For a long time, I assumed the recursive tail call optimization was a really smart optimization done by the compiler to transform a normal recursive call into a

For a long time, I assumed the recursive tail call optimization was a really smart optimization done by the compiler to transform a normal recursive call into a tall call. I was trying to figure out how a compiler could do that. Then later I learned that the optimization part is really done by human to transform the recursive call into a tail call. The "optimization" done by the compiler is relatively trivial in reusing the stack frame for the last function call.