Determine the fraction of operations on integers and floating point operands with VTune

[kkboyanov]

Hello,

Me and my team want to have a clearer view of what is going on in our applications, and more specifically what portion of the runtime the application spends on computations of float operands and what - on such with integer operands.

As I am relatively new to using the VTune Analyszer I would like to hear tour oppinions on what would be the best performance counter events to be selected to perform such ratio measurement from the many available events in the Activity Configuration -> Configure Sampling configuration window?

Thanks in advance for your suggestions!

Regards,
Konstantin Boyanov

[David_A_Intel1]

Hi Konstantin:

Events are specific to a processor. You need to tell us which processor you are collecting data on or, more specifically, which processor architecture. For example, Core2 or Corei7 processors?

[TimP]

Depending on more details of what is wanted, the question may be impossible to answer. Integer and floating point operations generally are executed in parallel on different execution units, so it may be the answer is tied up in how much time is spent on data movement.

[kkboyanov]

Hello,

The processors which we are intersted in observing opour program's behaviour are an Xeon E5540 @ 2.53GHz and an Xeon X5560 @ 2.80GHz. I agree that the my goal is so to speak widely defined, but it is also true that I don't need exact numbers (like 1048006 operations in the ALU) but instead a rough estimate what percentage of the runtime of a particular application is spend in processing integer data and what - in processing flaoting point data.

@Tim: When the INT and FP operations are executed on different units, then there should be some metric (event or a set of events) to describe the utilization of this execution units. Destinguishing between data movement and computation instructions (and measuring the time spent in such) sounds promissing, but again I am perplexed as to which set of events would provide for the best insights.

Regards,
Konstantin