60     DenseMatrix refMat2  = DenseMatrix::Zero(rows, depth);  in sparse_product()
61     DenseMatrix refMat2t = DenseMatrix::Zero(depth, rows);  in sparse_product()
62     DenseMatrix refMat3  = DenseMatrix::Zero(depth, cols);  in sparse_product()
63     DenseMatrix refMat3t = DenseMatrix::Zero(cols, depth);  in sparse_product()
64     DenseMatrix refMat4  = DenseMatrix::Zero(rows, cols);  in sparse_product()
65     DenseMatrix refMat4t = DenseMatrix::Zero(cols, rows);  in sparse_product()
68     DenseMatrix dm4 = DenseMatrix::Zero(rows, rows);  in sparse_product()
144     DenseMatrix refM2 = DenseMatrix::Zero(rows, cols);  in sparse_product()
145     DenseMatrix refM3 = DenseMatrix::Zero(rows, cols);  in sparse_product()
146     DenseMatrix d3 = DenseMatrix::Zero(rows, cols);  in sparse_product()
180     DenseMatrix refUp = DenseMatrix::Zero(rows, rows);  in sparse_product()
181     DenseMatrix refLo = DenseMatrix::Zero(rows, rows);  in sparse_product()
182     DenseMatrix refS = DenseMatrix::Zero(rows, rows);  in sparse_product()