Printf warning during compile?

[actorindp]

I popped a printf statement in user routine fast to show me seconds elapsed. (interrupt timer)

when I compile, the build completes but I get this warning;

user_routines_fast.c:135:Warning [2058] call of function without prototype

Is this something I have to worry about?
The printf statement itself is located in Process_Data_From_Local_IO

Thanks!

-Nick