"run as written" implies targeting an abstract machine that performs operations the way programmer imagines it does. This machine isn't specified anywhere. The

"run as written" implies targeting an abstract machine that performs operations the way programmer imagines it does. This machine isn't specified anywhere. The hard part is that programmers don't imagine the code to be executed in a naive unoptimized way, but still expect it to be reasonably well optimized (converted to "obviously" equivalent assembly), except where optimizations combine into a result they haven't thought of.