bitmap_ord_to_pos — find position of n-th set bit in bitmap
unsigned int bitmap_ord_to_pos ( | const unsigned long * buf, |
| unsigned int ord, | |
unsigned int nbits); |
bufpointer to bitmap
ordordinal bit position (n-th set bit, n >= 0)
nbits
number of valid bit positions in buf
Map the ordinal offset of bit ord in buf to its position in buf.
Value of ord should be in range 0 <= ord < weight(buf). If ord
>= weight(buf), returns nbits.
If for example, just bits 4 through 7 are set in buf, then ord
values 0 through 3 will get mapped to 4 through 7, respectively,
and all other ord values returns nbits. When ord value 3
gets mapped to (returns) pos value 7 in this example, that means
that the 3rd set bit (starting with 0th) is at position 7 in buf.
The bit positions 0 through nbits-1 are valid positions in buf.