Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend

The branch predictor is widely used to enhance processor performance, but it also constitutes one of the major energy-consuming components in processors. We found that approximately 32% of instruction blocks in a decoupled frontend do not contain branch instructions, while 30.8% of instruction block...

Full description

Saved in:
Bibliographic Details
Main Authors: Zilin Li, Jizeng Wei, Shuangsheng Li, Yaogong Yang
Format: Article
Language:English
Published: Wiley 2025-01-01
Series:IET Computers & Digital Techniques
Online Access:http://dx.doi.org/10.1049/cdt2/3359419
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850034675390611456
author Zilin Li
Jizeng Wei
Shuangsheng Li
Yaogong Yang
author_facet Zilin Li
Jizeng Wei
Shuangsheng Li
Yaogong Yang
author_sort Zilin Li
collection DOAJ
description The branch predictor is widely used to enhance processor performance, but it also constitutes one of the major energy-consuming components in processors. We found that approximately 32% of instruction blocks in a decoupled frontend do not contain branch instructions, while 30.8% of instruction blocks contain only conditional branches. However, because the type of instructions within a block cannot be determined during prediction, branch prediction must be executed every cycle. In this work, we propose the next block type (NBT) and no branch sequence table (NST) for predicting instruction block types. These mechanisms occupy minimal space and are straightforward to implement. For a four-way out-of-order processor, the NBT and NST reduce the branch predictor’s energy consumption by 52.36% and processor’s energy consumption by 4.1% without sacrificing the processor’s instructions per cycle (IPC) and branch prediction accuracy.
format Article
id doaj-art-36640cfdca644ac9af4b86a6f0d58f53
institution DOAJ
issn 1751-861X
language English
publishDate 2025-01-01
publisher Wiley
record_format Article
series IET Computers & Digital Techniques
spelling doaj-art-36640cfdca644ac9af4b86a6f0d58f532025-08-20T02:57:44ZengWileyIET Computers & Digital Techniques1751-861X2025-01-01202510.1049/cdt2/3359419Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled FrontendZilin Li0Jizeng Wei1Shuangsheng Li2Yaogong Yang3College of Intelligence and ComputingCollege of Intelligence and ComputingCollege of Intelligence and ComputingPhytium Technology Co., LtdThe branch predictor is widely used to enhance processor performance, but it also constitutes one of the major energy-consuming components in processors. We found that approximately 32% of instruction blocks in a decoupled frontend do not contain branch instructions, while 30.8% of instruction blocks contain only conditional branches. However, because the type of instructions within a block cannot be determined during prediction, branch prediction must be executed every cycle. In this work, we propose the next block type (NBT) and no branch sequence table (NST) for predicting instruction block types. These mechanisms occupy minimal space and are straightforward to implement. For a four-way out-of-order processor, the NBT and NST reduce the branch predictor’s energy consumption by 52.36% and processor’s energy consumption by 4.1% without sacrificing the processor’s instructions per cycle (IPC) and branch prediction accuracy.http://dx.doi.org/10.1049/cdt2/3359419
spellingShingle Zilin Li
Jizeng Wei
Shuangsheng Li
Yaogong Yang
Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
IET Computers & Digital Techniques
title Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
title_full Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
title_fullStr Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
title_full_unstemmed Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
title_short Energy-Efficient Branch Predictor via Instruction Block Type Prediction in Decoupled Frontend
title_sort energy efficient branch predictor via instruction block type prediction in decoupled frontend
url http://dx.doi.org/10.1049/cdt2/3359419
work_keys_str_mv AT zilinli energyefficientbranchpredictorviainstructionblocktypepredictionindecoupledfrontend
AT jizengwei energyefficientbranchpredictorviainstructionblocktypepredictionindecoupledfrontend
AT shuangshengli energyefficientbranchpredictorviainstructionblocktypepredictionindecoupledfrontend
AT yaogongyang energyefficientbranchpredictorviainstructionblocktypepredictionindecoupledfrontend