MetaCL: Automated “Meta” OpenCL Code Generation for High-Level Synthesis on FPGA

Abstract

Traditionally, FPGA programming has been done via a hardware description language (HDL). An HDL provides fine-grained control over reconfigurable hardware but with limited productivity due to a steep learning curve and tedious design cycle. Thus, high-level synthesis (HLS) approaches have been a significant boon to productivity, and in recent years, OpenCL has emerged as a vendor-agnostic HLS language that offers the added benefit of interoperation with other OpenCL platforms (e.g., CPU, GPU, DSP) and existing OpenCL software. However, OpenCL's productivity can also suffer from tedious boilerplate code and the need to manually coordinate the host (i.e., CPU) and device (i.e., FPGA or other device). So, we present MetaCL, a compiler-assisted interface that takes OpenCL kernel functions as input and automatically generates OpenCL host-side code as output. MetaCL produces more efficient and readable host-side code, ensures portability, and introduces minimal additional runtime overhead compared to unassisted Openf.L development.