New macro IS_POW2().

diff --git a/lib/util.h b/lib/util.h
index 8172b69e46c96e0a20d832f4a983d5aaa2bdd1b4..2086a2ba930c124b793d848cbe994fb6d49c2a90 100644 (file)
--- a/lib/util.h
+++ b/lib/util.h
@@ -69,6 +69,7 @@ extern const char *program_name;
 #define ARRAY_SIZE(ARRAY) (sizeof ARRAY / sizeof *ARRAY)
 #define ROUND_UP(X, Y) (((X) + ((Y) - 1)) / (Y) * (Y))
 #define ROUND_DOWN(X, Y) ((X) / (Y) * (Y))
+#define IS_POW2(X) ((X) && !((X) & ((X) - 1)))
 
 #ifndef MIN
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))