| BITOPS(3) | Library Functions Manual | BITOPS(3) | 
bitops —
#include <sys/bitops.h>
<sys/bitops.h> header
  provides macros and static inline functions related to
  bits and integers. Among these are:
<sys/bitops.h> header first
  appeared in NetBSD 4.0.
| December 4, 2012 | NetBSD 10.0 |