def greedy_router(problem_instance: dimod.BinaryQuadraticModel, qpu: Type[QPU]):
#find edge coloring for problem graph
#color_sets = edge_coloring.find_edge_coloring(problem_instance.to_networkx_graph())
#color_sets = sorted(color_sets, key=lambda color_set: len(color_set), reverse=True)
# find initial mapping and execute interaction gates
#initial_mapping, int_layer = int_pair_mapper(qpu, problem_instance, color_sets[0])
initial_mapping, int_layers = twoColorMapper(problem_instance, qpu)
route = Routing(problem_instance, qpu, initial_mapping=initial_mapping)
int_count = 0
for int_layer in int_layers:
for int_gate in int_layer:
int_count += 1
route.apply_int(int_gate)
print(int_count)
# find valid edge coloring
#route = Routing(problem_instance, qpu)
color_sets = edge_coloring.find_edge_coloring(route.remaining_interactions)
color_sets = sorted(color_sets, key=lambda color_set: len(color_set), reverse=True)
#finish remaining layers of color sets
for color_set in color_sets:
greedy_pair_mapper(route, color_set)
return route
def execute_all_possible_int_gates(routing: Routing, int_pairs: Set[frozenset]) -> bool:
int_graph = nx.Graph()
gate_executed = False
for int_pair in int_pairs:
hard_qb0 = routing.mapping.log2hard[list(int_pair)[0]]
hard_qb1 = routing.mapping.log2hard[list(int_pair)[1]]
if routing.qpu.graph.has_edge(hard_qb0, hard_qb1):
if routing.layers[-1].int_gate_applicable(frozenset((hard_qb0, hard_qb1))):
int_graph.add_edge(hard_qb1, hard_qb0)
gate_executed = True
matching = nx.maximal_matching(int_graph)
for match in matching:
gate = frozenset(match)
log_qb0 = routing.mapping.hard2log[list(match)[0]]
log_qb1 = routing.mapping.hard2log[list(match)[1]]
int_pair = frozenset((log_qb0, log_qb1))
routing.apply_int(gate)
int_pairs.remove(int_pair)
return gate_executed
class TestRouting(TestCase):
def setUp(self) -> None:
gr = nx.grid_2d_graph(2, 2)
gr.add_edge((0, 0), (1, 1))
self.qpu = Grid2dQPU(2, 2)
self.problem_instance = dimod.generators.random.uniform(gr, dimod.SPIN)
init_map = {cirq.GridQubit(*loc): loc for loc in self.problem_instance.variables}
self.initial_mapping = Mapping(self.qpu, self.problem_instance, initial_mapping=init_map)
self.routing = Routing(self.problem_instance, self.qpu, cp.deepcopy(self.initial_mapping))
def test_apply_swap(self) -> None:
self.routing.apply_swap(frozenset((cirq.GridQubit(0, 0), cirq.GridQubit(1, 0))))
self.assertEqual(self.initial_mapping.hard2log[cirq.GridQubit(0, 0)], self.routing.mapping.hard2log[cirq.GridQubit(1, 0)],
msg="application of swap gate did not update mapping")
self.assertEqual(self.initial_mapping.hard2log[cirq.GridQubit(1, 0)], self.routing.mapping.hard2log[cirq.GridQubit(0, 0)],
msg="application of swap gate did not update mapping")
self.assertTrue(self.routing.layers[0].gates[cirq.GridQubit(0, 0)][cirq.GridQubit(1, 0)]['swap'],
msg="did not add swap gate to layer")
self.routing.apply_swap(frozenset((cirq.GridQubit(0, 1), cirq.GridQubit(1, 1))))
self.assertEqual(self.initial_mapping.hard2log[cirq.GridQubit(0, 1)], self.routing.mapping.hard2log[cirq.GridQubit(1, 1)],
msg="application of swap gate did not update mapping")
self.assertEqual(self.initial_mapping.hard2log[cirq.GridQubit(1, 1)], self.routing.mapping.hard2log[cirq.GridQubit(0, 1)],
msg="application of swap gate did not update mapping")
self.assertTrue(self.routing.layers[0].gates[cirq.GridQubit(0, 1)][cirq.GridQubit(1, 1)]['swap'],
msg="did not add swap gate to layer")
self.routing.apply_swap(frozenset((cirq.GridQubit(0, 0), cirq.GridQubit(0, 1))))
self.assertTrue(self.routing.layers[1].gates[cirq.GridQubit(0, 0)][cirq.GridQubit(0, 1)]['swap'],
msg="did not add layer containing new swap gate")
self.routing.draw()
def test_apply_int(self) -> None:
self.routing.apply_int(frozenset((cirq.GridQubit(0, 0), cirq.GridQubit(1, 0))))
self.assertTrue(self.routing.layers[0].gates[cirq.GridQubit(0, 0)][cirq.GridQubit(1, 0)]['int'],
msg="did not add int gate to layer")
self.assertFalse(self.routing.remaining_interactions.has_edge(cirq.GridQubit(0, 0), cirq.GridQubit(1, 0)),
msg='interaction has not been deleted from routing.remaining_interactions')
self.routing.apply_int(frozenset((cirq.GridQubit(0, 1), cirq.GridQubit(1, 1))))
self.assertTrue(self.routing.layers[0].gates[cirq.GridQubit(0, 1)][cirq.GridQubit(1, 1)]['int'],
msg="did not add int gate to layer")
self.assertFalse(self.routing.remaining_interactions.has_edge(cirq.GridQubit(0, 1), cirq.GridQubit(1, 1)),
msg='interaction has not been deleted from routing.remaining_interactions')
self.routing.apply_int(frozenset((cirq.GridQubit(0, 0), cirq.GridQubit(0, 1))))
self.assertTrue(self.routing.layers[1].gates[cirq.GridQubit(0, 0)][cirq.GridQubit(0, 1)]['int'],
msg="did not add layer containing new int gate")
self.assertFalse(self.routing.remaining_interactions.has_edge(cirq.GridQubit(0, 0), cirq.GridQubit(0, 1)),
msg='interaction has not been deleted from routing.remaining_interactions')