Enum RegallocAlgorithm

#[non_exhaustive]
pub enum RegallocAlgorithm {
    Backtracking,
    SinglePass,
}

Possible register allocator algorithms for the Cranelift codegen backend.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Backtracking

Generates the fastest possible code, but may take longer.

This algorithm performs “backtracking”, which means that it may undo its earlier work and retry as it discovers conflicts. This results in better register utilization, producing fewer spills and moves, but can cause super-linear compile runtime.

SinglePass

Generates acceptable code very quickly.

This algorithm performs a single pass through the code, guaranteed to work in linear time. (Note that the rest of Cranelift is not necessarily guaranteed to run in linear time, however.) It cannot undo earlier decisions, however, and it cannot foresee constraints or issues that may occur further ahead in the code, so the code may have more spills and moves as a result.

Trait Implementations

impl Clone for RegallocAlgorithm

fn clone(&self) -> RegallocAlgorithm

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RegallocAlgorithm

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

Formats the value using the given formatter.

impl PartialEq for RegallocAlgorithm

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for RegallocAlgorithm

impl Eq for RegallocAlgorithm

impl StructuralPartialEq for RegallocAlgorithm