// g++ -O3 -DNDEBUG benchmarkX.cpp -o benchmarkX && time ./benchmarkX #include #include using namespace std; using namespace Eigen; #ifndef REPEAT #define REPEAT 10000 #endif #ifndef SCALAR #define SCALAR float #endif int main(int argc, char *argv[]) { typedef Matrix Mat; Mat m(100, 100); m.setRandom(); for (int a = 0; a < REPEAT; a++) { int r, c, nr, nc; r = Eigen::internal::random(0, 10); c = Eigen::internal::random(0, 10); nr = Eigen::internal::random(50, 80); nc = Eigen::internal::random(50, 80); m.block(r, c, nr, nc) += Mat::Ones(nr, nc); m.block(r, c, nr, nc) *= SCALAR(10); m.block(r, c, nr, nc) -= Mat::constant(nr, nc, 10); m.block(r, c, nr, nc) /= SCALAR(10); } cout << m[0] << endl; return 0; }