Ejemplo n.º 1
0
FLA_Error FLA_Svd_uv_unb_var1( dim_t n_iter_max, FLA_Obj A, FLA_Obj s, FLA_Obj U, FLA_Obj V, dim_t k_accum, dim_t b_alg )
{
    FLA_Error    r_val = FLA_SUCCESS;
    FLA_Datatype dt;
    FLA_Datatype dt_real;
    FLA_Datatype dt_comp;
    FLA_Obj      scale, T, S, rL, rR, d, e, G, H;
    dim_t        m_A, n_A;
    dim_t        min_m_n;
    dim_t        n_GH;
    double       crossover_ratio = 17.0 / 9.0;

    n_GH    = k_accum;

    m_A     = FLA_Obj_length( A );
    n_A     = FLA_Obj_width( A );
    min_m_n = FLA_Obj_min_dim( A );
    dt      = FLA_Obj_datatype( A );
    dt_real = FLA_Obj_datatype_proj_to_real( A );
    dt_comp = FLA_Obj_datatype_proj_to_complex( A );

    // Create matrices to hold block Householder transformations.
    FLA_Bidiag_UT_create_T( A, &T, &S );

    // Create vectors to hold the realifying scalars.
    FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rL );
    FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rR );

    // Create vectors to hold the diagonal and sub-diagonal.
    FLA_Obj_create( dt_real, min_m_n,      1, 0, 0, &d );
    FLA_Obj_create( dt_real, min_m_n-1,    1, 0, 0, &e );

    // Create matrices to hold the left and right Givens scalars.
    FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &G );
    FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &H );

    // Create a real scaling factor.
    FLA_Obj_create( dt_real, 1, 1, 0, 0, &scale );

    // Compute a scaling factor; If none is needed, sigma will be set to one.
    FLA_Svd_compute_scaling( A, scale );

    // Scale the matrix if scale is non-unit.
    if ( !FLA_Obj_equals( scale, FLA_ONE ) )
        FLA_Scal( scale, A );

    if ( m_A < crossover_ratio * n_A )
    {
        // Reduce the matrix to bidiagonal form.
        // Apply scalars to rotate elements on the superdiagonal to the real domain.
        // Extract the diagonal and superdiagonal from A.
        FLA_Bidiag_UT( A, T, S );
        FLA_Bidiag_UT_realify( A, rL, rR );
        FLA_Bidiag_UT_extract_real_diagonals( A, d, e );

        // Form U and V.
        FLA_Bidiag_UT_form_U( A, T, U );
        FLA_Bidiag_UT_form_V( A, S, V );

        // Apply the realifying scalars in rL and rR to U and V, respectively.
        {
            FLA_Obj UL, UR;
            FLA_Obj VL, VR;

            FLA_Part_1x2( U,   &UL, &UR,   min_m_n, FLA_LEFT );
            FLA_Part_1x2( V,   &VL, &VR,   min_m_n, FLA_LEFT );

            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, UL );
            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, VL );
        }

        // Perform a singular value decomposition on the bidiagonal matrix.
        r_val = FLA_Bsvd_v_opt_var1( n_iter_max, d, e, G, H, U, V, b_alg );
    }
    else // if ( crossover_ratio * n_A <= m_A )
    {
        FLA_Obj TQ, R;
        FLA_Obj AT,
                AB;
        FLA_Obj UL, UR;

        // Perform a QR factorization on A and form Q in U.
        FLA_QR_UT_create_T( A, &TQ );
        FLA_QR_UT( A, TQ );
        FLA_QR_UT_form_Q( A, TQ, U );
        FLA_Obj_free( &TQ );

        // Set the lower triangle of R to zero and then copy the upper
        // triangle of A to R.
        FLA_Part_2x1( A,   &AT,
                           &AB,   n_A, FLA_TOP );
        FLA_Obj_create( dt, n_A, n_A, 0, 0, &R );
        FLA_Setr( FLA_LOWER_TRIANGULAR, FLA_ZERO, R );
        FLA_Copyr( FLA_UPPER_TRIANGULAR, AT, R );

        // Reduce the matrix to bidiagonal form.
        // Apply scalars to rotate elements on the superdiagonal to the real domain.
        // Extract the diagonal and superdiagonal from A.
        FLA_Bidiag_UT( R, T, S );
        FLA_Bidiag_UT_realify( R, rL, rR );
        FLA_Bidiag_UT_extract_real_diagonals( R, d, e );

        // Form V from right Householder vectors in upper triangle of R.
        FLA_Bidiag_UT_form_V( R, S, V );

        // Form U in R.
        FLA_Bidiag_UT_form_U( R, T, R );

        // Apply the realifying scalars in rL and rR to U and V, respectively.
        FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, R );
        FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, V );

        // Perform a singular value decomposition on the bidiagonal matrix.
        r_val = FLA_Bsvd_v_opt_var1( n_iter_max, d, e, G, H, R, V, b_alg );

        // Multiply R into U, storing the result in A and then copying back
        // to U.
        FLA_Part_1x2( U,   &UL, &UR,   n_A, FLA_LEFT );
        FLA_Gemm( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                  FLA_ONE, UL, R, FLA_ZERO, A );
        FLA_Copy( A, UL );

        FLA_Obj_free( &R );
    }

    // Copy the converged eigenvalues to the output vector.
    FLA_Copy( d, s );

    // Sort the singular values and singular vectors in descending order.
    FLA_Sort_svd( FLA_BACKWARD, s, U, V );

    // If the matrix was scaled, rescale the singular values.
    if ( !FLA_Obj_equals( scale, FLA_ONE ) )
        FLA_Inv_scal( scale, s );

    FLA_Obj_free( &scale );
    FLA_Obj_free( &T );
    FLA_Obj_free( &S );
    FLA_Obj_free( &rL );
    FLA_Obj_free( &rR );
    FLA_Obj_free( &d );
    FLA_Obj_free( &e );
    FLA_Obj_free( &G );
    FLA_Obj_free( &H );

    return r_val;
}
Ejemplo n.º 2
0
FLA_Error REF_Svdd_uv_components( FLA_Obj A, FLA_Obj s, FLA_Obj U, FLA_Obj V,
                                  double* dtime_bred, double* dtime_bsvd, double* dtime_appq,
                                  double* dtime_qrfa, double* dtime_gemm )
/*
{
  *dtime_bred = 1;
  *dtime_bsvd = 1;
  *dtime_appq = 1;
  *dtime_qrfa = 1;
  *dtime_gemm = 1;

  return FLA_Svdd_external( FLA_SVD_VECTORS_ALL, A, s, U, V );
}
*/

{
  FLA_Datatype dt_A;
  FLA_Datatype dt_A_real;
  dim_t        m_A, n_A;
  dim_t        min_m_n;
  FLA_Obj      tq, tu, tv, d, e, Ur, Vr, W;
  FLA_Obj      eT, epsilonB;
  FLA_Uplo     uplo = FLA_UPPER_TRIANGULAR;
  double       crossover_ratio = 16.0 / 10.0;
  double       dtime_temp;

  dt_A      = FLA_Obj_datatype( A );
  dt_A_real = FLA_Obj_datatype_proj_to_real( A );
  m_A       = FLA_Obj_length( A );
  n_A       = FLA_Obj_width( A );

  min_m_n   = FLA_Obj_min_dim( A );

  FLA_Obj_create( dt_A,      min_m_n, 1,   0, 0, &tq );
  FLA_Obj_create( dt_A,      min_m_n, 1,   0, 0, &tu );
  FLA_Obj_create( dt_A,      min_m_n, 1,   0, 0, &tv );
  FLA_Obj_create( dt_A_real, min_m_n, 1,   0, 0, &d );
  FLA_Obj_create( dt_A_real, min_m_n, 1,   0, 0, &e );
  FLA_Obj_create( dt_A_real, n_A,     n_A, 0, 0, &Ur );
  FLA_Obj_create( dt_A_real, n_A,     n_A, 0, 0, &Vr );


  FLA_Part_2x1( e,   &eT,
                     &epsilonB,    1, FLA_BOTTOM );

  if ( m_A >= n_A )
  {
    if ( m_A < crossover_ratio * n_A )
    {
      dtime_temp = FLA_Clock();
      {
        // Reduce to bidiagonal form.
        FLA_Bidiag_blk_external( A, tu, tv );
        FLA_Bidiag_UT_extract_diagonals( A, d, eT );
      }
      *dtime_bred = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Divide-and-conquor algorithm.
        FLA_Bsvdd_external( uplo, d, e, Ur, Vr );
      }
      *dtime_bsvd = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Form U.
        FLA_Copy_external( Ur, U );
        FLA_Bidiag_apply_U_external( FLA_LEFT, FLA_NO_TRANSPOSE, A, tu, U );

        // Form V.
        FLA_Copy_external( Vr, V );
        FLA_Bidiag_apply_V_external( FLA_RIGHT, FLA_CONJ_TRANSPOSE, A, tv, V );
      }
      *dtime_appq = FLA_Clock() - dtime_temp;


      *dtime_qrfa = 0.0;
      *dtime_gemm = 0.0;
    }
    else
    {
      FLA_Obj AT,
              AB;
      FLA_Obj UL, UR;

      FLA_Part_2x1( A,   &AT,
                         &AB,        n_A, FLA_TOP );
      FLA_Part_1x2( U,   &UL, &UR,   n_A, FLA_LEFT );

      // Create a temporary n-by-n matrix R.
      FLA_Obj_create( dt_A, n_A, n_A, 0, 0, &W );

      dtime_temp = FLA_Clock();
      {
        // Perform a QR factorization.
        FLA_QR_blk_external( A, tq );
        FLA_Copyr_external( FLA_LOWER_TRIANGULAR, A, UL );
        FLA_Setr( FLA_LOWER_TRIANGULAR, FLA_ZERO, A );
      }
      *dtime_qrfa = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Form Q.
        FLA_QR_form_Q_external( U, tq );
      }
      *dtime_appq = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Reduce R to bidiagonal form.
        FLA_Bidiag_blk_external( AT, tu, tv );
        FLA_Bidiag_UT_extract_diagonals( A, d, eT );
      }
      *dtime_bred = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Divide-and-conquor algorithm.
        FLA_Bsvdd_external( uplo, d, e, Ur, Vr );
      }
      *dtime_bsvd = FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Form U in W.
        FLA_Copy_external( Ur, W );
        FLA_Bidiag_apply_U_external( FLA_LEFT, FLA_NO_TRANSPOSE, AT, tu, W );

        // Form V.
        FLA_Copy_external( Vr, V );
        FLA_Bidiag_apply_V_external( FLA_RIGHT, FLA_CONJ_TRANSPOSE, AT, tv, V );
      }
      *dtime_appq += FLA_Clock() - dtime_temp;


      dtime_temp = FLA_Clock();
      {
        // Multiply R into U, storing the result in A and then copying
        // back to U.
        FLA_Gemm_external( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                           FLA_ONE, UL, W, FLA_ZERO, A );
        FLA_Copy( A, UL );
      }
      *dtime_gemm = FLA_Clock() - dtime_temp;


      // Free R.
      FLA_Obj_free( &W );
    }
  }
  else
  {
    FLA_Check_error_code( FLA_NOT_YET_IMPLEMENTED );
  }

  // Copy singular values to output vector.
  FLA_Copy( d, s );

  // Sort singular values and vectors.
  FLA_Sort_svd( FLA_BACKWARD, s, U, V );

  FLA_Obj_free( &tq );
  FLA_Obj_free( &tu );
  FLA_Obj_free( &tv );
  FLA_Obj_free( &d );
  FLA_Obj_free( &e );
  FLA_Obj_free( &Ur );
  FLA_Obj_free( &Vr );

  return FLA_SUCCESS;
}
Ejemplo n.º 3
0
FLA_Error FLA_Svd_uv_var2_components( dim_t n_iter_max, dim_t k_accum, dim_t b_alg,
                                      FLA_Obj A, FLA_Obj s, FLA_Obj U, FLA_Obj V,
                                      double* dtime_bred, double* dtime_bsvd, double* dtime_appq,
                                      double* dtime_qrfa, double* dtime_gemm )
{
	FLA_Error    r_val = FLA_SUCCESS;
	FLA_Datatype dt;
	FLA_Datatype dt_real;
	FLA_Datatype dt_comp;
	FLA_Obj      T, S, rL, rR, d, e, G, H, RG, RH, W;
	dim_t        m_A, n_A;
	dim_t        min_m_n;
	dim_t        n_GH;
	double       crossover_ratio = 17.0 / 9.0;
	double       dtime_temp;

	n_GH    = k_accum;

	m_A     = FLA_Obj_length( A );
	n_A     = FLA_Obj_width( A );
	min_m_n = FLA_Obj_min_dim( A );
	dt      = FLA_Obj_datatype( A );
	dt_real = FLA_Obj_datatype_proj_to_real( A );
	dt_comp = FLA_Obj_datatype_proj_to_complex( A );

	// If the matrix is a scalar, then the SVD is easy.
	if ( min_m_n == 1 )
	{
		FLA_Copy( A, s );
		FLA_Set_to_identity( U );
		FLA_Set_to_identity( V );

		return FLA_SUCCESS;
	}

	// Create matrices to hold block Householder transformations.
	FLA_Bidiag_UT_create_T( A, &T, &S );

	// Create vectors to hold the realifying scalars.
	FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rL );
	FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rR );

	// Create vectors to hold the diagonal and sub-diagonal.
	FLA_Obj_create( dt_real, min_m_n,      1, 0, 0, &d );
	FLA_Obj_create( dt_real, min_m_n-1,    1, 0, 0, &e );

	// Create matrices to hold the left and right Givens scalars.
	FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &G );
	FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &H );

	// Create matrices to hold the left and right Givens matrices.
	FLA_Obj_create( dt_real, min_m_n, min_m_n, 0, 0, &RG );
	FLA_Obj_create( dt_real, min_m_n, min_m_n, 0, 0, &RH );
	FLA_Obj_create( dt,      m_A,     n_A,     0, 0, &W );

	if ( m_A >= n_A )
	{
		if ( m_A < crossover_ratio * n_A )
		{
			dtime_temp = FLA_Clock();
			{
			// Reduce the matrix to bidiagonal form.
			// Apply scalars to rotate elements on the sub-diagonal to the real domain.
			// Extract the diagonal and sub-diagonal from A.
			FLA_Bidiag_UT( A, T, S );
			FLA_Bidiag_UT_realify( A, rL, rR );
			FLA_Bidiag_UT_extract_diagonals( A, d, e );
			}
			*dtime_bred = FLA_Clock() - dtime_temp;

			dtime_temp = FLA_Clock();
			{
			// Form U and V.
			FLA_Bidiag_UT_form_U( A, T, U );
			FLA_Bidiag_UT_form_V( A, S, V );
			}
			*dtime_appq = FLA_Clock() - dtime_temp;

			// Apply the realifying scalars in rL and rR to U and V, respectively.
			{
				FLA_Obj UL, UR;
				FLA_Obj VL, VR;

				FLA_Part_1x2( U,   &UL, &UR,   min_m_n, FLA_LEFT );
				FLA_Part_1x2( V,   &VL, &VR,   min_m_n, FLA_LEFT );

				FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, UL );
				FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, VL );
			}

			dtime_temp = FLA_Clock();
			{
			// Perform a singular value decomposition on the bidiagonal matrix.
			r_val = FLA_Bsvd_v_opt_var2( n_iter_max, d, e, G, H, RG, RH, W, U, V, b_alg );
			}
			*dtime_bsvd = FLA_Clock() - dtime_temp;
		}
		else // if ( crossover_ratio * n_A <= m_A )
		{
			FLA_Obj TQ, R;
			FLA_Obj AT,
			        AB;
			FLA_Obj UL, UR;

			//FLA_QR_UT_create_T( A, &TQ );
			FLA_Obj_create( dt, 32, n_A, 0, 0, &TQ );

			dtime_temp = FLA_Clock();
			{
			// Perform a QR factorization on A and form Q in U.
			FLA_QR_UT( A, TQ );
			}
			*dtime_qrfa = FLA_Clock() - dtime_temp;

			dtime_temp = FLA_Clock();
			{
			FLA_QR_UT_form_Q( A, TQ, U );
			}
			*dtime_appq = FLA_Clock() - dtime_temp;

			FLA_Obj_free( &TQ );

			// Set the lower triangle of R to zero and then copy the upper
			// triangle of A to R.
			FLA_Part_2x1( A,   &AT,
			                   &AB,   n_A, FLA_TOP );
			FLA_Obj_create( dt, n_A, n_A, 0, 0, &R );
			FLA_Setr( FLA_LOWER_TRIANGULAR, FLA_ZERO, R );
			FLA_Copyr( FLA_UPPER_TRIANGULAR, AT, R );

			dtime_temp = FLA_Clock();
			{
			// Reduce the matrix to bidiagonal form.
			// Apply scalars to rotate elements on the superdiagonal to the real domain.
			// Extract the diagonal and superdiagonal from A.
			FLA_Bidiag_UT( R, T, S );
			FLA_Bidiag_UT_realify( R, rL, rR );
			FLA_Bidiag_UT_extract_diagonals( R, d, e );
			}
			*dtime_bred = FLA_Clock() - dtime_temp;

			dtime_temp = FLA_Clock();
			{
			// Form V from right Householder vectors in upper triangle of R.
			FLA_Bidiag_UT_form_V( R, S, V );

			// Form U in R.
			FLA_Bidiag_UT_form_U( R, T, R );
			}
			*dtime_appq += FLA_Clock() - dtime_temp;

			// Apply the realifying scalars in rL and rR to U and V, respectively.
			FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, R );
			FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, V );

			dtime_temp = FLA_Clock();
			{
			// Perform a singular value decomposition on the bidiagonal matrix.
			r_val = FLA_Bsvd_v_opt_var2( n_iter_max, d, e, G, H, RG, RH, W, R, V, b_alg );
			}
			*dtime_bsvd = FLA_Clock() - dtime_temp;

			dtime_temp = FLA_Clock();
			{
			// Multiply R into U, storing the result in A and then copying back
			// to U.
			FLA_Part_1x2( U,   &UL, &UR,   n_A, FLA_LEFT );
			FLA_Gemm( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
			          FLA_ONE, UL, R, FLA_ZERO, A );
			FLA_Copy( A, UL );
			}
			*dtime_gemm = FLA_Clock() - dtime_temp;

			FLA_Obj_free( &R );
		}
	}
	else // if ( m_A < n_A )
	{
		FLA_Check_error_code( FLA_NOT_YET_IMPLEMENTED );
	}

	// Copy the converged eigenvalues to the output vector.
	FLA_Copy( d, s );

	// Sort the singular values and singular vectors in descending order.
	FLA_Sort_svd( FLA_BACKWARD, s, U, V );

	FLA_Obj_free( &T );
	FLA_Obj_free( &S );
	FLA_Obj_free( &rL );
	FLA_Obj_free( &rR );
	FLA_Obj_free( &d );
	FLA_Obj_free( &e );
	FLA_Obj_free( &G );
	FLA_Obj_free( &H );
	FLA_Obj_free( &RG );
	FLA_Obj_free( &RH );
	FLA_Obj_free( &W );

	return r_val;
}
Ejemplo n.º 4
0
FLA_Error FLA_Svd_ext_u_unb_var1( FLA_Svd_type jobu, FLA_Svd_type jobv,
                                  dim_t n_iter_max,
                                  FLA_Obj A, FLA_Obj s, FLA_Obj U, FLA_Obj V,
                                  dim_t k_accum,
                                  dim_t b_alg )
{
    FLA_Error    r_val = FLA_SUCCESS;
    FLA_Datatype dt;
    FLA_Datatype dt_real;
    FLA_Datatype dt_comp;
    FLA_Obj      scale, T, S, rL, rR, d, e, G, H, C; // C is dummy.
    dim_t        m_A, n_A, min_m_n;
    dim_t        n_GH;
    double       crossover_ratio = 17.0 / 9.0;
    FLA_Bool     u_is_formed = FALSE, 
                 v_is_formed = FALSE;
    int          apply_scale;

    n_GH    = k_accum;

    m_A     = FLA_Obj_length( A );
    n_A     = FLA_Obj_width( A );
    min_m_n = min( m_A, n_A );
    dt      = FLA_Obj_datatype( A );
    dt_real = FLA_Obj_datatype_proj_to_real( A );
    dt_comp = FLA_Obj_datatype_proj_to_complex( A );

    // Create matrices to hold block Householder transformations.
    FLA_Bidiag_UT_create_T( A, &T, &S );

    // Create vectors to hold the realifying scalars.
    if ( FLA_Obj_is_complex( A ) )
    {
        FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rL );
        FLA_Obj_create( dt,      min_m_n,      1, 0, 0, &rR );
    }

    // Create vectors to hold the diagonal and sub-diagonal.
    FLA_Obj_create( dt_real, min_m_n,      1, 0, 0, &d );
    FLA_Obj_create( dt_real, min_m_n-1,    1, 0, 0, &e );

    // Create matrices to hold the left and right Givens scalars.
    FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &G );
    FLA_Obj_create( dt_comp, min_m_n-1, n_GH, 0, 0, &H );

    // Create a real scaling factor.
    FLA_Obj_create( dt_real, 1, 1, 0, 0, &scale );

    // Scale matrix A if necessary. 
    FLA_Max_abs_value( A, scale );
    apply_scale =
      ( FLA_Obj_gt( scale, FLA_OVERFLOW_SQUARE_THRES  ) == TRUE ) -     
      ( FLA_Obj_lt( scale, FLA_UNDERFLOW_SQUARE_THRES ) == TRUE ); 
    
    if ( apply_scale )
      FLA_Scal( apply_scale > 0 ? FLA_SAFE_MIN : FLA_SAFE_INV_MIN, A );   

    if ( m_A < crossover_ratio * n_A )
    {
        // Reduce the matrix to bidiagonal form.
        // Apply scalars to rotate elements on the superdiagonal to the real domain.
        // Extract the diagonal and superdiagonal from A.
        FLA_Bidiag_UT( A, T, S );
        if ( FLA_Obj_is_complex( A ) )
            FLA_Bidiag_UT_realify( A, rL, rR );
        FLA_Bidiag_UT_extract_real_diagonals( A, d, e );

        // Form U and V.
        if ( u_is_formed == FALSE )
        {
            switch ( jobu )
            {
            case FLA_SVD_VECTORS_MIN_OVERWRITE:
                if ( jobv != FLA_SVD_VECTORS_NONE )
                    FLA_Bidiag_UT_form_V_ext( FLA_UPPER_TRIANGULAR, A, S, FLA_NO_TRANSPOSE, V );
                v_is_formed = TRUE; // For this case, V should be formed here.
                U = A;
            case FLA_SVD_VECTORS_ALL:
            case FLA_SVD_VECTORS_MIN_COPY:
                FLA_Bidiag_UT_form_U_ext( FLA_UPPER_TRIANGULAR, A, T, FLA_NO_TRANSPOSE, U );
                u_is_formed = TRUE;
                break;
            case FLA_SVD_VECTORS_NONE:
                // Do nothing
                break;
            }
        }
        if ( v_is_formed == FALSE )
        {
            if ( jobv == FLA_SVD_VECTORS_MIN_OVERWRITE )
            {
                FLA_Bidiag_UT_form_V_ext( FLA_UPPER_TRIANGULAR, A, S, FLA_CONJ_TRANSPOSE, A );
                v_is_formed = TRUE; /* and */
                V = A; // This V is actually V^H.

                // V^H -> V
                FLA_Obj_flip_base( &V );
                FLA_Obj_flip_view( &V );
                if ( FLA_Obj_is_complex( A ) )
                    FLA_Conjugate( V );
            }
            else if ( jobv != FLA_SVD_VECTORS_NONE )
            {
                FLA_Bidiag_UT_form_V_ext( FLA_UPPER_TRIANGULAR, A, S, FLA_NO_TRANSPOSE, V );
                v_is_formed = TRUE;
            }
        }

        // For complex matrices, apply realification transformation.
        if ( FLA_Obj_is_complex( A ) && jobu != FLA_SVD_VECTORS_NONE )
        {
            FLA_Obj UL, UR;
            FLA_Part_1x2( U,   &UL, &UR,   min_m_n, FLA_LEFT );
            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, UL );
        }
        if ( FLA_Obj_is_complex( A ) && jobv != FLA_SVD_VECTORS_NONE )
        {
            FLA_Obj VL, VR;
            FLA_Part_1x2( V,   &VL, &VR,   min_m_n, FLA_LEFT );
            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, VL );
        }

        // Perform a singular value decomposition on the upper bidiagonal matrix.
        r_val = FLA_Bsvd_ext_opt_var1( n_iter_max,
                                       d, e, G, H,
                                       jobu, U, jobv, V,
                                       FALSE, C, // C is not referenced
                                       b_alg );
    }
    else // if ( crossover_ratio * n_A <= m_A )
    {
        FLA_Obj TQ, R;
        FLA_Obj AT,
                AB;

        // Perform a QR factorization on A.
        FLA_QR_UT_create_T( A, &TQ );
        FLA_QR_UT( A, TQ );

        // Set the lower triangle of R to zero and then copy the upper
        // triangle of A to R.
        FLA_Part_2x1( A,   &AT,
                           &AB,   n_A, FLA_TOP );
        FLA_Obj_create( dt, n_A, n_A, 0, 0, &R );
        FLA_Setr( FLA_LOWER_TRIANGULAR, FLA_ZERO, R );
        FLA_Copyr( FLA_UPPER_TRIANGULAR, AT, R );

        // Form U; if necessary overwrite on A.
        if ( u_is_formed == FALSE )
        {
            switch ( jobu )
            {
            case FLA_SVD_VECTORS_MIN_OVERWRITE:
                U = A;
            case FLA_SVD_VECTORS_ALL:
            case FLA_SVD_VECTORS_MIN_COPY:
                FLA_QR_UT_form_Q( A, TQ, U );
                u_is_formed = TRUE;
                break;
            case FLA_SVD_VECTORS_NONE:
                // Do nothing
                break;
            }
        }
        FLA_Obj_free( &TQ );

        // Reduce the matrix to bidiagonal form.
        // Apply scalars to rotate elements on the superdiagonal to the real domain.
        // Extract the diagonal and superdiagonal from A.
        FLA_Bidiag_UT( R, T, S );
        if ( FLA_Obj_is_complex( R ) )
            FLA_Bidiag_UT_realify( R, rL, rR );
        FLA_Bidiag_UT_extract_real_diagonals( R, d, e );

        if ( v_is_formed == FALSE )
        {
            if ( jobv == FLA_SVD_VECTORS_MIN_OVERWRITE )
            {
                FLA_Bidiag_UT_form_V_ext( FLA_UPPER_TRIANGULAR, R, S, FLA_CONJ_TRANSPOSE, AT );
                v_is_formed = TRUE; /* and */
                V = AT; // This V is actually V^H.

                // V^H -> V
                FLA_Obj_flip_base( &V );
                FLA_Obj_flip_view( &V );
                if ( FLA_Obj_is_complex( A ) )
                    FLA_Conjugate( V );
            }
            else if ( jobv != FLA_SVD_VECTORS_NONE )
            {
                FLA_Bidiag_UT_form_V_ext( FLA_UPPER_TRIANGULAR, R, S, FLA_NO_TRANSPOSE, V );
                v_is_formed = TRUE;
            }
        }

        // Apply householder vectors U in R.
        FLA_Bidiag_UT_form_U_ext( FLA_UPPER_TRIANGULAR, R, T, FLA_NO_TRANSPOSE, R );

        // Apply the realifying scalars in rL and rR to U and V, respectively.
        if ( FLA_Obj_is_complex( A ) && jobu != FLA_SVD_VECTORS_NONE )
        {
            FLA_Obj RL, RR;
            FLA_Part_1x2( R,   &RL, &RR,   min_m_n, FLA_LEFT );
            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_CONJUGATE,    rL, RL );
        }
        if ( FLA_Obj_is_complex( A ) && jobv != FLA_SVD_VECTORS_NONE )
        {
            FLA_Obj VL, VR;
            FLA_Part_1x2( V,   &VL, &VR,   min_m_n, FLA_LEFT );
            FLA_Apply_diag_matrix( FLA_RIGHT, FLA_NO_CONJUGATE, rR, VL );
        }

        // Perform a singular value decomposition on the bidiagonal matrix.
        r_val = FLA_Bsvd_ext_opt_var1( n_iter_max,
                                       d, e, G, H,
                                       jobu, R, jobv, V,
                                       FALSE, C,
                                       b_alg );

        // Multiply R into U, storing the result in A and then copying back
        // to U.
        if ( jobu != FLA_SVD_VECTORS_NONE )
        {
            FLA_Obj UL, UR;
            FLA_Part_1x2( U,   &UL, &UR,   min_m_n, FLA_LEFT );

            if ( jobu == FLA_SVD_VECTORS_MIN_OVERWRITE || 
                 jobv == FLA_SVD_VECTORS_MIN_OVERWRITE )
            {
                FLA_Obj_create_conf_to( FLA_NO_TRANSPOSE, UL, &C );
                FLA_Gemm( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                          FLA_ONE, UL, R, FLA_ZERO, C );
                FLA_Copy( C, UL );
                FLA_Obj_free( &C );
            }
            else
            {
                FLA_Gemm( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                          FLA_ONE, UL, R, FLA_ZERO, A );
                FLA_Copy( A, UL );
            }
        }
        FLA_Obj_free( &R );
    }

    // Copy the converged eigenvalues to the output vector.
    FLA_Copy( d, s );

    // No sort is required as it is applied on FLA_Bsvd.

    if ( apply_scale ) 
      FLA_Scal( apply_scale < 0 ? FLA_SAFE_MIN : FLA_SAFE_INV_MIN, s ); 

    // When V is overwritten, flip it again.
    if ( jobv == FLA_SVD_VECTORS_MIN_OVERWRITE )
    {
        // Always apply conjugation first wrt dimensions used; then, flip base.
        if ( FLA_Obj_is_complex( V ) )
            FLA_Conjugate( V );
        FLA_Obj_flip_base( &V );
    }

    FLA_Obj_free( &scale );
    FLA_Obj_free( &T );
    FLA_Obj_free( &S );

    if ( FLA_Obj_is_complex( A ) )
    {
        FLA_Obj_free( &rL );
        FLA_Obj_free( &rR );
    }

    FLA_Obj_free( &d );
    FLA_Obj_free( &e );
    FLA_Obj_free( &G );
    FLA_Obj_free( &H );

    return r_val;
}