[x264-devel] commit: Spare a vec_perm and a vec_mergeh though using a LUT of permutation vectors . (Guillaume Poirier )

maaanuuu at gmx.net maaanuuu at gmx.net
Tue Feb 10 16:37:02 CET 2009


Hello,

the output of this version differs slightly from earlier ones.


> +        CV(0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,  /*  
> pix=mod16, i_stride=mod8  */
> +           0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F),
> +    };

isn't i_stride always mod16 now? Then the permutation vector should be

CV(0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
        0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F)


> +    vec_u8_t perm = perm_tab[ ((i_stride & 8) >> 3) ];

I think ((i_stride & 8) >> 3) has no effect, the index depends on pix  
being mod16 or mod8, or am I wrong?


Manuel


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