INSTRUCTION LEVEL POWER ANALYSIS AND OPTIMIZATION OF SOFTWARE

The increasing popularity of power constrained mobile computers and em bedded computing applications drives the need for analyzing and optimi zing power in all the components of a system. Software constitutes a m ajor component of today's systems, and its role is projected to grow e ven further. Thus, an ever increasing portion of the functionality of today's systems is in the form of instructions, as opposed to gates. T his motivates the need for analyzing power consumption from the point of view of instructions-something that traditional circuit and gate le vel power analysis tools are inadequate for. This paper describes an a lternative, measurement based instruction level power analysis approac h that provides an accurate and practical way of quantifying the power cost of software. This technique has been applied to three commercial , architecturally different processors. The salient results of these a nalyses are summarized. Instruction level analysis of a processor help s in the development of models for power consumption of software execu ting on that processor. The power models for the subject processors ar e described and interesting observations resulting from the comparison of these models are highlighted. The ability to evaluate software in terms of power consumption makes it feasible to search for low power i mplementations of given programs. In addition, it can guide the develo pment of general tools and techniques for low power software. Several ideas in this regard as motivated by the power analysis of the subject processors are also described.