netprod does not support GPU

Hi, I have implemented an LSTM neural network using matlab. LSTM includes gates and i used netprod to implement them. It is running fine (but slow...) on the CPU.

I am trying to make it run on the GPU but netprod is not supported for GPU computations. I have implemented the LSTM using this blog post. below is what i have implemented.

Below is a crop of my network with red boxes showing the problematic parts:

Is there a way around it? I need something like netprod that runs on the GPU.

Thanks, Oshri