1 /*
2  *	BIRD Library -- Generic Bit Operations
3  *
4  *	(c) 1998 Martin Mares <mj@ucw.cz>
5  *
6  *	Can be freely distributed and used under the terms of the GNU GPL.
7  */
8 
9 #ifndef _BIRD_BITOPTS_H_
10 #define _BIRD_BITOPTS_H_
11 
12 /*
13  *	Bit mask operations:
14  *
15  *	u32_mkmask	Make bit mask consisting of <n> consecutive ones
16  *			from the left and the rest filled with zeroes.
17  *			E.g., u32_mkmask(5) = 0xf8000000.
18  *	u32_masklen	Inverse operation to u32_mkmask, -1 if not a bitmask.
19  */
20 
21 u32 u32_mkmask(uint n);
22 int u32_masklen(u32 x);
23 
24 u32 u32_log2(u32 v);
25 
u32_hash(u32 v)26 static inline u32 u32_hash(u32 v) { return v * 2902958171u; }
27 
u32_popcount(u32 v)28 static inline u8 u32_popcount(u32 v) { return __builtin_popcount(v); }
29 
30 #endif
31