Function interface models for hardware compilation

Abstract

The problem of synthesis of gate-level descriptions of digital circuits from behavioural specifications written in higherlevel programming languages (hardware compilation) has been studied for a long time yet a definitive solution has not been forthcoming. The argument of this essay is mainly methodological, bringing a perspective that is informed by recent developments in programming-language theory. We argue that one of the major obstacles in the way of hardware compilation becoming a useful and mature technology is the lack of a well defined function interface model, i.e. a canonical way in which functions communicate with arguments. We discuss the consequences of this problem and propose a solution based on new developments in programming language theory. We conclude by presenting a prototype implementation and some examples illustrating our principles.

Abstract Machines for Game Semantics, Revisited

“…The compositional nature of the compiler is very important because it gives rise to a very general notion of foreign-function interface, expressible both as control and as communication, which allows a program to interface with other programs, in a syntax-independent way (see [13] for a discussion), opening the door to the seamless development of heterogeneous open systems in a distributed setting.…”

“…By denotational we mean that it is compositionally defined on the syntax and by operational we mean that it can be effectively presented and can form a basis for compilation [13]. This feature was apparent from the earliest presentations of game semantics [18] and is not very surprising, although the operational aspects are less perspicuous than in interpretations based on process calculi or GOI, which quickly found applications in compiler [21] or interpreter [2] development and optimisation.…”

On the Compositionality of Round Abstraction

“…Consequently, higher-order functions are first-class citizens and their bookkeeping is handled through canonical structures borrowed from category theory-in particular, closed monoidal categories. The issue of sharing of resources is tackled by combining an elegant type system due to Reynolds [Rey78] with diagonal morphisms, which Ghica re-brands as activation managers in the context of hardware compilation [Ghi09b].…”

“…The algorithm forbids the aggregation of transitions that have the same label; as this corresponds, in the circuitry, to receiving the same signal several times on the same port, within the same clock cycle. The algorithm improves the efficiency of the resulting circuitry, since widely used circuits in the hardware compiler, such as the identity, no longer introduce any delays [Ghi09b].…”

Seamless Distributed Computing from the Geometry of Interaction

“…By contrast, in our methodology no code needs to be transmitted. Also note that GoI itself has been used before to compile PCF-like programs to unconventional architectures, namely reconfigurable digital circuits [7].…”