diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b0870aa1f851..635704a8be52 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-30  Felix Yang  <felix.yang@huawei.com>
+
+	* ira-costs.c (cost_classes_hasher::equal): Check equality of
+	memcmp and 0 if no difference exists for HV1 and HV2.
+
 2013-12-30  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/59501
diff --git a/gcc/ira-costs.c b/gcc/ira-costs.c
index c8d64d5e50ac..1d9e1a4e337e 100644
--- a/gcc/ira-costs.c
+++ b/gcc/ira-costs.c
@@ -154,8 +154,9 @@ cost_classes_hasher::hash (const value_type *hv)
 inline bool
 cost_classes_hasher::equal (const value_type *hv1, const compare_type *hv2)
 {
-  return hv1->num == hv2->num && memcmp (hv1->classes, hv2->classes,
-					 sizeof (enum reg_class) * hv1->num);
+  return (hv1->num == hv2->num
+	  && memcmp (hv1->classes, hv2->classes,
+		     sizeof (enum reg_class) * hv1->num) == 0);
 }
 
 /* Delete cost classes info V from the hash table.  */