> Incidentally, these 3 examples are also great at showing how compilers can be so very stupid at code generation. Observe that in all 3 cases, the return value

> Incidentally, these 3 examples are also great at showing how compilers can be so very stupid at code generation. Observe that in all 3 cases, the return value in eax after calling foo is written to memory --- then immediately read from memory again, into the exact same register. That's because code in article is compiled without optimizations. When you enable optimizations the compiler will do the right thing: https://godbolt.org/g/Lc7giO https://godbolt.org/g/Lc7giO