One embodiment of the invention provides a system that communicates feedback
from a compactor to a router to facilitate layout of an integrated circuit. The
system operates by first receiving a routing for a cell in an integrated circuit
layout at the compactor. The system then attempts to compact the routing. If compaction
of the routing fails, the system identifies an infeasibility path in the routing
and rips up traces on the infeasibility path while leaving other traces undisturbed.
The system then adjusts parameters associated with the routing process and reroutes
the cell using the adjusted parameters. The system then attempts to compact this rerouting.
