US Patent 9905046 Mapping multi-rate shading to monolithic programs

In multi-rate shading, a coarse-rate shading phase is added on top of existing pixel-rate phase to significantly improve performance with minimum impact to image quality. Two shading phases evaluated at different rates may be mapped to one monolithic program running on processor graphics single instruction multiple data (SIMD) engines. In one embodiment, multi-rate shading allows a single rendering pass to execute shading code at one or more different rates: per group of pixels, per pixel, and per sample.