Bridging the FPGA programmability-portability Gap via automatic OpenCL code generation and tuning

Programming FPGAs has been an arduous task that requires extensive knowledge of hardware design languages (HDLs), such as Verilog or VHDL, and low-level hardware details. With OpenCL support for FPGAs, the design, prototyping and implementation of an FPGA is increasingly moving towards a much higher level of abstraction, when compared to the intrinsically low-level nature of HDLs. On the other hand, in the context of traditional (i.e., CPU) software development, OpenCL is still considered to be low-level and complex because the programmer needs to manually expose parallelism in the code. In this work, we present our approach to enhancing FPGA programmability via GLAF, a visual programming framework, to automatically generate synthesizable OpenCL code with an array of FPGA-specific optimizations. We find that our tool facilitates the development process and produces functionally correct and well-performing code on the FPGA for our molecular modeling, gene sequence search, and filtering algorithms.