Fix scheduling in control flow with instructions of non-uniform durations

qiskit_ibm_runtime/transpiler/passes/scheduling/__init__.py

@@ -55,7 +55,7 @@
     # Generate the main Qiskit transpile passes.
     pm = generate_preset_pass_manager(optimization_level=1, backend=backend)
     # Configure the as-late-as-possible scheduling pass
-    pm.scheduling = PassManager([ALAPScheduleAnalysis(durations), PadDelay()])
+    pm.scheduling = PassManager([ALAPScheduleAnalysis(durations), PadDelay(durations)])
 
     qr = QuantumRegister(3)
     crz = ClassicalRegister(1, name="crz")
@@ -162,7 +162,7 @@
           [
               ConvertConditionsToIfOps(),
               ALAPScheduleAnalysis(durations),
-              PadDelay(),
+              PadDelay(durations),
           ]
     )
 

qiskit_ibm_runtime/transpiler/passes/scheduling/block_base_padder.py

@@ -263,7 +263,7 @@ def _get_node_duration(self, node: DAGNode) -> int:
             cal_key = tuple(indices), tuple(float(p) for p in node.op.params)
             duration = self._block_dag.calibrations[node.op.name][cal_key].duration
         else:
-            duration = node.op.duration
+            duration = self._durations.get(node.op, indices, unit="dt")
 
         if isinstance(duration, ParameterExpression):
             raise TranspilerError(

qiskit_ibm_runtime/transpiler/passes/scheduling/pad_delay.py

@@ -15,6 +15,7 @@
 from qiskit.circuit import Qubit
 from qiskit.circuit.delay import Delay
 from qiskit.dagcircuit import DAGNode, DAGOutNode
+from qiskit.transpiler.instruction_durations import InstructionDurations
 
 from .block_base_padder import BlockBasePadder
 
@@ -50,16 +51,23 @@ class PadDelay(BlockBasePadder):
     See :class:`BlockBasePadder` pass for details.
     """
 
-    def __init__(self, fill_very_end: bool = True, schedule_idle_qubits: bool = False):
+    def __init__(
+        self,
+        durations: InstructionDurations,
+        fill_very_end: bool = True,
+        schedule_idle_qubits: bool = False,
+    ):
         """Create new padding delay pass.
 
         Args:
+            durations: Durations of instructions to be used in scheduling.
             fill_very_end: Set ``True`` to fill the end of circuit with delay.
             schedule_idle_qubits: Set to true if you'd like a delay inserted on idle qubits.
                 This is useful for timeline visualizations, but may cause issues for execution
                 on large backends.
         """
         super().__init__(schedule_idle_qubits=schedule_idle_qubits)
+        self._durations = durations
         self.fill_very_end = fill_very_end
 
     def _pad(

qiskit_ibm_runtime/transpiler/passes/scheduling/scheduler.py

@@ -216,7 +216,8 @@ def _get_duration(self, node: DAGNode, dag: Optional[DAGCircuit] = None) -> int:
             duration = dag.calibrations[node.op.name][cal_key].duration
             node.op.duration = duration
         else:
-            duration = node.op.duration
+            # map to outer dag to get the appropriate durations
+            duration = self._durations.get(node.op, indices, unit="dt")
 
         if isinstance(duration, ParameterExpression):
             raise TranspilerError(

releasenotes/notes/fix-durations-with-control-flow-0cf6b5c48c387ca8.yaml

@@ -0,0 +1,10 @@
+---
+fixes:
+  - |
+    Fix assignment of instruction durations when scheduling circuits with   
+    control flow. Prior to this fix, the indices for instructions on inner 
+    blocks were not mapped to the physical indices in the outer dag.
+other:
+  - |
+    The :class:`~InstructionDurations` `durations` input is now also required 
+    for the constructor of :class:`~PadDelay`.