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Optimize LZO copy operations 

Originally committed as revision 7784 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Reimar Döffinger 2007-01-31 17:16:13 +00:00
parent ff3dac657d
commit 1db8c21c1f
1 changed files with 20 additions and 16 deletions
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36
libavcodec/lzo.c
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@ -66,6 +66,19 @@ static inline int get_len(LZOContext *c, int x, int mask) {
return cnt;
}
//#define UNALIGNED_LOADSTORE
#define BUILTIN_MEMCPY
#ifdef UNALIGNED_LOADSTORE
#define COPY2(d, s) *(uint16_t *)(d) = *(uint16_t *)(s);
#define COPY4(d, s) *(uint32_t *)(d) = *(uint32_t *)(s);
#elif defined(BUILTIN_MEMCPY)
#define COPY2(d, s) memcpy(d, s, 2);
#define COPY4(d, s) memcpy(d, s, 4);
#else
#define COPY2(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1];
#define COPY4(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1]; (d)[2] = (s)[2]; (d)[3] = (s)[3];
#endif
/**
* \brief copy bytes from input to output buffer with checking
* \param cnt number of bytes to copy, must be > 0
@ -82,10 +95,7 @@ static inline void copy(LZOContext *c, int cnt) {
c->error |= LZO_OUTPUT_FULL;
}
#if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
COPY4(dst, src);
src += 4;
dst += 4;
cnt -= 4;
@ -120,22 +130,16 @@ static inline void copy_backptr(LZOContext *c, int back, int cnt) {
dst += cnt;
} else {
#ifdef OUTBUF_PADDED
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
COPY2(dst, src);
COPY2(dst + 2, src + 2);
src += 4;
dst += 4;
cnt -= 4;
if (cnt > 0) {
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
dst[4] = src[4];
dst[5] = src[5];
dst[6] = src[6];
dst[7] = src[7];
COPY2(dst, src);
COPY2(dst + 2, src + 2);
COPY2(dst + 4, src + 4);
COPY2(dst + 6, src + 6);
src += 8;
dst += 8;
cnt -= 8;