Intel Corporation

Marvell International Limited

Qualcomm Incorporated

Marvellworld Trade Ltd.

Arm Limited

Sujat Jamil

R Frank O'Bleness

David E Miner

Hang T Nguyen

Steven J Tu

Samantha J Edirisooriya

Tom Marko Hameenanttila

Joseph Anthony Delgross

Muhammad Ahmed

Kim Richard Schuttenberg

Richard F Bryant

Quinn W Merrell

Jeffrey Kehl

Lucian Codrescu

Ajay Anant Ingle

Frank O'Bleness

Erich Plondke

William C Anderson

Tse-Yu Yeh

Paul Bassett

Michael Paul Corwin

Eitan Joshua

Erez Amit

Shaul Chapman

Gregory W Tse

Andres Rabago

Alexander J Honcharik

Russell J Robideau

Adi Habusha

Mark Norman Fullerton

Hong-Yi Chen

Harshvardhan P Sharangpani

Baker Mohammad

Sailesh Kottapalli

Noam Mizrahi

Judge K Arora

Max John Batley

Franco Ricci

Cameron B McNairy

Timothy S Beatty

Taylor Simpson

Moshe Raz

Amit Shmilovich

Lilian Atieno Hutchins

Donald Robert Padgett

Hang Hguyen

Husam Khshaiboun

Alexander Honcharik

In various embodiments, the present disclosure provides a system comprising a first plurality of processing cores, ones of the first plurality of processing cores coupled to a respective core interface module among a first plurality of core interface modules, the first plurality of core interface modules configured to be coupled to form in a first ring network of processing cores; a second plurality of processing cores, ones of the second plurality of processing cores coupled to a respective core interface module among a second plurality of core interface modules, the second plurality of core interface modules configured to be coupled to form a second ring network of processing cores; a first global interface module to form an interface between the first ring network and a third ring network; and a second global interface module to form an interface between the second ring network and the third ring network.

Interconnected ring network in a multi-processor system

An apparatus and method are provided for avoiding conflicting entries in a storage structure. The apparatus comprises a storage structure having a plurality of entries for storing data, and allocation circuitry, responsive to a trigger event for allocating new data into the storage structure, to determine a victim entry into which the new data is to be stored, and to allocate the new data into the victim entry upon determining that the new data is available. Conflict detection circuitry is used to detect when the new data will conflict with data stored in one or more entries of the storage structure, and to cause the data in said one or more entries to be invalidated. The conflict detection circuitry is arranged to perform, prior to a portion of the new data required for conflict detection being available, at least one initial stage detection operation to determine, based on an available portion of the new data, candidate entries whose data may conflict with the new data. A record of the candidate entries in then maintained, and, once the portion of the new data required for conflict detection is available, the conflict detection circuitry then performs a final stage detection operation to determine whether any of the candidate entries do contain data that conflicts with the new data. Any entries identified by the final stage detection operation as containing data that conflicts with the new data are then invalidated. This provides a particularly efficient mechanism for avoiding conflicting entries in a storage structure.

Apparatus and method for avoiding conflicting entries in a storage structure

Systems and techniques relating to hardware alias detection and management in caches are described. A cache controller can receive a cache request that specifies a virtual address, which includes a virtual page number (VPN) and a page offset; access, concurrently, one or more primary tags in a slot of the cache corresponding to a primary cache index that is based on a portion of the page offset and a portion of the VPN and one or more secondary tags in one or more slots corresponding to one or more secondary cache indices that are based on the portion of the page offset and one or more variations of the portion of the VPN; and determine whether there are any primary or secondary matching ways. The controller can write store data to a primary matching way if it exists and perform an alias management operation if any secondary matching ways exist.

Method and apparatus to use hardware alias detection and management in a virtually indexed physically tagged cache

A method can include executing a store instruction that instructs storing of data at an address and, in response to the store instruction, inserting a preloading instruction after the store instruction but before a dependent load instruction to the address. Executing the store instruction can include invalidating a data entry of a cache array at an address of the cache array corresponding to the address and writing the data to a backing memory at an address of the backing memory corresponding to the address. The preloading instruction can cause filling the data entry of the cache array, at the address of the cache array corresponding to the address, with the data from the backing memory at the address of the backing memory corresponding to the address and validating the data entry of the cache array.

Method and apparatus for use of a preload instruction to improve efficiency of cache

A circuit includes a Virtually Indexed Physically Tagged (VIPT) cache and a cache coherency circuit. The VIPT cache includes a plurality of sets and performs a memory operation by selecting, using a Virtual Set Address (VSA), a first tag of a first set. The cache coherency circuit is to detect cache aliasing during memory operations of the VIPT cache when a second tag maps a physical address to a second set of the VIPT cache, the second set being different than the first set. A method of managing a VIPT cache includes performing, by the VIPT cache, a memory operation and determining, using a cache coherency protocol, that cache aliasing has occurred during the memory operation.

Managing aliasing in a virtually indexed physically tagged cache

A microprocessor includes a front end module and a schedule queue module. The front end module is configured to retrieve first instructions, corresponding to a first thread, from an instruction cache, and retrieve second instructions, corresponding to a second thread, from the instruction cache. The front end module is also configured to decode the first instructions into first decoded instructions, and decode the second instructions into second decoded instructions. The schedule queue module is configured to selectively store the first decoded instructions and the second decoded instructions from the front end module and, for each stored decoded instruction, selectively issue the stored decoded instruction to an execution module. The schedule queue is further configured to reject storing an additional one of the first decoded instructions from the front end module in response to a count of the stored first decoded instructions in the schedule queue module exceeding a threshold.

Method and apparatus for sharing instruction scheduling resources among a plurality of execution threads in a multi-threaded processor architecture

Apparatus having corresponding methods and computer-readable media comprise: a speculative store buffer memory; and a speculative store buffer controller comprising a store address comparator to compare an address of a received store instruction with addresses of store instructions allocated in the speculative store buffer memory, and a store age comparator to compare an age of the received store instruction with an age of a matching store instruction allocated in the speculative store buffer memory, wherein the speculative store buffer controller replaces the store instruction allocated in the speculative store buffer memory with the received store instruction responsive to the store instruction allocated in the speculative store buffer memory being younger than the received store instruction.

Method and apparatus for processing speculative, out-of-order memory access instructions

A cache management unit manages allocation and configuration of a cache memory that is utilized by a multi-threaded processor. In some implementations, the cache management unit is configured to determine a number of active threads being executed by the multi-threaded processor, assign a separate cache unit to each active thread when the number of active threads is equal to a maximum number of active threads supported by the multi-threaded processor, and assign more than one cache unit to an active thread when the number of active threads is less than the maximum number of active threads.

Thread-aware cache memory management

Systems, methods, and other embodiments associated with reducing interrupt latency are described. According to one embodiment, an apparatus includes a buffer storing instructions awaiting execution by an execution device. The apparatus also includes an interrupt logic that, in response to receiving an interrupt, classifies instructions as either safe or unsafe. An unsafe instruction will cause the instructions to execute in a manner inconsistent with an instruction set architecture. The interrupt logic also establishes an interrupt boundary between safe and unsafe instructions, and causes the interrupt to be processed at the interrupt boundary such that the interrupt is processed before processing of the unsafe instructions.

Systems and methods for reducing interrupt latency

A system and method of tracking multiple non-identification tagged requests in a system with multiple responders are disclosed. In one embodiment, an electronic memory system comprises a memory configured to implement a plurality of response queues, wherein one response queue is associated with one responder from a plurality of responders, and wherein a responder is a device capable of resolving the memory request. A tracking module is configured to assign identification information to a memory request that is received and store the identification information in one or more queues of the plurality of response queues; and to transmit the memory request to each responder that is associated with the one or more queues. A response module is configured to associate the identification information in the one or more queues with a response upon receiving the response from the one or more responders.

Method and apparatus for associating requests and responses with identification information

An apparatus including a snoop filter decoupled from a cache and an associated method for snoop filtering are disclosed. The snoop filter is decoupled from the cache such that the cache changes states of lines in the cache from a first state that is a clean state, such as an exclusive (E) state, to a second state that is not a clean state, such as a modified (M) state, without the snoop filter's knowledge. The snoop filter buffers addresses of replaced lines that are unknown to be clean until a write-back associated with the replacement lines occurs, or until actual states of the replaced lines are determined by the snoop filter generating a snoop. A multi-level cache system in which a reallocation or replacement policy is biased to favor replacing certain lines such as inclusive lines, non-temporal lines or prefetched lines that have not been accessed, is also disclosed.

Method and apparatus having a snoop filter decoupled from an associated cache and a buffer for replacement line addresses

A processor for processing loop instructions can include an instruction reorder structure and a loop processing controller. The instruction reorder structure is configured to store decoded instructions according to program order and issue the decoded instructions for execution out of program order. The loop processing controller is configured to detect a loop in the decoded instructions stored in the instruction reorder structure and cause the instruction reorder structure to reissue the decoded instructions that form the loop for re-execution.

Detecting and reissuing of loop instructions in reorder structure

Devices, systems, methods, and other embodiments associated with a cache memory are described. In one embodiment, a cache tag array includes tag banks. The cache memory further includes a bank selector configured to receive an address and to apply a hash function that maps the address to one of the tag banks.

Cache memory bank selection

Aspects of the disclosure provide methods for cache efficiency. A method for cache efficiency can include storing data in a buffer entry in association with a cache array in response to a first store instruction that hits the cache array before the first store instruction is committed. Further, when a dependent load instruction is subsequent to the first store instruction, the method can include providing the data from the buffer entry in response to the first dependent load instruction. When a second store instruction overlaps an address of the first store instruction, the method can include coalescing data of the second store instruction in the buffer entry before the second store instruction is committed. When the second store instruction is followed by a second dependent load instruction, the method can include providing the coalesced data from the buffer entry in response to the second dependent load instruction.

Method and apparatus for improving cache efficiency

Growing community of inventors

Gilbert, AZ, United States of America

Sujat Jamil