Electrical computers and digital processing systems: processing – Processing control – Branching
Reexamination Certificate
2004-12-15
2008-11-18
Chan, Eddie P (Department: 2183)
Electrical computers and digital processing systems: processing
Processing control
Branching
C712S239000
Reexamination Certificate
active
07454602
ABSTRACT:
A method and apparatus for updating global branch history information are disclosed. A dynamic branch predictor within a data processing system includes a global branch history (GBH) buffer and a branch history table. The GBH buffer contains GBH information of a group of the most recent branch instructions. The branch history table includes multiple entries, each entry is associated with one or more branch instructions. The GBH information from the GBH buffer can be used to index into the branch history table to obtain a branch prediction signal. In response to a fetch group of instructions, a fixed number of GBH bits is shifted into the GBH buffer. The number of GBH bits is the same regardless of the number of branch instructions within the fetch group of instructions. In addition, there is a unique bit pattern associated with the case of no taken branch in the fetch group, regardless of the number of not-taken branches of even if there are any branches in the fetch group.
REFERENCES:
patent: 5687110 (1997-11-01), Tran et al.
patent: 6272624 (2001-08-01), Giacalone et al.
patent: 6374349 (2002-04-01), McFarling
patent: 6704860 (2004-03-01), Moore
patent: 7000096 (2006-02-01), Sinharoy
Yeh & Patt; A Comprehensive Instruction Fetch Mechanism for a Processor Supporting Speculative Execution; 1992; IEEE Computer Society Press; International Symposium on Microarchitecture; pp. 129-139.
Skadron, Martonosi & Clark; Speculative Updates of Local and Global Branch History: A Quantitative Analysis; Dec. 1998; Princeton Department of Computer Science; Technical Report TR-589-98; pp. 1-23.
Abernathy Chris M.
Bradford Jeffrey P.
Dale Jason N.
Heil Timothy H.
Chan Eddie P
Dillon & Yudell LLP
Faherty Corey S
International Business Machines - Corporation
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