Good alternative to bitwise operations

I'm trying to draw a simple 2D map using a shader like so



This was going really well until I tried to run an actual build. This is when I learned I can't use bitwise operators in my shader code ...

I'm currently using two bitmask parameters to determine where the walls should be drawn in. In this 3 x 5 grid map that I have there are 38 possible wall locations. I'd really prefer not to have wall1, wall2 ... wall38 different parameters passed in.

What is a good alternative to this?

 

You can use bitwise operators, but only when using DX10 or better. I think you need to compiler your shaders for target 3.5 (or better).

https://docs.unity3d.com/Manual/SL-ShaderCompileTargets.html
#pragma target 3.5

Alternatively: http://theinstructionlimit.com/encoding-boolean-flags-into-a-float-in-hlsl