How to measure a C functions execution time in ARM DS-5 under Timesys Linux?

[dragan]

Respected Colleagues,

can somebody share a sample how to measure execution time inside the ARM DS-5 GCC application for Vybrid VF61 A5 core, because generic way (shown bellow) doesn't work. Variable clock_t can not be linked to a code no matter that the time.h is included. Result is always zero.

#include <time.h>

clock_t start, end;
double cpu_time_used;

start = clock();
... /* Do the work. */
end = clock();
cpu_time_used = ((double) (end - start)) / CLOCKS_PER_SEC;

Thanks in advance.

With best regards,

Dragan Kujovic

[timesyssupport · Accepted solution]

Hello Dragan,

We have verified your code with our Timesys toolchain ,clock function works as expected. Between the two successive clock functions, if you do the work with less  than 1 unity i.e it executes in microseconds, will return zero. You can verify this with the precision of 10 floating point values in printf statement.

printf("cpu time used is %.10f \n",cpu_time_used);

Also you can try with gettimeofday() to get the execution time of your function.

Thanks,

Timesys Support

[dragan]

Thanks for your answer.

I think that something is wrong with project and compiling from ARM DS-5, because the variable clock_t is red underscored, but compiling pass without errors and warnings. time.h is included.

When I try from Linux shell "time sleep 2" it returns correct answer, but when I try it from application with reading

start = clock();

sleep(2); // 2 seconds

end = clock();

both start and end are populated with the same value, and because of that the result is allways zero.

I will try to further investigate this.

With best regards,

Dragan Kujovic

[alejandrolozan1]

Hi Dragan,

" I think that something is wrong with project and compiling from ARM DS-5, because the variable clock_t is red underscored, but compiling pass without errors and warnings. time.h is included."

Those problems in DS-5 are due the IDE is not able to find some symbols. You have to #include the correct file including the path.

Best Regards,

Alejandro

[karina_valencia]

can you help with this case?