Multidestination Message Passing Mechanism Conforming to Base Wormhole Routing Scheme

This paper proposes a novel concept of multidestination worm mechanism which allows a message to be propagated in a wormhole network conforming to the underlying base routing scheme (ecube, planar, turn, or fully adaptive). Using this model, any source has potential to deliver a message to multiple destinations in any valid path in the system conforming to the base routing scheme while encountering only a single communication start-up. The exibil-ity of sending unicast messages exists under this model as a subset operation. Two schemes are developed and evaluated under this model to perform fast multicasting on 2D/3D meshes/tori. Not only do these schemes demonstrate superiority over Umesh (unicast-based multicast) 25] and Hamiltonian-Path-based 24] schemes, they indicate a very unique and interesting result that the cost of multicast operations can be reduced or kept near-constant in e-cube systems as the degree of multicast (number of destinations/src) increases. The proposed schemes can also take advantage of routing-adaptivity and irregularity in system topology to further reduce the cost of multicast operations. These results are the rst ones in the wormhole-routing literature to propose multicasting schemes with such reduced overhead and provision for taking advantage of adaptivity. This multicast model lays a new foundation to build wormhole-routed distributed-memory systems with fast collective communication operations and distributed-shared-memory systems with fast cache-coherency support.