Accelerated reversal of speculative state changes and resource recovery

摘要

A method includes undoing, in reverse program order, changes in a state of a processing device caused by speculative instructions previously dispatched for execution in the processing device and concurrently deallocating resources previously allocated to the speculative instructions in response to interruption of dispatch of instructions due to a flush of the speculative instructions. A processor device comprises a retire queue to store entries for instructions that are awaiting retirement and a finite state machine. The finite state machine is to interrupt dispatch of instructions in response to a flush of speculative instructions previously dispatched for execution in the processing device and to undo, in reverse program order, changes in a state of the processing device caused by the speculative instructions while concurrently deallocating resources previously allocated to the speculative instructions.

主权项

1. A method for flushing speculative instructions previously dispatched for execution in a processing device, comprising:
undoing changes in a state of the processing device caused by the speculative instructions, the undoing performed instruction-by-instruction in reverse program order beginning with a youngest speculative instruction along an incorrectly predicted instruction path; and concurrently deallocating resources previously allocated to the speculative instructions.