Combining Algorithm Exploration with Instruction Set Design: A Case Study in Elliptic Curve Cryptography

In recent years, processor customization has matured to become a trusted way of achieving high performance with limited cost/energy in embedded applications. In particular, instruction set extensions (ISEs) have been proven very effective in many cases. A large body of work exists today on creating tools that can select efficient ISEs given an application source code: ISE automation is crucial for increasing the productivity of design teams. In this paper, we show that an additional motivation for automating the ISE process is to facilitate algorithm exploration: the availability of ISE can have a dramatic impact on the performance of different algorithmic choices to implement identical or equivalent functionality. System designers need fast feedbacks on the ISE-ability of various algorithmic flavors. We use a case study in elliptic curve (EC) cryptography to exemplify the following contributions: (I) ISE can reverse the relative performance of different algorithms for one and the same operation, and (2) automatic ISE, even without predicting speed-ups as precisely as detailed simulation can, is able to show exactly the trends that the designer should follow