eigen/bench/benchmarkX.cpp

// g++ -fopenmp -I .. -O3 -DNDEBUG -finline-limit=1000 benchmarkX.cpp -o b && time ./b

#include <iostream>

#include <Eigen/Core>

using namespace std;
using namespace Eigen;

#ifndef MATTYPE
#define MATTYPE MatrixXLd
#endif

#ifndef MATSIZE
#define MATSIZE 400
#endif

#ifndef REPEAT
#define REPEAT 100
#endif

int main(int argc, char *argv[]) {
  MATTYPE I = MATTYPE::Ones(MATSIZE, MATSIZE);
  MATTYPE m(MATSIZE, MATSIZE);
  for (int i = 0; i < MATSIZE; i++)
    for (int j = 0; j < MATSIZE; j++) {
      m(i, j) = (i + j + 1) / (MATSIZE * MATSIZE);
    }
  for (int a = 0; a < REPEAT; a++) {
    m = I + 0.0001 * (m + m * m);
  }
  cout << m(0, 0) << endl;
  return 0;
}