Struct Assignment 

pub struct Assignment { /* private fields */ }

Where every value in a function went.

Implementations

impl Assignment

pub fn empty(vregs: usize) -> Self

An assignment that says nothing yet about a function with that many values.

This and Assignment::put and Assignment::take_slot are how an allocator says what it decided. There will be a second one in M4 and it will not reach its answer this way, so what an assignment is has to be separable from how this file arrives at one, and the checker in crate::check reads an assignment without caring which allocator wrote it.

pub fn put(&mut self, reg: Reg, place: Place)

Records where a value went.

Panics

Panics on a physical register, which is somewhere already, and on a virtual one the function never handed out.

pub fn take_slot(&mut self, class: RegClass) -> u32

Takes a slot of the frame, of that class, and gives back which one it is.

Panics

Panics past four billion slots, which is a frame no machine has room for.

pub fn place(&self, reg: Reg) -> Option<Place>

Where a value lives, or None for a virtual register this function never mentions and for a physical one, which is already where it is.

pub fn slots(&self) -> &[RegClass]

The class of each slot of the frame, which is what says how wide it has to be.

pub fn spilled(&self) -> usize

How many values went to the stack.

Trait Implementations

impl Clone for Assignment

fn clone(&self) -> Assignment

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Assignment

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

Formats the value using the given formatter.