Add new features in QCircuit and fix circuit extraction (#63)

* fix phase_ids changes in rule pab

* update checks for phase gadgets

* fix check

* add max iter in simplify!

* parallel matching for p2 and p3

* avoid matching spiders in phase gadgets

* rm redundant

* avoid infinite simplify! for rule p2 and p3

* avoid infinite simplify! for rule p2 and p3

* add adjoint and vcat

* add tests

* resolve conflict

* fix wrong conversion and add new features

* fix circuit extraction

* rm test for debugging

* add more test

Author: ChenZhao44

src/circuit_extraction.jl

@@ -65,7 +65,11 @@ function circuit_extraction(zxg::ZXGraph{T, P}) where {T, P}
     M = biadjancency(nzxg, frontier, Ins)
     M, steps = gaussian_elimination(M)
     for step in steps
-        if step.op == :swap
+        if step.op == :addto
+            ctrl = step.r2
+            loc = step.r1
+            pushfirst_gate!(cir, Val{:CNOT}(), loc, ctrl)
+        elseif step.op == :swap
             q1 = step.r1
             q2 = step.r2
             pushfirst_gate!(cir, Val{:CNOT}(), q2, q1)
@@ -147,7 +151,7 @@ function update_frontier!(zxg::ZXGraph{T, P}, frontier::Vector{T}, cir::ZXDiagra
             end
             rem_edge!(zxg, v, w)
             if spider_type(zxg, w) == SpiderType.In
-                add_edge!(zxg, w, v, 1)
+                add_edge!(zxg, w, v, EdgeType.SIM)
             end
             deleteat!(frontier, frontier .== v)
             push!(frontier, w)
@@ -211,13 +215,11 @@ function gaussian_elimination(M::Matrix{T}, steps::Vector{GEStep} = Vector{GESte
         end
         while current_col <= nc
             r0 = findfirst(!iszero, M[i:nr, current_col])
-            if r0 != nothing
+            if r0 !== nothing
                 r0 += i - 1
                 r0 == i && break
-                r_temp = M[i,:]
-                M[i,:] = M[r0,:]
-                M[r0,:] = r_temp
-                step = GEStep(:swap, i, r0)
+                M[i,:] = M[i,:] .⊻ M[r0,:]
+                step = GEStep(:addto, r0, i)
                 push!(steps, step)
                 break
             else

src/qcircuit.jl

@@ -1,4 +1,4 @@
-import Base: show
+import Base: show, vcat, hcat, adjoint, getindex
 export QCircuit, QGate, random_circuit, gates, gate_count
 
 struct QGate
@@ -21,6 +21,15 @@ QGate(::Val{:Rx}, loc, theta) = QGate(:Rx, loc; param = theta)
 QGate(::Val{:CNOT}, loc, ctrl) = QGate(:CNOT, loc; ctrl = ctrl)
 QGate(::Val{:CZ}, loc, ctrl) = QGate(:CZ, loc; ctrl = ctrl)
 
+function adjoint(g::QGate)
+    g.name in (:X, :Z, :H, :CNOT, :CZ) && return g
+    g.name === :S && return QGate(Val(:Sdag), g.loc)
+    g.name === :Sdag && return QGate(Val(:S), g.loc)
+    g.name === :T && return QGate(Val(:Tdag), g.loc)
+    g.name === :Tdag && return QGate(Val(:T), g.loc)
+    g.name in (:shift, :Rz, :Rx) && return QGate(g.name, g.loc; param = -g.param)
+end
+
 function show(io::IO, g::QGate)
     if g.ctrl == 0
         if g.param === nothing
@@ -51,6 +60,30 @@ function show(io::IO, qc::QCircuit)
     end
 end
 
+function vcat(qcs::QCircuit...)
+    n = nqubits(qcs[1])
+    nqc = QCircuit(n)
+    for qc in qcs
+        n == nqubits(qc) || error("Can not catenate quantum circuits with different qubit numbers")
+        nqc.gates = [gates(nqc); gates(qc)]
+    end
+    return nqc
+end
+hcat(qcs::QCircuit...) = vcat(qcs...)
+
+function adjoint(qc::QCircuit)
+    adj_qc = QCircuit(nqubits(qc))
+    for i = gate_count(qc):-1:1
+        push_gate!(adj_qc, qc.gates[i]')
+    end
+    return adj_qc
+end
+
+function getindex(qc::QCircuit, i...)
+    n = nqubits(qc)
+    return QCircuit(n, gates(qc)[i...])
+end
+
 nqubits(qc::QCircuit) = qc.nbits
 gates(qc::QCircuit) = qc.gates
 gate_count(qc::QCircuit) = length(qc.gates)
@@ -171,13 +204,13 @@ function QCircuit(circ::ZXDiagram{T, P}) where {T, P}
                             push_gate!(qc, Val(:T), q)
                         elseif phase(circ, v) == 7//4
                             push_gate!(qc, Val(:Tdag), q)
-                        else
+                        elseif phase(circ, v) != 0
                             push_gate!(qc, Val(:shift), q, θ)
                         end
                     elseif spider_type(circ, v) == ZXCalculus.SpiderType.X
                         if phase(circ, v) == 1
                             push_gate!(qc, Val(:X), q)
-                        else
+                        else phase(circ, v) != 0
                             push_gate!(qc, Val(:Rx), q, θ)
                         end    
                     elseif spider_type(circ, v) == ZXCalculus.SpiderType.H
@@ -220,11 +253,11 @@ function QCircuit(circ::ZXDiagram{T, P}) where {T, P}
                                     push_gate!(qc, Val(:Z), qubit_loc(circ, v1))
                                 elseif phase(circ, v1) == 1//2
                                     push_gate!(qc, Val(:S), qubit_loc(circ, v1))
-                                elseif phase(circ, v) == 3//2
+                                elseif phase(circ, v1) == 3//2
                                     push_gate!(qc, Val(:Sdag), qubit_loc(circ, v1))
                                 elseif phase(circ, v1) == 1//4
                                     push_gate!(qc, Val(:T), qubit_loc(circ, v1))
-                                elseif phase(circ, v) == 7//4
+                                elseif phase(circ, v1) == 7//4
                                     push_gate!(qc, Val(:Tdag), qubit_loc(circ, v1))
                                 else        
                                     push_gate!(qc, Val(:shift), qubit_loc(circ, v1), phase(circ, v1)*π)

test/qcircuit.jl

@@ -1,4 +1,4 @@
-using ZXCalculus
+using ZXCalculus, Test
 
 qc = random_circuit(4, 100)
 @test gate_count(qc) == 100
@@ -40,4 +40,12 @@ pt_qc = QCircuit(pt_circ)
 
 ex_circ = clifford_simplification(circ)
 ex_qc = QCircuit(ex_circ)
-@test tcount(ex_circ) == tcount(ex_qc)
+@test tcount(ex_circ) == tcount(ex_qc)
+
+qc_id = [qc qc']
+zxd_id = ZXDiagram(qc_id)
+zxd_id = phase_teleportation(zxd_id)
+for _ = 1:5
+    global zxd_id = clifford_simplification(zxd_id)
+end
+@test ZXCalculus.nv(zxd_id) == 8