Region-level approximate computation reuse for power reduction in multimedia applications

Motivated by data value locality and quality tolerance present in multimedia applications, we propose a new micro-architecture, region-level approximate computation buffer (RACB), to reduce power consumption in such applications. The proposed RACB relaxes the exact matching into partial and approximate tag matching and applies it to regions of code in a program, thereby allowing for aggressive computation/execution reduction, in addition to reductions in memory accesses and pipeline activities. Our experiments demonstrate that a 64-entry RACB can yield up to 70% of region-level execution reduction without noticeable quality degradation in MPEG-2 video decoding, corresponding to 55.9% of system power savings with respect to the regions.