C++ MAGMA_D_REAL函数代码示例

magma_int_t
magma_dfrobenius(
    magma_d_matrix A,
    magma_d_matrix B,
    real_Double_t *res,
    magma_queue_t queue ){

    real_Double_t tmp2;
    magma_int_t i,j,k;
    *res = 0.0;
    
    for(i=0; i<A.num_rows; i++){
        for(j=A.row[i]; j<A.row[i+1]; j++){
            magma_index_t localcol = A.col[j];
            for( k=B.row[i]; k<B.row[i+1]; k++){
                if(B.col[k] == localcol){
                    tmp2 = (real_Double_t) fabs( MAGMA_D_REAL(A.val[j] )
                                                    - MAGMA_D_REAL(B.val[k]) );

                    (*res) = (*res) + tmp2* tmp2;
                }
            }
        }
    }

    (*res) =  sqrt((*res));

    return MAGMA_SUCCESS;
}

magma_int_t
magma_dprint_csr(
    magma_int_t n_row,
    magma_int_t n_col,
    magma_int_t nnz,
    double **val,
    magma_index_t **row,
    magma_index_t **col,
    magma_queue_t queue )
{
    printf( "Matrix in CSR format (row col val)\n" );
    printf( " %d %d %d\n", int(n_row), int(n_col), int(nnz) );
     
    magma_index_t info = 0, i=0, j=0;

    for(i=0; i < n_col; i++) {
        magma_index_t rowtemp1 = (*row)[i];
        magma_index_t rowtemp2 = (*row)[i+1];
        for(j=0; j < rowtemp2 - rowtemp1; j++) {
                printf(" %d %d %.2f\n", (rowtemp1+1), (*col)[rowtemp1+j]+1,
                    MAGMA_D_REAL((*val)[rowtemp1+j]) );
        }
    }
    
    return info;
}

/** @return true if either real(x) or imag(x) is INF. */
inline bool magma_d_isinf( double x )
{
#ifdef COMPLEX
    return isinf( MAGMA_D_REAL( x )) ||
           isinf( MAGMA_D_IMAG( x ));
#else
    return isinf( x );
#endif
}

void magma_dmake_hpd( magma_int_t N, double* A, magma_int_t lda )
{
    magma_int_t i, j;
    for( i=0; i<N; ++i ) {
        A(i,i) = MAGMA_D_MAKE( MAGMA_D_REAL( A(i,i) ) + N, 0. );
        for( j=0; j<i; ++j ) {
            A(j,i) = MAGMA_D_CNJG( A(i,j) );
        }
    }
}

void init_matrix( magma_int_t N, double *h_A, magma_int_t lda )
{
    magma_int_t ione = 1, n2 = N*lda;
    magma_int_t ISEED[4] = {0,0,0,1};
    lapackf77_dlarnv( &ione, ISEED, &n2, h_A );
    /* Symmetrize and increase the diagonal */
    for (magma_int_t i = 0; i < N; ++i) {
        h_A(i,i) = MAGMA_D_MAKE( MAGMA_D_REAL(h_A(i,i)) + N, 0 );
        for (magma_int_t j = 0; j < i; ++j)
            h_A(i, j) = MAGMA_D_CNJG( h_A(j, i) );
    }
}

extern "C" magma_int_t
magma_dmdiff(
    magma_d_matrix A, magma_d_matrix B,
    real_Double_t *res,
    magma_queue_t queue )
{
    magma_int_t info = 0;
    
    if( A.memory_location == Magma_CPU && B.memory_location == Magma_CPU
            && A.storage_type == Magma_CSR && B.storage_type == Magma_CSR ){
        real_Double_t tmp2;
        magma_int_t i,j,k;
        *res = 0.0;
        
        for(i=0; i<A.num_rows; i++) {
            for(j=A.row[i]; j<A.row[i+1]; j++) {
                magma_index_t localcol = A.col[j];
                for( k=B.row[i]; k<B.row[i+1]; k++) {
                    if (B.col[k] == localcol) {
                        tmp2 = (real_Double_t) fabs( MAGMA_D_REAL(A.val[j] )
                                                        - MAGMA_D_REAL(B.val[k]) );
    
                        (*res) = (*res) + tmp2* tmp2;
                    }
                }
            }
        }

        (*res) =  sqrt((*res));
    }
    else{
        printf("error: mdiff only supported for CSR matrices on the CPU.\n");
        info = MAGMA_ERR_NOT_SUPPORTED;
    }
    return info;
}

extern "C" magma_int_t
magma_drowentries(
    magma_d_matrix *A,
    magma_queue_t queue )
{
    magma_int_t info = 0;
    
    magma_index_t *length=NULL;
    magma_index_t i,j, maxrowlength=0;
    
    // check whether matrix on CPU
    if ( A->memory_location == Magma_CPU ) {
        // CSR
        if ( A->storage_type == Magma_CSR ) {
            CHECK( magma_index_malloc_cpu( &length, A->num_rows));
            for( i=0; i<A->num_rows; i++ ) {
                length[i] = A->row[i+1]-A->row[i];
                if (length[i] > maxrowlength)
                     maxrowlength = length[i];
            }
            A->max_nnz_row = maxrowlength;
        }
        // Dense
        else if ( A->storage_type == Magma_DENSE ) {
            CHECK( magma_index_malloc_cpu( &length, A->num_rows));

            for( i=0; i<A->num_rows; i++ ) {
                length[i] = 0;
                for( j=0; j<A->num_cols; j++ ) {
                    if ( MAGMA_D_REAL( A->val[i*A->num_cols + j] ) != 0. )
                        length[i]++;
                    }
                if (length[i] > maxrowlength)
                     maxrowlength = length[i];
            }
            A->max_nnz_row = maxrowlength;
        }
    } // end CPU case

    else {
        printf("error: matrix not on CPU.\n");
        info = MAGMA_ERR_NOT_SUPPORTED;
    }
cleanup:
    magma_free( length );
    return info;
}

double *generate_sym_matrix(int m) {
 	double *a;
 	magma_int_t i,j;
 	magma_int_t mm = m*m;
 	magma_err_t err;
 	err = magma_dmalloc_cpu ( &a , mm );

 	magma_int_t ione = 1;
 	magma_int_t ISEED [4] = {0 ,0 ,0 ,1};
 	lapackf77_dlarnv (&ione ,ISEED ,&mm ,a);
 	for(i=0; i<m; i++) {
 		MAGMA_D_SET2REAL (a[i*m+i],( MAGMA_D_REAL (a[i*m+i ])+1.* m ) );
 		for (j=0; j<i; j++)
 			a[i*m+j] = (a[j*m+i]);
 	} 

 	return a;
}

void magma_dprint( int m, int n, double *A, int lda )
{
    double c_zero = MAGMA_D_ZERO;
    
    printf( "[\n" );
    for( int i = 0; i < m; ++i ) {
        for( int j = 0; j < n; ++j ) {
            if ( MAGMA_D_EQUAL( *A(i,j), c_zero )) {
                printf( "   0.    " );
            }
            else {
                printf( " %8.4f", MAGMA_D_REAL( *A(i,j) ));
            }
        }
        printf( "\n" );
    }
    printf( "];\n" );
}

static void
GeneratePlaneRotation(double dx, double dy, double *cs, double *sn)
{
#if defined(PRECISION_s) | defined(PRECISION_d)
    if (dy == MAGMA_D_ZERO) {
        *cs = MAGMA_D_ONE;
        *sn = MAGMA_D_ZERO;
    } else if (MAGMA_D_ABS((dy)) > MAGMA_D_ABS((dx))) {
        double temp = dx / dy;
        *sn = MAGMA_D_ONE / magma_dsqrt( ( MAGMA_D_ONE + temp*temp));
        *cs = temp * (*sn);
    } else {
        double temp = dy / dx;
        *cs = MAGMA_D_ONE / magma_dsqrt( ( MAGMA_D_ONE + temp*temp ));
        *sn = temp * (*cs);
    }
#else   
    // below the code Joss Knight from MathWorks provided me with - this works. 
    // No idea why the above code fails for real - maybe rounding.
    real_Double_t rho = sqrt(MAGMA_D_REAL(MAGMA_D_CONJ(dx)*dx + MAGMA_D_CONJ(dy)*dy));
    *cs = dx / rho;
    *sn = dy / rho;
#endif
}

magma_int_t
magma_dcg_merge( magma_d_sparse_matrix A, magma_d_vector b, magma_d_vector *x,  
           magma_d_solver_par *solver_par ){

    // prepare solver feedback
    solver_par->solver = Magma_CGMERGE;
    solver_par->numiter = 0;
    solver_par->info = 0; 

    // some useful variables
    double c_zero = MAGMA_D_ZERO, c_one = MAGMA_D_ONE;
    magma_int_t dofs = A.num_rows;

    // GPU stream
    magma_queue_t stream[2];
    magma_event_t event[1];
    magma_queue_create( &stream[0] );
    magma_queue_create( &stream[1] );
    magma_event_create( &event[0] );

    // GPU workspace
    magma_d_vector r, d, z;
    magma_d_vinit( &r, Magma_DEV, dofs, c_zero );
    magma_d_vinit( &d, Magma_DEV, dofs, c_zero );
    magma_d_vinit( &z, Magma_DEV, dofs, c_zero );
    
    double *d1, *d2, *skp;
    magma_dmalloc( &d1, dofs*(1) );
    magma_dmalloc( &d2, dofs*(1) );
    // array for the parameters
    magma_dmalloc( &skp, 6 );       // skp = [alpha|beta|gamma|rho|tmp1|tmp2]


    // solver variables
    double alpha, beta, gamma, rho, tmp1, *skp_h;
    double nom, nom0, r0, betanom, den;

    // solver setup
    magma_dscal( dofs, c_zero, x->val, 1) ;                     // x = 0
    magma_dcopy( dofs, b.val, 1, r.val, 1 );                    // r = b
    magma_dcopy( dofs, b.val, 1, d.val, 1 );                    // d = b
    nom0 = betanom = magma_dnrm2( dofs, r.val, 1 );               
    nom = nom0 * nom0;                                           // nom = r' * r
    magma_d_spmv( c_one, A, d, c_zero, z );                      // z = A d
    den = MAGMA_D_REAL( magma_ddot(dofs, d.val, 1, z.val, 1) ); // den = d'* z
    solver_par->init_res = nom0;
    
    // array on host for the parameters
    magma_dmalloc_cpu( &skp_h, 6 );

    alpha = rho = gamma = tmp1 = c_one; 
    beta =  magma_ddot(dofs, r.val, 1, r.val, 1);
    skp_h[0]=alpha; 
    skp_h[1]=beta; 
    skp_h[2]=gamma; 
    skp_h[3]=rho; 
    skp_h[4]=tmp1; 
    skp_h[5]=MAGMA_D_MAKE(nom, 0.0);

    magma_dsetvector( 6, skp_h, 1, skp, 1 );
    
    if ( (r0 = nom * solver_par->epsilon) < ATOLERANCE ) 
        r0 = ATOLERANCE;
    if ( nom < r0 )
        return MAGMA_SUCCESS;
    // check positive definite
    if (den <= 0.0) {
        printf("Operator A is not postive definite. (Ar,r) = %f\n", den);
        return -100;
    }
    
    //Chronometry
    real_Double_t tempo1, tempo2;
    magma_device_sync(); tempo1=magma_wtime();
    if( solver_par->verbose > 0 ){
        solver_par->res_vec[0] = (real_Double_t) nom0;
        solver_par->timing[0] = 0.0;
    }
    
    // start iteration
    for( solver_par->numiter= 1; solver_par->numiter<solver_par->maxiter; 
                                                    solver_par->numiter++ ){

        magmablasSetKernelStream(stream[0]);
        
        // computes SpMV and dot product
        magma_dcgmerge_spmv1(  A, d1, d2, d.val, z.val, skp ); 
            
        // updates x, r, computes scalars and updates d
        magma_dcgmerge_xrbeta( dofs, d1, d2, x->val, r.val, d.val, z.val, skp ); 

        // check stopping criterion (asynchronous copy)
        magma_dgetvector_async( 1 , skp+1, 1, 
                                                    skp_h+1, 1, stream[1] );
        betanom = sqrt(MAGMA_D_REAL(skp_h[1]));

        if( solver_par->verbose > 0 ){
            magma_device_sync(); tempo2=magma_wtime();
            if( (solver_par->numiter)%solver_par->verbose==0 ) {
                solver_par->res_vec[(solver_par->numiter)/solver_par->verbose] 
//.........这里部分代码省略.........

extern "C" magma_int_t
magma_dpbicgstab(
    magma_d_matrix A, magma_d_matrix b, magma_d_matrix *x,
    magma_d_solver_par *solver_par,
    magma_d_preconditioner *precond_par,
    magma_queue_t queue )
{
    magma_int_t info = 0;
    
    // set queue for old dense routines
    magma_queue_t orig_queue=NULL;
    magmablasGetKernelStream( &orig_queue );

    // prepare solver feedback
    solver_par->solver = Magma_PBICGSTAB;
    solver_par->numiter = 0;
    solver_par->info = MAGMA_SUCCESS;

    // some useful variables
    double c_zero = MAGMA_D_ZERO, c_one = MAGMA_D_ONE,
                                            c_mone = MAGMA_D_NEG_ONE;
    
    magma_int_t dofs = A.num_rows*b.num_cols;

    // workspace
    magma_d_matrix r={Magma_CSR}, rr={Magma_CSR}, p={Magma_CSR}, v={Magma_CSR}, s={Magma_CSR}, t={Magma_CSR}, ms={Magma_CSR}, mt={Magma_CSR}, y={Magma_CSR}, z={Magma_CSR};
    CHECK( magma_dvinit( &r, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &rr,Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &p, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &v, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &s, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &t, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &ms,Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &mt,Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &y, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &z, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));

    
    // solver variables
    double alpha, beta, omega, rho_old, rho_new;
    double nom, betanom, nom0, r0, den, res;

    // solver setup
    CHECK(  magma_dresidualvec( A, b, *x, &r, &nom0, queue));
    magma_dcopy( dofs, r.dval, 1, rr.dval, 1 );                  // rr = r
    betanom = nom0;
    nom = nom0*nom0;
    rho_new = omega = alpha = MAGMA_D_MAKE( 1.0, 0. );
    solver_par->init_res = nom0;

    CHECK( magma_d_spmv( c_one, A, r, c_zero, v, queue ));              // z = A r
    den = MAGMA_D_REAL( magma_ddot(dofs, v.dval, 1, r.dval, 1) ); // den = z' * r

    if ( (r0 = nom * solver_par->epsilon) < ATOLERANCE )
        r0 = ATOLERANCE;
    if ( nom < r0 ) {
        solver_par->final_res = solver_par->init_res;
        solver_par->iter_res = solver_par->init_res;
        goto cleanup;
    }

    //Chronometry
    real_Double_t tempo1, tempo2;
    tempo1 = magma_sync_wtime( queue );
    if ( solver_par->verbose > 0 ) {
        solver_par->res_vec[0] = nom0;
        solver_par->timing[0] = 0.0;
    }

    solver_par->numiter = 0;
    // start iteration
    do
    {
        solver_par->numiter++;
        rho_old = rho_new;                                   // rho_old=rho
        rho_new = magma_ddot( dofs, rr.dval, 1, r.dval, 1 );  // rho=<rr,r>
        beta = rho_new/rho_old * alpha/omega;   // beta=rho/rho_old *alpha/omega
        magma_dscal( dofs, beta, p.dval, 1 );                 // p = beta*p
        magma_daxpy( dofs, c_mone * omega * beta, v.dval, 1 , p.dval, 1 );
                                                        // p = p-omega*beta*v
        magma_daxpy( dofs, c_one, r.dval, 1, p.dval, 1 );      // p = p+r

        // preconditioner
        CHECK( magma_d_applyprecond_left( A, p, &mt, precond_par, queue ));
        CHECK( magma_d_applyprecond_right( A, mt, &y, precond_par, queue ));

        CHECK( magma_d_spmv( c_one, A, y, c_zero, v, queue ));      // v = Ap

        alpha = rho_new / magma_ddot( dofs, rr.dval, 1, v.dval, 1 );
        magma_dcopy( dofs, r.dval, 1 , s.dval, 1 );            // s=r
        magma_daxpy( dofs, c_mone * alpha, v.dval, 1 , s.dval, 1 ); // s=s-alpha*v

        // preconditioner
        CHECK( magma_d_applyprecond_left( A, s, &ms, precond_par, queue ));
        CHECK( magma_d_applyprecond_right( A, ms, &z, precond_par, queue ));

        CHECK( magma_d_spmv( c_one, A, z, c_zero, t, queue ));       // t=As

        // preconditioner
        CHECK( magma_d_applyprecond_left( A, s, &ms, precond_par, queue ));
//.........这里部分代码省略.........

extern "C" magma_int_t
magma_dcg(
    magma_d_matrix A, magma_d_matrix b, magma_d_matrix *x,
    magma_d_solver_par *solver_par,
    magma_queue_t queue )
{
    magma_int_t info = 0;
    
    // set queue for old dense routines
    magma_queue_t orig_queue=NULL;
    magmablasGetKernelStream( &orig_queue );

    // prepare solver feedback
    solver_par->solver = Magma_CG;
    solver_par->numiter = 0;
    solver_par->info = MAGMA_SUCCESS;

    // local variables
    double c_zero = MAGMA_D_ZERO, c_one = MAGMA_D_ONE;
    
    magma_int_t dofs = A.num_rows * b.num_cols;

    // GPU workspace
    magma_d_matrix r={Magma_CSR}, p={Magma_CSR}, q={Magma_CSR};
    CHECK( magma_dvinit( &r, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &p, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    CHECK( magma_dvinit( &q, Magma_DEV, A.num_rows, b.num_cols, c_zero, queue ));
    
    // solver variables
    double alpha, beta;
    double nom, nom0, r0, betanom, betanomsq, den;

    // solver setup
    CHECK(  magma_dresidualvec( A, b, *x, &r, &nom0, queue));
    magma_dcopy( dofs, r.dval, 1, p.dval, 1 );                    // p = r
    betanom = nom0;
    nom  = nom0 * nom0;                                // nom = r' * r
    CHECK( magma_d_spmv( c_one, A, p, c_zero, q, queue ));             // q = A p
    den = MAGMA_D_REAL( magma_ddot(dofs, p.dval, 1, q.dval, 1) );// den = p dot q
    solver_par->init_res = nom0;
    
    if ( (r0 = nom * solver_par->epsilon) < ATOLERANCE )
        r0 = ATOLERANCE;
    if ( nom < r0 ) {
        solver_par->final_res = solver_par->init_res;
        solver_par->iter_res = solver_par->init_res;
        goto cleanup;
    }
    // check positive definite
    if (den <= 0.0) {
        printf("Operator A is not postive definite. (Ar,r) = %f\n", den);
        magmablasSetKernelStream( orig_queue );
        info = MAGMA_NONSPD; 
        goto cleanup;
    }

    //Chronometry
    real_Double_t tempo1, tempo2;
    tempo1 = magma_sync_wtime( queue );
    if ( solver_par->verbose > 0 ) {
        solver_par->res_vec[0] = (real_Double_t)nom0;
        solver_par->timing[0] = 0.0;
    }
    
    solver_par->numiter = 0;
    // start iteration
    do
    {
        solver_par->numiter++;
        alpha = MAGMA_D_MAKE(nom/den, 0.);
        magma_daxpy(dofs,  alpha, p.dval, 1, x->dval, 1);     // x = x + alpha p
        magma_daxpy(dofs, -alpha, q.dval, 1, r.dval, 1);      // r = r - alpha q
        betanom = magma_dnrm2(dofs, r.dval, 1);             // betanom = || r ||
        betanomsq = betanom * betanom;                      // betanoms = r' * r

        if ( solver_par->verbose > 0 ) {
            tempo2 = magma_sync_wtime( queue );
            if ( (solver_par->numiter)%solver_par->verbose==0 ) {
                solver_par->res_vec[(solver_par->numiter)/solver_par->verbose]
                        = (real_Double_t) betanom;
                solver_par->timing[(solver_par->numiter)/solver_par->verbose]
                        = (real_Double_t) tempo2-tempo1;
            }
        }

        if (  betanom  < r0 ) {
            break;
        }

        beta = MAGMA_D_MAKE(betanomsq/nom, 0.);           // beta = betanoms/nom
        magma_dscal(dofs, beta, p.dval, 1);                // p = beta*p
        magma_daxpy(dofs, c_one, r.dval, 1, p.dval, 1);     // p = p + r
        CHECK( magma_d_spmv( c_one, A, p, c_zero, q, queue ));   // q = A p
        den = MAGMA_D_REAL(magma_ddot(dofs, p.dval, 1, q.dval, 1));
                // den = p dot q
        nom = betanomsq;
    }
    while ( solver_par->numiter+1 <= solver_par->maxiter );
    
    tempo2 = magma_sync_wtime( queue );
//.........这里部分代码省略.........

/* ////////////////////////////////////////////////////////////////////////////
   -- Testing dgeqrf_mgpu
*/
int main( int argc, char** argv )
{
    TESTING_INIT();

    real_Double_t    gflops, gpu_perf, gpu_time, cpu_perf=0, cpu_time=0;
    double           error, work[1];
    double c_neg_one = MAGMA_D_NEG_ONE;
    double *h_A, *h_R, *tau, *h_work, tmp[1];
    double *d_lA[ MagmaMaxGPUs ];
    magma_int_t M, N, n2, lda, ldda, n_local, ngpu;
    magma_int_t info, min_mn, nb, lhwork;
    magma_int_t ione     = 1;
    magma_int_t ISEED[4] = {0,0,0,1}, ISEED2[4];

    magma_opts opts;
    parse_opts( argc, argv, &opts );
    opts.lapack |= (opts.check == 2);  // check (-c2) implies lapack (-l)

    magma_int_t status = 0;
    double tol, eps = lapackf77_dlamch("E");
    tol = opts.tolerance * eps;

    printf("ngpu %d\n", (int) opts.ngpu );
    if ( opts.check == 1 ) {
        printf("  M     N     CPU GFlop/s (sec)   GPU GFlop/s (sec)   ||R-Q'A||_1 / (M*||A||_1) ||I-Q'Q||_1 / M\n");
        printf("================================================================================================\n");

    } else {
        printf("    M     N   CPU GFlop/s (sec)   GPU GFlop/s (sec)   ||R||_F /(M*||A||_F)\n");
        printf("==========================================================================\n");
    }
    for( int i = 0; i < opts.ntest; ++i ) {
        for( int iter = 0; iter < opts.niter; ++iter ) {
            M = opts.msize[i];
            N = opts.nsize[i];
            min_mn = min(M, N);
            lda    = M;
            n2     = lda*N;
            ldda   = ((M+31)/32)*32;
            nb     = magma_get_dgeqrf_nb( M );
            gflops = FLOPS_DGEQRF( M, N ) / 1e9;

            // ngpu must be at least the number of blocks
            ngpu = min( opts.ngpu, int((N+nb-1)/nb) );
            if ( ngpu < opts.ngpu ) {
                printf( " * too many GPUs for the matrix size, using %d GPUs\n", (int) ngpu );
            }

            // query for workspace size
            lhwork = -1;
            lapackf77_dgeqrf( &M, &N, h_A, &M, tau, tmp, &lhwork, &info );
            lhwork = (magma_int_t) MAGMA_D_REAL( tmp[0] );

            // Allocate host memory for the matrix
            TESTING_MALLOC(    tau,    double, min_mn );
            TESTING_MALLOC(    h_A,    double, n2     );
            TESTING_HOSTALLOC( h_R,    double, n2     );
            TESTING_MALLOC(    h_work, double, lhwork );

            // Allocate device memory
            for( int dev = 0; dev < ngpu; dev++ ) {
                n_local = ((N/nb)/ngpu)*nb;
                if (dev < (N/nb) % ngpu)
                    n_local += nb;
                else if (dev == (N/nb) % ngpu)
                    n_local += N % nb;
                magma_setdevice( dev );
                TESTING_DEVALLOC(  d_lA[dev], double, ldda*n_local );
            }

            /* Initialize the matrix */
            for ( int j=0; j<4; j++ ) ISEED2[j] = ISEED[j]; // saving seeds
            lapackf77_dlarnv( &ione, ISEED, &n2, h_A );
            lapackf77_dlacpy( MagmaUpperLowerStr, &M, &N, h_A, &lda, h_R, &lda );

            /* =====================================================================
               Performs operation using LAPACK
               =================================================================== */
            if ( opts.lapack ) {
                double *tau;
                TESTING_MALLOC( tau, double, min_mn );
                cpu_time = magma_wtime();
                lapackf77_dgeqrf( &M, &N, h_A, &M, tau, h_work, &lhwork, &info );
                cpu_time = magma_wtime() - cpu_time;
                cpu_perf = gflops / cpu_time;
                if (info != 0)
                    printf("lapack_dgeqrf returned error %d: %s.\n",
                           (int) info, magma_strerror( info ));
                TESTING_FREE( tau );
            }

            /* ====================================================================
               Performs operation using MAGMA
               =================================================================== */
            magma_dsetmatrix_1D_col_bcyclic( M, N, h_R, lda, d_lA, ldda, ngpu, nb );

            gpu_time = magma_wtime();
//.........这里部分代码省略.........

/* ////////////////////////////////////////////////////////////////////////////
   -- Testing dgels
*/
int main( int argc, char** argv )
{
    TESTING_INIT();
    
    real_Double_t    gflops, gpu_perf, gpu_time, cpu_perf, cpu_time;
    double           gpu_error, cpu_error, error, Anorm, work[1];
    double  c_one     = MAGMA_D_ONE;
    double  c_neg_one = MAGMA_D_NEG_ONE;
    double *h_A, *h_A2, *h_B, *h_X, *h_R, *tau, *h_work, tmp[1];
    magmaDouble_ptr d_A, d_B;
    magma_int_t M, N, size, nrhs, lda, ldb, ldda, lddb, min_mn, max_mn, nb, info;
    magma_int_t lworkgpu, lhwork;
    magma_int_t ione     = 1;
    magma_int_t ISEED[4] = {0,0,0,1};

    magma_opts opts;
    opts.parse_opts( argc, argv );
 
    magma_int_t status = 0;
    double tol = opts.tolerance * lapackf77_dlamch("E");

    nrhs = opts.nrhs;
    
    printf("%%                                                           ||b-Ax|| / (N||A||)   ||dx-x||/(N||A||)\n");
    printf("%%   M     N  NRHS   CPU Gflop/s (sec)   GPU Gflop/s (sec)   CPU        GPU                         \n");
    printf("%%==================================================================================================\n");
    for( int itest = 0; itest < opts.ntest; ++itest ) {
        for( int iter = 0; iter < opts.niter; ++iter ) {
            M = opts.msize[itest];
            N = opts.nsize[itest];
            if ( M < N ) {
                printf( "%5d %5d %5d   skipping because M < N is not yet supported.\n", (int) M, (int) N, (int) nrhs );
                continue;
            }
            min_mn = min(M, N);
            max_mn = max(M, N);
            lda    = M;
            ldb    = max_mn;
            ldda   = magma_roundup( M, opts.align );  // multiple of 32 by default
            lddb   = magma_roundup( max_mn, opts.align );  // multiple of 32 by default
            nb     = magma_get_dgeqrf_nb( M, N );
            gflops = (FLOPS_DGEQRF( M, N ) + FLOPS_DGEQRS( M, N, nrhs )) / 1e9;
            
            lworkgpu = (M - N + nb)*(nrhs + nb) + nrhs*nb;
            
            // query for workspace size
            lhwork = -1;
            lapackf77_dgels( MagmaNoTransStr, &M, &N, &nrhs,
                             NULL, &lda, NULL, &ldb, tmp, &lhwork, &info );
            lhwork = (magma_int_t) MAGMA_D_REAL( tmp[0] );
            lhwork = max( lhwork, lworkgpu );
            
            TESTING_MALLOC_CPU( tau,    double, min_mn    );
            TESTING_MALLOC_CPU( h_A,    double, lda*N     );
            TESTING_MALLOC_CPU( h_A2,   double, lda*N     );
            TESTING_MALLOC_CPU( h_B,    double, ldb*nrhs  );
            TESTING_MALLOC_CPU( h_X,    double, ldb*nrhs  );
            TESTING_MALLOC_CPU( h_R,    double, ldb*nrhs  );
            TESTING_MALLOC_CPU( h_work, double, lhwork    );
            
            TESTING_MALLOC_DEV( d_A,    double, ldda*N    );
            TESTING_MALLOC_DEV( d_B,    double, lddb*nrhs );
            
            /* Initialize the matrices */
            size = lda*N;
            lapackf77_dlarnv( &ione, ISEED, &size, h_A );
            lapackf77_dlacpy( MagmaFullStr, &M, &N, h_A, &lda, h_A2, &lda );
            
            // make random RHS
            size = ldb*nrhs;
            lapackf77_dlarnv( &ione, ISEED, &size, h_B );
            lapackf77_dlacpy( MagmaFullStr, &M, &nrhs, h_B, &ldb, h_R, &ldb );
            
            // make consistent RHS
            //size = N*nrhs;
            //lapackf77_dlarnv( &ione, ISEED, &size, h_X );
            //blasf77_dgemm( MagmaNoTransStr, MagmaNoTransStr, &M, &nrhs, &N,
            //               &c_one,  h_A, &lda,
            //                        h_X, &ldb,
            //               &c_zero, h_B, &ldb );
            //lapackf77_dlacpy( MagmaFullStr, &M, &nrhs, h_B, &ldb, h_R, &ldb );
            
            /* ====================================================================
               Performs operation using MAGMA
               =================================================================== */
            magma_dsetmatrix( M, N,    h_A, lda, d_A, ldda );
            magma_dsetmatrix( M, nrhs, h_B, ldb, d_B, lddb );
            
            gpu_time = magma_wtime();
            magma_dgels_gpu( MagmaNoTrans, M, N, nrhs, d_A, ldda,
                             d_B, lddb, h_work, lworkgpu, &info );
            gpu_time = magma_wtime() - gpu_time;
            gpu_perf = gflops / gpu_time;
            if (info != 0) {
                printf("magma_dgels_gpu returned error %d: %s.\n",
                       (int) info, magma_strerror( info ));
            }
//.........这里部分代码省略.........