catalyst.passes.merge_rotations¶
- merge_rotations(qnode=None)[source]¶
Specify that the
-merge-rotations
MLIR compiler pass for merging roations (peephole) will be applied.The full list of supported gates are as follows:
qml.RX
,qml.CRX
,qml.RY
,qml.CRY
,qml.RZ
,qml.CRZ
,qml.PhaseShift
,qml.ControlledPhaseShift
,qml.MultiRZ
.Note
Unlike PennyLane circuit transformations, the QNode itself will not be changed or transformed by applying these decorators.
As a result, circuit inspection tools such as
draw()
will continue to display the circuit as written in Python.To instead view the optimized circuit, the MLIR must be viewed after the
"QuantumCompilationPass"
stage via theget_compilation_stage()
function.- Parameters
fn (QNode) – the QNode to apply the cancel inverses compiler pass to
- Return type
QNode
Example
In this example the three
qml.RX
will be merged in a single one with the sum of angles as parameter.from catalyst.debug import get_compilation_stage from catalyst.passes import merge_rotations dev = qml.device("lightning.qubit", wires=1) @qjit(keep_intermediate=True) @merge_rotations @qml.qnode(dev) def circuit(x: float): qml.RX(x, wires=0) qml.RX(0.1, wires=0) qml.RX(x**2, wires=0) return qml.expval(qml.PauliZ(0))
>>> circuit(0.54) Array(0.5965506257017892, dtype=float64)