Description
We often print a lot of not very useful warnings when we generate an rr-graph. They are "no fanin" and "no fanout" messages for rr-nodes at the edge of the chip that get cut off by the end of the array, and hence sometimes do not have edges. We should organize these messages more, and when they are not indicating a real problem, make them less scary.
Proposed Behaviour
We should print "xx nodes have no fanin". "yy of these nodes are at the chip edges; may simply be an edge effect".
"First zz nodes are: " (print current message for first zz nodes.
And we should also have a command line option to control the number of rr-graph fan-in/fan-out warnings (make the default 10 say). We'd print out "To see more warnings use --max_rr_graph_fanin_fanout_warnings"
And we'd do the same for any fanout warnings.
Current Behaviour
We just print one warning for each node with no fanin or fanout, which can be overwhelming and usually doesn't indicate a real problem.