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aligned bitstream writer (1% slower on p3 but perhaps its faster on p4?) 

Originally committed as revision 296 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-02-12 22:43:26 +00:00
parent 17592475b3
commit 4f0f8bfce3
1 changed files with 35 additions and 1 deletions
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36
libavcodec/common.h
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@ -9,6 +9,7 @@
#endif
//#define ALT_BITSTREAM_WRITER
//#define ALIGNED_BITSTREAM_WRITER
//#define ALT_BITSTREAM_READER
//#define ALIGNED_BITSTREAM
#define FAST_GET_FIRST_VLC
@ -238,8 +239,40 @@ static inline uint32_t unaligned32(const void *v) {
#endif //!ARCH_X86
#ifdef ALT_BITSTREAM_WRITER
static inline void put_bits(PutBitContext *s, int n, int value)
static inline void put_bits(PutBitContext *s, int n, unsigned int value)
{
#ifdef ALIGNED_BITSTREAM_WRITER
#ifdef ARCH_X86
asm volatile(
"movl %0, %%ecx \n\t"
"xorl %%eax, %%eax \n\t"
"shrdl %%cl, %1, %%eax \n\t"
"shrl %%cl, %1 \n\t"
"movl %0, %%ecx \n\t"
"shrl $3, %%ecx \n\t"
"andl $0xFFFFFFFC, %%ecx \n\t"
"bswapl %1 \n\t"
"orl %1, (%2, %%ecx) \n\t"
"bswapl %%eax \n\t"
"addl %3, %0 \n\t"
"movl %%eax, 4(%2, %%ecx) \n\t"
: "=&r" (s->index), "=&r" (value)
: "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n))
: "%eax", "%ecx"
);
#else
int index= s->index;
uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
value<<= 32-n;
ptr[0] |= be2me_32(value>>(index&31));
ptr[1] = be2me_32(value<<(32-(index&31)));
//if(n>24) printf("%d %d\n", n, value);
index+= n;
s->index= index;
#endif
#else //ALIGNED_BITSTREAM_WRITER
#ifdef ARCH_X86
asm volatile(
"movl $7, %%ecx \n\t"
@ -267,6 +300,7 @@ static inline void put_bits(PutBitContext *s, int n, int value)
index+= n;
s->index= index;
#endif
#endif //!ALIGNED_BITSTREAM_WRITER
}
#endif