variable numthread in compute shader?

As far as I know we currently have no compute shader multiple variant compilation, like in general shaders (https://docs.unity3d.com/Manual/SL-MultipleProgramVariants.html).
However similar behaviour can be achieved with compute shader kernels, where you can write multiple compute programs.

For example:

Code (csharp):

1. #pragma kernel CSMainLowEnd
2. #pragma kernel CSMainHighEnd
3.  
4. void MyFunction(uint3 id) { ...}
5.  
6. [numthreads(8,8,1)]
7. void CSMainLowEnd (uint3 id : SV_DispatchThreadID) { MyFunction(id); }
8.  
9. [numthreads(16,16,1)]
10. void CSMainHighEnd (uint3 id : SV_DispatchThreadID) { MyFunction(id); }

And then you can dispatch the CSMainLowEnd or CSMainHighEnd depending on you requirements.