Load speculation recovery

Abstract

Systems, apparatuses, and methods for managing dependencies between instruction operations when speculatively issuing load instruction operations. A processor may maintain dependency vectors for sources of instruction operations dispatched to the scheduler. The dependency vector may include a column for each cycle of the load recovery window and a row for each load execution pipeline. When a load speculatively issues, any instruction operation which is dependent on the load may have a bit set in the earliest bit position of its dependency vector to indicate the dependency. The bit may shift in the dependency vector toward the cancel bit position during each clock cycle as the load executes. If the load does not produce its data at the expected latency, an instruction operation may be canceled if there is a bit in the cancel bit position of the dependency vector row corresponding to the execution pipeline of the load.