diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bitops.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/bitops.c b/lib/bitops.c index 88cef78..b63274b 100644 --- a/lib/bitops.c +++ b/lib/bitops.c @@ -52,12 +52,13 @@ u32_masklen(u32 x) * * This function computes a integral part of binary logarithm of given * integer @v and returns it. The computed value is also an index of the - * first non-zero bit position. + * most significant non-zero bit position. */ u32 u32_log2(u32 v) { + /* The code from http://www-graphics.stanford.edu/~seander/bithacks.html */ u32 r, shift; r = (v > 0xFFFF) << 4; v >>= r; shift = (v > 0xFF ) << 3; v >>= shift; r |= shift; @@ -66,3 +67,4 @@ u32_log2(u32 v) r |= (v >> 1); return r; } + |