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How to calculate Clock Cycles count for a function

sumitgulati
Beginner
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I want to calculate cycles count for a function using vtune analyser.

My main concern is how to calculate the Cycles count for the stall period ..

Thanks in Advance

sumit

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1 Reply
David_A_Intel1
Employee
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The VTune analyzer does not measure the number of cycles that every instruction takes. That would cause your code to run at about 1/1000 the speed it normally runs! :-( Instead, it periodically notes where the processor is executing code and gives you a statistically accurate representation of where the processor is spending it's time. This means your code runs at almost full speed (we say <5% overhead for sampling).

On the Intel Core2 processor family, using the VTune analyzer, you can roughly calculate stalls due to cache misses. See this paper for more info.
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