 6.00x)
shuffle_bytes_3012_avx512icl:                            0.0 ( 0.00x)
shuffle_bytes_3210_c:                                   67.5 ( 1.00x)
shuffle_bytes_3210_ssse3:                               11.2 ( 6.00x)
shuffle_bytes_3210_avx2:                                11.2 ( 6.00x)
shuffle_bytes_3210_avx512icl:                            0.0 ( 0.00x)

I've not included the other function printed by the bench command.
I'm not sure if I'm missing something, the output doesn't look consistent
to me.
There are many 0.0 and I don't see any difference between ssse3 and avx2
either.
I'm running this on AMD Ryzen 7950x Zen4 machine.

I've inspected the assembly output for one of the ssse3/avx2/avx512 and it
seems to be as per my expectation.
Therefore I'm not sure if the checkasm is accurately measuring here.
Please let me know if I'm missing something here, I'm new to FFmpeg
development and this is my first patch submission.

Thanks,
Shreesh