Struct DefUseChain 

pub struct DefUseChain {
    pub register: u8,
    pub definitions: SmallVec<[Definition; 4]>,
    pub uses: SmallVec<[Use; 8]>,
}

Definition-use chain for a register.

Tracks all definitions and uses of a register, enabling data flow optimizations.

Memory Optimization

• definitions and uses: Use SmallVec - typically small lists (most registers have few defs/uses)
• register: Uses u8 (PowerPC has 32 GPRs, fits in 5 bits)

Fields

register: u8

Register number (0-31 for PowerPC GPRs)

definitions: SmallVec<[Definition; 4]>

Definitions of this register (instructions that write to it) Uses SmallVec - most registers have few definitions

uses: SmallVec<[Use; 8]>

Uses of this register (instructions that read from it) Uses SmallVec - most registers have few uses

Trait Implementations

impl Clone for DefUseChain

fn clone(&self) -> DefUseChain

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DefUseChain

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

Formats the value using the given formatter.