qiskit-aer/qiskit_aer/library/control_flow_instructions/jump.py

47 lines
1.3 KiB
Python

# This code is part of Qiskit.
#
# (C) Copyright IBM 2018, 2021.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""
Simulator instruction to set a program counter
"""
from qiskit.circuit import Instruction
from qiskit.circuit.classical.expr import Expr
class AerJump(Instruction):
"""
Jump instruction
This instruction sets a program counter to specified mark instruction.
"""
_directive = True
def __init__(self, jump_to, num_qubits, num_clbits=0):
super().__init__("jump", num_qubits, num_clbits, [jump_to])
self.condition_expr = None
def set_conditional(self, cond):
"""Set condition to perform this jump instruction.
Args:
cond (Expr or tuple): `Expr` to call `eval_bool` or tuple for `c_if`
Returns:
AerJump: jump instruction added specified condition
"""
if isinstance(cond, Expr):
self.condition_expr = cond
else:
self.c_if(*cond)
return self