diff --git a/libs/surfaceflinger/clz.h b/libs/surfaceflinger/clz.h
new file mode 100644
index 0000000..0ddf986
--- /dev/null
+++ b/libs/surfaceflinger/clz.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_SURFACE_FLINGER_CLZ_H
+
+#include <stdint.h>
+
+namespace android {
+
+int clz_impl(int32_t x);
+
+int inline clz(int32_t x)
+{
+#if defined(__arm__) && !defined(__thumb__)
+    return __builtin_clz(x);
+#else
+    return clz_impl(x);
+#endif
+}
+
+
+}; // namespace android
+
+#endif /* ANDROID_SURFACE_FLINGER_CLZ_H */