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 */
 55static __inline __uint16_t
 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
 66static __inline __uint32_t
 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__
 79static __inline __uint64_t
 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
 94static __inline __uint64_t
 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_ */