precise time measurement

Question

I\'m using time.h in C++ to measure the timing of a function.

clock_t t = clock();
someFunction();
printf(\"\\nTime taken: %.4fs\\n\", (float)(clock() - t)/         


        

Answer 1

I usually use the QueryPerformanceCounter function.

example:

LARGE_INTEGER frequency;        // ticks per second
LARGE_INTEGER t1, t2;           // ticks
double elapsedTime;

// get ticks per second
QueryPerformanceFrequency(&frequency);

// start timer
QueryPerformanceCounter(&t1);

// do something
...

// stop timer
QueryPerformanceCounter(&t2);

// compute and print the elapsed time in millisec
elapsedTime = (t2.QuadPart - t1.QuadPart) * 1000.0 / frequency.QuadPart;