[FFmpeg-devel] [PATCH] ac3dsp: RISC-V V float_to_fixed24

[flow gg]

> How did you test it?

I wrote a test, but it was a bit rough, so I want to modify it before
submitting. I've added it to this reply.

> This does not seem according to the C ABI. AFAIK `unsigned` is
sign-extended.

I'm a bit confused... because this passed in the tests I wrote in qemu.
Maybe there's a problem with my test？

> ALU right before dependent conditional branch should be avoided.

Should the sub be moved forward? I've modified it.

> SHxADD can be used advantageously.

Okay, I've made the modification

Rémi Denis-Courmont <remi at remlab.net> 于2023年11月22日周三 21:41写道：

> Hi,
>
> How did you test it? As per
> http://ffmpeg.org/pipermail/ffmpeg-devel/2023-June/310720.html we still
> don't have a FATE instance set up with the RISC-V Vector extension. The
> only testing consists of my manual runs of checkasm on a K230 board. (We
> *do* have Zba and Zbb now though, hence the existing extract_exponents()).
>
> Also:
> - This does not seem according to the C ABI. AFAIK `unsigned` is
> sign-extended.
> - ALU right before dependent conditional branch should be avoided.
> - SHxADD can be used advantageously.
>
>
> Le 22 novembre 2023 14:00:07 GMT+02:00, flow gg <hlefthleft at gmail.com> a
> écrit :
> >c910
> >    float_to_fixed24_c: 208.2
> >    float_to_fixed24_rvv_f32: 71.5
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