Fix oversights in generate_preset_pass_manager (Qiskit#12799)

* Fix oversight from Qiskit#12185 where two input parsing functions were not migrated from transpile to generate_preset_pm  with the others.

* Add fix to reno from Qiskit#12185

Author: ElePT

qiskit/compiler/transpiler.py

@@ -20,7 +20,6 @@
 
 from qiskit import user_config
 from qiskit.circuit.quantumcircuit import QuantumCircuit
-from qiskit.circuit.quantumregister import Qubit
 from qiskit.dagcircuit import DAGCircuit
 from qiskit.providers.backend import Backend
 from qiskit.providers.backend_compat import BackendV2Converter
@@ -339,10 +338,7 @@ def callback_func(**kwargs):
         if translation_method is None and hasattr(backend, "get_translation_stage_plugin"):
             translation_method = backend.get_translation_stage_plugin()
 
-    initial_layout = _parse_initial_layout(initial_layout)
-    approximation_degree = _parse_approximation_degree(approximation_degree)
     output_name = _parse_output_name(output_name, circuits)
-
     coupling_map = _parse_coupling_map(coupling_map)
     _check_circuits_coupling_map(circuits, coupling_map, backend)
 
@@ -425,27 +421,6 @@ def _parse_coupling_map(coupling_map):
         return coupling_map
 
 
-def _parse_initial_layout(initial_layout):
-    # initial_layout could be None, or a list of ints, e.g. [0, 5, 14]
-    # or a list of tuples/None e.g. [qr[0], None, qr[1]] or a dict e.g. {qr[0]: 0}
-    if initial_layout is None or isinstance(initial_layout, Layout):
-        return initial_layout
-    if isinstance(initial_layout, dict):
-        return Layout(initial_layout)
-    initial_layout = list(initial_layout)
-    if all(phys is None or isinstance(phys, Qubit) for phys in initial_layout):
-        return Layout.from_qubit_list(initial_layout)
-    return initial_layout
-
-
-def _parse_approximation_degree(approximation_degree):
-    if approximation_degree is None:
-        return None
-    if approximation_degree < 0.0 or approximation_degree > 1.0:
-        raise TranspilerError("Approximation degree must be in [0.0, 1.0]")
-    return approximation_degree
-
-
 def _parse_output_name(output_name, circuits):
     # naming and returning circuits
     # output_name could be either a string or a list

qiskit/transpiler/preset_passmanagers/generate_preset_pass_manager.py

@@ -18,10 +18,12 @@
 
 from qiskit.circuit.controlflow import CONTROL_FLOW_OP_NAMES
 from qiskit.circuit.library.standard_gates import get_standard_gate_name_mapping
+from qiskit.circuit.quantumregister import Qubit
 from qiskit.providers.backend_compat import BackendV2Converter
 from qiskit.transpiler.coupling import CouplingMap
 from qiskit.transpiler.exceptions import TranspilerError
 from qiskit.transpiler.instruction_durations import InstructionDurations
+from qiskit.transpiler.layout import Layout
 from qiskit.transpiler.passmanager_config import PassManagerConfig
 from qiskit.transpiler.target import Target, target_to_backend_properties
 from qiskit.transpiler.timing_constraints import TimingConstraints
@@ -319,6 +321,10 @@ def generate_preset_pass_manager(
         if backend_properties is None:
             backend_properties = target_to_backend_properties(target)
 
+    # Parse non-target dependent pm options
+    initial_layout = _parse_initial_layout(initial_layout)
+    approximation_degree = _parse_approximation_degree(approximation_degree)
+
     pm_options = {
         "target": target,
         "basis_gates": basis_gates,
@@ -470,3 +476,24 @@ def _parse_timing_constraints(backend, timing_constraints):
     elif backend is not None:
         timing_constraints = backend.target.timing_constraints()
     return timing_constraints
+
+
+def _parse_initial_layout(initial_layout):
+    # initial_layout could be None, or a list of ints, e.g. [0, 5, 14]
+    # or a list of tuples/None e.g. [qr[0], None, qr[1]] or a dict e.g. {qr[0]: 0}
+    if initial_layout is None or isinstance(initial_layout, Layout):
+        return initial_layout
+    if isinstance(initial_layout, dict):
+        return Layout(initial_layout)
+    initial_layout = list(initial_layout)
+    if all(phys is None or isinstance(phys, Qubit) for phys in initial_layout):
+        return Layout.from_qubit_list(initial_layout)
+    return initial_layout
+
+
+def _parse_approximation_degree(approximation_degree):
+    if approximation_degree is None:
+        return None
+    if approximation_degree < 0.0 or approximation_degree > 1.0:
+        raise TranspilerError("Approximation degree must be in [0.0, 1.0]")
+    return approximation_degree

releasenotes/notes/use-target-in-generate-preset-pm-5215e00d22d0205c.yaml

@@ -12,3 +12,9 @@ upgrade_transpiler:
     If a `backend` input of type :class:`.BackendV1` is provided, it will be 
     converted to :class:`.BackendV2` to expose its :class:`.Target`. This change does 
     not require any user action.
+
+fixes:
+  - |
+    A series of input-handling inconsistencies between :func:`.transpile` and :func:`.generate_preset_pass_manager` 
+    have been fixed. These inconsistencies would lead to different transpilation outputs for the same inputs, 
+    or :func:`.generate_preset_pass_manager` failing for certain input combinations accepted by :func:`.transpile`.