Arm Limited

Peter William Harris

David Paul Martin

Edvard Fielding

Peter Brian Wilson

Andreas Due Engh-Halstvedt

Jakob Axel Fries

Sandeep Kakarlapudi

Samuel Martin

Timothy Charles Thornton

Mladen Wilder

Donald Kenneth Felton

Robin Paul Fell

Rodolph Gérard Jacques Ascanio Jean-Denis Perfetta

Andreas Loeve Selvik

Amir Kleen

David James Bermingham

Michel Iwaniec

Lukasz Kulasza

A graphics processor performs graphics processing in respect of a region of a render output. The graphics processing comprises obtaining a scaling factor corresponding to a desired resolution for the region. The graphics processing further comprises, in accordance with the desired resolution, obtaining scaled graphics geometry to be rendered for the region and selecting a subregion of the region to be rendered in respect of the region. The selected subregion is then rendered using the scaled graphics geometry, thereby providing a subregion of data elements rendered in accordance with the desired resolution. The graphics processor can provide efficient and flexible graphics processing when performing variable resolution rendering.

Variable resolution graphics processing

When a renderer of a graphics processor is to perform a graphics rendering operation that uses one or more texture layers in accordance with contribution control data that controls the contribution that each texture layer makes to the rendering operation for a group of fragments, the renderer determines contribution control data for each fragment in the group, and based on the determined contribution control data, either: fetches and uses the texture data values for a texture layer for each fragment in the group from memory, or does not fetch texture data values for a texture layer for each fragment in the group from memory and instead uses a dummy value for the texture layer for each fragment in the group for the graphics rendering operation.

Using textures in graphics processing systems

When executing a shader program to perform graphics shading operations in a graphics processor, the graphics processor determines for instructions to be executed for the shader program, whether to replace the instructions with alternative instructions, based on the nature of the instructions and the values of input operands to be processed by the instructions, and either retains an instruction or replaces the instruction with an alternative instruction, accordingly.

Instruction execution in graphics processor shader programs

When a shader program is to be executed by a graphics processor, the graphics processor is caused to execute at least two variants of the shader program and the operation of the graphics processor when executing execution threads for the different variants of the shader program is monitored. A variant of the shader program to be executed by subsequent execution threads that are to execute the shader program is then selected based on the monitoring of the operation of the shading stage when executing the execution threads for the different variants of the shader program.

Shader program selection in graphics processing systems

When a graphics texture mapping apparatus is to perform a texture filtering operation that uses the data values of a plurality of texels, the texture mapper first determines whether any of the data values of the texels to be used for the texture filtering operation are the same, and then selects a texture filtering operation to be performed using data values of the texels based on the determination. The texture mapper then performs the selected texture filtering operation using one or more of the data values of the texels to provide the required texture filtering operation output result.

Graphics texture mapping

A graphics processing system includes a graphics processor and a memory for storing data to be used by and generated by the graphics processor. In a first rendering pass, the graphics processor generates an array of graphics data and stores the generated array of graphics data in the memory. The array of graphics data generated in the first rendering pass is used in a subsequent rendering pass. In the first rendering pass, the graphics processor determines one or more regions of the array of graphics data that have a particular characteristic, and generates information indicative of the one or more regions. In the subsequent rendering pass, the graphics processor uses the information indicative of the one or more regions to control the reading of the array of graphics data when it is to be used in the subsequent rendering pass.

Graphics processing systems

A graphics processing system includes a graphics processing pipeline, which includes a primitive generation stage and a pixel processing stage. The graphics processing system is arranged to process input data in the primitive generation stage to produce first primitive data associated with a first view of a scene and second primitive data associated with a second view of the scene. The graphics processing system is arranged to process the first primitive data in the pixel processing stage to produce first pixel-processed data associated with the first view. The graphics processing system is arranged to determine, for second pixel-processed data associated with the second view, whether to use the first pixel-processed data as the second pixel-processed data or whether to process the second primitive data in the pixel processing stage to produce the second pixel-processed data, and perform additional processing in the graphics processing pipeline based on the determining.

Graphics processing systems and graphics processors

A graphics processing system sorts graphics primitives for rendering into lists corresponding to different sub-regions of a render output to be generated, each list indicating primitives to be processed for the render output. A primitive list building unit divides a render target into various sub-regions, determines which sub-regions a primitive falls within and adds the primitive to the primitive lists corresponding to those sub-regions. The primitive list building unit also records the positions of the primitives in a pair of histograms which show the distribution of primitives across the render output. Once all primitives for the render output have been sorted into lists, the histograms are outputted to a predictor processor. The predictor processor then determines a set of sub-region sizes to be used when sorting primitives for the next render output to be generated into lists, based on the histograms.

Method and apparatus for processing graphics

The sequence of instructions for a shader programto be executed by a shader core of a graphics processor is divided into an initial set of instructionsthat perform 'global' common expressions of the shader program, a set of instructionsin the shader program that perform expressions that are common to a given work group within a set of work items that the shader program is to process, and a main instruction sequencethat needs to be executed independently for each work item. Execution threads are then able to start executing the shader program either at the beginning of the global common expressions, or at the beginning of the work group common expressions, or at the beginning of the main instruction sequence

Graphics processing

A graphics processing pipeline includes processing circuitry. The processing circuitry is configured to determine attribute information for an object to be rendered for a set of sampling points from a compressed representation of attribute information associated with the object, when the set of sampling points is being processed by the graphics processing pipeline to generate a render output. The processing circuitry is also configured to use the determined attribute information to control the processing of the set of sampling points by the graphics processing pipeline when generating the render output.

Method of and graphics processing pipeline for generating a render output using attribute information

A smart card comprising a data store and a processor, said smart card being operable to connect with a host data processing apparatus, said smart card comprising authentication logic operable when connected to said host data processing apparatus to identify a secure data processing domain having predetermined properties within said host data processing apparatus and in response to identify said secure data processing domain, said smart card is operable to delegate at least some data processing operations to be processed within said secure data processing domain of said host data processing apparatus.

Processing efficiency on secure systems having a host processor and smart card

A data processing apparatus and method are provided for managing access to a display buffer. The data processing apparatus has a display buffer for storing an array of display elements for subsequent output to a display controller, with each display element having a security permission indication associated therewith identifying whether that display element is a secure display element or a non-secure display element. At least one processing unit is provided for executing a non-secure process and a secure process, each process issuing access requests when seeking to access display elements in the display buffer, and each access request specifying a location in the display buffer. Interface logic is associated with the display buffer for receiving each access request and is arranged for at least each access request issued by the non-secure process to determine the security permission indication associated with the display element currently stored at the location specified by that access request. Based on the security permission indication, the interface logic then determines how that access request should be processed. Accordingly, the interface logic can selectively prevent access to secure display elements by the non-secure process, so as to protect the security of secure display elements contained within the display buffer.

Data processing apparatus and method for managing access to a display buffer

A method of impeding leakage of cache access behavioral information of a section of a sensitive process to an untrusted process, said sensitive and untrusted processes being performed by a processor within a data processing apparatus, said data processing apparatus further comprising at least one cache operable to store information required by said processor while performing said sensitive and untrusted processes, the method comprising the steps of prior to commencing processing of a section of said sensitive process by said processor, evicting information stored in locations of said at least one cache which may otherwise be evicted by said sensitive process loading information that may be required by said section of said sensitive process in said at least one cache; commencing processing of said section of said sensitive process by said processor; switching said processor during processing of said section of said sensitive process to said untrusted process in response to a switching request; on switching back to said section of said sensitive process from said untrusted process, evicting information stored in locations of said at least one cache which may otherwise be evicted by said sensitive process loading information that may be required by said section of said sensitive process in said at least one cache prior to recommencing processing of said section of said sensitive process.

Reducing information leakage between processes sharing a cache

A data processing apparatus is disclosed that comprises: at least one processor; a display for displaying data processed by said at least one processor; at least one display buffer for storing an array of display elements for subsequent output to said display, said display elements being secure display elements for displaying secure data and non-secure display elements; and a user interface; wherein said at least one processor is operable to execute at least one untrusted process and at least one secure process, said at least one secure process having access to secure data; said data processing apparatus further comprising: a secure user input for receiving a user input, said received user input not being accessible to said at least one untrusted process; and said data processing apparatus being responsive to an input received at said secure user input to transform data to be displayed on said display such that said secure display elements and said non-secure display elements are transformed differently to each other.

Growing community of inventors

Cambridge, United Kingdom

Peter William Harris