1. A method of configuring an integrated circuit device, that has a limited number of registers available for retiming, with a user logic design, said method comprising: placing and routing said user logic design on said integrated circuit device that has said limited number of registers available for retiming; retiming said placed and routed user logic design on said integrated circuit device that has said limited number of registers available for retiming; examining said retimed, placed and routed user logic design, on said integrated circuit device that has said limited number of registers available for retiming, for at least one path that lacks sufficient registers for retiming; rerouting said examined, retimed, placed and routed user logic design on said integrated circuit device that has said limited number of registers available for retiming, to find additional registers on said integrated circuit device that are available for retiming; and further retiming said at least one path, on said integrated circuit device that has said limited number of registers available for retiming, using said additional registers.