Check for non-ISA operation inside operation flow blocks (#1784)

* check isa inside control flow operations

* add a test to the sampler

* lint

* release note

* Update qiskit_ibm_runtime/utils/utils.py

Co-authored-by: Samuele Ferracin <[email protected]>

---------

Co-authored-by: Samuele Ferracin <[email protected]>
Co-authored-by: Kevin Tian <[email protected]>

CONTRIBUTING.md

@@ -133,7 +133,7 @@ needed so that users will understand what has changed, why it changed, and how
 they'll have to update their code.
 
 Towncrier will automatically add a link to the PR or Issue number you used in
-the file name once we build the relesae notes during the release.
+the file name once we build the release notes during the release.
 
 After you've finished writing your release note, you need to add the note
 file to your commit with `git add` and commit them to your PR branch to make

qiskit_ibm_runtime/utils/utils.py

@@ -47,6 +47,34 @@ def is_simulator(backend: BackendV1 | BackendV2) -> bool:
     return getattr(backend, "simulator", False)
 
 
+def _is_isa_circuit_helper(circuit: QuantumCircuit, target: Target) -> str:
+    """
+    A section of is_isa_circuit, separated to allow recursive calls
+    within blocks of conditional operations.
+    """
+    for instruction in circuit.data:
+        operation = instruction.operation
+
+        name = operation.name
+        qargs = tuple(circuit.find_bit(x).index for x in instruction.qubits)
+        if (
+            not target.instruction_supported(name, qargs)
+            and name != "barrier"
+            and not circuit.has_calibration_for(instruction)
+        ):
+            return (
+                f"The instruction {name} on qubits {qargs} is not supported by the target system."
+            )
+
+        if isinstance(operation, ControlFlowOp):
+            for sub_circ in operation.blocks:
+                sub_string = _is_isa_circuit_helper(sub_circ, target)
+                if sub_string:
+                    return sub_string
+
+    return ""
+
+
 def is_isa_circuit(circuit: QuantumCircuit, target: Target) -> str:
     """Checks if the circuit is an ISA circuit, meaning that it has a layout and that it
     only uses instructions that exist in the target.
@@ -64,18 +92,7 @@ def is_isa_circuit(circuit: QuantumCircuit, target: Target) -> str:
             f"but the target system requires {target.num_qubits} qubits."
         )
 
-    for instruction in circuit.data:
-        name = instruction.operation.name
-        qargs = tuple(circuit.find_bit(x).index for x in instruction.qubits)
-        if (
-            not target.instruction_supported(name, qargs)
-            and name != "barrier"
-            and not circuit.has_calibration_for(instruction)
-        ):
-            return (
-                f"The instruction {name} on qubits {qargs} is not supported by the target system."
-            )
-    return ""
+    return _is_isa_circuit_helper(circuit, target)
 
 
 def are_circuits_dynamic(circuits: List[QuantumCircuit], qasm_default: bool = True) -> bool:

release-notes/unreleased/1784.bug.rst

@@ -0,0 +1 @@
+Every circuit is checked to be ISA compliant. As part of this check, an error is raised if instructions that are not supported by the backend are detected. Previously, a bug caused some of the instructions to be skipped (those that reside inside bodies of control flow operations). We have fixed the bug in this release.

test/unit/test_estimator.py

@@ -21,6 +21,7 @@
 from qiskit.primitives.containers.estimator_pub import EstimatorPub
 
 from qiskit_ibm_runtime import Estimator, Session, EstimatorV2, EstimatorOptions, IBMInputValueError
+from qiskit_ibm_runtime.fake_provider import FakeSherbrooke
 
 from .mock.fake_runtime_service import FakeRuntimeService
 from ..ibm_test_case import IBMTestCase
@@ -286,3 +287,23 @@ def test_estimator_validations(self):
         obs = []
         with self.assertRaisesRegex(ValueError, "Empty observables array is not allowed"):
             inst.run(pubs=[(circ, obs)])
+
+    def test_gate_not_in_target(self):
+        """Test exception when circuits contain gates that are not basis gates"""
+        # pylint: disable=invalid-name,not-context-manager
+        backend = FakeSherbrooke()
+        estimator = EstimatorV2(backend=backend)
+        observable = SparsePauliOp("Z")
+
+        circ = QuantumCircuit(1, 1)
+        circ.x(0)
+        circ.measure(0, 0)
+        with circ.if_test((0, 1)):
+            with circ.if_test((0, 0)) as else_:
+                circ.x(0)
+            with else_:
+                circ.h(0)
+        circ.measure(0, 0)
+
+        with self.assertRaisesRegex(IBMInputValueError, " h "):
+            estimator.run(pubs=[(circ, observable)])

test/unit/test_sampler.py

@@ -21,7 +21,7 @@
 from qiskit.primitives.containers.sampler_pub import SamplerPub
 from qiskit.circuit.library import RealAmplitudes
 from qiskit_ibm_runtime import Sampler, Session, SamplerV2, SamplerOptions, IBMInputValueError
-from qiskit_ibm_runtime.fake_provider import FakeFractionalBackend
+from qiskit_ibm_runtime.fake_provider import FakeFractionalBackend, FakeSherbrooke
 
 from ..ibm_test_case import IBMTestCase
 from ..utils import bell, MockSession, dict_paritally_equal, get_mocked_backend, transpile_pubs
@@ -245,3 +245,22 @@ def test_run_fractional_dynamic_mix(self, use_fractional):
         inst = SamplerV2(mode=backend)
         with self.assertRaises(IBMInputValueError):
             inst.run([dynamic_circuit, fractional_circuit])
+
+    def test_gate_not_in_target(self):
+        """Test exception when circuits contain gates that are not basis gates"""
+        # pylint: disable=invalid-name,not-context-manager
+        backend = FakeSherbrooke()
+        sampler = SamplerV2(backend=backend)
+
+        circ = QuantumCircuit(1, 1)
+        circ.x(0)
+        circ.measure(0, 0)
+        with circ.if_test((0, 1)):
+            with circ.if_test((0, 0)) as else_:
+                circ.x(0)
+            with else_:
+                circ.h(0)
+        circ.measure(0, 0)
+
+        with self.assertRaisesRegex(IBMInputValueError, " h "):
+            sampler.run(pubs=[(circ)])