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| author | Marek Olšák <maraeo@gmail.com> | 2012-03-30 00:21:11 +0200 |
|---|---|---|
| committer | Marek Olšák <maraeo@gmail.com> | 2012-07-17 21:22:14 +0200 |
| commit | 6694a68d890a9aa491b5c3e8a576318bb6124e21 (patch) | |
| tree | 706c2010352f804a60334a71af22738d61b730b6 /src/gallium/auxiliary/util/u_math.h | |
| parent | 018e3f75d69490598d61059ece56d379867f3995 (diff) | |
| download | external_mesa3d-6694a68d890a9aa491b5c3e8a576318bb6124e21.zip external_mesa3d-6694a68d890a9aa491b5c3e8a576318bb6124e21.tar.gz external_mesa3d-6694a68d890a9aa491b5c3e8a576318bb6124e21.tar.bz2 | |
gallium/util: add util_bit_last - finds the last bit set in a word
Diffstat (limited to 'src/gallium/auxiliary/util/u_math.h')
| -rw-r--r-- | src/gallium/auxiliary/util/u_math.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index f35c35f..90b421e 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -477,6 +477,20 @@ unsigned ffs( unsigned u ) #endif /* FFS_DEFINED */ +/** + * Find last bit set in a word. The least significant bit is 1. + * Return 0 if no bits are set. + */ +static INLINE unsigned util_last_bit(unsigned u) +{ + unsigned r = 0; + while (u) { + r++; + u >>= 1; + } + return r; +} + /* Destructively loop over all of the bits in a mask as in: * |