This is definitely obsessive, but I am fascinated by how cleverly the compiler translates C code into machine instructions. Since I am a little fuzzy on some instructions, it
It's possible to use Xcode's step over, step in, and step out commands with the debugger. The trick is to hold the ctrl (Control) key while you mouse over the debugger step icons to change the context. Underneath each step icon, the line will change to a dot and you can then step at the instruction level.
See the attached screenshot highlighted with a red oval.