BITMAP_BITREMAP(9)                Basic Kernel Library Functions               BITMAP_BITREMAP(9)



NAME
       bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit

SYNOPSIS
       int bitmap_bitremap(int oldbit, const unsigned long * old, const unsigned long * new,
                           int bits);

ARGUMENTS
       oldbit
           bit position to be mapped

       old
           defines domain of map

       new
           defines range of map

       bits
           number of bits in each of these bitmaps

DESCRIPTION
       Let old and new define a mapping of bit positions, such that whatever position is held by
       the n-th set bit in old is mapped to the n-th set bit in new. In the more general case,
       allowing for the possibility that the weight 'w' of new is less than the weight of old,
       map the position of the n-th set bit in old to the position of the m-th set bit in new,
       where m == n % w.

       The positions of unset bits in old are mapped to themselves (the identify map).

       Apply the above specified mapping to bit position oldbit, returning the new bit position.

       For example, lets say that old has bits 4 through 7 set, and new has bits 12 through 15
       set. This defines the mapping of bit position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and
       of all other bit positions unchanged. So if say oldbit is 5, then this routine returns 13.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                        BITMAP_BITREMAP(9)