[bregma]

But what if, and stick with me here, a compiler is capable of reading and processing your code and through simple scalar evolution of the conditionals and phi-reduction, it can't tell the difference between a switch statement and a sequence of if statements by the time it finishes its single static analysis phase?

It turns out the algorithmic complexity of a switch statement and the equivalent series of if-statements is identical. The bijective mapping between them is close to the identity function. Does a naive compiler exist that doesn't emit the same instructions for both, at least outside of toy hobby project compilers written by amateurs with no experience?

[smaudet]

The issue with if statements (for compiled languages) is not one of "speed" but of correctness.

If statements are unbounded, unconstrained logic constructs, whereas switch statements are type-checkable. The concern about missing break statements here is irrelevant, where your linter/compiler can warn about missing switch cases they can easily warn about non-terminated (non-explicitly marked as fall-through) cases.

For non-compiled languages (so branch prediction is not possible because the code is not even loaded), switch statements also provide a speed-up, i.e. the parser can immediately evaluate the branch to execute vs being forced to evaluate intermediate steps (and the conditions to each if statement can produce side-effects e.g. if(checkAndDo()) { ... } else if (checkAndDoB()) { ... } else if (checkAndDoC()) { ... }

Which, of course, is a potential use of if statements that switches cannot use (although side-effects are usually bad, if you listened to your CS profs)... And again a sort of "static analysis" guarantee that switches can provide that if statements cannot.