My point is, whatever it is, it can't possibly be a function call, so how would it ever legitimately show in a profile? I like pcwalton's theory. The practical

My point is, whatever it is, it can't possibly be a function call, so how would it ever legitimately show in a profile? I like pcwalton's theory. 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.