d write out a profile data file
     called 'gmon.sum', which contains all the information from the
     profile data files that 'gprof' read in.  The file 'gmon.sum' may
     be one of the specified input files; the effect of this is to merge
     the data in the other input files into 'gmon.sum'.

     Eventually you can run 'gprof' again without '-s' to analyze the
     cumulative data in the file 'gmon.sum'.

'-v'
'--version'
     The '-v' flag causes 'gprof' to print the current version number,
     and then exit.