Making precise operand-store-compare predictions to avoid false dependencies

US10929142B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Gregory W. Alexander · Pflugerville, US
• James J. Bonanno · Wappingers Falls, US
• Adam B. Collura · Hopewell Junction, US
• James R. Cuffney · Poughkeepsie, US
• Yair Fried · Petah Tikva, IL
• Jonathan T. Hsieh · Poughkeepsie, US
• Jang-Soo Lee · Fishkill, US
• Edward T. Malley · New Rochelle, US
• Anthony Saporito · Highland, US
• Eyal Naor · Nes Ziona, IL

Key dates

• Filing date: Mar 20, 2019
• Grant date: Feb 23, 2021
• Expiry date: Apr 22, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/3844
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Provided are embodiments including a computer-implemented method, system and computer program product for determining precise operand-store-compare (OSC) predictions to avoid false dependencies. Some embodiments include detecting an instruction causing an OSC event, wherein the OSC event is at least one of a store-hit-load event or a load-hit-store event, marking an entry in a queue for the instruction based on the detected OSC event, wherein marking the entry comprises setting a bit and saving a tag in the entry in the queue. Some embodiments also include installing an address for the instruction and the tag in the history table responsive to completing the instruction.