公开(公告)号：US20220100666A1

公开(公告)日：2022-03-31

申请号：US17036442

申请日：2020-09-29

Applicant: Arm Limited

Inventor： Yasuo ISHII ,  Chang Joo LEE ,  James David DUNDAS ,  Muhammed Umar FAROOQ

IPC: G06F12/0864 ,  G06F9/38 ,  G06F12/0891

Abstract: A data processing apparatus and a method are disclosed. The data processing apparatus comprising: a prediction cache to store a plurality of prediction entries, each defining an association between a prediction cache lookup address and a predicted behaviour; prediction circuitry to select a prediction entry based on a prediction cache lookup of the prediction cache based on a given prediction cache lookup address and to determine the predicted behaviour associated with the given prediction cache lookup address based on the selected prediction entry; and a candidate prediction buffer to store a plurality of candidate predictions each indicative of a candidate prediction entry to be selected for inclusion in a subsequent prediction cache lookup, wherein the candidate prediction entry is selected in response to a candidate prediction lookup based on a candidate lookup address different to a candidate prediction cache lookup address indicated as associated with a candidate predicted behaviour in the candidate prediction entry.

公开(公告)号：US20220107901A1

公开(公告)日：2022-04-07

申请号：US17064068

申请日：2020-10-06

Applicant: Arm Limited

Inventor： Yasuo ISHII ,  James David DUNDAS ,  Chang Joo LEE ,  Muhammed Umar FAROOQ

IPC: G06F12/0897 ,  G06F12/0891 ,  G06F12/02

Abstract: First and second-level caches are provided. Cache control circuitry performs a first-level cache lookup of the first-level cache based on a lookup address, to determine whether the first-level cache stores valid cached data corresponding to the lookup address. When lookup hint information associated with the lookup address is available, the cache control circuitry determines based on the lookup hint information whether to activate or deactivate a second-level cache lookup of the second-level cache. The lookup hint information is indicative of whether the second-level cache is predicted to store valid cached data associated with the lookup address. When the second-level cache lookup is activated, the second-level cache lookup of the second-level cache is performed based on the lookup address to determine whether the second-level cache stores valid cached data corresponding to the lookup address.