[FFmpeg-devel] [PATCH 07/10] avfilter/vf_nlmeans: Move ff_nlmeans_init into a header

[Hendrik Leppkes]

On Fri, May 13, 2022 at 10:27 AM Andreas Rheinhardt
<andreas.rheinhardt at outlook.com> wrote:
>
> Soft Works:
> >
> >
> >> -----Original Message-----
> >> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> >> Andreas Rheinhardt
> >> Sent: Tuesday, May 3, 2022 8:38 AM
> >> To: ffmpeg-devel at ffmpeg.org
> >> Cc: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> >> Subject: [FFmpeg-devel] [PATCH 07/10] avfilter/vf_nlmeans: Move
> >> ff_nlmeans_init into a header
> >>
> >> This removes a dependency of checkasm on lavfi/vf_nlmeans.o
> >> and also allows to inline ff_nlmeans_init() irrespectively of
> >> interposing.
> >>
> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> >> ---
> >
> > [..]
> >
> >> +
> >> +static av_unused void ff_nlmeans_init(NLMeansDSPContext *dsp)
> >> +{
> >> +    dsp->compute_safe_ssd_integral_image =
> >> compute_safe_ssd_integral_image_c;
> >> +    dsp->compute_weights_line = compute_weights_line_c;
> >> +
> >> +    if (ARCH_AARCH64)
> >> +        ff_nlmeans_init_aarch64(dsp);
> >
> > Hi Andreas,
> >
> > the above breaks compilation for me:
> >
> > 1>libavfilterd.lib(libavfilter_vf_nlmeans.obj) : error LNK2019: unresolved external symbol ff_nlmeans_init_aarch64 referenced in function ff_nlmeans_init
> >
> > The reason is that I'm (obviously) not compiling stuff from the
> > libavfilter\aarch64 subfolder.
> >
> > It might need an #ifdef ?
> >
> > I haven't taken a deeper look at it, though.
> >
> > Thanks,
> > softworkz
> >
> >
>
> That surprises me: The earlier code did exactly the same; in fact, using
> if (ARCH_*) is our typical check for arches in dsp-init code.
> Is this the only place where this happens?
> #ifdef is certainly wrong: All ARCH_* are always defined; they are just
> 0 or 1.
> Anyway, will send a patch with #if.
>

The inlining due to the code coming from a header probably breaks
dead-code-elimination in some compilers.

- Hendrik