28 lines
472 B
C
28 lines
472 B
C
/* ffs -- Find the first bit set in the parameter
|
|
|
|
@deftypefn Supplemental int ffs (int @var{valu})
|
|
|
|
Find the first (least significant) bit set in @var{valu}. Bits are
|
|
numbered from right to left, starting with bit 1 (corresponding to the
|
|
value 1). If @var{valu} is zero, zero is returned.
|
|
|
|
@end deftypefn
|
|
|
|
*/
|
|
|
|
int
|
|
ffs (valu)
|
|
register int valu;
|
|
{
|
|
register int bit;
|
|
|
|
if (valu == 0)
|
|
return 0;
|
|
|
|
for (bit = 1; !(valu & 1); bit++)
|
|
valu >>= 1;
|
|
|
|
return bit;
|
|
}
|
|
|