[MCM-2] Add new ConvertToMidCircuitMeasure transpiler pass

qiskit_ibm_runtime/circuit/__init__.py

@@ -0,0 +1,15 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Module for vendor-specific circuit objects."""
+
+from .library import *

qiskit_ibm_runtime/circuit/library/__init__.py

@@ -0,0 +1,16 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Module for vendor-specific instructions."""
+
+
+from .mid_circuit_measure import MidCircuitMeasure

qiskit_ibm_runtime/circuit/library/mid_circuit_measure.py

@@ -0,0 +1,32 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""MidCircuitMeasure gate."""
+
+from qiskit.circuit import Instruction
+
+
+class MidCircuitMeasure(Instruction):
+    """
+    This instruction implements an alternative 'named' measurement definition
+    (1 classical bit, 1 quantum bit), whose name can be used to map to a corresponding
+    mid-circuit measurement instruction implementation on hardware.
+    """
+
+    def __init__(self, name="measure_2", label=None):
+        if not name.startswith("measure_"):
+            raise ValueError(
+                "Invalid name for mid-circuit measure instruction."
+                "The provided name must start with `measure_`"
+            )
+
+        super().__init__(name, 1, 1, [], label=label)

qiskit_ibm_runtime/transpiler/passes/__init__.py

@@ -28,11 +28,12 @@
    ConvertIdToDelay
    ConvertISAToClifford
    FoldRzzAngle
+   ConvertToMidCircuitMeasure
 
 See :mod:`qiskit_ibm_runtime.transpiler.passes.scheduling` for a collection of scheduling passes.
 """
 
-from .basis import ConvertIdToDelay, FoldRzzAngle
+from .basis import ConvertIdToDelay, FoldRzzAngle, ConvertToMidCircuitMeasure
 
 # circuit scheduling
 from .scheduling import ASAPScheduleAnalysis

qiskit_ibm_runtime/transpiler/passes/basis/__init__.py

@@ -13,4 +13,5 @@
 """Passes to layout circuits to IBM backend's instruction sets."""
 
 from .convert_id_to_delay import ConvertIdToDelay
+from .convert_mid_circ_meas import ConvertToMidCircuitMeasure
 from .fold_rzz_angle import FoldRzzAngle

qiskit_ibm_runtime/transpiler/passes/basis/convert_mid_circ_meas.py

@@ -0,0 +1,46 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Pass to convert mreplaces terminal measures in the middle of the circuit with
+MidCircuitMeasure instructions."""
+
+from qiskit.transpiler.basepasses import TransformationPass
+from qiskit.circuit.measure import Measure
+from qiskit.transpiler.passes.utils.remove_final_measurements import calc_final_ops
+
+
+class ConvertToMidCircuitMeasure(TransformationPass):
+    """This pass replaces terminal measures in the middle of the circuit with
+    MidCircuitMeasure instructions.
+    """
+
+    def __init__(self, target):
+        super().__init__()
+        self.target = target
+
+    def run(self, dag):
+        """Run the pass on a dag."""
+        mid_circ_measure = None
+        for inst in self.target.instructions:
+            if inst[0].name.startswith("measure_"):
+                mid_circ_measure = inst[0]
+                break
+        if not mid_circ_measure:
+            return dag
+
+        final_measure_nodes = calc_final_ops(dag, {"measure"})
+
+        for node in dag.op_nodes(Measure):
+            if node not in final_measure_nodes:
+                dag.substitute_node(node, mid_circ_measure, inplace=True)
+
+        return dag

release-notes/unreleased/2316.feat.rst

@@ -0,0 +1,9 @@
+The `qiskit-ibm-runtime` package has been extended with two new modules: :mod:`.circuit` and 
+:mod:`.circuit.library`. These modules are designed to mirror the structure of the 
+corresponding `qiskit` SDK modules, while providing vendor-specific implementations of 
+circuit objects and instructions.
+
+The first addition to this new circuit library is the :class:`.MidCircuitMeasure` class. 
+This class enables the creation of instructions that follow the naming convention 
+`measure_<identifier>`, which are mapped to specific mid-circuit measurement
+ hardware instructions matching that pattern.

test/unit/circuit/__init__.py

@@ -0,0 +1,11 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.

test/unit/circuit/test_mid_circ_meas.py

@@ -0,0 +1,90 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Tests for MidCircuitMeasure instruction."""
+
+from qiskit import QuantumCircuit, generate_preset_pass_manager
+from qiskit.circuit import Instruction
+from qiskit.providers.fake_provider import GenericBackendV2
+from qiskit.transpiler.exceptions import TranspilerError
+
+from qiskit_ibm_runtime.circuit import MidCircuitMeasure
+from qiskit_ibm_runtime.fake_provider import FakeVigoV2
+
+from ...ibm_test_case import IBMTestCase
+
+
+class TestMidCircuitMeasure(IBMTestCase):
+    """Test MidCircuitMeasure instruction."""
+
+    def test_instantiation(self):
+        """Test default instantiation."""
+        mcm = MidCircuitMeasure()
+        self.assertIs(mcm.base_class, MidCircuitMeasure)
+        self.assertIsInstance(mcm, Instruction)
+        self.assertEqual(mcm.name, "measure_2")
+        self.assertEqual(mcm.num_qubits, 1)
+        self.assertEqual(mcm.num_clbits, 1)
+
+    def test_instantiation_name(self):
+        """Test instantiation with custom name."""
+        with self.subTest("measure_3"):
+            mcm = MidCircuitMeasure("measure_3")
+            self.assertIs(mcm.base_class, MidCircuitMeasure)
+            self.assertIsInstance(mcm, Instruction)
+            self.assertEqual(mcm.name, "measure_3")
+            self.assertEqual(mcm.num_qubits, 1)
+            self.assertEqual(mcm.num_clbits, 1)
+
+        with self.subTest("measure_reset"):
+            mcm = MidCircuitMeasure("measure_reset")
+            self.assertIs(mcm.base_class, MidCircuitMeasure)
+            self.assertIsInstance(mcm, Instruction)
+            self.assertEqual(mcm.name, "measure_reset")
+            self.assertEqual(mcm.num_qubits, 1)
+            self.assertEqual(mcm.num_clbits, 1)
+
+        with self.subTest("invalid_name"):
+            with self.assertRaises(ValueError):
+                mcm = MidCircuitMeasure("invalid_name")
+
+    def test_circuit_integration(self):
+        """Test appending to circuit."""
+        mcm = MidCircuitMeasure()
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        qc.append(mcm, [0], [1])
+        qc.reset(0)
+        self.assertIs(qc.data[0].operation, mcm)
+        self.assertIs(qc.data[1].operation, mcm)
+
+    def test_transpiler_compat_without(self):
+        """Test that default pass manager FAILS if measure_2 not in Target."""
+        mcm = MidCircuitMeasure()
+        backend = FakeVigoV2()
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        with self.assertRaises(TranspilerError):
+            _ = pm.run(qc)
+
+    def test_transpiler_compat_with(self):
+        """Test that default pass manager PASSES if measure_2 is in Target
+        and doesn't modify the instruction."""
+        mcm = MidCircuitMeasure()
+        backend = GenericBackendV2(num_qubits=5, seed=0)
+        backend.target.add_instruction(mcm, {(i,): None for i in range(5)})
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        transpiled = pm.run(qc)
+        self.assertEqual(transpiled.data[0].operation.name, "measure_2")

test/unit/transpiler/passes/basis/test_convert_mid_circ_meas.py

@@ -0,0 +1,69 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Test the conversion of terminal Measure to MidCircuitMeasure."""
+
+from qiskit.circuit import QuantumCircuit
+from qiskit.circuit.library import Measure
+from qiskit.providers.fake_provider import GenericBackendV2
+from qiskit.transpiler import PassManager
+
+from qiskit_ibm_runtime.circuit import MidCircuitMeasure
+from qiskit_ibm_runtime.transpiler.passes.basis.convert_mid_circ_meas import (
+    ConvertToMidCircuitMeasure,
+)
+
+from .....ibm_test_case import IBMTestCase
+
+
+class TestConvertToMidCircuitMeasure(IBMTestCase):
+    """Tests the ConvertToMidCircuitMeasure pass"""
+
+    def setUp(self):
+        super().setUp()
+
+        num_qubits = 5
+        mcm = MidCircuitMeasure()
+        self.target_without = GenericBackendV2(num_qubits=num_qubits, seed=0).target
+        self.target_with = GenericBackendV2(num_qubits=num_qubits, seed=0).target
+        self.target_with.add_instruction(mcm, {(i,): None for i in range(num_qubits)})
+
+        self.qc = QuantumCircuit(2, 2)
+        self.qc.x(0)
+        self.qc.append(mcm, [0], [0])
+        self.qc.measure([0], [0])
+        self.qc.measure_all()
+
+    def test_transpile_with(self):
+        custom_pass = ConvertToMidCircuitMeasure(self.target_with)
+        pm = PassManager([custom_pass])
+        transpiled = pm.run(self.qc)
+        self.assertIsInstance(transpiled.data[1].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[2].operation, MidCircuitMeasure)
+        # [3] is the barrier
+        self.assertNotIsInstance(transpiled.data[4].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[4].operation, Measure)
+        self.assertNotIsInstance(transpiled.data[5].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[5].operation, Measure)
+
+    def test_transpile_without(self):
+        custom_pass = ConvertToMidCircuitMeasure(self.target_without)
+        pm = PassManager([custom_pass])
+        transpiled = pm.run(self.qc)
+        self.assertIsInstance(transpiled.data[1].operation, MidCircuitMeasure)
+        self.assertNotIsInstance(transpiled.data[2].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[2].operation, Measure)
+        # [3] is the barrier
+        self.assertNotIsInstance(transpiled.data[4].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[4].operation, Measure)
+        self.assertNotIsInstance(transpiled.data[5].operation, MidCircuitMeasure)
+        self.assertIsInstance(transpiled.data[5].operation, Measure)