[FFmpeg-devel] [PATCH 4/5] x86/opusdsp: implement FMA3 accelerated postfilter and deemphasis

[Lynne]

Mar 16, 2019, 4:33 PM by dev at lynne.ee <mailto:dev at lynne.ee>:

> 58893 decicycles in deemphasis_c,  130548 runs,    524 skips
> 9475 decicycles in deemphasis_fma3,  130686 runs,    386 skips -> 6.21x speedup
>
> 24866 decicycles in postfilter_c,   65386 runs,    150 skips
> 5268 decicycles in postfilter_fma3,   65505 runs,     31 skips -> 4.72x speedup
>
> Total decoder speedup: ~14%
>
> Deemphasis SIMD based on the following unrolling:
> const float c1 = CELT_EMPH_COEFF, c2 = c1*c1, c3 = c2*c1, c4 = c3*c1;
> float state = coeff;
>
> for (int i = 0; i < len; i += 4) {
>     y[0] = x[0] + c1*state;
>     y[1] = x[1] + c2*state + c1*x[0];
>     y[2] = x[2] + c3*state + c1*x[1] + c2*x[0];
>     y[3] = x[3] + c4*state + c1*x[2] + c2*x[1] + c3*x[0];
>
>     state = y[3];
>     y += 4;
>     x += 4;
> }
>

Ping to this part of the patchset while I fix android?