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Title: Controlling accesses to a branch prediction unit for sequences of fetch groups

Abstract

An electronic device handles accesses of a branch prediction functional block when executing instructions in program code. The electronic device includes a processor having the branch prediction functional block that provides branch prediction information for control transfer instructions (CTIs) in the program code and a minimum predictor use (MPU) functional block. The MPU functional block determines, based on a record associated with a given fetch group of instructions, that a specified number of subsequent fetch groups of instructions that were previously determined to include no CTIs or conditional CTIs that were not taken are to be fetched for execution in sequence following the given fetch group. The MPU functional block then, when each of the specified number of the subsequent fetch groups is fetched and prepared for execution, prevents corresponding accesses of the branch prediction functional block for acquiring branch prediction information for instructions in that subsequent fetch group.

Inventors:
; ; ;
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1771691
Patent Number(s):
10853075
Application Number:
16/725,203
Assignee:
Advanced Micro Devices, Inc. (Santa Clara, CA)
Patent Classifications (CPCs):
G - PHYSICS G06 - COMPUTING G06F - ELECTRIC DIGITAL DATA PROCESSING
DOE Contract Number:  
AC52-07NA27344; B620717
Resource Type:
Patent
Resource Relation:
Patent File Date: 12/23/2019
Country of Publication:
United States
Language:
English

Citation Formats

Agrawal, Varun, Kalamatianos, John, Yalavarti, Adithya, and Qian, Jingjie. Controlling accesses to a branch prediction unit for sequences of fetch groups. United States: N. p., 2020. Web.
Agrawal, Varun, Kalamatianos, John, Yalavarti, Adithya, & Qian, Jingjie. Controlling accesses to a branch prediction unit for sequences of fetch groups. United States.
Agrawal, Varun, Kalamatianos, John, Yalavarti, Adithya, and Qian, Jingjie. Tue . "Controlling accesses to a branch prediction unit for sequences of fetch groups". United States. https://www.osti.gov/servlets/purl/1771691.
@article{osti_1771691,
title = {Controlling accesses to a branch prediction unit for sequences of fetch groups},
author = {Agrawal, Varun and Kalamatianos, John and Yalavarti, Adithya and Qian, Jingjie},
abstractNote = {An electronic device handles accesses of a branch prediction functional block when executing instructions in program code. The electronic device includes a processor having the branch prediction functional block that provides branch prediction information for control transfer instructions (CTIs) in the program code and a minimum predictor use (MPU) functional block. The MPU functional block determines, based on a record associated with a given fetch group of instructions, that a specified number of subsequent fetch groups of instructions that were previously determined to include no CTIs or conditional CTIs that were not taken are to be fetched for execution in sequence following the given fetch group. The MPU functional block then, when each of the specified number of the subsequent fetch groups is fetched and prepared for execution, prevents corresponding accesses of the branch prediction functional block for acquiring branch prediction information for instructions in that subsequent fetch group.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2020},
month = {12}
}

Works referenced in this record:

State machine-based filtering of pattern history tables based on distinguishable pattern detection
patent, October 2013


Selectively blocking branch prediction for a predetermined number of instructions
patent, February 2018


Method and apparatus for dynamically managing instruction buffer depths for non-predicted branches
patent, August 2010


Fine-Grain Power Breakdown of Modern Out-of-Order Cores and Its Implications on Skylake-Based Systems
journal, December 2016