[XviD-devel] recent mmx patch (xvid_bench results)

[suxen_drol]

On Tue, 13 Apr 2004 22:02:48 +0200 Edouard Gomez <ed.gomez at free.fr> wrote:
> Edouard Gomez (ed.gomez at free.fr) wrote:
> > pete (p_ross at iprimus.com.au) wrote:
> > > it appears mmx 8to16sub is buggy.
> > 
> > transfer_8to16sub_mmx is indeed buggy. You missed
> > transfer_8to16sub2_mmx ;-)

you mean to say transfer_8to16sub2_mmx is buggy too?

> Ok it appears all changes are concerned, so i revert back the patch. Btw
> i know  why my visual tests  (the ones i  watch with my eyes  instead of
> just looking at  xvid_bench crcs) succeeded...  i tested  the usual 3dne
> functions for my AMD cpu :-)</me idiot>
> 
> But the CRC test passing is still a mistery to me.

err.. i havent had time to weed through the transfer code.

however the the crash was casused by some conditional moves. the cmov
instructions is generally supported by cpus with MMXEXT. my cpu which
only has MMX.

* quant_h263_intra_mmx has cmovs. this should be renamed to _xmm and  
version developed without the cmovs called '_mmx'.

* dequant_h263_intra_mmx has cmovs. we already have an _xmm version, and
i assume it is faster than the _mmx (somebody may want to check).
therefore, the cmovs should be replaced.

cheers,
-- pete