Samsung Electronics Co., Ltd.

Fuzhou Zou

Monika Tkaczyk

Eric C Quinnell

Madhu Saravana Sibi Govindan

Gerald David Zuraski, Jr

James David Dundas

Ryan J Hensley

Wichaya Top Changwatchai

Reshma C Jumani

Anhdung Ngo

According to one general aspect, an apparatus may include a branch prediction circuit configured to predict if a branch instruction will be taken or not. The apparatus may include a branch target buffer circuit configured to store a memory segment empty flag that indicates whether or not the memory segment after a target address includes at least one other branch instruction, wherein the memory segment empty flag was created during a commit stage of a prior occurrence of the branch instruction. The branch prediction circuit may be configured to skip over the memory segment if the memory segment empty flag indicates a lack of other branch instruction(s).

Branch prediction throughput by skipping over cachelines without branches

According to one general aspect, an apparatus may include an instruction fetch unit circuit configured to retrieve instructions from a memory. The apparatus may include an instruction decode unit configured to convert instructions into one or more micro-operations that are provided to an execution unit circuit. The apparatus may also include a micro-operation cache configured to store micro-operations. The apparatus may further include a branch prediction circuit configured to: determine when a kernel of instructions is repeating, store at least a portion of the kernel within the micro-operation cache, and provide the stored portion of the kernel to the execution unit circuit without the further aid of the instruction decode unit circuit.

Micro-operation cache using predictive allocation

The present disclosure includes a mispredict recovery apparatus, which may comprise an instruction execution unit, a branch predictor, and a misprediction recovery unit (MRU). The MRU may provide discrete cycle predictions after a misprediction redirect from the instruction execution unit. The MRU may include a branch confidence filter to generate prediction confidence information for predicted branches. The MRU may include a tag content-addressable memory (CAM). The tag CAM may store frequently mispredicting low-confidence branches, probe the misprediction redirect, and obtain the prediction confidence information from the branch confidence filter. The MRU may include a mispredict recovery buffer (MRB) to store an alternate path for frequently mispredicting low-confidence branches present in the tag CAM without storing the instructions themselves. Also disclosed is a method for recovering from mispredicts associated with the instruction fetch pipeline.

Mispredict recovery apparatus and method for branch and fetch pipelines

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Austin, TX, United States of America

Fuzhou Zou