Struct Slots 

pub struct Slots { /* private fields */ }

Which cell of the frame every local and every spill slot of a function is in.

Implementations

impl Slots

pub fn apart(locals: &[Local], widths: &[u32]) -> Self

The frame with nothing sharing anything: a cell of its own for every local and every spill slot, in the order the two lists are in.

This is the layout there was before this pass, and it is what a frame gets when nothing has asked for sharing and what it falls back to on a function with too many slots to pair up cheaply.

pub fn share( func: &Func, reach: &Reach, allocation: &Allocation, locals: &[Local], widths: &[u32], ) -> Self

The frame with everything that can share sharing, worked out from the allocator’s liveness.

reach is what reach said about this function before the allocator ran, widths is how many bytes a slot of each of the allocation’s spill slots takes, and locals is the function’s own objects in the order the lowering recorded them. func is the function the allocator has finished with, which is asked for the shape of its control flow and nothing else: the rewrite took the values away but it left every block and every edge where it was.

pub fn cells(&self) -> &[Cell]

The cells the frame is made of, which is what crate::frame places.

pub fn local(&self, local: usize) -> Option<usize>

Which cell a local is in.

pub fn slot(&self, slot: u32) -> Option<usize>

Which cell a spill slot is in.

pub fn saved(&self) -> usize

How many cells were saved by sharing, which is how many things went in beside something else.

This is a count rather than a number of bytes, because how many bytes it saved is the difference between two frames and a frame is not worked out here.

Trait Implementations

impl Clone for Slots

fn clone(&self) -> Slots

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Slots

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

Formats the value using the given formatter.

impl Default for Slots

fn default() -> Slots

Returns the “default value” for a type.

impl Eq for Slots

impl PartialEq for Slots

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Slots