Trustworthy Systems

A new verified compiler backend for CakeML


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


Chalmers University of Technology


University of Cambridge

University of Kent


We have developed and mechanically verified a new compiler backend for CakeML. Our new compiler features a sequence of intermediate languages that allows it to incrementally compile away high-level features and enables verification at the right levels of semantic detail. In this way, it resembles mainstream (unverified) compilers for strict functional languages. The compiler supports efficient curried multi-argument functions, configurable data representations, exceptions that unwind the call stack, register allocation, and more. The compiler targets several architectures: x86-64, ARMv6, ARMv8, MIPS-64, and RISC-V.

In this paper, we present the overall structure of the compiler, including its 12 intermediate languages, and explain how everything fits together. We focus particularly on the interaction between the verification of the register allocator and the garbage collector, and memory representations. The entire development has been carried out within the HOL4 theorem prover.

BibTeX Entry

    address          = {Nara, Japan},
    author           = {Tan, Yong Kiam and Myreen, Magnus and Kumar, Ramana and Fox, Anthony and Owens, Scott and Norrish,
    booktitle        = {International Conference on Functional Programming},
    keywords         = {cakeml},
    month            = sep,
    pages            = {14},
    paperurl         = {},
    title            = {A New Verified Compiler Backend for {CakeML}},
    year             = {2016}