Added u_popcount to abstract __builtin_popcount.
diff --git a/icd/common/icd-utils.h b/icd/common/icd-utils.h
index ac4f23d..c102158 100644
--- a/icd/common/icd-utils.h
+++ b/icd/common/icd-utils.h
@@ -35,6 +35,8 @@
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
 
+#define u_popcount(u) __builtin_popcount(u)
+
 #define STATIC_ASSERT(expr) do {            \
     (void) sizeof(char[1 - 2 * !(expr)]);   \
 } while (0)