Fix transpiler bugs about moved measurements and duplicated gates

src/qibo/transpiler/placer.py

@@ -46,11 +46,18 @@ def assert_mapping_consistency(layout: dict, connectivity: nx.Graph = None):
             qubits of the original connectivity graph. Defaults to ``None``.
     """
     values = sorted(layout.values())
+    physical_qubits = list(layout.keys())
     if connectivity is not None:
-        ref_keys = ["q" + str(i) for i in list(connectivity.nodes)]
+        if isinstance(physical_qubits[0], str):
+            ref_keys = ["q" + str(i) for i in list(connectivity.nodes)]
+        else:
+            ref_keys = list(connectivity.nodes)
     else:
-        ref_keys = ["q" + str(i) for i in range(len(values))]
-    if list(layout.keys()) != ref_keys:
+        if isinstance(physical_qubits[0], str):
+            ref_keys = ["q" + str(i) for i in range(len(values))]
+        else:
+            ref_keys = list(range(len(values)))
+    if physical_qubits != ref_keys:
         raise_error(
             PlacementError,
             "Some physical qubits in the layout may be missing or duplicated.",

src/qibo/transpiler/router.py

@@ -176,7 +176,7 @@ def __init__(
             self.circuit_blocks = blocks
         else:
             self.circuit_blocks = CircuitBlocks(circuit, index_names=True)
-        # Order the initial layout based on the hardware qubit name (this may create problems for a custom layout)
+        # Order the initial layout based on the hardware qubit names to avoid problems in custom layouts
         self.initial_layout = {
             key: value for key, value in sorted(initial_layout.items())
         }

tests/test_transpiler_pipeline.py

@@ -285,9 +285,8 @@ def test_custom_passes_wrong_pass():
         transpiled_circ, final_layout = custom_pipeline(circ)
 
 
-def test_bug_measurements():
-    connectivity = nx.Graph()
-    connectivity.add_edges_from([(0, 2), (1, 2), (2, 3), (2, 4)])
+def test_int_qubit_names():
+    connectivity = star_connectivity()
     transpiler = Passes(
         connectivity=connectivity,
         passes=[
@@ -302,6 +301,13 @@ def test_bug_measurements():
     circuit.add(gates.I(0))
     circuit.add(gates.H(0))
     circuit.add(gates.M(0))
-    transpiled_circuit, _ = transpiler(circuit)
-    assert transpiled_circuit.queue[2].qubits == (1,)
-    assert transpiled_circuit.queue[3].qubits == (1,)
+    transpiled_circuit, final_map = transpiler(circuit)
+    initial_layout = transpiler.get_initial_layout()
+    assert_transpiling(
+        original_circuit=circuit,
+        transpiled_circuit=transpiled_circuit,
+        connectivity=connectivity,
+        initial_layout=initial_layout,
+        final_layout=final_map,
+        native_gates=NativeGates.default(),
+    )

tests/test_transpiler_placer.py

@@ -40,10 +40,14 @@ def star_circuit():
     return circuit
 
 
-def test_assert_placement_true():
-    layout = {"q0": 0, "q1": 1, "q2": 2, "q3": 3, "q4": 4}
+@pytest.mark.parametrize("connectivity", [star_connectivity(), None])
+@pytest.mark.parametrize(
+    "layout",
+    [{"q0": 0, "q1": 1, "q2": 2, "q3": 3, "q4": 4}, {0: 0, 1: 1, 2: 2, 3: 3, 4: 4}],
+)
+def test_assert_placement_true(layout, connectivity):
     circuit = Circuit(5)
-    assert_placement(circuit, layout)
+    assert_placement(circuit, layout, connectivity=connectivity)
 
 
 @pytest.mark.parametrize("qubits", [5, 3])
@@ -56,8 +60,11 @@ def test_assert_placement_false(qubits, layout):
         assert_placement(circuit, layout)
 
 
-def test_mapping_consistency():
-    layout = {"q0": 0, "q1": 2, "q2": 1, "q3": 4, "q4": 3}
+@pytest.mark.parametrize(
+    "layout",
+    [{"q0": 0, "q1": 1, "q2": 2, "q3": 3, "q4": 4}, {0: 0, 1: 1, 2: 2, 3: 3, 4: 4}],
+)
+def test_mapping_consistency(layout):
     assert_mapping_consistency(layout)
 
 

tests/test_transpiler_unroller.py

@@ -119,3 +119,5 @@ def test_measurements_non_comp_basis():
     circuit.add(gates.M(0, basis=gates.X))
     transpiled_circuit = unroller(circuit)
     assert isinstance(transpiled_circuit.queue[2], gates.M)
+    # After transpiling the measurement gate should be in the computational basis
+    assert transpiled_circuit.queue[2].basis == [gates.Z]