Fix cz in transpiler (#558)

* experimental implementation for testing purposes

* added draft implementation

* added unit tests

* added changelog

* fix unit tests

* fix code quality check

* fix documentation

* add support for wait gates in circuit transpilation

* added documentation for wait gate in gate_decompositions

* fixed bug with None values in options

* add explanation for option method in gate_event_settings.post_init

* merge with main

* merge with main

* fix code quality complains

* fix test coverage

* fix test coverage

* fix test coverage

* add cz to data

* add 2q gate with spaces in test.data runcard to fix codecov

* add flipped cz to test_optimize_transpilation

src/qililab/pulse/circuit_to_pulses.py

@@ -17,7 +17,7 @@
 from dataclasses import asdict
 
 import numpy as np
-from qibo.gates import CZ, Gate, M
+from qibo.gates import Gate, M
 from qibo.models.circuit import Circuit
 
 from qililab.chip.nodes import Coupler, Qubit
@@ -90,9 +90,6 @@ def translate(  # pylint: disable=too-many-locals, too-many-branches
 
                 # handle control gates
                 else:
-                    # parse symmetry in CZ gates
-                    if isinstance(gate, CZ):
-                        gate = self._parse_check_cz(gate)
                     # extract gate schedule
                     gate_schedule = self._gate_schedule_from_settings(gate)
                     gate_qubits = self._get_gate_qubits(gate, gate_schedule)
@@ -262,24 +259,6 @@ def _gate_element_to_pulse_event(
             qubit=qubit,
         )
 
-    def _parse_check_cz(self, cz: CZ):
-        """Checks if CZ is defined in the runcard, otherwise returns its symmetric gate (with flipped qubits)
-        If none of those are defined in the runcard, a KeyError will be raised by platform.settings on trying
-        to find the gate with qubits flipped
-
-        Args:
-            cz (CZ): qibo CZ gate
-
-        Returns:
-            CZ: qibo CZ gate
-        """
-        cz_qubits = cz.qubits
-        try:
-            self.platform.gates_settings.get_gate(name=cz.__class__.__name__, qubits=cz_qubits)
-            return cz
-        except KeyError:
-            return CZ(cz_qubits[1], cz_qubits[0])
-
     def _update_time(self, time: dict[int, int], qubit: int, gate_time: int):
         """Creates new timeline if not already created and update time.
 

src/qililab/settings/runcard.py

@@ -159,12 +159,17 @@ def get_gate(self, name: str, qubits: int | tuple[int, int] | tuple[int]):
                 (qubits,) if isinstance(qubits, int) else qubits
             )  # tuplify so that the join method below is general
             gate_name = f"{name}({', '.join(map(str, gate_qubits))})"
+            gate_name_t = f"{name}({', '.join(map(str, gate_qubits[::-1]))})"
 
             # parse spaces in tuple if needed, check first case with spaces since it is more common
             if gate_name.replace(" ", "") in self.gates.keys():
                 return self.gates[gate_name.replace(" ", "")]
             if gate_name in self.gates.keys():
                 return self.gates[gate_name]
+            if gate_name_t.replace(" ", "") in self.gates.keys():
+                return self.gates[gate_name_t.replace(" ", "")]
+            if gate_name_t in self.gates.keys():
+                return self.gates[gate_name_t]
             raise KeyError(f"Gate {name} for qubits {qubits} not found in settings.")
 
         @property

tests/data.py

@@ -139,6 +139,30 @@ class Galadriel:
                     },
                 }
             ],
+            "CZ(0,1)": [
+                {
+                    "bus": "flux_line_q1_bus",
+                    "wait_time": 0,
+                    "pulse": {
+                        "amplitude": 1.0,
+                        "phase": 1.5707963267948966,
+                        "duration": 20,
+                        "shape": {"name": "rectangular"},
+                    },
+                }
+            ],
+            "CZ(0, 2)": [
+                {
+                    "bus": "flux_line_q0_bus",
+                    "wait_time": 0,
+                    "pulse": {
+                        "amplitude": 1.0,
+                        "phase": 1.5707963267948966,
+                        "duration": 20,
+                        "shape": {"name": "rectangular"},
+                    },
+                }
+            ],
         },
     }
 

tests/settings/test_runcard.py

@@ -105,6 +105,10 @@ def test_get_operation_settings(self, gates_settings):
                 gates_settings.OperationSettings,
             )
 
+    def test_get_parameter_fails(self, gates_settings):
+        with pytest.raises(ValueError, match="Could not find gate alias in gate settings."):
+            gates_settings.get_parameter(alias="alias", parameter=Parameter.DURATION)
+
     def test_get_operation_settings_raises_error_when_operation_does_not_exist(self, gates_settings):
         """Test the ``get_gate`` method of the Runcard.GatesSettings class."""
         name = "unkown_operation"
@@ -123,6 +127,15 @@ def test_get_gate(self, gates_settings):
             for gate_event in gates_settings.get_gate(name=gate_name, qubits=ast.literal_eval(gate_qubits))
         )
 
+        # check that CZs commute
+        # CZ(0,1) doesn't have spaces in the tuple string
+        assert isinstance(gates_settings.get_gate(name="CZ", qubits=(1, 0))[0], GateEventSettings)
+        assert isinstance(gates_settings.get_gate(name="CZ", qubits=(0, 1))[0], GateEventSettings)
+
+        # CZ(0, 2) has spaces in the tuple string
+        assert isinstance(gates_settings.get_gate(name="CZ", qubits=(2, 0))[0], GateEventSettings)
+        assert isinstance(gates_settings.get_gate(name="CZ", qubits=(0, 2))[0], GateEventSettings)
+
     def test_get_gate_raises_error(self, gates_settings):
         """Test that the ``get_gate`` method raises an error when the name is not found."""
         name = "test"

tests/transpiler/test_transpiler.py

@@ -253,11 +253,20 @@ def test_optimize_transpilation(platform):
         gates.RZ(0, 2),
         Drag(0, 3, 3),
         gates.CZ(0, 2),
+        gates.CZ(1, 0),
         Drag(1, 2, 3),
         gates.RZ(1, 0),
     ]
     # resulting gate list from optimization
-    result_gates = [Drag(0, 1, 1), gates.CZ(0, 1), gates.M(0), Drag(0, 3, 0), gates.CZ(0, 2), Drag(1, 2, 0)]
+    result_gates = [
+        Drag(0, 1, 1),
+        gates.CZ(0, 1),
+        gates.M(0),
+        Drag(0, 3, 0),
+        gates.CZ(0, 2),
+        gates.CZ(1, 0),
+        Drag(1, 2, -2),
+    ]
 
     # check that lists are the same
     optimized_gates = optimize_transpilation(3, test_gates, gates_settings=platform.gates_settings)