[FFmpeg-devel] [PATCH] libavcodec: fix building without asm

[wm4]

On Fri, 5 Feb 2016 21:45:00 +0100
Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> On Fri, Feb 5, 2016 at 9:33 PM, Michael Bradshaw <mjbshaw at gmail.com> wrote:
> > Hi,
> >
> > Attached patch fixes building ffmpeg on OS X with the following
> > configuration: --disable-optimizations --disable-asm
> >
> > Without this patch the following error is observed:
> >
> > LD ffmpeg_g
> > Undefined symbols for architecture x86_64:
> >   "_ff_spatial_idwt_init_mmx", referenced from:
> >       _ff_spatial_idwt_init2 in libavcodec.a(dirac_dwt.o)
> > ld: symbol(s) not found for architecture x86_64
> > clang: error: linker command failed with exit code 1 (use -v to see
> > invocation)
> > make: *** [ffmpeg_g] Error 1
> >
> >  
> 
> Clang fails to figure out that if (x && 0) is dead code? Oh my.

(You know that in theory ffmpeg shouldn't even rely on optional
optimizations for build success.)