A statically allocated parallel functional language

Abstract

We describe SAFL, a call-by-value first-order functional language which is syntactically restricted so that storage may be statically allocated to fixed locations. Evaluation of independent sub-expressions happens in parallel-we use locking techniques to protect shared-use function definitions (i.e. to prevent unrestricted parallel accesses to their storage locations for argument and return values). SAFL programs have a well defined notion of total (program and data) size which we refer to as ‘area’; similarly we can talk about execution ‘time’. Fold/unfold transformations on SAFL provide mappings between different points on the area-time spectrum. The space of functions expressible in SAFL is incomparable with the space of primitive recursive functions, in particular interpreters are expressible. The motivation behind SAFL is hardware description and synthesis-we have built an optimising compiler for translating SAFL to silicon.