Nvidia Corporation

Johnny S Rhoades

Emmett Michael Kilgariff

Ziyad Sami Hakura

Dale L Kirkland

Rui Manuel Bastos

Sean Jeffrey Treichler

Karim Abdalla

John Douglas Tynefield, Jr

Steven E Molnar

Michael C Shebanow

Cynthia Ann Edgeworth Allison

Brian Keith Cabral

James D Kelly

Andrew J Tao

Christian Rouet

Roger L Allen

Gary M Tarolli

Timothy John Purcell

Craig Michael Wittenbrink

James C Bowman

Karl M Wurstner

Mark J Kilgard

Cass Watson Everitt

Michael J M Toksvig

Philip Browning Johnson

Franklin C Crow

Rohit Kumar Gupta

Wei-Chao Chen

Gernot Schaufler

Michael Jm Toksvig

One embodiment of the present invention sets forth a technique for parallel distribution of primitives to multiple rasterizers. Multiple, independent geometry units perform geometry processing concurrently on different graphics primitives. A primitive distribution scheme delivers primitives from the multiple geometry units concurrently to multiple rasterizers at rates of multiple primitives per clock. The multiple, independent rasterizer units perform rasterization concurrently on one or more graphics primitives, enabling the rendering of multiple primitives per system clock.

Distributing primitives to multiple rasterizers

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

Time slice processing of tessellation and geometry shaders

A data structure that includes pointers to vertex attributes and primitive descriptions is generated and then processed within a general processing cluster. The general processing cluster includes a vertex attribute fetch unit that fetches from memory vertex attributes corresponding to the vertices defined by the primitive descriptions.

Distributed vertex attribute fetch

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.

Redistribution of generated geometric primitives

One embodiment of the present invention sets forth a technique for using a shared memory to store hardware-managed virtual buffers. A circular buffer is allocated within a general-purpose multi-use cache for storage of primitive attribute data rather than having a dedicated buffer for the storage of the primitive attribute data. The general-purpose multi-use cache is also configured to store other graphics data sinces the space requirement for primitive attribute data storage is highly variable, depending on the number of attributes and the size of primitives. Entries in the circular buffer are allocated as needed and released and invalidated after the primitive attribute data has been consumed. An address to the circular buffer entry is transmitted along with primitive descriptors from object-space processing to the distributed processing in screen-space.

Hardware-managed virtual buffers using a shared memory for load distribution

One embodiment of the present invention sets forth a technique for rendering graphics primitives in parallel while maintaining the API primitive ordering. Multiple, independent geometry units perform geometry processing concurrently on different graphics primitives. A primitive distribution scheme delivers primitives concurrently to multiple rasterizers at rates of multiple primitives per clock while maintaining the primitive ordering for each pixel. The multiple, independent rasterizer units perform rasterization concurrently on one or more graphics primitives, enabling the rendering of multiple primitives per system clock.

Order-preserving distributed rasterizer

An apparatus and method for converting color data from one color space to another color space. A driver determines that a set of shader program instructions perform a color conversion function and the set of shader program instructions are replaced with either a single shader program instruction or a flag is set within an existing shader program instruction to specify that output color data is represented in a nonlinear color format. The output color data is converted to the nonlinear color format prior to being stored in a frame buffer. Nonlinear color data read from the frame buffer is converted to a linear color format prior to shading, blending, or raster operations.

Optional color space conversion

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. Each shader pipeline has a shader gatekeeper that interacts with the shader distributor and with the shader instruction processor such that pixel data that passes through the shader pipelines is controlled and processed as required.

Scalable shader architecture

Systems and methods for dynamically canceling texture fetches may improve texture mapping performance. A shader program compiler inserts condition code writes and condition code comparison operations for shader program instructions that contribute to a texture read instruction and do not need to be executed if certain conditions are met. During execution of the shader program, the inserted condition codes are used to compute a dynamic writemask that indicates if the texture data resulting from the texture read is unnecessary. The dynamic writemask is used to cancel unnecessary texture fetches during execution of the shader program.

Dynamic texture fetch cancellation

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Durham, NC, United States of America

Johnny S Rhoades