Abstract: An apparatus is provided for controlling the operating mode of control circuitry, such that the control circuitry may change between two operating modes. In an allocation mode, data that is loaded in response to an instruction is allocated into storage circuitry from an intermediate buffer, and the data is read from the storage circuitry. In a non-allocation mode, the data is not allocated to the storage circuitry, and is read directly from intermediate buffer. The control of the operating mode may be performed by mode control circuitry, and the mode may be changed in dependence on the type of instruction that calls the data, and whether the data may be used again in the near future, or whether it is expected to be used only once.

Abstract: Methods and systems relating to improved processing architectures with pre-staged instructions are disclosed herein. A disclosed processor includes a memory, at least one functional processing unit, a bus, a set of instruction registers configured to be loaded, using the bus, with a set of pre-staged instructions from the memory, and a logic circuit configured to provide the set of pre-staged instructions from the set of instruction registers to the at least one functional processing unit in response to receiving an instruction from the instruction memory.

Abstract: Methods and systems relating to improved processing architectures with pre-staged instructions are disclosed herein. A disclosed processor includes an instruction memory, at least one functional processing unit, a bus, a set of instruction registers configured to be loaded, using the bus, with a set of pre-staged instructions from the instruction memory, and a logic circuit configured to provide the set of pre-staged instructions from the set of instruction registers to the at least one functional processing unit in response to receiving an instruction from the instruction memory.

Abstract: Methods and systems relating to improved processing architectures with pre-staged instructions are disclosed herein. A disclosed processor includes an instruction memory, at least one functional processing unit, a bus, a set of instruction registers configured to be loaded, using the bus, with a set of pre-staged instructions from the instruction memory, and a logic circuit configured to provide the set of pre-staged instructions from the set of instruction registers to the at least one functional processing unit in response to receiving an instruction from the instruction memory.

Abstract: Methods and systems relating to improved processing architectures with pre-staged instructions are disclosed herein. A disclosed processor includes an instruction memory, at least one functional processing unit, a bus, a set of instruction registers configured to be loaded, using the bus, with a set of pre-staged instructions from the instruction memory, and a logic circuit configured to provide the set of pre-staged instructions from the set of instruction registers to the at least one functional processing unit in response to receiving an instruction from the instruction memory.

Abstract: A request node is provided, that includes request circuitry for issuing outgoing memory access requests to a remote node. Status receiving circuitry receives statuses regarding remote memory access requests at the remote node and control circuitry controls at least one of a rate or an aggression at which the outgoing memory access requests are issued to the remote node in dependence on at least some of the statuses. The control circuitry is inhibited from controlling the rate or the aggression until multiple statuses are received.

Abstract: A request node is provided, that includes request circuitry for issuing outgoing memory access requests to a remote node. Status receiving circuitry receives statuses regarding remote memory access requests at the remote node and control circuitry controls at least one of a rate or an aggression at which the outgoing memory access requests are issued to the remote node in dependence on at least some of the statuses. The control circuitry is inhibited from controlling the rate or the aggression until multiple statuses are received.

Abstract: An apparatus is provided that includes cache circuitry that comprises a plurality of cache lines. The cache circuitry treats one or more of the cache lines as trace lines each having correlated addresses and each being tagged by a trigger address. Prefetch circuitry causes data at the correlated addresses stored in the trace lines to be prefetched.

Abstract: An apparatus is described, comprising load issuing circuitry configured to issue load operations to load data from memory, and memory ordering tracking storage circuitry configured to store memory ordering tracking information on issued load operations. The apparatus also includes control circuitry configured to access the memory ordering tracking storage circuitry to determine, using the memory ordering tracking information, whether at least one load operation has been issued in disagreement with a memory ordering requirement, and, if so, to determine whether to re-issue one or more issued load operations or to continue issuing load operations despite disagreement with the memory ordering requirement. Furthermore, the control circuitry is capable of merging the memory ordering tracking information for a plurality of issued load operations into a merged entry in the memory ordering tracking storage circuitry.

Abstract: A data processing apparatus is provided that includes a plurality of storage elements. Receiving circuitry receives a plurality of incoming data beats from cache circuitry and stores the incoming data beats in the storage elements. At least one existing data beat in the storage elements is replaced by an equal number of the incoming data beats belonging to a different cache line of the cache circuitry. The existing data beats stored in said plurality of storage elements form an incomplete cache line.

Abstract: An apparatus is described, comprising load issuing circuitry configured to issue load operations to load data from memory, and memory ordering tracking storage circuitry configured to store memory ordering tracking information on issued load operations. The apparatus also includes control circuitry configured to access the memory ordering tracking storage circuitry to determine, using the memory ordering tracking information, whether at least one load operation has been issued in disagreement with a memory ordering requirement, and, if so, to determine whether to re-issue one or more issued load operations or to continue issuing load operations despite disagreement with the memory ordering requirement. Furthermore, the control circuitry is capable of merging the memory ordering tracking information for a plurality of issued load operations into a merged entry in the memory ordering tracking storage circuitry.

Abstract: Storage circuitry is provided, that is designed to form part of a memory hierarchy. The storage circuitry comprises receiver circuitry for receiving a request to obtain data from the memory hierarchy. Transfer circuitry causes the data to be stored at a selected destination in response to the request, wherein the selected destination is selected in dependence on at least one selection condition. Tracker circuitry tracks the request while the request is unresolved. If at least one selection condition is met then the destination is the storage circuitry and otherwise the destination is other storage circuitry in the memory hierarchy.

Abstract: Apparatuses and methods for prefetch generation are disclosed. Prefetching circuitry receives addresses specified by load instructions and can cause retrieval of a data value from an address before that address is received. Stride determination circuitry determines stride values as a difference between a current address and a previously received address. Plural stride values corresponding to a sequence of received addresses are determined. Multiple stride storage circuitry stores the plurality of stride values determined by the stride determination circuitry. New address comparison circuitry determines whether a current address corresponds to a matching stride value based on the plurality of stride values stored in the multiple stride storage circuitry. Prefetch initiation circuitry can causes a data value to be retrieved from a further address, wherein the further address is the current address modified by the matching stride value of the plurality of stride values.

Abstract: An apparatus is provided that includes cache circuitry that comprises a plurality of cache lines. The cache circuitry treats one or more of the cache lines as trace lines each having correlated addresses and each being tagged by a trigger address. Prefetch circuitry causes data at the correlated addresses stored in the trace lines to be prefetched.

Abstract: Apparatuses and methods for prefetch generation are disclosed. Prefetching circuitry receives addresses specified by load instructions and can cause retrieval of a data value from an address before that address is received. Stride determination circuitry determines stride values as a difference between a current address and a previously received address. Plural stride values corresponding to a sequence of received addresses are determined. Multiple stride storage circuitry stores the plurality of stride values determined by the stride determination circuitry. New address comparison circuitry determines whether a current address corresponds to a matching stride value based on the plurality of stride values stored in the multiple stride storage circuitry. Prefetch initiation circuitry can causes a data value to be retrieved from a further address, wherein the further address is the current address modified by the matching stride value of the plurality of stride values.

Abstract: Storage circuitry is provided, that is designed to form part of a memory hierarchy. The storage circuitry comprises receiver circuitry for receiving a request to obtain data from the memory hierarchy. Transfer circuitry causes the data to be stored at a selected destination in response to the request, wherein the selected destination is selected in dependence on at least one selection condition. Tracker circuitry tracks the request while the request is unresolved. If at least one selection condition is met then the destination is the storage circuitry and otherwise the destination is other storage circuitry in the memory hierarchy.

Abstract: An apparatus and method are provided for efficient utilisation of an address translation cache. The apparatus has an address translation cache with a plurality of entries, where each entry stores address translation data used when converting a virtual address into a corresponding physical address of a memory system. Each entry identifies whether the address translation data stored therein is coalesced or non-coalesced address translation data, and also identifies a page size for a page within the memory system that is associated with that address translation data. Control circuitry is responsive to a virtual address, to perform a lookup operation within the address translation cache to produce, for each page size supported by the address translation cache, a hit indication to indicate whether a hit has been detected for an entry storing address translation data of the associated page size.

Abstract: An apparatus and method are provided for maintaining address translation data within an address translation cache. The address translation cache has a plurality of entries, where each entry is used to store address translation data used when converting a virtual address into a corresponding physical address of a memory system. Control circuitry is used to perform an allocation process to determine the address translation data to be stored in each entry. The address translation cache is used to store address translation data of a plurality of different types representing address translation data specified at respective different levels of address translation within a multiple-level page table walk. The plurality of different types comprises a final level type of address translation data that identifies a full translation from the virtual address to the physical address, and at least one intermediate level type of address translation data that identifies a partial translation of the virtual address.

Abstract: A data processing apparatus is provided including queue circuitry to respond to control signals each associated with a memory access instruction, and to queue a plurality of requests for data, each associated with a reference to a storage location. Resolution circuitry acquires a request for data, and issues the request for data, the resolution circuitry having a resolution circuitry limit. When a current capacity of the resolution circuitry is below the resolution circuitry limit, the resolution circuitry acquires the request for data by receiving the request for data from the queue circuitry, stores the request for data in association with the storage location, issues the request for data, and causes a result of issuing the request for data to be provided to said storage location.

Abstract: An apparatus and method are provided for efficient utilisation of an address translation cache. The apparatus has an address translation cache with a plurality of entries, where each entry stores address translation data used when converting a virtual address into a corresponding physical address of a memory system. Each entry identifies whether the address translation data stored therein is coalesced or non-coalesced address translation data, and also identifies a page size for a page within the memory system that is associated with that address translation data. Control circuitry is responsive to a virtual address, to perform a lookup operation within the address translation cache to produce, for each page size supported by the address translation cache, a hit indication to indicate whether a hit has been detected for an entry storing address translation data of the associated page size.