International Business Machines Corporation

Hung Oui Le

Alexander Erik Mericas

Joel Roger Davidson

A method and system for detecting flushed instructions without a flush indicator is provided. In order to monitor the flushing of an instruction in an instruction pipeline of a processor, an instruction is selected as a sampled instruction and the progress of the sampled instruction through the instruction pipeline is monitored. Upon selection of an instruction as a sampled instruction, a countdown value is initialized to a value equal to the maximum number of instructions within the instruction pipeline, and as instructions complete, the countdown value is decremented. If progress of the sampled instruction is detected as the instruction moves through the instruction pipeline, the countdown value is reinitialized. If the countdown value reaches zero, then a flush of the sampled instruction from the instruction pipeline is presumed, and an indication that the sampled instruction has been flushed is generated. In response to the indication that the sampled instruction has been flushed, a subsequent instruction may be selected as a subsequently sampled instruction.

Growing community of inventors

Austin, TX, United States of America

Hung Oui Le