Despite its simplicity, the TIM provides a remarkable level of performance. However, the simplicity of the TIM is also its weakness: although its performance is good it could be improved if it could take advantage of existing program analysis techniques. Fairbairn and Wray’s experience suggest that this is not straightforward: the use of strictness analysis led to no speed-up in their original TIM implementation. This paper describes the evolution of our implementation techniques over the past two years with the aim of using information obtained from sophisticated program analyses. The paper is in three parts.

The fiist part provides a brief introduction to Fairbaim and Wray’s original TIM. The first section describes a normal order version of the TIM. The second section illustrates the modification of the normal order TIM to support lazy evaluation. The third section describes how to use local sharing analysis to improve the compilation process.