I’m a Rust newbie, wondering how f32::clone could show up in a profile. Wouldn’t that be an inline no-op under any kind of optimization? I mean, cloning a float is, at worst, a MOV instruction, no?
Once you’ve found a small enough chunk of logic that’s worth optimizing, I’d recommend relying more on benchmarks and disassembly.
The practical implication is that trying to optimize "calls to f32::clone" because they're in a profile is a wild goose chase -- unless you have debug anti-optimization turned on, there shouldn't be any calls to f32::clone.