From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46672) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1db0Ih-0000dE-83 for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1db0Id-0000xh-Vp for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45298) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1db0Id-0000x8-Pz for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:07 -0400 From: Peter Xu Date: Fri, 28 Jul 2017 16:06:14 +0800 Message-Id: <1501229198-30588-6-git-send-email-peterx@redhat.com> In-Reply-To: <1501229198-30588-1-git-send-email-peterx@redhat.com> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [RFC 05/29] bitmap: introduce bitmap_count_one() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Laurent Vivier , Alexey Perevalov , Juan Quintela , Andrea Arcangeli , "Dr . David Alan Gilbert" , peterx@redhat.com Count how many bits set in the bitmap. Signed-off-by: Peter Xu --- 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; +} -- 2.7.4