Introduction

Abstract

Traditionally, program optimisation stands for various kinds of program transformations intended to improve the run-time performance of the generated code. Optimising transformations are usually applied as intermediate steps within the compilation process. More specifically, an optimising compiler principally proceeds in three stages [Muc97]:

• The front end translates the source program into an intermediate form. Usually, intermediate level programs are represented in terms of flow graphs built of quite elementary, yet machine-independent instructions.

• The optimiser performs several transformations on the intermediate level, each addressing a particular optimisation goal of interest.

• The back end finally translates the transformed intermediate program into machine-specific code. This stage particularly comprises typical machine-dependent tasks like register allocation [Cha82, CH90, Bri92b] and instruction scheduling [BR91, GM86].