|  | // g++ -O3 -DNDEBUG benchmarkX.cpp -o benchmarkX && time ./benchmarkX | 
|  |  | 
|  | #include <iostream> | 
|  | #include <Eigen/Core> | 
|  |  | 
|  | using namespace std; | 
|  | using namespace Eigen; | 
|  |  | 
|  | #ifndef VECTYPE | 
|  | #define VECTYPE VectorXLd | 
|  | #endif | 
|  |  | 
|  | #ifndef VECSIZE | 
|  | #define VECSIZE 1000000 | 
|  | #endif | 
|  |  | 
|  | #ifndef REPEAT | 
|  | #define REPEAT 1000 | 
|  | #endif | 
|  |  | 
|  | int main(int argc, char *argv[]) | 
|  | { | 
|  | VECTYPE I = VECTYPE::Ones(VECSIZE); | 
|  | VECTYPE m(VECSIZE,1); | 
|  | for(int i = 0; i < VECSIZE; i++) | 
|  | { | 
|  | m[i] = 0.1 * i/VECSIZE; | 
|  | } | 
|  | for(int a = 0; a < REPEAT; a++) | 
|  | { | 
|  | m = VECTYPE::Ones(VECSIZE) + 0.00005 * (m.cwise().square() + m/4); | 
|  | } | 
|  | cout << m[0] << endl; | 
|  | return 0; | 
|  | } |