root/tests/blas_test.cpp @ 291

#include <itpp/itbase.h>
using namespace itpp;

//These lines are needed for use of cout and endl
using std::cout;
using std::endl;

//#define NDEBUG

mat matmul ( mat &A, mat &B ) {
        mat C ( A.rows(),B.cols() );
        int i,j,k;
        double sum;

        for ( i=0;i<A.rows();i++ ) {
                for ( j=0;j<A.cols();j++ ) {
                        sum = 0.0;
                        for ( k=0;k<A.cols();k++ ) {
                                sum+=A._elem ( i,k ) *B._elem ( k,j );
                        }
                        C ( i,j ) = sum;
                }
        }
        return C;
}

void matmul2 ( int n,  double *A, double *B, double *C ) {
        int i,j,k;
        double sum;

        for ( i=0;i<n;i++ ) {
                for ( j=0;j<n;j++ ) {
                        sum = 0.0;
                        for ( k=0;k<n;k++ ) {
                                sum+=A [ i*n+k ] * B [ k*n+j ];
                        }
                        C[ i*n+j] = sum;
                }
        }
//      return C;
}

int main() {
        Real_Timer tt;
        vec exec_times ( 4 );
        vec exec_times_b ( 4 );
        vec exec_times_c ( 4 );

        mat A;
        mat B;
        mat C;

        vec vn="5 50 200 500";
        int n;

        for ( int i=0;i<vn.length();i++ ) {
                n = vn ( i );
                A = randu ( n,n );
                B = randu ( n,n );

                tt.tic();
                for ( int ii=0;ii<10;ii++ ) {C = matmul ( A,B );}
                exec_times ( i ) =tt.toc();

                tt.tic();
                for ( int ii=0;ii<10;ii++ ) {C = A*B;}
                exec_times_b ( i ) =tt.toc();

                C = zeros(n,n);
                tt.tic();
                for ( int ii=0;ii<10;ii++ ) { matmul2(n,A._data(),B._data(),C._data());}
                exec_times_c ( i ) =tt.toc();
        }
        cout << exec_times <<endl;
        cout << exec_times_b <<endl;
        cout << exec_times_c <<endl;

        it_file itf ( "blas_test.it" );
        itf << Name ( "exec_times" ) <<exec_times;
        itf << Name ( "exec_times_b" ) <<exec_times_b;
        itf << Name ( "exec_times_c" ) <<exec_times_c;

        return 0;
}