Invention Application
- Patent Title: Branch Predictor for Wide Issue, Arbitrarily Aligned Fetch
- Patent Title (中): 广泛问题的分支预测器,任意对齐获取
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Application No.: US14923947Application Date: 2015-10-27
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Publication No.: US20160048395A1Publication Date: 2016-02-18
- Inventor: Ian D. Kountanis , Gerard R. Williams, III , James B. Keller
- Applicant: Apple Inc.
- Main IPC: G06F9/38
- IPC: G06F9/38

Abstract:
In an embodiment, a processor may be configured to fetch N instruction bytes from an instruction cache (a “fetch group”), even if the fetch group crosses a cache line boundary. A branch predictor may be configured to produce branch predictions for up to M branches in the fetch group, where M is a maximum number of branches that may be included in the fetch group. In an embodiment, a branch direction predictor may be updated responsive to a misprediction and also responsive to the branch prediction being within a threshold of transitioning between predictions. To avoid a lookup to determine if the threshold update is to be performed, the branch predictor may detect the threshold update during prediction, and may transmit an indication with the branch.
Information query