There isn't any pattern to them, just an arbitrary collection of values that covers more than 32 bits. About any would do. The two functions are so the optimization works on different types. Yes, there's nothing to test that the transformation actually happens, other than inspecting the generated code. I used to mechanically test the obj2asm output, but that was a maintenance nightmare and I gave up on it.

A unittest/typemock system would, of course, be much better.