Technical Report: DCC-98-2
Multiple Specialization through Local Analysis
Michel Ferreira and Luís Damas
Departamento de Ciência de Computadores & LIACC
Faculdade de Ciências, Universidade do Porto
Rua do Campo Alegre, 823 4150 Porto, Portugal
March 1998
Abstract
Program specialization is normally supported by global analysis of
the program. Compilers use the information deduced to generate more
efficient, specialized implementations of the program. This
specialization can be
single or
multiple, depending if each
procedure of the program is specialized into one or more
versions. We present a Prolog compiler that does
multiple
specialization, using an algorithm that works over the WAM code,
deducing the reachable procedure activations based on local
analysis. The idea is to use the analysis that is done in the Prolog
to WAM compilation, and that generates local specialized
instructions, and to propagate this information through the entire
program. The creation of multiple versions of predicates allows the
propagation to be inter-procedural, and to achieve global program
specialization. Results from an implementation generating C code as
target language are presented, showing a performance comparable to
native code Prolog compilers.
Keywords: Prolog Compilation, Code Specialization, Program
Analysis.
