An efficient register allocation for a WAM Prolog compiler

Abstract

The authors outline an experiment on Warren abstract machine (WAM) based compiler technology. In preparation for a self-configured Prolog system on a multiple-node transputer network, a sequential Prolog compiler is needed as a test bed. The compiler generates intermediate WAM codes, enhancing both the efficiency and portability. Another feature used by the compiler is an efficient register allocation mechanism. The WAM 's parameter passing convention uses register k to pass the kth parameter to a procedure. Since the number of registers in the transputer is limited, data movements between registers are inevitable. The register allocation scheme minimizes data movement, and is somewhat different from that of minimizing the number of loads and stores in a conventional machine.