The multi-controlled gate by RZGate().control() is less optimized. #13473
Description
Environment
- Qiskit version: 1.3.0rc2
- Python version: 3.12.6
- Operating system: Sonoma 14.5
What is happening?
The multi-controlled gate by RZGate().control() is less optimized.
How can we reproduce the issue?
We create a circuit with a 6-qubit multi-controlled RZGate. We then transpile it to an Eagle device, and count the number of entangling gates.
from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
backend = service.backend("ibm_sherbrooke")
pm = generate_preset_pass_manager(optimization_level=3, backend=backend, seed_transpiler=12345)
import numpy as np
from qiskit import QuantumCircuit, QuantumRegister
from qiskit.circuit.library import RZGate
n=6; ang=np.pi/7
qr = QuantumRegister(n)
qc = QuantumCircuit(qr)
qc.append(RZGate(ang).control(n-1), qr)
isa_qc=pm.run(qc)
print(isa_qc.count_ops()['ecr'])
What should happen?
The above code outputs 266 in 1.3.0rc2, while 65 in 1.2.4.
Any suggestions?
No response