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%

Originally committed as revision 9340 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Graham Booker 2007-06-16 18:59:10 +00:00 committed by Guillaume Poirier
parent a444671542
commit f4a02f6e9b
1 changed files with 2 additions and 4 deletions

View File

@ -766,7 +766,6 @@ static inline vector unsigned char h264_deblock_mask ( register vector unsigned
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_deblock_mask ( register vector unsigned
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 */ \