Enum BackendRepr

pub enum BackendRepr {
    Uninhabited,
    Scalar(Scalar),
    ScalarPair(Scalar, Scalar),
    Vector {
        element: Scalar,
        count: u64,
    },
    Memory {
        sized: bool,
    },
}

The way we represent values to the backend

Previously this was conflated with the “ABI” a type is given, as in the platform-specific ABI. In reality, this implies little about that, but is mostly used to describe the syntactic form emitted for the backend, as most backends handle SSA values and blobs of memory differently. The psABI may need consideration in doing so, but this enum does not constitute a promise for how the value will be lowered to the calling convention, in itself.

Generally, a codegen backend will prefer to handle smaller values as a scalar or short vector, and larger values will usually prefer to be represented as memory.

Variants

Uninhabited

Scalar(Scalar)

ScalarPair(Scalar, Scalar)

Vector

Fields

element: Scalar

count: u64

Memory

Fields

sized: bool

If true, the size is exact, otherwise it’s only a lower bound.

Implementations

impl BackendRepr

pub fn is_unsized(&self) -> bool

Returns true if the layout corresponds to an unsized type.

pub fn is_sized(&self) -> bool

pub fn is_signed(&self) -> bool

Returns true if this is a single signed integer scalar

pub fn is_uninhabited(&self) -> bool

Returns true if this is an uninhabited type

pub fn is_scalar(&self) -> bool

Returns true if this is a scalar type

pub fn is_bool(&self) -> bool

Returns true if this is a bool

pub fn inherent_align<C: HasDataLayout>( &self, cx: &C, ) -> Option<AbiAndPrefAlign>

Returns the fixed alignment of this ABI, if any is mandated.

pub fn inherent_size<C: HasDataLayout>(&self, cx: &C) -> Option<Size>

Returns the fixed size of this ABI, if any is mandated.

pub fn to_union(&self) -> Self

Discard validity range information and allow undef.

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

Trait Implementations

impl Clone for BackendRepr

fn clone(&self) -> BackendRepr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for BackendRepr

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

Formats the value using the given formatter.

impl Hash for BackendRepr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<__CTX> HashStable<__CTX> for BackendRepr

where __CTX: HashStableContext,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl PartialEq for BackendRepr

fn eq(&self, other: &BackendRepr) -> 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 BackendRepr

impl Eq for BackendRepr

impl StructuralPartialEq for BackendRepr

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 96 bytes

Size for each variant:

• Uninhabited: 0 bytes
• Scalar: 64 bytes
• ScalarPair: 96 bytes
• Vector: 80 bytes
• Memory: 5 bytes