Mode Analysis Domains for Typed Logic Programs

Precise mode information is important for compiler optimisations and in program development tools. Within the framework of abstract compilation, the precision of a mode analysis depends, in part, on the expressiveness of the abstract domain and its associated abstraction function. This paper considers abstract domains for polymorphically typed logic programs and shows how specialised domains may be constructed for each type in the program. These domains capture the degree of instantiation to a high level of precision. By providing a generic definition of abstract unification, the abstraction of a program using these domains is formalised. The domain construction procedure is fully implemented using the Godel language and tested on a number of example programs to demonstrate the viability of the approach.