Krioma.net

This is really more of a reminder for myself... how to draw random numbers fast in c/c++. (download [random.cpp]) and compile like so: g++ -O2 -o random random.cpp

#include ‹iostream›
#include ‹cmath›
#include ‹fstream›
#include ‹cstdlib›
using namespace std;
#define PI M_PI
#define RAD PI/180.0
#define SIG5 5.0*sig
#define SIG10 10.0*sig
#define SIG20 20.0*sig

unsigned long long int rdtsc();

int main (int argc, char* argv[]) //take in commandline arguements
{
int ii = 0;
srandom(rdtsc());
while (ii ‹ 100)
{
cout ‹‹ rand(); //RAND_MAX;
cout ‹‹ "\t";
cout ‹‹RAND_MAX;
cout ‹‹ "\n";
ii +=1;
}

return 0;
}

unsigned long long int rdtsc(void) //Call a Random number.
{
unsigned long long int x;
unsigned a, d;

__asm__ volatile("rdtsc" : "=a" (a), "=d" (d));

return ((unsigned long long)a) | (((unsigned long long)d) ‹‹ 32);;
}