Creating efficient systems for object-oriented languages

Increasingly computer science research has been done using workstations with high-resolution bitmap display systems. Smalltalk-80↑ is a very attractive programming language for such computation environments, since it has very sophisticated graphical systems and programming environments. Unfortunately there are still very few computer systems on which Smalltalk-80 can run with satisfactory speed, and furthermore they are quite expensive. In order to make Smalltalk-80 accessible to a large group of people at low cost,. we have developed compiler techniques useful to generate efficient code for standard register machines such as MC68000. We have also extended Smalltalk-80 to include type expressions, which allow compilers to generate efficient code