diff --git a/kernel-src/include/util.h b/kernel-src/include/util.h
index 287bfea0..1bace0df 100644
--- a/kernel-src/include/util.h
+++ b/kernel-src/include/util.h
@@ -8,4 +8,8 @@ static inline long abs(long x) {
 	return x < 0 ? -x : x;
 }
 
+static inline long ilog2(long x) {
+	return sizeof(long) * 8 - __builtin_clz(x) - 1;
+}
+
 #endif