Method units

src/allocation_unit.rs:108–136

Returns an iterator over the units in an allocation.

(self, reginfo: &impl RegInfo)

impl Allocation {
    /// Returns an iterator over the units in an allocation.
    pub(crate) fn units(self, reginfo: &impl RegInfo) -> impl Iterator<Item = AllocationUnit> + '_ {
        enum EitherIter<A, B> {
            A(A),
            B(B),
        }
        impl<A, B> Iterator for EitherIter<A, B>
        where
            A: Iterator,
            B: Iterator<Item = A::Item>,
        {
            type Item = A::Item;

            fn next(&mut self) -> Option<Self::Item> {
                match self {
                    EitherIter::A(a) => a.next(),
                    EitherIter::B(b) => b.next(),
                }
            }
        }

        match self.kind() {
            AllocationKind::PhysReg(reg) => {
                EitherIter::A(reginfo.reg_units(reg).map(AllocationUnit::reg))
            }
            AllocationKind::SpillSlot(slot) => {
                EitherIter::B(iter::once(AllocationUnit::spillslot(slot)))
            }
        }
    }
}