diff options
| -rw-r--r-- | src/gallium/auxiliary/util/u_math.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index 731a11475e..9ed1ab6d8e 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -491,6 +491,26 @@ util_next_power_of_two(unsigned x) /** + * Return number of bits set in n. + */ +static INLINE unsigned +util_bitcount(unsigned n) +{ +#if defined(PIPE_CC_GCC) + return __builtin_popcount(n); +#else + /* XXX there are more clever ways of doing this */ + unsigned bits = 0; + while (n) { + bits += (n & 1); + n = n >> 1; + } + return bits; +#endif +} + + +/** * Clamp X to [MIN, MAX]. * This is a macro to allow float, int, uint, etc. types. */ |