In some applications, a signiticant amount of CPU time is spent on dispatching megamorphic virtual/interface calls. This appears in the profile as vtable stub or itable stub. However, this does not give any clue on why the particular call site is megamorphic and how to optimize it.

I propose adding a pseudo-frame on top of v/itable stub with the actual type of an object the virtual method is called on. This should make clear the propotion of different receivers for the particular call site: