[Qemu-devel] [PATCH v2 14/15] qcow2: small math optimization

[Frediano Ziglio <freddy77@gmail.com>]

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
---
 block/qcow2-refcount.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 14b2f67..0e31868 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -140,10 +140,7 @@ static unsigned int next_refcount_table_size(BDRVQcowState *s,
 static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a,
     uint64_t offset_b)
 {
-    uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
-    uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
-
-    return (block_a == block_b);
+    return !((offset_a ^ offset_b) >> (2 * s->cluster_bits - REFCOUNT_SHIFT));
 }
 
 /*
-- 
1.7.1