1.\" $NetBSD: popcount.3,v 1.5 2011/08/22 01:36:04 dholland Exp $ 2.\" 3.\" Copyright (c) 2009 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Joerg Sonnenberger. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd August 22, 2011 31.Dt POPCOUNT 3 32.Os 33.Sh NAME 34.Nm popcount , 35.Nm popcountl , 36.Nm popcountll , 37.Nm popcount32 , 38.Nm popcount64 39.Nd count number of bits set in a bit string 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In strings.h 44.Ft unsigned int 45.Fn popcount "unsigned int value" 46.Ft unsigned int 47.Fn popcountl "unsigned long value" 48.Ft unsigned int 49.Fn popcountll "unsigned long long value" 50.In stdint.h 51.Ft unsigned int 52.Fn popcount32 "uint32_t value" 53.Ft unsigned int 54.Fn popcount64 "uint64_t value" 55.Sh DESCRIPTION 56The 57.Nm 58functions returns the number of bits set in 59.Fa value . 60.Sh SEE ALSO 61.Xr ffs 3 62.Sh HISTORY 63The 64.Fn popcount , 65.Fn popcountl , 66.Fn popcountll , 67.Fn popcount32 , 68and 69.Fn popcount64 70functions appeared in 71.Nx 6.0 . 72