TLIA: Efficient Reconfigurable Architecture for Control-Intensive Kernels with Triggered-Long-Instructions

摘要

Coarse-Grained Reconfigurable Architectures (CGRAs), which provide high performance, low power and flexibility, is viewed as a promising trend for computing. CGRAs are mostly employed to process compute-intensive kernels because of their inefficiency for control flows. Various methods have been proposed to alleviate this problem, and triggered instruction is one of the state-of-the-art techniques. In this paper, a reconfigurable architecture called Triggered-Long-Instruction Architecture (TLIA) is proposed to enhance the triggered instructions with parallel condition method. In the proposed architecture, triggered instruction set is employed on processing elements (PEs). In this way, over-serialized execution and branch instructions are both eliminated. In the meanwhile, each PE has an improved data-path with three ALUs which is inspired by the parallel condition method. In this way, the amount of parallelism inside each control flow is increased by paralleling predicate computations and predicated operations. Moreover, multiple triggered instructions, which may have internal control dependence, can be executed on PEs in parallel. The strategy of issuing instructions is implemented in hardware, and verified by FPGA. Experimental results show that the performance is improved by 20.9 to 140.0 percent, the area is reduced by 24.5 percent, and the power is reduced by 32.5 percent over the equivalent Triggered Instruction Architecture (TIA).