MASA: a multithreaded processor architecture for parallel symbolic computing

MASA is a “first cut” at a processor architecture intended as a building block for a multiprocessor that can execute parallel Lisp programs efficiently. MASA features a tagged architecture, multiple contexts, fast trap handling, and a synchronization bit in every memory word. MASA's principal novelty is its use of multiple contexts both to support multithreaded execution —interleaved execution from separate instruction streams—and to speed up procedure calls and trap handling in the same manner as register windows. A project is under way to evaluate MASA-like architectures for executing programs written in Multilisp.