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Hello students, pipelining is a computer architecture technique used to improve the cpu performance by breaking down the execution of the instruction into multiple stages, allowing multiple instructions to be processed simultaneously.
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However, pipeline can introduce subtle bugs and unexpected behavior if not implemented correctly.
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So, there are a few examples of how pipelining bugs have led to issues in the computer usage and the design.
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Pipelining stalls and the data hazards.
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What happened? in pipelining process, the data hazards occur when an instruction depends on the result of a previous instruction that has not completed its execution in the pipeline.
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This can lead to pipeline stalls where the processor has to wait for the data to become available.
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Resolution to address this issue, techniques like forwarding also known as data forwarding or bypassing and speculating execution are used.
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Forwarding allows the result of the instruction to be forwarded directly by the subsequent dependent instruction.
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Reducing stalls.
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Speculative execution involves predicting the outcome of the branches and the execution instruction speculatively to mitigate stalls caused by the branch.
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Control hazards and branch predictions what happened? when branch instruction can cause control hazards in the pipeline since the processor may not know the target of a branch until later in the pipeline.
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Lead to pipeline bubble stalls if the wrong branch prediction is made.
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Branch prediction techniques like static prediction, dynamic prediction and speculative execution are used to minimize the impact of the branch.
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Static prediction assumes that the branch always follows a certain pattern.
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Dynamic prediction uses history and heuristics to predict the branch outcome more accurately.
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Instruction reordering and out -of -order execution what happened? out -of -order execution is a technique that allows the processor to execute instructions in a different order than they appear in the program to maximize pipeline utilization.
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However, it can introduce bugs if the results are not committed in the correct order...