[FFmpeg-cvslog] r24926 - trunk/libavcodec/x86/vp56dsp.asm

[Michael Niedermayer]

On Mon, Sep 06, 2010 at 09:15:35PM +0100, M?ns Rullg?rd wrote:
> Michael Niedermayer <michaelni at gmx.at> writes:
> 
> > On Thu, Aug 26, 2010 at 10:09:27AM -0400, Ronald S. Bultje wrote:
> >> Hi,
> >> 
> >> On Wed, Aug 25, 2010 at 11:41 AM, mru <subversion at mplayerhq.hu> wrote:
> >> > Author: mru
> >> > Date: Wed Aug 25 17:41:11 2010
> >> > New Revision: 24926
> >> >
> >> > Log:
> >> > VP6: fix vp6_filter_diag4_mmx/sse on 64-bit
> >> >
> >> > The stride can be negative and must be sign extended before being
> >> > used in pointer arithmetic.
> >> >
> >> > Modified:
> >> > ? trunk/libavcodec/x86/vp56dsp.asm
> >> >
> >> > Modified: trunk/libavcodec/x86/vp56dsp.asm
> >> > ==============================================================================
> >> > --- trunk/libavcodec/x86/vp56dsp.asm ? ?Wed Aug 25 17:32:29 2010 ? ? ? ?(r24925)
> >> > +++ trunk/libavcodec/x86/vp56dsp.asm ? ?Wed Aug 25 17:41:11 2010 ? ? ? ?(r24926)
> >> > @@ -127,6 +127,9 @@ cglobal vp6_filter_diag4_%1, 5, 7, %2
> >> > ? ? sub ? ? ? ? rsp, 8*15
> >> > ? ? movq ? ? ? ? m6, [pw_64]
> >> > ?%endif
> >> > +%ifdef ARCH_X86_64
> >> > + ? ?movsxd ? ? ? r2, r2d
> >> > +%endif
> >> 
> >> This "problem" is biting me in other places too, and I don't like this
> >> at all. Does anyone have opinions on best way forward from here?
> >> 
> >> <crazy>
> >> How about making all SIMD-related int->long?
> >> </crazy>
> >
> > i previously said that all things used as array indexes should be 64bit on
> > x86-64 (that is unless something else is faster for a specific case)
> > we (ramiro maybe?) tried long somewhen for sws until it was found out that
> > windows has 32bit long on x86-64 IIRC
> > x86_reg is the correct thing to use but IIRC that lead to some ehm discussion
> > about using something that says x86 in generic code. Iam not sure what the
> > result was or if i just gave up in light of that "discussion".
> > of course it can be renamed ...
> 
> That would be correct on x86.  It would not be correct on various
> other systems.  I'm afraid there is no one size fits all solution
> here.

which systems?

besides the current hardcoded use of int is worse than a typedef on all
systems

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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