gprof_compare is a little utility which can help you profile differences in runtime between multiple runs of the same application. First, use gprof to obtain profiling information for the software in question. Now, make a change to the software or input, run gprof again, and compare the profiling traces using gprof_compare:

% gprof_compare gmon1.out gmon2.out

If you sort the output using "sort -n -k 1" then you'll be able to find the functions which changed the most in terms of the number of calls. This is very useful in finding scaling issues in data-intensive code, and verifying that performance-related changes do what you want them to do, and only what you want them to do.

Erik Garrison [email protected]