Efficient dynamic dispatch without virtual function tables

Abstract

IntroductionSmallEiffel is an Eiffel 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.SmallEiffel 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 efficiently. 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 different branches of a dispatch site lead to the same code. I The advantage of this approach is that it greatly speeds up execution time and considerably decreases the amount of generated code.Permission to make digital/hard copy of part or all this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copying is by permission of ACM, Inc. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. OOPSLA '97 IO/97 GA, USA 8 1997 ACM 0.89791-908-4/97/0010...$3.50 ,

Lightweight generics in embedded systems through static analysis

“…Some implementation schemes are based on branch prediction rather than indirections through tables. For instance, binary tree dispatch (BTD) can be employed to implement virtual calls [23]. As well, tagging can be employed for dispatching open type expressions at run-time [9].…”

Efficient compilation of .NET programs for embedded systems

“…Some implementations are based on binary tree dispatch (BTD) rather than method tables [ZCC97]. The efficiency of BTD relies on conditional branch prediction.…”

Fast Generic Dispatch for Common Lisp

“…Perhaps the work that is most similar to ours is that of Zendra et al [7]. Like the present work, they are interested in performance improvements to dispatch on modern architectures by eliminating table lookups.…”