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36 * @(#)types.h 8.6 (Berkeley) 2/19/95
40 #ifndef _SYS_BITCOUNT_H_
41 #define _SYS_BITCOUNT_H_
43 #include <sys/_types.h>
46 #define __bitcount64(x) __builtin_popcountll((__uint64_t)(x))
47 #define __bitcount32(x) __builtin_popcount((__uint32_t)(x))
48 #define __bitcount16(x) __builtin_popcount((__uint16_t)(x))
49 #define __bitcountl(x) __builtin_popcountl((unsigned long)(x))
50 #define __bitcount(x) __builtin_popcount((unsigned int)(x))
53 * Population count algorithm using SWAR approach
54 * - "SIMD Within A Register".
56 static __inline __uint16_t
57 __bitcount16(__uint16_t _x)
60 _x = (_x & 0x5555) + ((_x & 0xaaaa) >> 1);
61 _x = (_x & 0x3333) + ((_x & 0xcccc) >> 2);
62 _x = (_x + (_x >> 4)) & 0x0f0f;
63 _x = (_x + (_x >> 8)) & 0x00ff;
67 static __inline __uint32_t
68 __bitcount32(__uint32_t _x)
71 _x = (_x & 0x55555555) + ((_x & 0xaaaaaaaa) >> 1);
72 _x = (_x & 0x33333333) + ((_x & 0xcccccccc) >> 2);
73 _x = (_x + (_x >> 4)) & 0x0f0f0f0f;
74 _x = (_x + (_x >> 8));
75 _x = (_x + (_x >> 16)) & 0x000000ff;
80 static __inline __uint64_t
81 __bitcount64(__uint64_t _x)
84 _x = (_x & 0x5555555555555555) + ((_x & 0xaaaaaaaaaaaaaaaa) >> 1);
85 _x = (_x & 0x3333333333333333) + ((_x & 0xcccccccccccccccc) >> 2);
86 _x = (_x + (_x >> 4)) & 0x0f0f0f0f0f0f0f0f;
87 _x = (_x + (_x >> 8));
88 _x = (_x + (_x >> 16));
89 _x = (_x + (_x >> 32)) & 0x000000ff;
93 #define __bitcountl(x) __bitcount64((unsigned long)(x))
95 static __inline __uint64_t
96 __bitcount64(__uint64_t _x)
99 return (__bitcount32(_x >> 32) + __bitcount32(_x));
102 #define __bitcountl(x) __bitcount32((unsigned long)(x))
104 #define __bitcount(x) __bitcount32((unsigned int)(x))
107 #endif /* !_SYS_BITCOUNT_H_ */