Dynamically rewriting branch instructions in response to cache line eviction

US8782381B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Tong Chen · Brookline, US
• Brian Flachs · Austin, US
• Brad W. Michael · Cedar Park, US
• Mark Richard Nutter · Austin, US
• John Kevin Patrick O'Brien · South Salem, US
• Kathryn M. O'Brien · South Salem, US
• Tao Zhang · Beijing, CN

Key dates

• Filing date: Apr 12, 2012
• Grant date: Jul 15, 2014
• Expiry date: Apr 12, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F12/12
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Mechanisms are provided for evicting cache lines from an instruction cache of the data processing system. The mechanisms store, for a portion of code in a current cache line, a linked list of call sites that directly or indirectly target the portion of code in the current cache line. A determination is made as to whether the current cache line is to be evicted from the instruction cache. The linked list of call sites is processed to identify one or more rewritten branch instructions having associated branch stubs, that either directly or indirectly target the portion of code in the current cache line. In addition, the one or more rewritten branch instructions are rewritten to restore the one or more rewritten branch instructions to an original state based on information in the associated branch stubs.