Benchmarking code with time.h

sam91suger · **Joined:** Wed Aug 19, 2009 9:05 am **Posts:** 7

Hello,

I have a piece of code that I need to benchmark on a Olimex SAM9-l9260 board running a Linux version 2.6.26.3-olimex (dimitar@lindev.vm) (gcc version 4.2.3 (Sourcery

kernel.

I tried to use time.h like this:

Code:

      printf("Computation start\n");
      t1 = clock();

      "DO THE STUFF"
      
      t2 = clock()-t1;
      printf("Computation end\n");
      
      printf ("%.6f\n", (double)(t2+0.0) / CLOCKS_PER_SEC);

But a get unresonable values

Anybody have a clue if and how time.h works in this scenario (I don't have to have processor time, wall-clock time is fine for me if that is the only one possible)...

Hope for luck!

Best/Carl

MattFunke · **Joined:** Tue Jul 07, 2009 7:27 pm **Posts:** 7

Forgive me for asking the stupid questions, but:

* Is CLOCKS_PER_SEC a float?

* What kind of "unreasonable values" are you getting?

sam91suger · **Joined:** Wed Aug 19, 2009 9:05 am **Posts:** 7

CLOCKS_PER_SEC seems to be a float, the line

Code:

printf("Clops: %.6f\n"(double)CLOCKS_PER_SEC);

Generates the result:

Clops: 1000000.000000

After a good nights sleep and some measuring with a regular stopwatch the values does not seem unreasonable anymore....

Problem solved...

Benchmarking code with time.h

Who is online