better unrolling in preset passmanagers

qiskit/transpiler/preset_passmanagers/level1.py

@@ -206,9 +206,8 @@ def _opt_control(property_set):
     if coupling_map and not coupling_map.is_symmetric:
         pm1.append(_direction_check)
         pm1.append(_direction, condition=_direction_condition)
-        pm1.append(_unroll)
     pm1.append(_reset)
-    pm1.append(_depth_check + _opt, do_while=_opt_control)
+    pm1.append(_depth_check + _opt + _unroll, do_while=_opt_control)
     pm1.append(_scheduling)
 
     return pm1

qiskit/transpiler/preset_passmanagers/level2.py

@@ -203,7 +203,6 @@ def _opt_control(property_set):
     if coupling_map and not coupling_map.is_symmetric:
         pm2.append(_direction_check)
         pm2.append(_direction, condition=_direction_condition)
-        pm2.append(_unroll)
     pm2.append(_reset)
     pm2.append(_depth_check + _opt + _unroll, do_while=_opt_control)
     pm2.append(_scheduling)

qiskit/transpiler/preset_passmanagers/level3.py

@@ -214,7 +214,6 @@ def _opt_control(property_set):
     if coupling_map and not coupling_map.is_symmetric:
         pm3.append(_direction_check)
         pm3.append(_direction, condition=_direction_condition)
-        pm3.append(_unroll)
     pm3.append(_reset)
     pm3.append(_depth_check + _opt + _unroll, do_while=_opt_control)
     pm3.append(_scheduling)

releasenotes/notes/bugfix-respect-basis-d2204b9b7c403722.yaml

@@ -0,0 +1,9 @@
+---
+fixes:
+  - |
+    Fixed an issue with the preset pass managers
+    :class:`~qiskit.transpiler.preset_passmanagers.level_0_pass_manager` and
+    :class:`~qiskit.transpiler.preset_passmanagers.level_1_pass_manager`
+    (which corresponds to ``optimization_level`` 0 and 1 for
+    :func:`~qiskit.compiler.transpile`) where in some cases they would
+    produce circuits not in the requested basis.

test/python/transpiler/test_preset_passmanagers.py

@@ -87,22 +87,22 @@ def test_level0_keeps_reset(self):
         result = transpile(circuit, basis_gates=None, optimization_level=0)
         self.assertEqual(result, circuit)
 
-    def test_level2_respects_basis(self):
-        """Test that level2 with commutative cancellation respects basis"""
+    @combine(level=[0, 1, 2, 3], name='level{level}')
+    def test_respect_basis(self, level):
+        """Test that all levels respect basis"""
         qc = QuantumCircuit(3)
         qc.h(0)
         qc.h(1)
         qc.cp(np.pi / 8, 0, 1)
         qc.cp(np.pi / 4, 0, 2)
-        result = transpile(qc, basis_gates=['id', 'rz', 'sx', 'x', 'cx'],
-                           optimization_level=2)
+        basis_gates = ['id', 'rz', 'sx', 'x', 'cx']
+        result = transpile(qc, basis_gates=basis_gates,
+                           coupling_map=[[0, 1], [2, 1]],
+                           optimization_level=level)
 
         dag = circuit_to_dag(result)
-        op_nodes = [node.name for node in dag.topological_op_nodes()]
-        # Assert no u1 or rx gates from commutative cancellation end up in
-        # end up in the output since they're not in the target basis gates
-        self.assertNotIn('u1', op_nodes)
-        self.assertNotIn('rx', op_nodes)
+        circuit_ops = set(node.name for node in dag.topological_op_nodes())
+        self.assertEqual(circuit_ops.union(set(basis_gates)), set(basis_gates))
 
 
 @ddt