公开(公告)号：US20240354253A1

公开(公告)日：2024-10-24

申请号：US18758994

申请日：2024-06-28

Applicant: SIFive, Inc.

Inventor： Binayak Tiwari ,  Benoy Alexander ,  John Ingallis ,  Mohit Gupta

IPC: G06F12/0862

CPC classification number: G06F12/0862 ,  G06F2212/602

Abstract: Described is a system and method for implementing a prefetcher with an out-of-order filtered prefetcher training queue. A processing system includes a prefetcher and a prefetcher training queue connected to the prefetcher. The prefetcher training queue configured to receive one or more demand requests from one or more load-store units, allocate a prefetcher training queue entry for a non-duplicative demand request, and send, to the prefetcher, a stored demand request together with a hit or miss indicator, wherein the prefetcher training queue sends stored demand requests without regard to program order.

公开(公告)号：US20240184581A1

公开(公告)日：2024-06-06

申请号：US18497170

申请日：2023-10-30

Applicant: SiFive, Inc.

Inventor： Benoy Alexander ,  John Ingalls ,  Binayak Tiwari

IPC: G06F9/30 ,  G06F9/38

CPC classification number: G06F9/30047 ,  G06F9/3816 ,  G06F9/3836

Abstract: Described herein is a bit pattern matching hardware prefetcher which captures complex repeating patterns, allows out-of-order (OOO) training, and allows OOO confirmations. The prefetcher includes a plurality of prefetch engines. Each prefetch engine is associated with a zone, each zone has a plurality of subzones, and each subzone has a plurality of cache lines. The prefetcher includes an access map for each subzone. Each bit position represents a cache line in the plurality of cache lines. The prefetcher determines whether a demand request matches one of the plurality of prefetch engines, updates, with respect to the demand request, a bit position in an access map for a subzone in a matching prefetch engine, determines a pattern from an access map for a subzone when a defined number of demand requests have been matched to the subzone; and generates a prefetch request based on at least the determined pattern.