[FFmpeg-cvslog] r10159 - trunk/libavcodec/i386/snowdsp_mmx.c

[michael]

Author: michael
Date: Tue Aug 21 01:02:59 2007
New Revision: 10159

Log:
slightly change horizontal lift3 so it needs 1 bit less headroom


Modified:
   trunk/libavcodec/i386/snowdsp_mmx.c

Modified: trunk/libavcodec/i386/snowdsp_mmx.c
==============================================================================
--- trunk/libavcodec/i386/snowdsp_mmx.c	(original)
+++ trunk/libavcodec/i386/snowdsp_mmx.c	Tue Aug 21 01:02:59 2007
@@ -333,18 +333,18 @@ void ff_snow_horizontal_compose97i_mmx(D
                 "movq   12(%1), %%mm6        \n\t"
                 "paddd    (%1), %%mm2        \n\t"
                 "paddd   8(%1), %%mm6        \n\t"
-                "movq    %%mm2, %%mm0        \n\t"
-                "movq    %%mm6, %%mm4        \n\t"
-                "pslld      $2, %%mm2        \n\t"
-                "pslld      $2, %%mm6        \n\t"
+                "pxor    %%mm0, %%mm0        \n\t" //note: the 2 xor could be avoided if we would flip the rounding direction
+                "pxor    %%mm4, %%mm4        \n\t"
                 "psubd   %%mm2, %%mm0        \n\t"
                 "psubd   %%mm6, %%mm4        \n\t"
                 "psrad      $1, %%mm0        \n\t"
                 "psrad      $1, %%mm4        \n\t"
-                "movq     (%0), %%mm2        \n\t"
-                "movq    8(%0), %%mm6        \n\t"
                 "psubd   %%mm0, %%mm2        \n\t"
                 "psubd   %%mm4, %%mm6        \n\t"
+                "movq     (%0), %%mm0        \n\t"
+                "movq    8(%0), %%mm4        \n\t"
+                "paddd   %%mm0, %%mm2        \n\t"
+                "paddd   %%mm4, %%mm6        \n\t"
                 "movq    %%mm2, (%2)         \n\t"
                 "movq    %%mm6, 8(%2)        \n\t"
                 :: "r"(&src[i]), "r"(&b[i]), "r"(&temp[i])