Method backward

modules/commons/common_layers.py:475–478

(ctx, grad_output)

    @staticmethod
    def backward(ctx, grad_output):
        i = ctx.saved_variables[0]
        sigmoid_i = torch.sigmoid(i)
        return grad_output * (sigmoid_i * (1 + i * (1 - sigmoid_i)))


class CustomSwish(nn.Module):