Function chain_summary 

pub fn chain_summary(cast: Option<i32>, steps: &[ChainStep]) -> String

Name a chain by the operators it lowers to, in order: Mul+Add, Cast+Mul+Mul.

Not a fixed label like “Chain”. A count of steps says nothing about what a kernel computes, and neither does a category name; the operator sequence is exactly what the backend emits, so it is what the diagnostic reports.