An OpenCL optimizing compiler for reconfigurable processors

This paper presents simple and efficient optimization techniques for an OpenCL compiler that targets reconfigurable processors. The target architecture consists of a generalpurpose processor core and an embedded reconfigurable accelerator with vector units. The accelerator is able to switch its architecture between the VLIW mode and the Coarse Grained Reconfigurable Array (CGRA) mode to achieve high performance. One big problem of this architecture is programming difficulty and OpenCL can be a good solution. However, since OpenCL does not guarantee performance portability, hardware dependent optimization is still necessary. Hence, we develop an OpenCL compiler framework that exploits the mode switching capability and vector units. To measure the effectiveness of the techniques, we have implemented the OpenCL framework and evaluate their performance with fourteen OpenCL benchmark applications.