add helper is_power_of_2()

Add is_power_of_2() to test if a value is a power of 2.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/bits.h b/bits.h
index c0dc952e..63a663c2 100644
--- a/bits.h
+++ b/bits.h
@@ -58,4 +58,9 @@ static inline long long bits_extend(long long val, unsigned size, int is_signed)
 	return val;
 }
 
+static inline int is_power_of_2(long long val)
+{
+	return val && !(val & (val - 1));
+}
+
 #endif