Abstract: One embodiment of the present invention sets forth a technique for redistributing geometric primitives generated by tessellation and geometry shaders for per-vertex by multiple graphics pipelines. Geometric primitives that are generated in a first processing stage are collected and redistributed more evenly and in smaller batches to the multiple graphics pipelines for vertex processing in a second processing stage. The smaller batches do not exceed the resource limits of a graphics pipeline and the per-vertex processing workloads of the graphics pipelines in the second stage are balanced. Therefore, the performance of the tessellation and geometry shaders is improved.

Abstract: A method of organizing memory for storage of texture data, in accordance with one embodiment of the invention, includes accessing a size of a mipmap level of a texture map. A block dimension may be determined based on the size of the mipmap level. A memory space (e.g., computer-readable medium) may be logically divided into a plurality of whole number of blocks of variable dimension. The dimension of the blocks is measured in units of gobs and each gob is of a fixed dimension of bytes. A mipmap level of a texture map may be stored in the memory space. A texel coordinate of said mipmap level may be converted into a byte address of the memory space by determining a gob address of a gob in which the texel coordinate resides and determining a byte address within the particular gob.

Abstract: Circuits, methods, and apparatus that provide for partial texture load instructions. Instead of one instruction that may take several shader passes to complete, several instructions are issued, where each instruction is an instruction to retrieve a part or portion of a texture. While each instruction is performed, the other shader circuits can perform other instructions, thus increasing the utilization of the shader circuits when large textures are read from memory. Since several shader passes may be required to read a texture, if a particular instruction needs the texture, one exemplary embodiment reorders instructions such that other instructions are performed before the particular instruction that needs the texture.

Abstract: Circuits, methods, and apparatus that provide texture caches and related circuits that store and retrieve texels in a fast and efficient manner. One such texture circuit provides an increased number of bilerps for each pixel in a group of pixels, particularly when trilinear or aniso filtering is needed. For trilinear filtering, texels in a first and second level of detail are retrieved for a number of pixels during a clock cycle. When aniso filtering is performed, multiple bilerps can be retrieved for each of a number of pixels during one clock cycle.

Abstract: A scalable shader architecture is disclosed. In accord with that architecture, a shader includes multiple shader pipelines, each of which can perform processing operations on rasterized pixel data. Shader pipelines can be functionally removed as required, thus preventing a defective shader pipeline from causing a chip rejection. The shader includes a shader distributor that processes rasterized pixel data and then selectively distributes the processed rasterized pixel data to the various shader pipelines, beneficially in a manner that balances workloads. A shader collector formats the outputs of the various shader pipelines into proper order to form shaded pixel data. A shader instruction processor (scheduler) programs the individual shader pipelines to perform their intended tasks.

Abstract: A method and system for optimizing graphics program execution by allowing the sharing of shader resources is disclosed. The method includes accessing a graphics program using a shader pipeline. If a texture projective instruction is included in the graphics program, a determination is made as to whether a texture projective parameter q indicates a non-projective texture. If the texture projective parameter indicates a non-projective texture, the texture projective instruction is demoted and a resulting demoted texture instruction is executed using a plurality of interpolators of the shader pipeline, which requires fewer shader resources.

Abstract: A new, useful, and non-obvious shader processor architecture having a shader register file that acts both as an internal storage register file for temporarily storing data within the shader processor and as a First-In First-Out (FIFO) buffer for a subsequent module. Some embodiments include automatic, programmable hardware conversion between numeric formats, for example, between floating point data and fixed point data.

Abstract: Circuits, methods, and apparatus that provide texture caches and related circuits that store and retrieve texels in a fast and efficient manner. One such texture circuit provides an increased number of bilerps for each pixel in a group of pixels, particularly when trilinear or aniso filtering is needed. For trilinear filtering, texels in a first and second level of detail are retrieved for a number of pixels during a clock cycle. When aniso filtering is performed, multiple bilerps can be retrieved for each of a number of pixels during one clock cycle.

Abstract: A system and method for performing tessellation in a single pass through a graphics processor divides the processing resources within the graphics processor into sets for performing different tessellation operations. Vertex data and tessellation parameters are routed directly from one processing resource to another instead of being stored in memory. Therefore, a surface patch description is provided to the graphics processor and tessellation is completed in a single uninterrupted pass through the graphics processor without storing intermediate data in memory.

Abstract: Circuits, methods, and apparatus that provide texture caches and related circuits that store and retrieve texels in a fast and efficient manner. One such texture circuit provides an increased number of bilerps for each pixel in a group of pixels, particularly when trilinear or aniso filtering is needed. For trilinear filtering, texels in a first and second level of detail are retrieved for a number of pixels during a clock cycle. When aniso filtering is performed, multiple bilerps can be retrieved for each of a number of pixels during one clock cycle.

Abstract: Methods and systems for texture mapping in a computer-implemented graphics pipeline are described. A sample group is identified as including a divergent pixel. A determination is made whether an operand of an instruction executing on the divergent pixel satisfies a condition. A scheme for determining a level of detail for the texture mapping is selected depending on whether or not the condition is satisfied.

Abstract: A system and method controls the scheduling of program instructions included in a shader program for execution by a processing pipeline. One or more fence instructions may be inserted into the shader program. Each fence instruction specifies a constraint that is applied to control the scheduling of another program instruction in the shader program. Controlling the scheduling of program instructions for execution by the processing pipeline may result in a more efficient use of computing resources and improved performance.

Abstract: A method and apparatus of operating a shader having multiple texture or shader processing stations. That method includes feeding the output of a texture or shader processing station directly into the input of another texture or shader processing station. Further, only a subset of the processing stations has access to a shader register file.

Abstract: Circuits, methods, and apparatus that provide for partial texture load instructions. Instead of one instruction that may take several shader passes to complete, several instructions are issued, where each instruction is an instruction to retrieve a part or portion of a texture. While each instruction is performed, the other shader circuits can perform other instructions, thus increasing the utilization of the shader circuits when large textures are read from memory. Since several shader passes may be required to read a texture, if a particular instruction needs the texture, one exemplary embodiment reorders instructions such that other instructions are performed before the particular instruction that needs the texture.

Abstract: A system and method for providing antialiased memory access includes receiving a request to access a memory address. The memory address is examined to determine if the memory address is within a virtual frame buffer. If the memory address is within a virtual frame buffer then the memory address is transformed into one or more physical addresses within a frame buffer that is utilized for antialiasing. The frame buffer may be a single memory space containing subpixel information corresponding to pixels of the virtual frame buffer. Subpixels located at the physical addresses within the frame buffer are then accessed. The disclosed invention provides for direct access by a software application.

Abstract: A graphical shader and a method of distributing graphical data to shader pipelines in a graphical shader are disclosed. In accordance with the method, a shader pipeline input delay is set. Further, a group of the graphical data is distributed to a shader pipeline of the graphical shader to be processed. The method includes waiting for the shader pipeline input delay to elapse. After the shader pipeline input delay has elapsed, another group of the graphical data is distributed to another shader pipeline of the graphical shader to be processed. In another embodiment, a graphical shader includes a plurality of shader pipelines for processing graphical data. Further, the graphical shader includes a shader distributor for distributing a group of the graphical data to one of the shader pipelines and for distributing another group of the graphical data to another one of the shader pipelines after a shader pipeline input delay has elapsed.

Abstract: Apparatuses and methods are presented for a hierarchical processor. The processor comprises, at a first level of hierarchy, a plurality of similarly structured first level components, wherein each of the plurality of similarly structured first level components includes at least one combined function module capable of performing multiple classes of graphics operations, each of the multiple classes of graphics operations being associated with a different stage of graphics processing.

Abstract: A scalable shader architecture is disclosed. In accord with that architecture, a shader includes multiple shader pipelines, each of which can perform processing operations on rasterized pixel data. Shader pipelines can be functionally removed as required, thus preventing a defective shader pipeline from causing a chip rejection. The shader includes a shader distributor that processes rasterized pixel data and then selectively distributes the processed rasterized pixel data to the various shader pipelines, beneficially in a manner that balances workloads. A shader collector formats the outputs of the various shader pipelines into proper order to form shaded pixel data. A shader instruction processor (scheduler) programs the individual shader pipelines to perform their intended tasks.

Abstract: A method of optimizing perspective correction computations to be executed in a programmable fragment shader, identifying a sequence of program instructions; determining whether the sequence of program instructions can be optimized based on the status of the bit; sourcing one or more interpolated texture map coordinates to thereby disable the perspective correction computation comprising division by (1/w); and enabling the optimized execution of one of a plurality of perspective computation functions by a sought operation in a shader unit without division of the interpolated texture maps coordinates by (1/w). The optimized function includes able mapping, projective mapping, normalization, or scaling invariant operations.

Abstract: A fragment processor includes a fragment shader distributor, a fragment shader collector, and a plurality of fragment shader pipelines. Each fragment shader pipeline executes a fragment shader program on a segment of fragments. The plurality of fragment shader pipelines operate in parallel, executing the same or different fragment shader programs. The fragment shader distributor receives a stream of fragments from a rasterization unit and dispatches a portion of the stream of fragments to a selected fragment shader pipeline until the capacity of the selected fragment shader pipeline is reached. The fragment shader distributor then selects another fragment shader pipeline. The capacity of each of the fragment shader pipelines is limited by several different resources. As the fragment shader distributor dispatches fragments, it tracks the remaining available resources of the selected fragment shader pipeline.