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

Michael Bradshaw mjbshaw at gmail.com
Fri Feb 5 22:10:54 CET 2016


On Friday, February 5, 2016, Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> On Fri, Feb 5, 2016 at 9:33 PM, Michael Bradshaw <mjbshaw at gmail.com
> <javascript:;>> 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.


Well, this is with --disable-optimizations so the lack of dead code
optimization here shouldn't be surprising. I'm actually surprised it even
works at all with optimizations turned off.

On a separate note, I just realized that patch has a spurious new line. I
can send a new patch if that bugs anyone.


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