Enum OptCost 

pub enum OptCost {
    Cheap = 0,
    Medium = 1,
    Heavy = 2,
}

How expensive an optimization pass is to RUN on the live path — the lever the tiered optimizer uses to decide WHEN (at which hotness tier) to pay for it. Orthogonal to MemClass (which is about the OUTPUT’s memory cost). The derived Ord makes a tier gate a single comparison: Cheap < Medium < Heavy is exactly the tier-inclusion order T1 ⊂ T2 ⊂ T3.

Variants

Cheap = 0

A single structural sweep, no fixpoint (inline, DCE, TCO).

Medium = 1

A whole-function analysis or one bounded fixpoint (GVN, LICM, oracle, fusion, the capped PE-light fixpoint).

Heavy = 2

A cloning / region-growing pass (the full PE fixpoint, unroll, scalarize, recursion unfold, equality saturation).

Trait Implementations

impl Clone for OptCost

fn clone(&self) -> OptCost

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for OptCost

impl Debug for OptCost

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for OptCost

impl Ord for OptCost

fn cmp(&self, other: &OptCost) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for OptCost

fn eq(&self, other: &OptCost) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for OptCost

fn partial_cmp(&self, other: &OptCost) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for OptCost