Hi How can i get the def-use and use-def chains using df_analyse() function . I tried this but didnt worked. struct df *df; df = df_init (); df_analyse (df, 0, DF_ALL); df_dump (df, DF_ALL, stderr); df_finish (df); I need to determine the definition and use of each register (live range of each register) used in a program.. I appreciate any kind of help or suggestions. kripashankar __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages! http://promotions.yahoo.com/new_mail