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| author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2013-06-16 21:56:41 -0400 |
|---|---|---|
| committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2013-06-16 21:56:41 -0400 |
| commit | 7fd98c571f781c32d5de0ec83be3f38b678e73fe (patch) | |
| tree | 42ad0868b475294a72206ee1a1a7a814c94d8f1d /celt/mathops.h | |
| parent | ee2506b2c7e9a0ef05eb489ed554d38d9b71a3e5 (diff) | |
| download | opus-7fd98c571f781c32d5de0ec83be3f38b678e73fe.tar.gz | |
Converts denormalise_bands() to use 16-bit multiplications
Diffstat (limited to 'celt/mathops.h')
| -rw-r--r-- | celt/mathops.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/celt/mathops.h b/celt/mathops.h index 18a66be1..44fa97c6 100644 --- a/celt/mathops.h +++ b/celt/mathops.h @@ -190,6 +190,13 @@ static inline opus_val16 celt_log2(opus_val32 x) #define D1 22804 #define D2 14819 #define D3 10204 + +static inline opus_val32 celt_exp2_frac(opus_val16 x) +{ + opus_val16 frac; + frac = SHL16(x, 4); + return ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac)))))); +} /** Base-2 exponential approximation (2^x). (Q10 input, Q16 output) */ static inline opus_val32 celt_exp2(opus_val16 x) { @@ -200,8 +207,7 @@ static inline opus_val32 celt_exp2(opus_val16 x) return 0x7f000000; else if (integer < -15) return 0; - frac = SHL16(x-SHL16(integer,10),4); - frac = ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac)))))); + frac = celt_exp2_frac(x-SHL16(integer,10)); return VSHR32(EXTEND32(frac), -integer-2); } |