PennyLane code for QSVT example

# import time
# import pennylane as qml
# from catalyst import qjit
# from pennylane import numpy as np


# def reflect_around_zero(data):
#     """Implements the reflection around zero operator."""
#     def circuit(data):
#         qml.PauliX(wires=data[0])
#         qml.Hadamard(wires=data[0])
#         qml.ctrl(qml.PauliX, control=data[1:len(data)], control_values=[0]*(len(data)-1))(wires=data[0])
#         qml.Hadamard(wires=data[0])
#         qml.PauliX(wires=data[0])
#     return circuit

# def get_cir_be(data, block):
#     """Constructs the controlled block-encoding circuit."""
#     def circuit():
#         qml.Hadamard(wires=block[0])
#         qml.Hadamard(wires=block[2])
#         qml.ctrl(qml.Adder,control=block[0], control_values=1)(2, data+[block[1]], 2**(len(data)+1), work_wires=[])
#         qml.Adder(2**(len(data)+1)-1, data+[block[1]], 2**(len(data)+1), work_wires=[])
#         qml.ctrl(reflect_around_zero(data), control=block[2])(data)
#         qml.Hadamard(wires=block[0])
#         qml.Hadamard(wires=block[2])
#     return circuit

# def apply_projector_controlled_phase(phase, block_reg, aux_reg):
#     def circuit():
#         qml.ctrl(qml.PauliX, control=block_reg, control_values=[0]*len(block_reg))(wires=aux_reg)
#         qml.RZ(phase, wires=aux_reg)
#         qml.ctrl(qml.PauliX, control=block_reg, control_values=[0]*len(block_reg))(wires=aux_reg)
#     return circuit

# def apply_qsvt_step(phase1, phase2, u, data, block, qsvt_aux):
#     def circuit():
#         u()
#         apply_projector_controlled_phase(phase1, block, qsvt_aux)()
#         qml.adjoint(u)()
#         apply_projector_controlled_phase(phase2, block, qsvt_aux)()
#     return circuit

# def get_qsvt_circuit(qsvt_phases, size):
#     dev = qml.device("lightning.qubit", wires=size + 3)

#     @qml.qnode(dev)
#     def qsvt_circuit():
#         block = [size, size+1, size+2]
#         qsvt_aux = size + 3
#         data = list(range(size))

#         cir_be = get_cir_be(data, block)
#         qml.Hadamard(wires=qsvt_aux)
#         apply_projector_controlled_phase(qsvt_phases[0], block, qsvt_aux)()
#         for i in range((len(qsvt_phases) - 1) // 2):
#             apply_qsvt_step(qsvt_phases[2 * i + 1],  qsvt_phases[2 * i + 2], cir_be , data, block, qsvt_aux)()

#         cir_be()
#         apply_projector_controlled_phase(qsvt_phases[-1], block, qsvt_aux)()
#         qml.Hadamard(wires=qsvt_aux)

#     return qsvt_circuit

# SIZE = 6
# DEGREE = 3
# QSVT_PHASES = [1.280311896404252, 8.127145628464149, 1.8439603212845617, -5.002873410775335]


# start_time = time.time()
# qsvt_cir = get_qsvt_circuit(QSVT_PHASES, SIZE)
# cir = qml.transforms.decompose(qsvt_cir, gate_set={qml.CNOT, qml.RZ, qml.RY, qml.RX})
# jitted_cir = qjit(cir)
# transpilation_time = time.time()-start_time
# cx_counts = jitted_cir.mlir.count("CNOT")
# print(f"==== pennylane for {SIZE}==== time: {transpilation_time}")