Cray Incorporated

Marvell Asia Pte., Ltd.

Daniel Jonathan Ernst

Sanyam Mehta

Harold Wade Cain, Iii

James Robert Kohn

Luiz DeRose

Heidi Lynn Poxon

Nagesh Bangalore Lakshminarayana

Rabin Sugumar

A system for processing gather and scatter instructions can implement a front-end subsystem, a back-end subsystem, or both. The front-end subsystem includes a prediction unit configured to determine a predicted quantity of coalesced memory access operations required by an instruction. A decode unit converts the instruction into a plurality of access operations based on the predicted quantity, and transmits the plurality of access operations and an indication of the predicted quantity to an issue queue. The back-end subsystem includes a load-store unit that receives a plurality of access operations corresponding to an instruction, determines a subset of the plurality of access operations that can be coalesced, and forms a coalesced memory access operation from the subset. A queue stores multiple memory addresses for a given load-store entry to provide for execution of coalesced memory accesses.

Method and apparatus for back end gather/scatter memory coalescing

Method and apparatus for front end gather/scatter memory coalescing

A method for prefetching data into a cache is provided. The method allocates an outstanding request buffer ('ORB'). The method stores in an address field of the ORB an address and a number of blocks. The method issues prefetch requests for a degree number of blocks starting at the address. When a prefetch response is received for all the prefetch requests, the method adjusts the address of the next block to prefetch and adjusts the number of blocks remaining to be retrieved and then issues prefetch requests for a degree number of blocks starting at the adjusted address. The prefetching pauses when a maximum distance between the reads of the prefetched blocks and the last prefetched block is reached. When a read request for a prefetched block is received, the method resumes prefetching when a resume criterion is satisfied.

High-bandwidth prefetcher for high-bandwidth memory

Growing community of inventors

West St. Paul, MN, United States of America

Daniel Jonathan Ernst