[Liboil] idct8x8_s16_mmx seems kind of broken...

[Adam D. Moss]

Adam D. Moss wrote:	
> I'm using the oil_idct8x8_s16() function and I find
> that when liboil selects idct8x8_s16_mmx, the artifacts
> are pretty bad (see attached images), almost regardless
> of the distribution or strength of the DCT coefficients.
> 
> idct8x8_s16_ref is very nearly as fast here and gives
> perfect results as far as I'm concerned (bit-identical to
> idct8x8_f64_c for my tests).

P.S: This is CVS liboil compiled with GCC 4.0.1 - thanks
for the recent zigzag fix by the way, I thought I was
going mad...

--Adam