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

[Edouard Gomez]

suxen_drol (suxen_drol at hotmail.com) wrote:
> err.. i havent had time to weed through the transfer code.

The error was that the new code was doing the sub operations on bytes,
to save cycles, but that isn't possible because of overflows, and signed
8 to 16 conversions using a simple unpack operation.
 
> 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.

Ok doki, we'll just place a test somewhere to avoid that sigill problem.

-- 
Edouard Gomez