Commit fc7deeea authored by Peter Xu's avatar Peter Xu Committed by Juan Quintela
Browse files

bitmap: introduce bitmap_count_one() 



Count how many bits set in the bitmap.

Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent ab089e05

include/qemu/bitmap.h

+10 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 
                       const unsigned long *bitmap2, long bits);

int slow_bitmap_intersects(const unsigned long *bitmap1,

                           const unsigned long *bitmap2, long bits);

long slow_bitmap_count_one(const unsigned long *bitmap, long nbits);



static inline unsigned long *bitmap_try_new(long nbits)

{
@@ -216,6 +217,15 @@ static inline int bitmap_intersects(const unsigned long *src1, 
    }

}



static inline long bitmap_count_one(const unsigned long *bitmap, long nbits)

{

    if (small_nbits(nbits)) {

        return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits));

    } else {

        return slow_bitmap_count_one(bitmap, nbits);

    }

}



void bitmap_set(unsigned long *map, long i, long len);

void bitmap_set_atomic(unsigned long *map, long i, long len);

void bitmap_clear(unsigned long *map, long start, long nr);

util/bitmap.c

+15 −0
Original line number Diff line number Diff line
@@ -355,3 +355,18 @@ int slow_bitmap_intersects(const unsigned long *bitmap1, 
    }

    return 0;

}



long slow_bitmap_count_one(const unsigned long *bitmap, long nbits)

{

    long k, lim = nbits / BITS_PER_LONG, result = 0;



    for (k = 0; k < lim; k++) {

        result += ctpopl(bitmap[k]);

    }



    if (nbits % BITS_PER_LONG) {

        result += ctpopl(bitmap[k] & BITMAP_LAST_WORD_MASK(nbits));

    }



    return result;

}