Invention Grant
- Patent Title: Zero cycle load bypass in a decode group
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Application No.: US16705023Application Date: 2019-12-05
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Publication No.: US11416254B2Publication Date: 2022-08-16
- Inventor: Deepankar Duggal , Kulin N. Kothari , Conrado Blasco , Muawya M. Al-Otoom
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Kowert Hood Munyon Rankin and Goetzel PC
- Agent Rory D. Rankin
- Main IPC: G06F9/30
- IPC: G06F9/30 ; G06F9/38

Abstract:
Systems, apparatuses, and methods for implementing zero cycle load bypass operations are described. A system includes a processor with at least a decode unit, control logic, mapper, and free list. When a load operation is detected, the control logic determines if the load operation qualifies to be converted to a zero cycle load bypass operation. Conditions for qualifying include the load operation being in the same decode group as an older store operation to the same address. Qualifying load operations are converted to zero cycle load bypass operations. A lookup of the free list is prevented for a zero cycle load bypass operation and a destination operand of the load is renamed with a same physical register identifier used for a source operand of the store. Also, the data of the store is bypassed to the load.
Public/Granted literature
- US20210173654A1 ZERO CYCLE LOAD BYPASS Public/Granted day:2021-06-10
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