Data Parallel Logic Programming in ACE

&ACE is a high performance Parallel Prolog System developed at the Laboratory for Logic, Databases, and Advanced Programming that exploits and-parallelism from Prolog programs. &ACE was developed to exploit MIMD parallelism. However, SPMD parallelism also arises naturally in many Prolog programs. In this paper we develop runtime techniques that allow systems that have primarily been designed to exploit MIMD parallelism (such as &ACE) to also efficiently exploit SPMD parallelism. These runtime techniques have been incorporated in the &ACE system. Performance of &ACE augmented with these techniques on programs containing SPMD parallelism is presented. 1 Introduction Parallelism and Logic Programming Technology Parallel processing of numerical problems has been an active area of research for almost two decades now [12, 22, 23]. There are parallelizing compilers and other tools available for parallel numerical processing that programmers can use without being experts on parallel process..