Abstract: One embodiment of the present invention sets forth a technique for storing only the enabled components for each enabled vector and writing only enabled components to one or more specified render targets. A shader program header (SPH) file provides per-component mask bits for each render target. Each enabled mask bit indicates that the pixel shader generates the corresponding component as an output to the raster operations unit. In the hardware, the per-component mask bits are combined with the applications programming interface (API)-level per-component write masks to determine the components that are updated by the shader program. The combined mask is used as the write enable bits for components in one or more render targets. One advantage of the combined mask is that the components that are not updated are not forwarded from the pixel shader to the ROP, thereby saving bandwidth between those processing units.

Abstract: One embodiment of the present invention sets forth a technique for storing only the enabled components for each enabled vector and writing only enabled components to one or more specified render targets. A shader program header (SPH) file provides per-component mask bits for each render target. Each enabled mask bit indicates that the pixel shader generates the corresponding component as an output to the raster operations unit. In the hardware, the per-component mask bits are combined with the applications programming interface (API)-level per-component write masks to determine the components that are updated by the shader program. The combined mask is used as the write enable bits for components in one or more render targets. One advantage of the combined mask is that the components that are not updated are not forwarded from the pixel shader to the ROP, thereby saving bandwidth between those processing units.