Struct LiveInterval 

pub struct LiveInterval {
    pub vreg: LcnfVarId,
    pub start: u32,
    pub end: u32,
    pub uses: Vec<u32>,
    pub defs: Vec<u32>,
    pub spill_weight: f64,
}

The live interval [start, end) of a virtual register.

start is the instruction index where the vreg is first defined, end is one past the last use.

Fields

vreg: LcnfVarId

The virtual register this interval belongs to.

start: u32

Inclusive start (def point).

end: u32

Exclusive end (last use + 1).

uses: Vec<u32>

All use points (instruction indices where this vreg is read).

defs: Vec<u32>

All def points (instruction indices where this vreg is written).

spill_weight: f64

Spill weight: higher = more costly to spill.

Implementations

impl LiveInterval

pub fn new(vreg: LcnfVarId, start: u32, end: u32) -> Self

Create a new live interval.

pub fn overlaps(&self, other: &LiveInterval) -> bool

Returns true if this interval overlaps with other.

pub fn length(&self) -> u32

Length of the live interval in instructions.

pub fn add_use(&mut self, pos: u32)

Add a use point.

pub fn add_def(&mut self, pos: u32)

Add a def point.

pub fn compute_spill_weight(&mut self)

Compute spill weight = total uses / length (more uses → costlier to spill).

Trait Implementations

impl Clone for LiveInterval

fn clone(&self) -> LiveInterval

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LiveInterval

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

Formats the value using the given formatter.

impl PartialEq for LiveInterval

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for LiveInterval