Method for data validity tracking to determine fast or slow mode processing at a reservation station

Devices, systems, and methods may perform micro-operation processing with data validity tracking to determine fast or slow mode processing at a reservation station. A method includes determining whether a condition related to validity of data in a reorder buffer of an out-of-order subsystem of a processor core is met, based on a criterion other than a valid data indication from said reorder buffer. In one embodiment, in a fast mode a reservation station may dispatch micro-operations to execution and in a slow mode the reservation station may wait for a valid indication from the reorder buffer prior to dispatching the micro-operation.