Struct Narrowed 

pub struct Narrowed {
    pub name: &'static str,
    pub into: &'static str,
    pub writes: u32,
}

One instruction that writes a constant, and the narrower one that writes the same register.

Narrower means fewer bytes of the number written out, and on this machine it also means fewer bytes of instruction: the sixty-four bit move carries a prefix byte saying so and the thirty-two bit move does not, and a number too wide to sign extend from thirty-two bits is written out whole where the narrower instruction writes four bytes of it.

It says the same thing only for the numbers the narrower instruction can hold and only on a machine where writing part of a register clears the rest of it, which is why Narrowed::writes is here rather than the pass working the range out from the name.

Fields

name: &'static str

The opcode that takes the constant.

into: &'static str

The opcode that takes the same constant in fewer bytes.

writes: u32

How many bits of the register the narrower opcode writes. The rest of the register is cleared rather than left alone, so the two say the same thing for a number that is not negative and fits in this many bits, and disagree for every other number.

Trait Implementations

impl Clone for Narrowed

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 Narrowed

impl Debug for Narrowed

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

Formats the value using the given formatter.

impl Eq for Narrowed

impl PartialEq for Narrowed

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Narrowed