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US 9,519,586 B2Granted
Methods and apparatus to reduce cache pollution caused by data prefetching
AssigneeQUALCOMM Incorporated
InventorMatthew M. Gilbert
Life of this patent
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AssigneeQUALCOMM Incorporated
InventorMatthew M. Gilbert
Estimating the term…
Efficient techniques are described for reducing cache pollution by use of a prefetch logic that recognizes exits from software loops or function returns to cancel any pending prefetch request operations. The prefetch logic includes a loop data address monitor to determine a data access stride based on repeated execution of a memory access instruction in a program loop. Data prefetch logic then speculatively issues prefetch requests according to the data access stride. A stop prefetch circuit is used to cancel pending prefetch requests in response to an identified loop exit. The prefetch logic may also recognize a return from a called function and cancel any pending prefetch request operations associated with the called function. When prefetch requests are canceled, demand requests, such as based on load instructions, are not canceled. This approach to reduce cache pollution uses program flow information to throttle data cache prefetching.
A method for canceling prefetch requests, the method comprising:
A method for canceling prefetch requests, the method comprising:
An apparatus for canceling prefetch requests, the apparatus comprising:
A computer-readable non-transitory medium encoded with computer-readable program data and code, the computer-readable program data and code when executed operable to:
An apparatus for canceling prefetch requests comprising:
Dependencies are inferred from the claim text.