Before revision:  We focus on identifying valuable information from the source code, which results in the idea of utilizing an intermediate representation, "energy operation " , to capture the energy characteristics. The experiment results show that the energy model at such a high-level can reduce the error margin to within 10\% and enable energy breakdown at function-level, which helps developers understand the energy-related features of the code .
After revision:  We focus on identifying valuable information from the source code, which results in the idea of utilizing an intermediate representation, "energy operation " identified directly from the source code and able to provide more valuable information for code optimization. We apply the approach to a class of applications based on a game-engine, and explain the wider applicability of the method .