System and method for speculative execution in a geometry accelerator

Abstract

A system and method for performing speculative execution of state machine operation in a graphics accelerator. In accordance with one aspect of the invention, the method includes the step of executing steps in a first state machine that is operating on a graphic primitive. As is known, a graphic primitive is defined by a plurality of vertices. In accordance with the invention, the preferred embodiment receives the coordinate parameters for the second to last primitive vertex. Then it evaluates one or more conditions that indicate whether steps in a second state machine need to be executed, based upon parameters of primitive vertices already received. It then branches to and begins executing steps in another state machine, based upon the tentative conditions, and continuing execution of the steps in the transformation state machine in parallel with the continued execution of the steps in the another state machine. After a predetermined number of states, the method reevaluates the one or more conditions, at which time the value of the one or more conditions is no longer tentative, but determinative of the next state information. Then, the method invokes a reset condition, aborts execution of the steps in the another state machine, and returns execution to a predetermined step in the first state machine, if the one or more conditions of the evaluating and reevaluating steps are inconsistent. If, however, the one or more conditions of the evaluating and reevaluating steps are equal or consistent, the method terminates the execution of the first state machine and continues executing the steps in the another state machine.