elif activation_fn is nn_ops.relu:
        self.assertRegex(module_str, r'stablehlo.maximum.*\n.*return')
    else:
      # Check activation functions are implicit.
      self.assertNotRegex(module_str, r'stablehlo.clamp.*\n.*return')
      self.assertNotRegex(module_str, r'stablehlo.maximum.*\n.*return')

  @parameterized.parameters(
      testing.parameter_combinations([{
          'same_scale_op': (
              'concatenate',