Abstract: A context-information-dependent instruction causes a context-information-dependent operation to be performed based on specified context information indicative of a specified execution context. A context information translation cache 10 stores context information translation entries each specifying untranslated context information and translated context information. Lookup circuitry 14 performs a lookup of the context information translation cache based on the specified context information, to identify whether the context information translation cache includes a matching context information translation entry which is valid and which specifies untranslated context information corresponding to the specified context information. When the matching context information translation entry is identified, the context-information-dependent operation is performed based on the translated context information specified by the matching context information translation entry.

Abstract: Apparatuses, methods, and programs for performing a translation of a virtual address of a memory access to a physical address associated with a memory location to be accessed are disclosed. A page table descriptor is accessed when performing the translation, which comprises translation parameters for the translation. The descriptor further comprises an integrity check value, wherein the integrity check value is dependent on the translation parameters.

Abstract: Circuitry comprises memory address translation circuitry to access memory circuitry storing translation information defining memory address translations from input memory addresses to respective output memory addresses; in which the translation information stored by the memory circuitry comprises a hierarchy of page table levels from a highest page table level to a lowest page table level, each page table level having one or more level tables each comprising two or more entries, in which an entry of a level table at a page table level other than a last page table level of the hierarchy points to a level table at a next lower page table level in the hierarchy; the memory address translation circuitry being configured to select an entry of a level table at each page table level according to a selection value, the selection value being dependent upon a portion, applicable to that page table level, of a given input memory address; in which the memory circuitry is configured to store entries as groups of entries,

Abstract: Data processing apparatuses, methods of data processing, complementary instructions and programs related to ring buffer administration are disclosed. An enqueuing operation performs an atomic compare-and-swap oper-ation to store a first processed data item indication to an enqueuing-target slot in the ring buffer contingent on an in-order marker not being present there and, when successful, determines that a ready-to-dequeue condition is true for the first processed data item indication. A dequeuing operation, when the ready-to-de-queue condition for a dequeuing-target slot is true, comprises writing a null data item to the dequeuing-target slot and, when dequeuing in-order, further comprises, dependent on whether a next contiguous slot has null content, determining a retirement condition and, when the retirement condition is true, performing a retirement process on the next contiguous slot comprising making the next con-tiguous slot available to a subsequent enqueuing operation.

Abstract: A data processing apparatus is provided, that includes communication configured for receiving, from an origin Peripheral Component Interconnect Express (PCIe) device, a translated PCIe packet comprising a destination field that comprises a physical address of a destination PCIe device. Permission circuitry transmits a permission check packet, separate to the translated PCIe packet, to a root port to determine whether the origin PCIe device has permission to access the destination PCIe device. Buffer circuitry stores the translated PCIe packet until a response to the permission check packet is received.

Abstract: A data processing apparatus includes receive circuitry that receives an indication of a trigger block of instructions.

Abstract: A data processing apparatus is provided that includes bimodal control flow prediction circuitry for performing a prediction of whether a conditional control flow instruction will be taken. Storage circuitry stores, in association with the control flow instruction, a stored state of the data processing apparatus and reversal circuitry reverses the prediction in dependence on the stored state of the data processing apparatus corresponding with a current state of the data processing apparatus when execution of the control flow instruction is to be performed.

Abstract: A cache is provided having a plurality of entries for storing data. In response to a given access request, lookup circuitry performs a lookup operation in the cache to determine whether one of the entries in the cache is allocated to store data associated with the memory address indicated by the given access request, with a hit indication or a miss indication being generated dependent on the outcome of that lookup operation. During a single lookup period, the lookup circuitry is configured to perform lookup operations in parallel for up to N access requests. In addition, allocation circuitry is provided that is able to determine, during the single lookup period, at least N candidate entries for allocation from amongst the plurality of entries, and to cause one of the candidate entries to be allocated for each of the up to N access requests for which the lookup circuitry generates a miss indication.

Abstract: A data processing apparatus is provided that includes storage circuitry to store a plurality of interconnected instructions. Analysis circuitry analyses the instructions to determine a degree of uniqueness of profile measurements of a control flow path fragments within the instructions.

Abstract: Processing circuitry (16) and an instruction decoder (9) supports a load chunk instruction and a store chunk instruction which can be useful for implementing memory copy functions and other library functions for manipulating or comparing blocks of memory. Number of bytes to load or store in response to these instructions is determined based on an implementation specific condition. As well as loading or storing bytes of data, the load chunk instruction and (10) store chunk instruction also designated a load/store length value as data corresponding to an architecturally visible register, which provides an indication of a number of bytes loaded or stored.

Abstract: A method for processing an image captured by an image sensor. The method comprises receiving first pre-tonemapped intensity values of a first image captured by the image sensor. The method comprises applying a first tonemapping function having a first tonemapping strength to the first pre-tonemapped intensity values to generate first tonemapped intensity values. The method comprises receiving second pre-tonemapped intensity values of a second image captured by the image sensor, the second image captured subsequent to the first image. The method comprises, based on a difference between the first tonemapped intensity values and a target for the first tonemapped intensity values, determining a second tonemapping function having a second tonemapping strength. The method comprises applying the second tonemapping function to the second pre-tonemapped intensity values to generate second tonemapped intensity values.

Abstract: There is provided a data processing apparatus comprising a plurality of registers, each of the registers having data bits to store data and metadata bits to store metadata. Each of the registers is adapted to operate in a metadata mode in which the metadata bits and the data bits are valid, and a data mode in which the data bits are valid and the metadata bits are invalid. Mode bit storage circuitry indicates whether each of the registers is in the data mode or the metadata mode. Execution circuitry is responsive to a memory operation that is a store operation on one or more given registers.

Abstract: Disclosed herein is a data processing system comprising a processing unit operable to process data to generate a sequence of outputs, wherein the processing unit is configurable, when generating a sequence of outputs, such that the data processing for generating an output in the sequence of outputs will be performed within a respective processing period for the output. A controller for the processing unit is configured to cause the processing unit, when generating a sequence of outputs, during a respective processing period for at least one output in the sequence of outputs, to also undergo one or more fault detection test(s) such that both processing of data for the output and fault detection testing is performed during the respective processing period for the output.

Abstract: Aspects of the present disclosure relate to an apparatus comprising processing circuitry, prefetch circuitry and prefetch metadata storage comprising a plurality of entries. Metadata items, each associated with a given stream of instructions, are stored in the prefetch metadata storage. Responsive to a given entry of the plurality of entries being associated with the given stream associated with a given metadata item, the given entry is updated. Responsive to no entry of the plurality of entries being associated with the given stream associated with a given metadata item, an entry is selected according to a default replacement policy, the given stream is allocated thereto, and the selected entry is updated based on the given metadata item. Responsive to a switch condition being met, the default selection policy is switched to an alternative selection policy comprising locking one or more entries by preventing allocation of streams to the locked entries.

Abstract: When generating a render output in which primitives to be rendered are to be clipped against a user-defined clip plane defined for the render output, and a primitive to be rendered is intersected by a user-defined clip plane defined for the render output, an edge representing the intersection of the primitive with the user-defined clip plane is determined. The rasteriser, when rasterising the primitive, then tests one or more regions of the render output being generated against the determined edge representing the intersection of the primitive with the user-defined clip plane to determine whether the region or regions should not be rendered for the primitive on the basis of the user-defined clip plane.

Abstract: A data processing apparatus is provided. Rename circuitry performs a register rename stage of a pipeline by storing, in storage circuitry, mappings between registers. Each of the mappings is associated with an elimination field value. Operation elimination circuitry replaces an operation that indicates an action is to be performed on data from a source register and stored in a destination register, with a new mapping in the storage circuitry that references the destination register and has the elimination field value set. Operation circuitry responds to a subsequent operation that accesses the destination register when the elimination field value is set; by obtaining contents of the source register, performing the action on the contents to obtain a result, and returning the result.

Abstract: A computer implemented method of storing and retrieving feature map data of a neural network the method comprising receiving a first portion of feature map data from local storage, selecting a first set of subportions of the first portion of feature map data, compressing the subportions to produce a first plurality of sections of compressed feature map data and instructing the storage of the sections into external storage. The method also comprises receiving a second plurality of sections of compressed feature map data from the external storage, decompressing the sections to produce a second set of subportions of the second portion of feature map data and storing the second portion of feature map data in local storage. The first and second sets of subportions each correspond to a predetermined format of subdivision and the method comprises selecting the predetermined format of subdivision from a plurality of predetermined formats of subdivision.

Abstract: An apparatus comprising a cache comprising a plurality of cache entries, cache access circuitry responsive to a cache access request to perform, based on a target memory address associated with the cache access request, a cache lookup operation, tracking circuitry to track pending requests to modify cache entries of the cache, and prediction circuitry responsive to the cache access request to make a prediction of whether the pending requests tracked by the tracking circuitry include a pending request to modify a cache entry associated with the target memory address, wherein the cache access circuitry is responsive to the cache access request to determine, based on the prediction, whether to perform an additional lookup of the tracking circuitry. A method and a non-transitory computer-readable medium to store computer-readable code for fabrication of the apparatus are also provided.

Abstract: A control table (22) defines information for controlling a processing component (20) to perform an operation. The table (22) comprises entries each corresponding to a variable size region defined by a first limit address and one of a second limit address and size. A binary search procedure is provided for looking up the table, comprising a number of search window narrowing steps, each narrowing a current search window of candidate entries to a narrower search window comprising fewer entries, based on a comparison of a query address against the first limit address of a selected candidate entry of the current search window. The comparison is independent of the second limit address or size of the selected candidate entry. After the search window is narrowed to a single entry, the query address is compared with the second limit address or size of that single entry.

Abstract: Dynamic power management for an on-chip memory, such as a system cache memory as well as other memories, is provided. The memory includes wordline sections, input/output (I/O) circuitry, and control circuitry. Each wordline section includes a number of wordlines, and each wordline section is coupled to a different wordline control circuitry. The control circuitry is configured to, in response to receiving an access request including an address, decode the address including determine, based on the address, an associated wordline, and determine, based on the associated wordline, an associated wordline section. The control circuitry is further configured to apply power to wordline control circuitry coupled to the associated wordline section.