Add transpile() support for extracting instruction schedule map from BackendV2

qiskit/compiler/transpiler.py

@@ -666,9 +666,14 @@ def _parse_basis_gates(basis_gates, backend, circuits):
 def _parse_inst_map(inst_map, backend, num_circuits):
     # try getting inst_map from user, else backend
     if inst_map is None:
-        if hasattr(backend, "defaults"):
-            inst_map = getattr(backend.defaults(), "instruction_schedule_map", None)
-
+        backend_version = getattr(backend, "version", 0)
+        if not isinstance(backend_version, int):
+            backend_version = 0
+        if backend_version <= 1:
+            if hasattr(backend, "defaults"):
+                inst_map = getattr(backend.defaults(), "instruction_schedule_map", None)
+        else:
+            inst_map = backend.target.instruction_schedule_map()
     # inst_maps could be None, or single entry
     if inst_map is None or isinstance(inst_map, InstructionScheduleMap):
         inst_map = [inst_map] * num_circuits

releasenotes/notes/add-v2-backend-support-in-transpiler-parse-inst-map-a617801850178d05.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixed support in :func:`~qiskit.compiler.transpile` for passing a
+    :class:`~qiskit.pulse.InstructionMap` to the underlying :class:`~qiskit.transpiler.PassManager`
+    based on the :class:`~qiskit.transpiler.Target` for :class:`~qiskit.providers.backend.BackendV2` based
+    backends.

test/python/providers/test_backend_v2.py

@@ -21,6 +21,8 @@
 
 from qiskit.circuit import QuantumCircuit, ClassicalRegister, QuantumRegister
 from qiskit.compiler import transpile
+from qiskit.compiler.transpiler import _parse_inst_map
+from qiskit.pulse.instruction_schedule_map import InstructionScheduleMap
 from qiskit.test.base import QiskitTestCase
 from qiskit.test.mock.fake_backend_v2 import FakeBackendV2, FakeBackend5QV2
 from qiskit.test.mock.fake_mumbai_v2 import FakeMumbaiV2
@@ -165,3 +167,8 @@ def test_transpile_mumbai_target(self):
         expected.measure(qr[0], cr[0])
         expected.measure(qr[1], cr[1])
         self.assertEqual(expected, tqc)
+
+    def test_transpile_parse_inst_map(self):
+        """Test that transpiler._parse_inst_map() supports BackendV2."""
+        inst_map = _parse_inst_map(inst_map=None, backend=self.backend, num_circuits=1)[0]
+        self.assertIsInstance(inst_map, InstructionScheduleMap)