Leveraging register windows to reduce physical registers to the bare minimum

View/Open
Document typeArticle
Defense date2010-12
Rights accessOpen Access
Abstract
Register window is an architectural technique that reduces memory operations required to save and restore registers across procedure calls. Its effectiveness depends on the size of the register file. Such register requirements are normally increased for out-of-order execution because it requires registers for the in-flight instructions, in addition to the architectural ones. However, a large register file has an important cost in terms of area and power and may even affect the cycle time. In this paper, we propose a software/hardware early register release technique that leverage register windows to drastically reduce the register requirements, and hence, reduce the register file cost. Contrary to the common belief that out-of-order processors with register windows would need a large physical register file, this paper shows that the physical register file size may be reduced to the bare minimum by using this novel microarchitecture. Moreover, our proposal has much lower hardware complexity than previous approaches, and requires minimal changes to a conventional register window scheme. Performance studies show that the proposed technique can reduce the number of physical registers to the number of logical registers plus one (minimum number to guarantee forward progress) and still achieve almost the same performance as an unbounded register file.
CitationQuiñones, E., Parcerisa, J.M, González, A. Leveraging register windows to reduce physical registers to the bare minimum. "IEEE transactions on computers", Desembre 2010, vol. 59, núm. 12, p. 1598-1610.
ISSN0018-9340
Publisher versionhttp://ieeexplore.ieee.org/document/5453344/?arnumber=5453344
Files | Description | Size | Format | View |
---|---|---|---|---|
05453344.pdf | 2,020Mb | View/Open |
All rights reserved. This work is protected by the corresponding intellectual and industrial
property rights. Without prejudice to any existing legal exemptions, reproduction, distribution, public
communication or transformation of this work are prohibited without permission of the copyright holder