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asm implementation of mid_pred.

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20% faster huffyuv decoding, 4% faster ffv1.

Originally committed as revision 6254 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Loren Merritt 2006-09-15 00:36:49 +00:00
parent 2a2311bee3
commit 93a319f13b
1 changed files with 16 additions and 1 deletions
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17
libavutil/common.h
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@ -235,7 +235,22 @@ static inline int av_log2_16bit(unsigned int v)
/* median of 3 */
static inline int mid_pred(int a, int b, int c)
{
#if 0
#if (defined(ARCH_X86) && __CPU__ >= 686 || defined(ARCH_X86_64)) && !defined(RUNTIME_CPUDETECT)
int i=a, j=a;
asm volatile(
"cmp %4, %2 \n\t"
"cmovg %4, %0 \n\t"
"cmovl %4, %1 \n\t"
"cmp %4, %3 \n\t"
"cmovg %3, %0 \n\t"
"cmovl %3, %1 \n\t"
"cmp %3, %2 \n\t"
"cmovl %1, %0 \n\t"
:"+&r"(i), "+&r"(j)
:"r"(a), "r"(b), "r"(c)
);
return i;
#elif 0
int t= (a-b)&((a-b)>>31);
a-=t;
b+=t;