[FFmpeg-devel] [PATCH] lavc/rv34dsp: optimise R-V V idct_dc_add
flow gg
hlefthleft at gmail.com
Thu May 23 06:31:52 EEST 2024
Unfortunately I only test to obtain benchmarks and basic correctness. I
always feel the need for a professional to write the tests.
Rémi Denis-Courmont <remi at remlab.net> 于2024年5月23日周四 04:35写道:
>
>
> Le 22 mai 2024 23:28:54 GMT+03:00, "Rémi Denis-Courmont" <remi at remlab.net>
> a écrit :
> >This removes one stray LI and reworks the vector arithmetic to avoid
> >changing the vector configuration. On K230, this takes the 46.5 cycle
> >count down from 46.5 to 43.5.
> >---
> > libavcodec/riscv/rv34dsp_rvv.S | 13 ++++++-------
> > 1 file changed, 6 insertions(+), 7 deletions(-)
> >
> >diff --git a/libavcodec/riscv/rv34dsp_rvv.S
> b/libavcodec/riscv/rv34dsp_rvv.S
> >index f1f6345012..e8aff7e570 100644
> >--- a/libavcodec/riscv/rv34dsp_rvv.S
> >+++ b/libavcodec/riscv/rv34dsp_rvv.S
> >@@ -36,16 +36,15 @@ func ff_rv34_idct_dc_add_rvv, zve32x
> > vsetivli zero, 4, e8, mf4, ta, ma
> > vlse32.v v0, (a0), a1
> > li t1, 169
> >+ li t2, 128
> > mul t1, t1, a2
> >- li a2, 255
> >+ vsetivli zero, 4*4, e8, m1, ta, ma
> >+ vwsubu.vx v2, v0, t2
> > addi t1, t1, 512
> > srai t1, t1, 10
> >- vsetivli zero, 4*4, e16, m2, ta, ma
> >- vzext.vf2 v2, v0
> >- vadd.vx v2, v2, t1
> >- vmax.vx v2, v2, zero
> >- vsetvli zero, zero, e8, m1, ta, ma
> >- vnclipu.wi v0, v2, 0
> >+ vwadd.wx v2, v2, t1
>
> Hmm, this should not work, as t1 has more than 8 bits. Maybe checkasm is
> sloppy here.
>
> >+ vnclip.wi v0, v2, 0
> >+ vxor.vx v0, v0, t2
> > vsetivli zero, 4, e8, mf4, ta, ma
> > vsse32.v v0, (a0), a1
> >
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>
More information about the ffmpeg-devel
mailing list