+ * @ingroup irana
+ * @defgroup execfreq Basic Block Execution Frequency
+ *
+ * Execution frequencies specify how often a basic block is expected to get
+ * executed during execution of a function.
+ * For example the start block has a natural execution frequency of 1.0, the
+ * two branches of a simple if 0.5, nodes in a simple loop 10.0 ...
+ * Execution frequencies can either get estimated based on the structure of the
+ * control flow graph or can be calculated based on profile information.
+ * @{