Enum regalloc2::OperandPos

pub enum OperandPos {
    Early,
    Late,
}

The “position” of the operand: where it has its read/write effects. These are positions “in” the instruction, and “early” and “late” are relative to the instruction’s main effect or computation. In other words, the allocator assumes that the instruction (i) performs all reads and writes of “early” operands, (ii) does its work, and (iii) performs all reads and writes of its “late” operands.

A “write” (def) at “early” or a “read” (use) at “late” may be slightly nonsensical, given the above, if the read is necessary for the computation or the write is a result of it. A way to think of it is that the value (even if a result of execution) could have been read or written at the given location without causing any register-usage conflicts. In other words, these write-early or use-late operands ensure that the particular allocations are valid for longer than usual and that a register is not reused between the use (normally complete at “Early”) and the def (normally starting at “Late”). See Operand for more.

Variants

Early

Late

Trait Implementations

impl Clone for OperandPos

fn clone(&self) -> OperandPos

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for OperandPos

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

Formats the value using the given formatter.

impl PartialEq<OperandPos> for OperandPos

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

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

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

This method tests for !=.

impl Copy for OperandPos

impl Eq for OperandPos

impl StructuralEq for OperandPos

impl StructuralPartialEq for OperandPos