Abstract: A method, program product and system for conducting a ray tracing operation where the rendering compute requirement is reduced by varying the size of bounding volumes into which image data is divided and/or by varying a number of primitives included within nodes of an acceleration data structure that correspond to the bounding volumes.

Abstract: A circuit arrangement and method utilize texture data prefetching to prefetch texture data used by an anisotropic filtering algorithm. In particular, stride-based prefetching may be used to prefetch texture data for use in anisotropic filtering, where the value of the stride, or difference between successive accesses, is based upon a distance in a memory address space between sample points taken along the line of anisotropy used in an anisotropic filtering algorithm.

Abstract: A circuit arrangement and method utilize texture data prefetching to prefetch texture data used by an anisotropic filtering algorithm. In particular, stride-based prefetching may be used to prefetch texture data for use in anisotropic filtering, where the value of the stride, or difference between successive accesses, is based upon a distance in a memory address space between sample points taken along the line of anisotropy used in an anisotropic filtering algorithm.

Abstract: A method, computer-readable medium, and apparatus for context switching between a first thread and a second thread. The method includes detecting an exception, wherein the exception is generated in response to receiving a packet of information directed to one of the first thread and the second thread, and in response to detecting the exception, invoking an exception handler. The exception handler is configured to execute one or more instructions removing access to at least a portion of a processor cache. The portion of the processor cache contains cached information for the first thread using a first address translation. Removing access to the portion of the processor cache prevents the second thread using a second address translation from accessing the cached information in the processor cache. The exception handler is also configured to branch to at least one of the first thread and the second thread.

Abstract: Embodiments of the invention are generally related to image processing, and more specifically to vector units for supporting image processing. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: According to embodiments of the invention, a normally recursive ray tracing algorithm may be partitioned to form an iterative ray tracing algorithm. The resulting portions of the iterative ray tracing algorithm may be executed by a plurality of processing elements. Furthermore, according to embodiments of the invention, a network of inboxes may be used to transfer information which defines original rays and secondary rays (information unlikely to be reused for subsequently issued rays and subsequently rendered frames) between processing elements, and a shared memory cache may store information relating to a three dimensional scene (information likely to be reused for subsequently issued rays and subsequently rendered frames). Using a plurality of processing elements to perform ray tracing and storing information in the shared memory cache which is likely to be reused for subsequent rays and subsequent frames, the performance of a ray tracing image processing system may be improved.

Abstract: A circuit arrangement and method provide a hybrid rendering architecture capable of interfacing a streaming geometry frontend with a physical rendering backend using a dynamic accelerated data structure (ADS) generator. The dynamic ADS generator effectively parallelizes the generation of the ADS, such that an ADS may be built using a plurality of parallel threads of execution. By doing so, both the frontend and backend rendering processes are amendable to parallelization, and enabling if so desired real time rendering using physical rendering techniques such as ray tracing and photon mapping. Furthermore, streaming geometry frontends such as OpenGL and DirectX compatible frontends can readily be adapted for use with physical rendering backends, thereby enabling developers to continue to develop with raster-based API's, yet still obtain the benefits of physical rendering techniques.

Abstract: According to embodiments of the invention, rays may be stochastically culled before they are issued into the three-dimensional scene. Stochastically culling rays may reduce the number of rays which need to be traced by the image processing system. Furthermore, by stochastically culling rays before they are issued into the three-dimensional scene, minor imperfections may be added to the final rendered image, thereby improving the realism of the rendered image. Therefore, stochastic culling of rays may improve the performance of the image processing system by reducing workload imposed on the image processing system and improving the realism of the images rendered by the image processing system. According to another embodiment of the invention, the realism of images rendered by the image processing system may also be improved by stochastically adding secondary rays after ray-primitive intersections have occurred.

Abstract: A method and apparatus for executing instructions in a processor are provided. In one embodiment of the invention, the method includes receiving a plurality of instructions. The plurality of instructions includes first instructions in a first thread and second instructions in a second thread. The method further includes forming a common issue group including an instruction of a first instruction type and an instruction of a second instruction type. The method also includes issuing the common issue group to a first execution unit and a second execution unit. The instruction of the first instruction type is issued to the first execution unit and the instruction of the second instruction type is issued to the second execution unit.

Abstract: A circuit arrangement, program product and method stream level of detail components between hardware threads in a multithreaded circuit arrangement to perform physics collision detection. Typically, a master hardware thread, e.g., a component loader hardware thread, is used to retrieve level of detail data for an object from a memory and stream the data to one or more slave hardware threads, e.g., collision detection hardware threads, to perform the actual collision detection. Because the slave hardware threads receive the level of detail data from the master thread, typically the slave hardware threads are not required to load the data from the memory, thereby reducing memory bandwidth requirements and accelerating performance.

Abstract: According to embodiments of the invention, rays may be stochastically culled before they are issued into the three-dimensional scene. Stochastically culling rays may reduce the number of rays which need to be traced by the image processing system. Furthermore, by stochastically culling rays before they are issued into the three-dimensional scene, minor imperfections may be added to the final rendered image, thereby improving the realism of the rendered image. Therefore, stochastic culling of rays may improve the performance of the image processing system by reducing workload imposed on the image processing system and improving the realism of the images rendered by the image processing system. According to another embodiment of the invention, the realism of images rendered by the image processing system may also be improved by stochastically adding secondary rays after ray-primitive intersections have occurred.

Abstract: According to embodiments of the invention, a step value and a step-interval cache coherency protocol may be used to update and invalidate data stored within cache memory. A step value may be an integer value and may be stored within a cache directory entry associated with data in the memory cache. Upon reception of a cache read request, along with the normal address comparison to determine if the data is located within the cache a current step value may be compared with the stored step value to determine if the data is current. If the step values match, the data may be current and a cache hit may occur. However, if the step values do not match, the requested data may be provided from another source. Furthermore, an application may update the current step value to invalidate old data stored within the cache and associated with a different step value.

Abstract: A circuit arrangement and method support a multithreaded rendering architecture capable of dynamically routing pixel fragments from a pixel fragment generator to any pixel shader from among a pool of pixel shaders. The pixel fragment generator is therefore not tied to a specific pixel shader, but is instead able to utilize multiple pixel shaders in a pool of pixel shaders to minimize bottlenecks and improve overall hardware utilization and performance during image processing.

Abstract: A multirate execution unit is capable of being operated in a plurality of modes, with the execution unit being capable of clocked at multiple different rates relative to a multithreaded issue unit such that, in applications where maximum performance is desired, the execution unit can be clocked at a rate that is faster than the clock rate for the multithreaded issue unit, and in applications where a lower power profile is desired, the execution unit can be throttled back to a slower rate to reduce the power consumption of the execution unit. When the execution unit is clocked at a faster rate than the multithreaded issue unit, the issue unit is permitted to issue more instructions per cycle than when the execution unit is throttled to the slower rate to increase overall instruction throughput.

Abstract: A processing unit includes multiple execution units and sequencer logic that is disposed downstream of instruction buffer logic, and that is responsive to a sequencer instruction present in an instruction stream. In response to such an instruction, the sequencer logic issues a plurality of instructions associated with a long latency operation to one execution unit, while blocking instructions from the instruction buffer logic from being issued to that execution unit. In addition, the blocking of instructions from being issued to the execution unit does not affect the issuance of instructions to any other execution unit, and as such, other instructions from the instruction buffer logic are still capable of being issued to and executed by other execution units even while the sequencer logic is issuing the plurality of instructions associated with the long latency operation.

Abstract: The present invention is generally related to integrated circuit devices, and more particularly, to methods, systems and design structures for the field of image processing, and more specifically to vector units for supporting image processing. A dual vector unit implementation is described wherein two vector units are configured receive data from a common register file. The vector units may independently and simultaneously process instructions. Furthermore, the vector units may be adapted to perform scalar operations thereby integrating the vector and scalar processing. The vector units may also be configured to share resources to perform an operation, for example, a cross product operation.

Abstract: A circuit arrangement, program product and circuit arrangement render stereoscopic images in a multithreaded rendering software pipeline using first and second rendering channels respectively configured to render left and right views for the stereoscopic image. Separate transformations are applied to received vertex data to generate transformed vertex data for use by each of the first and second rendering channels in rendering the left and right views for the stereoscopic image.

Abstract: A software-accessible special purpose register is architected into a processing unit in order to implement persistent vector multiplexer control of a vector-based execution unit. A persistent swizzle instruction is defined in an instruction set for the vector-based execution unit and is used to cause state information to be stored in the special purpose register such that the operand vectors processed by subsequent vector instructions executed by the vector-based execution unit will be selectively shuffled using the persisted state information. As a result, when multiple vector instructions require a common custom word ordering for one or more operand vectors, a single persistent swizzle instruction may be used to select the desired custom word ordering for all of the vector instructions.

Abstract: Persistent vector multiplexer control is used in a vector-based execution unit to control the shuffling of words in operand vectors processed by the execution unit. In addition, a persistent swizzle instruction is defined in an instruction set for the vector-based execution unit and is used to cause state information to be persisted such that the operand vectors processed by subsequent vector instructions executed by the vector-based execution unit will be selectively shuffled using the persisted state information. As a result, when multiple vector instructions require a common custom word ordering for one or more operand vectors, a single persistent swizzle instruction may be used to select the desired custom word ordering for all of the vector instructions.