AerUnitaryBackend: call transpile before run (#142)

CQCL · Aug 29, 2023 · 3a05202 · 3a05202
1 parent 74208fd
commit 3a05202
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Showing 3 changed files with 25 additions and 11 deletions.
diff --git a/pytket/extensions/qiskit/backends/aer.py b/pytket/extensions/qiskit/backends/aer.py
@@ -29,6 +29,7 @@
 )
 
 import numpy as np
+from qiskit import transpile  # type: ignore
 from qiskit.providers.aer.noise import NoiseModel  # type: ignore
 from qiskit.quantum_info.operators import Pauli as qk_Pauli  # type: ignore
 from qiskit.quantum_info.operators.symplectic.sparse_pauli_op import SparsePauliOp  # type: ignore
@@ -110,6 +111,7 @@ class _AerBaseBackend(Backend):
     _required_predicates: List[Predicate]
     _noise_model: Optional[NoiseModel] = None
     _has_arch: bool = False
+    _needs_transpile: bool = False
 
     @property
     def required_predicates(self) -> List[Predicate]:
@@ -248,6 +250,9 @@ def process_circuits(
                     qc.save_unitary()
                 qcs.append(qc)
 
+            if self._needs_transpile:
+                qcs = transpile(qcs, self._qiskit_backend)
+
             seed = cast(Optional[int], kwargs.get("seed"))
             job = self._qiskit_backend.run(
                 qcs,
@@ -539,6 +544,7 @@ class AerUnitaryBackend(_AerBaseBackend):
 
     _memory = False
     _noise_model = None
+    _needs_transpile = True
 
     _qiskit_backend_name = "aer_simulator_unitary"
 

diff --git a/tests/backend_test.py b/tests/backend_test.py
@@ -30,7 +30,7 @@
 
 from qiskit_ibm_provider import IBMProvider  # type: ignore
 
-from pytket.circuit import Circuit, OpType, BasisOrder, Qubit, reg_eq, Unitary2qBox  # type: ignore
+from pytket.circuit import Circuit, OpType, BasisOrder, Qubit, reg_eq, Unitary2qBox, QControlBox, CircBox  # type: ignore
 from pytket.passes import CliffordSimp  # type: ignore
 from pytket.pauli import Pauli, QubitPauliString  # type: ignore
 from pytket.predicates import CompilationUnit, NoMidMeasurePredicate  # type: ignore
@@ -1230,3 +1230,21 @@ def test_ecr_gate_compilation(ibm_sherbrooke_backend: IBMQBackend) -> None:
             circ, optimisation_level
         )
         assert ibm_sherbrooke_backend.valid_circuit(compiled_circ)
+
+
+def test_unitary_backend_transpiles() -> None:
+    """regression test for https://github.com/CQCL/pytket-qiskit/issues/142"""
+    backend = AerUnitaryBackend()
+    n_ancillas = 5  # using n_ancillas <=4 doees not raise an error
+    n_spins = 1
+    circ = Circuit(n_ancillas + n_spins)
+    trgt = Circuit(n_spins)
+    trgt.X(0)
+
+    circ.add_qcontrolbox(
+        QControlBox(CircBox(trgt), n_ancillas), list(range(n_ancillas + n_spins))
+    )
+
+    compiled_circ = backend.get_compiled_circuit(circ, optimisation_level=0)
+    # using optimisation_level >= 1 does not raise an error
+    backend.run_circuit(compiled_circ)
diff --git a/tests/qiskit_backend_test.py b/tests/qiskit_backend_test.py
@@ -20,7 +20,6 @@
 
 from qiskit import QuantumCircuit, execute  # type: ignore
 from qiskit.opflow import CircuitStateFn, CircuitSampler  # type: ignore
-from qiskit.providers import JobStatus  # type: ignore
 from qiskit.utils import QuantumInstance  # type: ignore
 from qiskit.algorithms import Grover, AmplificationProblem  # type: ignore
 from qiskit.transpiler.exceptions import TranspilerError  # type: ignore
@@ -107,15 +106,6 @@ def test_unitary() -> None:
         assert np.allclose(u, u2)
 
 
-def test_cancel() -> None:
-    b = AerBackend()
-    tb = TketBackend(b)
-    qc = circuit_gen()
-    job = execute(qc, tb, shots=1024)
-    job.cancel()
-    assert job.status() in [JobStatus.CANCELLED, JobStatus.DONE]
-
-
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_qiskit_counts(belem_emulator_backend: IBMQEmulatorBackend) -> None:
     num_qubits = 2