Computer Intensity

I have tried several examples of source code in the provided literature and I have never gotten a compute intensity reading yet. Please provide some source code and compiler directives that will give me a computer intensity reading. Please make it in c. Believe me I have tried and have come with nothing - bupkiss.

THX 1138

Hi THX 1138,

The compute intensity is shown when the “-Minfo=ccff,intensity” flag is used. Keep in mind though, for loops with dynamic sizes (i.e the loop bounds aren’t known until runtime), the intensity shown may be symbolic. For these cases, you need to add profile-guided feedback.

To use PFO, first add “-Mpfi” to your compilation flags and then run your code using a representative data set. “-Mpfi” instruments your code used to generate profile information. Next, recompile your code with “-Mpfo -Minfo=ccff,intensity” to view the intensity.

Note that some intensity information may still be symbolic. In these cases, the loops were most like not executed during runtime.

Hope this helps,

Hi THX 1138,

The thought occurred to me that you might be using 32-bit. Intensity information is only available for 64-bit compilations.

  • Mat