code: public static int cusolverDnSorgtr_bufferSize(
          cusolverDnHandle handle, 
          int uplo, 
          int n, 
          Pointer A, 
          int lda, 
          Pointer tau, 
          int[] lwork)
      {
          return checkResult(cusolverDnSorgtr_bufferSizeNative(handle, uplo, n, A, lda, tau, lwork));
      }
docs: generate unitary Q comes from sytrd