Trustworthy Systems

Verifying efficient function calls in CakeML


Scott Owens, Michael Norrish, Ramana Kumar, Yong Kiam Tan and Magnus Myreen

University of Kent


Carnegie Mellon University

Chalmers University of Technology

Australian National University


We have designed an intermediate language (IL) for the CakeML compiler that supports the verified, efficient compilation of functions and calls. Verified compilation steps include batching of multiple curried arguments, detecting calls to statically known functions, and specialising calls to known functions with no free variables. Finally, we verify the translation to a lower-level IL that only supports closed, first-order functions. These compilation steps resemble those found in other compilers (especially OCaml). Our contribution here is the design of the semantics of the IL, and the demonstration that our verification techniques over this semantics work well in practice at this scale. The entire development was carried out in the HOL4 theorem prover.

BibTeX Entry

    address          = {Oxford},
    author           = {Owens, Scott and Norrish, Michael and Kumar, Ramana and Tan, Yong Kiam and Myreen, Magnus},
    booktitle        = {International Conference on Functional Programming},
    date             = {2017-9-4},
    month            = sep,
    numpages         = {26},
    paperurl         = {},
    publisher        = {ACM},
    title            = {Verifying Efficient Function Calls in {CakeML}},
    year             = {2017}