| Message ID | 1501229198-30588-6-git-send-email-peterx@redhat.com |
|---|---|
| State | New |
| Headers | show |
* Peter Xu (peterx@redhat.com) wrote: > Count how many bits set in the bitmap. > > Signed-off-by: Peter Xu <peterx@redhat.com> > --- > include/qemu/bitmap.h | 10 ++++++++++ > util/bitmap.c | 15 +++++++++++++++ > 2 files changed, 25 insertions(+) > > diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h > index 460d899..9c18da0 100644 > --- a/include/qemu/bitmap.h > +++ b/include/qemu/bitmap.h > @@ -83,6 +83,7 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, > int slow_bitmap_intersects(const unsigned long *bitmap1, > const unsigned long *bitmap2, long bits); > void slow_bitmap_invert(unsigned long *bitmap, long nbits); > +long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); > > static inline unsigned long *bitmap_try_new(long nbits) > { > @@ -226,6 +227,15 @@ static inline void bitmap_invert(unsigned long *bitmap, long nbits) > } > } > > +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); > diff --git a/util/bitmap.c b/util/bitmap.c > index 9b7408c..73a1063 100644 > --- a/util/bitmap.c > +++ b/util/bitmap.c > @@ -368,3 +368,18 @@ void slow_bitmap_invert(unsigned long *bitmap, long nbits) > bitmap[k] ^= BITMAP_LAST_WORD_MASK(nbits); > } > } > + > +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; > +} Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> (I checked what happens with BITMAP_LAST_WORD_MASK(0) interestingly it's all 1 - so you do need that if) > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index 460d899..9c18da0 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -83,6 +83,7 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, int slow_bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, long bits); void slow_bitmap_invert(unsigned long *bitmap, long nbits); +long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); static inline unsigned long *bitmap_try_new(long nbits) { @@ -226,6 +227,15 @@ static inline void bitmap_invert(unsigned long *bitmap, long nbits) } } +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); diff --git a/util/bitmap.c b/util/bitmap.c index 9b7408c..73a1063 100644 --- a/util/bitmap.c +++ b/util/bitmap.c @@ -368,3 +368,18 @@ void slow_bitmap_invert(unsigned long *bitmap, long nbits) bitmap[k] ^= BITMAP_LAST_WORD_MASK(nbits); } } + +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; +}
Count how many bits set in the bitmap. Signed-off-by: Peter Xu <peterx@redhat.com> --- include/qemu/bitmap.h | 10 ++++++++++ util/bitmap.c | 15 +++++++++++++++ 2 files changed, 25 insertions(+)