Interprocessor Collective Communication Library (intercom)

In this paper, we outline a uniied approach for building a library of collective communication operations that performs well on a cross-section of problems encountered in real applications. The target architecture is a two-dimensional mesh with worm-hole routing , but the techniques also apply to higher dimensional meshes and hypercubes. We stress a general approach , addressing the need for implementations that perform well for various sized vectors and grid dimensions , including non-power-of-two grids. This requires the development of general techniques for building hybrid algorithms. Finally, our approach also supports collective communication within a group of nodes, which is required by many scalable algorithms. Results from the Intel Paragon system are included.