Dept. of Computer Science and Engineering
Oregon Graduate Institute of Science & Technology
The Hawk language is a domain-specific extension of the pure functional language Haskell, and is used to specify and reason about processor microarchitectures at a high level of abstraction. We apply functional language technology and reasoning principles to concisely specify pipelined microarchitectures in Hawk and verify them through a domain-specific microarchitecture algebra. We develop a remarkably simple set of local equational laws governing processor components such as register files, bypass logic, and execution units. Many of these laws are verified in Isabelle, a higher order logic theorem prover. The laws are used to incrementally simplify a complex pipelined microarchitecture, removing pipeline stages and simplifying control logic, while retaining cycle-accurate behavior with respect to the original pipelined design. Proving these laws requires defining mutually recursive functions over coinductively defined streams. Such definitions are not directly supported in current theorem provers. We develop a generalization of well-founded recursion, called Converging Equivalence Relations, that allows these definitions to be added conservatively in a straightforward and modular fashion.
Matthews, John Robert, "Algebraic specification and verification of processor microarchitectures" (2000). Scholar Archive. 107.