Code Optimization of Periodic Preemptive Hard Real-Time Multitasking Systems

In hard real-time systems, each task has to provably finish its execution within its respective deadline. Compiler optimizations can be used to improve each task´s timing behavior. However, current compilers do not consider tasks´ deadlines and can therefore not be used to reliably optimize hard real-time systems with regard to its schedulability. We propose a compiler optimization framework based on Integer-Linear Programming which allows for schedulability aware code optimizations of hard real-time multitasking systems. We evaluate the framework using an instruction scratchpad optimization. The results show that our approach can be used to improve the schedulability of hard real-time systems significantly.