[FFmpeg-devel] [PATCH] avfilter, swresample, swscale: use fabs, fabsf instead of FFABS

Ganesh Ajjanagadde gajjanag at mit.edu
Thu Oct 22 23:15:34 CEST 2015

On Thu, Oct 22, 2015 at 4:51 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> Ganesh Ajjanagadde <gajjanag <at> mit.edu> writes:
>> To put an end to a long and tortuous thread, and
>> due to the lack of relevant outstanding objections,
>> pushed.
> To sum it up:
> Several developers have explained to you that the
> numbers you posted show that FFmpeg is now either
> slower or equally fast, you have pushed with a
> commit message that claims that your patch makes
> FFmpeg faster.

I was far more nuanced because I know there are people like you who do
not understand such things. Seems like I failed at that anyway. I am
sorry, but I can only repeat the first two lines:
"It is well known that fabs and fabsf are at least as fast and sometimes
faster than the FFABS macro, at least on the gcc+glibc combination."

That statement is completely accurate. I did not claim "within
FFmpeg", since like I said usually there is no difference.

>From where the "slower" comes from god knows.

> How do you call such a claim without any base?

Look at the asm, etc etc. Clement has already showed the difference.
"Without any base" is a completely incorrect and illogical statement.
Paul is clearly convinced enough to start using it in his own filters.

> Carl Eugen
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