[Ffmpeg-devel] weird snow segfaults on amd64

Michael Niedermayer michaelni
Mon Apr 18 03:23:16 CEST 2005


Hi

On Monday 18 April 2005 03:08, Aurelien Jacobs wrote:
> On Sun, 17 Apr 2005 16:21:40 +0200
>
> Michael Niedermayer <michaelni at gmx.at> wrote:
> > btw, maybe try to disable the START/STOP_TIMER macros (a trivial #if ...
> > ->  #if 0 change in common.h), i think gcc misscompiles them on AMD64
>
> Right ! Disabling START/STOP_TIMER fix the segfault on AMD64.
> I investigated a bit further and it seems that the "=A" constraint don't
> work properly on AMD64. Maybe rdtsc modify the full rax/rdx and "=A" only
> backup/restore eax/edx or something like that ?
> So I've written an AMD64 specific rdtsc() implementation. I know it's not
> very nice but I can't come with a cleaner solution.
> Should I apply it ?

yes

[...]
-- 
Michael

"nothing is evil in the beginning. Even Sauron was not so." -- Elrond





More information about the ffmpeg-devel mailing list