This is more spec-compliant because it does not rely
on dead-code elimination by the compiler. Especially
MSVC has problems with this, as can be seen in
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296373.html
or
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/297022.html
This commit does not eliminate every instance where we rely
on dead code elimination: It only tackles branching to
the initialization of arch-specific dsp code, not e.g. all
uses of CONFIG_ and HAVE_ checks. But maybe it is already
enough to compile FFmpeg with MSVC with whole-programm-optimizations
enabled (if one does not disable too many components).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The code represents a considerable maintenance burden and it is not
clear that it gives a noticeable benefit to outweigh this after 10
years of improvements in compiler technology since its creation.
Also use the resulting 16bpp functions for anything >8 and <=16, not just
9 and 10. This fixes 12 and 14bpp H264 support.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Arnie Chang
Andreas Rheinhardt
Shiyou Yin
周晓勇
Janne Grunau
Michael Niedermayer
Diego Biurrun
Ronald S. Bultje