The Named-State Register File: implementation and performance

Abstract

Context switches are slow in conventional processors because the entire processor state must be saved and restored, even if much of the state is not used before the next context switch. This paper introduces the Named-State Register File, a fine-grain associative register file. The NSF uses hardware and software techniques to efficiently manage registers among sequential or parallel procedure activations. The NSF holds more live data per register than conventional register files, and requires much less spill and reload traffic to switch between concurrent contexts. The NSF speeds execution of some sequential and parallel programs by 9% to 17% over alternative register file organizations. The NSF has access time comparable to a conventional register file and only adds 5% to the area of a typical processor chip.<>