Low-Energy Instruction Precision Assignment for Multi-mode Multiplier Under Accuracy and Performance Constraints.

Floating-point (FP) multipliers are the main energy consumers in many FP applications. Recently several FP multipliers with multiple- precision modes have been designed to trade energy consumption with output accuracy of FP multiplication operation (MOP). To effectively apply these multi-mode multipliers to FP applications, this paper presents a fast instruction precision assignment method for reducing energy consumption under accuracy and performance constraints. To easily set and check the accuracy constraint, we first build an affine arithmetic based error model to evaluate the overall output accuracy loss caused by inaccurate FP MOPs. Moreover, a simplified instruction scheduling method is also developed to quickly check the performance constraint. Based on these two check functions and the characteristics of proposed multi-mode multiplier, a fast Tabu search (TS) algorithm is then proposed to assign the precision mode of each FP MOP under the accuracy and performance constraints imposed on the given application. Experimental results show that the proposed fast TS algorithm can find the precision assignment with more energy saving and less searching time when compared to previous methods. [ABSTRACT FROM AUTHOR]