alt Hacker NewsYou're not wrong but I think the point is to differentiate between the computer science "academic" answer and the engineering "pragmatic" answer. The former is concerned about correctly describing all possible behavior of the compiler, whereas the latter is concerned about what the actual experience is when using the compiler in practice.
You might argue that this is redefining the question in a way that changes the answer, but I'd argue that's also an academic objection; pragmatically, the important thing isn't the exact language but the intent behind the question, and for an engineer being asked this question, it's a lot more likely that the person asking has context for asking that cares about more than just the literal phrasing of "are compilers deterministic?"
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It matters a lot. For instance, many compilers will put time stamps in their output streams. This can mess up the downstream if your goal is a bit-by-bit identical piece of output across multiple environments.
And that's just one really low hanging fruit type of example, there are many more for instance selecting a different optimization path when memory pressure is high and so on.
> ... the important thing isn't the exact language but the intent behind the question ...
If we're not going to assume the input state is known then we definitely can't say what the intent behind the question is - for many engineering applications the compiler is deterministic. Debian has the whole reproducible builds thing going which has been a triumph of pragmatic engineering on a remarkable scale. And suggests that, pragmatically, compilers may be deterministic.