Advanced Micro Devices, Inc.
System and method for processing a load micro-operation by allocating an address generation scheduler queue entry without allocating a load queue entry

Abstract:

A system and method for a virtual load queue is described. Load micro-operations are processed through an instruction pipeline without requiring an entry in a load queue (LDQ). An address generation scheduler queue (AGSQ) entry is allocated to the load micro-operation and a LDQ entry is not allocated to the load micro-operation. The LDQ entries are reserved for the N oldest load micro-operations, where N is the depth of the LDQ. Deallocation of the AGSQ entry is done if the load micro-operation is one of the N oldest load micro-operations, or upon successful completion of the load micro-operation. Deallocation of the AGSQ entry is not done if the load micro-operation gets a bad status and is not one of the N oldest micro-operations. Consequently, the AGSQ acts as a virtual queue for the LDQ and mitigates the limiting effect of the LDQ depth.