diff options
| author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-10-11 16:47:00 -0400 |
|---|---|---|
| committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-10-11 16:47:00 -0400 |
| commit | 4541bbcc22c6289f3a2a70fda88a9aa372535b58 (patch) | |
| tree | db4b21988e8db63302f6d74e44902ed2668fa294 /silk/Inlines.h | |
| parent | 37378626205c46690629dd6291ec528703b4ae60 (diff) | |
| download | opus-4541bbcc22c6289f3a2a70fda88a9aa372535b58.tar.gz | |
Gets rid of a "safe" signed overflow in silk_DIV32_varQ()
Diffstat (limited to 'silk/Inlines.h')
| -rw-r--r-- | silk/Inlines.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/silk/Inlines.h b/silk/Inlines.h index 50060e63..765e7708 100644 --- a/silk/Inlines.h +++ b/silk/Inlines.h @@ -117,7 +117,8 @@ static inline opus_int32 silk_DIV32_varQ( /* O returns a good approximatio result = silk_SMULWB(a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ /* Compute residual by subtracting product of denominator and first approximation */ - a32_nrm -= silk_LSHIFT( silk_SMMUL(b32_nrm, result), 3 ); /* Q: a_headrm */ + /* It's OK to overflow because the final value of a32_nrm should always be small */ + a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw( silk_SMMUL(b32_nrm, result), 3 )); /* Q: a_headrm */ /* Refinement */ result = silk_SMLAWB(result, a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ |