Clock Cycle Measurement

[classic_phone]

something i found interesting to share:
------------------------------------------------------------
//#put above main
extern __inline__ unsigned long long int rdtsc()
{
unsigned long long int x;
__asm__ volatile (".byte 0x0f, 0x31" : "=A" (x));
return x;
}

//#inside main
//#declare on top
unsigned long start, end;
//#before manipulation
start = rdtsc();
//#after manipulation
end = rdtsc();
//#to see output
cout << "Running Time : "
<< end - start << endl;

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u may try to use above partion of code to measure clock cycles needed to execute ur code. its sumthing similary to ordinary timer used in c++

[jonnin]

be careful with it, some newer cpu's vary their clock speed so clock cycles measured with the time stamp register are no longer directly one to one mapped to the CPU frequency for all machines.