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| BITMAP_ORD_TO_POS(9) | Basic Kernel Library Functions | BITMAP_ORD_TO_POS(9) |
NAME¶
bitmap_ord_to_pos - find position of n-th set bit in bitmap
SYNOPSIS¶
unsigned int bitmap_ord_to_pos(const unsigned long * buf, unsigned int ord, unsigned int nbits);
ARGUMENTS¶
buf
pointer to bitmap
ord
ordinal bit position (n-th set bit, n >= 0)
nbits
number of valid bit positions in buf
DESCRIPTION¶
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.
COPYRIGHT¶
| June 2017 | Kernel Hackers Manual 4.9. |