Donald Bren School of Information and Computer Sciences

Static Single Assignment Form is a common intermediate representation for optimizing compilers but several of its features are difficult to implement in a traditional imperative interpreter. An interpreter for Static Single Assignment would enable mixed-mode (interpreting and compiling) virtual machines to be developed around program representations in Static Single Assignment Form. We propose an extension to Static Single Assignment Form, Interpretable Static Single Assignment (ISSA). Each of Interpretable Static Single Assignment's instructions, including the phi instruction,' has self-contained operational semantics. In addition, we describe a prototype interpreter of Interpretable Static Single Assignment and report on its performance.