maths: add log2

maths.cpp

@@ -40,6 +40,26 @@ template bool is_pow2 (uint32_t);
 template bool is_pow2 (uint64_t);
 
 
+//-----------------------------------------------------------------------------
+template <typename T>
+T
+log2 (T v) {
+    static_assert (std::is_integral<T>::value,
+                   "log2 is only implemented for integers");
+
+    T l = 0;
+    while (v) {
+        v >>= 1;
+        l  += 1;
+    }
+
+    return l;
+}
+
+template uint32_t log2 (uint32_t);
+template uint64_t log2 (uint64_t);
+
+
 //-----------------------------------------------------------------------------
 template <typename T>
 double

maths.hpp

@@ -36,6 +36,11 @@ bool
 is_pow2 (T value) pure;
 
 
+template <typename T>
+T
+log2 (T val) pure;
+
+
 template <typename T>
 double
 rootsquare (T a, T b) pure;