[Speex-dev] SSE bug on Win32 with GCC 4.2.1

Jean-Marc Valin jean-marc.valin at usherbrooke.ca
Thu Aug 23 08:17:45 PDT 2007


> FFMpeg had problems with SSE missaligned stack variables under
> Windows too. Now, with gcc 4.2 available on Windows they solved it
> with __attribute__((force_align_arg_pointer)) set for publicly visible
> functions. You may find their patch and short description in this mail:
> http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-August/034010.html
> 
> Speex may follow similar way to solve this problem.

Looks a bit scary (and likely to cause problems in the future). Not
quite sure how to handle that. My first idea would be to abort
compilation if someone's trying to use SSE with environments that have
this bug and then print a message saying "if you really know what you're
doing and want to live dangerously, do that". Otherwise, is there a
compiler option to force alignment on every single function? It's a bit
of overkill, but since Speex is really small, I don't think it'd be an
issue.

	Jean-Marc


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