Introduce is_power2 helper

We will need it for hash tables

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/nasmlib.h b/nasmlib.h
index 26001097..fb2e6e3d 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -422,4 +422,7 @@ static inline bool overflow_unsigned(int64_t value, int bytes)
 
 int idata_bytes(int opcode);
 
+/* check if value is power of 2 */
+#define is_power2(v)   ((v) && ((v) & ((v) - 1)) == 0)
+
 #endif