Enum cranelift_codegen::ir::ArgumentExtension

pub enum ArgumentExtension {
    None,
    Uext,
    Sext,
}

Function argument extension options.

On some architectures, small integer function arguments and/or return values are extended to the width of a general-purpose register.

This attribute specifies how an argument or return value should be extended if the platform and ABI require it. Because the frontend (CLIF generator) does not know anything about the particulars of the target’s ABI, and the CLIF should be platform-independent, these attributes specify how to extend (according to the signedness of the original program) rather than whether to extend.

For example, on x86-64, the SystemV ABI does not require extensions of narrow values, so these ArgumentExtension attributes are ignored; but in the Baldrdash (SpiderMonkey) ABI on the same platform, all narrow values are extended, so these attributes may lead to extra zero/sign-extend instructions in the generated machine code.

Variants

None

No extension, high bits are indeterminate.

Uext

Unsigned extension: high bits in register are 0.

Sext

Signed extension: high bits in register replicate sign bit.

Trait Implementations

impl Clone for ArgumentExtension

fn clone(&self) -> ArgumentExtension

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ArgumentExtension

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

Formats the value using the given formatter.

impl Hash for ArgumentExtension

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, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<ArgumentExtension> for ArgumentExtension

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

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

This method tests for !=.

impl Copy for ArgumentExtension

impl Eq for ArgumentExtension

impl StructuralEq for ArgumentExtension

impl StructuralPartialEq for ArgumentExtension