Bugfix: transpile() fails in a circuit with delay ops.

CHANGELOG.rst

@@ -2,6 +2,12 @@
 Changelog
 =========
 
+Version 17.4
+============
+
+* Bugfix: The ``delay`` operation is now accepted by the standard transpiler.
+  `#151 <https://github.com/iqm-finland/qiskit-on-iqm/pull/151>`_
+
 Version 17.3
 ============
 

src/iqm/qiskit_iqm/iqm_transpilation.py

@@ -71,6 +71,7 @@ def run(self, dag: DAGCircuit) -> DAGCircuit:
         dag = Optimize1qGatesDecomposition(self._intermediate_basis).run(dag)
         for node in dag.topological_op_nodes():
             if node.name == 'u':
+                # convert into PRX + RZ
                 qubit_index = dag.find_bit(node.qargs[0])[0]
                 if math.isclose(node.op.params[0], 0, abs_tol=TOLERANCE):
                     dag.remove_op_node(node)
@@ -97,13 +98,14 @@ def run(self, dag: DAGCircuit) -> DAGCircuit:
                 # makes no sense to convert it into active z rotations if we hit a barrier?
                 pass
             elif node.name == 'move':
+                # acts like iSWAP with RZ, moving it to the other component
                 qb, res = dag.find_bit(node.qargs[0])[0], dag.find_bit(node.qargs[1])[0]
                 rz_angles[res], rz_angles[qb] = rz_angles[qb], rz_angles[res]
-            elif node.name == 'cz':
-                pass  # rz_angles are commute through CZ gates
+            elif node.name in {'cz', 'delay'}:
+                pass  # commutes with RZ gates
             else:
                 raise ValueError(
-                    f'Unexpected operation {node.name} in circuit given to IQMOptimizeSingleQubitGates pass'
+                    f"Unexpected operation '{node.name}' in circuit given to IQMOptimizeSingleQubitGates pass"
                 )
 
         if not self._drop_final_rz:

tests/conftest.py

@@ -45,15 +45,21 @@ def linear_3q_architecture_static():
     )
 
 
+def _1q_loci(qubits: list[str]) -> tuple[tuple[str, ...], ...]:
+    """One-qubit loci for the given qubits."""
+    return tuple((q,) for q in qubits)
+
+
 @pytest.fixture
 def linear_3q_architecture():
+    qubits = ['QB1', 'QB2', 'QB3']
     return DynamicQuantumArchitecture(
         calibration_set_id=UUID('59478539-dcef-4b2e-80c8-122d7ec3fc89'),
-        qubits=['QB1', 'QB2', 'QB3'],
+        qubits=qubits,
         computational_resonators=[],
         gates={
             'prx': GateInfo(
-                implementations={'drag_gaussian': GateImplementationInfo(loci=(('QB1',), ('QB2',), ('QB3',)))},
+                implementations={'drag_gaussian': GateImplementationInfo(loci=_1q_loci(qubits))},
                 default_implementation='drag_gaussian',
                 override_default_implementation={},
             ),
@@ -63,7 +69,7 @@ def linear_3q_architecture():
                 override_default_implementation={},
             ),
             'measure': GateInfo(
-                implementations={'constant': GateImplementationInfo(loci=(('QB1',), ('QB2',), ('QB3',)))},
+                implementations={'constant': GateImplementationInfo(loci=_1q_loci(qubits))},
                 default_implementation='constant',
                 override_default_implementation={},
             ),
@@ -73,22 +79,19 @@ def linear_3q_architecture():
 
 @pytest.fixture
 def adonis_architecture():
+    qubits = ['QB1', 'QB2', 'QB3', 'QB4', 'QB5']
     return DynamicQuantumArchitecture(
         calibration_set_id=UUID('59478539-dcef-4b2e-80c8-122d7ec3fc89'),
-        qubits=['QB1', 'QB2', 'QB3', 'QB4', 'QB5'],
+        qubits=qubits,
         computational_resonators=[],
         gates={
             'prx': GateInfo(
-                implementations={
-                    'drag_gaussian': GateImplementationInfo(loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',)))
-                },
+                implementations={'drag_gaussian': GateImplementationInfo(loci=_1q_loci(qubits))},
                 default_implementation='drag_gaussian',
                 override_default_implementation={},
             ),
             'cc_prx': GateInfo(
-                implementations={
-                    'prx_composite': GateImplementationInfo(loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',)))
-                },
+                implementations={'prx_composite': GateImplementationInfo(loci=_1q_loci(qubits))},
                 default_implementation='prx_composite',
                 override_default_implementation={},
             ),
@@ -102,9 +105,7 @@ def adonis_architecture():
                 override_default_implementation={},
             ),
             'measure': GateInfo(
-                implementations={
-                    'constant': GateImplementationInfo(loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',)))
-                },
+                implementations={'constant': GateImplementationInfo(loci=_1q_loci(qubits))},
                 default_implementation='constant',
                 override_default_implementation={},
             ),
@@ -114,20 +115,24 @@ def adonis_architecture():
 
 @pytest.fixture
 def move_architecture():
+    qubits = ['QB1', 'QB2', 'QB3', 'QB4', 'QB5', 'QB6']
     return DynamicQuantumArchitecture(
         calibration_set_id=UUID('26c5e70f-bea0-43af-bd37-6212ec7d04cb'),
-        qubits=['QB1', 'QB2', 'QB3', 'QB4', 'QB5', 'QB6'],
+        qubits=qubits,
         computational_resonators=['CR1'],
         gates={
             'prx': GateInfo(
                 implementations={
-                    'drag_gaussian': GateImplementationInfo(
-                        loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',), ('QB6',))
-                    ),
+                    'drag_gaussian': GateImplementationInfo(loci=_1q_loci(qubits)),
                 },
                 default_implementation='drag_gaussian',
                 override_default_implementation={},
             ),
+            'cc_prx': GateInfo(
+                implementations={'prx_composite': GateImplementationInfo(loci=_1q_loci(qubits))},
+                default_implementation='prx_composite',
+                override_default_implementation={},
+            ),
             'cz': GateInfo(
                 implementations={
                     'tgss': GateImplementationInfo(
@@ -152,9 +157,7 @@ def move_architecture():
             ),
             'measure': GateInfo(
                 implementations={
-                    'constant': GateImplementationInfo(
-                        loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',), ('QB6',))
-                    ),
+                    'constant': GateImplementationInfo(loci=_1q_loci(qubits)),
                 },
                 default_implementation='constant',
                 override_default_implementation={},
@@ -241,16 +244,15 @@ def hypothetical_fake_architecture():
 
 @pytest.fixture
 def ndonis_architecture():
+    qubits = ['QB1', 'QB2', 'QB3', 'QB4', 'QB5', 'QB6']
     return DynamicQuantumArchitecture(
         calibration_set_id=UUID('26c5e70f-bea0-43af-bd37-6212ec7d04cb'),
-        qubits=['QB1', 'QB2', 'QB3', 'QB4', 'QB5', 'QB6'],
+        qubits=qubits,
         computational_resonators=['CR1'],
         gates={
             'prx': GateInfo(
                 implementations={
-                    'drag_gaussian': GateImplementationInfo(
-                        loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',), ('QB6',))
-                    ),
+                    'drag_gaussian': GateImplementationInfo(loci=_1q_loci(qubits)),
                 },
                 default_implementation='drag_gaussian',
                 override_default_implementation={},
@@ -289,9 +291,7 @@ def ndonis_architecture():
             ),
             'measure': GateInfo(
                 implementations={
-                    'constant': GateImplementationInfo(
-                        loci=(('QB1',), ('QB2',), ('QB3',), ('QB4',), ('QB5',), ('QB6',))
-                    ),
+                    'constant': GateImplementationInfo(loci=_1q_loci(qubits)),
                 },
                 default_implementation='constant',
                 override_default_implementation={},

tests/test_iqm_transpilation.py

@@ -150,8 +150,12 @@ def test_optimize_single_qubit_gates_preserves_layout(backend):
 def test_qiskit_native_transpiler(move_architecture, optimization_level):
     """Tests that a simple circuit is transpiled correctly using the Qiskit transpiler."""
     backend, _ = get_mocked_backend(move_architecture)
+    # circuit should contain all our supported operations to make sure the transpiler can handle them
     qc = QuantumCircuit(2)
     qc.h(0)
+    qc.barrier(0, 1)
+    qc.delay(10, 0, unit='ns')
+    qc.reset(0)
     qc.cx(0, 1)
     qc.measure_all()
     transpiled_circuit = transpile(qc, backend=backend, optimization_level=optimization_level)