Apple inc. (20240354111). Re-use of Speculative Control Transfer Instruction Results from Wrong Path simplified abstract
Contents
Re-use of Speculative Control Transfer Instruction Results from Wrong Path
Organization Name
Inventor(s)
Yuan C. Chou of Los Gatos CA (US)
Deepankar Duggal of Sunnyvale CA (US)
Debasish Chandra of Fremont CA (US)
Niket K. Choudhary of Santa Clara CA (US)
Richard F. Russo of San Jose CA (US)
Re-use of Speculative Control Transfer Instruction Results from Wrong Path - A simplified explanation of the abstract
This abstract first appeared for US patent application 20240354111 titled 'Re-use of Speculative Control Transfer Instruction Results from Wrong Path
The disclosed techniques involve re-using speculative results from an incorrect execution path. When a first control transfer instruction is mispredicted, a second control transfer instruction may have been executed on the wrong path due to the misprediction. Result storage circuitry records information indicating the determined direction for the second control transfer instruction. Control flow tracker circuitry stores information indicating a reconvergence point for the first control transfer instruction. Re-use control circuitry tracks registers written by instructions prior to the reconvergence point, determines that the second control transfer instruction does not depend on data from any instruction between the first control transfer instruction and the reconvergence point, and uses the recorded determined direction for the second control transfer instruction, despite the misprediction of the first control transfer instruction.
- Result storage circuitry records determined direction for second control transfer instruction
- Control flow tracker circuitry stores reconvergence point for first control transfer instruction
- Re-use control circuitry tracks registers and determines independence of second control transfer instruction
- Utilizes recorded determined direction for second control transfer instruction
- Improves efficiency by re-using speculative results from incorrect execution paths
Potential Applications: - High-performance computing systems - Real-time processing applications - Embedded systems - Network processing units
Problems Solved: - Optimizing execution paths in the presence of mispredictions - Improving overall system performance - Reducing unnecessary data dependencies
Benefits: - Enhanced system efficiency - Faster processing speeds - Reduced resource wastage - Improved overall system reliability
Commercial Applications: Title: "Enhancing System Efficiency through Re-Use of Speculative Results" This technology could be applied in industries such as: - Semiconductor manufacturing - Cloud computing services - Telecommunications infrastructure - Data centers
Questions about the technology: 1. How does the re-use of speculative results improve system performance? 2. What are the potential drawbacks of re-using speculative results in execution paths?
Original Abstract Submitted
disclosed techniques relate to re-use of speculative results from an incorrect execution path. in some embodiments, when a first control transfer instruction is mispredicted, a second control transfer instruction may have been executed on the wrong path because of the misprediction. result storage circuitry may record information indicating a determined direction for the second control transfer instruction. control flow tracker circuitry may store, for the first control transfer instruction, information indicating a reconvergence point. re-use control circuitry may track registers written by instructions prior to the reconvergence point, determine, based on the tracked registers, that the second control transfer instruction does not depend on data from any instruction between the first control transfer instruction and the reconvergence point, and use the recorded determined direction for the second control transfer instruction, notwithstanding the misprediction of the first control transfer instruction.
