Optimizing procedure calls and returns

When a procedure is activated as a logical last statement in another procedure, optimization could be done to the procedure call and return. Several optimizations are discussed. The first optimization is based on the idea of reusing the current stack frame. With this approach, it is necessary to compute the order of passing parameters. A tactic of computing the dependency of parameters and a heuristic method of breaking the cyclic dependencies are therefore proposed. However, this approach has severe restrictions imposed on the kinds of procedure that can be called; in particular, the called procedure cannot contain references to the calling procedure. To remove all such restrictions, the second and third methods of optimization are put forwards. The second optimization revolves around the concept of continuation closure. It uses the normal stack frame of standard implementation, but alters its continuation closure to achieve quick procedure exit. The third optimization builds upon the concept of para‐stack frame and common continuation closure for achieving fast procedure exit. Various other refinements are also considered.