Invention Grant
- Patent Title: Apparatus and method for handling dependency conditions between floating-point instructions
- Patent Title (中): 用于处理浮点指令之间依赖条件的装置和方法
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Application No.: US12428459Application Date: 2009-04-22
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Publication No.: US08458444B2Publication Date: 2013-06-04
- Inventor: Yuan C. Chou , Jared C. Smolens , Jeffrey S. Brooks
- Applicant: Yuan C. Chou , Jared C. Smolens , Jeffrey S. Brooks
- Applicant Address: US CA Redwood City
- Assignee: Oracle America, Inc.
- Current Assignee: Oracle America, Inc.
- Current Assignee Address: US CA Redwood City
- Agency: Meyertons, Hood, Kivlin, Kowert & Goetzel, P.C.
- Main IPC: G06F9/30
- IPC: G06F9/30

Abstract:
Techniques for handling dependency conditions, including evil twin conditions, are disclosed herein. An instruction may designate a source register comprising two portions. The source register may be a double-precision register and its two portions may be single-precision portions, each specified as destinations by two other single-precision instructions. Execution of these two single-precision instructions, especially on a register renaming machine, may result in the appropriate values for the two portions of the source register being stored in different physical locations, which can complicate execution of an instruction stream. In response to detecting a potential dependency, one or more instructions may be inserted in an instruction stream to enable the appropriate values to be stored within one physical double precision register, eliminating an actual or potential evil twin dependency. Embodiments including a compiler that inserts instructions in a generated instruction stream to eliminate dependency conditions are also contemplated.
Public/Granted literature
- US20100274992A1 APPARATUS AND METHOD FOR HANDLING DEPENDENCY CONDITIONS Public/Granted day:2010-10-28
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