VLIW architecture optimization for an efficient computation of stereoscopic video applications

This paper presents two new architecture optimizations to improve the processing performance of video applications with a high degree of data parallelism in VLIW processors. On the one hand, a new register file access mechanism, called X4 operation mode, allows to access wide operands made up of several consecutive registers in the register file, while keeping its normal functionality (i.e. single read/write register access). On the other hand, a new functional unit is proposed to efficiently process a typical stereoscopic video application based on a rank transformation and a semi-global-matching algorithm. An evaluation of those enhanced mechanisms is performed using a generic VLIW architecture and the resulting VLIW processor is compared with other CPU/GPU and FPGA implementations. The proposed architecture provides the full flexibility of a programmable processor, while processing 640×480 stereo video sequences under real-time conditions, what is not possible with the compared CPUs or GPUs.