Modular SAIL: dream or reality?

Abstract: In order to truly benefit from RISC-V ISA modularity, the community has to address the issue of compositionality, going beyond modules at the specification level covering larger subsets of the RISC-V development flow including emulation, simulation and verification. In this paper we introduce modular SAIL, an experiment to inject compositionality into the SAIL-RISCV golden model. We show that it is, in principle, not difficult to adapt the SAIL-RISCV flow (and ideally the SAIL compiler itself) to support modules at the emulator level. We back our findings by a comparative study of the resulting pluggable emulator's performance using both static and dynamic binding, which both exhibit same functional behavior as the original monolithic emulator (aka RISC-V ISS).