OVERVIEW AND INDUSTRIAL APPLICATION OF CODE GENERATOR GENERATORS

During the past 10 to 15 years, there has been active research in the area of automatically generating the code generator part of compilers from formal specifications. However, little has been reported on the a pplication of these systems in an industrial setting. This paper attem pts to fill this gap, in addition to providing a tutorial overview of the most well-known methods. Four systems for automatic generation of code generators are described in this paper. CGSS, BEG, TWIG and BURG. CGSS is an older Graham-Glanville style system based on pattern match ing through parsing, whereas BEG, TWIG, and BURG are more recent syste ms based on tree pattern matching combined with dynamic programming. A n industrial-strength code generator previously implemented for a spec ial-purpose language using the CGSS system is described and compared i n some detail to our new implementation based on the BEG system. Sever al problems of integrating local and global register allocations withi n automatically generated code generators are described, and some solu tions are proposed. In addition, the specification of a full code gene rator for SUN SPARC with register windows using the BEG system is desc ribed. We finally conclude that current technology of automatically ge nerating code generators is viable in an industrial setting. However, further research needs to be done on the problem of properly integrati ng register allocation and instruction scheduling with instruction sel ection, when both are generated from declarative specifications.