IIA: a novel method to optimize media instruction set of embedded processor
Keming Chen, Guojun Yu, Peng Liu, Qingdong Yao · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2006
To accelerate media processing, many media enhancement instructions have been adopted into the instruction set of embedded processors. In this paper, a novel method, called interaction between instructions and algorithms (IIA), is proposed to optimize these media enhancement instructions. Based on the analysis for inherent characteristics of video processing algorithms and processor's architecture, three measures are proposed: three single-cycle instructions for manipulation on bit level are implemented to speed up variable-length decoding; a data path is designed to solve data misalignment in SIMD processing instead of software programs; a memory architecture is proposed to support 128-bit word parallel processing. All these suggestions are used in the optimization of an embedded processor, MediaDSP3200 which fuses RISC architecture and DSP computation capability thoroughly and achieves reduced instruction and 64-bit SIMD instruction set with various addressing mode in a unified RISC pipeline stage architecture. Simulation results show that this optimization method can reduce more than 26.4% of clock cycles for VLD, 47.8% for IDCT and 66.8% for MC in real-time processing.