Architecture-Aware Custom Instruction Generation for Reconfigurable Processors

Instruction set extension is becoming extremely popular for meeting the tight design constraints in embedded systems. This mechanism is now widely supported by commercially available FPGA (Field-Programmable Gate Array) based reconfigurable processors. In this paper, we present a design flow that automatically enumerates and selects custom instructions from an application DFG (Data-Flow Graph) in an architecture-aware manner. Unlike previously reported methods, the proposed enumeration approach identifies custom instruction patterns that can be mapped onto the target FPGA in a predictable manner. Our investigation shows that using this strategy the selection process can make a more informed decision for selecting a set of custom instructions that will lead to higher performance at lower cost. Experimental results based on six applications from a widely-used benchmark suite show that the proposed design flow can achieve significantly higher performance gain when compared to conventional design approaches.