Merge pull request #169 from unitaryfund/mapomatic_experiment

Use the VF2 layout algorithm to optimize for two-qubit gate count

ucc/tests/test_vf2_post_layout.py

@@ -0,0 +1,99 @@
+# # This file has been modified from the original version in Qiskit.
+
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 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.
+
+
+"""Test the VF2Layout pass"""
+
+import rustworkx
+
+
+
+from qiskit import QuantumRegister, QuantumCircuit
+from qiskit.circuit import ControlFlowOp
+from qiskit.circuit.library import CXGate, XGate
+from qiskit.transpiler import CouplingMap, Layout, TranspilerError
+from qiskit.transpiler.passes.layout.vf2_post_layout import VF2PostLayoutStopReason
+from qiskit.converters import circuit_to_dag
+from qiskit.providers.fake_provider import Fake5QV1, GenericBackendV2
+from qiskit.circuit import Qubit
+from qiskit.transpiler.target import Target, InstructionProperties
+
+from ucc import compile
+from ucc.transpiler_passes import VF2PostLayout
+
+
+seed = 42
+
+# 5 qubits bidirectional legacy coupling maps
+BOGOTA_CMAP = [[0, 1], [1, 0], [1, 2], [2, 1], [2, 3], [3, 2], [3, 4], [4, 3]]
+LIMA_CMAP = [[0, 1], [1, 0], [1, 2], [1, 3], [2, 1], [3, 1], [3, 4], [4, 3]]
+YORKTOWN_CMAP = [
+    [0, 1],
+    [0, 2],
+    [1, 0],
+    [1, 2],
+    [2, 0],
+    [2, 1],
+    [2, 3],
+    [2, 4],
+    [3, 2],
+    [3, 4],
+    [4, 2],
+    [4, 3],
+]
+
+def assertLayoutV2(dag, target, property_set):
+        """Checks if the circuit in dag was a perfect layout in property_set for the given
+        coupling_map"""
+
+        layout = property_set["post_layout"]
+
+        def run(dag, wire_map):
+            for gate in dag.two_qubit_ops():
+                physical_q0 = wire_map[gate.qargs[0]]
+                physical_q1 = wire_map[gate.qargs[1]]
+                qargs = (physical_q0, physical_q1)
+                assert target.instruction_supported(gate.name, qargs)
+            for node in dag.op_nodes(ControlFlowOp):
+                for block in node.op.blocks:
+                    inner_wire_map = {
+                        inner: wire_map[outer] for outer, inner in zip(node.qargs, block.qubits)
+                    }
+                    run(circuit_to_dag(block), inner_wire_map)
+
+        run(dag, {bit: layout[bit] for bit in dag.qubits if bit in layout})
+
+
+def test_2q_circuit_5q_backend_v2():
+    """A simple example, without considering the direction
+        0 - 1
+    qr1 - qr0
+    """
+    backend = GenericBackendV2(
+        num_qubits=5,
+        basis_gates=["cx", "id", "rz", "sx", "x"],
+        coupling_map=YORKTOWN_CMAP,
+        seed=seed,
+    )
+
+    qr = QuantumRegister(2, "qr")
+    circuit = QuantumCircuit(qr)
+    circuit.cx(qr[1], qr[0])  # qr1 -> qr0
+    tqc = compile(circuit)
+    initial_layout = tqc._layout
+    dag = circuit_to_dag(tqc)
+    pass_ = VF2PostLayout(target=backend.target, seed=seed, strict_direction=False)
+    pass_.run(dag)
+    assertLayoutV2(dag, backend.target, pass_.property_set)
+    assert pass_.property_set["post_layout"] != initial_layout

ucc/transpiler_passes/__init__.py

@@ -8,4 +8,6 @@
 from .collect_1q_runs import Collect1qRuns
 from .optimize_1q_decomposition import Optimize1qGatesDecomposition
 from .spectral_mapping import SpectralMapping
-from .sabre_layout import SabreLayout
+from .sabre_layout import SabreLayout
+# from .layout.mapomatic_layout import MapomaticLayout
+from .layout.vf2_post_layout import VF2PostLayout