GPGPU on Accelerating Wave PDE

#include <windows.h>

/*
	Usage example

	StartCounter();

	// Event to be measured

	printf("%3lf - time elapsed\n", GetCounter());

*/

double PCFreq = 0.0;
__int64 CounterStart = 0;

void StartCounter()
{
	LARGE_INTEGER li;
	if(!QueryPerformanceFrequency(&li))
		printf("QUERYPERFORMANCE FAILED\n");

	PCFreq = double(li.QuadPart)/1000.0;

	QueryPerformanceCounter(&li);
	CounterStart = li.QuadPart;
}

double GetCounter()
{
	LARGE_INTEGER li;
	QueryPerformanceCounter(&li);

	return double(li.QuadPart-CounterStart)/PCFreq;
}