From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46590) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1db0IY-0000Xw-OH for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1db0IX-0000tB-7j for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55232) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1db0IX-0000sq-16 for qemu-devel@nongnu.org; Fri, 28 Jul 2017 04:07:01 -0400 From: Peter Xu Date: Fri, 28 Jul 2017 16:06:13 +0800 Message-Id: <1501229198-30588-5-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 04/29] bitmap: introduce bitmap_invert() 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 It is used to invert the whole bitmap. Signed-off-by: Peter Xu --- include/qemu/bitmap.h | 10 ++++++++++ util/bitmap.c | 13 +++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index c318da1..460d899 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -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); +void slow_bitmap_invert(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 void bitmap_invert(unsigned long *bitmap, long nbits) +{ + if (small_nbits(nbits)) { + *bitmap ^= BITMAP_LAST_WORD_MASK(nbits); + } else { + slow_bitmap_invert(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 efced9a..9b7408c 100644 --- a/util/bitmap.c +++ b/util/bitmap.c @@ -355,3 +355,16 @@ int slow_bitmap_intersects(const unsigned long *bitmap1, } return 0; } + +void slow_bitmap_invert(unsigned long *bitmap, long nbits) +{ + long k, lim = nbits/BITS_PER_LONG; + + for (k = 0; k < lim; k++) { + bitmap[k] ^= ULONG_MAX; + } + + if (nbits % BITS_PER_LONG) { + bitmap[k] ^= BITMAP_LAST_WORD_MASK(nbits); + } +} -- 2.7.4