Struct MoveEnv 

pub struct MoveEnv {
    pub free: RegSet,
    pub scratch_slot: Option<StackSlot>,
    pub victim_slot: Option<StackSlot>,
    pub swap: bool,
}

What the resolver may use besides the moves’ own locations.

Examples

use backend_lang::RegSet;
use backend_lang::mir::StackSlot;
use backend_lang::moves::MoveEnv;
use backend_lang::x86_64::R11;

let env = MoveEnv::new()
    .with_free(RegSet::of(&[R11]))
    .with_scratch_slot(StackSlot::new(4))
    .with_victim_slot(StackSlot::new(5));
assert!(env.free.contains(R11));

Fields

free: RegSet

Registers the caller guarantees are dead here and may be overwritten. Registers that are a source or destination of a move are ignored.

scratch_slot: Option<StackSlot>

A stack slot (of the largest class’s spill size) for a cycle’s saved value when no free register of its class exists.

victim_slot: Option<StackSlot>

A stack slot to save a borrowed register in, for a memory-to-memory move when no free register exists.

swap: bool

Whether register cycles may be resolved with swaps (honoured only on targets that have them). On by default.

Implementations

impl MoveEnv

pub const fn new() -> MoveEnv

No free registers, no slots, swaps allowed.

Examples

use backend_lang::moves::MoveEnv;

assert!(MoveEnv::new().free.is_empty());
assert!(MoveEnv::new().swap);

pub const fn with_free(self, free: RegSet) -> MoveEnv

With free as the free registers.

Examples

use backend_lang::RegSet;
use backend_lang::moves::MoveEnv;
use backend_lang::x86_64::R10;

assert!(MoveEnv::new().with_free(RegSet::of(&[R10])).free.contains(R10));

pub const fn with_scratch_slot(self, slot: StackSlot) -> MoveEnv

With slot as the scratch slot.

Examples

use backend_lang::mir::StackSlot;
use backend_lang::moves::MoveEnv;

let env = MoveEnv::new().with_scratch_slot(StackSlot::new(0));
assert_eq!(env.scratch_slot, Some(StackSlot::new(0)));

pub const fn with_victim_slot(self, slot: StackSlot) -> MoveEnv

With slot as the victim slot.

Examples

use backend_lang::mir::StackSlot;
use backend_lang::moves::MoveEnv;

let env = MoveEnv::new().with_victim_slot(StackSlot::new(1));
assert_eq!(env.victim_slot, Some(StackSlot::new(1)));

pub const fn with_swap(self, swap: bool) -> MoveEnv

With swaps allowed or not.

Examples

use backend_lang::moves::MoveEnv;

assert!(!MoveEnv::new().with_swap(false).swap);

Trait Implementations

impl Clone for MoveEnv

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for MoveEnv

impl Debug for MoveEnv

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

Formats the value using the given formatter.

impl Default for MoveEnv

fn default() -> MoveEnv

Returns the “default value” for a type.

impl Eq for MoveEnv

impl PartialEq for MoveEnv

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MoveEnv