Compiler-based optimizations impact on embedded software power consumption

Compilers traditionally are not exposed to the energy details of the processor. In this paper, we present a quantitative study wherein we examine the influence of the global performance optimizations -o0 to -o3, of the code composer studio C/C++ compiler, on the energy and power consumption. The results show that the most aggressive performance optimization option -o3 reduce the execution time, on average, by 95%, while it increases the power consumption by 25%. Moreover, we inspect the optimizations effect on some other execution characteristics, such as the memory references and the data cache miss rate. The results show that the memory references decreases by 94%, while the IPC increases by 250% and consequently lead to the consumed power increase.