how to get the wall time of special code line?

[sun__lei]

how to get the wall time of special code line?

[ArthurRatz]

Here's an example:

std::clock_t start = std::clock();

// do some work

std::clock_t finish = std::clock();

std::double_t time_span = finish - start;

std::cout << "Execution time: " << time_span << "\n";

Good luck.

[Bernard]

At least you may use a partially ordered RDTSCP instruction.

Be aware, that assembly implementation may run in the "shadow" of RDTSCP instruction (i.e. execute faster (in terms of pipeline stage of execution, than RDTSCP instruction)