Nik Sultana

André DeHon, Hans Giesen, Nik Sultana et al.

This paper argues for an accelerator development toolchain that takes into account the whole system containing the accelerator. With whole-system visibility, the toolchain can better assist accelerator scoping and composition in the context of the expected workloads and intended performance objectives. Despite being focused on the 'meta-level' of accelerators, this would build on existing and ongoing DSLs and toolchains for accelerator design. Basing this on our experience in programmable networking and reconfigurable-hardware programming, we propose an integrative approach that relies on three activities: (i) generalizing the focus of acceleration to offloading to accommodate a broader variety of non-functional needs -- such as security and power use -- while using similar implementation approaches, (ii) discovering what to offload, and to what hardware, through semi-automated analysis of a whole system that might compose different offload choices that changeover time, (iii) connecting with research and state-of-the-art approaches for using domain-specific languages (DSLs) and high-level synthesis (HLS) systems for custom offload development. We outline how this integration can drive new development tooling that accepts models of programs and resources to assist system designers through design-space exploration for the accelerated system.

Christoph Benzmüller, Maximilian Claus, Nik Sultana

We present an automated verification of the well-known modal logic cube in Isabelle/HOL, in which we prove the inclusion relations between the cube's logics using automated reasoning tools. Prior work addresses this problem but without restriction to the modal logic cube, and using encodings in first-order logic in combination with first-order automated theorem provers. In contrast, our solution is more elegant, transparent and effective. It employs an embedding of quantified modal logic in classical higher-order logic. Automated reasoning tools, such as Sledgehammer with LEO-II, Satallax and CVC4, Metis and Nitpick, are employed to achieve full automation. Though successful, the experiments also motivate some technical improvements in the Isabelle/HOL tool.

Christoph Benzmüller, Nik Sultana

Recent improvements of the LEO-II theorem prover are presented. These improvements include a revised ATP interface, new translations into first-order logic, rule support for the axiom of choice, detection of defined equality, and more flexible strategy scheduling.