Курсовой Visual C++. Определение типа, скорости процессора

float CGettheProcessorSpeedDlg::ProcSpeedCalc()
{
/*
RdTSC:
It's the Pentium instruction "ReaD Time Stamp Counter". It measures the
number of clock cycles that have passed since the processor was reset, as a
64-bit number. That's what the <CODE>_emit lines do.*/
#define RdTSC __asm _emit 0x0f __asm _emit 0x31
 
// variables for the clock-cycles:
 
__int64 cyclesStart = 0, cyclesStop = 0;
// variables for the High-Res Preformance Counter:
 
unsigned __int64 nCtr = 0, nFreq = 0, nCtrStop = 0;
 
 
    // retrieve performance-counter frequency per second:
 
    if(!QueryPerformanceFrequency((LARGE_INTEGER *) &nFreq)) return 0;
 
    // retrieve the current value of the performance counter:
 
    QueryPerformanceCounter((LARGE_INTEGER *) &nCtrStop);
 
    // add the frequency to the counter-value:
 
    nCtrStop += nFreq;
 
 
    _asm
        {// retrieve the clock-cycles for the start value:
 
            RdTSC
            mov DWORD PTR cyclesStart, eax
            mov DWORD PTR [cyclesStart + 4], edx
        }
 
        do{
        // retrieve the value of the performance counter
 
        // until 1 sec has gone by:
 
             QueryPerformanceCounter((LARGE_INTEGER *) &nCtr);
          }while (nCtr < nCtrStop);
 
    _asm
        {// retrieve again the clock-cycles after 1 sec. has gone by:
 
            RdTSC
            mov DWORD PTR cyclesStop, eax
            mov DWORD PTR [cyclesStop + 4], edx
        }
 
// stop-start is speed in Hz divided by 1,000,000 is speed in MHz
 
return    ((float)cyclesStop-(float)cyclesStart) / 1000000;
}