Eecient Dynamic Dispatch without Virtual Function Tables. the Smalleiiel Compiler

SmallEi el is an Ei el compiler which uses a fast simple type inference mechanism to remove most late binding calls, replacing them by static bindings. Starting from the system's entry point, it compiles only statically living code, which saves compiling and then removing dead code. As the whole system is analyzed at compile time, multiple inheritance and genericity do not cause any overhead. SmallEi el features a coding scheme which eliminates the need for virtual function tables. Dynamic dispatch is implemented without any array access but uses a simple static binary branch code. We show that this implementation makes it possible to use modern hardware very e ciently. It also allows us to inline more calls even when dynamic dispatch is required. Some more dispatch sites are removed after the type inference algorithm has been performed, if the di erent branches of a dispatch site lead to the same code. The advantage of this approach is that it greatly speeds up execution time and considerably decreases the amount of generated code.