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Factorize READ_FLIP_SIGN() optimization out

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Originally committed as revision 23098 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2010-05-11 21:20:33 +00:00
parent 0c0d88aed5
commit 4b070a7a61
1 changed files with 17 additions and 13 deletions
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30
libavcodec/mpegaudiodec.c
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@ -1407,6 +1407,22 @@ static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_
} }
} }
/* Following is a optimized code for
INTFLOAT v = *src
if(get_bits1(&s->gb))
v = -v;
*dst = v;
*/
#if CONFIG_FLOAT
#define READ_FLIP_SIGN(dst,src)\
v = AV_RN32A(src) ^ (get_bits1(&s->gb)<<31);\
AV_WN32A(dst, v);
#else
#define READ_FLIP_SIGN(dst,src)\
v= -get_bits1(&s->gb);\
*(dst) = (*(src) ^ v) - v;
#endif
static int huffman_decode(MPADecodeContext *s, GranuleDef *g, static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
int16_t *exponents, int end_pos2) int16_t *exponents, int end_pos2)
{ {
@ -1538,19 +1554,7 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
int v; int v;
int pos= s_index+idxtab[code]; int pos= s_index+idxtab[code];
code ^= 8>>idxtab[code]; code ^= 8>>idxtab[code];
/* Following is a optimized code for READ_FLIP_SIGN(g->sb_hybrid+pos, RENAME(exp_table)+exponents[pos])
INTFLOAT v = RENAME(exp_table)[ exponents[pos] ];
if(get_bits1(&s->gb))
v = -v;
g->sb_hybrid[pos] = v;
*/
#if CONFIG_FLOAT
v = AV_RN32A(RENAME(exp_table)+exponents[pos]) ^ (get_bits1(&s->gb)<<31);
AV_WN32A(g->sb_hybrid+pos, v);
#else
v= -get_bits1(&s->gb);
g->sb_hybrid[pos] = (RENAME(exp_table)[ exponents[pos] ] ^ v) - v;
#endif
} }
s_index+=4; s_index+=4;
} }