The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jan. 02, 2018

Filed:

Aug. 12, 2013
Applicant:

International Business Machines Corporation, Armonk, NY (US);

Inventors:

Timothy H. Heil, Sammamish, WA (US);

Andrew D. Hilton, Durham, NC (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F 9/38 (2006.01);
U.S. Cl.
CPC ...
G06F 9/3844 (2013.01); G06F 9/3848 (2013.01); G06F 9/3861 (2013.01);
Abstract

This disclosure includes a method for performing branch prediction by a processor having an instruction pipeline. The processor speculatively updates a global history register having fetch group history and branch history, fetches a fetch group of instructions, and assigns a global history vector to the instructions. The processor predicts any branches in the fetch group using the global history vector and a predictor, and evaluates whether the fetch group contains a predicted taken branch. If the fetch group contains a predicted taken branch, the processor flushes subsequently fetched instructions in the pipeline following the predicted taken branch, repairs the global history register to the global history vector, and updates the global history register based on branch prediction information. If the fetch group does not contain a predicted taken branch, the processor updates the global history register with a branch history value for each branch in the fetch group.


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