Apple inc. (20240354109). Re-use of Speculative Load Instruction Results from Wrong Path simplified abstract
Contents
Re-use of Speculative Load 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 Load Instruction Results from Wrong Path - A simplified explanation of the abstract
This abstract first appeared for US patent application 20240354109 titled 'Re-use of Speculative Load Instruction Results from Wrong Path
The patent application describes techniques for re-using speculative results from an incorrect execution path in a computer system.
- Result storage circuitry records information about destination registers of speculatively-executed load instructions.
- Control flow tracker circuitry stores information about a reconvergence point for a mispredicted control transfer instruction.
- Re-use control circuitry tracks registers written by instructions before the reconvergence point and determines if a load instruction does not depend on data from instructions between the control transfer instruction and the reconvergence point.
- The re-use control circuitry then uses the value from a recorded destination register, based on speculative execution, for the load instruction, despite the misprediction of the control transfer instruction.
Potential Applications: - This technology can be applied in high-performance computing systems to improve efficiency and reduce latency. - It can also be used in microprocessor design to enhance the overall performance of the processor.
Problems Solved: - Addresses the issue of wasted computational resources due to mispredicted control transfer instructions. - Improves the overall efficiency of computer systems by re-using speculative results.
Benefits: - Increased performance and efficiency in computer systems. - Reduction in computational waste and latency. - Enhanced reliability of speculative execution in processors.
Commercial Applications: Title: "Efficient Speculative Result Re-Use Technology for Enhanced Processor Performance" This technology can be commercialized by semiconductor companies for integration into their processor designs to offer faster and more efficient computing solutions for various applications such as data centers, AI systems, and mobile devices.
Questions about the technology: 1. How does this technology improve the overall performance of computer systems? - This technology enhances performance by re-using speculative results from incorrect execution paths, reducing computational waste and improving efficiency. 2. What are the potential applications of this technology beyond high-performance computing systems? - This technology can also be applied in microprocessor design to optimize processor performance and efficiency.
Original Abstract Submitted
disclosed techniques relate to re-use of speculative results from an incorrect execution path. in some embodiments, when a control transfer instruction is mispredicted, a load instruction may have been executed on the wrong path. in disclosed embodiments, result storage circuitry records information that indicates destination registers of speculatively-executed load instructions including a first load instruction. control flow tracker circuitry may store information indicating a reconvergence point for the control transfer instruction. re-use control circuitry may track registers written by instructions prior to the reconvergence point, determine that the first load instruction does not depend on data from any instruction between the control transfer instruction and the reconvergence point, and use, as a result of the first load instruction, a value from a recorded destination register that was written based on speculative execution of the first load, notwithstanding the misprediction of the control transfer instruction.
