Method query

expander_compiler/src/layering/wire.rs:29–100

given a parent layer layout, this function query the layout of a sub circuit

(
        &self,
        layer_layout_pool: &mut Pool<LayerLayout>,
        circuits: &HashMap<usize, IrContext<'_, C>>,
        vs: &[usize], // variables to query (in parent layer)
        f: F,    

impl LayoutQuery {
    // given a parent layer layout, this function query the layout of a sub circuit
    fn query<F, C: Config>(
        &self,
        layer_layout_pool: &mut Pool<LayerLayout>,
        circuits: &HashMap<usize, IrContext<'_, C>>,
        vs: &[usize], // variables to query (in parent layer)
        f: F,         // f(i) = id of i-th variable in the sub circuit
        cid: usize,   // target circuit id
        lid: usize,   // target layer id
    ) -> SubLayout
    where
        F: Fn(usize) -> usize,
    {
        if vs.is_empty() {
            let subl = LayerLayout {
                circuit_id: cid,
                layer: lid,
                size: 1,
                inner: LayerLayoutInner::Dense {
                    placement: vec![EMPTY],
                },
            };
            let id = layer_layout_pool.add(&subl);
            return SubLayout {
                id,
                offset: 0,
                insn_id: EMPTY,
            };
        }
        let mut ps = vec![0; vs.len()];
        let mut l: usize = 1 << 62;
        let mut r: usize = 0;
        for (i, x) in vs.iter().enumerate() {
            ps[i] = if let Some(x) = self.var_pos.get(x) {
                *x
            } else {
                EMPTY
            };
            if ps[i] != EMPTY {
                l = l.min(ps[i]);
                r = r.max(ps[i]);
            }
        }
        let mut xor = if l <= r { l ^ r } else { 0 };
        xor |= xor >> 1;
        xor |= xor >> 2;
        xor |= xor >> 4;
        xor |= xor >> 8;
        xor |= xor >> 16;
        xor |= xor >> 32;
        xor ^= xor >> 1;
        let n = if xor == 0 { 1 } else { xor << 1 };
        let offset = if l <= r { l & !(n - 1) } else { 0 };
        let mut placement = vec![EMPTY; n];
        for i in 0..vs.len() {
            if ps[i] != EMPTY {
                placement[ps[i] - offset] = f(i);
            }
        }