T_LIBM_CHECK_NAN
T_LIBM_CHECK_NAN(i, acos, x[i]);
T_LIBM_CHECK_NAN(i, acosf, x[i]);
T_LIBM_CHECK_NAN(0, atan, T_LIBM_NAN);
T_LIBM_CHECK_NAN(0, atanf, T_LIBM_NAN);
T_LIBM_CHECK_NAN(0, exp2, T_LIBM_NAN);
T_LIBM_CHECK_NAN(0, exp2f, T_LIBM_NAN);