PadDelay
class PadDelay(fill_very_end=True)
Bases: qiskit.transpiler.passes.scheduling.padding.base_padding.BasePadding
Padding idle time with Delay instructions.
Consecutive delays will be merged in the output of this pass.
durations = InstructionDurations([("x", None, 160), ("cx", None, 800)])
qc = QuantumCircuit(2)
qc.delay(100, 0)
qc.x(1)
qc.cx(0, 1)
The ASAP-scheduled circuit output may become
┌────────────────┐
q_0: ┤ Delay(160[dt]) ├──■──
└─────┬───┬──────┘┌─┴─┐
q_1: ──────┤ X ├───────┤ X ├
└───┘ └───┘
Note that the additional idle time of 60dt on the q_0
wire coming from the duration difference between Delay
of 100dt (q_0
) and XGate
of 160 dt (q_1
) is absorbed in the delay instruction on the q_0
wire, i.e. in total 160 dt.
See BasePadding
pass for details.
Create new padding delay pass.
Parameters
fill_very_end (bool
) – Set True
to fill the end of circuit with delay.
Methods
name
PadDelay.name()
Return the name of the pass.
run
PadDelay.run(dag)
Run the padding pass on dag
.
Parameters
dag (DAGCircuit
) – DAG to be checked.
Returns
DAG with idle time filled with instructions.
Return type
Raises
TranspilerError – When a particular node is not scheduled, likely some transform pass is inserted before this node is called.
Attributes
is_analysis_pass
Check if the pass is an analysis pass.
If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.
is_transformation_pass
Check if the pass is a transformation pass.
If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).