code: def gelu_grad(x):
      # CREDITS: Fast implementation proposed in
      # https://github.com/NVIDIA/Megatron-LM/blob/main/megatron/model/fused_bias_gelu.py#L30
      tanh_out = tanh(0.79788456 * x * (1 + 0.044715 * x * x))
      return 0.5 * x * (
          (1 - tanh_out * tanh_out)
          * (0.79788456 + 0.1070322243 * x * x)
      ) + 0.5 * (1 + tanh_out)
  
file_path: xformers/xformers/triton/k_activations.py
imports: import math
  from typing import Optional
  import triton
  import triton.language
  from xformers.components import Activation
label_desc: Use image node_id 13 for calling a global function with example usage: gelu_grad(x) and returns: unknown