controlled gates label awareness

Qiskit · Apr 25, 2020 · 7f3db35 · 7f3db35
1 parent 93c27fa
commit 7f3db35
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Showing 13 changed files with 138 additions and 55 deletions.
diff --git a/qiskit/circuit/add_control.py b/qiskit/circuit/add_control.py
@@ -66,8 +66,9 @@ def add_control(operation: Union[Gate, ControlledGate],
     if isinstance(operation, UnitaryGate):
         # attempt decomposition
         operation._define()
-    return control(operation, num_ctrl_qubits=num_ctrl_qubits, label=label,
-                   ctrl_state=ctrl_state)
+    cgate = control(operation, num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
+    cgate.base_gate.label = operation.label
+    return cgate
 
 
 def control(operation: Union[Gate, ControlledGate],

diff --git a/qiskit/extensions/standard/h.py b/qiskit/extensions/standard/h.py
@@ -87,7 +87,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CHGate(label=label, ctrl_state=ctrl_state)
+            gate = CHGate(label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
         return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
                                ctrl_state=ctrl_state)
 

diff --git a/qiskit/extensions/standard/ms.py b/qiskit/extensions/standard/ms.py
@@ -36,9 +36,10 @@ class MSGate(Gate):
     """
 
     @deprecate_arguments({'n_qubits': 'num_qubits'})
-    def __init__(self, num_qubits, theta, *, n_qubits=None):  # pylint:disable=unused-argument
+    def __init__(self, num_qubits, theta, *, n_qubits=None,  # pylint:disable=unused-argument
+                 label=None):
         """Create new MS gate."""
-        super().__init__('ms', num_qubits, [theta])
+        super().__init__('ms', num_qubits, [theta], label=label)
 
     def _define(self):
         from qiskit.extensions.standard.rxx import RXXGate

diff --git a/qiskit/extensions/standard/rx.py b/qiskit/extensions/standard/rx.py
@@ -80,9 +80,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CRXGate(self.params[0], label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CRXGate(self.params[0], label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted RX gate.

diff --git a/qiskit/extensions/standard/ry.py b/qiskit/extensions/standard/ry.py
@@ -80,9 +80,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CRYGate(self.params[0], label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CRYGate(self.params[0], label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted RY gate.

diff --git a/qiskit/extensions/standard/rz.py b/qiskit/extensions/standard/rz.py
@@ -58,9 +58,9 @@ class RZGate(Gate):
         Reference for virtual Z gate implementation:
         `1612.00858 <https://arxiv.org/abs/1612.00858>`_
     """
-    def __init__(self, phi):
+    def __init__(self, phi, label=None):
         """Create new RZ gate."""
-        super().__init__('rz', 1, [phi])
+        super().__init__('rz', 1, [phi], label=label)
 
     def _define(self):
         """
@@ -89,9 +89,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CRZGate(self.params[0], label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CRZGate(self.params[0], label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted RZ gate

diff --git a/qiskit/extensions/standard/swap.py b/qiskit/extensions/standard/swap.py
@@ -56,9 +56,9 @@ class SwapGate(Gate):
         |a, b\rangle \rightarrow |b, a\rangle
     """
 
-    def __init__(self):
+    def __init__(self, label=None):
         """Create new SWAP gate."""
-        super().__init__('swap', 2, [])
+        super().__init__('swap', 2, [], label=label)
 
     def _define(self):
         """
@@ -91,9 +91,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CSwapGate(label=None, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CSwapGate(label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         """Return inverse Swap gate (itself)."""

diff --git a/qiskit/extensions/standard/u1.py b/qiskit/extensions/standard/u1.py
@@ -107,11 +107,14 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CU1Gate(self.params[0], label=label, ctrl_state=ctrl_state)
-        if ctrl_state is None and num_ctrl_qubits > 1:
-            return MCU1Gate(self.params[0], num_ctrl_qubits)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CU1Gate(self.params[0], label=label, ctrl_state=ctrl_state)
+        elif ctrl_state is None and num_ctrl_qubits > 1:
+            gate = MCU1Gate(self.params[0], num_ctrl_qubits, label=label)
+        else:
+            return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
+                                   ctrl_state=ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         r"""Return inverted U1 gate (:math:`U1(\lambda){\dagger} = U1(-\lambda)`)"""
@@ -222,9 +225,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if ctrl_state is None:
-            return MCU1Gate(self.params[0], num_ctrl_qubits=num_ctrl_qubits + 1)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = MCU1Gate(self.params[0], num_ctrl_qubits=num_ctrl_qubits + 1, label=label)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted CU1 gate (:math:`CU1(\lambda){\dagger} = CU1(-\lambda)`)"""
@@ -281,9 +285,10 @@ class MCU1Gate(ControlledGate):
         The singly-controlled-version of this gate.
     """
 
-    def __init__(self, lam, num_ctrl_qubits):
+    def __init__(self, lam, num_ctrl_qubits, label=None):
         """Create new MCU1 gate."""
-        super().__init__('mcu1', num_ctrl_qubits + 1, [lam], num_ctrl_qubits=num_ctrl_qubits)
+        super().__init__('mcu1', num_ctrl_qubits + 1, [lam], num_ctrl_qubits=num_ctrl_qubits,
+                         label=label)
         self.base_gate = U1Gate(lam)
 
     def _define(self):
@@ -314,9 +319,11 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if ctrl_state is None:
-            return MCU1Gate(self.params[0], num_ctrl_qubits=num_ctrl_qubits + self.num_ctrl_qubits)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = MCU1Gate(self.params[0], num_ctrl_qubits=num_ctrl_qubits + self.num_ctrl_qubits,
+                            label=label)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted MCU1 gate (:math:`MCU1(\lambda){\dagger} = MCU1(-\lambda)`)"""

diff --git a/qiskit/extensions/standard/u3.py b/qiskit/extensions/standard/u3.py
@@ -88,9 +88,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CU3Gate(*self.params, label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CU3Gate(*self.params, label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def to_matrix(self):
         """Return a Numpy.array for the U3 gate."""

diff --git a/qiskit/extensions/standard/x.py b/qiskit/extensions/standard/x.py
@@ -105,7 +105,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         Returns:
             ControlledGate: controlled version of this gate.
         """
-        return MCXGate(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
+        gate = MCXGate(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         r"""Return inverted X gate (itself)"""
@@ -216,7 +218,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         if ctrl_state is None:
             ctrl_state = 2**num_ctrl_qubits - 1
         new_ctrl_state = (self.ctrl_state << num_ctrl_qubits) | ctrl_state
-        return MCXGate(num_ctrl_qubits=num_ctrl_qubits + 1, label=label, ctrl_state=new_ctrl_state)
+        gate = MCXGate(num_ctrl_qubits=num_ctrl_qubits + 1, label=label, ctrl_state=new_ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         """Return inverted CX gate (itself)."""
@@ -389,7 +393,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         if ctrl_state is None:
             ctrl_state = 2**num_ctrl_qubits - 1
         new_ctrl_state = (self.ctrl_state << num_ctrl_qubits) | ctrl_state
-        return MCXGate(num_ctrl_qubits=num_ctrl_qubits + 2, label=label, ctrl_state=new_ctrl_state)
+        gate = MCXGate(num_ctrl_qubits=num_ctrl_qubits + 2, label=label, ctrl_state=new_ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         """Return an inverted CCX gate (also a CCX)."""
@@ -441,9 +447,9 @@ class RCCXGate(Gate):
     of Fig. 3.
     """
 
-    def __init__(self):
+    def __init__(self, label=None):
         """Create a new simplified CCX gate."""
-        super().__init__('rccx', 3, [])
+        super().__init__('rccx', 3, [], label=label)
 
     def _define(self):
         """
@@ -584,7 +590,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         if ctrl_state is None:
             ctrl_state = 2**num_ctrl_qubits - 1
         new_ctrl_state = (self.ctrl_state << num_ctrl_qubits) | ctrl_state
-        return MCXGate(num_ctrl_qubits=num_ctrl_qubits + 3, label=label, ctrl_state=new_ctrl_state)
+        gate = MCXGate(num_ctrl_qubits=num_ctrl_qubits + 3, label=label, ctrl_state=new_ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         """Invert this gate. The C3X is its own inverse."""
@@ -622,9 +630,9 @@ class RC3XGate(Gate):
     of Fig. 4.
     """
 
-    def __init__(self):
+    def __init__(self, label=None):
         """Create a new RC3X gate."""
-        super().__init__('rcccx', 4, [])
+        super().__init__('rcccx', 4, [], label=label)
 
     def _define(self):
         """
@@ -773,7 +781,9 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         if ctrl_state is None:
             ctrl_state = 2**num_ctrl_qubits - 1
         new_ctrl_state = (self.ctrl_state << num_ctrl_qubits) | ctrl_state
-        return MCXGate(num_ctrl_qubits=num_ctrl_qubits + 4, label=label, ctrl_state=new_ctrl_state)
+        gate = MCXGate(num_ctrl_qubits=num_ctrl_qubits + 4, label=label, ctrl_state=new_ctrl_state)
+        gate.base_gate.label = self.label
+        return gate
 
     def inverse(self):
         """Invert this gate. The C4X is its own inverse."""
@@ -853,7 +863,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
         """
         if ctrl_state is None:
             # use __class__ so this works for derived classes
-            return self.__class__(self.num_ctrl_qubits + num_ctrl_qubits)
+            gate = self.__class__(self.num_ctrl_qubits + num_ctrl_qubits, label=label,
+                                  ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
         return super().control(num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
 

diff --git a/qiskit/extensions/standard/y.py b/qiskit/extensions/standard/y.py
@@ -98,9 +98,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CYGate(label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CYGate(label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted Y gate (:math:`Y{\dagger} = Y`)"""

diff --git a/qiskit/extensions/standard/z.py b/qiskit/extensions/standard/z.py
@@ -97,9 +97,10 @@ def control(self, num_ctrl_qubits=1, label=None, ctrl_state=None):
             ControlledGate: controlled version of this gate.
         """
         if num_ctrl_qubits == 1:
-            return CZGate(label=label, ctrl_state=ctrl_state)
-        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label,
-                               ctrl_state=ctrl_state)
+            gate = CZGate(label=label, ctrl_state=ctrl_state)
+            gate.base_gate.label = self.label
+            return gate
+        return super().control(num_ctrl_qubits=num_ctrl_qubits, label=label, ctrl_state=ctrl_state)
 
     def inverse(self):
         r"""Return inverted Z gate (itself)."""

diff --git a/test/python/circuit/test_controlled_gate.py b/test/python/circuit/test_controlled_gate.py
@@ -40,7 +40,7 @@
                                         U3Gate, CHGate, CRZGate, CU3Gate,
                                         MSGate, Barrier, RCCXGate, RC3XGate,
                                         MCU1Gate, MCXGate, MCXGrayCode, MCXRecursive,
-                                        MCXVChain)
+                                        MCXVChain, C3XGate, C4XGate)
 from qiskit.circuit._utils import _compute_control_matrix
 import qiskit.extensions.standard as allGates
 
@@ -756,7 +756,7 @@ def test_open_controlled_gate(self):
         ctrl_state = 0
         cgate = base_gate.control(num_ctrl_qubits, ctrl_state=ctrl_state)
         target_mat = _compute_control_matrix(base_mat, num_ctrl_qubits, ctrl_state=ctrl_state)
-        np.set_printoptions(linewidth=200,)
+        np.set_printoptions(linewidth=200, )
         self.assertEqual(Operator(cgate), Operator(target_mat))
 
         ctrl_state = 7
@@ -978,5 +978,57 @@ def test_ctrl_state_one(self, gate, controlled_gate):
         # Operator(controlled_gate.to_matrix()))
 
 
+@ddt
+class TestControlledGateLabel(QiskitTestCase):
+    """Tests for controlled gate labels."""
+    gates_and_args = [(XGate, []),
+                      (YGate, []),
+                      (ZGate, []),
+                      (HGate, []),
+                      (CXGate, []),
+                      (CCXGate, []),
+                      (C3XGate, []),
+                      (C4XGate, []),
+                      (MCXGate, [5]),
+                      (U1Gate, [0.1]),
+                      (CYGate, []),
+                      (CZGate, []),
+                      (CU1Gate, [0.1]),
+                      (SwapGate, []),
+                      (CCXGate, []),
+                      (RZGate, [0.1]),
+                      (RXGate, [0.1]),
+                      (RYGate, [0.1]),
+                      (CRYGate, [0.1]),
+                      (CRXGate, [0.1]),
+                      (CSwapGate, []),
+                      (U3Gate, [0.1, 0.2, 0.3]),
+                      (CHGate, []),
+                      (CRZGate, [0.1]),
+                      (CU3Gate, [0.1, 0.2, 0.3]),
+                      (MSGate, [5, 0.1]),
+                      (RCCXGate, []),
+                      (RC3XGate, []),
+                      (MCU1Gate, [0.1, 1]),
+                      (MCXGate, [5])
+                      ]
+
+    @data(*gates_and_args)
+    @unpack
+    def test_control_label(self, gate, args):
+        """Test gate(label=...).control(label=...)"""
+        cgate = gate(*args, label='a gate').control(label='a controlled gate')
+        self.assertEqual(cgate.label, 'a controlled gate')
+        self.assertEqual(cgate.base_gate.label, 'a gate')
+
+    @data(*gates_and_args)
+    @unpack
+    def test_control_label_1(self, gate, args):
+        """Test gate(label=...).control(1, label=...)"""
+        cgate = gate(*args, label='a gate').control(1, label='a controlled gate')
+        self.assertEqual(cgate.label, 'a controlled gate')
+        self.assertEqual(cgate.base_gate.label, 'a gate')
+
+
 if __name__ == '__main__':
     unittest.main()