The complexity of software systems have become a barrier for scientific model development and software modernization. In this study, we present a procedure to use compiler-based technologies to better understand complex scientific code. The approach requires no extra software installation and configuration and its software analysis can be transparent to developer and users. We designed a sample code to illustrate the data collection and analysis procedure from compiler technologies and showed a case study that used the information from interprocedure analysis to analyze a scientific function module extracted from an Earth System Model. We believe this study provides a new path to better understand legacy scientific code.