A method includes receiving an identification of a plurality of cells to be included in an integrated circuit (IC) layout, including a list of pairs of cells within the plurality of cells to be connected to each other. First routing paths are identified, to connect a maximum number of the pairs of cells using one-dimensional (1-D) routing between cells within those pairs of cells. Second routing paths are selected from a predetermined set of two-dimensional (2-D) routing patterns to connect any of the pairs of cells which cannot be connected by 1-D routing. The first and second routing paths are output to a machine readable storage medium to be read by a control system for controlling a semiconductor fabrication process to fabricate the IC.