PAC: Program Analysis for Approximation-aware Compilation

Approximate computing is a paradigm for trading off program accuracy to save energy in memory or computational resources. However, determining feasible program approximations is difficult to achieve. Popular solutions involve programmer in annotating instructions or data that can be approximated. Recently, program testing based techniques have also been explored. But these are computationally expensive and time consuming as they require running the applications many times over. In this paper, we propose PAC - Program Analysis for Approximation aware Compilation, a compiler framework to extract feasible approximation in a program. The state-of-the-art competitors only partition instructions or program data into accurate or approximable. In PAC, instructions and program data are assigned with a degree of accuracy required to maintain user specified Quality-of-Service (QoS) of an application. Such information allows the approximation to be fine-tuned in line with changes in the QoS requirements.