Register set reordering for a graphics processor based upon the type of primitive to be rendered

DETAILED DESCRIPTION The present invention provides a technique and protocol for reordering the register sets comprising the register file based upon the type of primitive to be rendered.
Thus, the present invention eliminates from consideration parameters that are not required to render the indicated primitive.
As a result, the host processor only transmits necessary parameter values, and the graphics controller only loads and transfers the parameters necessary to render the particular primitive.
Primitive parameters are generated by a software driver in a system processor, and are provided to the graphics processor in the form of a display list.
The software driver places into the display only the parameters necessary to render the indicated primitive.
In the preferred embodiment, the graphics processor includes a prefetch unit that obtains the display list either directly from the system processor, or from system memory through a read operation.
In addition, the prefetch unit preferably also retrieves instructions from the system memory in the form of operational codes (or "opcodes").
The graphics processor also preferably includes an internal instruction execution unit that receives the opcode from the prefetch unit and decodes the opcode.
The execution unit also receives the display list and stores the display list in a register file.
The execution unit, as part of its opcode decoding, determines the type of primitive that is to be rendered, and accordingly, causes only the necessary register values from the register file to be transmitted to polygon and texture engines for rendering the primitive.