Compilers like GCC are deterministic and the source code already fully defines the behavior. LLMs are non-deterministic and will accept ambiguity, filling in details where you haven’t. These sorts of comparisons aren’t really fair.

In the case of writing, it’s like hiring someone to write a book for you vs. hiring someone to translate a book you wrote into another language. In the first case, you didn’t really define the message for readers, whereas in the second case you did, and the translator is converting that same message for another audience to consume.

Sure, but I don't know what GCC's behavior is, and I don't vet behavior differences between compiler upgrades. As long as the output works, why does it matter that the black box is deterministic?