[Ffmpeg-devel] SSE2 Crashing

Michael Niedermayer michaelni
Sat Aug 19 00:38:22 CEST 2006


On Fri, Aug 18, 2006 at 11:12:41PM +0200, Marco Manfredini wrote:
> Loren Merritt wrote:
> >DECLARE_ALIGNED_8 is supposed to be __attribute__ ((aligned (8))).
> >The fix is to use DECLARE_ALIGNED_16 if it needs to be aligned 16. Hence 
> >the name.
> Despite its name, DECLARE_ALIGNED_8 means aligned(4) in one and 
> aligned(16) in another case already. 

thats a bug IMO

> The next thing is, that the choice 
> between 8 and 16 byte alignments is done in the libavcodec/*.c routines 
> which most on them only pretend to know what alignment the target needs. 
> (like that dv.c selects 8 byte aligments, which didn't work here, 
> because dv.c has no idea that it calls SSE Routines which expect 16 byte 
> alignment).
> So what is the reason that there isn't simply one DECLARE_ALIGNED macro 
> which produces the maximum required alignment for the target-specific 
> routines?

well send a patch which adds such a macro

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is

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