I am trying to find bottlenecks in my program (currently in the "low-hanging fruit" stage), and using a profiler I get something like the following:

The thing I see in this is that RtlInitializeExceptionChain takes up the far majority of the time, and functions from my actual program don't even make it onto this top list. I would like to know if anyone knows what RtlInitializeExceptionChain does, how it is called, and how I can reorganize my program to not call it so much?
Some other information about my project: it is a COM API using ATL, and the program being profiled is a "testing" C++ program which consumes this API.
Thanks!