Community
cancel
Showing results for 
Search instead for 
Did you mean: 
sumitgulati
Beginner
59 Views

How to calculate Clock Cycles count for a function

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

0 Kudos
1 Reply
David_A_Intel1
Employee
59 Views

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.
Reply