Comment by tooltower
5 years ago
In particular, the author is talking about CPU registers being spilled to memory, and the need for setting up or tearing down stack frames. Those things can only be eliminated by the compiler for extremely simple functions. The error-handling often isn't.
If you really care about performance there’s no particular reason the whole stack has to be set up at function beginning/end. Compilers are not flexible enough about this, or other things like how they won’t store values in the frame pointer register on i386.
I believe the optimization to do this is called “shrink-wrapping”.