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watery01 / libyuv

Automatically exported from code.google.com/p/libyuv
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pmulhuw #182

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
pmulhw is signed.  consider pmulhuw for interpolation where the values are 
unsigned.
may help with filtering, matrix math and yuv conversion.

eg
pmullw     xmm3, kYToRgb                             
paddsw     xmm0, xmm3           /* B += Y */         
paddsw     xmm1, xmm3           /* G += Y */         
paddsw     xmm2, xmm3           /* R += Y */         
psraw      xmm0, 6                                   
psraw      xmm1, 6                                   
psraw      xmm2, 6                                   
packuswb   xmm0, xmm0           /* B */              
packuswb   xmm1, xmm1           /* G */              
packuswb   xmm2, xmm2           /* R */

Original issue reported on code.google.com by fbarch...@chromium.org on 5 Feb 2013 at 10:40

GoogleCodeExporter commented 9 years ago 
Deferring for now.  Will consider this on case by case for AVX2

Original comment by fbarch...@chromium.org on 19 Mar 2013 at 6:56