How can I write programs for the xbox and use its GPU?

Background
I've experimented with OpenCL with the C++ programming language on a Windows PC to write simple programs to a PC's GPU. In other words, I used it as a GPGPU. Under simple calculations I mean that I made two arrays, each containing 1 million items, than I added the corresponding parts of the two arrays.
So if I have X[1000000] and Y[1000000], then I would do:

for(int i=0; i<1000000; i++)
{
     Output[i]=X[i]+Y[i]
}

What do I want to do?
I want to do the same thing on the Xbox One S, as what I did on the PC. I want to write a program for the Xbox One S that normally runs on the cpu (I am NOT trying to create a program that I will force to run on the GPU). When it makes calculations that are like the one described above, it will load it in the GPU and the GPU will calculate it to increase speeds.

What did I already do on my Xbox?
I've already made UWP apps (coded in C++) on my Xbox. I wanted to continue writing my GPU programs using the UWP, but, however I didn't find any tutorial that explained how to do this.

What do I expect in the answer?
I want an answer that has a guide/tutorial linked or even in the answer that explains how to do this. The guide/tutorial (the solution to my program) has to be:

Written in C++
Preferably uses OpenCL, but this is not required, only if possible

What's my knowledge about these kinds of softwares?
I know Visual Studio C++ (MSVC) very well, so the most ideal would be if the guide/tutorial used MSVC. I also know a little about Unity, so I would also appreciate if the guide/tutorial would be about writing this in Unity (but also in C++). But if this isn't possible, any other tool would also work fine.

PS: I did a lot of research on this, but didn't find a guide/tutorial that explained this. That's why I'm asking here on Stack overflow. I'm pretty new to Stack overflow, so please do not just say (if this question is poorly written) "this answer doesn't meet the answer requirments.

Solution

You have to apply to the ID@Xbox program. To do this, you need a company. Applying to this program isn't just a fill-out-a-form-and-get-automatically-accepted thing. Microsoft will verify you. Microsoft doesn't want to give their software development kits to anybody mainly to prevent cheating in games. Unfortunately, this isn't possible any other way.