code: def hard_silu(x):
      """Hard SiLU activation function, also known as Hard Swish.
  
      It is defined as:
  
      - `0` if `if x < -3`
      - `x` if `x > 3`
      - `x * (x + 3) / 6` if `-3 <= x <= 3`
  
      It's a faster, piecewise linear approximation of the silu activation.
  
      Args:
          x: Input tensor.
  
      Reference:
  
      - [A Howard, 2019](https://arxiv.org/abs/1905.02244)
      """
      x = backend.convert_to_tensor(x)
      return ops.hard_silu(x)
  
imports: from keras import backend
  from keras import ops
  from keras.api_export import keras_export
label_desc: Use image node_id 15 for calling a global function with example usage: hard_silu(x) and returns: ops