Compatibility study of compile-time optimizations for power and reliability

Historically compiler optimizations have been used mainly for improving embedded systems performance. However, for a wide range of today's power restricted, battery operated embedded devices, power consumption becomes a crucial problem that is addressed by modern compilers. Biomedical implants are one good example of such embedded systems. In addition to power, such devices need to also satisfy high reliability levels. Therefore, performance, power and reliability optimizations should all be considered while designing and programming implantable systems. Various software optimizations, e.g., during compilation, can provide the necessary means to achieve this goal. Additionally the system can be configured to trade-off between the above three factors based on the specific application requirements. In this paper we categorize previous works on compiler optimizations for low power and fault tolerance. Our study considers differences in instruction count and memory overhead, fault coverage and hardware modifications. Finally, the compatibility of different methods from both optimization classes is assessed. Five compatible pairs that can be combined with few or no limitations have been identified.