1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1991, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)types.h 8.6 (Berkeley) 2/19/95
37 */
38
39 #ifndef _SYS_BITCOUNT_H_
40 #define _SYS_BITCOUNT_H_
41
42 #include <sys/_types.h>
43
44 #ifdef __POPCNT__
45 #define __bitcount64(x) __builtin_popcountll((__uint64_t)(x))
46 #define __bitcount32(x) __builtin_popcount((__uint32_t)(x))
47 #define __bitcount16(x) __builtin_popcount((__uint16_t)(x))
48 #define __bitcountl(x) __builtin_popcountl((unsigned long)(x))
49 #define __bitcount(x) __builtin_popcount((unsigned int)(x))
50 #else
51 /*
52 * Population count algorithm using SWAR approach
53 * - "SIMD Within A Register".
54 */
55 static __inline __uint16_t
__bitcount16(__uint16_t _x)56 __bitcount16(__uint16_t _x)
57 {
58
59 _x = (_x & 0x5555) + ((_x & 0xaaaa) >> 1);
60 _x = (_x & 0x3333) + ((_x & 0xcccc) >> 2);
61 _x = (_x + (_x >> 4)) & 0x0f0f;
62 _x = (_x + (_x >> 8)) & 0x00ff;
63 return (_x);
64 }
65
66 static __inline __uint32_t
__bitcount32(__uint32_t _x)67 __bitcount32(__uint32_t _x)
68 {
69
70 _x = (_x & 0x55555555) + ((_x & 0xaaaaaaaa) >> 1);
71 _x = (_x & 0x33333333) + ((_x & 0xcccccccc) >> 2);
72 _x = (_x + (_x >> 4)) & 0x0f0f0f0f;
73 _x = (_x + (_x >> 8));
74 _x = (_x + (_x >> 16)) & 0x000000ff;
75 return (_x);
76 }
77
78 #ifdef __LP64__
79 static __inline __uint64_t
__bitcount64(__uint64_t _x)80 __bitcount64(__uint64_t _x)
81 {
82
83 _x = (_x & 0x5555555555555555) + ((_x & 0xaaaaaaaaaaaaaaaa) >> 1);
84 _x = (_x & 0x3333333333333333) + ((_x & 0xcccccccccccccccc) >> 2);
85 _x = (_x + (_x >> 4)) & 0x0f0f0f0f0f0f0f0f;
86 _x = (_x + (_x >> 8));
87 _x = (_x + (_x >> 16));
88 _x = (_x + (_x >> 32)) & 0x000000ff;
89 return (_x);
90 }
91
92 #define __bitcountl(x) __bitcount64((unsigned long)(x))
93 #else
94 static __inline __uint64_t
__bitcount64(__uint64_t _x)95 __bitcount64(__uint64_t _x)
96 {
97
98 return (__bitcount32(_x >> 32) + __bitcount32(_x));
99 }
100
101 #define __bitcountl(x) __bitcount32((unsigned long)(x))
102 #endif
103 #define __bitcount(x) __bitcount32((unsigned int)(x))
104 #endif
105
106 #endif /* !_SYS_BITCOUNT_H_ */
107