| 
POPCOUNT(3) | 
Library Functions Manual | 
POPCOUNT(3) | 
NAME
 popcount, popcountl, popcountll, popcount32, popcount64 — count number of bits set in a bit string
LIBRARY
 Standard C Library (libc, -lc)
SYNOPSIS
 #include <strings.h>
unsigned int
popcount(unsigned int value);
unsigned int
popcountl(unsigned long value);
unsigned int
popcountll(unsigned long long value);
#include <stdint.h>
unsigned int
popcount32(uint32_t value);
unsigned int
popcount64(uint64_t value);
 
DESCRIPTION
 The popcount functions returns the number of bits set in value.
HISTORY
 The popcount(), popcountl(), popcountll(), popcount32(), and popcount64() functions appeared in NetBSD 6.0.