Bamboo -- Translating MPI applications to a latency-tolerant, data-driven form

We present Bamboo, a custom source-to-source translator that transforms MPI C source into a data-driven form that automatically overlaps communication with available computation. Running on up to 98304 processors of NERSC´s Hopper system, we observe that Bamboo´s overlap capability speeds up MPI implementations of a 3D Jacobi iterative solver and Cannon´s matrix multiplication. Bamboo´s generated code meets or exceeds the performance of hand optimized MPI, which includes split-phase coding, the method classically employed to hide communication. We achieved our results with only modest amounts of programmer annotation and no intrusive reprogramming of the original application source.