Add MeasureReset instruction

qiskit_ibm_runtime/circuit/library/__init__.py

@@ -12,4 +12,4 @@
 
 """Module for vendor-specific instructions."""
 
-from .mid_circuit_measure import MidCircuitMeasure, MidCircuitReset
+from .mid_circuit_measure import MeasureReset, MidCircuitMeasure, MidCircuitReset

qiskit_ibm_runtime/circuit/library/mid_circuit_measure.py

@@ -19,14 +19,14 @@ class MidCircuitMeasure(Instruction):
     """Alternative 'named' measurement definition.
 
     This instruction implements an alternative 'named' measurement definition
-    (1 classical bit, 1 quantum bit), whose name can be used to map to a corresponding
+    (one classical bit, one quantum bit), whose name can be used to map to a corresponding
     mid-circuit measurement instruction implementation on hardware.
     """
 
     def __init__(self, name: str = "measure_2", label: str | None = None) -> None:
         if not name.startswith("measure_"):
             raise ValueError(
-                "Invalid name for mid-circuit measure instruction."
+                "Invalid name for mid-circuit measure instruction. "
                 "The provided name must start with `measure_`"
             )
 
@@ -37,15 +37,39 @@ class MidCircuitReset(Instruction):
     """Alternative 'named' reset definition.
 
     This instruction implements an alternative 'named' reset definition
-    (1 quantum bit), whose name can be used to map to a corresponding
+    (one quantum bit), whose name can be used to map to a corresponding
     mid-circuit reset instruction implementation on hardware.
     """
 
     def __init__(self, name: str = "reset_2", label: str | None = None) -> None:
         if not name.startswith("reset_"):
             raise ValueError(
-                "Invalid name for mid-circuit reset instruction."
+                "Invalid name for mid-circuit reset instruction. "
                 "The provided name must start with `reset_`"
             )
 
         super().__init__(name, 1, 0, [], label=label)
+
+
+class MeasureReset(Instruction):
+    """A reset that exposes the measurement it performs internally.
+
+    This instruction implements a reset operation whose intermediate measurement
+    result is captured in a classical bit, making it observable to the user.
+    It uses one quantum bit and one classical bit, and its name can be used to
+    map to a corresponding hardware-level implementation, and must start with
+    ``measure_reset``.
+
+    The semantics are: measure the qubit into the classical bit, then
+    conditionally flip the qubit back to ``|0>`` — i.e., a reset whose measurement
+    outcome is retained.
+    """
+
+    def __init__(self, name: str = "measure_reset", label: str | None = None) -> None:
+        if not name.startswith("measure_reset"):
+            raise ValueError(
+                "Invalid name for MeasureReset instruction. "
+                "The provided name must start with `measure_reset`"
+            )
+
+        super().__init__(name, 1, 1, [], label=label)

test/unit/circuit/test_mid_circ_meas.py

@@ -17,7 +17,7 @@
 from qiskit.providers.fake_provider import GenericBackendV2
 from qiskit.transpiler.exceptions import TranspilerError
 
-from qiskit_ibm_runtime.circuit import MidCircuitMeasure, MidCircuitReset
+from qiskit_ibm_runtime.circuit import MeasureReset, MidCircuitMeasure, MidCircuitReset
 from qiskit_ibm_runtime.fake_provider import FakeVigoV2
 
 from ...ibm_test_case import IBMTestCase
@@ -92,62 +92,121 @@ def test_transpiler_compat_with(self):
         transpiled = pm.run(qc)
         self.assertEqual(transpiled.data[0].operation.name, "measure_2")
 
-    class TestMidCircuitReset(IBMTestCase):
-        """Test MidCircuitReset instruction."""
 
-        def test_instantiation(self):
-            """Test default instantiation."""
-            mcr = MidCircuitReset()
+class TestMidCircuitReset(IBMTestCase):
+    """Test MidCircuitReset instruction."""
+
+    def test_instantiation(self):
+        """Test default instantiation."""
+        mcr = MidCircuitReset()
+        self.assertIs(mcr.base_class, MidCircuitReset)
+        self.assertIsInstance(mcr, Instruction)
+        self.assertEqual(mcr.name, "reset_2")
+        self.assertEqual(mcr.num_qubits, 1)
+        self.assertEqual(mcr.num_clbits, 0)
+
+    def test_instantiation_name(self):
+        """Test instantiation with custom name."""
+        with self.subTest("reset_3"):
+            mcr = MidCircuitReset("reset_3")
             self.assertIs(mcr.base_class, MidCircuitReset)
             self.assertIsInstance(mcr, Instruction)
-            self.assertEqual(mcr.name, "reset_2")
+            self.assertEqual(mcr.name, "reset_3")
             self.assertEqual(mcr.num_qubits, 1)
             self.assertEqual(mcr.num_clbits, 0)
 
-        def test_instantiation_name(self):
-            """Test instantiation with custom name."""
-            with self.subTest("reset_3"):
-                mcr = MidCircuitReset("reset_3")
-                self.assertIs(mcr.base_class, MidCircuitReset)
-                self.assertIsInstance(mcr, Instruction)
-                self.assertEqual(mcr.name, "reset_3")
-                self.assertEqual(mcr.num_qubits, 1)
-                self.assertEqual(mcr.num_clbits, 0)
-
-            with self.subTest("invalid_name"):
-                with self.assertRaises(ValueError):
-                    MidCircuitReset("invalid_name")
-
-        def test_circuit_integration(self):
-            """Test appending to circuit."""
-            mcr = MidCircuitReset()
-            qc = QuantumCircuit(1, 2)
-            qc.append(mcr, [0])
-            qc.append(mcr, [0])
-            qc.reset(0)
-            self.assertIs(qc.data[0].operation, mcr)
-            self.assertIs(qc.data[1].operation, mcr)
-
-        def test_transpiler_compat_without(self):
-            """Test that default pass manager FAILS if reset_2 is not in Target."""
-            mcr = MidCircuitReset()
-            backend = FakeVigoV2()
-            pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
-            qc = QuantumCircuit(1, 2)
-            qc.append(mcr, [0])
-            with self.assertRaises(TranspilerError):
-                _ = pm.run(qc)
-
-        def test_transpiler_compat_with(self):
-            """Test default PM passes if reset_2 is in Target.
-
-            Verifies it does not modify the instruction.
-            """
-            mcr = MidCircuitReset()
-            backend = GenericBackendV2(num_qubits=5, seed=0)
-            backend.target.add_instruction(mcr, {(i,): None for i in range(5)})
-            pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
-            qc = QuantumCircuit(1, 2)
-            qc.append(mcr, [0])
-            transpiled = pm.run(qc)
-            self.assertEqual(transpiled.data[0].operation.name, "reset_2")
+        with self.subTest("invalid_name"):
+            with self.assertRaises(ValueError):
+                MidCircuitReset("invalid_name")
+
+    def test_circuit_integration(self):
+        """Test appending to circuit."""
+        mcr = MidCircuitReset()
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcr, [0])
+        qc.append(mcr, [0])
+        qc.reset(0)
+        self.assertIs(qc.data[0].operation, mcr)
+        self.assertIs(qc.data[1].operation, mcr)
+
+    def test_transpiler_compat_without(self):
+        """Test that default pass manager FAILS if reset_2 is not in Target."""
+        mcr = MidCircuitReset()
+        backend = FakeVigoV2()
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcr, [0])
+        with self.assertRaises(TranspilerError):
+            _ = pm.run(qc)
+
+    def test_transpiler_compat_with(self):
+        """Test default PM passes if reset_2 is in Target.
+
+        Verifies it does not modify the instruction.
+        """
+        mcr = MidCircuitReset()
+        backend = GenericBackendV2(num_qubits=5, seed=0)
+        backend.target.add_instruction(mcr, {(i,): None for i in range(5)})
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcr, [0])
+        transpiled = pm.run(qc)
+        self.assertEqual(transpiled.data[0].operation.name, "reset_2")
+
+
+class TestMeasureReset(IBMTestCase):
+    """Test MeasureReset instruction."""
+
+    def test_instantiation(self):
+        """Test default instantiation."""
+        mr = MeasureReset()
+        self.assertIs(mr.base_class, MeasureReset)
+        self.assertIsInstance(mr, Instruction)
+        self.assertEqual(mr.name, "measure_reset")
+        self.assertEqual(mr.num_qubits, 1)
+        self.assertEqual(mr.num_clbits, 1)
+
+    def test_instantiation_name(self):
+        """Test instantiation with custom name."""
+        with self.subTest("measure_reset_2"):
+            mr = MeasureReset("measure_reset_2")
+            self.assertIs(mr.base_class, MeasureReset)
+            self.assertIsInstance(mr, Instruction)
+            self.assertEqual(mr.name, "measure_reset_2")
+            self.assertEqual(mr.num_qubits, 1)
+            self.assertEqual(mr.num_clbits, 1)
+
+        with self.subTest("invalid_name"):
+            with self.assertRaises(ValueError):
+                MeasureReset("invalid_name")
+
+    def test_circuit_integration(self):
+        """Test appending to circuit."""
+        mr = MeasureReset()
+        qc = QuantumCircuit(1, 1)
+        qc.append(mr, [0], [0])
+        self.assertIs(qc.data[0].operation, mr)
+
+    def test_transpiler_compat_without(self):
+        """Test that default pass manager FAILS if measure_reset is not in Target."""
+        mr = MeasureReset()
+        backend = FakeVigoV2()
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 1)
+        qc.append(mr, [0], [0])
+        with self.assertRaises(TranspilerError):
+            _ = pm.run(qc)
+
+    def test_transpiler_compat_with(self):
+        """Test default PM passes if measure_reset is in Target.
+
+        Verifies it does not modify the instruction.
+        """
+        mr = MeasureReset()
+        backend = GenericBackendV2(num_qubits=5, seed=0)
+        backend.target.add_instruction(mr, {(i,): None for i in range(5)})
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 1)
+        qc.append(mr, [0], [0])
+        transpiled = pm.run(qc)
+        self.assertEqual(transpiled.data[0].operation.name, "measure_reset")