Automating and Optimizing Data Transfers for Many-core Coprocessors

Orchestrating data transfers between CPUs and a coprocessor manually is cumbersome, particularly for multi-dimensional arrays and other data structures with multi-level pointers, which are common in scientific computations. This work describes a system that includes both compile-time and runtime solutions for this problem, with the overarching goal of improving programmer productivity while maintaining performance. We implemented our best compile-time solution, partial linearization with pointer reset, as a source-to-source transformation, and evaluated our work by multiple C benchmarks. Our experiment results demonstrate that our best compile-time solution can perform 2.5x-5x faster than original runtime solution, and the CPU-Coprocessor code with it can achieve 1.5x-2.5x speedup over the 16-thread CPU version.