[FFmpeg-cvslog] r9340 - trunk/libavcodec/ppc/h264_altivec.c
gpoirier
subversion
Sat Jun 16 20:59:11 CEST 2007
Author: gpoirier
Date: Sat Jun 16 20:59:10 2007
New Revision: 9340
Log:
Use a faster way to compute 255-val: Instead of creating a vector of
all 255s, and then doing the subtraction, nor of the vector with itself: saves
one instruction and a register.
Patch by Graham Booker % gbooker A tamu P edu%
Modified:
trunk/libavcodec/ppc/h264_altivec.c
Modified: trunk/libavcodec/ppc/h264_altivec.c
==============================================================================
--- trunk/libavcodec/ppc/h264_altivec.c (original)
+++ trunk/libavcodec/ppc/h264_altivec.c Sat Jun 16 20:59:10 2007
@@ -766,7 +766,6 @@ static inline vector unsigned char h264_
const vector unsigned char A0v = vec_sl(vec_splat_u8(10), vec_splat_u8(4)); \
\
register vector unsigned char pq0bit = vec_xor(p0,q0); \
- register vector unsigned char temp; \
register vector unsigned char q1minus; \
register vector unsigned char p0minus; \
register vector unsigned char stage1; \
@@ -775,11 +774,10 @@ static inline vector unsigned char h264_
register vector unsigned char delta; \
register vector unsigned char deltaneg; \
\
- temp = (vector unsigned char)vec_cmpeq(p0, p0); \
- q1minus = vec_xor(temp, q1); /* 255 - q1 */ \
+ q1minus = vec_nor(q1, q1); /* 255 - q1 */ \
stage1 = vec_avg(p1, q1minus); /* (p1 - q1 + 256)>>1 */ \
stage2 = vec_sr(stage1, vec_splat_u8(1)); /* (p1 - q1 + 256)>>2 = 64 + (p1 - q1) >> 2 */ \
- p0minus = vec_xor(temp, p0); /* 255 - p0 */ \
+ p0minus = vec_nor(p0, p0); /* 255 - p0 */ \
stage1 = vec_avg(q0, p0minus); /* (q0 - p0 + 256)>>1 */ \
pq0bit = vec_and(pq0bit, vec_splat_u8(1)); \
stage2 = vec_avg(stage2, pq0bit); /* 32 + ((q0 - p0)&1 + (p1 - q1) >> 2 + 1) >> 1 */ \
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