At least the Rust compiler (TFA's project is written in Rust) tries to configure LLVM specifically to avoid these discrepancies, and to treat all basic floating-point operations exactly as written with round-to-nearest behavior [0]. It does not have any of the -ffast-math options that the author('s LLM) is panicking about.

The main caveat is that on x86 targets without SSE2, LLVM is deeply wired to use the x87 instructions without attempting to emulate the IEEE overflow/underflow behavior [1]. So perhaps it could be possible to exhibit a discrepancy, but only by compiling for i586 and an ancient target-cpu. It's very doubtful that this was the cause of the original client vs. server issue in TFA's introduction.

[0] https://rust-lang.github.io/rfcs/3514-float-semantics.html

[1] https://github.com/rust-lang/rust/issues/114479