It's not that people do better than compilers, it's just compilers often do badly. That's why checking disassembly in tight spots is the integral procedure in our team. Compilers and people together by definition do not worse than compilers alone.

Also, this is an odd choice of program to compare. Compilers often do suboptimal on superscalarisation, inlining, or simplifying control flow. In this example, there is not enough space to go wrong nor for a compiler neither for a programmer.