Struct SingleUseConsts

Source

pub(crate) struct SingleUseConsts;

Expand description

Various parts of MIR building introduce temporaries that are commonly not needed.

Notably, if CONST and match CONST end up being used-once temporaries, which obfuscates the structure for other passes and codegen, which would like to always be able to just see the constant directly.

At higher optimization levels fancier passes like GVN will take care of this in a more general fashion, but this handles the easy cases so can run in debug.

This only removes constants with a single-use because re-evaluating constants isn’t always an improvement, especially for large ones.

It also removes never-used constants, since it had all the information needed to do that too, including updating the debug info.

SingleUseConsts

Struct SingleUseConsts Copy item path

Trait Implementations§

impl<'tcx> MirPass<'tcx> for SingleUseConsts

fn policy(&self, sess: &Session) -> PassPolicy

fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>)

fn name(&self) -> &'static str

fn profiler_name(&self) -> &'static str

fn is_mir_dump_enabled(&self) -> bool

Auto Trait Implementations§

impl DynSend for SingleUseConsts

impl DynSync for SingleUseConsts

impl Freeze for SingleUseConsts

impl RefUnwindSafe for SingleUseConsts

impl Send for SingleUseConsts

impl Sync for SingleUseConsts

impl Unpin for SingleUseConsts

impl UnsafeUnpin for SingleUseConsts

impl UnwindSafe for SingleUseConsts

Blanket Implementations§

impl<T> Aligned for T

const ALIGN: Alignment

impl<T> Any for Twhere T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Twhere T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T, R> CollectAndApply<T, R> for T

fn collect_and_apply<I, F>(iter: I, f: F) -> Rwhere I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

type Output = R

impl<T> ErasedDestructor for Twhere T: 'static,

impl<T> From<T> for T

fn from(t: T) -> T

impl<T> Instrument for T

fn instrument(self, span: Span) -> Instrumented<Self> ⓘ

fn in_current_span(self) -> Instrumented<Self> ⓘ

impl<T, U> Into<U> for Twhere U: From<T>,

fn into(self) -> U

impl<T> IntoEither for T

fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘwhere F: FnOnce(&Self) -> bool,

impl<K> IntoQueryKey<K> for K

fn into_query_key(self) -> K

impl<T> MaybeResult<T> for T

type Error = !

fn from(_: Result<T, <T as MaybeResult<T>>::Error>) -> T

fn to_result(self) -> Result<T, <T as MaybeResult<T>>::Error>

impl<T> Pointable for T

const ALIGN: usize

type Init = T

unsafe fn init(init: <T as Pointable>::Init) -> usize

unsafe fn deref<'a>(ptr: usize) -> &'a T

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

unsafe fn drop(ptr: usize)

impl<T> Same for T

type Output = T

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

impl<I, T, U> Upcast<I, U> for Twhere U: UpcastFrom<I, T>,

fn upcast(self, interner: I) -> U

impl<I, T> UpcastFrom<I, T> for T

fn upcast_from(from: T, _tcx: I) -> T

impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

fn vzip(self) -> V

impl<T> WithSubscriber for T

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> ⓘwhere S: Into<Dispatch>,

fn with_current_subscriber(self) -> WithDispatch<Self> ⓘ

Layout§

Struct SingleUseConsts

impl<T> Any for T
where T: 'static + ?Sized,

impl<T> Borrow<T> for T
where T: ?Sized,

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn collect_and_apply<I, F>(iter: I, f: F) -> R
where I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

impl<T> ErasedDestructor for T
where T: 'static,

impl<T, U> Into<U> for T
where U: From<T>,

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
where F: FnOnce(&Self) -> bool,

impl<T, U> TryFrom<U> for T
where U: Into<T>,

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> ⓘ
where S: Into<Dispatch>,