Invention Application
- Patent Title: RESERVATION STATIONS TO INCREASE INSTRUCTION LEVEL PARALLELISM
- Patent Title (中): 预定站提高指导级并行性
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Application No.: US09144302Application Date: 1998-08-31
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Publication No.: US20030014613A1Publication Date: 2003-01-16
- Inventor: NARESH H. SONI
- Main IPC: G06F015/00
- IPC: G06F015/00 ; G06F009/30 ; G06F009/40

Abstract:
A data processing system having a distributed reservation station is provided which stores basic blocks of code in the form of microprocessor instructions. The present invention is capable of distributing basic blocks of code to the various distributed reservation stations. Due to the smaller number of entries in the distributed reservation stations, the look up time required to find a particular instruction is much less than in a centralized reservation station. Additional instruction level parallelism is achieved by maintaining single basic blocks of code in the distributed reservation stations. This is because instructions which are grouped together are less likely to use the same resources, e.g. registers and memory locations, therefore, they will exhibit more data, control and resource independence. In contrast, when instructions are not associated with one another (e.g. in different basic blocks) they are more likely to use the same resources (execution units), data resources (registers) and be subject to control dependencies (branching), thus causing a greater chance of dependency that may cause instructions to have to wait for resources to become available. Also, with a distributed reservation station, an independent scheduler can be used for each one of the distributed reservation stations. When the instruction is ready for execution, the scheduler will remove that instruction from the distributed reservation station and queue that instruction(s) for immediate execution at the particular execution unit. Multiple independent schedulers will provide greater efficiency when compared to a single scheduler which must contend with approximately 20-24 instructions that have increased dependency on one another.
Public/Granted literature
- US06742111B2 Reservation stations to increase instruction level parallelism Public/Granted day:2004-05-25
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