LECTURE FRÉQUENCE PROCESSEUR

//Instruction de lecture Assembleur bas niveau pour le compilateur GCC MinGW

#define rdtsc(low,high) \
      asm volatile( \
         "xorl %%eax, %%eax\n\t" \
         "cpuid\n\t" \
         "rdtsc\n\t" \
         : "=a" (low), "=d" (high) \
         : \
         : "%ebx", "%ecx");

//Lecture du compteur processeur :

//Renvoi la fréquence du processeur
double LireFrequenceCpu(int cpuNumber){
	LARGE_INTEGER freq1, freq2;
	double frequence;
	DWORD tick1, tick2;

	// Lit la frequence du chronomêtre Windows


	// Avant
	rdtsc(freq1.LowPart, freq1.HighPart);
	//On place le chrono à 1ms
	//timeBeginPeriod(1);
	//tick1 = GetTickCount();
	tick1 = timeGetTime();

	//Pause de 1s pour pouvoir lire la fréquence...
	for (int i=0; i<100; i++)
		Sleep(10);

	// Apres
	rdtsc(freq2.LowPart, freq2.HighPart);
	//tick2 = GetTickCount();
	tick2 = timeGetTime();

	//On replace le timer à sa position d'origine
	//timeEndPeriod(1);

	frequence  = ((double)(freq2.QuadPart-freq1.QuadPart));
	frequence /= (double) ((tick2 - tick1));
	return (frequence*1000);
}


//Utilisation finale (avec MSR)

	cout << "Nombre de core : ";
	int nombreCore;
	cin>>nombreCore;
	DWORD eax, edx;

	timeBeginPeriod(1);
	LireFrequenceCpu(1); //La première lecture est toujours mauvaise...
	for(int i=0; i<nombreCore; i++)
	{
		cout << "Core " << i << " :";
		cout << endl << endl;
		SetThreadAffinityMask(GetCurrentThread(), 1 >> i);

		Rdmsr(0x198, &eax, &edx);
		int currentCoeff = ((eax>>8)&0xFF);
		int maxCoeff = ((edx>>8)&0xFF);

		cout << "Frequence lu : " << FormatFrequence(LireFrequenceCpu(1 >> i)) << " MHz" << endl;
		double frequence = FormatFrequence((LireFrequenceCpu(1 >> i)/maxCoeff)*currentCoeff);
		cout << "Frequence actuelle : " << frequence << " MHz" << endl;
		cout << "FSB : " << (frequence/currentCoeff) << " MHz" << endl << endl;
		
		cout << hex << "eax : " << eax << " edx : " << edx << dec << endl;
		cout << "Coefficient actuel : " << currentCoeff << endl;
		cout << "Coefficient max : " << maxCoeff << endl << endl << endl;
	}
	timeEndPeriod(1);