util: Utility function to check if a number is a power of two.

src/gallium/auxiliary/util/u_math.h

@@ -340,6 +340,16 @@ util_is_inf_or_nan(float x)
 }
 
 
+/**
+ * Test whether x is a power of two.
+ */
+static INLINE boolean
+util_is_pot(unsigned x)
+{
+   return (x & (x - 1)) == 0;
+}
+
+
 /**
  * Find first bit set in word.  Least significant bit is 1.
  * Return 0 if no bits set.