Struct Env 

pub struct Env { /* private fields */ }

What the allocator is allowed to use.

The order is the calling convention’s, because which register to hand out first follows from which ones a call destroys, and rucc-target is where a convention says so. The scratch registers are held back out of the order and are what a spilled value is read into at each instruction that wants it, so a class needs as many of them as one of its instructions has register operands. Nothing here uses them, since a spilled value is only read once the rewrite is writing the instruction that reads it, but they are held back here because this is what decides what everything else may have.

Implementations

impl Env

pub fn new() -> Self

An environment offering nothing, which is what a target that has said nothing offers.

pub fn with( self, class: RegClass, order: &[PhysReg], scratch: &[PhysReg], ) -> Self

The same environment, with that class described.

pub fn order(&self, class: RegClass) -> &[PhysReg]

The registers it may hand out in a class, in the order it prefers them.

pub fn scratch(&self, class: RegClass) -> &[PhysReg]

The registers held back in a class for reading a spilled value into.

Trait Implementations

impl Clone for Env

fn clone(&self) -> Env

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Env

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

Formats the value using the given formatter.

impl Default for Env

fn default() -> Env

Returns the “default value” for a type.