[FFmpeg-devel] PATCH Fix SSE core-dumps when decoding AAC on optimized ffmpeg with shared libraries compiled under Mingw (win32)

[Art Clarke]

On Wed, Oct 22, 2008 at 2:11 PM, Jason Garrett-Glaser
<darkshikari at gmail.com> wrote:
>> * it also moves where the uninitialized variables live from the common
>> section to the .bss section, and gcc can remember alignment of
>> non-common sections, so that's the nature of the fix.
>
> There's a problem with that which I encountered during x264
> development: apparently on MinGW, .bss is not guaranteed to be 16-byte
> aligned.  This caused crashes in x264 until we solved the problem by
> padding the array which caused the crash with a single "1" at the end
> to force gcc to place it outside of .bss.
>
That's true, but I believe you can issue an align instruction that
will cause .bss to start aligning correctly.  That's essentially what
the dsputils_mmx code that was crashing on windows attempted to do in
the common space (where the align instruction was ignored).  Could be
wrong though.

- Art