Accuracy of operand store compare prediction using confidence counter

US9606805B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Khary J. Alexander · Poughkeepsie, US
• Jane H. Bartik · Poughkeepsie, US
• Jatin Bhartia · Ghaziabad, IN
• James J. Bonanno · Wappingers Falls, US
• Adam B. Collura · Hopewell Junction, US
• Jang-Soo Lee · Fishkill, US
• James R. Mitchell · Poughkeepsie, US
• Anthony Saporito · Highland, US

Key dates

• Filing date: Oct 19, 2015
• Grant date: Mar 28, 2017
• Expiry date: Oct 19, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/3861
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Technical solutions are described for dynamically managing an operand-store-compare (OSC) prediction table for load and store operations executed out-of-order. One general aspect includes a method that includes receiving a request to retire a queue entry corresponding to an instruction. The method also includes identifying an OSC prediction for the instruction based on an OSC prediction table entry, where the OSC prediction indicates if the instruction is predicted to hit an OSC hazard. The method also includes determining if the instruction hit the OSC hazard. The method also includes in response to the OSC prediction indicating that the instruction is predicted to hit the OSC hazard and the instruction not hitting the OSC hazard, invalidating the OSC prediction table entry corresponding to the instruction. The present document further describes examples of other aspects such as methods, computer products.