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| author | Ondrej Zajicek <santiago@crfreenet.org> | 2009-03-31 21:17:00 +0200 |
|---|---|---|
| committer | Ondrej Zajicek <santiago@crfreenet.org> | 2009-03-31 21:17:00 +0200 |
| commit | c60cdd8c3926a1b3d9156327e8aae64986084ff4 (patch) | |
| tree | a6ee8b63c24478687d5ac03149a28f2a8044bcab /lib/bitops.c | |
| parent | b1a597e0c3821c791a41278454e74261cf1b95fb (diff) | |
| download | bird-c60cdd8c3926a1b3d9156327e8aae64986084ff4.tar bird-c60cdd8c3926a1b3d9156327e8aae64986084ff4.zip | |
Cleanup changes
Diffstat (limited to 'lib/bitops.c')
| -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; } + |