I can successfully emerge kprof on AMD64 and Run/use it and it seems to run perfectly. It sohuld be keyworded ~amd64
Aight, I'm not much of a coder, but it compiles fine here and seems to do what it is advertising (that is running and viewing profiling output ^^). So I give this program a "go" for ~amd64 :)
«amd64 wanted.»