Convert (ffs(val) - 1) to ctz32(val)

This commit was generated mechanically by coccinelle from the following
semantic patch:

@@
expression val;
@@
- (ffs(val) - 1)
+ ctz32(val)

The call sites have been audited to ensure the ffs(0) - 1 == -1 case
never occurs (due to input validation, asserts, etc).  Therefore we
don't need to worry about the fact that ctz32(0) == 32.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1427124571-28598-5-git-send-email-stefanha@redhat.com
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/block.c b/block.c
index f2f8ae77c1..d7781eebff 100644
--- a/block.c
+++ b/block.c
@@ -5452,7 +5452,7 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity,
         return NULL;
     }
     bitmap = g_new0(BdrvDirtyBitmap, 1);
-    bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
+    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity));
     QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
     return bitmap;
 }