Invention Grant
- Patent Title: Predictive fetching and decoding for selected instructions
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Application No.: US13931656Application Date: 2013-06-28
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Publication No.: US09619230B2Publication Date: 2017-04-11
- Inventor: Michael K. Gschwind , Valentina Salapura
- Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
- Applicant Address: US NY Armonk
- Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
- Current Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
- Current Assignee Address: US NY Armonk
- Agency: Heslin Rothenberg Farley & Mesiti P.C.
- Agent William A. Kinnaman, Jr., Esq.; Blanche E. Schiller, Esq.
- Main IPC: G06F9/38
- IPC: G06F9/38 ; G06F9/30

Abstract:
Predictive fetching and decoding for selected instructions (e.g., operating system instructions, hypervisor instructions or other such instructions). A determination is made that a selected instruction, such as a system call instruction, an asynchronous interrupt, a return from system call instruction or return from asynchronous interrupt, is to be executed. Based on determining that such an instruction is to be executed, a predicted address is determined for the selected instruction, which is the address to which processing transfers in order to provide the requested services. Then, fetching of instructions beginning at the predicted address prior to execution of the selected instruction is commenced. Further, speculative state relating to a selected instruction, including, for instance, an indication of the privilege level of the selected instruction or instructions executed on behalf of the selected instruction, is predicted and maintained.
Public/Granted literature
- US20150006855A1 PREDICTIVE FETCHING AND DECODING FOR SELECTED INSTRUCTIONS Public/Granted day:2015-01-01
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