AI Applications in C++: How costly are virtual functions? What are the possible optimizations?

Question

In an AI application I am writing in C++,

1. there is not much numerical computation
2. there are lot of structures for which run-time polymorphism is ne

Answer 1

Virtual functions tend to be a lookup and indirection function call. On some platforms, this is fast. On others, e.g., one popular PPC architecture used in consoles, this isn't so fast.

Optimizations usually revolve around expressing variability higher up in the callstack so that you don't need to invoke a virtual function multiple times within hotspots.