FFS32(3) | Library Functions Manual | FFS32(3) |
ffs32
, ffs64
,
fls32
, fls64
—
#include <sys/bitops.h>
int
ffs32
(uint32_t
n);
int
ffs64
(uint64_t
n);
int
fls32
(uint32_t
n);
int
fls64
(uint64_t
n);
ffs32
() and ffs64
()
functions find the first bit set in n and return the
index of that bit. Conversely, the fls32
() and
fls64
() functions find the last bit set in
n, returning the index of the bit.
The search always starts from the bit 1 (the least significant bit). If the argument n is zero, each function returns zero.
<sys/bitops.h>
header. The
standard C library includes a more portable
ffs(3) for user applications.
uint32_t n = 0x44; /* 01000100 */ int f, l; f = ffs32(n); l = fls32(n);
April 8, 2011 | NetBSD 9.0 |